CA1295078C

CA1295078C - Extended-wear lenses

Info

Publication number: CA1295078C
Application number: CA000500476A
Authority: CA
Inventors: Nick Stoyan
Original assignee: Bausch and Lomb Inc
Current assignee: Bausch and Lomb Inc
Priority date: 1985-01-29
Filing date: 1986-01-28
Publication date: 1992-01-28
Anticipated expiration: 2009-01-28
Also published as: WO1986004343A1; EP0209597A1

Abstract

EXTENDED-WEAR LENSES

Abstract of the Disclosure There are provided extended-wear lenses formed by polymerizing an organosilicon monomer system, at least a portion of which is a hydroxyorganosilicon monomer, a fluoroorgano monomer, a hydrophilic,monomer, and a crosslinking agent. A UV-absorbing agent is optionally present.

Description

129~

C270^16701:JPG:129 -1-Background of the Invention The present invention is directed to eye-compati~le lenses, particularly hard contact lens~s having excellent oxygen permeability and wettability.
Con~act lenses pres~ntly on the market are classi-fied into two large groups: soft contact lenses and hard contact lense~ Hard contact lenses are better able than soft contact lenses to retain v~sual characteristics, but are less comfortabl~. The art has sought to increas~
oxygen permeability of hard contact lenses, to extend the lenyth of time they can be worn without causins corneal damage or discomfort.
One proposed solution has been th~ ~ormation of a copolymer of methyl methacrylate and a siloxane methacry-late co~poun~. This solution has heen less than satis-factory, since the lenses off~red are not as hard, rigid, nor wettahle as lenses formed from polymethyl methacryl-ate. In addition, such lenses are fra~ile and have poor mechanical processahility.

S~ 8 l The object of the present invention is to overcome the deficiencies in the state of thle ar~ by offering lenses having a ~igh degree of oxygen permeability, excellent wettability, and, if desired, ultraviolet absorption. ~he primary benefit of UV ahsorptivity is the resistance to user development of cataracts.

Summar~ of the Invention The present invention is directed to eye-compatible, oxygen-permeable lenses of excellent wettahility, formeA
of copolymers of an organosilicon monomer system which prèferahly comprlses an organosilane or an organo-siloxane of the general formula:

CH2 = C - Rl OH
( 1 ) Coo-~cH2-cH-cH2o)a- (CH2)h-X

wherein Rl is hydrogen or methyl, a is 0 or 1, b is from l to about 4, and X is an organosilicon moiety containing up to about 16 silicon atoms. At least a portion, and as much as 100 percent, of the organosilicon monomer system is a hydroxyorganosilicon monomer which is a monomer having at least one hydroxyl group bonded to silicon.
Preferably from 0.l to about 10~percent by weight of the monomers is a hydroxyorganosilicon monomer.
A second component is a fluoroorgano monomer of the formula:

CH2 = C - Ml (2) CO~M)a-tCH2)c-y :

~s~

l wherein Ml is hydrogen, alkyl, fluoroalkyl, alkyl car-boxy, carboxy ester, alkyl carboxy ester, fluorinated carboxy ester, fluorinated alkyl carboxy ester, cyano, or phenyl, M is hydroxy alkyl, alkyl ether, or hydroxy alkyl ether, a is as defined above, c is from 0 to 4, and Y is a fluorocarbon group, preferably containing from about 2 to about 21 fluorine atoms.
At least one hydrophilic monomer is included, prefer-ably an unsaturated carboxylic acid capable of inducing wettability, and is present in an amount sufficient to provide in the resultant polymer a receding contact angle of about 45 or less. Methacrylic acid is preferred.
A UV absorbing agent, if desired, snay be included.
In this instance, the UV-absorbing agent may be a UV-absorbing monomer, preferably a hydroxybenzophenone or abenzotriazole compound of the formula:

( H2 = C ~ Rl ~ (3) Coo-~CH2-cHo~-cH2o)a- (CH2)b ~ Z
~ ~ d wherein Rl, a and b are as defined above, d is l or 2, and Z is:

OH O OH
Lo.
OH

; or ~N~

t~ ~

1 wherein R2 is hydro9en, alkyl or hydroxy. Alternately or in addition, the UV-absorbing monomer may be a benzo-triazole of the formula:
t~H

