US3567809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of varying the pore diameters of fine pores in cellulose acetate film
Assignee: Fujifilm Holdings Corp
•
Filing: 1967-10-06
•
Granted: 1971-03-02
•
Expires: 1987-10-06
Abstract
Abstract A METHOD FOR VARYING THE PORE DIAMETER OF FINE PORES IN A CELLULOSE ACETATE FILM. THE FILM IS MADE BY CASTING A SOLUTION CONTAINING TOW CELLULOSE DERIVATIVES, EACH HAVING AN ACETATE LINKAGE, A PLASTICIZER AND WATER, AND DRYING IN TWO STAGES, FIRST AT FROM 15* TO 45*C., AND SECONDLY AT FROM 80* TO 120*C. CONTROL OF PORE SIZE IS EFFECTED BY VARYING TYPE AND AMOUNT OF PLASTICIZER WHICH IS A SINGLE OR OR MIXTURE OF GLYCERINE DERIVATIVE, GLYCOL DERIVATIVE AND ORGANIC PHOSPHATE PLASTICIZERS.
Inventors
- 👤 Wataru Ueno
- 👤 Hideo Kawaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:35
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/08; B01D71/12; B01D71/14; B01D71/18; B01D67/00; B01D67/0002; B01D67/0009; B01D67/0011; B01D71/16; C; C08; C08L; C08L1/00; C08L1/08; C08L1/10; C08L1/12; B01D2323/00; B01D2323/15; B01D2323/20
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |