PURPOSE: To obtain the titled precursor excellent in storage stability, adhesion of film, etc., by reacting a tetracarboxylic acid dianhydride with a diaminosiloxane, a diamine, an aminosiloxane compound and a silylating agent in two specified stages.
CONSTITUTION: A homogeneous reaction solution is formed by reacting A mol of a tetracarboxylic acid dianhydride of formula I with B2 mol of a diaminosiloxane of formula II, E2 mol of a diamine of formula III and D2 mol of an aminosilicone compound of formula IV at 0W60°C for 0.2W6hr in such amounts that the relationships of formulas VI and VII can be satisfied. This reaction mixture is reacted together with water necessary for the hydrolysis of the alkoxy groups by heating to 60W200°C for 0.5W30hr in the presence of a silylating agent of formula IX in an amount of F mol in the range of formula VIII to a degree of imidation (a) represented by formula X (wherein W is formula XI, p is formula XII and Q is formula XIII) of 50W100% and to an intrinsic viscosity of 0.05W5dl/g to obtain the titled precursor.
KUTSUZAWA KICHIYA
KONOTSUNE SHIRO
