Liquid crystal aligning agent and liquid crystal display element

Abstract

This liquid crystal aligning agent contains: a polymer α which is obtained from a compound having a polymerizable group that has a polymerizable unsaturated hydrocarbon group; at least one type of polymer β which is selected from among a polyimide, a polyamic acid, a polyamic acid ester, a polyamide, and a polyurea; and either the compound A or the compound B described below.　Compound A: a compound represented by formula (Add1-A) Compound B: a compound represented by formula (Add1-B), which is a compound having two to four glycidyl groups in each molecule and at least one unsaturated bond in each molecule (In formula (Add1-A), n, m1, and m2 each independently represent 1 or 2.　X1 and X2 each represent a single bond, an oxygen atom, -NR- (wherein R is a hydrogen atom or a methyl group), or an ester bond.　A represents a specific group.) (In formula (Add1-B), G represents a group represented by formula (G-1).　Z represents a group represented by formula (Z-1) or (Z-2).)

Description

Liquid crystal alignment agent and liquid crystal display element

[0001] The present invention relates to a liquid crystal alignment agent, a liquid crystal display element, and a method for manufacturing a liquid crystal display element.

[0002] In recent years, liquid crystal display elements (LCDs) have been widely used in displays for mobile phones, computers, and televisions. LCDs possess characteristics such as thinness, light weight, and low power consumption, and are expected to be applied to further content such as VR (Virtual Reality) and ultra-high-definition displays in the future. Various display methods have been proposed for LCDs, including TN (Twisted Nematic), IPS (In-Plane Switching), and VA (Vertical Alignment), but all of these methods utilize a film (liquid crystal alignment film) that guides the liquid crystals into a desired orientation state.

[0003] In particular, for products equipped with touch panels such as tablet PCs, smartphones, and smart TVs, the IPS method is preferred because it is less likely to cause display distortion when touched. In recent years, liquid crystal display elements using the FFS (Fringe Field Switching) method and liquid crystal alignment technologies using optical alignment methods have been used to improve contrast and viewing angle characteristics.

[0004] A liquid crystal alignment film is a component of a liquid crystal display element, formed on the surface of a substrate that sandwiches the liquid crystal, and plays the role of aligning the liquid crystal in a specific direction between the substrates. In addition to aligning the liquid crystal in a specific direction, such as parallel to the substrate, the liquid crystal alignment film is sometimes required to control the pre-tilt angle of the liquid crystal. This ability to control the orientation of the liquid crystal in a liquid crystal alignment film (hereinafter referred to as "alignment control ability") is given by performing an alignment treatment on the organic film that constitutes the liquid crystal alignment film.

[0005] However, the FFS method has drawbacks compared to the IPS method, such as higher substrate manufacturing costs and the occurrence of a unique display defect called Vcom shift. On the other hand, while the photo-alignment method has advantages over the rubbing alignment method, such as being more adaptable to element enlargement and significantly improving display characteristics, it also has fundamental challenges (display defects due to decomposition products when using photo-decomposition type materials, and burn-in due to insufficient alignment force when using photo-isomerization type materials). Currently, liquid crystal display element manufacturers and liquid crystal alignment film manufacturers are employing various methods to solve these problems.

[0006] In recent years, it has been discovered that by forming a compatible interface between the polymer and the liquid crystal (a liquid-liquid interface in a completely wet state) at the contact interface between the liquid crystal and the substrate in liquid crystal cells, a "zero-plane anchoring" state without orientation restricting force in the in-plane direction can be created, and liquid crystal switching devices with no switching threshold and orientation memory properties have been reported (see Patent Document 1).

[0007] A weak-anchoring IPS method has been proposed that utilizes weak-anchoring technology. Compared to conventional IPS methods, this method can achieve improved contrast ratio and significantly lower voltage operation (see Patent Document 2).

[0008] The weak anchoring IPS method is created by using a liquid crystal alignment film with strong anchoring energy on one side of the substrate, and an organic thin film with no anchoring energy on the other side of the substrate (equipped with electrodes that generate a transverse electric field).

[0009] In recent years, a weak anchoring IPS method has been proposed that uses a method of directly attaching a dense polymer brush to the substrate (see Patent Document 3).

[0010] Furthermore, as an alternative method, a weakly anchored IPS method has been proposed, which uses a liquid crystal alignment film capable of generating photoradicals and a compound capable of radical polymerization, and weakly anchors the liquid crystal by irradiating it with UV light to induce a radical reaction (see Patent Document 4). This technology enables improved contrast ratio, significantly lower voltage driving, faster response, and reduced burn-in using a mass-producible method.

[0011] Japanese Patent Publication No. 2006-84536, Japanese Patent Publication No. 2013-231757, Japanese Patent Publication No. 2018-028621, Japanese Patent No. 7234924

[0012] The present inventors have proposed block copolymers having block segments that are insoluble in liquid crystals or become insoluble upon heating and block segments that are compatible with liquid crystals, as well as polymer alloys of the same with polyamic acid, polyamic acid esters, and polyimides as materials exhibiting weak anchoring properties (see Japanese Patent Application No. 2021-96448 and WO2022 / 260048).

[0013] However, materials exhibiting the aforementioned weak anchoring properties generally have low mechanical strength and poor adhesion to the sealant used when manufacturing liquid crystal display elements, which can lead to problems such as breakage during the manufacturing process. Furthermore, in recent years, liquid crystal display elements have been used in portable devices such as mobile PCs and tablets, and there is a growing demand for even higher resistance to external impacts. Therefore, when using weak anchoring technology for liquid crystal display elements, it is necessary to ensure sufficiently high adhesion strength with the sealant.

[0014] If these technical challenges can be resolved, it is conceivable that panel manufacturers will benefit greatly, not only from lower power consumption in LCDs, but also from improved yield during panel manufacturing and increased panel reliability.

[0015] This invention was made to solve the above-mentioned problems, and aims to provide a liquid crystal alignment agent with excellent seal adhesion strength and display characteristics, a liquid crystal display element using the same, and a method for manufacturing a liquid crystal display element using the same.

[0016] The inventors of the present invention conducted diligent research to solve the above problems and, as a result, found that they could solve the above problems, and completed the present invention having the following gist.

[0017] [1] A liquid crystal aligning agent containing a polymer α obtained from a compound having a polymerizable group having an unsaturated hydrocarbon group capable of undergoing polymerization, at least one polymer β selected from polyimide, polyamic acid, polyamic acid ester, polyamide, and polyurea, and a compound selected from the following compound A and the following compound B. Compound A: A compound represented by the following formula (Add1-A) Compound B: A compound represented by the following formula (Add1-B) which has two or more and four or less glycidyl groups in the molecule and has at least one unsaturated bond in the molecule (In the formula (Add1-A), n1, m1, and m2 each independently represent 1 or 2. When n1 is 1 and m1 is 1, X １ represents a single bond, an oxygen atom, -NR- (R is a hydrogen atom or a methyl group), or an ester bond. When n1 is 1 and m1 is 2, X １ represents a nitrogen atom. When n1 is 1 and m2 is 1, X ２ represents a single bond, an oxygen atom, -NR- (R is a hydrogen atom or a methyl group), or an ester bond. When n1 is 1 and m2 is 2, X ２ represents a nitrogen atom. When n1 is 1 and at least one of X １ and X ２ is an oxygen atom, a nitrogen atom, -NR- (R is a hydrogen atom or a methyl group), or an ester bond, A represents a divalent hydrocarbon group having a ring structure and having 6 to 18 carbon atoms. When n1 is 1, m1 is 1, m2 is 1, and X １ and X ２ are single bonds, A represents a divalent organic group obtained by removing hydrogen atoms of hydroxy groups on both sides from (poly)ethylene glycol, (poly)propylene glycol, or (poly)butylene glycol having a molecular weight of 1000 or less. When n1 is 2, m1 and m2 represent 1, X １ and X ２ represent oxygen atoms, and A represents a trivalent hydrocarbon group having 1 to 6 carbon atoms.) (In formula (Add1-B), Y represents a single bond or a divalent group represented by any of the following formulas (Y-1) to (Y-8). G represents a group represented by the following formula (G-1). X represents an oxygen atom, a -NR- (where R is a hydrogen atom or a methyl group), or an ester bond. Z represents a group represented by any of the following formulas (Z-1) to (Z-2). j and k are each independent integers between 1 and 2. m and n are each independent integers between 0 and 1, and m + n ≥ 1. If there are multiple G, X, and Z, the multiple G, X, and Z may be the same or different from each other.) (In equations (Y-1) to (Y-8), R １ and R ２ Each of these independently represents a hydrogen atom, a fluorine atom, a hydrocarbon group having 1 to 2 carbon atoms, or a fluorinated hydrocarbon group having 1 to 2 carbon atoms. * represents a bonding site. (In formula (G-1), * represents a bonding site.) (In formulas (Z-1) to (Z-2), * represents a bonding site.) [2] The liquid crystal alignment agent according to [1], wherein the polymerizable group is at least one selected from a (meth)acryloyloxy group, a (meth)acrylamide group, an allyl group, a styryl group, and a maleimide group. [3] The liquid crystal alignment agent according to [1] or [2], wherein the compound represented by formula (Add1-A) is selected from the following formulas. (wherein i is an integer from 1 to 22, j is an integer from 1 to 16, and k is an integer from 1 to 13.) [4] The liquid crystal alignment agent according to any one of [1] to [3], wherein the content of the compound represented by formula (Add1-A) is 1 to 30% by mass relative to the total amount of polymer components contained in the liquid crystal alignment agent. [5] The liquid crystal alignment agent according to [1] or [2], wherein the compound represented by formula (Add1-B) has the following structure. [6] A liquid crystal alignment agent according to any one of [1], [2], and [5], wherein the content of the compound represented by formula (Add1-B) is 1 to 30% by mass relative to the total amount of polymer components contained in the liquid crystal alignment agent. [7] A liquid crystal alignment agent according to any one of [1] to [6], wherein the fired film obtained by coating and firing the liquid crystal alignment agent exhibits weak anchoring properties. [8] A weak anchoring liquid crystal alignment agent used for forming the liquid crystal alignment film of a liquid crystal cell having a liquid crystal and a liquid crystal alignment film, wherein the polymer α contains at least one selected from the group consisting of polymer A, polymer B, and polymer C below. Polymer A: A block copolymer having a block segment (A) that is compatible with the liquid crystal and a block segment (B) that is not compatible with the liquid crystal or becomes insoluble in the liquid crystal by firing. Polymer B: A graft copolymer having a stem polymer and branch polymers bonded to the stem polymer as side chains of the stem polymer, wherein the branch polymers are compatible with the liquid crystal, and the stem polymer is not compatible with the liquid crystal or becomes insoluble in the liquid crystal by firing. Polymer C: A polymer having polymer units compatible with the liquid crystal and reacting with polymer β by heating. [9] The liquid crystal alignment agent according to [8], wherein the block segment (A) in polymer A, the branch polymer in polymer B, and the liquid crystal compatible polymer unit in polymer C contain as a component at least one selected from the group consisting of a compound represented by the following formula (2), a compound represented by the following formula (3), a compound represented by the following formula (4), and a compound represented by the following formula (5), and the block segment (B) in polymer A and the stem polymer in polymer B contain as a component a compound represented by the following formula (6). (In formula (2), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, X represents a single bond, ether bond, ester bond, amide bond, urethane bond, urea bond, or thioether bond, R １ represents an alkyl group having 1 to 20 carbon atoms, which may have a bonding group inserted, and n is an integer from 1 to 2. When n is 2, there are two X and R １They may be the same or they may be different. (In formula (3), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, S represents a saturated hydrocarbon group having 1 to 6 carbon atoms with a single bond or an inserted bonding group, T represents an organic group represented by the following formula (3-T), and n is an integer from 1 to 2. When n is 2, the two T's may be the same or different. However, when n is 2, S represents a saturated hydrocarbon group having 1 to 6 carbon atoms with an inserted bonding group.) (In formula (3-T), * indicates a bonding site. X is a single bond, ether bond, ester bond, amide bond, urethane bond, urea bond, thioether bond, -Si(R) １ ) (Caution ２ ) - (R １ and R ２ Each of these represents an alkyl group that is independently bonded to Si. ), -Si(R ３ ) (Caution ４ )-O-(R ３ and R ４ Each of these represents an alkyl group that is independently bonded to Si. ), and -N (R ５ ) - (R ５ represents a hydrogen atom or alkyl group bonded to N. (The bond group is selected from , and Cy represents a non-aromatic cyclic group with 6 to 20 members.) (In formula (4), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, and R １ The 'X' represents an aliphatic hydrocarbon group having a straight or branched structure with 1 to 10 carbon atoms, and each of the three 'X's independently represents a hydrogen atom or the following formula (4-X). However, at least one of the three 'X's represents the formula (4-X). (In formula (4-X), Y represents a single bond, -O-, -S-, or -N(R)- (where R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms bonded to N), and * indicates a bonding site. ２ , R ３ , and R ４ Each of these independently represents an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group which may have substituents. (In formula (5), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, and R １~R ３ Each of these independently represents an alkylene group having 1 to 6 carbon atoms, which may have a single bond or an inserted bonding group, and Ar represents an aromatic hydrocarbon group which may have a substituent, X １ and X ２ Each of these independently represents a hydrogen atom or an aromatic hydrocarbon group which may have substituents, and R １ X １ and R ２ X ２ and R １ X １ and R ２ X ２ The carbon atom bonded to it may form a ring together with it. However, R １ X １ , R ２ X ２ and R ３ The total number of carbon atoms is 1 or more. (In formula (6), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, and n is an integer between 1 and 2. Z represents a group represented by the following formula (6-Z). When n is 2, the two Zs may be the same or different.) (In formula (6-Z), L is an optionally protected amino group, an optionally protected aniline group, an optionally protected hydroxyl group, an optionally protected phenol group, an optionally protected thiol group, an optionally protected thiophenol group, an optionally protected carboxyl group, an optionally protected benzoic acid group, an optionally protected isocyanate group, a C2-C5 cyclic ether group, a maleimide group, a carboxylic anhydride group, an N-hydroxysuccinimide ester group, an oxazoline group, a trialkoxysilyl group, a vinyl group optionally substituted with a C1-C16 alkyl group, an ethynyl group optionally substituted with a C1-C16 alkyl group, an allyl group, a styryl group, an α- The first part represents a functional group selected from the group consisting of a hydroxyacetophenone group, an α-aminoalkylphenone group, an oxime ester group, and an acylphosphine oxide group. J represents a single bond or an aliphatic hydrocarbon group having 1 to 10 carbon atoms. K and Q each independently represent a linking group selected from a single bond, an ether bond, an ester bond, an amide bond, a urea bond, a urethane bond, and a thioether bond. P represents a single bond or a phenylene group. R represents a single bond or an alkylene group having 1 to 16 carbon atoms. * represents a bonding site. m is an integer from 1 to 3. When m is 2 or 3, multiple K, P, Q, R and L may be the same or different. However, when J is a single bond, m is 1.)

[10] The liquid crystal alignment agent according to [8] or [9], wherein the branch polymer in polymer B is derived from a macromonomer represented by the following formula (7). (In formula (7), P represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, Q is a structure obtained by polymerizing a monomer containing at least one of the compounds represented by formulas (2) to (5), and n is an integer from 1 to 2. When n is 2, the two Qs may be the same or different.)

[11] The liquid crystal alignment agent according to [8] or [9], wherein the polymer C is a polymer represented by the following formula (8). (In formula (8), A represents an n-valent organic group with a molecular weight of 500 or less, selected from the following formulas (8-A-1) to (8-A-16), which has a group that reacts with the polymer β upon heating. Q is a divalent polymer unit compatible with the liquid crystal, containing as a component at least one selected from the group consisting of compounds represented by formulas (2) to (5). R is a monovalent organic group with a molecular weight of 500 or less, selected from the following formulas (8-R-1) to (8-R-11), which does not react with the polymer β upon heating. n is an integer from 1 to 2. When n is 2, the two Qs and Rs may be the same or different.) (In formulas (8-A-1) to (8-A-16), R １ and R ２ Each of these independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, R ３ and R ４ Each of the symbols independently represents a single bond or a linear or branched alkylene group with 1 to 12 carbon atoms, and X represents an oxygen atom or a sulfur atom. * represents a bonding site. (In formulas (8-R-1) to (8-R-11), R １ and R ２ Each of these independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, R ３ and R ４ Each of the following independently represents a single bond or a linear or branched alkylene group having 1 to 12 carbon atoms. * represents a bonding site.)

[12] The liquid crystal alignment agent according to any one of [8] to

[11] , wherein polymer A to polymer C are polymers obtained by living polymerization or chain transfer polymerization.

[13] A liquid crystal display element comprising a liquid crystal alignment film formed using the liquid crystal alignment agent according to any one of [1] to

[12] .

[14] The liquid crystal display element according to

[13] , which is a transverse electric field liquid crystal display element.

[15] A method for manufacturing a liquid crystal display element, comprising coating and firing the liquid crystal alignment agent according to any one of [1] to

[12] .

[16] The method for manufacturing a liquid crystal display element according to

[15] , wherein the liquid crystal display element is a transverse electric field liquid crystal display element.

[0018] According to the present invention, it is possible to improve the seal adhesion strength without impairing the display characteristics compared to the conventional technology, and in addition to reducing power consumption and improving display characteristics, it is possible to reduce damage that occurs during the manufacturing of liquid crystal display elements in industrial production and damage after commercialization. By using the materials and methods of the present invention, it is possible to provide materials, transverse electric field liquid crystal display elements, and longitudinal electric field liquid crystal display elements that can exhibit better display characteristics and improved seal adhesion compared to the conventional technology.

[0019] This is a schematic cross-sectional view showing an example of the transverse field liquid crystal display element of the present invention. This is a schematic cross-sectional view showing another example of the transverse field liquid crystal display element of the present invention.

[0020] (Liquid Crystal Alignment Agent) The liquid crystal alignment agent of the present invention contains polymer α, polymer β, and one of the following compounds A and B. Polymer α is a polymer obtained from a polymerizable group having polymerizable unsaturated hydrocarbon groups. Polymer β is at least one polymer selected from polyimide, polyamic acid, polyamic acid ester, polyamide, and polyurea. Compound A: A compound represented by the following formula (Add1-A) Compound B: A compound having two to four glycidyl groups in the molecule and at least one unsaturated bond in the molecule, represented by the following formula (Add1-B) The compound represented by formula (Add1-A) may be referred to as "specific additive A". The compound represented by formula (Add1-B) may be referred to as "specific additive B". Specific additive A and specific additive B may be collectively referred to as "specific additive".

[0021] << Compound represented by formula (Add1-A) >> (In equation (Add1-A), n1, m1, and m2 each independently represent 1 or 2. When n1 is 1 and m1 is 1, X １ This represents a single bond, an oxygen atom, -NR- (where R is a hydrogen atom or a methyl group), or an ester bond. When n1 is 1 and m1 is 2, X １ This represents a nitrogen atom. When n1 is 1 and m2 is 1, X ２This represents a single bond, an oxygen atom, -NR- (where R is a hydrogen atom or a methyl group), or an ester bond. When n1 is 1 and m2 is 2, X ２ represents a nitrogen atom. n1 is 1 and X １ and X ２ When at least one of them is an oxygen atom, a nitrogen atom, a -NR- (where R is a hydrogen atom or a methyl group), or an ester bond, A represents a divalent hydrocarbon group having 6 to 18 carbon atoms and a ring structure. n1 is 1, m1 is 1, m2 is 1 and X １ and X ２ When it is a single bond, A represents a divalent organic group obtained by removing the hydrogen atoms from the hydroxyl groups on both sides of (poly)ethylene glycol, (poly)propylene glycol, or (poly)butylene glycol, with a molecular weight of 1000 or less. When n1 is 2, m1 and m2 represent 1, and X １ and X ２ (where represents an oxygen atom, and A represents a trivalent hydrocarbon group with 1 to 6 carbon atoms.)

[0022] In divalent hydrocarbon groups having 6 to 18 carbon atoms and possessing a ring structure, aliphatic hydrocarbon rings or aromatic rings are preferred as the ring structure. The aliphatic hydrocarbon ring may be a saturated aliphatic hydrocarbon ring or an unsaturated aliphatic hydrocarbon ring. The aromatic ring may be an aromatic hydrocarbon ring or an aromatic heterocycle. Examples of aromatic hydrocarbon rings include benzene rings and naphthalene rings. The ring structure in divalent hydrocarbon groups having 6 to 18 carbon atoms and possessing a ring structure may be monocyclic or polycyclic. The number of ring structures is not particularly limited and may be one or two. Examples of the number of carbon atoms constituting one ring structure (monocyclic or polycyclic) include 6 to 10. Examples of monocyclic saturated aliphatic hydrocarbon rings and unsaturated aliphatic hydrocarbon rings include cyclohexane rings and cyclohexene rings. The polycyclic ring may be a fused ring, a bridged ring, or a spiro ring. An example of a fused saturated aliphatic hydrocarbon ring is a decahydronaphthalene ring. Examples of saturated aliphatic hydrocarbon rings that act as bridge rings include norbornene rings. Furthermore, divalent hydrocarbon groups having 6 to 18 carbon atoms and possessing a ring structure may be groups in which two or three rings are bonded, with or without a bonding group. Examples of such bonding groups include methylene groups and isopropylene groups.

[0023] The number of carbon atoms in the trivalent hydrocarbon group having 1 to 6 carbon atoms may be, for example, 3 to 6 or 4 to 6. The hydrocarbon group in the trivalent hydrocarbon group having 1 to 6 carbon atoms is preferably an acyclic group.

[0024] Unlike conventional polyamic acids and polyimides used in liquid crystal alignment films, polymer α used in this invention is highly hydrophobic and has poor mechanical strength. This results in poor adhesion to sealants used in the manufacture of liquid crystal display elements, and even if adhesion is achieved, problems such as fracture at the polymer α layer occur. On the other hand, through diligent verification, it has been found that these problems can be solved by using a specific additive A, and that seal adhesion and seal adhesion strength can be improved without impairing display characteristics compared to conventional additives with crosslinking properties. In formula (Add1-A), "A" represents the central skeleton of the additive, and the structure of this part is considered particularly important because it is thought to control the compatibility state of polymer α and polymer β. Preferred structures for "A" in formula (Add1-A) include a trivalent hydrocarbon group having 1 to 6 carbon atoms, a divalent hydrocarbon group having 6 to 18 carbon atoms with a ring structure, or a divalent organic group having a polyethylene glycol, polypropylene glycol, or polybutylene glycol skeleton with a molecular weight of 1000 or less. Specific structures include the following. In the formula, * represents a combination. i is an integer from 1 to 22, j is an integer from 1 to 16, and k is an integer from 1 to 13.

[0025] In formula (Add1-A), X １ and X ２ The 'm' represents the bonding group to the glycidyl group, and can be a single bond, an oxygen atom, a nitrogen atom, a -NR- (where R is a hydrogen atom or a methyl group), or an ester bond. In the formula, n, m1, and m2 represent the number of glycidyl groups, each independently being 1 to 2. Since these are determined by the structure of A, there is no particular limit to which is preferred. The following structure is particularly preferred in terms of availability, ease of synthesis, and properties. (In the formula, i is an integer between 1 and 22, j is an integer between 1 and 16, and k is an integer between 1 and 13.)

[0026] <<Compound represented by formula (Add1-B)>> (In formula (Add1-B), Y represents a single bond or a divalent group represented by any of the following formulas (Y-1) to (Y-8). G represents a group represented by the following formula (G-1). X represents an oxygen atom, a -NR- (where R is a hydrogen atom or a methyl group), or an ester bond. Z represents a group represented by any of the following formulas (Z-1) to (Z-2). j and k are each independent integers between 1 and 2. m and n are each independent integers between 0 and 1, and m + n ≥ 1. If there are multiple G, X, and Z, the multiple G, X, and Z may be the same or different from each other.) (In equations (Y-1) to (Y-8), R １ and R ２ Each of these independently represents a hydrogen atom, a fluorine atom, a hydrocarbon group having 1 to 2 carbon atoms, or a fluorinated hydrocarbon group having 1 to 2 carbon atoms. * represents a bonding site. (In formula (G-1), * represents a bonding site.) (In equations (Z-1) to (Z-2), * represents a bonding site.)

[0027] Unlike conventional polyamic acids and polyimides used in liquid crystal alignment films, polymer α used in this invention is highly hydrophobic and has poor mechanical strength. This results in poor adhesion to sealants used in the manufacture of liquid crystal display elements, and even if adhesion is achieved, problems such as fracture at the polymer α layer occur. However, through diligent verification, it has been found that these problems can be solved by using a specific additive B represented by formula (Add1-B). It has been found that seal adhesion and seal adhesion strength can be improved without impairing display characteristics compared to conventional additives with crosslinking properties.

[0028] In formula (Add1-B), Y is a single bond or a bonding group represented by any of the above formulas (Y-1) to (Y-8). In formula (Y-1), R １ and R ２ Each of these is preferably independently a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0029] In formula (Add1-B), G is the group represented by formula (G-1) above (glycidyl group). X represents the bonding group to the glycidyl group and is a single bond, an oxygen atom, -NR- (R is a hydrogen atom or a methyl group), or an ester bond. In the formula, j and k represent the number of groups having a glycidyl group (-X-G), and are independently 1 to 2. From the viewpoint of availability and ease of synthesis, it is preferable that j=k=1 or j=k=2, and more preferably that j=k=1. The structure that is particularly preferred from the viewpoint of availability, ease of synthesis, and properties is the following structure.

[0030] The content of specific additives is not particularly limited, but is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, and even more preferably 10 to 20% by mass, relative to the total amount of polymer contained in the liquid crystal alignment agent.

[0031] The polymer α used in the present invention is obtained from a compound having a polymerizable group that has a polymerizable unsaturated hydrocarbon group. The aforementioned compound may be referred to as a "specific monomer." As the polymerizable group of the specific monomer for obtaining polymer α, at least one selected from (meth)acryloyloxy group, (meth)acrylamide group, allyl group, styryl group, and maleimide group is preferred.

[0032] The liquid crystal alignment agent containing the polymer α described above can be used as a weak anchoring liquid crystal alignment agent. The fired film obtained by coating and firing the weak anchoring liquid crystal alignment agent exhibits weak anchoring properties, and a weak anchoring liquid crystal display element can be obtained by using this film in a liquid crystal display element.

[0033] To achieve both good coatability, seal adhesion, film strength, and orientation characteristics of the orientation film, it is essential to use polymer α and polymer β in combination. In addition, the mixing ratio of polymer α and polymer β is an important factor. Details of polymer β will be explained below. To suitably achieve the aforementioned characteristics, it is preferable to keep the mass ratio of polymer α to polymer β small. A preferred introduction ratio (polymer α / polymer β) is 0.1 / 99.9 to 50 / 50 (mass ratio), and more preferably 1.0 / 99.0 to 40 / 60 (mass ratio).

[0034] (Weak Anchoring) In the present invention, "weak anchoring" means that there is a force that restricts the orientation of liquid crystal molecules relative to the substrate in the azimuthal or polar angular direction, but there is no anchoring strength (i.e., interfacial elastic energy that maintains the position of the liquid crystal molecules or returns them to their original state even if the orientation of the liquid crystal molecules changes), or if there is, it is weaker than the intermolecular forces between liquid crystals, and in the weak anchoring of the present invention, the azimuthal anchoring strength (A ２ ) is 10 －５ [J / ! ２ This refers to the case where the value is smaller than ]. As described in Japanese Patent Publication No. 2013-231757, it is known that a polymer capable of forming a completely wet state with the liquid crystal is provided at the substrate interface, and when this polymer comes into contact with the liquid crystal, a polymer-liquid crystal mixed layer is formed, and a weak anchoring state is exhibited.

[0035] (Weakly anchoring alignment film) In the present invention, "weakly anchoring alignment film" refers to a film that forms a weakly anchoring state by coming into contact with a liquid crystal, and is not limited to solid films but also includes liquid films that cover a solid surface.

[0036] (Weakly Anchored Liquid Crystal Display Element) A weakly anchored liquid crystal display element can be fabricated by coating the weakly anchored alignment film and the strongly anchored alignment film defined above onto an electrode-equipped substrate and bonding them together as a pair. In a weakly anchored liquid crystal display element, because the azimuthal angle anchoring intensity of one of the liquid crystal alignment films is extremely small, it is possible to induce a change in liquid crystal orientation with a weak electric field or external field energy, and it is possible to change the orientation of liquid crystal molecules in regions that normally do not move. In particular, in display elements using comb-tooth electrodes such as IPS and FFS, it becomes possible to drive liquid crystal molecules on electrodes with weak electric field strength, thus enabling higher transmittance and lower driving voltage compared to a liquid crystal display element in which both alignment films are strongly anchored alignment films.

[0037] Azimuthal anchoring strength is an index that represents the strength of the interfacial elastic energy between liquid crystal molecules and liquid crystal alignment films in the azimuthal direction. Methods used to calculate azimuthal anchoring strength include the torque balance method, the strong electric field method, the geometry method (external field application method), and the Fredericks transition method.

[0038] (Weakly Anchoring Liquid Crystal Alignment Agent) A weakly anchoring liquid crystal alignment agent, which is one embodiment of the present invention, is used to form a liquid crystal alignment film in a liquid crystal cell having a liquid crystal and a liquid crystal alignment film. The weakly anchoring liquid crystal alignment agent contains polymer α, polymer β, a compound from either compound A or compound B, and a solvent. Polymer α preferably contains at least one selected from the group consisting of polymer A, polymer B, and polymer C. In this specification, polymer α may be written as polymer (α), but polymer α and polymer (α) are synonymous. In this specification, polymer β may be written as polymer (β), but polymer β and polymer (β) are synonymous. In this specification, polymer A may be written as polymer (A), but polymer A and polymer (A) are synonymous. In this specification, polymer B may be written as polymer (B), but polymer B and polymer (B) are synonymous. In the specification, polymer C may sometimes be written as polymer (C), but polymer C and polymer (C) are synonymous.

[0039] Unlike polyamic acids and polyimides conventionally used in liquid crystal alignment films, the block copolymers and graft copolymers used in this invention have high hydrophobicity and poor mechanical strength. This results in poor adhesion to sealants used in the manufacture of liquid crystal display elements, and even if adhesion is achieved, problems such as fracture at the polymer α layer occur. It has been found that these problems can be solved by using the aforementioned specific additives in the weak anchoring liquid crystal alignment agent of this invention, enabling the provision of materials and weak anchoring liquid crystal display elements that exhibit better display characteristics and improved seal adhesion compared to conventional technologies.

[0040] (Polymer α selected from polymer (A), polymer (B), and polymer (C)) The weakly anchoring liquid crystal alignment agent of the present invention is used to form a liquid crystal alignment film in a liquid crystal cell having a liquid crystal and a liquid crystal alignment film. The weakly anchoring liquid crystal alignment agent of the present invention is characterized by containing polymer (α) which contains at least one selected from the group consisting of polymer (A), polymer (B), and polymer (C) which are polymers that exhibit weak anchoring properties, polymer (β) which does not exhibit weak anchoring properties, a compound of compound A and compound B, and a solvent. Polymer (A): A block copolymer having block segments (A) which are compatible with the liquid crystal and block segments (B) which are not compatible with the liquid crystal or become insoluble in the liquid crystal by firing. Polymer (B): A graft copolymer having a stem polymer and branch polymers bonded to the stem polymer as side chains of the stem polymer, wherein the branch polymers are compatible with the liquid crystal and the stem polymer is not compatible with the liquid crystal or becomes insoluble in the liquid crystal by firing. Polymer (C): A polymer having polymer units compatible with the liquid crystal and reacting with polymer (β) upon heating.

[0041] (Polymer A (Block Copolymer)) One embodiment of the "polymer" in the present invention is a copolymer contained in a weakly anchoring liquid crystal alignment agent.

[0042] The block copolymer [polymer (A)] has block segments (A) that are compatible with liquid crystals and block segments (B) that are not compatible with liquid crystals or become insoluble in liquid crystals by firing. Block segments (A) consist of polymers that remain compatible with liquid crystals even after the copolymer is fired.

[0043] The block segment (A) preferably contains as a component at least one selected from the group consisting of the compound represented by the following formula (2), the compound represented by the following formula (3), the compound represented by the following formula (4), and the compound represented by the following formula (5).

[0044] The block segment (B) preferably contains a compound represented by the following formula (6) as a constituent component.

[0045] The block copolymer may have three or more block segments.

[0046] The block copolymer is preferably a copolymer in which the main chain extends in a linear manner without branching. In the present invention, by using a block segment compatible with liquid crystals as the block segment of the block copolymer contained in one embodiment of the liquid crystal alignment agent, it is possible to produce a weakly anchoring film more easily than by conventional methods.

[0047] The applicant has discovered and filed patent applications for radical polymerizable compounds contained in a liquid crystal composition that can stably produce a weakly anchored transverse electric field liquid crystal display element without generating a pre-tilt angle, and which contribute to the generation of weak anchoring, specifically the compounds represented by formula (2), formula (3), formula (4), and formula (5) below (Japanese Patent Application Nos. 2020-134149, 2020-163212, 2021-041196, WO2022 / 030602, PCT / JP2021 / 35557 (WO2022 / 071286), WO2019 / 004433. By reference herein, the contents of these applications and publications are incorporated herein to the same extent as if they were fully expressed).

[0048] Furthermore, the applicant has discovered and filed a patent application (Japanese Patent Application No. 2021-96448 and PCT / JP2022 / 22993 (WO2022 / 260048). By being cited herein, the contents of this application are incorporated herein to the same extent as if they were fully expressed.)

[0049] The block segment (A) primarily plays a role in exhibiting weak anchoring characteristics.

[0050] (In formula (2), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, X represents a single bond, ether bond, ester bond, amide bond, urethane bond, urea bond, or thioether bond, R １ represents an alkyl group having 1 to 20 carbon atoms, which may have a bonding group inserted, and n is an integer from 1 to 2. When n is 2, there are two X and R １ These may be the same or different.) Examples of bonding groups in C1-C20 alkyl groups that may have a bonding group inserted include ether bonds, ester bonds, amide bonds, urethane bonds, urea bonds, thioether bonds, and -Si(R １１ ) (Caution １２ ) - (R １１ and R １２ Each of these represents an alkyl group that is independently bonded to Si. ), -Si(R １３ ) (Caution １４ )-O-(R １３ and R １４ Each of these represents an alkyl group that is independently bonded to Si. ), -N (R １５ ) - (R １５ R represents a hydrogen atom or alkyl group bonded to N. １１ ~R １５Examples of the alkyl group in [this context] include alkyl groups having 1 to 6 carbon atoms.

[0051] (In Formula (3), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, S represents a single bond or a saturated hydrocarbon group having 1 to 6 carbon atoms in which a bonding group may be inserted, T represents an organic group represented by the following Formula (3-T), and n is an integer of 1 to 2. When n is 2, the two Ts may be the same or different. However, when n is 2, S represents a saturated hydrocarbon group having 1 to 6 carbon atoms in which a bonding group may be inserted.)

[0052] (In Formula (3-T), * indicates the bonding site. X is a single bond, an ether bond, an ester bond, an amide bond, a urethane bond, a urea bond, a thioether bond, -Si(R １ )(R ２ )-(R １ and R ２ each independently represent an alkyl group bonded to Si.), -Si(R ３ )(R ４ )-O-(R ３ and R ４ each independently represent an alkyl group bonded to Si.), and -N(R ５ )-(R ５ represents a hydrogen atom or an alkyl group bonded to N.) is a bonding group selected from these, and Cy represents a non-aromatic cyclic group having 6 to 20 ring members.)

[0053] The saturated hydrocarbon group in S in formula (3) refers to an (n + 1)-valent group formed by removing n + 1 hydrogen atoms from a saturated hydrocarbon (n is the same integer as n in formula (3)). When n is 1, the saturated hydrocarbon group is an alkylene group. In S in formula (3), the saturated hydrocarbon group having 1 to 6 carbon atoms with a linking group inserted therein means an (n + 1)-valent group in which a linking group is inserted between carbon-carbon bonds in a saturated hydrocarbon group having 2 to 6 carbon atoms, or an (n + 1)-valent group in which a linking group is inserted between a saturated hydrocarbon group having 1 to 6 carbon atoms and an atom (e.g., a carbon atom) bonded thereto. Examples of the linking group in S in formula (3) include a carbon-carbon unsaturated bond, an ether bond (—O—), an ester bond (—COO— or —OCO—), an amide bond (—CONH— or —NHCO—), etc. Examples of the carbon-carbon unsaturated bond include a carbon-carbon double bond, etc. For the saturated hydrocarbon group having 1 to 6 carbon atoms with a carbon-carbon double bond inserted therein, it is preferable that the carbon-carbon double bond is present not at the terminal but inside. When n is 1, examples of the alkylene group having 1 to 6 carbon atoms in which a linking group may be inserted include an alkylene group having 1 to 6 carbon atoms, an oxyalkylene group having 1 to 6 carbon atoms, etc. The alkylene group having 1 to 6 carbon atoms may be a linear alkylene group, a branched alkylene group, or a cyclic alkylene group.

[0054] In X of formula (3-T), —Si(R １ )(R ２ )—, R １ and R ２ are each independently an alkyl group bonded to Si, for example, an alkyl group having 1 to 6 carbon atoms. In X of formula (3-T), —Si(R ３ )(R ４ )—O—, R ３ and R ４ are each independently an alkyl group bonded to Si, for example, an alkyl group having 1 to 6 carbon atoms. In X of formula (3-T), —N(R ５ )—, R ５ is a hydrogen atom or an alkyl group bonded to N. The alkyl group is, for example, an alkyl group having 1 to 6 carbon atoms.

[0055] In formula (3-T), Cy is a non-aromatic cyclic group with 6 to 20 members, preferably a non-aromatic cyclic group with 8 to 18 members. Cy may also be a non-aromatic cyclic group with 12 to 20 members. In formula (3-T), X is bonded to an atom constituting the ring in Cy. Examples of atoms constituting the ring in a non-aromatic cyclic group include carbon atoms, oxygen atoms, nitrogen atoms, and silicon atoms. The bond between atoms constituting the ring may be a single bond, a double bond, or a triple bond, but a single bond is preferred. Examples of rings in a non-aromatic cyclic group include cyclic alkanes, cyclic ethers, and cyclic siloxanes. An example of a cyclic ether is a crown ether. For example, in 12-crown-4, the atoms constituting the ring are carbon atoms and oxygen atoms, and the number of members is 12. The ring may be monocyclic or polycyclic. Examples of the number of rings in a polycyclic ring include 2 to 4. In polycyclic compounds, there are three possible ways in which the rings are bonded to each other: • Sharing of one atom: e.g., spirocyclic compounds • Sharing of two atoms: cases where two rings share two atoms, such as decalin • Bridged structure: cases where two rings can be considered to share three or more atoms, such as norbornane. In the case of polycyclic compounds, the number of ring members is determined by the number of atoms constituting the ring. For example, norbornane is a seven-membered ring. The atoms constituting the ring may have halogen atoms or C1-C6 alkyl groups bonded to them instead of hydrogen atoms. Examples of halogen atoms include fluorine atoms and chlorine atoms.

[0056] (In formula (4), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, and R １ The 'X' represents an aliphatic hydrocarbon group having a straight or branched structure with 1 to 10 carbon atoms, and each of the three 'X's independently represents a hydrogen atom or the following formula (4-X). However, at least one of the three 'X's represents the formula (4-X).

[0057] (In formula (4-X), Y represents a single bond, -O-, -S-, or -N(R)- (where R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms bonded to N), and * indicates a bonding site. ２ , R ３ , and R ４ Each of these independently represents an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group which may have substituents.

[0058] R in equation (4) １ The aliphatic hydrocarbon group in this product has 1 to 10 carbon atoms, and may have 1 to 8 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms.

[0059] R in equation (4-X) ２ , R ３ , and R ４ The C1-C6 alkyl group in this expression may, for example, be a C1-C5 alkyl group or a C1-C4 alkyl group. These alkyl groups may have a linear or branched structure.

[0060] R in equation (4-X) ２ , R ３ , and R ４ The aromatic hydrocarbon group in the compound may be unsubstituted, or its hydrogen atoms may be substituted by substituents. Examples of substituents on the aromatic hydrocarbon group that may have substituents include halogen atoms, C1-C4 alkyl groups, C1-C4 alkoxy groups, C1-C4 halogenated alkyl groups, and C1-C4 halogenated alkoxy groups. The halogenation in halogenated alkyl groups and halogenated alkoxy groups may be total halogenation or partial halogenation. Examples of halogen atoms include fluorine atoms and chlorine atoms. Examples of aromatic hydrocarbon groups that may have substituents include phenyl groups and naphthyl groups. The number of substituents on the aromatic hydrocarbon group is not particularly limited.

[0061] In equation (4), there is one or more equations (4-X), which may be one, two, or three. In equation (4), the three X values ​​are independent of each other. Therefore, if there are two or more equations (4-X) in equation (4), the two or more equations (4-X) may have the same structure or different structures.

[0062] In equation (4-X), R ２ , R ３ , and R ４ At least one of them may be an aromatic hydrocarbon group which may have substituents. Therefore, in formula (4-X), R ２ , R ３ , and R ４ One of them may be an aromatic hydrocarbon group having a substituent, and R ２ , R ３ , and R ４ The two of these may be aromatic hydrocarbon groups having substituents, and R ２ , R ３ , and R ４ These three may be aromatic hydrocarbon groups having substituents.

[0063] (In formula (5), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, and R １ ~R ３ Each of these independently represents an alkylene group having 1 to 6 carbon atoms, which may have a single bond or an inserted bonding group, and Ar represents an aromatic hydrocarbon group which may have a substituent, X １ and X ２ Each of these independently represents a hydrogen atom or an aromatic hydrocarbon group which may have substituents, and R １ X １ and R ２ X ２ and R １ X １ and R ２ X ２ The carbon atom bonded to it may form a ring together with it. However, R １ X １ , R ２ X ２ and R ３The total number of carbon atoms is 1 or more.

[0064] R in equation (5) １ ~R ３ In this context, an alkylene group having 1 to 6 carbon atoms with an inserted bonding group refers to a divalent group in which a bonding group is inserted between carbon atoms within the alkylene group having 1 to 6 carbon atoms, or a divalent group in which a bonding group is inserted between the alkylene group having 1 to 6 carbon atoms and the carbon atom bonded to it. Examples of bonding groups include carbon-carbon unsaturated bonds, ether bonds (-O-), ester bonds (-COO- or -OCO-), and amide bonds (-CONH- or -NHCO-). Examples of unsaturated bonds include carbon-carbon double bonds, but it is preferable that the alkylene group having 1 to 6 carbon atoms with an inserted bonding group has a carbon-carbon double bond internally rather than at its terminal. Examples of alkylene groups having 1 to 6 carbon atoms that may have a bonded bonding group include alkylene groups having 1 to 6 carbon atoms and oxyalkylene groups having 1 to 6 carbon atoms. The oxygen atoms in the oxyalkylene group having 1 to 6 carbon atoms are, for example, M and R in formula (5). １ , R ２ , and R ３ It bonds with the carbon atom that is bonded to it. The alkylene group having 1 to 6 carbon atoms may be a linear alkylene group, a branched alkylene group, or a cyclic alkylene group.

[0065] X in equation (5) １ and X ２ Examples of optionally substituted aromatic hydrocarbon groups include optionally substituted phenyl groups and naphthyl groups. Examples of substituents include halogen atoms, C1-C4 alkyl groups, C1-C4 alkoxy groups, C1-C4 halogenated alkyl groups, and C1-C4 halogenated alkoxy groups. The halogenation in halogenated alkyl groups and halogenated alkoxy groups may be total halogenation or partial halogenation. Examples of halogen atoms include fluorine atoms and chlorine atoms.

[0066] R in equation (5) １Examples include single bonds and alkylene groups having 1 to 6 carbon atoms. More specifically, examples of alkylene groups having 1 to 6 carbon atoms include linear alkylene groups having 1 to 6 carbon atoms. R in formula (5) ２ Examples include single bonds and alkylene groups having 1 to 6 carbon atoms. More specifically, examples of alkylene groups having 1 to 6 carbon atoms include linear alkylene groups having 1 to 6 carbon atoms. R in formula (5) ３ Examples include single bonds and alkylene groups having 1 to 6 carbon atoms. More specifically, examples of alkylene groups having 1 to 6 carbon atoms include linear alkylene groups having 1 to 6 carbon atoms. X in formula (5) １ Examples include hydrogen atoms and phenyl groups. ２ Examples include hydrogen atoms and phenyl groups. In formula (5), Ar can be a phenyl group, for example.

[0067] R in equation (5) １ X １ , R ２ X ２ and R ３ The total number of carbon atoms is not particularly limited as long as it is 1 or more, but it may be 2 or more. Also, R in formula (5) １ , R ２ , and R ３ The total number of carbon atoms may be, for example, 18 or less, 15 or less, or 10 or less. Also, X in formula (5) １ and X ２ If R is a hydrogen atom, １ , R ２ , and R ３ The total number of carbon atoms is not particularly limited as long as it is 1 or more, but it may be 2 or more. Note that X in formula (5) １ and X ２ In the case of an aromatic hydrocarbon group in which at least one of the groups may have substituents, R １ , R ２ , and R ３ The total number of carbon atoms may be zero.

[0068] In equation (5), R １ X１ and R ２ X ２ and R １ X １ and R ２ X ２ Examples of rings formed by the bonded carbon atoms include hydrocarbon rings having 3 to 13 carbon atoms, which may have a bonding group inserted. The bonding group is as described above.

[0069] By using the structure of the above compound, it is easier to achieve high-speed response when the voltage is turned off, reduced burn-in, high backlight transmittance in low-temperature environments, and low-voltage driving.

[0070] The block segment (A) may be a single polymer of the above compound, or multiple compounds may be used in combination. When combining, random copolymerization or block copolymerization may be used. When combining with compound species compatible with liquid crystals, the ratio is not particularly limited, regardless of the combination method. When combining with compound species that become insoluble in liquid crystals as described below, the preferred combination ratio of compound species that become insoluble in liquid crystals is 30 mol% or less, more preferably 20 mol% or less, from the viewpoint of maintaining properties, but is not limited. It is preferable to use these combination methods, compound species to be combined, and combination ratios within a range that yields the desired physical properties, display characteristics, electrical characteristics, etc.

[0071] The polymerizable unsaturated hydrocarbon group of the polymerizable compound used to form block segment (A) has the following preferred structure, but is not limited to these. (In the formula, R １ , and R ２ Each of the following independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, and X, Y, and Z independently represent an oxygen atom or a sulfur atom. *, * １ and * ２ * represents the bonding site, １ and * ２ Either one of them may be replaced with a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms.

[0072] The polymerizable compound compatible with liquid crystals used to form block segments (A) in polymer (A) has the following preferred structure, but is not limited to these.

[0073]

[0074] The block segment (A) is mainly swollen into the liquid crystal in a thin film state and plays a role in forming a weak anchoring film. Since the physical properties of the weak anchoring film differ greatly depending on the molecular weight of the block segment (A), optimization of the molecular weight is important, although it is not strictly necessary. From the viewpoint of forming a good weak anchoring film, the preferred molecular weight of the block segment (A) is 1,000 to 100,000, and more preferably 3,000 to 50,000. This molecular weight is the number-average molecular weight (Mn) in polystyrene terms, measured by gel permeation chromatography (GPC). Furthermore, the molecular weight distribution PDI (Mw / Mn), which is the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) in polystyrene terms, measured by GPC, is preferably 3.0 or less, and more preferably 2.0 or less.

[0075] The block segment (B) contributes to the stability of the weakly anchored liquid crystal alignment film in the thin film state.

[0076] The block segment (B) preferably has a side chain structure having at least one functional group selected from the group consisting of trialkoxysilyl group, isocyanate group, blocked isocyanate group, epoxy group, oxetane group, vinyl group, allyl group, oxazoline group, amino group, protected amino group, aniline group, protected aniline group, hydroxy group, protected hydroxy group, phenol group, protected phenol group, thiol group, protected thiol group, thiophenol group, protected thiophenol group, aldehyde group, carboxyl group, maleimide group, N-hydroxysuccinimide ester group, C5-C18 aromatic hydrocarbon group which may have a bonding group inserted, C5-C18 aromatic heterocyclic group which may have a bonding group inserted, cinnamic acid group, cinnamic acid aromatic ester group, alkyl cinnamic acid ester group, cinnamyl group, phenylbenzoate group, azobenzene group, N-benzylideneaniline group, stilbene group, and tran group. Specific examples of bonding groups include the specific examples of bonding groups listed in the description of formula (2). In that case, block segment (B) includes, for example, a polymerizable compound having the above-mentioned functional group and a polymerizable group having a polymerizable unsaturated hydrocarbon group as a constituent component.

[0077] An example of a polymerizable compound used to form block segments (B) is represented by the following formula (6).

[0078] (In formula (6), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, and n is an integer between 1 and 2. Z represents a group represented by the following formula (6-Z). When n is 2, the two Zs may be the same or different.)

[0079] (In formula (6-Z), L is an optionally protected amino group, an optionally protected aniline group, an optionally protected hydroxyl group, an optionally protected phenol group, an optionally protected thiol group, an optionally protected thiophenol group, an optionally protected carboxyl group, an optionally protected benzoic acid group, an optionally protected isocyanate group, a C2-C5 cyclic ether group, a maleimide group, a carboxylic anhydride group, an N-hydroxysuccinimide ester group, an oxazoline group, a trialkoxysilyl group, a vinyl group optionally substituted with a C1-C16 alkyl group, an ethynyl group optionally substituted with a C1-C16 alkyl group, an allyl group, a styryl group, an α- This represents a functional group selected from the group consisting of hydroxyacetophenone, α-aminoalkylphenone, oxime ester, and acylphosphine oxide groups. J represents a single bond or an aliphatic hydrocarbon group having 1 to 10 carbon atoms. K and Q independently represent linking groups selected from single bonds, ether bonds, ester bonds, amide bonds, urea bonds, urethane bonds, and thioether bonds. P represents a single bond or a phenylene group. R represents a single bond or an alkylene group having 1 to 16 carbon atoms. * represents a bonding site. m is an integer from 1 to 3. If m is 2 or 3, multiple K, P, Q, R, and L may be the same or different. However, if J is a single bond, m is 1.

[0080] An example of a polymerizable compound used to form block segment (B) is a compound having a polymerizable group with a polymerizable unsaturated hydrocarbon group and a thermosetting structure. The following structures are preferred for the above thermosetting structure, i.e., group L in formula (6-Z). However, it is not limited to these.

[0081] (X, Y, and Z each independently represent an oxygen atom or a sulfur atom. R １ , R ２ and R ３ Each of these independently represents an alkyl group having 1 to 18 carbon atoms. ４ and R ５Each of these independently represents a single bond or an alkylene group having 1 to 18 carbon atoms. Et represents an ethyl group. * represents a bonding site.

[0082] By using the above compound structure in the block segment (B), polymer A is less likely to dissolve into the liquid crystal due to the heat generated by liquid crystal driving and backlight illumination, thus reducing the likelihood of defects.

[0083] The block segment (B) may be a single polymer of the above compound, or multiple compounds may be used in combination. When combining compounds, random copolymerization or block copolymerization may be used. When combining with compound species that are incompatible with liquid crystals or that become incompatible with liquid crystals after firing, the ratio is not particularly limited regardless of the combination method. When combining with compound species compatible with liquid crystals, the preferred combination ratio of liquid crystal-compatible compound species from the viewpoint of suppressing elution into the liquid crystal is 70 mol% or less, and more preferably 50 mol% or less. However, as stated above, the block segment (B) is merely a block segment that contributes to the stability of the film and does not significantly affect the weak anchoring characteristics, so the compound species to be combined and the method of combination are not particularly limited as long as the stabilization of the film is complemented.

[0084] The polymerizable group having a polymerizable unsaturated hydrocarbon group used in the formation of block segment (B) preferably has the same structure as the polymerizable group having a polymerizable unsaturated hydrocarbon group described in block segment (A).

[0085] Polymerizable compounds that are incompatible with or become incompatible with liquid crystals upon firing, forming block segments (B) in polymer (A), are preferably structured as follows. However, they are not limited to these structures.

[0086] (In formulas (B-1) to (B-19), Me represents a methyl group and Et represents an ethyl group.)

[0087] The block segment (B) is primarily responsible for stabilization in the thin film state and does not significantly affect the physical properties of the weakly anchored film. It is sufficient that the film stability is complemented by the block segment (B), and the optimal molecular weight for complementing film stability is not particularly limited as it varies depending on the compound used. Furthermore, depending on the compound used, advantages in solvent selectivity and coatability can be obtained, so it is best to control the compound species and molecular weight that make up the block segment (B) according to the application and purpose. Here, stabilization in the thin film state means that when the thin film after firing comes into contact with the liquid crystal, the block segment (B) becomes insoluble in the liquid crystal, so that the block copolymer constituting the thin film does not dissolve into the liquid crystal.

[0088] One embodiment of polymer (A) is a copolymer having block segments (A) that are compatible with liquid crystals and block segments (B) that are insoluble in liquid crystals or become insoluble in liquid crystals by calcination. However, the number of blocks is not limited, and a configuration having multiple block segments such as (A)-(B)-(A) is also possible, and the number and combination of these block segments are not particularly limited. Block segments that impart electrical properties can also be introduced. On the other hand, from the viewpoint of ease of synthesis, the number of block segments is preferably around 2 to 4, and from the viewpoint of film stability, it is preferable that the block segment at the end of the polymer is block segment (B).

[0089] As described above, the block segment (A) compatible with the liquid crystal governs the weak anchoring characteristics, and the molecular weight of block segment (A) greatly influences these characteristics; therefore, the molecular weight ratio between block segment (A) and block segment (B) is not limited.

[0090] Polymer (A) can be obtained, for example, by living polymerization. Living polymerization is a polymerization reaction that does not involve side reactions such as chain transfer or termination reactions during the polymerization reaction, and it is possible to obtain polymers with a narrow molecular weight distribution and a highly controlled structure. For example, one method is to introduce a stable covalent species called a dormant species into the polymerization active site to suppress the deactivation of the active site and prevent side reactions such as chain transfer or termination reactions from occurring. Living polymerization can be performed using radicals, cations, or anions as active species, and it is important to choose the appropriate method depending on the structure and properties of the polymerizable compound used. When obtaining the block copolymer, which is polymer (A), the polymerization method does not need to be particularly limited, but cationic polymerization and anionic polymerization often use alkali metals, metal complexes, or halogen compounds when generating active species, and in liquid crystal displays, the inclusion of metal residues or halogen compounds can cause burn-in or display defects, so it is preferable to use radical polymerization, which does not use metals or halogen compounds as much as possible. Living radical polymerization includes living radical polymerization (NMP) using nitroxides as the dormant species, atom transfer radical polymerization (ATRP) using metal complexes, reversible addition-elimination chain transfer polymerization (RAFT polymerization) using sulfur compounds as the dormant, living radical polymerization (TERP) using organotellurium compounds, etc., and reversible transfer catalytic polymerization (RTCP) using alkyl iodide compounds as the dormant species and phosphorus compounds or alcohols as catalysts. Preferred polymerization methods include living radical polymerization such as NMP, RTCP, and RAFT polymerization, with NMP or RAFT polymerization being particularly preferred.

[0091] When NMP is used, examples of polymerization initiators include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), benzoyl peroxide, 1,1'-bis(tert-butylperoxy)cyclohexane, and hydrogen peroxide. The amount of polymerization initiator used is usually 0.000001 to 0.1 moles, preferably 0.00001 to 0.01 moles, per mole of monomer used. Examples of nitroxides include compounds represented by the following formulas (N-1) to (N-12). The amount of nitroxide used is usually 0.000001 to 0.1 moles, preferably 0.00001 to 0.01 moles, per mole of monomer used. The reaction temperature in the above polymerization is preferably 20 to 200°C, more preferably 40 to 150°C, and the reaction time is preferably 1 to 168 hours, more preferably 8 to 72 hours.

[0092]

[0093] When using RTCP, in addition to low molecular weight dormant species (dormant species) that contribute to the development of living properties, it is necessary to use an iodide catalyst or hydride catalyst and a polymerization initiator for the purpose of promoting the reaction. Examples of polymerization initiators that can be used include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), benzoyl peroxide, 1,1'-bis(tert-butylperoxy)cyclohexane, and hydrogen peroxide. The ratio of polymerization initiator used is usually 0.000001 to 0.1 moles, preferably 0.00001 to 0.01 moles, per mole of monomer used. Examples of low molecular weight dormant species (dormant species) include compounds represented by the following formulas (Q-1) to (Q-3). The proportion of low molecular weight dormant species used is typically 0.000001 to 0.1 moles, preferably 0.00001 to 0.01 moles, per mole of monomer used. Examples of iodide catalysts include compounds represented by the following formulas (P-1) to (P-4). The proportion of iodide catalyst used is typically 0.000001 to 0.1 moles, preferably 0.00001 to 0.01 moles, per mole of monomer used. Examples of hydride catalysts include compounds represented by the following formulas (O-1) to (O-6). The proportion of hydride catalyst used is typically 0.000001 to 0.1 moles, preferably 0.00001 to 0.01 moles, per mole of monomer used. Typically, the reaction temperature in the above polymerization is preferably 20 to 200°C, more preferably 40 to 150°C, and the reaction time is preferably 1 to 168 hours, more preferably 8 to 72 hours.

[0094]

[0095]

[0096]

[0097] When using RAFT polymerization, examples of polymerization initiators include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), benzoyl peroxide, 1,1'-bis(tert-butylperoxy)cyclohexane, and hydrogen peroxide. The proportion of polymerization initiator used is usually 0.000001 to 0.1 moles, preferably 0.00001 to 0.01 moles, per mole of monomer used. As chain transfer agents (RAFT agents), trithiocarbonates, dithiobenzoates, dithiocarbamates, and xanthanates are preferred, and specific examples include compounds represented by the following formulas (R-1) to (R-24). The proportion of chain transfer agents used is usually 0.000001 to 0.1 moles, preferably 0.00001 to 0.01 moles, per mole of monomer used. The reaction temperature in the polymerization described above is preferably 20 to 200°C, more preferably 40 to 150°C, and the reaction time is preferably 1 to 168 hours, more preferably 8 to 72 hours.

[0098]

[0099] Living radical activity in RAFT polymerization occurs because, as the majority of the living chain is dormant (resting), there are compounds that can reversibly inactivate the growing radical species, and a rapid equilibrium exists between the active chain and the dormant chain.

[0100] Using RAFT polymerization enables precise control of polymer end structures, advanced molecular weight control, and molecular weight distribution control.

[0101] To precisely synthesize functional polymers using RAFT polymerization, it is necessary to select an appropriate chain transfer agent considering the reactivity of the monomers.

[0102] In RAFT polymerization, the polymer ends can be controlled by thermally or chemically modifying the RAFT ends present at the growth ends. Thermal modification involves heating to a temperature above the thermal decomposition temperature of the RAFT agent used, thereby modifying the ends into unsaturated hydrocarbon groups. Chemical modification involves contact with primary or secondary amines, which leads to aminolysis and modification of the ends into thiol bonds. Furthermore, contact with new monomers and radical generators allows for the creation of new block segments at the ends.

[0103] In RAFT polymerization, molecular weight control is possible by using the following formula (eq1). Specifically, the number-average molecular weight (Mn) changes linearly with the ratio of the molar concentration of the monomer to the molar concentration of the chain transfer agent, thus enabling molecular weight control. (In the above formula (eq1), Mn （ｔｈｅｏｒ） The symbol represents the molecular weight of the polymer, and [Monomer] ０ [CTA] represents the molar concentration of monomer. ０ represents the molar concentration of the chain transfer agent, M ｍｏｎｏｍｅｒ represents the molecular weight of the monomer, and conv. represents the polymerization conversion rate. ＣＴＡ (This represents the molecular weight of the chain transfer agent.)

[0104] Furthermore, if the copolymer obtained by the above polymerization is dissolved in the reaction solution, the reaction solution may be used as is for the preparation of the liquid crystal alignment agent, or the copolymer contained in the reaction solution may be isolated before being used for the preparation of the liquid crystal alignment agent.

[0105] For radical polymerization, known compounds such as radical polymerization initiators (radical thermal polymerization initiators, radical photopolymerization initiators) and reversible addition-cleavage chain transfer (RAFT) polymerization reagents can be used as polymerization initiators.

[0106] Radical thermal polymerization initiators are compounds that generate radicals when heated above their decomposition temperature. Examples of such radical thermal polymerization initiators include ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), diacyl peroxides (acetyl peroxide, benzoyl peroxide, etc.), hydroperoxides (hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyketals (dibutyl peroxycyclohexane, etc.), alkyl peroxyesters (tert-butyl peroxyneodecanoate, tert-butyl peroxypivalate, tert-amyl peroxy-2-ethylcyclohexanoate, etc.), persulfates (potassium persulfate, sodium persulfate, ammonium persulfate, etc.), and azo compounds (azobisisobutyronitrile, 2,2'-bis(2-hydroxyethyl)azobisisobutyronitrile, etc.). Radical thermal polymerization initiators may be used individually or in combination of two or more.

[0107] The radical photopolymerization initiator is not particularly limited as long as it is a compound that initiates radical polymerization by light irradiation. Examples of such radical photopolymerization initiators include benzophenone, Michla's ketone, 4,4'-bis(diethylamino)benzophenone, xanthone, thioxanthone, isopropylxanthone, 2,4-diethylthioxanthone, 2-ethylanthraquinone, acetophenone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-2-methyl-4'-isopropylpropiophenone, 1-hydroxycyclohexylphenyl ketone, isopropylbenzoin ether, isobutylbenzoin ether, 2 ,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, camphorquinone, benzantrone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 4-ethyl dimethylaminobenzoate, 4-isoamyl dimethylaminobenzoate, 4,4'-bis(tert-butylperoxycarbonyl)benzophenone, 3,4,4'-tris(tert-butylperoxy Cicarbonyl)benzophenone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-(4'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-pentyloxy Styryl)-4,6-bis(trichloromethyl)-s-triazine, 4-[p-N,N-di(ethoxycarbonylmethyl)]-2,6-di(trichloromethyl)-s-triazine, 1,3-bis(trichloromethyl)-5-(2'-chlorophenyl)-s-triazine, 1,3-bis(trichloromethyl)-5-(4'-methoxyphenyl)-s-triazine, 2-(p-dimethylaminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzothiazole, 2-mercaptobenzothiazole, 3,3'-Carbonylbis(7-diethylaminocoumarin), 2-(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetrakis(4-ethoxycarbonylphenyl)-1,2'-biimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4-dichlorophenyl) 2,2'-Bimidazole, 2,2'-Bis(2,4,6-Trichlorophenyl)-4,4',5,5'-Trichlorophenyl-1,2'-Bimidazole, 3-(2-Methyl-2-dimethylaminopropionyl)carbazole, 3,6-Bis(2-Methyl-2-morpholinopropionyl)-9-n-Dodecylcarbazole, 1-Hydroxycyclohexylphenyl ketone, Bis(η5-2,4-Cyclo Lopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium, 3,3',4,4'-tetrakis(tert-butylperoxycarbonyl)benzophenone, 3,3',4,4'-tetrakis(tert-hexylperoxycarbonyl)benzophenone, 3,3'-bis(methoxycarbonyl)-4,4'-bis(tert-butylperoxycarbonyl)benzophenone, 3,4'-bis( Examples include methoxycarbonyl)-4,3'-bis(tert-butylperoxycarbonyl)benzophenone, 4,4'-bis(methoxycarbonyl)-3,3'-bis(tert-butylperoxycarbonyl)benzophenone, 2-(3-methyl-3H-benzothiazole-2-ylidene)-1-naphthalene-2-yl-ethane, and 2-(3-methyl-1,3-benzothiazole-2(3H)-ylidene)-1-(2-benzoyl)ethane. The radical photopolymerization initiator may be used alone or in combination of two or more.

[0108] The organic solvent used in the synthesis of polymer (A) can be any solvent that does not chemically react with the compound species constituting the copolymer and does not scavenge radicals. For example, a compound represented by the following formula (S1) can be used. (In formula (S1), Q １ and Q ２ Each of these independently represents an alkyl group having 1 to 4 carbon atoms, Q ３ Q represents a linear, branched, or cyclic alkyl group having 1 to 8 carbon atoms, an alkoxyalkyl group having 2 to 8 carbon atoms, an alkylcarbonylalkyl group having 4 to 8 carbon atoms, or a hydrogen atom. １ Q ２ and Q ３ The total number of carbon atoms is 4 or more.) Examples of compounds represented by formula (S1) include N,N-diethylacetamide, N,N-diethylformamide, N,N-dibutylformamide, N,N-dipropylacetamide, N,N-dimethylpropionamide, N,N-diethylpropionamide, 3-methoxy-N,N-dimethylpropanamide, 2-methoxy-N,N-diethylacetamide, 3-methoxy-N,N-diethylpropanamide, 4-oxo-N,N-diethylpentanamide, and N,N-diethylcyclohexanecarboamide.

[0109] Other organic solvents include, for example, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methyl-ε-caprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethylphosphoramide, γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, and Cylnonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether (butyl cellosolve), propylene glycol, propylene glycol monoacetate, propylene Polypropylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1,4-Dioxane, n-Hexane, n-Pentane, n-Octane, Cyclohexane, 2-Ethyl-1-Hexanol, Benzene, Xylene, Toluene, Ethylbenzene, Isopropylbenzene, Tert-Butylbenzene, Tetrahydrofuran, Diethyl Ether, Cyclohexanone, Ethylene Carbonate, Propylene Carbonate, Methyl Lactate, Ethyl Lactate, Methyl Acetate, Ethyl Acetate, N-Butyl Acetate, Propylene Glycol Monoethyl Ether Acetate, Methyl Pyruvate, Ethyl Pyruvate, Methyl 3-Methoxypropionate, Ethyl 3-Methoxypropionate, Methyl 3-Ethoxypropionate, Ethyl 3-Ethoxypropionate, Ethoxypropionic Acid, 3-Methoxypropionic Acid, Propyl 3-Methoxypropionate, Butyl 3-Methoxypropionate, Diglyceride, 4-Hydroxy-4-Methyl-2-Pentanone, 3-Ethoxy-N,N-Dimethylpropanamide, 3-Butoxy-N,N-dimethylpropanamide, propyl pyruvate, butyl pyruvate, pentyl pyruvate, hexyl pyruvate, 2-ethylhexyl pyruvate, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, pentyl acetoacetate, hexyl acetoacetate, 2-ethylhexyl acetoacetate, methyl levulinate, ethyl levulinate, propyl levulinate, butyl levulinate, pentyl levulinate, hexyl levulinate, 2-ethylhexyl levulinate, dimethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, dimethyl phthalate, dimethyl maleate, diethyl malonate, diethyl succinate, diethyl glutarate, diethyl adipate, diethyl phthalate, diethyl maleate, dipropyl malonate Examples include dipropyl succinate, dipropyl glutarate, dipropyl adipate, dipropyl phthalate, dipropyl maleate, dibutyl malonate, dibutyl succinate, dibutyl glutarate, dibutyl adipate, dibutyl phthalate, dibutyl maleate, dipentyl malonate, dipentyl succinate, dipentyl glutarate, dipentyl adipate, dipentyl phthalate, dipentyl maleate, dihexyl malonate, dihexyl succinate, dihexyl glutarate, dihexyl adipate, dihexyl phthalate, dihexyl maleate, di-2-ethylhexyl malonate, 2-ethylhexyl succinate, 2-ethylhexyl glutarate, 2-ethylhexyl adipate, 2-ethylhexyl phthalate, and 2-ethylhexyl maleate. These organic solvents may be used individually or in combination.

[0110] The radical polymerization method is not particularly limited, and emulsion polymerization, suspension polymerization, dispersion polymerization, precipitation polymerization, bulk polymerization, solution polymerization, etc., can be used. The organic solvent used in the radical polymerization reaction is not particularly limited as long as it dissolves the resulting polymer. These organic solvents may be used individually or as a mixture of two or more.

