US4231905A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymethylmethacrylate cellulosic copolymer lens material
Assignee: Sunsoft Corp
•
Filing: 1979-06-25
•
Granted: 1980-11-04
•
Expires: 1999-06-25
Abstract
Abstract A gas permeable dimensionally stable contact lens material which is a transparent, optically clear methylmethacrylate cellulosic copolymer.
Inventors
- 👤 Charles W. Neefe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:18
CPC Classifications
G; G02; G02C; G02C7/00; G02C7/02; G02C7/04; C; C08; C08F; C08F251/00; C08F251/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
77 words
A gas permeable, dimensionally stable, optically clear contact lens material made by the steps of dissolving in monomeric methylmethacrylate 2% to 80% by weight of the methylmethacrylate of a soluble solid cellulose ether or ester polymer material which does not prevent the polymerization of the monomeric methylmethacrylate, polymerizing the methylmethacrylate cellulosic solution to form a ridged transparent contact lens material which has a faster recovery from being flexed than a polymethylmethacrylate or a cellulosic contact lens material.
Claim 2
Dependent Claim
77 words
A gas permeable, dimensionally stable, optically clear contact lens material made by the steps of dissolving in monomeric methylmethacrylate 2% to 80% by weight of the methylmethacrylate of a soluble solid cellulose ether or ester polymer material which does not prevent the polymerization of the monomeric methylmethacrylate, polymerizing the methylmethacrylate cellulosic solution to form a ridged transparent contact lens material which has a faster recovery from being flexed than a polymethylmethacrylate or a cellulosic contact lens material.
Claim 3
Dependent Claim
14 words
A material as in claim 1 wherein the soluble cellulosic material is Ethyl Cellulose.
Claim 4
Dependent Claim
14 words
A material as in claim 1 wherein the soluble cellulosic material is Cellulose Acetate.
Claim 5
Dependent Claim
15 words
A material as in Claim 1 wherein the soluble cellulosic material is Cellulose Acetate Propionate.
Claim 6
Dependent Claim
15 words
A material as in claim 1 wherein the soluble cellulosic material is Cellulose Acetate Butyrate.
Claim 7
Dependent Claim
14 words
A material as in cliam 1 wherein the soluble cellulosic material is Cellulose Nitrate.
Claim 8
Dependent Claim
14 words
A material as in cliam 1 wherein the soluble cellulosic material is Cellulose Nitrate.
References Cited (Backward Citations)
US3900250A
Cited
JPS5130749A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-04 | 1984-05-05 | 1984-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-04 | 1988-05-05 | 1988-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-04 | 1992-05-05 | 1992-11-04 | $7700.00 | Window Closed / Lapsed |