Patent US4090010A successfully refreshed from Google Patents.
US4090010A
Expired / Lapsed
US
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Water vapor permeable microporous sheet materials and their method of manufacture
Assignee: Porvair PLC
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Filing: 1973-06-11
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Granted: 1978-05-16
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Expires: 1993-06-11
Abstract
Abstract There is disclosed a process in which both non-solvent e.g., water and filler particles e.g., microscopic sodium chloride are added in certain proportions to a polymer solution e.g., polyurethane in dimethylformamide preferably at elevated temperature and coagulated by immersion in non-solvent. This results in a more rapid coagulation time than when solvent or filler alone are used and also results in a microporous product of improved properties and novel pore structure.
Inventors
- 👤 Eric Albert Warwicker
- 👤 David Price
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:46
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; D; D06; D06N; D06N3/00; D06N3/0043; D06N3/0052; C08J2375/00; Y; Y10; Y10S; Y10S428/00; Y10S428/904; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/249979
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2700694A
Cited
US2783894A
Cited
US3100721A
Cited
US3190766A
Cited
US3222208A
Cited
US3450650A
Cited
US3524753A
Cited
US3496000A
Cited
GB1217341A
Cited
GB1217342A
Cited
US3729538A
Cited
US3791997A
Cited
US3536796A
Cited
US3687715A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-15 | 1981-11-14 | 1982-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-15 | 1985-11-14 | 1986-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-15 | 1989-11-14 | 1990-05-16 | $7700.00 | Window Closed / Lapsed |