Patent US2926104A successfully refreshed from Google Patents.
US2926104A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making microporous filter film
Assignee: Individual
•
Filing: 1955-06-27
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Granted: 1960-02-23
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Expires: 1975-06-27
Abstract
No abstract record available.
Inventors
- 👤 Goetz Alexander
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:41
CPC Classifications
B; B29; B29C; B29C67/00; B29C67/20; Y; Y10; Y10S; Y10S264/00; Y10S264/61; Y10S55/00; Y10S55/05
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
160 words
THE METHOD OF MAKING A UNIFORM MICROPOROUS FILTER FROM A SOLUTION OF CELLULOSE ESTER IN A WATER-MISCIBLE SOLVENT THEREFOR COMPRISING THE STEPS OF FORMING A LIQUID LAYER OF A CELLULOSE ESTER-WATER MISSIBLE SOLVENT SOLUTION ON A MOVING SURFACE, MOVING SAID SURFACE WITH THE LIQUID LAYER THEREON THROUGH A GELATION ZONE, CONTACTING THE LAYER IN SAID GELATION ZONE WITH A COUNTERFLOW OF AIR AND WATER VAPOR TO EVAPORATE SAID SOLVENT AND ABSORB WATER VAPOR INTO SAID CELLULOSE ESTER LAYER THEREBY PRECIPITATING SAID CELLULOSE ESTER IN THE FORM OF A GEL AND COVERTING SAID GEL INTO A MICROPOROUS, UNIFORM FILM ON SAID SURFACE, THEREAFTER MOVING SAID SURFACE WITH SAID MICROPOROUS FILM THEREON INTO A SECOND ZONE, DRYING THE FILM IN SAID SECOND ZONE BY HEATING SAME WITH A CURRENT OF DRY, HOT GAS WHICH IS CHEMICALLY INERT TO SAID FILM, TO A TEMPERATURE WHEREIN SAID FILM BECOMES THEREMOPLASTIC, AND CONTINUING THE HEATING OF SAID FILM UNTIL THE MICROPOROUS STRUCTURE THEREOF IS STABILIZED.
Claim 2
Independent Claim
160 words
THE METHOD OF MAKING A UNIFORM MICROPOROUS FILTER FROM A SOLUTION OF CELLULOSE ESTER IN A WATER-MISCIBLE SOLVENT THEREFOR COMPRISING THE STEPS OF FORMING A LIQUID LAYER OF A CELLULOSE ESTER-WATER MISSIBLE SOLVENT SOLUTION ON A MOVING SURFACE, MOVING SAID SURFACE WITH THE LIQUID LAYER THEREON THROUGH A GELATION ZONE, CONTACTING THE LAYER IN SAID GELATION ZONE WITH A COUNTERFLOW OF AIR AND WATER VAPOR TO EVAPORATE SAID SOLVENT AND ABSORB WATER VAPOR INTO SAID CELLULOSE ESTER LAYER THEREBY PRECIPITATING SAID CELLULOSE ESTER IN THE FORM OF A GEL AND COVERTING SAID GEL INTO A MICROPOROUS, UNIFORM FILM ON SAID SURFACE, THEREAFTER MOVING SAID SURFACE WITH SAID MICROPOROUS FILM THEREON INTO A SECOND ZONE, DRYING THE FILM IN SAID SECOND ZONE BY HEATING SAME WITH A CURRENT OF DRY, HOT GAS WHICH IS CHEMICALLY INERT TO SAID FILM, TO A TEMPERATURE WHEREIN SAID FILM BECOMES THEREMOPLASTIC, AND CONTINUING THE HEATING OF SAID FILM UNTIL THE MICROPOROUS STRUCTURE THEREOF IS STABILIZED.
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) | 1963-02-22 | 1963-08-24 | 1964-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-02-22 | 1967-08-24 | 1968-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-02-22 | 1971-08-24 | 1972-02-23 | $7700.00 | Window Closed / Lapsed |