PURPOSE: To obtain a molded or coated article which is uniform in qualities and contains only a small at. of the remaining solvent and which, when it is a coated article, exhibits a good adhesion between the coating film and the substate by compounding a polyamic acid having siloxane bonds in the main chain with a specific solvent.
CONSTITUTION: A pref. polyamic acid having siloxane bonds in the main chain is a homo- or copolymer which has structural units of formula I or formulas I and II. A pref. solvent is a mixture of solvents selected from the group consisting of a water-sol. ether, a water-sol. alcohol, a water-sol. ketone, and water or is a compd. having an ether group and an alcoholic hydroxyl group in the molecule. When a mixture of a water-sol. ether with water is used as the solvent, the mixing ratio by wt. of the former to the latter is pref. (96:4)-(70:30); when a water-sol. ether is mixed with a water-sol. alcohol, the wt. ratio of the former to the latter is pref. (90:10)-(50:50); and when a water-sol. ketone is mixed with water, the wt. ratio of the former to the latter is pref. (90:10)-(40:60).
TOMIOKA ISAO
IWAYA YOSHIAKI
