EP0247596A2
Expired / Lapsed
EP
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Porous membrane
Assignee: Mitsubishi Chemical Corp
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Filing: 1987-05-27
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Granted: —
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Expires: 2007-05-27
Abstract
Abstract Disclosed is a porous membrane consisting of a film-forming polymer characterized in that: (a) in at least one surface thereof, pores extending in a direction substantially perpendicular to the membrane surface are present at a surface pore density of 20 to 80%, said pores having an average pore diameter within the range of 0.01 to 100 mu m, a ratio of major to minor axis within the range of 1.0 to 2.0, and a coefficient of variation of pore diameter within the range of 0 to 50%; and (b) the overall porosity of said porous membrane is within the range of 20 to 90%.
Inventors
- 👤 Hajime Itoh
- 👤 Hiroshi Takahashi
- 👤 Kouji Ohbori
- 👤 Hideaki Habara
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 20:10
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/06; B01D69/02; B01D2323/00; B01D2323/02; B01D2323/12; B01D2323/30; B01D2325/00; B01D2325/02; B01D2325/022; B01D67/00; B01D67/0002; B01D67/0009; B01D67/0016; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/269; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/2935; Y10T428/2973; Y10T428/2975; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31928; Y10T428/31931; Y10T428/31935
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
101 words
A porous membrane consisting of a film-forming polymer, characterized in that: (a) in at least one surface thereof, pores extending in a direction substantially perpendicular to the membrane surface are present at a surface pore density of 20 to 80%, said pores having an average pore diameter within the range of 0.01 to 100 µm, a ratio of major to minor axis within the range of 1.0 to 2.0, and a coefficient of variation of pore diameter within the range of 0 to 50%; and (b) the overall porosity of said porous membrane is within the range of 20 to 90%.
Claim 2
Dependent Claim
101 words
A porous membrane consisting of a film-forming polymer, characterized in that: (a) in at least one surface thereof, pores extending in a direction substantially perpendicular to the membrane surface are present at a surface pore density of 20 to 80%, said pores having an average pore diameter within the range of 0.01 to 100 µm, a ratio of major to minor axis within the range of 1.0 to 2.0, and a coefficient of variation of pore diameter within the range of 0 to 50%; and (b) the overall porosity of said porous membrane is within the range of 20 to 90%.
Claim 3
Dependent Claim
34 words
The porous membrane as claimed in claim 1 wherein said pores extending in a direction substantially perpendicular to the membrane surface have an average pore diameter within the range of 0.01 to 10 µm.
Claim 4
Dependent Claim
48 words
The porous membrane as claimed in claim 2 wherein said pores extending in a direction substantially perpendicular to the membrane surface are present at a surface pore density of 35 to 75% and the overall porosity of said porous membrane is within the range of 50 to 80%.
Claim 5
Dependent Claim
49 words
The porous membrane as claimed in claim 1 wherein said pores extending in a direction substantially perpendicular to the membrane surface are present in one membrane surface and another membrane surface consists of a void layer which comprises voids having a larger pore diameter than that of said pores.
Claim 6
Dependent Claim
34 words
The porous membrane as claimed in claim 4 wherein said pores extending in a direction substantially perpendicular to the membrane surface have an average pore diameter within the range of 0.01 to 10 µm.
Claim 7
Dependent Claim
47 words
The porous membrane as claimed in claim 8 wherein said pores extending in a direction substantially perpendicular to the membrane surface are present at a surface pore density of 35 to 75% and the overall porosity of said pores is within the range of 50 to 80%.
Claim 8
Dependent Claim
43 words
The porous membrane as claimed in claims 1 to 6 wherein said film-forming polymer is a polymer that is insoluble in water and soluble in one or more solvents having a water-solubility of not greater than 50 g per 100 g of water.
Claim 9
Dependent Claim
28 words
The porous membrane as claimed in claims 1 to 6 wherein said film-forming polymer is a (meth)acrylic ester polymer or a polymer blend containing a (meth)acrylic ester polymer.
Claim 10
Dependent Claim
36 words
The porous membrane as claimed in claims 1 to 6, wherein said film-forming polymer is a polymer blend containing a (meth)acrylic ester polymer, and a fluorinated polyolefin or a copolymer of two or more fluorinated polyolefins.
Claim 11
Dependent Claim
30 words
The porous membrane as claimed in claims 1 to 6 wherein said film forming polymer is a copolymer of styrene or a derivative thereof and acrylonitrile or a derivative thereof.
Claim 12
Dependent Claim
23 words
The porous membrane as claimed in claims 1 to 6 wherein at least a part of the pore surfaces have been made hydrophilic.
Claim 13
Dependent Claim
28 words
The porous membrane as claimed in claims 1 to 6 which is continuous in its lengthwise direction and has been made by use of a moving support body.
References Cited (Backward Citations)
No citation records indexed.
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