The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 08, 1991
Filed:
Mar. 28, 1988
Haruhisa Miyake, Yokohama, JP;
Hiroaki Ito, Yokohama, JP;
Koji Suzuki, Yokohama, JP;
Ryoji Yamada, Yokohama, JP;
Asahi Glass Company Ltd., Tokyo, JP;
Abstract
A cation exchange fluoropolymer membrane comprising at least three integrally laminated layers including a main layer made of a perfluorocarbon polymer having carboxylic acid groups as its ion exchange groups with an ion exchange capacity of from 1.4 to 2.0 meq/g dry resin and having a thickness of from 50 to 250 .mu.m, a sulfonic acid film surface layer formed on one side of said main layer, made of a perfluorocarbon polymer having sulfonic acid groups as its ion exchange groups with an ion exchange capacity of from 0.5 to 1.5 meq/g dry resin and having a thickness of from 5 to 50 m, and a carboxylic acid film surface layer formed on the other side of said main layer, made of a perfluorcarbon polymer having carboxylic acid groups as its ion exchange groups with an ion exchange capacity of from 0.5 to 1.3 meq/g dry resin and having a thickness of from 5 to 50 .mu.m, said sulfonic acid film surface layer and carboxylic acid film surface layer constituting the outer-most layers, respectively.