US3607793A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for forming porous structures
Assignee: Hercules LLC
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Filing: 1968-02-23
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Granted: 1971-09-21
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Expires: 1988-02-23
Abstract
Abstract An improved method is taught for preparing porous structures from olefin polymers by heating a dispersion of such polymers in a hydrocarbon liquid to a temperature above the solution temperature, cooling slowly to form a gel and extracting the hydrocarbon liquid. The improvement resides in employing, as a starting material a polymer in the form of particles no larger than about 0.5 Mu .
Inventors
- 👤 Bert H Mahlman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:13
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; C08J2201/00; C08J2201/04; C08J2201/052; Y; Y10; Y10S; Y10S526/00; Y10S526/904; Y10S526/908; Y10S526/909
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
23 words
Process according to claim 1 wherein the high boiling oRganic liquid is a hydrocarbon which is a liquid at above about 100* C.
Claim 2
Dependent Claim
30 words
Process according to claim 1 where the organic diluent is removed by extraction with an organic solvent which has essentially no solvent power for crystalline polypropylene at the extraction temperatures.
Claim 3
Dependent Claim
21 words
Process according to claim 1 wherein the slurry is formed into the desired shape prior to heating to effect dissolution thereof.
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) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |