| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyamic acid good in liquid crystal aligning when made into a liquid crystal film, and useful as a liquid crystal aligning agent with a wide pretilt angle by reaction between a specific tetracarboxylic acid dianhydride and a specific diamine compound. SOLUTION: This polyamic acid is obtained by reaction between (A) a tetracarboxylic acid dianhydride including a compound of formula I (R1 is a 5-30C alkyl, halogen, 1-30C haloalkyl or a univalent organic group having steroidal skeleton; X is a single bond or bivalent bond group; R2 and R3 are each H or a univalent organic group; (a) is 1-4; (b) is 0-3) and (B) a diamine compound of the formula H2N-R4-NH2 (R4 is a bivalent organic group). By the way, the compound of formula I is prepared by ene reaction between maleic anhydride and the reaction product formed by Diels-Alder reaction between maleic anhydride and a styrene derivative of formula II. |