~N ~ ~_ R2 \--C)~2 wherein Rl and R2 are as defined above, and R3 is H or alkyl, preferably a Cl-Clo alkyl. Alternately, UV-absorbing agents may be non-reactive homopolymers and copolymers preferably containing the UV monomers which are added to the monomer system undergoing reaction, and which become physically entrained in the formed lens.
A final component is a crosslinking monomer which is a crosslinking agent, preferably an organosilicon monomer, present in an amount up to about S, preferably up to about 2, percent by weight based on the total weight of the monomers.
It has been found that the total organosilicon-monomer content of the polymer may range from about 10 to about 40 percent by weight, preferably from about 15 to about 35 percent by weight based on the total weight of the monomers. The hydrophilic monomer may be present in an amount of from ahout 1 to about lS percent hy weight, preferably from ahout 2 to about 1~ percent hy weight based on the total weight of the monomers. ~he UV-absorhing agent if present, whether monomeric or not, may be present in an amount of from ahout 0.1 to about 20 percent, preferably from about 2 to about 10 percent hy weight based on the total weight of the monomers and/or agent, and the crosslinking monomer may he present in an amount up to about 2 percent by weight based on the total weight of the monomers. The balance of the monomer system may he solely the fluoroorgano monomers. It is desired ~5~

1 that the lens have a Shore D hardness ~reater than ahout 78, preferably from about 80 to about 85. There may be desirably included other monomers, such as acrylates, methacrylates, itaconic esters, styrenes, fluorinated styrenes, alkyl styrenes, fluorinated alkyl styrenes, and the like, present in a concentration of up to about 50 percent by weight of the concentration of the fluoro-organo monomer, typically up to about 5 percent by weight based on the total wei~ht of the monomers which can effectively be used to modify properties such as hardness, machinability, wettability, oxygen permeability, and the like.
It is desire~ to provide an oxygen permeahility at 35C greater than 50 x 10 11(cm2/sec.)(ml O2/ml x mm Hg).
When using low-cost fluoroorgano compounds such as 2,2,2-trifluoroethylmethacrylate, the orqanosilicon content of the monomer system must be high, typically in the range of from 25 percent to 30 percent or more by weight based on the total weight of the monomers. Organo-silicon monomer content can be advantageously reduced,however, by inclusion of high-performance fluoroorgano-monomers such as hexafluoroisopropyl esters of an unsaturated carhoxylic acid containing from 2 to about 6 carbon atoms and 1 or 2 carboxyl groups, preferably hexa-fluoroisopropylmethacrylate.

' ~2~ 7~3 Detailed Description The present invention is directed to eye-compatible, i.e., ocular-compati~le, lenses, in particular, hard con-tact lenses formed of an interpolymerized amount of anorganosilicon monomer system containing at least one hydroxyorganosilicon ~onomer, at least one fluoroorgano compound, at least one monomeric unsaturated carhoxylic acid hydrophilic monomer, and, if desired, a UV-absorbing agent, which may be a monomer formed of a monomer which is a benzotriazole and/or benzophenone and at least one crosslinking monomer. Other reactiv~ monomers such as acrylates, methAcrylat~s, itaconic esters, styrenes, fluorinated styrenes, alkyl styrenes, fluorinated alkyl styrenes, and the like, may be included as part of the polymerizable composition, to achieve a lens of desired hardness for machinability, wettability, oxygen perme-ability, and the like, and can be present in an amount of up to about 50 percent by weight of the fluoroorgano monomer content of the polymers.
The organosilicon monomers which may be used in accordance with the instant invention include organo-silicon monomers which are organosilanes and/or organo-siloxanes of the general formula:

CH2 = C - Rl (1) COO-(CH2-CHOH-CH2O)a (CH2)h-X

wherein Rl is hydrogen or methyl, a is 0 or 1, b is from 1 to about 4, and X is an organosilicon moiety containing up to a~out 26 silicon atoms. At least a portion or all of the organosilicon monomer system is a hydroxyorgano-silicon monomer, namely, a monomer having at l~ast one hydroxyl group honded to silicon.

~2~ 7~

1 Preferred organosilicon compounc~s are acrylates and methacrylates of the general formula:

CH2 = C -- Rl I t2) Coo(-c~2-cHoH-cH2-o-)a~(c~2)b-x l4 l6 lR6 wherein X' is -Si-(CH2)b-7i-R7 or -Si-R7 , each of R4 and Rs is independently a Cl-Cs alkyl, phenyl, hydroxyl, or -O-Si(CH3)3, and each of R6, R7 and P~8 is independently selected from Cl-Cs alkyl; -CH2=CH2; phenyl;
hydroxyl; -CH20H;

-o-si-o-si (CH3)3 ; -O-Si-OH

O-Si(CH3)3 -O-SiCE33 ; 0-Si-[OSi(CH3)3]3 ; or \ 0-Si(CH3)3 CH2 = C - Rl . Coo-(cH2-cHoH-cH2-o-)a~~cH2)b-wherein Rl, a, and b are as defined above.

3L2~

16701 ~8-1 The representative monomers included are:
tris(trimethylsiloxy)silylpropylme~hacrylate, 1,3-bis~-methacryloxypropyl)-1,1,3,3-tetra(trimethyl-siloxy)disiloxane, vinyl di(trimethylsiloxy)silylpropylmethacrylate, pentamethyldisiloxy-~-methacryloxypropylsilane, trimethylsilylpropylmethacrylate, m~thyl di(trimethylsiloxy)silylpropylmethacrylate, an~
tris(trimethylsiloxy~silylpropylglycerolmethacrylate, and the like. Tris~trimethylsiloxy)-~-methacryl~xypropyl-silane is presently preferred. Anoth~r important monomer is 1,3-bis-(~-methacryloxypropyl)-1,1,3,3-tetra(trimethyl-siloxy)disiloxane, as it serves as a crosslinking agent without sacrificing oxygen permea~ility. When used for this purpose, concentration may vary from about 0.1 to about 2 parts by weight ~ased on the total weight of the reactanks.
Representative hydroxyorganosilicon monomers incluAe hydroxy-di(trimethylsiloxy)silylpropyl methacrylate, hydroxy-~i(trimethylsiloxy)-~-methacryloxypropyl silane, hydroxy-methyl~trimethylsiloxy)methacryloxymethyl silane, hydroxy-methyl(trimethylsiloxy)me~hacryloxyethyl silane, hydroxy-methyl(trimethylsiloxy~methacryloxypropyl silane, hydroxy-~i(trimethylsiloxy)-~-~ethacryloxyethyl silane, 26 hydroxy-di(trimethylsiloxy)-m~thacryloxy methyl silane, hydroxy-(trimethylsiloxy)-(pentamethyldisiloxy)-meth-acryloxy-methyl silane, hydroxy-~trimethylsiloxy)-(pen~amethyldisiloxy)-~-methacryloxyethyl silane, and the like. Hydroxy-di(trimethylsiloxy)silylpropyl methacrylate is preferred.
Other useful organosilicon ronomer~s are disclosed in U,S. P~tents 4,152,508 to Ellis; 4,153,641 to Deichert et al; 4,189,546 to Deichert et al; and 4,463,149 to Ellis.

1~!3S~

1~701 -9-1 While total concentrations of organosilicon monomers may range from about 10 to about 40 parts by weight based on the total weight of the monomers, the preferred range is ~rom about 15 to about 35 parts by weight. Oxygen per-meability (all other factors being constant) will increase with an increase in organosilicon monomer content. At higher levels, the lens becomes more difficult to machine, requiring inclusion of monomers such as acrylates, meth-acrylates and the like, may be employed as part of the monomer system to yield a lens having a Shore D hardness greater than about 78, preferably from about 80 to about 85. Oxygen permeability and wettability cf the lens is enhanced by the presence of the hydroxyorganosilicon monomer. Although the presently preferred concentration of the hydroxyorganosilicon monomer is from about 0.1 to about 10 percent by weight of the total monomer, it may be the exclusive organosilicon monomer, except for any multifunctional organosilicon monomer used as a crosslinking monomer.
The fluoroorgano monomers utile in the practice of the instant invention are generally compounds of the formula:
CH2 = C - Ml I (3) COO-~M~a-(CH2)C Y

wherein Ml is hydrogen, alkyl, fluoroalkyl, alkyl car-boxy, carboxy ester, alkyl carboxy ester, fluorinated carboxy ester, fluorinated alkyl carboxy ester, cyano, or phenyl, ~ is hydroxy alkyl, alkyl ether, or hydroxy alkyl ether, a is as defined above, c is from Q to 4, and Y is ~ a fluorocarbon group. Preferably, Y has ths general ; formula:

CnF2n~l or CnF2nH

12~

1 High-performance fluorinated compounds are hexafluoroiso-propyl esters of unsaturated carboxylic acids containing from 2 to about 10 carbon atoms and 1 or 2 carboxyl groups.
Illustrative of fluoroorgano monomers are:
2,2,2-trifluoroethylmethacrylate, hexafluorobutylmethacrylate, hexafluoroisopropylmethacrylate, pentafluoro-n-propylmethacrylate, and the like.
Hexafluoroisopropylmethacrylate is the preferred monomer for oxygen permeability, with 2,2,2-trifluoroethyl-methacrylate being preferred for cost. Perfluoro or fluorinated styrenes may also be used.
Hydrophilic monomers are included in the composition to induce wettability. They preferably comprise an unsat-urated carboxylic acid, most preferably methacrylic acid,for compatability of monomers and wearer comfort. Acrylic acid is functional but less desirable. Other monomers such as 2-hydroxyethylmethacrylate, vinyl pyrrolidone, and the ; Z like may be used. Concentration may be from about 0.1 to about 15 or more percent by weight, preferably from about 2 to about 10 percent by weight hased on the total weight of the monomers.
The amount of hydrophilic monomer present depends on whe~her a UV-absor~ing agent, as described below, is employed, as the latter also has the capability of being hydrophilic. If a UV-a~sorbing agent is employed, whether in monomeric or polymeric form, its concentration may range from about ~.1 to about 20 percent by weight, pre-ferably from about 2 to about 10 percent by weight basedon the total weight of the monomers and agent. The UV-absorbing agents used herein cooperate with the hydro-philic monomer to induce wettability and antisepticability,i.e., self-sterilizable, in consequence of hydroxy-substi-tuted benzene moieties. In the polymerized state, the ~:

~2~5~7~

1 VV-absorbing agents absorb in the rar~ge of from about 300nm to ahout 450nm, pre~erably with no less than about 70~ UV radia~ion at 370nm. Preferred UV-absorbing agents are, or are formed of, monomers of the formula:

( CH2 = C - Rl ~ (4) Coo-(cH2-cHoH-cH2-o-)a~~cH2-)b ~ Z
~ d wherein Rl is hydrogen or methyl, a is 0 or 1, b is from about 1 to ahout 3, d is 1 or 2, and 7. is:

O~ O OH

15 R2~ ~o_ OH

~ ~ ~ ; or ~ ~ ~ -~2 wherein R~ is hydrogen; an alkyl, preferably a Cl-Cs alkyl or hydroxyl, and c is 1 or 2. In the alternative or in addition, there may be employed a phenyl benzotriazole of the formula:
OH

~0 ~N~ ~_ R
wherein Rl and R2 are as defined above, preferably a Cl Clo alkyl, and R3 is H, alkyl, preferably a Cl-Clo alkyl, or hydroxyl.

~2~ o~

1 Preferred UV-absorbing monomers for forming agents include:
2-hydroxy-4-(2-methacryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-acryloyloxyethoxy)benzoDhenone, 2-hydroxy-4-~2-hydroxy-3-methacryloxypropyl)benzophenone, 2-(2-hydroxy-5-vinylphenyl)-2H-benzotriazole, and the like. They may be added to the monomer system and interpolymeri2ed therewith, or added as part of the non-reactive homopolymers and copolymers ~hich are added to the monomer system and are physically entrained in the final ~olymer formed.
The hard contact lenses of the instant invention are formulated to have high oxygen permeability (~k) of at least about 15 and preferably greater than 50, as expressed in units of 10 11(cm2/sec.)(ml 02/ml x mm H~) and as determined at 35C. Values are achieved using high concentrations of the organosilicon monomer and/or selection of the fluoroorgano monomer. ~Jith compositions of high or~anosilicon-monomer content there are displayed increased brittleness and a reduction in capability to undergo machining. At lea~st one crosslinking agent, such as a multi-functional organosilicon monomer, a fluoro-organo monomer, an acrylate and/or a methacrylate, is employed in an amount sufficient to control hardness of the lens in the range of Shore D hardness of from about 80 to about 85. A highly multi-functional organosilicon monomer is preferred, as it does not interfere with oxygen permeability. Other crosslinking a~ents which may be used include ethylene ~lycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, and the like.
Lens formation is by free radical polymerization such as azobisisobutyronitrile (AIBN) and peroxide catalysts under conditions set forth in U.S. Patent ~s~

16701 -13~
1 3,808,179, Colorants and the like may be added prior to monomer polymerization.
It is preferred to form the lens base in sheet form between layers of a non-adherent surface. The sheet is cut into smaller lense precursors from which the lens is ground to user specifications. Spin-casting, as described for instance in U.S. Patent 3,408,429 may also be used.

~ithout limiting, the following Examples are illus-10 trative of the instant invention. With reference to the Examples, properties of the contact lenses were measure~
according to the following methods.
Oxygen permeability values were determined using a test method developed by Dr. Irving Fatt of Berkeley, 15 Californiat and disclosed in the paper, entitled: "Oxy~en Transmissibility and Permeability of Gas Permeable Hard Contact Lenses and Materials~ by Irving Fatt, Ph.D., International Contact Lens Clinic, Vol. II, No. 3, March 1984. The instrument was a polarogra~hic cell with 20 a curved surface for finished lenses, polaro~raphic amplifier, recorder and a constant temperature chamher equipped with a temperature control unit. The measure ments were made at 35C and the units of oxy~en permea-bility ~Dk) are (cm2/sec.)(ml 02/ml x mm Hg).
The water wettability of the contact lense material was determined by the sesile drop method using a Rame-Hart goniometer with an environmental chamber. Both the advancing and the receding contact an~les were determined.
The ha~dness was measured as Shore D at 22C usin~ a hardness tester, and percent light transmission was measured using a recordin~ spectrophotometer.
; The absorption spectra of the copolymer were determine~ on a ~Perkin Elmer" UV-Vis spectrophotometer using 0.1-0.1~mm-thin ~ptically polished discs. The amount of materials extractable from the lenses were evaluated by first storin~ the~ in a saline solution for 10 days at 35C. The lenses were then rinsed with ~,s 1295~B

1 distilled water, dried, weighed, and placed in stoppered, 25cc volumetric flasks, again containing saline as the extracting medium. The saline was analyzed daily for its extxacted ultraviolet absorber by placin~ 4cc of the extract in a spectrophotometer cell and determining the absorption at 320nm. The a~sorption values were compared agains`t the calibration curve made for the pure ultravio-let absorber. Extractables can also be determined by the Soxhlet extraction method, using water as the solvent.
The amount of extractables was determined only for a few of the materials in the Examples. Based on 0.04 gr average lens weight, extractables were found, on the average, to be less than 1 x 10-4 mc grams/lens/day.
For a few selected copolymer materials, the leacha-bility-diffusibility was evaluated by cytotoxicity assay-agar overlay method.
The assay is based on the method described by Guess, W.L., Rosenbluth, S.A., Schmidt, B., and Autian, J., in "Aqar Diffusion Method for Toxicity Screenin~ of Plastics on Cultured Cell Monolayers", J. Pharm. Sci. 5~:1545-1547, 1965, and is designed to detect the response of a mammalian monolayer cell culture to readily diffusible components ~rom materials or test solutions applied to the surface of an agar layer overlayin~ the monolayer.
The response of the cell monolayer is evaluated, with respect to the discoloration of the red-stained mono-layer, under and aro~lnd the sample when the petri dish is viewed against a white back~round. Loss of color of the stained cells is considered to be a physiologically si~
nificant reaction of the cells. The extent of discolora-tion is confirmed by examination of the monolayer on an inverted microscope, and the extent of lysis of the cells within the discoloration zone is estimated. Typically, discoloration of cells precedes lysis, as manifested by a region and a region showing lysis~ A sample-is reported as "cytotoxic" only if lysis is observed.

~s~

E~ nd Controls A-F
Candidate lens compositions were formulated as shown in Table I. The mixture was homogenized, degassed and placed in a polymerization cell made of two glass plates separated by a seal and held together by spring clampsO
After filling, the cell was purged with nitrogen, sealed and placed in a circulating water bath at 60C for 10 hours. After the initial pol~nerization period, the cell was heated at 80C for 3 hours, 100C for one hour, and then allowed to cool to room temperature. The clamps were then removed and the transparent sheet heated for 2 hours at 100C. The plastic sheet, about 1/4-inch in thickness, was cut into squares, then formed to discs which were used to prepare corneal contact lenses using conventional hard-contact-lens-making equipment. The properties of the lens mat~rials are also shown in Table I.
Of the controls, Control A was too brittle to be used as a functional lens! and brittleness was attributed to excessive organosilicon-monomer content. The brittle-ness of the remaining control was attributed to the levelof silicon monomer employed and an excessive amount of a crosslinking and/or wetting monomer.

Controls G-U
..
Following the procedure of Examples 1-11, there were prepared a number of polymers of the formulations shown in Table II. Polymers of Controls G-O and U failed ~ecause they could not retain their radius of curvature.
Failure was attributed to too high an organosilicon-monomer content. Controls P-I were too brittle to be machinable. They shattered in the lathe.

_,I ,_ . ,~ ~ ~ ~ ~ U~
--l --o ~, u ~ o ~ ~ a, O_1 0 . ~ ~ ~ ~ Z
o ~ co _, a~~ o t~ o ~ ~ ~

~1 ~ c C ,~ Z
rt r O 1~
--I I ~ r- c _I r I l c ~ ~ ~ r ~ ~ m O N

X h ¦_I C ~ `J O N t~ CO , , o~ ~ o ~ ~o z ~ . ~
~n ~1 ~ o O ~ ~ o ~ ~ ~

~ ~ r z u C ~ C~ t.~ r 2s V U`l V
V

s ~ :~1 g, C
X ~ ~ ~
v l ~ Q' U~ ' ~
~1 ~c~ 0 ~ ~ Q ~ 31 o ~ c ~ j~ r^ ~ Q~ C ~
~,1 U .,, ,~ V ~ Col, ~ ~ ~ V QF Q~ C ~ Q~

