Patent US3772235A successfully refreshed from Google Patents.
US3772235A
Expired / Lapsed
US
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Copolymers and hydrogels of unsaturated heterocyclic compounds
Assignee: CooperVision Inc
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Filing: 1971-10-05
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Granted: 1973-11-13
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Expires: 1991-10-05
Abstract
Abstract WATER INSOLUBLE BUT WATER SWELLABLE POLYMER COMPRISING CERTAIN N-VINYL OR N-ALLYL HETEROCYCLIC COMPOUNDS; AND GLYCIDYL METHACRYLATE, AND/OR GLYCIDYL ACRYLATE AND/ OR GLYCIDYL CROTONATE. THE POLYMER MAY BE SWELLED IN AQUEOUS SOLUTION TO PROVIDE A TRANSPARENT HYDROGEL HAVING EXCELLENT PHYSICAL AND OPTICAL PROPERTIES, AND SUITABLE IN AN OPHTHALMIC LENS.
Inventors
- 👤 P Stamberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:00
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/04; G02B1/041; G02B1/043; C; C08; C08F; C08F220/00; C08F220/02; C08F220/10; C08F220/26; C08F220/32; C08F220/325; C08F26/00; C08F26/06; C08G; C08G65/00; C08G65/02; C08G65/26; Y; Y10; Y10S; Y10S524/00; Y10S524/916
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-12 | 1977-05-14 | 1977-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-12 | 1981-05-14 | 1981-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-12 | 1985-05-14 | 1985-11-13 | $7700.00 | Window Closed / Lapsed |