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:
Oct. 18, 1977
Filed:
Jun. 27, 1975
Applicant:
Inventor:
Donald S Johnson, Scotia, NY (US);
Assignee:
General Electric Company, Schenectady, NY (US);
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
2605 / ; 2603 / ; 2603463 ;
Abstract
A method is provided for making aromatic bis(ether dicarboxylic acid)s, such as 2,2-bis[4(3,4-dicarboxyphenoxy)phenyl] propane. The corresponding aromatic bis(etherimide) is hydrolyzed in base to produce a tetraacid salt which is directly acidified with concentrated mineral acid such as sulfuric acid. The resulting aqueous mixture containing a paste is heated to produce the aromatic bis(ether dicarboxylic acid) in ready filterable form.