Polyimide film-forming polyamide acid solution
AssigneeNitto Electric Industrial Co., Ltd.
InventorsKazumi Higashi, Yuzuru Noda
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Abstract
A polyamide acid solution is disclosed, comprising a polyamide acid comprising as main components at least one recurring unit selected from the recurring units of the formulae (I) to (IV) and a recurring unit of formula (V), dissolved in an organic solvent comprising as a main component an amide type polar solvent having a boiling point of 170.degree. C. or less. The solution is capable of forming a polyimide film which has colorless transparency free from coloration and strong adhesion to a substrate for liquid crystal cell enough to prevent penetration of water into interface between the substrate and film. The solution is particularly useful for forming a liquid crystal oriented film.
Claims10
A polyamide acid solution comprising a polyamide acid comprising as main components at least one recurring unit selected from the group consisting of a recurring unit represented by formula (I) ##STR9## wherein X.sub.1, X.sub.2, X.sub.3 and X.sub.4, which may be the same or different, each represents H, CH.sub.3, C.sub.2 H.sub.5, NO.sub.2, F, COOH or Cl;
- and m represents a positive integer;
- a recurring unit represented by formula (II) ##STR10## wherein X.sub.5 represents O, SO.sub.2, CH.sub.2, S or CO;
- and m is the same as defined above;
- a recurring unit represented by formula (III) ##STR11## wherein m is the same as defined above;
- and a recurring unit represented by formula (IV) ##STR12## wherein X.sub.6 represents SO.sub.2, C(CH.sub.3).sub.2 or C(CF.sub.3).sub.2 ;
- and m is the same as defined above, and a recurring unit represented by formula (V) ##STR13## wherein R represents a divalent hydrocarbon group;
- R' represents a monovalent hydrocarbon group;
- y represents an integer of from 1 to 4;
- and n represents a positive integer selected so that n/(m+n) ranges from 0.01 to 0.05, dissolved in an organic solvent comprising as a main component an amide type polar solvent having a boiling point of 170.degree. C. or less.
Dependencies are inferred from the claim text.