EP0143552A2
Expired / Lapsed
EP
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Composite membrane and process for the production thereof
Assignee: Nitto Denko Corp
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Filing: 1984-10-26
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Granted: —
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Expires: 2004-10-26
Abstract
Abstract A composite membrane comprises an anisotropic membrane having a porous layer continuously connected to a dense surface layer bearing a thin, cross-linked silicone resin film. The membrane is formed of a polyimide resin having a repeating unit of the formula: <CHEM> wherein A is a tetravalent aliphatic or aromatic group, and R<1> is a divalent aromatic, alicyclic or aliphatic hydrocarbon group, or a divalent organic group comprising the hydrocarbon groups linked together through a divalent organic linking group. The membrane is useful for separation of organic solutions containing relatively small solutes of molecular weight of 10 to 1,000, liquid/liquid separation, and concentration and separation of gases.
Inventors
- 👤 Yoshitaka C/O Nitto Electric Kazuse
- 👤 Akio C/O Nitto Electric Iwama
- 👤 Shinichi C/O Nitto Electric Chikura
- 👤 Kentaro C/O Nitto Electric Tasaka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 20:19
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/12; B01D69/125; B01D71/00; B01D71/06; B01D71/58; B01D71/62; B01D71/64; B01D71/70; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/24992; Y10T428/31504; Y10T428/31652; Y10T428/31663; Y10T428/31721
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
119 words
A composite membrane comprising an organic resin substrate bearing a silicone resin thin film on a surface thereof, characterised in that the substrate is an anisotropic membrane having a porous layer continuously connected to a dense surface layer and formed of a polyimide resin consisting essentially of a repeating unit represented by the following general formula (I): wherein A is a tetravalent aliphatic or aromatic group, and R 1 is a divalent aromatic, alicyclic or aliphatic hydrocarbon group, or a divalent organic group comprising. the hydrocarbon groups linked together through a divalent organic linking group, and in that the thin film is formed of a cross-linked silicone resin and borne by the dense surface layer of the anisotropic membrane.
Claim 2
Dependent Claim
119 words
A composite membrane comprising an organic resin substrate bearing a silicone resin thin film on a surface thereof, characterised in that the substrate is an anisotropic membrane having a porous layer continuously connected to a dense surface layer and formed of a polyimide resin consisting essentially of a repeating unit represented by the following general formula (I): wherein A is a tetravalent aliphatic or aromatic group, and R 1 is a divalent aromatic, alicyclic or aliphatic hydrocarbon group, or a divalent organic group comprising. the hydrocarbon groups linked together through a divalent organic linking group, and in that the thin film is formed of a cross-linked silicone resin and borne by the dense surface layer of the anisotropic membrane.
Claim 3
Dependent Claim
23 words
A membrane as claimed in Claim 1, which the polyimide resin anisotropic membrane has a molecular weight cut-off of from 1,000 to 100,000.
Claim 4
Dependent Claim
33 words
A membrane as claimed in Claim 1 or 2, in which the polyimide resin consists essentially of a repeating unit of the following general formula (II): wherein R 1 is as defined above.
Claim 5
Dependent Claim
38 words
A process for producing a composite membrane which comprises contacting a solution of a cross-linkable silicone resin in an organic solvent with the dense surface layer of an anisotropic membrane as defined in Claim 1, 2 or 3.
Claim 6
Dependent Claim
134 words
A process as claimed in Claim 4, wherein the cross-linkable silicone resin is represented by the following general formula (VI): wherein X1 and X 2 are each independently a reactive group selected from vinyl groups, acryloxyalkyl groups, methacryloxyalkyl groups, hydroxy groups, hydroxyalkyl groups, acyloxy groups, aminoalkyl group and carboxyalkyl groups, R 2 , R 3 , R 4 , R 5 , R and R are each independently an organic group selected from alkyl groups, halogenated alkyl groups, vinyl groups and aryl groups, and n is an integer of from 400 to 1,000, the repeating unit in the formula (VI) optionally being partially replaceable by a unit of the following general formula (VIA): wherein R 8 , R 9 , R and R have the same meaning as R 2 to R 7 .
Claim 7
Dependent Claim
145 words
A process as claimed in Claim 4, wherein the cross-linkable silicone resin is represented by the following general formula (a): wherein X 1 , X 2 , X 3 , X 4 , X 5 and X 6 are each independently a monovalent organic group with proviso that at least three groups thereof are each independently a reactive group selected from acyloxy groups, alkoxy groups, ketoxime groups, alkyl-substituted amino groups and amide groups, R 2 and R 3 are each independently an organic group selected from alkyl groups, halogenated alkyl groups, vinyl groups and aryl groups, and n is an integer of from 400 to 1,000, the repeating unit in the general formula (a) optionally being partially replaceable by a unit of the following general formula (aa): wherein R , R , R 6 and R have the same meaning as R and R .
Claim 8
Dependent Claim
36 words
A process as claimed in any of Claims 4 to 6, wherein the cross-linkable silicone resin has an average molecular weight equivalent to or greater than the molecular weight cut-off of the polyimide resin anisotropic membrane.
Claim 9
Dependent Claim
29 words
A process as claimed in any of Claims 4 to 7, wherein the concentration of the cross-linkable silicone resin in the solution is from 0.01 to 10% by weight.
Claim 10
Dependent Claim
26 words
A process as claimed in any one of Claims 4 to 8, wherein the thin film is irradiated with electromagnetic waves to increase the cross-linking density.
Claim 11
Dependent Claim
27 words
A process as claimed in any one of Claims 4 to 9, wherein the average molecular weight of the cross-linkable silicone resin is from 10,000 to 200,000.
References Cited (Backward Citations)
No citation records indexed.
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