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:
Apr. 28, 1998
Filed:
Jun. 06, 1996
Applicant:
Inventors:
Assignee:
Ube Industries, Ltd., Yamaguchi, JP;
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528353 ; 528125 ; 528128 ; 528171 ; 528172 ; 528173 ; 528174 ; 528179 ; 528180 ; 528182 ; 528183 ; 528188 ; 528220 ; 528226 ; 528229 ; 528350 ; 428357 ; 428364 ; 428396 ; 4284111 ; 4284735 ; 55 16 ; 55158 ;
Abstract
An aromatic polyimide having a recurring unit of the formula (I): ##STR1## wherein Ar is a divalent aromatic group having one or two benzene rings which has a sulfonate group of --SO.sub.3 H, --SO.sub.3 M, and --SO.sub.3 N(L).sub.4 on the ring, wherein M is an alkali metal and L is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, is favorably employed in the form of a semipermeable film for gas separation.