Patent US3928700A successfully refreshed from Google Patents.
US3928700A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing thin cellulose nitrate film
Assignee: United States Department of Energy
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Filing: 1974-05-30
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Granted: 1975-12-23
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Expires: 1994-05-30
Abstract
Abstract An improved method for forming a thin nitrocellulose film of reproducible thickness is described. The film is a cellulose nitrate film, 10 to 20 microns in thickness, cast from a solution of cellulose nitrate in tetrahydrofuran, said solution containing from 7 to 15 percent, by weight, of dioctyl phthalate, said cellulose nitrate having a nitrogen content of from 10 to 13 percent.
Inventors
- 👤 Sebastian B Lupica
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:04
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/02; C08J3/09; C08J3/091; C08J3/095; C08K; C08K5/00; C08K5/04; C08K5/10; C08K5/12; C08J2301/00; C08J2301/08; C08J2301/16; C08J2301/18; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/266
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
78 words
A CELLULOSE NITRATE FILM 100O0 02000 MICRONS IN THICKNESS, UNIFORMLY THICK WITHIN $0.5 MICRON, SAID FILM FORMED BY A METHOD WHICH COMPRISES FORMING A SOLUTION OF CELLULOSE NITRATE CONTAINING 10-13 PERCENT BY WEIGHT NITROGEN IN TETRAHYDROFURAN, SAID SOLUTION CONTAINING 7-15 PERCENT BY WEIGHT DIOCTYL PHTHALATE BASED ON THE WEIGHT OF CELLULOSE NITRATE, EVAPORATING SAID SOLUTION ON A FLAT SURFACE, DRYING THE RESULTANT FILM, REMOVING SAID FILM FROM SAID SURFACE. AND THEN ANNEALING SAID FILM TO EMOVE RESIDUAL SOLVENT.
Claim 2
Dependent Claim
78 words
A CELLULOSE NITRATE FILM 100O0 02000 MICRONS IN THICKNESS, UNIFORMLY THICK WITHIN $0.5 MICRON, SAID FILM FORMED BY A METHOD WHICH COMPRISES FORMING A SOLUTION OF CELLULOSE NITRATE CONTAINING 10-13 PERCENT BY WEIGHT NITROGEN IN TETRAHYDROFURAN, SAID SOLUTION CONTAINING 7-15 PERCENT BY WEIGHT DIOCTYL PHTHALATE BASED ON THE WEIGHT OF CELLULOSE NITRATE, EVAPORATING SAID SOLUTION ON A FLAT SURFACE, DRYING THE RESULTANT FILM, REMOVING SAID FILM FROM SAID SURFACE. AND THEN ANNEALING SAID FILM TO EMOVE RESIDUAL SOLVENT.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |