US3948871A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composition for hard type contact lens with wettable surface
Assignee: Butterfield George H and Son
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Filing: 1974-02-04
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Granted: 1976-04-06
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Expires: 1994-02-04
Abstract
Abstract A contact lens of the hard type, but exhibiting wettable surface characteristics, is produced from a polymer composition consisting essentially of about 90% by weight methyl methacrylate and about 10% by weight of neutralized hydroxy ethyl methacrylate.
Inventors
- 👤 George H. Butterfield, Jr.
- 👤 George H. Butterfield, Sr., deceased
- 👤 executor by David Gordon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:10
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/04; G02B1/041; G02B1/043
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
59 words
A contact lens composition consisting essentially of the polymerization product of from about 85% to about 95% by weight of methyl methacrylate and from about 5% to about 15% by weight of hydroxy ethyl methacrylate, the hydroxy ethyl methacrylate being substantially neutralized to a pH of between about 6.5 and about 8.5 prior to combining with the methyl methacrylate.
Claim 2
Dependent Claim
59 words
A contact lens composition consisting essentially of the polymerization product of from about 85% to about 95% by weight of methyl methacrylate and from about 5% to about 15% by weight of hydroxy ethyl methacrylate, the hydroxy ethyl methacrylate being substantially neutralized to a pH of between about 6.5 and about 8.5 prior to combining with the methyl methacrylate.
Claim 3
Dependent Claim
38 words
The contact lens composition of claim 1 wherein neutralization of said hydroxy ethyl methacrylate is achieved by reaction with at least one of the materials selected from the group consisting of alkali metal hydroxides and alkaline earth bases.
Claim 4
Dependent Claim
28 words
The contact lens composition of claim 1 wherein the polymerization product contains about 90% by weight of methyl methacrylate and about 10% by weight of hydroxy ethyl methacrylate.
Claim 5
Dependent Claim
33 words
The contact lens composition of claim 3 wherein the hydroxy ethyl methacrylate is neutralized with calcium hydroxide to a pH of between about 6.5 and 8.5 prior to combining with the methyl methacrylate.
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) | 1979-04-06 | 1979-10-06 | 1980-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-06 | 1983-10-06 | 1984-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-06 | 1987-10-06 | 1988-04-06 | $7700.00 | Window Closed / Lapsed |