[0111] Furthermore, even if the solvent does not dissolve the polymer to be produced, it may be mixed with the organic solvent mentioned above and used, as long as the produced polymer does not precipitate. Note that in radical polymerization, oxygen in the organic solvent inhibits the polymerization reaction, so it is preferable to use an organic solvent that has been degassed to the greatest extent possible. If the block copolymer obtained by the above polymerization is dissolved in the reaction solution, the reaction solution may be used directly for the preparation of the liquid crystal alignment agent, or the block copolymer contained in the reaction solution may be isolated before being used for the preparation of the liquid crystal alignment agent. The polymerization temperature during radical polymerization can be selected from any temperature between 30 and 150°C, but is preferably in the range of 50 to 100°C. The reaction can be carried out at any concentration, but if the concentration is too low, it becomes difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high, making uniform stirring difficult. Therefore, the monomer concentration is preferably 5 to 70% by mass, more preferably 10 to 50% by mass. Additionally, organic solvents may be added during the polymerization process to create a gradient in the polymerization concentration.

[0112] The polymer produced from the reaction solution obtained by the above reaction can be recovered by precipitation by adding the reaction solution to a poor solvent, although this reprecipitation treatment is not essential. Examples of poor solvents that can be used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, and water. The polymer precipitated by adding it to a poor solvent can be recovered by filtration and then dried at room temperature or by heating under atmospheric pressure or reduced pressure. Furthermore, the amount of impurities in the polymer can be reduced by repeating the operation of redissolving the recovered polymer in an organic solvent and recovering it by reprecipitation 2 to 10 times. Examples of poor solvents in this case include alcohols, ketones, and hydrocarbons, and it is preferable to use three or more poor solvents selected from these to further increase the efficiency of purification.

[0113] (Polymer B (Graft Copolymer)) One embodiment of the "graft copolymer" in the present invention is a graft copolymer contained in a weakly anchoring liquid crystal alignment agent. The weakly anchoring liquid crystal alignment agent is used to form a film that aligns liquid crystals used in liquid crystal display elements, i.e., a liquid crystal alignment film. The weakly anchoring liquid crystal alignment agent is also used to form a liquid crystal alignment film in a liquid crystal cell having liquid crystal and a liquid crystal alignment film. The graft copolymer [polymer (B)] has a stem polymer and branch polymers bonded to the stem polymer as side chains of the stem polymer. The branch polymer is compatible with liquid crystal. The stem polymer is not compatible with liquid crystal or becomes insoluble in liquid crystal by firing.

[0114] Graft copolymers are a general term for polymers having a branched structure, and refer to polymers that simultaneously have a polymer corresponding to the "stem" and polymers corresponding to the "branches" attached to the stem as side chains. One embodiment of the liquid crystal alignment agent of the present invention uses a graft copolymer, which is characterized by having branch polymers that are compatible with liquid crystals, while the graft copolymer itself is not compatible with liquid crystals or becomes insoluble in liquid crystals upon firing. That is, the branch polymers that are compatible with liquid crystals become compatible with the liquid crystal and swell, contributing to the formation of a weak anchoring state, while the graft copolymer itself is not compatible with liquid crystals or becomes insoluble in liquid crystals upon firing. This prevents the elution of the graft copolymer into the liquid crystal, and by fixing it to the substrate, crosslinking the polymers with each other, and crosslinking with sealing components, a weak anchoring liquid crystal display element with excellent film hardness and seal adhesion strength can be obtained.

[0115] The graft copolymer of the present invention is characterized by having branch polymers that are compatible with liquid crystals, while also being incompatible with liquid crystals or becoming insoluble in liquid crystals upon firing. In order to make the graft copolymer incompatible with liquid crystals, or to make the graft copolymer insoluble in liquid crystals upon firing, the stem polymer has a structure that is incompatible with liquid crystals or becomes insoluble in liquid crystals upon firing.

[0116] The graft copolymer of the present invention has branch polymers that are compatible with liquid crystals and stem polymers that are not compatible with liquid crystals or become insoluble due to heat, etc., but it is preferable that these are linked in a random arrangement by free radical polymerization. This provides high seal adhesion, solvent selectivity, and coatability.

[0117] The applicant has found and filed a patent application (Japanese Patent Application No. 2021-156886 and WO2023 / 048278) for a weak anchoring liquid crystal alignment agent containing polymer (B) that is easily manufactured, has good coatability, exhibits good adhesion to seals, does not generate a pre-tilt angle, and yields a weak anchoring liquid crystal alignment film that simultaneously achieves low-voltage drive and high-speed response when the voltage is turned off.

[0118] In the graft copolymer of the present invention, the "branch polymer" primarily plays a role in exhibiting weak anchoring properties.

[0119] The structure of the branched polymer compatible with liquid crystals is not particularly limited as long as it is compatible with liquid crystals, but for example, the branched polymer can be obtained by using a macromonomer represented by the following formula (7).

[0120] (In formula (7), P represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, Q is a structure obtained by polymerizing a monomer containing at least one of the compounds represented by formulas (2) to (5), and n is an integer between 1 and 2. When n is 2, the two Qs may be the same or different.)

[0121] By using the structure of the above compound, it is easier to achieve high-speed response when the voltage is turned off, reduced burn-in, high backlight transmittance in low-temperature environments, and low-voltage driving.

[0122] In branched polymers, the structure excluding the terminals (for example, the structure of Q in formula (7)) may be a single polymer structure using only one monomer represented by formulas (2) to (5) above, or a copolymer structure combining multiple monomers. When combining multiple monomers, random copolymerization or block copolymerization may be used. When combining monomers represented by formulas (2) to (5) above, the ratio is not particularly limited, regardless of the combination method. When combining with the liquid crystal-insoluble compound species described below, the preferred combination ratio of liquid crystal-insoluble monomers from the viewpoint of maintaining properties is 30 mol% or less, more preferably 20 mol% or less, but this is not limited. These synthesis methods, monomers to be combined, and combination ratios are preferably used within a range that yields the desired physical properties, display characteristics, electrical properties, etc.

[0123] The structure of P in formula (7) above, and the polymerizable group having a polymerizable unsaturated hydrocarbon group used in the formation of Q, should be selected from polymerizable groups having a polymerizable unsaturated hydrocarbon group that can be used in the polymerizable compound used in the formation of block segment (A) or block segment (B) in polymer A. However, it is not limited to these.

[0124] In polymer B, the branched polymer plays a significant role in the development of weak anchoring properties. Since the physical properties of the weak anchoring film change depending on the molecular weight of the branched polymer, optimizing the molecular weight is important. From the viewpoint of forming a good weak anchoring film, the preferred number-average molecular weight of the branched polymer is 1,000 to 100,000, more preferably 3,000 to 50,000, and the molecular weight distribution (PDI), expressed as the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn), is preferably 3.0 or less, more preferably 2.0 or less. Note that when the graft copolymer is synthesized by the grafting through method using macromonomers, the molecular weight referred to here corresponds to the molecular weight of the macromonomer.

[0125] In the graft copolymer of the present invention, the "stem polymer" primarily plays a role in stabilizing the weakly anchored liquid crystal alignment film in the thin film state.

[0126] The structure of the "core polymer," which is incompatible with liquid crystals or becomes insoluble in liquid crystals upon firing, is not particularly limited as long as it dissolves in liquid crystals. For example, the core polymer can be obtained by using a compound represented by formula (6) above. In other words, the core polymer may contain, for example, the compound represented by formula (6) as a constituent component.

[0127] By using the above compound structure, polymer B is less likely to dissolve into the liquid crystal due to the heat generated during liquid crystal driving and backlight illumination, thus reducing the likelihood of defects.

[0128] The "core polymer" may be a single polymer of the above compound, or multiple compounds may be used in combination. When combining with compound species that are incompatible with liquid crystals or that become incompatible with liquid crystals after firing, the ratio is not particularly limited, regardless of the combination method. When combining with compound species compatible with liquid crystals, the preferred combination ratio of liquid crystal-compatible compound species from the viewpoint of suppressing elution into the liquid crystal is 70 mol% or less, and more preferably 50 mol% or less. However, as stated above, the "core polymer" is merely a unit that contributes to the stability of the film and does not significantly affect the weak anchoring characteristics, so the compound species to be combined and the method of combination are not particularly limited, as long as the stabilization of the film is complemented.

[0129] The polymerizable group having a polymerizable unsaturated hydrocarbon group used in the formation of the "stem polymer" should be selected from polymerizable groups having a polymerizable unsaturated hydrocarbon group that can be used in the polymerizable compound used in the formation of block segment (A) or block segment (B) in polymer A. However, it is not limited to these.

[0130] The "stem polymer" is primarily responsible for stabilization in the thin film state and does not significantly affect the physical properties of the weakly anchored film. It is sufficient that the film stability is complemented by the "stem polymer," and the optimal molecular weight for complementing film stability is not particularly limited as it varies depending on the compound used. On the other hand, the introduction ratio of "branch polymers" and "stem polymers" is also an important factor in achieving both the coatability, seal adhesion, film strength, and good weak anchoring properties of the weakly anchored oriented film. For example, branch polymers play an important role in weak anchoring properties, and if their introduction ratio is too high, the film strength may be impaired or thermal curing may be inhibited, so it is necessary to consider an appropriate introduction amount. As mentioned above, the amount and molecular weight of the "stem polymer" do not affect (or have little effect on) weak anchoring properties, so in order to achieve both of the aforementioned properties, it is preferable to keep the ratio of the number of macromonomers represented by formula (7) used in the synthesis of branch polymers small to the number of monomers represented by formula (6) used in the synthesis of branch polymers. A preferred introduction ratio (macromonomer represented by formula (7) / monomer represented by formula (6)) is 0.1 / 99.9 to 50 / 50 (moles / mol), and more preferably 0.2 / 99.8 to 30 / 70 (moles / mol).

[0131] Considering the strength of the resulting coating film, the workability during coating film formation, and the uniformity of the coating film, the weight-average molecular weight of the graft copolymer, as measured by the GPC (Gel Permeation Chromatography) method, is preferably 2,000 to 5,000,000, and more preferably 5,000 to 2,000,000.

[0132] The macromonomer represented by formula (7), which is the raw material for forming the branch polymer of the graft copolymer polymer B, can be obtained, for example, by a combination of living polymerization, chain transfer polymerization, and polymer end modification reactions. For example, as reported in the reference below, a chain transfer polymer having a carboxylic acid group at one end can be synthesized by chain transfer polymerization of methyl methacrylate using thioglycolic acid as the chain transfer agent, and a macromonomer having a methacrylic acid group at one end can be synthesized by polymer reaction of this polymer with glycidyl methacrylate (Ito, K., Usami, N., Yamashita, Y.: Macromolecules, 13, 216 1980). It has also been reported that polymers having radically polymerizable unsaturated bonds at the end groups can be obtained by continuous bulk polymerization at high temperatures of 200°C or higher (Toagosei Research Annual Report TREND 2002 No. 5).

[0133] The main methods for synthesizing graft copolymers include the Grafting-to method, which directly introduces branch polymers into a stem polymer; the Grafting-from method, which extends branch polymers by polymerizing monomers from a macroinitiator (a stem polymer with polymerization active sites); and the Grafting-through method, which polymerizes macromonomers (polymers with polymerizable functional groups at one end). However, since any of these methods are available, the synthesis method is not limited.

[0134] The method for producing graft copolymers is not particularly limited, and general industrial methods can be used. Specifically, they can be produced using the above-mentioned monomers by radical polymerization, cationic polymerization, or anionic polymerization. Among these, radical polymerization is particularly preferred from the viewpoint of ease of reaction control and the influence of halogen and metal residues.

[0135] As the polymerization initiator for radical polymerization used in the synthesis of polymer (B), known compounds such as radical polymerization initiators (radical thermal polymerization initiators, radical photopolymerization initiators) and reversible addition-cleavage chain transfer (RAFT) polymerization reagents can be used, and it is preferable to select from radical polymerization initiators that can be used in the synthesis of polymer A.

[0136] The organic solvent used in the synthesis of polymer (B) can be any solvent that does not chemically react with the compound species constituting the copolymer and does not scavenge radicals. It is preferable to select an organic solvent that can be used in the synthesis of polymer A. Furthermore, the organic solvent may be used alone or in a mixture of two or more.

[0137] Furthermore, even if the solvent does not dissolve the polymer to be produced, it may be mixed with the organic solvent mentioned above and used, as long as the produced polymer does not precipitate. Note that in radical polymerization, oxygen in the organic solvent inhibits the polymerization reaction, so it is preferable to use an organic solvent that has been degassed to the greatest extent possible. If the graft copolymer obtained by the above polymerization is dissolved in the reaction solution, the reaction solution may be used directly for the preparation of the liquid crystal alignment agent, or the graft copolymer contained in the reaction solution may be isolated before being used for the preparation of the liquid crystal alignment agent. The polymerization temperature during radical polymerization can be selected from any temperature between 30 and 150°C, but is preferably in the range of 50 to 100°C. The reaction can be carried out at any concentration, but if the concentration is too low, it becomes difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high, making uniform stirring difficult. Therefore, the monomer concentration is preferably 1 to 50% by mass, more preferably 5 to 40% by mass. The reaction can be carried out at a high concentration initially, and then the organic solvent can be added.

[0138] In the radical polymerization reaction described above, if the ratio of radical polymerization initiator to monomer is high, the molecular weight of the resulting polymer will be low, and if it is low, the molecular weight of the resulting polymer will be high. Therefore, the ratio of radical initiator to monomer is preferably 0.1 to 10 mol% relative to the monomer to be polymerized. In addition, various monomer components, solvents, initiators, etc. can be added during polymerization.

[0139] The polymer produced from the reaction solution obtained by the above reaction can be recovered by precipitation by adding the reaction solution to a poor solvent, although this reprecipitation treatment is not essential. Examples of poor solvents that can be used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, and water. The polymer precipitated by adding it to a poor solvent can be recovered by filtration and then dried at room temperature or by heating under atmospheric pressure or reduced pressure. Furthermore, the amount of impurities in the polymer can be reduced by repeating the operation of redissolving the recovered polymer in an organic solvent and recovering it by reprecipitation 2 to 10 times. Examples of poor solvents in this case include alcohols, ketones, and hydrocarbons, and it is preferable to use three or more poor solvents selected from these to further increase the efficiency of purification.

[0140] (Polymer C) Polymer (C) is a polymer that has polymer units compatible with liquid crystals and reacts with polymer (β) upon heating.

[0141] Polymer (C) is a liquid crystal-compatible polymer that can be synthesized by polymerizing monomers compatible with liquid crystals (for example, living polymerization or chain transfer polymerization), and is characterized by its ability to chemically react with polymer (β) upon heating, becoming insoluble in liquid crystals.

[0142] Polymer (C) is used as a weakly anchoring liquid crystal alignment agent, intended to be mixed with polymer (β). Polymer (C) plays a role in exhibiting weak anchoring properties, while polymer (β) plays a role in suppressing the elution of polymer (C) into the liquid crystal. In the process of coating and firing a polymer blend consisting of polymer (C) and polymer (β) mixed in any ratio, polymer (C), which is compatible with liquid crystals, migrates to the surface, and weak anchoring properties are exhibited on the surface of the thin film. Furthermore, the chemical bonding between polymer (C) and polymer (β) in competition with the surface migration of polymer (C) can suppress the elution of polymer (C) into the liquid crystal. It is known that surface migration properties are determined by the difference in thermal expansion coefficients and polarity of each polymer. Polymer (C), which is compatible with liquid crystals, has a large thermal expansion coefficient and low polarity, while polymer (β) has a small thermal expansion coefficient and high polarity, so polymer (C) easily migrates to the surface during the coating and firing processes.

[0143] It is preferable to use a polymer (β) that reacts with the reactive groups contained in polymer (C) upon heating, and that also has excellent coatability, solvent selectivity, and adhesion to films, substrates, and seals. This allows for the expression of good and stable weak anchoring characteristics, and the weak anchoring orientation agent is characterized by good solvent selectivity and coatability, and excellent adhesion to films, seals, and substrates. However, the polymerization method is not limited as long as polymer (C) is a polymer that has polymer units compatible with liquid crystals and reacts with polymer (β). Furthermore, the type of polymer and polymerization method are not particularly limited as long as polymer (β) reacts with polymer (C) and can suppress the elution of polymer (C) into the liquid crystal.

[0144] The applicant has found and filed a patent application (Japanese Patent Application No. 2022-6921 and WO2023 / 140322) that a weak anchoring liquid crystal alignment agent containing a polymer such as polymer (C) (a polymer having polymer units compatible with liquid crystals and reacting with other polymers used in combination) can be easily manufactured, has good coatability, has good adhesion to seals, does not generate a pre-tilt angle, and can simultaneously achieve low-voltage driving and high-speed response when the voltage is turned off) to provide a weak anchoring liquid crystal alignment film.

[0145] In the weakly anchoring liquid crystal alignment agent of the present invention, which comprises a polymer blend of polymer (C) and polymer (β), polymer (C) primarily plays a role in exhibiting weak anchoring properties.

[0146] One embodiment of polymer (C) is a polymer represented by the following formula (8).

[0147] (In formula (8), A represents an n-valent organic group with a molecular weight of 500 or less, selected from the following formulas (8-A-1) to (8-A-16), which has a group that reacts with the polymer β upon heating. Q is a divalent polymer unit compatible with liquid crystal, containing as a component at least one selected from the group consisting of compounds represented by formulas (2) to (5). R is a monovalent organic group with a molecular weight of 500 or less, selected from the following formulas (8-R-1) to (8-R-11), which does not react with the polymer β upon heating. n is an integer from 1 to 2. When n is 2, the two Qs and Rs may be the same or different.)

[0148] (In formulas (8-A-1) to (8-A-16), R １ and R ２ Each of these independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, R ３ and R ４ Each of the symbols independently represents a single bond or a linear or branched alkylene group with 1 to 12 carbon atoms, and X represents an oxygen atom or a sulfur atom. * represents a bonding site.

[0149] (In formulas (8-R-1) to (8-R-11), R １ and R ２ Each of these independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, R ３ and R ４ Each of these independently represents a single bond or a linear or branched alkylene group having 1 to 12 carbon atoms. * represents a bonding site.) The number of carbon atoms in the linear or branched alkyl group having 1 to 12 carbon atoms varies depending on the group, for example, and may be 1 to 6 or 6 to 12. The number of carbon atoms in the linear or branched alkylene group having 1 to 12 carbon atoms may be 1 to 6 or 1 to 3.

[0150] In formula (8), A is a group selected from the above formulas (8-A-1) to (8-A-16). These are, for example, partial structures of RAFT agents in RAFT polymerization and chain transfer agents in chain transfer polymerization, which will be described later. For example, the -S-C(=S)- group reacts with amino groups, protected amino groups, hydroxyl groups, protected hydroxyl groups, thiol groups, protected thiol groups, carboxyl groups, protected carboxyl groups, isocyanate groups, protected isocyanate groups, maleimide groups, carboxylic anhydride groups, vinyl groups, allyl groups, styryl groups, (meth)acrylic groups, and (meth)acrylamide groups. The number of carbon atoms in a linear or branched alkyl group having 1 to 12 carbon atoms may be, for example, 1 to 6 or 1 to 3. The number of carbon atoms in a linear or branched alkylene group having 1 to 12 carbon atoms may be, for example, 1 to 6 or 1 to 3.

[0151] In formula (8), R is a group selected from formulas (8-R-1) to (8-R-11) above. These are, for example, partial structures of the RAFT agent in RAFT polymerization, which will be described later.

[0152] In formula (8), Q is a divalent polymer unit compatible with liquid crystals, which contains at least one compound selected from the group consisting of compounds represented by formulas (2) to (5) as a constituent component.

[0153] The monomer used in the synthesis of polymer C may be a single component or a combination of multiple monomers. Furthermore, other radical polymerization monomers, as described below, may also be used in combination.

[0154] The structure of Q in the polymer represented by formula (8), which is an example of polymer (C), may be a single polymer structure using only one compound (monomer) represented by formulas (2) to (5) above, or a copolymer structure combining multiple monomers. When combining multiple monomers, random copolymerization or block copolymerization may be used. When combining monomers represented by formulas (2) to (5) above, the ratio is not particularly limited, regardless of the combination method. When combining with the compound species that become insoluble in liquid crystals as described below, the preferred combination ratio of the compound species that become insoluble in liquid crystals is 30 mol% or less, more preferably 20 mol% or less, from the viewpoint of maintaining properties, but is not limited. It is preferable to use these synthesis methods, monomers to be combined, and combination ratios within a range that can obtain the desired physical properties, display characteristics, electrical properties, etc.

[0155] Examples of compounds that become insoluble in liquid crystal include the compound represented by formula (6), a compound having a polymerizable group with the aforementioned polymerizable unsaturated hydrocarbon group and a highly polar structure, a compound having a polymerizable group with the aforementioned polymerizable unsaturated hydrocarbon group and a rigid structure, and a compound having a polymerizable group with the aforementioned polymerizable unsaturated hydrocarbon group and a thermosetting structure.

[0156] One embodiment of a polymer blend comprising polymer (C) and polymer (β) is characterized by comprising polymer (C), which is obtained by polymerizing one or more monomers that have a group that reacts with polymer (β) upon heating and are compatible with liquid crystals, and polymer (β), which reacts with polymer (C) upon heating to suppress the elution of polymer (C) into the liquid crystal. This provides high seal adhesion, solvent selectivity, and coatability.

[0157] The temperature at which the group in polymer (C) reacts with polymer (β) upon heating and the site in polymer (β) that reacts with the n-valent organic group A of polymer (C) upon heating are reacted is not particularly limited, but for example, it may be 150°C or higher, or 200°C or higher.

[0158] To achieve both good coatability, seal adhesion, film strength, and weak anchoring properties in a weak anchoring-oriented film, it is preferable to use polymer (C) and polymer (β) in combination. In addition, the mixing ratio of polymer (C) and polymer (β) is an important factor. For example, polymer (C), which is the component that exhibits weak anchoring properties, plays an important role in weak anchoring properties, and if the proportion of polymer (C) introduced is too high, the strength of the film may be impaired or thermal curing may be inhibited, so it is necessary to consider an appropriate amount to introduce. On the other hand, the amount and molecular weight of polymer (β) introduced do not affect (or have little effect on) weak anchoring properties, so in order to suitably achieve each of the above properties, it is preferable to keep the mass ratio of polymer (C) to polymer (β) small. A preferred introduction ratio (polymer C / polymer β) is 0.1 / 99.9 to 50 / 50 (mass ratio), and more preferably 1.0 / 99.0 to 40 / 60 (mass ratio).

[0159] The polymerizable group having a polymerizable unsaturated hydrocarbon group used in the formation of Q in formula (8) above may be selected from polymerizable groups having a polymerizable unsaturated hydrocarbon group that can be used in the polymerizable compound used in the formation of block segment (A) or block segment (B) in polymer A above. However, it is not limited to these.

[0160] When polymer (C) comes into contact with liquid crystal in a thin film state, it forms a polymer-liquid crystal mixed layer, exhibiting weak anchoring properties. The thickness of the polymer-liquid crystal mixed layer formed changes depending on the molecular weight of polymer C, and the weak anchoring properties change accordingly; therefore, optimizing the molecular weight is important. From the viewpoint of forming a good weak anchoring film, the preferred number-average molecular weight of polymer C is 1,000 to 100,000, more preferably 3,000 to 50,000, and the molecular weight distribution (PDI), expressed as the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn), is preferably 3.0 or less, more preferably 2.0 or less.

[0161] Polymer (C) is preferably obtained by living polymerization or chain transfer polymerization.

[0162] When obtaining polymer (C), the polymerization method does not need to be particularly limited, but cationic polymerization and anionic polymerization often use alkali metals, metal complexes, and halogen compounds when generating active species. In liquid crystal displays, the inclusion of metal residues and halogen compounds can cause burn-in and display defects, so it is preferable to use radical polymerization that does not use metals or halogen compounds as much as possible. Examples of living radical polymerization include living radical polymerization (NMP) using nitroxides as the dormant species, atom transfer radical polymerization (ATRP) using metal complexes, reversible addition-elimination chain transfer polymerization (RAFT polymerization) using sulfur compounds as the dormant, living radical polymerization (TERP) using organotellurium compounds, etc., and reversible transfer catalytic polymerization (RTCP) using alkyl iodide compounds as the dormant species and phosphorus compounds or alcohols as catalysts. Preferred polymerization methods include living radical polymerization such as NMP, RTCP, and RAFT polymerization, with NMP or RAFT polymerization being particularly preferred. It is also preferable to use chain transfer polymerization.

[0163] When using chain transfer polymerization, examples of polymerization initiators to use include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), benzoyl peroxide, 1,1'-bis(tert-butylperoxy)cyclohexane, and hydrogen peroxide. The amount of polymerization initiator used is usually 0.000001 to 0.1 moles, preferably 0.00001 to 0.01 moles, per mole of monomer used. Thiols are preferably used as chain transfer agents, and specific examples include compounds represented by the following formulas (S-1) to (S-16). The amount of chain transfer agent used is usually 0.000001 to 0.1 moles, preferably 0.00001 to 0.01 moles, per mole of monomer used. The reaction temperature in the polymerization described above is preferably 20 to 200°C, more preferably 40 to 150°C, and the reaction time is preferably 1 to 168 hours, more preferably 8 to 72 hours.

[0164] (In formulas (S-1) to (S-16), Me represents a methyl group and Et represents an ethyl group.)

[0165] By using chain transfer polymerization, it becomes possible to control the polymer end structure, molecular weight, and molecular weight distribution.

[0166] In chain transfer polymerization, polymers are obtained through a competitive reaction between chain transfer and growth reactions. The molecular weight and molecular weight distribution of polymers obtained by chain transfer polymerization are determined by the chain transfer constant (Cs) (Cs = kc / kp), which is calculated from the chain transfer rate constant (kc) and the growth rate constant (kp). Generally, chain transfer polymerization is best performed with a Cs value in the range of 1 to 60, and the selection of monomer species and chain transfer agents used, as well as their correct combination, are important.

[0167] The chain transfer constant (Cs) varies greatly depending on the type of monomer and chain transfer agent used, so it is necessary to select it correctly.

[0168] As a polymerization initiator for radical polymerization used in the synthesis of polymer (C), known compounds such as radical polymerization initiators (radical thermal polymerization initiators, radical photopolymerization initiators) and reversible addition-cleavage chain transfer (RAFT) polymerization reagents can be used, and it is preferable to select from radical polymerization initiators that can be used in the synthesis of polymer A.

[0169] The organic solvent used in the synthesis of polymer (C) can be any solvent that does not chemically react with the compound species constituting the copolymer and does not scavenge radicals. It is preferable to select an organic solvent that can be used in the synthesis of polymer A.

[0170] The organic solvent used in the chain transfer polymerization reaction is not particularly limited as long as it dissolves the resulting polymer. The organic solvent may be used alone or as a mixture of two or more.

[0171] Furthermore, even if the solvent does not dissolve the polymer to be produced, it may be mixed with the organic solvent mentioned above and used, as long as the produced polymer does not precipitate. Note that in radical polymerization, oxygen in the organic solvent inhibits the polymerization reaction, so it is preferable to use an organic solvent that has been degassed to the greatest extent possible. If the polymer (C) obtained by the above polymerization is dissolved in the reaction solution, the reaction solution may be used directly for the preparation of the liquid crystal alignment agent, or the polymer (C) contained in the reaction solution may be isolated before being used for the preparation of the liquid crystal alignment agent. The polymerization temperature during radical polymerization can be selected from any temperature between 30 and 150°C, but is preferably in the range of 50 to 100°C. The reaction can be carried out at any concentration, but if the concentration is too low, it becomes difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high, making uniform stirring difficult. Therefore, the monomer concentration is preferably 1 to 50% by mass, more preferably 5 to 40% by mass. The reaction can be carried out at a high concentration initially, and then the organic solvent can be added.

[0172] In the radical polymerization reaction described above, if the ratio of radical polymerization initiator to monomer is high, the molecular weight of the resulting polymer will be low, and if it is low, the molecular weight of the resulting polymer will be high. Therefore, the ratio of radical initiator to monomer is preferably 0.1 to 10 mol% relative to the monomer to be polymerized. In addition, various monomer components, solvents, initiators, etc. can be added during polymerization.

[0173] The polymer produced from the reaction solution obtained by the above reaction can be recovered by precipitation by adding the reaction solution to a poor solvent, although this reprecipitation treatment is not essential. Examples of poor solvents that can be used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, and water. The polymer precipitated by adding it to a poor solvent can be recovered by filtration and then dried at room temperature or by heating under atmospheric pressure or reduced pressure. Furthermore, the amount of impurities in the polymer can be reduced by repeating the operation of redissolving the recovered polymer in an organic solvent and recovering it by reprecipitation 2 to 10 times. Examples of poor solvents in this case include alcohols, ketones, and hydrocarbons, and it is preferable to use three or more poor solvents selected from these to further increase the efficiency of purification.

[0174] (Polymer β (a polymer that does not exhibit weak anchoring properties)) Polymer β is at least one polymer selected from polyimide, polyamic acid, polyamic acid ester, polyamide, and polyurea.

[0175] Polymer (β) is a polymer that does not exhibit weak anchoring properties, and plays a role in controlling the viscosity of varnishes (e.g., liquid crystal alignment agents), which is difficult to achieve with polymer (α), as well as improving the mechanical strength, seal adhesion, and coatability of liquid crystal alignment films.

[0176] Suitable polymers for polymer (β) include polyimides, polyamic acids, polyamic acid esters, polyamides, and polyureas.

[0177] When polyamic acids, polyimides, or polyamic acid esters are used as polymer (β), a carboxyl group is present, generated from the reaction of tetracarboxylic dianhydride and diamine, and a (anhydride) carboxylic acid or amino group is present at the polymer chain terminals. Therefore, unless the imidization rate is 100%, all polyamic acids and polyimides are polymers (β) having carboxyl groups, and for example, they are polymers that react with polymer (C) upon heating. Examples of polymers (β) include polymers consisting of the following diamines and tetracarboxylic dianhydride.

[0178] The following diamines can be used as diamine components in the synthesis of polyamic acids and polyimides. Specifically, p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diaminobiphen 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 4,4'- Diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminodiphenylmethane, 2,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldianiline, 3,3'-sulfonyldianiline, bis(4-aminophenyl)silane, bis( 3-aminophenyl)silane, dimethyl-bis(4-aminophenyl)silane, dimethyl-bis(3-aminophenyl)silane, 4,4'-thiodianiline, 3,3'-thiodianiline, 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl(4,4'-diaminodiphenyl)amine, N-methyl(3,4'-diaminodiphenyl)amine, N-methyl(2,2'-diaminodiphenyl)amine, N-methyl(2,3'-diaminodiphenyl)amine, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 2,2'-diaminobenzophenone, 2,3'-diaminobenzophenone, 1,4-diaminonaphthalene, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminona Phthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 1,2-bis(4-aminophenyl)ethane, 1,2-bis(3-aminophenyl)ethane, 1,3-bis(4-aminophenyl)propane, 1,3-bis(3-aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1,4-bis(3-aminophenyl)butane, bis(3,5-diethyl-4-aminophenyl)methane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene , 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4'-[1,4-phenylenebis(methylene)]dianiline, 4,4'-[1,3-phenylenebis(methylene)]dianiline, 3,4'-[1,4-phenylenebis(methylene)]dianiline, 3,4'-[1,3-phenylenebis(methylene)]dianiline, 3,3'-[1,4-phenylenebis(methylene] ]dianiline, 3,3'-[1,3-phenylenebis(methylene)]dianiline, 1,4-phenylenebis[(4-aminophenyl)methanone], 1,4-phenylenebis[(3-aminophenyl)methanone], 1,3-phenylenebis[(4-aminophenyl)methanone], 1,3-phenylenebis[(3-aminophenyl)methanone], 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-aminobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), bis(4-aminophenyl)terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate, N,N'-(1,4-phenylene)bis(4-aminobenzamide), N,N'-(1,3-phenylene)bis(4-aminobenzamide), N,N'-(1,4-phenylene)bis(3-aminobenzamide), N,N'-(1,3-phenylene)bis(3-aminobenzamide), N,N'-bis(4- (Aminophenyl) terephthalamide, N,N'-bis(3-aminophenyl) terephthalamide, N,N'-bis(4-aminophenyl) isophthalamide, N,N'-bis(3-aminophenyl) isophthalamide, 9,10-bis(4-aminophenyl) anthracene, 4,4'-bis(4-aminophenoxy) diphenyl sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl] hexafluoropropane, 2,2-bis(4-aminophenyl) hexafluoro Propane, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)propane, 2,2-bis(3-amino-4-methylphenyl)propane, trans-1,4-bis(4-aminophenyl)cyclohexane, 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, bis(4-aminophenoxy)methane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4 -aminophenoxy)propane, 1,3-bis(3-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,4-bis(3-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,5-bis(3-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,6-bis(3-aminophenoxy)hexane, 1,7-bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,Aromatic diamines such as 8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy)decane, 1,11-bis(4-aminophenoxy)undecane, 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane; alicyclic diamines such as bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane; 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, Examples include aliphatic diamines such as 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, and 1,12-diaminododecane; diamines having a urea structure such as 1,3-bis[2-(p-aminophenyl)ethyl]urea and 1,3-bis[2-(p-aminophenyl)ethyl]-1-tert-butoxycarbonylurea; diamines having a nitrogen-containing unsaturated heterocyclic structure such as N-p-aminophenyl-4-p-aminophenyl(tert-butoxycarbonyl)aminomethylpiperidine; and diamines having an N-Boc group (Boc represents a tert-butoxycarbonyl group) such as N-tert-butoxycarbonyl-N-(2-(4-aminophenyl)ethyl)-N-(4-aminobenzyl)amine. The above diamines can be used individually or in combination of two or more types.

[0179] The tetracarboxylic dianhydrides reacted with the above-mentioned diamine components are not particularly limited. Specifically, pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7-anthracenetetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,3',4'-biphenyltetracarboxylic acid, bis(3,4-dicarboxyphenyl) ether, 3,3',4,4'-benzophenonetetracarboxylic acid, bis(3,4-dicarboxyphenyl) ether Xyphenyl) sulfone, bis(3,4-dicarboxyphenyl)methane, 2,2-bis(3,4-dicarboxyphenyl)propane, 1,1,1,3,3,3-hexafluoro-2,2-bis(3,4-dicarboxyphenyl)propane, bis(3,4-dicarboxyphenyl)dimethylsilane, bis(3,4-dicarboxyphenyl)diphenylsilane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis(3,4-dicarboxyphenyl)pyridine, 3,3',4,4'-diphenylsulfonetetracarbone 1,3-Diphenyl-1,2,3,4-Cyclobutanetetracarboxylic acid, 3,4,9,10-Perylenetetracarboxylic acid, 1,3-Diphenyl-1,2,3,4-Cyclobutanetetracarboxylic acid, 1,2,3,4-Cyclopentanetetracarboxylic acid, 1,2,4,5-Cyclohexanetetracarboxylic acid, 1,2,3,4-Tetramethyl-1,2,3,4-Cyclobutanetetracarboxylic acid, 1,2-Dimethyl-1,2,3,4-Cyclobutanetetracarboxylic acid, 1,3-Dimethyl-1,2,3,4-Cyclobutanetetracarboxylic acid Lobutanetetracarboxylic acid, 1,2,3,4-cycloheptanetetracarboxylic acid, 2,3,4,5-tetrahydrofurantetracarboxylic acid, 3,4-dicarboxy-1-cyclohexylsuccinic acid, 2,3,5-tricarboxycyclopentylacetic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic acid, bicyclo[4.3.0]nonane-2,4,7,9-tetracarboxylic acid, bicyclo[4.4.0]decane-2,4,7,9-tetracarboxylic acid, bicyclo[4.4.0]decane-2,4,8,10-tetracarboxylic acid, tricyclo[6.3.0.0<2,6>]undecane-3,5,9,11-tetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid, bicyclo[2.2.2]octa-7-ene-2,3 Examples include dianhydrides of tetracarboxylic acids such as 5,6-tetracarboxylic acid, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexane-1,2-dicarboxylic acid, tetracyclo[6.2.1.1.0<2,7>]dodeca-4,5,9,10-tetracarboxylic acid, 3,5,6-tricarboxynorbornane-2,3,5,6-tetracarboxylic acid, and 1,2,4,5-cyclohexanetetracarboxylic acid. Of course, one or more types of tetracarboxylic acid dianhydrides may be used in combination.

[0180] In the synthesis of polymers that are polyamic acid esters, the structure of the tetracarboxylic acid dialkyl ester reacted with the above-mentioned diamine component is not particularly limited, but specific examples are given below. Specific examples of aliphatic tetracarboxylic acid diesters include 1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2,3,4-cyclopentanetetracarboxylic acid dialkyl ester, 2,3,4,5-tetrahydrofurantetracarboxylic acid dialkyl ester, 1,2,4,5-cyclohexanetetracarboxylic acid dialkyl ester, and 3,4-dicarboxy-1-cyclohexylsuccinate dialkyl ester. Dialkyl esters for 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinate, 1,2,3,4-butanetetracarboxylic acid, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic acid, 3,3',4,4'-dicyclohexyltetracarboxylic acid, 2,3,5-tricarboxycyclopentyl acetate, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic acid, tricyclo[4.2.1.0<2,5>]nonane-3,4,7,8-tetracarboxylic acid-3,4:7,8-dialkyl ester, hexacyclo[6.6.0.1<2,7>.0<3,6>.1<9,14>. Examples include 0<10,13>]hexadecane-4,5,11,12-tetracarboxylic acid-4,5:11,12-dialkyl esters and 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid dialkyl esters.Examples of aromatic tetracarboxylic acid dialkyl esters include pyromellitic acid dialkyl ester, 3,3',4,4'-biphenyltetracarboxylic acid dialkyl ester, 2,2',3,3'-biphenyltetracarboxylic acid dialkyl ester, 2,3,3',4'-biphenyltetracarboxylic acid dialkyl ester, 3,3',4,4'-benzophenonetetracarboxylic acid dialkyl ester, 2,3,3',4'-benzophenonetetracarboxylic acid dialkyl ester, bis(3,4-dicarboxyphenyl)ether dialkyl ester, bis(3,4-dicarboxyphenyl)sulfone dialkyl ester, 1,2,5,6-naphthalenetetracarboxylic acid dialkyl ester, and 2,3,6,7-naphthalenetetracarboxylic acid dialkyl ester.

[0181] When polymer (β) is a polyurea, an isocyanate group or an amino group is present at the polymer chain terminal group; therefore, all polyureas are polymers (β) having an isocyanate group or an amino group. Examples of such polymers (β) include polymers composed of a diamine and a diisocyanate. Examples of diamines include the diamine components used in the synthesis of polyamic acids and polyimides mentioned above. The diisocyanate reacted with the above-mentioned diamine component in the synthesis of polyureas is not particularly limited and can be used depending on availability, etc. The specific structure of the diisocyanate is shown below.

[0182] In the formula R ２ , and R ３ This represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms.

[0183] Aliphatic diisocyanates, shown in formulas (K-1) to (K-5), have the advantage of improving solvent solubility despite their lower reactivity, while aromatic diisocyanates, such as those shown in formulas (K-6) to (K-13), are highly reactive and improve heat resistance, but have the disadvantage of reducing solvent solubility. Formulas (K-1), (K-7), (K-8), (K-9), and (K-10) are preferred in terms of versatility and properties, formula (K-12) is preferred from the viewpoint of electrical properties, and formula (K-13) is preferred from the viewpoint of liquid crystal alignment. Two or more diisocyanates can also be used in combination, and it is preferable to apply them in various ways depending on the properties to be obtained.

[0184] Furthermore, some of the diisocyanates can be replaced with the tetracarboxylic dianhydrides described above, and the product may be used in the form of a copolymer of polyamic acid and polyurea, or it may be used in the form of a copolymer of polyimide and polyurea by chemical imidation.

[0185] When polymer (β) is a polyamide, a carboxyl group or an amino group is present at the polymer chain terminals; therefore, all polyamides are polymers (β) that have a carboxyl group or an amino group. Examples of such polymers (β) include polymers composed of dicarboxylic acids and diamines.

[0186] Examples of dicarboxylic acids include aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, and heterocyclic dicarboxylic acids. Examples of aliphatic dicarboxylic acids include malonic acid, oxalic acid, dimethylmalonic acid, succinic acid, fumaric acid, glutaric acid, adipic acid, muconic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 3,3-diethylsuccinic acid, azelaic acid, sebacic acid, and suberic acid. Examples of alicyclic dicarboxylic acids include 1,1-cyclopropanedicarboxylic acid, 1,2-cyclopropanedicarboxylic acid, 1,1-cyclobutanedicarboxylic acid, 1,2-cyclobutanedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 3,4-diphenyl-1,2-cyclobutanedicarboxylic acid, 2,4-diphenyl-1,3-cyclobutanedicarboxylic acid, 1-cyclobutene-1,2-dicarboxylic acid, 1-cyclobutene-3,4-dicarboxylic acid, 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,1-cyclohexanedicarboxylic acid, and 1,2-cyclophenyl Examples include chlorohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,4-(2-norbornene)dicarboxylic acid, norbornene-2,3-dicarboxylic acid, bicyclo[2.2.2]octane-1,4-dicarboxylic acid, bicyclo[2.2.2]octane-2,3-dicarboxylic acid, 2,5-dioxo-1,4-bicyclo[2.2.2]octanedicarboxylic acid, 1,3-adamantanedicarboxylic acid, 4,8-dioxo-1,3-adamantanedicarboxylic acid, 2,6-spiro[3.3]heptanedicarboxylic acid, 1,3-adamantanediacetic acid, camphoric acid, etc.Aromatic dicarboxylic acids include o-phthalic acid, isophthalic acid, terephthalic acid, 5-methylisophthalic acid, 5-tert-butylisophthalic acid, 5-aminoisophthalic acid, 5-hydroxyisophthalic acid, 2,5-dimethylterephthalic acid, tetramethylterephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-anthracenedicarboxylic acid, 1,4-anthraquinonedicarboxylic acid, 2,5-biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 1,5-biphenylenedicarboxylic acid, 4,4''-terphenyldicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylethanedicarboxylic acid, 4,4'-diphenylpropanedicarboxylic acid, and 4,4'-diphenyl Hexafluoropropanedicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-bibenzyldicarboxylic acid, 4,4'-stilbenidicarboxylic acid, 4,4'-transdicarboxylic acid, 4,4'-carbonyldibenzoic acid, 4,4'-sulfonyldibenzoic acid, 4,4'-dithiodibenzoic acid, p-phenylenediacetic acid, 3,3'-p-phenylenedipropionic acid, 4-carboxycinnamic acid, p- Examples of dicarboxylic acids include phenylenediacrylic acid, 3,3'-[4,4'-(methylenedi-p-phenylene)]dipropionic acid, 4,4'-[4,4'-(oxydi-p-phenylene)]dipropionic acid, 4,4'-[4,4'-(oxydi-p-phenylene)]dibutyric acid, (isopropylidenedi-p-phenylenedioxy)dibutyric acid, and bis(p-carboxyphenyl)dimethylsilane. Examples of dicarboxylic acids containing heterocycles include 1,5-(9-oxofluorene)dicarboxylic acid, 3,4-franzicarboxylic acid, 4,5-thiazoledicarboxylic acid, 2-phenyl-4,5-thiazoledicarboxylic acid, 1,2,5-thiadiazole-3,4-dicarboxylic acid, 1,2,5-oxadiazole-3,4-dicarboxylic acid, 2,3-pyridinedicarboxylic acid, 2,4-pyridinedicarboxylic acid, 2,5-pyridinedicarboxylic acid, 2,6-pyridinedicarboxylic acid, 3,4-pyridinedicarboxylic acid, and 3,5-pyridinedicarboxylic acid.

[0187] The dicarboxylic acids used may be in the form of acid dihalides or anhydrous structures. These dicarboxylic acids are particularly preferred to be those capable of yielding linear polyamides in order to maintain the orientation of the liquid crystal molecules. Among these, terephthalic acid, isoterephthalic acid, 1,4-cyclohexanedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylethanedicarboxylic acid, 4,4'-diphenylpropanedicarboxylic acid, 4,4'-diphenylhexafluoropropanedicarboxylic acid, 2,2-bis(phenyl)propanedicarboxylic acid, 4,4''-terphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,5-pyridinedicarboxylic acid, or their acid dihalides are preferably used. Some of these compounds have isomers, and mixtures containing these is also acceptable. Furthermore, two or more compounds may be used in combination. Note that the dicarboxylic acids used in this invention are not limited to the above-mentioned exemplary compounds.

