U.S. patent application number 13/785415 was filed with the patent office on 2014-09-11 for curable solid particulate compositions.
This patent application is currently assigned to PPG INDUSTRIES OHIO, INC.. The applicant listed for this patent is PPG INDUSTRIES OHIO, INC.. Invention is credited to Anthony M. Chasser, Simion Coca, Susan F. Donaldson.
Application Number | 20140256874 13/785415 |
Document ID | / |
Family ID | 50391373 |
Filed Date | 2014-09-11 |
United States Patent
Application |
20140256874 |
Kind Code |
A1 |
Chasser; Anthony M. ; et
al. |
September 11, 2014 |
CURABLE SOLID PARTICULATE COMPOSITIONS
Abstract
The present invention relates to curable solid particulate
compositions that include: (a) a first reactant having at least two
cyclic carbonate groups; and (b) a second reactant having at least
two active hydrogen groups that are reactive with the cyclic
carbonate groups of the first reactant. With some embodiments, the
first reactant is a polyol residue having at least two cyclic
carbonate groups, such as bisphenol A that has been reacted with
epichlorohydrin, and in which the oxirane groups thereof have been
converted to cyclic carbonate groups. The active hydrogen groups of
the second reactant, with some embodiments, are each independently
selected from hydroxyl groups, thiol groups, and amine groups. The
curable solid particulate compositions, with some embodiments, are
in the form of curable powder coating compositions.
Inventors: |
Chasser; Anthony M.;
(Allison Park, PA) ; Donaldson; Susan F.; (Allison
Park, PA) ; Coca; Simion; (Pittsburgh, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PPG INDUSTRIES OHIO, INC. |
Cleveland |
OH |
US |
|
|
Assignee: |
PPG INDUSTRIES OHIO, INC.
Cleveland
OH
|
Family ID: |
50391373 |
Appl. No.: |
13/785415 |
Filed: |
March 5, 2013 |
Current U.S.
Class: |
524/612 |
Current CPC
Class: |
C09D 169/005 20130101;
C09D 5/03 20130101; C08G 64/1608 20130101; C09D 169/00 20130101;
C09D 175/04 20130101; C08G 2150/20 20130101 |
Class at
Publication: |
524/612 |
International
Class: |
C09D 169/00 20060101
C09D169/00 |
Claims
1. A curable solid particulate composition comprising: (a) a first
reactant having at least two cyclic carbonate groups; and (b) a
second reactant having at least two active hydrogen groups that are
reactive with the cyclic carbonate groups of said first
reactant.
2. The curable solid particulate composition of claim 1, wherein
said first reactant is selected from, polyol residues having at
least two cyclic carbonate groups, isocyanurates having at least
two cyclic carbonate groups, polyesters having at least two cyclic
carbonate groups, polyethers having at least two cyclic carbonate
groups, polyurethanes having at least two cyclic carbonate groups,
polymers prepared by free radical polymerization having at least
two cyclic carbonate groups, polymers prepared by controlled
radical polymerization having at least two cyclic carbonate groups,
and combinations of two or more thereof.
3. The curable solid particulate composition of claim 2, wherein
polyol residues having at least two cyclic carbonate groups are
each independently formed from a polyol residue having at least two
oxirane groups that have been converted to cyclic carbonate
groups.
4. The curable solid particulate composition of claim 3, wherein
said polyol residue is a residue of a polyol selected from
glycerin, trimethylolpropane, trimethylolethane,
trishydroxyethylisocyanurate, pentaerythritol, ethylene glycol,
propylene glycol, trimethylene glycol, butanediol, heptanediol,
hexanediol, octanediol, 4,4'-(propane-2,2-diyl)dicyclohexanol,
4,4'-methylenedicyclohexanol, neopentyl glycol,
2,2,3-trimethylpentane-1,3-diol, 1,4-dimethylolcyclohexane,
2,2,4-trimethylpentane diol, 4,4'-(propane-2,2-diyl)diphenol,
4,4'-methylenediphenol, and combinations thereof.
5. The curable solid particulate composition of claim 4, wherein
said polyol is selected from 4,4'-(propane-2,2-diyl)diphenol,
4,4'-(propane-2,2-diyl)dicyclohexanol, 4,4'-methylenediphenol,
4,4'-methylenedicyclohexanol, and combinations thereof.
6. The curable solid particulate composition of claim 2, wherein
isocyanurates having at least two cyclic carbonate groups are each
independently formed from an isocyanurate having at least two
oxirane groups that have been converted to cyclic carbonate
groups.
7. The curable solid particulate composition of claim 6, wherein
said isocyanurate having at least two oxirane groups is
tris(2,3-epoxypropyl)isocyanurate.
8. The curable solid particulate composition of claim 2, wherein,
polyesters having at least two cyclic carbonate groups are each
individually formed from a polyester having at least two oxirane
groups that have been converted to cyclic carbonate groups,
polyethers having at least two cyclic carbonate groups are each
individually formed from a polyether having at least two oxirane
groups that have been converted to cyclic carbonate groups, and
polyurethanes having at least two cyclic carbonate groups, are each
individually formed from a polyurethane having at least two oxirane
groups that have been converted to cyclic carbonate groups.
9. The curable solid particulate composition of claim 2, wherein,
polymers prepared by free radical polymerization having at least
two cyclic carbonate groups each independently comprise at least
two residues of oxirane functional ethylenically unsaturated
monomers in which the oxirane groups have been converted to cyclic
carbonate groups, and polymers prepared by controlled radical
polymerization having at least two cyclic carbonate groups each
independently comprise at least two residues of oxirane functional
ethylenically unsaturated monomers in which the oxirane groups have
been converted to cyclic carbonate groups.
10. The curable solid particulate composition of claim 1, wherein
each active hydrogen group of said second reactant is independently
chosen from hydroxyl groups, thiol groups, and amine groups.
11. The curable solid particulate composition of claim 10, wherein
each active hydrogen group of said second reactant is independently
selected from amine groups, and each amine group of said second
reactant is independently selected from primary amines and
secondary amines.
12. The curable solid particulate composition of claim 11, wherein
said second reactant comprises at least one of linear or branched
aliphatic amines, cycloaliphatic amines, heterocycloaliphatic
amines, aromatic amines, and heteroaromatic amines.
13. The curable solid particulate composition of claim 12, wherein
said second reactant comprises at least one of diaminocyclohexane,
4,4'-methylenedi(cyclohexylamine),
4,4'-(propane-2,2-diyl)dicyclohexanamine,
3,3'-dimethyl-methylenedi(cyclohexylamine),
4,4'-(propane-2,2-diyl)dianiline, 4,4'-methylenedianiline,
piperazine, N-amino ethyl piperazine,
5-amino-1-aminomethyl-1,3,3-trimethyl-cyclohexane, diamino ethane,
diamino propane, diaminobutane, diaminopentane, diaminohexane,
diaminoheptane, diaminooctane, diaminodecane, diaminoundecane,
diaminododecane, dicyanamide, 4,4'-diaminodiphenyl sulfone, and
melamine.
14. The curable solid particulate composition of claim 1, wherein
the ratio of cyclic carbonate equivalents of said first reactant to
amine equivalents of said second reactant is from 0.7:1 to 2:1.
15. The curable solid particulate composition of claim 1, wherein
said first reactant is present in said curable solid particulate
composition in an amount of from 50 to 98 percent by weight, based
on total resin solids weight, and said second reactant is present
in said curable solid particulate composition in an amount of from
2 to 50 percent by weight, based on total resin solids weight.
16. The curable solid particulate composition of claim 1, wherein
said first reactant is resinous and has a glass transition
temperature.
17. The curable solid particulate composition of claim 1, wherein
said first reactant is crystalline and has a crystalline melting
point.
18. The curable solid particulate composition of claim 1, wherein
said curable solid particulate composition is free flowing.
19. The curable solid particulate composition of claim 18, wherein
said curable solid particulate composition is a powder coating
composition.
20. The curable solid particulate composition of claim 1, wherein
said curable solid particulate composition is thermosetting.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to curable solid particulate
compositions that include a first reactant having at least two
cyclic carbonate groups, and a second reactant having at least two
active hydrogen groups that are reactive with the cyclic carbonate
groups of the first reactant.
BACKGROUND OF THE INVENTION
[0002] Reducing the environmental impact of coatings compositions,
in particular that associated with emissions into the air of
volatile organic compounds during their use, has been an area of
ongoing investigation and development in recent years. Accordingly,
interest in powder coatings has been increasing due, in part, to
their inherently low volatile organic content (VOC), which
significantly reduces air emissions during the application process.
While both thermoplastic and thermosetting powder coatings
compositions are commercially available, thermosetting powder
coating compositions are typically more desirable because of the
superior physical properties, such as hardness and solvent
resistance, provided thereby.
[0003] Low VOC coatings are particularly desirable in a number of
applications, such as the automotive original equipment manufacture
(OEM) market, industrial market, and appliance market, due to the
relatively large volume of coatings that are used in such markets.
In addition to the requirement of low VOC levels, many
manufacturers have strict performance requirements of the coatings
that are used. In the case of basecoats, examples of such
requirements include good corrosion resistance, substrate adhesion,
and overcoat adhesion. In the case of topcoats, examples of such
requirements include good corrosion resistance, adhesion (to
undercoats and/or clear coatings applied thereover), exterior
durability, solvent resistance, gloss, and appearance. While liquid
coatings can provide such properties, they have the undesirable
drawback of higher VOC levels relative to powder coatings, which
have essentially zero VOC levels.
[0004] Curable powder coating compositions are available in a
number of chemistries, such as: powder coating compositions that
include epoxide functional polymer and epoxide reactive
crosslinking agent; carboxylic acid functional polymer and
betahydroxyalkylamide functional crosslinking agent; and hydroxyl
functional polymer and capped isocyanate functional crosslinking
agent. Presently available curable powder coating compositions can
be subject to undesirable properties, such as insufficient storage
stability at room temperature.
[0005] It would be desirable to develop new curable powder coating
compositions that provide coatings having performance properties
that are at least the same as those of presently available liquid
and powder coating compositions. It would be further desirable that
such newly developed powder coating compositions also possess at
least a sufficient degree of storage stability at room
temperature.
SUMMARY OF THE INVENTION
[0006] In accordance with the present invention, there is provided
a curable solid particulate composition comprising: (a) a first
reactant having at least two cyclic carbonate groups; and (b) a
second reactant having at least two active hydrogen groups that are
reactive with the cyclic carbonate groups of said first
reactant.
[0007] In further accordance with the present invention, there is
provided a method of coating a substrate with the curable solid
particulate composition of the present invention.
[0008] In further accordance with the present invention, there is
provided a coated substrate that comprises the curable solid
particulate composition of the present invention in the form of a
coating over at least a portion of at least one surface of the
substrate.
[0009] The features that characterize the present invention are
pointed out with particularity in the claims, which are annexed to
and form a part of this disclosure. These and other features of the
invention, its operating advantages, and the specific objects
obtained by its use will be more fully understood from the
following detailed description in which non-limiting embodiments of
the invention are illustrated and described.
DETAILED DESCRIPTION OF THE INVENTION
[0010] As used herein, the articles "a," "an," and "the" include
plural referents unless otherwise expressly and unequivocally
limited to one referent.
