U.S. patent application number 17/468747 was filed with the patent office on 2021-12-30 for free radical polymerizable adhesion-promoting interlayer compositions and methods of use.
The applicant listed for this patent is PRC-DeSoto International, Inc.. Invention is credited to Kevin Cheng, JianCheng Liu, Bruce Virnelson, Chu Ran Zheng.
Application Number | 20210402748 17/468747 |
Document ID | / |
Family ID | 1000005828014 |
Filed Date | 2021-12-30 |
United States Patent
Application |
20210402748 |
Kind Code |
A1 |
Liu; JianCheng ; et
al. |
December 30, 2021 |
FREE RADICAL POLYMERIZABLE ADHESION-PROMOTING INTERLAYER
COMPOSITIONS AND METHODS OF USE
Abstract
Adhesion-promoting compositions and the use of the
adhesion-promoting compositions to provide adhesion-promoting
interlayers to enhance adhesion between adjoining layers of
sulfur-containing sealants are disclosed. In repair applications,
the adhesion-promoting compositions can enhance the adhesion of an
overlying radiation-curable sulfur-containing sealant to a damaged
or aged sulfur-containing sealant.
Inventors: |
Liu; JianCheng; (Arcadia,
CA) ; Zheng; Chu Ran; (Arcadia, CA) ; Cheng;
Kevin; (San Gabriel, CA) ; Virnelson; Bruce;
(Huntersville, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PRC-DeSoto International, Inc. |
Sylmar |
CA |
US |
|
|
Family ID: |
1000005828014 |
Appl. No.: |
17/468747 |
Filed: |
September 8, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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16721416 |
Dec 19, 2019 |
11173692 |
|
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17468747 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B32B 2305/72 20130101;
B32B 27/286 20130101; B32B 27/308 20130101; B32B 27/26 20130101;
B32B 27/40 20130101 |
International
Class: |
B32B 27/28 20060101
B32B027/28; B32B 27/26 20060101 B32B027/26; B32B 27/30 20060101
B32B027/30; B32B 27/40 20060101 B32B027/40 |
Claims
1. An adhesion-promoting composition, comprising: a free radical
polymerizable compound; a free radical initiator; and a volatile
organic solvent.
2. The adhesion-promoting composition of claim 1, comprising: from
15 wt % to 45 wt % of the free radical polymerizable compound; from
0.2 wt % to 2 wt % of the free radical initiator; and from 55 wt %
to 85 wt % of the volatile organic solvent, wherein wt % is based
on the total weight of the adhesion-promoting composition.
3. The adhesion-promoting composition of claim 1, comprising: from
15 wt % to 25 wt % of the free radical polymerizable compound; from
0.2 wt % to 0.6 wt % of the free radical initiator; and from 75 wt
% to 85 wt % of the volatile organic solvent, wherein wt % is based
on the total weight of the adhesion-promoting composition.
4. The adhesion-promoting composition of claim 1, comprising: from
35 wt % to 45 wt % of the free radical polymerizable compound; from
0.6 wt % to 1.0 wt % of the free radical initiator; and from 55 wt
% to 65 wt % of the volatile organic solvent, wherein wt % is based
on the total weight of the adhesion-promoting composition.
5. The adhesion-promoting composition of claim 1, wherein the free
radical polymerizable compound comprises a multifunctional
(meth)acrylate or a combination of multifunctional
(meth)acrylates.
6. The adhesion-promoting composition of claim 1, wherein the free
radical polymerizable compound comprises: a polythiol or a
combination of polythiols; and an ethylenically unsaturated free
radical polymerizable compound or a combination of ethylenically
unsaturated free radical polymerizable compounds.
7. The adhesion-promoting composition of claim 1, wherein the free
radical initiator comprises one or more free radical
photoinitiators.
8. An adhesion-promoting interlayer prepared using the
adhesion-promoting composition of claim 1.
9. A method of sealing a surface, comprising applying the
adhesion-promoting composition of claim 1 to a sulfur-containing
sealant layer; drying the applied adhesion-promoting composition;
applying a free radical polymerizable sulfur-containing sealant
composition to the dried adhesion-promoting composition; and
initiating free radical polymerization of the sulfur-containing
sealant composition to cure the sulfur-containing sealant
composition, and thereby seal the surface.
Description
[0001] This application is a divisional of U.S. application Ser.
No. 16/721,416, filed on Dec. 19, 2019, now allowed, which is
incorporated by reference in its entirety.
FIELD
[0002] The disclosure relates to adhesion-promoting compositions
and the use of the adhesion-promoting compositions to provide
adhesion-promoting interlayers to enhance adhesion between
adjoining layers of sulfur-containing sealants. In repair
applications, the adhesion-promoting compositions can enhance the
adhesion of an overlying radiation-curable sulfur-containing
sealant to a damaged or aged sulfur-containing sealant.
BACKGROUND
[0003] It is desirable that a sealant adhere to a variety of
substrates including to underlying sealant layers. A sealant layer
can become damaged and/or aged during use and it can become
necessary to repair the damaged and/or sealant with a layer of
fresh sealant.
SUMMARY
[0004] According to the present invention, adhesion-promoting
compositions comprise a free radical polymerizable compound; a free
radical initiator; and a volatile organic solvent.
[0005] According to the present invention, multilayer sealants
comprise a first sulfur-containing sealant layer, wherein the first
sulfur-containing sealant layer comprises a cross-linked first
sulfur-containing prepolymer; an adhesion-promoting interlayer
overlying the first sulfur-containing sealant layer; and a second
sulfur-containing sealant layer overlying the adhesion-promoting
interlayer, wherein the second sulfur-containing sealant layer
comprises a free radical polymerized second sulfur-containing
prepolymer, wherein the adhesion-promoting interlayer comprises a
crosslinked free radical polymerized compound.
[0006] According to the present invention, methods of sealing a
surface comprise applying the adhesion-promoting composition of
claim 1 to a sulfur-containing sealant layer; drying the applied
adhesion-promoting composition; applying a free radical
polymerizable sulfur-containing sealant composition to the dried
adhesion-promoting composition; and initiating free radical
polymerization of the sulfur-containing sealant composition to cure
the sulfur-containing sealant composition, and thereby seal the
surface.
DETAILED DESCRIPTION
[0007] For purposes of the following detailed description, it is to
be understood that embodiments provided by the present disclosure
may assume various alternative variations and step sequences,
except where expressly specified to the contrary. Moreover, other
than in any operating examples, or where otherwise indicated, all
numbers expressing, for example, quantities of ingredients used in
the specification and claims are to be understood as being modified
in all instances by the term "about." Accordingly, unless indicated
to the contrary, the numerical parameters set forth in the
following specification and attached claims are approximations that
may vary depending upon the desired properties to be obtained by
the present invention. At the very least, and not as an attempt to
limit the application of the doctrine of equivalents to the scope
of the claims, each numerical parameter should at least be
construed in light of the number of reported significant digits and
by applying ordinary rounding techniques.
[0008] Notwithstanding that the numerical ranges and parameters
setting forth the broad scope of the invention are approximations,
the numerical values set forth in the specific examples are
reported as precisely as possible. Any numerical value, however,
inherently contains certain errors necessarily resulting from the
standard variation found in their respective testing
measurements.
[0009] Also, it should be understood that any numerical range
recited herein is intended to include all sub-ranges subsumed
therein. For example, a range of "1 to 10" is intended to include
all sub-ranges between (and including) the recited minimum value of
1 and the recited maximum value of 10, that is, having a minimum
value equal to or greater than 1 and a maximum value of equal to or
less than 10.
[0010] A dash ("-") that is not between two letters or symbols is
used to indicate a point of bonding for a substituent or between
two atoms. For example, --CONH.sub.2 is attached through the carbon
atom.
[0011] "Alkanediyl" refers to a diradical of a saturated or
unsaturated, branched or straight-chain, acyclic hydrocarbon group,
having, for example, from 1 to 18 carbon atoms (C.sub.1-18), from 1
to 14 carbon atoms (C.sub.1-14), from 1 to 6 carbon atoms
(C.sub.1-6), from 1 to 4 carbon atoms (C.sub.1-4), or from 1 to 3
hydrocarbon atoms (C.sub.1-3). A branched alkanediyl has a minimum
of three carbon atoms. An alkanediyl can be C.sub.2-14 alkanediyl,
C.sub.2-10 alkanediyl, C.sub.2-8 alkanediyl, C.sub.2-6 alkanediyl,
C.sub.2-4 alkanediyl, or C.sub.2-3 alkanediyl. Examples of
alkanediyl groups include methane-diyl (--CH.sub.2--),
ethane-1,2-diyl (--CH.sub.2CH.sub.2--), propane-1,3-diyl and
iso-propane-1,2-diyl (e.g., --CH.sub.2CH.sub.2CH.sub.2-- and
--CH(CH.sub.3)CH.sub.2--), butane-1,4-diyl
(--CH.sub.2CH.sub.2CH.sub.2CH.sub.2--), pentane-1,5-diyl
(--CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.2--), hexane-1,6-diyl
(--CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.2--),
heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl,
decane-1,10-diyl, and dodecane-1,12-diyl. Alkanediyl groups can
include single, double, and/or triple bonds between carbon
atoms.
[0012] "Alkanecycloalkyl" refers to a saturated hydrocarbon group
having one or more cycloalkyl and/or cycloalkanediyl groups and one
or more alkyl and/or alkanediyl groups, where cycloalkyl,
cycloalkanediyl, alkyl, and alkanediyl are defined herein. Each
cycloalkyl and/or cycloalkanediyl group(s) can be C.sub.3-6,
C.sub.5-6, cyclohexyl or cyclohexanediyl. Each alkyl and/or
alkanediyl group(s) can be C.sub.1-6, C.sub.1-4, C.sub.1-3, methyl,
methanediyl, ethyl, or ethane-1,2-diyl. An alkanecycloalkyl group
can be C.sub.4-18 alkanecycloalkyl ane, C.sub.4-16
alkanecycloalkyl, C.sub.4-12 alkanecycloalkyl, C.sub.4-8
alkanecycloalkyl, C.sub.6-12 alkanecycloalkyl, C.sub.6-10
alkanecycloalkyl, or C.sub.6-9 alkanecycloalkyl. Examples of
alkanecycloalkyl groups include 1,1,3,3-tetramethylcyclohexane and
cyclohexylmethane.
[0013] "Alkanecycloalkanediyl" refers to a diradical of an
alkanecycloalkane group. An alkanecycloalkanediyl group can be
C.sub.4-18 alkanecycloalkanediyl, C.sub.4-16 alkanecycloalkanediyl,
C.sub.4-12 alkanecycloalkanediyl, C.sub.4-8 alkanecycloalkanediyl,
C.sub.6-12 alkanecycloalkanediyl, C.sub.6-10 alkanecycloalkanediyl,
or C.sub.6-9 alkanecycloalkanediyl. Examples of
alkanecycloalkanediyl groups include
1,1,3,3-tetramethylcyclohexane-1,5-diyl and
cyclohexylmethane-4,4'-diyl.
[0014] "Alkanearene" refers to a hydrocarbon group having one or
more aryl and/or arenediyl groups and one or more alkyl and/or
alkanediyl groups, where aryl, arenediyl, alkyl, and alkanediyl are
defined here. Each aryl and/or arenediyl group(s) can be
C.sub.6-12, C.sub.6-10, phenyl or benzenediyl. Each alkyl and/or
alkanediyl group(s) can be C.sub.1-6, C.sub.1-4, C.sub.1-3, methyl,
methanediyl, ethyl, or ethane-1,2-diyl. An alkanearene group can be
C.sub.4-18 alkanearene, C.sub.4-16 alkanearene, C.sub.4-12
alkanearene, C.sub.4-8 alkanearene, C.sub.6-12 alkanearene,
C.sub.6-10 alkanearene, or C.sub.6-9 alkanearene. Examples of
alkanearene groups include diphenyl methane.
[0015] "Alkanearenediyl" refers to a diradical of an alkanearene
group. An alkanearenediyl group can be C.sub.4-18 alkanearenediyl,
C.sub.4-16 alkanearenediyl, C.sub.4-12 alkanearenediyl, C.sub.4-8
alkanearenediyl, C.sub.6-12 alkanearenediyl, C.sub.6-10
alkanearenediyl, or C.sub.6-9 alkanearenediyl. An example of an
alkanearenediyl group is diphenyl methane-4,4'-diyl.
[0016] "Alkenyl" group refers to the structure --CR.dbd.C(R).sub.2
where the alkenyl group is a terminal group and is bonded to a
larger molecule. In such embodiments, each R can independently
comprise, for example, hydrogen and C.sub.1-3 alkyl. Each R can be
hydrogen and an alkenyl group can have the structure
--CH.dbd.CH.sub.2.
[0017] "Alkynyl" group refers to the structure --C.ident.CR where
the alkynyl group is a terminal group and is bonded to a larger
molecule. In such embodiments, each R can independently comprise,
for example, hydrogen or C.sub.1-3 alkyl. Each R can be hydrogen
and an alkynyl group can have the structure --C.ident.CH.
[0018] "Alkoxy" refers to a --OR group where R is alkyl as defined
herein. Examples of alkoxy groups include methoxy, ethoxy,
n-propoxy, isopropoxy, and n-butoxy. An alkoxy group can be, for
example, C.sub.1-8 alkoxy, C.sub.1-6alkoxy, C.sub.1-4 alkoxy, or
C.sub.1-3 alkoxy.
[0019] "Alkyl" refers to a monoradical of a saturated, branched or
straight-chain, acyclic hydrocarbon group having, for example, from
1 to 20 carbon atoms, from 1 to 10 carbon atoms, from 1 to 6 carbon
atoms, from 1 to 4 carbon atoms, or from 1 to 3 carbon atoms. It
will be appreciated that a branched alkyl has a minimum of three
carbon atoms. An alkyl group can be, for example, C.sub.1-6 alkyl,
C.sub.1-4 alkyl, or C.sub.1-3 alkyl. Examples of alkyl groups
include methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl,
tert-butyl, n-hexyl, n-decyl, and tetradecyl.
[0020] "Arenediyl" refers to diradical monocyclic or polycyclic
aromatic group. Examples of arenediyl groups include benzene-diyl
and naphthalene-diyl. An arenediyl group can be, for example,
C.sub.6-12 arenediyl, C.sub.6-10 arenediyl, C.sub.6-9 arenediyl, or
benzene-diyl.
[0021] "Cycloalkanediyl" refers to a diradical saturated monocyclic
or polycyclic hydrocarbon group. A cycloalkanediyl group can be,
for example, C.sub.3-12 cycloalkanediyl, C.sub.3-8 cycloalkanediyl,
C.sub.3-6 cycloalkanediyl, or C.sub.5-6 cycloalkanediyl. Examples
of cycloalkanediyl groups include cyclohexane-1,4-diyl,
cyclohexane-1,3-diyl and cyclohexane-1,2-diyl.
[0022] "Cycloalkyl" refers to a saturated monocyclic or polycyclic
hydrocarbon mono-radical group. A cycloalkyl group can be, for
example, C.sub.3-12 cycloalkyl, C.sub.3-8 cycloalkyl, C.sub.3-6
cycloalkyl, or C.sub.5-6 cycloalkyl.
[0023] "Heteroalkanediyl" refers to an alkanediyl group in which
one or more of the carbon atoms are replaced with a heteroatom,
such as N, O, S, and/or P. In a heteroalkanediyl, the one or more
heteroatoms can be N and/or O.
[0024] "Heterocycloalkanediyl" refers to a cycloalkanediyl group in
which one or more of the carbon atoms are replaced with a
heteroatom, such as N, O, S, and/or P. In a heterocycloalkanediyl,
the one or more heteroatoms can be N and/or O.
[0025] "Heteroarenediyl" refers to an arenediyl group in which one
or more of the carbon atoms are replaced with a heteroatom, such as
N, O, S, and/or P. In a heteroarenediyl, the one or more
heteroatoms can be N and/or O.
[0026] A "polyalkenyl" refers to a compound having at least two
alkenyl groups. The at least two alkenyl groups can be terminal
alkenyl groups and such polyalkenyls can be referred to as
alkenyl-terminated compounds. Alkenyl groups can also be pendent
alkenyl groups. A polyalkenyl can be a dialkenyl, having two
alkenyl groups. A polyalkenyl can have more than two alkenyl groups
such as from three to six alkenyl groups. A polyalkenyl can
comprise a single type of polyalkenyl, can be a combination of
polyalkenyls having the same alkenyl functionality, or can be a
combination of polyalkenyls having different alkenyl
functionalities.
[0027] A "polyalkenyl prepolymer" refers to a polyalkenyl having at
least one repeat unit in the polyalkenyl backbone. A polyalkenyl
prepolymer generally can have a molecular weight in the range from
500 Da to 6,000 Da, such as from 500 Da to 4,000 Da or from 500 Da
to 2,000 Da.
[0028] A "monomeric polyalkenyl" refers to a polyalkenyl that does
not include repeat units in the polyalkenyl backbone. A monomeric
polyalkenyl generally has a molecular weight that is less than that
of a polyalkenyl prepolymer. Monomeric polyalkenyls can be
difunctional or have an alkenyl functionality greater than two.
[0029] A "polyalkynyl" refers to a compound having at least two
alkynyl groups. The at least two alkynyl groups can be terminal
alkynyl groups and such polyalkynyls can be referred to as
alkynyl-terminated compounds. Alkynyl groups can also be pendent
alkynyl groups. A polyalkynyl can be a dialkenyl, having two
alkynyl groups. A polyalkynyl can have more than two alkynyl groups
such as from three to six alkynyl groups. A polyalkynyl can
comprise a single type of polyalkynyl, can be a combination of
polyalkynyls having the same alkynyl functionality, or can be a
combination of polyalkynyls having different alkynyl
functionalities.
[0030] A "polyalkynyl prepolymer" refers to a polyalkynyl having at
least one repeat unit in the polyalkynyl backbone. A polyalkynyl
prepolymer generally can have a number average molecular weight in
the range from 500 Da to 6,000 Da, such as from 500 Da to 4,000 Da
or from 500 Da to 2,000 Da.
[0031] A "monomeric polyalkynyl" refers to a polyalkynyl that does
not include repeat units in the polyalkynyl backbone. A monomeric
polyalkynyl generally has a molecular weight that is less than that
of a polyalkynyl prepolymer. Monomeric polyalkynyls can be
difunctional or have an alkynyl functionality greater than two.
[0032] A "multifunctional (meth)acrylate" refers to a compound
having at least two (meth)acryloyl groups. The at least two
(meth)acryloyl groups can be terminal (meth)acryloyl groups and
such multifunctional (meth)acrylates can be referred to as
(meth)acryloyl-terminated compounds. (Meth)acryloyl groups can also
be pendent (meth)acryloyl groups. A multifunctional (meth)acrylate
can be a di(meth)acrylate, having two (meth)acryloyl groups. A
multifunctional (meth)acrylate can have more than two
(meth)acryloyl groups such as from three to six (meth)acryloyl
groups. A multifunctional (meth)acrylate can comprise a single type
of multifunctional (meth)acrylate, can be a combination of
multifunctional (meth)acrylates having the same (meth)acryloyl
functionality, or can be a combination of multifunctional
(meth)acrylates having different (meth)acryloyl
functionalities.
[0033] A "multifunctional (meth)acrylate prepolymer" refers to a
multifunctional (meth)acrylate having at least one repeat unit in
the multifunctional (meth)acrylate backbone. A multifunctional
(meth)acrylate prepolymer generally can have a number average
molecular weight in the range from 500 Da to 6,000 Da, such as from
500 Da to 4,000 Da or from 500 Da to 2,000 Da.
[0034] A "monomeric multifunctional (meth)acrylate" refers to a
multifunctional (meth)acrylate that does not include repeat units
in the multifunctional (meth)acrylate backbone. A monomeric
multifunctional (meth)acrylate generally has a molecular weight
that is less than that of a multifunctional (meth)acrylate
prepolymer. Monomeric multifunctional (meth)acrylates can be
difunctional or have a (meth)acryloyl functionality greater than
two.
[0035] "Reaction product of" means a chemical reaction product(s)
of at least the recited reactants and can include partial reaction
products as well as fully reacted products and other reaction
products that are present in a lesser amount. For example, a
"prepolymer comprising the reaction product of reactants" refers to
a prepolymer or combination of prepolymers that are the reaction
product of the recited reactants.
[0036] A compound having a thiol functionality, or an alkenyl
functionality refers to a compound which has reactive thiol or
alkenyl groups, respectively. The reactive thiol or alkenyl groups
may be terminal groups bonded to the ends of the molecule, may be
bonded to the backbone of the molecule, or the compound may contain
thiol or alkenyl groups that are terminal groups and are bonded to
the backbone.
[0037] As used herein, the term "cure" or "cured" as used in
connection with a composition, e.g., "composition when cured" or a
"cured composition", means that any curable or cross-linkable
components of the composition are at least partially reacted or
crosslinked.
[0038] The term "equivalent" refers to the number of functional
reactive groups of the substance.
[0039] "Equivalent weight" is effectively equal to the molecular
weight of a substance, divided by the valence or number of
functional reactive groups of the substance.
[0040] A "backbone" of a prepolymer refers to the segment between
the reactive terminal groups. A prepolymer backbone typically
includes repeating subunits. For example, the backbone of a
polythiol HS--[R].sub.n--SH is --[R].sub.n--.
[0041] A "core" of a polyfunctionalizing agent B(--V).sub.z refers
to the moiety B. A "core" of a compound or a polymer refers to the
segment between the reactive terminal groups. For example, the core
of a polythiol HS--R--SH will be --R--. A core of a compound or
prepolymer can also be referred to as a backbone of a compound or a
backbone of a prepolymer. A core of a polyfunctionalizing agent can
be an atom or a structure such as a cycloalkane, a substituted
cycloalkane, heterocycloalkane, substituted heterocycloalkane,
arene, substituted arene, heteroarene, or substituted heteroarene
from which moieties having a reactive functional are bonded.
[0042] "Prepolymer" includes homopolymers and copolymers. For
thiol-terminated prepolymers, molecular weights are number average
molecular weights "Mn" as determined by end group analysis using
iodine titration. For prepolymers that are not thiol-terminated,
the number average molecular weights are determined by gel
permeation chromatography using polystyrene standards. A prepolymer
comprises reactive groups capable of reacting with another compound
such as a curing agent or crosslinker to form a cured polymer. A
prepolymer such as a chain-extended polythioether prepolymer
provided by the present disclosure can be combined with a curing
agent to provide a curable composition, which can cure to provide a
cured polymer network. Prepolymers are liquid at room temperature
(23.degree. C.) and pressure (760 torr; 101 kPa).
[0043] "Oligomers" generally have a lower molecular weight than a
prepolymer and can comprise, for example, less than 10 repeat
units, less than 8 repeat units, less than 6 repeat units, or less
than 4 repeat units.
[0044] A prepolymer includes multiple repeating subunits bonded to
each other than can be the same or different. The multiple
repeating subunits make up the backbone of the prepolymer.
[0045] A "curable composition" refers to a composition that
comprises at least two reactants capable of reacting to form a
cured composition. For example, a curable composition can comprise
an isocyanate-terminated chain-extended polythioether prepolymer
and a polyamine capable of reacting to form a cured polymer. A
curable composition may include a catalyst for the curing reaction
and other components such as, for example, filler, pigments, and
adhesion promoters. A curable composition may be curable at room
temperature or may require exposure to elevated temperature such as
a temperature above room temperature or other condition(s) to
initiate and/or to accelerate the curing reaction. A curable
composition can be a free radical polymerizable composition in
which the curing reaction proceeds in the presence of free
radicals. A curable composition may initially be provided as a
two-part composition including, for example, a separate base
component and an accelerator component. The base composition can
contain one of the reactants participating in the curing reaction
such as an isocyanate-terminated chain-extended polythioether
prepolymer and the accelerator component can contain the other
reactant such as a polyamine. The two components can be mixed
shortly before use to provide a curable composition. A curable
composition can exhibit a viscosity suitable for a particular
method of application. For example, a Class A sealant composition,
which is suitable for brush-on applications, can be characterized
by a viscosity from 1 poise to 500 poise (0.1 Pa-sec to 50 Pa-sec).
A Class B sealant composition, which is suitable for fillet seal
applications, can be characterized by a viscosity from 4,500 poise
to 20,000 poise (450 Pa-sec to 2,000 Pa-sec). A Class C sealant
composition, which is suitable for fay seal applications, can be
characterized by a viscosity from 500 poise to 4,500 poise (50
Pa-sec to 450 Pa-sec). The viscosity of the sealant compositions
(curable compositions) is measured as described herein. After the
two components of a sealant system are combined and mixed, the
curing reaction can proceed, and the viscosity of the curable
composition can increase and at some point, will no longer be
workable, as described herein. The duration between when the two
components are mixed to form the curable composition and when the
curable composition can no longer be reasonably or practically
applied to a surface for its intended purpose can be referred to as
the working time. As can be appreciated, the working time can
depend on a number of factors including, for example, the curing
chemistry, the catalyst used, the application method, and the
temperature. Once a curable composition is applied to a surface
(and during application), the curing reaction can proceed to
provide a cured composition. A cured composition develops a
tack-free surface, cures, and then fully cures over a period of
time. A curable composition can be considered to be cured when the
hardness of the surface is at least Shore 30A for a Class B sealant
or a Class C sealant. After a sealant has cured to a hardness of
Shore 30A it can take from several days to several weeks for a
curable composition fully cure. A composition is considered fully
cured when the hardness no longer increases. Depending on the
formulation, a fully cured sealant can exhibit, for example, a
hardness from Shore 40A to Shore 70A. All Shore hardness values
disclosed herein are determined according to ISO 868. For coating
applications, a curable composition can have a viscosity, for
example, from 200 cps to 800 cps (0.2 Pa-sec to 0.8 Pa-sec). For
sprayable coating and sealant compositions, a curable composition
can have a viscosity, for example, from 15 cps to 100 cps (0.015
Pa-sec to 0.1 Pa-sec), such as from 20 cps to 80 cps (0.02 Pa-sec
to 0.0.8 Pa-sec).
[0046] "SCOD" refers to cure on demand sealants. Cure-on-demand
sealants can include free radical polymerizable compositions in
which the curing reaction proceeds in the presence of free
radicals. Free radicals can be generated using radiation-activated
free radical initiators, thermally-activated free radical
initiators, and/or chemically-activated free radical initiators.
SCOD sealants can be formulated as Class A, Class B, or Class C
sealants as described in the preceding paragraph. A SCOD sealant in
which the free radical curing reaction is initiated upon exposure
to UV is referred to as a UV SCOD sealant.
[0047] "Substituted" refers to a group in which one or more
hydrogen atoms are each independently replaced with the same or
different substituent(s). A substituent can comprise halogen,
--S(O).sub.2OH, --S(O).sub.2, --SH, --SR where R is C.sub.1-6
alkyl, --COOH, --NO.sub.2, --NR.sub.2 where each R is independently
hydrogen and C.sub.1-3 alkyl, --CN, .dbd.O, C.sub.1-6 alkyl,
--CF.sub.3, --OH, phenyl, C.sub.2-6 heteroalkyl, C.sub.5-6
heteroaryl, C.sub.1-6 alkoxy, or --C(O)R where R is C.sub.1-6
alkyl. A substituent can be --OH, --NH.sub.2, or C.sub.1-3
alkyl.
[0048] "Derived from" as in "a moiety derived from a compound"
refers to a moiety that is generated upon reaction of a parent
compound with a reactant. For example, a bis(alkenyl) compound
CH.sub.2.dbd.CH--R--CH.dbd.CH.sub.2 can react with another compound
such as a compound having thiol groups to produce the moiety
--(CH.sub.2).sub.2--R--(CH.sub.2).sub.2-- derived from the reaction
of the alkenyl groups with the thiol groups. For example, for a
parent diisocyanate having the structure
O.dbd.C.dbd.N--R--N.dbd.C.dbd.O, a moiety derived from the
diisocyanate has the structure --C(O)--NH--R--NH--C(O)--. As
another example, for a parent non-linear short chain diol having
the structure HO--R--OH, a moiety derived from the non-linear
short-chain diol has the structure --O--R--O--.
[0049] "Derived from the reaction of --V with a thiol" refers to a
moiety --V'-- that results from the reaction of a thiol group with
a moiety comprising a terminal group reactive with a thiol group.
For example, a group V-- can comprise
CH.sub.2.dbd.CH--CH.sub.2--O--, where the terminal alkenyl group
CH.sub.2.dbd.CH-- is reactive with a thiol group --SH. Upon
reaction with a thiol group, the moiety --V'-- is
--CH.sub.2--CH.sub.2--CH.sub.2--O--.
[0050] "Dark cure" refers to curing mechanisms that do not require
exposure to actinic radiation such as UV radiation to initiate the
curing reaction. Actinic radiation may be applied to a dark cure
system to accelerate curing of all or a part of a composition but
exposing the composition to actinic radiation is not necessary to
cure the sample. A dark cure composition can fully cure under dark
conditions without exposure to actinic radiation.
[0051] Glass transition temperature T.sub.g is determined by
dynamic mechanical analysis (DMA) using a TA Instruments Q800
apparatus with a frequency of 1 Hz, an amplitude of 20 microns, and
a temperature ramp of -80.degree. C. to 25.degree. C., with the
T.sub.g identified as the peak of the tan 5 curve.
[0052] When reference is made to a chemical group defined, for
example, by a number of carbon atoms, the chemical group is
intended to include all sub-ranges of carbon atoms as well as a
specific number of carbon atoms. For example, a C.sub.2-10
alkanediyl includes a C.sub.2-4 alkanediyl, C.sub.5-7 alkanediyl,
and other sub-ranges, a C.sub.2 alkanediyl, a C.sub.6 alkanediyl,
and alkanediyls having other specific number(s) of carbon atoms
from 2 to 10.
[0053] A polyfunctionalizing agent can have the structure of
Formula (1):
B(--V).sub.z (1)
where B is the core of the polyfunctionalizing agent, each V is a
moiety terminated in a reactive functional group such as a thiol
group, an alkenyl group, an alkynyl group, an epoxy group, an
isocyanate group, or a Michael acceptor group, and z is an integer
from 3 to 6, such as 3, 4, 5, or 6. In polyfunctionalizing agents
of Formula (1), each --V can have the structure, for example,
--R--SH or --R--CH.dbd.CH.sub.2, where R can be, for example,
C.sub.2-10 alkanediyl, C.sub.2-10 heteroalkanediyl, substituted
C.sub.2-10 alkanediyl, or substituted C.sub.2-10
heteroalkanediyl.
[0054] When the moiety V is reacted with another compound the
moiety --V.sup.1-- results and is said to be derived from the
reaction with the other compound. For example, when V is
--R--CH.dbd.CH.sub.2 and is reacted, for example, with a thiol
group, the moiety V.sup.1 is --R--CH.sub.2--CH.sub.2-- is derived
from the reaction.
[0055] In polyfunctionalizing agents of Formula (1), B can be, for
example C.sub.2-8 alkane-triyl, C.sub.2-8 heteroalkane-triyl,
C.sub.5-8 cycloalkane-triyl, C.sub.5 s heterocycloalkane-triyl,
substituted C.sub.5 s cycloalkene-triyl, C.sub.5-8
heterocycloalkane-triyl, C.sub.6 arene-triyl, C.sub.4-5
heteroarene-triyl, substituted C.sub.6 arene-triyl, or substituted
C.sub.4-5 heteroarene-triyl.
[0056] In polyfunctionalizing agents of Formula (1), B can be, for
example, C.sub.2-8 alkane-tetrayl, C.sub.2-8 heteroalkane-tetrayl,
C.sub.5-10 cycloalkane-tetrayl, C.sub.5-10
heterocycloalkane-tetrayl, C.sub.6-10 arene-tetrayl, C.sub.4
heteroarene-tetrayl, substituted C.sub.2-8 alkane-tetrayl,
substituted C.sub.2-8 heteroalkane-tetrayl, substituted C.sub.5-10
cycloalkane-tetrayl, substituted C.sub.5-10
heterocycloalkane-tetrayl, substituted C.sub.6-10 arene-tetrayl,
and substituted C.sub.4-10 heteroarene-tetrayl.
[0057] Examples of suitable alkenyl-terminated polyfunctionalizing
agents include triallyl cyanurate (TAC), triallylisocyanurate
(TAIC),
1,3,5-triallyl-1,3,5-triazinane-2,4,6-trione1,3-bis(2-methylallyl)-6-meth-
ylene-5-(2-oxopropyl)-1,3,5-triazinone-2,4-dione,
tris(allyloxy)methane, pentaerythritol triallyl ether,
1-(allyloxy)-2,2-bis((allyloxy)methyl)butane,
2-prop-2-ethoxy-1,3,5-tris(prop-2-enyl)benzene,
1,3,5-tris(prop-2-enyl)-1,3,5-triazinane-2,4-dione, and
1,3,5-tris(2-methylallyl)-1,3,5-triazinane-2,4,6-trione,
1,2,4-trivinylcyclohexane, and combinations of any of the
foregoing.
[0058] A polyfunctionalizing agent of Formula (1) can be thiol
terminated.
[0059] Examples of suitable trifunctional thiol-terminated
polyfunctionalizing agents include, for example,
1,2,3-propanetrithiol, 1,2,3-benzenetrithiol,
heptane-1,3-7-trithiol, 1,3,5-triazine-2,4-6-trithiol,
isocyanurate-containing trithiols, and combinations thereof, as
disclosed in U.S. Application Publication No. 2010/0010133, and the
polythiols described in U.S. Pat. Nos. 4,366,307; 4,609,762; and
5,225,472. Combinations of polyfunctionalizing agents may also be
used.
[0060] Examples of suitable polythiol polyfunctionalizing agents
include pentaerythritol tetra(3-mercapto-propionate) (PETMP),
trimethylol-propane tri(3-mercaptopropionate) (TMPMP),
tris[2-(3-mercapto-propionyloxy)ethyl]isocyanurate (TEMPIC),
di-pentaerythritol hexa(3-mercaptopropionate) (di-PETMP),
tri(3-mercaptopropionate) pentaerythritol, triethylolethane
tri-(3-mercaptopropionate), and combinations of any of the
foregoing.
[0061] Examples of suitable mercapto-acetate polythiol
polyfunctionalizing agents include pentaerythritol
tetramercaptoacetate (PRTMA), trimethylolpropane trimercaptoacetate
(TMPMA), di-trimethylolpropane tetramercaptoacetate, and
combinations of any of the foregoing.
[0062] Examples of suitable polythiol polyfunctionalizing agents
include, tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate,
2,3-di(2-mercaptoethylthio)-1-propane-thiol, and combinations of
any of the foregoing.
[0063] Other examples of polythiol polyfunctionalizing agents and
polythiol monomers include pentaerythritol
tetra(3-mercaptopropionate) (PETMP), pentaerythritol
tetramercaptoacetate (PETMA), dipentaerythritol
tetra(3-mercaptopropionate), dipentaerythritol
tetramercaptoacetate, dipentaerythritol
penta(3-mercaptopropionate), dipentaerythritol
pentamercaptoacetate, dipentaerythritol hexa(3-mercaptopropionate),
dipentaerythritol hexamercaptoacetate, ditrimethylolpropane
tetra(3-mercaptopropionate), ditrimethylolpropane
tetramercaptoacetate, and also alkoxylated, for example,
ethoxylated and/or propoxylated, such as ethoxylated, products of
these compounds. Examples include, pentaerythritol
tetra(3-mercaptopropionate) (PETMP), pentaerythritol
tetramercaptoacetate (PETMA), dipentaerythritol
tetra(3-mercaptopropionate), dipentaerythritol
tetramercaptoacetate, dipentaerythritol
penta(3-mercaptopropionate), dipentaerythritol
pentamercaptoacetate, dipentaerythritol hexa(3-mercaptopropionate),
dipentaerythritol hexamercaptoacetate, ditrimethylolpropane
tetra(3-mercaptopropionate), ditrimethylolpropane
tetramercaptoacetate, particularly pentaerythritol
tetra(3-mercaptopropionate) (PETMP), pentaerythritol
tetramercaptoacetate (PETMA), dipentaerythritol
hexa(3-mercaptopropionate), dipentaerythritol hexamercaptoacetate,
ditrimethylolpropane tetra(3-mercaptopropionate), and
ditrimethylolpropane tetramercaptoacetate.
[0064] Suitable polythiol polyfunctionalizing agents are
commercially available, for example, from Bruno Bock Thiochemicals
under the Thiocure.RTM. tradename.
[0065] "Derived from a polyfunctionalizing agent" refers to a
moiety that results from the reaction of a polyfunctionalizing
agent with a reactive functional group. For example, a moiety
derived from the polyfunctionalizing agent triallyl cyanurate of
Formula (2a):
##STR00001##
results in a moiety having the structure of Formula (2b):
##STR00002##
where the segments are bonded to the other reactants.
[0066] "Polythiol polyfunctionalizing agent" refers to a polythiol
having, for example, from 3 to 6 terminal thiol groups. A polythiol
polyfunctionalizing agent can have a molecular weight, for example,
less than 1,400 Da, less than 1,200 Da, less than 1,000 Da, less
than 800 Da, less than 700 Da, less than 600 Da, less than 500 Da,
less than 400 Da, less than 300 Da, less than 200 Da, or less than
100 Da. Polythiol polyfunctionalizing agents can be represented by
the formula B(--V).sub.z, where B.sup.4 represents a core of a
z-valent polyfunctionalizing agent B(--V).sub.z, z is an integer
from 3 to 6; and each --V is a moiety comprising a terminal thiol
(--SH) group.
[0067] A polythiol or a polyalkenyl can be a polythiol
polyfunctionalizing agent or a polyalkenyl polyfunctionalizing
agent, respectively.
[0068] "Composition" is intended to encompass a product comprising
the specified components in the specified amounts, as well as any
product which results, directly or indirectly, from the combination
of the specified ingredients in the specified amounts.
[0069] "Average molecular weight" refers to number average
molecular weight. Number average molecular weight can be determined
by gel permeation chromatography using a polystyrene standard, or
for thiol-terminated prepolymers, can be determined using iodine
titration.
[0070] "Sulfur-containing prepolymer" refers to a prepolymer in
which the repeating unit of the prepolymer backbone comprises
sulfur atom such as --S-- or --S.sub.n-- groups. Thiol-terminated
prepolymers have reactive thiol groups at the ends of the
prepolymer backbone. Prepolymers can have pendent reactive thiol
groups extending from the prepolymer backbone. Prepolymers having
only thiol-terminal and/or only pendent thiol groups are not
encompassed by a sulfur-containing prepolymer.
[0071] "Sulfur-containing sealant" refers to a sealant composition
having a sulfur content, for example, greater than 10 wt %, greater
than 15 wt %, greater than 17.5 wt %, greater than 20 wt %, greater
than 25 wt %, or greater than 30 wt %, where wt % is based on the
total weight of the organic constituents of the sealant
composition. Organic constituents of a sealant composition can
include polymerizable constituents such as prepolymers, monomers
and polyfunctionalizing agents, adhesion promoters, and other
organic additives. A sulfur-containing sealant can have a sulfur
content, for example, from 10 wt % to 35 wt %, from 10 wt % to 30
wt %, from 10 wt % to 25 wt %, from 10 wt % to 20 wt %, from 12 wt
% to 20 wt %, or from 14 wt % to 20 wt %, where wt % is based on
the total weight of the sealant composition. Sealant compositions
having a high sulfur content can be more resistant to fluids and
solvents.
[0072] Reference is now made to certain compounds, compositions,
and methods of the present invention. The disclosed compounds,
compositions, and methods are not intended to be limiting of the
claims. To the contrary, the claims are intended to cover all
alternatives, modifications, and equivalents.
[0073] Adhesion between layers of sulfur-containing sealants can be
enhanced by using a free radical-polymerizable composition between
the layers. A free radical-polymerizable composition can be applied
over an incumbent sulfur-containing sealant layer. The incumbent
sealant layer can be a fresh sealant layer or a damaged and/or aged
sealant layer. A sulfur-containing sealant layer such as a free
radical polymerizable sulfur-containing sealant layer can be
applied over a cured or uncured adhesion-promoting interlayer. The
free radical-polymerizable adhesion-promoting layer can be useful
for repairing damaged and/or aged sulfur-containing sealant
layers.
[0074] A free radical-polymerizable adhesion-promoting interlayer
can be prepared from a composition comprising a free
radical-polymerizable compound, a photoinitiator, and a volatile
solvent.
[0075] Free radical polymerizable compounds can comprise
ethylenically unsaturated compounds. Free radical polymerizable
compounds include multifunctional (meth)acrylates, polythiols and
polyalkenyls and/or polyalkynyls.
[0076] Multifunctional (meth)acrylates, polythiols, polyalkenyls,
and polyalkynyls can comprise a combination of compounds having a
different chemical structure and/or having a different reactive
functionality. A reactive functionality refers to a (meth)acryloyl
group, a thiol group, an alkenyl group, or an alkynyl group.
[0077] Free radical polymerizable compounds can have an average
reactive functionality, for example, of 2, two or more, three or
more, four or more, or 6 or more.
[0078] Free radical polymerizable compounds can have an average
reactive functionality, for example, from 2 to 10, from 2 to 8,
from 2 to 6, from 2 to 4, or from 2 to 3.
[0079] Free radical polymerizable compounds can have a molecular
weight, for example, from 150 Da to 2,000 Da, from 200 Da to 1,500
Da, from 300 Da to 1,000 Da, or from 400 Da to 800 Da. Free radical
polymerizable compounds can have a molecular weight, for example,
less than 2,000 Da, less than 1,500 Da, less than 1,000 Da, less
than 800 Da, less than 700 Da, less than 600 Da, or less than 500
Da. Free radical polymerizable compounds can have a molecular
weight, for example, greater than 150 Da, greater than 250 Da,
greater than 500 Da, greater than 1,000 Da, or greater than 1,500
Da.
[0080] Free radical polymerizable compounds can comprise monomers,
oligomers, prepolymers, or a combination of any of the foregoing.
An oligomeric or polymeric free radical polymerizable compound can
comprise a core terminated with free radical reactive groups.
Examples of suitable cores include aliphatic polyurethanes,
aromatic polyurethanes, bisphenol A type epoxides, bisphenol F type
epoxides, novolac type epoxides, polyesters, silicones, and
melamines. An oligomer or prepolymer can be prepared, for example,
by reacting a multifunctional compound with a compound comprising a
free radical reactive group and a group reactive with the core
compound. For example, a diacrylate oligomer can be prepared by
reacting 4,4'-isopropylidenediphenol, 1-chloro-2,3-epoxy propane,
and acrylic acid to provide the corresponding bisphenol A epoxy
diacrylate.
[0081] The core of an oligomeric or a polymeric free radical
polymerizable compound can comprise repeating segments.
[0082] An adhesion-promoting composition provided by the present
disclosure can comprise, for example, from 10 wt % to 89 wt %, from
10 wt % to 60 wt % of a free radical polymerizable compound or
combination of free radical polymerizable compounds, from 15 wt %
to 55 wt %, from 20 wt % to 50 wt %, from 25 wt % to 45 wt %, or
from 30 wt % to 40 wt %, where wt % is based on the total weight of
the adhesion-promoting composition. An adhesion-promoting
composition provided by the present disclosure can comprise, for
example, greater than 10 wt % of a free radical polymerizable
compound or combination of free radical polymerizable compounds,
greater than 15 wt %, greater than 20 wt %, greater than 25 wt %,
greater than 30 wt %, greater than 35 wt %, greater than 40 wt %,
greater than 45 wt %, greater than 50 wt %, greater than 60 wt %,
greater than 70 wt % or greater than 90 wt %, where wt % is based
on the total weight of the adhesion-promoting composition. An
adhesion-promoting composition provided by the present disclosure
can comprise, for example, less than 60 wt % of a free radical
polymerizable compound or combination of free radical polymerizable
compounds, less than 100 wt %, less than 80 wt %, less than 60 wt
%, less than 50 wt %, less than 45 wt %, less than 40 wt %, less
than 35 wt %, less than 30 wt %, less than 25 wt %, less than 20 wt
%, or less than 15 wt %, where wt % is based on the total weight of
the adhesion-promoting composition.
[0083] An adhesion-promoting composition provided by the present
disclosure can comprise, for example, from 0.1 wt % to 20 wt % of a
free radical initiator or combination of free radical initiators,
from 0.1 wt % to 15 wt %, from 0.1 wt % to 10 wt %, from 0.2 wt %
to 4.5 wt %, from 0.3 wt % to 4.0 wt %, from 0.5 wt % to 3 wt %, or
from 1 wt % to 2.5 wt %, where wt % is based on the total weight of
the adhesion-promoting composition. An adhesion-promoting
composition provided by the present disclosure can comprise, for
example, greater than 0.1 wt % of a free radical initiator or
combination of free radical initiators, greater than 0.25 wt %,
greater than 0.5 wt %, greater than 0.75 wt %, greater than 1 wt %,
greater than 2 wt %, greater than 3 wt %, greater than 4 wt %,
greater than 6 wt %, greater than 10 wt %, or greater than 15 wt %,
where wt % is based on the total weight of the adhesion-promoting
composition. An adhesion-promoting composition provided by the
present disclosure can comprise, for example, less than 10 wt % of
a free radical initiator or combination of free radical initiators,
less than 15 wt %, less than 10 wt %, less than 6 wt % less than 4
wt %, less than 3 wt %, less than 2 wt %, less than 1 wt %, or less
than 0.5 wt %, where wt % is based on the total weight of the
adhesion-promoting composition.
[0084] An adhesion-promoting composition provided by the present
disclosure can comprise, for example, from 0 wt % to 90 wt % of a
volatile organic solvent or combination of volatile organic
solvents, from 5 wt % to 90 wt %, from 15 wt % to 90 wt %, from 25
wt % to 90 wt %, from 35 wt % to 90 wt %, from 45 wt % to 85 wt %,
from 50 wt % to 80 wt %, from 55 wt % to 75 wt %, or from 60 wt %
to 70 wt %, where wt % is based on the total weight of the
adhesion-promoting composition. An adhesion-promoting composition
provided by the present disclosure can comprise, for example,
greater than 0 wt % of a volatile organic solvent or combination of
volatile organic solvents, greater than 10 wt %, greater than 20 wt
%, greater than 30 wt %, greater than 45 wt %, greater than 50 wt
%, greater than 55 wt %, greater than 60 wt %, greater than 65 wt
%, greater than 70 wt %, greater than 75 wt %, greater than 80 wt
%, or greater than 85 wt %, where wt % is based on the total weight
of the adhesion-promoting composition. An adhesion-promoting
composition provided by the present disclosure can comprise, for
example, less than 90 wt % of a volatile organic solvent or
combination of volatile organic solvents, less than 85 wt %, less
than 80 wt %, less than 75 wt %, less than 70 wt %, less than 65 wt
%, less than 60 wt %, less than 55 wt %, less than 50 wt %, less
than 40 wt %, less than 30 wt %, less than 20 wt %, less than 10 wt
%, or less than 5 wt %, where wt % is based on the total weight of
the adhesion-promoting composition.
[0085] An adhesion-promoting composition provided by the present
disclosure can comprise, for example, from 10 wt % to <99.9 wt %
of a free radical polymerizable compound or combination of free
radical polymerizable compounds, from 0.1 wt % to 20 wt % of a free
radical initiator or a combination of free radical initiators; and
from >0 wt % to 89.9 wt % of a volatile organic solvent or
combination of volatile organic solvents, where wt % is based on
the total weight of the adhesion-promoting composition. An
adhesion-promoting composition provided by the present disclosure
can comprise, for example, from 20 wt % to 89.6 wt % of a free
radical polymerizable compound or combination of free radical
polymerizable compounds, from 0.4 wt % to 15 wt % of a free radical
initiator or a combination of free radical initiators; and from 10
wt % to 79.6 wt % of a volatile organic solvent or combination of
volatile organic solvents, where wt % is based on the total weight
of the adhesion-promoting composition. An adhesion-promoting
composition provided by the present disclosure can comprise, for
example, from 30 wt % to 79 wt % of a free radical polymerizable
compound or combination of free radical polymerizable compounds,
from 1 wt % to 10 wt % of a free radical initiator or a combination
of free radical initiators; and from 20 wt % to 69 wt % of a
volatile organic solvent or combination of volatile organic
solvents, where wt % is based on the total weight of the
adhesion-promoting composition.
[0086] An adhesion-promoting composition provided by the present
disclosure can comprise, for example, greater than 10 wt % of a
free radical polymerizable compound or combination of free radical
polymerizable compounds, greater than 0.1 wt % of a free radical
initiator or a combination of free radical initiators; and greater
than 0 wt % of a volatile organic solvent or combination of
volatile organic solvents, where wt % is based on the total weight
of the adhesion-promoting composition. An adhesion-promoting
composition provided by the present disclosure can comprise, for
example, greater than 20 wt % of a free radical polymerizable
compound or combination of free radical polymerizable compounds,
greater than 1 wt % of a free radical initiator or a combination of
free radical initiators; and greater than 10 wt % of a volatile
organic solvent or combination of volatile organic solvents, where
wt % is based on the total weight of the adhesion-promoting
composition. An adhesion-promoting composition provided by the
present disclosure can comprise, for example, greater than 30 wt %
of a free radical polymerizable compound or combination of free
radical polymerizable compounds, greater than 5 wt % of a free
radical initiator or a combination of free radical initiators; and
greater than 20 wt % of a volatile organic solvent or combination
of volatile organic solvents, where wt % is based on the total
weight of the adhesion-promoting composition.
[0087] An adhesion-promoting composition provided by the present
disclosure can comprise, for example, less than 100 wt % of a free
radical polymerizable compound or combination of free radical
polymerizable compounds, less than 20 wt % of a free radical
initiator or a combination of free radical initiators; and less
than 90 wt % of a volatile organic solvent or combination of
volatile organic solvents, where wt % is based on the total weight
of the adhesion-promoting composition. An adhesion-promoting
composition provided by the present disclosure can comprise, for
example, less than 80 wt % of a free radical polymerizable compound
or combination of free radical polymerizable compounds, less than
10 wt % of a free radical initiator or a combination of free
radical initiators; and less than 70 wt % of a volatile organic
solvent or combination of volatile organic solvents, where wt % is
based on the total weight of the adhesion-promoting composition. An
adhesion-promoting composition provided by the present disclosure
can comprise, for example, less than 60 wt % of a free radical
polymerizable compound or combination of free radical polymerizable
compounds, less than 5 wt % of a free radical initiator or a
combination of free radical initiators; and less than 30 wt % of a
volatile organic solvent or combination of volatile organic
solvents, where wt % is based on the total weight of the
adhesion-promoting composition.
[0088] An adhesion-promoting composition provided by the present
disclosure can comprise, for example, from 10 wt % to 59.9 wt % of
a free radical polymerizable compound or combination of free
radical polymerizable compounds, from 0.1 wt % to 5 wt % of a free
radical initiator or a combination of free radical initiators; and
from 40 wt % to 89.9 wt % of a volatile organic solvent or
combination of volatile organic solvents, where wt % is based on
the total weight of the adhesion-promoting composition.
[0089] An adhesion-promoting composition provided by the present
disclosure can comprise, for example, from 20 wt % to 49.5 wt % of
a free radical polymerizable compound or combination of free
radical polymerizable compounds, from 0.5 wt % to 4 wt % of a free
radical initiator or a combination of free radical initiators; and
from 50 wt % to 79.5 wt % of a volatile organic solvent or
combination of volatile organic solvents, where wt % is based on
the total weight of the adhesion-promoting composition. An
adhesion-promoting composition provided by the present disclosure
can comprise, for example, from 20 wt % to 40 wt % of a free
radical polymerizable compound or combination of free radical
polymerizable compounds, from 1 wt % to 3 wt % of a free radical
initiator or a combination of free radical initiators; and from 55
wt % to 75 wt % of a volatile organic solvent or combination of
volatile organic solvents, where wt % is based on the total weight
of the adhesion-promoting composition.
[0090] An adhesion-promoting composition provided by the present
disclosure can comprise, for example, greater than 10 wt % of a
free radical polymerizable compound or combination of free radical
polymerizable compounds, greater than 0.1 wt % of a free radical
initiator or a combination of free radical initiators; and greater
than 40 wt % of a volatile organic solvent or combination of
volatile organic solvents, where wt % is based on the total weight
of the adhesion-promoting composition. An adhesion-promoting
composition provided by the present disclosure can comprise, for
example, greater than 20 wt % of a free radical polymerizable
compound or combination of free radical polymerizable compounds,
greater than 1 wt % of a free radical initiator or a combination of
free radical initiators; and greater than 50 wt % of a volatile
organic solvent or combination of volatile organic solvents, where
wt % is based on the total weight of the adhesion-promoting
composition. An adhesion-promoting composition provided by the
present disclosure can comprise, for example, greater than 30 wt %
of a free radical polymerizable compound or combination of free
radical polymerizable compounds, greater than 2 wt % of a free
radical initiator or a combination of free radical initiators; and
greater than 60 wt % of a volatile organic solvent or combination
of volatile organic solvents, where wt % is based on the total
weight of the adhesion-promoting composition.
[0091] An adhesion-promoting composition provided by the present
disclosure can comprise, for example, less than 60 wt % of a free
radical polymerizable compound or combination of free radical
polymerizable compounds, less than 5 wt % of a free radical
initiator or a combination of free radical initiators; and less
than 90 wt % of a volatile organic solvent or combination of
volatile organic solvents, where wt % is based on the total weight
of the adhesion-promoting composition. An adhesion-promoting
composition provided by the present disclosure can comprise, for
example, less than 50 wt % of a free radical polymerizable compound
or combination of free radical polymerizable compounds, less than 4
wt % of a free radical initiator or a combination of free radical
initiators; and less than 80 wt % of a volatile organic solvent or
combination of volatile organic solvents, where wt % is based on
the total weight of the adhesion-promoting composition. An
adhesion-promoting composition provided by the present disclosure
can comprise, for example, less than 40 wt % of a free radical
polymerizable compound or combination of free radical polymerizable
compounds, less than 3 wt % of a free radical initiator or a
combination of free radical initiators; and less than 70 wt % of a
volatile organic solvent or combination of volatile organic
solvents, where wt % is based on the total weight of the
adhesion-promoting composition.
[0092] An adhesion-promoting composition can comprise, for example,
from 10 wt % to <99.9 wt % of the free radical polymerizable
compound; from 0.1 wt % to 20 wt % of the free radical initiator;
and from 0 wt % to 89.9 wt % of the volatile organic solvent,
wherein wt % is based on the total weight of the composition.
[0093] An adhesion-promoting composition can comprise, for example,
from 15 wt % to 89.8 wt % of the free radical polymerizable
compound; from 0.2 wt % to 18 wt % of the free radical initiator;
and from 10 wt % to 84.8 wt % of the volatile organic solvent,
wherein wt % is based on the total weight of the composition.
[0094] An adhesion-promoting composition can comprise, for example,
from 20 wt % to 89.6 wt % of the free radical polymerizable
compound; from 0.4 wt % to 15 wt % of the free radical initiator;
and from 10 wt % to 79.6 wt % of the volatile organic solvent,
wherein wt % is based on the total weight of the composition.
[0095] An adhesion-promoting composition can comprise, for example,
from 15 wt % to 45 wt % of the free radical polymerizable compound;
from 0.2 wt % to 2 wt % of the free radical initiator; and from 55
wt % to 85 wt % of the volatile organic solvent, wherein wt % is
based on the total weight of the composition.
[0096] An adhesion-promoting composition can comprise, for example,
from 20 wt % to 40 wt % of the free radical polymerizable compound;
from 0.2 wt % to 2 wt % of the free radical initiator; and from 65
wt % to 75 wt % of the volatile organic solvent, wherein wt % is
based on the total weight of the composition.
[0097] An adhesion-promoting composition can comprise, for example,
from 15 wt % to 25 wt % of the free radical polymerizable compound;
from 0.2 wt % to 0.6 wt % of the free radical initiator; and from
75 wt % to 85 wt % of the volatile organic solvent, wherein wt % is
based on the total weight of the composition.
[0098] An adhesion-promoting composition can comprise, for example,
from 35 wt % to 45 wt % of the free radical polymerizable compound;
from 0.6 wt % to 1.0 wt % of the free radical initiator; and from
55 wt % to 65 wt % of the volatile organic solvent, wherein wt % is
based on the total weight of the composition.
[0099] Adhesion-promoting compositions provided by the present
disclosure can comprise a multifunctional (meth)acrylate or
combination of multifunctional (meth)acrylates.
[0100] Suitable multifunctional (meth)acrylates can comprise two or
more (meth)acryloyl groups. For example, a multifunctional
(meth)acrylate can have a (meth)acryloyl functionality from 2 to
10, from 2 to 8, from 2 to 6, or from 2 to 4. A multifunctional
(meth)acrylate can have a (meth)acryloyl functionality greater than
2, greater than 3, greater than 4, greater than 5, greater than 6,
or greater than 8.
[0101] Suitable multifunctional (meth)acrylates can have a
molecular weight, for example, from 150 Da to 2,000 Da, from 200 Da
to 1,500 Da, from 300 Da to 1,000 Da, or from 400 Da to 800 Da. A
multifunctional (meth)acrylate can have a molecular weight, for
example, less than 2,000 Da, less than 1,500 Da, less than 1,000
Da, less than 800 Da, less than 700 Da, less than 600 Da, or less
than 500 Da. A multifunctional (meth)acrylate can have a molecular
weight, for example, greater than 2,000 Da, greater than 1,500 Da,
greater than 1,000 Da, greater than 800 Da, greater than 700 Da,
greater than 600 Da, greater than 500 Da, or greater than 150
Da.
[0102] A multifunctional (meth)acrylate can be a monomeric
multifunctional (meth)acrylate, an oligomeric multifunctional
(meth)acrylate, a polymeric multifunctional (meth)acrylate, or a
combination thereof.
[0103] An oligomeric or polymeric (meth)acrylate comprises a core
terminated with (meth)acryloyl groups. Examples of suitable cores
include aliphatic polyurethanes, aromatic polyurethanes, bisphenol
A type epoxy, novolac type epoxy, polyesters, silicones, and
melamines. A multifunctional (meth)acrylate oligomer can be
prepared, for example, by reacting a difunctional compound with
acrylic acid to provide the corresponding multifunctional
(meth)acrylate.
[0104] Examples of multifunctional (meth)acrylates include
trimethylolpropane triacrylate (TMPTA) and tripropylene glycol
diacrylate (TPGDA).
[0105] Examples of suitable difunctional acrylates include
1,6-hxanediol diacrylate, 1,6-hexanediol diacrylate (HDDA),
hydroxypivalic acid neopentyl glycol diacrylate, neopentylglycol
diacrylate, tripropylene glycol diacrylate, dipropylene glycol
diacrylate (DPGDA), triethylene glycol diacrylate, bisphenol A
(EO).sub.z diacrylate (z=3, 4, 10, 20, or 30), tricyclodecane
dimethanol diacrylate, tetraethylene glycol diacrylate,
polyethylene glycol 400 diacrylate, polyethylene glycol 200
diacrylate, polyethylene glycol 600 diacrylate, bisphenol F
(EO).sub.z diacrylate (z=3 to 30), and polypropylene glycol 400
diacrylate.
[0106] Examples of suitable trifunctional acrylates include
trimethylol propane triacrylate (TMPTA), tripropylene glycol
diacrylate (TPGDA), trimethylol propane (EO).sub.z triacrylate
(z=3, 6, 9, or 15), glycerine (PO).sub.3 triacrylate,
pentaerythritol triacrylate, trimethylolpropane (PO).sub.3
triacrylate, and tris(2-hydroxyethyl)isocyanurate triacrylate.
[0107] Examples of suitable multifunctional acrylates include
pentaerythritol (EO).sub.m tetraacrylate (m=3 to 30), ditrimethylol
propane tetraacrylate, pentaerythritol tetraacrylate,
dipentaerythritol pentaacrylate, and dipentaerythritol
hexacrylate.
[0108] Examples of suitable difunctional methacrylates include
1,6-hexanediol dimethacrylate, 1,4-butanediol dimethacrylate,
neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate,
diethylene glycol dimethacrylate, triethylene glycol
dimethacrylate, tetraethylene glycol dmethacrylate, bisphenol A
(EO).sub.z dimethacrylate (z=3, 4, 10, or 30), 1,3-butylene glycol
dimethacrylate, polyethylene glycol 400 dimethacrylate,
polyethyleneglycol 200 dimethacrylate, and ethoxylated
polypropyleneglycol dimethacrylate.
[0109] Examples of suitable trifunctional methacrylates include
trimethylol propane trimethacrylate.
[0110] Examples of (meth)acrylate oligomers and (meth)acrylate
prepolymer include aliphatic polyurethane (meth)acrylates, aromatic
polyurethane (meth)acrylates, bisphenol A epoxy (meth)acrylates
(bisphenol A type), bisphenol F epoxy (meth)acrylates, novolac
epoxy (meth)acrylates, polyester (meth)acrylates, silicone
(meth)acrylates, melamine (meth)acrylates, polybutadiene
(meth)acrylates, and dendritic (meth)acrylates.
[0111] Adhesion-promoting compositions provided by the present
disclosure can comprise a polythiol or a combination of polythiols
and a poly alkenyl or a combination of poly alkenyls.
[0112] Adhesion-promoting compositions provided by the present
disclosure can comprise a polythiol or a combination of polythiols
and a polyalkynyl or a combination of polyalkynyls.
[0113] Adhesion-promoting compositions provided by the present
disclosure can comprise a polythiol or a combination of polythiols;
and a combination of: a polyalkenyl or a combination of
polyalkenyls, and a polyalkynyl or a combination of
polyalkynyls.
[0114] In compositions comprising a combination of polyalkyenyls
and polyalkynyls, the molar ratio of polyalkenyls to polyalkynyls
can be, for example, from 5 to 60, from 10 to 50, from 15 to 40, or
from 20 to 30. In compositions comprising a combination of
polyalkyenyls and polyalkynyls, the molar ratio of polyalkenyls to
polyalkynyls can be, for example, greater than 5, greater than 10,
greater than 15, greater than 20, greater than 30, greater than 40,
or greater than 50 In compositions comprising a combination of
polyalkyenyls and polyalkynyls, the molar ratio of polyalkenyls to
polyalkynyls can be, for example, from less than 70, less than 60,
less than 50, less than 40, less than 30, less than 20, or less
than 10.
[0115] In compositions comprising a combination of polyalkyenyls
and polyalkynyls, the equivalents ratio of alkenyl groups to
alkynyl groups can be, for example, from 5 to 60, from 10 to 50,
from 15 to 40, or from 20 to 30. In compositions comprising a
combination of polyalkyenyls and polyalkynyls, the equivalents
ratio of alkenyl groups to alkynyl groups can be, for example,
greater than 5, greater than 10, greater than 15, greater than 20,
greater than 30, greater than 40, or greater than 50 In
compositions comprising a combination of polyalkyenyls and
polyalkynyls, the equivalents ratio of alkenyl groups to alkynyl
groups can be, for example, from less than 70, less than 60, less
than 50, less than 40, less than 30, less than 20, or less than
10.
[0116] Adhesion-promoting compositions provided by the present
disclosure can comprise a polythiol or a combination of
polythiols.
[0117] Suitable polythiols can comprise two or more polythiols
groups. For example, a polythiols can have a thiol functionality
from 2 to 10, from 2 to 8, from 2 to 6, or from 2 to 4. A
polythiols can have a thiol functionality greater than 2, greater
than 4, greater than 6, or greater than 8.
[0118] Suitable polythiols can have a molecular weight, for
example, from 150 Da to 2,000 Da, from 200 Da to 1,500 Da, from 300
Da to 1,000 Da, or from 400 Da to 800 Da. A polythiol can have a
molecular weight, for example, less than 2,000 Da, less than 1,500
Da, less than 1,000 Da, less than 800 Da, less than 700 Da, less
than 600 Da, or less than 500 Da. A polythiol can have a molecular
weight, for example, greater than 2,000 Da, greater than 1,500 Da,
greater than 1,000 Da, greater than 800 Da, greater than 700 Da,
greater than 600 Da, greater than 500 Da, or greater than 150
Da.
[0119] A polythiols can comprise a polythiol prepolymer, a
monomeric polythiol, an oligomeric polythiol, a polymeric
polythiol, or a combination of any of the foregoing.
[0120] A thiol-terminated monomer/oligomer can have the structure
of Formula (3):
HS--R.sup.1--SH (3)
wherein,
[0121] R.sup.1 is selected from C.sub.2-6 alkanediyl, C.sub.6-8
cycloalkanediyl, C.sub.6-10 alkanecycloalkanediyl, C.sub.5-8
heterocycloalkanediyl, and
--[--(CHR.sup.3).sub.p--X-].sub.q--(CHR.sup.3).sub.r--; wherein,
[0122] each R.sup.3 is independently selected from hydrogen and
methyl; [0123] each X is independently selected from --O--, --S--,
--NH--, and --N(--CH.sub.3)--; [0124] p is an integer from 2 to 6;
[0125] q is an integer from 1 to 5; and [0126] r is an integer from
2 to 10.
[0127] A polythiol monomer/oligomer of Formula (3) can have a
sulfur content, for example, greater than 5 wt %, greater than 10
wt %, greater than 15 wt %, or greater than 25 wt %, where wt % is
based on the weight of the polythiol.
[0128] In a dithiol of Formula (3), R.sup.1 can be
--[--(CHR.sup.3).sub.p--X-].sub.q--(CHR.sup.3).sub.r--.
[0129] In a dithiol of Formula (3), X can be --O-- or --S--, and
thus --[--(CHR.sup.3).sub.p--X-].sub.q--(CHR.sup.3).sub.r-- in
Formula (1) can be
--[(CHR.sup.3).sub.p--O-].sub.q--(CHR.sup.3).sub.r--,
--[(--CHR.sup.3--).sub.p-S-].sub.q--(CHR.sup.3).sub.r--,
--[(CH.sub.2).sub.p--O-].sub.q--(CH.sub.2).sub.r--, or
--[(CH.sub.2).sub.p--S-].sub.q--(CH.sub.2).sub.r--. In a dithiol of
Formula (3), p and r can be equal, such as where p and r can be
both two.
[0130] In a dithiol of Formula (3), R.sup.1 can be C.sub.2-6
alkanediyl or
--[--(CHR.sup.3).sub.p--X-].sub.q--(CHR.sup.3).sub.r--.
[0131] In a dithiol of Formula (3), R.sup.1 can be
--[--(CHR.sup.3).sub.p--X-].sub.q--(CHR.sup.3).sub.r--, where X can
be --O--, or X can be --S--.
[0132] In a dithiol of Formula (3), R.sup.1 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, or X can be
--O--, or X can be --S--
[0133] In a dithiol of Formula (3) where R.sup.1 can be
--[--(CHR.sup.3).sub.p--X-].sub.q--(CHR.sup.3).sub.r--, p can be 2,
r can be 2, q is 1, and X can be --S--; p can be 2, q can be 2, r
can be 2, and X is --O--; or p can be 2, r can be 2, q can be 1,
and X can be --O--.
[0134] In a dithiol of Formula (3) where R.sup.1 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, p can be 2, r
can be 2, q can be 1, and X can be --S--; p can be 2, q can be 2, r
can be 2, and X can be --O--; or p can be 2, r can be 2, q can be
1, and X can be --O--.
[0135] In a dithiol of Formula (3) where R.sup.1 can be
--[--(CHR.sup.3).sub.p--X-].sub.q--(CHR.sup.3).sub.r--, each
R.sup.3 can be hydrogen, or at least one R.sup.3 can be methyl.
[0136] In a dithiol of Formula (3), each R.sup.1 can be derived
from dimercaptodioxaoctane (DMDO) or each R.sup.1 is derived from
dimercaptodiethylsulfide (DMDS).
[0137] In a dithiol of Formula (3), each p can be independently 2,
3, 4, 5, or 6; or each p can be the same and can be 2, 3, 4, 5, or
6.
[0138] In a dithiol of Formula (3), each r can be 2, 3, 4, 5, 6, 7,
or 8.
[0139] In a dithiol of Formula (3), each q can be 1, 2, 3, 4, or
5.
[0140] Examples of suitable dithiols include 1,2-ethanedithiol,
1,2-propanedithiol, 1,3-propanedithiol, 1,3-butanedithiol,
1,4-butanedithiol, 2,3-butanedithiol, 1,3-pentanedithiol,
1,5-pentanedithiol, 1,6-hexanedithiol,
1,3-dimercapto-3-methylbutane, dipentenedimercaptan,
ethylcyclohexyldithiol (ECHDT), dimercaptodiethylsulfide,
methyl-substituted dimercaptodiethylsulfide, dimethyl-substituted
dimercaptodiethylsulfide, dimercaptodioxaoctane,
1,5-dimercapto-3-oxapentane, and a combination of any of the
foregoing. A polythiol may have one or more pendent groups selected
from a lower (e.g., C.sub.1-6) alkyl group, a lower alkoxy group,
and a hydroxyl group. Suitable alkyl pendent groups include, for
example, C.sub.1-6 linear alkyl, C.sub.3-6 branched alkyl,
cyclopentyl, and cyclohexyl.
[0141] Other examples of suitable dithiols include
dimercaptodiethylsulfide (DMDS) (in Formula (3), R.sup.1 is
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, wherein p is
2, r is 2, q is 1, and X is --S--); dimercaptodioxaoctane (DMDO)
(in Formula (1), R.sup.1 is
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, wherein p is
2, q is 2, r is 2, and X is --O--); and 1,5-dimercapto-3-oxapentane
(in Formula (3), R.sup.1 is
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, wherein p is
2, r is 2, q is 1, and X is --O--). It is also possible to use
dithiols that include both a heteroatom in the carbon backbone and
a pendent alkyl group, such as a pendent methyl group. Such
compounds include, for example, methyl-substituted DMDS, such as
HS--CH.sub.2CH(CH.sub.3)--S--CH.sub.2CH.sub.2--SH,
HS--CH(CH.sub.3)CH.sub.2--S--CH.sub.2CH.sub.2--SH and dimethyl
substituted DMDS, such as
HS--CH.sub.2CH(CH.sub.3)--S--CHCH.sub.3CH.sub.2--SH and
HS--CH(CH.sub.3)CH.sub.2--S--CH.sub.2CH(CH.sub.3)--SH.
[0142] A polythiol can comprise a polythiol of Formula (1a):
B(--V).sub.z (1a)
[0143] wherein, [0144] B comprises a core of a z-valent
polyfunctionalizing agent B(--V).sub.z; [0145] z is an integer from
3 to 6; and [0146] each --V is independently a moiety comprising a
terminal thiol group.
[0147] In polythiols of Formula (1a), V can be, for example,
thiol-terminated C.sub.1-10 alkanediyl, thiol-terminated C.sub.1-10
heteroalkanediyl, thiol-terminated substituted C.sub.1-10
alkanediyl, or thiol-terminated substituted C.sub.1-10
heteroalkanediyl.
[0148] In polythiols of Formula (1a), z can be, for example, 3, 4,
5, or 6.
[0149] In polythiols of Formula (1a), z can be 3. Suitable
trifunctional polythiols include, for example,
1,2,3-propanetrithiol, isocyanurate-containing trithiols, and
combinations thereof, as disclosed in U.S. Application Publication
No. 2010/0010133, and the polythiols described in U.S. Pat. Nos.
4,366,307; 4,609,762; and 5,225,472. Mixtures polythiols of Formula
(1a) may also be used.
[0150] Isocyanurates as disclosed, for example, in U.S. Application
Publication No. 2011/0319559.
[0151] A dithiol can comprise a sulfur-containing dithiol meaning
that the moiety between the two terminal thiol groups comprises at
least one thioether --S-- group or a polysulfide group --S--S--.
For example, in dithiols of Formula (3), R.sup.1 in a
sulfur-containing dithiol of Formula (3) can comprise at least one
thioether --S-- group.
[0152] Suitable thiol-terminated monomers include, for example,
mercapto-propionates, mercapto-acetates, mercapto-acrylates, and
other polythiols.
[0153] Examples of suitable mercapto-propionates include
pentaerythritol tetra (3-mercapto-propionate) (PETMP),
trimethylol-propane tri(3-mercaptopropionate) (TMPMP), glycol
di(3-mercaptopropionate) (GDMP),
tris[2-(3-mercapto-propionyloxy)ethyl]isocyanurate (TEMPIC),
di-pentaerythritol hexa(3-mercaptopropionate) (di-PETMP),
tri(3-mercaptopropionate) pentaerythritol, and triethylolethane
trim-mercaptopropionate).
[0154] Examples of suitable thiols include ethoxylated
trimethylolpropane tri(3-mercaptopropionate) and polycaprolactone
tetra-3-mercaptopropionate.
[0155] Examples of suitable mercapto-acetates include
pentaerythritol tetramercaptoacetate (PRTMA), trimethylolpropane
trimercaptoacetate (TMPMA), glycol dimercaptoacetate (GDMA),
ethyleneglycol dimercaptoacetate, and di-trimethylolpropane
tetramercaptoacetate.
[0156] A small molecule polythiol can have a thiol-functionality,
for example, from 2 to 6. A small molecule polythiol can be a
sulfur-containing small molecule polythiol. A small molecule
polythiol can comprise a polyfunctionalizing agent having a thiol
functionality, for example, from 3 to 6.
[0157] Examples of suitable trifunctional thiol-terminated
polyfunctionalizing agents include, for example,
1,2,3-propanetrithiol, 1,2,3-benzenetrithiol, 1,1,1-butanetrithiol,
heptane-1,3-7-trithiol, 1,3,5-triazine-2,4-6-trithiol,
isocyanurate-containing trithiols, and combinations thereof, as
disclosed in U.S. Application Publication No. 2010/0010133, and the
polythiols described in U.S. Pat. Nos. 4,366,307; 4,609,762; and
5,225,472. Combinations of polyfunctionalizing agents may also be
used.
[0158] Examples of suitable polythiol polyfunctionalizing agents
include pentaerythritol tetra(3-mercapto-propionate) (PETMP),
trimethylol-propane tri(3-mercaptopropionate) (TMPMP), glycol
di(3-mercaptopropionate) (GDMP),
tris[2-(3-mercapto-propionyloxy)ethyl]isocyanurate (TEMPIC),
di-pentaerythritol hexa(3-mercaptopropionate) (di-PETMP),
tri(3-mercaptopropionate) pentaerythritol, triethylolethane
tri-(3-mercaptopropionate), and combinations of any of the
foregoing.
[0159] Examples of suitable mercapto-acetate polythiol
polyfunctionalizing agents include pentaerythritol
tetramercaptoacetate (PRTMA), trimethylolpropane trimercaptoacetate
(TMPMA), glycol dimercaptoacetate (GDMA), ethyleneglycol
dimercaptoacetate, di-trimethylolpropane tetramercaptoacetate, and
combinations of any of the foregoing.
[0160] Examples of suitable mercapto-acrylate polythiol
polyfunctionalizing agents include
tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate,
2,3-di(2-mercaptoethylthio)-1-propane-thiol,
dimercaptodiethylsulfide (2,2'-thiodiethanethiol),
dimercaptodioxaoctane (2,2'-(ethylenedioxy)diethanethiol,
1,8-dimercapto-3,6-dioxaoctane, and combinations of any of the
foregoing.
[0161] Suitable polythiol polyfunctionalizing agents are
commercially available, for example, from Bruno Bock Thiochemicals
under the Thiocure.RTM. tradename.
[0162] Other examples of suitable polythiols include
4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane,
4-mercaptomethyl-3,6-dithia-1,8-octanedithiol
(2,2'-((3-mercaptopropane-1,2-diyl)bis(sulfanediyl))bis(ethane-1-thiol),
7-hydroxymethyl-3,6,9,12-tetrathia-1,14-tetradecanedithiol
(2,3-bis((2-((2-mercaptoethyl)thio)ethyl)thio)propan-1-ol) and/or
isomers thereof, 2,5-dimercaptomethyl-1,4-dithiane
((1,4-dithiane-2,5-diyl)dimethanethiol), and combinations of any of
the foregoing.
[0163] Other examples of suitable polythiols include
2,5-dimercaptomethyl-1,4-dithiane,
2-ethyl-2-(mercaptomethyl)propane-1,3-dithiol,
1,2,3-trimercaptopropane,
2,2-bis(mercaptomethyl)propane-1,3-dithiol,
4-mercaptomethyl-3,6-dithia-1,8-octanedithiol,
1,3-dimercapto-2-propanol, 3-mercapto-1,2-propanediol,
2-mercapto-1,3-propanediol, 2,3-dimercapto-1-propanol,
7-hydroxymethyl-1,14-dimercapto-3,6,9,12-tetrathiatetradecane,
4,8-bis(mercaptomethyl)-1,11-dimercapto-3,6,9-trithiaundecane and
regioisomers thereof such as the 4,7- and 5,7-regioisomers, and
combinations of any of the foregoing.
[0164] A polythiol can have, for example, a sulfur content from 0
wt % to 50 wt %, from 5 wt % to 40 wt %, from 10 wt % to 40 wt % or
from 20 wt % to 40 wt %, where wt % is based on the total weight of
the polythiol. A polythiol can be selected such that when reacted
with a polyalkenyl and/or a polyalkynyl, the product can have a
sulfur content, for example, greater than 5 wt %, greater than 10
wt %, greater than 15 wt %, greater than 20 wt %, or greater than
25 wt %. For example, the product can have a sulfur content from 5
wt % to 50 wt %, from 10 wt % to 40 wt %, from 15 wt % to 30 wt %,
or from 10 wt % to 20 wt %, where wt % is based on the total weight
of the reaction product.
[0165] Adhesion-promoting compositions provided by the present
disclosure can comprise a polyalkenyl or a combination of
polyalkenyls.
[0166] Suitable polyalkenyls can comprise two or more polythiols
groups. For example, a polyalkenyls can have an alkenyl
functionality from 2 to 10, from 2 to 8, from 2 to 6, or from 2 to
4. Polyalkenyls can have an alkenyl functionality greater than 2,
greater than 3, greater than 4, greater than 5, greater than 6, or
greater than 8.
[0167] Suitable polyalkenyls can have a molecular weight or an
average molecular weight, for example, from 150 Da to 2,000 Da,
from 200 Da to 1,500 Da, from 300 Da to 1,000 Da, or from 400 Da to
800 Da. Polyalkenyls can have a molecular weight, for example, less
than 2,000 Da, less than 1,500 Da, less than 1,000 Da, less than
800 Da, less than 700 Da, less than 600 Da, or less than 500 Da. A
polyalkenyl can have a molecular weight, for example, greater than
2,000 Da, greater than 1,500 Da, greater than 1,000 Da, greater
than 800 Da, greater than 700 Da, greater than 600 Da, greater than
500 Da, or greater than 150 Da.
[0168] Polyalkenyls can comprise a polyalkenyl prepolymer, a
monomeric polyalkenyl, an oligomeric polyalkenyl, a polymeric
polyalkenyl, or a combination of any of the foregoing.
[0169] A polyalkenyl can have, for example, a sulfur content from 0
wt % to 50 wt %, from 5 wt % to 40 wt %, from 10 wt % to 40 wt % or
from 20 wt % to 40 wt %, where wt % is based on the total weight of
the polyalkenyl. A polyalkenyl can be selected such that when
reacted with a polythiol, the product can have a sulfur content,
for example, greater than 5 wt %, greater than 10 wt %, greater
than 15 wt %, greater than 20 wt %, or greater than 25 wt %. For
example, the product can have a sulfur content from 5 wt % to 50 wt
%, from 10 wt % to 40 wt %, from 15 wt % to 30 wt %, or from 10 wt
% to 20 wt %, where wt % is based on the total weight of the
reaction product.
[0170] A polyalkenyl may or may not contain sulfur atoms.
[0171] Examples of suitable polyalkenyl monomers, oligomers and
prepolymers include divinyl ethers such as divinyl ethers having
the structure of Formula (4):
CH.sub.2.dbd.CH--O--(--R.sup.2--O--).sub.m--CH.dbd.CH.sub.2 (4)
where m can be from 0 to 50 and R.sup.2 in Formula (4) can be
selected from C.sub.2-6 n-alkanediyl, C.sub.3-6 branched
alkanediyl, C.sub.6-8 cycloalkanediyl, C.sub.6-10
alkanecycloalkanediyl, and
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where p can
be an integer ranging from 2 to 6, q can be an integer from 1 to 5,
r can be an integer from 2 to 10, and X can be O or S. In a divinyl
ether of Formula (4), R.sup.2 can be, for example, C.sub.2-6
n-alkanediyl, C.sub.3-6 branched alkanediyl, C.sub.6-8
cycloalkanediyl, C.sub.6-10 alkanecycloalkanediyl,
--[(CH.sub.2).sub.p--O-].sub.q--(CH.sub.2).sub.r--, or
--[(CH.sub.2).sub.p--S-].sub.q--(CH.sub.2).sub.r--.
[0172] In divinyl ethers of Formula (4), m can be an integer from 0
to 50, such as an integer from 1 to 6, from 1 to 4, or from 1 to
3.
[0173] In divinyl ethers of Formula (4), m can be 1, 2, 3, 4, 5, or
6.
[0174] In divinyl ethers of Formula (4), each R.sup.2 can
independently be C.sub.2-6 alkanediyl such as 1,2-ethane-diyl,
1,3-propane-diyl, 1,4-butane-diyl, 1,5-pentane-diyl, or
1,6-hexane-diyl.
[0175] In divinyl ethers of Formula (4), each R.sup.2 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--.
[0176] In divinyl ethers of Formula (4), each R.sup.2 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each p
can be 2, each r can be 2, and q can be 1, 2, 3, 4, or 5.
[0177] Suitable di vinyl ethers include, for example, compounds
having at least one oxyalkanediyl group, such as from 1 to 4
oxyalkanediyl groups, i.e., compounds in which m in Formula (4) can
be an integer ranging from 1 to 4. In a divinyl ether of Formula
(4) m can be an integer ranging from 2 to 4. It is also possible to
employ commercially available divinyl ether mixtures that are
characterized by a non-integral average value for the number of
oxyalkanediyl units per molecule. Thus, m in Formula (4) can also
be a rational number from 0 to 10.0, such as from 1.0 to 10.0, from
1.0 to 4.0, or from 2.0 to 4.0, such as 2.5, which represents an
average functionality.
[0178] Examples of suitable vinyl ethers include, divinyl ether,
ethylene glycol divinyl ether (EG-DVE) (R.sup.2 in Formula (4) is
ethanediyl and m is 1), butanediol divinyl ether (BD-DVE) (R.sup.2
in Formula (4) is butanediyl and m is 1), hexanediol divinyl ether
(HD-DVE) (R.sup.2 in Formula (4) is hexanediyl and m is 1),
diethylene glycol divinyl ether (DEG-DVE; R.sup.2 in Formula (4) is
ethanediyl and m is 2), triethylene glycol divinyl ether (TEG-DVE;
R.sup.2 in Formula (4) is ethanediyl and m is 3), tetraethylene
glycol divinyl ether (R.sup.2 in Formula (4) is ethanediyl and m is
4), cyclohexanedimethanol divinyl ether, polytetrahydrofuryl
divinyl ether; trivinyl ether monomers, such as trimethylolpropane
trivinyl ether; tetrafunctional ether monomers, such as
pentaerythritol tetravinyl ether; and combinations of two or more
such polyvinyl ether monomers. A polyvinyl ether may have one or
more pendent groups selected from alkyl groups, hydroxyl groups,
alkoxy groups, and amine groups.
[0179] Other useful divinyl ethers include compounds in which
R.sup.2 in Formula (4) is polytetrahydrofuryl (poly-THF) or
polyoxyalkanediyl, such as those having an average of about 3
monomer units.
[0180] A polyalkenyl can have the structure of Formula (1b):
B(--V).sub.z (1b)
[0181] wherein, [0182] B comprises a core of a z-valent
polyfunctionalizing agent B(--V).sub.z; [0183] z is an integer from
3 to 6; and [0184] each --V is independently a moiety comprising a
terminal alkenyl group.
[0185] In polyalkenyls of Formula (1b), z can be, for example, 3,
4, 5, or 6.
[0186] A polyalkenyl of Formula (1b) can be trifunctional, that is,
compounds where z is 3. Suitable trifunctionalizing polyalkenyls
include, for example, triallyl cyanurate (TAC), and
trimethylolpropane trivinyl ether. Combinations of polyalkenyl
compounds may also be used.
[0187] Examples of suitable polyalkenyl monomers having an alkenyl
functionality greater than two include, for example, triallyl
cyanurate (TAC), triallyl isocyanurate (TAIC), trimethylolpropane
trivinyl ether, 2,4,6-triallyloxy-1,3,5-triazine,
1,3,5-triacryloylhexahydro-1,3,5-triazine, and
tris[2-(acryloyloxy)ethyl] isocyanurate.
[0188] A divinyl ether can comprise a sulfur-containing
bis(alkenyl) ether. An example of a suitable sulfur-containing
divinyl ether is allyl sulfide.
[0189] A sulfur-containing bis(alkenyl) ether can have the
structure of Formula (5):
CH.sub.2.dbd.CH--O--(CH.sub.2).sub.n--Y'--R.sup.4--Y'--(CH.sub.2).sub.n--
-O--CH.dbd.CH.sub.2 (5)
[0190] wherein, [0191] each n is independently an integer from 1 to
4; [0192] each Y' is independently selected from --O-- and --S--;
and [0193] R.sup.4 is selected from C.sub.2-6 n-alkanediyl,
C.sub.3-6 branched alkanediyl, O, x cycloalkanediyl, C.sub.6-10
alkanecycloalkanediyl, and
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, wherein,
[0194] each X is independently selected from --O--, --S--, and
--S--S--; [0195] p is an integer from 2 to 6; [0196] q is an
integer from 1 to 5; and [0197] r is an integer from 2 to 6; and
[0198] at least one Y' is --S--, or R.sup.4 is
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r-- and at least
one X is --S-- or --S--S--.
[0199] In sulfur-containing bis(alkenyl) ethers of Formula (5),
each n can be 1, 2, 3, or 4.
[0200] In sulfur-containing bis(alkenyl) ethers of Formula (5),
each Y' can be --O-- or each Y' can be --S--.
[0201] In sulfur-containing bis(alkenyl) ethers of Formula (5),
R.sup.4 can be C.sub.2-6 n-alkanediyl, such as ethane-diyl,
n-propane-diyl, n-butane-diyl, n-pentane-diyl, or
n-hexane-diyl.
[0202] In sulfur-containing bis(alkenyl) ethers of Formula (5),
R.sup.4 can be C.sub.2-6 n-alkanediyl; both Y' can be --S-- or one
Y' can be --S-- and the other Y' can be --O--.
[0203] In sulfur-containing bis(alkenyl) ethers of Formula (5),
R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--.
[0204] In sulfur-containing bis(alkenyl) ethers of Formula (5),
R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each X
can be --O-- or each X can be --S--S-- or at least one X can be
--O-- or at least one X can be --S--S--.
[0205] In sulfur-containing bis(alkenyl) ethers of Formula (5),
R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each X
can be --S-- or at least one X can be --S--.
[0206] In sulfur-containing bis(alkenyl) ethers of Formula (5),
R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each p
can be 2 and r can be 2.
[0207] In sulfur-containing bis(alkenyl) ethers of Formula (5),
R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where q can
be 1, 2, 3, 4, or 5.
[0208] In sulfur-containing bis(alkenyl) ethers of Formula (5),
R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each p
can be 2, r can be 2, and q can be 1, 2, 3, 4, or 5.
[0209] In sulfur-containing bis(alkenyl) ethers of Formula (5),
R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each X
can be --S--; each p can be 2, r can be 2, and q can be 1, 2, 3, 4,
or 5.
[0210] In sulfur-containing bis(alkenyl) ethers of Formula (5),
R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each X
can be --O--; each p can be 2, r can be 2, and q can be 1, 2, 3, 4,
or 5.
[0211] In sulfur-containing bis(alkenyl) ethers of Formula (5),
R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each X
can be --O--; and each Y' can be --S--.
[0212] In sulfur-containing bis(alkenyl) ethers of Formula (5),
R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each X
can be --S--; and each Y' can be --O--.
[0213] In sulfur-containing bis(alkenyl) ethers of Formula (5),
each n can be 2, each Y' can be independently selected from --O--
and --S--, and R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each X
can be independently selected from --O--, --S--, and --S--S--, p
can be 2, q can be selected from 1 and 2, and r can be 2.
[0214] In sulfur-containing bis(alkenyl) ethers of Formula (5),
each n can be 2, each Y' can be independently selected from --O--
and --S--, and R.sup.4 can be C.sub.2-4 alkanediyl, such as
ethanediyl, n-propanediyl, or n-butanediyl.
[0215] Sulfur-containing bis(alkenyl) ethers can comprise
sulfur-containing bis(alkenyl) ethers of Formula (5a), Formula
(5b), Formula (5c), Formula (5d), Formula (5e), Formula (5f),
Formula (5g), Formula (5h), or a combination of any of the
foregoing:
CH.sub.2.dbd.CH--O--(CH.sub.2).sub.2--S--(--(CH.sub.2).sub.2--O--).sub.2-
-(CH.sub.2).sub.2--S--(CH.sub.2).sub.2--O--CH.dbd.CH.sub.2 (5a)
CH.sub.2.dbd.CH--O--(CH.sub.2).sub.2--S--(CH.sub.2).sub.2--S--(CH.sub.2)-
.sub.2--S--(CH.sub.2).sub.2--O--CH.dbd.CH.sub.2 (5b)
CH.sub.2.dbd.CH--O--(CH.sub.2).sub.2--S--(CH.sub.2).sub.2--O--(CH.sub.2)-
.sub.2--S--(CH.sub.2).sub.2--O--CH.dbd.CH.sub.2 (5d)
CH.sub.2.dbd.CH--O--(CH.sub.2).sub.2--S--(CH.sub.2).sub.2--S--(CH.sub.2)-
.sub.2--O--CH.dbd.CH.sub.2 (5d)
CH.sub.2.dbd.CH--O--(CH.sub.2).sub.2--S--(CH.sub.2).sub.2--O--(CH.sub.2)-
.sub.2--O--CH.dbd.CH.sub.2 (5e)
CH.sub.2.dbd.CH--O--(CH.sub.2).sub.2--O--(CH.sub.2).sub.2--S--(CH.sub.2)-
.sub.2--O--(CH.sub.2).sub.2--O--CH.dbd.CH.sub.2 (5f)
CH.sub.2.dbd.CH--O--(CH.sub.2).sub.2--O--(CH.sub.2).sub.2--S--(CH.sub.2)-
.sub.2--S--(CH.sub.2).sub.2--O--(CH.sub.2).sub.2--O--CH.dbd.CH.sub.2
(5g)
CH.sub.2.dbd.CH--O--(CH.sub.2).sub.2--O--(CH.sub.2).sub.2--S--S--(CH.sub-
.2).sub.2--O--(CH.sub.2).sub.2--O--CH.dbd.CH.sub.2 (5h)
[0216] Examples of suitable sulfur-containing bis(alkenyl) ethers
include 3,9,12,18-tetraoxa-6,15-dithiaicosa-1,19-diene,
3,6,15,18-tetraoxa-9,12-dithiaicosa-1,19-diene,
3,15-dioxa-6,9,12-trithiaheptadeca-1,16-diene,
3,9,15-trioxa-6,12-dithiaheptadeca-1,16-diene,
3,6,12,15-tetraoxa-9-thiaheptadeca-1,16-diene,
3,12-dioxa-6,9-dithiatetradeca-1,13-diene,
3,6,12-trioxa-9-thiatetradeca-1,13-diene,
3,6,13,16-tetraoxa-9,10-dithiaoctadeca-1,17-diene, and combinations
of any of the foregoing.
[0217] Sulfur-containing bis(alkenyl) ethers can be prepared by
reacting a dithiol, a diol, or a compound comprising both terminal
thiol and hydroxyl groups with a chlorovinyl ether.
[0218] For example, a sulfur-containing bis(alkenyl) ether can
comprise reaction products of reactants comprising:
[0219] (a) a compound of Formula (6):
Y--R.sup.4--Y (6) [0220] wherein, [0221] each Y is independently
selected from --OH and --SH; [0222] R.sup.4 is selected from
C.sub.2-6 n-alkanediyl, C.sub.3-6 branched alkanediyl, C.sub.6-8
cycloalkanediyl, C.sub.6-10 alkanecycloalkanediyl, and
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, wherein,
[0223] each X is independently selected from --O--, --S--, and
--S--S--; [0224] each p is independently an integer from 2 to 6;
[0225] q is an integer from 1 to 5; and [0226] r is an integer from
2 to 6; and [0227] at least one Y is --SH, or R.sup.4 is
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r-- and at least
one X is --S--; and
[0228] (b) a compound having the structure of Formula (7):
CH.sub.2.dbd.CH--O--(CH.sub.2).sub.t--Cl (7) [0229] wherein t is an
integer from 1 to 6.
[0230] Compounds of Formula (6) can be dithiols in which each Y is
--SH.
[0231] Compounds of Formula (6) can be diols in which each Y is
--OH.
[0232] In compounds of Formula (6), one Y can be --SH and the other
Y can be --OH.
[0233] In compounds of Formula (6), R.sup.4 can be C.sub.2-6
n-alkanediyl, such as ethane-diyl, n-propane-diyl, n-butane-diyl,
n-pentane-diyl, or n-hexane-diyl.
[0234] In compounds of Formula (6), R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--.
[0235] In compounds of Formula (6), R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each X
can be --O-- or each X can be --S--S--.
[0236] In compounds of Formula (6), R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each X
can be --S--.
[0237] In compounds of Formula (6), R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each p
can be 2 and r can be 2.
[0238] In compounds of Formula (6), R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where q can
be 1, 2, 3, 4, or 5.
[0239] In compounds of Formula (6), R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each p
can be 2 and r can be 2; and q can be 1, 2, 3, 4, or 5.
[0240] In compounds of Formula (6), R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each X
can be --S--; each p can be 2, r can be 2, and q can be 1, 2, 3, 4,
or 5.
[0241] In compounds of Formula (6), R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, where each X
can be --O--; each p can be 2, r can be 2, and q can be 1, 2, 3, 4,
or 5.
[0242] In compounds of Formula (6), R.sup.4 can be
--[--(CH.sub.2).sub.p--X-].sub.q--(CH.sub.2).sub.r--, at least one
X can be --O-- and at least one X can be --S--.
[0243] A compound of Formula (6) can comprise dimercaptodioxaoctane
(DMDO), dimercaptodiethylsulfide (DMDS), 2,2-thiodiethanethiol,
2-mercaptoethyl ether, 1,2-ethanedithiol, mercaptoethanol,
thiodiglycol, 3,6-dithia-1,8-octanediol, 2-hydroxyethyldisulfide,
or a combination of any of the foregoing.
[0244] A compound of Formula (6) can comprise a compound of Formula
(6a), Formula (6b), Formula (6c), Formula (6d), Formula (6e),
Formula (6f), Formula (6g), Formula (6h), or a combination of any
of the foregoing:
HS--(CH.sub.2).sub.2--O--(CH.sub.2).sub.2--O--(CH.sub.2).sub.2--SH
(6a)
HS--(CH.sub.2).sub.2--S--(CH.sub.2).sub.2--SH (6b)
HS--(CH.sub.2).sub.2--O--(CH.sub.2).sub.2--SH (6c)
HS--(CH.sub.2).sub.2--SH (6d)
HS--(CH.sub.2).sub.2--OH (6e)
HO--(CH.sub.2).sub.2--S--(CH.sub.2).sub.2--OH (6f)
HO--(CH.sub.2).sub.2--S--(CH.sub.2).sub.2--S--(CH.sub.2).sub.2--OH
(6g)
HO--(CH.sub.2).sub.2--S--S--(CH.sub.2).sub.2--OH (6h)
[0245] In chlorovinyl ethers of Formula (7), t can be 1, 2, 3, 4,
5, or 6. For example, a chlorovinyl ether of Formula (7) can
comprise (chloromethoxy)ethane, (2-chloroethoxy) ethane,
1-chloro-3-(vinyloxy)propane, 1-chloro-4-(vinyloxy)butane,
1-chloro-5-(vinyloxy)pentane, 1-chloro-6-(vinyloxy)hexane, or a
combination of any of the foregoing.
[0246] Sulfur-containing bis(alkenyl) ethers can be prepared by
reacting a dithiol, a diol, or a compound comprising both terminal
thiol and hydroxyl groups with a chlorovinyl ether in the presence
of a catalyst such as potassium hydroxide at an elevated
temperature such as 80.degree. C.
[0247] Sulfur-containing bis(alkenyl) ethers of Formula (5) are
difunctional. Sulfur-containing alkenyl ethers provided by the
present disclosure can also include sulfur-containing polyalkenyl
ethers having a functionality greater than two, such as a
functionality from 3 to 6.
[0248] For example, a sulfur-containing poly(alkenyl) ether can
have the structure of Formula (1c):
B(--V).sub.z (1c)
[0249] wherein, [0250] B comprises a core of a z-valent
polyfunctionalizing agent B(--V).sub.z; [0251] z is an integer from
3 to 6; and [0252] each --V is a moiety comprising a
sulfur-containing alkenyl ether moiety having a terminal alkenyl
group.
[0253] A sulfur-containing multifunctional(alkenyl) ether can be
derived from a sulfur-containing bis(alkenyl) ether of Formula (5),
by reacting a sulfur-containing bis(alkenyl) ether of Formula (5)
with a polyfunctionalizing agent of Formula (1a), where the
polyfunctionalizing agent of Formula (1a) comprises terminal groups
reactive with alkenyl groups such as thiol groups.
[0254] For example, a polyfunctional sulfur-containing
poly(alkenyl) ether can have the structure of Formula (8):
{CH.sub.2.dbd.CH--O--(CH.sub.2).sub.2--Y'--R.sup.4--Y'--(CH.sub.2).sub.n-
--O--(CH.sub.2).sub.2--V'-}.sub.zB (8)
where n, Y', and R.sup.4 are defined as in Formula (5), z and B are
defined as in Formula (1), and --V'-- can be derived from the
reaction of --V with an alkenyl group.
[0255] In sulfur-containing multifunctional (alkenyl) ethers of
Formula (8), B(--V).sub.z can be a polythiol such as any of those
disclosed herein, such as 1,2,3-propane trithiol and
isocyanurate-containing trithiols.
[0256] Sulfur-containing multifunctional (alkenyl) ethers of
Formula (8) can be prepared by reacting a sulfur-containing
bis(alkenyl) ether of Formula (5) with a thiol-terminated
polyfunctionalizing agent B(--V).sub.z of Formula (1a) in the
presence of a suitable catalyst such as an amine catalyst.
[0257] Multifunctional sulfur-containing (alkenyl) ethers can be
used to prepare multifunctional sulfur-containing (alkenyl)
ether-containing polythioether prepolymers provided by the present
disclosure. For example, the reactants can include
sulfur-containing multifunctional (alkenyl) ethers as part of the
alkenyl component. Sulfur-containing multifunctional (alkenyl)
ethers can be the only polyfunctional reactant having a
functionality greater than 2 or may be used in combination with an
alkenyl-terminated polyfunctionalizing agent such as triallyl
cyanurate or triallylisocyanurate.
[0258] Similarly, multifunctional polyalkenyl ethers can have the
structure of Formula (9):
{CH.sub.2.dbd.CH--O--(--R.sup.2--O--).sub.m--(CH.sub.2).sub.2--V'--}.sub-
.ZB (9)
where m, z, R.sup.2, and B are defined as in Formula (4) and
Formula (1), and V' is derived from the reaction of an alkenyl
group an V.
[0259] A polyalkenyl can have an alkenyl functionality greater than
2, such as 3, 4, 5, or 6. Examples of suitable polyalkenyls include
1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and triallyl
cyanurate (2,4,6-triallyloxy-1,3,5-triazine).
[0260] Polythioethers comprising a moiety derived from a
sulfur-containing polyalkenyl ether and methods of preparing
polythioether prepolymers are disclosed, for example, in PCT
International Publication No. WO 2018/085650.
[0261] Adhesion-promoting compositions provided by the present
disclosure can comprise a polyalkynyl or a combination of
polyalkynyls.
[0262] Suitable polyalkynyl can comprise two or more alkynyl
groups. For example, a polyalkynyl can have an alkenyl
functionality from 2 to 10, from 2 to 8, from 2 to 6, or from 2 to
4. Polyalkynyl can have an alkynyl functionality greater than 2,
greater than 3, greater than 4, greater than 5, greater than 6, or
greater than 8.
[0263] Suitable polyalkynyls can have a molecular weight or an
average molecular weight, for example, from 150 Da to 2,000 Da,
from 200 Da to 1,500 Da, from 300 Da to 1,000 Da, or from 400 Da to
800 Da. Polyalkynyls can have a molecular weight, for example, less
than 2,000 Da, less than 1,500 Da, less than 1,000 Da, less than
800 Da, less than 700 Da, less than 600 Da, or less than 500 Da. A
polyalkynyl can have a molecular weight, for example, greater than
2,000 Da, greater than 1,500 Da, greater than 1,000 Da, greater
than 800 Da, greater than 700 Da, greater than 600 Da, greater than
500 Da, or greater than 150 Da.
[0264] Polyalkynyls can be polyalkynyl prepolymers, monomeric
polyalkynyls, oligomeric polyalkynyls, polymeric polyalkynyls, or a
combination of any of the foregoing.
[0265] Polyalkynyls may or may not include sulfur atoms.
[0266] Examples of suitable polyalkynyls include 1,7-octadiyne,
1,6-heptadiyne, 1,4-diethynylbenzene, 1,8-decadiyne, ethylene
glycol 1,2-bis(2-propynyl) ether, and combinations of any of the
foregoing.
[0267] Adhesion-promoting compositions provided by the present
disclosure are polymerizable by free-radical mechanisms.
Adhesion-promoting compositions comprise a free radical initiator
such as, for example, a radiation-activated free radical initiator,
a thermally-activated free radical initiator, a
chemically-activated free radically initiator, or a combination of
any of the foregoing. A free radical initiator can be activated by
exposure to radiation, heat, or at ambient conditions (25.degree.
C./50% RH) without exposing the composition to electromagnetic or
thermal energy.
[0268] An adhesion-promoting composition can include, for example,
both a radiation-activated free radical initiator and a
chemically-activated free radical initiator. In such compositions,
all or a portion of the adhesion-promoting composition can be
exposed to radiation to at least partially cure the
adhesion-promoting composition, and chemically-activated free
radicals can complete or fully cure the adhesion-promoting
composition.
[0269] Adhesion-promoting compositions can include one
radiation-activated free radical initiator or combination of
radiation-activated free radical initiators.
[0270] A radiation-activated free radical initiator can generate
free radicals upon exposure to actinic radiation.
[0271] Actinic radiation includes .alpha..-rays, .gamma.-rays,
X-rays, ultraviolet (UV) light (200 nm to 400 nm) including UV-A
(320 nm to 400 nm), UV-B (280 nm to 320 nm), and UV-C (200 nm to
280 nm), visible light (400 nm to 770 nm), blue light (450 nm to
490 nm), infrared (>700 nm), near-infrared (0.75 .mu.m to 1.4
.mu.m), or an electron beam. For example, a radiation-activated
free radical initiator can be a photoinitiator such as a visible
photoinitiator or a UV photoinitiator.
[0272] The free radical photopolymerization reaction can be
initiated by exposing an adhesive-promoting composition provided by
the present disclosure to actinic radiation such as UV radiation,
for example, for less than 180 seconds, less than 120 seconds, less
than 90 seconds, less than 60 seconds, less than 30 seconds, less
than 15 seconds, or less than 5 seconds.
[0273] The free radical photopolymerization reaction can be
initiated by exposing an adhesive-promoting composition provided by
the present disclosure to actinic radiation such as UV radiation,
for example, for from 5 seconds to 180 seconds, from 5 seconds to
120 seconds, from 10 seconds to 90 seconds, from 15 seconds to 60
seconds, for rom 20 seconds to 40 seconds.
[0274] The UV radiation can include radiation at a wavelength of
394 nm.
[0275] The total power of the UV exposure can be, for example, from
50 mW/cm.sup.2 to 500 mW/cm.sup.2, from 50 mW/cm.sup.2 to 400
mW/cm.sup.2, from 50 mW/cm.sup.2 to 300 mW/cm.sup.2, from 100
mW/cm.sup.2 to 300 mW/cm.sup.2, or from 150 mW/cm.sup.2 to 250
mW/cm.sup.2.
[0276] Actinic radiation-curable adhesive-promoting compositions
provided by the present disclosure can be exposed to a UV dose of 1
J/cm.sup.2 to 4 J/cm.sup.2 to cure the composition. The UV source
is a 8 W lamp with a UVA spectrum. Other doses and/or other UV
sources can be used. A UV dose for curing a composition can be, for
example, from 0.5 J/cm.sup.2 to 4 J/cm.sup.2, from 0.5 J/cm.sup.2
to 3 J/cm.sup.2, from 1 J/cm.sup.2 to 2 J/cm.sup.2, or from 1
J/cm.sup.2 to 1.5 J/cm.sup.2.
[0277] Actinic radiation-curable adhesive-promoting compositions
provided by the present disclosure can also be cured with radiation
at blue wavelength ranges such as using a light-emitting diode.
[0278] Actinic radiation-curable adhesive-promoting compositions
can be substantially transmissive to actinic radiation, partially
transmissive to actinic radiation, or substantially opaque to
actinic radiation.
[0279] Actinic radiation-curable adhesive-promoting compositions
provided by the present disclosure comprise a photopolymerization
initiator or a combination of photopolymerization initiators.
[0280] A photopolymerization initiator can comprise a free radical
photoinitiator, a cationic photoinitiator, a photolatent base
generator, a photolatent metal catalyst, or a combination of any of
the foregoing. Exposure of the photopolymerization initiator to
suitable actinic radiation can activate the polymerization
initiator, for example, by generating free radicals, producing
cations, producing Lewis acids, or releasing activated
catalysts.
[0281] Suitable photoinitiators include, for example, aromatic
ketones and synergistic amines, alkyl benzoin ethers, thioxanthones
and derivatives, benzyl ketals, acylphosphine oxide, ketoxime ester
or .alpha.-acyloxime esters, cationic quaternary ammonium salts,
acetophenone derivatives, and combinations of any of the
foregoing.
[0282] Examples of suitable UV photoinitiators include
.alpha.-hydroxyketones, benzophenone,
.alpha.,.alpha.-diethoxyacetophenone, 4,4-diethylaminobenzophenone,
2,2-dimethoxy-2-phenylacetophenone, 4-isopropylphenyl
2-hydroxy-2-propyl ketone, 1-hydroxycyclohexyl phenyl ketone,
isoamyl p-dimethylaminobenzoate, methyl 4-dimethylaminobenzoate,
methyl O-benzoylbenzoate, benzoin, benzoin ethyl ether, benzoin
isopropyl ether, benzoin isobutyl ether,
2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-isopropylthioxanthone,
dibenzosuberone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and
bisacyclophosphine oxide.
[0283] Examples of suitable benzophenone photoinitiators include
2-hydroxy-2-methyl-1-phenyl-1-propanone,
2-hydroxy-1,4,4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone,
.alpha.-dimethoxy-.alpha.-phenylacetophenone,
2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl) phenyl]-1-butanone,
and
2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone.
[0284] Examples of suitable oxime photoinitiators include
(hydroxyimino)cyclohexane,
1-[4-(phenylthio)phenyl]-octane-1,2-dione-2-(0-benzoyloxime),
1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethanone-1-(0-acetyloxim-
e), trichloromethyl-triazine derivatives),
4-(4-methoxystyryl)-2,6-trichloromethyl-1,3,5-triazine),
4-(4-methoxyphenyl)-2,6-trichloromethyl-1,3,5-triazine, and
.alpha.-aminoketone
(1-(4-morpholinophenyl)-2-dimethylamino-2-benzyl-butan-1-one).
[0285] Examples of suitable phosphine oxide photoinitiators include
diphenyl (2,4,6-trimethylbenzoyl)-phosphine oxide (TPO) and
phenylbis(2,4,6-trimethyl benzoyl) phosphine oxide (BAPO).
[0286] Other examples of suitable UV photoinitiators include the
Irgacure.RTM. products from BASF or Ciba, such as Irgacure.RTM.
184, Irgacure.RTM. 500, Irgacure.RTM. 1173, Irgacure.RTM. 2959,
Irgacure.RTM. 745, Irgacure.RTM.651, Irgacure.RTM. 369,
Irgacure.RTM. 907, Irgacure.RTM. 1000, Irgacure.RTM. 1300,
Irgacure.RTM. 819, Irgacure.RTM. 819DW, Irgacure.RTM. 2022,
Irgacure.RTM. 2100, Irgacure.RTM. 784, Irgacure.RTM. 250;
Irgacure.RTM. MBF, Darocur.RTM. 1173, Darocur.RTM. TPO,
Darocur.RTM. 4265, and combinations of any of the foregoing.
[0287] A UV photoinitiator can comprise, for example,
2,2-dimethoxy-1,2-diphenylethan-1-one (Irgacure.RTM. 651, Ciba
Specialty Chemicals),
2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide (Darocur.RTM. TPO,
Ciba Specialty Chemicals), or a combination thereof.
[0288] Other examples of suitable photoinitiators include
Darocur.RTM. TPO (available from Ciba Specialty Chemicals),
Fucirin.RTM. TPO (available from BASF), Speedcure.RTM. TPO
(available from Fambson), Irgacure.RTM. TPO (available from Ciba
Specialty Chemicals, and Omnirad.RTM. (available from IGM Resins),
and combinations of any of the foregoing.
[0289] A photopolymerization initiator can comprise a cationic
photoinitiator or a combination of cationic photoinitiators.
[0290] Examples of suitable cationic photoinitiators include
hexafluoroantimonates, sulfonium salts, perfluorobutane sulfonates,
and iodium salts.
[0291] Polymerizable compositions provided by the present
disclosure can comprise one or more free radial initiators such as
thermally-activated free radical initiators. A thermally-activated
free radical initiator can become active at elevated temperature,
such as at a temperature greater than 25.degree. C.
[0292] Examples of suitable thermally-activated free radical
initiators include organic peroxy compounds, azobis(organonitrile)
compounds, N-acyloxyamine compounds, O-imino-isourea compounds, and
combinations of any of the foregoing. Examples of suitable organic
peroxy compounds, that may be used as thermal polymerization
initiators include peroxymonocarbonate esters, such as
tertiarybutylperoxy 2-ethylhexyl carbonate and tertiarybutylperoxy
isopropyl carbonate; peroxyketals, such as 1,1-di-(tert-butyl
peroxy)-3,3,5-trimethylcyclohexane; peroxydicarbonate esters, such
as di(2-ethylhexyl)peroxydicarbonate, di(secondary
butyl)peroxydicarbonate and diisopropylperoxydicarbonate;
diacyperoxides such as 2,4-dichlorobenzoyl peroxide, isobutyryl
peroxide, decanoyl peroxide, lauryl peroxide, propionyl peroxide,
acetyl peroxide, benzoyl peroxide, and p-chlorobenzoyl peroxide;
peroxyesters such as tot-butylpcroxy pivalate, tert-butylpcroxy
octylate, and tot-butylperoxyisobutyrate; methylethylketone
peroxide, acetylcyclohexane sulfonyl peroxide, and combinations of
any of the foregoing. Other examples of suitable peroxy compounds
include 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, and/or
1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane. Examples of
suitable azobis(organonitrile) compounds that may be used as
thermal polymerization initiators include azobis(isobutyronitrile),
2,2'-azobis(2-methyl-butanenitrile), and/or
azobis(2/1-dimethylvaleronitrile). A thermally-activated free
radical initiator can comprise
1-acetoxy-2,2,6,6-tetramethylpiperidine and/or
1,3-dicyclohexyl-O--(N-cyclohexylideneamino)-isourea.
[0293] Adhesion-promoting compositions provided by the present
disclosure, can be exposed to actinic radiation for a sufficient
time to fully or partially cure the surface of the composition. The
full depth of the composition can then cure with time via dark cure
mechanisms, for example, in which free radicals are generated by
chemical mechanisms. Providing a fully or partially cured surface
can facilitate handling of the article comprising the
adhesion-promoting interlayer and can provide structural strength
and integrity while the article is being fabricated and fully
cures.
[0294] Adhesion-promoting compositions provided by the present
disclosure can comprise a chemically-activated free radical
initiator or a combination of chemically-activated free radical
initiators. Chemically-activated free radical initiators refer to
compounds and complexes capable of generating free radicals without
being activated by actinic radiation and/or by exposure to
heat.
[0295] Chemically-activated free radical initiators can facilitate
curing of portions of an adhesion-promoting composition not exposed
to actinic radiation and can effectively extend the depth of cure.
For example, adhesion-promoting compositions can be at least partly
curable upon exposure to actinic radiation and such compositions
can include a photopolymerization initiator. The actinic radiation
can be applied to at least a portion of an adhesion-promoting
composition. The adhesion-promoting composition can be accessible
to the actinic radiation and the portion of the adhesion-promoting
composition exposed to the actinic radiation can be cured to a
certain surface depth and/or to a certain radiation does. A portion
of the adhesion-promoting composition may not be accessible or may
be incompletely accessible to actinic radiation either because of
absorption or scattering of the actinic radiation such that the
adhesion-promoting composition prevents the actinic radiation from
interacting with the full thickness of the adhesion-promoting
composition.
[0296] Chemically-activated free radical initiators can also be
included in adhesion-promoting compositions that are not curable
upon exposure to actinic radiation. For example, an overlying layer
of a sulfur-containing sealant may not be transmissive or may be
only partially transmissive to actinic radiation such as UV
radiation.
[0297] In dark cure mode, i.e., when actinic radiation such as UV
radiation is not used to generate free radicals,
chemically-activated free radical initiators provide an alternate
radical initiation mechanism that takes place in absence of actinic
radiation.
[0298] Examples of suitable chemically-activated free radical
initiators include combinations of metal complexes and organic
peroxides, trialkylborane complexes, and peroxide-amine redox
initiators.
[0299] Examples of suitable chemically-activated free radical
initiators are disclosed, for example, in U.S. application Ser. No.
16/373,668 filed on Apr. 3, 2019, and in PCT International
Publication No. WO 2018/227149.
[0300] Combinations of metal complexes and organic peroxides can be
used as free radical initiators in adhesion-promoting compositions
provided by the present disclosure. Combinations of metal complexes
and organic peroxides can also impart useful dual cure properties
to radiation curable compositions such as actinic radiation-curable
adhesion-promoting compositions. The cure dynamics can depend on
the combination of metal complexes and organic peroxides. Using
different solvent mixtures to disperse the metal complexes it is
also possible to control the gel time of an adhesion-promoting
composition and control the time to fully cure an
adhesion-promoting composition under dark conditions. Physical
properties and adhesion of adhesion-promoting compositions cured
using a dark cure redox radial initiated reaction are comparable to
those of compositions cured using actinic radiation only (in the
absence of the dark cure catalyst system) such as UV-radiation.
Such dual cure adhesion-promoting compositions have several
advantages. For example, in geometries and configurations where it
is not possible to directly expose an adhesion-promoting
composition to actinic radiation, a portion of the
adhesion-promoting composition can be exposed to the actinic
radiation thereby initiating dark cure redox curing mechanisms that
can propagate through unexposed areas of the adhesion-promoting
composition. As another example, an overlying sulfur-containing
sealant layer may not be sufficiently transmissive to actinic
radiation to partially or fully activate radiation-activated free
radical initiators in the adhesion-promoting composition. For
example, the overlying sulfur-containing sealant layer can contain
constituents that absorb and/or scatter incident actinic radiation.
Dual cure mechanisms can further provide opportunities to control
the cure rate of an adhesion-promoting composition, which can lead
to improved properties such as improved tensile strength, %
elongation, solvent resistance, and adhesion. The use of dark-cure
catalysts can expand the range of materials used in the
sulfur-containing sealant layer.
[0301] Adhesion-promoting compositions provided by the present
disclosure can comprise a metal complex or combination of metal
complexes capable of generating free radicals. Suitable metal
complexes are capable of reacting with organic peroxides at
temperatures from 20.degree. C. to 25.degree. C. to generate free
radicals.
[0302] Suitable metal complexes include metal(II) (M.sup.2+) and
metal(III) (M.sup.3+) complexes. The anions can be compatible with
the other components of an adhesion-promoting composition. For
example, suitable anions include organic anions.
[0303] In the presence of a suitable organic peroxides, suitable
metal complexes can provide a fully cured adhesion-promoting
composition, for example, within 7 days, within 10 days, within 14
days, within 21 days, or within 28 days.
[0304] Suitable metal complexes include metal complexes of cobalt,
copper, manganese, iron, vanadium, potassium, cerium, and aluminum.
Suitable ligands include organic ligands.
[0305] Examples of suitable metal(II) complexes include
manganese(II) bis(tetramethylcyclopentadienyl), manganese(II)
2,4-pentanedioante, manganese(II) acetylacetonate, iron(II)
acetylacetonate, iron(II) trifluoromethanesulfonate, iron(II)
fumarate, cobalt(II) acetylacetonate, copper(II) acetylacetonate,
and combinations of any of the foregoing.
[0306] Examples of suitable metal(III) complexes include
manganese(III) 2,4-pentanedionate, manganese(III) acetylacetonate,
manganese(III) methanesulfonate, iron(III)acetylacetonate, and
combinations of any of the foregoing.
[0307] Examples of suitable metal complexes include Mn(III)(acac)3,
Mn(III)(2,2'-bipyridyl)2(acac).sub.3, Mn(II)(acac).sub.2,
V(acac).sub.3(2,2'-bipyridyl), Fe(III)acac).sub.3, and combinations
of any of the foregoing.
[0308] Suitable Mn complexes can be formed with ligands including,
for example, 2,2'-bipyridine, 1,10-phenanthroline,
1,4,7-trimethyl-4,7-triazacyclononane,
1,2-bis(4,7-dimethyl-1,4,7-triazacyclononan-1-yl)-ethane,
N,N,N',N'',N''',N'''-hexamethyltriethylenetetraamine,
acetylacetonate (acac), N,N'-bis(alicylidene)cyclohexylenediamine,
5,10,15,20-tetrakisphenylporphyrin,
5,10,15,20-tetrakis(4'-methoxyphenyl)porphyrin, porphyrin,
6-amino-1,4,6-trimethyl-1,4-diazacycloheptane,
6-dimethylamino-1,4-bis(pyridine-2-ylmethyl)-6-methyl-1,4-diazacyclohepta-
ne,
1,4,6-trimethyl-6[N-pyridin-2-ylmethyl)-N-methylamino]-1,4-dizazcycloh-
eptane, 4,11-dimethyl-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane,
and combinations of any of the foregoing.
[0309] Suitable Fe complexes can be formed with ligands including,
for example, 1,4-deazacycloheptane-based ligands such as
6-amino-1,4,6-trimethyl-1,4-diazacycloheptane,
6-dimethylamino-1,4-bis(pyridine-2-ylmethyl)-6-methyl-1,4-diazacyclohepta-
ne,
1,4,6-trimethyl-6[N-(pyrinin-2-ylmethyl)-N-methylamino]-1,4-diazacyclo-
heptane, bisphendimethyl 3-methyl-9-oxo-2, and
4-dipyridin-2-yl-7-(pyridin-2-ylmethyl)-3,7-diazbicyclo[3.3.1]nonane-1,3--
dicarboxylate; ferrocene-based ligands such as ferrocene,
acylferrocene, benzeneacycloferrocene,
N,N-bis(pyridin-2-ylmethyl)-1,1-bis(pyridine-2-yl)-1-amino-ethane;
and combinations of any of the foregoing.
[0310] Suitable metal complexes can be, for example, trivalent or
tetravalent.
[0311] The ligand of the metal complex can be selected to improve
the storage stability of a formulation containing the metal
complex. Metal complexes with an acetylacetonate ligand are
observed to be storage stable.
[0312] Adhesion-promoting compositions provided by the present
disclosure can comprise, for example, from 0.01 wt % to 3 wt % of a
metal complex, from 0.05 wt % to 2.5 wt %, from 0.1 wt % to 2 wt %,
or from 0.5 wt % to 1.5 wt %, where wt % is based on the total
weight of the adhesion-promoting composition.
[0313] Adhesion-promoting compositions provided by the present
disclosure can comprise an organic peroxide or combination of
organic peroxides.
[0314] Examples of suitable organic peroxides include ketone
peroxides, diacyl peroxides, hydroperoxides, dialkyl peroxides,
peroxyketals, alkyl per esters, and percarbonates.
[0315] Suitable organic peroxides include tert-butyl peroxide,
cumene hydroperoxide, p-methane hydroperoxide, di-tert-butyl
peroxide, tert-butylcumyl peroxide, acetyl peroxide, isobutyryl
peroxide, octanoyl peroxide, dibenzoyl peroxide,
3,5,5-trimethylhexanoyl peroxide, and tot-butyl peroxyisobutyrate.
Additional examples of suitable organic peroxides include benzoyl
peroxide, tert-butyl perbenzoate, o-methylbenzoyl peroxide,
p-methylbenzoyl peroxide, di-tert-butyl peroxide, dicumyl peroxide,
1,1-bis(tert-butylperoxy)-3,3,5-trimethyl cyclohexane,
1,1-di(tert-butylperoxy)cyclohexane,
2,5-dimethyl-2,5-di(tert-butylperoxy)hexane,
2,5-dimethyl-2,5-di(tert-butylperoxy)hexane,
1,6-bis(p-toluoylperoxy carbonyloxy)hexane, di(4-methylbenzoyl
peroxy)hexamethylene bis-carbonate, tert-butylcumyl peroxide,
methyl ethyl ketone peroxide, cumene hydroperoxide,
2,5-dimethyl-2,5-di(tert-butylperoxy)hexane,
2,5-dimethyl-2,5-di(benzoylperoxy)hexane,
2,5-dimethyl-2,5-di(tert-butyperoxy)hexane,
1,3-bis(tert-butylperoxypropyl)benzene,
di-tert-butylperoxy-diisopropylbenzene, tot-butylperoxybenzene,
2,4-dichlorobenzoyl peroxide,
1,1-dibutylperoxy-3,3,5-trimethylsiloxane,
n-butyl-4,4-di-tert-butyl peroxyvalerate, and combinations of any
of the foregoing.
[0316] Examples of suitable organic peroxides include
3,3,5,7,7-pentamethyl-1,2,4-trioxepane,
2,5-dimethyl-2,5-di(tert-butylpcroxy)hexyne-3, di-tert-butyl
peroxide, 2,5-di methy 1-2,5-di(tert-butylperoxy)hexane, tert-butyl
cumyl peroxide, di(tert-butylperoxyisopropyl)benzene, dicumyl
peroxide, butyl 4,4-di(tert-butylperoxy) valerate, tert-butylpcroxy
2-ethylhexyl carbonate,
1,1-di(tert-butylperoxy-3,3,5-trimethylcyclohexane, tert-butyl
peroxybenzoate, di(4-methylbenzoyl) peroxide, dibenzoyl peroxide,
and di(2,4-dichlorobenzoyl) peroxide, which are commercially
available, for example, from AkzoNobel.
[0317] Adhesion-promoting compositions comprising an organic
peroxide can also contain a metal salt, such as, for example,
Fe(II) sulfate heptahydrate or Mn(III)-stearate.
[0318] Adhesion-promoting compositions provided by the present
disclosure can comprise, for example, from 0.1 wt % to 5 wt %, from
0.2 wt % to 3 wt % of an organic peroxide, from 0.5 wt % to 3 wt %,
from 0.7 wt % to 2.5 wt %, from 0.1 wt % to 2 wt %, from 0.2 wt %
to 2 wt %, or from 0.2 wt % to 1 wt %, where wt % is based on the
total weight of the adhesion-promoting composition.
[0319] Metal complexes and organic peroxides can be provided in
dilute solutions of a solvent. For example, the solutions can
comprise from 1 wt % to 15 wt %, or from 5 wt % to 15 wt % of the
metal complex or organic peroxide. Examples of solvents include
acetylacetone, HB-40.RTM. (combination of terphenyls), toluene,
water, isopropanol, methyl propyl ketone, hexanes, methanol, and
cyclohexane.
[0320] The solvent can influence the curing time of an
adhesion-promoting composition. For example in
Fe(III)(acetylacetonate).sub.3 and Mn(III)(acetylacetonate).sub.3
systems, increasing the ratio of toluene to acetylacetonate in the
solution can make the metal center more available for reaction by
shifting the equilibrium in a direction where the ligand(s) can
leave more easily. This mechanism should also be applicable with
other ligand and metal-ligand complexes such as 2-ethylhexanoic
acid and cobalt(II)bis(2-ethylhexanoate). Thus, by using different
metals, organic anions, and solvent compositions, the cure time and
the application time can be selected for dual cure systems.
[0321] Suitable solvents can have, for example, a polarity similar
to that of toluene. Suitable solvents include, for example,
toluene, o-xylene, cyclohexane, diethyl ether, methyl-tert-butyl
ether, hexane, and ethyl acetate.
[0322] Suitable organic peroxides include those commercially
available under the tradename Trigonox.RTM., Butanox.RTM., and
Perkodox.RTM. from AkzoNobel, and, under the tradename Cadox.RTM.
from Summit Composites Pty, Ltd.
[0323] Trialkylborane complexes can be used to generate free
radicals. In the process, a blocked trialkylborane B(--R).sub.3(-L)
where each R is an alkyl such as a C.sub.1-8 alkyl, and L is a
ligand can be deblocked to form a trialkylborane B(--R).sub.3. The
deblocking can take place in the presence of an acid and/or a
co-catalyst. At room temperature (25.degree. C.) the un-blocked
trialkyl borane can oxidize in the presence of atmospheric O.sub.2
to form the peroxide R.sub.2B--O--O--R, which upon fragmentation
provides several radicals including the borinate radical
B(R).sub.2O*, an alkyl radical R*, a peroxy radical R--O--O*, and
an alkoxy radial R--O*, in increasing order of reactivity. Reaction
of the trialkyl borane with oxygen is necessary to generate the
free radical. Thus, when used as the only radical catalyst in a
coreactive composition system the depth of cure will be limited by
the diffusion of atmospheric oxygen from the surface.
[0324] To extend the generation of free radicals using trialkyl
boranes a co-catalyst can be used to provide a source of oxygen.
The co-catalyst should provide a source of oxygen radicals at room
temperature and suitable illumination conditions and be able to
deblock the ligand from the borane complex under dark
conditions.
[0325] For example, under dark cure conditions, i.e., when actinic
radiation such as UV radiation is not used to generate free
radicals, the decomposition of a trialkyl borane complex
tri-n-butylborane-3-methoxypropylamine (TnBB-MOPA), in the presence
of a co-catalyst tetrabutylammonium persulfate (TBAPS) to generate
free radicals and initiate the polymerization reaction.
[0326] The use of organoborane complexes in combination with a dark
cure co-catalyst can provide cured adhesion-promoting composition
compositions with properties similar to those of UV-cured
adhesion-promoting compositions.
[0327] Adhesion-promoting compositions provided by the present
disclosure can comprise an organoborane complex or a combination of
organoborane complexes. An organoborane complex comprises an
organoborane complexed with a ligand.
[0328] Adhesion-promoting compositions can comprise, for example,
from 0.1 wt % to 4 wt % of an organoborane complex, from 0.5 wt %
to 3.5 wt %, from 1 wt % to 3 wt %, or from 1.5 wt % to 2.5 wt % of
an organoborane complex, where wt % is based on the total weight of
the adhesion-promoting composition.
[0329] An organoborane complex can comprise an organoborane
compound and a blocking ligand. When the organoborane becomes
unblocked, the organoborane can react with oxygen or an oxygen
source to provide a source of radicals for promoting a free radical
initiated reaction such as a thiol-ene polymerization reaction.
[0330] An organoborane radical initiator may be any organoborane
compound known in the art capable of generating free radicals.
Examples of suitable organoboranes include tri-functional boranes
having the structure of Formula (10):
##STR00003##
where each of R.sup.10 can independently be selected from hydrogen,
C.sub.1-20 alkyl, C.sub.1-20 alkoxy, C.sub.5-10 cycloalkyl, and
C.sub.6-8 aryl. For example, each R.sup.10 can be independently
selected from C.sub.1-20 alkyl, C.sub.1-15 alkyl, C.sub.1-10 alkyl,
or C.sub.1-5 alkyl.
[0331] Examples of suitable organoboranes include tri-methylborane,
tri-ethylborane, tri-n-butylborane, tri-n-octylborane,
tri-sec-butylborane, tri-dodecylborane, phenyldiethylborane, and
combinations of any of the foregoing. An organoborane can comprise
tri-n-butylborane.
[0332] An organoborane can be an organosilicon-functional
organoborane and may include a functional group including at least
one of a silicon atom, a siloxane prepolymer, and a siloxane
polymer. Examples of suitable organosilicon-functional
organoboranes are described in PCT International Publication No. WO
2006/073695. An organosilicon-functional organoborane may include a
complex including at least one a silicon atom, a siloxane
prepolymer, and/or a siloxane polymer.
[0333] An organoborane initiator can be derived from decomplexation
of an air-stable complex of an organoborane compound and an
organonitrogen compound. For example, an organoborane initiator can
be derived from an organoborane-organonitrogen complex. Suitable
organoborane initiators include, for example, organoborane-amine
complexes, organoborane-azole complexes, organoborane-amidine
complexes, organoborane-heterocyclic nitrogen complexes,
amido-organoborate complexes, and combinations thereof. An
organoborane-amine complex can comprise a trialkylborane-amine
complex. Additional examples of suitable organoborane initiators
are described in U.S. Publication No. 2007/0141267, U.S. Pat. No.
7,247,596, and PCT International Publication No. 2007044735. An
organoborane initiator can be referred to as an organoborane-amine
complex.
[0334] An organoborane-amine complex includes a complex formed
between an organoborane and a suitable amine that renders the
organoborane-amine complex stable at ambient conditions. Any
suitable organoborane-amine complex known in the art may be used.
An organoborane-amine complex can be capable of initiating
polymerization or cross-linking of the radical curable organic
compound through introduction of an amine-reactive compound, and/or
by heating. For example, an organoborane-amine complex can be
destabilized at ambient temperatures through exposure to suitable
amine-reactive compounds. Pleat may be applied if needed or
desired. An organoborane-amine complex can have the structure of
Formula (11):
##STR00004##
where R.sup.11 can independently be selected from hydrogen,
C.sub.1-12 alkyl, C.sub.1-12 heteroalkyl, C.sub.5-12 cycloalkyl,
C.sub.5-12heterocycloalkyl, C.sub.6-12, alkylaryl, an organosilane
group, an organosiloxane group, a C.sub.1-12 alkanediyl group
capable of functioning as a covalent bridge to the boron, a
divalent organosiloxane group capable of functioning as a covalent
bridge to the boron, and halogen substituted homologues thereof,
such that at least one of R.sup.10 includes one or more silicon
atoms and is covalently bonded to boron. In C.sub.1-12 heteroalkyl
and C.sub.5-12 heterocycloalkyl the one or more heteroatoms can be
O. Each R.sup.11 can have the structure
--(CH.sub.2).sub.n1--O--(CH.sub.2).sub.n2, where n1 is an integer
from 1 to 10, from 1 to 8, from 1 to 6, or from 1 to 4; and each n2
can be an integer from 1 to 8, from 1 to 6, from 1 to 4, or from 1
to 2.
[0335] Any suitable amine ligand can be used to form the
organoborane-amine complex. Examples of suitable amines include at
least one of an alkyl group, an alkoxy group, an imidazole group,
an amidine group, an ureido group, and combinations thereof.
Suitable amines include, for example, 1,3 propane diamine,
1,6-hexanediamine, methoxypropylamine, pyridine, isophorone
diamine, 3-aminopropyltrimethoxysilane,
aminomethyltrimethoxysilane, 3-aminopropyltriethoxysilane,
aminomethyltriethoxysilane, 2-(trimethoxysilylethyl)pyridine,
aminopropylsilanetriol, 3-(m-aminophenoxy)propyltrimethoxysilane,
3-aminopropyldiisopropylmethoxysilane, aminophenyltrimethoxysilane,
3-aminopropyltris(methoxyethoxethoxy)silane,
tert-4-(2-aminoethyl)-3-aminopropyltrimethoxysilane,
N.sub.1-(6-aminohexyl)aminomethyltrimethoxysilane,
N-(2-aminoethyl)-11-aminoundecyltrimethoxysilane,
aminoethylaminomethylphenethyltrimethoxysilane,
N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane,
N-(2-aminoethyl)-3-aminoisobutylmethyldimethoxysilane,
(3-trimethoxysilylpropyl)diethylene-triamine,
1,1,2,4-tetramethyl-1-sila-2-azacyclopentane, amine functional
organopolysiloxanes including at least one amine functional group
such as 3-aminopropyl, 6-aminohexyl, 11-aminoundecyl,
3-(N-allylamino)propyl, N-(2-aminoethyl)-3-aminopropyl,
aminomethyl, N-(2-aminoethyl)-3-aminoisobutyl, p-aminophenyl,
2-ethylpyridine, and 3-propylpyrrole, nitrogen compounds including
N-(3-triethyoxysilylpropyl)-4,5-dihydroimidazole,
ureidopropyltriethoxysilane, and combinations of any of the
foregoing. An amine ligand can be selected from amine-functional
alkoxysilanes, amine-functional organopolysiloxanes, and
combinations thereof. In another embodiment, the amine includes
N-(2-aminoethyl)-3-aminopropyltrimethoxysilane. An amine ligand can
be selected from 2-methoxyethyl amine, 3-methoxypropyl amine,
4-methoxybutyl amine, and combinations of any of the foregoing.
[0336] An organoborane complex can be physically and/or chemically
attached (bound) to a solid particle such as a phase support or an
inorganic particle to control working times, as well as to
stabilize liquid phase organoborane-amine complexes against
separating during storage.
[0337] Organoborane-amine complexes are capable of being deblocked
in an acidic environment.
[0338] Examples of suitable organoborane complexes include
trialkylborane-amine complexes such as
tris(n-butyl)borane-3-methoxyproylamine,
triethylborane-1,3-diaminopropane, and
triethylborane-diethylenetriamine, available, for example, from
Callery.
[0339] Adhesion-promoting compositions provided by the present
disclosure can comprise a radical oxidizing agent or a combination
of radical oxidizing agents. A suitable radical oxidizing agent is
capable of forming free radicals at room temperature and can serve
as a source of oxygen for the generation of free radicals by the
organoborane.
[0340] Adhesion-promoting compositions provided by the present
disclosure can comprise, for example, from 0.1 wt % to 4 wt %, from
0.5 wt % to 3.5 wt %, from 1 wt % to 3 wt % or from 1.5 wt % to 2.5
wt %, of a radical oxidizing agent, where wt % is based on the
total weight of the adhesion-promoting composition.
[0341] Examples of suitable radical oxidizing agents include
bis(tetrabutylammonium) persulfate (TBAPS), and other
bis(tetraalkylammonium persulfates such as bis(tetramethylammonium)
persulfate, bis(tetraethylammonium) persulfate,
bis(tributylmethylammonium) persulfate, and combinations of any of
the foregoing.
[0342] In certain adhesion-promoting compositions the radical
oxidizing agent comprises tetrabutylammonium persulfate (TB APS)
and the organoborane complex comprises the
tri-n-butylborane-3-methoxypropylamine complex (TnBB-MOPA).
[0343] A chemically initiated free radical generator can comprise a
peroxide and an amine where the peroxide and amine form a
peroxide-amine redox initiator. The amine can comprise, for
example, dihydroxyethyl-p-toluidine, N,N-diisopropylethylamine, and
N,N,N',N'',N''-pentamethyl-diethylenetriamine. The peroxide can
comprise, for example, di-tert-butyl peroxide, methyl ethyl ketone
peroxide, and benzoyl peroxide.
[0344] Adhesion-promoting compositions provided by the present
disclosure can comprise a solvent or combination of solvents. The
solvent can comprise an organic solvent or a combination of organic
solvents. An organic solvent can comprise a volatile organic
solvent that facilitates the ability of the adhesion-promoting
composition to dry when applied to an underlying sealant layer
and/or substrate.
[0345] A suitable volatile organic solvent can have a high vapor
pressure at 25.degree. C. such as greater than 10 mm Hg, greater
than 25 Hg, greater than 50 mm Hg, greater than 150 mm Hg, or
greater than 200 mm Hg.
[0346] Examples of suitable solvents include acetone, methylethyl
ketone, methyl acetate, diethyl ether, isopropanol and combinations
of any of the foregoing.
[0347] Adhesion-promoting compositions provided by the present
disclosure can comprise a polymerization moderator or a combination
of polymerization moderators. A polymerization moderator can
minimize the formation of any distortions or defects, e.g.,
striations and or cracks/fissures, in a polymerized
adhesion-promoting composition.
[0348] Examples of suitable polymerization moderators include
dilauryl thiodipropionate, 1-isopropyl-4-methyl-1,4-cyclohexadiene
(.gamma.-terpinene); 1-isopropyl-4-methyl-1,3-cyclohexadiene
(.alpha.-terpinene); 1-methyl-4-(propan-2-ylidene)cyclohex-1-ene,
(terpinolene); and .alpha.-methyl styrene dimer,
1,1-diphenylethylene, cis-1,2-diphenylethylene,
3,7,7-trimethylbicyclo[4.1.0]hept-3-ene (3-carene),
4-isopropenyl-1-methylcyclohexene (dipentene),
(5)-(+4-isopropenyl-1-methylcyclohexene ((S)-limonene),
2,6-dimethyl-2,4,6-octatriene, 4-tert-butylpyrocatechol,
triphenylmethane, and combinations of any of the foregoing.
[0349] A polymerization moderator can comprise
1-isopropyl-4-methyl-1,4-cyclohexadiene;
1-isopropyl-4-methyl-1,3-cyclohexadiene;
1-methyl-4-(propan-2-ylidene)cyclohex-1-ene;
2,6-dimethyl-2,4,6-octatriene, .alpha.-methyl styrene dimer, or a
combination of any of the foregoing. An .alpha.-methyl styrene
dimer refers to a polymerization moderator such as
2,4-diphenyl-4-methyl-1-pentene, and optionally at least one of
2,4-diphenyl-4-methyl-2-pentene and/or 2-phenyl-1-propene (which is
also referred to as, di-methyl styrene). An .alpha.-methyl styrene
dimer polymerization moderator can include 90 wt % to 93 wt % of
2,4-diphenyl-4-methyl-1-pentene, from 6 wt % to 8 wt % of
2,4-diphenyl-4-methyl-2-pentene, and from 0.25 wt % to 0.75 wt % of
2-phenyl-1-propene, wherein wt % is based on the weight of the
.alpha.-methyl styrene dimer.
[0350] An adhesion-promoting composition provided by the present
disclosure can comprise, for example, from 0.01 wt % to 15 wt %, or
from 0.1 wt % to 8 wt %, or from 0.3 wt % to 5 wt %, of a
polymerization moderator, wherein wt % is based on the total weight
of the adhesion-promoting composition.
[0351] Adhesion-promoting compositions provided by the present
disclosure can comprise colorants such as pigments, dyes, or a
combination thereof. An adhesion-promoting composition can
comprise, for example, from 0.5 wt % to 10 wt % from 1 wt % to 8 wt
%, or from 2 wt % to 6 wt %, or less than 10 wt %, less than 8 wt
%, less than 6 wt %, less than 4 wt %, less than 2 wt %, or less
than 1 wt % of the adhesion-promoting composition, where wt % is
based on the total weight of the adhesion-promoting
composition.
[0352] A colorant such as a pigment and/or dye can be included in
an adhesion-promoting composition to facilitate the ability of an
operator to visually inspect a surface to determine whether an
adhesion-promoting composition has been applied to a surface and/or
whether a sufficient amount of an adhesion-promoting composition
has been applied to a surface. In this way, an operator can
determine that a homogeneous adhesion-promoting composition has
been uniformly applied across the surface before applying an
overlying sulfur-containing sealant.
[0353] Examples of suitable inorganic pigments include
metal-containing inorganic pigments such as those containing
cadmium, carbon, chromium, cobalt, copper, iron oxide, lead,
mercury, titanium, tungsten, and zinc. Examples further include
ultramarine blue, ultramarine violet, reduced tungsten oxide,
cobalt aluminate, cobalt phosphate, manganese ammonium
pyrophosphate and/or metal-free inorganic pigments. In particular
embodiments the inorganic pigment nanoparticles comprise
ultramarine blue, ultramarine violet, Prussian blue, cobalt blue
and/or reduced tungsten oxide. Examples of specific organic
pigments include indanthrone, quinacridone, phthalocyanine blue,
copper phthalocyanine blue, and perylene anthraquinone.
[0354] Additional examples of suitable pigments include iron oxide
pigments, in all shades of yellow, brown, red and black; in all
their physical forms and grain categories; titanium oxide pigments
in all the different inorganic surface treatments; chromium oxide
pigments also co-precipitated with nickel and nickel titanates;
black pigments from organic combustion (e. g., carbon black); blue
and green pigments derived from copper phthalocyanine, also
chlorinated and brominated, in the various .alpha., .beta. and
.epsilon. crystalline forms; yellow pigments derived from lead
sulfochromate; yellow pigments derived from lead bismuth vanadate;
orange pigments derived from lead sulfochromate molybdate; yellow
pigments of an organic nature based on arylamides; orange pigments
of an organic nature based on naphthol; orange pigments of an
organic nature based on diketo-pyrrolo-pyrrole; red pigments based
on manganese salts of azo dyes; red pigments based on manganese
salts of beta-oxynaphthoic acid; red organic quinacridone pigments;
and red organic anthraquinone pigments.
[0355] Examples of suitable dyes include acridines, anthraquinones,
arylmethane dyes, azo dyes, phthalocyanine dyes, quinone-imine dyes
including azin dyes, indamins, indophenyls, oxazins, oxazones, and
thiazines, thiazole dyes, saffranin dyes, xanthene dyes including
fluorene dyes. Examples of suitable dyes include Alcian blue,
Alcian yellow, Alizarin, Alizarin red, Alizarin yellow, Azophloxin,
Bismarck brown R, Bismarck brown Y, Brilliant cresyl blue,
Chrysoidine R, Crisoidine Y, Congo red, Crystal violet, Ethyl
green, Fuchsin acid, Gentian violet, Janus green, Lissamine fast
yellow, Malachite green, Martius yellow, Meldola blude, Metanil
yellow, Methyl orange, Methyl red, Naphthalene black, Naphthol
green, Naphthol yellow, Orange G, Purpurin, Rose bengal, Sudan II,
Titan yellow, Tropaeolin O, Tropaeolin OO, Tropaeolin OOO, Victoria
blue, and Xylene cyanol.
[0356] The amount of dye or pigment added to an adhesion-promoting
composition can be sufficient to facilitate visual inspection and
not compromise the ability to of the adhesion-promoting interlayer
to provide sufficient adhesion between the adjoining
sulfur-containing sealants.
[0357] Adhesion-promoting compositions provided by the present
disclosure can comprise a photochromic material or a combination of
photochromic materials. A photochromic material can be a reversible
photochromic material or a non-reversable photochromic
material.
[0358] In certain applications it can be desirable that a
photochromic agent that is sensitive to the degree of cure be used.
Such agents can provide a visual indication that the
adhesion-promoting composition has been exposed to a desired amount
of actinic radiation, or example, to cure the coreactive
composition. Certain photochromic agents can be used as cure
indicators. A cure indicator can facilitate the ability to assess
the extent of cure of a sealant by visual inspection.
[0359] Adhesion-promoting compositions provided by the present
disclosure can comprise a photochromic material or a combination of
photochromic materials. A photochromic material can be a reversible
photochromic material or a non-reversable photochromic material. A
photochromic material can be a thermally reversible photochromic
material or a thermally non-reversable photochromic material.
[0360] A photochromic material can be a compound that is activated
by absorbing actinic radiation having a particular wavelength, such
as UV radiation, which causes a change in a feature of the
photochromic material. A feature change is an identifiable change
in a feature of the photochromic material which can be detected
using an instrument or visually. Examples of feature changes
include a change of color or color intensity and a change in
structure or other interactions with energy in the visible UV,
infrared (IR), near IR or far IR portions of the electromagnetic
spectrum such as absorption and/or reflectance. A color change at
visible wavelengths refers to a color change at wavelengths within
a range from 400 nm to 800 nm.
[0361] A photochromic material can be activated by absorbing
radiation energy (visible and non-visible light) having a
particular wavelength, such as UV light, to undergo a feature
change such as a color change. The feature change can be a change
of feature of the photochromic material alone or it can be a change
of feature of a coreactive composition. Examples of suitable
photochromic materials include spiropyrans, spiropyrimidines,
spirooxazines, diarylethenes, photochromic quinones, azobenzenes,
other photochromic dyes and combinations thereof. These
photochromic materials can undergo a reversible or irreversible
feature change when exposed to radiation where the first and second
states can be different colors or different intensities of the same
color.
[0362] Examples of suitable photochromic agents include
spiropyrans. Spiropyrans are photochromic molecules that change
color and/or fluoresce under different wavelength light sources.
Examples of suitable photochromic spiropyrans include
1',3'-dihydro-8-methoxy-1',3',3'-trimethyl-6-nitrospiro[2H-1benzopyran-2,-
2'-(2H)-indole];
1',3'-dihydro-1',3',3'-trimethyl-6-nitrospiro[2H-1-benzopyran-2,2'-(2H)-i-
-indole];
1,3-dihydro-1,3,3-trimethylspiro[2H-indole-2,3'-[3H]naphth[2,1-b-
][1,4]oxazine];
6,8-dibromo-1',3'-dihydro-1',3',3'-trimethylspiro[2H-1-benzopyran-2,2'-(2-
H)-indole];
5-chloro-1,3-dihydro-1,3,3-trimethylspiro[2H-indole-2,3'-[3H]phenanthr[9,-
10-b][1,4]oxazine];
6-bromo-trimethyl-8-nitrospiro[2H-1-benzopyran-2,2'-(2H)-indole];
5-chloro-1,3-dihydro-1,3,3-trimethylspiro[2H-indole-2,3'-[3H]naphth[2,1-b-
-][1,4]oxazine];
1',3'-dihydro-5'-methoxy-1+,3,3,-trimethyl-6-nitrospiro[2H-1-benzopyran-2-
,2'(2H)-indole];
1,3-dihydro-1,3,3-trimethylspiro[2H-indole-2,3'-[3H]phenanthr[9,10-b][1,4-
-]oxazine];
5-methoxy-1,3,3-trimethylspiro[indoline-2,3'-[3H]naphtha[2,1-b]-pyran];
8'-methacryloxymethyl-3-methyl-6'-nitro-1-selenaspiro-[2H-1'-benzopyran-2-
,2'-benzoselenenazoline];
3-isopropyl-8'-methacryloxymethyl-5-methoxy-6'-nitro-1-selenaspiro[2H-1'--
benzopyran-2,2'-benzoselenazoline];
3-isopropyl-8'-methacryloxymethyl-5-methoxy-6'-nitro-1-selenaspiro[2H-1
benzopyran-2,2'-benzoselenazoline];
8'-methacryloxymethyl-5-methoxy-2-methyl-6'-nitro-1-selenaspiro[2H-1'-ben-
-zopyran-2,2'-benzoselenazoline];
2,5-dimethyl-8'-methacryloxymethyl-6'-nitro-1-selenaspiro[2H-1'-benzopyra-
n-2,2'-benzoselenazoline];
8'-methacryloxymethyl-5-methoxy-3-methyl-6'-nitrospiro[benzoselenazoline--
2,2'(2'H)-1'-benzothiopyran];
8-methacryloxymethyl-6-nitro-trimethylspiro[2H-1-benzothiopyran-2,2'-indo-
line];
3,3-dimethyl-1-isopropyl-8'-methacryloxymethyl-6'-nitrospiro-[indol-
ine-2,-2'(2'H)-1'-benzothiopyran];
3,3-dimethyl-8'-methacryloxymethyl-6'-nitro-1-octadecylspiro[indoline-2,2-
'(2'H)-1'-benzothiopyran] and combinations of any of the
foregoing.
[0363] Azobenzenes are capable of photoisomerization between trans-
and cis-isomers. Examples of suitable photochromic azobenzenes
include azobenzene;
4-[bis(9,9-dimethylfluoren-2-yl)amino]azobenzene;
4-(N,N-dimethylamino)azobenzene-4'-isothiocyanate;
2,2'-dihydroxyazobenzene; 1,1'-dibenzyl-4,4'-bipyridinium
dichloride; 1,1'-diheptyl-4,4'-bipyridinium dibromide;
2,2',4'-trihydroxy-5-chloroazobenzene-3-sulfonic acid, and
combinations of any of the foregoing.
[0364] Examples of suitable photochromic spirooxazines include
1,3-dihydro-1,3,3-trimethylspiro[2H-indole-2,3'-[3H]phenanthr[9,10-b](1,4-
-)oxazine]; 1,3,3-trimethyl
spiro(indoline-2,3'-(3/f)naphth(2,1-b)(1,4)oxazine);
3-ethyl-9'-methoxy-1,3-dimethylspiro(indoline-2,3'-(3H)naphth(2,1-b)(1,4)-
-oxazine);
1,3,3-trimethylspiro(indoline-2,3'-(3H)pyrido(3,2-f)-(1,4)benzo-
x-azine);
1,3-dihydrospiro(indoline-2,3'-(3H)pyrido(3,2-f)-(1,4)benzoxazin-
e), and combinations of any of the foregoing.
[0365] Examples of suitable photochromic spiropyrimidines include
2,3-dihydro-2-spiro-4'-[8'-aminonaphthalen-1'(4'H)-one]pyrimidine;
2,3-dihydro-2-spiro-7'-[8'-imino-7',8'-dihydronaphthalen-r-amine]pyrimidi-
ne, and combinations of any of the foregoing.
[0366] Examples of suitable photochromic diarylethenes include
2,3-bis(2,4,5-trimethyl-3-thienyl)maleic anhydride;
2,3-bis(2,4,5-trimethyl-3-thienyl)maleimide;
cis-1,2-dicyano-1,2-bis(2,4,5-trimethyl-3-thienyl)ethane;
1,2-bis[2-methylbenzo[b]thiophen-3-yl]-3,3,4,4,5,5-hexafluoro-1-cyclopent-
ene;
1,2-bis(2,4-dimethyl-5-phenyl-3-thienyl)-3,3,4,4,5,5-hexafluoro-1-cyc-
lopentene; stilbene; dithienylethenes, and combinations of any of
the foregoing.
[0367] Examples of suitable photochromic quinones include
1-phenoxy-2,4-dioxyanthraquinone;
6-phenoxy-5,12-naphthacenequinone; 6-phenoxy-5,12-pentacenequinone;
1,3-dichloro-6-phenoxy-7,12-phthaloylpyrene, and combinations of
any of the foregoing.
[0368] Other examples of suitable photochromic agents that can be
used as cure indicators include ethyl violet and Disperse Red
177.
[0369] An adhesion-promoting composition provided by the present
disclosure can include, for example, from 0.1 wt % to 10 wt % of a
photochromic agent, such as from 0.1 wt % to 5 wt % or from 0.1 wt
% to 2 wt %, where wt % is based on the total weight of the
adhesion-promoting composition.
[0370] An adhesion-promoting composition provided by the present
disclosure can be used to provide an interlayer that enhances
adhesion between an underlying sulfur-containing sealant and an
overlying sulfur-containing sealant.
[0371] An adhesion-promoting interlayer can be, for example, from 1
.mu.m to 20 .mu.m thick, from 1 .mu.m to 10 .mu.m, from 2 .mu.m to
8 .mu.m, or from 4 .mu.m to 6 .mu.m thick. An adhesion-promoting
interlayer can have a thickness, for example, less than 10 .mu.m,
less than 8 .mu.m, less than 6 .mu.m, less than 4 .mu.m, or less
than 2 .mu.m. An adhesion-promoting interlayer can have a
thickness, for example, greater than 10 .mu.m, greater than 8
.mu.m, greater than 6 .mu.m, greater than 4 .mu.m, or greater than
2 .mu.m.
[0372] After an adhesion-promoting composition provided by the
present disclosure is applied to an underlying sulfur-containing
sealant, the applied adhesion-promoting composition is dried to
remove the solvent. Thus, the adhesion-promoting interlayer
comprises the radical polymerization product of the free radical
polymerizable compounds within the applied adhesion-promoting
composition.
[0373] An underlying sulfur-containing sealant can be a freshly
applied sealant, which can be uncured, partially cured, or fully
cured.
[0374] An underlying sulfur-containing sealant can be an incumbent
sulfur-containing sealant, meaning that the sulfur-containing
sealant, has been cured and used for its intended purpose for a
period of time. The incumbent sulfur-containing sealant can be
undamaged, damaged, or aged. A damaged and/or aged surface can be
weathered, abraded, cut, delaminated, pitted, dented, and/or
impacted.
[0375] Sulfur-containing sealants can be based on polythioether
prepolymers, polysulfide prepolymers, sulfur-containing polyformal
prepolymers, or monosulfides. Sulfur-containing sealants can be
prepared by reacting a sulfur-containing prepolymer with a suitable
curing agent that is reactive with the sulfur-containing
prepolymer. For example, thiol-terminated sulfur-containing
prepolymers can be reacted with a polyepoxide or polyalkenyl curing
agent. In other sealants thiol-terminated sulfur-containing
prepolymers can be condensed in the presence of a metal oxide to
provide a cured sulfur-containing sealant. In other sealants, a
thiol-terminated prepolymer can be reacted with a polyalkenyl via a
free radical mechanism.
[0376] In general, a sulfur-containing sealant has a sulfur content
of greater than 10 wt %, such as greater than 15 wt %, or greater
than 20 wt %, where wt % is based on the total weight of the
sulfur-containing sealant.
[0377] An underlying sulfur-containing sealant can comprise any
sealant chemistry.
[0378] An overlying sulfur-containing sealant can be a free radical
polymerizable sulfur-containing sealant, such as a
sulfur-containing sealant that is curable upon exposure to actinic
radiation, such as UV radiation.
[0379] An overlying sulfur-containing sealant can be transmissive
to actinic radiation that after the sulfur-containing sealant is
applied to a dried adhesion-promoting interlayer, both the
sulfur-containing sealant and the adhesion-promoting interlayer are
exposed to the actinic radiation and cure via free radical
polymerization. In this way, free radical polymerizable groups in
the overlying sulfur-containing sealant layer can react with free
radical polymerizable groups in the adhesion-promoting interlayer
thereby covalently bonding the overlying sulfur-containing sealant
and the adhesion-promoting interlayer.
[0380] With respect to adhesion between the incumbent
sulfur-containing sealant and the adhesion-promoting interlayer,
for polysulfides, it is believed that the generation of free
radicals causes chain-scission of disulfide bonds that subsequently
react with (meth)acryloyl, alkenyl, and/or alkynyl groups of the
adhesion-promoting interlayer. For polythioethers it is believed
that hydrogens on the .alpha.carbon adjacent a sulfur atom can be
extracted to free radicals to create a reactive center on a
polythioether backbone that can react with (meth)acryloyl, alkenyl,
and/or alkynyl groups of the adhesion-promoting interlayer. Also,
any unreacted thiol groups in the incumbent sealant can react with
the (meth)acryloyl, alkenyl, and/or alkynyl groups of the
adhesion-promoting interlayer.
[0381] An underlying or incumbent sulfur-containing sealant can be
derived from any suitable curing chemistry. Examples of suitable
curing chemistries include, thiol/thiol, thiol/alkenyl,
thiol/alkynyl, thiol/isocyanate, thiol/epoxy, and thiol/Michael
acceptor curing chemistries.
[0382] The sulfur-containing precursor compounds can comprise
monomers, oligomers, prepolymers, and combinations thereof. For
example, a sulfur-containing compound can comprise a
sulfur-containing oligomer, such as a thiol-terminated
sulfur-containing oligomer. For example, a sulfur-containing
compound can comprise a sulfur-containing prepolymer, such as a
thiol-terminated sulfur-containing prepolymer. Examples of suitable
prepolymers include polythioethers, polysulfides, sulfur-containing
polyformals, monosulfides, and combinations of any of the
foregoing.
[0383] Examples of sulfur-containing sealants include
thiol-terminated polythioether prepolymers cured with polyepoxides,
thiol-terminated polythioether prepolymers cured with polyalkenyls,
and polysulfides cured with metal oxides.
[0384] Specific examples of sulfur-containing sealants include
PR2001, PR1828, PR1750, PR1776 and PR2007, each of which is
commercially available from PPG Aerospace.
[0385] A sulfur-containing prepolymer can comprise a
thiol-terminated polythioether prepolymer or combinations of
thiol-terminated polythioether prepolymers. Examples of suitable
thiol-terminated polythioether prepolymers are disclosed, for
example, in U.S. Pat. No. 6,172,179. A thiol-terminated
polythioether prepolymer can comprise Permapol.RTM. P3.1E,
Permapol.RTM. P3.1E-2.8, Permapol.RTM. L56086, or a combination of
any of the foregoing, each of which is available from PPG
Aerospace. These Permapol.RTM. products are encompassed by the
thiol-terminated polythioether prepolymers of Formula (12)-(12c).
Thiol-terminated polythioethers include prepolymers described in
U.S. Pat. No. 7,390,859 and urethane-containing polythiols
described in U.S. Application Publication Nos. 2017/0369757 and
2016/0090507.
[0386] A thiol-terminated polythioether prepolymer can comprise a
thiol-terminated polythioether prepolymer comprising at least one
moiety having the structure of Formula (12):
--[S--(CH.sub.2).sub.2--O--(R.sup.2--O--).sub.m(CH.sub.2).sub.2--S--R.su-
p.1].sub.n- (12)
[0387] where, [0388] each R.sup.1 can independently be selected
from C.sub.2-10 n-alkanediyl, C.sub.3-6 branched alkanediyl,
C.sub.6-8 cycloalkanediyl, C.sub.6-10 alkanecycloalkanediyl, and
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, wherein each
R.sup.3 can be selected from hydrogen and methyl; [0389] each
R.sup.2 can independently be selected from C.sub.2-10 n-alkanediyl,
C.sub.3-6 branched alkanediyl, C.sub.6-8 cycloalkanediyl,
C.sub.6-14 alkanecycloalkanediyl, and
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r--; [0390] each X can
independently be selected from O, S, and NR, wherein R can be
selected from hydrogen and methyl; [0391] m ranges from 0 to 50;
[0392] n can be an integer ranging from 1 to 60; [0393] p can be an
integer ranging from 2 to 6; [0394] q can be an integer ranging
from 1 to 5; and [0395] r can be an integer ranging from 2 to
10.
[0396] In moieties of Formula (12), R.sup.1 can be
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r-- wherein each X
can independently be can be selected from O and S.
[0397] In moieties of Formula (12), R.sup.1 can be
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, each X can be O
or each X can be S.
[0398] In moieties of Formula (12), R.sup.1 can be
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r--, where p can be 2,
X can be O, q can be 2, r can be 2, R.sup.2 can be ethanediyl, m
can be 2, and n can be 9.
[0399] In moieties of Formula (12), each R.sup.1 can be derived
from 1,8-dimercapto-3,6-dioxaoctane (DMDO), each R.sup.1 can be
derived from dimercaptodiethylsulfide (DMDS), or a combination
thereof.
[0400] In moieties of Formula (12), each m can independently be an
integer from 1 to 3. Each m can be the same and can be 1, 2, or
3.
[0401] In moieties of Formula (12), n can be an integer from 1 to
30, an integer from 1 to 20, an integer from 1 to 10, or an integer
from 1 to 5. In addition, n may be any integer from 1 to 60.
[0402] In moieties of Formula (12), each p can independently be 2,
3, 4, 5, and 6. Each p can be the same and can be 2, 3, 4, 5, or
6.
[0403] In moieties of Formula (12), each q can independently be 1,
2, 3, 4, or 5. Each q can be the same and can be 1, 2, 3, 4, or
5.
[0404] In moieties of Formula (12), each r can independently be 2,
3, 4, 5, 6, 7, 8, 9, or 10.
[0405] In moieties of Formula (12), each r can be the same and can
be 2, 3, 4, 5, 6, 7, 8, 9, or 10.
[0406] In moieties of Formula (12), each r can independently be an
integer from 2 to 4, from 2 to 6, or from 2 to 8.
[0407] In moieties of Formula (12), each R.sup.2 can independently
be selected from a C.sub.2-10 n-alkanediyl group, a C.sub.3-6
branched alkanediyl group, and a
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r-- group.
[0408] In moieties of Formula (12), each R.sup.2 can independently
be a C.sub.2-10 n-alkanediyl group.
[0409] In moieties of Formula (12), each R.sup.2 can independently
comprise a --[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r-- group,
where each X can be O or S.
[0410] Thiol-terminated sulfur-containing prepolymer of Formula
(12) can comprise a thiol-terminated polythioether prepolymer or
combination of thiol-terminated polythioether prepolymers, where E
comprises the backbone of a polythioether prepolymer.
[0411] A thiol-terminated polythioether prepolymer can have the
structure of Formula (13):
HS-(E-SH).sub.w--SH (13)
[0412] wherein, each E can comprise a moiety having the structure
of Formula (14):
--S--R.sup.1--[S-A-S--R.sup.1--].sub.n--S-- (14)
[0413] wherein, [0414] n can be an integer from 1 to 60; [0415]
each R.sup.1 can independently be selected from C.sub.2-10
alkanediyl, C.sub.6-8 cycloalkanediyl, C.sub.6-14
alkanecycloalkanediyl, C.sub.5-8 heterocycloalkanediyl, and
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, where, [0416] p
can be an integer from 2 to 6; [0417] q can be an integer from 1 to
5; [0418] r can be an integer from 2 to 10; [0419] each R.sup.3 can
independently be selected from hydrogen and methyl; and [0420] each
X can independently be selected from O, S, S--S, and NR, wherein R
can be selected from hydrogen and methyl; and [0421] each A can
independently be a moiety derived from a polyvinyl ether of Formula
(15) and a polyalkenyl polyfunctionalizing agent of Formula
(16):
[0421] CH.sub.2.dbd.CH--O--(R.sup.2--O).sub.m--CH.dbd.CH.sub.2
(15)
B(--R.sup.70--CH.dbd.CH.sub.2).sub.z (16)
[0422] wherein, [0423] m can be an integer from 0 to 50; [0424]
each R.sup.2 can independently be selected from C.sub.1-10
alkanediyl, C.sub.6-8 cycloalkanediyl, C.sub.6-14
alkanecycloalkanediyl, and
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, wherein p, q,
r, R.sup.3, and X are as defined as for R.sup.1; [0425] B
represents a core of a z-valent, polyalkenyl polyfunctionalizing
agent B(--R.sup.70--CH.dbd.CH.sub.2).sub.z wherein, [0426] z can be
an integer from 3 to 6; and [0427] each R.sup.70 can independently
be selected from C.sub.1-10 alkanediyl, C.sub.1-10
heteroalkanediyl, substituted C.sub.1-10 alkanediyl, and
substituted C.sub.1-10 heteroalkanediyl.
[0428] In moieties of Formula (14), R.sup.1 can be C.sub.2-10
alkanediyl.
[0429] In moieties of Formula (14), R.sup.1 can be
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--.
[0430] In moieties of Formula (14), X can be selected from O and S,
and thus --[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r-- in
Formula (14) can be
--[(CHR.sup.3).sub.p--O-].sub.q(CHR.sup.3).sub.r-- or
--[(CHR.sup.3).sub.p--S-].sub.q(CHR.sup.3).sub.r--. P and r can be
equal, such as where p and r can both be two.
[0431] In moieties of Formula (14), R.sup.1 can be selected from
C.sub.2-6 alkanediyl and
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--.
[0432] In moieties of Formula (14), R.sup.1 can be
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, and X can be O,
or X can be S.
[0433] In moieties of Formula (14) where R.sup.1 can be
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, p can be 2, r
can be 2, q can be 1, and X can be S; or p can be 2, q can be 2, r
can be 2, and X can be O; or p can be 2, r can be 2, q can be 1,
and X can be O.
[0434] In moieties of Formula (14) where R.sup.1 can be
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, each R.sup.3
can be hydrogen, or at least one R.sup.3 can be methyl.
[0435] In moieties of Formula (14), R.sup.1 can be
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r-- wherein each X can
independently be selected from O and S. In polythioethers of
Formula (5), R.sup.1 can be
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r-- each X can be O or
each X can be S.
[0436] In moieties of Formula (14), R.sup.1 can be
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r--, where p can be 2,
X can be O, q can be 2, r can be 2, R.sup.2 can be ethanediyl, m
can be 2, and n can be 9.
[0437] In moieties of Formula (14), each R.sup.1 can be derived
from 1,8-dimercapto-3,6-dioxaoctane (DMDO;
2,2-(ethane-1,2-diylbis(sulfanyl))bis(ethan-1-thiol)), or each
R.sup.1 can be derived from dimercaptodiethylsulfide (DMDS;
2,2'-thiobis(ethan-1-thiol)), and combinations thereof.
[0438] In moieties of Formula (14), each p can independently be
selected from 2, 3, 4, 5, and 6. Each p can be the same and can be
2, 3, 4, 5, or 6.
[0439] In moieties of Formula (14) each q can independently be 1,
2, 3, 4, or 5. Each q can be the same and can be 1, 2, 3, 4, or
5.
[0440] In moieties of Formula (14), each r can independently be 2,
3, 4, 5, 6, 7, 8, 9, or 10. Each r can be the same and can be 2, 3,
4, 5, 6, 7, 8, 9, or 10.
[0441] In moieties of Formula (14), each r can independently be an
integer from 2 to 4, from 2 to 6, or from 2 to 8.
[0442] In moieties of Formula (14), each A can be derived from a
polyvinyl ether such as a divinyl ether. A divinyl ether can
comprise a divinyl ether having the structure of Formula (15).
[0443] In divinyl ethers of Formula (15), m can be an integer from
0 to 50, such as from 0 to 40, from 0 to 20, from 0 to 10, from 1
to 50, from 1 to 40, from 1 to 20, from 1 to 10, from 2 to 50, from
2 to 40, from 2 to 20, or from 2 to 10.
[0444] In divinyl ethers of Formula (15), each R.sup.2 can
independently be selected from a C.sub.2-10 n-alkanediyl group, a
C.sub.3-6 branched alkanediyl group, and a
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r-- group.
[0445] In divinyl ethers of Formula (15), each R.sup.2 can
independently be a C.sub.2-10 n-alkanediyl group, such as
methanediyl, ethanediyl, n-propanediyl, or n-butanediyl.
[0446] In divinyl ethers of Formula (15), each R.sup.2 can
independently comprise a
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r-- group, where each
X can be O or S.
[0447] In divinyl ethers of Formula (15), each R.sup.2 can
independently comprise a
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r-- group.
[0448] In divinyl ethers of Formula (15), each m can be
independently an integer from 1 to 3. Each m can be the same and
can be 1, 2, or 3.
[0449] In divinyl ethers of Formula (15), each R.sup.2 can
independently be selected from a C.sub.2-10 n-alkanediyl group, a
C.sub.3-6 branched alkanediyl group, and a
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r-- group.
[0450] In divinyl ethers of Formula (15), each R.sup.2 can
independently be a C.sub.2-10 n-alkanediyl group.
[0451] In divinyl ethers of Formula (15), each R.sup.2 can
independently be a --[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r--
group, where each X can be O or S.
[0452] In divinyl ethers of Formula (15), each R.sup.2 can
independently be a --[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r--
group, where each X can be O or S, and each p can independently be
2, 3, 4, 5, and 6.
[0453] In divinyl ethers of Formula (15), each p can be the same
and can be 2, 3, 4, 5, or 6.
[0454] In divinyl ethers of Formula (15), each R.sup.2 can
independently be a --[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r--
group, where each X can be O or S, and each q can independently be
1, 2, 3, 4, or 5.
[0455] In divinyl ethers of Formula (15), each q can be the same
and can be 1, 2, 3, 4, or 5.
[0456] In divinyl ethers of Formula (15), each R.sup.2 can
independently be a --[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r--
group, where each X can be O or S, and each r can independently be
2, 3, 4, 5, 6, 7, 8, 9, or 10.
[0457] In divinyl ethers of Formula (15), each r can be the same
and can be 2, 3, 4, 5, 6, 7, 8, 9, or 10. In divinyl ethers of
Formula (15), each r can independently be an integer from 2 to 4,
from 2 to 6, or from 2 to 8.
[0458] Examples of suitable divinyl ethers include ethylene glycol
divinyl ether (EG-DVE) butanediol divinyl ether (BD-DVE) hexanediol
divinyl ether (HD-DVE), diethylene glycol divinyl ether (DEG-DVE),
triethylene glycol divinyl ether, tetraethylene glycol divinyl
ether, polytetrahydrofuryl divinyl ether, cyclohexane di methanol
divinyl ether, and combinations of any of the foregoing.
[0459] A divinyl ether can comprise a sulfur-containing divinyl
ether. Examples of suitable sulfur-containing divinyl ethers are
disclosed, for example, in PCT Publication No. WO 2018/085650.
[0460] In moieties of Formula (14) each A can independently be
derived from a polyalkenyl polyfunctionalizing agent. A polyalkenyl
polyfunctionalizing agent can have the structure of Formula (16),
where z can be 3, 4, 5, or 6.
[0461] In polyalkenyl polyfunctionalizing agents of Formula (16),
each R.sup.70 can independently be selected from C.sub.1-10
alkanediyl, C.sub.1-10 heteroalkanediyl, substituted C.sub.1-10
alkanediyl, or substituted C.sub.1-10 heteroalkanediyl. The one or
more substituent groups can be selected from, for example, --OH,
.dbd.O, C.sub.1-4 alkyl, and C.sub.1-4 alkoxy. The one or more
heteroatoms can be selected from, for example, O, S, and a
combination thereof.
[0462] Examples of suitable polyalkenyl polyfunctionalizing agents
include triallyl cyanurate (TAC), triallylisocyanurate (TAIC),
1,3,5-triallyl-1,3,5-triazinane-2,4,6-trione),
1,3-bis(2-methylallyl)-6-methylene-5-(2-oxopropyl)-1,3,5-triazinone-2,4-d-
ione, tris(allyloxy)methane, pentaerythritol triallyl ether,
1-(allyloxy)-2,2-bis((allyloxy)methyl)butane,
2-prop-2-ethoxy-1,3,5-tris(prop-2-enyl)benzene,
1,3,5-tris(prop-2-enyl)-1,3,5-triazinane-2,4-dione, and
1,3,5-tris(2-methylallyl)-1,3,5-triazinane-2,4,6-trione,
1,2,4-trivinylcyclohexane, trimethylolpropane trivinyl ether, and
combinations of any of the foregoing.
[0463] In moieties of Formula (14) the molar ratio of vinyl ether
moieties derived from a divinyl ether to alkenyl moieties derived
from a polyalkenyl polyfunctionalizing agent can be, for example,
from 10:1 to 1,000:1, from 10:1 to 100:1, or from 20:1 to
100:1.
[0464] In moieties of Formula (14), each R.sup.1 can be
--(CH.sub.2).sub.2--O--(CH.sub.2).sub.2--O--(CH.sub.2).sub.2--;
each R.sup.2 can be --(CH.sub.2).sub.2--; and m can be an integer
from 1 to 4.
[0465] In moieties of Formula (14), R.sup.2 can be derived from a
divinyl ether such a diethylene glycol divinyl ether, a polyalkenyl
polyfunctionalizing agent such as triallyl cyanurate, or a
combination thereof.
[0466] In moieties of Formula (14), each A can independently be
selected from a moiety of Formula (15a) and a moiety of Formula
(16a):
--(CH.sub.2).sub.2--O--(R.sup.2--O).sub.m--(CH.sub.2).sub.2--
(15a)
B{--R.sup.70--(CH.sub.2).sub.2-}.sub.2{--R.sup.70--(CH.sub.2).sub.2--S---
[--R.sup.1--S-A-S--R.sup.1--].sub.n--SH}.sub.z-2 (16a)
[0467] where m, R.sup.1, R.sup.2, R.sup.70, A, B, m, n, and z are
defined as in Formula (14), Formula (15), and Formula (16).
[0468] In moieties of Formula (14),
[0469] each R.sup.1 can be
--(CH.sub.2).sub.2--O--(CH.sub.2).sub.2--O--(CH.sub.2).sub.2--;
[0470] each R.sup.2 can be --(CH.sub.2).sub.2--;
[0471] m can be an integer from 1 to 4; and
[0472] the polyfunctionalizing agent
B(--R.sup.70--CH.dbd.CH.sub.2).sub.Z comprises triallyl cyanurate
where z is 3 and each R.sup.70 is
--O--CH.sub.2--CH.dbd.CH.sub.2.
[0473] A thiol-terminated polythioether prepolymer can have the
structure of Formula (14a):
HS--R.sup.1--[S-A-S--R.sup.1--].sub.n--SH (14a)
[0474] wherein, [0475] n can be an integer from 1 to 60; [0476]
each R.sup.1 can independently be selected from C.sub.2-10
alkanediyl, C.sub.6-8 cycloalkanediyl, C.sub.6-14
alkanecycloalkanediyl, C.sub.5-8 heterocycloalkanediyl, and
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, wherein, [0477]
p can be an integer from 2 to 6; [0478] q can be an integer from 1
to 5; [0479] r can be an integer from 2 to 10; [0480] each R.sup.3
can independently be selected from hydrogen and methyl; and [0481]
each X can independently be selected from O, S, and NR, wherein R
can be selected from hydrogen and methyl; and [0482] each A can
independently be selected from a moiety derived from a polyvinyl
ether of Formula (15) and a moiety derived from a polyalkenyl
polyfunctionalizing agent of Formula (16):
[0482] CH.sub.2.dbd.CH--O--(R.sup.2--O).sub.m--CH.dbd.CH.sub.2
(15)
B(--R.sup.70--CH.dbd.CH.sub.2).sub.z (16) [0483] wherein, [0484]
each R.sup.2 can independently be selected from C.sub.1-10
alkanediyl, C.sub.6-8 cycloalkanediyl, C.sub.6-14
alkanecycloalkanediyl, and
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, wherein p, q,
r, R.sup.3, and X are as defined as for R.sup.1; [0485] m can be an
integer from 0 to 50; [0486] B represents a core of a z-valent,
polyalkenyl polyfunctionalizing agent
B(--R.sup.70--CH.dbd.CH.sub.2).sub.z wherein, [0487] z can be an
integer from 3 to 6; and [0488] each R.sup.70 can independently be
selected from C.sub.1-10 alkanediyl, C.sub.1-10 heteroalkanediyl,
substituted C.sub.1-10 alkanediyl, and substituted C.sub.1-10
heteroalkanediyl.
[0489] In thiol-terminated polythioether prepolymers of Formula
(14a), R.sup.1 can be C.sub.2-10 alkanediyl.
[0490] In thiol-terminated polythioether prepolymers of Formula
(14a), R.sup.1 can be
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--.
[0491] In thiol-terminated polythioether prepolymers of Formula
(14a), X can be selected from O and S, and thus
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r-- in Formula (14a)
can be --[(CHR.sup.3).sub.p--O-].sub.q(CHR.sup.3).sub.r-- or
--[(CHR.sup.3).sub.p--S-].sub.q(CHR.sup.3).sub.r--. P and r can be
equal, such as where p and r can be both two.
[0492] In thiol-terminated polythioether prepolymers of Formula
(14a), R.sup.1 can be selected from C.sub.2-6 alkanediyl and
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--.
[0493] In thiol-terminated polythioether prepolymers of Formula
(14a), R.sup.1 can be
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, and X can be O,
or X can be S.
[0494] In thiol-terminated polythioether prepolymers of Formula
(14a), where R.sup.1 can be
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, p can be 2, r
can be 2, q can be 1, and X can be S; or p can be 2, q can be 2, r
can be 2, and X can be O; or p can be 2, r can be 2, q can be 1,
and X can be O.
[0495] In thiol-terminated polythioether prepolymers of Formula
(14a), where R.sup.1 can be
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, each R.sup.3
can be hydrogen, or at least one R.sup.3 can be methyl.
[0496] In thiol-terminated polythioether prepolymers of Formula
(14a), R.sup.1 can be
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r-- wherein each X can
independently be selected from O and S. In thiol-terminated
polythioethers of Formula (5a), R.sup.1 can be
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r-- each X can be O or
each X can be S.
[0497] In thiol-terminated polythioether prepolymers of Formula
(14a), R.sup.1 can be
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r--, where p can be 2,
X can be O, q can be 2, r can be 2, R.sup.2 can be ethanediyl, m
can be 2, and n can be 9.
[0498] In thiol-terminated polythioether prepolymers of Formula
(14a), each R.sup.1 can be derived from
1,8-dimercapto-3,6-dioxaoctane (DMDO;
2,2-(ethane-1,2-diylbis(sulfanyl))bis(ethan-1-thiol)), or each
R.sup.1 can be derived from dimercaptodiethylsulfide (DMDS;
2,2'-thiobis(ethan-1-thiol)), and combinations thereof.
[0499] In thiol-terminated polythioether prepolymers of Formula
(14a), each p can independently be selected from 2, 3, 4, 5, and 6.
Each p can be the same and can be 2, 3, 4, 5, or 6.
[0500] In thiol-terminated polythioether prepolymers of Formula
(14a), each q can independently be 1, 2, 3, 4, or 5. Each q can be
the same and can be 1, 2, 3, 4, or 5.
[0501] In thiol-terminated polythioether prepolymers of Formula
(14a), each r can independently be 2, 3, 4, 5, 6, 7, 8, 9, or 10.
Each r can be the same and can be 2, 3, 4, 5, 6, 7, 8, 9, or
10.
[0502] In thiol-terminated polythioether prepolymers of Formula
(14a), each r can independently be an integer from 2 to 4, from 2
to 6, or from 2 to 8.
[0503] In thiol-terminated polythioether prepolymers of Formula
(14a), each A can independently be selected from a moiety of
Formula (15a) and a moiety of Formula (16a):
--(CH.sub.2).sub.2--O--(R.sup.2--O).sub.m--(CH.sub.2).sub.2--
(15a)
B{--R.sup.70--(CH.sub.2).sub.2-}.sub.2{--R.sup.70--(CH.sub.2).sub.2--S---
[--R.sup.1--S-A-S--].sub.n--R.sup.1--SH}.sub.z-2 (16a)
where m, R.sup.1, R.sup.2, R.sup.70, A, B, m, n, and z are defined
as in Formula (14), Formula (15), and Formula (16).
[0504] In thiol-terminated polythioether prepolymers of Formula
(14a) the molar ratio of moieties derived from a divinyl ether to
moieties derived from a polyalkenyl polyfunctionalizing agent can
be, for example, of 200:1, 150:1, 100:1, 50:1, or 25:1.
[0505] A thiol-terminated polythioether prepolymer can comprise a
thiol-terminated polythioether prepolymer of Formula (12a), a
thiol-terminated polythioether prepolymer of Formula (12b), a
thiol-terminated polythioether prepolymer of Formula (12c), or a
combination of any of the foregoing:
HS--R.sup.1--[S--(CH.sub.2).sub.2--O--(R.sup.2--O).sub.m(CH.sub.2).sub.2-
--S--R.sup.1--].sub.nSH (12a)
{HS--R.sup.1--[S--(CH.sub.2).sub.2--O--(R.sup.2--O--).sub.m(CH.sub.2).su-
b.2--S--R.sup.1--].sub.n--S--V'-}.sub.zB (12b)
{R.sup.4--S--R.sup.1--[S--(CH.sub.2).sub.2--O--(R.sup.2--O--).sub.m(CH.s-
ub.2).sub.2--S--R.sup.1--].sub.n--S--V'-}.sub.zB (12c)
[0506] wherein, [0507] each R.sup.1 can independently be selected
from C.sub.2-10 alkanediyl, C.sub.6-8 cycloalkanediyl, C.sub.6-14
alkanecycloalkanediyl, C.sub.5-8 heterocycloalkanediyl, and
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, wherein, [0508]
p can be an integer from 2 to 6; [0509] q can be an integer from 1
to 5; [0510] r can be an integer from 2 to 10; [0511] each R.sup.3
can independently be selected from hydrogen and methyl; and [0512]
each X can independently be selected from O, S, and NR, wherein R
can be selected from hydrogen and methyl; [0513] each R.sup.2 can
independently be selected from C.sub.1-10 alkanediyl, C.sub.6-8
cycloalkanediyl, C.sub.6-14 alkanecycloalkanediyl, and
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, wherein p, q,
r, R.sup.3, and X are as defined as for R.sup.1; [0514] m can be an
integer from 0 to 50; [0515] n can be an integer from 1 to 60;
[0516] B represents a core of a z-valent, polyfunctionalizing agent
B(--V).sub.z wherein, [0517] z can be an integer from 3 to 6; and
[0518] each V can be a moiety comprising a terminal group reactive
with a thiol; [0519] each --V'-- can be derived from the reaction
of --V with a thiol; and [0520] each R.sup.4 can independently be
selected from hydrogen and a moiety of Formula (12), which is bound
to a prepolymer of Formula (12c).
[0521] In prepolymers of Formula (12a)-(12c), R.sup.1 can be
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r, where p can be 2, X
can be O, q can be 2, r can be 2, R.sup.2 can be ethanediyl, m can
be 2, and n can be 9.
[0522] In prepolymers of Formula (12a)-(12c), R.sup.1 can be
selected from C.sub.2-6 alkanediyl and
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--.
[0523] In prepolymers of Formula (12a)-(12c), R.sup.1 can be
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, X can be O or X
can be S.
[0524] In prepolymers of Formula (12a)-(12c), where R.sup.1 can be
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, p can be 2, r
can be 2, q can be 1, and X can be S; or wherein p can be 2, q can
be 2, r can be 2, and X can be O; or p can be 2, r can be 2, q can
be 1, and X can be O.
[0525] In prepolymers of Formula (12a)-(12c), R.sup.1 can be
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, and each
R.sup.3 can be hydrogen or at least one R.sup.3 can be methyl.
[0526] In prepolymers of Formula (12a)-(12c), each R.sup.1 can be
the same, or at least one R1 can be different.
[0527] In prepolymers of Formula (12a)-(12c), each m can be
independently an integer from 1 to 3. Each m can be the same and
can be 1, 2, or 3.
[0528] In prepolymers of Formula (12a)-(12c), n can be an integer
from 1 to 30, an integer from 1 to 20, an integer from 1 to 10, or
an integer from 1 to 5. The variable n may be any integer from 1 to
60.
[0529] In prepolymers of Formula (12a)-(12c), each p can
independently be 2, 3, 4, 5, and 6. Each p can be the same and can
be 2, 3, 4, 5, or 6.
[0530] In prepolymers of Formula (12a)-(12c), each q can
independently be 1, 2, 3, 4, or 5. Each q can be the same and can
be 1, 2, 3, 4, or 5.
[0531] In prepolymers of Formula (12a)-(12c), each r can
independently be 2, 3, 4, 5, 6, 7, 8, 9, or 10.
[0532] In prepolymers of Formula (12a)-(12c), each r can
independently be an integer from 2 to 4, from 2 to 6, or from 2 to
8.
[0533] Various methods can be used to prepare thiol-terminated
polythioether prepolymers of Formula (12a)-(12c). Examples of
suitable thiol-terminated polythioether prepolymers, and methods
for their production, are described in U.S. Pat. Nos. 6,172,179,
6,232,401, and 8,932,685. Such thiol-terminated polythioether
prepolymers may be difunctional, that is, linear prepolymers having
two terminal thiol groups, or can be polyfunctional, that is,
branched prepolymers having three or more terminal thiol
groups.
[0534] Thiol-terminated polythioether prepolymers are liquid at
room temperature and can have a glass transition temperature
T.sub.g, for example, less than -20.degree. C., less than
-30.degree. C., or less than -40.degree. C., where the glass
transition temperature T.sub.g is determined by Dynamic Mass
Analysis (DMA) using a TA Instruments Q800 apparatus with a
frequency of 1 Hz, an amplitude of 20 microns, and a temperature
ramp of -80.degree. C. to 25.degree. C., with the T.sub.g
identified as the peak of the tan 5 curve.
[0535] Thiol-terminated polythioether prepolymers can exhibit a
viscosity, for example, within a range from 20 poise to 500 poise
(2 Pa-sec to 50 Pa-sec), from 20 poise to 200 poise (2 Pa-sec to 20
Pa-sec) or from 40 poise to 120 poise (4 Pa-sec to 12 Pa-sec),
measured using a Brookfield CAP 2000 viscometer, with a No. 6
spindle, at speed of 300 rpm, and a temperature of 25.degree.
C.
[0536] Thiol-terminated polythioether prepolymers can be
characterized by a number average molecular weight and/or a
molecular weight distribution. Thiol-terminated polythioether
prepolymers can exhibit a number average molecular weight, for
example, from 500 Da to 20,000 Da, from 2,000 Da to 5,000 Da, or
from 1,000 Da to 4,000 Da. Thiol-terminated polythioether
prepolymers can exhibit a polydispersity (Mw/Mn; weight average
molecular weight/number average molecular weight), for example,
from 1 to 20, or from 1 to 5. The backbone of a thiol-terminated
polythioether prepolymer can be modified to improve the properties
such as adhesion, tensile strength, elongation, UV resistance,
hardness, and/or flexibility of sealants and coatings prepared
using polythioether prepolymers. For example, adhesion-promoting
groups, antioxidants, metal ligands, and/or urethane linkages can
be incorporated into the backbone of a polythioether prepolymer to
improve one or more performance attributes. Examples of
backbone-modified polythioether prepolymers are disclosed, for
example, in U.S. Pat. No. 8,138,273 (urethane containing), U.S.
Pat. No. 9,540,540 (sulfone-containing), U.S. Pat. No. 8,952,124
(bis(sulfonyl)alkanol-containing), U.S. Pat. No. 9,382,642
(metal-ligand containing), U.S. Application Publication No.
2017/0114208 (antioxidant-containing), PCT International
Publication No. WO 2018/085650 (sulfur-containing divinyl ether),
and PCT International Publication No. WO 2018/031532
(urethane-containing).
[0537] Thiol-terminated polythioether prepolymers include
prepolymers described in U.S. Application Publication Nos.
2017/0369737 and 2016/0090507.
[0538] A thiol-terminated urethane-containing prepolymer can
comprise a thiol-terminated urethane-containing prepolymer of
Formula (17a), a thiol-terminated urethane-containing prepolymer of
Formula (17b), or a combination thereof:
R.sup.30--C(.dbd.O)--NH--R.sup.20--NH--C(.dbd.O)--[--R.sup.60--C(.dbd.O)-
--NH--R.sup.20--NH--C(.dbd.O)--].sub.w--R.sup.60--C(.dbd.O)--NH--R.sup.20--
-NH--C(.dbd.O)--R.sup.30 (17a)
B[--V'--S--R.sup.50--S--(CH.sub.2).sub.2--O--R.sup.13--O--[--C(.dbd.O)---
NH--R.sup.20--NH--C(.dbd.O)--R.sup.60--].sub.w--C(.dbd.O)--NH--R.sup.20--N-
H--C(.dbd.O)--R.sup.30].sub.z (17b)
[0539] wherein, [0540] w is an integer from 1 to 100; [0541] each
R.sup.13 independently be selected from C.sub.2-10 alkanediyl;
[0542] each R.sup.20 independently comprises a core of a
diisocyanate; [0543] each R.sup.30 independently is a moiety
comprising at least one terminal thiol group; [0544] each R.sup.50
independently comprises a core of a sulfur-containing prepolymer;
[0545] each R.sup.60 independently comprises a moiety having the
structure of Formula (18):
[0545]
--O--R.sup.13--O--(CH.sub.2).sub.2--S--R.sup.50--S--(CH.sub.2).su-
b.2--O--R.sup.13--O-- (18) [0546] B represents a core of a
z-valent, polyfunctionalizing agent B(--V).sub.z wherein, [0547] z
is an integer from 3 to 6; and [0548] each V is a moiety comprising
a terminal group reactive with a thiol group; and [0549] each
--V'-- is derived from the reaction of --V with a thiol.
[0550] A moiety --C(.dbd.O)--NH--R.sup.20--NH--C(.dbd.O)-- can be
derived from a diisocyanate of Formula (19):
O.dbd.C.dbd.N--R.sup.20--N.dbd.C.dbd.O (19)
[0551] In moieties of Formula (19), R.sup.20 can be a core of an
aliphatic diisocyanate such as 4,4'-methylene dicyclohexyl
diisocyanate and has the structure of Formula (20):
##STR00005##
[0552] An isocyanate-terminated urethane-containing prepolymer can
comprise an isocyanate-terminated urethane-containing prepolymer of
Formula (21a), an isocyanate-terminated urethane-containing
prepolymer of Formula (21b), or a combination thereof:
O.dbd.C.dbd.N--R.sup.20--NH--C(.dbd.O)--[--R.sup.60--C(.dbd.O)--NH--R.su-
p.20--NH--C(.dbd.O)--].sub.w--R.sup.60--C(.dbd.O)--NH--R.sup.20--N.dbd.C.d-
bd.O (21a)
B{--V'--S--R.sup.50--S--(CH.sub.2).sub.2--O--R.sup.13--O--[--C(.dbd.O)---
NH--R.sup.20--NH--C(.dbd.O)--R.sup.60--].sub.w--C(.dbd.O)--NH--R.sup.20--N-
.dbd.C.dbd.O}.sub.z (21b)
[0553] wherein, [0554] w is an integer from 1 to 100; [0555] each
R.sup.13 independently can be selected from C.sub.2-10 alkanediyl;
[0556] each R.sup.20 independently comprises a core of a
diisocyanate; [0557] each R.sup.50 independently comprises a core
of a sulfur-containing prepolymer; [0558] each R.sup.60
independently comprises a moiety having the structure of Formula
(18):
[0558]
--O--R.sup.13--O--(CH.sub.2).sub.2--S--R.sup.50--S--(CH.sub.2).su-
b.2--O--R.sup.13--O-- (18) [0559] B represents a core of a
z-valent, polyfunctionalizing agent B(--V).sub.z wherein, [0560] z
is an integer from 3 to 6; and [0561] each V is a moiety comprising
a terminal group reactive with a thiol group; and [0562] each
--V'-- is derived from the reaction of --V with a thiol.
[0563] In prepolymers of Formula (21a) and Formula (21b), each
R.sup.50 can be derived from a polythioether. For example, each
R.sup.50 can haves the structure of Formula (22):
--R.sup.1--[--S--(CH.sub.2).sub.s--O--(R.sup.2--O).sub.m--(CH.sub.2).sub-
.2--S--R.sup.1--].sub.n- (22) [0564] wherein, [0565] each R.sup.1
independently is selected from C.sub.2-10 alkanediyl, C.sub.6-8
cycloalkanediyl, C.sub.6-14 alkanecycloalkanediyl, C.sub.5-8
heterocycloalkanediyl, and
--[(--CHR.sup.3--).sub.p--X--].sub.q--(--CHR.sup.3--).sub.r--,
wherein: [0566] p is an integer from 2 to 6; [0567] q is an integer
from 1 to 5; [0568] r is an integer from 2 to 10; [0569] each
R.sup.3 is independently selected from hydrogen and methyl; and
[0570] each X is independently selected from --O--, --S--, and
--NR--, wherein R is selected from hydrogen and methyl; [0571] each
R.sup.2 is independently selected from C.sub.1-10 alkanediyl,
C.sub.6-8 cycloalkanediyl, C.sub.6-14 alkanecycloalkanediyl, and
--[(--CHR.sup.3--).sub.p--X--].sub.q--(--CHR.sup.3--).sub.r--,
wherein p, q, r, R.sup.3, and X are as defined as for R.sup.1;
[0572] m is an integer from 0 to 50; [0573] n is an integer from 1
to 60; and [0574] s is an integer from 2 to 6.
[0575] In prepolymers of Formula (21a) and Formula (21b), w can be
an integer from 1 to 50, from 2 to 50, or from 1 to 20 or from 2 to
20.
[0576] An isocyanate-terminated urethane-containing adduct can
comprise the reaction product of reactants comprising a
hydroxyl-terminated sulfur-containing adduct and a
diisocyanate.
[0577] Thiol-terminated urethane-containing prepolymers can
comprise a backbone of Formula (23):
--S--R.sup.1--[S-A-S--R.sup.1--].sub.sS- (23)
[0578] wherein, [0579] s is an integer from 1 to 60; [0580] each
R.sup.1 is selected from C.sub.2-10 alkanediyl, C.sub.6-8
cycloalkanediyl, C.sub.6-10 alkanecycloalkanediyl, and
--[(CHR--).sub.p--X--].sub.q--(CHR).sub.r--, wherein each R is
independently selected from hydrogen and methyl, wherein, [0581]
each X is independently selected from --O-- and --S-- [0582] each p
is independently an integer from 2 to 6; [0583] q is an integer
from 1 to 5; and [0584] r is an integer from 2 to 10; [0585] each A
independently is selected from a moiety of Formula (24) and a
moiety of Formula (25):
[0585]
--(CH.sub.2).sub.2--O--R.sup.5--Y'--C(.dbd.O)--NH--R.sup.4--NH--C-
(.dbd.O)--Y'--R.sup.5--O--(CH.sub.2).sub.2-- (24)
--(CH.sub.2).sub.2--O--(R.sup.2--O).sub.m--(CH.sub.2).sub.2--
(25)
[0586] wherein, [0587] m is an integer from 0 to 50; [0588] each Y'
is independently selected from --NH-- and --O--; and [0589] each
R.sup.2 is selected from C.sub.2-6 n-alkanediyl, C.sub.3-6 branched
alkanediyl, C.sub.6-8 cycloalkanediyl, C.sub.6-10
alkanecycloalkanediyl, and
--[(CH.sub.2--).sub.pO-].sub.q--(CH.sub.2--).sub.r--, wherein,
[0590] each p is independently an integer ranging from 2 to 6;
[0591] q is an integer from 1 to 5; and [0592] r is an integer from
2 to 10; [0593] R.sup.4 comprises a core of a diisocyanate; [0594]
each R.sup.5 is independently selected from C.sub.1-10 alkanediyl;
and [0595] at least one A comprises a moiety of Formula (24).
[0596] Thiol-terminated urethane-containing prepolymers can
comprise reaction products of reactants comprising:
[0597] (a) a polythiol comprising a dithiol of Formula (3):
HS--R.sup.1--SH (3) [0598] wherein R.sup.1 is selected from
C.sub.2-10 alkanediyl, C.sub.6-8 cycloalkanediyl, C.sub.6-10
alkanecycloalkanediyl, C.sub.5-8 heterocycloalkanediyl, and
--[(CHR--).sub.pX-].sub.q--(CHR).sub.r--, wherein: [0599] each p is
independently an integer from 2 to 6; [0600] q is an integer from 1
to 5; [0601] r is an integer from 2 to 10; [0602] each R is
independently selected from hydrogen and methyl; and [0603] each X
is independently selected from --O--, --S--, and --NR.sup.5--,
wherein R.sup.5 is selected from hydrogen and methyl;
[0604] (b) a urethane/urea-containing bis(alkenyl) ether of Formula
(26):
CH.sub.2.dbd.CH--O--R.sup.5--Y'--C(.dbd.O)--NH--R.sup.4--NH--C(.dbd.O)---
Y'--R.sup.5--O--CH.dbd.CH.sub.2 (26) [0605] wherein, [0606] each Y'
is independently selected from --NH-- and --O--; [0607] R.sup.4
comprises a core of a diisocyanate; and [0608] each R.sup.5
independently is selected from C.sub.1-10 alkanediyl; and
[0609] (c) a divinyl ether of Formula (4):
CH.sub.2.dbd.CH--O--(R.sup.2--O--).sub.m--CH.dbd.CH.sub.2 (4)
[0610] wherein, [0611] m is 0 to 50; and [0612] each R.sup.2 is
independently selected from C.sub.2-6 n-alkanediyl, C.sub.3-6
branched alkanediyl, C.sub.6-8 cycloalkanediyl, C.sub.6-10
alkanecycloalkanediyl, and
--[(CH.sub.2--).sub.p--O--].sub.q--(--CH.sub.2--).sub.r--, wherein,
[0613] each p is independently an integer ranging from 2 to 6;
[0614] q is an integer from 1 to 5; and [0615] r is an integer from
2 to 10.
[0616] A dithiol and a urethane/urea-containing bis(alkenyl) ether
can include any of those disclosed herein.
[0617] A polythiol can further comprise a polythiol of Formula
(1d):
B(--V).sub.z (1d)
[0618] wherein, [0619] B represents a core of a z-valent
polyfunctionalizing agent B(--V).sub.z, [0620] z is an integer from
3 to 6; and [0621] each --V is a moiety comprising terminal thiol
group.
[0622] A thiol-terminated sulfur-containing prepolymer can comprise
a thiol-terminated polysulfide prepolymer or a combination of
thiol-terminated polysulfide prepolymers.
[0623] A polysulfide prepolymer refers to a prepolymer that
contains one or more polysulfide linkages, i.e., --S.sub.x--
linkages, where x is from 2 to 4, in the prepolymer backbone. A
polysulfide prepolymer can have two or more sulfur-sulfur linkages.
Suitable thiol-terminated polysulfide prepolymers are commercially
available, for example, from AkzoNobel and Toray Industries, Inc.
under the tradenames Thioplast.RTM. and from Thiokol-LP.RTM.,
respectively.
[0624] Examples of suitable polysulfide prepolymers are disclosed,
for example, in U.S. Pat. Nos. 4,623,711; 6,172,179; 6,509,418;
7,009,032; and 7,879,955.
[0625] Examples of suitable thiol-terminated polysulfide
prepolymers include are liquid polysulfide prepolymers that are
blends of di- and tri-functional molecules where the difunctional
polysulfide prepolymers have the structure of Formula (27a) and E
in the thiol-terminated prepolymer of Formula (13) can be a moiety
of Formula (27):
--(--R--S--S--).sub.n--R-- (27)
HS--(--R--S--S--).sub.n--R--SH (27a)
and the trifunctional polysulfide polymers can have the structure
of Formula (28a) and E in the thiol-terminated prepolymer of
Formula (13) can be a moiety of Formula (28):
--S--(--R--S--S--).sub.a--CH.sub.2--CH{--CH.sub.2--(--S--S--R--).sub.b---
S--}{--(--S--S--R--).sub.c--S--} (28)
HS--(--R--S--S--).sub.a--CH.sub.2--CH{--CH.sub.2--(--S--S--R--).sub.b--S-
H}{--(--S--S--R--).sub.c--SH} (28a)
where each R is
--(CH.sub.2).sub.2--O--CH.sub.2--O--(CH.sub.2).sub.2--, and
n=a+b+c, where the value for n may be from 7 to 38 depending on the
amount of the trifunctional cross-linking agent
(1,2,3,-trichloropropane; TCP) used during synthesis of the
polysulfide prepolymer. Such thiol-terminated polysulfide
prepolymers include Thioplast.TM. G polysulfides/resins such as
Thioplast.TM. G1, Thioplast.TM. G4, Thioplast.TM. G10,
Thioplast.TM. G12, Thioplast.TM. G21, Thioplast.TM. G22,
Thioplast.TM. G44, Thioplast.TM. G122, and Thioplast.TM. G131,
which are commercially available from AkzoNobel. Thioplast.TM. G
polysulfides can have a number average molecular weight from 1,000
Da to 6,500 Da, a SH content from 1% to greater than 5.5%, and a
cross-linking density from 0% to 2.0%.
[0626] Examples of suitable thiol-terminated polysulfide
prepolymers also include Thiokol.TM. LP polysulfides available from
Toray Industries, Inc. such as Thiokol.TM. LP2, Thiokol.TM. LP3,
Thiokol.TM. LP12, Thiokol.TM. LP23, Thiokol.TM. LP33, and
Thiokol.TM. LP55. Thiokol.TM. LP polysulfides have a number average
molecular weight from 1,000 Da to 7,500 Da, a --SH content from
0.8% to 7.7%, and a cross-linking density from 0% to 2%.
Thiokol.TM. LP polysulfide prepolymers have the general structure
of Formula (29a) and E in the thiol-terminated prepolymer of
Formula (13) can be a moiety of Formula (29):
--S--[(CH.sub.2).sub.2--O--CH.sub.2--O--(CH.sub.2).sub.2--S--S-].sub.n---
(CH.sub.2).sub.2--O--CH.sub.2--O--(CH.sub.2).sub.2--S-- (29)
HS--[(CH.sub.2).sub.2--O--CH.sub.2--O--(CH.sub.2).sub.2--S--S-].sub.n--(-
CH.sub.2).sub.2--O--CH.sub.2--O--(CH.sub.2).sub.2--SH (29a)
where n can be such that the number average molecular weight from
1,000 Da to 7,500 Da, such as, for example an integer from 8 to
80.
[0627] A thiol-terminated sulfur-containing prepolymer can comprise
a Thiokol-LP.RTM. polysulfide, a Thioplast.RTM. G polysulfide, or a
combination thereof.
[0628] A thiol-terminated polysulfide prepolymer can comprise a
thiol-terminated polysulfide prepolymer of Formula (30a) and E in
the thiol-terminated prepolymer of Formula (13) can be a moiety of
Formula (30):
--R--(S.sub.y--R).sub.t-- (30)
HS--R--(S.sub.y--R).sub.t--SH (30a)
[0629] where, [0630] t can be an integer from 1 to 60; [0631] q can
be an integer from 1 to 8; [0632] p can be an integer from 1 to 10;
[0633] r can be an integer from 1 to 10; [0634] y has an average
value within a range from 1.0 to 1.5; and [0635] each R can
independently be selected from branched alkanediyl, branched
arenediyl, and a moiety having the structure
--(CH.sub.2).sub.p--O--(CH.sub.2).sub.q--O--(CH.sub.2).sub.r--.
[0636] In thiol-terminated polysulfide prepolymers of Formula (30a)
and moieties of Formula (30a), t can be, for example, an integer
from 2 to 60, from 1 to 40, or from 1 to 20.
[0637] In thiol-terminated polysulfide prepolymers of Formula (30a)
and moieties of Formula (30a), q can be, for example, an integer
from 1 to 6, or an integer from 1 to 4. For example, q can be 1, 2,
3, 4, 5 or 6.
[0638] In thiol-terminated polysulfide prepolymers of Formula (30a)
and moieties of Formula (30a), each p can be, for example, an
integer from 1 to 6 or from 1 to 4. For example, each p can be 1,
2, 3, 4, 5, 6, 7, 8, 9, or 10.
[0639] In thiol-terminated polysulfide prepolymers of Formula (30a)
and moieties of Formula (30a), each r can be, for example, an
integer from 1 to 6 or from 1 to 4. For example, each p can be 1,
2, 3, 4, 5, 6, 7, 8, 9, or 10.
[0640] In thiol-terminated polysulfide prepolymers of Formula (30a)
and moieties of Formula (30a), y can have a value of 1.
[0641] In thiol-terminated polysulfide prepolymers of Formula (30a)
and moieties of Formula (30a), y can have an average value, for
example, of 1, such as from 1.05 to 2, or from 1.1 to 1.8.
[0642] In thiol-terminated polysulfide prepolymers of Formula (30a)
and moieties of Formula (30a), R can be
--(CH.sub.2).sub.p--O--(CH.sub.2).sub.q--O--(CH.sub.2).sub.r--.
[0643] In thiol-terminated polysulfide prepolymers of Formula (30a)
and moieties of Formula (30a), R can be
--(CH.sub.2).sub.p--O--(CH.sub.2).sub.q--O--(CH.sub.2).sub.r--,
each q can be 1, 2, 3, or 4, and each p and r can be 1 or 2.
[0644] In thiol-terminated polysulfide prepolymers of Formula (30a)
and moieties of Formula (30a), 0% to 20% of the R groups can
comprise branched alkanediyl or branched arenediyl, and 80% to 100%
of the R groups can be
--(CH.sub.2).sub.p--O--(CH.sub.2).sub.q--O--(CH.sub.2)
[0645] In thiol-terminated polysulfide prepolymers of Formula (30a)
and moieties of Formula (30a), a branched alkanediyl or a branched
arenediyl can be --R.sup.1(-A).sub.n- where R.sup.1 is a
hydrocarbon group, n is 1 or 2, and A is a branching point. A
branched alkanediyl can have the structure
--CH.sub.2--CH(--CH.sub.2--)--.
[0646] Thiol-terminated polysulfide prepolymers of Formula (30a)
and moieties of Formula (30a) can be prepared by reacting an
.alpha.,.omega.-dihalo organic compounds, a metal hydrosulfide, a
metal hydroxide, and an optional polyfunctionalizing agent.
Examples of suitable .alpha.,.omega.-dihalo organic compounds
include bis(2-chloroethyl)formal. Examples of suitable metal
hydrosulfides and metal hydroxides include sodium hydrosulfide and
sodium hydroxide. Examples of suitable polyfunctionalizing agents
include 1,2,3-trichloropropane, 1,1,1-tris(chloromethyl)propane,
1,1,1-tris(chloromethyl)ethane, and
1,3,5-tris(chloromethyl)benzene.
[0647] Examples of thiol-terminated polysulfide prepolymers of
Formula (30) and (30a) are disclosed, for example, in U.S.
Application Publication No. 2016/0152775, in U.S. Pat. No.
9,079,833, and in U.S. Pat. No. 9,663,619.
[0648] A thiol-terminated polysulfide prepolymer can comprise a
thiol-terminated polysulfide prepolymer of Formula (31a) and E in
the thiol-terminated prepolymer of Formula (13) can be a moiety of
Formula (31):
--(R--O--CH.sub.2--O--R--S.sub.m--).sub.n-1--R--O--CH.sub.2--O--R--
(31)
HS--(R--O--CH.sub.2--O--R--S.sub.m--).sub.n-1--R--O--CH.sub.2--O--R--SH
(31a)
where R is C.sub.2-4 alkanediyl, m is an integer from 1 to 8, and n
is an integer from 2 to 370.
[0649] In thiol-terminated polysulfide prepolymers of Formula (31)
and (31a), m can have an average value, for example, greater than
1, such as from 1.05 to 2, or from 1.1 to 1.8.
[0650] In thiol-terminated polysulfide prepolymers of Formula (31)
and (31a), m can be, for example, an integer from 1 to 6, and
integer from 1 to 4, or the integer 1, 2, 3, 4, 5, 6, 7, or 8.
[0651] In thiol-terminated polysulfide prepolymers of Formula (31)
and (31a), n can be, for example, an integer from 2 to 200 or an
integer from 2 to 100.
[0652] In thiol-terminated polysulfide prepolymers of Formula (31)
and (31a), each R can independently be selected from ethanediyl,
1,3-propanediyl, 1,1-propanediyl, 1,2-propanediyl, 1,4-butanediyl,
1,1-butanediyl, 1,2-butanediyl, and 1,3-butanediyl.
[0653] Examples of thiol-terminated polysulfide prepolymers of
Formula (31) and (31a) are disclosed, for example, in JP
62-53354.
[0654] Thiol-terminated polysulfide prepolymers can be liquid at
room temperature. Thiol-terminated monosulfide prepolymers can have
a viscosity of no more than 1,500 poise (150 Pa-sec), such as 40
poise to 500 poise (4 Pa-sec to 50 Pa-sec), at a temperature of
about 25.degree. C. and a pressure of about 760 mm Hg (101 kPa)
determined according to ASTM D-2849 .sctn. 79-90 using a Brookfield
CAP 2000 viscometer with a No. 6 spindle, at speed of 300 rpm, and
a temperature of 23.degree. C.
[0655] Thiol-terminated polysulfide prepolymers can have a number
average molecular weight within a range from 300 Da to 10,000 Da,
such as within a range 1,000 Da to 8,000 Da. Thiol-terminated
polysulfide prepolymers can have a glass transition temperature
T.sub.g less than -40.degree. C., less than -55.degree. C., or less
than -60.degree. C. The glass transition temperature T.sub.g is
determined by Dynamic Mass Analysis (DMA) using a TA Instruments
Q800 apparatus with a frequency of 1 Hz, an amplitude of 20
microns, and a temperature ramp of -80.degree. C. to 25.degree. C.,
with the T.sub.g identified as the peak of the tan 5 curve.
[0656] A thiol-terminated sulfur-containing prepolymer can comprise
a thiol-terminated sulfur-containing polyformal prepolymer or a
combination of thiol-terminated sulfur-containing polyformal
prepolymers. Sulfur-containing polyformal prepolymers useful in
sealant applications are disclosed, for example, in U.S. Pat. No.
8,729,216 and in U.S. Pat. No. 8,541,513.
[0657] A thiol-terminated sulfur-containing prepolymer can comprise
a thiol-terminated sulfur-containing polyformal prepolymer
comprising a moiety of Formula (32):
--R.sup.1--(S).sub.p--R.sup.1--[O--C(R.sup.2).sub.2--O--R.sup.1--(S).sub-
.p--R.sup.1--].sub.n- (32)
where n can be an integer from 1 to 50; each p can independently be
selected from 1 and 2; each R.sup.1 can be C.sub.2-6 alkanediyl;
and each R.sup.2 can independently be selected from hydrogen,
C.sub.1-6 alkyl, C.sub.7-12 phenylalkyl, substituted C.sub.7-12
phenylalkyl, C.sub.6-12 cycloalkylalkyl, substituted C.sub.6-12
cycloalkylalkyl, C.sub.3-12 cycloalkyl, substituted C.sub.3-12
cycloalkyl, C.sub.6-12 aryl, and substituted C.sub.6-12 aryl.
[0658] A thiol-terminated sulfur-containing polyformal prepolymer
can have the structure of Formula (32a):
R.sup.3--R.sup.1--(S).sub.p--R.sup.1--[O--C(R.sup.2).sub.2--O--R.sup.1---
(S).sub.p--R.sup.1--].sub.n--R.sup.3 (32a)
where n can be an integer from 1 to 50; each p can independently be
selected from 1 and 2; each R.sup.1 can be C.sub.2-6 alkanediyl;
each R.sup.2 can independently be selected from hydrogen, C.sub.1-6
alkyl, C.sub.7-12 phenylalkyl, substituted C.sub.7-12 phenylalkyl,
C.sub.6-12 cycloalkylalkyl, substituted C.sub.6-12 cycloalkylalkyl,
C.sub.3-12 cycloalkyl, substituted C.sub.3-12 cycloalkyl,
C.sub.6-12 aryl, and substituted C.sub.6-12 aryl; and each R.sup.3
comprises a thiol-terminated group.
[0659] In sulfur-containing polyformal moieties of Formula (32) and
prepolymers of Formula (32a), each R.sup.1 can independently be
selected from C.sub.2-6 alkanediyl, C.sub.2-4 alkanediyl, C.sub.2-3
alkanediyl, and ethane-1,2-diyl. In sulfur-containing polyformal
moieties of Formula (32) and prepolymers of Formula (32a), each
R.sup.1 can be ethane-1,2-diyl.
[0660] In sulfur-containing polyformal moieties of Formula (32) and
prepolymers of Formula (32a), each R.sup.2 can independently be
selected from hydrogen, C.sub.1-6 alkyl, C.sub.1-4 alkyl, C.sub.1-3
alkyl, and C.sub.1-2 alkyl. In sulfur-containing polyformal
moieties of Formula (32) and prepolymers of Formula (32a), each
R.sup.2 can be selected from hydrogen, methyl, and ethyl.
[0661] In sulfur-containing polyformal moieties of Formula (32) and
prepolymers of Formula (32a), each R.sup.1 is the same and can be
selected from C.sub.2-3 alkanediyl such as ethane-1,2-diyl and
propane-1,3-diyl; and each R.sup.2 is the same and can be selected
from hydrogen and C.sub.1-3 alkyl such as methyl, ethyl, or propyl.
In sulfur-containing polyformal moieties of Formula (32) and
prepolymers of Formula (32a), each R.sup.1 can be
ethane-1,2-diyl.
[0662] In sulfur-containing polyformal moieties of Formula (32) and
prepolymers of Formula (32a), each R.sup.2 can be hydrogen. In
sulfur-containing polyformal moieties of Formula (32) and
prepolymers Formula (32a), each R.sup.1 can be ethane-1,2-diyl and
each R.sup.2 can be hydrogen.
[0663] In sulfur-containing polyformal moieties of Formula (32) and
prepolymers of Formula (32a), n can be an integer selected from 1
to 50, an integer from 2 to 40, an integer from 4 to 30, or n can
be an integer from 7 to 30.
[0664] In sulfur-containing polyformal moieties of Formula (32) and
prepolymers of Formula (32a), each p is the same and can be 1, and
each p is the same and can be 2.
[0665] In sulfur-containing polyformal moieties of Formula (32) and
prepolymers of Formula (32a) can have a number average molecular
weight from 200 Da to 6,000 Da, from 500 Da to 5,000 Da, from 1,000
Da to 5,000 Da, from 1,500 Da to 4000 Da, or from 2,000 Da to 3,600
Da.
[0666] In sulfur-containing polyformal prepolymers of Formula
(32a), each R.sup.3 can be a thiol-terminated group and can be a
group of Formula (a), Formula (b), Formula (c), Formula (d),
Formula (e), or Formula (f):
HS--R.sup.7--R.sup.6--O-- (a)
HS--R.sup.7--O-- (b)
HS--R.sup.7--NH--C(.dbd.O)--O-- (c)
HS--R.sup.7--C(.dbd.O)--O--R.sup.9--NH--C(.dbd.O)--O-- (d)
HS--R.sup.7--C(.dbd.O)--NH--R.sup.9--NH--C(.dbd.O)--O-- (e)
HS--R.sup.7--C(.dbd.O)--O-- (f)
where each R.sup.6 comprises a moiety derived from a diisocyanate
or a moiety derived from an ethylenically unsaturated
monoisocyanate; each R.sup.7 can be selected from C.sub.2-14
alkanediyl and C.sub.2-14 heteroalkanediyl; and each R.sup.9 can be
selected from C.sub.2-6 alkanediyl, C.sub.2-6 heteroalkanediyl,
C.sub.6-12 arenediyl, substituted C.sub.6-12 arenediyl, C.sub.6-12
heteroarenediyl, substituted C.sub.6-12 heteroarenediyl, C.sub.3 12
cycloalkanediyl, substituted C.sub.3-12 cycloalkanediyl, C.sub.3-12
heterocycloalkanediyl, substituted C.sub.3-12
heterocycloalkanediyl, C.sub.7-18 alkanearenediyl, substituted
C.sub.7-18heteroalkanearenediyl, C.sub.4-18 alkanecycloalkanediyl,
and substituted C.sub.4-18 alkanecycloalkanediyl.
[0667] Sulfur-containing polyformal prepolymers can have the
structure of Formula (32b):
{R.sup.3--R.sup.1--(S).sub.p--R.sup.1--[O--C(R.sup.2).sub.2--O--R.sup.1--
-(S).sub.p--R.sup.1--].sub.n--O--C(R.sup.2).sub.2--O-}.sub.mZ
(32b)
where each n can be an integer selected from 1 to 50; m can be an
integer selected from 3 to 6; p can independently be selected from
1 and 2; each R.sup.1 can independently be C.sub.2-6 alkanediyl;
each R.sup.2 can independently be selected from hydrogen, C.sub.1-6
alkyl, C.sub.7-12 phenylalkyl, substituted C.sub.7-12 phenylalkyl,
C.sub.6-12 cycloalkylalkyl, substituted C.sub.6-12 cycloalkylalkyl,
C.sub.3-12 cycloalkyl, substituted C.sub.3-12 cycloalkyl,
C.sub.6-12 aryl, and substituted C.sub.6-12 aryl; each R.sup.3
comprises a thiol-terminated group; and Z can be derived from the
core of an m-valent parent polyol Z(OH).sub.m.
[0668] In sulfur-containing polyformal prepolymers of Formula
(32b), each R.sup.1 can independently be selected from C.sub.2-6
alkanediyl, C.sub.2-4 alkanediyl, C.sub.2-3 alkanediyl, and
ethane-1,2-diyl. In sulfur-containing polyformal prepolymers of
Formula (24b), each R.sup.1 can be ethane-1,2-diyl.
[0669] In sulfur-containing polyformal prepolymers of Formula
(32b), each R.sup.2 can independently be selected from hydrogen,
C.sub.1-6 alkyl, C.sub.1-4 alkyl, C.sub.1-3 alkyl, and C.sub.1-2
alkyl. In sulfur-containing polyformal prepolymers of Formula
(24b), each R.sup.2 can be selected from hydrogen, methyl, and
ethyl.
[0670] In sulfur-containing polyformal prepolymers of Formula
(32b), each R.sup.1 can be the same and can be selected from
C.sub.2-3 alkanediyl such as ethane-1,2-diyl or propane-1,3-diyl;
and each R.sup.2 can be the same and can be selected from hydrogen
and C.sub.1-3 alkyl such as methyl, ethyl, or propyl. In
sulfur-containing polyformal prepolymers of Formula (32b), each
R.sup.1 can be ethane-1,2-diyl. In sulfur-containing polyformal
prepolymers of Formula (32b), each R.sup.2 can be hydrogen. In
sulfur-containing polyformal prepolymers of Formula (32b), each
R.sup.1 can be ethane-1,2-diyl and each R.sup.2 can be
hydrogen.
[0671] In sulfur-containing polyformal prepolymers of Formula
(32b), m can be 3, m can be 4, m can be 5, or m can be 6.
[0672] In sulfur-containing polyformal prepolymers of Formula (32b)
where m is 3, the parent polyol Z(OH).sub.m is a triol of Formula
(33):
##STR00006##
where each R.sup.2 can independently be C.sub.1-6 alkanediyl, or a
triol of Formula (34):
##STR00007##
where each R.sup.2 can independently be C.sub.1-6 alkanediyl.
Accordingly, in these embodiments Z can have the structure of
Formula (33a) or Formula (34b):
##STR00008##
respectively, where each R.sup.2 can independently be C.sub.1-6
alkanediyl.
[0673] In sulfur-containing polyformal prepolymers of Formula
(32b), each n can be an integer selected from 1 to 50, an integer
selected from 2 to 40, an integer selected from 4 to 30, or an
integer selected from 7 to 30.
[0674] In sulfur-containing polyformal prepolymers of Formula (32b)
has a number average molecular weight from 200 Da to 6,000 Da, from
500 Da to 5,000 Da, from 1,000 Da to 5,000 Da, from 1,500 Da to
4000 Da, or from 2,000 Da to 3,600 Da.
[0675] In sulfur-containing polyformal prepolymers of Formula
(32b), R.sup.3 can be bonded to a polyfunctionalizing agent
B(V).sub.Z through a moiety of Formula (32).
[0676] In sulfur-containing polyformal prepolymers of Formula
(32b), each R.sup.3 can be the same.
[0677] A thiol-terminated sulfur-containing prepolymer can comprise
a thiol-terminated monosulfide prepolymer or a combination of
thiol-terminated monosulfide prepolymers.
[0678] A thiol-terminated monosulfide prepolymer can comprise a
thiol-terminated monosulfide prepolymer comprising a moiety of
Formula (35):
--S--R.sup.2--[--S--(R--X).sub.p--(R.sup.1--X).sub.q--R.sup.2--].sub.n---
S-- (35)
wherein,
[0679] each R can independently be selected from C.sub.2-10
alkanediyl, such as C.sub.2-6 alkanediyl; C.sub.2-10 branched
alkanediyl, such as C.sub.3-6 branched alkanediyl or a C.sub.3-6
branched alkanediyl having one or more pendant groups which can be,
for example, alkyl groups, such as methyl or ethyl groups;
C.sub.6-8 cycloalkanediyl; C.sub.6-14 alkylcycloalkyanediyl, such
as C.sub.6-10 alkylcycloalkanediyl; and C.sub.8-10 alkylarenediyl;
each R.sup.1 can independently be selected from C.sub.1-10
n-alkanediyl, such as C.sub.1-6 n-alkanediyl, C.sub.2-10 branched
alkanediyl, such as C.sub.3-6 branched alkanediyl having one or
more pendant groups which can be, for example, alkyl groups, such
as methyl or ethyl groups; C.sub.6-8 cycloalkanediyl; C.sub.6-14
alkylcycloalkanediyl, such as C.sub.6-10 alkylcycloalkanediyl; and
C.sub.8-10 alkylarenediyl; each R.sup.2 can independently be
selected from C.sub.1-10 n-alkanediyl, such as C.sub.1-6
n-alkanediyl, C.sub.2-10 branched alkanediyl, such as C.sub.3-6
branched alkanediyl having one or more pendant groups which can be,
for example, alkyl groups, such as methyl or ethyl groups;
C.sub.6-8 cycloalkanediyl group; C.sub.6-14 alkylcycloalkanediyl,
such as a C.sub.6-10 alkylcycloalkanediyl; and C.sub.8-10
alkylarenediyl;
[0680] each X can independently be selected from O or S;
[0681] p can be an integer from 1 to 5;
[0682] q can be an integer from 0 to 5; and
[0683] n can be an integer from 1 to 60, such as from 2 to 60, from
3 to 60, or from 25 to 35.
[0684] In moieties of Formula (35), each X can independently be
selected from S, O, and NR.sup.3, where R.sup.3 comprises C.sub.1-4
alkyl; p can be an integer from 1 to 5; q can be an integer from 0
to 5; n can be an integer from 1 to 60; each R can independently be
selected from C.sub.2-10 alkanediyl, O, x cycloalkanediyl,
C.sub.1-4 alkylcycloalkanediyl, and C.sub.8-10 alkylarenediyl; each
R.sup.1 can independently be selected from C.sub.1-10 alkanediyl,
C.sub.6-8 cycloalkanediyl, C.sub.1-4 alkylcycloalkanediyl, and
C.sub.8-10 alkylarenediyl; and each R.sup.2 can independently be
selected from C.sub.2-10 alkanediyl, C.sub.6-8 cycloalkanediyl,
C.sub.1-4 alkylcycloalkanediyl, and C.sub.8-10 alkylarenediyl.
[0685] A thiol-terminated monosulfide prepolymer can comprise a
thiol-terminated monosulfide prepolymer of Formula (35a), a
thiol-terminated monosulfide prepolymer of Formula (35b), a
thiol-terminated monosulfide prepolymer of Formula (35c), or a
combination of any of the foregoing:
HS--R.sup.2--[--S--(R--X).sub.p--(R.sup.1--X).sub.q--R.sup.2--].sub.n--S-
H (35a)
{HS--R.sup.2--[--S--(R--X).sub.p--(R.sup.1--X).sub.q--R.sup.2--].sub.n---
S--V'-}.sub.zB (35b)
{R.sup.4--S--R.sup.2--[--S--(R--X).sub.p--(R.sup.1--X).sub.q--R.sup.2--]-
.sub.n--S--V'-}.sub.zB (35c)
[0686] wherein, [0687] each R can independently be selected from
C.sub.2-10 alkanediyl, such as C.sub.2-6 alkanediyl; C.sub.2-10
branched alkanediyl, such as C.sub.3-6 branched alkanediyl or a
C.sub.3-6 branched alkanediyl having one or more pendant groups
which can be, for example, alkyl groups, such as methyl or ethyl
groups; C.sub.6-8 cycloalkanediyl; C.sub.6-14
alkylcycloalkyanediyl, such as C.sub.6-10 alkylcycloalkanediyl; and
C.sub.8-10 alkylarenediyl; [0688] each R.sup.1 can independently be
selected from C.sub.1-10 n-alkanediyl, such as C.sub.1-6
n-alkanediyl, C.sub.2-10 branched alkanediyl, such as C.sub.3-6
branched alkanediyl having one or more pendant groups which can be,
for example, alkyl groups, such as methyl or ethyl groups;
C.sub.6-8 cycloalkanediyl; C.sub.6-14 alkylcycloalkanediyl, such as
C.sub.6-10 alkylcycloalkanediyl; and C.sub.8-10 alkylarenediyl;
[0689] each R.sup.2 can independently be selected from C.sub.1-10
n-alkanediyl, such as C.sub.1-6 n-alkanediyl, C.sub.2-10 branched
alkanediyl, such as C.sub.3-6 branched alkanediyl having one or
more pendant groups which can be, for example, alkyl groups, such
as methyl or ethyl groups; C.sub.6-8 cycloalkanediyl group;
C.sub.6-14 alkylcycloalkanediyl, such as a C.sub.6-10
alkylcycloalkanediyl; and C.sub.8-10 alkylarenediyl; [0690] each X
can independently be selected from O and S; [0691] p can be an
integer from 1 to 5; [0692] q can be an integer from 0 to 5; and
[0693] n can be an integer from 1 to 60, such as from 2 to 60, from
3 to 60, or from 25 to 35 and [0694] B represents a core of a
z-valent polyfunctionalizing agent B(--V).sub.z wherein: [0695] z
can be an integer from 3 to 6; and [0696] each V can be a moiety
comprising a terminal group reactive with a thiol group; [0697]
each --V'-- can be derived from the reaction of --V with a thiol;
and [0698] each R.sup.4 can independently be selected from hydrogen
and a bond to a polyfunctionalizing agent B(--V).sub.z through a
moiety of Formula (35).
[0699] In thiol-terminated monosulfide prepolymers of Formula
(35)-(35c): [0700] each X can independently be selected from S, O,
and NR.sup.3, where R.sup.3 be selected from C.sub.1-4 alkyl;
[0701] p can be an integer from 1 to 5; [0702] q can be an integer
from 0 to 5; [0703] n can be an integer from 1 t0 60; [0704] each R
can independently be selected from C.sub.2-10 alkanediyl, C.sub.6-8
cycloalkanediyl, C.sub.1-4 alkylcycloalkanediyl, and C.sub.8-10
alkylarenediyl; [0705] each R.sup.1 can independently be selected
from C.sub.1-10 alkanediyl, C.sub.6-8 cycloalkanediyl, C.sub.1-4
alkylcycloalkanediyl, and C.sub.8-10 alkylarenediyl; [0706] each
R.sup.2 can independently be selected from C.sub.2-10 alkanediyl,
C.sub.6-8 cycloalkanediyl, C.sub.1-4 alkylcycloalkanediyl, and
C.sub.8-10 alkylarenediyl; [0707] B represents a core of a z-valent
polyfunctionalizing agent B(--V).sub.z wherein: [0708] z can be an
integer from 3 to 6; and [0709] each V can be a moiety comprising a
terminal group reactive with a thiol group; [0710] each --V'-- can
be derived from the reaction of --V with a thiol; and [0711] each
R.sup.4 can independently be selected from hydrogen and a bond to a
polyfunctionalizing agent B(--V).sub.z through a moiety of Formula
(35).
[0712] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), each X can independently be S or O, each X can
be S, or each X can be O.
[0713] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), p can be an integer from 2 to 6, or p can be 1,
2, 3, 4, 5, or 6.
[0714] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), q can be an integer from 1 to 5, q can be an
integer from 2 to 5, or q can be 0, 1, 2, 3, 4, or 5.
[0715] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), n can be an integer from 2 to 60, from 3 to 60,
or from 25 to 35.
[0716] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), each R can independently be selected from
C.sub.2-10 alkanediyl and C.sub.6-8 cycloalkanediyl, each R can be
C.sub.2-10 alkanediyl, or each R can be C.sub.6-8
cycloalkanediyl.
[0717] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), each R can be selected from C.sub.2-6
alkanediyl, C.sub.2-4 alkanediyl, C.sub.3-10 alkanediyl, and
C.sub.3-6 alkanediyl.
[0718] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), each R can be selected from ethanediyl,
1,3-propanediyl, 1,2-propanediyl, 1,4-butanediyl, and
1,3-butanediyl.
[0719] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), each R.sup.1 can independently be selected from
C.sub.1-10 alkanediyl and C.sub.6-8 cycloalkanediyl, each R can be
C.sub.1-10 alkanediyl, or each R.sup.1 can be C.sub.6-8
cycloalkanediyl.
[0720] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), each R.sup.1 can be selected from C.sub.1-6
alkanediyl, C.sub.1-4 alkanediyl, C.sub.2-10 alkanediyl, and
C.sub.2-6 alkanediyl.
[0721] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), each R.sup.1 can be selected from methanediyl,
ethanediyl, 1,3-propanediyl, 1,2-propanediyl, 1,4-butanediyl, and
1,3-butanediyl.
[0722] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), each R.sup.2 can independently be selected from
C.sub.2-10 alkanediyl and C.sub.6-8 cycloalkanediyl, each R.sup.2
can be C.sub.2-10 alkanediyl, or each R.sup.2 can be C.sub.6-8
cycloalkanediyl.
[0723] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), each R.sup.2 can be selected from C.sub.2-6
alkanediyl, C.sub.2-4 alkanediyl, C.sub.3-10 alkanediyl, and
C.sub.3-6 alkanediyl.
[0724] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), each R.sup.2 can be selected from ethanediyl,
1,3-propanediyl, 1,2-propanediyl, 1,4-butanediyl, and
1,3-butanediyl.
[0725] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), p can be 1 or 2, q can be 1 or 2, n can be an
integer from 1 to 60 or an integer from 25 to 35, each X can be O
or S, each R can be C.sub.2-4 alkanediyl, each R.sup.1 can be
C.sub.1-4 alkanediyl, and each R.sup.2 can be C.sub.2-4
alkanediyl.
[0726] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), p can be 1 or 2, q can be 1 or 2, n can be an
integer from 1 to 60 or an integer from 25 to 35, each X can be O
or S, each R can be C.sub.2 alkanediyl, each R.sup.1 can be
C.sub.1-4 alkanediyl, and each R.sup.2 can be C.sub.2
alkanediyl.
[0727] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), p can be 1 or 2, q can be 1 or 2, n can be an
integer from 1 to 60 or an integer from 25 to 35, each X can be O,
each R can be C.sub.2 alkanediyl, each R.sup.1 can be C.sub.1-4
alkanediyl, and each R.sup.2 can be C.sub.2 alkanediyl.
[0728] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c), B(--V).sub.z can be selected from
1,2,3-trichloropropane, 1,1,1-tris(chloromethyl)propane,
1,1,1-tris(chloromethyl)ethane, 1,3,5-tris(chloromethyl)benzene,
and a combination of any of the foregoing.
[0729] In thiol-terminated monosulfide moieties or prepolymers of
Formula (35c) each R.sup.4 can independently selected from hydrogen
and a bond to a polyfunctionalizing agent B(V).sub.Z through a
moiety of Formula (35). A thiol-terminated monosulfide moiety or
prepolymer can have an average thiol functionality, for example,
from 2.05 to 2.9, such as from 2.1 to 2.8, or from 2.2 to 2.6.
[0730] Thiol-terminated monosulfide moieties or prepolymers of
Formula (35)-(35c) can be prepared by reacting an
.alpha.,.omega.-dihalo organic compounds, a metal hydrosulfide, a
metal hydroxide, and an optional polyfunctionalizing agent.
Examples of suitable .alpha.,.omega.-dihalo organic compounds
include bis(2-chloroethyl)formal. Examples of suitable metal
hydrosulfides and metal hydroxides include sodium hydrosulfide and
sodium hydroxide. Examples of suitable polyfunctionalizing agents
include 1,2,3-trichloropropane, 1,1,1-tris(chloromethyl)propane,
1,1,1-tris(chloromethyl)ethane, and
1,3,5-tris(chloromethyl)benzene. Methods of synthesizing
thiol-terminated monosulfide moieties or prepolymers of Formula
(35)-(35c) are disclosed, for example, in U.S. Pat. No.
7,875,666.
[0731] A thiol-terminated monosulfide prepolymer can comprise a
thiol-terminated monosulfide prepolymer comprising a moiety of
Formula (36) and E in the thiol-terminated prepolymer of Formula
(13) can be a moiety of Formula (36a):
-[--S--(R--X).sub.p--C(R.sup.1).sub.2--(X--R).sub.q-].sub.n--S--
(36)
H--[--S--(R--X).sub.p--C(R.sup.1).sub.2--(X--R).sub.q-].sub.n--SH
(36a)
wherein,
[0732] each R can independently be selected from C.sub.2-10
alkanediyl, such as C.sub.2-6 alkanediyl; a C.sub.3-10 branched
alkanediyl, such as a C.sub.3-6 branched alkanediyl or a C.sub.3-6
branched alkanediyl having one or more pendant groups which can be,
for example, alkyl groups, such as methyl or ethyl groups; a
C.sub.6-8 cycloalkanediyl; a C.sub.6-14 alkylcycloalkyanediyl, such
as a C.sub.6-10 alkylcycloalkanediyl; and a C.sub.8-10
alkylarenediyl;
[0733] each R.sup.1 can independently be selected from hydrogen,
C.sub.1-10 n-alkyl, such as a C.sub.1-6 n-alkyl, C.sub.3-10
branched alkyl, such as a C.sub.3-6 branched alkyl having one or
more pendant groups which can be, for example, alkyl groups, such
as methyl or ethyl groups; a C.sub.6-8 cycloalkyl group; a
C.sub.6-14 alkylcycloalkyl, such as a C.sub.6-10 alkylcycloalkyl;
and a C.sub.8-10 alkylaryl;
[0734] each X can independently be selected from O and S;
[0735] p can be an integer from 1 to 5;
[0736] q can be an integer from 1 to 5; and
[0737] n can be an integer from 1 to 60, such as from 2 to 60, from
3 to 60, or from 25 to 35.
[0738] A thiol-terminated monosulfide prepolymer can comprise a
thiol-terminated monosulfide prepolymer of Formula (36a), a
thiol-terminated monosulfide prepolymer of Formula (36b), a
thiol-terminated monosulfide prepolymer of Formula (36c), or a
combination of any of the foregoing:
H--[--S--(R--X).sub.p--C(R.sup.1).sub.2--(X--R).sub.q-].sub.n--SH
(36a)
{H--[--S--(R--X).sub.p--C(R.sup.1).sub.2--(X--R).sub.q-].sub.n--S--V'-}.-
sub.zB (36b)
{R.sup.4--[--S--(R--X).sub.p--C(R.sup.1).sub.2--(X--R).sub.q-].sub.n--S--
-V'-}.sub.zB (36c)
wherein,
[0739] each R can independently be selected from C.sub.2-10
alkanediyl, such as C.sub.2-6 alkanediyl; a C.sub.3-10 branched
alkanediyl, such as a C.sub.3-6 branched alkanediyl or a C.sub.3-6
branched alkanediyl having one or more pendant groups which can be,
for example, alkyl groups, such as methyl or ethyl groups; a
C.sub.6-8 cycloalkanediyl; a C.sub.6-14 alkylcycloalkyanediyl, such
as a C.sub.6-10 alkylcycloalkanediyl; and a C.sub.8-10
alkylarenediyl;
[0740] each R.sup.1 can independently be selected from hydrogen,
C.sub.1-10 n-alkyl, such as a C.sub.1-6 n-alkyl, C.sub.3-10
branched alkyl, such as a C.sub.3-6 branched alkyl having one or
more pendant groups which can be, for example, alkyl groups, such
as methyl or ethyl groups; a C.sub.6-8 cycloalkyl group; a
C.sub.6-14 alkylcycloalkyl, such as a C.sub.6-10 alkylcycloalkyl;
and a C.sub.8-10 alkylaryl;
[0741] each X can independently be selected from O and S;
[0742] p can be an integer from 1 to 5;
[0743] q can be an integer from 1 to 5;
[0744] n can be an integer from 1 to 60, such as from 2 to 60, from
3 to 60, or from 25 to 35;
[0745] B represents a core of a z-valent polyfunctionalizing agent
B(--V).sub.z wherein: [0746] z can be an integer from 3 to 6; and
[0747] each V can be a moiety comprising a terminal group reactive
with a thiol group;
[0748] each --V'-- can be derived from the reaction of --V with a
thiol; and
[0749] each R.sup.4 can independently be selected from hydrogen and
a bond to a polyfunctionalizing agent B(--V).sub.z through a moiety
of Formula (36).
[0750] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), each X can independently be selected from S and
O; p can be an integer from 1 to 5; q can be an integer from 1 to
5; n can be an integer from 1 to 60; each R can independently be
C.sub.2-10 alkanediyl; each R.sup.1 can independently be selected
from hydrogen and C.sub.1-10 alkanediyl; B represents a core of a
z-valent polyfunctionalizing agent B(--V).sub.z wherein: z can be
an integer from 3 to 6; and each V can be a moiety comprising a
terminal group reactive with a thiol group; each --V'-- can be
derived from the reaction of --V with a thiol; and each R.sup.4 can
independently be hydrogen or can be bonded to a polyfunctionalizing
agent B(--V).sub.z through a moiety of Formula (36).
[0751] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), each X can be S, or each X can be O.
[0752] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), p can be an integer from 2 to 5, or q can be 1,
2, 3, 4, or 5.
[0753] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), p can be an integer from 2 to 5, or q can be 1,
2, 3, 4, or 5.
[0754] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), n can be an integer from 2 to 60, from 3 to 60,
or from 25 to 35.
[0755] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), each R can independently be selected from
C.sub.2-6 alkanediyl and C.sub.2-4 alkanediyl.
[0756] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), each R can be selected from ethanediyl,
1,3-propanediyl, 1,2-propanediyl, 1,4-butanediyl, and
1,3-butanediyl.
[0757] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), each R can be selected from C.sub.2-10
n-alkanediyl, C.sub.2-10 branched alkanediyl, and a combination
thereof.
[0758] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), each R.sup.1 can independently be selected from
hydrogen and C.sub.2-6 alkyl.
[0759] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), each R.sup.1 can independently be selected from
hydrogen, ethanediyl, 1,3-propyl, 1,2-propyl, 1,4-butyl, and
1,3-butyl.
[0760] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), each R.sup.1 can be selected from C.sub.1-10
n-alkyl, C.sub.1-10 branched alkyl, and a combination thereof.
[0761] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), each X can be O, p can be 1 or 2, q can be 1 or
2, n can be 1 to 60 such as 2 to 60, each R can be C.sub.2-4
alkanediyl such as ethanediyl, and each R.sup.1 can be
hydrogen.
[0762] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), each X can be O, p can be 1, q can be 1, n can
be 1 to 60 such as 2 to 60, each R can be C.sub.2-4 alkanediyl such
as ethanediyl, and each R.sup.1 can be hydrogen.
[0763] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), each X can be O, p can be 2, q can be 2, n can
be 1 to 60 such as 2 to 60, each R can be C.sub.2-4 alkanediyl such
as ethanediyl, and each R.sup.1 can be hydrogen.
[0764] In thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c), B(--V).sub.z can be selected from
1,2,3-trichloropropane, 1,1,1-tris(chloromethyl)propane,
1,1,1-tris(chloromethyl)ethane, 1,3,5-tris(chloromethyl)benzene,
and a combination of any of the foregoing.
[0765] Thiol-terminated monosulfide moieties or prepolymers of
Formula (36)-(36c) can be prepared by reacting an
.alpha.,.omega.-dihalo organic compounds, a metal hydrosulfide, a
metal hydroxide, and an optional polyfunctionalizing agent.
Examples of suitable .alpha.,.omega.-dihalo organic compounds
include bis(2-chloroethyl)formal. Examples of suitable metal
hydrosulfides and metal hydroxides include sodium hydrosulfide and
sodium hydroxide. Examples of suitable polyfunctionalizing agents
include 1,2,3-trichloropropane, 1,1,1-tris(chloromethyl)propane,
1,1,1-tris(chloromethyl)ethane, and
1,3,5-tris(chloromethyl)benzene. Methods of synthesizing
thiol-terminated monosulfides of Formula (36)-(36c) are disclosed,
for example, in U.S. Pat. No. 8,466,220.
[0766] Thiol-terminated monosulfide moieties and prepolymers can
have a number average molecular weight within a range from 300 Da
to 10,000 Da, such as within a range 1,000 Da to 8,000 Da, where
the molecular weight is determined by gel-permeation chromatography
using a polystyrene standard. Thiol-terminated monosulfide
prepolymers can have a glass transition temperature T.sub.g less
than -40.degree. C., less than -55.degree. C., or less than
-60.degree. C. The glass transition temperature T.sub.g is
determined by Dynamic Mass Analysis (DMA) using a TA Instruments
Q800 apparatus with a frequency of 1 Hz, an amplitude of 20
microns, and a temperature ramp of -80.degree. C. to 25.degree. C.,
with the T.sub.g identified as the peak of the tan 5 curve.
[0767] A sulfur-containing prepolymer can comprise a
sulfur-containing perfluoroether prepolymer, a perfluorosilicone
prepolymer, or a combination thereof.
[0768] An overlying sulfur-containing sealant can be a free radical
polymerizable sulfur-containing sealant including sealants actinic
radiation-curable sulfur-containing sealants such as UV-curable
sealants.
[0769] Actinic radiation can be used to initiate free radical
polymerization mechanisms. Free radical polymerization can proceed
via the absorption by a photoinitiator of actinic radiation such as
ultraviolet (UV) light to generate free radicals, which react with
double bonds to cause chain reaction and polymerization. For
example, in a thiol/ene reaction, a free radical generated by the
photoinitiator abstracts a hydrogen from a thiol group creating a
thienyl radical that can add to an alkylene group or an alkynyl
group, creating a sulfur-carbon bond and a .beta.-carbon radical,
which initiates chain propagation. Cationic polymerization proceeds
the absorption of a photoinitiator of actinic radiation to generate
a Lewis acid which reacts with functional groups such as epoxy
groups resulting in polymerization.
[0770] In free radical e-beam curing; electrons open double bonds
initiating polymerization, and in cationic e-beam curing electrons
decompose photoinitiator to form an acid.
[0771] Energy curable chemistries include reactions through double
bonds including groups such as acryloyl groups
(R--O--C(.dbd.O)--CH.dbd.CH.sub.2), methacryloyl groups
(R--O--C(.dbd.O)--C(--CH.sub.3).dbd.CH.sub.2), allyl groups
(R--CH.dbd.CHR), alkenyl groups (R--CH.sub.2--CH.dbd.CH.sub.2), and
alkynyl groups (R--CH.sub.2--C.ident.CH).
[0772] An overlying sealant can comprise a polythiol and a
polyalkenyl and/or a polyalkynyl. The polythiol, polyalkenyl, and
polyalkynyl can independently comprise a monomer, an oligomer, a
prepolymer, or a combination of any of the foregoing.
[0773] For example, a polythiol can comprise a thiol-terminated
sulfur-containing prepolymer and the polyalkenyl and/or polyalkynyl
can comprise a monomer.
[0774] A thiol-terminated sulfur-containing prepolymer can comprise
a thiol-terminated polythioether, a thiol-terminated polysulfide, a
thiol-terminated sulfur-containing polyformal prepolymer, a
thiol-terminated monosulfide, or a combination of any of the
foregoing.
[0775] Examples of free radical polymerizable sulfur-containing
sealant compositions are disclosed, for example, in U.S.
Application Publication No. 2015/0086726 and in U.S. Pat. No.
10,280,348.
[0776] Free radical polymerizable sealant compositions can comprise
a polythiol or combination of polythiols. A polythiol can be a
polythiol prepolymer, a small molecule polythiol, a
thiol-terminated polyfunctionalizing agent, or a combination of any
of the foregoing.
[0777] A polythiol prepolymer can comprise, or example, any
suitable thiol-terminated prepolymer.
[0778] A polythiol prepolymer can comprise, for example, a
thiol-terminated sulfur-containing prepolymer.
[0779] Free radical polymerizable sealant compositions can comprise
a thiol-terminated sulfur-containing prepolymer such as a
thiol-terminated polythioether prepolymer, a thiol-terminated
polysulfide prepolymer, a thiol-terminated sulfur-containing
polyformal prepolymer, a thiol-terminated monosulfide prepolymer,
or a combination of any of the foregoing. A sulfur-containing
prepolymer refers to a prepolymer that has one or more thioether
--S.sub.n-- groups, where n can be, for example, 1 to 6, in the
backbone of the prepolymer. Prepolymers that contain only thiol or
other sulfur-containing groups either as terminal groups or as
pendent groups of the prepolymer are not encompassed by
sulfur-containing prepolymers. The prepolymer backbone refers to
the portion of the prepolymer having repeating segments. Thus, a
prepolymer having the structure
HS--R--R(--CH.sub.2--SH)--[--R--(CH.sub.2).sub.2--S(O).sub.2--(-
CH.sub.2)--S(O).sub.2].sub.n--CH.dbd.CH.sub.2 where each R is a
moiety that does not contain a thioether group, is not encompassed
by a sulfur-containing prepolymer. A prepolymer having the
structure
HS--R--R(--CH.sub.2--SH)--[--R--(CH.sub.2).sub.2--S(O).sub.2--(CH.sub.2)--
-S(O).sub.2].sub.n--CH.dbd.CH.sub.2 where at least one R is a
moiety that contains a thioether group is encompassed by a
sulfur-containing prepolymer.
[0780] A thiol-terminated sulfur-containing prepolymer can comprise
a thiol-terminated sulfur-containing prepolymer or a combination of
thiol-terminated sulfur-containing prepolymers. The
thiol-terminated sulfur-containing prepolymers may have the same or
different functionality. A thiol-terminated sulfur-containing
prepolymer can have an average functionality, for example, from 2
to 6, from 2 to 4, from 2 to 3, from 2.3 to 2.8, or from 2.05 to
2.5. For example, a thiol-terminated sulfur-containing prepolymer
can comprise a difunctional thiol-terminated sulfur-containing
prepolymer, a trifunctional thiol-terminated sulfur-containing
prepolymer, or a combination thereof.
[0781] Free radical polymerizable sealant compositions can
comprise, for example, from 40 wt % to 80 wt %, from 40 wt % to 75
wt %, from 45 wt % to 70 wt %, or from 50 wt % to 70 wt % of a
thiol-terminated sulfur-containing prepolymer or combination of
thiol-terminated sulfur-containing prepolymers, such as a
thiol-terminated polythioether prepolymer, a thiol-terminated
polysulfide prepolymer, a thiol-terminated sulfur-containing
polyformal prepolymer, a thiol-terminated monosulfide prepolymer,
or a combination of any of the foregoing, where wt % is based on
the total weight of the composition.
[0782] A sulfur-containing prepolymer can comprise a
thiol-terminated polythioether prepolymer or combinations of
thiol-terminated polythioether prepolymers. Examples of suitable
thiol-terminated polythioether prepolymers are disclosed, for
example, in U.S. Pat. No. 6,172,179. A thiol-terminated
polythioether prepolymer can comprise Permapol.RTM. P3.1E,
Permapol.RTM. P3.1E-2.8, Permapol.RTM. L56086, or a combination of
any of the foregoing, each of which is available from PPG
Aerospace. These Permapol.RTM. products are encompassed by the
thiol-terminated polythioether prepolymers of Formula (12)-(12c).
Thiol-terminated polythioethers include prepolymers described in
U.S. Pat. No. 7,390,859 and urethane-containing polythiols
described in U.S. Application Publication Nos. 2017/0369757 and
2016/0090507.
[0783] A thiol-terminated polythioether prepolymer can comprise a
thiol-terminated polythioether prepolymer comprising at least one
moiety having the structure of Formula (12):
--[S--(CH.sub.2).sub.2--O--(R.sup.2--O--).sub.m(CH.sub.2).sub.2--S--R.su-
p.1].sub.n- (12)
[0784] where, [0785] each R.sup.1 can independently be selected
from C.sub.2-10 n-alkanediyl, C.sub.3-6 branched alkanediyl,
C.sub.6-8 cycloalkanediyl, C.sub.6-10 alkanecycloalkanediyl, and
--[(CHR.sup.3).sub.p--X-].sub.q(CHR.sup.3).sub.r--, wherein each
R.sup.3 can be selected from hydrogen and methyl; [0786] each
R.sup.2 can independently be selected from C.sub.2-10 n-alkanediyl,
C.sub.3-6 branched alkanediyl, C.sub.6-8 cycloalkanediyl,
C.sub.6-14 alkanecycloalkanediyl, and
--[(CH.sub.2).sub.p--X-].sub.q(CH.sub.2).sub.r--; [0787] each X can
independently be selected from O, S, and NR, wherein R can be
selected from hydrogen and methyl; [0788] m ranges from 0 to 50;
[0789] n can be an integer ranging from 1 to 60; [0790] p can be an
integer ranging from 2 to 6; [0791] q can be an integer ranging
from 1 to 5; and [0792] r can be an integer ranging from 2 to
10.
[0793] In addition to free radical polymerizable compounds, a
sealant composition can include filler, reactive diluents, rheology
agents, plasticizers, antioxidants, thermal stabilizers, adhesion
promoters, colorants, and combinations of any of the foregoing.
[0794] An overlying sealant composition can be transmissive to
actinic radiation such that the underlying adhesion-promoting layer
can be exposed to actinic radiation incident on the overlying
sealant at an energy or range of energies sufficient to activate
free radical initiator within the adhesion-promoting interlayer.
For example, the overlying sealant composition can transmit greater
than 1%, greater than 10%, greater than 25%, greater than 75%, or
greater than 90% of the relevant energy or range of energies.
[0795] The transmissibility of the overlying sulfur-containing
sealant can depend, for example, on the composition of the organic
materials, on the type and amount of filler, and/or of the
thickness of the sealant layer.
[0796] Adhesion-promoting interlayers can be applied to a damaged
and/or layer of a sulfur-containing sealant to enhance adhesion of
an overlying layer of a fresh, newly applied, sulfur-containing
sealant.
[0797] The two layers of sulfur-containing sealant can be the same
or different. For example, the underlying or damaged layer of
sealant can be based on a polythioether and the overlying or layer
of fresh sealant can be based on a polysulfide.
[0798] The two layers of sulfur-containing sealant can be based on
the same type of sulfur-containing prepolymer but can have
different compositions. For example, both sealants can comprise
polythioethers, but can have a different content of an additive,
such as a filler, or a different type of additive such as different
types of filler.
[0799] The underlying sulfur-containing sealant can be cured be
cured using any suitable curing chemistry. For example, the
underlying sulfur-containing sealant can comprise the reaction
product of a polythiol and a curing agent such as a polyepoxide,
polyalkenyl, polyalkynyl, polyfunctional Michael acceptor, or
polyisocyanate curing agent. An underlying sealant can comprise the
condensation reaction product of polythiols.
[0800] An underlying sealant can be a freshly applied sealant that
can be uncured, partially cured, or fully cured.
[0801] An underlying sealant can be an incumbent sealant meaning
that the sealant has been used for its intended purpose. An
incumbent sealant can be used, i.e., aged, or can be damaged such
as abraded, scraped, delaminated, impacted, and/or cut.
[0802] Before applying an adhesion-promoting composition provided
by the present disclosure to provide an adhesion-promoting
interlayer overlying a sulfur-containing sealant layer, the
underlying sealant layer can be abraded. The surface can be abraded
by hand sanding using, for example, a very fine grade aluminum
oxide abrasive pad such as a Scotch-Brite.TM. 7447 hand pad
available from 3M. The objective of the abrasion is to remove
particulates and loose portions of the damage/weathered
surface.
[0803] In certain applications, an underlying sulfur-containing
surface is not abraded.
[0804] After the surface has been abraded, the surface can be wiped
with a cleaning solvent to remove the particulates and oils from
the sealant surface. A cleaning solvent can comprise a volatile
organic solvent such as methylethyl ketone or ethyl lactate such as
DS-108 available from Socomore.
[0805] The adhesion-promoting composition can be applied to an
untreated or treated sulfur-containing sealant layer by wiping,
spraying, or brushing the adhesion-promoting composition across the
surface, for example, using a saturated gauze. The amount of the
adhesion-promoting composition can result in a dried thickness, for
example, from 1 .mu.m to 20 .mu.m or from 1 .mu.m to 10 .mu.m.
[0806] The applied adhesion-promoting composition can then be
dried. The adhesion-promoting composition can be dried by heating
or by leaving at ambient conditions (25.degree. C./50% RH) until
the solvent has evaporated. For example, at a temperature of about
25.degree. C. the applied adhesion-promoting composition can be
left to dry for about 10 minutes.
[0807] In certain applications, the dried adhesion-promoting
composition can be partially cured or fully cured, for example by
exposing the dried adhesion-promoting composition to actinic
radiation for a period of time.
[0808] After the applied adhesion-promoting composition is dried or
cured, a layer of a free radical polymerizable sulfur-containing
sealant composition can be applied over the dried or cured
adhesion-promoting composition.
[0809] The free radical polymerization reaction of the
sulfur-containing sealant composition and the underlying
adhesion-promoting composition can then be initiated. For example,
the sulfur-containing sealant composition and the underlying
adhesion-promoting composition can be exposed to actinic radiation,
such as UV radiation sufficient to initiate the free radical
reaction. Initiating the free radical polymerization reaction can
included activating the free radical initiator in the overlying
sulfur-containing sealant only, in the case where the
adhesion-promoting interlayer has been fully cured or activating
the free radical initiator in both the overlying sulfur-containing
sealant and in the adhesion-promoting interlayer to simultaneously
cure both the overlying sulfur-containing sealant and the
adhesion-promoting interlayer.
[0810] Multilayer sealant systems provided by the present
disclosure comprise an underlying sulfur-containing sealant, and
adhesion-promoting interlayer contacting the underlying
sulfur-containing sealant, and a sulfur-containing sealant
overlying and contacting the adhesion-promoting interlayer. The
first, underlying sulfur-containing sealant layer can be coated on
a substrate such as a metal substrate. The substrate can be part of
a vehicle such as a vehicular, marine, transport, or aerospace
vehicle.
[0811] Multilayer sealant systems provided by the present
disclosure can be used as sealants or coatings such as for a
vehicle and aerospace, and in particular, as sealants or coatings
where resistance to hydraulic fluid is desired. A sealant refers to
a curable composition that has the ability when cured to resist
atmospheric conditions such as moisture (e.g., from 5% RH to 100%
RH) and temperature (e.g., from -30.degree. C. to 40.degree. C.)
and at least partially block the transmission of materials such as
water, water vapor, fuel, solvents, and/or liquids and gases.
[0812] Multilayer sealant systems provided by the present
disclosure can be used to seal surfaces and can be used to repair
and/or restore damaged and/or aged surfaces to reseal a surface or
maintain the integrity of a sealed surface.
[0813] Multilayer sealant systems can be provided as kits, such as
kits for repairing damaged sealant surfaces. A kit can include, for
example, a container comprising an adhesion-promoting composition
provided by the present disclosure and a container comprising a
free radical polymerizable sulfur-containing sealant composition. A
kit can further include, for example, an abrasion pad, a cleaning
solvent, an applicator such as a gauze pad for applying the
adhesion-promoting composition, and an applicator such as a brush
for applying the free radical polymerizable sulfur-containing
sealant composition. A repair kit can include a polymerization
initiator such as UV or visible source for curing of the adhesion
promoting composition and the free radical polymerizable
sulfur-containing sealant composition.
[0814] Compositions, including sealants and adhesion-promoting
compositions provided by the present disclosure may be applied to
any of a variety of substrates. Examples of substrates to which a
composition may be applied include metals such as titanium,
stainless steel, steel alloy, aluminum, and aluminum alloy, any of
which may be anodized, primed, organic-coated or chromate-coated;
epoxy; urethane; graphite; fiberglass composite; Kevlar.RTM.;
acrylics; and polycarbonates. Compositions provided by the present
disclosure may be applied to a substrate such as aluminum and
aluminum alloy.
[0815] Sealant systems provided by the present disclosure may be
formulated as Class A, Class B, or Class C sealants. A Class A
sealant refers to a brushable sealant having a viscosity of 1 poise
to 500 poise (0.1 Pa-sec to 50 Pa-sec) and is designed for brush
application. A Class B sealant refers to an extrudable sealant
having a viscosity from 4,500 poise to 20,000 poise (450 Pa-sec to
2,000 Pa-sec) and is designed for application by extrusion via a
pneumatic gun. A Class B sealant can be used form fillets and
sealing on vertical surfaces or edges where low slump/slag is
required. A Class C sealant has a viscosity from 500 poise to 4,500
poise (50 Pa-sec to 450 Pa-sec) and is designed for application by
a roller or combed tooth spreader. A Class C sealant can be used
for fay surface sealing. Viscosity can be measured according to
Section 5.3 of SAE Aerospace Standard AS5127/1C published by SAE
International Group.
[0816] Sealant systems including an adhesion-promoting interlayer
provided by the present disclosure can be used to seal and/or
reseal apertures, surfaces, joints, fillets, fay surfaces, and
fasteners including apertures, surfaces, fillets, joints, fay
surfaces fasteners of vehicles including aerospace vehicles.
Surfaces including vehicular surfaces such as aerospace surfaces,
sealed with a sealant system including an adhesion-promoting
interlayer are included within the scope of the disclosure.
[0817] A cured sealant system can have a thickness, for example,
from 5 mils to 25 mils (127 .mu.m to 635 .mu.m) such as from 10
mils to 20 mils (254 .mu.m to 508 .mu.m).
[0818] The free radical photopolymerization reaction can be
initiated by exposing a composition provided by the present
disclosure to actinic radiation such as UV radiation, for example,
for less than 180 seconds, less 120 seconds, less than 90 seconds,
less than 60 seconds, or less than 30 seconds.
[0819] The free radical photopolymerization reaction can be
initiated by exposing a composition provided by the present
disclosure to actinic radiation such as UV radiation, for example,
for from 5 seconds to 180 seconds, from 15 seconds to 120 seconds,
from 15 seconds to 90 seconds, or from 15 seconds to 60
seconds.
[0820] The UV radiation can include radiation at a wavelength at
394 urn.
[0821] The total power of the UV exposure can be, for example, from
50 mW/cm.sup.2 to 50 W/cm.sup.2, from 100 mW/cm.sup.2 to 20
W/cm.sup.2, from 150 mW/cm.sup.2 to 10 W/cm.sup.2, from 200
mW/cm.sup.2 to 5 W/cm.sup.2, or from 250 mW/cm.sup.2 to 2
W/cm.sup.2.
[0822] In certain applications provided by the present disclosure a
sealant system can be curable without exposure to actinic radiation
such as UV radiation. Composition can be at least partly curable
upon exposure to actinic radiation and such compositions can
include a photoionization. The actinic radiation such as UV
radiation can be applied to at least a portion of an applied
sealant. The sealant can be accessible to the actinic radiation and
the portion of sealant exposed to the UV radiation can be cured to
a certain depth below the surface. For example, the actinic
radiation can be initiated the photopolymerization reaction to a
depth, for example, of at least 4 mm, at least 6 mm, at least 8 mm,
or at least 10 mm. A portion of the sealant may not be accessible
to actinic radiation either because of absorption or scattering of
the actinic radiation of the sealant which prevents the actinic
radiant from interacting with the full thickness of the sealant. A
portion of the sealant may be obscured by the geometry of the part
being sealed or may be obscured by an overlying structure.
[0823] Cured sealant systems, such as cured sealants, exhibit
properties acceptable for use in vehicle and aerospace sealant
applications. In general, it is desirable that sealants used in
aviation and aerospace applications exhibit the following
properties: peel strength greater than 20 pounds per linear inch
(pli) on Aerospace Material Specification (AMS) 3265B substrates
determined under dry conditions, following immersion in JRF Type I
for 7 days, and following immersion in a solution of 3% NaCl
according to AMS 3265B test specifications; tensile strength
between 300 pounds per square inch (psi) and 400 psi (2.75 MPa);
tear strength greater than 50 pounds per linear inch (pli) (8.75
N/mm); elongation between 250% and 300%; and hardness greater than
40 Durometer A. These and other cured sealant properties
appropriate for aviation and aerospace applications are disclosed
in AMS 3265B. It is also desirable that, when cured, compositions
of the present disclosure used in aviation and aircraft
applications exhibit a percent volume swell not greater than 25%
following immersion for one week at 60.degree. C. (140.degree. F.)
and ambient pressure in Jet Reference Fluid (JRF) Type 1. Other
properties, ranges, and/or thresholds may be appropriate for other
sealant applications.
[0824] Cured sealant systems can be fuel-resistant. The term "fuel
resistant" means that a composition, when applied to a substrate
and cured, can provide a cured product, such as a sealant, that
exhibits a percent volume swell of not greater than 40%, in some
cases not greater than 25%, in some cases not greater than 20%, and
in other cases not more than 10%, after immersion for one week at
140.degree. F. (60.degree. C.) and ambient pressure in JRF Type I
according to methods described in ASTM D792 (American Society for
Testing and Materials) or AMS 3269 (Aerospace Material
Specification). JRF Type I, as employed for determination of fuel
resistance, has the following composition: toluene: 28.+-.1% by
volume; cyclohexane (technical): 34.+-.1% by volume; isooctane:
38.+-.1% by volume; and tertiary dibutyl disulfide: 1.+-.0.005% by
volume (see AMS 2629, issued Jul. 1, 1989, .sctn. 3.1.1 etc.,
available from SAE (Society of Automotive Engineers)).
[0825] Sealant systems can exhibit a tensile elongation of at least
200% and a tensile strength of at least 200 psi when measured in
accordance with the procedure described in AMS 3279, .sctn.
3.3.17.1, test procedure AS5127/1, .sctn. 7.7. In general, for a
Class A sealant there is no tensile and elongation requirement. For
a Class B sealant, as a general requirement, tensile strength is
equal to or greater than 200 psi (1.38 MPa) and elongation is equal
to or greater than 200%. Acceptable elongation and tensile strength
can be different depending on the application.
[0826] Sealant systems can exhibit a lap shear strength of greater
than 200 psi (1.38 MPa), such as at least 220 psi (1.52 MPa), at
least 250 psi (1.72 MPa), and, in some cases, at least 400 psi
(2.76 MPa), when measured according to the procedure described in
SAE AS5127/1 paragraph 7.8.
[0827] A cured sealant system prepared from a composition meets or
exceeds the requirements for aerospace sealants as set forth in AMS
3277.
[0828] A cured sealant system provided by the present disclosure
can exhibit a peel strength greater than 10 pli and 100% cohesive
failure or greater than 20 pli/100% cf.
[0829] Sealant systems including an adhesion-promoting interlayer
provided by the present disclosure can meet the requirements of AMS
draft specification G9-16AA.
[0830] Apertures, surfaces, joints, fillets, fay surfaces including
apertures, surfaces, fillets, joints, and fay surfaces of aerospace
vehicles, sealed with compositions are also disclosed.
[0831] Sealant systems including an adhesion-promoting interlayer
provided by the present disclosure can be used to seal a part
including a surface of a vehicle.
[0832] The term "vehicle" is used in its broadest sense and
includes all types of aircraft, spacecraft, watercraft, and ground
vehicles. For example, a vehicle can include, aircraft such as
airplanes including private aircraft, and small, medium, or large
commercial passenger, freight, and military aircraft; helicopters,
including private, commercial, and military helicopters; aerospace
vehicles including, rockets and other spacecraft. A vehicle can
include a ground vehicle such as, for example, trailers, cars,
trucks, buses, vans, construction vehicles, golf carts,
motorcycles, bicycles, trains, and railroad cars. A vehicle can
also include watercraft such as, for example, ships, boats, and
hovercraft.
[0833] A sealant system can be used in a F/A-18 jet or related
aircraft such as the F/A-18E Super Hornet and F/A-18F; in the
Boeing 787 Dreamliner, 737, 747, 717 passenger jet aircraft, a
related aircraft (produced by Boeing Commercial Airplanes); in the
V-22 Osprey; VH-92, S-92, and related aircraft (produced by NAVAIR
and Sikorsky); in the G650, G600, G550, G500, G450, and related
aircraft (produced by Gulfstream); and in the A350, A320, A330, and
related aircraft (produced by Airbus). Compositions provided by the
present disclosure can be used in any suitable commercial,
military, or general aviation aircraft such as, for example, those
produced by Bombardier Inc. and/or Bombardier Aerospace such as the
Canadair Regional Jet (CRJ) and related aircraft; produced by
Lockheed Martin such as the F-22 Raptor, the F-35 Lightning, and
related aircraft; produced by Northrop Grumman such as the B-2
Spirit and related aircraft; produced by Pilatus Aircraft Ltd.;
produced by Eclipse Aviation Corporation; or produced by Eclipse
Aerospace (Kestrel Aircraft).
[0834] Sealant systems provided by the present disclosure can be
used to seal parts and surfaces of vehicles such as fuel tank
surfaces and other surfaces exposed to or potentially exposed to
aerospace solvents, aerospace hydraulic fluids, and aerospace
fuels.
[0835] The present invention includes parts sealed with a sealant
system provided by the present disclosure, and assemblies and
apparatus comprising a part sealed with a composition provided by
the present disclosure.
[0836] The present invention includes vehicles comprising a part
such as a surface sealed with a sealant system provided by the
present disclosure. For example, an aircraft comprising a fuel tank
or portion of a fuel tank sealed with a sealant system provided by
the present disclosure is included within the scope of the
invention.
ASPECTS OF THE INVENTION
[0837] The invention is further defined by the following
aspects.
[0838] Aspect 1. A multilayer sealant comprising: a first
sulfur-containing sealant layer, wherein the first
sulfur-containing sealant layer comprises a cross-linked first
sulfur-containing prepolymer; an adhesion-promoting interlayer
overlying the first sulfur-containing sealant layer; and a second
sulfur-containing sealant layer overlying the adhesion-promoting
interlayer, wherein the second sulfur-containing sealant layer
comprises a free radical polymerized second sulfur-containing
prepolymer, wherein the adhesion-promoting interlayer comprises a
crosslinked free radical polymerized compound.
[0839] Aspect 2. The multilayer sealant of aspect 1, wherein the
free radical polymerized compound is derived from a multifunctional
(meth)acrylate.
[0840] Aspect 3. The multilayer sealant of aspect 1, wherein the
free radical polymerized compound comprises a reaction product of:
a polythiol; and an ethylenically unsaturated free radical
polymerizable compound.
[0841] Aspect 4. The multilayer sealant of aspect 3, wherein the
ethylenically unsaturated free radical polymerizable compound
comprises a polyalkenyl, a polyalkynyl, or a combination
thereof.
[0842] Aspect 5. The multilayer sealant of any one of aspects 3 to
4, wherein the free radical polymerizable compound comprises a
monomer, an oligomer, a prepolymer, or a combination thereof.
[0843] Aspect 6. The multilayer sealant of any one of aspects 1 to
5, wherein the first sulfur-containing sealant layer comprises a
damaged and/or aged sealant layer.
[0844] Aspect 7. The multilayer sealant of aspect 6, wherein the
damaged and/or aged sealant layer is abraded.
[0845] Aspect 8. The multilayer sealant of any one of aspects 1 to
7, wherein each of the first sulfur-containing prepolymer and the
second sulfur-containing prepolymer independently comprises a
polythioether prepolymer, a polysulfide prepolymer, a
sulfur-containing polyformal prepolymer, a monosulfide prepolymer,
or a combination of any of the foregoing.
[0846] Aspect 9. The multilayer sealant of any one of aspects 1 to
7, wherein each of the first sulfur-containing sealant layer and
the second sulfur-containing sealant layer has a sulfur content
greater than 10 wt %, where wt % is based on the total weight of
the respective sealant layers.
[0847] Aspect 10. The multilayer sealant of any one of aspects 1 to
7, wherein each of the first sulfur-containing sealant layer and
the second sulfur-containing sealant independently comprises the
reaction product of reactants comprising: a sulfur-containing
prepolymer and a curing agent; the reaction product of a
thiol/thiol condensation reaction; or the reaction product of a
free radical initiated thiol/alkenyl reaction and/or thiol/alkynyl
reaction.
[0848] Aspect 11. The multilayer sealant of aspect 10, wherein the
curing agent comprises a polyepoxide, a polyalkenyl, a polyalkynyl,
a polyfunctional Michael acceptor, a polythiol, or a combination of
any of the foregoing.
[0849] Aspect 12. The multilayer sealant of any one of aspects 10
to 11, wherein the sulfur-containing prepolymer comprises a
thiol-terminated polythioether prepolymer, a thiol-terminated
polysulfide prepolymer, a thiol-terminated sulfur-containing
polyformal prepolymer, a thiol-terminated monosulfide prepolymer,
or a combination of any of the foregoing.
[0850] Aspect 13. The multilayer sealant of any one of aspects 1 to
12, wherein the adhesion-promoting interlayer comprises a
polymerized epoxy (meth)acrylate monomer, a polymerized epoxy
(meth)acrylate oligomer, a polymerized urethane (meth)acrylate
monomer such as a difunctional epoxy (meth)acrylate monomer, a
polymerized urethane (meth)acrylate oligomer such as a difunctional
epoxy (meth)acrylate oligomer, a polymerized trifunctional
(meth)acrylate monomer, a polymerized trifunctional (meth)acrylate
oligomer, or a combination of any of the foregoing.
[0851] Aspect 14. The multilayer sealant of any one of aspects 1 to
12, wherein the adhesion-promoting interlayer comprises a
polymerized bisphenol A type epoxy (meth)acrylate oligomer, such as
a polymerized difunctional bisphenol A type epoxy (meth)acrylate
oligomer.
[0852] Aspect 15. The multilayer sealant of any one of aspects 1 to
12, wherein the adhesion-promoting interlayer comprises a
polymerized urethane di(meth)acrylate monomer or a polymerized
urethane di(meth)acrylate oligomer.
[0853] Aspect 16. The multilayer sealant of any one of aspects 1 to
15, wherein the adhesion-promoting interlayer comprises a free
radical catalyzed reaction product of the adhesion-promoting
composition of any one of aspects 32 to 49.
[0854] Aspect 17. The multilayer sealant of any one of aspects 1 to
16, wherein the adhesion-promoting interlayer has a thickness from
1 .mu.m to 20 .mu.m, such as from 1 .mu.m to 10 .mu.m.
[0855] Aspect 18. The multilayer sealant of any one of aspects 1 to
17, wherein the second sulfur-containing sealant layer comprises
the free radical catalyzed reaction product of reactants
comprising: a polythiol; and a polyalkenyl and/or a
polyalkynyl.
[0856] Aspect 19. The multilayer sealant of aspect 18, wherein, the
polythiol comprises a sulfur-containing prepolymer and/or the
polyalkenyl and/or the polyalkynyl comprises a sulfur-containing
prepolymer.
[0857] Aspect 20. The multilayer sealant of aspect 18, wherein, the
polythiol comprises a monomer, an oligomer, a prepolymer, or a
combination of any of the foregoing; and the polyalkenyl and/or the
polyalkynyl independently comprises a monomer, an oligomer, a
prepolymer, or a combination of any of the foregoing.
[0858] Aspect 21. The multilayer sealant of aspect 18, wherein the
polythiol comprises a thiol-terminated polythioether
prepolymer.
[0859] Aspect 22. The multilayer sealant of aspect 18, wherein the
polythiol comprises a thiol-terminated polythioether prepolymer and
the polyalkenyl and/or a polyalkynyl comprises a monomeric
polyalkenyl and/or polyalkynyl.
[0860] Aspect 23. The multilayer sealant of any one of aspects 1 to
22, wherein the second sulfur-containing sealant layer is
transmissive to actinic radiation.
[0861] Aspect 24. The multilayer sealant of any one of aspects 1 to
23, wherein the first sulfur-containing sealant layer overlies a
substrate.
[0862] Aspect 25. The multilayer sealant of aspect 24, wherein the
substrate comprises a surface of a vehicle.
[0863] Aspect 26. The multilayer sealant of aspect 24, wherein the
substrate comprises a surface of an aerospace vehicle.
[0864] Aspect 27. The multilayer sealant of aspect 24, wherein the
substrate comprises a surface of a part.
[0865] Aspect 28. The multilayer sealant of aspect 27, wherein the
part comprises a vehicle part.
[0866] Aspect 29. The multilayer sealant of aspect 27, wherein the
part comprises an aerospace vehicle part.
[0867] Aspect 30. A vehicle comprising the multilayer sealant of
any one of aspects 1 to 29.
[0868] Aspect 31. An aerospace vehicle comprising the multilayer
sealant of any one of aspects 1 to 29.
[0869] Aspect 32. An adhesion-promoting composition, comprising: a
free radical polymerizable compound; a free radical initiator; and
a volatile organic solvent.
[0870] Aspect 33. The adhesion-promoting composition of aspect 32,
comprising:
[0871] from 10 wt % to <99.9 wt % of the free radical
polymerizable compound;
[0872] from 0.1 wt % to 20 wt % of the free radical initiator;
and
[0873] from 0 wt % to 89.9 wt % of the volatile organic
solvent,
[0874] wherein wt % is based on the total weight of the
composition.
[0875] Aspect 34. The adhesion-promoting composition of aspect 32,
comprising:
[0876] from 15 wt % to 89.8 wt % of the free radical polymerizable
compound;
[0877] from 0.2 wt % to 18 wt % of the free radical initiator;
and
[0878] from 10 wt % to 84.8 wt % of the volatile organic
solvent,
[0879] wherein wt % is based on the total weight of the
composition.
[0880] Aspect 35. The adhesion-promoting composition of aspect 32,
comprising:
[0881] from 20 wt % to 89.6 wt % of the free radical polymerizable
compound;
[0882] from 0.4 wt % to 15 wt % of the free radical initiator;
and
[0883] from 10 wt % to 79.6 wt % of the volatile organic
solvent,
[0884] wherein wt % is based on the total weight of the
composition.
[0885] Aspect 36. The adhesion-promoting composition of aspect 32,
comprising:
[0886] from 15 wt % to 45 wt % of the free radical polymerizable
compound;
[0887] from 0.2 wt % to 2 wt % of the free radical initiator;
and
[0888] from 55 wt % to 85 wt % of the volatile organic solvent,
[0889] wherein wt % is based on the total weight of the
composition.
[0890] Aspect 37. The adhesion-promoting composition of aspect 32,
comprising:
[0891] from 15 wt % to 25 wt % of the free radical polymerizable
compound;
[0892] from 0.2 wt % to 0.6 wt % of the free radical initiator;
and
[0893] from 75 wt % to 85 wt % of the volatile organic solvent,
[0894] wherein wt % is based on the total weight of the
composition.
[0895] Aspect 38. The adhesion-promoting composition of aspect 32,
comprising:
[0896] from 35 wt % to 45 wt % of the free radical polymerizable
compound;
[0897] from 0.6 wt % to 1.0 wt % of the free radical initiator;
and
[0898] from 55 wt % to 65 wt % of the volatile organic solvent,
[0899] wherein wt % is based on the total weight of the
composition.
[0900] Aspect 39. The adhesion-promoting composition of any one of
aspects 32 to 38, wherein the free radical polymerizable compound
has a reactive functionality of two or more.
[0901] Aspect 40. The adhesion-promoting composition of any one of
aspects 32 to 39, wherein the free radical polymerizable compound
comprises a multifunctional (meth)acrylate or a combination of
multifunctional (meth)acrylates.
[0902] Aspect 41. The adhesion-promoting composition of any one of
aspects 32 to 39, wherein the free radical polymerizable compound
comprises: a polythiol or a combination of polythiols; and an
ethylenically unsaturated free radical polymerizable compound or a
combination of ethylenically unsaturated free radical polymerizable
compounds.
[0903] Aspect 42. The adhesion-promoting composition of any one of
aspects 32 to 39, wherein the ethylenically unsaturated free
radical polymerizable compound or compounds comprise a polyalkenyl,
a polyalkynyl, or a combination thereof.
[0904] Aspect 43. The adhesion-promoting composition of any one of
aspects 32 to 42, wherein the free radical polymerizable compound
comprises a monomer, an oligomer, a prepolymer, or a combination
thereof.
[0905] Aspect 44. The adhesion-promoting composition of any one of
aspects 32 to 43, wherein the free radical polymerizable compound
has a molecular weight of at least 150 Da.
[0906] Aspect 45. The adhesion-promoting composition of any one of
aspects 32 to 44, wherein the free radical initiator comprises a
radiation activated free radical initiator, a thermally activated
free radical initiator, a chemically-activated free radical
initiator, or a combination of any of the foregoing.
[0907] Aspect 46. The adhesion-promoting composition of any one of
aspects 32 to 44, wherein the free radical initiator is one or more
free radical photoinitiators.
[0908] Aspect 47. The adhesion-promoting composition of any one of
aspects 32 to 46, wherein the volatile organic solvent has a vapor
pressure greater than 10 mm Hg at 25.degree. C.
[0909] Aspect 48. The adhesion-promoting composition of any one of
aspects 32 to 47, wherein the composition comprises a colorant.
[0910] Aspect 49. The adhesion-promoting composition of any one of
aspects 32 to 48, wherein the adhesion-promoting composition
consists of: the free radical polymerizable compound; the free
radical initiator; and the volatile organic solvent or the free
radical polymerizable compound; the free radical initiator; the
volatile organic solvent, and a colorant.
[0911] Aspect 50. A method of sealing a surface, comprising:
applying the adhesion-promoting composition of any one of aspects
32 to 49 to a sulfur-containing sealant layer; drying the applied
adhesion-promoting composition; applying a free radical
polymerizable sulfur-containing sealant composition to the dried
adhesion-promoting composition; and initiating free radical
polymerization of the sulfur-containing sealant composition to cure
the sulfur-containing sealant composition, and thereby seal the
surface.
[0912] Aspect 51. The method of aspect 50, wherein initiating free
radical polymerization further comprises initiating free radical
polymerization of the dried adhesion-promoting composition, such as
exposing the dried adhesion-promoting composition to actinic
radiation.
[0913] Aspect 52. The method of aspect 50, wherein initiating free
radical polymerization comprises exposing the applied free radical
polymerizable sulfur-containing sealant composition and the dried
adhesion-promoting composition to actinic radiation.
[0914] Aspect 53. The method of any one of aspects 50 to 52,
further comprising, after drying the adhesion-promoting
composition, initiating free radical polymerization of the dried
adhesion-promoting composition to provide an at least partially
cured adhesion-promoting composition; and applying the free radical
polymerizable sulfur-containing sealant composition comprises
applying to the at least partially cured adhesion-promoting
composition.
[0915] Aspect 54. The method of any one of aspects 50 to 53,
wherein applying the adhesion-promoting composition comprises
applying a layer of the adhesion-promoting composition that, when
dried, has a thickness from 1 .mu.m to 20 .mu.m, such as from 1
.mu.m to 10 .mu.m.
[0916] Aspect 55. The method of any one of aspects 50 to 54,
wherein applying the adhesion-promoting composition comprises
wiping, spraying, or brushing the adhesion-promoting composition
onto the sulfur-containing sealant layer.
[0917] Aspect 56. The method of any one of aspects 50 to 55,
wherein the sulfur-containing sealant composition comprises a
polythiol and a polyalkenyl and/or a polyalkynyl.
[0918] Aspect 57. The method of claim 56, wherein the polythiol
comprises a thiol-terminated polythioether prepolymer.
[0919] Aspect 58. The method of any one of aspects 50 to 57,
further comprising, before applying the adhesion-promoting
composition, applying a first sulfur-containing sealant composition
to a substrate to provide the first sulfur-containing sealant
layer.
[0920] Aspect 59. The method of any one of aspects 50 to 58,
further comprising, before applying the adhesion-promoting
composition, cleaning the surface of a sulfur-containing sealant
layer with a volatile organic solvent.
[0921] Aspect 60. The method of claim 59, further comprising,
before cleaning the surface, abrading the surface of the first
sulfur-containing sealant layer.
[0922] Aspect 61. The method of any one of aspects 50 to 60,
wherein sealing a surface comprises repairing a sealed surface.
[0923] Aspect 62. The method of any one of aspects 50 to 51,
wherein the first sulfur-containing sealant layer comprises an
incumbent sulfur-containing sealant layer.
[0924] Aspect 63. The method of aspect 62, wherein the incumbent
sulfur-containing sealant layer comprises a damaged and/or aged
sulfur-containing sealant layer.
[0925] Aspect 64. The method of aspect 63, wherein the method
comprises repairing the damaged and/or aged sulfur-containing
sealant layer.
[0926] Aspect 65. The method of any one of aspects 63 to 64,
wherein the incumbent sulfur-containing sealant layer comprises the
reaction product of reactants comprising: a thiol-terminated
sulfur-containing prepolymer; and a curing agent.
[0927] Aspect 66. The method of aspect 65, wherein the
thiol-terminated sulfur-containing prepolymer comprises a
thiol-terminated polythioether, a thiol-terminated polysulfide, a
thiol-terminated sulfur-containing polyformal, a thiol-terminated
monosulfide, or a combination of any of the foregoing.
[0928] Aspect 67. The method of any one of aspects 65, 60, 66,
wherein the curing agent comprises a polyepoxide, a polyalkenyl, a
polyalkynyl, a polyfunctional Michael acceptor, a polythiol, or a
combination of any of the foregoing.
[0929] Aspect 68. The method of any one of aspects 50 to 67,
wherein the sulfur-containing sealant layer comprises the
condensation reaction products of a thiol-terminated
sulfur-containing prepolymer.
[0930] Aspect 69. The method of any one of aspects 50 to 68,
wherein the sulfur-containing sealant layer comprises the free
radical polymerization product of a polythiol and a polyalkenyl
and/or polyalkynyl.
[0931] Aspect 70. The method of aspect 69, wherein the polythiol
comprises a thiol-terminated sulfur-containing prepolymer.
[0932] Aspect 71. The method of any one of aspects 69 to 70,
wherein, the polythiol comprises a sulfur-containing prepolymer;
and/or the polyalkenyl and/or the polyalkynyl comprises a
sulfur-containing prepolymer.
[0933] Aspect 72. The method of aspect 71, wherein, the polythiol
comprises a monomer, an oligomer, a prepolymer, or a combination of
any of the foregoing; and a polyalkenyl and/or the polyalkynyl
independently comprises a monomer, an oligomer, a prepolymer, or a
combination of any of the foregoing.
[0934] Aspect 73. The method of any one of aspects 50 to 72,
wherein each of the sulfur-containing sealant layer and the
sulfur-containing sealant composition independently have a
sulfur-content greater than 10 wt %, wherein wt % is based on the
total weight of the sulfur-containing sealant layer or the
sulfur-containing sealant composition, respectively.
[0935] Aspect 74. The method of any one of aspects 50 to 73,
wherein the sulfur-containing sealant layer overlies a
substrate.
[0936] Aspect 75. The method of aspect 74, wherein the substrate
comprises a surface of a vehicle.
[0937] Aspect 76. The method of aspect 74, wherein the substrate
comprises a surface of an aerospace vehicle.
[0938] Aspect 77. The method of aspect 74, wherein the substrate
comprises a surface of a part.
[0939] Aspect 78. The method of aspect 77, wherein the part
comprises a vehicle part.
[0940] Aspect 79. The method of aspect 77, wherein the part
comprises an aerospace vehicle part.
[0941] Aspect 80. A vehicle comprising a surface sealed using the
method of any one of aspects 50 to 79.
[0942] Aspect 81. An aerospace vehicle comprising a surface sealed
using the method of any one of aspects 50 to 79.
[0943] Aspect 82. A damaged and/or aged sulfur-containing sealant
layer repaired using the method of any one of aspects 50 to 79.
[0944] Aspect 83. A vehicle comprising the repaired
sulfur-containing sealant layer of aspect 82.
[0945] Aspect 84. An aerospace vehicle comprising the repaired
sulfur-containing sealant layer of aspect 82.
[0946] Aspect 85. A sealant repair kit comprising: a container
comprising an adhesion-promoting composition of claim 1; and a
container comprising a free radical polymerizable sulfur-containing
sealant composition.
[0947] Aspect 86. The sealant repair kit of aspect 85, further
comprising an abrasion pad, a cleaning solvent, an applicator for
the adhesion-promoting composition, an applicator for the free
radical polymerizable sulfur-containing sealant composition, a
source for initiating a free radical reaction, or a combination of
any of the foregoing.
[0948] Aspect 87. Use of the adhesion promoting composition of any
one of claims 32 to 49 to promote adhesion between a first
sulfur-containing sealant layer and a second sulfur-containing
sealant layer, wherein, the first sulfur-containing sealant layer
comprises a cross-linked first sulfur-containing prepolymer; and
wherein the second sulfur-containing sealant layer comprises a free
radical polymerized second sulfur-containing prepolymer.
[0949] Aspect 88. The use of aspect 87, wherein the
adhesion-promoting composition comprises a crosslinked free radical
polymerized compound.
[0950] Aspect 89. The use of aspect 88, wherein the free radical
polymerized compound is derived from a multifunctional
(meth)acrylate.
[0951] Aspect 90. The use of aspect 88, wherein the free radical
polymerized compound comprises the reaction product of: a
polythiol; and an ethylenically unsaturated free radical
polymerizable compound.
[0952] Aspect 91. The use of aspect 90, wherein the ethylenically
unsaturated free radical polymerizable compound comprises a
polyalkenyl, a polyalkynyl, or a combination thereof.
[0953] Aspect 92. The use of aspect 88, wherein the free radical
polymerizable compound comprises a monomer, an oligomer, or a
combination thereof.
[0954] Aspect 93. The use of any one of aspects 87 to 92, wherein
the adhesion-promoting composition further comprises a free radical
initiator.
[0955] Aspect 94. The use of aspect 93, wherein the free radical
initiator comprises a radiation-activated free radical initiator, a
thermally activated free radical initiator, a chemically-activated
free radical initiator, or a combination of any of the
foregoing.
[0956] Aspect 95. The use of any one of aspects 87 to 94, wherein
the first sulfur-containing sealant layer comprises a damaged
and/or aged sealant layer.
[0957] Aspect 96. The use of aspect 95, wherein the damaged and/or
aged sealant layer is abraded.
[0958] Aspect 97. The use of any one of aspects 87 to 96, wherein
each of the first sulfur-containing prepolymer and the second
sulfur-containing prepolymer independently comprises a
polythioether prepolymer, a polysulfide prepolymer, a
sulfur-containing polyformal prepolymer, a monosulfide prepolymer,
or a combination of any of the foregoing.
[0959] Aspect 98. The use of any one of aspects 87 to 97, wherein
each of the first sulfur-containing sealant layer and the second
sulfur-containing sealant layer has a sulfur content greater than
10 wt %, where wt % is based on the total weight of the respective
sealant layers.
[0960] Aspect 99. The use of any one of aspects 87 to 97, wherein
each of the first sulfur-containing sealant layer and the second
sulfur-containing sealant independently comprises the reaction
product of reactants comprising a sulfur-containing prepolymer and
a curing agent; the reaction product of a thiol/thiol condensation
reaction; or the reaction product of a free radical initiated
thiol/alkenyl reaction and/or thiol/alkynyl reaction.
[0961] Aspect 100. The use of aspect 99, wherein the curing agent
comprises a polyepoxide, a polyalkenyl, a polyalkynyl, a
polyfunctional Michael acceptor, a polythiol, or a combination of
any of the foregoing.
[0962] Aspect 101. The use of any one of aspects 99 to 100, wherein
the sulfur-containing prepolymer comprises a thiol-terminated
polythioether prepolymer, a thiol-terminated polysulfide
prepolymer, a thiol-terminated sulfur-containing polyformal
prepolymer, a thiol-terminated monosulfide prepolymer, or a
combination of any of the foregoing.
[0963] Aspect 102. The use of any one of aspects 87 to 101, wherein
the adhesion-promoting composition comprises a polymerized epoxy
(meth)acrylate monomer such as a difunctional epoxy (meth)acrylate
monomer, a polymerized epoxy (meth)acrylate oligomer, such as a
difunctional epoxy (meth)acrylate oligomer, a polymerized urethane
(meth)acrylate monomer, a polymerized urethane (meth)acrylate
oligomer, a polymerized trifunctional (meth)acrylate monomer, a
polymerized trifunctional (meth)acrylate oligomer, or a combination
of any of the foregoing.
[0964] Aspect 103. The use of any one of aspects 87 to 101, wherein
the adhesion-promoting composition comprises a polymerized
bisphenol A type epoxy (meth)acrylate oligomer, such as a
polymerized difunctional bisphenol A type epoxy (meth)acrylate
oligomer.
[0965] Aspect 104. The use of any one of aspects 87 to 101, wherein
the adhesion-promoting composition comprises a polymerized urethane
di(meth)acrylate monomer or a polymerized urethane di(meth)acrylate
oligomer.
[0966] Aspect 105. The use of any one of aspects 87 to 101, wherein
the adhesion-promoting composition comprises a free radical
catalyzed reaction product of the adhesion-promoting composition of
any one of claims 32 to 49.
[0967] Aspect 106. The use of any one of aspects 87 to 105, wherein
the adhesion-promoting composition has a thickness from 1 .mu.m to
20 .mu.m, such as from 1 .mu.m to 10 .mu.m.
[0968] Aspect 107. The use of any one of aspects 87 to 106, wherein
the second sulfur-containing sealant layer comprises the free
radical catalyzed reaction product of reactants comprising: a
polythiol; and a polyalkenyl and/or a polyalkynyl.
[0969] Aspect 108. The use of any one of aspects 87 to 107, wherein
the polythiol comprises a sulfur-containing prepolymer and/or the
polyalkenyl and/or the polyalkynyl comprises a sulfur-containing
prepolymer.
[0970] Aspect 109. The use of any one of aspects 87 to 107,
wherein, the polythiol comprises a monomer, an oligomer, a
prepolymer, or a combination of any of the foregoing; and the
polyalkenyl and/or the polyalkynyl independently comprises a
monomer, an oligomer, a prepolymer, or a combination of any of the
foregoing.
[0971] Aspect 110. The use of any one of aspects 87 to 107, wherein
the polythiol comprises a thiol-terminated polythioether
prepolymer.
[0972] Aspect 111. The use of any one of aspects 87 to 107, wherein
the polythiol comprises a thiol-terminated polythioether prepolymer
and the polyalkenyl and/or a polyalkynyl comprises a monomeric
polyalkenyl and/or polyalkynyl.
[0973] Aspect 112. The use of any one of aspects 87 to 111, wherein
the second sulfur-containing sealant layer is transmissive to
actinic radiation.
[0974] Aspect 113. The use of any one of aspects 87 to 112, wherein
the first sulfur-containing sealant layer overlies a substrate.
[0975] Aspect 114. The use of claim 113, wherein the substrate
comprises a surface of a vehicle.
[0976] Aspect 115. The use of aspect 113, wherein the substrate
comprises a surface of an aerospace vehicle.
[0977] Aspect 116. The use of aspect 113, wherein the substrate
comprises a surface of a part.
[0978] Aspect 117. The use of aspect 116, wherein the part
comprises a vehicle part.
[0979] Aspect 118. The use of aspect 116, wherein the part
comprises an aerospace vehicle part.
EXAMPLES
[0980] Embodiments provided by the present disclosure are further
illustrated by reference to the following examples, which describe
the compositions provided by the present disclosure and uses of
such compositions. It will be apparent to those skilled in the art
that many modifications, both to materials, and methods, may be
practiced without departing from the scope of the disclosure.
Example 1
Bisphenol A-Based Epoxy Acrylate Adhesion-Promoting Interlayer
[0981] The ability of an adhesion-promoting interlayer was tested
on a variety of sulfur-containing sealants. The experiments were
carried out according to AMS draft specification G9-16AA.
[0982] Test panels were prepared and tested according to AS5127/1
(8.2).
[0983] AMS4045 aluminum alloy panels measuring 0.025 to
0.040.times.2.75.times.6 inches (0.64 to 1.02.times.69.8.times.152
mm) were anodized with sulfuric acid according to AS5127 (6.3) and
overcoated with AMS-C-22725 (see 8.5).
[0984] At least two test panels were used to qualify the adhesion
system to AMS3277 and to AMS3276.
[0985] PR2001 and PR1828 were selected from the AMS3277 qualified
product list and PR1750 was selected for testing from the AMS3276
product list.
[0986] AS5127/1 also requires that the sealant adhere to
itself.
[0987] PR1776 and PR2007 are not required to be tested for G9-16AA
qualification but were included to evaluate the robustness of the
adhesion-promoting interlayer to enhance adhesion between a variety
of different sulfur-containing sealant compositions.
[0988] A summary of the sulfur-containing sealants used is provided
in Table 1.
TABLE-US-00001 TABLE 1 Composition of sulfur-containing sealants.
Thiol-terminated Curing Sealant.sup.1 Description Prepolymer Agent
PR-2001 Class B rapid curing fuel polythioether polyepoxide tank
sealant PR-1828 Class B rapid curing fuel polythioether polyepoxide
tank sealant UV SCOD Class B UV-cured fuel polythioether
polyalkenyl tank sealant PR-1750 Class B fuel tank sealant
polysulfide MnO.sub.2 cured PR-1776 Class B, high temperature
polysulfide MnO.sub.2 cured fuel tank sealant PR-2007 Class B light
weight polysulfide MnO.sub.2 cured (SG 1.1) fuel tank sealant
.sup.1All sealants except for UV SCOD are commercially available
from PPG Aerospace.
[0989] A 0.25 in-thick (6.4 mm-thick) layer of each
sulfur-containing sealant was applied to the test panels and fully
cured according to specification. For each sealant, one set of test
panels was evaluated after standard curing (dry) and another set of
test panels was evaluated after standard curing (dry) and
conditioning by immersing the sealant-containing test panels in JRF
Type I for 3 days at 140.degree. F. (60.degree. C.); followed by 3
days in dry air at 120.degree. F. (49.degree. C.); and followed by
7 days thermal aging at 250.degree. F. (121.degree. C.)
(conditioned).
[0990] The as-cured or conditioned sealants were abraded with a
Scotch-Brite.TM. 7447 pad (available from 3M) and then wiped with
methyl ethyl ketone before applying an overlying layer of the
UV-curable sealant.
[0991] An adhesion-promoting composition was applied to the abraded
and solvent cleaned sealants with a gauze pad. The constituents of
the adhesion-promoting composition are provided in Table 2.
TABLE-US-00002 TABLE 2 Adhesion-promoting composition. Content
Product Material (wt %) Sartomer .RTM. CN110.sup.1 difunctional
bisphenol A-based 40.0 epoxy acrylate oligomer Irgacure .RTM.
TPO.sup.2 diphenyl(2,4,6- 0.8 trimethylbenzoyl)phosphine oxide
Acetone solvent 59.2 .sup.1Sartomer .RTM. CN-110,
4,4`-isopropylidenediphenol, oligomeric reaction products with
1-chloro-2,3-epoxy propane, ester with acrylic acid, available from
Arkema. .sup.2Irgacure .RTM. TPO,
diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, available from
Ciba.
[0992] After drying for 10 min at 25.degree. C./50% RH, the
thickness of the adhesion-promoting layer was about 3 .mu.m. A UV
SCOD sealant was then applied over the adhesion-promoting layer to
a thickness of 0.125 in (3.175 mm). A pre-primed peel medium, for
example, a 30-mesh stainless steel screen, was placed on top of the
UV SCOD sealant, before an overcoat of the UV SCOD sealant was
applied with a thickness of 0.03 in (0.762 mm). The UV SCOD sealant
and adhesion-promoting interlayer were exposed to UV at 395 nm (LED
source) for 2 min at 0.26 W/cm.sup.2 using an OmniCure.RTM. AC475
8W UV LED lamp (Excelitas Technologies). The adhesion of the cured
sealant system was evaluated within 24 hours.
[0993] The peel strength (pli) and percentage cohesive failure (%
cf) for the different sealant systems is provided in Table 3.
Specification G9-16AA requires the peel strength to be at least 10
pli (113 N-cm) and 100% cohesive strength.
TABLE-US-00003 TABLE 3 Adhesion test results. PR-2001 PR-1828 UV
SCOD PR-1750 PR-1776 PR-2007 pli, % cf.sup.5 pli, % cf pli, % cf
pli, % cf pli, % cf pli, % cf Dry.sup.1 BI.sup.3 - 18 h.sup.6 .sup.
56, 100.sup.6 48, 100 37, 100 51, 100 55, 100.sup.1 .sup. 34,
100.sup.1 AI.sup.4 48, 100 37, 100 43, 100 .sup. 47, 100.sup.1 47,
100.sup.1 37, 100 BI - 1 h 60, 100 53, 100 48, 100 34, 100 -- -- BI
- 2 h 78, 100 56, 100 56, 100 73, 100 -- -- BI - 3 h 77, 100 41,
100 40, 100 55, 100 -- -- Conditioned.sup.2 BI - 18 h 41, 100 30,
100 28, 100 .sup. 28, 100.sup.2 -- -- AI 27, 100 .sup. 23,
100.sup.1 38, 100 35, 100 -- -- BI - 1 h 28, 100 20, 100 32, 100
.sup. 34, 100.sup.2 -- 31, 100 BI - 2 h 28, 100 22, 100 26, 100 --
-- 36, 100 BI - 3 h 35, 100 31, 100 23, 100 -- -- 30, 100 AI -- --
-- 48, 100 -- -- .sup.1Dry: Sealant panels did not undergo
conditioning. .sup.2Conditioned: Sealant panels went through
conditioning cycle (140.degree. F. (60.degree. C.) 3 d in JRF Type
I followed by 3 d air dry at 120.degree. F. (49.degree. C.) and 7 d
heat aging under 250.degree. F. (121.degree. C.). .sup.3BI: Before
Immersion. .sup.4AI: After JRF Type I immersion for 7 days at
140.degree. F. (60.degree. C.). .sup.5Peel strength (pli), %
cohesive failure. .sup.6Peel strength measured up to 18 h after
curing; time indicates time measurement was made after UV cure.
Example 2
Bisphenol A-Based Epoxy Acrylate Adhesion-Promoting Interlayer
[0994] A test panel was prepared using the PR1750 sealant as in
Example 1.
[0995] The adhesion-promoting composition described in Example 1
was applied to the PR1750 test panel as described in Example 1, and
following application, the adhesion-promoting composition was
exposed to UV radiation for 30 sec under the conditions described
in Example 1 to fully cure the adhesion-promoting composition.
[0996] A UV SCOD sealant was applied to the cured
adhesion-promoting interlayer and cured as described in Example 1.
The peel strength and % cohesive failure were determined as
described in Example 1. The results are presented in Table 4.
TABLE-US-00004 TABLE 4 Adhesion-promoting composition. Sealant Peel
Test Formula Application (dry) (17 h) 20 wt % Sartomer .RTM. CN110
Precured adhesion- PR-1750 80.3 pli, 0.4 wt % Irgacure .RTM. TPO
promoting interlayer 100% CF 79.6 wt % acetone
Example 3
Urethane Dimethacrylate Adhesion-Promoting Interlayer
[0997] Adhesion testing was performed as described in Example 1
except that the difunctional bisphenol A-based epoxy acrylate
oligomer was replaced with a urethane dimethacrylate (UDMA;
R'CH.sub.2[C(CH.sub.3)(R)CH.sub.2].sub.2CH.sub.2R', R is H or
CH.sub.3, R' is
NHCO.sub.2CH.sub.2CH.sub.2O.sub.2CC(CH.sub.3).dbd.CH.sub.2). The
adhesion was evaluated within 24 h of peel specimen preparation on
dry sealant substrates including UV SCOD, PR2001, PR1828 and
PR1750. The results are presented in Table 5.
TABLE-US-00005 TABLE 5 Adhesion test results. Peel strength %
cohesive Sealant (pli) failure UV SCOD 35 100 PR2001 55 100 PR1828
61 100 PR1750 38 100
Example 4
Bisphenol A-Based Epoxy Acrylate Adhesion-Promoting Interlayer
[0998] A bisphenol A-based epoxy acrylate adhesion-promoting
composition was prepared having the constituents indicated in Table
6.
TABLE-US-00006 TABLE 6 Adhesion-promoting composition. Content
Product Material (wt %) Sartomer .RTM. CN110 difunctional bisphenol
A-based 40.00 epoxy acrylate oligomer KeyPlast .RTM. Blue A.sup.1
blue dye 0.05 Irgacure .RTM. TPO dipheny1(2,4,6- 0.80
trimethylbenzoyl)phosphine oxide Acetone solvent 59.15
.sup.1KeyPlast .RTM. Blue A, anthraquinone-based pigment available
from Milliken Chemical.
[0999] Test panels were prepared as in Example 1, with the addition
that the adhesion-promoting composition was applied with a
Scotch-Brite.TM. 7447 pad. After applying the adhesion-promoting
composition and the overlying UV SCOD sealant, both layers were
simultaneously cured using the UV exposure conditions of Example
1.
[1000] The peel strength and % cohesive failure for the dry test
panels determined as described in Example 1 are presented in Table
7.
TABLE-US-00007 TABLE 7 Dry peel strength and % cohesive failure.
PR-2001 PR-1828 UV SCOD PR-1750 (pli, % cf) (pli, % cf) (pli, % cf)
(phi, % cf) BI-15 min 36, 100 37, 100 35, 100 36, 95 BI-1 h 38, 100
45, 100 40, 100 39, 95 BI-4 h 31, 100 39, 100 39, 100 33, 100 BI-24
h 45, 100 34, 100 34, 100 46, 100 AI 47, 100 23, 100 50, 100 47,
100
Example 5
Bisphenol A-Based Epoxy Acrylate Adhesion-Promoting Interlayer
[1001] A bisphenol A-based epoxy acrylate adhesion-promoting
composition was prepared having the constituents indicated in Table
8.
TABLE-US-00008 TABLE 8 Adhesive-promoting composition. Content
Product Material (wt %) Sartomer .RTM. CN110 difunctional bisphenol
A-based 20.0 epoxy acrylate oligomer Irgacure@ TPO diphenyl(2,4,6-
0.4 trimethylbenzoyl)phosphine oxide Acetone solvent 79.6
[1002] Test panels were prepared as in Example 1, except that the
adhesion-promoting composition was applied by spraying the sealant
twice using a Preval.RTM. Sprayer. The adhesion-promoting
composition was left to dry for 1 min between spray applications.
After spraying for the second time, the adhesion-promoting
composition was allowed to dry for 30 min and then irradiated with
UV from 30 sec as described in Example 1.
[1003] After the adhesion-promoting composition was fully cured, a
UV SCOD sealant was applied to the cured adhesion-promoting
interlayer and exposed to UV for 2 min as described in Example
1.
[1004] The peel strength and % cohesive failure for dry and
conditioned test panels determined as described in Example 1 are
presented in Table 9.
TABLE-US-00009 TABLE 9 Dry peel strength and % cohesive failure.
PR2001 PR1828 UV SCOD PR1776M PR2001 PR1828 UV SCOD Dry.sup.1 (pli,
% cf) Conditioned.sup.2 (pli, % cf) BI - 17 h 36, 100 40, 100 35,
100 54, 100 26, 100 31, 100 29, 100
Example 6
Bisphenol A-Based Epoxy Acrylate Adhesion-Promoting Interlayer
[1005] A bisphenol A-based epoxy acrylate adhesion-promoting
composition was prepared having the constituents indicated in Table
10.
TABLE-US-00010 TABLE 10 Adhesion-promoting composition. Content
Product Material (wt %) Sartomer .RTM. CN110 difunctional bisphenol
A- 20.0 based epoxy acrylate oligomer Irgacure .RTM. TPO
diphenyl(2,4,6- 0.4 trimethylbenzoyl)phosphine oxide Acetone
solvent 79.6
[1006] Test panels were prepared as in Example 1, except that the
adhesion-promoting composition was applied by spraying the
underlying sealant once using a Preval.RTM. Sprayer. The
adhesion-promoting composition was allowed to dry for 30 min and
then irradiated with UV for 30 sec as described in Example 1.
[1007] After the adhesion-promoting composition was fully cured, a
UV SCOD sealant was applied to the cured adhesion-promoting
interlayer and exposed to UV for 2 min as described in Example
1.
[1008] The peel strength and % cohesive failure for dry and
conditioned test panels determined as described in Example 1 are
presented in Table 11.
TABLE-US-00011 TABLE 11 Dry peel strength and % cohesive failure.
PR2007 P/S870 PR1782 PR1772 UV SCOD ph, % cf phi, % cf phi, % cf
phi, % cf phi, % cf BI-2 h 32, 100 41, 100 41, 100 36, 100 36, 100
BI-24 h 29, 100 38, 100 45, 100 33, 100 33, 100
Example 7
Comparative Examples
[1009] The adhesion of an underlying sulfur-containing sealant
layer to an overlying UV SCOD sulfur-containing sealant was
evaluated using different adhesion-promoting interlayers.
[1010] The test panels were prepared and evaluated according the
Example 1.
[1011] The content of the various adhesion-promoting interlayer
compositions evaluated is provided in Table 12. In Comparative Test
Panels 1-8 the adhesion-promoting compositions were applied using a
gauze pad and allowed to dry, the sulfur-containing sealant applied
using a brush and fully cured, before applying an overlying UV SCOD
sealant, which was UV cured. Test panel 9 was prepared as for Test
Panels 1-8, however, both the adhesion promoting interlayer and the
UV SCOD sealant were simultaneously cured using UV. For Comparative
Test Panels 10-11, the adhesion-promoting composition was cured by
exposure to UV, after which the MnO-cured polysulfide sealant
(PR-1750) was applied and fully cured, before applying an overlying
layer of the UV SCOD sealant, which was cured by exposure to UV.
All test panels were evaluated as-prepared (dry conditions) except
that in Comparative Example 6, test panels with PR-1782 were tested
following conditioning as described in Example 1.
TABLE-US-00012 TABLE 12 Multilayer sealants, cure conditions, and
adhesion results. UV Cure Adhesion-Promoting Adhesion-promoting
Sulfur-containing Interlayer Composition Interlayer Sealant.sup.9
Adhesion.sup.10 1 PR-188.sup.1 No.sup.6 PR-2001 100% AF 2
PR-142.sup.1 No.sup.6 PR-2001 100% AF 3 PR-148 clear.sup.1 No.sup.6
PR-2001 100% AF 4 PR-1826.sup.1 No.sup.6 PR-2001 100% AF 5
PR-187.sup.1 No.sup.6 PR-2001 100% AF 6 5 wt % Laromer .RTM.
PR-9000.sup.2 No.sup.6 PR-2001, PR-1776M, 100% AF in isopropanol
PR-1750, PR-1828 (dry and conditioned), PR-1782 7 1 wt % Laromer
.RTM. PR9000.sup.2 No.sup.6 PR-2001, PR-1776M, 100% AF in
isopropanol PR-1750 8 1 wt % Laromer .RTM. PR9000.sup.2 No.sup.6
PR-2001, PR-1776M 100% AF with 0.001% dibutyltin PR-1750 dilaurate
in isopropanol 9 10 wt % Sartomer .RTM. CN-110.sup.3
Simultaneous.sup.7 PR-2001, PR-1776M, 100% AF 0.2 wt % Irgacure
.RTM. 651/89.sup.4 PR-1750, UV SCOD 89.8 wt % methyl ethyl ketone
10 10 wt % Sartomer .RTM. CN-110.sup.3 Precured adhesion PR-1750 48
pli, 0.2 wt % Irgacure .RTM. TPO4 promoter.sup.8 45% CF.sup.9 89.8
wt % acetone 11 5 wt % Sartomer .RTM. CN-110.sup.3 precured
adhesion PR-1750 39 pli, 0.1 wt % Irgacure .RTM. TPO.sup.4
promoters 80% CF 94.9 wt% acetone .sup.1Commercially available
sealants from PPG Aerospace containing solvents and
organo-functional organosilanes. .sup.2Laromer .RTM. PR9000,
isocyanate-functional aliphatic acrylic ester available from BASF.
These adhesion promoting compositions did not include a
photoinitator. .sup.3Sartomer .RTM. CN-110, difunctional bisphenol
A-based epoxy acrylate oligomer available from Sartomer.
.sup.4Irgacure .RTM. 651, 2,2-dimethoxy-1,2-diphenylethan-1-one,
Ciba Specialty Chemicals. .sup.5Irgacure .RTM. TPO,
diphenyl(2,4,6-trimehtylbenzoyl)phosphine oxide, Ciba Specialty
Chemicals. .sup.6The adhesion-promoting compositions did not
include a photoinitiator and therefore were not directly UV-cured.
.sup.7Sealant and adhesion-promoting interlayer cured
simultaneously. .sup.8Adhesion-promoting interlayer cured, sealant
applied over cured interlayer, and applied sealant cured. .sup.9See
Example 1 for description of sealants. .sup.10Dry measurement
unless noted; 24 h peel data: AF 100% adhesive failure; CF cohesive
failure; pli/% cohesive failure.
[1012] Finally, it should be noted that there are alternative ways
of implementing the embodiments disclosed herein. Accordingly, the
present embodiments are to be considered as illustrative and not
restrictive. Furthermore, the claims are not to be limited to the
details given herein and are entitled to their full scope and
equivalents thereof.
* * * * *