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. 23, 1993
Filed:
Dec. 17, 1990
Applicant:
Inventors:
John A Kreuz, Columbus, OH (US);
Richard F Sutton, Jr, Circleville, OH (US);
Stuart N Milligan, Circleville, OH (US);
Assignee:
E. I. du Pont de Nemours and Company, Wilmington, DE (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08C / ; C08C / ; C08C / ; C08F / ;
U.S. Cl.
CPC ...
528125 ; 528126 ; 528128 ; 528170 ; 528172 ; 528173 ; 528176 ; 528179 ; 528184 ; 528185 ; 528188 ; 528220 ; 528229 ; 5283291 ; 528350 ; 528353 ; 525262 ; 525282 ; 525422 ; 525436 ; 524600 ; 4284735 ;
Abstract
Tetrapolyimide films derived from 3,3',4,4'-benzophenone tetracarboxylic dianhydride, pyromellitic acid dianhydride, p-phenylene diamine and 4,4'-diaminodiphenyl ether, and their preparation, are described. The tetrapolymer films have low water absorption, low coefficients of thermal and hygroscopic expansion, high modulus and are caustic etachable and can be used in flexible printed circuit and tape automated bonding applications.