US3767731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Contact lenses from hydrophilic gel polymers of polyvinylpyrrolidone monomeric vinylpyrrolidone and methacrylic modifier
Assignee: Individual
•
Filing: 1971-12-20
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Granted: 1973-10-23
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Expires: 1991-12-20
Abstract
Abstract A PLASTIC OR RESIN PRODUCT OBTAINED BY MIXING COMMINUTED POLYVINYLPYRROLIDONE, VINYLPYRROLIDONE, A MODIFIER SUCH AS AN ORGANIC METHACRYLATE, OPTIONALLY A CROSSLINKING AGENT, AND OPTIONALLY A CATALYST; AND CAUSING POLYMERIZATION TO TAKE PLACE BY ELEVATING THE TEMPERATURE. THE INVENTIVE PRODUCT IS INSOLUBLE IN WATER BUT IS HYDRATABLE WITH WATER, AND MAY TAKE UP AS MUCH AS 90% BY WEIGHT OF WATER. THE HYDRATED PRODUCT IS OPTICALLY TRANSPARENT AND ESPECIALLY SUITABLE FOR CONTACT LENSES.
Inventors
- 👤 M Seiderman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:55
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/04; G02B1/041; G02B1/043; C; C08; C08F; C08F220/00; C08F220/02; C08F220/10; C08F220/12; C08F220/20; C08F26/00; C08F26/06; C08F271/00; C08F271/02
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) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |