US4810384A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrophilic PVDF semipermeable membrane
Assignee: Rhone Poulenc Recherches SA
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Filing: 1987-06-29
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Granted: 1989-03-07
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Expires: 2007-06-29
Abstract
Abstract Hydrophilic semipermeable membranes which retain their capacity for filtration, even after drying, and which are well adapted for either ultrafiltration or microfiltration, are comprised of at least 70% by weight of polyvinylidene fluoride (PVFD) and up to 30% by weight of a hydrophilic polymer compatible therewith, e.g., a cellulose acetate or sulfonated polysulfone.
Inventors
- 👤 Albert Fabre
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:24
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/30; B01D71/32; B01D71/34; C; C08; C08L; C08L27/00; C08L27/02; C08L27/12; C08L27/16
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
45 words
A hydrophilic semipermeable membrane comprising at least 70% by weight of polyvinylidene fluoride, and a minor effective amount, no more than 30% by weight, of a hydrophilic polymer compatible therewith selected from the group consisting of sulfonated polysulfone and copolymers of acrylonitrile and sulfone monomers.
Claim 2
Dependent Claim
45 words
A hydrophilic semipermeable membrane comprising at least 70% by weight of polyvinylidene fluoride, and a minor effective amount, no more than 30% by weight, of a hydrophilic polymer compatible therewith selected from the group consisting of sulfonated polysulfone and copolymers of acrylonitrile and sulfone monomers.
Claim 3
Dependent Claim
27 words
The semipermeable membrane as defined by claim 1, comprising at least 85% by weight of polyvinylidene fluoride and no more than 15% by weight of sulfonated polysulfone.
Claim 4
Dependent Claim
32 words
The semipermeable membrane as defined by claim 1, comprising at least 85% by weight of polyvinylidene fluoride and no more than 15% by weight of a copolymer of acrylonitrile and sulfone monomers.
Claim 5
Dependent Claim
14 words
The semipermeable membrane as defined by claim 1, comprising a hollow fiber shaped article.
Claim 6
Dependent Claim
13 words
The semipermeable membrane as defined by claim 1, comprising a planar shaped article.
Claim 7
Dependent Claim
15 words
The semipermeable membrane as defined by claims 4 or 5, comprising an isotropic shaped article.
Claim 8
Dependent Claim
15 words
The semipermeable membrane as defined by claims 4 or 5, comprising an anisotropic shaped article.
Claim 9
Dependent Claim
14 words
The semipermeable membrane as defined by claim 7, comprising a reinforcing porous support layer.
Claim 10
Dependent Claim
19 words
The semipermeable membrane as defined by claim 1, heat-treated to a temperature of from 65° C. to 95° C.
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) | 1992-03-06 | 1992-09-05 | 1993-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-06 | 1996-09-05 | 1997-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-06 | 2000-09-05 | 2001-03-07 | $7700.00 | Window Closed / Lapsed |