US4720343A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Macroporous asymmetrical hydrophilic membrane made of a synthetic polymer
Assignee: Hoechst AG
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Filing: 1982-12-10
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Granted: 1988-01-19
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Expires: 2002-12-10
Abstract
Abstract Disclosed are asymmetrical macroporous membranes based on a synthetic polymer comprising a polymeric mixture of 5 to 70% by weight polyvinylpyrrolidone having a molecular weight ≧100,000 Dalton and 95 to 30% by weight of a polymer selected from a group consisting of a polysulfone, a polyether sulfone and an aromatic or araliphatic polyamide, each of the percentages by weight being relative to the total weight of the polymeric mixture. The membrane has a water absorbency of at least 11% by weight of water, relative to its total weight, at 100% relative humidity and 25° C. Also disclosed is a process for preparation of the membranes.
Inventors
- 👤 Axel Walch
- 👤 Juergen Wildhardt
- 👤 Dieter Beissel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 21:28
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/44; B01D71/441; B01D69/00; B01D69/02; B01D71/56; B01D71/66; B01D71/68; C; C08; C08L; C08L39/00; C08L39/04; C08L39/06; B01D2323/00; B01D2323/12; B01D2325/00; B01D2325/02; B01D2325/022; B01D2325/34; B01D2325/36
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
87 words
An asymmetrical macroporous membrane, comprising: a polymeric mixture comprised of from about 5-70% by weight of polyvinylpyrrolidone having a molecular weight ≧100,000 Dalton and from about 95 to 30% by weight of a polymer selected from polysulfone, polyether sulfone, or an aromatic or araliphatic polyamide, the percentages by weight being relative to the total weight of the polymeric mixture, and the membrane having a water absorbency of at least about 11% by weight of water, relative to its total weight, at 100% relative humidity and 25° C.
Claim 2
Dependent Claim
87 words
An asymmetrical macroporous membrane, comprising: a polymeric mixture comprised of from about 5-70% by weight of polyvinylpyrrolidone having a molecular weight ≧100,000 Dalton and from about 95 to 30% by weight of a polymer selected from polysulfone, polyether sulfone, or an aromatic or araliphatic polyamide, the percentages by weight being relative to the total weight of the polymeric mixture, and the membrane having a water absorbency of at least about 11% by weight of water, relative to its total weight, at 100% relative humidity and 25° C.
Claim 3
Dependent Claim
29 words
A membrane as claimed in claim 1, wherein the polymeric mixture is comprised of from about 5-70% by weight of polyvinylpyrrolidone and from about 95-30% by weight of polysulfone.
Claim 4
Dependent Claim
30 words
A membrane as claimed in claim 1, wherein the polymeric mixture is comprised of from about 5-70% by weight of polyvinylpyrrolidone and from about 95-30% by weight of polyether sulfone.
Claim 5
Dependent Claim
33 words
A membrane as claimed in claim 1, wherein the polymeric mixture is comprised of from about 5-70% by weight of polyvinylpyrrolidone and from about 95-30% by weight of an aromatic or araliphatic polyamide.
Claim 6
Dependent Claim
24 words
A membrane as claimed in claim 1, wherein the molecules of the polymers forming the membrane are linked to one another by chemical bonding.
Claim 7
Dependent Claim
24 words
A membrane as claimed in claim 1, further comprising at least one permselective or reactive layer generated or bonded on or in the membrane.
References Cited (Backward Citations)
US3615024A
Cited
US4026977A
Cited
US3775308A
Cited
US4051300A
Cited
US4230583A
Cited
US4207182A
Cited
US4208508A
Cited
US4229291A
Cited
DE3018667A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-18 | 1991-07-20 | 1992-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-18 | 1995-07-20 | 1996-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-18 | 1999-07-20 | 2000-01-19 | $7700.00 | Window Closed / Lapsed |