Polyamide with a diamine compound and it has a silphenylene residues, polyamic acid, polyimide, liquid crystal alignment treating agent as well as a liquid crystal display device

摘要

PROBLEM TO BE SOLVED: To obtain a new diamine compound containing a specific silphenylene residue, having excellent solubility in solvents and orientation uniformity of a polymer chain by rubbing, and useful as a liquid crystal orienting agent. SOLUTION: A diamine compound containing a silphenylene group expressed by formula I (R1 to R4 are each a 1-6C alkyl or phenyl; X1 and X2 are each an ether bond, or the like; (m) is 2-20), e.g. a compound of formula II. The compound of formula I can be produced by reacting a silphenylene compound of formula III with an alkenyl compound of formula IV in the presence of a hydrosilylation catalyst (e.g. platinum) preferably in a solvent (e.g. hexane) at 40-100 deg.C in an inert gas atmosphere (e.g. argon) and reducing the nitro group of the produced dinitro compound at -100 to +150 deg.C preferably in a solvent (e.g. an alcohol).