US5514461A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vinylidene fluoride porous membrane and method of preparing the same
Assignee: Kureha Corp
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Filing: 1994-10-05
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Granted: 1996-05-07
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Expires: 2014-10-05
Abstract
Abstract A polyvinylidene fluoride porous membrane has an asymmetrical structure, excellent mechanical strength such as tensile strength at break and elongation at break, and a desirable narrow range of pore diameter distribution. A method of preparing the porous membrane is also disclosed. The membrane comprises a vinylidene fluoride resin having an inherent viscosity from 1.3 to 15.0 (dl/g), and the membrane comprises pores which satisfy the following numerical expression (A): 4.0<P.sub.1 /P.sub.2 ≦10.00 (A) wherein P 1 is an average pore diameter (μm) in a surface which has a larger average pore diameter, and P 2 is an average pore diameter (μm) in the other surface of the membrane.
Inventors
- 👤 Kazuhiro Meguro
- 👤 Toshiya Mizuno
- 👤 Yoshikiti Teramoto
- 👤 Hiroshi Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:54
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/02; B01D71/00; B01D71/06; B01D71/30; B01D71/32; B01D71/34; B29; B29C; B29C48/00; B29C48/001; B29C48/0018; B29C48/25; B29C48/88; B29C48/911; B29C48/9135; B29C48/914; H; H01; H01M; H01M50/00; H01M50/40; H01M50/409; H01M50/411; H01M50/414; H01M50/426; H01M50/489; H01M50/491; H01M50/494; B29C48/03; B29C48/07; B29C48/08; B29C48/30; B29C48/305; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/24298; Y10T428/24942; Y10T428/249921; Y10T428/249953; Y10T428/249961; Y10T428/249975; Y10T428/249978; Y10T428/31504; Y10T428/3154
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
126 words
A vinylidene fluoride porous membrane which comprises a vinylidene fluoride resin, said membrane having pores which satisfy the following numerical expression (A): 4.0<P.sub.1 /P.sub.2 ≦10.00 (A) in which P 1 is an average pore diameter in a surface which has a larger average pore diameter, and P 2 is an average pore diameter in the other surface of the membrane; wherein the inherent viscosity of the vinylidene fluoride resin which constitutes the porous membrane is from 1.3 to 15.0 when measured on a sample of the porous membrane, and the following numerical expression (B) is satisfied: (Tb×Eb/(100-φ)×100≧1,000 (B) wherein φ is a porosity in % by volume, Tb is a tensile strength at break in MPa, and Eb is % elongation at the point of break.
Claim 2
Dependent Claim
126 words
A vinylidene fluoride porous membrane which comprises a vinylidene fluoride resin, said membrane having pores which satisfy the following numerical expression (A): 4.0<P.sub.1 /P.sub.2 ≦10.00 (A) in which P 1 is an average pore diameter in a surface which has a larger average pore diameter, and P 2 is an average pore diameter in the other surface of the membrane; wherein the inherent viscosity of the vinylidene fluoride resin which constitutes the porous membrane is from 1.3 to 15.0 when measured on a sample of the porous membrane, and the following numerical expression (B) is satisfied: (Tb×Eb/(100-φ)×100≧1,000 (B) wherein φ is a porosity in % by volume, Tb is a tensile strength at break in MPa, and Eb is % elongation at the point of break.
Claim 3
Dependent Claim
59 words
The vinylidene fluoride porous membrane according to claim 1, wherein a ratio P 4 /P 3 is not more than 2.0, where P 3 is a mean flow pore diameter measured by a half-dry method as defined in ASTM F-316-86, and P 4 is a maximum pore diameter measured by a bubble point method as defined in ASTM F-316-86.
Claim 4
Dependent Claim
44 words
The vinylidene fluoride porous membrane according to claim 1, wherein said vinylidene fluoride resin is at least one selected from the group consisting of homopolymers of vinylidene fluoride and copolymers of vinylidene fluoride which contain not less than 70 mol % of vinylidene fluoride.
Claim 5
Dependent Claim
35 words
The vinylidene fluoride porous membrane according to claim 3, wherein said copolymer contains at least one comonomer selected from the group consisting of ethylene tetrafluoride, propylene hexafluoride, ethylene trifluoride, ethylene chloride trifluoride and vinyl fluoride.
Claim 6
Dependent Claim
21 words
The vinylidene fluoride porous membrane according to claim 1, wherein said membrane has a thickness of from 10 to 300 μm.
Claim 7
Dependent Claim
22 words
The vinylidene fluoride porous membrane according to claim 1, wherein the mean flow pore diameter P 3 is 0.01 to 10 μm.
Claim 8
Dependent Claim
22 words
The vinylidene fluoride porous membrane according to claim 1, wherein the mean flow pore diameter P 3 is 0.01 to 2.0 μm.
Claim 9
Dependent Claim
22 words
The vinylidene fluoride porous membrane according to claim 1, wherein the maximum pore diameter P 4 is not more than 10.0 μm.
Claim 10
Dependent Claim
11 words
The vinylidene fluoride porous membrane according to claim 1, wherein (Tb×Eb/(100-φ))×100=5,000-50,000.
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