EP0037730B1
Expired / Lapsed
EP
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Asymmetric ultrafiltration membrane and production thereof
Assignee: Brunswick Corp
•
Filing: 1981-04-06
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Granted: 1985-09-11
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Expires: 2001-04-06
Abstract
No abstract record available.
Inventors
- 👤 Wolfgang J. Wrasidlo
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 23:46
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/02; B01D71/00; B01D71/06; B01D71/50; B01D71/58; B01D71/62; B01D71/64
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
74 words
An asymmetric ultrafiltration membrane having a water permeability of at least 0.2 cm/min at one psi (6.9 kPa), the membrane comprising an open honeycomb structure constituting the majority of the membrane and, integral therewith, a skin, the open honeycomb structure and the skin both being of a polymeric material having a glass transition temperature of at least 200°C, said polymeric material not being a polyquinoxaline, a polyquinoline, a poly-as-triazine, a polypyrazinoquinoxaline or a polyanthrazoline.
Claim 2
Dependent Claim
74 words
An asymmetric ultrafiltration membrane having a water permeability of at least 0.2 cm/min at one psi (6.9 kPa), the membrane comprising an open honeycomb structure constituting the majority of the membrane and, integral therewith, a skin, the open honeycomb structure and the skin both being of a polymeric material having a glass transition temperature of at least 200°C, said polymeric material not being a polyquinoxaline, a polyquinoline, a poly-as-triazine, a polypyrazinoquinoxaline or a polyanthrazoline.
Claim 3
Dependent Claim
21 words
A membrane according to claim 1, wherein the polymeric material has a modulus of elasticity of at least 6.9x10 5 kPa.
Claim 4
Dependent Claim
40 words
A membrane according to claim 2, wherein the ratio of the water permeability of the membrane to the square root of the molecular weight cut-off of the polymeric material is greater than 2x10- 3 cm/min at one psi (6.9 kPa).
Claim 5
Dependent Claim
17 words
A membrane according to any of claims 1 to 3, wherein the polymeric material is a polyimide.
Claim 6
Dependent Claim
24 words
A membrane according to any of claims 1 to 4, wherein the water permeability is at least 0.4 cm/min at one psi (6.9 kPa).
Claim 7
Dependent Claim
39 words
A membrane according to any of claims 1 to 5, wherein the honeycomb structure has a wall thickness which decreases as the distance from the skin increases and/or a mesh which increases as the distance from the skin increases.
Claim 8
Dependent Claim
43 words
A method of producing a membrane according to claim 1, which comprises casting a solution containing not more than 13% by weight of the polymeric material into a quench liquid which is a non-solvent for the polymeric material but miscible with the solvent.
Claim 9
Dependent Claim
18 words
A method according to claim 7, wherein the solution contains not more than 10% of the polymeric material.
Claim 10
Dependent Claim
17 words
A method according to claim 8, wherein the solution contains 3 to 7% of the polymeric material.
Claim 11
Independent Claim
24 words
A method according to any of claims 7 to 9, wherein the polymeric material is as defined in either of claims 2 and 4.
Claim 12
Independent Claim
24 words
A method according to any of claims 7 to 10, wherein the solvent is one or more of dimethylformamide, meta-cresol, cresylic acid and chloroform.
Claim 13
Independent Claim
16 words
A method according to any of claims 7 to 11, wherein the quench liquid is water.
References Cited (Backward Citations)
No citation records indexed.
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