U.S. patent application number 13/865705 was filed with the patent office on 2013-09-05 for curable adhesive compositions.
This patent application is currently assigned to PixelOptics, Inc.. The applicant listed for this patent is PIXELOPTICS, INC.. Invention is credited to Omar Mohamed Buazza, Yassin Turshani.
Application Number | 20130230706 13/865705 |
Document ID | / |
Family ID | 42320743 |
Filed Date | 2013-09-05 |
United States Patent
Application |
20130230706 |
Kind Code |
A1 |
Turshani; Yassin ; et
al. |
September 5, 2013 |
CURABLE ADHESIVE COMPOSITIONS
Abstract
Curable adhesive compositions are provided that exhibit a high
refractive index.
Inventors: |
Turshani; Yassin; (Madeira
Beach, FL) ; Buazza; Omar Mohamed; (Roanoke,
VA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PIXELOPTICS, INC. |
Roanoke |
VA |
US |
|
|
Assignee: |
PixelOptics, Inc.
Roanoke
VA
|
Family ID: |
42320743 |
Appl. No.: |
13/865705 |
Filed: |
April 18, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12758118 |
Apr 12, 2010 |
|
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|
13865705 |
|
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|
|
61168401 |
Apr 10, 2009 |
|
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Current U.S.
Class: |
428/212 |
Current CPC
Class: |
B32B 2307/50 20130101;
C08F 2/50 20130101; B32B 27/08 20130101; C08J 3/28 20130101; B32B
7/12 20130101; B32B 2535/00 20130101; Y10T 428/287 20150115; B32B
27/365 20130101; Y10T 428/24942 20150115; C09J 133/14 20130101;
C09J 133/16 20130101; B32B 2255/26 20130101; B32B 2255/10 20130101;
Y10T 428/2891 20150115; B32B 2307/418 20130101; Y10T 428/2878
20150115; B32B 2551/00 20130101; Y10T 428/2852 20150115; Y10T
428/31515 20150401; Y10T 428/2896 20150115; B32B 2405/00 20130101;
Y10T 428/31547 20150401 |
Class at
Publication: |
428/212 |
International
Class: |
C09J 133/14 20060101
C09J133/14 |
Claims
1-44. (canceled)
45. A device, comprising: a) a first ophthalmic component, b) a
second ophthalmic component, and c) a curable adhesive composition
disposed between the first and second ophthalmic components,
wherein the adhesive composition comprises at least one high
index-high viscosity component having a refractive index, before
curing, of at least 1.56 at 25.degree. C., and a viscosity, before
curing, of at least 15,000cP at 25.degree. C., and a
photoinitiator, wherein the refractive index of the adhesive
composition, after curing, is: i) about equal to the refractive
index of at least one of the first ophthalmic component and the
second ophthalmic component, ii) between the refractive index of
the first lens and the refractive index of the second lens, or iii)
about equal to the average refractive index of the first ophthalmic
component and the second ophthalmic component.
46. The device of claim 45, wherein the refractive index of the
adhesive composition, after curing, is within 0.03 of the
refractive index of at least one of the first ophthalmic component
and the second ophthalmic component.
47. The device of claim 45, wherein at least one of the first
ophthalmic component and the second ophthalmic component has a
refractive index of about 1.67.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application Nos. 61/168,401 filed Apr. 10, 2009; 61/229,031
filed Jul. 28, 2009; and 61/234,536 filed Aug. 17, 2010, each of
which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to curable laminating
adhesives. More particularly, the present invention is directed to
UV curable adhesive compositions having a refractive index that
matches the refractive index of one or more substrates.
BACKGROUND OF THE INVENTION
[0003] Adhesives have been widely used in various industries for
many years, and numerous adhesives are commercially available. But
finding a suitable commercially available adhesive to meet certain
requirements is not always possible. In some cases, a suitable
adhesive can be designed to meet particular specifications, and can
take advantage of the availability of new monomers, additives,
curing agents and new advanced in polymer processing
technology.
[0004] Curable adhesives are well known. These include adhesives
that are curable by radiation generally, as well as those that are
curable by ultraviolet or visible light in particular.
Unfortunately, known curable adhesives may suffer from a number of
disadvantages. For example, many adhesives suffer from insufficient
adhesion and/or inappropriate refractive index to match the
refractive indices of the intended substrates. Many adhesives have
a refractive index (RI) that is lower than 1.60, which is not
suitable for lenses (e.g., electro-active lenses or composite
lenses) made of plastic materials having an RI of 1.67 or higher.
While there are a few adhesive compositions with high RI, they
suffer from poor adhesion, unsuitable viscosity, or poor batch
life. Some adhesives also require the use of solvents that must be
evaporated during curing, and thus are not suitable for one or more
electro-active assembly processes.
[0005] A need therefore exists for curable adhesives, especially UV
curable adhesives, that exhibit a high RI, and preferably improved
adhesion and viscosity.
BRIEF SUMMARY OF THE INVENTION
[0006] In one embodiment, curable adhesive compositions are
provided that exhibit a high refractive index, acceptable
viscosity, and/or acceptable adhesion. In another embodiment,
devices are provided that include the adhesive composition disposed
between two substrates.
[0007] In one embodiment, the curable adhesive composition
comprises at least one high index-high viscosity component having a
refractive index, before curing, of at least 1.56 at 25.degree. C.,
and a viscosity, before curing, of at least 15,000 cP at 25.degree.
C., and a photoinitiator. The adhesive composition has a refractive
index, after curing, of greater than 1.50. In one aspect, the
adhesive composition is curable by ultraviolet radiation.
[0008] The high index-high viscosity component may be an aromatic
urethane acrylate (e.g., brominated aromatic urethane acrylate),
tribromophenyl acrylate, or
9,9-bis{4-(2-acryloyloxyethoxy)phenyl}fluorene.
[0009] The photoinitiator may include a radical photoinitiator, a
cationic photoinitiator, or an anionic photoinitiator.
[0010] The radical photoinitiator may be selected from the
non-limiting group of
bis(2,3,6-trimethlbenzoyl)-phenylphosphineoxide,
1-hydroxcyclohexylphenylketone,
2-hydroxy-2-methyl-1-phenyl-propan-1-one,
bis(2,6-dimethoxybezoyl)-2,4,4-trimethylpentyl phosphe-ine oxide,
2,4,6-trimethylbezoyldiphenylphosphine,
2,2-dimethoxy-2-phenylacetophenone,
4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methlpropyl)ketone, 2-methyl
thioxanthone, 2-isopropyl thioxanthone, 2-chloro thioxanthone,
thoxanthone, xanthene, bezophenoe,
2-methyl-1-[4-methylthio)phenyl]-2-morpholino propan-1-one, and
2-benzyl-2-N,N-dimethlamino-1-(-morpholinophenyl)-1-butanone.
Preferably, the radical photoinitiator is at least one of
bis(2,3,6-trimethlbenzoyl)-phenylphosphineoxide,
1-hydroxcyclohexylphenylketone, or
2-hydroxy-2-methyl-1-phenyl-propan-1-one.
[0011] The cationic photoinitiator may be selected from the
non-limiting group of triaryl sulfonium salt hexafluoroantimonate,
triaryl sulfonium hexafluorophosphate,
bis(4-diphenylsulfomo)-phenyl]sufide-bis-hexafluorophosphate,
di(alkylphenyl)iodonium salt, diaryl iodonium hexafluroantimonate,
and iron-arene complex.
[0012] The anionic pbotoinitiator may be selected from the
non-limiting group of O-nitrobenzyl derivatives, metal amine
complexes, (cyclopentadienyl)ruthenium complexes, and
(cyclopentadienyl)osmium complexes.
[0013] In another embodiment, the photoinitiator comprises at least
one additive, such as a co-catalyst, a phosphine, and/or an amine.
The additive can be phosphonium salts, tera alkylphosphonium
bromide, tera alkylphosphonium chloride, triphenyl phosphine,
trimethoxy phenyl phosphine, trichloro phenyl phosphine, alkyl
amine primary, dialkyl amine, or trialkyamine.
[0014] In one embodiment, the composition includes at least one
vinyl resin (e.g., NTT #6205).
