Patent DE372145C successfully refreshed from Google Patents.
Patent US4776959A successfully refreshed from Google Patents.
US4776959A
Expired / Lapsed
US
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Hydrophilic porous membrane and method for manufacturing thereof
Assignee: Terumo Corp
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Filing: 1987-04-13
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Granted: 1988-10-11
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Expires: 2007-04-13
Abstract
Abstract A hydrophilic porous membrane comprises a porous membrane made of a hydrophobic polymer and a coating formed on at least one surface of the porous membrane and on the inner surface of pores of the membrane with a water-insoluble hydrophilic polymer soluble in a solvent exhibiting satisfactory stability and a satisfactory wetting property with respect to the hydrophobic polymer and a method for the manufacture of the hydrophilic porous membrane.
Inventors
- 👤 Masaaki Kasai
- 👤 Noriyuki Koyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:45
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
73 words
A hydrophilic porous membrane, comprising a porous membrane made of a hydrophobic polymer and a coating formed on at least one surface of said porous membrane and on the inner surface of porous of said porous membrane with a water-insoluble vinyl alcohol-vinyl acetate copolymer having a saponification degree of 15 to 60 mol % and soluble in a solvent exhibiting satisfactory stability and a satisfactory wetting property with respect to said hydrophobic polymer.
Claim 2
Dependent Claim
73 words
A hydrophilic porous membrane, comprising a porous membrane made of a hydrophobic polymer and a coating formed on at least one surface of said porous membrane and on the inner surface of porous of said porous membrane with a water-insoluble vinyl alcohol-vinyl acetate copolymer having a saponification degree of 15 to 60 mol % and soluble in a solvent exhibiting satisfactory stability and a satisfactory wetting property with respect to said hydrophobic polymer.
Claim 3
Dependent Claim
23 words
A hydrophilic porous membrane according to claim 1, wherein said hydrophobic polymer is a fluorine resin type polymer or a polyolefin type polymer.
Claim 4
Dependent Claim
18 words
A hydrophilic porous membrane according to claim 1, wherein said hydrophobic polymer is a fluorine resin type polymer.
Claim 5
Dependent Claim
17 words
A hydrophilic porous membrane according to claim 3, wherein said fluorine resin type polymer is polyvinylidene fluoride.
Claim 6
Dependent Claim
25 words
A hydrophilic porous membrane according to claim 1 wherein the saponification of said water insoluble vinyl alcohol-vinyl acetate copolymer is 25 to 45 mol %.
Claim 7
Dependent Claim
30 words
A hydrophilic porous membrane according to claim 5 wherein the porous membrane has a thickness of 100 to 200 μm and an average pore diameter of 0.1 to 0.6 μm.
Claim 8
Dependent Claim
30 words
A method according to claim 6, wherein said solvent is at least one member selected from the group consisting of methanol, ethanol, isopropanol, and mixtures of said alcohols with water.
Claim 9
Dependent Claim
30 words
A hydrophilic porous membrane according to claim 1 wherein the porous membrane has a thickness of 50 to 300 μm and an average pore diameter of 0.1 to 1.0 μm.
Claim 10
Independent Claim
140 words
A method for the manufacture of a hydrophilic porous membrane, comprising the steps of: (a) preparing a porous membrane of a hydrophobic polymer, (b) impregnating said porous membrane with a solution obtained by dissolving a water-insoluble vinyl alcohol-vinyl acetate copolymer having 15 to 60 mol% of saponification degree in a solvent exhibiting a satisfactory ability to dissolve said copolymer, and exhibiting satisfactory stability and a satisfactory wetting property with respect to said hydrophobic polymer, wherein the concentration of said hydrophilic polymer in said solution is in the range of 0.1 to 10% by weight, and the duration of said impregnation of said porous membrane of a hydrophobic polymer with said solution of water-insoluble hydrophilic polymer is in the range of 1 to 30 seconds, and (c) drying the impregnated porous membrane to adhere said hydrophilic polymer with said hydrophobic polymer.
Claim 11
Independent Claim
140 words
A method for the manufacture of a hydrophilic porous membrane, comprising the steps of: (a) preparing a porous membrane of a hydrophobic polymer, (b) impregnating said porous membrane with a solution obtained by dissolving a water-insoluble vinyl alcohol-vinyl acetate copolymer having 15 to 60 mol% of saponification degree in a solvent exhibiting a satisfactory ability to dissolve said copolymer, and exhibiting satisfactory stability and a satisfactory wetting property with respect to said hydrophobic polymer, wherein the concentration of said hydrophilic polymer in said solution is in the range of 0.1 to 10% by weight, and the duration of said impregnation of said porous membrane of a hydrophobic polymer with said solution of water-insoluble hydrophilic polymer is in the range of 1 to 30 seconds, and (c) drying the impregnated porous membrane to adhere said hydrophilic polymer with said hydrophobic polymer.
Claim 12
Dependent Claim
21 words
A method according to claim 9, wherein said hydrophobic polymer is a fluorine resin type polymer or a polyolefin type polymer.
Claim 13
Dependent Claim
16 words
A method according to claim 9, wherein said hydrophobic polymer is a fluorine resin type polymer.
Claim 14
Dependent Claim
15 words
A method according to claim 11, wherein said fluorine resin type polymer is polyvinylidene fluoride.
Claim 15
Dependent Claim
36 words
A method according to claim 9, wherein said impregnation of said porous membrane of a hydrophobic polymer with the solution of said water-insoluble hydrophilic polymer is effected by immersion of said porous membrane in said solution.
Claim 16
Dependent Claim
23 words
A method according to claim 9, wherein the saponification of said water insoluble vinyl alcohol-vinyl acetate copolymer is 25 to 45 mol %.
Claim 17
Dependent Claim
21 words
A method according to claim 9, wherein drying said hydrophilic porous membrane is carried out at a temperature of 60°-80° 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) | 1991-10-11 | 1992-04-11 | 1992-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-11 | 1996-04-11 | 1996-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-11 | 2000-04-11 | 2000-10-11 | $7700.00 | Window Closed / Lapsed |