Patent US3786034A successfully refreshed from Google Patents.
US3786034A
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US
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Polyurethane polymers for use in soft lenses and method of producing soft lenses
Assignee: Frigitronics Inc
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Filing: 1972-06-23
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Granted: 1974-01-15
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Expires: 1992-06-23
Abstract
Abstract THE USE OF WATER ABSORBTIVE POLYURETHANE POLYMERS OF RESINS OF LOW EQUIVALENT WEIGHT AND HIGH MOLECULAR WEIGHT AND SLIGHTLY IN EXCESS OF EQUIMOLAR RATIO OF POLYISOCYANATES OR URETHANE LINKAGE PRECURSORS FOR MAKING SOFT LENSES AND FOR SOFT CONTACT LENSES MADE FROM SAID POLYMER.
Inventors
- 👤 E Blair
- 👤 D Hudgin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:12
CPC Classifications
C; C08; C08G; C08G71/00; C08G71/04; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/48; C08G18/64; C08G18/6415; C08G18/6423; G; G02; G02B; G02B1/00; G02B1/04; G02B1/041; G02B1/043; C08G2210/00
Claims Analysis
Total Claims: 0
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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) | 1977-01-14 | 1977-07-16 | 1978-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-14 | 1981-07-16 | 1982-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-14 | 1985-07-16 | 1986-01-15 | $7700.00 | Window Closed / Lapsed |