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:
Jun. 22, 1982
Filed:
Oct. 01, 1980
Applicant:
Inventors:
Assignee:
Sumitomo Chemical Company, Limited, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08L / ;
U.S. Cl.
CPC ...
525139 ; 428521 ; 525328 ; 528159 ;
Abstract
A process for the production of a phenolic resin modified with a liquid polybutadiene being useful as an impregnating varnish in the production of a copper-clad laminate for a printed circuit, which comprises preparing an adduct of a liquid polybutadiene having a number average molecular weight of 150 to 5,000 with an .alpha., .beta.-unsaturated dicarboxylic acid or its anhydride, subjecting the adduct to an addition reaction with one or plurality of phenols in the presence of an acid catalyst to obtain a composition and reacting the composition with formaldehyde in the presence of a basic catalyst.