Patent US2831623A successfully refreshed from Google Patents.
US3069728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of ion selective permeable membrane
Assignee: ChampionX LLC
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Filing: 1957-07-22
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Granted: 1962-12-25
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Expires: 1977-07-22
Abstract
No abstract record available.
Inventors
- 👤 Mindick Morris
- 👤 Harold I Patzelt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:14
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2206; C08J5/2218; C08J5/2231; C08J2329/00; C08J2329/14
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
80 words
THE METHOD OF PRODUCING AN ION SELECTIVE PERMEABLE MEMBRANE WHICH COMPRISES CASTING A SOLVENT SOLUTION OF A THERMOPLASTIC FILM-FORMING POLYMER CONTAINING NO ION EXCHANGE GROUPS ON A METAL SURFACE IN A THIN LAYER, REMOVING SOLVENT FROM SAID LAYER TO PRODUCE A FILM OF SAID POLYMER, CASTING A HOMOGENEOUS MOLECULAR DISPERSION IN A SOLVENT OF 40% TO 90% BY WEIGHT OF A WATER INSOLUBLE ACID AND ALKALI RESISTANT THERMOPLASTIC FILM-FORMING POLYMER AND 10% TO 60% BY WEIGHT OF A LINEAR POLYELECTROLYTE
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) | 1965-12-24 | 1966-06-25 | 1966-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-12-24 | 1970-06-25 | 1970-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-12-24 | 1974-06-25 | 1974-12-25 | $7700.00 | Window Closed / Lapsed |