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. 21, 1981
Filed:
Feb. 19, 1980
Applicant:
Inventors:
Chiang-Ying M Tung, Thousand Oaks, CA (US);
Charles L Hamermesh, Westlake Village, CA (US);
Assignee:
Rockwell International Corporation, El Segundo, CA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
521106 ; 521157 ; 528 49 ; 528 51 ; 528 73 ;
Abstract
A polyimide foam is provided which has improved resistance to crumbling and to high temperatures. The foam is produced by reacting polymethylene polyphenylisocyanate (PAPI) with benzophenone-3,3',4,4'-tetracarboxylic acid dianhydride (BTDA) in the presence of furfuryl alcohol and concentrated phosphoric acid (PA). The ratio of PA to PAPI, (PA/PAPI), must be approximately 20 to 26% by weight.