POLYIMIDE PRECURSOR, METHOD FOR PRODUCING POLYIMIDE PRECURSOR, METHOD FOR PRODUCING POLYIMIDE PRECURSOR SOLUTION IN ORGANIC SOLVENT, METHOD FOR PRODUCING CAST FILM, AND METHOD FOR PRODUCING POLYIMIDE FILM

摘要

A polyimide precursor, which has a recurring structure unit represented by the following unit structure formula (1a) or unit structure formula (1b); and a polyimide produced by the imidation of the polyimide precursor. The control of the percentage of the silylation in the process of the formation of the polyimide precursor makes the reaction system less prone to formation of a salt and results in the preparation of a uniform and viscous polyimide precursor solution in an organic solvent. The above polyimide can combine the two desirable characteristics of a low dielectric constant and a low linear thermal expansion coefficient.