To provide a liquid crystal aligning agent useful to obtain a liquid crystal alignment film which exhibits a high voltage retention characteristic even under high temperature conditions and which has a low accumulation charge, and a liquid crystal display device which is less susceptible to lowering of contrast or to image persistence.
A liquid crystal aligning agent comprising at least one selected from a polyamic acid obtained by reactive polymerization of a tetracarboxylic dianhydride component with a diamine component, and a polyimide obtained by cyclodehydration of the polyamic acid, characterized in that at least part of the tetracarboxylic dianhydride component is a tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure, and at least part of the diamine component is a diamine represented by the following formula (1):
(wherein two among R
1
to R
10
are primary amino groups, and the rest are hydrogen atoms or monovalent organic groups other than primary amino groups, provided that they may be the same or different from one another), and a liquid crystal display device having a liquid crystal alignment film obtained from this liquid crystal aligning agent.
提供一种液晶定向剂,用于获得一种液晶定向膜,该膜即使在高温条件下也具有高电压保持特性且具有低积累电荷,并且液晶显示装置不易降低对比度或出现图像残留。该液晶定向剂包括至少选自通过四
羧酸二酐组分与二胺组分的反应聚合获得的聚
酰亚胺酸和通过聚
酰亚胺酸的环化脱
水获得的聚
酰亚胺,其特征在于四
羧酸二酐组分的至少一部分是具有脂环结构或脂肪族结构的四
羧酸二酐,而二胺组分的至少一部分是由以下公式(1)表示的二胺:(其中R1到R10中的两个是一级
氨基,其余为氢原子或除一级
氨基外的单价有机基团,但它们可以相同或不同),以及使用该液晶定向剂获得的液晶显示装置的液晶定向膜。