3 5 ~ --C ~ ~ v ~_ XI ~c"~X~ ,Iz ~vvC~L~C ¦V ¢~~
~ ¢ ¢ ~ C ~C U IE-1 ~ Z l' 7~
i~7Cl -' 7 1 _ o~
~1 ~ o u u~ o ~ ~ ~ ~ z ", ~1 ! r~) N CC~

~ j o ;~I N N Cl) 3~ N a:

c ~ o o o u~ . N ~ Z

-- 2~ c ~ f- C ~ o ~ z u "

G ~ t ~ 3 ~2 ~ ~-- s ~ ~ o 2 ~ ~ ~ S ~ ~ r ~ ~ u r v ~5~

U~ _ ~ o : E I ~ O N

~I q' ~ ~ u~ ~ ~ c U~
v K ~P o c u~
~ .
3 ~ '' I ~ ~ ~ o ~
~ ~ I ~ ~r o _ ¦ ~ N N ~ D N
IJ~ r o , " C~ ~r o o Lr ~ Cc ~ ¦ --, I ~n ~ ~ C
~1 ~1 ~ u~ u~ " u~
~L~
W
w ~ r s~ ~
,~ _, h v ~0 h _I X u~

w v ~ lt~

~ v V ~ ~, VW ~ ~V~ Sv ~? v U~ W~
:~, v :~ ~ 0 ~, r ~) v O ~ ~ t W
r a~ S v ~ ~.1 v (~ 5 S ~ n~
~-~ V r ~ ~ ~U) g ~ ~ ~ o~ ~ C 0 ~ ~æ

n~
~1 ~ o o In ~ O U n co ~ ~ o n ~
U~ ~ o O ,,, o ~ ~, ~¦ ~ o n n n ~ ~ ~¦ ~r o o m n LO
~1 ~1 ~ ~
1 5 ~ ~ o ¦ ~r N ~ ~

~zl ~r o o ~ n u) u ~ o u ~
~1 "

~ ¦ ~ ~ 8 V ~

3~ ~v~

= D ~ C ~

5~P~

Example 12 Following the procedure of Examples 1-11, an oxygen-permeable copolymer was prepared from a mixture of 22 parts by weight tris(trimethylsiloxy)-~-methacryloxy-propylsilane, 2.7 parts by weight hydroxy~di(trirnethyl-siloxy)silylpropylmethacrylate, 0.3 parts by weight 1,3 bis(~-methacryloxypropyl)-1,1,3,3-tetra(trimethyl-siloxy)disiloxane, 65 parts by weight trifluoroethyl methacrylate, 5 parts by weight 2-hydroxy-4-(2-acryloxy-ethoxy)benzophenone, 5 parts by weight methacrylic acid,and 0.02 parts hy weigllt AIBN. The properties of this lens material are shown in Table III.
TABLE III

Oxyqen Permeability 54 Contact Anyle 20 Light Transmission Transparent Hardness 84 Cytotoxicity Assay Negative Example 13 ~he procedure of Examples 1-11 was repeated, except Z5 that the formulation contained 28.5 parts by weight tris(trimethylsiloxy)-r-methacryloxypropylsilane, 1.3 parts by weight hydroxy-di(trimethylsiloxy)silylpropyl-methacrylate, 0.2 parts by weight 1,3 bis(~-methacryloxy-propyl)-1,1,3,3-tetra(trimethylsiloxy)disiloxane, 65 parts by weight hexafluoroethylmethacrylate, 5 parts by weight methacrylic acid, and 0~2 parts by weight AIBN.
Average oxy~en permeability was 398 x 10 11(cm2/sec.) (ml O2/ml x mm Hg).

Claims

1. An oxygen-permeable lens comprising an interpolymerized amount of:
a) an organosilicon monomer system present in an amount of from about lo to about 40 percent by weight based on the total weight of the monomer and in which at least a portion of the organosilicon monomer system is at least one hydroxyorganosilicon monomer having at least one hydroxyl group attached to silicon of the organosilicon moiety;
b) at least one hydrophilic monomer present in an amount sufficient to provide in the resultant polymer a contact angle of less than about 45°;
c) at least one crosslinking monomer, the total of crosslinking monomer being present in an amount up to about 5 percent by weight based on the total weight of the monomers; and d) the balance of the monomers comprising at least one fluoroorgano monomer of the formula:
wherein M1 is hydrogen, alkyl, fluoroalkyl, alkyl carboxy, carboxy ester, alkyl carboxy ester, fluorinated carboxy ester, cyano, or phenyl, M is hydroxy alkyl, alkyl ether, or hydroxy alkyl ether, a is as defined above, c is from 0 to 4, and Y is a fluorocarbon group.

