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

Abstract

The invention provides a liquid crystal aligning agent, a liquid crystal alignment film, a liquid crystal element, a polymer and a compound, which have excellent coating property, and can obtain a liquid crystal element which is not easy to reduce in performance even under the condition of long-term use in a high-temperature environment and is high in reliability. The liquid crystal aligning agent contains a polymer (P), and the polymer (P) is at least one selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, and has a partial structure represented by formula (1). R1 represents an alkyl group having 2-20 carbon atoms, a fluoroalkyl group, or the like; and R2 represents an (n1 + 1)-valent aromatic ring group, an (n1 + 1)-valent alicyclic group, or an (n1 + 1)-valent heterocyclic group. And R4 is a divalent aromatic ring group. And Z1 and Z2 each represents a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkoxy group having 1-5 carbon atoms, an alkyl group having 1-6 carbon atoms, or a fluoroalkyl group having 1-6 carbon atoms. Z1 and Z2 do not simultaneously become hydrogen atoms. And R5 represents a linear alkanediyl group having 1-12 carbon atoms, or the like. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, a liquid crystal element, a polymer and a compound. Background Art

[0002] Liquid crystal elements include a liquid crystal alignment film that aligns liquid crystal molecules in a liquid crystal layer in a specific direction. Liquid crystal alignment films are typically formed by applying a liquid crystal alignment agent, made by dissolving a polymer component in an organic solvent, to a substrate surface, preferably by heating the substrate.

[0003] As methods for obtaining an organic film with a liquid crystal orientation restriction force, there are previously known methods of rubbing the organic film, obliquely evaporating silicon oxide, and forming a monomolecular film having a long-chain alkyl group. In addition, there are known methods of irradiating a photosensitive organic film with light (photo-alignment method). Among these methods, the photo-alignment method can uniformly impart liquid crystal orientation to the film while suppressing the generation of static electricity or dust, and therefore various studies have been conducted in recent years (for example, see Patent Document 1 or Patent Document 2). Patent Document 1 and Patent Document 2 disclose the use of a polymer having a cinnamate structure and the formation of a liquid crystal alignment film by a photo-alignment method.

[0004] In recent years, LCD televisions have become increasingly popular, and large-scale production lines, known as "8th Generation" and "10th Generation," are now in operation. Advantages of using large-scale production lines to increase the size of substrates include reducing process time and costs by allowing multiple panels to be produced from a single substrate, and accommodating the increased size of liquid crystal display elements themselves. On the other hand, there are disadvantages: ensuring uniform printing of liquid crystal alignment agents over large areas is difficult due to the increased size of the substrates. In contrast, the use of inkjet coating methods for forming liquid crystal alignment films is under investigation because they promise uniform coating.

[0005] [Prior art literature]

[0006] [Patent Document]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-100099

[0008] [Patent Document 2] Japanese Patent Application Laid-Open No. 2022-173076 Summary of the Invention

[0009] [Problems to be solved by the invention]

[0010] Liquid crystal devices have historically been primarily used in televisions, but their use as display devices has expanded in recent years. They are used in a wide range of applications, including automotive devices, digital signage, and mobile tablets, across a wide range of scenarios. Furthermore, as their applications expand, their use in previously unimagined harsh environments is also increasing.

[0011] Therefore, liquid crystal elements are required to have high reliability and little degradation of performance even when used for a long time in a high-temperature environment. In order to ensure reliability that can withstand long-term use in a high-temperature environment (hereinafter also referred to as "high-temperature reliability"), it is believed to be effective to introduce a rigid mesogen structure into the polymer. However, when a rigid mesogen structure is introduced into the polymer, there is a concern that the solubility of the polymer will be reduced, making it impossible to ensure the coating properties of the liquid crystal alignment agent. In this case, there is a concern that the performance of the liquid crystal element will be reduced or the product yield will be reduced.

[0012] The present invention has been made in view of the above-mentioned problems, and a main object of the present invention is to provide a liquid crystal aligning agent that exhibits excellent coating properties and can provide a liquid crystal element with high reliability that is less likely to deteriorate in performance even when used for a long period of time in a high-temperature environment.

[0013] [Technical means to solve the problem]

[0014] According to one aspect of the present invention, a liquid crystal aligning agent is provided, comprising a polymer (P) which is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide and has a partial structure represented by the following formula (1).

[0015] [Chemistry 1]

[0016]

[0017] (In formula (1), R 1 is an alkyl group, a fluoroalkyl group or a cyanated alkyl group having 2 to 20 carbon atoms; X 1 For single bonds, oxygen atoms, * 1 -COO- or * 1 -OCO-;"* 1 " indicates that the 1 Bond of R 2 is an (n1+1)-valent aromatic ring group, a (n1+1)-valent alicyclic group or a (n1+1)-valent heterocyclic group; R 3 is a single bond, a divalent aromatic ring group, a divalent alicyclic group or a divalent heterocyclic group; X 2 For single bonds, oxygen atoms, * 2 -COO-,* 2 -OCO-,* 2-R 6 O-, * 2 -OR 6 -, an alkanediyl group or vinylene group having 1 to 3 carbon atoms; R 6 is an alkanediyl group having 1 to 3 carbon atoms; 2 "Indicates that the 3 Bond of R 4 is a divalent aromatic ring group; Z 1 and Z 2 are independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms; wherein Z 1 and Z 2 Will not become a hydrogen atom at the same time; X 3 is an oxygen atom, a sulfur atom or -NR 7 -;R 7 is a hydrogen atom or a monovalent organic group; R 5 It is a straight-chain alkanediyl group having 1 to 12 carbon atoms, or one or more methylene groups in a straight-chain alkanediyl group having 1 to 12 carbon atoms are replaced by -O-, -COO- or -NR 8 CO-substituted and connected to X through -CH2- 3 Bonding divalent group; R 8 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; n1 is an integer of 1 to 3; n2 is an integer of 0 to 3; wherein, when n1 is 2 or more, multiple X 1 Same or different, multiple R 1 Same or different; when n2 is 2 or more, multiple X 2 Same or different, multiple R 3 The same or different; "*" indicates a bonding bond).

[0018] According to the present invention, in another embodiment, a liquid crystal alignment film is provided, which is formed using the liquid crystal alignment agent. In addition, according to the present invention, in another embodiment, a liquid crystal element is provided, which includes the liquid crystal alignment film. Furthermore, according to the present invention, in another embodiment, a polymer is provided, which is any one of polyamic acid, polyamic acid ester and polyimide, and contains a structural unit derived from a diamine having a partial structure represented by the formula (1).

[0019] Furthermore, according to another embodiment of the present invention, there is provided a compound represented by any one of the following formulas (2-1) to (2-3).

[0020] [Chemistry 2]

[0021]

[0022] (In formula (2-1) to formula (2-3), R1 is an alkyl group, a fluoroalkyl group or a cyanated alkyl group having 2 to 20 carbon atoms; X 1 For single bonds, oxygen atoms, * 1 -COO- or * 1 -OCO-;"* 1 "Indicates that the 1 Bond of R 2 is an (n1+1)-valent aromatic ring group, a (n1+1)-valent alicyclic group or a (n1+1)-valent heterocyclic group; R 3 is a single bond, a divalent aromatic ring group, a divalent alicyclic group or a divalent heterocyclic group; X 2 For single bonds, oxygen atoms, * 2 -COO-,* 2 -OCO-,* 2 -R 6 O-, * 2 -OR 6 -, an alkanediyl group or vinylene group having 1 to 3 carbon atoms; R 6 is an alkanediyl group having 1 to 3 carbon atoms; 2 "Indicates that the 3 Bond of R 4 is a divalent aromatic ring group; Z 1 and Z 2 are independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms; wherein Z 1 and Z 2 Will not become a hydrogen atom at the same time; X 3 For oxygen atoms, sulfur atoms, -NR 7 -;R 7 is a hydrogen atom or a monovalent organic group; R 5 It is a straight-chain alkanediyl group having 1 to 12 carbon atoms, or one or more methylene groups in a straight-chain alkanediyl group having 1 to 12 carbon atoms are replaced by -O-, -COO- or -NR 8 CO-substituted and connected to X through -CH2- 3 Bonding divalent group; R 8 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; n1 is an integer from 1 to 3; n2 is an integer from 0 to 3; R 10 、R 11 、R 12 、R 13 and R 14 are independently a substituent; n3 is an integer of 0 to 3; n4 and n5 are independently an integer of 0 to 3; n6 and n7 are independently an integer of 0 to 5; n8 and n9 are independently an integer of 0 to 4; wherein, when n1 is 2 or more, multiple X 1 Same or different, multiple R 1Same or different; when n2 is 2 or more, multiple X 2 Same or different, multiple R 3 Same or different; when n3 is 2 or more, multiple R 10 Same or different, when n6 is 2 or more, multiple R 11 Same or different, when n7 is 2 or more, multiple R 12 Same or different, when n8 is 2 or more, multiple R 13 Same or different, when n9 is 2 or more, multiple R 14 same or different).

[0023] [Effects of the Invention]

[0024] According to the liquid crystal aligning agent of the present invention, it shows excellent coating properties, and even when used for a long time in a high-temperature environment, it is difficult to reduce the performance and it is possible to obtain a liquid crystal element with high reliability. DETAILED DESCRIPTION

[0025] Hereinafter, matters related to aspects of the present disclosure will be described in detail.

[0026] Here, in this specification, the numerical range described using "to" means that the numerical values ​​described before and after "to" are included as the lower limit and upper limit. The so-called "structural unit" refers to a unit that mainly constitutes the main chain structure and is a unit containing at least two or more in the main chain structure. Typically, a structural unit is a repeating unit composed of a single monomer. In addition, a structural unit can also be obtained by reacting a repeating unit having a reactive group with a compound having a functional group that can react with the reactive group.

[0027] In this specification, the term "hydrocarbon group" means a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The so-called "chain hydrocarbon group" refers to a straight-chain hydrocarbon group and a branched hydrocarbon group that does not contain a cyclic structure but only a chain structure in the main chain. Among them, it can be saturated or unsaturated. The so-called "alicyclic hydrocarbon group" refers to a hydrocarbon group that only contains the structure of an alicyclic hydrocarbon as a ring structure, and does not contain an aromatic ring structure. Among them, it is not necessary to contain only the structure of an alicyclic hydrocarbon, and also includes a group having a chain structure in a part thereof. The so-called "aromatic hydrocarbon group" refers to a hydrocarbon group that contains an aromatic ring structure as a ring structure. Among them, it is not necessary to contain only the aromatic ring structure, and also may contain a chain structure or an alicyclic hydrocarbon structure in a part thereof. The so-called "organic group" refers to an atomic group formed by removing any hydrogen atom from a compound containing carbon (i.e., an organic compound).

[0028] The "main chain" of a polymer refers to the "trunk" portion of the polymer containing the longest atomic chain. This "trunk" portion may contain a ring structure. For example, "having a specific structure in the main chain" means that the specific structure constitutes a portion of the main chain. A "side chain" refers to a portion that branches from the "trunk" portion of the polymer.

[0029] Liquid Crystal Alignment Agent

[0030] The liquid crystal aligning agent of the present disclosure contains a polymer (P) which is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, and has a partial structure represented by the following formula (1).

[0031] [Chemistry 3]

[0032]

[0033] (In formula (1), R 1 is an alkyl group, a fluoroalkyl group or a cyanated alkyl group having 2 to 20 carbon atoms; X 1 For single bonds, oxygen atoms, * 1 -COO- or * 1 -OCO-;"* 1 "Indicates that the 1 Bond of R 2 is an (n1+1)-valent aromatic ring group, a (n1+1)-valent alicyclic group or a (n1+1)-valent heterocyclic group; R 3 is a single bond, a divalent aromatic ring group, a divalent alicyclic group or a divalent heterocyclic group; X 2 For single bonds, oxygen atoms, * 2 -COO-,* 2 -OCO-,* 2 -R 6 O-, * 2 -OR 6 -, an alkanediyl group or vinylene group having 1 to 3 carbon atoms; R 6 is an alkanediyl group having 1 to 3 carbon atoms; 2 "Indicates that the 3 Bond of R 4 is a divalent aromatic ring group; Z 1 and Z 2 are independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms; wherein Z 1 and Z 2 Will not become a hydrogen atom at the same time; X 3 is an oxygen atom, a sulfur atom or -NR 7 -;R 7 is a hydrogen atom or a monovalent organic group; R 5It is a straight-chain alkanediyl group having 1 to 12 carbon atoms, or one or more methylene groups in a straight-chain alkanediyl group having 1 to 12 carbon atoms are replaced by -O-, -COO- or -NR 8 CO-substituted and connected to X through -CH2- 3 Bonding divalent group; R 8 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; n1 is an integer of 1 to 3; n2 is an integer of 0 to 3; wherein, when n1 is 2 or more, multiple X 1 Same or different, multiple R 1 Same or different; when n2 is 2 or more, multiple X 2 Same or different, multiple R 3 The same or different; "*" indicates a bond).

