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Patent US4450262A successfully refreshed from Google Patents.
US4450262A
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Hydrophilic copolymer compositions useful as contact lenses
Assignee: Biospecific Technologies Inc
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Filing: 1982-08-11
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Granted: 1984-05-22
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Expires: 2002-08-11
Abstract
Abstract Novel hydrophilic copolymers are prepared containing a major portion of polymerized units of an hydroxyalkyl acrylate or methacrylate monomer and a minor portion of a nitro-substituted aryl acrylate or methacrylate monomer, and optionally with a minor amount of an alkylene glycol diacrylate or methacrylate as a cross-linking agent. These copolymers are made by a free radical polymerization mechanism or by gamma radiation of the reaction mixture. These copolymers are particularly useful as soft contact lens polymers, being extremely resistant to clouding and/or discoloration in use.
Inventors
- 👤 Nancy J. Drake
- 👤 Michael D. Hilston
- 👤 Mary A. O'Malley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:28
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/04; G02B1/041; G02B1/043; C; C08; C08F; C08F220/00; C08F220/02; C08F220/10; C08F220/20
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
100 words
A hydrophilic copolymer adapted to the fabrication of soft contact lenses resistant to the diffusion of proteins and other lens opacifying agents therein, which polymer comprises (a) at least about 93% by weight of polymerized units of a hydroxy containing acrylate or alkacrylate having the structural formula: ##STR4## wherein R represents hydrogen or alkyl from 1 to 6 carbon atoms; R' represents hydrogen or alkyl from 1 to 6 carbon atoms; and n is an integer of 1 to 6; and (b) at least about 0.6% to about 7.0% by weight of polymerized units of a p-nitrophenyl acrylate or methacrylate.
Claim 2
Dependent Claim
100 words
A hydrophilic copolymer adapted to the fabrication of soft contact lenses resistant to the diffusion of proteins and other lens opacifying agents therein, which polymer comprises (a) at least about 93% by weight of polymerized units of a hydroxy containing acrylate or alkacrylate having the structural formula: ##STR4## wherein R represents hydrogen or alkyl from 1 to 6 carbon atoms; R' represents hydrogen or alkyl from 1 to 6 carbon atoms; and n is an integer of 1 to 6; and (b) at least about 0.6% to about 7.0% by weight of polymerized units of a p-nitrophenyl acrylate or methacrylate.
Claim 3
Dependent Claim
28 words
The hydrophilic copolymer of claim 1 which additionally contains at least about 0.10% to about 0.99% by weight of polymerized units of a cross-linking agent as component (c).
Claim 4
Dependent Claim
12 words
The copolymer of claim 1 in which component (a) is hydroxyethyl methacrylate.
Claim 5
Dependent Claim
41 words
The hydrophilic copolymer of claim 2 in which the cross-linking agent is an alkylene glycol diacrylate monomer having the structural formula: ##STR5## wherein R represents hydrogen or alkyl of 1-4 carbon atoms; and n is an integer of 1 to 20.
Claim 6
Dependent Claim
15 words
The hydrophilic copolymer of claim 4 in which the cross-linking monomer is ethylene glycol dimethacrylate.
Claim 7
Dependent Claim
64 words
A method for producing the hydrophilic copolymer of claim 1 which comprises copolymerizing a monomeric mixture consisting essentially of an hydroxyalkyl methacrylate and a p-nitrophenyl methacrylate in the presence of from 0.05% to about 2% by weight of the monomers of a free radical polymerization catalyst and at a temperature ranging between room temperature and 90° C. for a time period of 10-16 hours.
Claim 8
Dependent Claim
27 words
The method of claim 6 in which the monomeric mixture consists of about 94% to 99.4% hydroxyethyl methacrylate by weight and about 0.6% to 6% para-nitrophenyl methacrylate.
Claim 9
Dependent Claim
27 words
The method of claim 6 in which the monomeric mixture consists of about 98% to 99.4% hydroxyethyl methacrylate by weight and about 0.6% to 2.0% para-nitrophenyl methacrylate.
Claim 10
Dependent Claim
17 words
The method of claim 6 wherein the free radical polymerization catalyst is an ammonium persulfate-sodium metabisulfite combination.
Claim 11
Dependent Claim
20 words
The method of claim 7 in which the monomeric mixture additionally contains ethylene glycol dimethacrylate monomer as a cross-linking agent.
References Cited (Backward Citations)
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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) | 1987-05-22 | 1987-11-21 | 1988-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-22 | 1991-11-21 | 1992-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-22 | 1995-11-21 | 1996-05-22 | $7700.00 | Window Closed / Lapsed |