Liquid crystal aligning agent, liquid crystal alignment film, method for producing same, liquid crystal element and polymer

1. A liquid crystal aligning agent comprising a polymer (P) having at least one selected from the group consisting of a partial structure represented by the following Formula (1) and a partial structure represented by the following Formula (2):

In Formula (1) and Formula (2), X 1 is a tetravalent organic group having a cyclobutane ring structure and has at least one substituent in a ring portion of a cyclobutane ring; X 2 is a divalent organic group represented by the following Formula (4); R 5 and R 6 each are independently a hydrogen atom or a monovalent organic group having 1 to 6 carbon atoms,

*-A 1 -Y 1 -Z 1 -Y 2 -A 2 -*  (4)

In Formula (4), A 1 and A 2 each are independently a divalent aromatic ring group and may have a substituent in a ring portion; here, at least one of A 1 and A 2 is a divalent nitrogen-containing heterocyclic group in which two hydrogen atoms are removed from a ring portion of one nitrogen-containing heterocyclic ring selected from the group consisting of a pyridine ring, a pyrazine ring, a pyrimidine ring and a pyridazine ring and may have a substituent in a ring portion; Y 1 and Y 2 each are independently an oxygen atom, a sulfur atom, or —NR 7 —, wherein R 7 is a hydrogen atom or a monovalent organic group; Z 1 is a divalent organic group having an aliphatic structure and 1 to 15 carbon atoms, at least one substituent for Y 1 and Y 2 and Z 1 may be bonded to form a ring structure, and substituents for Y 1 and Y 2 may be bonded to form a ring structure together with Z 1 , and * indicates a bond.

2. The liquid crystal aligning agent according to claim 1 ,

wherein Z 1 is a divalent organic group represented by the following Formula (5):

In Formula (5), R 9 and R 10 each are independently an alkanediyl group, and a total number of carbon atoms for R 9 and R 10 is 1 to 15; here, in Formula (4), at least one substituent for Y 1 and Y 2 and R 9 may be bonded to form a ring structure, at least one substituent for Y 1 and Y 2 and R 10 may be bonded to form a ring structure, and at least one substituent for Y 1 and Y 2 and a substituent for Y 3 may be bonded to form a ring structure together with R 9 or R 10 ; Y 3 is an oxygen atom, a sulfur atom, or —NR 8 —, wherein R 8 is a hydrogen atom or a monovalent organic group; p is an integer of 0 to 4; when p is 2 or more, a plurality of R 9 's and Y 3 's may be the same or different from each other.

3. The liquid crystal aligning agent according to claim 1 ,

wherein X 1 is a tetravalent organic group represented by the following Formula (3):

In Formula (3), R 1 to R 3 each are independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a thioalkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, or —COR 20 , wherein R 20 is an alkyl group having 1 to 6 carbon atoms, a fluorine-containing alkyl group, an alkoxy group or a fluorine-containing alkoxy group; R 4 is a halogen atom, an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a thioalkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, or —COR 20 ; here, adjacent groups among R 1 to R 4 may be bonded to form a ring structure, and * indicates a bond.

4. The liquid crystal aligning agent according to claim 1 ,

wherein A 1 and A 2 are both a divalent nitrogen-containing heterocyclic group in which two hydrogen atoms are removed from a ring portion of one nitrogen-containing heterocyclic ring selected from the group consisting of a pyridine ring, a pyrazine ring, a pyrimidine ring and a pyridazine ring, and

wherein Y 1 and Y 2 are bonded to carbon atoms adjacent to nitrogen atoms in the ring of the nitrogen-containing heterocyclic ring with respect to the nitrogen-containing heterocyclic ring that A 1 and A 2 have.

5. The liquid crystal aligning agent according to claim 4 ,

wherein the nitrogen-containing heterocyclic ring that A 1 and A 2 have is a pyridine ring, and

wherein bonding sites of Y 1 and Y 2 on the pyridine ring are at the ortho position with respect to a nitrogen atom of the pyridine ring and at the para position with respect to a nitrogen atom in Formula (1) and Formula (2) which is bonded to X 2 .

6. The liquid crystal aligning agent according to claim 1 ,

wherein at least one of Y and Y 2 is —NR 7 —.

7. A liquid crystal alignment film formed using the liquid crystal aligning agent according to claim 1 .

8. A method for producing a liquid crystal alignment film, comprising

a photo-alignment process in which a coating film is framed using the liquid crystal aligning agent according to claim 1 , and a light emission treatment is performed on the coating film to impart a liquid crystal alignment ability.

9. The method for producing a liquid crystal alignment film according to claim 8 , further comprising

a contact process in which the coating film subjected to the light emission treatment is brought into contact with water, a water-soluble organic solvent, or a solvent in which water and a water-soluble organic solvent are mixed.

10. The method for producing a liquid crystal alignment film according to claim 9 , further comprising

a heating process in which the coating film subjected to the light emission treatment is heated in a temperature range of 120° C. or higher and 280° C. or lower in at least one of before the contact process and after the contact process.

11. A liquid crystal element comprising the liquid crystal alignment film according to claim 7 .

12. A polymer comprising at least one selected from the group consisting of a partial structure represented by the following Formula (1) and a partial structure represented by the following Formula (2):

In Formula (1) and Formula (2), X 1 is a tetravalent organic group having a cyclobutane ring structure and has at least one substituent in a ring portion of a cyclobutane ring; X 2 is a divalent organic group represented by the following Formula (4); R 5 and R 6 each are independently a hydrogen atom or a monovalent organic group having 1 to 6 carbon atoms,

*-A 1 -Y 1 -Z 1 -Y 2 -A 2 -*  (4)

In Formula (4), A 1 and A 2 each are independently a divalent aromatic ring group and may have a substituent in a ring portion; here, at least one of A 1 and A 2 is a divalent nitrogen-containing heterocyclic group in which two hydrogen atoms are removed from a ring portion of one nitrogen-containing heterocyclic ring selected from the group consisting of a pyridine ring, a pyrazine ring, a pyrimidine ring and a pyridazine ring and may have a substituent in a ring portion; Y 1 and Y 2 each are independently an oxygen atom, a sulfur atom, or —NR 7 —, wherein R 7 is a hydrogen atom or a monovalent organic group; Z 1 is a divalent organic group having an aliphatic structure and 1 to 15 carbon atoms, at least one substituent for Y 1 and Y 2 and Z 1 may be bonded to form a ring structure, and substituents for Y 1 and Y 2 may be bonded to form a ring structure together with Z 1 , and * indicates a bond.