2. An oxygen-permeable lens as claimed in claim 1 which the organosilicon monomer system includes monomers of the formula wherein R1 is hydrogen or methyl, a is 0 or 1, b is from 1 to about 4, and X is an organosilicon moiety containing up to about 16 silicon atoms.

3. An oxygen-permeable lens as claimed in claim 1 in which at least one UV-absorbing agent is present in an amount of from about 0.1 to about 20 percent by weight based on the weight of the UV-absorbing agent and the monomers.

4. An oxygen-permeable lens as claimed in claim 2 in which at least one UV-absorbing agent is present in an amount of from about 0.1 to about 20 percent by weight based on the weight of the UV-absorbing agent and the monomers.

5. An oxygen-permeable lens as claimed in claim 4 in which the UV-absorbing agent comprises a polymerized amount of at least one monomer selected from the group consisting of a hydroxybenzophenone or benzotriazole of the formula:

wherein R1, a is 0 or 1, b is from 1 to about 4, d is 1 or 2, and Z is:

;

; or wherein R2 is hydrogen, alkyl or hydroxy and a phenyl benzotriazole of the formula:

wherein R1 and R2 are as defined above, and R3 is H;
alkyl or hydroxyl.

6. An oxygen-permeable lens as claimed in claim 1 in which the organosilicon monomer is present in a concentration of from about 15 to about 30 percent by weight based on the total weight of interpolymerized monomers.

7. An oxygen-permeable lens as claimed in claim 2 in which the organosilicon monomer is present in a concentration of from about 15 to about 30 percent by weight based on the total weight of interpolymerized monomers.

8. An oxygen-permeable lens as claimed in claim 1 in which the hydroxyorganosilicon monomer is present in an amount of from about 0.1 to about 10 percent by weight of the total weight of the interpolymerized monomers.

9. An oxygen-permeable lens as claimed in claim 2 in which the hydroxyorganosilicon monomer is present in an amount of from about 0.1 to about 10 percent by weight of the total weight of the interpolymerized monomers.

10. An oxygen-permeable lens as claimed in claim 5 in which the hydroxyorganosilicon monomer is present in an amount of from about 0.1 to about 10 percent by weight of the total weight of the interpolymerized monomers.

11. An oxygen-permeable lens as claimed in claim 1, 2 or 3, in which the oxygen permeability is at least about 15 x 10-11(cm2/sec.) (ml O2/ml x mm Hg).

12. An oxygen-permeable lens as claimed in claim 1, 2 or 3, in which the oxygen permeability is at least about 50 x 10-11(cm2/sec.) (ml O2/ml x mm Hg) and a Shore hardness greater than about 78.

13. An oxygen-permeable lens as claimed in claim 2 in which the organosilicon monomers are selected from compounds of the formula:

Claim 13, continued. . .

wherein X' is or wherein each of R4 and R5 is independently a C1-C5 alkyl, phenyl, hydroxyl, or -O-Si(CH3)3, and each of R6, R7 and R8 is independently selected from C1-C5; -CH2=CH2;
phenyl; hydroxyl; -CH2OH;

; ;

; O-Si-[OSi(CH3)]3 ; or wherein R1 is hydrogen or methyl, a is 0 or 1, and b is from 1 to about 4.

14. An oxygen-permeable lens as claimed in claim 1 in which the organosilicon monomer is selected from tris(trimethylsiloxy)-?-methacryloxypropylsilane, 1,3-bis-(?-methacryloxypropyl-)1,1,3,3-tetra(trimethyl-siloxy)disiloxane and mixtures thereof, and in which the hydroxyorganosilicon monomer is hydroxy-di-(trimethyl-siloxy)silylpropylmethacrylate.

15. An oxygen-permeable lens as claimed in claim 10 in which the organosilicon monomer is selected from tris(trimethylsiloxy)-?-methacryloxypropylsilane, 1,3-bis-(?-methacryloxypropyl-)1,1,3,3-tetra(trimethyl-siloxy) disiloxane and mixtures thereof, and in which the hydroxyorganosilicon monomer is hydroxy-di-(trimethyl-siloxy)silylpropylmethacrylate.

16. An oxygen-permeable lens as claimed in claim 1 in which the fluoroorgano monomer comprises 2,2,2-tri-fluoroethylmethacrylate, hexafluorobutylmethacrylate, and mixtures thereof.

