US4135942A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Keratin membrane
Assignee: National Institute of Advanced Industrial Science and Technology
•
Filing: 1977-07-11
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Granted: 1979-01-23
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Expires: 1997-07-11
Abstract
Abstract Keratin membrane containing aliphatic polyvalent alcohol having excellent toughness and flexibility and showing excellent ion-permeability.
Inventors
- 👤 Masayoshi Kikkawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 00:58
CPC Classifications
C; C08; C08L; C08L89/00; C08L89/04; C08L89/06; B; B01; B01D; B01D71/00; B01D71/06; B01D71/74
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
23 words
Keratin membrane containing aliphatic polyvalent alcohol in an amount of from 1 to 15 gm. based on one (1) gram of dry keratin.
Claim 2
Dependent Claim
23 words
Keratin membrane containing aliphatic polyvalent alcohol in an amount of from 1 to 15 gm. based on one (1) gram of dry keratin.
Claim 3
Dependent Claim
15 words
Keratin membrane according to claim 1, in which said aliphatic polyvalent alcohol is alkylene glycol.
Claim 4
Dependent Claim
15 words
Keratin membrane according to claim 1, in which said aliphatic polyvalent alcohol is polyalkylene glycol.
Claim 5
Dependent Claim
14 words
Keratin membrane according to claim 1, in which said aliphatic polyvalent alcohol is glycerol.
Claim 6
Dependent Claim
15 words
Keratin membrane according to claim 1, in which said membrane is subjected to water washing.
References Cited (Backward Citations)
US3642498A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-01-22 | 1982-07-24 | 1983-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-22 | 1986-07-24 | 1987-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-22 | 1990-07-24 | 1991-01-23 | $7700.00 | Window Closed / Lapsed |