U.S. patent application number 13/100400 was filed with the patent office on 2013-01-31 for high refractive index ophthalmic device materials with reduced tack.
This patent application is currently assigned to NOVARTIS AG. The applicant listed for this patent is Ali E. Akinay, Charles Freeman, Walter R. Laredo, Chance Lehman, Joseph I. Weinschenk, III. Invention is credited to Ali E. Akinay, Charles Freeman, Walter R. Laredo, Chance Lehman, Joseph I. Weinschenk, III.
Application Number | 20130030079 13/100400 |
Document ID | / |
Family ID | 47562271 |
Filed Date | 2013-01-31 |
United States Patent
Application |
20130030079 |
Kind Code |
A1 |
Lehman; Chance ; et
al. |
January 31, 2013 |
HIGH REFRACTIVE INDEX OPHTHALMIC DEVICE MATERIALS WITH REDUCED
TACK
Abstract
High refractive index copolymers with reduced tack are
disclosed. The copolymers, which are particularly suitable for use
as ophthalmic device materials, comprise a benzhydryl methacrylate
or benzydryl methacrylate derivative monomer.
Inventors: |
Lehman; Chance; (Dallas,
TX) ; Freeman; Charles; (Granbury, TX) ;
Laredo; Walter R.; (Fort Worth, TX) ; Akinay; Ali
E.; (Mansfield, TX) ; Weinschenk, III; Joseph I.;
(Fort Worth, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lehman; Chance
Freeman; Charles
Laredo; Walter R.
Akinay; Ali E.
Weinschenk, III; Joseph I. |
Dallas
Granbury
Fort Worth
Mansfield
Fort Worth |
TX
TX
TX
TX
TX |
US
US
US
US
US |
|
|
Assignee: |
NOVARTIS AG
Basel
CH
|
Family ID: |
47562271 |
Appl. No.: |
13/100400 |
Filed: |
May 4, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61331586 |
May 5, 2010 |
|
|
|
Current U.S.
Class: |
523/106 ;
526/326 |
Current CPC
Class: |
G02B 1/043 20130101;
A61F 2/14 20130101; C08F 220/301 20200201; C08F 220/18 20130101;
C08F 220/301 20200201; C08F 222/102 20200201; C08F 220/1806
20200201; C08F 220/286 20200201; C08F 222/102 20200201; A61F 2/16
20130101; C08F 220/1807 20200201; C08F 220/301 20200201; C08F
220/1807 20200201; C08F 222/102 20200201; C08F 220/286 20200201;
C08F 220/286 20200201 |
Class at
Publication: |
523/106 ;
526/326 |
International
Class: |
G02C 7/04 20060101
G02C007/04; C08F 220/18 20060101 C08F220/18 |
Claims
1. An ophthalmic device material comprising a) 50-93% (w/w) of a
polymerizable monomer of structure (I): ##STR00009## wherein: A is
H or CH.sub.3; B is (CH.sub.2).sub.m or [O(CH.sub.2).sub.2].sub.z;
m is 2-6; z is 1-10; Y is nothing, O, S, or NR', provided that if Y
is O, S, or NR', then B is (CH.sub.2).sub.m; R' is H, CH.sub.3,
C.sub.n'H.sub.2n'+1, iso-OC.sub.3H.sub.7, C.sub.6H.sub.5, or
CH.sub.2C.sub.6H.sub.5; n'=1-10; w is 0-6, provided that
m+w.ltoreq.8; and D is H, Cl, Br, C.sub.1-C.sub.4 alkyl,
C.sub.1-C.sub.4 alkoxy, C.sub.6H.sub.5, or CH.sub.2C.sub.6H.sub.5;
b) 5-20% (w/w) of a benzhydryl methacrylate monomer of structure
(II): ##STR00010## wherein: E and F are independently H,
C.sub.1-C.sub.4 alkyl, C.sub.1-C.sub.4 alkoxy, CF.sub.3, F, Cl, Br,
or N(CH.sub.3).sub.2; and c) a polymerizable cross-linking
agent.
2. The ophthalmic device material of claim 1 wherein the monomer of
structure (I) is selected from the group consisting of:
2-ethylphenoxy acrylate; phenyl acrylate; benzyl acrylate;
2-phenylethyl acrylate; 3-phenylpropyl acrylate; 4-phenylbutyl
acrylate; 4-methylphenyl acrylate; 4-methylbenzyl acrylate;
2-2-methylphenylethyl acrylate; 2-3-methylphenylethyl acrylate;
2-4-methylphenylethyl acrylate; 2-(4-propylphenyl)ethyl acrylate;
2-(4-(1-methylethyl)phenyl)ethyl acrylate; 2-(4-methoxyphenyl)ethyl
acrylate; 2-(4-cyclohexylphenyl)ethyl acrylate;
2-(2-chlorophenyl)ethyl acrylate; 2-(3-chlorophenyl)ethyl acrylate;
2-(4-chlorophenyl)ethyl acrylate; 2-(4-bromophenyl)ethyl acrylate;
2-(3-phenylphenyl)ethyl acrylate; 2-(4-phenylphenyl)ethyl acrylate;
2-(4-benzylphenyl)ethyl acrylate; and their corresponding
methacrylates.
3. The ophthalmic device material of claim 1 wherein, for the
monomer of structure (I), A is H, B is (CH.sub.2).sub.m, m is 2-5,
Y is nothing or O, w is 0-1, and D is H.
4. The ophthalmic device material of claim 3 wherein the monomer of
structure (I) is selected from the group consisting of:
2-phenylethyl acrylate; 4-phenylbutyl acrylate; 5-phenylpentyl
acrylate; 2-benzyloxyethyl acrylate; and 3-benzyloxypropyl
acrylate.
5. The ophthalmic device material of claim 1 wherein the ophthalmic
device material comprises a total of 75-90% (w/w) of the monomer of
structure (I).
