Polyimidesiloxane solution and method of coating substrates
AssigneeOccidental Chemical Corporation
InventorsSergio R. Rojstaczer, David Y. Tang, John A. Tyrell
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Abstract
Disclosed is a solution which comprises (a) a substantially fully imidized polyimidesiloxane; and (b) a solvent which comprises at least 50 wt % of a substituted pyrrolidone having the general formula ##STR1## where R is aliphatic or cycloaliphatic from C.sub.3 to C.sub.10. Also disclosed is a method of forming a coating on a substrate by applying the solution to the substrate and evaporating the solvent. Coatings formed from this solution are not subject to whitening as are coatings formed from the same polymers in other solvents.
Claims20
A solution of about 5 to about 50 wt % solids comprising
- (A) a substantially fully imidized polyimidesiloxane;
- and
- (B) a solvent which comprises at least 50 wt %, based on solvent weight, of a liquid substituted pyrrolidone having the formula ##STR7## where R is aliphatic or cycloaliphatic from C.sub.3 to C.sub.10.
A solution comprising
- (A) about 5 to about 50 wt % of a polyimidesiloxane that is at least 90% imidized, which comprises the reaction product of an aromatic dianhydride with an aromatic diamine that does not contain siloxane groups and an aliphatic diamine that contains siloxane groups, where said aliphatic diamine comprises about 1 to about 30 wt % of said polyimidesiloxane weight;
- and
- (B) about 50 to about 95 wt % of a solvent which comprises
- (1) at least about 90 wt %, based on solvent weight, of a liquid substituted pyrrolidone having the formula ##STR9## where R is alkyl or cycloalkyl from C.sub.3 to C.sub.10 ;
- and (2) up to about 10 wt %, based on solvent weight, of an organic co-solvent having a boiling point of about 50.degree. to about 210.degree. C.
A solution consisting essentially of
- (A) about 5 to about 50 wt % of a polyimidesiloxane that is at least 95% imidized;
- and
- (B) about 50 to about 95 wt % N-cyclohexyl pyrrolidone.
Dependencies are inferred from the claim text.