[0011] Unless otherwise indicated, all ranges or ratios disclosed
herein are to be understood to encompass any and all subranges or
subratios subsumed therein. For example, a stated range or ratio of
"1 to 10" should be considered to include any and all subranges
between (and inclusive of) the minimum value of 1 and the maximum
value of 10; that is, all subranges or subratios beginning with a
minimum value of 1 or more and ending with a maximum value of 10 or
less, such as but not limited to, 1 to 6.1, 3.5 to 7.8, and 5.5 to
10.
[0012] As used herein, unless otherwise indicated, left-to-right
representations of linking groups, such as divalent linking groups,
are inclusive of other appropriate orientations, such as, but not
limited to, right-to-left orientations. For purposes of
non-limiting illustration, the left-to-right representation of the
divalent linking group
##STR00001##
or equivalently --C(O)O--, is inclusive of the right-to-left
representation thereof,
##STR00002##
or equivalently --O(O)C-- or --OC(O)--.
[0013] Other than in the operating examples, or where otherwise
indicated, all numbers expressing quantities of ingredients,
reaction conditions, and so forth used in the specification and
claims are to be understood as modified in all instances by the
term "about."
[0014] As used herein, molecular weight values of polymers, such as
weight average molecular weights (Mw) and number average molecular
weights (Mn), are determined by gel permeation chromatography using
appropriate standards, such as polystyrene standards.
[0015] As used herein, polydispersity index (PDI) values represent
a ratio of the weight average molecular weight (Mw) to the number
average molecular weight (Mn) of the polymer (i.e., Mw/Mn).
[0016] As used herein, the term "polymer" means homopolymers (e.g.,
prepared from a single monomer species), copolymers (e.g., prepared
from at least two monomer species), and graft polymers.
[0017] As used herein, the term "(meth)acrylate" and similar terms,
such as "(meth)acrylic acid ester" means methacrylates and/or
acrylates. As used herein, the term "(meth)acrylic acid" means
methacrylic acid and/or acrylic acid.
[0018] As used herein, spatial or directional terms, such as
"left", "right", "inner", "outer", "above", "below", and the like,
relate to the invention as it is described herein. However, it is
to be understood that the invention can assume various alternative
orientations and, accordingly, such terms are not to be considered
as limiting.
[0019] As used herein, the terms "formed over," "deposited over,"
"provided over," "applied over," "residing over," or "positioned
over," mean formed, deposited, provided, applied, residing, or
positioned on but not necessarily in direct (or abutting) contact
with the underlying element, or surface of the underlying element.
For example, a layer "positioned over" a substrate does not
preclude the presence of one or more other layers, coatings, or
films of the same or different composition located between the
positioned or formed layer and the substrate.
[0020] As used herein, the term "free flowing" with regard to the
curable solid particulate compositions of the present invention
means a curable solid particulate composition having the handling
characteristics of a substantially dry particulate composition,
having a minimum of dumping or aggregation between individual
particles.
[0021] As used herein, the terms "hydroxyl" and "hydroxy" both mean
--OH groups.
[0022] All documents, such as but not limited to issued patents and
patent applications, referred to herein, and unless otherwise
indicated, are to be considered to be "incorporated by reference"
in their entirety.
[0023] As used herein, recitations of "linear or branched" groups,
such as linear or branched alkyl, are herein understood to include:
a methylene group or a methyl group; groups that are linear, such
as linear C.sub.2-C.sub.20 alkyl groups; and groups that are
appropriately branched, such as branched C.sub.3-C.sub.20 alkyl
groups.
[0024] As used herein, the term "aliphatic" means groups that are
non-aromatic, such as but not limited to alkyl groups.
[0025] As used herein, the term "alkyl" means linear or branched
alkyl, such as but not limited to, linear or branched
C.sub.1-C.sub.20 alkyl, or linear or branched C.sub.1-C.sub.10
alkyl, or linear or branched C.sub.2-C.sub.10 alkyl. Examples of
alkyl groups from which the various alkyl groups of the present
invention can be selected from, include, but are not limited to,
methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl,
tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, and
decyl. Alkyl groups of the various components of the present
invention can, with some embodiments, include one or more
unsaturated linkages selected from --CH.dbd.CH-- groups and/or one
or more --C.ident.C-- groups, provided the alkyl group is free of
two or more conjugated unsaturated linkages. With some embodiments,
the alkyl groups are free of unsaturated linkages, such as
--CH.dbd.CH-- groups and --C.ident.C-- groups.
[0026] As used herein, the term "cycloaliphatic" means cyclic
groups that are non-aromatic, such as, but not limited to
cycloalkyl groups.
[0027] As used herein, the term "cycloalkyl" means groups that are
appropriately cyclic, such as but not limited to, C.sub.3-C.sub.12
cycloalkyl (including, but not limited to, cyclic C.sub.5-C.sub.7
alkyl) groups. Examples of cycloalkyl groups include, but are not
limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and
cyclooctyl. The term "cycloalkyl" as used herein also includes:
bridged ring polycycloalkyl groups (or bridged ring polycyclic
alkyl groups), such as but not limited to, bicyclo[2.2.1]heptyl (or
norbornyl) and bicyclo[2.2.2]octyl; and fused ring polycycloalkyl
groups (or fused ring polycyclic alkyl groups), such as, but not
limited to, octahydro-1H-indenyl, and decahydronaphthalenyl.
[0028] As used herein, the term "heterocycloaliphatic" means cyclic
groups that are non-aromatic, such as but not limited to
heterocycloalkyl groups, and which have at least one hetero atom in
the cyclic ring, such as, but not limited to, O, S, N, P, and
combinations thereof.
[0029] As used herein, the term "heterocycloalkyl" means groups
that are appropriately cyclic, such as but not limited to,
C.sub.3-C.sub.12 heterocycloalkyl groups or C.sub.5-C.sub.7
heterocycloalkyl groups, and which have at least one hetero atom in
the cyclic ring, such as, but not limited to, O, S, N, P, and
combinations thereof. Examples of heterocycloalkyl groups include,
but are not limited to, imidazolyl, tetrahydrofuranyl,
tetrahydropyranyl, and piperidinyl. The term "heterocycloalkyl" as
used herein also includes: bridged ring polycyclic heterocycloalkyl
groups, such as but not limited to, 7-oxabicyclo[2.2.1]heptanyl;
and fused ring polycyclic heterocycloalkyl groups, such as but not
limited to, octahydrocyclopenta[b]pyranyl, and
octahydro-1H-isochromenyl.
[0030] As used herein, the term "aryl" and related terms, such as
"aromatic", means cyclic groups that are aromatic, and includes,
but is not limited to, C.sub.5-C.sub.18 aryl, such as but not
limited to, C.sub.5-C.sub.10 aryl (including fused ring polycyclic
aryl groups). Examples of aryl groups include, but are not limited
to, phenyl, naphthyl, and anthracenyl.
[0031] As used herein, the term "heteroaryl" and related terms,
such as "heteroaromatic", includes but is not limited to
C.sub.5-C.sub.18 heteroaryl, such as but not limited to
C.sub.5-C.sub.10 heteroaryl (including fused ring polycyclic
heteroaryl groups) and means an aryl group having at least one
hetero atom (such as but not limited to O, S, and N, and
combinations thereof) in the aromatic ring, or in at least one
aromatic ring in the case of a fused ring polycyclic heteroaryl
group. Examples of heteroaryl groups include, but are not limited
to, furanyl, pyranyl, pyridinyl, isoquinoline, and pyrimidinyl.
[0032] As used herein, remarks with regard to the active hydrogen
groups of the second reactant being reactive with the cyclic
carbonate groups of the first reactant, are inclusive of the cyclic
carbonate groups of the first reactant and the active hydrogen
groups of the second reactant being reactive with each other.
[0033] The first reactant of the curable solid particulate
compositions of the present invention includes at least two cyclic
carbonate groups. With some embodiments, and for purposes of
non-limiting illustration, the cyclic carbonate groups of the first
reactant can be represented by the following Formula (I),
##STR00003##
[0034] With some embodiments of the present invention, the first
reactant is formed from a precursor material that has at least two
oxirane groups (such as a polyester having at least two oxirane
groups), in which at least two oxirane groups thereof have been
converted to cyclic carbonate groups. More particularly, at least
two of the oxirane groups and, with some embodiments, substantially
all of the oxirane groups, of the precursor material are converted
to cyclic carbonate groups.
[0035] Conversion of the oxirane groups of the precursor material
can be conducted, with some embodiments, in accordance with
art-recognized methods. For purposes of non-limiting illustration,
conversion of oxirane groups to cyclic carbonate groups is provided
in the following general Scheme (I),
##STR00004##
[0036] With reference to general Scheme (I) and in accordance with
some embodiments, (A) represents a precursor material having n
oxirane groups that are converted to cyclic carbonate groups, and
(B) represents the first reactant of the compositions of the
present invention having n cyclic oxirane groups. The group R, with
some embodiments, represents a residue of a material to which n
oxirane groups are bonded by divalent linking group L in (A), and
to which n cyclic carbonate groups are bonded by divalent linking
group L in (B). For purposes of non-limiting illustration, with
some embodiments the first reactant is selected from a polyester
having at least two cyclic carbonate groups, in which case and
correspondingly R is the polyester (or residue of the
polyester).
[0037] In accordance with some embodiments, R of precursor material
(A) and first reactant (B) of Scheme (I) is in each case a residue
of a material selected from vegetable oils, polyols, isocyanurates,
polyesters, polyethers, polyurethanes, polymers prepared by free
radical polymerization, polymers prepared by controlled radical
polymerization, and combinations of two or more thereof.
[0038] With further reference to general Scheme (I), Subscript n,
with some embodiments, is at least 2, such as from 2 to 100, or
from 2 to 80, or from 2 to 50, or from 2 to 40, or from 2 to 30, or
from 2 to 20, or from 2 to 10, or from 2 to 5, in each case
inclusive of the recited values. Divalent linking group L can, with
some embodiments, be selected from a bond, a divalent alkyl group,
a divalent cycloalkyl group, a divalent heterocycloalkyl group, a
divalent aryl group, a divalent heteroaryl group, and a heteroatom,
such as, but not limited to, O, N, S, and P, and combinations of
two or more thereof (such as, but not limited to, a combination of
a divalent alkyl group and one or more heteroatoms, such as O, N,
S, and P). With some embodiments, divalent linking group L is a
divalent methylene oxide group represented by the following Formula
(II),
--O--CH.sub.2-- Formula (II)
[0039] With some embodiments, the divalent oxygen (--O--) of
Formula (II) is bonded to R of (A) and (B), and the divalent
methylene group (--CH.sub.2--) is bonded to the oxirane group of
(A) and the cyclic carbonate group of (B), of Scheme (I).
[0040] Precursor material (A) can be formed in accordance with
art-recognized methods, such as but not limited to: reaction of an
active hydrogen functional material (such as, but not limited to, a
hydroxyl and/or thiol functional material) with an oxirane
functional material having a group that is reactive with active
hydrogen groups (such as, but not limited to, reactive with
hydroxyls and/or thiols); and reaction of an ethylenically
unsaturated material with an oxygen source, such as, but not
limited to, ozone and a peroxyacid, which converts each (or at
least two) ethylencially unsaturated group into an oxirane
group.
[0041] With some embodiments, precursor material (A) is formed, in
accordance with art-recognized methods, from reaction of: (i) a
hydroxyl functional material R--(OH).sub.n, where n is as described
above; with (ii) an oxirane functional material having at least one
oxirane group and a group that is reactive with the hydroxyls of
the hydroxyl functional material, such as, but not limited to,
epichlorohydrin
##STR00005##
With some embodiments, when precursor material (A) is the result of
the reaction of a hydroxyl functional material R--(OH).sub.n and
epichlorohydrin, divalent linking group L is represented by Formula
(II) above.
[0042] With some further embodiments, precursor material (A) is
formed, in accordance with art-recognized methods, from reaction
of: (i) a material that includes at least two ethylenically
unsaturated groups; and (ii) an oxygen source, such as, but not
limited to, a peroxyacid, such as, but not limited to,
haloperoxybenzoic acid, such as m-chloroperoxybenzoic acid. The
material that includes at least two ethylenically unsaturated
groups is, with some embodiments, selected from one or more
vegetable oils, such soybean oil, in which case precursor material
(A) is an expoxidized vegetable oil, such as epoxidized soybean
oil. As used herein, the term "vegetable oil" also includes nut
oils. With some embodiments, the vegetable oil includes, but is not
limited to, palm oil, soybean oil, rapeseed oil, sunflower seed
oil, peanut oil, cottonseed oil, palm kernel oil, coconut oil,
olive oil, corn oil, grape seed oil, hazelnut oil, linseed oil,
rice bran oil, safflower oil, sesame seed oil, and combinations of
two or more thereof.
[0043] With some further embodiments, the material that includes at
least two ethylenically unsaturated groups (from which precursor
material (A) can be prepared, with some embodiments) is selected
from vegetable oils having at least two ethylenically unsaturated
groups, polyols having at least two ethylenically unsaturated
groups, isocyanurates having at least two ethylenically unsaturated
groups, polyesters having at least two ethylenically unsaturated
groups, polyethers having at least two ethylenically unsaturated
groups, polyurethanes having at least two ethylenically unsaturated
groups, polymers prepared by free radical polymerization having at
least two ethylenically unsaturated groups, and polymers prepared
by controlled radical polymerization having at least two
ethylenically unsaturated groups.
[0044] The conversion of oxirane groups of (A) to cyclic carbonate
groups of (B), as represented in general Scheme (I), is typically
conducted under conditions of elevated temperature (as represented
by the term Heat), such as from 70.degree. C. to 140.degree. C., in
the presence of gaseous carbon dioxide, and optionally a solvent,
such as an inert solvent. The carbon dioxide can, with some
embodiments, be bubbled continuously through the reaction medium.
With some further embodiments, a measured quantity of carbon
dioxide is charged to the reaction optionally under elevated
pressure, such as from 60 to 150 psi. The reaction can be conducted
in the presence of a suitable solvent, such as an alcohol, for
example, isobutanol. The reaction is typically conducted in the
presence of a suitable catalyst, such as a tetraalkyl ammonium
iodide and/or tetraalkyl ammonium bromide, for example,
tetrabutylammonium iodide and/or tetrabutylammonium bromide. After
art-recognized work-up procedures, the product (B) is isolated.
[0045] With additional reference to general Scheme (I) and in
accordance with some embodiments, (A) represents a precursor
monomer having n oxirane groups bonded thereto, such as a radically
polymerizable oxirane functional ethylenically unsaturated monomer.
Correspondingly, (B) represents a monomer having n cyclic carbonate
groups bonded thereto, such as a radically polymerizable cyclic
carbonate functional ethylenically unsaturated monomer, from which
the first reactant of the compositions of the present invention can
be prepared, such as by controlled radical polymerization or free
radical polymerization. With some non-limiting embodiments where
(A) represents a precursor monomer and (B) represents a monomer,
subscript n is at least 1, such as from 1 to 4, or from 1 to 3, or
1 to 2, inclusive of the recited values.
[0046] In accordance with some embodiments, a polymer is prepared
by controlled radical polymerization or free radical polymerization
from a radically polymerizable oxirane functional precursor
monomer, such as represented by (A) in Scheme (I). After formation
of the polymer, the oxirane groups of the oxirane functional
precursor monomer residues (or units) that have been incorporated
into the polymer backbone, are converted to cyclic carbonate
groups, with some embodiments.
[0047] In accordance with some embodiments of the present
invention, the first reactant, of the curable particulate
composition, is selected from: polyol residues having at least two
cyclic carbonate groups; isocyanurates having at least two cyclic
carbonate groups; polyesters having at least two cyclic carbonate
groups; polyethers having at least two cyclic carbonate groups;
polyurethanes having at least two cyclic carbonate groups; polymers
prepared by free radical polymerization having at least two cyclic
carbonate groups; polymers prepared by controlled radical
polymerization having at least two cyclic carbonate groups; and
combinations of two or more thereof.
[0048] As used herein, the term "polyol residue" and related terms,
such as "polyol residues," "polyol," and "polyols," with regard to
polyol residues having at least two cyclic carbonate groups, means
residues of polyols that are structurally distinguishable from: the
polyester residues of the polyesters having at least two cyclic
carbonate groups; the polyether residues of the polyethers having
at least two cyclic carbonate groups; the polyurethane residues of
the polyurethanes having at least two cyclic carbonate groups;
polymer residues of the polymers prepared by free radical
polymerization having at least two cyclic carbonate groups; and the
polymer residues of the polymers prepared by controlled radical
polymerization having at least two cyclic carbonate groups. With
some embodiments, the term "polyol residue" and related terms with
regard to polyol residues having at least two cyclic carbonate
groups, is a non-polymeric material that is free of repeating
monomer units (or monomer residues).
[0049] The polyol residues having at least two cyclic carbonate
groups are, with some embodiments, each independently formed from a
polyol residue having at least two oxirane groups that have been
converted to cyclic carbonate groups. The oxirane groups can be
converted to cyclic carbonate groups in accordance with
art-recognized methods, such as described previously herein with
reference to general Scheme (I), in which case R represents a
polyol residue.
[0050] With some embodiments, the polyol residue (from which the
polyol residues having at least two cyclic carbonate groups are
formed) is a residue of a polyol selected from aliphatic polyols
and/or aromatic polyols. In accordance with some further
embodiments, the polyol residue (from which the polyol residues
having at least two cyclic carbonate groups are formed) is a
residue of a polyol selected from glycerin, trimethylolpropane,
trimethylolethane, trishydroxyethylisocyanurate, pentaerythritol,
ethylene glycol, propylene glycol, trimethylene glycol, butanediol,
heptanediol, hexanediol, octanediol,
4,4'-(propane-2,2-diyl)dicyclohexanol,
4,4'-methylenedicyclohexanol, neopentyl glycol,
2,2,3-trimethylpentane-1,3-diol, 1,4-dimethylolcyclohexane,
2,2,4-trimethylpentane diol, 4,4'-(propane-2,2-diyl)diphenol, and
4,4'-methylenediphenol.
[0051] The polyol residue, with some embodiments, (from which the
polyol residues having at least two cyclic carbonate groups are
formed) is a residue of a polyol selected from
4,4'-(propane-2,2-diyl)diphenol,
4,4'-(propane-2,2-diyl)dicyclohexanol, 4,4'-methylenediphenol,
4,4'-methylenedicyclohexanol, and combinations thereof.
[0052] The polyol residue having at least two oxirane groups can be
formed in accordance with art-recognized methods. With some
embodiments, the polyol residue having at least two oxirane groups
is formed from the reaction of one mole of a polyol having at least
two hydroxyl groups, with at least two moles of epichlorohydrin
under art-recognized reaction and work-up conditions.
[0053] The cyclic carbonate equivalent weight of the polyol
residues having at least two cyclic carbonate groups is, with some
embodiments, less than or equal to 1000 grams/equivalent, such as
from 100 to 1000 grams/equivalent.
[0054] In accordance with some further embodiments of the present
invention, the isocyanurates having at least two cyclic carbonate
groups, from which the first reactant can be selected, are each
independently formed from an isocyanurate having at least two
oxirane groups that have been converted to cyclic carbonate groups.
The oxirane groups, of the oxirane functional isocyanurate, can be
converted to cyclic carbonate groups in accordance with
art-recognized methods, such as described previously herein with
reference to general Scheme (I), in which case R represents an
isocyanurate.
[0055] The isocyanurate having at least two oxirane groups is, with
some embodiments, tris(2,3-epoxypropyl)isocyanurate. At least two
of the oxirane groups of the tris(2,3-epoxypropyl)isocyanurate are
converted to cyclic carbonate groups, such as described previously
herein with reference to Scheme (I), with some embodiments. With
some further embodiments, all three of the oxirane groups of the
tris(2,3-epoxypropyl)isocyanurate are converted to cyclic carbonate
groups, such as described previously herein with reference to
Scheme (I).
[0056] The cyclic carbonate equivalent weight of the isocyanurates
having at least two cyclic carbonate groups is, with some
embodiments, less than or equal to 1000 grams/equivalent, such as
from 100 to 1000 grams/equivalent.
[0057] In accordance with some additional embodiments of the
present invention, the polyesters having at least two cyclic
carbonate groups, from which the first reactant can be selected,
are each individually formed form a polyester having at least two
oxirane groups that have been converted to cyclic carbonate groups.
With some embodiments, at least two hydroxyl groups of a polyester
having at least two hydroxyl groups are reacted with an oxirane
functional material, such as a 1-halo-2,3-epoxy propane, such as
epichlorohydrin, so as to form a polyester having at least two
oxirane groups, in accordance with art-recognized methods. At least
two of the oxirane groups of the polyester having at least two
oxirane groups can subsequently be converted to cyclic carbonate
groups in accordance with art-recognized methods, such as described
previously herein with reference to general Scheme (I), in which
case R represents a polyester.
[0058] Hydroxyl functional polyesters, from which polyesters having
at least two cyclic carbonate groups can be prepared, typically
have an average of at least two hydroxyl groups per polyester
molecule. Polyesters having hydroxyl functionality can be prepared
by art-recognized methods, which include reacting carboxylic adds
(or their anhydrides) having acid functionalities of at least 2,
and polyols having hydroxy functionalities of at least 2. The molar
equivalents ratio of carboxylic acid groups to hydroxy groups of
the reactants is selected such that the resulting polyester has
hydroxyl functionality and a desired molecular weight.
[0059] Examples of multifunctional carboxylic acids useful in
preparing hydroxyl functional polyesters include, but are not
limited to, benzene-1,2,4-tricarboxylic acid, phthalic acid,
tetrahydrophthalic acid, hexahydrophthalic acid,
endobicyclo-2,2,1,5-heptyne-2,3-dicarboxylic acid,
tetrachlorophthalic acid, cyclohexanedioic acid, succinic acid,
isophthalic acid, terephthalic acid, azelaic acid, maleic acid,
trimesic acid, 3,6-dichlorophthalic acid, adipic acid, sebacic
acid, and like multifunctional carboxylic acids.
[0060] Examples of polyols useful in preparing hydroxyl functional
polyesters include, but are not limited to, the polyols recited
previously herein with regard to the polyols from which the polyol
residues having at least two cyclic carbonate groups can be
prepared. With some embodiments, polyols (from which polyesters
having at least two cyclic carbonate groups can be prepared)
include, but are not limited to, glycerin, trimethylolpropane,
trimethylolethane, trishydroxyethylisocyanurate, pentaerythritol,
ethylene glycol, propylene glycol, trimethylene glycol, 1,3-, 1,2-
and 1,4-butanediols, heptanediol, hexanediol, octanediol,
2,2-bis(4-cyclohexanol)propane, neopentyl glycol,
2,2,3-trimethylpentane-1,3-diol, 1,4-dimethylolcyclohexane,
2,2,4-trimethylpentane diol, and like polyols.
[0061] Polyesters having at least two cyclic carbonate groups, from
which the first reactant can be selected, have an Mn of less than
or equal to 10,000, such as from 1,000 to 10,000, or from 2,000 to
7,000, with some embodiments. The cyclic carbonate equivalent
weight of the polyesters having at least two cyclic carbonate
groups is, with some embodiments, less than or equal to 3000
grams/equivalent, such as from 300 to 2,000 grams/equivalent.
[0062] With some embodiments, the polyethers having at least two
cyclic carbonate groups, from which the first reactant can be
selected, are each individually formed from a polyether having at
least two oxirane groups that have been converted to cyclic
carbonate groups. With some embodiments, at least two hydroxyl
groups of a polyether having at least two hydroxyl groups are
reacted with an oxirane functional material, such as a
1-halo-2,3-epoxy propane, such as epichlorohydrin, so as to form a
polyether having at least two oxirane groups, in accordance with
art-recognized methods. At least two of the oxirane groups of the
polyether having at least two oxirane groups can subsequently be
converted to cyclic carbonate groups in accordance with
art-recognized methods, such as described previously herein with
reference to general Scheme (I), in which case R represents a
polyether.
[0063] The polyethers, from which the polyethers having at least
two cyclic carbonate groups of the present invention can be
prepared, can themselves be prepared in accordance with
art-recognized methods. With some embodiments, the polyethers can
be prepared from polyols having two or more hydroxy groups and
polyepoxides having two or more epoxide groups, which are reacted
in proportions such that the resulting polyether has hydroxy
functionality or oxirane functionality. The polyols and
polyepoxides used in the preparation of the epoxide functional
polyether may be selected from, for example, aliphatic,
cycloaliphatic, and aromatic polyols and polyepoxides, and mixtures
thereof. Specific examples of polyols include those recited
previously herein. Polyepoxides useful in preparing the hydroxy
functional polyether include, with some embodiments, those
resulting from the reaction of a polyol and epichlorohydrin. With
some embodiments, one or more of the polyols recited previously
herein can be reacted with epichlorohydrin, so as to result in the
formation of a polyepoxide. For purposes of non-limiting
illustration, the hydroxy functional polyether can be prepared,
with some embodiments, from: 4,4'-(propane-2,2-diyl)diphenol and
the diglycidyl ether of 4,4'-(propane-2,2-diyl)diphenol; or
4,4'-(propane-2,2-diyl)dicylcohexanol and the diglycidyl ether of
4,4'-(propane-2,2-diyl)dicylcohexanol.
[0064] The polyethers having at least two cyclic carbonate groups,
with some embodiments, can have an Mn of less than 10,000, such as
from 1,000 and 7,000. The cyclic carbonate equivalent weight of the
polyethers having at least two cyclic carbonate groups is, with
some embodiments, less than or equal to 3,000 grams/equivalent,
such as from 300 and 2,000 grams/equivalent.
[0065] The polyurethanes having at least two cyclic carbonate
groups, from which the first reactant can be selected, with some
embodiments, are each individually formed from a polyurethane
having at least two oxirane groups that have been converted to
cyclic carbonate groups. The polyurethane having at least two
oxirane groups can be prepared from a polyurethane having at least
two hydroxyl groups. At least two hydroxy groups of the hydroxy
functional polyurethane can be reacted with an oxirane functional
material, such as epichlorohydrin, which results in formation of
the polyurethane having at least two oxirane groups. At least two
of the oxirane groups of the polyurethane having at least two
oxirane groups can be converted to cyclic oxirane groups in
accordance with art-recognized methods, such as described
previously herein with reference to Scheme-(I), in which case R
represents a polyurethane.
[0066] Hydroxyl functional polyurethanes can be prepared in
accordance with art-recognized methods, such as by reaction of a
polyisocyanate having at least two isocyanate groups, with a polyol
having at least two hydroxy groups, with an appropriate molar
excess of hydroxyl groups, so as to form a hydroxyl functional
polyurethane having at least 2 hydroxyl groups. Examples of
polyisocyanates useful in the preparation of polyurethane polyols
include, with some embodiments, aliphatic, aromatic, cycloaliphatic
and heterocyclic polyisocyanates, and mixtures of such
polyisocyanates.
[0067] Further examples of polyisocyanates useful in the
preparation of polyurethane polyols include, but are not limited
to, toluene-2,4-diisocyanate; toluene-2,6-diisocyanate; diphenyl
methane-4,4'-diisocyanate; diphenyl methane-2,4'-diisocyanate;
para-phenylene diisocyanate; biphenyl diisocyanate;
3,3'-dimethyl-4,4'-diphenylene diisocyanate;
tetramethylene-1,4-diisocyanate; hexamethylene-1,6-diisocyanate;
2,2,4-trimethyl hexane-1,6-diisocyanate; lysine methyl ester
diisocyanate; bis(isocyanato ethyl)fumarate; isophorone
diisocyanate; ethylene diisocyanate; dodecane-1,12-diisocyanate;
cyclobutane-1,3-diisocyanate; cyclohexane-1,3-diisocyanate;
cyclohexane-1,4-diisocyanate; methyl cyclohexyl diisocyanate;
hexahydrotoluene-2,4-diisocyanate;
hexahydrotoluene-2,6-diisocyanate;
hexahydrophenylene-1,3-diisocyanate;
hexahydrophenylene-1,4-diisocyanate;
perhydrodiphenylmethane-2,4'-diisocyanate;
perhydrodiphenylmethane-4,4'-diisocyanate, and mixtures
thereof.
[0068] Examples of polyols having at least two hydroxyl groups,
from which the hydroxy functional polyurethane can be prepared,
include, but are not limited to, those polyols recited previously
herein. With some embodiments, the polyols, from which the hydroxy
functional polyurethane can be prepared, can be selected from those
recited previously herein with regard to the polyols from which the
polyol residues having at least two cyclic carbonate groups can be
prepared. With some further embodiments, the polyols, from which
the hydroxy functional polyurethane can be prepared, can be
selected from those recited previously herein with regard to the
hydroxy functional polyester.
[0069] The polyurethanes having at least two cyclic carbonate
groups, with some embodiments, can have an Mn of less than 10,000,
such as from 100 and 7,000. The cyclic carbonate equivalent weight
of the polyurethanes having at least two cyclic carbonate groups
is, with some embodiments, less than or equal to 3,000
grams/equivalent, such as from 100 to 2,000 grams/equivalent.
[0070] With some embodiments, polymers prepared by free radical
polymerization having at least two cyclic carbonate groups, from
which the first reactant can be selected, each independently
include or have at least two residues of oxirane functional
ethylenically unsaturated monomers in which the oxirane groups have
been converted to cyclic carbonate groups. The oxirane groups of
the oxirane functional ethylenically unsaturated monomers can be
converted to cyclic carbonate groups before and/or after the
polymer has been prepared by free radical polymerization.
[0071] Polymers prepared by free radical polymerization having at
least two cyclic carbonate groups can, with some embodiments, be
prepared by copolymerizing epoxide functional ethylenically
unsaturated radically polymerizable monomer(s), such as a glycidyl
functional (meth)acrylate, such as glycidyl(meth)acrylate, with
ethylenically unsaturated radically polymerizable monomer(s) free
of epoxide functionality, such as alkyl(meth)acrylates. Polymers
prepared by free radical polymerization having at least two cyclic
carbonate groups can, with some further embodiments, be prepared by
copolymerizing cyclic carbonate functional ethylenically
unsaturated radically polymerizable monomer(s), such as a cyclic
carbonate functional (meth)acrylate, such as
(2-oxo-1,3-dioxolan-4-yl)methyl methacrylate, with ethylenically
unsaturated radically polymerizable monomer(s) free of cyclic
carbonate functionality, such as alkyl(meth)acrylates.
[0072] With some embodiments, the polymers prepared by free radical
polymerization having at least two cyclic carbonate groups are
acrylic polymers having at least two cyclic carbonate groups.
[0073] The conventional free radical polymerization methods by
which the cyclic carbonate functional polymer can be prepared
involve, with some embodiments, the use of free radical initiators,
such as organic peroxides and/or azo type compounds. Optionally,
chain transfer agents can also be used, such as alpha-methyl
styrene dimer and/or tertiary dodecyl mercaptan.
[0074] Examples of oxirane functional ethylenically unsaturated
radically polymerizable monomers that can be used, with some
embodiments, in the preparation of the polymers prepared by free
radical polymerization having at least two cyclic carbonate groups
include, but are not limited to, glycidyl(meth)acrylate,
3,4-epoxycyclohexylmethyl(meth)acrylate,
2-(3,4-epoxycyclohexyl)ethyl(meth)acrylate and allyl glycidyl
ether. Examples of cyclic carbonate functional ethylenically
unsaturated radically polymerizable monomers that can be used, with
some embodiments, in the preparation of the polymers prepared by
free radical polymerization having at least two cyclic carbonate
groups include, but are not limited to, the previously recited
oxirane functional (meth)acrylate monomers, in which the oxirane
groups thereof have been converted to cyclic carbonate groups in
accordance with art-recognized methods, such as described
previously herein with reference to Scheme (I), such as
(2-oxo-1,3-dioxolan-4-yl)methyl methacrylate.
[0075] Ethylenically unsaturated radically polymerizable monomer(s)
free of epoxide functionality and free of cyclic carbonate
functionality that can be used to prepare the polymers prepared by
free radical polymerization having at least two cyclic carbonate
groups include, but are not limited to, vinyl monomers, allylic
monomers, olefins, and other ethylenically unsaturated monomers
that are radically polymerizable.
[0076] Classes of vinyl monomers that are free of oxirane and
cyclic carbonate functionality include, but are not limited to,
(meth)acrylates, vinyl aromatic monomers, vinyl halides and vinyl
esters of carboxylic acids. With some embodiments, the
(meth)acrylates are selected from at least one of
alkyl(meth)acrylates having from 1 to 20 carbon atoms in the alkyl
group. Examples of alkyl(meth)acrylates having from 1 to 20 carbon
atoms in the alkyl group that can be used include, but are not
limited to, methyl(meth)acrylate, ethyl(meth)acrylate,
propyl(meth)acrylate, isopropyl(meth)acrylate, butyl(meth)acrylate,
isobutyl(meth)acrylate, tert-butyl(meth)acrylate,
2-ethylhexyl(meth)acrylate, lauryl(meth)acrylate,
isobornyl(meth)acrylate, cyclohexyl(meth)acrylate and
3,3,5-trimethylcyclohexyl(meth)acrylate.
[0077] Examples of vinyl aromatic monomers that are free of oxirane
and cyclic carbonate functionality include, but are not limited to,
styrene, p-chloromethylstyrene, divinyl benzene, vinyl naphthalene
and divinyl naphthalene. Vinyl halides from which M may be derived
include, but are not limited to, vinyl chloride and vinylidene
fluoride. Vinyl esters of carboxylic acids that are free of oxirane
and cyclic carbonate functionality include, but are not limited to,
vinyl acetate, vinyl butyrate, vinyl 3,4-dimethoxybenzoate and
vinyl benzoate.