6. The ophthalmic device, material of claim 1 wherein the monomer
of structure (II) is selected from the group consisting of:
benzhydryl methacrylate; 4,4'-difluorobenzhydryl methacrylate;
4,4'-dimethoxybenzhydryl methacrylate; 4,4'-dichloroobenzhydryl
methacrylate; 2-methylbenzhydryl methacrylate; 4-methylbenzhydryl
methacrylate; 4-methoxybenzhydryl methacrylate;
4-(trifluoromethyl)benzhydryl methacrylate; 4-chlorobenzhydryl
methacrylate; 2-(trifluoromethyl)benzhydryl methacrylate;
3-(trifluoromethyl)benzhydryl methacrylate; 4,4'-dimethylbenzhydryl
methacrylate; 4,4'-bis(dimethylamino)benzhydryl methacrylate;
3-chloro-4'-ethylbenzhydryl methacrylate;
4-chloro-4'-ethylbenzhydryl methacrylate;
3-chloro-4'-methylbenzhydryl methacrylate;
3-chloro-4'-methoxybenzhydryl methacrylate; 3,4'-dichlorobenzhydryl
methacrylate; 4-methoxy-3'-methylbenzhydryl methacrylate;
3-chloro-3'-methylbenzhydryl methacrylate;
3-chloro-3'-methoxybenzhydryl methacrylate;
4-(dimethylamino)-3'-methylbenzhydryl methacrylate;
4-(dimethylamino)-4'-methylbenzhydryl methacrylate;
4-chloro-3'-fluorobenzhydryl methacrylate;
3,3'-bis(trifluoromethyl)benzhydryl methacrylate;
3,4'-dimethylbenzhydryl methacrylate; 4-ethylbenzhydryl
methacrylate; 4-tert-butylbenzhydryl methacrylate;
4-methoxy-4'-methylbenzhydryl methacrylate;
3-fluoro-3'-methylbenzhydryl methacrylate;
3-fluoro-4'-methylbenzhydryl methacrylate;
3-fluoro-4'-methoxybenzhydryl methacrylate;
4-(dimethylamino)-3'-fluorobenzhydryl methacrylate;
4-(dimethylamino)-4'fluorobenzhydryl methacrylate;
3-methoxy-3'-methylbenzhydryl methacrylate;
3-methoxy-4'-methylbenzhydryl methacrylate;
4-fluoro-4'-methoxybenzhydryl methacrylate;
4-fluoro-3'-methoxybenzhydryl methacrylate;
3-chloro-3'-fluorobenzhydryl methacrylate;
4-chloro-3'-methoxybenzhydryl methacrylate;
4-chloro-4'-methoxybenzhydryl methacrylate; 3,3'-dimethylbenzhydryl
methacrylate; 4-fluorobenzhydryl methacrylate; 4-bromobenzhydryl
methacrylate; 3-chloro-4'-(dimethylamino)benzhydryl methacrylate;
4-ethyl-4'-fluorobenzhydryl methacrylate; 3,3'-difluorobenzhydryl
methacrylate; 4-fluoro-4'-methylbenzhydryl methacrylate;
3-chloro-4'-fluorobenzhydryl methacrylate;
3-fluoro-3'-methoxybenzhydryl methacrylate;
4-tert-butyl-4'-fluorobenzhydryl methacrylate; 4-ethyl-3'-fluoro
benzhydrylmethacrylate; 3,4'-difluorobenzhydryl methacrylate; and
4-ethyl-3'-methylbenzhydryl methacrylate.
7. The ophthalmic device material of claim 1 wherein, for the
monomer of structure (II), E and F independently are H, CH.sub.3,
CF.sub.3, F, or Cl.
8. The ophthalmic device material of claim 1 wherein the ophthalmic
device material comprises a total of 8-15% (w/w) of the monomer of
structure (II).
9. The ophthalmic device material of claim 1 wherein the
cross-linking agent is selected from the group consisting of
ethylene glycol dimethacrylate; diethylene glycol dimethacrylate;
triethylene glycol dimethacrylate, tetraethylene glycol
dimethacrylate, allyl methacrylate; 1,3-propanediol dimethacrylate;
2,3-propanediol dimethacrylate; 1,6-hexanediol dimethacrylate;
1,4-butanediol dimethacrylate;
CH.sub.2.dbd.C(CH.sub.3)C(.dbd.O)O--(CH.sub.2CH.sub.2O).sub.p--C(.dbd.O)C-
(CH.sub.3).dbd.CH.sub.2 where p=1-50; and
CH.sub.2.dbd.C(CH.sub.3)C(.dbd.O)O(CH.sub.2).sub.tO--C(.dbd.O)C(CH.sub.3)-
.dbd.CH.sub.2 where t=3-20; and their corresponding acrylates.
10. The ophthalmic device material of claim 9 wherein the
cross-linking agent is selected from the group consisting of:
ethylene glycol dimethacrylate; diethylene glycol dimethacrylate;
triethylene glycol dimethacrylate; triethylene glycol diacrylate;
and 1,4-butanediol diacrylate.
11. The ophthalmic device material of claim 1 wherein the
ophthalmic device material further comprises an agent selected from
the group consisting of UV-absorbers; colored dyes; and additives
to reduce or eliminate glistenings.
12. The ophthalmic device material of claim 11 wherein the
ophthalmic device material comprises
2-(2'-hydroxy-3'-methallyl-5'-methyl phenyl)benzotriazole.
13. The ophthalmic device material of claim 11 wherein the
ophthalmic device material comprises a yellow dye.
14. The ophthalmic device material of claim 11 wherein the
ophthalmic device material comprises hydroxyethyl methacrylate.
15. The ophthalmic device material of claim 11 wherein the
ophthalmic device material comprises an additive of structure
(IIIa) or (IIIb): ##STR00011## where, for IIIa and IIIb, e=1-50;
X=--O--, NH--, --N(CH.sub.3)--, --N(CH.sub.2CH.sub.3)--, or
--N(C.sub.6H.sub.5)--; Y=--H, --(CH.sub.2).sub.pOH,
--CH.sub.2CH.sub.2N(CH.sub.3).sub.2,
--CH.sub.2CH.sub.2N(CH.sub.2CH.sub.3).sub.2,
--CH.sub.2CH(OH)CH.sub.2OH, --(CH.sub.2CH.sub.2O).sub.qCH.sub.3,
--(CH.sub.2CH.sub.2O).sub.qH,
--(CH.sub.2CH.sub.2O).sub.qC.sub.6H.sub.5, or ##STR00012## p=1-12;
q=1-230; T, T' independently=O(CH.sub.2).sub.d',
NH(CH.sub.2).sub.d', NCH.sub.3(CH.sub.2).sub.d',
O(CH.sub.2).sub.d'C.sub.6H.sub.4,
O(CH.sub.2CH.sub.2O).sub.d'CH.sub.2,
O(CH.sub.2CH.sub.2CH.sub.2O).sub.d'CH.sub.2,
O(CH.sub.2CH.sub.2CH.sub.2CH.sub.2O).sub.d'CH.sub.2, or nothing;
K=(CH.sub.2).sub.a', O(CH.sub.2CH.sub.2O).sub.b', O, or nothing,
provided that if T and T'=nothing, then K.noteq.nothing; d'=0-12;
a'=1-12; b'=1-24; L=H, Cl, Br, --CH.sub.2C(O)CH.sub.3,
CH.sub.2C(O)C(CH.sub.3).sub.3, --CH.sub.2C(O)C.sub.6H.sub.5,
--CH.sub.2C(O)C.sub.6H.sub.4OH,
--CH.sub.2C(O)C.sub.6H.sub.4OCH.sub.3, ##STR00013## or
--CH.sub.2CH.dbd.CH.sub.2; R.sup.4, R.sup.5 independently=H,
CH.sub.3, CH.sub.2CH.sub.3, CH.sub.2CH.sub.2CH.sub.3,
CH(CH.sub.3).sub.2, CH.sub.2CH.sub.2CH.sub.2CH.sub.3, or
CH.sub.2CH(CH.sub.3).sub.2; R.sub.5=--CO.sub.2CH.sub.3,
--CO.sub.2CH.sub.2CH.sub.3, --CN, or
--CONHCH.sub.2CH.sub.2CH.sub.2CH.sub.3; and R.sup.7, R.sup.8
independently=H, CH.sub.3, CH.sub.2CH.sub.3, or CH.sub.2OH.
16. The ophthalmic device material of claim 15 wherein the
ophthalmic device material further comprises hydroxyethyl
methacrylate.
17. The ophthalmic device material of claim 1 wherein the
ophthalmic device material has a T.sub.g.ltoreq.37.degree. C.
18. The ophthalmic device material of claim 1 wherein the
ophthalmic device material has an elongation of at least 130%.
19. The ophthalmic device material of claim 1 wherein the
ophthalmic device material has a refractive index.gtoreq.1.55 in a
fully hydrated state at 35.degree. C., a Young's Modulus less than
60 MPa, and an equilibrium water content of less than 1.8 weight %
across the temperature range of 16-45.degree. C.
20. An ophthalmic device comprising the ophthalmic device material
of claim 1, wherein the ophthalmic device is selected from the
group consisting of: intraocular lenses; contact lenses;
keratoprostheses; intracorneal lenses; corneal inlays or rings; and
glaucoma filtration devices.
21. An intraocular lens comprising the ophthalmic device material
of claim 1.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. .sctn.119
to U.S. Provisional Patent Application No. 61/331,586, filed May 5,
2010, the entire contents of which are incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] This invention relates to high refractive index polymers and
their use in ophthalmic lenses, particularly intraocular lenses
that can be inserted through small incisions.
BACKGROUND OF THE INVENTION
[0003] High refractive index acrylic materials are known for use in
intraocular lenses (IOLs). For example, U.S. Pat. No. 5,290,892
discloses high refractive index acrylic materials suitable for use
as IOL materials. The materials are foldable and thus capable of
being inserted through small incisions. These acrylic materials
contain, as principal components, two aryl acrylic monomers.
[0004] Soft acrylic materials can be tacky. It is generally
desirable to reduce the amount of surface tack in materials
intended for use as a foldable intraocular lens. Tacky materials
can be difficult to handle and unfold. Approaches to eliminate tack
include surface treatments, such as the plasma gas treatments
described in U.S. Pat. No. 5,603,774. Other approaches include the
use of components or additives, such as those described in U.S.
Pat. Nos. 6,241,766; 6,245,106; 7,585,900; and 7,714,039.
SUMMARY OF THE INVENTION
[0005] This invention is directed to acrylic ophthalmic device
materials that do not have problematic levels of tack or surface
adhesion. The ophthalmic device materials are formed by
copolymerizing a composition comprising
a) 50-93% of a polymerizable monomer of the structure:
##STR00001##
wherein: [0006] A is H or CH.sub.3; [0007] B is (CH.sub.2).sub.m or
[O(CH.sub.2).sub.2].sub.z; [0008] m is 2-6; [0009] z is 1-10;
[0010] Y is nothing, O, S, or NR', provided that if Y is O, S, or
NR', then B is (CH.sub.2).sub.m; [0011] R' is H, CH.sub.3,
C.sub.n'H.sub.2n'+1, iso-OC.sub.3H.sub.7, C.sub.6H.sub.5, or
CH.sub.2C.sub.6H.sub.5; [0012] n'=1-10; [0013] w is 0-6, provided
that m+w.ltoreq.8; and [0014] D is H, Cl, Br, C.sub.1-C.sub.4
alkyl, C.sub.1-C.sub.4 alkoxy, C.sub.6H.sub.5, or
CH.sub.2C.sub.6H.sub.5; b) 5-20% of a benzhydryl methacrylate
monomer of the structure
##STR00002##
[0014] wherein: [0015] E and F are independently H, C.sub.1-C.sub.4
alkyl, C.sub.1-C.sub.4 alkoxy, CF.sub.3, F, Cl, Br, or
N(CH.sub.3).sub.2; and c) a polymerizable cross-linking agent.
[0016] These device materials can be used to form intraocular
lenses with low surface tack and high refractive indexes. Lenses
made of these materials are flexible and transparent, can be
inserted into the eye through a relatively small incision, and
recover their original shape after having been inserted.
[0017] Among other factors, the present invention is based upon the
finding that the ophthalmic device materials obtained by
copolymerizing the specified monomers with a cross-linking agent
have relatively low surface adhesion or tack when compared to
copolymeric materials containing other methacrylate components.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Unless indicated otherwise, all ingredient amounts expressed
in percentage terms are presented as % w/w.
[0019] The ophthalmic device materials of the present invention are
formed by copolymerizing a composition comprising 50-93% of a
polymerizable monomer of the structure (I):
##STR00003##
wherein: [0020] A is H or CH.sub.3; [0021] B is (CH.sub.2).sub.m or
[O(CH.sub.2).sub.2].sub.z; [0022] m is 2-6; [0023] z is 1-10;
[0024] Y is nothing, O, S, or NR', provided that if Y is O, S, or
NR', then B is (CH.sub.2).sub.m; [0025] R' is H, CH.sub.3,
C.sub.n'H.sub.2n'+1, iso-OC.sub.3H.sub.7, C.sub.6H.sub.5, or
CH.sub.2C.sub.6H.sub.5; [0026] n'=1-10; [0027] w is 0-6, provided
that m+w.ltoreq.8; and [0028] D is H, Cl, Br, C.sub.1-C.sub.4
alkyl, C.sub.1-C.sub.4 alkoxy, C.sub.6H.sub.5, or
CH.sub.2C.sub.6H.sub.5.
[0029] Monomers of structure (I) can be made by methods known in
the art. For example, the conjugate alcohol of the desired monomer
can be combined in a reaction vessel with methyl acrylate,
tetrabutyl titanate (catalyst), and a polymerization inhibitor such
as 4-benzyloxy phenol. The vessel can then be heated to facilitate
the reaction and distill off the reaction by-products to drive the
reaction to completion. Alternative synthesis schemes involve
adding acrylic acid to the conjugate alcohol and catalyzing with a
carbodiimide or mixing the conjugate alcohol with acryloyl chloride
and a base such as pyridine or triethylamine.
