| abstract |
An object of the present invention is to provide a polyimide film having both high heat resistance and high transparency and having both a low thermal expansion coefficient and a low Rth. A polyimide film prepared by imidizing a polyamic acid varnish, wherein the polyamic acid varnish contains a diamine compound, tetracarboxylic dianhydride, and a metal alkoxide in an organic solvent, and is further a sol-gel by addition of water. Reactants can be imidized to obtain polyimide films, which can be widely used as films, coatings, molded parts and insulating materials in fields such as electrical, electronic, automotive and aerospace industries. is there. [Selection figure] None |