US3729538A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for preparing vapour permeable flexible sheet materials
Assignee: Porous Plastics Ltd
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Filing: 1970-10-02
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Granted: 1973-04-24
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Expires: 1990-10-02
Abstract
Abstract FOR A METHOD OF MAKING WATER VAPOUR PERRMEABLE FLEXIBLE SHEET MATERIALS WHICH FIND USES AS REPLACEMENTS FOR LEATHER IN WHICH THE MATERIAL IS FORMED FROM A LAYER OF A MIXTURE OF POWDERED REMOVABLE FILLER DISPERSED THROUGH POLYMER SOLUTION WHICH ADHERES TO A TEMPORARY BACKER AND IS COAGULATED AND THE FILLER LEACHED OUT BY SUITABLE LIQUID TREATMENT THE ADVANTAGES OF CERTAIN RATIOS OF POLYMER TO SOLVENT AND CERTAIN RELATIVELY HIGH RATIOS BELOW 3:1 OF FILLER TO POLYMER IN THE MIXTURE ARE SET OUT.
Inventors
- 👤 V Cunningham
- 👤 D Boutle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:51
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/26; C08J2201/00; C08J2201/04; C08J2201/054; C08J2201/0542; C08J2201/0544; Y; Y10; Y10S; Y10S264/00; Y10S264/77; Y10S428/00; Y10S428/904
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-23 | 1976-10-23 | 1977-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-23 | 1980-10-23 | 1981-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-23 | 1984-10-23 | 1985-04-24 | $7700.00 | Window Closed / Lapsed |