U.S. patent application number 17/549453 was filed with the patent office on 2022-03-31 for glycidyl ether based optical coating compositions.
The applicant listed for this patent is The Walman Optical Company. Invention is credited to Gerald D. Treadway.
Application Number | 20220098439 17/549453 |
Document ID | / |
Family ID | 1000006024328 |
Filed Date | 2022-03-31 |
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United States Patent
Application |
20220098439 |
Kind Code |
A1 |
Treadway; Gerald D. |
March 31, 2022 |
GLYCIDYL ETHER BASED OPTICAL COATING COMPOSITIONS
Abstract
A combination comprising a substrate and cured coating
composition formed of the hydrolysis product of an epoxy functional
alkoxy silane in combination with one or more monoaromatic (mono-
or di) glycidyl ethers, the cured coating providing improved
adhesion as compared to previous known UV curable coatings. The
coating composition includes at least one monoaromatic di- or
monoglycidyl ethers, and most preferably includes resorcinol
diglycidyl ether.
Inventors: |
Treadway; Gerald D.;
(Penngrove, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Walman Optical Company |
Minneapolis |
MN |
US |
|
|
Family ID: |
1000006024328 |
Appl. No.: |
17/549453 |
Filed: |
December 13, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14624036 |
Feb 17, 2015 |
11198795 |
|
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17549453 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08G 77/14 20130101;
C09D 183/06 20130101; C08G 77/20 20130101; G02B 1/10 20130101; G02B
1/041 20130101 |
International
Class: |
C09D 183/06 20060101
C09D183/06 |
Claims
1. A combination comprising a substrate having a cured coating
formed by the application of ultraviolet radiation to an
organofunctional silane composition that comprises a monoaromatic
mono- or diglycidyl ether, wherein the cured coating exhibits
acceptable adhesion resistance, as determined by crosshatch
adhesion testing under conditions of deionized water and humidity
testing.
2. A combination according to claim 1, wherein the cured coating
also exhibits acceptable adhesion resistance, as determined by
crosshatch adhesion testing under conditions of QUV testing.
3. A combination according to claim 1 wherein the monoaromatic
glyciidyl ether is selected from the group consisting of a)
1,3-benzenediol-2,2'-[oxybis(methylene)]dioxirane ("RDGE"); b)
o-cresyl glycidyl ether; 2-[(2-methylphenoxy)methyl]oxirane; c)
2-[(4-tert-butylphenoxy)methyl]oxirane; d)
2-(phenoxymethyl)oxirane; e) 2-[(4-nonylphenoxy)methyl]oxirane); f)
1,4-bis(glycidyloxy) benzene); and combinations thereof.
4. A combination according to claim 3, wherein the monoaromatic
glycidyl ether comprises RDGE.
5. A combination according to claim 1, wherein the substrate is
selected from the group consisting of polycarbonate and high index
substrates.
6. A combination according to claim 5, wherein the substrate
comprises a high index substrate.
7. A combination according to claim 1, wherein the silane
composition comprises: a) a partially hydrolyzed alkoxy-functional
silane, selected from the group consisting of epoxy-, vinyl- and
acryloxy-functional alkoxysilanes, b) a substantially
non-hydrolyzed alkoxy-functional silane, c) an ethylenically
unsaturated monomer, d) a cationic photoinitiator, and e) a free
radical initiator.
8. A combination according to claim 7, wherein the substrate is
selected from the group consisting of polycarbonate and high index
substrates.
9. A combination according to claim 8, wherein the composition
comprises RDGE as the glycidyl ether.
10. A combination according to claim 1 wherein the composition
consists essentially of RDGE as the ether, the substrate comprises
a high index substrate, and the cured coating exhibits acceptable
adhesion resistance, as determined by crosshatch adhesion testing
under conditions of QUV testing.
11. A method of coating a composition upon the surface of a
polymeric material, the method comprising the steps of: a)
providing an organofunctional silane composition and substrate, b)
coating and curing the composition to provide a combination
according to claim 1.
12. A method according to claim 11, wherein the cured coating also
exhibits acceptable adhesion resistance, as determined by
crosshatch adhesion testing under conditions of QUV testing.
13. A method according to claim 11 wherein the monoaromatic
glyciidyl ether is selected from the group consisting of a)
1,3-benzenediol-2,2'-[oxybis(methylene)]dioxirane ("RDGE"); b)
o-cresyl glycidyl ether; 2-[(2-methylphenoxy)methyl]oxirane; c)
2-[(4-tert-butylphenoxy)methyl]oxirane; d)
2-(phenoxymethyl)oxirane; e) 2-[(4-nonylphenoxy)methyl]oxirane); f)
1,4-bis(glycidyloxy) benzene); and combinations thereof.
14. A method according to claim 13, wherein the monoaromatic
glycidyl ether comprises RDGE.
15. A method according to claim 11, wherein the substrate is
selected from the group consisting of polycarbonate and high index
substrates.
16. A method according to claim 15, wherein the substrate comprises
a high index substrate.
17. A method according to claim 11, wherein the silane composition
comprises: a) a partially hydrolyzed alkoxy-functional silane,
selected from the group consisting of epoxy-, vinyl- and
acryloxy-functional alkoxysilanes, b) a substantially
non-hydrolyzed alkoxy-functional silane, c) an ethylenically
unsaturated monomer, d) a cationic photoinitiator, and e) a free
radical initiator.
18. A method according to claim 17, wherein the substrate is
selected from the group consisting of polycarbonate and high index
substrates.
19. A method according to claim 18, wherein the composition
comprises RDGE as the glycidyl ether.
20. A method according to claim 11 wherein the composition consists
essentially of RDGE as the ether, the substrate comprises a high
index substrate, and the cured coating exhibits acceptable adhesion
resistance, as determined by crosshatch adhesion testing under
conditions of QUV testing.
Description
CROSS REFERENCE
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/624,036, filed Feb. 17, 2015, the entire
contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of transparent
coatings for polymeric objects such as eyeglass lenses.
BACKGROUND
[0003] There is an ongoing need and desire to provide coating
compositions that are capable of providing lenses and other such
surfaces with improved combinations of properties. For instance,
Applicant's U.S. Pat. No. 6,100,313 provides, inter alia, a coating
composition that accepts dye well, that provides exceptional
abrasion-resistance (AR), and that is substantially free of
volatiles. The composition includes a partially hydrolyzed
epoxy-functional alkoxysilane, and can also include a polymerizable
ether selected from the group consisting of glycidyl ethers, allyl
ethers and vinyl ethers.
[0004] Glycidyl ethers said to be useful in the invention of the
'313 patent include "triglycidyl ether, .gamma.-glycidoxypropyl
trimethoxy silane, triglycidyl ether, 1,4-butanediol diglycidyl
ether, Bisphenol A diglycidyl ether, the C8-C14 alkyl glycidyl
ethers, butyl glycidyl ether, cresyl glycidyl ether, phenyl
glycidyl ether, nonylphenyl glycidyl ether, p-tert-butylphenyl
glycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol
diglycidyl ether, resorcinol diglycidyl ether, polyglycidyl ethers
of aliphatic polyols, cyclohexane dimethanol diglycidyl ether,
2-ethylhexyl glycidyl ether, polyglycol diepoxide, polyglycidyl
ether of castor oil, trimethylolethane triglycidyl ether,
trimethylolpropane triglycidyl ether, dibromoneopentyl glycol
diglycidyl ether, and 3,4-epoxycyclohexyl
methyl-3,4-epoxycyclohexane carboxylate. Glycidyl ethers, if used
alone as the polymerizable ether, are present preferably in a
weight concentration (solids basis) of from about 10% to about
50%."
[0005] Also, Applicant's US patent application Serial No. U.S. Ser.
No. 13/789,998 ("Oxetane") describes a combination comprising a
coated and cured composition as a layer upon the surface of a
polymeric material, that includes a partially hydrolyzed
organo-functional alkoxysilane and a polymerizable aromatic
oxetane, such as 1,4-Bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene,
which is an aromatic, difunctional oxetane available commercially
as "OXT-121").
[0006] The optical and other industries continue to seek materials,
and corresponding surface treatments or coatings, that provide
improved properties, such as adhesion, tintability, abrasion
resistance, and solubility.
SUMMARY OF THE INVENTION
[0007] In one embodiment, the present invention provides a
combination comprising a substrate and cured coating formed of the
hydrolysis product of an epoxy functional alkoxy silane in
combination with one or more monoaromatic (mono- or di)glycidyl
ethers. A coating of this invention preferably exhibits an optimal
combination of properties that meet or exceed those provided by
conventional coatings, including to provide improved adhesion
resistance, preferably without the need for a primer, and as
determined by crosshatch adhesion tests according to ASTM 3359
(including those involving deionized water, humidity and/or QUV
testing). The compositions can be adapted to be tintable as well,
using conventional methods and as described herein.
[0008] In one embodiment, the invention provides a coating
composition for forming an abrasion-resistant coating upon a
substrate, the composition comprising an ether selected from the
group consisting of: [0009] a. resorcinol diglycidyl ether (also
referred to as 1,3-benzenediol-2,2'-[oxybis(methylene)]dioxirane
(1:1) ("RDGE"), [0010] b. cresyl glycidyl ether (also referred to
as epoxidized ortho cresol, o-cresyl glycidyl ether;
2-[(2-methylphenoxy)methyl]oxirane, Tradename GE10), [0011] c.
p-tert-butylphenyl glycidyl ether (also referred to as
p-tert-butylphenyl-1-(2,3-epoxy)propyl ether; IUPAC Name:
2-[(4-tert-butylphenoxy)methyl]oxirane, Tradename GE11), [0012] d.
phenyl glicidyl ether (also referred to as epoxidized phenol,
2-(phenoxymethyl)oxirane, an aromatic monofunctional compound
(monoepoxide), Tradename GE13), [0013] e. nonylphenyl glycidyl
ether (also referred to as 2-[(4-nonylphenoxy)methyl]oxirane), and
[0014] f. hydroquinone diglycidyl ether (also referred to as
1,4-bis(glycidyloxy) benzene).
[0015] In a particularly preferred embodiment, the ether comprises
RDGE (compound (A) above), either alone or in combination with one
or more other ethers, including aliphatic or other monoaromatic
ethers from within the list provided above. In addition to improved
adhesion, RDGE tends to provide improved solubility for use in
compositions of the present invention, particularly as compared to
ethers (B) through (F) listed above.
[0016] Though each of monoaromatic ethers (A) through (E) (though
not (F)) as described herein can be found within the listing of
ethers described in the '313 patent, coatings of the present
invention provide a surprising and optimal combination of
properties that include usefulness with a variety of substrates. In
turn, a composition of this invention can provide comparable or
improved properties selected from the group consisting of adhesion
resistance, stability, tintability, and abrasion resistance, among
others. In a particularly preferred embodiment, a composition that
includes RDGE can be used to provide a UV curable coating having
the potential to meet each of three different adhesion tests used
in the optical industry (deionized water, humidity, and QUV), which
taken together are typically considered to provide the most
stringent adhesion tests used in the industry. Prior UV cured
coatings, at their closest, tend to meet only two or fewer of such
tests, and particularly when used on High Index substrates, can
tend to meet only one of such tests, at most.
[0017] To the best of applicant's awareness, compositions of the
present invention provide the only known UV curable, and optionally
tintable, coating capable of meeting each of these tests, and in
particularly the stringent QUV test.
BRIEF DESCRIPTION OF THE DRAWING
[0018] In the Drawing, FIG. 1 provides a chart showing common
names, IUPAC names, structures and formulas for each of the
preferred glycidyl ethers of this invention.
DETAILED DESCRIPTION
[0019] A UV-cured composition of the present invention can be used
as a base coat to provide abrasion resistance (e.g., as determined
by Bayer abrasion) that approximates that of a comparable thermally
cured base coating, when used as the base coat for an
antireflective coating (stack) positioned thereon. The present
composition, however, provides various advantages over such thermal
cure coatings, including shorter processing times, while having the
potential to provide tintability that is as good or better than
conventional compositions.
[0020] In turn, the composition is particularly well suited for use
as the base coat, before the application of one or more additional
layers. Such additional layers often include, for instance, a
quartz or oxide (e.g., silicon dioxide) layer, followed by a
plurality of coated layers. The resulting "stack" of coated layers
can be applied in order to provide an improved array of properties
to the overall coated material, including in particular abrasion
resistance, as compared to conventional compositions. Applicant has
discovered the manner in which particular polymerizable monomers
from the group described herein as monoaromatic (mono- or
di)glycidyl ethers can be used in combination with organofunctional
silanes in order to provide improved compositions, and
corresponding base coats having excellent adhesion to polycarbonate
and other substrates. More preferably, and desirably, the
compositions of this invention have comparable or even improved
tintability, as compared to conventional compositions.
[0021] The formation of an abrasion resistant coating, for use on
eyeglass lenses, will typically begin with the application of a
composition of this invention, e.g., by spin coating and curing the
composition with ultraviolet energy. Thereafter, the coated base
composition can be subjected to one or more intermediate
treatments, for instance, it can be tinted using conventional
means, e.g., by dipping the coated lens into a tint bath.
[0022] Once the base composition has been applied, cured, and
tinted, the lens material can be subjected to a conventional
coating machine, for the application of an antireflection coating,
in the form of a `stack` or plurality of layers. Once coated with
the composition of this invention, in the form of an initial base
coat, the coated lens is typically degassed (e.g., under suitable
conditions of time, vacuum, and temperature), followed by the
application of an intermediate layer (e.g., quartz or silicon
dioxide), which itself can be compacted by e-beam or other means,
and finally by the application of one or more AR coatings applied
by means of vapor deposition.
[0023] The composition can be used to provide an improved
combination of properties, particularly for use in coating lenses
and other transparent polymeric materials. Such lens materials
include those having an array of properties (e.g., refractive
index), and preferably includes both polycarbonate and high index
lenses. The coating composition is itself substantially solvent
free, and in turn, provides minimal, if any, detectable volatiles
in the course of its application, curing, or use. Detectable
volatiles are likely to be found, if at all, upon the elimination
of methanol upon curing of certain compositions.
[0024] Compositions of this invention are particularly well suited
for polymeric substrates, and particularly high refractive index
substrates intended for optical applications, including
thermosetting and thermoplastic polycarbonates, as well as
polyurethanes. Such substrates can be used for a variety of
applications, including for automotive instrumentation, aviation
gauges and instruments, display and/or shielding windows, eyewear
lenses, handheld meters and devices, molded display windows and
panels, outdoor equipment gauges and displays, test &
laboratory instrument displays, screen printing POP signage,
thermoformed displays, medical displays and panels, and video and
LED filters.
[0025] In a further preferred embodiment, a coated substrate of
this invention comprises a high index material. Particularly
preferred high index materials of this type comprise a
polyisocyanate compound and a polythiol compound, to provide are
described in U.S. Pat. No. 5,652,321, the disclosure of which is
incorporated herein by reference. Such materials are described as
having an extremely high refractive index and excellent heat
resistance, as exemplified in commercial products such as the MR8
and MR10 lines of lenses available from Mitsui Toatsu Chemicals,
Inc.
[0026] Given the present description, those skilled in the art will
appreciate the manner in which a monoaromatic glycidyl ether can be
selected and used to provide desired performance, for instance,
based upon the overall formulation, the substrate being coated,
additional AR or other coatings to be used, and conditions of
use.
[0027] When used in a composition adapted to provide a
substantially non-tintable coating, the monoaromatic (mono- or
digylcidyl) ether can be present in the coating compositions of the
invention at a weight concentration (solids basis) of between about
1 and about 10 weight percent, more preferably between about 2 and
about 8 weight percent, and most preferably between about 4 and
about 6 weight percent. When used in a composition adapted to
provide a substantially tintable coating (e.g., for use in crafting
sunglasses), the monoaromatic ether can be present in the coating
compositions of the invention at a weight concentration (solids
basis) between about 1 and about 40 weight percent, more preferably
between about 10 and about 30 weight percent, and most preferably
between about 15 and about 25 weight percent. Increasing amounts
within these ranges tend to correspond with improved properties,
such as improved adhesion. Those skilled in the art, given the
present description, will understand the manner in which a
`tintable` coating of this type is typically one that can be coated
using standard conditions (e.g., dipping in BPI Black for 15
minutes at 95-1000) so as to provide between 18-22% transmission,
as compared to a substantially non-tintable coating, which under
comparable conditions would result in between 40-45% transmission.
The word "substantially", as used with respect to the present
invention, will typically refer to an amount or level sufficient
for its intended use.
[0028] In a preferred embodiment, a composition of the present
invention comprises a partially hydrolyzed organo-functional
alkoxysilane in combination with a monoaromatic glycidyl ether, and
optionally other ingredients. The organo-functional alkoxysilane
can be of any suitable type, and is preferably selected from the
group consisting of epoxy-, vinyl- and acryloxy-functional
alkoxysilanes. The organo-functional alkoxysilane, when present,
can be used in any suitable amount, e.g., between about 10 and
about 60 weight percent, and more preferably between about 20 and
about 50 weight percent.