[0188] Depending on the type of polymer (α) used, for example when polymer C is used, polymer (β) is preferably a polymer that contains at least one selected from the group consisting of an amino group, a protected amino group, a hydroxyl group, a protected hydroxyl group, a thiol group, a protected thiol group, a carboxyl group, a protected carboxyl group, an isocyanate group, a protected isocyanate group, a maleimide group, a carboxylic anhydride group, a vinyl group, an allyl group, a styryl group, a (meth)acrylic group, and a (meth)acrylamide group as a reacting site. However, these organic groups are not necessarily required and can be selected as appropriate. Here, the protecting group in a protected amino group, a protecting group in a protected hydroxyl group, a protecting group in a protected thiol group, a protecting group in a protected carboxyl group, and a protecting group in a protected isocyanate group are groups that are removed by heating to produce an amino group, a hydroxyl group, a thiol group, a carboxyl group, and an isocyanate group, respectively. Examples of protecting groups for protected amino groups include tert-butoxycarbonyl group, benzyloxycarbonyl group, 9-fluorenylmethyloxycarbonyl group, allyloxycarbonyl group, phthaloyl group, nitrobenzenesulfonyl group, (2-trimethylsilyl)-ethanesulfonyl group, 2,2,2-trichloroethoxycarbonyl group, and azide group. Examples of protecting groups for protected hydroxyl groups include tetrahydropyranyl group, methoxymethyl ether group, trityl group, tert-butyl group, trialkylsilyl group, tert-butoxycarbonyl group, benzyl group, and acetyl group. Examples of protecting groups for protected thiol groups include tert-butoxycarbonyl group, benzyloxycarbonyl group, 9-fluorenylmethyloxycarbonyl group, allyloxycarbonyl group, phthaloyl group, nitrobenzenesulfonyl group, (2-trimethylsilyl)-ethanesulfonyl group, 2,2,2-trichloroethoxycarbonyl group, and azide group. Examples of protecting groups for protected carboxyl groups include methyl ester group, benzyl ester group, and tert-butyl ester group. Examples of protecting groups for protected isocyanate groups include tert-butyl group, dimethylpyrazole group, methyl ethyl ketone oxime group, and lactam group.

[0189] In order to obtain polyamic acids, polyamic acid esters, polyureas, and polyamides by reacting a diamine (also referred to as the "diamine component") with a component selected from tetracarboxylic dianhydride (also referred to as the "tetracarboxylic dianhydride component"), tetracarboxylic diesters, diisocyanates, and dicarboxylic acids, known synthetic methods can be used. Generally, this method involves reacting the diamine component with one or more components selected from tetracarboxylic dianhydride components, tetracarboxylic diesters, diisocyanates, and dicarboxylic acids in an organic solvent.

[0190] Polyamic acids can be synthesized by reacting (polycondensation reaction) a tetracarboxylic acid derivative component containing the tetracarboxylic dianhydride to be used with the above-mentioned diamine component in the presence of an organic solvent at -20 to 150°C, preferably 0 to 50°C, for 30 minutes to 24 hours, preferably 1 to 12 hours.

[0191] Polyamic acid esters can be produced by known methods such as (1) esterifying the above polyamic acid, (2) reacting a tetracarboxylic acid derivative component containing a tetracarboxylic acid diester dichloride with the above diamine component, or (3) polycondensing a tetracarboxylic acid derivative component containing a tetracarboxylic acid diester with a diamine.

[0192] Polyimides can be synthesized by known methods such as (1) directly heating a solution of the polyamic acid or polyamic acid ester, or (2) catalytic imidation by adding a catalyst (e.g., a basic catalyst such as pyridine, or an acid anhydride such as acetic anhydride) to a solution of the polyamic acid or polyamic acid ester. The polyimides of the present invention do not necessarily need to have a 100% ring-closing rate (also called the imidation rate) of the functional groups of the polyamic acid or polyamic acid ester, and can be arbitrarily adjusted according to the application and purpose.

[0193] Polyureas can be synthesized by reacting (polycondensation reaction) the above-mentioned diisocyanate and diamine component in the presence of an organic solvent at -20 to 150°C, preferably 0 to 50°C, for 30 minutes to 24 hours, preferably 1 to 12 hours.

[0194] Polyamides can be produced by known methods such as (1) a reaction between a dicarboxylic acid dichloride derivative component and the above-mentioned diamine component, or (2) a polycondensation between a dicarboxylic acid derivative component and a diamine.

[0195] The organic solvent used in the synthesis of polymer (β) can be any solvent that does not chemically react with the compound species constituting the copolymer and does not scavenge radicals. It is preferable to select from organic solvents that can be used in the synthesis of polymer (A) described above. Furthermore, the organic solvent may be used alone or in mixture of two or more.

[0196] The weight-average molecular weight (Mw) of the polymer (β) measured by gel permeation chromatography (GPC) in terms of polystyrene is preferably 1,000 to 500,000, and more preferably 2,000 to 300,000. Furthermore, the molecular weight distribution (Mw / Mn), expressed as the ratio of Mw to the number-average molecular weight (Mn) measured by GPC in terms of polystyrene, is preferably 15 or less, and more preferably 10 or less. Being within this molecular weight range allows for excellent liquid crystal orientation and excellent coating properties to be obtained regardless of the coating method.

[0197] (Organic solvent) The organic solvent used in the liquid crystal alignment agent of the present invention is not particularly limited, and examples include compounds represented by the following formula (S1). (In formula (S1), Q １ and Q ２ Each of these independently represents an alkyl group having 1 to 4 carbon atoms, Q ３ Q represents a linear, branched, or cyclic alkyl group having 1 to 8 carbon atoms, an alkoxyalkyl group having 2 to 8 carbon atoms, an alkylcarbonylalkyl group having 4 to 8 carbon atoms, or a hydrogen atom. １ Q ２ and Q ３The total number of carbon atoms is 4 or more.) Examples of compounds represented by formula (S1) include N,N-diethylacetamide, N,N-diethylformamide, N,N-dibutylformamide, N,N-dipropylacetamide, N,N-dimethylpropionamide, N,N-diethylpropionamide, 3-methoxy-N,N-dimethylpropanamide, 2-methoxy-N,N-diethylacetamide, 3-methoxy-N,N-diethylpropanamide, 4-oxo-N,N-diethylpentanamide, and N,N-diethylcyclohexanecarboamide.

[0198] Furthermore, examples of organic solvents include N,N-dimethylformamide, N,N-dimethylacetamide, N-methylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethylphosphoramide, γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl Isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol tert-butyl ether, propylene glycol monomethyl ether acetate, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl Ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate,Ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol Diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, 2-ethyl-1,3-hexanediol, ethylene glycol, propylene glycol (1,2-propanediol), 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4- Pentanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 2,3-hexanediol, 2,4-hexanediol, 2,5-hexanediol, 3,5-hexanediol, 1,2-heptaneglycol, 1,3-heptanediol, 1,4-heptanediol, 1,5-heptanediol, 1,6-heptanediol, 1,7-heptanediol, 1,2-octanediol , 1,4-octanediol, 1,8-octanediol, 1,2-nonanediol, 1,3-nonanediol, 1,5-nonanediol, 1,6-nonanediol, 1,9-nonanediol, 1,2-decanediol, 1,5-decanediol, 1,8-decanediol, 1,10-decanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, diethylene glycol, dipropylene glycol, dibutylene glycol, glycerol, 2-ethyl-1-hexanol, methyl pyruvate,Ethyl pyruvate, propyl pyruvate, butyl pyruvate, pentyl pyruvate, hexyl pyruvate, 2-ethylhexyl pyruvate, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, pentyl acetoacetate, hexyl acetoacetate, 2-ethylhexyl acetoacetate, methyl levulinate, ethyl levulinate, propyl levulinate, butyl levulinate, pentyl levulinate, hexyl levulinate, 2-ethylhexyl levulinate, dimethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, dimethyl phthalate, dimethyl maleate, diethyl malonate, diethyl succinate, diethyl glutarate, diethyl adipate, diethyl phthalate, diethyl maleate, dipropyl malonate, dipropyl succinate, dipropyl glutarate Examples include ropil, dipropyl adipate, dipropyl phthalate, dipropyl maleate, dibutyl malonate, dibutyl succinate, dibutyl glutarate, dibutyl adipate, dibutyl phthalate, dibutyl maleate, dipentyl malonate, dipentyl succinate, dipentyl glutarate, dipentyl adipate, dipentyl phthalate, dipentyl maleate, dihexyl malonate, dihexyl succinate, dihexyl glutarate, dihexyl adipate, dihexyl phthalate, dihexyl maleate, di-2-ethylhexyl malonate, 2-ethylhexyl succinate, 2-ethylhexyl glutarate, 2-ethylhexyl adipate, 2-ethylhexyl phthalate, 2-ethylhexyl maleate, etc., but other solvents that can be used are also acceptable. These organic solvents may be used individually or in combination. From the viewpoint of coatability and storage stability, it is preferable to use the compound represented by formula (S1) as the organic solvent. While there are no particular restrictions on the content of the compound represented by formula (S1) in the liquid crystal alignment agent, it is preferably 10 to 90% by mass of the total solvent contained in the liquid crystal alignment agent, more preferably 20 to 70% by mass. However, it is not necessarily required to use the compound represented by formula (S1), and a suitable organic solvent can be appropriately selected from the aforementioned organic solvents.

[0199] Furthermore, it is preferable to use a solvent that improves the uniformity and smoothness of the coating film by mixing it with a highly soluble organic solvent.

[0200] Solvents that improve the uniformity and smoothness of the coating film include, for example, isopropyl alcohol, methoxymethyl pentanol, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether (butyl cellosolve), propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol-tert-butyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether, and dipropylene glycol monoacetate. Monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, n-hexane, n-pentane, n-octane, diethyl ether, milk Methyl acid, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-methoxypropionate, ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol,Propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, 2-ethyl-1-hexanol, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, pentyl pyruvate, hexyl pyruvate, 2-ethylhexyl pyruvate, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, pentyl acetoacetate, hexyl acetoacetate, 2-ethylhexyl acetoacetate, methyl levulinate, ethyl levulinate, propyl levulinate, butyl levulinate, pentyl levulinate, hexyl levulinate, 2-ethylhexyl levulinate, dimethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, dimethyl phthalate, dimethyl maleate, Diethyl malonate, diethyl succinate, diethyl glutarate, diethyl adipate, diethyl phthalate, diethyl maleate, dipropyl malonate, dipropyl succinate, dipropyl glutarate, dipropyl adipate, dipropyl phthalate, dipropyl maleate, dibutyl malonate, dibutyl succinate, dibutyl glutarate, dibutyl adipate, dibutyl phthalate, dibutyl maleate, dipentyl malonate, dipentyl succinate, glutaric acid Examples include dipentyl, dipentyl adipate, dipentyl phthalate, dipentyl maleate, dihexyl malonate, dihexyl succinate, dihexyl glutarate, dihexyl adipate, dihexyl phthalate, dihexyl maleate, di-2-ethylhexyl malonate, 2-ethylhexyl succinate, 2-ethylhexyl glutarate, 2-ethylhexyl adipate, 2-ethylhexyl phthalate, and 2-ethylhexyl maleate. Multiple types of these solvents may be mixed. When using these solvents, they preferably constitute 5 to 60% by mass of the total solvent content in the liquid crystal alignment agent, and more preferably 10 to 40% by mass.

[0201] The liquid crystal alignment agent of the present invention may contain components other than those mentioned above. Examples include compounds that improve film thickness uniformity and surface smoothness when the composition contained in the liquid crystal alignment agent is applied, compounds that improve adhesion between the composition contained in the liquid crystal alignment agent and the substrate, and compounds that further improve the film strength of the composition contained in the liquid crystal alignment agent.

[0202] Compounds that improve film thickness uniformity and surface smoothness include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants. More specifically, examples include F-Top EF301, EF303, EF352 (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), Megafac F171, F173, R-30 (manufactured by DIC Corporation), Florard FC430, FC431 (manufactured by 3M Corporation), Asahiguard AG710 (manufactured by AGC Corporation), Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by AGC Seimi Chemical Co., Ltd.). When using these surfactants, the usage ratio is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, per 100 parts by mass of the total amount of polymer contained in the composition contained in the weak anchoring liquid crystal alignment agent.

[0203] Specific examples of compounds that improve the adhesion between the composition contained in the liquid crystal alignment agent and the substrate include functional silane-containing compounds. For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-(3-triethoxysilyl)propyl Examples include triethylenetetramine, N-(3-trimethoxysilyl)propyltriethylenetetramine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonylacetate, 9-triethoxysilyl-3,6-diazanonylacetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and N-phenyl-3-aminopropyltriethoxysilane.

[0204] Furthermore, in order to further increase the film strength of the liquid crystal alignment film, phenolic compounds such as 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane and tetra(methoxymethyl)bisphenol may be added. When using these compounds, it is preferable that the amount is 0.1 to 30 parts by mass, and more preferably 1 to 20 parts by mass, per 100 parts by mass of the total amount of polymer contained in the weak anchoring liquid crystal alignment agent. In addition to the above, dielectric or conductive substances may be added to the composition contained in the liquid crystal alignment agent for the purpose of changing the electrical properties of the weak anchoring liquid crystal alignment film, such as dielectric constant and conductivity, as long as the effects of the present invention are not impaired.

[0205] (Liquid crystal alignment film and liquid crystal display element) The liquid crystal display element according to the present invention comprises a liquid crystal alignment film formed using the above-mentioned liquid crystal alignment agent. The operating mode of the liquid crystal display element is preferably selected depending on the type of polymer (α) used. For example, when polymer (α) is polymer (A), polymer (B), or polymer (C), which are polymers that contribute to the expression of weak anchoring properties, in-plane switching type (IPS type, FFS type) and optically compensated bend type (OCB type) are preferred. When polymer (α) is a polymer that constitutes a liquid crystal alignment agent having an alignment restricting force in the azimuthal angle direction, vertical alignment type (UV2A type) is preferred.

[0206] The liquid crystal display element of the present invention can be manufactured, for example, by a method including the following steps (1) to (4).

[0207] <Process (1): Process of applying liquid crystal alignment agent to the substrate> Process (1) is the process of applying a liquid crystal alignment agent to the substrate. A specific example of process (1) is as follows: The liquid crystal alignment agent is applied to one side of a substrate on which a patterned transparent conductive film is provided, by an appropriate application method such as a roll coater, spin coat, printing, inkjet, or spray method. The material of the substrate is not particularly limited as long as it is a highly transparent substrate, and in addition to glass and silicon nitride, plastics such as acrylic and polycarbonate can also be used. Furthermore, in the case of reflective liquid crystal display elements, an opaque material such as a silicon wafer can be used for only one side of the substrate, and in this case, a light-reflecting material such as aluminum can be used for the electrodes. Furthermore, when manufacturing IPS type or FFS type liquid crystal display elements, a substrate on which electrodes made of a comb-shaped patterned transparent conductive film or metal film are provided and a counter substrate on which no electrodes are provided are used. An IPS substrate, which is a comb-tooth electrode substrate used in an IPS type liquid crystal display element, has, for example, a base material, a plurality of linear electrodes formed on the base material and arranged in a comb-tooth pattern, and a liquid crystal alignment film formed on the base material so as to cover the linear electrodes. An FFS substrate, which is a comb-tooth electrode substrate used in an FFS type liquid crystal display element, has, for example, a base material, a surface electrode formed on the base material, an insulating film formed on the surface electrode, a plurality of linear electrodes formed on the insulating film and arranged in a comb-tooth pattern, and a liquid crystal alignment film formed on the insulating film so as to cover the linear electrodes.

[0208] More preferred examples of methods for coating a liquid crystal alignment agent onto a substrate and forming a film include printing methods such as screen printing, offset printing, or flexographic printing, as well as spin coating, inkjet printing, or spraying. Among these, coating and film formation methods using flexographic printing, spin coating, or inkjet printing are particularly suitable.

[0209] A weakly anchored liquid crystal display element is manufactured using a first or second substrate equipped with a weakly anchored alignment film formed using the weakly anchored liquid crystal alignment agent of the present invention, and a second or first substrate equipped with a strongly anchored horizontal alignment film. In this invention, the first substrate may be a substrate having comb-tooth electrodes and the second substrate may be a counter substrate. Alternatively, the second substrate may be a substrate having comb-tooth electrodes and the first substrate may be a counter substrate.

[0210] <Step (2): Step of firing the coated liquid crystal alignment agent> Step (2) is a step of firing the liquid crystal alignment agent coated on the substrate to form a film. A specific example of Step (2) is as follows. After coating the liquid crystal alignment agent on the substrate in Step (1), the solvent can be evaporated or the polyamic acid can be thermally imidized using a heating means such as a hot plate, a heat-circulating oven, or an IR (infrared) oven. The drying and firing steps after coating the liquid crystal alignment agent can be performed at any temperature and time, and may be performed multiple times. The temperature for firing the liquid crystal alignment agent can be, for example, 40 to 180°C. From the viewpoint of shortening the process, it may also be performed at 40 to 150°C. The firing time is not particularly limited, but examples include 1 to 10 minutes or 1 to 5 minutes. When thermally imidizing the polyamic acid is performed, a step of firing at, for example, 150 to 300°C or 150 to 250°C may be added after the above steps. The firing time is not particularly limited, but examples include firing times of 5 to 40 minutes or 5 to 30 minutes. The film thickness of the film-like material after firing is preferably 5 to 300 nm, and more preferably 10 to 200 nm, because if it is too thin, the reliability of the liquid crystal display element may decrease.

[0211] <Step (3): Step of orientation treatment on the film obtained in step (2)> Step (3) is a step of orientation treatment on the film obtained in step (2), depending on the case. Specifically, in the case of horizontally oriented liquid crystal display elements such as the IPS method or FFS method, the coating film is subjected to a horizontal uniaxial orientation ability imparting treatment. Furthermore, in the case of a weakly anchoring liquid crystal alignment agent coated substrate in a weakly anchoring liquid crystal display element, the fired coating film can be used as is as the liquid crystal alignment film, but the coating film may also be subjected to an orientation ability imparting treatment. On the other hand, in the case of vertically oriented liquid crystal display elements such as UV2A mode, the coating film is subjected to an azimuthal uniaxial orientation ability imparting treatment. Methods for orientation treatment of liquid crystal alignment films include the rubbing orientation method and the photo-alignment method. As for the photo-alignment method, a method is used in which the surface of the film-like material is irradiated with radiation deflected in a certain direction, and depending on the case, preferably a heat treatment is performed at a temperature of 150 to 250°C to impart liquid crystal alignment properties (also called liquid crystal alignment ability). As radiation, ultraviolet light or visible light having a wavelength of 100 to 800 nm can be used. In particular, ultraviolet light having a wavelength of 100 to 400 nm, and more preferably 200 to 380 nm, is used.

[0212] The radiation doses mentioned above range from 1 to 10,000 mJ / cm². ２ Preferably, 100 to 5,000 mJ / cm² is preferred. ２ This is more preferable. Furthermore, when irradiating with radiation, the substrate having the above-mentioned film may be irradiated while being heated at 50 to 250°C in order to improve the liquid crystal alignment. The liquid crystal alignment film produced in this manner can stably align liquid crystal molecules in a certain direction.

[0213] Furthermore, the coating film irradiated with polarized radiation or the coating film that has undergone rubbing orientation treatment using the above method may be subjected to contact treatment with water or a solvent. Alternatively, the film that has undergone the orientation treatment may be subjected to heat treatment without contact treatment. Furthermore, the film that has undergone contact treatment may be subjected to further heat treatment.

[0214] The solvent used in the above contact treatment is not particularly limited, as long as it is a solvent that dissolves the decomposition products generated from the film-like material by irradiation with radiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, cyclohexyl acetate, etc. The solvent may be used individually or in combination of two or more types.

[0215] The heat treatment temperature for the irradiated coating film is more preferably 50 to 300°C, and even more preferably 120 to 250°C. The heat treatment time is preferably 1 to 30 minutes in each case.

[0216] <Step (4): Process for manufacturing liquid crystal cells> Two substrates on which liquid crystal alignment films have been formed as described above are prepared, and liquid crystal is placed between the two substrates which are placed opposite each other. Specifically, the following two methods can be used. In the first method, the two substrates are first placed opposite each other with a gap (cell gap) in between so that their respective liquid crystal alignment films face each other. Next, the periphery of the two substrates is bonded together using a sealant, and the liquid crystal composition is injected and filled into the cell gap partitioned by the substrate surface and the sealant, and after it comes into contact with the film surface, the injection hole is sealed.

[0217] The second method is called the ODF (One Drop Fill) method. In this method, a UV-curable sealant is applied to a predetermined location on one of two substrates on which a liquid crystal alignment film has been formed, and then liquid crystal composition is dropped onto several predetermined locations on the surface of the liquid crystal alignment film. The other substrate is then bonded together so that the liquid crystal alignment films face each other, and the liquid crystal composition is spread over the entire surface of the substrate and brought into contact with the film surface. Next, the entire surface of the substrate is irradiated with UV light to cure the sealant. In either method, it is desirable to further remove the flow orientation during liquid crystal filling by heating the liquid crystal composition to a temperature at which it forms an isotropic phase, and then slowly cooling it to room temperature. When rubbing alignment treatment is performed on the coating film, the two substrates are arranged facing each other so that the rubbing directions in each coating film are at a predetermined angle to each other, for example, orthogonal or antiparallel. As the sealant, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as spacers can be used. The above liquid crystal composition is not particularly limited and is a composition containing at least one liquid crystal compound (liquid crystal molecule), and various liquid crystal compositions with positive or negative dielectric anisotropy can be used. Hereinafter, a liquid crystal composition with positive dielectric anisotropy will also be called a positive-type liquid crystal, and a liquid crystal composition with negative dielectric anisotropy will also be called a negative-type liquid crystal. The above liquid crystal composition may contain a liquid crystal compound having a fluorine atom, a hydroxyl group, an amino group, a fluorine atom-containing group (e.g., a trifluoromethyl group), a cyano group, an alkyl group, an alkoxy group, an alkenyl group, an isothiocyanate group, a heterocycle, a cycloalkane, a cycloalkene, a steroid skeleton, a benzene ring, or a naphthalene ring, and may also contain a compound having two or more rigid parts (mesogenic skeletons) that exhibit liquid crystallinity within the molecule (e.g., a bimesogenic compound in which two rigid biphenyl structures or terphenyl structures are linked by an alkylene group). Examples of liquid crystal compositions include liquid crystal compositions exhibiting a nematic phase, liquid crystal compositions exhibiting a smectic phase, or liquid crystal compositions exhibiting a cholesteric phase, with liquid crystal compositions exhibiting a nematic phase being preferred. Furthermore, the above liquid crystal compositions may contain additives from the viewpoint of improving liquid crystal alignment.Examples of such additives include photopolymerizable monomers such as compounds having polymerizable groups; optically active compounds (e.g., S-811 from Merck KGaA); antioxidants; ultraviolet absorbers; dyes; defoamers; polymerization initiators; or polymerization inhibitors. Examples of positive liquid crystals include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, or MLC-7081 from Merck KGaA. Examples of negative liquid crystals include MLC-6608, MLC-6609, MLC-6610, or MLC-7026-100 from Merck KGaA.

