US3989656A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dextran-alkyl methacrylate graft composition for contact lens and corneas
Assignee: Karme Co Ltd
•
Filing: 1975-01-06
•
Granted: 1976-11-02
•
Expires: 1995-01-06
Abstract
Abstract A dextran-alkyl methacrylate graft composition consisting essentially of a dextran unit of the formula (1) ##SPC1## Wherein n is an integer of 5 to 150,000, and a poly(alkyl methacrylate) unit of the formula (2) ##EQU1## WHEREIN M IS AN INTEGER OF 50 TO 200,000 AND R is an alkyl group having 1 to 4 carbon atoms, And a process for producing the same.
Inventors
- 👤 Sadayoshi Kamiya
- 👤 Tokihiko Yamamoto
- 👤 Yasuhiko Onishi
- 👤 Shusaburo Hokkoku
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 01:04
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/54; C02F1/5263; C08; C08F; C08F251/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
113 words
A contact lens consisting essentially of a graft copolymer composition which consists essentially of a dextran unit of the formula ##SPC3## wherein n is an integer of 5 to 150,000 and a poly(alkyl methacrylate) unit of the formula ##EQU3## wherein m is an integer of 50 to 20,000, R is an alkyl group having 1 to 4 carbons, and the ratio of formula (2) unit to formula (1) unit is 50 to 3000% by weight, with the proviso that the graft composition is water- and acetone- insoluble at 25° C., the composition having been heated to from about 170° to 230° C. under a pressure of about 50 to 150 kg/cm 2 .
Claim 2
Dependent Claim
113 words
A contact lens consisting essentially of a graft copolymer composition which consists essentially of a dextran unit of the formula ##SPC3## wherein n is an integer of 5 to 150,000 and a poly(alkyl methacrylate) unit of the formula ##EQU3## wherein m is an integer of 50 to 20,000, R is an alkyl group having 1 to 4 carbons, and the ratio of formula (2) unit to formula (1) unit is 50 to 3000% by weight, with the proviso that the graft composition is water- and acetone- insoluble at 25° C., the composition having been heated to from about 170° to 230° C. under a pressure of about 50 to 150 kg/cm 2 .
Claim 3
Dependent Claim
24 words
The contact lens molded article of claim 1 wherein the temperature is about 180° C. and the pressure is about 100 Kg/cm 2 .
Claim 4
Dependent Claim
32 words
The contact lens molded article of claim 1 wherein the temperature is maintained for about six minutes, after which the pressure is applied for about one minute, while still maintaining the temperature.
Claim 5
Dependent Claim
17 words
The contact lens molded article of claim 1 wherein the graft composition is a dextran/methyl methacrylate copolymer.
Claim 6
Dependent Claim
89 words
An artificial cornea consisting essentially of a graft copolymer composition which consists essentially of a dextran unit of the formula ##SPC4## wherein n is an integer of 5 to 150,000 and a poly(alkyl methacrylate) unit of the formula ##STR2## wherein m is an integer of 50 to 20,000, R is an alkyl group having 1 to 4 carbons, and the ratio of formula (2) unit to formula (1) unit is 50 to 3000% by weight, with the proviso that the graft composition is water- and acetoneinsoluble at 25° C.
Claim 7
Dependent Claim
89 words
An artificial cornea consisting essentially of a graft copolymer composition which consists essentially of a dextran unit of the formula ##SPC4## wherein n is an integer of 5 to 150,000 and a poly(alkyl methacrylate) unit of the formula ##STR2## wherein m is an integer of 50 to 20,000, R is an alkyl group having 1 to 4 carbons, and the ratio of formula (2) unit to formula (1) unit is 50 to 3000% by weight, with the proviso that the graft composition is water- and acetoneinsoluble at 25° C.
References Cited (Backward Citations)
US3081143A
Cited
US3635857A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-11-02 | 1980-05-03 | 1980-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-02 | 1984-05-03 | 1984-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-02 | 1988-05-03 | 1988-11-02 | $7700.00 | Window Closed / Lapsed |