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. 12, 1999
Filed:
May. 21, 1997
Applicant:
Inventors:
Assignee:
DuPont Toray, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528183 ; 528176 ; 528185 ; 528187 ;
Abstract
A polyimide copolymer containing a block polyimide polymer component composed of a rigid aromatic diamine compound and an aromatic tetracarboxylic acid compound and a random polyimide copolymer component composed of a flexible aromatic diamine compound and at least two types of aromatic tetracarboxylic acid compounds is prepared by a two-stage polymerization process. Resin molded products prepared from the polyimide copolymer have high modulus, low thermal expansion and low water absorption and can be used as TAB base films that require higher processability and precision.