[0218] The liquid crystal alignment film of the present invention is also preferably used in the following liquid crystal display elements: A liquid crystal display element (PSA type liquid crystal display element) having a liquid crystal layer between a pair of substrates equipped with electrodes, wherein a liquid crystal composition containing a polymerizable compound that polymerizes by at least one of active energy rays and heat is placed between the pair of substrates, and the polymerizable compound is polymerized by at least one of irradiation with active energy rays and heating while a voltage is applied between the electrodes. Furthermore, the liquid crystal alignment film of the present invention is also preferably used in the following liquid crystal display elements: A liquid crystal display element (SC-PVA mode type liquid crystal display element) having a liquid crystal layer between a pair of substrates equipped with electrodes, wherein a liquid crystal alignment film containing a polymerizable group that polymerizes by at least one of active energy rays and heat is placed between the pair of substrates, and a voltage is applied between the electrodes.

[0219] Then, a liquid crystal display element can be obtained by laminating a polarizing plate to the outer surface of the liquid crystal cell as needed. Examples of polarizing plates to be laminated to the outer surface of the liquid crystal cell include a polarizing plate made by sandwiching a polarizing film called an "H film," which is made by stretching and oriented polyvinyl alcohol while absorbing iodine, between cellulose acetate protective films, or a polarizing plate made of the H film itself.

[0220] Figure 1 is a schematic cross-sectional view showing an example of a transverse electric field liquid crystal display element of the present invention, and is an example of an IPS type liquid crystal display element. In the transverse electric field liquid crystal display element 1 illustrated in Figure 1, liquid crystal 3 is sandwiched between a comb-tooth electrode substrate 2 having a liquid crystal alignment film 2c and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-tooth electrode substrate 2 has a base material 2a, a plurality of linear electrodes 2b formed on the base material 2a and arranged in a comb-tooth shape, and a liquid crystal alignment film 2c formed on the base material 2a so as to cover the linear electrodes 2b. The counter substrate 4 has a base material 4b and a weakly anchored liquid crystal alignment film or a strongly anchored horizontal alignment film (liquid crystal alignment film 4a) formed on the base material 4b. The liquid crystal alignment film 2c is, for example, the weakly anchored alignment film or the strongly anchored horizontal alignment film of the present invention. The liquid crystal alignment films provided on the counter substrates are each made from a combination of a strongly anchored alignment film and a weakly anchored liquid crystal alignment film. In this transverse electric field liquid crystal display element 1, when a voltage is applied to the linear electrode 2b, an electric field is generated between the linear electrode 2b as shown by the electric field lines L.

[0221] Figure 2 is a schematic cross-sectional view showing another example of the transverse electric field liquid crystal display element of the present invention, and is an example of an FFS type liquid crystal display element. In the transverse electric field liquid crystal display element 1 illustrated in Figure 2, liquid crystal 3 is sandwiched between a comb-tooth electrode substrate 2 having a liquid crystal alignment film 2h and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-tooth electrode substrate 2 has a base material 2d, a surface electrode 2e formed on the base material 2d, an insulating film 2f formed on the surface electrode 2e, a plurality of linear electrodes 2g formed on the insulating film 2f and arranged in a comb-tooth shape, and a liquid crystal alignment film 2h formed on the insulating film 2f so as to cover the linear electrodes 2g. The counter substrate 4 has a base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 4a is the same as the liquid crystal alignment film 4a in Figure 1 described above. The liquid crystal alignment film 2h is the same as the liquid crystal alignment film 2c in Figure 1 described above. In this transverse electric field liquid crystal display element 1, when a voltage is applied to the surface electrode 2e and the linear electrode 2g, an electric field is generated between the surface electrode 2e and the linear electrode 2g, as shown by the electric field lines L.

[0222] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The abbreviations for the compounds and the methods for measuring each property are as follows.

[0223] (Component A: A component that is compatible with liquid crystal)

[0224] (Component B: an insoluble component in liquid crystal, or a component that becomes insoluble upon firing.) Me represents a methyl group, and Et represents an ethyl group.

[0225] (RAFT agent)

[0226] (Polymerization initiator)

[0227] (Chain transport agent)

[0228] (Diamine)

[0229] (Tetracarboxylic acid dianhydride)

[0230] (Specific additives)

[0231] (Additives)

[0232] (Solvents) DMSO: Dimethyl sulfoxide MeCN: Acetonitrile AcOEt: Ethyl acetate THF: Tetrahydrofuran NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve DEAc: N,N-diethylacetamide DMF: N,N-dimethylformamide PB: Propylene glycol monobutyl ether

[0233] (Viscosity Measurement) The viscosity of polyamic acid solutions and other materials was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample volume of 1.1 mL (milliliters), a cone rotor TE-1 (1°34', R24), and a temperature of 25°C.

[0234] (Measurement of molecular weight of polymers other than polyamic acid) The molecular weight of polymers other than polyamic acid was measured using a room-temperature gel permeation chromatography (GPC) apparatus (CBM-20A) (Shimadzu Corporation) and columns (Shodex® KF-804L and KF-803L in series) (Resonac Corporation) as follows: Column temperature: 40°C Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min Standard samples for calibration curve preparation: Standard polystyrene (molecular weight: 197,000, 55,100, 12,800, 3,950, 1,260) (Tosoh Corporation)

[0235] (Measurement of Molecular Weight of Polyamic Acid) The molecular weight of polyamic acid was measured using a room-temperature gel permeation chromatography (GPC) apparatus (SSC-7200 (manufactured by Senshu Science Co., Ltd.) and columns (Shodex® KD-803 and KD-805 in series) (manufactured by Resonaq Corporation) as follows: Column temperature: 50°C Eluent: DMF (Lithium bromide monohydrate (LiBr·H) as an additive) ２ (O) 30 mmol / L, anhydrous crystalline phosphoric acid (o-phosphate) 30 mmol / L, THF 10 ml / L) Flow rate: 1.0 mL / min Standard sample for calibration curve preparation: EasiVial PEG / PEO polyethylene glycol oxide PL2080-0201 (molecular weight: approx. 1,500, approx. 4,000, approx. 13,000, approx. 30,000, approx. 70,000, approx. 130,000, approx. 500,000, approx. 1,000,000, approx. 1,500,000) (manufactured by GL Sciences).

[0236] <Synthesis of Additives> (Synthesis of Add-B1)

[0237] In a 50 mL four-necked flask, 3,3'-diallylbiphenyl-4,4'-diol (3.0 g, 11.3 mmol), epichlorohydrin (10.4 g, 112.6 mmol), tetrabutylammonium chloride (TBACl, 0.94 g, 3.4 mmol), and DMSO (3 g) were charged and stirred at 80°C. After the reaction was complete, the reaction mixture was poured into AcOEt (50 g), deionized water (50 g) was added, and the organic phase was extracted. The obtained organic phase was washed twice with deionized water (50 g) and then concentrated under reduced pressure to obtain 5.1 g of Add-B1-1 (brown liquid, 100% yield).

[0238] Add-B1-1 (5.1 g, 11.3 mmol), potassium carbonate (4.7 g, 33.9 mmol), and MeCN (50 g) were charged into a 200 mL four-necked flask and stirred at 80°C. After the reaction was complete, the reaction mixture was filtered to separate the precipitate, and the filtrate was concentrated under reduced pressure. The resulting concentrate was isolated by silica gel column isolation using an AcOEt / Heptane (volume ratio = 1:3) solution to obtain 2.4 g of Add-B1 (white solid, yield 56%).

[0239] １ H-NMR (500MHz) in DMSO-d ６ : δ (ppm) = 7.36-7.41 (m, 4H), 7.02-7.03 (d, 2H), 5.97-6.03 (m, 2H), 5.07-5.11 (d, 2H), 5.02-5.04 (d, 2H), 4.34-4.37 (d, 2H), 3.90-3.93 (m, 2H), 3.31-3.40 (m, 6H), 2.84-2.86 (m, 2H), 2.73-2.75 (m, 2H).

[0240] (Add-B2 synthesis)

[0241] ​In a 100 mL four-necked flask, 2,2'-diallylbisphenol A (14.0 g, 45.4 mmol), epichlorohydrin (42.0 g, 453.9 mmol), tetrabutylammonium chloride (3.8 g, 13.6 mmol), and DMSO (14 g) were charged and stirred at 80°C. After the reaction was complete, the reaction mixture was poured into AcOEt (100 g), deionized water (100 g) was added, and the organic phase was extracted. The obtained organic phase was washed twice with deionized water (100 g) and then concentrated under reduced pressure to obtain 22.4 g of Add-B2-1 (brown liquid, 100% yield).

[0242] Add-B2-1 (22.4 g, 45.4 mmol), potassium carbonate (18.8 g, 136.2 mmol), and MeCN (220 g) were charged into a 300 mL four-necked flask and stirred at 80°C. After the reaction was complete, the reaction mixture was filtered to remove precipitates, and the filtrate was concentrated under reduced pressure. The resulting concentrate was isolated by silica gel column isolation using an AcOEt / Heptane (volume ratio = 1:3) solution to obtain 9.7 g of Add-B2 (clear liquid, yield 51%).

[0243] １ H-NMR (500MHz) in DMSO-d ６ : δ (ppm) = 6.95-6.99 (m, 4H), 6.84-6.86 (d, 2H), 5.86-5.93 (m, 2H), 4.95-5.00 (m, 4H), 4.25-4.28 (d, 2H), 3.83-3.86 (m, 2H), 3.27-3.32 (m, 6H), 2.81-2.83 (m, 2H), 2.70-2.71 (m, 2H), 1.55 (s, 6H).

[0244] ​<Synthesis of Polymers Composed of a Single Block Segment> (Synthesis Example 1-1) In a 100 ml round-bottom flask equipped with a stirring bar and a nitrogen inlet tube, A-1 (8.35 g, 58.7 mmol), R-1 (376 mg, 0.931 mmol), and AIBN (76.4 mg, 0.465 mmol) were weighed out, THF (8.80 g) was added, and the mixture was stirred at room temperature until dissolved. After purging the system with nitrogen, the mixture was heated and stirred in an oil bath set to 60°C for 12 hours. After heating and stirring, methanol (50 g) was gently added to the reaction solution while stirring to precipitate the solid, and the mixture was stirred for 30 minutes. This precipitate was separated by filtration, and the slurry was washed twice again with methanol (50 g) for 30 minutes each time. The solid was then vacuum-dried at 50°C to obtain the polymer (p(A-1)). The number average molecular weight (Mn) was 7,800, and the weight average molecular weight (Mw) was 8,500.

[0245] (Synthesis Examples 1-2 to 1-7) By carrying out the same procedure as in Synthesis Example 1-1, except that the types and amounts of raw materials (monomers), initiators, and control agents used were replaced with those shown in Table 1 below, polymers (p(A-2)) to (p(A-7)) shown in Table 1 below were obtained.

[0246]

[0247] <Synthesis of Diblock Polymer> (Synthesis Example 2-1) In a 100 ml round-bottom flask equipped with a stirring bar and a nitrogen inlet tube, p(A-1) (5.27 g, 0.676 mmol), B-2 (5.41 g, 18.6 mmol), and AIBN (55.5 mg, 0.338 mmol) obtained in Synthesis Example 1-1 were weighed out, THF (16.0 g) was added, and the mixture was stirred at room temperature to dissolve. After that, the system was purged with nitrogen and heated and stirred in an oil bath set to 60°C for 12 hours. After heating and stirring, methanol (50 g) was gently added to the reaction solution while stirring to precipitate the solid, and the mixture was stirred for 30 minutes. This precipitate was separated by filtration, and the slurry was washed twice again with methanol (50 g) for 30 minutes each time. The solid was then vacuum dried at 50°C to obtain the diblock polymer (BC-1). The number-average molecular weight was 13,600, and the weight-average molecular weight was 16,000.

[0248] (Synthesis Examples 2-2 to 2-12) The same procedure as in Synthesis Example 2-1 was followed, except that the types and amounts of raw materials (polymers and monomers), the amount of initiator, and the polymerization concentration were replaced with those shown in Table 2 below, to obtain the diblock polymers (BC-2) to (BC-12) shown in Table 2 below.

[0249]

[0250] <Synthesis of Macromonomers> (Synthesis Example 3-1) In a 100 ml round-bottom flask equipped with a stirring bar and a nitrogen inlet tube, A-5 (10.0 g, 78.0 mmol), S-1 (0.216 g, 2.34 mmol), and AIBN (0.128 g, 0.780 mmol) were weighed out, THF (10.3 g) was added, and the mixture was stirred at room temperature until dissolved. After purging the system with nitrogen, the mixture was heated and stirred in an oil bath set to 60°C for 12 hours. After heating and stirring, the reaction solution was gently poured in with cold methanol (30 g) while stirring to precipitate a solid, and the mixture was stirred for 30 minutes. This precipitate was separated by filtration, and the slurry was washed twice again with cold methanol (30 g) for 30 minutes each. The solid was then vacuum dried at 50°C to obtain the prepolymer. Mn: 6,000, Mw: 9,900. In a 100 ml round-bottom flask equipped with a stirring bar and a nitrogen inlet tube, the prepolymer synthesized by the above method (10.0 g, 1.67 mmol), B-5 ​​(0.829 g, 5.83 mmol), hydroquinone (8.1 mg), N,N-dimethyllaurylamine (2.0 mg), and xylene (20.0 g) were added and stirred at room temperature until dissolved. The mixture was then heated and stirred in an oil bath set to 140°C for 6 hours. After heating and stirring, methanol (50 g) was gently added to the reaction solution while stirring to precipitate the solid, and the mixture was stirred for 30 minutes. This precipitate was separated by filtration, and the slurry was washed twice again with methanol (50 g) for 30 minutes each. The solid was then vacuum-dried at 50°C to obtain macromonomer pM(A-5). The Mn: 6,100 and Mw: 9,900 were observed.

[0251] <Synthesis of Graft Copolymer> (Synthesis Example 4-1) In a 100 ml round-bottom flask equipped with a stirring bar and a nitrogen inlet tube, pM (A-5) (1.00 g, 0.164 mmol), B-2 (1.57 g, 5.40 mmol), and AIBN (27.4 mg, 0.167 mmol) were weighed out, THF (3.86 g) was added, and the mixture was stirred at room temperature until dissolved. After purging the system with nitrogen, the mixture was heated and stirred in an oil bath set to 60°C for 12 hours. After heating and stirring, methanol (30 g) was gently added to the reaction solution while stirring to precipitate the solid, and the mixture was stirred for 30 minutes. This precipitate was separated by filtration, and the slurry was washed twice again with methanol (30 g) for 30 minutes each time. The solid was then vacuum dried at 50°C to obtain graft copolymer (GP-1). The number-average molecular weight (Mn) was 65,700, and the weight-average molecular weight (Mw) was 137,300.

[0252] <Synthesis of Polyamic Acid> (Synthesis Example 5-1) In a 100 mL four-necked flask equipped with a mechanical stirrer and a nitrogen inlet tube, DA-4 (8.59 g: 30.0 mmol) was weighed out, DEAc (84.9 g) was added, and the mixture was stirred under a nitrogen atmosphere to dissolve it. Then, while maintaining the temperature below 10°C in an ice bath, TC-1 (6.39 g: 28.5 mmol) was added, and the mixture was reacted at room temperature under a nitrogen atmosphere for 18 hours to obtain a polyamic acid solution (PAA-1) with a viscosity of approximately 620 mPa·s and a solid content concentration of 15% by mass. The molecular weight of this polyamic acid was 12,600 (number average molecular weight) and 28,500 (weight average molecular weight).

[0253] (Synthesis Example 5-2) In a 100 mL four-necked flask equipped with a mechanical stirrer and a nitrogen inlet tube, DA-1 (1.62 g: 15.0 mmol), DA-2 (2.20 g: 9.00 mmol), and DA-3 (1.76 g: 6.00 mmol) were weighed out, DEAc (48.9 g) was added, and the mixture was stirred under a nitrogen atmosphere to dissolve. Then, while maintaining a temperature of 10°C or lower in an ice bath, TC-1 (6.66 g: 29.7 mmol) was added, and the mixture was reacted at room temperature under a nitrogen atmosphere for 18 hours to obtain a polyamic acid solution (PAA-2) with a viscosity of approximately 1200 mPa·s and a solid content concentration of 20% by mass. The molecular weight of this polyamic acid was 8,600 (number average molecular weight) and 19,400 (weight average molecular weight).

[0254] <Preparation of Weakly Anchoring Liquid Crystal Alignment Agent> (Preparation Example A1) In a 10 mL vial equipped with a stirring bar, weigh out 0.09 g of BC-1 obtained in Synthesis Example 2-1, 1.80 g of PAA-1 solution obtained in Synthesis Example 5-1, 54.0 mg of specific additive Add-A1, 2.91 g of DEAc, and 1.20 g of PB, and stir at room temperature for 1 hour to obtain a weakly anchoring liquid crystal alignment agent (WAS-A-1).

[0255] (Preparation Examples A2 to A38) The same procedure as in Preparation Example A1 was followed, except that the polymer, type and amount of additives used were replaced with those shown in Tables 3-1 and 3-2, to obtain the weak anchoring liquid crystal alignment agents (WAS-A-2) to (WAS-A-38) shown in Tables 3-1 and 3-2 below.

[0256]

[0257]

[0258] In the table, "mass%" represents the mass percentage (%) of each component in the liquid crystal alignment agent. In the table, "phr" represents the amount of additive added (mass%) relative to the total amount of polymer in the liquid crystal alignment agent.

[0259] <Fabrication of Liquid Crystal Display Elements> The following describes the method for fabricating liquid crystal cells to evaluate liquid crystal alignment and electro-optic response. First, a substrate with electrodes was prepared. The substrate used was an alkali-free glass substrate measuring 30 mm x 35 mm with a thickness of 0.7 mm. ITO (INDIUM-TIN-OXIDE) electrodes with a comb-shaped pattern having an electrode width of 3 μm, a spacing of 6 μm between electrodes, and an angle of 10° with respect to the long side of the substrate were formed on the substrate, forming pixels. The size of each pixel was 10 mm vertically and approximately 5 mm horizontally. Hereafter, this will be referred to as the IPS substrate. Next, the liquid crystal alignment agents (WAS-A-1 to WAS-A-38) and the liquid crystal alignment agent for horizontal alignment (NRB-U973 (manufactured by Nissan Chemical Corporation)) obtained by the above method were filtered through a filter with a pore size of 1.0 mm. Then, the prepared IPS substrates and a glass substrate (hereinafter referred to as the opposing substrate) having an ITO film deposited on its back surface and columnar spacers with a height of 3.0 μm were coated and deposited by spin coating. Next, the substrates were dried on a hot plate at 80°C for 2 minutes, and then baked at 230°C for 30 minutes to obtain a coating with a thickness of 100 nm. For the coating on the IPS substrate, the orientation treatment was performed in the direction along the comb teeth, and for the coating on the opposing substrate, the orientation treatment was performed in the direction perpendicular to the comb teeth electrodes. For the orientation treatment of NRB-U973, the photo-alignment method was used, and for WAS-A-1 to WAS-A-38, no orientation treatment was performed, and the substrates were used as they were after baking. In the photo-alignment method, a UV exposure system manufactured by Ushio Inc. was used, and linearly polarized UV light with an extinction ratio of approximately 26:1 was irradiated at a wavelength of 254 nm with an irradiation dose of 300 mJ / cm². ２Orientation treatment was performed by irradiating with polarized UV light and then heating at 230°C for 30 minutes. Subsequently, using the two types of substrates described above, the substrates were combined in the combinations shown in Tables 4-1 and 4-2 below, so that their respective orientation directions were parallel. The surrounding area was sealed, leaving a liquid crystal injection port (sealant: XN-1500T (manufactured by Mitsui Chemicals, Inc.)), and the sealant was cured by heating at 150°C for 60 minutes to create empty cells with a cell gap of approximately 3.0 μm. Liquid crystal (MLC-3019 (manufactured by Merck, Inc.)) was vacuum injected into these empty cells at room temperature, and the injection port was sealed to create antiparallel oriented liquid crystal cells. The obtained liquid crystal cells constitute an IPS type liquid crystal display element. Subsequently, the obtained liquid crystal cells were heated at 120°C for 30 minutes to obtain a liquid crystal display element.

[0260] <Evaluation of Initial Orientation> Using a polarizing microscope, the polarizer was set to crossed nicols, and the liquid crystal cell was fixed in the state where its brightness was lowest. From there, the liquid crystal cell was rotated 1°, and the orientation state of the liquid crystal was observed. If no or very minor orientation defects such as unevenness or domains were observed, it was defined as "good," and if they were clearly observed, it was defined as "poor."

[0261] <V-T Curve Measurement and Evaluation of Drive Threshold Voltage, Maximum Brightness Voltage, and Transmittance> A white LED backlight and a luminance meter were set up so that the optical axis was aligned, and a liquid crystal cell (liquid crystal display element) with a polarizing plate attached to minimize brightness was set between them. Voltage was applied in 1V increments up to 8V, and the V-T curve was measured by measuring the brightness at each voltage. Voltage was applied from a no-voltage state, and the voltage value (Vth) at 10% of the maximum transmittance brightness was estimated. From the obtained V-T curve, the voltage value (Vmax) at which the brightness is maximized was estimated. In addition, the maximum transmittance (Tmax) was estimated by comparing the maximum transmittance brightness in the V-T curve with the transmittance brightness at 100% in parallel nicols via a liquid crystal cell with no voltage applied.

[0262] <Measurement of Response Time (Ton, Toff)> Using the same equipment as used for the V-T curve measurement above, the luminance meter was connected to an oscilloscope, and the response time (Ton) when the voltage that produced maximum brightness was applied and the response time (Toff) when the voltage was returned to 0V were measured.

[0263] <Evaluation of burn-in due to long-term AC drive> Vmax was applied to only the first pixel of the above IPS-driven liquid crystal cell at a constant temperature of 60°C and a frequency of 30 Hz for 120 hours. After that, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited once. Immediately thereafter, voltage was applied to both the first pixel that was long-term AC-driven and the second pixel that was not AC-driven, in the same manner as above, up to 8V at 1V intervals, and the V-T curve with and without voltage application was measured by measuring the brightness at the voltage. Vth measured at the second pixel, 第二画素 Based on the brightness in the first pixel driven by long-term AC, 第一画素 The burn-in ratio was calculated from the rate of change in brightness. The calculation formula is as follows: Calculated value = L1 / L2 L1: Vth at the first pixel, 第一画素 Brightness value L2: Vth in the second pixel, 第二画素 In the calculation, a brightness value of 1.25 or higher was considered "poor," and a value less than 1.25 was considered "good."

[0264] The evaluation results are shown in Tables 4-1 and 4-2.

[0265]

[0266]

[0267] In IPS liquid crystal display elements fabricated using the weak anchoring liquid crystal alignment agent of the present invention, all liquid crystal display elements of Examples A1 to A22 showed a decrease in threshold voltage (Vth) and maximum brightness voltage (Vmax) and an improvement in maximum transmittance (Tmax) compared to Comparative Example A17. In addition, Examples A1 to A22 showed similar levels of Vth, Vmax, Tmax, and burn-in compared to Comparative Examples A1 to A14 and Comparative Example A16, indicating equivalent liquid crystal alignment characteristics. Comparative Example A15, however, exhibited poor burn-in characteristics.