[0029] Suitable acryloxy-functional organosilanes include, are
selected from the group consisting of:
3((meth)acryloxypropyl)trimethoxy silane,
3((meth)acryloxyproply)methyl dimethoxy silane, and
3((meth)acryloxypropyl)dimethyl methoxy silane, including
combinations thereof.
[0030] Suitable vinyl-functional organosilanes include, but are
selected from the group consisting of: vinyldimethyl ethoxysilane,
vinylmethyl dimethoxysilane, vinylphenyl diethoxysilane,
vinyltrimethoxysilane, and vinyltriethoxysilane, including
combinations thereof.
[0031] Suitable epoxy functional alkoxy silane precursors, for use
in preparing the at least partially hydrolyzed polymerizable
ingredient, are selected from the group consisting of
epoxyalkylalkoxysilanes of the following structure:
Q-R.sub.1--Si(R.sub.2).sub.m--(OR.sub.3).sub.3-m,
[0032] The epoxy functional alkoxy silane precursor of the at least
partially hydrolyzed polymerizable ingredient is preferably an
epoxyalkylalkoxysilane of the following structure:
Q-R.sub.1--Si(R.sub.2).sub.m--(OR.sub.3).sub.3-m,
[0033] wherein R.sub.1 is a C.sub.1-C.sub.14 alkylene group,
R.sub.2 and R.sub.3 independently are C.sub.1-C.sub.4 alkyl groups
and Q is a glycidoxy or epoxycyclohexyl group, and m is 0 or 1. The
alkoxy groups are at least partially hydrolyzed to form silanol
groups with the release of the R.sub.3OH alcohol, and some
condensation of the silanol groups occurs. Epoxy reactivity is
preserved, however. Many epoxy-functional alkoxysilanes are
suitable as hydrolysis precursors, including
glycidoxymethyl-trimethoxysilane, glycidoxymethyltriethoxysilane,
glycidoxymethyl-tripropoxysilane, glycidoxymethyl-tributoxysilane,
b-glycidoxyethyltrimethoxysilane, b-glycidoxyethyltriethoxysilane,
b-glycidoxyethyl-tripropoxysilane,
b-glycidoxyethyl-tributoxysilane, b-glycidoxyethyltrimethoxysilane,
a-glycidoxyethyl-triethoxysilane,
a-glycidoxyethyl-tripropoxysilane, a-glycidoxyethyltributoxysilane,
g-glycidoxypropyl-trimethoxysilane,
g-glycidoxypropyl-triethoxysilane,
g-glycidoxypropyl-tripropoxysilane,
g-glycidoxypropyltributoxysilane,
b-glycidoxypropyl-trimethoxysilane,
b-glycidoxypropyl-triethoxysilane,
b-glycidoxypropyl-tripropoxysilane,
b-glycidoxypropyltributoxysilane,
a-glycidoxypropyl-trimethoxysilane,
a-glycidoxypropyl-triethoxysilane,
a-glycidoxypropyl-tripropoxysilane,
a-glycidoxypropyltributoxysilane,
g-glycidoxybutyl-trimethoxysilane,
d-glycidoxybutyl-triethoxysilane,
d-glycidoxybutyl-tripropoxysilane,
d-glycidoxybutyl-tributoxysilane,
d-glycidoxybutyl-trimethoxysilane,
g-glycidoxybutyl-triethoxysilane,
g-glycidoxybutyl-tripropoxysilane, g-propoxybutyl-tributoxysilane,
d-glycidoxybutyl-trimethoxysilane,
d-glycidoxybutyl-triethoxysilane,
d-glycidoxybutyl-tripropoxysilane,
a-glycidoxybutyl-trimethoxysilane,
a-glycidoxybutyl-triethoxysilane,
a-glycidoxybutyl-tripropoxysilane,
a-glycidoxybutyl-tributoxysilane,
(3,4-epoxycyclohexyl)-methyl-trimethoxysilane,
(3,4-epoxycyclohexyl)methyl-triethoxysilane,
(3,4-epoxycyclohexyl)methyl-tripropoxysilane,
(3,4-epoxycyclohexyl)-methyl-tributoxysilane,
(3,4-epoxycyclohexyl)ethyl-triethoxysilane,
(3,4-epoxycyclohexyl)ethyl-triethoxysilane,
(3,4-epoxycyclohexyl)ethyl-tripropoxysilane,
(3,4-epoxycyclohexyl)-ethyl-tributoxysilane,
(3,4-epoxycyclohexyl)propyl-trimethoxysilane,
(3,4-epoxycyclohexyl)propyl-triethoxysilane,
(3,4-epoxycyclohexyl)propyl-tripropoxysilane,
(3,4-epoxycyclohexyl)propyl-tributoxysilane,
(3,4-epoxycyclohexyl)butyl-trimethoxysilane,
(3,4-epoxycyclohexy)butyl-triethoxysilane,
(3,4-epoxycyclohexyl)-butyl-tripropoxysilane, and
(3,4-epoxycyclohexyl)butyl-tributoxysilane.
[0034] A particularly preferred organo-functional alkoxysilane is
.gamma.-glicidoxypropyl trimethoxy silane due to its wide
commercial availability.
[0035] Hydrolysis of the alkoxy-functional alkoxysilane precursor
may occur in an acidic environment, and reference is made to U.S.
Pat. No. 4,378,250, the teachings of which are incorporated herein
by reference. Hydrolysis of the alkoxy groups liberates the
associated alcohol to form silanol groups; these, in turn, are
relatively unstable and tend to condense spontaneously. Preferably,
the alkoxysilane is reacted with a stoichiometricly sufficient
quantity of water to hydrolyze at least 50% of the alkoxy groups
and most preferably from about 60% to about 70% of the alkoxy
groups. For the hydrolysis of an epoxy-functional trialkoxy silane,
good results have been obtained by reacting the silane with a
stoichiometricly sufficient quantity of water to hydrolyze
two-thirds of the alkoxy groups.
[0036] The composition of this invention further comprises a
monomeric organofunctional silane, and more preferably a monomeric
(silanol free) alkoxy functional silane, which can also be referred
to as an unhydrolyzed alkoxy functional alkoxy silane. In turn,
certain preferred compositions can include both hydrolyzed and
unhydrolyzed alkoxy functional alkoxy silanes, with the latter
being present in an amount sufficient to reduce the viscosity of
the composition itself. It is noted that, while the "hydrolysis
product" of such a silane can certainly include compounds that are
themselves partially hydrolyzed (depending on the mole ratio of
water to alkoxy groups as described herein), whereas an
unhydrolyzed silane of the sort claimed is clearly one that is
prepared and used in the substantial absence of water. As described
herein, water is removed from the hydrolysis product component,
prior to the addition of an unhydrolyzed component, in order to
permit the latter to retain its unhydrolyzed nature. Hence, when
and to the extent "partially hydrolyzed" silanes might be discussed
in the art, these compounds tend to be different than, and not at
all suggestive of the use of both hydrolyzed and unhydrolyzed
silane components as presently described.
[0037] In turn, the composition desirably includes an effective
amount up of a suitable non-hydrolyzed alkoxy functional silane,
including those selected from the silanes listed above. When used
in combination with an organofunctional polysiloxane, the
non-hydrolyzed epoxy functional alkoxy silane desirably is present
in an amount not less than about 5%, preferably at least about 20%,
and most preferably from about 40% to about 50% by weight, solids
basis. Preferably, the epoxy functional alkoxy silane that is
included as the non-hydrolyzed component also is of the same or
similar type as that employed to make the hydrolyzed component. It
should be understood that the hydrolyzed and non-hydrolyzed
components may be different and each may utilize one or a blend of
different epoxy functional alkoxy silanes, as desired.
[0038] The monomeric silane is optional, and therefore used in an
amount of between about 0% and about 50%, and more preferably
between about 10% and about 40%, and even more preferably between
about 20% and about 40% by weight of the composition, with
typically more monomeric silane (e.g., about 35 to about 45%) being
used in substantially non-tintable compositions, as compared to
substantially tintable compositions (e.g., having about 35% to
about 45% by weight).
[0039] A composition of the present invention can further comprise
one or more additional reactive ingredients, selected from the
group consisting of one or more non-hydrolyzed silanes, one or more
polyermizable ethers, and one or more ethylenically unsaturated
monomer components, desirably an acrylic monomer component that
preferably includes a monomer having an acrylic functionality of
not more than two. The use of an acrylic monomer, though optional,
is particularly preferred for use in compositions intended to coat
conventional, e.g., polycarbonate, substrates, as compared to high
index materials.
[0040] A wide variety of ethylenically unsaturated monomers
(including oligomers) can be employed in the coating composition of
the invention, and acrylic monomers and oligomers, particularly
those having acrylic functionalities of not greater than two, are
preferred. Useful acrylic compounds for improving adhesion to
polycarbonate substrates include both mono and di-functional
monomers, but other or additional polyfunctional acrylic monomers
may also be included.
[0041] Examples of monofunctional acrylic monomers include acrylic
and methacrylic esters such as ethyl acrylate, butyl acrylate,
2-hydroxypropyl acrylate, cyclohexyl acrylate, 2-ethylhexyl
acrylate, methyl methacrylate, ethyl methacrylate, and the like.
Examples of polyfunctional acrylic monomers, including both
difunctional and tri and tetrafunctional monomers, include
neopentylglycol diacrylate, pentaerythritol triacrylate,
1,6-hexanediol diacrylate, trimethylolpropane triacrylate,
tetraethylene glycol diacrylate, 1,3-butylene glycol diacrylate,
trimethylolpropane trimethacrylate, 1,3-butylene glycol
dimethacrylate, ethylene glycol dimethacrylate, pentaerythritol
tetraacrylate, tetraethylene glycol dimethacrylate, 1,6-hexanediol
dimethacrylate, ethylene glycol diacrylate, diethylene glycol
diacrylate, glycerol diacrylate, glycerol triacrylate,
1,3-propanediol diacrylate, 1,3-propanediol dimethacrylate,
1,2,4-butanetriol trimethacrylate, 1,4-cyclohexanediol diacrylate,
1,4-cyclohexanediol dimethacrylate, pentaerythritol diacrylate,
1,5-pentanediol dimethacrylate, and the like. The
acrylic-functional monomers and oligomers desirably are employed at
a weight concentration of at least about 10% by weight, preferably
from about 10% to about 50%, and most preferably from about 10% to
about 25%, all on a solids basis.
[0042] The composition preferably also contains one or more
cationic initiators, sufficient to polymerize the epoxy-functional
components, and one or more free radical initiators sufficient to
initiate polymerization of the ethylenically unsaturated coating
components (e.g., acrylic-functional components).
[0043] Useful cationic initiators for the purposes of this
invention can include thermal or photoinitators (e.g., UV
initiators) and include the aromatic onium salts, including salts
of Group Va elements, such as phosphonium salts, e.g., triphenyl
phenacylphosphonium hexafluorophosphate, salts of Group VIa
elements, such as sulfonium salts, e.g., triphenylsulfonium
tetrafluoroborate, triphenylsulfonium hexafluorophosphate and
triphenylsulfonium hexafluoroantimonate, and salts of Group VIIa
elements, such as iodonium salts, e.g., diphenyliodonium chloride.