[0034] Hereinafter, the polymer (P) contained in the liquid crystal aligning agent of the present disclosure and the components optionally formulated will be described in detail. In addition, unless otherwise specified, each component may be used alone or in combination of two or more.

[0035] <Polymer(P)>

[0036] The partial structure represented by the formula (1)

[0037] In the formula (1), R 1 The alkyl group having 2 to 20 carbon atoms represented by R includes ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, etc. These may be linear or branched. 1 The fluoroalkyl group having 2 to 20 carbon atoms represented by R 1 A group in which at least one hydrogen atom in the group exemplified by the alkyl group having 2 to 20 carbon atoms represented by is substituted with a fluorine atom. 1 The cyanoalkyl group represented by R 1 A group in which at least one hydrogen atom in the group exemplified as an alkyl group having 2 to 20 carbon atoms represented by is substituted with a cyano group.

[0038] From the viewpoint of obtaining a liquid crystal element with more excellent liquid crystal orientation, R 1 The carbon number is preferably 3 or more, more preferably 4 or more. In terms of ensuring the solubility of the polymer (P) and the coating properties of the liquid crystal aligning agent, R 1 The number of carbon atoms is preferably 18 or less, more preferably 15 or less. From the viewpoint of obtaining a liquid crystal element with better liquid crystal orientation, R 1 A straight chain is preferred.

[0039] X1 For single bonds, oxygen atoms, * 1 -COO- or * 1 -OCO-. Among these, X 1 Preferably it is a single bond or an oxygen atom. 1 It is a single bond or an oxygen atom, and a liquid crystal element with better high-temperature reliability can be obtained.

[0040] R 2 It is an (n1+1)-valent aromatic ring group, a (n1+1)-valent alicyclic group or a (n1+1)-valent heterocyclic group. Among these, the (n1+1)-valent aromatic ring group is a group formed by removing (n1+1) hydrogen atoms from the ring part of a substituted or unsubstituted aromatic ring. As the aromatic ring, aromatic hydrocarbon rings and aromatic heterocyclic rings can be listed. Regarding specific examples of these, as aromatic hydrocarbon rings, benzene ring, naphthalene ring, anthracene ring, etc. can be listed. As aromatic heterocyclic rings, nitrogen-containing aromatic heterocyclic rings such as pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring and imidazole ring; oxygen-containing aromatic heterocyclic rings such as furan ring; sulfur-containing aromatic heterocyclic rings such as thiophene ring, etc. can be listed. Among these, from the viewpoint of making the liquid crystal orientation of the liquid crystal element and the solubility of the polymer (P) better, the group that constitutes R 2 The aromatic ring of the (n1+1)-valent aromatic ring group represented is preferably an aromatic hydrocarbon ring or a nitrogen-containing aromatic heterocycle, more preferably a benzene ring, a naphthalene ring or a pyridine ring, and still more preferably a benzene ring.

[0041] The (n1+1)-valent alicyclic group is a group formed by removing (n1+1) hydrogen atoms from the ring portion of a substituted or unsubstituted alicyclic ring. Examples of the alicyclic ring include a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cyclooctane ring, a cyclopentene ring, and a cyclohexene ring. Among these, a cyclohexane ring is preferred in terms of obtaining a liquid crystal cell with better liquid crystal orientation.

[0042] A (n1+1) valent heterocyclic group is a group formed by removing (n1+1) hydrogen atoms from a substituted or unsubstituted heterocyclic ring. The heterocyclic ring may be an aliphatic heterocyclic ring or an aromatic heterocyclic ring. Specific examples of aliphatic heterocyclic rings include nitrogen-containing aliphatic heterocyclic rings such as piperidine ring and piperazine ring; oxygen-containing aliphatic heterocyclic rings such as tetrahydrofuran and tetrahydropyran; and sulfur-containing aliphatic heterocyclic rings such as tetrahydrothiophene. Specific examples of aromatic heterocyclic rings include the rings exemplified in the description of the (n1+1) valent aromatic ring group. Among these, R 2 The heterocyclic ring in the (n1+1)-valent heterocyclic group represented by is more preferably a pyrrole ring, a pyridine ring, a pyrimidine ring, a piperidine ring or a piperazine ring.

[0043] In R 2When the ring portion has a substituent, examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), a cyano group, a nitro group, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, and a fluoroalkyl group having 1 to 6 carbon atoms.