[0268] <Preparation of Adhesion Evaluation Samples> The liquid crystal alignment agents obtained in the above preparation examples A1 to A38 were filtered through a 1.0 μm filter, then spin-coated onto glass substrates with transparent electrodes. After drying on a hot plate at 80°C for 2 minutes, they were baked at 230°C for 20 minutes to obtain a coating with a thickness of 100 nm. Similarly, a liquid crystal alignment film using NRB-U973 was formed on all opposing substrates. Two substrates were prepared, and 4 μm diameter bead spacers were scattered on the liquid crystal alignment film surface of one substrate, after which a sealant (Mitsui Chemicals XN-1500T) was dropped onto it. At that time, the amount of sealant dropped was adjusted so that the diameter of the sealant after bonding was approximately 3 mm. Next, the film surfaces of the two substrates were placed facing each other and bonded together so that the overlap width of the substrates was 1 cm. After fixing the bonded substrates together with clips, they were heat-cured at 120°C for 1 hour to prepare a sample for adhesion evaluation.

[0269] <Measurement of Seal Adhesion> The prepared sample was tested using a Shimadzu AGS-X 500N desktop precision universal tester. After fixing the edges of the upper and lower substrates, pressure was applied from the upper center of the substrate, and the pressure (N) at which peeling occurred was measured. The adhesion force (also called seal peel strength or seal adhesion) was evaluated using the pressure (N / mm) normalized by the diameter of the measured sealant. A value of 2.0 N / m or higher was evaluated as "good," and a value of less than 2.0 N / m was evaluated as "poor." The details of the example and the evaluation results are shown in Tables 5-1 and 5-2.

[0270]

[0271]

[0272] Examples A23 to A44 show improved adhesion compared to Comparative Examples A18 to A31, demonstrating that the weak anchoring liquid crystal alignment agent of the present invention possesses high adhesion. Comparative Example A32 (WAS-A-37) has good adhesion, but its burn-in characteristics are poor, as shown in Comparative Example A15 (WAS-A-37). Similarly, Comparative Example A16 (WAS-A-38) has good burn-in characteristics, but its adhesion is poor, as shown in Comparative Example A33 (WAS-A-38). In contrast, the weak anchoring liquid crystal alignment agent of the present invention achieves both good adhesion and display characteristics.

[0273] <Preparation of Weakly Anchoring Liquid Crystal Alignment Agent> (Preparation Example B1) In a 10 mL vial equipped with a stirring bar, weigh out 0.09 g of BC-1 obtained in Synthesis Example 2-1, 1.80 g of PAA-1 solution obtained in Synthesis Example 5-1, 54.0 mg of specific additive Add-B1, 2.91 g of DEAc, and 1.20 g of PB, and stir at room temperature for 1 hour to obtain a weakly anchoring liquid crystal alignment agent (WAS-B-1).

[0274] (Preparation Examples B2 to B33) The same procedure as in Preparation Example B1 was followed, except that the polymer, type and amount of additives used were replaced with those shown in Tables 6-1 and 6-2, to obtain the weak anchoring liquid crystal alignment agents (WAS-B-2) to (WAS-B-33) shown in Tables 6-1 and 6-2 below.

[0275]

[0276]

[0277] In the table, "mass%" represents the mass percentage (%) of each component in the liquid crystal alignment agent. In the table, "phr" represents the amount of additive added (mass%) relative to the total amount of polymer in the liquid crystal alignment agent.

[0278] <Fabrication of Liquid Crystal Display Elements> The following describes the method for fabricating liquid crystal cells to evaluate liquid crystal alignment and electro-optic response. First, a substrate with electrodes was prepared. The substrate used was an alkali-free glass substrate measuring 30 mm x 35 mm with a thickness of 0.7 mm. ITO (INDIUM-TIN-OXIDE) electrodes with a comb-shaped pattern having an electrode width of 3 μm, a spacing of 6 μm between electrodes, and an angle of 10° with respect to the long side of the substrate were formed on the substrate, forming pixels. The size of each pixel was 10 mm vertically and approximately 5 mm horizontally. Hereafter, this will be referred to as the IPS substrate. Next, the liquid crystal alignment agents (WAS-B-1 to WAS-B-33) and the liquid crystal alignment agent for horizontal alignment (NRB-U973 (manufactured by Nissan Chemical Corporation)) obtained by the above method were filtered through a filter with a pore size of 1.0 mm. Then, the prepared IPS substrates and a glass substrate (hereinafter referred to as the opposing substrate) having an ITO film deposited on its back surface and columnar spacers with a height of 3.0 μm were coated and deposited by spin coating. Next, the films were dried on a hot plate at 80°C for 2 minutes, and then baked at 230°C for 30 minutes to obtain a coating with a thickness of 100 nm. For the coating on the IPS substrate, the orientation treatment was performed in the direction along the comb teeth, and for the coating on the opposing substrate, the orientation treatment was performed in the direction perpendicular to the comb teeth electrodes. For the orientation treatment of NRB-U973, the photo-alignment method was used, and for WAS-B-1 to WAS-B-33, no orientation treatment was performed, and the substrates were used as they were after baking. In the photo-alignment method, a UV exposure system manufactured by Ushio Inc. was used, and linearly polarized UV light with an extinction ratio of approximately 26:1 was irradiated at a wavelength of 254 nm with an irradiation dose of 300 mJ / cm². ２The orientation treatment was performed by irradiating with polarized UV light and then heating at 230°C for 30 minutes. Subsequently, using the two types of substrates described above, the substrates were combined in the combinations shown in Tables 7-1 and 7-2 below, so that their respective orientation directions were parallel. The surrounding area was sealed, leaving a liquid crystal injection port (sealant: XN-1500T (manufactured by Mitsui Chemicals, Inc.)), and the sealant was cured by heating at 150°C for 60 minutes to create empty cells with a cell gap of approximately 3.0 μm. Liquid crystal (MLC-3019 (manufactured by Merck, Inc.)) was vacuum injected into these empty cells at room temperature, and the injection port was sealed to create antiparallel oriented liquid crystal cells. The obtained liquid crystal cells constitute an IPS type liquid crystal display element. Subsequently, the obtained liquid crystal cells were heated at 120°C for 30 minutes to obtain a liquid crystal display element.

[0279] <Evaluation of Initial Orientation> Using a polarizing microscope, the polarizer was set to crossed nicols, and the liquid crystal cell was fixed in the state where its brightness was lowest. From there, the liquid crystal cell was rotated 1°, and the orientation state of the liquid crystal was observed. If no or very minor orientation defects such as unevenness or domains were observed, it was defined as "good," and if they were clearly observed, it was defined as "poor."

[0280] <V-T Curve Measurement and Evaluation of Drive Threshold Voltage, Maximum Brightness Voltage, and Transmittance> A white LED backlight and a luminance meter were set up so that the optical axis was aligned, and a liquid crystal cell (liquid crystal display element) with a polarizing plate attached to minimize brightness was set between them. Voltage was applied in 1V increments up to 8V, and the V-T curve was measured by measuring the brightness at each voltage. Voltage was applied from a no-voltage state, and the voltage value (Vth) at 10% of the maximum transmittance brightness was estimated. From the obtained V-T curve, the voltage value (Vmax) at which the brightness is maximized was estimated. In addition, the maximum transmittance (Tmax) was estimated by comparing the maximum transmittance brightness in the V-T curve with the transmittance brightness at 100% in parallel nicols via a liquid crystal cell with no voltage applied.

[0281] <Measurement of Response Time (Ton, Toff)> Using the same equipment as used for the V-T curve measurement above, the luminance meter was connected to an oscilloscope, and the response time (Ton) when the voltage that produced maximum brightness was applied and the response time (Toff) when the voltage was returned to 0V were measured.

[0282] <Evaluation of burn-in due to long-term AC drive> Vmax was applied to only the first pixel of the above IPS-driven liquid crystal cell at a constant temperature of 60°C and a frequency of 30 Hz for 120 hours. After that, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited once. Immediately thereafter, voltage was applied to both the first pixel that was long-term AC-driven and the second pixel that was not AC-driven, in the same manner as above, up to 8V at 1V intervals, and the V-T curve with and without voltage application was measured by measuring the brightness at the voltage. Vth measured at the second pixel, 第二画素 Based on the brightness in the first pixel driven by long-term AC, 第一画素 The burn-in ratio was calculated from the rate of change in brightness. The calculation formula is as follows: Calculated value = L1 / L2 L1: Vth at the first pixel, 第一画素 Brightness value L2: Vth in the second pixel, 第二画素 In the calculation, a brightness value of 1.25 or higher was considered "poor," and a value less than 1.25 was considered "good."

[0283] The evaluation results are shown in Tables 7-1 and 7-2.

[0284]

[0285]

[0286] In IPS liquid crystal display elements fabricated using the weak anchoring liquid crystal alignment agent of the present invention, all liquid crystal display elements of Examples B1 to B17 showed a decrease in threshold voltage (Vth) and maximum brightness voltage (Vmax) and an improvement in maximum transmittance (Tmax) compared to Comparative Example B17. In addition, Examples B1 to B17 showed similar levels of Vth, Vmax, Tmax, and burn-in compared to Comparative Examples B1 to B14 and Comparative Example B16, indicating equivalent liquid crystal alignment characteristics. Comparative Example B15, however, exhibited poor burn-in characteristics.

[0287] <Preparation of Adhesion Evaluation Samples> The liquid crystal alignment agents obtained in Preparation Examples B1 to B33 were each filtered through a 1.0 μm filter, then spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at 80 °C for 2 minutes, and fired at 230 °C for 20 minutes to obtain a coating film with a thickness of 100 nm. Also, in the same manner as the above method, a liquid crystal alignment film using NRB-U973 was formed on all the opposing substrates. Two obtained substrates were each prepared. After spraying bead spacers with a diameter of 4 μm on the liquid crystal alignment film surface of one substrate, a sealant (XN-1500T manufactured by Mitsui Chemicals, Inc.) was dropped. At that time, the amount of sealant dropped was adjusted so that the diameter of the sealant after bonding would be about 3 mm. Next, the film surfaces facing each other were bonded together so that the overlapping width of the substrates would be 1 cm. After fixing the bonded substrates with clips, they were thermally cured at 120 °C for 1 hour to prepare a sample for adhesion evaluation.

[0288] <Measurement of Seal Adhesion Strength> The prepared sample was fixed at the end portions of the upper and lower substrates using a tabletop precision universal testing machine AGS-X 500N manufactured by Shimadzu Corporation, and then pushed in from above the central part of the substrate, and the pressure (N) at the time of peeling was measured. In addition, the adhesion strength (also referred to as seal peeling strength and seal adhesion) was evaluated using the pressure (N / mm) normalized by the measured diameter of the sealant. A pressure of 2.0 N / mm or more was evaluated as "good", and less than 2.0 N / mm was evaluated as "bad". The contents of the examples and the evaluation results are shown in Tables 8-1 and 8-2.

[0289]

[0290]

[0291] Examples B18 to B34 have improved adhesion compared to Comparative Examples B18 to B31, and the weak anchoring liquid crystal alignment agent of the present invention has high adhesion. Although Comparative Example B32 (WAS-B-32) has good adhesion, as shown in Comparative Example B15 (WAS-B-32), it has poor baking characteristics. Also, although Comparative Example B16 (WAS-B-33) has good baking characteristics, as in Comparative Example B33 (WAS-B-33), its adhesion is poor. In contrast, the weak anchoring liquid crystal alignment agent of the present invention achieves both good adhesion and display characteristics.

[0292] 1. Transverse electric field liquid crystal display element 2. Comb-tooth electrode substrate 2a. Substrate 2b. Linear electrode 2c. Liquid crystal alignment film 2d. Substrate 2e. Surface electrode 2f. Insulating film 2g. Linear electrode 2h. Liquid crystal alignment film 3. Liquid crystal 4. Opposing substrate 4a. Liquid crystal alignment film 4b. Substrate L. Electric field lines

Claims

1. A liquid crystal alignment agent comprising polymer α obtained from a polymerizable compound having polymerizable unsaturated hydrocarbon groups, at least one polymer β selected from polyimide, polyamic acid, polyamic acid ester, polyamide, and polyurea, and one of the following compounds A and B. Compound A: A compound represented by the following formula (Add1-A) Compound B: A compound represented by the following formula (Add1-B) that has two to four glycidyl groups in its molecule and at least one unsaturated bond in its molecule (In formula (Add1-A), n1, m1, and m2 each independently represent 1 or 2.) When n1 is 1 and m1 is 1, X １ This represents a single bond, an oxygen atom, -NR- (where R is a hydrogen atom or a methyl group), or an ester bond. When n1 is 1 and m1 is 2, X １ This represents a nitrogen atom. When n1 is 1 and m2 is 1, X ２ This represents a single bond, an oxygen atom, -NR- (where R is a hydrogen atom or a methyl group), or an ester bond. When n1 is 1 and m2 is 2, X ２ represents a nitrogen atom. n1 is 1 and X １ and X ２ When at least one of the atoms is an oxygen atom, a nitrogen atom, a -NR- group (where R is a hydrogen atom or a methyl group), or an ester bond, A represents a divalent hydrocarbon group having 6 to 18 carbon atoms and a ring structure. When n1 is 1, m1 is 1, m2 is 1 and X １ and X ２ are single bonds, A represents a divalent organic group obtained by removing the hydrogen atoms of the hydroxy groups on both sides from (poly)ethylene glycol, (poly)propylene glycol, or (poly)butylene glycol having a molecular weight of 1000 or less. When n1 is 2, m1 and m2 represent 1, X １ and X ２ represent oxygen atoms, and A represents a trivalent hydrocarbon group having 1 to 6 carbon atoms.) (In formula (Add1 - B), Y represents a single bond or a divalent group represented by any one of the following formulas (Y - 1) to (Y - 8). G represents a group represented by the following formula (G - 1). X represents an oxygen atom, -NR- (R is a hydrogen atom or a methyl group), or an ester bond. Z represents a group represented by any one of the following formulas (Z - 1) to (Z - 2). j and k are each independently an integer of 1 to 2. m and n are each independently an integer of 0 to 1 and satisfy m + n ≧ 1. When a plurality of G, X, and Z are present respectively, the plurality of G, X, and Z may be the same as or different from each other.) (In formulas (Y - 1) to (Y - 8), R １ and R ２ each independently represent a hydrogen atom, a fluorine atom, a hydrocarbon group having 1 to 2 carbon atoms, or a fluorinated hydrocarbon group having 1 to 2 carbon atoms. * represents a bonding site.) (In formula (G - 1), * represents a bonding site.) (In formulas (Z - 1) to (Z - 2), * represents a bonding site.) 2. The liquid crystal alignment agent according to claim 1, wherein the polymerizable group is at least one selected from a (meth)acryloyloxy group, a (meth)acrylamide group, an allyl group, a styryl group, and a maleimide group.

3. The liquid crystal alignment agent according to claim 1, wherein the compound represented by the formula (Add1-A) is selected from the following formulas. (In the formula, i is an integer between 1 and 22, j is an integer between 1 and 16, and k is an integer between 1 and 13.) 4. The liquid crystal alignment agent according to claim 1, wherein the content of the compound represented by formula (Add1-A) is 1 to 30% by mass relative to the total amount of polymer components contained in the liquid crystal alignment agent.

5. The liquid crystal alignment agent according to claim 1, wherein the compound represented by formula (Add1-B) has the following structure.

6. The liquid crystal alignment agent according to claim 1, wherein the content of the compound represented by formula (Add1-B) is 1 to 30% by mass relative to the total amount of polymer components contained in the liquid crystal alignment agent.

7. The liquid crystal alignment agent according to claim 1, wherein the fired film obtained by applying and firing the liquid crystal alignment agent exhibits weak anchoring properties.

8. A weak anchoring liquid crystal alignment agent used for forming a liquid crystal alignment film in a liquid crystal cell having a liquid crystal and a liquid crystal alignment film, wherein the polymer α contains at least one selected from the group consisting of polymer A, polymer B, and polymer C described below, according to claim 1. Polymer A: A block copolymer having a block segment (A) that is compatible with the liquid crystal and a block segment (B) that is not compatible with the liquid crystal or becomes insoluble in the liquid crystal by firing. Polymer B: A graft copolymer having a stem polymer and branch polymers bonded to the stem polymer as side chains of the stem polymer, wherein the branch polymers are compatible with the liquid crystal, and the stem polymer is not compatible with the liquid crystal or becomes insoluble in the liquid crystal by firing. Polymer C: A polymer having polymer units compatible with the liquid crystal, and which reacts with polymer β upon heating.

9. The liquid crystal alignment agent according to claim 8, wherein the block segment (A) in polymer A, the branch polymer in polymer B, and the polymer unit compatible with the liquid crystal in polymer C each contain as a component at least one selected from the group consisting of a compound represented by the following formula (2), a compound represented by the following formula (3), a compound represented by the following formula (4), and a compound represented by the following formula (5), and the block segment (B) in polymer A and the stem polymer in polymer B each contain as a component a compound represented by the following formula (6). (In formula (2), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, X represents a single bond, ether bond, ester bond, amide bond, urethane bond, urea bond, or thioether bond, R １ represents an alkyl group having 1 to 20 carbon atoms, which may have a bonding group inserted, and n is an integer from 1 to 2. When n is 2, there are two X and R １ They may be the same or they may be different. (In formula (3), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, S represents a saturated hydrocarbon group having 1 to 6 carbon atoms with a single bond or an inserted bonding group, T represents an organic group represented by the following formula (3-T), and n is an integer from 1 to 2. When n is 2, the two T's may be the same or different. However, when n is 2, S represents a saturated hydrocarbon group having 1 to 6 carbon atoms with an inserted bonding group.) (In formula (3-T), * indicates a bonding site. X is a single bond, ether bond, ester bond, amide bond, urethane bond, urea bond, thioether bond, -Si(R) １ ) (Caution ２ ) - (R １ and R ２ Each of these represents an alkyl group that is independently bonded to Si. ), -Si(R ３ ) (Caution ４ )-O-(R ３ and R ４ Each of these represents an alkyl group that is independently bonded to Si. ), and -N (R ５ ) - (R ５ represents a hydrogen atom or alkyl group bonded to N. (The bond group is selected from , and Cy represents a non-aromatic cyclic group with 6 to 20 members.) (In formula (4), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, and R １ The 'X' represents an aliphatic hydrocarbon group having a straight or branched structure with 1 to 10 carbon atoms, and each of the three 'X's independently represents a hydrogen atom or the following formula (4-X). However, at least one of the three 'X's represents the formula (4-X). (In formula (4-X), Y represents a single bond, -O-, -S-, or -N(R)- (where R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms bonded to N), and * indicates a bonding site. ２ , R ３ , and R ４ Each of these independently represents an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group which may have substituents. (In formula (5), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, and R １ ~R ３ Each of these independently represents an alkylene group having 1 to 6 carbon atoms, which may have a single bond or an inserted bonding group, and Ar represents an aromatic hydrocarbon group which may have a substituent, X １ and X ２ Each of these independently represents a hydrogen atom or an aromatic hydrocarbon group which may have substituents, and R １ X １ and R ２ X ２ and R １ X １ and R ２ X ２ The carbon atom bonded to it may form a ring together with it. However, R １ X １ , R ２ X ２ and R ３ The total number of carbon atoms is 1 or more. (In formula (6), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, and n is an integer between 1 and 2. Z represents a group represented by the following formula (6-Z). When n is 2, the two Zs may be the same or different.) (In formula (6-Z), L is an optionally protected amino group, an optionally protected aniline group, an optionally protected hydroxyl group, an optionally protected phenol group, an optionally protected thiol group, an optionally protected thiophenol group, an optionally protected carboxyl group, an optionally protected benzoic acid group, an optionally protected isocyanate group, a C2-C5 cyclic ether group, a maleimide group, a carboxylic anhydride group, an N-hydroxysuccinimide ester group, an oxazoline group, a trialkoxysilyl group, a vinyl group optionally substituted with a C1-C16 alkyl group, an ethynyl group optionally substituted with a C1-C16 alkyl group, an allyl group, a styryl group, an α- This represents a functional group selected from the group consisting of hydroxyacetophenone, α-aminoalkylphenone, oxime ester, and acylphosphine oxide groups. J represents a single bond or an aliphatic hydrocarbon group having 1 to 10 carbon atoms. K and Q independently represent linking groups selected from single bonds, ether bonds, ester bonds, amide bonds, urea bonds, urethane bonds, and thioether bonds. P represents a single bond or a phenylene group. R represents a single bond or an alkylene group having 1 to 16 carbon atoms. * represents a bonding site. m is an integer from 1 to 3. If m is 2 or 3, multiple K, P, Q, R, and L may be the same or different. However, if J is a single bond, m is 1.

10. The liquid crystal alignment agent according to claim 8, wherein the branch polymer in polymer B is derived from a macromonomer represented by the following formula (7). (In formula (7), P represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, Q is a structure obtained by polymerizing a monomer containing at least one of the compounds represented by formulas (2) to (5), and n is an integer from 1 to 2. When n is 2, the two Qs may be the same or different.) 11. The liquid crystal aligning agent according to claim 8, wherein the polymer C is a polymer represented by the following formula (8). (In formula (8), A represents an n-valent organic group having a molecular weight of 500 or less and having a group that reacts with the polymer β by heating, selected from the following formulas (8-A-1) to (8-A-16). Q is a divalent polymer unit compatible with the liquid crystal, containing at least one selected from the group consisting of the compounds represented by the above formulas (2) to (5) as a constituent component. R is a monovalent organic group having a molecular weight of 500 or less and not reacting with the polymer β by heating, selected from the following formulas (8-R-1) to (8-R-11). n is an integer of 1 to 2. When n is 2, the two Qs and Rs may be the same or different from each other.) (In formulas (8-A-1) to (8-A-16), R １ and R ２ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, R ３ and R ４ each independently represent a single bond or a linear or branched alkylene group having 1 to 12 carbon atoms, and X represents an oxygen atom or a sulfur atom. * represents a bonding site.) (In formulas (8-R-1) to (8-R-11), R １ and R ２ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, R ３ and R ４ each independently represent a single bond or a linear or branched alkylene group having 1 to 12 carbon atoms. * represents a bonding site.) 12. The liquid crystal alignment agent according to claim 8, wherein polymers A to C are polymers obtained by living polymerization or chain transfer polymerization.

13. A liquid crystal display element comprising a liquid crystal alignment film formed using the liquid crystal alignment agent described in any one of claims 1 to 12.

14. The liquid crystal display element according to claim 13, which is a transverse electric field liquid crystal display element.

15. A method for manufacturing a liquid crystal display element, comprising applying and firing a liquid crystal alignment agent according to any one of claims 1 to 12.

16. The method for manufacturing a liquid crystal display element according to claim 15, wherein the liquid crystal display element is a transverse electric field liquid crystal display element.

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