Patent ID: 6746730
Filing Date: 2004-06-08
Classification: C08L,C09D,C09K,G02F,Y10T

Abstract:
A varnish composition which comprises a polymer component containing a polyamic acid B represented by formula (1), a polyamic acid A represented by formula (2) and a soluble polyimide represented by formula (3), and a solvent for dissolving the polymer component, in which the weight ratio of the polyamic acid A to the soluble polyimide in the polymer component is 1/99 to 99/1, the sum of the polyamic acid A and the soluble polyimide accounts for 1 to 80% by weight of the polymer component, the polyamic acid B accounts for 99 to 20% by weight of the polymer component, and the proportion of the polymer component in the whole varnish composition is 0.1 to 40% by weight; wherein R1 is a tetravalent organic radical derived from tetracarboxylic acids, R2 is a divalent organic radical derived from a diamine, each of which is a radical having no side chain, a radical having an alkyl side chain of less than 3 carbon atoms or a radical comprising a mixture of these, and m is a positive integer; wherein R3 is a tetravalent organic radical derived from tetracarboxylic acids, R4 is a divalent organic radical derived from a diamine, at least one of R3 and R4 is a radical having a side chain of 3 or more carbon atoms or a radical comprising said radical, and n is a positive integer; and wherein R5 is a tetravalent organic radical derived from tetracarboxylic acids, R6 is a divalent organic radical derived from a diamine, and p is a positive integer.