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:
Mar. 05, 1991
Filed:
Apr. 05, 1990
Applicant:
Inventors:
Assignee:
Ube Industries, Ltd., Yamaguchi, JP;
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
55 16 ; 55158 ; 210640 ; 21050039 ;
Abstract
A pervaporation separation method of water from an organic material aqueous solution at a high separating efficiency is effected by using a specific asymmetric separating membrane comprising a heat-resistant, solvent-soluble aromatic imide polymer prepared by the polymerization and imidization of an aromatic tetracarboxylic acid component comprising, as a principal ingredient, at least one biphenyl tetracarboxylic acid compound with an aromatic diamine component comprising a principal member selected from: ##STR1## and an additional member selected from another aromatic diamine compounds having 2 to 5 benzene ring structures and different from the diamine compounds (I) and (II).