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. 26, 1976
Filed:
Dec. 23, 1974
Applicant:
Inventors:
Vasily Vladimirovich Korshak, Moscow, SU;
Svetlana Vasilievna Vinogradova, Moscow, SU;
Yakov Semenovich Vygodsky, Moscow, SU;
Zinaida Vasilievna Geraschenko, Moscow, SU;
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
260 / ; 260 65 ; 260 / ; 260 / ; 260 / ; 260 / ;
Abstract
A method of preparing polyimides by polycondensation of diamines and dianhydrides of tetracarboxylic acids in the presence of a catalyst, viz. a carboxylic acid such as acetic, benzoic, a tetracarboxylic acid taken in an amount of from 0.25 to 10, preferably from 0.8 to 2.5 COOH groups per one unit of a polyimide in a polar organic solvent medium which is inert with respect to the starting diamines and dianhydrides and immiscible with water at a temperature within the range of from 100.degree. to 220.degree. C.