Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal element

Abstract

This invention provides a liquid crystal alignment agent that can produce a liquid crystal alignment film that exhibits good liquid crystal alignment properties while possessing insulating film resistance, thereby obtaining a liquid crystal element with excellent contrast. The liquid crystal alignment agent comprises: a polymer (P) having, within the same molecule or in different molecules, at least one partial structure (a2) selected from the group consisting of a nitrogen-containing aromatic heterocyclic structure having one or two nitrogen atoms, a partial structure represented by formula (2), and a partial structure represented by formula (3), and having a weight average molecular weight of 5,000 or more; and a compound (A) having, within one molecule, at least two groups selected from the group consisting of (meth)acrylic, vinylphenyl, and maleimino groups, and having a molecular weight of less than 5,000. In formula (1), R1 is a hydrogen atom, etc. A1, A2, and A3 are hydrocarbon cyclic groups. In formulas (2) and (3), Y1 and Y2 are thermally detachable groups, etc.