Patent ID: 6252033
Filing Date: 2001-06-26
Classification: C08G

Abstract:
A method for the preparation of polyamic acid, which comprises reacting a mixture containing:at least one tetracarboxylic dianhydride;at least one aromatic diamine;at least one diamine with a siloxane structure, represented by the following general formula I: ##STR5##wherein R4 is an alkylene group containing 1-20 carbon atoms and n' is the number of a recurring unit from 1 to 20; andat least one alkyl or aryl cyclohexylidene dianiline represented by the following general formula II or III: ##STR6##wherein R represents --CH.sub.3, --CH.sub.2 CH.sub.3, --C(CH.sub.3).sub.2 (CH.sub.2 CH.sub.3), or a phenyl group.