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:
Dec. 26, 1995
Filed:
Feb. 01, 1994
Masamichi Maruta, Kawagoe, JP;
Hidehisa Nanai, Kawagoe, JP;
Yoshihiro Moroi, Kawagoe, JP;
Hiroshi Takahashi, Kawagoe, JP;
Seiji Hasegawa, Kawagoe, JP;
Central Glass Company, Limited, Yamaguchi, JP;
Abstract
A polyimide precursor composition solution includes a tetracarboxylic acid component containing not less than 70 mol % of at least one selected from the group consisting of benzenetetracarboxylic acid and its reactive derivatives; a maleimide compound; and a diamine component containing not less than 70 mol % of 2,2'-substituted-4,4'-benzidine represented by the general formula (I) and siloxydiamine amounting to from 1 to 10 mol %. The tetracarboxylic acid component, the maleimide compound and the diamine component are dissolved in a solvent which is consisting essentially of .gamma.-butyrolactone. The amount of the tetracarboxylic acid component is substantially equivalent to that of the diamine component. The amount of the maleimide compound is from 5 to 30 wt % of the total weight of the tetracarboxylic acid and the diamine component. A polyimide coating film prepared from the polyamide precursor solution is very low in residual stress and superior in adhesion to a substrate, has a very flat surface and can be desirably treated by wet etching process with an etching solution which is not hazardous. ##STR1## wherein R are the same or different ones selected from the group consisting of CF.sub.3, CH.sub.3, C.sub.2 H.sub.5, OCH.sub.3, OC.sub.2 H.sub.5, Cl, Br and phenyl group.