US3663470A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing polyvinyl acetal porous articles and the shaped porous articles made therefrom
Assignee: Kanegafuchi Spinning Co Ltd
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Filing: 1970-05-28
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Granted: 1972-05-16
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Expires: 1990-05-28
Abstract
Abstract POLYVINYL ACETAL POROUS ARTICLES HAVING USEFUL AND EXCELLENT PROPERTIES AS COSMETIC SPONGE PUFF, SPONGE HANDKERCHIEF, FILTERING MEDIA AND THE LIKE ARE PRODUCED BY REACTING AN AQUEOUS SOLUTION OF POLYVINYL ALCOHOL WITH AN ALDEHYDE AND AN ACID CATALYST IN THE PRESENCE OF AT LEAST ONE WATER SOLUBLE INORGANIC SALT, WITH OR WITHOUT A PORE FORMING AGENT.
Inventors
- 👤 Hiroshi Nishimura
- 👤 Shizuo Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:20
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; B; B32; B32B; B32B27/00; C08F; C08F8/00; C08F8/48; C08J2329/00; C08J2329/14
Claims Analysis
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |