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:
Dec. 03, 1991
Filed:
Aug. 07, 1989
Applicant:
Inventors:
Assignee:
Kanegafuchi Chemical Ind. Co., Ltd., Osaka, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08G / ; C08G / ; C08G / ;
U.S. Cl.
CPC ...
528353 ; 528126 ; 528128 ; 528173 ; 528179 ; 528185 ; 528188 ; 528351 ; 528352 ; 4284735 ;
Abstract
Disclosed is a film of polyimide having repeating units of formula (1) and a birefringence (.DELTA.n) of at least 0.13: ##STR1## wherein R.sup.1 is an aromatic group having a valency of 4, at carbon atoms constituting the aromatic ring, and R.sup.2 is an aromatic group having a valency of 2, at carbon atoms constituting the aromatic ring. This polyimide film exhibits good thermal dimensional stability.