Patent US1856505A successfully refreshed from Google Patents.
US2894289A
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Method of making permeselective membranes
Assignee: Dow Chemical Co
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Filing: 1956-03-01
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Granted: 1959-07-14
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Expires: 1976-03-01
Abstract
No abstract record available.
Inventors
- 👤 Harper Billy Gene
- 👤 Jr John Henry Brown
- 👤 Moore John Clarke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:32
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0002; B01D67/0023; B01D67/003; Y; Y10; Y10S; Y10S424/00; Y10S424/07; Y10S521/00; Y10S521/919
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
103 words
A PROCESS FOR THE PREPARATION OF PERMESELECTIVE MEMBRANES WHICH COMPRISES DISSOLVING AT LEAST TWO DIFFERENT MATERIALS, AT LEAST ONE OF SAID MATERIALS BEING A FILMFORMING MATERIAL, IN A COMMON SOLVENT TO PROVIDE A FILMFORMING SOLUTION THEREOF; DEPOSITING SAID SOLUTION IN A FILMIFORM LAYER; REMOVING SAID COMMON SOLVENT FROM THE FILMIFORM LAYER OF SAID FILM-FORMING SOLUTION TO FORM A CONTINUOUS PHASE FILM OF SAID MATERIALS AND EXTRACTING AT LEAST ONE OF THE MATERIALS FROM THE FILM WITH A SELECTIVE SOLVENT FOR LESS THAN ALL THE MATERIALS IN THE FILM, SAID SELECTIVE SOLVENT BEING SUBSTANTIALLY NON-DISSOLVENT OF THE FILM-FORMING MATERIALS CONSTITUTING SAID CONTINUOUS PHASE FILM.
Claim 2
Dependent Claim
103 words
A PROCESS FOR THE PREPARATION OF PERMESELECTIVE MEMBRANES WHICH COMPRISES DISSOLVING AT LEAST TWO DIFFERENT MATERIALS, AT LEAST ONE OF SAID MATERIALS BEING A FILMFORMING MATERIAL, IN A COMMON SOLVENT TO PROVIDE A FILMFORMING SOLUTION THEREOF; DEPOSITING SAID SOLUTION IN A FILMIFORM LAYER; REMOVING SAID COMMON SOLVENT FROM THE FILMIFORM LAYER OF SAID FILM-FORMING SOLUTION TO FORM A CONTINUOUS PHASE FILM OF SAID MATERIALS AND EXTRACTING AT LEAST ONE OF THE MATERIALS FROM THE FILM WITH A SELECTIVE SOLVENT FOR LESS THAN ALL THE MATERIALS IN THE FILM, SAID SELECTIVE SOLVENT BEING SUBSTANTIALLY NON-DISSOLVENT OF THE FILM-FORMING MATERIALS CONSTITUTING SAID CONTINUOUS PHASE FILM.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-07-13 | 1963-01-12 | 1963-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-07-13 | 1967-01-12 | 1967-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-07-13 | 1971-01-12 | 1971-07-14 | $7700.00 | Window Closed / Lapsed |