[0030] Suitable monomers of structure (I) include, but are not
limited to: 2-ethylphenoxy acrylate; phenyl acrylate; benzyl
acrylate; 2-phenylethyl acrylate; 3-phenylpropyl acrylate;
4-phenylbutyl acrylate; 4-methylphenyl acrylate; 4-methylbenzyl
acrylate; 2-2-methylphenylethyl acrylate; 2-3-methylphenylethyl
acrylate; 2-4-methylphenylethyl acrylate; 2-(4-propylphenyl)ethyl
acrylate; 2-(4-(1-methylethyl)phenyl)ethyl acrylate;
2-(4-methoxyphenyl)ethyl acrylate; 2-(4-cyclohexylphenyl)ethyl
acrylate; 2-(2-chlorophenyl)ethyl acrylate; 2-(3-chlorophenyl)ethyl
acrylate; 2-(4-chlorophenyl)ethyl acrylate; 2-(4-bromophenyl)ethyl
acrylate; 2-(3-phenylphenyl)ethyl acrylate; 2-(4-phenylphenyl)ethyl
acrylate; 2-(4-benzylphenyl)ethyl acrylate; and their corresponding
methacrylates.
[0031] Preferred monomers of formula (I) are those wherein A is H,
B is (CH.sub.2).sub.m, m is 2-5, Y is nothing or O, w is 0-1, and D
is H. Most preferred are 2-phenylethyl acrylate; 4-phenylbutyl
acrylate; 5-phenylpentyl acrylate; 2-benzyloxyethyl acrylate; and
3-benzyloxypropyl acrylate.
[0032] Although the total amount of the monomer of structure (I)
contained in the device materials of the present invention is
generally 50-93% by weight, and is preferably 75-90% by weight, of
the total amount of polymerizable components of the ophthalmic
device materials, such amount may comprise one monomer of structure
(I) or combinations of monomers of structure (I).
[0033] In addition to the monomer(s) of structure I, the
copolymeric device materials of the present invention comprise
5-20% of a benzhydryl methacrylate monomer of structure (II):
##STR00004##
wherein: [0034] E and F are independently H, C.sub.1-C.sub.4 alkyl,
C.sub.1-C.sub.4 alkoxy, CF.sub.3, F, Cl, Br, or N(CH.sub.3).sub.2;
and
[0035] Monomers of structure (II) are commercially available or can
be made by methods known in the art. Suitable monomers of structure
(II) include, but are not limited to: benzhydryl methacrylate;
4,4'-difluorobenzhydryl methacrylate; 4,4'-dimethoxybenzhydryl
methacrylate; 4,4'-dichloroobenzhydryl methacrylate;
2-methylbenzhydryl methacrylate; 4-methylbenzhydryl methacrylate;
4-methoxybenzhydryl methacrylate; 4-(trifluoromethyl)benzhydryl
methacrylate; 4-chlorobenzhydryl methacrylate;
2-(trifluoromethyl)benzhydryl methacrylate;
3-(trifluoromethyl)benzhydryl methacrylate; 4,4'-dimethylbenzhydryl
methacrylate; 4,4'-bis(dimethylamino)benzhydryl methacrylate;
3-chloro-4'-ethylbenzhydryl methacrylate;
4-chloro-4'-ethylbenzhydryl methacrylate;
3-chloro-4'-methylbenzhydryl methacrylate;
3-chloro-4'-methoxybenzhydryl methacrylate; 3,4'-5
dichlorobenzhydryl methacrylate; 4-methoxy-3'-methylbenzhydryl
methacrylate; 3-chloro-3'-methylbenzhydryl methacrylate;
3-chloro-3'-methoxybenzhydryl methacrylate;
4-(dimethylamino)-3'-methylbenzhydryl methacrylate;
4-(dimethylamino)-4'-methylbenzhydryl methacrylate;
4-chloro-3'-fluorobenzhydryl methacrylate;
3,3'-bis(trifluoromethyl)benzhydryl methacrylate;
3,4'-dimethylbenzhydryl methacrylate; 4-ethylbenzhydryl
methacrylate; 4-tert-butylbenzhydryl methacrylate;
4-methoxy-4'-methylbenzhydryl methacrylate;
3-fluoro-3'-methylbenzhydryl methacrylate;
3-fluoro-4'-methylbenzhydryl methacrylate;
3-fluoro-4'-methoxybenzhydryl methacrylate;
4-(dimethylamino)-3'-fluorobenzhydryl methacrylate;
4-(dimethylamino)-4'fluorobenzhydryl methacrylate;
3-methoxy-3'-methylbenzhydryl methacrylate;
3-methoxy-4'-methylbenzhydryl methacrylate;
4-fluoro-4'-methoxybenzhydryl methacrylate;
4-fluoro-3'-methoxybenzhydryl methacrylate;
3-chloro-3'-fluorobenzhydryl methacrylate;
4-chloro-3'-methoxybenzhydryl methacrylate;
4-chloro-4'-methoxybenzhydryl methacrylate; 3,3'-dimethylbenzhydryl
methacrylate; 4-fluorobenzhydryl methacrylate; 4-bromobenzhydryl
methacrylate; 3-chloro-4'-(dimethylamino)benzhydryl methacrylate;
4-ethyl-4'-fluorobenzhydryl methacrylate; 3,3'-difluorobenzhydryl
methacrylate; 4-fluoro-4'-methylbenzhydryl methacrylate;
3-chloro-4'-fluorobenzhydryl methacrylate;
3-fluoro-3'-methoxybenzhydryl methacrylate;
4-tert-butyl-4'-fluorobenzhydryl methacrylate; 4-ethyl-3'-fluoro
benzhydrylmethacrylate; 3,4'-difluorobenzhydryl methacrylate; and
4-ethyl-3'-methylbenzhydryl methacrylate.
[0036] Preferred monomers of structure (II) are those wherein E and
F independently are H, CH.sub.3, CF.sub.3, F, or Cl.
[0037] Although the total amount of the monomer of structure (II)
contained in the device materials of the present invention is 5-20%
by weight, is preferably 8-15% by weight, and is most preferably
10-15% by weight, of the total amount of polymerizable components
of the device materials, such amount may comprise one monomer of
structure (II) or combinations of monomers of structure (II).
