Patent US4618649A successfully refreshed from Google Patents.
US4618649A
Expired / Lapsed
US
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Copolymers of poly(vinyl trifluoroacetate) or poly(vinyl alcohol)
Assignee: 3M Co
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Filing: 1985-05-08
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Granted: 1986-10-21
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Expires: 2005-05-08
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, vinyl ethers, 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 ophthalmic devices such as contact lenses, corneal implants and transplants, and intraocular lenses.
Inventors
- 👤 Ronald F. Ofstead
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:54
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: 20
Claim 1
Independent Claim
46 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.
Claim 2
Dependent Claim
46 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.
Claim 3
Dependent Claim
39 words
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 alochol) copolymer
Claim 4
Dependent Claim
39 words
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 alochol) copolymer
Claim 5
Dependent Claim
27 words
solvolysis product are insoluble therein. 2. The poly(vinyl alcohol) copolymer according to claim 1 wherein said non-aqueous mild base is selected from ammonium hydroxide and organic amines.
Claim 6
Dependent Claim
37 words
The 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, vinyl ethers, and disubstituted ethylenes.
Claim 7
Dependent Claim
16 words
The poly(vinyl alcohol) copolymer according to claim 2 containing vinyl alcohol and vinyl acetate monomer units.
Claim 8
Dependent Claim
19 words
The poly(vinyl alcohol) copolymer according to claim 1 having a tensile strength of at least 6.9 kg/cm 2 .
Claim 9
Dependent Claim
12 words
A shaped article comprising a poly(vinyl alcohol) copolymer according to claim 1.
Claim 10
Dependent Claim
12 words
The shaped article according to claim 6 which is an ophthalmic device.
Claim 11
Dependent Claim
12 words
The shaped article according to claim 6 which is a contact lens.
Claim 12
Dependent Claim
12 words
The shaped article according to claim 6 which is an intraocular lens.
Claim 13
Dependent Claim
12 words
The shaped article according to claim 6 which is a corneal transplant.
Claim 14
Dependent Claim
12 words
The shaped article according to claim 6 which is a corneal implant.
Claim 15
Dependent Claim
113 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 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 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.
Claim 16
Dependent Claim
113 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 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 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.
Claim 17
Dependent Claim
17 words
The process according to claim 12 wherein said base is selected from ammonium hydroxide and organic amines.
Claim 18
Dependent Claim
42 words
The process according to claim 12 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, vinyl ethers, and distributed ethylenes.
Claim 19
Dependent Claim
36 words
The process according to claim 13 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 20
Dependent Claim
18 words
The process according to claim 13 wherein said comonomer is a vinyl ester or a copolymerizable disubstituted ethylene.
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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) | 1989-10-20 | 1990-04-21 | 1990-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-20 | 1994-04-21 | 1994-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-20 | 1998-04-21 | 1998-10-21 | $7700.00 | Window Closed / Lapsed |