[0015] In another embodiment, the composition contains at least one
sulfur component, including, without limitation, 2-bis(2-mercapto
ethylthio)-3-mercapto propane, trimethylolpropane
tris(3-mercaptopropionate), 2-mercaptoethylthio-3-propanthiol
sulfide, pentaerythritol tetrakis(2-mercaptopropoinate),
2,2'-thiodiethanethiol,
trimethyloltris(3-mercaptopropoinate)oethylthio-3 propanthiol
sulfide, 2,5-dimercaptomethyl-1,4-dithiane,
4,5-(mercaptomethylthio)-1,3-dithiolane,
4,6-(mercaptomethylthio)-1,3-dithiane,
1,1,3,3-tetra(mercaptomethylthio)propane, 2,3-episulfide propanyl
disulfide, and 2,3-episulfide propanyl sulfide.
[0016] In another embodiment, the composition contains at least one
acrylic component, including, without limitation, polyethylene
glycol o-phenyl phenyl ether acrylate, urethane acrylate, aliphatic
urethane acrylate, acrylic oligomer, 2(2-ethoxyethoxy)ethyl
acrylate, 2-phenoxyethyl acrylate, ethoxylated (4)
trimethylolpropane triacrylate, ethoxylated (6)trimethylolpropane
triacrylate, isobornyl acrylates, glycidyl methacrylate, 1,6
hexanediol diacrylate, alkoxylated phenol acrylate, alkoxylated
phenol diacrylate, 2 hydroxyethyl acrylate,
phenylthioethylacrylate, alkoxylated nonylphenol acrylate,
ethoxlyated tribromo phenyl acrylate, tetrahydrofurfuryl acrylate,
tetrahydrofurfuryl methacrylate, and polyethylene glycol (200)
diacrylate. In one embodiment, the composition contains urethane
acrylate.
[0017] In another embodiment, the composition contains a bisphenol
A, including, without limitation, ethoxylated (10) bisphenol A
diacrylate, ethoxylated (4) bisphenol A diacrylate, ethoxylated (4)
bisphenol A dimethacrylate, diallylether bisphenol A, and ortho
diallyl bisphenol A.
[0018] In another embodiment, the composition contains at least one
naphthalene component including, without limitation, 1-chloro
naphthalene, 1-bromo naphthalene, and 1-naphthaldehyde.
[0019] In another embodiment, the composition contains at least one
epoxy resin including, without limitation, poly[(phenyl glycidyl
ether)-co-formaldehyde]oligomeric epoxide and epoxy acrylates.
[0020] In one embodiment, the adhesive composition has a refractive
index, after curing, of about 1.60 to about 1.74. These
compositions can contain about 0.01 wt % to about 5 wt % of at
least one photoinitiator and about 1 wt % to about 70 wt % of at
least one high index-high viscosity component selected from the
group consisting of brominated aromatic urethane acrylate;
tribromophenyl aery late; and
9,9-bis{4-(2-acryloyloxyethoxy)phenyl}fluorene. The photoinitiator
may include one or more of
bis(2,3,6-trimethlbenzoyl)-phenylphosphineoxide, triaryl sulfonium
salt hexafluoroantimonate, and triaryl sulfonium
hexafluorophosphate. The adhesive composition may also contain
about 10 wt % to about 95 wt % of at least one vinyl resin.
[0021] These adhesive compositions may also contain about 2 wt % to
about 50 wt % of at least one acrylic component selected from the
group consisting of polyethylene glycol o-phenyl phenyl ether
acrylate; urethane acrylate; acrylic oligomer; isobornyl acrylates;
phenylthioethylacrylate; and ethoxlyated tribromo phenyl
acrylate.
[0022] These adhesive compositions may also contain at least one
sulfur component selected from the non-limiting group consisting of
1,2-bis(2-mercapto ethylthio)-3-mercapto propane;
trimethylolpropane tris(3-mercaptopropionate);
2-mercaptoethylthio-3-propanthiol sulfide; pentaerythritol
tetrakis(2-mercaptopropoinate); 2,2'-thiodiethanethiol;
trimethyloltris(3-mercaptopropoinate)oethylthio-3 propanthiol
sulfide; 2,5-dimercaptomethyl-1,4-dithiane;
4,5-(mercaptomethylthio)-1,3-dithiolane;
4,6-(mercaptomethylthio)-1,3-dithiane;
1,1,3,3-tetra(mercaptomethylthio)propane; 2,3-episulfide propanyl
disulfide; and 2,3-episulfide propanyl sulfide. Preferably, the
composition comprises about 1 wt % to about 30 wt % of at least one
sulfur component selected from the group consisting of
1,2-bis(2-mercapto ethyltbio)-3-mercapto propane;
trimethylolpropane tris(3-mercaptopropionate);
2-mercaptoethylthio-3-propanthiol sulfide; pentaerythritol
tetrakis(2-mercaptopropoinate); and 2,2'-thiodiethanethiol.
[0023] These adhesive compositions may also contain about 5 wt % to
about 25 wt % of at least one at least one naphthalene component
selected from the group consisting of 1-chloro naphthalene; 1-bromo
naphthalene; and 1-naphthaldehyde.
[0024] These adhesive compositions may also contain a bisphenol A
component selected from the group consisting of diallylether
bisphenol A and ortho diallyl bisphenol A.
[0025] These adhesive compositions may also contain an epoxy resin
selected from the group consisting of poly[(phenyl glycidyl
ether)-co-formaldehyde]oligomeric epoxide; and epoxy acrylates.
[0026] In another embodiment, the adhesive composition has a
refractive index, after curing, of about 1.55 to about 1.60. These
compositions can contain about 0.01 wt % to about 5 wt % of at
least one photo initiator; about 10 wt % to about 60 wt % of at
least one high index-high viscosity component selected from the
group consisting of brominated aromatic urethane acrylates;
tribromo phenyl aery late; and
9,9-bis{4-(2-acryioyioxyethoxy)phenyl}fluorine; and about 1 wt % to
about 60 wt % of at least one acrylic component selected from the
group consisting of 2(2-ethoxyethoxy) thyl acrylate; 2-phenoxyethyl
aery late; ethoxylated (4) trimethylolpropane triacrylate;
ethoxylated (6) trimethylolpropane triacrylate; alkoxylated phenol
acrylate; 2 hydroxyethyl acrylate; polyethylene glycol o-phenyl
phenyl ether acrylate; urethane acrylate; isobornyl acrylates; and
alkoxylated nonylphenol acrylate.
[0027] In one embodiment, these adhesive compositions can contain
about 0.01 wt % to about 5 wt % of at least one photoinitiator
selected from the group consisting of
bis(2,3,6-trimethlbenzoyl)-phenylphosphineoxide;
1-hydroxcyclohexylphenylketone; and
2-hydroxy-2-methyl-1-phenyl-propan-1-one; about 10 wt % to about 60
wt % of at least one high index-high viscosity component selected
from the group consisting of brominated aromatic urethane
acrylates; and about 1 wt % to about 60 wt % of at least one
acrylic component selected from the group consisting of
2(2-ethoxyethoxy) ethyl acrylate; 2-phenoxyethyl acrylate;
ethoxylated (4) trimethylolpropane triacrylate; ethoxylated (6)
trimethylolpropane triacrylate; alkoxylated phenol acrylate; and 2
hydroxyethyl acrylate.
[0028] These adhesive compositions may also contain a sulfur
component selected from the group consisting of
2-mercaptoethylthio-3-propanthiol sulfide; 2,2'-thiodiethanethiol;
and trimethyloltris(3-mercaptopropoinate)oethylthio-3 propanthiol
sulfide.
[0029] These adhesive compositions may also contain an epoxy resin
(e.g., epoxy acrylates).
[0030] These adhesive compositions may also contain a bisphenol A
component selected from the group consisting of ethoxylated (10)
bisphenol A diacrylate; ethoxylated (4) bisphenol A diacrylate; and
ethoxylated (4) bisphenol A dimethacrylate.
[0031] These adhesive compositions may also contain triallyl
isocyanurate.
[0032] In a yet another embodiment, the adhesive composition has a
refractive index, after curing, of about 1.49 to about 1.55. These
adhesive compositions can contain about 0.01 wt % to about 5 wt %
of at least one pbotoinitiator; and about 5 wt % to about 80 wt %
of at least one acrylic component selected from the group
consisting of aliphatic urethane acrylate; acrylic oligomer;
ethoxylated (4) trimetbyiolpropane triacrylate; ethoxylated (6)
trimetbyiolpropane triacrylate; glycidyl methacrylate; 1,6
hexanediol diacrylate; alkoxylated phenol acrylate; alkoxylated
phenol diacrylate; 2 hydroxyethyl acrylate; alkoxylated nonylphenol
acrylate; ethoxylated (10) bisphenol A diacrylate; 2-phenoxyethyl
acrylate; isobornyl acrylates; tetrahydrofurfuryl acrylate;
tetrahydrofurfuryl methacrylate; and polyethylene glycol (200)
diacrylate.
[0033] In one embodiment of these adhesive compositions, the
acrylic component is selected from the non-limiting group of
aliphatic urethane acrylate; acrylic oligomer; ethoxylated (4)
trimethylolpropane triacrylate; ethoxylated (6) trimethylolpropane
triacrylate; glycidyl methacrylate; 1,6 hexanediol diacrylate;
alkoxylated phenol acrylate; 2 hydroxyethyl acrylate; alkoxylated
nonylphenol acrylate; and ethoxylated (10) bisphenol A
diacrylate.
[0034] These adhesive compositions may also contain about 10 wt %
to about 50 wt % of at least one high index-high viscosity
component (e.g., brominated aromatic urethane acrylates).
[0035] These adhesive compositions may also contain a sulfur
component selected from the group consisting of trimethylolpropane
tris(3-mercaptopropionate) and pentaerythritol
tetrakis(2-mercaptopropoinate).
[0036] In another embodiment, a device is provided. The device
comprises a first and second substrate, e.g., ophthalmic component,
and a curable adhesive composition (as described in any of the
embodiments) disposed between the first and second ophthalmic
components. The refractive index of the adhesive composition, after
curing, is i) about equal to the refractive index of at least one
of the first ophthalmic component and the second ophthalmic
component, ii) between the refractive index of the first lens and
the refractive index of the second lens, or iii) about equal to the
average refractive index of the first ophthalmic component and the
second ophthalmic component. In one embodiment, the refractive
index of the adhesive composition, after curing, is within 0.03 of
the refractive index of at least one of the first ophthalmic
component and the second ophthalmic component. In another
embodiment, at least one of the first ophthalmic component and the
second ophthalmic component has a refractive index of about
1.67.
[0037] Additional features, advantages, and embodiments of the
invention may be set forth or apparent from the following detailed
description and claims. Moreover, both the foregoing summary of the
invention and the following detailed description are exemplary and
intended to provide further explanation without limiting the scope
of the invention as claimed.
DETAILED DESCRIPTION OF THE INVENTION
[0038] In one embodiment, curable adhesive compositions are
provided that exhibit a high refractive index, acceptable
viscosity, and/or acceptable adhesion. Devices are also provided
that include the adhesive composition disposed between two
substrates.
[0039] An exemplary assembly process for fabricating electro-active
lenses is described in U.S. Publication 2009/0256977, which is
hereby incorporated by reference in its entirety. A portion of the
assembly process can include two preformed plastic lenses, one of
which has a lens surface comprising a diffractive pattern filled
with electro-active material (i.e., liquid crystal), that are
subsequently bonded together. Because of the diffractive pattern,
the laminate surfaces can generate a thin cavity (e.g., in the
range of 30-70 microns thick). The thickness of this cavity can
depend on the diffractive design.
Refractive Index
[0040] The cavity formed between the lens substrates can be filled
with a UV curable adhesive composition having a refractive index
(RI) that matches the RI of the preformed lenses to hide the seal
features. If the two preformed lenses have different RIs, the value
of RI of the adhesive composition can be between (e.g., an average
of) the two RIs of the preformed lenses) to reduce or eliminate
light interference due to the difference in RI of the two preformed
lenses. For example, when adhering a polycarbonate lens (RI 1.58)
to a Trivex.RTM. lens (RI 1.53), a suitable adhesive composition
can have an RI, after curing, of about 1.55. The compositions may
be suitable for adhering a wide variety of lens materials,
including electro-active lenses and composite lenses. In some
embodiments, the adhesives are particularly suitable for use with
plastic materials having an RI of about 1.67 or higher. The
adhesives may be used to laminate one or more of the following
substrate materials: polycarbonate (RI 1.58), Trivex.RTM. (RI
1.53), and MR-10 (RI 1.67). The laminated substrates may be the
same as, or different from, one another.
[0041] Unless otherwise specified, the refractive index of the
adhesive composition is reported after curing at 25.degree. C.,
(Curing increases the RI of the adhesive composition by about
0.01-0.05, more specifically about 0.03.) In contrast, unless
otherwise specified, the RI of the individual components of the
adhesive are reported before curing at 25.degree. C.
[0042] The adhesive compositions provided herein have a refractive
index of at least 1.49, preferably at least 1.50, 1.53, 1.55, 1.56,
1.57, 1.60, 1.63, 1.65, 1.67, or 1.70. The adhesive compositions
described herein are categorized as high index, mid-index, and low
index adhesives (see Examples), but such distinctions are used
merely to categorize the compositions relative to one another. All
of the compositions described herein, including the "low" and "mid"
index examples, have a refractive index that is higher than most
typical adhesives. The low index adhesives described herein have a
refractive index of about 1.49 to about 1.55. The mid-index
adhesives have a refractive index of about 1.55 to about 1.6. The
high index adhesives have a refractive index of about 1.6 to about
1.74.
Viscosity
[0043] Viscosity of an adhesive composition is an important
parameter that affects manufacturing. Viscosity is not a
predictable feature of a composition; it can not be calculated
strictly by weight average. For example, although adding a low
viscosity component to a composition will dilute the viscosity of
the composition, the precise reduction in viscosity cannot be
predicted based on the amount, e.g, percent weight, and viscosity
of the individual component added. Accordingly, achieving an
acceptable viscosity of the adhesive composition requires an
understanding of the manufacturing process to be employed as well
as the balancing of the various adhesive components as taught
herein.
[0044] Accordingly, the curable adhesive can have a predetermined
or desired viscosity value to flush away the excess liquid crystal
that may overflow into the cavity during the assembly process. As
an example, compositions with viscosity of about 100 cP or less may
break the diffractive seal during the filling process and
consequently could contaminate the electro-active material inside
the diffractive pattern. But low viscosity adhesive compositions
may be suitable to laminate two preformed lenses that do not
comprise diffractive patterns. Preferably, the viscosity of the
adhesive composition, before curing, is about 200 to about 5000 cP,
about 1000to about 3000 cP, or about 1000 to about 2000 cP.
[0045] The adhesive compositions provided herein can also be used
in surface casting, which includes applying the adhesive
composition to one preformed lens and then casting another lens on
the top of the original preformed lens.
Adhesion
[0046] Adhesion performance is also a high priority. For a strong,
durable bond, the adhesive compositions can be designed to avoid
frozen-in stresses and voids, which can be caused by adhesive
shrinkage. In general, the lower the shrinkage rate, the better the
adhesion. To reduce shrinkage rate, the adhesive can comprise
monomers with a lower number of reactive functional groups, or they
can comprise high molecular weight oligomers or pre-polymers. It is
desired for the adhesive composition to be able to wet and spread
on a substrate surface. This molecular- level contact allows the
forces of adhesion to develop, removes entrapped air from the
interface, and maximize the area over which bond can develop. For a
clean, smooth substrate, wetting and spreading is governed by the
surface tensions of the two materials. The lower the surface
tension of the adhesive, the better the wetting. Aside from surface
tension, surface preparation, especially of plastic substrates, is
an important step to improve adhesion performance. Methods such as
chemical etching and plasma can be used to improve the adhesion
performance of the adhesive compositions. Another efficient method
to improve adhesion performance of the adhesive compositions is to
treat the surface with functionalized alkoxysilanes, such as
acryloxy trimethoxy silane.
[0047] The adhesive compositions described herein can be formed as
blends of reactive monomers, oligomers or pre-polymers,
photoinitiator(s), and optional silane coupling agent. In
particular, the adhesive compositions can contain a high index-high
viscosity component and a pbotoinitiator.
Reactive Monomers, Oligomers, and Pre-polymers
[0048] In one embodiment, the curable adhesive composition contains
at least one high index-high viscosity component having a
refractive index, before curing, of at least 1,56 at 25.degree. C.,
and a viscosity, before curing, of at least 15,000 cP at 25.degree.
