Patent US3880818A successfully refreshed from Google Patents.
US3880818A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Physiologically compatible plastic contact lenses and a method for their production
Assignee: Individual
•
Filing: 1973-09-28
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Granted: 1975-04-29
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Expires: 1993-09-28
Abstract
Abstract There is disclosed a soft contact lens made by forming a lens of a hard acrylic acid-type polymer and then softening the formed lens by esterifying pendant carboxyl groups with alkyl groups, hydroxyalkyl groups or alkoxyalkyl groups which contain no more than eleven carbon atoms.
Inventors
- 👤 Mitchel Shen
- 👤 Robert B Mandell
- 👤 Lawrence Stark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:04
CPC Classifications
B; B29; B29D; B29D11/00; C; C08; C08F; C08F8/00; C08F8/14; C08F2810/00; C08F2810/20; Y; Y10; Y10S; Y10S526/00; Y10S526/936
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
19 words
A PHYSIOLOGICALLY COMPATIBLE CONTACT LENS COMPRISING A THREE-DIMENSIONAL ACRYLIC-TYPE POLYMER CONSISTING ESSENTIALLY OF MIXED ESTER MONOMERS OF THE FOROULA
Claim 2
Dependent Claim
19 words
A PHYSIOLOGICALLY COMPATIBLE CONTACT LENS COMPRISING A THREE-DIMENSIONAL ACRYLIC-TYPE POLYMER CONSISTING ESSENTIALLY OF MIXED ESTER MONOMERS OF THE FOROULA
Claim 3
Dependent Claim
13 words
The contact lens of claim 1 wherein Y has from 1-3 carbon atoms.
Claim 4
Dependent Claim
21 words
The contact lens of claim 1 wherein from 10 to 50 mole percent of the groups designated Z are alkoxyalkyl groups.
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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) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |