High flash point/low surface energy solvent systems for polyimide conformal coatings

摘要

An improved wire enamel consisting essentially of the following materials by weight wherein basis is wire enamel weight; at least 50% by wt. of a polar organic solvent; about 2-8% by wt. of a polyimide precursor which can be cured to yield a polyimide polymer; about 0.5 to about 25% by weight of the substituted aliphatic hydrocarbon solvent for the polyimide precursor having a surface tension and polarity greater than that of the halogenated aliphatic hydrocarbon described below or a substituted aromatic hydrocarbon having a dipole moment less than or equal to the dipole moment of the halogenated aliphatic hydrocarbon described below; about 5 to 40% by wt. of a halogenated aliphatic hydrocarbon; and 0 to about 1% by wt. of an organosilane which increases the adhesion of the polyimide to an underlying substrate.