Polyimide varnish.

摘要

A polyimide varnish which is a solution having a polyimide and/or a polyimide precursor dissolved in an organic solvent and which is useful for forming a polyimide coating film on a substrate by coating the solution on the substrate followed by heat treatment, wherein from 5 wt% to 60 wt% of the organic solvent is a lactic acid derivative of the formula (I): wherein each of R<1> and R<2> which are independent of each other, is hydrogen, a C1-5 alkyl group or a C1-5 alkenyl group.