US3810814A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Asymmetric polymer membranes of reduced elastic modulus
Assignee: General Electric Co
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Filing: 1972-12-18
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Granted: 1974-05-14
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Expires: 1992-12-18
Abstract
Abstract AN IMPROVED METHOD IS DISCLOSED FOR THE MANUFACTURE OF DRY ASYMMETRIC MEMBRANES, WHICH COMPRISES A POROUS LAYER OF INTERCONNECTED CRYSTALS OF POLYMER MATERIAL AND, INTEGRAL THEREWITH, A DENSE LESS CRYSTALLINE SURFACE LAYER FORMING ONE FACE OF THE MEMBRANE. FINELY DIVIDED GRAFTED ELASTOMERIC MATERIAL COMPATIBLE WITH THE SYSTEM IS INCLUDED IN THE CASTING SOLUTION AND THE COMPLEED MEMBRANE EMBODIES THE TINY ELASTOMERIC PARTICLES APPARENTLY UNIFORMLY DISTRIBUTED THERETHROUGH. THE USE OF ELASTOMERIC PARTICLES HAVING POLYSTYRENE CHAINS GRAFTED THERETO IS SPECIFICALLY DESCRIBED AS BEING ADDED FOR PREPARING ASYMMETRIC POLYXYLYLENE OXIDE MEMBRANES.
Inventors
- 👤 C Herrick
- 👤 A Shultz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:36
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/52; B01D71/522; B01D71/5223; B01D69/00; B01D69/02; B01D69/06; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249961; Y10T428/249978; Y10T428/249987; Y10T428/249988; Y10T428/249989; Y10T428/25; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 0
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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) | 1977-05-13 | 1977-11-12 | 1978-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-13 | 1981-11-12 | 1982-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-13 | 1985-11-12 | 1986-05-14 | $7700.00 | Window Closed / Lapsed |