Liquid crystal aligning agent containing crosslinking agent and polymer that has site having isocyanate group and/or blocked isocyanate group and site having photoreactivity, liquid crystal alignment film, and liquid crystal display element

A liquid crystal aligning agent comprising the following component (A), the following component (B), and an organic solvent:

• Component (A):
• a polymer comprising a (A-1) site having an isocyanate group and/or a blocked isocyanate group;
• and a (A-2) site having photoalignment;
• Component (B):
• a compound comprising in a molecule of the compound two or more functional groups, each of which is at least one selected from the group consisting of an amino group and a hydroxyl group,
• wherein the (A-1) site having an isocyanate group and/or a blocked isocyanate group is represented by following formula (1), wherein Ia represents an isocyanate group or a blocked isocyanate group,
• Sa represents a spacer unit, the bonding pointer left of Sa represents bonding to the backbone of a polymer of the component (A) optionally via a spacer:
• —Sa—Ia (1),
• wherein the (A-1) site having an isocyanate group and/or a blocked isocyanate group is derived from a monomer represented by the formula (1m),
• Ma-MbSa—Ia]c (1m);
• wherein Ma represents a first polymerizable group,
• Mb represents a single bond, a divalent heterocycle, a trivalent heterocycle, a tetravalent heterocycle, a substituted or unsubstituted linear or branched alkyl group having a carbon number of 1 to 10, a divalent aromatic group, a trivalent aromatic group, a tetravalent aromatic ring, a divalent alicyclic group, a trivalent alicyclic group, a tetravalent alicyclic group, a divalent condensed cyclic group, a trivalent condensed cyclic group or a tetravalent condensed cyclic group, wherein each group may be unsubstituted, or one or more hydrogen atoms in each group may be substituted with a fluorine atom, a chlorine atom, a cyano group, a methyl group, or a methoxy group,
• Sa represents a spacer unit,
• Ia represents an isocyanate group or a blocked isocyanate group, and
• c represents an integer of 1 to 3;
• and
• wherein Sa in the formula (1) and/or the formula (1m) is represented by the formula (2):
• —W1-A1-W2-A2-W3— (2)
• wherein the bonding left of W1 represents bonding to Mb,
• the bonding right of W3 represents bonding to Ia,
• W1, W2, and W3 each independently represents a single bond, a divalent heterocycle, —(CH2)n— wherein n represents 1 to 20, —OCH2—, —CH2O—, —COO—, —OCO—, —CH═CH—, —CF═CF—, —CF2O—, —OCF2—, —CF2CF2— or —C≡C—, wherein one or more non-adjacent CH2 groups in these substituents may be independently substituted with —O—, —CO—, —CO—O—, —O—CO—, —Si(CH3)2—O—Si(CH3)2—, —NR—, —NR—CO—, —CO—NR—, —NR—CO—O—, —OCO—NR—, —NR—CO—NR—, —CH═CH—, —C≡C— or —O—CO—O—, wherein R represents independently a hydrogen or a linear or branched alkyl group having a carbon number of 1 to 5,
• A1 and A2 each independently represents a divalent aromatic group, a divalent alicyclic group, a divalent heterocyclic group, or a divalent condensed cyclic group, wherein each group may be unsubstituted, or one or more hydrogen atoms in each group may be substituted with a fluorine atom, a chlorine atom, a cyano group, a methyl group or a methoxy group.