[0078] As used herein, by "olefin" and like terms is meant
unsaturated aliphatic hydrocarbons having one or more double bonds,
such as obtained by cracking petroleum fractions. Examples of
olefins that are free of oxirane and cyclic carbonate functionality
include, but are not limited to, propylene, 1-butene,
1,3-butadiene, Isobutylene and diisobutylene.
[0079] As used herein, by "allylic monomer(s)" is meant monomers
containing substituted and/or unsubstituted allylic functionality,
such as one or more radicals represented by the following Formula
(I),
H.sub.2C.dbd.C(R.sub.1)--CH.sub.2-- (I)
[0080] With reference to Formula (I), R.sub.1 is hydrogen, halogen
or a C.sub.1 to C.sub.4 alkyl group. With some embodiments, R.sub.1
is hydrogen or methyl and consequently Formula (I) represents an
unsubstituted (meth)allyl radical. Examples of allylic monomers
that are free of oxirane and cyclic carbonate functionality
include, but are not limited to: (meth)allyl alcohol; (meth)allyl
ethers, such as methyl(meth)allyl ether; allyl esters of carboxylic
acids, such as (meth)allyl acetate, (meth)allyl butyrate,
(meth)allyl 3,4-dimethoxybenzoate and (meth)allyl benzoate.
[0081] Other ethylenically unsaturated radically polymerizable
monomers that are free of oxirane and cyclic carbonate
functionality include, but are not limited to: cyclic anhydrides,
such as maleic anhydride, 1-cyclopentene-1,2-dicarboxylic anhydride
and itaconic anhydride; esters of acids that are unsaturated but do
not have alpha, beta-ethylenic unsaturation, such as methyl ester
of undecylenic acid; and diesters of ethylenically unsaturated
dibasic acids, such as diethyl maleate.
[0082] The polymers prepared by free radical polymerization having
at least two cyclic carbonate groups (or cyclic carbonate
functional polymers prepared by free radical polymerization) can
have, with some embodiments, a cyclic carbonate equivalent weight
of at least 100 grams/equivalent, or at least 200 grams/equivalent.
The cyclic carbonate equivalent weight of the polymer is, with some
embodiments, less than 10,000 grams/equivalent, or less than 5,000
grams/equivalent, or less than 1,000 grams/equivalent. The cyclic
carbonate equivalent weight of the cyclic carbonate functional
polymer prepared by free radical polymerization can range between
any combination of these values, inclusive of the recited values,
such as from 100 to 10,000 grams/equivalent, or from 200 to 5,000
grams/equivalent, or from 200 to 1,000 grams/equivalent, inclusive
of the recited values.
[0083] The number average molecular weight (Mn) of the polymers
prepared by free radical polymerization having at least two cyclic
carbonate groups (or the cyclic carbonate functional polymer
prepared by free radical polymerization) is with some embodiments
at least 250, or at least 500, or at least 1,000, or at least
2,000. The cyclic carbonate functional polymer prepared by
controlled radical polymerization also has, with some embodiments,
an Mn of less than 16,000, or less than 10,000, or less than 5,000.
The Mn of the cyclic carbonate functional polymer prepared by free
radical polymerization can, with some embodiments, range between
any combination of these values, inclusive of the recited values,
such as from 250 to 16,000, or from 500 to 10,000, or from 1,000 to
5,000, or from 2,000 to 5,000, inclusive of the recited values.
[0084] In accordance with some further embodiments, polymers
prepared by controlled radical polymerization having at least two
cyclic carbonate groups each independently have or include at least
two residues of oxirane functional ethylenically unsaturated
monomers in which the oxirane groups have been converted to cyclic
carbonate groups. The oxirane groups of the oxirane functional
ethylenically unsaturated monomers can be converted to cyclic
carbonate groups before and/or after the polymer has been prepared
by controlled radical polymerization in accordance with
art-recognized methods, such as described previously herein with
reference to Scheme (I).
[0085] Controlled radical polymerization methods include, but are
not limited to, atom transfer radical polymerization (ATRP), single
electron transfer polymerization (SETP), reversible
addition-fragmentation chain transfer (RAFT), and
nitroxide-mediated polymerization (NMP).
[0086] Controlled radical polymerization, such as ATRP, is
described generally as a "living polymerization," i.e., a
chain-growth polymerization that propagates with essentially no
chain transfer and essentially no chain termination. The molecular
weight of a polymer prepared by controlled radical polymerization
can be controlled by the stoichiometry of the reactants, such as
the initial concentration of monomer(s) and initiator(s). In
addition, controlled radical polymerization also provides polymers
having characteristics including, but not limited to: narrow
molecular weight distributions, such as polydispersity index (PDI)
values less than 2.5; and/or well defined polymer chain structure,
such as block copolymers and alternating copolymers, with some
embodiments.
[0087] For purposes of non-limiting illustration of controlled
radical polymerization processes, the ATRP process will be
described in further detail. The ATRP process can be described
generally as including: polymerizing one or more radically
polymerizable monomers in the presence of an initiation system;
forming a polymer; and isolating the formed polymer. The initiation
system includes, with some embodiments: an initiator having a
radically transferable atom or group; a transition metal compound,
such as a catalyst, which participates in a reversible redox cycle
with the initiator; and a ligand, which coordinates with the
transition metal compound. The ATRP process is described in further
detail in U.S. Pat. Nos. 5,763,548, 5,789,487, 5,807,937,
6,538,091, 6,887,962, and 7,572,874. With some embodiments, the
polymers prepared by controlled radical polymerization having at
least two cyclic carbonate groups, are prepared generally in
accordance with the ATRP method disclosed at column 4, line 12,
through column 5, line 67 of U.S. Pat. No. 6,265,489 B1, which
disclosure is incorporated herein by reference.
[0088] With some embodiments, the ATRP initiator is selected from
halomethane, methylenedihalide, haloform, carbon tetrahalide,
1-halo-2,3-epoxypropane, methanesulfonyl halide, p-toluenesulfonyl
halide, methanesulfenyl halide, p-toluenezsulfenyl halide,
1-phenylethyl halide, C.sub.1-C.sub.8-alkyl ester of
2-halo-C.sub.1-C.sub.6-carboxylic acid, p-halomethylstyrene,
mono-hexakis (alpha-halo-C.sub.1-C.sub.6-alkyl)benzene,
diethyl-2-halo-2-methyl malonate, ethyl 2-bromoisobutyrate and
mixtures thereof. With some further embodiments, the initiator is
diethyl-2-bromo-2-methyl malonate.
[0089] Catalysts that can be used in some embodiments in preparing
polymers prepared by controlled radical polymerization (such as
ATRP) having at least two cyclic carbonate groups, include any
transition metal compound that can participate in a redox cycle
with the initiator and the growing polymer chain. With some
embodiments, the transition metal compound is selected such that it
does not form direct carbon-metal bonds with the polymer chain.
Transition metal catalysts useful in the present invention may be
represented by the following Formula (II),
TM.sup.n+X.sub.t (II)
[0090] With reference to Formula (II), TM represents the transition
metal, t is the formal charge on the transition metal having a
value of from 0 to 7, and X is a counterion or covalently bonded
component Examples of the transition metal (TM) include, but are
not limited to, Cu, Fe, Au, Ag, Hg, Pd, Pt, Co, Mn, Ru, Mo, Nb and
Zn. Examples of X include, but are not limited to, halogen,
hydroxy, oxygen, C.sub.1-C.sub.6-aloxy, cyano, cyanato,
thiocyanato, and azido. With some embodiments, the transition metal
is Cu(I) and X is a halogen, such as chloride. Accordingly, with
some embodiments, a class of transition metal catalysts are the
copper halides, such as Cu(I)Cl. With some embodiments the
transition metal catalyst contains a small amount, such as 1 mole
percent, of a redox conjugate, for example, Cu(II)Cl.sub.2 when
Cu(I)Cl is used.
[0091] Ligands that can be used in preparing the polymers prepared
by controlled radical polymerization (such as ATRP) having at least
two cyclic carbonate groups, include, but are not limited to
compounds having one or more nitrogen, oxygen, phosphorus and/or
sulfur atoms, which can coordinate to the transition metal catalyst
compound, such as through sigma and/or pi bonds. Classes of useful
ligands include, but are not limited to: unsubstituted and
substituted pyridines and bipyridines; porphyrins; cryptands; crown
ethers, such as 18-crown-6; polyamines, such as ethylenediamine;
glycols, such as alkylene glycols, such as ethylene glycol; carbon
monoxide; and coordinating monomers, such as styrene, acrylonitrile
and hydroxyalkyl(meth)acrylates. With some embodiments, the ligand
is selected from one or more substituted bipyridines, such as
4,4'-dialkylbipyridyls.
[0092] In preparing the polymers prepared by controlled radical
polymerization (such as ATRP) having at least two cyclic carbonate
groups, the amounts and relative proportions of initiator,
transition metal compound and ligand are those for which ATRP is
most effectively performed. The amount of initiator used can vary
widely and is typically present in the reaction medium in a
concentration of from 10.sup.-4 moles/liter (M) to 3 M, such as
from 10.sup.-3 M to 10.sup.-1 M. As the molecular weight of the
cyclic carbonate functional polymer can be directly related to the
relative concentrations of initiator and monomer(s), the molar
ratio of initiator to monomer is an important factor in polymer
preparation, with some embodiments.
[0093] The oxirane functional monomers and monomers that are free
of oxirane functionality, from which the polymers prepared by
controlled radical polymerization having at least two cyclic
carbonate groups can be prepared, include but are not limited to
those classes and examples recited previously herein with regard to
the polymers prepared by free radical polymerization having at
least two cyclic carbonate groups.
[0094] The cyclic carbonate functional polymer can, with some
embodiments, have polymer architecture selected from linear
polymers, branched polymers, hyperbranched polymers, star polymers,
graft polymers, and mixtures thereof. The form, or gross
architecture, of the polymer can be controlled by the choice of
initiator and monomers used in its preparation. Linear cyclic
carbonate functional polymers can be prepared by using initiators
having one or two radically transferable groups, such as
diethyl-2-halo-2-methyl malonate and alpha, alpha'-dichloroxylene.
Branched cyclic carbonate functional polymers can be prepared by
using branching monomers, such as monomers containing radically
transferable groups or more than one ethylenically unsaturated
radically polymerizable group, such as 2-(2-bromopropionoxy)ethyl
acrylate, p-chloromethylstyrene and diethyleneglycol
bis(methacrylate). Hyperbranched cyclic carbonate functional
polymers can be prepared by increasing the amount of branching
monomer used.
[0095] Star cyclic carbonate functional polymers can be prepared
using initiators having three or more radically transferable
groups, such as hexakis(bromomethyl)benzene. Star polymers can be
prepared by art-recognized core-arm or arm-core methods. In the
core-arm method, the star polymer is prepared by polymerizing
monomers in the presence of the polyfunctional initiator, such as
hexakis(bromomethyl)benzene. Polymer chains, or arms, of similar
composition and architecture grow out from the initiator core, in
the core-arm method. With the arm-core method, the arms are
prepared separately from the core and can optionally have different
compositions, architecture, molecular weight, and PDI's. The arms
can have different cyclic carbonate equivalent weights, and some
can have no cyclic carbonate functionality. After the preparation
of the arms, they are attached to the core by art-recognized
methods, so as to result in the formation of an arm-core
polymer.
[0096] The cyclic carbonate functional polymers prepared by
controlled radical polymerization can have, with some embodiments,
a cyclic carbonate equivalent weight of at least 100
grams/equivalent, or at least 200 grams/equivalent. The cyclic
carbonate equivalent weight of the polymer is, with some
embodiments, less than 10,000 grams/equivalent, or less than 5,000
grams/equivalent, or less than 1,000 grams/equivalent. The cyclic
carbonate equivalent weight of the cyclic carbonate functional
polymer prepared by controlled radical polymerization can range
between any combination of these values, inclusive of the recited
values, such as from 100 to 10,000 grams/equivalent, or from 200 to
5,000 grams/equivalent, or from 200 to 1,000 grams/equivalent,
inclusive of the recited values.
[0097] The number average molecular weight (Mn) of the polymers
prepared by controlled radical polymerization having at least two
cyclic carbonate groups (or the cyclic carbonate functional polymer
prepared by controlled radical polymerization) is with some
embodiments at least 250, or at least 500, or at least 1,000, or at
least 2,000. The cyclic carbonate functional polymer prepared by
controlled radical polymerization also has, with some embodiments,
an Mn of less than 16,000, or less than 10,000, or less than 5,000.
The Mn of the cyclic carbonate functional polymer prepared by
controlled radical polymerization can, with some embodiments, range
between any combination of these values, inclusive of the recited
values, such as from 250 to 16,000, or from 500 to 10,000, or from
1,000 to 5,000, or from 2,000 to 5,000, inclusive of the recited
values.
[0098] Prior to use in the curable sold particulate compositions of
the present invention, the ATRP transition metal catalyst and its
associated ligand are, with some embodiments, separated or removed
from the cyclic carbonate functional polymer. The ATRP catalyst is
removed, with some embodiments, prior to conversion of the
precursor polymer to the cyclic carbonate functional polymer.
Removal of the ATRP catalyst is achieved, with some embodiments,
using known methods, including, for example, adding a catalyst
binding agent to the mixture of the oxirane functional polymer or
cyclic carbonate functional polymer, solvent and catalyst, followed
by filtering. Examples of suitable catalyst binding agents include,
but are not limited to, alumina, silica, clay, or combinations
thereof. A mixture of the oxirane functional polymer or cyclic
carbonate functional polymer, solvent and ATRP catalyst can be
passed through a bed of catalyst binding agent, with some
embodiments. Alternatively, the ATRP catalyst can be oxidized in
situ and retained in the oxirane functional polymer or cyclic
carbonate functional polymer.
[0099] Each first reactant of the curable solid particulate
compositions of the present invention can be prepared, with some
embodiments, in the absence of solvent, such as by a bulk
polymerization process. With some embodiments, the first reactant
is prepared in the presence of a solvent, such as water and/or an
organic solvent Classes of useful organic solvents include, but are
not limited to, esters of carboxylic adds, ethers, cyclic ethers,
C.sub.5-C.sub.10 alkanes, C.sub.5-C.sub.8 cycloalkanes, aromatic
hydrocarbon solvents, halogenated hydrocarbon solvents, amides,
nitrites, sulfoxides, sulfones, and mixtures thereof. Supercritical
solvents, such as CO.sub.2, C.sub.1-C.sub.4 alkanes and
fluorocarbons, can also be employed. With some embodiments aromatic
hydrocarbon solvents are used, such as xylene, and mixed aromatic
solvents such as those commercially available from Exxon Chemical
America under the trademark SOLVESSO.
[0100] The solvent is removed or separated from the first reactant
prior to incorporation of the first reactant into the curable solid
particulate composition, with some embodiments. The solvent can be
removed by art-recognized methods, such as by distillation under
conditions of reduced pressure and, optionally, elevated
temperature, with some embodiments.
[0101] The first reactant, with some embodiments is present in the
curable solid particulate composition of the present invention in
an amount of at least 50 percent by weight, or at least 70 percent
by weight, or at least 80 percent by weight, based on total weight
of resin solids of the curable solid particulate composition. The
curable solid particulate composition also, with some embodiments,
contains the first reactant in an amount of less than or equal to
98 percent by weight, or less than or equal to 95 percent by
weight, or less than or equal to 90 percent by weight, based on
total weight of resin solids of the curable solid particulate
composition. The first reactant can, with some embodiments, be
present in the curable solid particulate composition of the present
invention in an amount ranging between any combination of these
values, inclusive of the recited values, such as from 50 to 98
percent by weight, or from 70 to 95 percent by weight, or from 80
to 90 percent by weight, in each case based on total weight of
resin solids of the curable solid particulate composition.
[0102] The curable solid particulate compositions of the present
invention also include a second reactant having at least two active
hydrogen groups that are reactive with the cyclic carbonate groups
of the first reactant. With some embodiments, each active hydrogen
group of the second reactant is independently chosen from hydroxyl
groups, thiol groups, hydrazide groups, and amine groups.
[0103] Second reactants having at least two hydroxyl groups can,
with some embodiments, be selected from one or more of the hydroxy
functional precursor or intermediate materials used to prepare the
first reactants as described previously herein. With some
embodiments, the second reactant can be selected from: one or more
of the polyols used to prepare the polyol residues having at least
two cyclic carbonate groups; one or more of the hydroxy functional
polyesters used to prepare the polyesters having at least two
cyclic carbonate groups; one or more of the hydroxy functional
polyethers used to prepare the polyethers having at least two
cyclic carbonate groups; one or more of the hydroxy functional
polyurethanes used to prepare the polyurethanes having at least two
cyclic carbonate groups; and combinations thereof.
[0104] Second reactants having at least two hydroxyl groups can,
with some embodiments, be selected from: polymers prepared by free
radical polymerization that have at least two hydroxyl groups; or
polymers prepared by controlled radical polymerization that have at
least two hydroxyl groups. With some embodiments, such polymers
include at least two residues of hydroxy functional ethylenically
unsaturated monomers, such as, but not limited to, hydroxy
functional C.sub.1-C.sub.20 linear, branched or cyclic
alkyl(meth)acrylates. Such polymers can be prepared in accordance
with the methods and monomers as described previously herein with
regard to the first reactant.
[0105] Second reactants having at least two thiol groups can be
prepared by art-recognized methods. With some embodiments, a
hydroxy functional material, such as described previously herein
with regard to the hydroxy functional second reactant or hydroxy
functional precursor/intermediate materials from which the first
reactant can be prepared, is reacted with epithiochlorohydrin,
which results in the formation of an intermediate material having
at least two thiirane groups. The thiirane groups of the
intermediate material can, with some embodiments, be subsequently
ring-opened in accordance with art-recognized methods so as to form
a material having at least two thiol groups, from which the second
reactant can be chosen.
[0106] Each active hydrogen group of the second reactant is, in
accordance with some embodiments, independently selected from amine
groups, and each amine group of the second reactant is
independently selected from primary amines and secondary
amines.
[0107] The second reactant, with some embodiments, includes linear
or branched aliphatic amines, cycloaliphatic amines,
heterocycloaliphatic amines, aromatic amines, heteroaromatic
amines, and combinations of two or more thereof.
[0108] In accordance with some further embodiments, the second
reactant includes diaminocyclohexane,
4,4'-methylenedi(cyclohexylamine),
4,4'-propane-2,2-diyl)dicyclohexanamine,
3,3'-dimethyl-methylenedi(cyclohexylamine),
4,4'-(propane-2,2-diyl)dianiline, 4,4'-methylenedianiline,
piperazine, N-amino ethyl piperazine,
5-amino-1-aminomethyl-1,3,3-trimethyl-cyclohexane, diamino ethane,
diamino propane, diaminobutane, diaminopentane, diaminohexane,
diaminoheptane, diaminooctane, diaminodecane, diaminoundecane,
diaminododecane, dicyanamide, 4,4'-diaminodiphenyl sulfone,
melamine, and combinations of two or more thereof.
[0109] The second reactant (b) is present, with some embodiments,
in the curable particulate composition of the present invention in
an amount of at least 2 percent by weight, or at least 5 percent by
weight, or at least 10 percent by weight, based on total weight of
resin solids of the curable particulate composition. The second
reactant (b) can also, with some embodiments be present in the
curable particulate composition in an amount of less than or equal
to 50 percent by weight, or less than or equal to 30 percent by
weight, or less than or equal to 20 percent by weight, based on
total weight of resin solids of the curable particulate
composition. The second reactant can be present in the curable
particulate composition of the present invention in an amount
ranging between any combination of these values, inclusive of the
recited values, such as from 2 to 50 percent by weight, or from 5
to 30 percent by weight, or from 10 to 20 percent by weight, based
on total weight of resin solids of the curable particulate
composition, and, inclusive of the recited values.
[0110] The first reactant (a) is present in the curable solid
particulate composition, with some embodiments, in an amount of
from 50 to 98 percent by weight, based on total resin solids weight
of the curable solid particulate composition; and the second
reactant is present in the curable solid particulate composition,
with some embodiments, in an amount of from 2 to 50 percent by
weight, based on total resin solids weight of the curable solid
particulate composition.
[0111] To achieve a suitable level of cure with the curable solid
particulate composition of the present invention, the equivalent
ratio of cyclic carbonate equivalents of the first reactant (a) to
active hydrogen equivalents of the second reactant (b) is, with
some embodiments, from 0.7:1 to 2:1, or from 0.8:1 to 1.3:1.
[0112] The curable solid particulate composition of the present
invention can also, with some embodiments, include pigments and
fillers. Examples of pigments include, but are not limited to:
inorganic pigments, such as titanium dioxide and iron oxides;
organic pigments, such as phthalocyanines, anthraquinones,
quinacridones and thioindigos; and carbon blacks. Examples of
fillers include, but are not limited to: silica, such as
precipitated silicas; clay; and barium sulfate. When used in the
composition of the present invention, pigments and fillers can,
with some embodiments, be present in amounts of from 0.1 percent to
70 percent by weight, based on the total weight of the curable
solid particulate composition.
[0113] The curable solid particulate composition of the present
invention can, with some embodiments, optionally contain additives
such as, but not limited to: waxes for flow and wetting; flow
control agents, such as poly(2-ethylhexyl)acrylate; degassing
additives such as benzoin; adjuvant resin to modify and optimize
coating properties; antioxidants; and ultraviolet (UV) light
absorbers. Examples of useful antioxidants and UV light absorbers
include, but are not limited to, those available commercially from
BASF under the trademarks IRGANOX and TINUVIN. These optional
additives, when used, can be present in amounts up to 20 percent by
weight, based on total weight of the curable solid particulate
composition.
[0114] The curable solid particulate composition of the present
invention can, with some embodiments, be prepared by first dry
blending the first reactant (a), the second reactant (b), and,
optionally, additives, such as flow control agents, degassing
agents, antioxidants and UV absorbing agents, in a dry blender,
such as a HENSCHEL blade dry blender. The dry blender is operated
for a period of time that is at least sufficient to result in a
homogenous dry blend of the materials charged thereto. The
homogenous dry blend is then melt blended in a melt blender, such
as an extruder, such as a twin screw co-rotating extruder, operated
within a temperature range of 80.degree. C. to 140.degree. C., or
from 100.degree. C. to 125.degree. C. The extrudate of the curable
solid particulate composition of the present invention is cooled
and, when used as a powder coating composition, is typically milled
to an average particle size of from 15 to 40 microns, or from 20 to
30 microns, with some embodiments.
[0115] The first reactant and second reactant of the curable solid
particulate composition of the present invention are each
independently: resinous and having a glass transition temperature
(Tg); or crystalline and having a crystalline melting point. By
"resinous" is meant that the reactant is composed of a majority of
amorphous domains, and, can optionally have some crystalline
domains. By "crystalline" is meant that the reactant has a majority
of crystalline domains, and, optionally some, such as a minority,
of amorphous domains. With some embodiments, a crystalline reactant
of the curable solid particulate composition includes some
amorphous domains.
[0116] The curable solid particulate compositions of the present
invention, with some embodiments, melt and flow when exposed to
elevated temperature, such as under conditions of cure. In
accordance with some further embodiments, when exposed to elevated
temperature, such as under conditions of cure, the curable solid
particulate compositions of the present invention melt and flow,
substantially uniformly, so as to form coatings having
substantially uniform thicknesses and, optionally, smooth
surfaces.
[0117] One or more components of the curable particulate
compositions, such as the first reactant and/or the second
reactant, are crystalline materials that have lower melt
viscosities relative to the melt viscosities of a resinous
component or material (having a Tg rather than a melting point).
The lower melt viscosity of the crystalline material can, with some
embodiments, reduce the overall melt viscosity of the curable solid
particulate compositions of the present invention, when they are
exposed to elevated temperature, such as under conditions cure,
which can result in improved flow and appearance of the resulting
cured product, such as a cured coating. With some embodiments, the
first and/or second reactants are crystalline materials
independently having a melt viscosity of from 5 centipoise (cps) to
75 cps, such as from 7 cps to 60 centipoise (cps), or from 10 cps
to 50 cps, as measured at a temperature of 100.degree. C. using an
appropriate device, such as an REL heated cone and plate viscometer
commercially available from Research Equipment Ltd.
[0118] With some embodiments, the first and/or second reactants are
resinous materials (having a Tg) which each independently have a
melt viscosity of from 10 to 100 poise, or from 20 to 80 poise, or
from 30 to 70 poise, as measured at a temperature of 125.degree. C.
to 150.degree. C., using an appropriate device, such as an REL
heated cone and plate viscometer commercially available from
Research Equipment Ltd.
[0119] The glass transition temperatures and/or melting points of
the first and/or second reactants can be determined in accordance
with art-recognized methods. With some embodiments, glass
transition temperature values and melting point values are
determined using differential scanning calorimetry (DSC) in
accordance with art-recognized analytical methods.
[0120] In accordance with some embodiments, the first reactant and
the second reactant are each resinous materials and each
independently have glass transition temperatures (determined by DSC
analysis) of from 30.degree. C. to 80.degree. C., or from
35.degree. C. to 50.degree. C. With some embodiments, at least one
of the first reactant and the second reactant is a resinous
material.
[0121] With some embodiments, one of the first reactant and the
second reactant is a crystalline material, and the other of the
first reactant and the second reactant is a resinous material. The
crystalline first reactant or crystalline second reactant can, with
some embodiments, have a melting point (as determined by DSC
analysis) of at least 80.degree. C. and less than or equal to
300.degree. C., or at least 100.degree. C. and less than or equal
to 300.degree. C., or at least 110.degree. C. and less than or
equal to 200.degree. C., or at least 115.degree. C. and less than
or equal to 150.degree. C., or at least 120.degree. C. and less
than or equal to 130.degree. C., inclusive of the recited values,
any combination of these recited lower and upper values, and any
intervening values.
[0122] With some embodiments, the first reactant is resinous and
has a glass transition temperature, such as of from 30.degree. C.
to 80.degree. C., or from 35.degree. C. to 50.degree. C., as
measured by DSC.
[0123] With some further embodiments, the first reactant is
crystalline and has a crystalline melting point, such as at least
80.degree. C. and less than or equal to 300.degree. C., or at least
100.degree. C. and less than or equal to 300.degree. C., or at
least 110.degree. C. and less than or equal to 200.degree. C., or
at least 115.degree. C. and less than or equal to 150.degree. C.,
or at least 120.degree. C. and less than or equal to 130.degree.
C., inclusive of the recited values, any combination of these
recited lower and upper values, and any intervening values, as
determined by DSC.
[0124] The curable solid particulate composition of the present
invention can, with some embodiments, be free flowing.
[0125] The curable solid particulate composition of the present
invention can be cured by any suitable methods. With some
embodiments, the curable solid particulate composition is
thermosetting, and is curable by exposure to elevated temperature.
As used herein, by "cured" is meant a three-dimensional crosslink
network formed by covalent bond formation, such as between the
cyclic oxirane groups of the first reactant and the active hydrogen
groups of the second reactant. The temperature at which the
thermosetting composition of the present invention is cured is
variable and depends in part on the amount of time during which
curing is conducted. With some embodiments, the thermosetting
composition is cured at a temperature within the range of
80.degree. C. to 204.degree. C., or from 149.degree. C. to
204.degree. C., or from 154.degree. C. to 177.degree. C., for a
period of 20 to 60 minutes.
[0126] In accordance with some further embodiments, the curable
solid particulate composition of the present invention is a powder
coating composition. With some further embodiments, the curable
solid particulate composition of the present invention is a
thermosetting powder coating composition.
[0127] The curable solid particulate composition of the present
invention can, with some embodiments be used to coat a substrate,
such as when it is in the form of a curable powder coating
composition. The present invention also relates to a method of
coating a substrate that involves: (a) applying to the substrate a
thermosetting composition; (b) coalescing the thermosetting
composition to form a substantially continuous film; and (c) curing
the thermosetting composition by exposure to elevated temperature.
The thermosetting composition includes, or is defined by, the
curable solid particulate composition of the present invention as
previously described herein.
[0128] The curable solid particulate composition of the present
invention can be applied, with some embodiments, to the substrate
by any appropriate art-recognized methods. With some embodiments,
the curable solid particulate composition (which can be a
thermosetting composition with some embodiments) is in the form of
a dry powder, such as a powder coating, and is applied by spray
application. Alternatively, the dry powder can be slurried in a
liquid medium such as water, and spray applied. As used herein, the
term "curable solid particulate composition" means a curable solid
particulate composition that can be in dry powder form or in the
form of a slurry that includes one or more liquids, such as water
and, optionally, one or more organic solvents, such as
alcohols.
[0129] When the substrate is electrically conductive, the curable
solid particulate composition can be electrostatically applied,
with some embodiments. Electrostatic spray application generally
involves drawing the curable solid particulate composition from a
fluidized bed and propelling it through a corona field. The
particles of the curable solid particulate composition become
charged as they pass through the corona field and are attracted to
and deposited upon the electrically conductive substrate, which is
grounded. As the charged particles begin to build up, the substrate
becomes insulated, thus, limiting further particle deposition. This
insulating phenomenon can limit the film build of the deposited
composition to a maximum of 3 to 6 mils (75 to 150 microns), with
some embodiments.
[0130] Alternatively, when the substrate is not electrically
conductive, for example, as is the case with many plastic
substrates, the substrate is preheated prior to application of the
curable solid particulate composition, with some embodiments. The
preheated temperature of the substrate is equal to or greater than
that of the melting point of the curable solid particulate
composition, but less than its cure temperature, with some
embodiments. With spray application over preheated substrates, film
builds of the curable solid particulate composition in excess of 6
mils (150 microns) can be achieved, such as 10 to 20 mils (254 to
508 microns). Substrates that can be coated by the method of the
present invention include, but are not limited to: metal
substrates, such as ferrous substrates and aluminum substrates;
plastic substrates, such as sheet molding compound based plastics;
inorganic substrates, such as ceramic substrates, and glass
substrates comprising silica-based glass; wood; and combinations of
two or more thereof.
[0131] After application to the substrate, the curable solid
particulate composition of the present invention is then coalesced
to form a substantially continuous film, with some embodiments.
Coalescing of the applied curable solid particulate composition is
generally achieved through the application of heat at a temperature
equal to or greater than that of the melting point of the curable
solid particulate composition, but less than its cure temperature.
In the case of preheated substrates, the application and coalescing
steps can be achieved in essentially one step.
[0132] The coalesced curable solid particulate composition of the
present invention is next cured by the application of heat. The
temperature at which the curable solid particulate composition of
the present invention is cured is variable and depends in part on
the amount of time during which curing is conducted. Temperatures
at which the curable solid particulate composition can be cured
include, but are not limited to, those temperatures and ranges as
recited previously herein, such as from 80.degree. C. to
204.degree. C., or from 149.degree. C. to 204.degree. C., or from
154.degree. C. to 177.degree. C., for a period of 20 to 60
minutes.
[0133] The curable solid particulate composition of the present
invention can be applied as a single layer or multiple layered
coating, in which each layer has the same or different
compositions. The curable solid particulate composition of the
present Invention can be applied in conjunction with one or more
other coating compositions, such as, but not limited to, primers,
base coats, and/or clear coatings. The curable solid particulate
compositions of the present invention can be used to form (or as)
primers, base coats, and/or clear coatings. As used herein, the
term "clear coatings" includes, with some embodiments, transparent
top coats. Coatings formed from the curable solid particulate
compositions of the present invention can, with some embodiments,
have a thickness of from 0.5 to 6 mils (13 to 150 microns), or from
1 to 3 mils (25 to 75 microns).
[0134] The present invention is more particularly described in the
following examples, which are intended to be illustrative only,
since numerous modifications and variations therein will be
apparent to those skilled in the art. Unless otherwise specified,
all parts and percentages are by weight.
EXAMPLES
Synthesis Example A
[0135] A bis(cyclic carbonate) of the diglycidyl ether of
4,4'-(propane-2,2-diyl)diphenol was prepared using the materials
and related amounts as summarized in the following Table A-1.
TABLE-US-00001 TABLE A-1 Weight (grams) diglycidyl ether of
4,4'-(propane-2,2-diyl)diphenol.sup.(1) 400 tetrabutylammonium
bromide 10 triphenyl phosphite 1.2 1-methoxy-2-propanol.sup.(2) 266
.sup.(1)Obtained commercially from Momentive under the tradename
EPON 880 liquid epoxy resin. .sup.(2)Obtained commercially from Dow
Chemical Company under the tradename DOWANOL PM solvent.
[0136] The Ingredients as listed in the above Table A-1 were
charged to a 1 gallon stainless steel pressure reactor that was
equipped with an overhead stirrer, gas inlet, outlet pipes, a
heating jacket, thermocouple, and pressure gauge. The reactor was
closed and charged with gaseous CO.sub.2 to a pressure of 50 psi.
With constant stirring at a rate of 500 rpm, the contents of the
reactor were heated to and held at 130.degree. C. for 4.5 hours.
The contents of the reactor were subjected to distillation at
reduced pressure, after which the reduced solids contents of the
reactor were removed therefrom.
[0137] The cyclic carbonate functional product of Synthesis Example
A was analyzed by NMR and it was determined that 87 percent of the
glycidyl ether groups of the diglycidyl ether of
4,4'-(propane-2,2-diyl)diphenol feed material had been converted to
cyclic carbonate groups. The cyclic carbonate functional product of
Synthesis Example A was found to have a solids of 70.3 percent by
weight, as determined at a temperature of 110.degree. C. for 60
minutes. For reference, a schematic representation of Synthesis
Example A is provided in the following Scheme (II).
