US3718532A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microporous sheets and processes
Assignee: DVSG Holding GmbH
•
Filing: 1970-04-08
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Granted: 1973-02-27
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Expires: 1990-04-08
Abstract
Abstract Microporous sheet having pores of controlled size and arrangement and process of making in which temperature and composition are coordinated to control growth of size of nonsolvent liquid droplets constituting the discontinuous phase of an emulsion of which the continuous phase is a heated liquid polymeric reactive material which sets through reaction to solid condition and in which process the droplets are removed after setting of the reactive material to leave spaces constituting openings or pores in the solidified material. Pores of smaller size relative to the size of pores in the body of the sheet are provided in the sheet by control of the temperature of a casting surface.
Inventors
- 👤 S Hayes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:14
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; C08J9/283; C08J2201/00; C08J2201/04; C08J2201/05; C08J2201/0502; Y; Y10; Y10S; Y10S264/00; Y10S264/13; Y10S264/62; Y10S428/00; Y10S428/904; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249961; Y10T428/249978; Y10T428/249979
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
41 words
Microporous sheet material as defined in claim 1 in which said finer cells have an average diameter of the order of about 1 to about 20 microns and said coarser cells have an average diameter of at least about 30 microns.
Claim 2
Dependent Claim
24 words
Microporous sheet material as defined in claim 2 in which said zone of finer cells is of the order of 0.001 inch in thickness.
Claim 3
Dependent Claim
22 words
Microporous sheet material as defined in claim 2 in which said zone of finer cells is over about 0.002 inch in thickness.
References Cited (Backward Citations)
US3190842A
Cited
US3413184A
Cited
US3551364A
Cited
US3496001A
Cited
US3520767A
Cited
US3539388A
Cited
US3524791A
Cited
US3565982A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-27 | 1976-08-28 | 1977-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-27 | 1980-08-28 | 1981-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-27 | 1984-08-28 | 1985-02-27 | $7700.00 | Window Closed / Lapsed |