US4277572A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Galvanic cell separator
Assignee: Furukawa Electric Co Ltd
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Filing: 1979-08-13
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Granted: 1981-07-07
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Expires: 1999-08-13
Abstract
Abstract A galvanic cell separator composed of polyvinyl alcohol having a crystallinity of 0.4 or more to be used with a galvanic cell containing alkaline electrolyte, and a method of manufacturing the same.
Inventors
- 👤 Kunihiko Fujiwara
- 👤 Kazuya Osawa
- 👤 Yoshiteru Takeda
- 👤 Toshiaki Yabumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:29
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/24; H01M10/26; H01M50/00; H01M50/40; H01M50/489; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
47 words
A method for manufacturing a galvanic cell separator which comprises the steps of (a) heating a polyvinyl alcohol film until the polyvinyl alcohol has a crystallinity of at least 0.4 and subsequently (b) contacting the surface of said polyvinyl alcohol film with an aqueous solution of permanganate.
Claim 2
Independent Claim
47 words
A method for manufacturing a galvanic cell separator which comprises the steps of (a) heating a polyvinyl alcohol film until the polyvinyl alcohol has a crystallinity of at least 0.4 and subsequently (b) contacting the surface of said polyvinyl alcohol film with an aqueous solution of permanganate.
Claim 3
Dependent Claim
29 words
The method as defined in claim 1 wherein in step (a) the polyvinyl alcohol film is treated until the polyvinyl alcohol has a crystallinity ranging from 0.5 to 0.6.
Claim 4
Dependent Claim
19 words
The method as defined in claim 1 wherein in step (a) the heating is carried in a non-oxidizing atmosphere.
Claim 5
Dependent Claim
25 words
The method as defined in claim 1 wherein in step (a) the heating is carried out at a temperature of from 130° to 240° C.
Claim 6
Dependent Claim
31 words
The method as defined in claim 1 wherein in step (b) the concentration of permanganate in the aqueous solution of permanganate ranges from 0.001 gram equivalent per liter to saturation concentration.
References Cited (Backward Citations)
US3518242A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-07-06 | 1985-01-05 | 1985-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-06 | 1989-01-05 | 1989-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-06 | 1993-01-05 | 1993-07-07 | $7700.00 | Window Closed / Lapsed |