The aromatic onium salts and their use as cationic initiators in
the polymerization of epoxy compounds are described in detail in
U.S. Pat. No. 4,058,401, "Photocurable Compositions Containing
Group VIA Aromatic Onium Salts," by J. V. Crivello issued Nov. 15,
1977; U.S. Pat. No. 4,069,055, "Photocurable Epoxy Compositions
Containing Group VA Onium Salts," by J. V. Crivello issued Jan. 17,
1978; U.S. Pat. No. 4,101,513, "Catalyst For Condensation Of
Hydrolyzable Silanes And Storage Stable Compositions Thereof," by
F. J. Fox et al. issued Jul. 18, 1978; and U.S. Pat. No. 4,161,478,
"Photoinitiators," by J. V. Crivello issued Jul. 17, 1979, the
disclosures of which are incorporated herein by reference. Other
cationic initiators can also be used in addition to those referred
to above; for example, the phenyldiazonium hexafluorophosphates
containing alkoxy or benzyloxy radicals as substituents on the
phenyl radical as described in U.S. Pat. No. 4,000,115,
"Photopolymerization Of Epoxides," by Sanford S. Jacobs issued Dec.
28, 1976, the disclosure of which is incorporated herein by
reference. Preferred cationic initiators for use in the
compositions of this invention are the salts of Group VIa elements
and especially the sulfonium salts. Particular cationic catalysts
include diphenyl iodonium salts of tetrafluoro borate, hexafluoro
phosphate, hexafluoro arsenate, and hexafluoro antimonate; and
triphenyl sulfonium salts of tetrafluoroborate, hexafluoro
phosphate, hexafluoro arsenate, and hexafluoro antimonate.
[0044] Although photoactivated free-radical initiator are
preferred, thermally activated free radical and cationic initiators
may also be used. Useful photoinitiators for this purpose are the
haloalkylated aromatic ketones, chloromethylbenzophenones, certain
benzoin ethers, certain acetophenone derivatives such as
diethoxyacetophenone and 2-hydroxy-2-methyl-1-phenylpropan-1-one. A
preferred class of free-radical photoinitiators is the benzil
ketals, which produce rapid cures. A preferred photoinitiator is
.alpha.,.alpha.-dimethoxy-.alpha.-phenyl acetophenone
(Iragacure.TM. 651, Ciba-Geigy, disclosed in U.S. Pat. Nos.
3,715,293 and 3,801,329). The most preferred photoinitiator, in
accordance with this invention, is
2-hydroxy-2-methyl-1-phenylpropane-1-one (Darocure.TM. 1173,
Ciba-Geigy Corporation). Specific examples of photoinitiators
include ethyl benzoin ether, isopropyl benzoin ether,
dimethoxyphenyl acetophenone, diethoxy acetophenone, and
benzophenone.
[0045] A preferred class of free-radical photoinitiators is the
benzil ketals, which produce rapid cures. Suitable photoinitiators
include .alpha.,.alpha.-dimethoxy-.alpha.-phenyl acetophenone
(Iragacure.TM. 651), and 2-hydroxy-2-methyl-1-phenylpropane-1-one
(Darocure.TM. 1173, Ciba-Geigy Corporation). A preferred
photoiniator is 1-hydroxycyclohexyl phenyl ketone (available as
Irgacure 184). Specific examples of photoinitiators include ethyl
benzoin ether, isopropyl benzoin ether, dimethoxyphenyl
acetophenone, diethoxy acetophenone, and benzophenone. Other
examples of suitable initiators are diethoxy acetophenone ("DEAP",
First Chemical Corporation) and 1-benzoyl-1-hydroxycyclohexane
("Irgacure 184", Ciba Geigy).
[0046] Compositions of the present invention can be used to coat a
variety of materials, generally polymeric materials, and most
preferably those used for the manufacture of optical lenses. Those
skilled in the corresponding art will appreciate the manner in
which the lens material chosen for a particular use or prescription
can be differentiated by various factors, including its weight,
thickness, transmission of radiant energy and optical
performance.
[0047] A composition of this invention can include other
ingredients as well, e.g., other materials that are reactive with
the epoxy groups such as hydroxyl bearing compounds such as
trimethylol propane or cyclohexane dimethanol may be used to modify
the composition. In addition, the composition can include one or
more flow control agents such as BYK 307, rheology modifiers such
as cellulose acetate butyrate, metal oxides such as colloidal
titanium dioxide, colloidal silica, etc.
[0048] The following table shows the index of refraction of some
available lens materials.
TABLE-US-00001 Lens Material Index of Refraction allyl diglycol
carbonate (e.g., "CR-39") 1.498 Crown Glass 1.523 Polycarbonate
1.586 MR8 1.6 MR10 1.67
[0049] With certain preferred embodiments as described herein, a
composition of the present invention can be detected by virtue of
the significant concentration of aromatic groups associated with
the glycidyl ethers described herein, as compared to what will
typically be a considerably smaller concentration of aromatic
groups, if any, that may be associated with one or more initiators
described herein.
EXAMPLES
[0050] The invention may be better understood by reference to the
following non-limiting examples. Unless otherwise indicated, the
concentration of ingredients in a composition is described as a
percentage (solids basis) based on the weight of the overall
composition. Cured coatings were subjected to several tests,
outlined as follows:
[0051] Materials and Methods
[0052] Glycidyl ethers suitable for use in a composition of this
invention are described herein, the structures and suitable sources
for which are shown in FIG. 1.
Additional Ingredients:
[0053] A187 Glycidoxy propyl trimethoxy silane (GE Silicones)
A186 Epoxy Cyclohexyl Trimethoxy Silane (GE Silicones)
[0054] A 1630 Methyl trimethoxy silane (Crompton Corp) SR 9209
alkoxylated aliphatic diacrylate (Sartomer, Inc.) SR 444
pentaerythritol triacrylate (Sartomer, Inc.) SR-351
trimethylolpropane triacrylate (TMPTA, Sartomer, Inc.) SR-238 1,6
hexanediol diacrylate (HDODA, Sartomer, Inc.) DEAP 2,2-diethoxy
acetophenone, free radical initiator (First Chemical Corporation)
CPI 6976 Cationic initiator (Aceto Corp.) CPI 6972 Cationic
initiator (Aceto Corp.) Irgacure 184 Free radical photoiniator
(Ciba Geigy) Irgacure 250 Cationic photoiniator (Ciba Geigy)
Uvacure 1502 Cycloaliphatic epoxy resin (UCB Chemicals Corp)
OXT-121 (1,4-Bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, CAS No.
142627-97-2 (Toagosei Co.) BYK 307 Silicone type flow control agent
(BYK-Chemie) HELOXY.TM. 107 diglycidyl ether of cyclohexane
dimethanol (Momentive, Inc.) HELOXY.TM. 48 low viscosity aliphatic
triglycidyl ether (Momentive, Inc.)
EXAMPLES
[0055] Preparation--a stripped, hydrolyzed epoxy silane resin
(resin A) was prepared as the reaction product of nonhydrolyzed
silane (A187), together with H2O, and (10%) HCl, in the manner
described in U.S. Pat. No. 6,100,313 and U.S. Ser. No. 12/987,650,
the disclosures of which are incorporated herein by reference.
Various compositions were prepared as described herein, based upon
the master batch, and were coated on a variety of conventional lens
materials that included a polycarbonate, a 1.6 high index material,
and a 1.67 high index material. All amounts are in weight percent,
unless otherwise indicated. Initial results are provided below.
[0056] The various compositions were coated on conventional
polycarbonate and high index lenses, cured and evaluated for both
adhesion and other properties.
[0057] Experiments were also performed to determine the effect of
various compositions in coating high index lenses, and in
particular, those lenses prepared from polymers sold under the
brandnames MR8 and MR10. All samples were coated on 1.6 RI lenses
made from monomer blend MR8 at 4-5 microns thickness and UV cured
using high pressure mercury lamp. The same results were obtained
when coated on 1.67 RI lenses made from MR10 monomer blend. The
samples were evaluated for adhesion as per ASTM D 3359 as described
herein.
[0058] Experiments were performed in order to compare a silane
composition containing RDGE, a preferred ether of the present
invention, in combination with various other compositions,
including:
[0059] i) a composition that instead contained a trifunctional
aliphatic ether (in particular, trimethylolpropane triglycidyl
ether, of the type described in Applicant's prior U.S. Pat. No.
6,100,313), and
[0060] ii) a composition that instead contained
1,4-Bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, which is an
aromatic, difunctional oxetane available commercially as
"OXT-121"), and
[0061] iii) a composition that included RDGE, in combination with
one or more conventional aliphatic glycidyl ethers.
For purposes of the present specification, adhesion is preferably
determined by means of ASTM 3359, using test methods conventional
in the optical (e.g., eyeglass) lens coating industry, though with
the notable exception that the lenses are provided in ground,
polished form (as routinely done in commercial applications), as
compared to first being chemically etched. Briefly, this industry
standard test involves scoring the cured coating with a blade
assembly in a cross-hatched fashion to leave diamond-shaped
patches. This is followed by an attempt to lift the diamond-shaped
patches from the substrate through the use of a pressure sensitive
adhesive tape that is applied to the cross hatched surface and then
pulled away. The degree to which the cross-hatched portions of the
coating remain adhered to the substrate provides a measure of
adhesion to that substrate, and is reported as the percentage of
diamond-shapes that remain adhered to the substrate. Crosshatch
adhesion tests were run under three conditions, in the manner
described in Colts Laboratories catalog of standard services
available at www.colts-laboratories.com, which include: (1) boiling
water (deionized water). This involves a standard crosshatch
adhesion test in which a series of fine cuts are first made across
and into the surface of the coated test lens, which is then
subjected to boiling water for a period of time, before tape is
placed firmly on the crosshatched area and quickly pulled off. (2)
Cycle humidity oven (CHOCA). This involves a 3 day adhesion test in
which coated lenses are submitted to both a crosshatch test and a
cycle humidity test. The crosshatch cuts are completed prior to the
start of the humidity portion, thereby attempting to replicate what
might occur under actual conditions. In this test the oven cycles
to 95% RH three times at 65 C, and the test lenses are inspected
following each 8 hour cycle. (3) Cycle humidity QUV/crosshatch,
which mimics the most aggressive components of accelerated
weathering. This involves a 3 day adhesion test in which coated
lenses are submitted to both a crosshatch test and the cycle
humidity test. The crosshatch cuts are completed prior to the start
of the humidity portion, thereby attempting to replicate what may
occur under actual conditions. The QUV equipment alternates between
UVA and condensation cycles.
[0062] Results were scored according to standard acceptable
proceedures (as provided, for instance, by Colts Laboratories).
Standard protocols and operating procedures were followed to
determine crosshatch adhesion results under the following three
categories: [0063] 5B--the edges of the cuts are completely smooth,
none of the squares of the crosshatched area are detached. [0064]
4B--small flakes of the coating are detached at the intersections
of the squares, less than 5% of the total area is affected. [0065]
3B--small flakes of the coating are detached along the edges and at
intersections of cuts. The area affected is 5-15% of the total
area. [0066] 2B--the coating has flaked along the edges and on
parts of the squares. The area affected is 15-35% of the total
area. [0067] 1B--the coating has flaked along edges of the cuts in
large ribbons and whole squares are detached. The area affected is
35-655 of the total area. [0068] 0B--flaking and detachment worse
than Classification 1 (greater than 65%). Tintability--A coated and
cured sample is immersed in BPI Black Dye (Brain Power Inc.) at
98-102.degree. C. for 15 minutes and then rinsed with water and
dried. Transmissivity is measured spectrophotometrically, and
tintability is reported as percentage transmissivity. Bayer
abrasion (scratch resistance) testing--is performed by suitable
modification of the oscillating sand method (ASTM-F735-94 Standard
Test Method for Abrasion Resistance of Transparent Plastics and
coatings), modified slightly to allow for use in the optical field.
The test consists of a small pan that is shaken back and forth a
distance of 4 inches, at 150 cycles for 4 minutes, using abrasion
media the material known as Aluminum Oxide from Black Lab corp.
Designation AO-14 Brown. Holes have been placed through the center
section of the pan to allow the lenses to protrude up through the
center of each hole, allowing the abrasion to take place without
the loss of media.
Experiments
[0069] A composition (a) having an ether of this invention (RDGE-H)
was compared with one (b) having an ether exemplified in the
"oxetane" application described above. Surprisingly, as shown in
Table 1, it was found that the composition containing RDGE passed
each of the crosshatch adhesion tests (deionized water, humidity,
QUV), as compared to the oxetane composition, which passed only the
deionized water test, but failed the humidity and QUV tests. Unless
otherwise indicated, all ingredients are indicated as weight
percentages, based on the weight of the compositions
themselves.
TABLE-US-00002 TABLE 1 (b) Oxetane (a) RDGE (OXT121) A18790 42.5
47.5 (Resin A, hydrolyzed epoxy silane) A187 (glycidoxypropyl
trimethoxy 37.4 31.7 silane) BDDA (butane diol diacrylate) 10.7 7.9
Glycidyl ether RDGE 5.3 0 Oxetane OXT 121 0 7.9 IRG184 (free
radical initiator) 0.29 0.4 CPI 6976 (cationic initator) 4.37 4.35
BYK307 (flow control agent) 0.25 0.25 TOTAL 100 100 PROPERTIES/TEST
RESULTS Tint BPI black (% transmission) -- -- Bayer abrasion 2.2
2.3 Boiling DI water - PC 5B 5B Boiling DI MR8 (1.60) 5B 5B Boiling
DI MR10 (1.67) 5B 5B Humidity PC 5B 5B Humidity 1.60 MR8 (1.60) 5B
5B Humidity 1.67 MR10 (1.67) 5B 5B QUV PC 5B 5B (for the first of 3
cycles) (0B second cycle) QUV MR8 (1.60) 5B 0B QUV MR10 (1.67) 5B
0B
[0070] Experiments were also performed to compare compositions
having an ether of this invention (composition (a)--RDGE) with one
exemplified in Applicant's above-captioned '313 patent and
currently used in corresponding commercial products such as UV-87
available from Walman Ultra-Optics (composition (b) having Heloxy
5048), as well as the combination of both ethers (composition (c)).
Tintability was adjusted in the manner commonly accepted in the
optical industry, in order to render the transmission of each
comparable, and less than 23. In Table 2, it can be seen that both
compositions with RDGE performed surprisingly better than the
composition b, having conventional ether. Specific amounts of
ingredients were determined in order to approximate the same
tintability and adhesion in each.
TABLE-US-00003 TABLE 2 (c) Both RDGE and (b) Heloxy Heloxy (a) RDGE
5048 5048 A18790 30.0 31.6 30.15 (Resin A, hydrolyzed epoxy silane)
A187 (glycidoxypropyl trimethoxy 30.35 20.0 16.0 silane) BDDA
(butane diol diacrylate) 20.0 18.75 25.1 Glycidyl ether RDGE 15.0 0
10.05 Heloxy 5048 polymerizable 0 25.0 15.08 ether
trimethylolypropane IRG184 (free radical initiator) 0.6 0.56 0.75
CPI 6976 (cationic initator) 3.8 3.85 3.52 BYK307 (flow control)
0.25 0.25 0.25 TOTAL 100 100 100 PROPERTIES/TEST RESULTS Tint BPI
black (% transmission) 20.0 22.2 22.0 Boiling DI water/PC 5B 5B 5B
Boiling DI water MR8 (1.60) 5B 0B 5B Boiling DI water MR10 (1.67)
5B 0B 5B Humidity PC 5B 0B 5B Humidity MR8 (1.60) 5B 0B 5B Humidity
MR10 (1.67) 5B 0B 5B QUV PC 5B 0B 5B QUV MR8 (1.60) 5B 0B 5B QUV
MR10 (1.67) 5B 0B 5B
TABLE-US-00004 TABLE 3 Adhesion test 1 Adhesion Adhesion (deionized
test 2 test 3 Adhesion test 1 water) (humidity) (QUV) RDGE on PC
Pass Pass Pass Heloxy 5048 on PC Pass Fail Fail Oxetane on PC Pass
Pass Fail RDGE on MR8 (1.60) Pass Pass Pass Heloxy 5048 on MR8
(1.60) Fail Fail Fail Oxetane on MR8(1.60) Pass Pass Fail RDGE on
MR10 (1.67) Pass Pass Pass Heloxy 5048 on MR10 (1.67) Fail Fail
Fail Oxetane on MR10 (1.67) Pass Pass Fail
[0071] Results are summarized in Table 3 above. It can be seen,
that under the conditions of the current experiments, the
composition based upon the use of RDGE surprisingly passed each of
adhesion tests 1-3, as compared to compositions previously known
and described, which failed one or more tests, most notably the QUV
adhesion test.
* * * * *
References