| 摘要 |
PROBLEM TO BE SOLVED: To obtain a liquid crystal alignment agent having excellent transparency by incorporating a polyamic acid and/or polyimide having a specified content of aromatic rings in the polymer. SOLUTION: The liquid crystal alignment agent used contains a polyamide acid and/or polyimide having <=25 wt.% of aromatic rings to the total weight of the polymer. The polyamic acid used is preferably a polymer having a recurring unit expressed by formula I. The polyimide used is preferably a polymer having a recurring unit expressed by formula II. In formulae I and II, R is a tetravalent aliphatic group, and R' is a divalent org. group. By reducing the content of the total aromatic rings in the polymer in this way, the absorbance of the polymer is decreased and an alignment film having excellent transparency can be obtd. |