17. An oxygen-permeable lens as claimed in claim 2 in which the fluoroorgano monomer comprises 2,2,2-tri-fluoroethylmethacrylate, hexafluorobutylmethacrylate, and mixtures thereof.

18. An oxygen-permeable lens as claimed in claim 1 in which the hydrophilic monomer is methacrylic acid.

19. An oxygen-permeable lens as claimed in claim 2 in which the hydrophilic monomer is methacrylic acid.

20. An oxygen-permeable lens as claimed in claim 14 in which the hydrophilic monomer is methacrylic acid.

21. An oxygen-permeable lens as claimed in claim 3 in which the UV-absorbing monomer is selected form the group consisting of 2-hydroxy-4 (2-methacryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-acryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-hydroxy-3-methacryloxypropyl)benzophenone, 2-(2-hydroxy-5-vinylphenyl)-2H-benzotriazole, and mixtures thereof.

22. An oxygen-permeable lens comprising an interpolymerized amount of:
a) an organosilicon monomer system including the formula:

wherein R1 is hydrogen or methyl, a is 0 or 1, b is from 1 to about 4, and X is an organosilicon moiety containing up to about 16 silicon atoms, the total organosilicon monomer being present in an amount of from about 10 to about 35 percent by weight based on the total weight of the monomers and in which from about 0.1 to about 10 percent by weight of the total monomers is an hydroxy oragnosilicon monomer having at least one hydroxyl group attached to a silicon of the organosilicon moiety;
b) a UV-absorbing agent containing an interpolymerized amount of at least one monomer selected from the group consisting of a hydroxybenzophenone or benzotriazole of the formula:

wherein R1, a and b are as defined above, d is 1 or 2, and Z is:

;

Claim 22, continued...

; or wherein R2 is hydrogen, alkyl or hydroxy and a phenyl benzotriazole of the formula:

.

wherein R1 and R2 are as defined above, and R3 is H;
alkyl, preferably a C1-C10 alkyl, or hydroxyl, said UV-absorbing agent being present in an amount of from about 0 to about 10 percent by weight based on the total weight of the agent and the monomers;
c) methacrylic acid in an amount sufficient to provide in the resultant polymer a contact angle of less than ahout 45°;
d) at least one crosslinking monomer, the total of crosslinking monomers being present in a concentration of from about 0.1 to about 2 percent by weight based on the total weight of the monomers; and e) the balance of the monomers comprising at least one fluoroorgano monomer of the formula:

Claim 22, continued...

wherein M1 is hydrogen, alkyl, fluoroalkyl, alkyl carboxy, carboxy ester, alkyl carboxy ester, fluorinated carboxy ester, cyano, or phenyl, M is hydroxy alkyl, alkyl ether, or hydroxy alkyl ether, a is as defined above, c is from 0 to 4, and Y is a fluorocarbon group preferably containing from about 2 to about 21 fluorine atoms, said lens having a Shore D hardness from about 80 to about 85 and containing sufficient organosilicon monomer to provide an oxygen permeability of at least 50 x 10-11(cm2/sec.)(ml O2/ml x mm Hg).

23. An oxygen-permeable lens as claimed in claim 22 in which the organosilicon monomer is present in a concentration of from about 15 to about 35 percent by weight based on the total weight of interpolymerized monomers.

24. An oxygen-permeable lens as claimed in claim 22 in which the organosilicon monomer is selected from the group consisting of tris(trimethylsiloxy)-?-methacryloxy-propylsilane, 1,3-bis-(? -methacryloxypropyl)1,1,3,3-tetra(-trimethylsiloxy)disiloxane and mixtures thereof, and in which the hydroxyorganosilicon monomer is hydroxy-di(trimethylsiloxy)silylpropylmethacrylate.

25. An oxygen permeable lens as claimed in claim 22 in which the fluoroorgano monomer comprises 2,2,2-trifluoroethylmethacrylate, hexafluorobutylmethacrylate, and mixtures thereof.

26. An oxygen-permeable lens as claimed in claim 25 in which the UV-absorbing monomer is selected form the group consisting of 2-hydroxy-4-(2-methacryloyloxyethoxy)benzophenone, 2-hydroxy 4-(2-acryloyloxyethoxy)benzophenone, 2-hydroxy-4(2-hydroxy-3-methacryloxypropyl)benzophenone, 2-(2-hydroxy-5-vinylphenyl)-2H-benzotriazole, and mixtures thereof.

27. An oxygen-permeable lens as claimed in claim 5 wherein R3 is C1-C10 alkyl.

28. An oxygen-permeable lens as claimed in claim 1 wherein the fluorocarbon group contains from about 2 to about 21 fluorine atoms.