US4694037A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Copolymers of poly(vinyl trifluoroacetate) or poly(vinyl alcohol)
Assignee: 3M Co
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Filing: 1985-03-15
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Granted: 1987-09-15
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Expires: 2005-03-15
Abstract
Abstract Novel, non-crosslinked copolymers of vinyl trifluoroacetate (VTA) and up to 5 weight percent of the VTA of certain comonomers, such as vinyl esters or disubstituted ethylene monomers, are disclosed. Solvolysis of these copolymers provides novel water-insoluble, non-crosslinked, poly(vinyl alcohol) copolymers which can by hydrated to copolymers having controllably variable hydrogel properties and high strength. Such poly(vinyl alcohol) copolymers are particularly desirable as optical devices such as contact lenses.
Inventors
- 👤 Ronald F. Ofstead
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:35
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/04; G02B1/041; G02B1/043; C; C08; C08F; C08F218/00; C08F218/02; C08F218/04; C08F8/00; C08F8/44; C08J; C08J5/00; C08J5/18; C08F2810/00; C08F2810/50
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
120 words
A process for preparing a polymer hydrogel comprising the steps: a. admixing (1) 95 to 99.99 weight percent of vinyl trifluoroacetate monomer, and (2) 0.01 to 5 weight percent of a comonomer selected from vinyl esters, vinyl ethers, and copolymerizable disubstituted ethylenes, b. allowing said admixture to react so as to form a poly(vinyl trifluoroacetate) copolymer, and c. solvolyzing said poly(vinyl trifluoroacetate) copolymer in a mild base in a non-aqueous diluent so as to produce a poly(vinyl alcohol) copolymer, said base in a non-aqueous diluent being selected so that the poly(vinyl trifluoroacetate) copolymer and the copolymeric poly(vinyl alcohol) solvolysis product are insoluble therein, and d. hydrating said poly(vinyl alcohol) copolymer in water or normal saline to produce said polymer hydrogel.
Claim 2
Dependent Claim
120 words
A process for preparing a polymer hydrogel comprising the steps: a. admixing (1) 95 to 99.99 weight percent of vinyl trifluoroacetate monomer, and (2) 0.01 to 5 weight percent of a comonomer selected from vinyl esters, vinyl ethers, and copolymerizable disubstituted ethylenes, b. allowing said admixture to react so as to form a poly(vinyl trifluoroacetate) copolymer, and c. solvolyzing said poly(vinyl trifluoroacetate) copolymer in a mild base in a non-aqueous diluent so as to produce a poly(vinyl alcohol) copolymer, said base in a non-aqueous diluent being selected so that the poly(vinyl trifluoroacetate) copolymer and the copolymeric poly(vinyl alcohol) solvolysis product are insoluble therein, and d. hydrating said poly(vinyl alcohol) copolymer in water or normal saline to produce said polymer hydrogel.
Claim 3
Dependent Claim
17 words
The process according to claim 1 wherein said base is selected from ammonium hydroxide and organic amines.
Claim 4
Dependent Claim
38 words
The process according to claim 1 wherein said poly(vinyl alcohol) copolymer comprises 85 to 99.97 weight percent of vinyl alcohol monomer units and 0.03 to 15 weight percent of comonomer units derived from vinyl esters and disubstituted ethylenes.
Claim 5
Dependent Claim
36 words
The process according to claim 1 wherein said copolymerizable disubstituted ethylene is an ester or anhydride of a lower alkyl (C 1 to C 4 )-substituted or unsubstituted dicarboxylic acid having up to 8 carbon atoms.
Claim 6
Dependent Claim
18 words
The process according to claim 1 wherein said comonomer is a vinyl ester or a copolymerizable disubstituted ethylene.
Claim 7
Dependent Claim
22 words
The process according to claim 1 wherein said polymer hydrogel absorbs water in the range of 10 to 95 percent by weight.
Claim 8
Dependent Claim
14 words
The process according to claim 1 wherein said polymer hydrogel is a shaped article.
Claim 9
Dependent Claim
14 words
The process according to claim 7 wherein said shaped article is a contact lens.
Claim 10
Dependent Claim
15 words
The process according to claim 7 wherein said shaped article is a corneal implant lens.
References Cited (Backward Citations)
US2436144A
Cited
US3220960A
Cited
US3427298A
Cited
US3361858A
Cited
US3388199A
Cited
US3882005A
Cited
JPS5391995A
Cited
JPS53103092A
Cited
JPS5834867A
Cited
US4528325A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-09-14 | 1991-03-16 | 1991-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-14 | 1995-03-16 | 1995-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-14 | 1999-03-16 | 1999-09-15 | $7700.00 | Window Closed / Lapsed |