Patent US3658735A successfully refreshed from Google Patents.
US3658735A
Expired / Lapsed
US
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Solution of a graft copolymer of cellulose
Assignee: Tomoegawa Paper Manufacturing Co Ltd
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Filing: 1969-06-11
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Granted: 1972-04-25
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Expires: 1989-06-11
Abstract
Abstract THE PRESENT INVENTION IS DIRECTED TO A SOLUTION OF A GRAFT COPOLYMER OF CELLULOSE COMPRISING EITHER (1) A POLAR ORGANIC SOLVENT OR A MIXED SOLVENT CONTAINING A POLAR ORGANIC SOLVENT, SULFUROUS ANHYDRIDE, AN AMINE AND A GRAFT COPOLYMER OF CELLULOSE OR (2) LIQUID SULFUROUS ANHYDRIDE, AN AMINE AND A GRAFT COPOLYMER OF CELLULOSE. SUCH SOLUTION IS CAPABLE OF DISSOLVING CELLULOSE AND VARIOUS KINDS OF POLYMERS.
Inventors
- 👤 Osakazu Nakao
- 👤 Saburo Nakagawa
- 👤 Juichi Hirose
- 👤 Shigeyuki Yamazaki
- 👤 Takashi Amano
- 👤 Toshio Nakamura
- 👤 Hiroyuki Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:46
CPC Classifications
D; D01; D01F; D01F2/00; D01F2/24; D01F2/28; C; C08; C08B; C08B1/00; C08B1/003; C08F; C08F251/00; C08F251/02
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) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |