US4528325A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Copolymers of poly(vinyl trifluoroacetate) or poly(vinyl alcohol)
Assignee: 3M Co
•
Filing: 1983-06-03
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Granted: 1985-07-09
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Expires: 2003-06-03
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 be 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
2026-11-05 22:58
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: 13
Claim 1
Independent Claim
125 words
A non-crosslinked poly(vinyl alcohol) copolymer which is the reaction product of: a. a non-crosslinked poly(vinyl trifluoroacetate) copolymer having a molecular weight in the range of 200,000 to 4,000,000 which is the reaction product of: 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; and b. a mild base in a non-aqueous diluent selected so that the poly(vinyl trifluoroacetate) copolymer and its poly(vinyl alcohol) copolymer solvolysis product are insoluble therein, said poly(vinyl alcohol) copolymer being a hydrogel capable of absorbing water in the range of 10 to 95 weight percent without dissolving therein, and having a tensile strength of at least 6.9 kg/cm 2 .
Claim 2
Dependent Claim
125 words
A non-crosslinked poly(vinyl alcohol) copolymer which is the reaction product of: a. a non-crosslinked poly(vinyl trifluoroacetate) copolymer having a molecular weight in the range of 200,000 to 4,000,000 which is the reaction product of: 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; and b. a mild base in a non-aqueous diluent selected so that the poly(vinyl trifluoroacetate) copolymer and its poly(vinyl alcohol) copolymer solvolysis product are insoluble therein, said poly(vinyl alcohol) copolymer being a hydrogel capable of absorbing water in the range of 10 to 95 weight percent without dissolving therein, and having a tensile strength of at least 6.9 kg/cm 2 .
Claim 3
Dependent Claim
21 words
The poly(vinyl alcohol) copolymer according to claim 1 wherein said non-aqueous mild base is selected from ammonium hydroxide and organic amines.
Claim 4
Dependent Claim
35 words
A poly(vinyl alcohol) copolymer according to claim 2 having 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
16 words
A poly(vinyl alcohol) copolymer according to claim 2 containing vinyl alcohol and vinyl acetate monomer units.
Claim 6
Dependent Claim
38 words
The poly(vinyl alcohol) copolymer 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 7
Dependent Claim
20 words
The poly(vinyl alcohol) copolymer according to claim 1 wherein said comonomer is a vinyl ester or a copolymerizable disubstituted ethylene.
Claim 8
Dependent Claim
12 words
A shaped article comprising a poly(vinyl alcohol) copolymer according to claim 1.
Claim 9
Dependent Claim
150 words
A process for preparing a poly(vinyl alcohol) copolymer 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 having a molecular weight in the range of 200,000 to 4,000,000, and c. solvolyzing said poly(vinyl trifluoroacetate) copolymer in a mild base in a non-aqueous diluent so as to produce said 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, said poly(vinyl alcohol) copolymer being a hydrogel capable of absorbing water in the range of 10 to 95 weight percent without dissolving therein, and having a tensile strength of at least 6.9 kg/cm 2 .
Claim 10
Dependent Claim
150 words
A process for preparing a poly(vinyl alcohol) copolymer 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 having a molecular weight in the range of 200,000 to 4,000,000, and c. solvolyzing said poly(vinyl trifluoroacetate) copolymer in a mild base in a non-aqueous diluent so as to produce said 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, said poly(vinyl alcohol) copolymer being a hydrogel capable of absorbing water in the range of 10 to 95 weight percent without dissolving therein, and having a tensile strength of at least 6.9 kg/cm 2 .
Claim 11
Dependent Claim
17 words
The process according to claim 8 wherein said base is selected from ammonium hydroxide and organic amines.
Claim 12
Dependent Claim
40 words
The process according to claim 8 wherein said poly(vinyl alcohol) copolymer comprises 85 to 99.97 weight percent of a vinyl alcohol monomer units and 0.03 to 15 weight percent of a comonomer units derived from vinyl esters and disubstituted ethylenes.
Claim 13
Dependent Claim
12 words
The shaped article according to claim 7 which is an optical device.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-08 | 1989-01-07 | 1989-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-08 | 1993-01-07 | 1993-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-08 | 1997-01-07 | 1997-07-09 | $7700.00 | Window Closed / Lapsed |