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. 09, 1997
Filed:
May. 17, 1996
Tomoegawa Paper Co., Ltd., Tokyo, JP;
Abstract
Novel polyimides which are soluble in various organic solvents and excellent in thermal resistance, processability are disclosed. The polyimides comprise repeating units represented by the following formula (1) and/or (2) and having a number average molecular weight of 4,000-200,000. ##STR1## wherein Ar is a divalent group represented by the following formula (2) or (3): ##STR2## wherein Y is --O--, --CO--, --S--, --SO.sub.2 -- or --C(CH.sub.3).sub.2 --, ##STR3## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each a C.sub.1-4 alkyl group or a C.sub.1-4 alkoxy group, Ra is a divalent group having 2-6 benzene rings, X.sup.1 represents NH, NR (wherein R is a C.sub.1-4 alkyl group or a C.sub.1-4 alkoxy group) or S, Rb is C.sub.2-20 alkylene group, ether group or dimethylsiloxane group, and X.sub.2 represents NH, NR (wherein R is a C.sub.1-4 alkyl group or a C.sub.1-4 alkoxy group), ##STR4##