##STR00006##
[0138] With reference to Scheme (II), product (A-II) had a melt
viscosity of 16 centipoise (cps) as measured at a temperature of
100.degree. C. using an REL heated cone and plate viscometer
commercially available from Research Equipment Ltd.
[0139] With reference to Scheme (II), starting material (A-I) and
product (A-II) were analyzed by differential scanning calorimetry
(DSC), and the melting points for each are summarized in the
following Table A-2. Prior to measuring the melting point by DSC,
the bis(cyclic carbonate) product (A-II) was placed in an oven at
100.degree. C. for 30 minutes to drive of remaining solvent. The
dried bis(cyclic carbonate) product (A-II) was found to have a
solids of 98 percent by weight. The DSC analysis was conducted
using a TAI Discovery DSC apparatus. In each case, specimens were
sealed in aluminum hermetic pans, which were subjected to the
following sequence of cooling and heating: (i) cooling to
-90.degree. C.; heating to 175.degree. C.; cooling to -90.degree.
C.; and heating to 175.degree. C. Heating was conducted in each
case at a rate of 20.degree. C./minute. The DSC was operated with a
nitrogen purge rate of 50 mL/minute, and was calibrated with
indium, tin, and zinc standards. Melting points were determined
manually from the final heating cycle.
TABLE-US-00002 TABLE A-2 Material Melting Point (A-I) -42.degree.
C. (A-II) 128.degree. C.
Synthesis Example B
[0140] A bis(cyclic carbonate) of the diglycidyl ether of
4,4'-(propane-2,2-diyl)dicyclohexanol was prepared using the
materials and related amounts as summarized in the following Table
B-1.
TABLE-US-00003 TABLE B-1 Weight (grams) diglycidyl ether of
4,4'-(propane-2,2-diyl)dicyclohexanol.sup.(3) 400
tetrabutylammonium bromide 10 triphenyl phosphite 1.2 butyl acetate
266 .sup.(3)Obtained commercially from Momentive under the
tradename EPONEX 1510 liquid epoxy resin.
[0141] The ingredients as listed in the above Table B-1 were
charged to a 1 gallon stainless steel pressure reactor that was
equipped with an overhead stirrer, gas inlet, outlet pipes, a
heating Jacket, thermocouple, and pressure gauge. The reactor was
dosed and charged with gaseous CO.sub.2 to a pressure of 50 psi.
With constant stirring at a rate of 500 rpm, the contents of the
reactor were heated to and held at 130.degree. C. for 4.5 hours.
The contents of the reactor were subjected to distillation at
reduced pressure, after which the reduced solids contents of the
reactor were removed therefrom.
[0142] The cyclic carbonate functional product of Synthesis Example
B was analyzed by NMR and it was determined that 91 percent of the
glycidyl ether groups of the diglycidyl ether of
4,4'-(propane-2,2-diyl)dicyclohexanol feed material had been
converted to cyclic carbonate groups. The cyclic carbonate
functional product of Synthesis Example B was found to have a
solids of 66.8 percent by weight, as determined at a temperature of
110.degree. C. for 60 minutes. For reference, a schematic
representation of Synthesis Example B is provided in the following
Scheme (III).
##STR00007##
[0143] With reference to Scheme (III), product (B-II) had a melt
viscosity of 10 centipoise (cps) as measured at a temperature of
100.degree. C. using an REL heated cone and plate viscometer
commercially available from Research Equipment Ltd.
[0144] With reference to Scheme (III), starting material (B-I) and
product (B-II) were analyzed by differential scanning calorimetry
(DSC), and the melting points for each are summarized in the
following Table B-2. Prior to measuring the melting point by DSC,
the bis(cyclic carbonate) product (B-II) was placed in an oven at
100.degree. C. for 30 minutes to drive of remaining solvent. The
dried bis(cyclic carbonate) product (B-II) was found to have a
solids of 98 percent by weight, at determined at 160.degree. C. for
5 minutes. The melting points recited in Table B-2 were determined
in accordance with the DSC analysis as described with regard to
Table A-2 previously herein.
TABLE-US-00004 TABLE B-2 Material Melting Point (B-I) -42.degree.
C. (B-II) 84.degree. C.
Curable Composition Examples
Curable Composition 1
[0145] A metal panel was preheated to a temperature of 200.degree.
C. on a nickel-plated hotplate having a surface temperature of
200.degree. C. The bis(cyclic carbonate) product (A-II) of
Synthesis Example A was placed in an oven at 100.degree. C. for 30
minutes to drive of remaining solvent. The dried bis(cyclic
carbonate) product (A-II) was found to have a solids of 98 percent
by weight.
[0146] The dried bis(cyclic carbonate) product (A-II) of Synthesis
Example A and dicyanamide were mixed together on the preheated
panel, while still on the hotplate, in a stoichiometric ratio of
1:1, in a weight totaling about 50 grams. The composition was mixed
by hand using a stainless steel spatula on the preheated panel for
about 10 seconds. The mixed molten composition was then drawn-down
on the preheated panel using a draw-down bar so as to form a film
having a thickness of 5 mils (127 micrometers). The metal panel
with film drawn-down thereon was removed from the hotplate and
allowed to cool and solidify.
[0147] Additional coated panels were prepared in accordance with
the above method, and placed in an oven at a temperature of
93.degree. C. (200.degree. F.) for 5 minutes and 25 minutes, and an
oven at a temperature of 160.degree. C. (320.degree. F.) for 5
minutes and 25 minutes. The panels were removed from the oven and
allowed to cool to room temperature, after which they were
subjected to double rubs by hand using a red-rag saturated with
methyl ethyl ketone (MEK), which had been drawn over a human index
finger. The results of the MEK double rub testing are summarized in
the following Table 1.
Comparative Curable Composition 1
[0148] Metal panels were coated with a molten composition composed
of the feed material (A-I) of Synthesis Example A and dicyanamide
(in a stoichiometric ratio of 1:1) in accordance with the
description provided for Curable Composition 1 above. The coated
metal panels were placed in an oven at a temperature of 93.degree.
C. (200.degree. F.) for 5 minutes and 25 minutes, and an oven at a
temperature of 160.degree. C. (320.degree. F.) for 5 minutes and 25
minutes. The panels were removed from the oven and allowed to cool
to room temperature, after which they were subjected to double rubs
by hand using a red-rag saturated with methyl ethyl ketone (MEK),
which had been drawn over a human index finger. The results of the
MEK double rub testing are summarized in the following Table 1.
TABLE-US-00005 TABLE 1 MEK Double Rub Results Oven Exposure
Comparative Curable Conditions Composition 1 Curable Composition 1
5 min @93.degree. C. 0.5 MEK double rubs 70 MEK double rubs 25 min
@93.degree. C. 5 MEK double rubs +100 MEK double rubs 5 min
@160.degree. C. 10 MEK double rubs +100 MEK double rubs 25 min
@160.degree. C. +100 MEK double rubs +100 MEK double rubs
[0149] Films having MEK double rub values of +100 showed no change
in visual appearance (by naked eye) after being subjected to 100
double rubs, and were considered to be fully cured. Films having
MEK double rub values of less than 100 (e.g., 10 MEK double rubs)
were considered to be less than fully cured because the film was
observed to have disappeared (i.e., to have been fully solubilized
by the MEK) after the indicated number of double rubs.
[0150] With reference to Table 1, Curable Composition 1, which is a
non-limiting representative embodiment of the present invention,
provided films having a significantly improved cure response
relative to Comparative Curable Composition 1. Films prepared from
Curable Composition 1 were observed to have been fully cured after
25 minutes at 93.degree. C., relative to films prepared from
Comparative Curable Composition 1, which were not observed to have
obtained full cure until 25 minutes at 160.degree. C.
Curable Composition 2
[0151] The bis(cyclic carbonate) product (B-II) of Synthesis
Example B was placed in an oven at 100.degree. C. for 30 minutes,
to drive off remaining solvent. The resulting dried bis(cyclic
carbonate) product (B-II) was found to have a solids of 98 percent
by weight, as determined at 160.degree. C. for 5 minutes. Metal
panels were coated with a molten composition composed of the dried
bis(cyclic carbonate) product material (B-II) of Synthesis Example
B and dicyanamide (in a stoichiometric ratio of 1:1) in accordance
with the description provided for Curable Composition 1 above.
[0152] The coated metal panels were placed in an oven at a
temperature of 93.degree. C. (200.degree. F.) for 5 minutes and 25
minutes, and an oven at a temperature of 160.degree. C.
(320.degree. F.) for 5 minutes and 25 minutes. The panels were
removed from the oven and allowed to cool to room temperature,
after which they were subjected to double rubs by hand using a
red-rag saturated with methyl ethyl ketone (MEK), which had been
drawn over a human index finger. The results of the MEK double rub
testing are summarized in the following Table 2.
Comparative Curable Composition 2
[0153] Metal panels were coated with a molten composition composed
of the feed material (B-I) of Synthesis Example B and dicyanamide
(in a stoichiometric ratio of 1:1) in accordance with the
description provided for Curable Composition 1 above. The coated
metal panels were placed in an oven at a temperature of 93.degree.
C. (200.degree. F.) for 5 minutes and 25 minutes, and an oven at a
temperature of 160.degree. C. (320.degree. F.) for 5 minutes and 25
minutes. The panels were removed from the oven and allowed to cool
to room temperature, after-which they were subjected to double rubs
by hand using a red-rag saturated with methyl ethyl ketone (MEK),
which had been drawn over a human index finger. The results of the
MEK double rub testing are summarized in the following Table 2.
TABLE-US-00006 TABLE 2 MEK Double Rub Results Oven Exposure
Comparative Curable Conditions Composition 2 Curable Composition 2
5 min @93.degree. C. 0 MEK double rubs 30 MEK double rubs 25 min
@93.degree. C. 5 MEK double rubs +100 MEK double rubs 5 min
@160.degree. C. 10 MEK double rubs +100 MEK double rubs 25 min
@160.degree. C. 50 MEK double rubs +100 MEK double rubs
[0154] As discussed with regard to the MEK double rub results
presented in Table 1, and with reference to Table 2, films having
MEK double rub values of +100 showed no change in visual appearance
(by naked eye) after being subjected to 100 double rubs, and were
considered to be fully cured. Films having MEK double rub values of
less than 100 (e.g., 10 MEK double rubs) were considered to be less
than fully cured because the film was observed to have disappeared
(i.e., to have been fully solubilized by the MEK) after the
indicated number of double rubs.
[0155] With reference to Table 2, Curable Composition 2, which is a
non-limiting representative embodiment of the present invention,
provided films having a significantly improved cure response
relative to Comparative Curable Composition 2. Films prepared from
Curable Composition 2 were observed to have been fully cured after
25 minutes at 93.degree. C., relative to films prepared from
Comparative Curable Composition 2, which were not observed to have
obtained full cure after 25 minutes at 160.degree. C.
[0156] The above results demonstrate that curable compositions
according to the present invention provide improved cure response,
such as full cure at lower temperatures, relative to comparative
compositions that have oxirane functional reactants rather than
cyclic carbonate functional reactants.
[0157] The present invention has been described with reference to
specific details of particular embodiments thereof. It is not
intended that such details be regarded as limitations upon the
scope of the invention except insofar as and to the extent that
they are included in the accompanying claims.
* * * * *