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:
Jul. 19, 1983
Filed:
Aug. 04, 1981
Applicant:
Inventors:
Joseph G Robinson, Winchcombe, GB;
David I Barnes, Cheltenham, GB;
Assignee:
Coal Industry (Patents) Limited, London, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528229 ; 4284735 ; 525472 ; 528220 ; 528233 ; 528247 ; 528353 ;
Abstract
This invention relates to an improved polyimide resin and to a method of its production. The improved polyimide resin is made from phenanthrene which is converted via a 9, 10-diol to oligomers of diphenic anhydride units linked by keto bridges. The oligomers are reacted with from 0.1 to 0.6 of an equivalent quantity of an aromatic primary diamine. The remaining anhydride groups are reacted with a monofunctional amine to give a polyimide of low cross-link density. The resin will find use for instance in forming glasscloth laminates.