C. In one embodiment, the high index-high viscosity component has a
refractive index of at least about 1.58, 1.60, or 1.62. In one
embodiment, the high index-high viscosity component has a viscosity
of at least about 20,000, 40,000, 60,000, 70,000, 80,000, or 90,000
cP at 25.degree. C. Exemplary high index-high viscosity components
include, but are not limited to, aromatic urethane acrylate (e.g.,
brominated aromatic urethane acrylate), tribromophenyl acrylate, or
9,9-bis{4-(2-acryloyloxyethoxy)phenyl}fluorene. A high index-high
viscosity component (or a combination of more than one high
index-high viscosity components) can be present in an amount of
about 1 to about 70%, about 10 to about 60%, about 10% to about
50%, about 10% to about 30%, or about 10% to about 20%.
[0049] The selection of the resin, in addition to good adhesion,
can be made to establish mainly the refractive index match between
the cured composition and the substrates. In the case of laminating
two preformed lenses with one comprising a diffractive pattern, the
RI match should be the same or very close, e.g., within 0.02, to
hide the diffractive seal features. For example, when laminating
two plastic lenses made of RI of 1.67 with a diffractive pattern,
the RI of the adhesive composition can be about 1.64 to about 1.70.
Even though some commercially available adhesives may exhibit a
high RI, they often exhibit poor adhesion. For example, a
formulation made of 100% composition #8323 or 100% composition of
#6205 (supplied by NTT Advanced Technology Corp.), the adhesion
performance is very poor, and furthermore, the adhesive broke the
diffractive seal and contaminated the liquid crystal inside the
diffractive region.
[0050] Resin blends were prepared that are suitable for use in
laminating preformed high refractive lenses, such as lenses
manufactured from MR-10 (RI=1.67). In one embodiment, an adhesive
for bonding two MR-10 lenses contains:
[0051] 5-60% vinyl resin (NTT #6205),
[0052] 10-50% 9,9-Bis[-4-(2-acryloxyethoxy)phenyl]Fluorene (NKE
A-BPEF supplied by Kowa American Corp.)
[0053] 10-50% Tribromophenyl acrylate (BR-30 supplied by Kowa)
[0054] 0-20% Aromatic monoacrylate oligomer (CN-131B supplied by
Sartomer}
[0055] 0-30% of a sulfur component, and
[0056] 0.01-5% Phenyl bis(2,4,6-trimethyl benzoyl)phosphine oxide
(Irgacure 819 supplied by Ciba).
[0057] Unless otherwise specified, component amounts, here and
throughout the specification, are provided as weight percents of
the total composition.
[0058] In this formulation, if the amount of NTT #6205 is less than
5%), the final RI of the adhesive composition may be too low, and
there may be insufficient RI match to the MR-10preformed lenses. On
the other hand, if the amount of NTT #6205 is higher than 60%, then
the RI may be too high, and the adhesion performance becomes
poor.
[0059] A sulfur component, e.g., a multifunctional thiol resin,
provides the film with, in addition to high RI, desirable
mechanical properties that improve adhesion. The exemplary resin
blend described above suitable for laminating MR-10 lenses may
include as the sulfur component:
[0060] 2-Mercaptoethylthio-3propane sulfide (supplied by
Mitsui);
[0061] 1,2-Bis(2-mercaptoethyl)-3-mercaptopropane (supplied by
Mitsui);
[0062] 2,5-dimercaptomethyl-1,4 dithiane (supplied by
Sigma-Aldrich); [0063] 2,2'-Thiodiethanthiol (supplied by
Sigma-Aldrich);
[0064] Trimethylol propane tris3-mercaptopropoinate and/or 2,
mercaptoethylthio 3-propanethiol sulfide; or
[0065] 2,5-dimercaptomethyl-1,4dithiane; Pentaerythritol
tetrakis-3-mercaptopropoinate; and/or 2,3-mercapto propane.
[0066] Another exemplary composition includes: 20-60% composition
#8323 (supplied by NTT), 10-50% CN-2600, 10-20% NKE-10, and 0.01-5%
Irgacure 819
[0067] Other exemplary compositions include 30-60% vinyl resin (NTT
#6205) and 0.01-5% Irgacure 819, as well as: 20-40% CN-2600, and
10-50% NK-A-BPEF (supplied by Kowa); or 30-65% Vinyl Naphthalene,
0-70% CN-2600, 0-50% 1,2-bis(2-mercapto ethyl thio)propane, and
0-70% NK-A-BPEF.
[0068] Yet other exemplary compositions include 0-40% vinyl resin
(NTT #6205) and 0.01-5% Irgacure 819, as well as:
[0069] 10-50% 1,2-bis(2-mercapto ethyl thio)propane (supplied by
Mitsui Chemical), 5-40% Chloro Naphthalene and/or Naphthaldehyde,
0-20% CN-2600, and 0-70 NK-A-BPEF;
[0070] 30-70% of 2,3-Episulfide propane sulfide (supplied by MGC),
30-70% CN-2600, 0-20% NK-A-BPEF, and 0-10% NKE-10; or
[0071] 0-40% 1,2-bis(2-mercapto ethyl thio)propane (supplied by
Mitsui Chemical), 5-40% CN-2600, and 20-50% NK-A-BPEF-10.
[0072] Resin blends suitable for use in surface casting Trivex.RTM.
to preformed MR-10 lenses can include 30-70% CN-2600 and 30-70%
NK-10.
[0073] Resin blends suitable for use in surface casting Trivex.RTM.
to preformed polycarbonate lenses can include 5-50% CN-2600, 5-15%
Ethoxylated (6)trimethylolpropane triacrylate (SR 499), 20-50%
Ethoxylated(4)bisphenol A diacrylate (SR601), 5-15% 2-Hydroxy ethyl
acrylate, and 5-10%, Alkoxylated phenol acrylate (D9088).
[0074] Commercially available components that may be useful for
preparing the curable adhesive compositions include, but are not
limited to:
[0075] High refractive index resins #6205 , #8322 and #8323 (NTT
Advanced Technology Corp.)
[0076] Polyethylene glycol 0-phenyl phenyl ether acrylate (NKE-10);
9,9 Bis[4-(2-acryloxyethoxy)phenyl fluorene (NK. A-BPEF); and
tribromophenyl acrylate (Kowa American Corp.)
[0077] Brominated aromatic urethane acrylates oligomer (CN-2600)
(Sartomer).
[0078] 1-vinyl Naphthalene, 2-vinyl Naphthalene, 1-chloro
Naphthalene, and N-vinyl carbazole (Sigma-Aldrich).
[0079] Divinyl Benzene, 2,6-diphenyl-1,4-phenylene oxide, diphenyl
methane bis(4-phenyl)carbamate, alpha-nephthyl methacrylate,
alpha-naphthyl, carbonyl methacrylate, beta-naphthyl methacrylate,
and styrene sulfide (Scientific Polymer Products, Inc.)
[0080] 2,3-Episulfide propane sulfide (supplied by MGC)
[0081] 2,3-Episulfide propane disulfide,
1,2-bis(2-mercaptoethylthio)-3mercaptopropane, and 2-mercaptoethyl
sulfide (Mitsui Chemicals)
[0082] Acrylic oligomer (CN131B), Epoxy acrylate oligomer (CN110),
Epoxy methacrylate (CN151), Ethoxylated (3)-bisphenol A diacrylate
(SR349), Ethoxylated (2) bisphenol A dimethacrylate (SR348),
Ethoxylated (4) bisphenol A diacrylate (SR601), 2-Phenoxyethyl
acrylate (SR339), Alkoxylated phenol acrylate (D9088), Ethoxylated
(2) bisphenol A dimethacrylate SR101, Ethoxylated (6) bispehenol A
dimethacrylate (SR504), Alkoxylated phenol acrylate (SR614),
Ethoxylated (6) trimethylolpropane triacrylate (SR499), Alkoxylated
aliphatic diacrylate (SR9209), Polyethylene glycol(400)diacrylate
(SR344), 1,6 Hexanediol diacrylate (SR239), Tetrahydrofurfuryl
acrylate (SR285), Isobornyl Acrylat (SR506A), Tetrahydrofurfuryl
methacrylate (SR203), and Ethoxylated (10) bisphenol A diacrylate
(SR602) (Sartomer).
Photoinitiators
[0083] The photoinitiator absorbs light and is responsible for the
production of free radicals in a free radical polymerized system or
cations in a cationic photoinitiated system. There are many
photoinitiators commercially available, and a suitable
photoinitiator can be selected by considering the following
factors:
[0084] 1) The types of base resin employed: Free radical
polymerized resin or cationic polymerized resin.
[0085] 2) The radiation source: The absorption bands of the
photoinitiators should generally substantially overlap the emission
spectra of the light source.
[0086] 3) The absorption bands of the lens laminate: The adhesive
can be used to bond two substrates, e.g., preformed transparent
plastic lenses. One or both substrates may block UV block light (a
common practice for eye protection from sunlight). In this case,
the absorption band of the photointiator can be outside the
absorption band of the substrates.
[0087] The photoinitiator concentration can be about 0.01 to about
10%, preferably about 0.01to about 5%, about 0.1 to about 3%, or
about 0.1 to about 1.5%.
[0088] Preferred components of the photoinitiator system include
one or more of: Phenyl bis(2,4,6-trimethyl benzoyl)phosphine oxide
(Irgacure 819),
[0089] 1-Hydroxy cyclohexyl phenyl-ketone (Irgacure 184),
[0090] 2-Hydroxy 2-methyl 1-phenyl 1-propane (Daracure 1173),
[0091] Triaryl sulfonium salt hexafluoroantimonate and triaryl
sulfonium hexafluorophosphate (Cyracure.COPYRGT. UVI-6976).
[0092] The photoinitiator may include a radical photoinitiator, a
cationic photoinitiator, or an anionic photoinitiator.
[0093] Radical photoinitiator include, but are not limited to,
bis(2,3,6-trimethlbenzoyl)-phenylphosphineoxide,
1-hydroxcyclohexylphenylketone,
2-hydroxy-2-methyl-1-phenyl-propan-1-one,
bis(2,6-dimethoxybezoyl)-2,4,4-trimethylpentyl phosphe-ine oxide,
2,4,6-trimethylbezoyldiphenylphosphine,
2,2-dimethoxy-2-phenylacetophenone,
4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methlpropyl)ketone, 2-methyl
thioxanthone, 2-isopropyl thioxanthone, 2-chloro thioxanthone,
thoxanthone, xanthene, bezophenoe,
2-methyl-1-[4-methylthio)phenyl]-2-morpholino propan-1-one, and
2-benzyl-2-N,N-dimethlamino-1-(-morpholinophenyl)-1-butanone.
Preferred exemplary radical photoinitiators include
bis(2,3,6-trimethlbenzoyl)-phenylphosphineoxide,
1-hydroxcyclohexylphenylketone, and
2-hydroxy-2-methyl-1-1-phenyl-propan-1-one.
[0094] Cationic photoinitiators include, but are not limited to,
triaryl sulfonium salt hexafluoroantimonate; triaryl sulfonium
hexafluorophosphate,
bis(4-diphenylsulfonio)-phenyl]sufid-bis-hexafluorophosphate,
di(alkylphenyl) iodonium salt, diaryl iodonium hexafluroantimonate,
and iron-arene complex.
[0095] Anionic photoinitiators include, but are not limited to,
O-nitrobenzyl derivatives, metal amine complexes,
(cyclopentadienyl)ruthenium complexes, and (cyclopentadienyl)osmium
complexes.
[0096] In one embodiment, the photoinitiator system includes at
least one additive such as a co-catalyst, a phosphine, and/or an
amine. Exemplary additives include, but are not limited to,
phosphonium salts, tera alkylphosphonium bromide, tera
alkylphosphonium chloride, triphenyl phosphine, trimethoxy phenyl
phosphine, trichloro phenyl phosphine, alkyl amine primary, dialkyl
amine, and trialkyamine.
Additional Adhesive Components
[0097] The adhesive composition may further contain up to about 10%
of a partially or fully hydrolyzed silane coupling agent as an
adhesion promoter/coupling agent. Exemplary silanes include, but
are not limited to, 3-Methacryloxypropyl trimethoxysilane,
3-Amino-propyl trimethoxysilane, and
3-Glycidoxypropyltrimethoxysilane.
[0098] The composition may contain at least one vinyl resin.
Without being bound by theory, it is believed that the vinyl resin
advantageously exhibits a lower viscosity to dilute the high
index-high viscosity component while simultaneously improving
adhesion. A preferred vinyl resin is NTT #6205. The vinyl resin(s)
can be present in an amount of, e.g., about 10 to about 95%, about
20 to about 60%, or about 30 to about 40%.
[0099] The composition may contain at least one sulfur component.
Without being bound by theory, it is thought that the sulfur
component improves adhesion. Exemplary sulfur components include,
but are not limited to, 2-bis(2-mercapto ethylthio)-3-mercapto
propane, trimethylolpropane tris(3-mercaptopropionate),
2-mercaptoethylthio-3-propanthiol sulfide, pentaerythritol
tetrakis(2-mercaptopropoinate), 2,2'-thiodiethanethiol,
trimethyloltris(3-mercaptopropoinate)oethylthio-3 propanthiol
sulfide, 2,5-dimercaptomethyl-1,4-dithiane,
4,5-(mercaptomethylthio)-1,3-dithiolane,
4,6-(mercaptomethylthio)-1,3-dithiane,
1,1,3,3-tetra(mercaptomethylthio)propane, 2,3-episulfide propanyl
disulfide, and 2,3-episulfide propanyl sulfide. The sulfur
components) can be present in an amount of, e.g., about 1 to about
30%, about 5 to about 20%, or about 5 to about 10%).
[0100] The composition may contain at least one acrylic component.
Without being bound by theory, it is believed that the acrylic
component improves adhesion. Moreover, some acrylic components may
also advantageously contribute to the high refractive index of the
final composition. For example, aromatic acrylates, and
particularly halogenated aromatic acrylates exhibit high RI.
Exemplary acrylic components include, but are not limited to,
polyethylene glycol o-phenyl phenyl ether acrylate, urethane
acrylate, aliphatic urethane acrylate, acrylic oligomer,
2(2-ethoxyethoxy) ethyl acrylate, 2-phenoxyethyl acrylate,
ethoxylated (4) trimethylolpropane triacrylate, ethoxylated (6)
trimethylolpropane triacrylate, isobornyl acrylates, glycidyl
methacrylate, 1,6 hexanediol diacrylate, alkoxylated phenol
acrylate, alkoxylated phenol diacrylate, 2 hydroxyethyl acrylate,
phenylthioethylacrylate, alkoxylated nonylphenol acrylate,
ethoxlyated tribromo phenyl acrylate, tetrahydrofurfuryl acrylate,
tetrahydrofurfuryl methacrylate, and polyethylene glycol (200)
diacrylate. In one embodiment, the acrylic component includes a
urethane acrylate. The acrylic component(s) can be present in an
amount of, e.g., about 5 to about 80%, about 1 to about 60%, or
about 2 to about 50%, about 5to about 30%.
[0101] The composition may contain a bisphenol A Without being
bound by theory, it is believed that the bisphenol A improves the
mechanical properties of the adhesive composition by, e.g.,
preventing film breakdown. Exemplary bisphenol A components
include, but are not limited to, ethoxylated (10) bisphenol A
diacrylate, ethoxylated (4) bisphenol A diacrylate, ethoxylated (4)
bisphenol A dimethacrylate, diallylether bisphenol A, and ortho
diallyl bisphenol A. The bisphenol component(s) can be present in
an amount of, e.g., about 1 to about 70%, about 5 to about 25%, or
about 30 to about 60%.
[0102] The composition may contain at least one naphthalene
component. Without being bound by theory, it is believed that the
naphthalene component exhibits a relatively high refractive index
(though not typically as high as the high index-high viscosity
component) while exhibiting a lower viscosity to balance the high
index-high viscosity component. Exemplary naphthalene components
include, but are not limited to, 1-chloro naphthalene, 1-bromo
naphthalene, and 1-naphthaldehyde. The naphthalene components) can
be present in an amount of, e.g., about 5 to about 25%o or about
10% to about 2%.
[0103] The composition may contain at least one epoxy resin.
Exemplary epoxy resins include, but are not limited to,
poly[(phenyl glycidyl ether)-co-formaldehyd]oligomeric epoxide and
epoxy acrylates.
[0104] In some cases, particular components may be preferred
depending on the desired refractive index outcome. To that end,
preferred components for the low, mid-, and high index adhesives
are provided. Numerous low, mid-, and high index adhesive
compositions are also provided in the Examples.
[0105] The low index adhesives provided herein (RI of about 1.49 to
about 1.55) generally comprise at least one acrylic component in
addition to the photoinitiator and high index-high viscosity
component. Preferred components include:
[0106] about 0.01 wt % to about 5 wt % of at least one
photoinitiator; and
[0107] about 5 wt % to about 80 wt % of at least one acrylic
component selected from the group consisting of aliphatic urethane
acrylate; acrylic oligomer; ethoxylated (4) trimethylolpropane
triacrylate; ethoxylated (6) trimethylolpropane triacrylate;
glycidyl methacrylate; 1,6 hexanediol diacrylate; alkoxylated
phenol acrylate; alkoxylated phenol diacrylate; 2 hydroxyethyl
acrylate; alkoxylated nonylphenol acrylate; ethoxylated (10)
bisphenol A diacrylate; 2-phenoxyethyl acrylate; isobornyl
acrylates; tetrahydrofurfuryl acrylate; tetrahydrofurfuryl
methacrylate; and polyethylene glycol (200) diacrylate; more
particularly
[0108] at least one acrylic component selected from the group
consisting of aliphatic urethane acrylate; acrylic oligomer;
ethoxylated (4) trimethylolpropane triacrylate; ethoxylated (6)
trimethylolpropane triacrylate; glycidyl methacrylate; 1,6
hexanediol diacrylate; alkoxylated phenol acrylate; 2 hydroxyethyl
acrylate; alkoxylated nonylphenol acrylate; and ethoxylated (10)
bisphenol A diacrylate.
[0109] Additional preferred components for the low index adhesives
include:
[0110] about 10 wt % to about 50 wt % of at least one high
index-high viscosity component selected from the group consisting
of brominated aromatic urethane acrylates; and/or
[0111] a sulfur component selected from the group consisting of
trimethylolpropane tris(3-mercaptopropionate) and pentaerythritol
tetrakis(2-mercaptopropoinate)
[0112] The mid-index adhesives provided herein (RI of about 1.55 to
about 1.6) generally comprise at least one of an acrylic component
in addition to the photoinitiator and high index-high viscosity
component. Preferred components include:
[0113] about 0.01 wt % to about 5 wt % of at least one
photoinitiator; more particularly
[0114] about 0,01 wt % to about 5 wt % of at least one radical
photoinitiator selected from the group consisting of
bis(2,3,6-trimethlbenzoyl)-phenylphosphirieoxide;
1-hydroxcyclohexylphenylketone; and 2-hydroxy-2-methyl-l
-phenyl-propan-1-one;
[0115] about 10 wt % to about 60 wt % of at least one high
index-high viscosity component selected from the group consisting
of brominated aromatic urethane acrylates; tribromo phenyl
acrylate; and 9,9-bis{4-(2-acryloyloxyethoxy)phenyl}fluorine; more
particularly
[0116] about 10 wt % to about 60 wt % of at least one high
index-high viscosity component selected from the group consisting
of brominated aromatic urethane acrylates;
[0117] about 1 wt % to about 60 wt % of at least one acrylic
component selected from the group consisting of
2(2-ethoxyethoxy)ethyl acrylate; 2-phenoxyethyl acrylate;
ethoxylated (4) trimethylolpropane triacrylate; ethoxylated (6)
trimethylolpropane triacrylate; alkoxylated phenol acrylate; 2
hydroxyethyl acrylate; polyethylene glycol o-phenyl phenyl ether
acrylate; urethane acrylate; isobornyl acrylates; and alkoxylated
nonylphenol acrylate; more particularly about 1 wt % to about 60 wt
% of at least one acrylic component selected from the group
consisting of 2(2-ethoxyethoxy)ethyl acrylate; 2-phenoxyethyl
acrylate; ethoxylated (4) trimethylolpropane triacrylate;
ethoxylated (6) trimethylolpropane triacrylate; alkoxylated phenol
acrylate; and 2 hydroxyethyl acrylate.
[0118] Additional preferred components for the mid-index adhesives
include:
[0119] a sulfur component selected from the group consisting of
2-mercaptoethylthio-3-propanthiol sulfide; 2,2'-thiodiethanethiol;
and trimethyloltris(3-mercaptopropoinate)oethylthio-3propanthiol
sulfide;
[0120] an epoxy resin selected from the group consisting of epoxy
acrylates;
[0121] a bisphenol A component selected from the group consisting
of ethoxylated (10) bisphenol A diacrylate; ethoxylatedH (4)
bisphenol A diacrylate; and ethoxylatedH (4) bisphenol A
dimethacrylate; and/or
[0122] triallyl isocyanurate.
[0123] The high index adhesives provided herein (RI of about 1.6 to
about 1.74) generally comprise a photoinitiator and high index-high
viscosity component. Preferred components include:
[0124] about 0,01 wt % to about 5 wt % of at least one
photoinitiator (e.g.,
bis(2,3,6-trimethlbenzoyl)-phenylphosphineoxide, triaryl sulfonium
salt hexafluoroantimonate, and/or triaryl sulfonium
hexafluorophosphate); and
[0125] about 1 wt % to about 70 wt % of at least one high
index-high viscosity component selected from the group consisting
of brom.in.ated aromatic urethane acrylate; tribromophenyl
acrylate; and 9,9-bis{4-(2-acryloyloxyethoxy)phenyl}fluorine.
[0126] In one embodiment, the high index adhesive includes at least
one vinyl resin (e.g., NTT #6205). The vinyl resin may be present
in an amount of, e.g., about 10 wt % to about 95 wt %.
[0127] Additional preferred components for the high index adhesives
include:
[0128] about 2 wt % to about 50 wt % of at least one acrylic
component selected from the group consisting of polyethylene glycol
o-phenyl phenyl ether acrylate; urethane acrylate; acrylic
oligomer; isobornyl acrylates; phenylthioethylacrylate; and
ethoxlyated tribromo phenyl acrylate;
[0129] at least one sulfur component selected from the group
consisting of 1,2-bis(2-mercaptoethylthio)-3-mercapto propane;
trimethylolpropane tris(3-mercaptopropionate);
2-mercaptoethylthio-3-propanthiol sulfide; pentaerythritol
tetrakis(2-mercaptopropoinate); 2,2'-thiodiethanethiol;
trimethyloltris(3-mercaptopropoinate)oethylthio-3 propanthiol
sulfide; 2,5-dimercaptomethyl-1,4-dithiane;
4,5-(mercaptomethylthio)-1,3-dithiolane;
4,6-(mercaptomethylthio)-1,3-dithiane;
1,1,3,3-tetra(mercaptomethylthio)propane; 2,3-episulfide propanyl
disulfide; and 2,3-episulfide propanyl sulfide, more
particularly
[0130] about 1 wt % to about 30 wt % of at least one sulfur
component selected from the group consisting of 1,2-bis(2-mercapto
ethylthio)-3-mercapto propane; trimethylolpropane
tris(3-mercaptopropionate); 2-mercaptoethylthio-3-propanthiol
sulfide; pentaerythritol tetrakis(2-mercaptopropoinate); and
2,2'-thiodiethanethiol;
[0131] about 5 wt % to about 25 wt % of at least one at least one
naphthalene component selected from the group consisting of
1-chloro naphthalene; 1-bromo naphthalene; and
1-naphthaldehyde;
[0132] a bisphenol A component selected from the group consisting
of diallylether bisphenol A; and ortho diallyl bisphenol A;
and/or
[0133] an epoxy resin selected from the group consisting of
poly[(phenyl glycidyl ether)-co-formaldehyde]oligomeric epoxide;
and epoxy acrylates.
Light Source
[0134] The adhesive compositions are curable by exposure to
radiation (a light source), preferably ultraviolet or
ultraviolet-visible light. Curing can be conducted after the
lamination process, which means the light passes through the lens
assembly to reach the adhesive. In cases where the lens assembly
includes a UV blocker, the light source can provide emission bands
of wavelengths longer than 400 nm such as Actinic light sources or
LED light sources.
[0135] The exposure time required to cure the adhesive compositions
can vary and can depend on the light source, photoinitiator
concentration, and the distance of the source from the substrate.
One of ordinary skill in the art would readily appreciate how to
adapt the exposure time accordingly.
[0136] Exemplary light sources include, but are not limited to:
[0137] Medium Pressure Vapor Lamp Source: Six-inch lamp operating
at a power level of approximately 200 watt per inch. The curing
chamber can include a conveyer transporting the sample underneath
the lamp. The plane of the conveyer can be positioned approximately
3 inches from the lamp. The light energy can be set at
approximately 1000 mJ/cm2 measured with Model ILT 390 Light Bug
from International Light, Inc. over the range of 250 to 400 nm in
one pass;
[0138] Actinic Light Source: Two sets of four fluorescent lamps can
be positioned above and below to provide substantially uniform
radiation over the plane of the curing stage. Approximately 4.9
mW/cm2 measured at the plane of sample from the top lamps and
approximately 4.1 mW/cm2 from the bottom lamps with International
light meter model IL1400A with XRL 140A detector. These lamps emit
activating light in the range of greater than about 380 nm and are
commercially available from Philips Electronics as model
TLD-15W/03;
[0139] LED sources, such as a custom LED array with a main
wavelength at 411.+-.4 nm;
[0140] DYMAX Blue Wave.TM. 50 UV Spot Light with the UV main output
of about 3000.+-. mW/cm2 at 365 nm, 410 nm, and at 430nm.
Devices
[0141] As previously mentioned, the adhesive compositions provided
herein can be used to bond substrates, e.g., ophthalmic components.
The adhesive can be applied in a number of ways readily apparent to
one of ordinary skill, in the art including, but not limited to,
spinning, dipping, brushing, spraying, and filling.
[0142] The substrates to be laminated can be the same as or
different from one another. In one embodiment, the adhesive is
disposed between two substrates, each, with a different RI. For
example, adhesive compositions were found to adhere surface casting
Trivex.RTM. (RI=1.53) resin to a preformed polycarbonate lens
(RI=1.58), or surface casting Trivex.RTM. to a preformed MR-10lens
(RI=1.67). When the substrates have different RIs, the RI of the
cured adhesive composition can have a RI value close to the average
RI of the two lenses. For example, when laminating preformed
Trivex.RTM. lens or surface casting Trivex.RTM. resin to a
preformed polycarbonate lens (RI=1.58), the RI of the cured
adhesive composition should be in the range of about 1.54 to about
1.57, and preferably about 1.55 to about 1.56. The advantage of
having an adhesive RI close to the RI of both lenses is to reduce
or eliminate light interference resulting from the difference in RI
of the two lenses.
[0143] Accordingly, in another embodiment, a device is provided.
The device comprises a) a first substrate, e.g., ophthalmic
component, b) a second substrate, e.g., ophthalmic component, and
c) a curable adhesive composition disposed between the first and
second ophthalmic components. The adhesive can be any of the
adhesives described herein, such as those comprising at least one
high index-high viscosity component having a refractive index,
before curing, of at least 1.56 at 25.degree. C., and a viscosity,
before curing, of at least 15,000 cP at 25.degree. C., and a
photoinitiator. The refractive index of the adhesive composition,
after curing, is i) about equal to the refractive index of at least
one of the first ophthalmic component and the second ophthalmic
component, ii) between the refractive index of the first lens and
the refractive index of the second lens, or iii) about equal to the
average refractive index of the first ophthalmic component and the
second ophthalmic component. In one embodiment, the refractive
index of the adhesive composition, after curing, is within 0.03,
preferably within 0.02, of the refractive index of at least one of
the first ophthalmic component and the second ophthalmic component.
In another embodiment, at least one of the first ophthalmic
component and the second ophthalmic component has a refractive
index of about 1.67.
EXAMPLES
Mixing the Components:
[0144] The amount of the solid photoinitiator to be used can be
taken from pre-dissolved concentrated form in the range of 3-6% by
weight. High viscosity and/or non-pourable components can be
preheated and mixed with others. Solid monomers or oligomers can
also be preheated and mixed with a low viscosity component before
adding a predetermined amount of initiator. The final composition
can be mixed for at least 10 to 15 minutes away from light before
storing it in a brown polypropylene bottle at regular room
temperature conditions.
Sample Preparation
[0145] The components that form the light curable adhesive were
used as received. Exemplary components are listed in the Tables
below.
[0146] Assembly and Curing: About 0.5 g of the adhesive is placed
on a first substrate, e.g., a pre-cleaned round, flat piece of
uncoated MR-10 having a diameter of about 44 mm and a thickness of
about 1.2 mm (supplied by PixelOptics, Inc.). A second substrate,
e.g., the same as the first, is placed with a gentle contact to the
adhesive on top the first piece until the adhesive spreads to the
edge of the substrates. The assembly then proceeds to the curing
step, e.g., it is placed on an actinic light source curing stage.
The curing stage is about 5mm thick round clear crown glass and is
about 80 mm in diameter. The assembly is exposed to the light from
the top and bottom for 1.5 min. The cured assembly is examined and
left at room temperature for at least 10 min before the adhesion
test.
[0147] Refractive Index Measurement: Abbe-3L Refractometer from
Fisher Scientific was used to measure the refractive index of the
adhesives in liquid state (before curing) or solid cured state.
This Refractometer has an index range from 1.30 to 1.71 relative to
Sodium D line (589.3nm), 1-bromonaphthalene from Fisher Scientific
was used as contact liquid for solid test pieces with indices less
1.64 nD, and Series M 1.75 nD from Cargill was used as contact
liquid for solid test pieces with indices more than 1.64 nD.
[0148] Adhesion Strength: The adhesion strength was evaluated based
on how much effort was needed to separate the two glued pieces. A
hand-held, mold scraper tool commercially available under parts
code TTAR 05-020 for the handle and TTAR 05-021 for the de-molding
blade from Optical Dynamics was used to separate the two glued
pieces and assign poor, good or excellent adhesion ratings as
follows:
[0149] Poor: Easy to de laminate from both sample pieces by hand
without using the scraper tool.
[0150] Good: The two sample pieces were difficult to delaminate
using a razor blade.
[0151] Excellent: The two sample pieces do not delaminate using the
scraper tool unless excessive force is applied. For this case,
separation was associated with broken portions, with, the cured
adhesive randomly remaining on the separate pieces of the test
sample.
[0152] The adhesive compositions that exhibited good RI match and
good adhesion in the initial screening tests were further tested
for adhesion performance and RI match in actual lens laminates to
form composite lens. The adhesion performance was tested by
surfacing and edging of the final lens laminate looking for any
sign of delamination. All preferred adhesive compositions show good
RI match and good or excellent adhesion.
[0153] The invention can be further illustrated by referring to the
following adhesive compositions in the Tables below. (RI=refractive
index; visc.=viscosity; comp.=composition)
TABLE-US-00001 TABLE I Exemplary Components RI visc Chemical Name
Proprietary Name Phenyl bis(2,4,6-trimethyl benzoyl) phosphine
oxide Irgacure 819 1-Hydroxy cyclohexyl phenyl-ketone Irgacure 184
2-Hydroxy 2-methyl 1-phenyl 1-propane Darocur 1173 1.579; 164000;
Brominated Aromatic Urethane Acrylates CN2600 1.58 72000 1.6 solid
Tribromophenyl Acrylate BR30 1.621 91000
9,9-Bis{4-(2-acryloyloxyethoxy)phenyl}fluorene NK-BPEF at 60 C.
1.68 18 vinyl resin NTT #6205 Epoxy oligomer EP45HT 1.576 150
polyethylene glycol o-phenyl phenyl ether acrylate NK-Ester
A-Len-10 1.55 56000 Urethane acrylate CN9167 Aliphatic urethane
acrylate CN2922 1.5255 250 acrylic oligomer CN 131B 1.4366 6
2(2-ethoxyethoxy) ethyl acrylate SR 256 1.516 12 2-phenoxyethyl
acrylate SR 339 1.534 1080 ethoxylated (4) trimethylolpropane
triacrylate SR 601 ethoxylated (4) bisphenol diacrylate 1.4691 95
ethoxylated (6) trimethylolpropane triacrylate SR 499 1.47 9
Isobornyl acrylates SR 506 Glycidyl methacrylate SR 379 1.456
<10 1,6 hexanediol diacrylate SR 238 1.495* 65 alkoxylated
phenol acrylate CD 9088 1.449 5 2 hydroxyethyl acrylate 2-HEA 1.555
<10 Phenylthioethylacrylate PTEA Alkoxylated nonylphenol
acrylate 614 Glycidyl methacrylate SR 379 ethoxylated (10)
bisphenol diacrylate SR 602 Ortho diallyl bisphenol A Diallylether
bisphenol A 1.633 70 1,2-bis(2-mercapto ethylthio)-3-mercapto
propane 1.523; 67; 190 Trimethylolpropane
tris(3-mercaptopropionate) 1.517 1.64 250
2-mercaptoethylthio-3-propanthiol sulfide 1.53 250 Pentaerythritol
tetrakis(3-mercaptopropionate) 1.59 <10 2,2'-Thiodiethanethiol
1.631 <10 1-Chloro Naphthalene 1.656 <10 1-Bromo Naphthalene
1.6515 <10 1-Naphthaldehyde 1-Naphthylamine 1-Naphthol For the
exemplary components, RI and viscosity were measured at 25.degree.
C., except where noted by *, which were provided at the closest
temperature available. The RI of the compositions before and after
curing was measured at 23.degree. C.
TABLE-US-00002 TABLE II Exemplary High Index Adhesive Compositions
H1 H2 H3 H4 H5 H6 H7 H8 Irgacure 819 0.41 0.41 0.316 0.276 0.295
0.193 0.18 0.15 CN2600 21.74 14.32 16.06 3.98 9.6 2.78 2.65 BR30
24.17 NK-Ester A-BPEF 36.32 58.58 48.23 41 39 24.16 NTT #6205 60
59.9 47.3 37.16 41.88 26.33 24.74 16.67 NK-Ester A-Len-10 17.85
25.27 CN 131B 9.55 1,2-bis(2-mereapto 30 23.39 25.3
ethylithio)-3-mereapto propane 1-Chloro Naphthalene 10.04
Trimethylolpropane tris(3- mercaptopropionate) Composition 1.64
1.64 1.64 1.64 1.64 1.64 1.64 1.62 RI (pre-cure) Composition 1.674
1.67 1.669 1.663 1.669 1.676 1.672 1.660 RI (cured) H9 H10 H11 H12
Irgaeure 819 0.15 0.17 0.15 0.15 CN2600 57.69 38.01 BR30 20.91
36.12 NK-Ester A-BPEF 20.91 19.54 NTT #6205 23.63 14.58 NK-Ester
A-Len-10 2.6 42.16 61.84 CN 131B 8.91 1,2-bis(2-mereapto 25.49 16.2
ethylithio)-3-mereapto propane 1-Chloro Naphthalene
Trimethylolpropane 10.8 tris(3- mercaptopropionate) Composition
1.6303 1.6173 1.5813 1.58 RI (pre-cure) Composition 1.668 1.648
1.608 1.609 RI (cured) H13 H14 H15 H16 H17 H18 H19 H20 Irgacure 819
0.24 0.219 0.152 0.19 0.19 0.19 0.22 0.21 Cyracure UVI6976 CN2600
22.41 8 BR30 15.6 15.78 15.68 15.83 15.33 NK- BPEF 17.88 19.6 15.6
15.78 15.68 15.83 15.33 19.73 NTT #6205 36.74 33.21 34.5 32.12
31.92 32.23 31.44 30.38 EP45HT NK-Ester A-Len-10 CN9167 9.02 9.837
9.837 21.2 21.07 21.29 23.6 CN131B 5.89 4.45 4.48 5.26 3.94 SR 506
3.14 PTEA 6.58 6.118 6.118 Diallylether bisphenol A
Trimethylolpropane 8.22 14.507 7.52 8.46 tris(3-
mercaptopropionate) 2- 12.34 17.59 5.67 Mercaptoethylthio-
3-propanthiol sulfide Pentaerythritol 10.45 2.95 3 tetrakis(3-
mercaptopropionate) H21 H22 H23 H24 H25 H26 Irgacure 819 0.21 0.06
0.33 0.41 0.26 Cyracure 1.03 UVI6976 CN2600 5.08 23.08 4.55 44.5
BR30 13.9 NK- BPEF 12.88 20.20 46.04 NTT #6205 32.9 60 90 EP45HT
98.97 NK-Ester A-Len-10 16.86 5.12 6.44 CN9167 21.67 11.49 CN131B
3.44 SR 506 PTEA 17.40 Diallylether 4.76 bisphenol A
Trimethylolpropane 6.04 tris(3- mercaptopropionate) 2- 4.03
Mercaptoethylthio- 3-propanthiol sulfide Pentaerythritol
tetrakis(3- mercaptopropionate) H13 H14 H15 H16 H17 H18 H19 H20
2,2'- 6.644 6.644 11 7.2 7.02 Thiodiethanethiol 1-Bromo 8.98 9.88
Naphthalene 1-Chloro Naphthalene 1- Naphthaldehyde 1- Naphthylamine
4.82 1- Naphthol Composition 1.629 1.616 1.616 1.613 1.618 1.616
1.627 1.609 RI (pre- cure) Composition 1.668 1.651 1.651 1.647
1.6505 1.647 1.657 1.638 RI (cured) H21 H22 H23 H24 H25 H26 2,2'-
Thiodiethanethiol 1-Bromo 11.49 Naphthalene 1-Chloro 17.85
Naphthalene 1- Naphthaldehyde 10.6 1- Naphthylamine 1- Naphthol
3.74 Composition 1.616 1.64 1.67 1.61 1.606 1.583 RI (pre- cure)
Composition 1.642 1.668 1.70 1.628 1.627 1.603 RI (cured) H27 H28
H29 H30 H31 H32 H33 H34 Igacure 819 0.38 0.50 0.58 0.30 0.49 0.28
0.28 0.21 Cyracure 0.23 UVI6976 SR 506 10.08 10.18 CN2600
Tribromophenyl Acrylate NK- BPEF 41.15 68.15 51.10 40.83 42.83
24.76 22.26 18.17 NTT #6205 42.20 37.93 30.94 2-Mercaptoethylthio-
16.45 3propanthiol sulfide EP45HT 22.82 NK-ester A-Len-10 CN9167
25.21 20.13 21.54 12.54 11.19 9.14 PTEA 12.45 13.30 13.50 11.37
13.56 7.84 7.05 5.75 Ortho diallyl bisphenol A 18.05 9.61 8.00
2,2'-Thiodiethanethiol 19.37 1-Chloro Naphthalene 1-Bromo
Naphthalene 22.97 21.58 12.47 11.21 9.16 Composition RI 1.608 1.606
1.592 1.59 1.6040 1.6370 1.6180 1.618 (pre-cure) Composition RI
1.6290 1.60 1.6160 1.6313 1.6710 1.6540 1.6570 (cured)
[0154] The compositions listed in the table above yield adhesives
that provide a good RI match, as indicated by the invisible seal
fixtures of the diffractive pattern region. Most exhibit good
adhesion, while some (labeled in bold) exhibit excellent adhesion
strength.
TABLE-US-00003 TABLE III Exemplary Mid Index Adhesive Compositions
M1 M2 M3 M4 M5 M6 M7 Irgacure 819 0.30 0.30 0.30 0.30 0.3 Irgacure
184 1.20 1.20 1.20 1.20 3 3 Darocur 1173 1.2 CN2600 19.7 19.7 32.15
44.6 19.7 19.4 31.66 SR 256 2.66 SR 339 6.21 SR 601 45.3 45.3 35.05
24.8 SR 499 9.85 9.85 9.57 9.28 CD 9088 8.87 8.15 7.44 2-HEA 14.78
14.78 13.58 12.38 SR 602 SR 256 2.66 SR 339 6.21 SR 601 45.31 44.62
34.52 SR 499 9.85 9.7 9.42 CD 9088 8.73 8.04 2-HEA 14.78 14.55
13.38 Composition RI (pre-cure) 1.52 1.52 1.53 1.53 1.520 1.520
1.525 Composition RI (cured) 1.55 1.55 1.55 1.56 1.550 1.550
1.555
[0155] The compositions listed in the table above yield adhesives
that provide good adhesion and good RI match. These compositions
may be useful to surface cast Trivex.RTM. to preformed MR-10 lens,
since they have an RI between the RI of MR-10 (1.67) and
Trivex.RTM. (1.53).
TABLE-US-00004 TABLE IV Exemplary Low-Index Adhesive Compositions
L1 L2 L3 L4 L5 Irgacure 819 0.26 0.35 0.10 0.37 0.3 Irgacure 184
1.47 Darocur 1173 1.2 CN2600 31.84 19.63 19.7 CN2922 69.11 17.08 CN
131B 14.85 SR 499 9.81 9.85 SR 379 SR 238 17.85 36.14 CD 9088 8.83
8.87 2-HEA 25.10 14.73 14.78 614 15.20 SR 379 12.78 SR 602 59.35
45.16 SR 601 45.31 Composition RI 1.473 1.507 1.504 1.508 1.520
(pre-cure) Composition RI (cured) 1.495 1.537 NA 1.538 1.549
[0156] The compositions listed in the table above yield adhesives
that provide good adhesion and also good RI match. These
composition may be useful to adhere polycarbonate and Trivex.RTM.
substrates, since they have an RI between the RI of polycarbonate
(1.58) and Trivex.RTM. (1.53).
* * * * *