US4532277A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrophilized cellulose esters, process for their preparation, their use as biomedical materials and contact lenses produced from these
Assignee: Bayer AG
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Filing: 1983-12-27
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Granted: 1985-07-30
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Expires: 2003-12-27
Abstract
Abstract Contact lenses and implants for human medicine can be fabricated from a polymer blend comprising 98-80% by weight of component A and 2-20% by weight of component B wherein: component A is a cellulose ester of an aliphatic carboxylic acid with up to 40% by weight of total component A of an ethylene/vinyl acetate copolymer having 30-98% by weight, relative to ethylene/vinyl acetate, of incorporated vinyl acetate and component B is a homopolymer or copolymer of water-soluble vinyl monomers and up to 10% by weight relative to the total polymer B of multifunctional crosslinker vinyl compounds.
Inventors
- 👤 Frank Wingler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:10
CPC Classifications
C; C08; C08F; C08F251/00; C08F251/02; C08L; C08L1/00; C08L1/08; C08L1/10
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
130 words
A polymer blend comprising 98-80% by weight of component A and 2-20% by weight of component B wherein: component A is a cellulose ester of an aliphatic carboxylic acid with up to 40% by weight of total component A of an ethylene/vinyl acetate copolymer having 30-98% by weight, relative to ethylene/vinyl acetate, of incorporated vinyl acetate and component B is a homopolymer or copolymer of acrylic acid, methacrylic acid, acrylamide, methacrylamide, diacetone-acrylamide, vinyl pyrrolidone, or compounds of the formula ##STR4## wherein R is H or CH 3 , R' is H, CH 3 or C 2 H 5 and A is a straight-chain or branched alkylene moiety having 1 to 4 carbon atoms; and up to 10% by weight relative to the total polymer B of multifunctional crosslinker vinyl compounds.
Claim 2
Dependent Claim
130 words
A polymer blend comprising 98-80% by weight of component A and 2-20% by weight of component B wherein: component A is a cellulose ester of an aliphatic carboxylic acid with up to 40% by weight of total component A of an ethylene/vinyl acetate copolymer having 30-98% by weight, relative to ethylene/vinyl acetate, of incorporated vinyl acetate and component B is a homopolymer or copolymer of acrylic acid, methacrylic acid, acrylamide, methacrylamide, diacetone-acrylamide, vinyl pyrrolidone, or compounds of the formula ##STR4## wherein R is H or CH 3 , R' is H, CH 3 or C 2 H 5 and A is a straight-chain or branched alkylene moiety having 1 to 4 carbon atoms; and up to 10% by weight relative to the total polymer B of multifunctional crosslinker vinyl compounds.
Claim 3
Dependent Claim
16 words
The polymer blend according to claim 1 wherein component A consists essentially of pure cellulose ester.
Claim 4
Dependent Claim
32 words
The polymer blend according to claim 1 wherein component A is a blend of 99 to 70% by weight of cellulose ester and 30 to 1% by weight of ethylene/vinyl acetate copolymer.
Claim 5
Dependent Claim
32 words
The polymer blend according to claim 3 wherein component A is a blend of 95 to 85% by weight of cellulose ester and 15 to 5% by weight of ethylene/vinyl acetate polymer.
Claim 6
Dependent Claim
43 words
The polymer blend according to claim 1 wherein the cellulose ester is a cellulose acetobutyrate comprising 30 to 50% by weight of butyric acid moieties, 10 to 26% by weight of acetic acid moieties, and 0.7 to 1.95% by weight of hydroxyl moieties.
Claim 7
Dependent Claim
16 words
The polymer blend according to claim 5 wherein component A consists essentially of pure cellulose ester.
Claim 8
Dependent Claim
32 words
The polymer blend according to claim 5 wherein component A is a blend of 99 to 70% by weight of cellulose ester and 30 to 1% by weight of ethylene/vinyl acetate copolymer.
Claim 9
Dependent Claim
32 words
The polymer blend according to claim 7 wherein component A is a blend of 95 to 85% by weight of cellulose ester and 15 to 5% by weight of ethylene/vinyl acetate copolymer.
Claim 10
Dependent Claim
23 words
The polymer blend according to claim 1 wherein the ethylene/vinyl acetate copolymer has a vinyl acetate content of 60 to 80% by weight.
Claim 11
Dependent Claim
61 words
The polymer blend according to claim 1 wherein the water-soluble vinyl monomers of the homopolymer or copolymer of component B are vinylpyrrolidone or compounds of the formula ##STR5## wherein R is H or CH 3 , R' is H, CH 3 or C 2 H 5 and A is a straight-chain or branched alkylene moiety having 1 to 4 carbon atoms.
Claim 12
Dependent Claim
45 words
Process for the preparation of polymer blends according to claim 1 which comprises impregnating 98 to 80% by weight of component A with 2 to 20% by weight of a water-soluble vinyl monomer and then the impregnated material is exposed to the action of light.
Claim 13
Dependent Claim
20 words
Process according to claim 11 wherein the impregnated material additionally contains 0.01 to 0.5% by weight of a radical initiator.
Claim 14
Dependent Claim
19 words
Process according to claim 11 wherein the impregnated material is exposed to a temperature of 60° to 220° C.
Claim 15
Dependent Claim
17 words
Process according to claim 11 wherein the impregnated material is exposed in the form of a melt.
Claim 16
Dependent Claim
14 words
Process according to claim 11 wherein the impregnated material is exposed in solid form.
Claim 17
Dependent Claim
22 words
As an article of manufacture, lenses to be worn in direct eye contact and comprising a polymer blend according to claim 1.
References Cited (Backward Citations)
US4193897A
Cited
US4360635A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-29 | 1989-01-28 | 1989-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-29 | 1993-01-28 | 1993-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-29 | 1997-01-28 | 1997-07-30 | $7700.00 | Window Closed / Lapsed |