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:
Aug. 04, 1987
Filed:
Apr. 22, 1986
Applicant:
Inventors:
Assignee:
Japan Synthetic Rubber Co., Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
549242 ;
Abstract
A process for producing benzophenone tetracarboxylic dianhydride, which comprises adding benzophenone tetracarboxylic acid to a solvent comprising, as the main constituent, an organic compound having a boiling point of more than 100.degree. C. and being inert to benzophenone tetracarboxylic acid and benzophenone tetracarboxylic anhydrides, and heating the resulting mixture. This process enables one to produce benzophenone tetracarboxylic dianhydride having a very low moisture absorbency.