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Patent US3565259A successfully refreshed from Google Patents.
US3565259A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of porous membranes
Assignee: Kalle GmbH and Co KG
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Filing: 1969-01-24
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Granted: 1971-02-23
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Expires: 1989-01-24
Abstract
Abstract This invention relates to an improvement in a process for the manufacture of porous membranes, and to the membranes so produced. In the process, porous membranes having an oriented capillary structure are produced by diffusion of multivalent cations into polyelectrolyte sols, and the improvement comprises dehydrating, on porous supports, layers of the capillary gel obtained, and then drying them.
Inventors
- 👤 Otto Meyer-Berge
- 👤 Ursula Heyse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:07
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0095; B01D69/00; B01D69/14; B01D69/141; B01D69/148
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
17 words
A process according to claim 1 in which pressure is applied to the gel layer during dehydration.
Claim 2
Dependent Claim
20 words
A process according to claim 1 in which dehydration is effected on a rotating cylindrical support of highly dehydrating material.
Claim 3
Dependent Claim
23 words
A process according to claim 1 in which, after dehydration, the membrane is treated with at least one water-miscible solvent and then dried.
Claim 4
Dependent Claim
19 words
A process according to claim 1 in which the membranes are stabilized by the introduction of a polymerizable material.
Claim 5
Dependent Claim
16 words
A process according to claim 5 in which the pOlymerizable material forms a polyurethane upon polymerization.
Claim 6
Dependent Claim
31 words
A process according to claim 1 in which, before drying, the dehydrated membrane is impregnated with a compound selected from the group consisting of a glycerol, a glycol, or a polyglycol.
Claim 7
Dependent Claim
28 words
A process according to claim 1 in which the dehydrated membrane is impregnated with an aqueous solution or dispersion of a synthetic resin, and the resin is cured.
Claim 8
Dependent Claim
20 words
A process according to claim 1 in which drying is effected by clamping the membrane to a smooth, curved surface.
Claim 9
Dependent Claim
16 words
A process according to claim 1 in which suction is applied to the supports during dehydration.
Claim 10
Dependent Claim
27 words
A porous membrane produced by the process according to claim 1 and having an oriented capillary structure and a thickness between about 50 to 400 Mu .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-22 | 1974-08-24 | 1975-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-22 | 1978-08-24 | 1979-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-22 | 1982-08-24 | 1983-02-23 | $7700.00 | Window Closed / Lapsed |