[0038] The ophthalmic device materials of the present invention
also contain a polymerizable cross-linking agent. The cross-linking
agent may be any terminally ethylenically unsaturated compound
having more than one unsaturated group. Suitable cross-linking
agents include, for example: ethylene glycol dimethacrylate;
diethylene glycol dimethacrylate; triethylene glycol
dimethacrylate, tetraethylene glycol dimethacrylate, allyl
methacrylate; 1,3-propanediol dimethacrylate; 2,3-propanediol
dimethacrylate; 1,6-hexanediol dimethacrylate; 1,4-butanediol
dimethacrylate;
CH.sub.2.dbd.C(CH.sub.3)C(.dbd.O)O--(CH.sub.2CH.sub.2O).sub.p--C(.dbd.O)C-
(CH.sub.3).dbd.CH.sub.2 where p=1-50; and
CH.sub.2.dbd.C(CH.sub.3)C(.dbd.O)O(CH.sub.2).sub.tO--C(.dbd.O)C(CH.sub.3)-
.dbd.CH.sub.2 where t=3-20; and their corresponding acrylates. A
preferred cross-linking monomer is
CH.sub.2.dbd.C(CH.sub.3)C(.dbd.O)O--(CH.sub.2CH.sub.2O).sub.p--C(.dbd.O)C-
(CH.sub.3).dbd.CH.sub.2 where p is such that the number-average
molecular weight is about 400, about 600, or about 1000. Other
preferred cross-linking monomers are ethylene glycol dimethacrylate
(EGDMA), diethylene glycol dimethacrylate, triethylene glycol
dimethacrylate, triethylene glycol diacrylate, and 1,4-butanediol
diacrylate (BDDA).
[0039] Generally, the total amount of the cross-linking component
is at least 0.1% by weight and, depending on the identity and
concentration of the remaining components and the desired physical
properties, can range to about 20% by weight. The preferred
concentration range for the cross-linking component is 1-5% for
small, hydrophobic compounds with molecular weights typically less
than 500 Daltons, and 5-17% (w/w) for larger, hydrophilic compounds
with molecular weights typically between 500-5000 Daltons.
[0040] In addition to one or more monomers of structure (I), one or
more monomers of structure (II), and one or more cross-linking
agents, the copolymeric device materials of the present invention
may also contain other ingredients, including, but not limited to,
UV-absorbers, colored dyes, and hydroxyethyl methacrylate and other
additives to reduce or eliminate glistenings.
[0041] An ultra-violet absorbing agent can also be included in the
materials of the present invention. The ultraviolet absorbing agent
can be any compound which absorbs ultraviolet light, i.e., light
having a wavelength shorter than about 400 nm, but does not absorb
any substantial amount of visible light. The ultraviolet absorbing
compound is incorporated into the monomer mixture and is entrapped
in the polymer matrix when the monomer mixture is polymerized.
Suitable ultraviolet absorbing compounds include substituted
benzophenones, such as 2-hydroxybenzophenone, and
2-(2-hydroxyphenyl)benzotriazoles. It is preferred to use an
ultraviolet absorbing compound which is copolymerizable with the
monomers and is thereby covalently bound to the polymer matrix. In
this way possible leaching of the ultraviolet absorbing compound
out of the lens and into the interior of the eye is minimized.
Examples of suitable copolymerizable ultraviolet absorbing
compounds are the substituted 2-hydroxybenzophenones disclosed in
U.S. Pat. No. 4,304,895 and the
2-hydroxy-5-acryloxyphenyl-2H-benzotriazoles disclosed in U.S. Pat.
No. 4,528,311. A preferred ultraviolet absorbing compound is
2-(2'-hydroxy-3'-methallyl-5'-methyl phenyl)benzotriazole.
[0042] In addition to ultraviolet absorbing materials, ophthalmic
devices made of the copolymers of the present invention may include
colored dyes, such as the yellow dyes disclosed in U.S. Pat. No.
5,470,932.
[0043] The device materials of the present invention may also
contain additives to reduce or eliminate glistenings. Examples of
such additives include hydroxyalkyl methacrylates, such as
hydroxyethyl methacrylate, and those disclosed in U.S. Published
Patent Application Nos. 20090088493, 20090088544, 20090093603, and
20090093604. In one embodiment, the device materials of the present
invention contain both an hydroxyakyl methacrylate and another
additive to reduce or eliminate glistenings. Preferred additives
are hydroxyethyl methacrylate and those of structures (IIIa) and
(IIIb).
##STR00005##
where, for IIIa and IIIb, [0044] e=1-50; [0045] X=--O--, NH--,
--N(CH.sub.3)--, --N(CH.sub.2CH.sub.3)--, or --N(C.sub.6H.sub.5)--;
[0046] Y=--H, --(CH.sub.2).sub.pOH,
--CH.sub.2CH.sub.2N(CH.sub.3).sub.2,
--CH.sub.2CH.sub.2N(CH.sub.2CH.sub.3).sub.2,
--CH.sub.2CH(OH)CH.sub.2OH, --(CH.sub.2CH.sub.2O).sub.qCH.sub.3,
--(CH.sub.2CH.sub.2O).sub.qH,
--(CH.sub.2CH.sub.2O).sub.qC.sub.6H.sub.5, or
[0046] ##STR00006## [0047] p=1-12; [0048] q=1-230; [0049] T, T'
independently=O(CH.sub.2).sub.d', NH(CH.sub.2).sub.d',
NCH.sub.3(CH.sub.2).sub.d', O(CH.sub.2).sub.d'C.sub.6H.sub.4,
O(CH.sub.2CH.sub.2O).sub.d'CH.sub.2,
O(CH.sub.2CH.sub.2CH.sub.2O).sub.d'CH.sub.2,
O(CH.sub.2CH.sub.2CH.sub.2CH.sub.2O).sub.d'CH.sub.2, or nothing;
[0050] K=(CH.sub.2).sub.a', O(CH.sub.2CH.sub.2O).sub.b', O, or
nothing, provided that if T and T'=nothing, then K.noteq.nothing;
[0051] d'=0-12; [0052] a'=1-12; [0053] b'=1-24; [0054] L=H, Cl, Br,
--CH.sub.2C(O)CH.sub.3, CH.sub.2C(O)C(CH.sub.3).sub.3,
--CH.sub.2C(O)C.sub.6H.sub.5, --CH.sub.2C(O)C.sub.6H.sub.4OH,
--CH.sub.2C(O)C.sub.6H.sub.4OCH.sub.3,
[0054] ##STR00007## or --CH.sub.2CH.dbd.CH.sub.2; [0055] R.sup.4,
R.sup.5 independently=H, CH.sub.3, CH.sub.2CH.sub.3,
CH.sub.2CH.sub.2CH.sub.3, CH(CH.sub.3).sub.2,
CH.sub.2CH.sub.2CH.sub.2CH.sub.3, or CH.sub.2CH(CH.sub.3).sub.2;
[0056] R.sub.6=--CO.sub.2CH.sub.3, --CO.sub.2CH.sub.2CH.sub.3,
--CN, or --CONHCH.sub.2CH.sub.2CH.sub.2CH.sub.3; and [0057]
R.sup.7, R.sup.8 independently=H, CH.sub.3, CH.sub.2CH.sub.3, or
CH.sub.2OH.
[0058] The proportions of the monomers to be included in the
copolymeric device materials of the present invention should be
chosen so that the resulting copolymer has a glass transition
temperature (T.sub.g) not greater than about 37.degree. C., which
is normal human body temperature. Copolymers having glass
transition temperatures higher than 37.degree. C. are not suitable
for use in foldable IOLs; such lenses could only be rolled or
folded at temperatures above 37.degree. C. and would not unroll or
unfold at normal body temperature. It is preferred to use
copolymers having a glass transition temperature somewhat below
normal body temperature and no greater than normal room
temperature, e.g., about 20-25.degree. C., in order that IOLs made
of such copolymers can be rolled or folded conveniently at room
temperature. T.sub.g is measured by differential scanning
calorimetry at 10.degree. C./min., and is determined at the
midpoint of the transition of the heat flux curve.
[0059] For use in IOLs, the materials of the present invention
preferably exhibit sufficient strength to allow devices made of
them to be folded or manipulated without fracturing. Thus, the
copolymers of the present invention will have an elongation (%
strain at break) of at least 100%, preferably at least 130%, and
most preferably between 130 and 300%. This property indicates that
lenses made of such materials generally will not crack, tear or
split when folded. Elongation of polymer samples is determined on
dumbbell shaped tension test specimens with a 20 mm total length,
length in the grip area of 4.88 mm, overall width of 2.49 mm, 0.833
mm width of the narrow section, a fillet radius of 8.83 mm, and a
thickness of 0.9 mm. Testing is performed on samples at ambient
conditions using an Instron Material Tester (Model No. 4442 or
equivalent) with a 50 Newton load cell. The grip distance is set at
14 mm and a crosshead speed is set at 500 mm/minute and the sample
is pulled until failure. The elongation (strain) is reported as a
fraction of the displacement at failure to the original grip
distance. Since the materials to be tested are essentially soft
elastomers, loading them into the Instron machine tends to make
them buckle. To remove the slack in the material sample a pre-load
is placed upon the sample. This helps to reduce the slack and
provide a more consistent reading. Once the sample is pre-loaded to
a desired value (typically 0.03 to 0.05 N) the strain is set to
zero and the test is begun.
[0060] The device materials of the present invention preferably
have a refractive index of 1.55 to 1.56 or higher in their fully
hydrated state at 35.degree. C. For IOL applications, the stiffness
of the device material must be low enough to permit folding and
injection through a small diameter opening (e.g., 1-3 mm) without
tearing or deforming after injection. In a preferred embodiment,
the Young's Modulus of the device material will be less than 60
MPa, preferably less than 50 MPa, and most preferably between 5-40
MPa.
[0061] The copolymeric device materials preferably have an
equilibrium water content of less than 1.8 weight % across the
temperature range of 16-45.degree. C. and preferably less than 1.6
weight % in the temperature range of 16-23.degree. C. The device
materials are preferably resistant to glistenings such that when
equilibrated in water at 45.degree. C. and subsequently allowed to
cool to ambient temperature (approximately 22.degree. C.) should
produce very few to no microvacuoles as detected by microscopic
examination.
[0062] The copolymers of this invention are prepared by
conventional polymerization methods. For example, a mixture of the
liquid monomers of structure (I), structure (II), and a
cross-linking agent in the desired proportions, together with any
other polymerizable components, such as a UV absorber, yellow dye,
and/or additive to reduce or eliminate glistenings, and a
conventional thermal free-radical initiator is prepared. The
mixture can then be introduced into a mold of desired shape, and
the polymerization carried out by heating to activate the
initiator. Typical thermal free radical initiators include
peroxides, such as benzoyl peroxide, peroxycarbonates, such as
bis-(4-t-butylcyclohexyl)peroxydicarbonate, azonitriles, such as
azobisisobutyronitrile (AlBN), and the like. A preferred initiator
is AlBN. Alternatively, the monomers can be photopolymerized by
using a mold which is transparent to actinic radiation of a
wavelength capable of initiating polymerization. Conventional
photoinitiator compounds, e.g., a benzophenone-type photoinitiator,
can also be introduced to facilitate the polymerization. Regardless
of the chosen initiator or curing method, the curing process should
be controlled to avoid rapid polymerization, which may yield
polymerized materials having more tack than the same materials
polymerized more slowly.
[0063] Once the ophthalmic device materials of the present
invention have been cured, they are extracted in a suitable solvent
to remove as much of the unreacted components of the materials as
possible. Examples of suitable solvents include acetone, methanol,
and cyclohexane. A preferred solvent for extraction is acetone.
[0064] IOLs constructed of the disclosed ophthalmic device
materials can be of any design capable of being rolled or folded
into a small cross section that can fit through a relatively
smaller incision. For example, the IOLs can be of what is known as
a one piece or multipiece design. Typically, an IOL comprises an
optic and at least one haptic. The optic is that portion which
serves as the lens and the haptics are attached to the optic and
are like arms which hold the optic in its proper place in the eye.
The optic and haptic(s) can be of the same or different material. A
multipiece lens is so called because the optic and the haptic(s)
are made separately and then the haptics are attached to the optic.
In a single piece lens, the optic and the haptics are formed out of
one piece of material. Depending on the material, the haptics are
then cut, or lathed, out of the material to produce the IOL.
[0065] In addition to IOLs, the ophthalmic device materials of the
present invention are also suitable for use in other devices,
including contact lenses, keratoprostheses, intracorneal lenses,
corneal inlays or rings, and glaucoma filtration devices.
[0066] The invention will be further illustrated by the following
examples which are intended to be illustrative, but not
limiting.
Example 1
[0067] The formulations shown in Table 1 were prepared as follows.
Components were taken from the refrigerator, freezer or cabinet and
set on lab bench for about 2 hours. The components were weighed in
the indicated ratios, dissolved, and vortex mixed in a 20 ml glass
vial. Each formulation was purged with nitrogen for 2 minutes,
placed under high vacuum (<0.5 mm Hg) for 2 minutes, injected
through a 0.2 micron PTFE filter into standard polypropylene slab
molds or lens wafers, and then heated: room temp. to 70.degree. C.
(20 min.), 70.degree. C. (60 min.), 70-90.degree. C. (60 min.),
90-105.degree. C. (60 min.).
TABLE-US-00001 TABLE 1 Formulation PEA BzhyMA PMA BDDA PolyPEGMA
PERK A 92.8 2.5 -- 1.6 3.1 1.0 B 90.2 5.0 -- 1.6 3.2 1.0 C 87.8 7.6
-- 1.6 3.0 1.0 D 92.8 -- 2.7 1.5 3.1 1.0 E 90.0 -- 5.1 1.6 3.3 1.0
F 87.7 -- 7.5 1.5 3.3 1.0 G 84.8 9.9 -- 1.6 3.7 1.0 H 83.4 12.0 --
1.5 3.1 1.0 I 81.5 14.1 -- 1.5 2.9 1.0 PEA BzhyMA PMA BDDA
PolyPEGMA AIBN J 85.2 10.2 -- 1.5 3.1 1.3 K 83.4 12.0 -- 1.5 3.0
1.3 L 81.4 14.0 -- 1.5 3.1 1.3 PEA: 2-phenyl methacrylate BzhyMA:
benzhydryl methacrylate BDDA: 1,4-butanediol diacrylate PMA: phenyl
methacrylate PolyPEGMA: methacrylate terminated macromonomer of
poly(ethylene glycol) monomethyl ether methacrylate (MW = 550), Mn
(SEC): 4100 Daltons, Mn (NMR): 3200 Daltons, PDI = 1.50 PERK:
Perkadox 16s AlBN: 2,2' azobisisobutyronitrile
Example 2
[0068] The mechanical properties of the copolymeric device
materials of Example 1 were evaluated. Tensile bar specimens in the
fashion of "dogbones" were cut from each sample group using a die
and press. Typically 3 specimens per slab were prepared and 9 total
specimens per formulation. Tensile properties were measured using
an Instron 5543 extensometer at 500 mm/min crosshead speed. Stress
at break, % strain at break, Young's modulus, the 25% secant
modulus, and 100% secant modulus data were obtained. The results
are shown in Table 2.
TABLE-US-00002 TABLE 2 Stress Strain 100% Modulus at at Young's
Secant (Secant Break SD Break SD Modulus SD Modulus SD 25%) SD
Formulation (MPa) (.+-.) (%) (.+-.) (MPa) (.+-.) (MPa) (.+-.) (MPa)
(.+-.) A 2.2 0.4 132.2 8.8 4.1 0.3 1.3 0.0 1.5 0.0 B 2.5 0.2 140.6
4.7 5.1 0.3 1.3 0.0 1.6 0.0 C 2.6 0.2 144.4 4.8 6.7 0.5 1.3 0.0 1.9
0.1 D 1.8 0.2 134.5 6.7 3.9 0.2 1.0 0.0 1.3 0.0 E 2.4 0.3 141.8 7.1
5.2 0.3 1.2 0.0 1.6 0.0 F 2.6 0.3 147.7 5.5 7.1 0.3 1.3 0.0 2.0 0.0
G 3.3 0.5 146.9 8.7 9.2 0.5 1.6 0.0 2.4 0.1 H 4.2 0.4 158.3 5.3
14.5 0.5 1.8 0.0 3.2 0.1 I 4.8 0.5 157.4 6.9 21.8 1.2 2.3 0.1 4.4
0.2 J 3.8 0.4 163.0 7.5 10.8 0.8 1.6 0.0 2.8 0.1 K 4.4 0.6 162.9
9.5 14.9 0.7 2.0 0.0 3.8 0.1 L 5.1 0.5 162.6 7.7 21.8 1.6 2.6 0.1
5.6 0.2
Example 3
[0069] The formulations were also subjected to adhesion testing.
Slabs were individually removed from the casting molds and punched
to 10-mm disks using a metal die and press. One side of the disk
was untouched and placed facing up in a plastic petri dish. Samples
were covered with a dish cover and measured for adhesion within one
hour of de-molding. The adhesion apparatus was carefully positioned
and centered over the 8 mm post. A 500N load cell was used for
testing. The post was positioned 1.0 mm above the hangar bottom
when in the start position. The load cell was calibrated using the
software calibration (Bluehill). The load cell was tared with a 300
g weight on the hanger. A 10 mm disk was carefully positioned onto
the 8 mm post and a 300 g weight placed on top of the sample. The
sample plus weight were allowed to sit, untouched, for 1 minute
followed by initiating the adhesion test. The hanger assembly was
then pulled upward by the instrument, pulling off the sample from
the 8 mm post. Max. load (N) and Energy (mJ) are shown in Table
3.
TABLE-US-00003 TABLE 3 Max load SD SD Formulation (N) (.+-.) Energy
(.+-.) A 46.4 7.5 3.4 0.4 B 48.9 3.6 9.6 2.8 C 46.1 5.3 5.1 1.3 D
52.8 5.7 13.8 0.8 E 52.7 5.5 12.4 3.4 F 53.2 5.3 8.5 3.5 G 41.3 5.9
4.2 0.5 H 36.4 4.7 2.2 0.3 I 32.9 2.7 2 0.2 J 37 7 3.0 0.5 K 27 2
2.5 0.2 L 24 3 2.0 0.3
Example 4
[0070] Each formulation was also tested to determine its
equilibrium water content, refractive index, % extractables, and
resistance to microvacuole (glistening) formation. Slabs were
hydrated in a waterbath at 35.degree. C. and the % EWC and
refractive index determined. Separately, three-five polymer slabs
of each cured formulation were weighed for % extractables. The
polymer slabs were extracted in acetone for at least 16 hours at
ambient temperature with one solvent change out after the first
hour, and then allowed to dry while covered with aluminum foil at
ambient temperature for 8 hours. Slabs were further dried under
reduced atmosphere at 60.degree. C. for at least 16 hours. Slabs
were removed and cooled to room temperature (23.degree. C.).
Previously weighed slabs were weighed again for % extractables.
Glistening resistance was determined by placing three lenses of
each formulation into 20-mL vials containing .about.20 mL deionized
water and incubating them in a waterbath at 45.degree. C. for 24
hours. The sample vials were removed from the water bath and placed
on the lab bench to cool to room temperature (typically
23-24.degree. C.). After cooling to room temperature, each lens was
imaged using an Olympus BX60 microscope under bright field (BF) and
dark field (DFA) settings at 10.times. with a 2.times. magnifier.
The equilibrium water content ("EWC"), refractive index ("RI"), %
extractables ("Extracts"), and glistening ("Glistenings") results
are shown in Table 4.
TABLE-US-00004 TABLE 4 Glistening Formula- EWC SD RI ave SD
Extracts SD # per tion (%) (.+-.) -- (.+-.) (%) (.+-.) locale A
0.72 0.18 1.5462 0.0006 1.28 0.04 0-5 B 0.84 0.10 1.5488 0.0004
1.45 0.16 0-5 C 0.68 0.03 1.5508 0.0003 1.59 0.14 0-5 D 0.81 0.19
1.5507 0.0003 1.89 0.24 0-5 E 0.76 0.05 1.5538 0.0013 1.79 0.14 0-5
F 0.77 0.06 1.5478 0.0008 1.80 0.13 0-5 G 1.15 0.33 1.5507 0.0018
1.45 0.06 0-5 H 0.90 0.21 1.5538 0.0013 1.27 0.07 0-10 I 0.64 0.08
1.5560 0.0000 1.36 0.09 0-10 J 1.12 0.11 1.5572 0.0003 2.41 0.10 --
K 1.13 0.12 1.5591 0.0004 2.30 0.09 -- L 0.93 0.15 1.5604 0.0011
2.22 0.13 --
Example 5
[0071] Sample lenses made of formulations G-I were plasma treated
with Argon gas (per U.S. Pat. No. 5,603,774) and evaluated in an
injection test to determine the force required to push a lens
through an IOL delivery cartridge. The reported force values in
Table 5 include the 10-12 N baseline force attained from pushing a
plunger through an empty cartridge.
TABLE-US-00005 TABLE 5 Force Nozzle Temp. No (N) Stress(0-5)
.degree. C. Formulation G 1 24.4 0 18.4 2 26.0 0 18.4 3 20.5 0 18.4
4 20.4 0 18.4 5 26.0 0 18.4 Formulation H 1 33.6 0 18.4 2 Broken
Haptic Ball 3 32.9 0 18.4 4 32.1 0 18.4 Formulation I 1 47.0 4 18.4
2 55.3 5(Split) 18.4 3 67.0 5(Split) 18.4 4 56.6 5(Split) 18.4
Example 6
[0072] The formulation shown in Table 6a was prepared in the manner
described in Example 1, except that it was cured using three
different curing profiles in order to investigate the effect of the
curing profile on tack. The curing conditions and tack results are
shown in Table 6b. The results showed that slower heating ramp
rates resulted in improved tack performance. One sample was cured
with a heating ramp from room temperature to 90.degree. C. in 15
minutes, a second sample was cured with a heating ramp from room
temperature to 70.degree. C. in 15 min., and a third was cured with
a heating ramp from room temperature to 70.degree. C. in 20
minutes. The first sample was judged to have moderate tack, whereas
the second and third samples were judged to have low tack.
TABLE-US-00006 TABLE 6a Formulation PEA BzhyMA TEGDMA PolyPEGMA
AIBN M 84.0 11.5 1.5 3.0 1.0 TEGDMA: triethylene gycol
dimethacrylate
TABLE-US-00007 TABLE 6b Cure Conditions of Formulation M Max Load
(N) % Extractables .sup.1RT to 90.degree. C. in 15 minutes 40 .+-.
4 6.0 .+-. 0.1 .sup.1RT to 70.degree. C. in 15 minutes 34 .+-. 5
4.8 .+-. 0.1 .sup.1RT to 90.degree. C. in 20 minutes 29 .+-. 5 4.8
.+-. 0.2 .sup.1Samples were soaked at 90.degree. C. or 70.degree.
C. for 1 hour, then ramp heated to 110.degree. C. in 20 minutes,
and soaked at 110.degree. C. for 2 hours.
Example 7
[0073] The formulations shown in Table 7 were prepared in the
manner described in Example 1, except that the following curing
profile was used: room temperature to at least 60.degree. C. in
10-30 min. for 1 hour, then to at least 90.degree. C. in 10-30 min.
for 2 hours.
TABLE-US-00008 TABLE 7 Poly Formulation PEA BzhyMA TEGDMA TEGDA
DEGDMA PEGMA PERK V-65 AIBN TBPO ABCC M 84.0 11.5 1.5 -- -- 3.0 --
-- 1.0 -- -- N 84.0 11.5 1.5 -- -- 3.0 1.8 -- -- -- -- O 84.0 11.5
1.5 -- -- 3.0 -- 1.0 -- -- -- P 84.0 11.5 1.5 -- -- 3.0 -- -- --
1.0 -- Q 84.0 11.5 1.5 -- -- 3.0 -- -- -- -- 1.0 R 84.0 11.5 2.0 --
-- 3.0 -- -- -- 1.0 -- S 84.0 11.5 -- -- 1.5 3.0 -- -- 1.0 -- -- T
84.0 11.5 -- 1.5 -- 3.0 -- -- -- 1.0 -- TEGDA: triethylene gycol
diacrylate DEGDMA: diethylene glycol diamethacrylate V-65:
2,2'-Azobis(2.4-dimethyl valeronitrile) TBPO: Trigonox 21S
(tert-butyl peroxy-2-ethylhexanoate) ABCC:
1,1'-azobis(cyclohexanecarbonitrile)
Example 8
[0074] In order to investigate the effect of the initiator on tack,
formulations M, P, R, S, and T from Example 8 were tested for tack
and acetone extractables using the procedures described in Examples
2-4 above. The results are shown in Table 8. Initiators with
relatively higher 1 hour half-life decomposition temperatures, such
as AlBN and TBPO, resulted in slower curing and better tack
performance.
TABLE-US-00009 TABLE 8 Tack Acetone Formulation Load (N)
Extractables (%) M 30 .+-. 4 4.8 .+-. 0.1 P 26 .+-. 4 4.4 .+-. 0.1
R 24 .+-. 3 3.9 .+-. 0.1 S 28 .+-. 4 6.0 .+-. 0.1 T 33 .+-. 5 2.4
.+-. 0.1
Example 9
[0075] Synthesis of 4,4'-dimethoxybenzhydryl methacrylate. In a 1 L
round-bottom flask equipped with magnetic stirrer and nitrogen
inlet was added 700 ml anhydrous THF containing BHT as inhibitor,
98 g anhydrous pyridine, and 51.6 g (211 mmol) of
4,4'-dimethoxybenzhydrol. The reaction mixture was cooled to
-10.degree. C. and 26.5 g (254 mmol) methacryloyl chloride was
added dropwise over 10 minutes. The reaction mixture was stirred at
-10-0.degree. C. for 1 hour and then stirred at ambient temperature
for 20 hours. The solid was filtered and the filtrate was extracted
using Et.sub.2O/water. The organic layer was washed with 1 N
NaHCO.sub.3, 1 N HCl, brine, and water and then dried with
MgSO.sub.4, filtered, and concentrated under reduced pressure to
give the desired crude product which was recrystallized from cold
ether/hexanes at -20.degree. C.
##STR00008##
Example 10
[0076] Additional formulations representative of the present
invention are shown in Table 9. These formulations can be prepared
by the procedure described in Example 1.
TABLE-US-00010 TABLE 9 Formula- tion PEA BzhyMA BDDA HEMA PolyPEGMA
PERK U 80.2 5.0 1.6 10.0 3.2 1.0 V 87.8 7.6 1.6 5.0 3.0 1.0 W 80.0
9.9 1.6 4.8 3.7 1.0 X 80.4 12.0 1.5 3.0 3.1 1.0 Y 80.0 14.1 1.5 1.5
2.9 1.0
[0077] The invention having now been fully described, it should be
understood that it may be embodied in other specific forms or
variations without departing from its spirit or essential
characteristics. Accordingly, the embodiments described above are
to be considered in all respects as illustrative and not
restrictive, the scope of the invention being indicated by the
appended claims rather than by the foregoing description, and all
changes which come within the meaning and range of equivalency of
the claims are intended to be embraced therein.
* * * * *