Patent US4451630A successfully refreshed from Google Patents.
US4451630A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrogel contact lenses for permanent wear
Assignee: COOPERVISION TECHNOLOGY Inc
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Filing: 1983-06-16
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Granted: 1984-05-29
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Expires: 2003-06-16
Abstract
Abstract A process is disclosed for the preparation of hydrogel contact lenses having improved mechanical properties, said process comprising polymerizing, in the presence of an azo type initiator, a monomer mixture comprising from 25% to 50% by weight of N-vinyl pyrrolidone, up to 5% by weight of methacrylic or acrylic acid, 0.1 to 1% by weight of 1,3,5-tris(propenoxy)-2,4,6-triazine (TPT), or perhydro-2,4,6,-triketo-1,3,5,-tris (propene-2)- 1,3,5 - triazine (T.T.P.T.), as a cross-linking monomer, the balance being essentially hydroxy alkyl acrylate or methacrylate, wherein the alkyl group is ethyl or propyl.
Inventors
- 👤 Ivor B. Atkinson
- 👤 Barry C. Holdstock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:05
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/04; G02B1/041; G02B1/043; C; C08; C08F; C08F220/00; C08F220/02; C08F220/10; C08F220/20; C08F226/00; C08F226/06; C08F226/10
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
98 words
A process for the preparation of a contact lens comprising a hydrogel having a water content from about 50% to 85% by weight of water, which process comprises polymerizing, in the presence of an azo type initiator, a monomer mixture comprising from 25% to 50% by weight of N-vinyl pyrrolidone, up to 5% by weight of methacrylic or acrylic acid, 0.1 to 1% by weight of 1,3,5-tris(propenoxy)-2,4,6-triazine (TPT), or perhydro-2,4,6,-triketo-1,3,5-tris(propene-2)-1,3,5-triazine (T.T.P.T.), as a cross-linking monomer, the balance being essentially hydroxy alkyl acrylate or methacrylate, wherein the alkyl group is ethyl or propyl and subsequently swelling in aqueous medium.
Claim 2
Dependent Claim
98 words
A process for the preparation of a contact lens comprising a hydrogel having a water content from about 50% to 85% by weight of water, which process comprises polymerizing, in the presence of an azo type initiator, a monomer mixture comprising from 25% to 50% by weight of N-vinyl pyrrolidone, up to 5% by weight of methacrylic or acrylic acid, 0.1 to 1% by weight of 1,3,5-tris(propenoxy)-2,4,6-triazine (TPT), or perhydro-2,4,6,-triketo-1,3,5-tris(propene-2)-1,3,5-triazine (T.T.P.T.), as a cross-linking monomer, the balance being essentially hydroxy alkyl acrylate or methacrylate, wherein the alkyl group is ethyl or propyl and subsequently swelling in aqueous medium.
Claim 3
Dependent Claim
22 words
A process according to claim 1, wherein said polymerisation mixture contains less than 0.1% of cross-linking monomer other than TPT or TTPT.
Claim 4
Dependent Claim
27 words
A process according to claim 1 wherein the TPT or TTPT is employed in an amount of from 0.1 to 0.5% by weight of the monomer mixture.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-29 | 1987-11-28 | 1988-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-29 | 1991-11-28 | 1992-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-29 | 1995-11-28 | 1996-05-29 | $7700.00 | Window Closed / Lapsed |