[0044] In terms of ensuring good coating properties of the liquid crystal alignment agent and reliability of the liquid crystal element (especially high temperature reliability) and obtaining a liquid crystal element with less alternating current (AC) residual image, R 2 It is preferably an (n1+1)-valent alicyclic group or an (n1+1)-valent aliphatic heterocyclic group, more preferably an (n1+1)-valent alicyclic group, and particularly preferably a group formed by removing (n1+1) hydrogen atoms from the ring portion of a substituted or unsubstituted cyclohexane ring. As liquid crystal elements become more versatile, further improvements in display quality are required for liquid crystal elements, and with this, AC afterimages are required to be less likely to occur. In this regard, by making R 2 It is preferably an (n1+1)-valent alicyclic group or an (n1+1)-valent aliphatic heterocyclic group, and more preferably an (n1+1)-valent alicyclic group, and a liquid crystal element with further reduced generation of AC afterimages can be obtained.

[0045] R 3 is a single bond, a divalent aromatic ring group, a divalent alicyclic group or a divalent heterocyclic group. 2 The groups exemplified in the description of are groups corresponding to divalent aromatic ring groups, divalent alicyclic groups, and divalent heterocyclic groups. In terms of obtaining a liquid crystal element with further reduced generation of AC afterimages, R 3 It is preferably a divalent alicyclic group or a divalent aliphatic heterocyclic group, more preferably a divalent alicyclic group, and particularly preferably a substituted or unsubstituted cyclohexylene group.

[0046] X 2 For single bonds, oxygen atoms, * 2 -COO-,* 2 -OCO-,* 2 -R 6 O-, * 2 -OR 6 -, an alkanediyl group or vinylene group having 1 to 3 carbon atoms, R 6 It is an alkanediyl group having 1 to 3 carbon atoms. 6 The alkanediyl group having 1 to 3 carbon atoms represented by X may be linear or branched. 2 Preferably a single bond, an oxygen atom, * 2 -R 6 O-, * 2 -OR 6-, an alkanediyl group or vinylene group having 1 to 3 carbon atoms, more preferably a single bond, an oxygen atom, *, from the viewpoint of further improving the solubility of the polymer (P) and the liquid crystal orientation of the liquid crystal cell 2 -CH2O-,* 2 -OCH2-, methylene or ethylene.

[0047] As R 4 The divalent aromatic ring group represented by R 2 The (n1+1)-valent group exemplified in the description of is a group corresponding to a divalent aromatic ring group. In terms of obtaining a liquid crystal element with further reduced generation of AC afterimages, R 4 Particularly preferred is a substituted or unsubstituted phenylene group.

[0048] Z 1 and Z 2 are hydrogen, halogen, cyano, nitro, alkoxy, alkyl, or fluoroalkyl groups having 1 to 6 carbon atoms. 1 and Z 2 It will not become a hydrogen atom at the same time. Among these, halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. As alkoxy groups with 1 to 5 carbon atoms, methoxy, ethoxy, propoxy, butoxy and pentoxy groups are listed. These may be straight-chain or branched. Specific examples of alkyl or fluoroalkyl groups with 1 to 6 carbon atoms include 2 Among the groups exemplified in the description of , the group corresponds to an alkyl group or a fluoroalkyl group having 1 to 6 carbon atoms.

[0049] In terms of being able to obtain a liquid crystal element with less reduction in voltage holding ratio even when irradiated with backlight for a long time in a high temperature environment and having better high temperature reliability, Z 1 and Z 2 Preferably, one of them is a halogen atom, a cyano group, a nitro group, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms, and Z is particularly preferably 1 is a hydrogen atom and Z 2 is a halogen atom, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms. 1 and Z 2 In the group other than a hydrogen atom, a halogen atom, an alkoxy group having 1 to 3 carbon atoms, an alkyl group having 1 to 4 carbon atoms, or a fluoroalkyl group having 1 to 4 carbon atoms is preferably a group other than a hydrogen atom, and an alkyl group having 1 to 3 carbon atoms is more preferably a group other than a hydrogen atom.

[0050] In X 3 -NR 7 -In the case of R 7The monovalent organic group represented by the present invention includes a monovalent hydrocarbon group having 1 to 10 carbon atoms and a monovalent leaving group. The monovalent leaving group is preferably a group that is released by heat or light and replaced by a hydrogen atom. Specific examples of the monovalent leaving group include carbamate leaving groups, amide leaving groups, imide leaving groups, and sulfonamide leaving groups. Among these, carbamate leaving groups are preferred in terms of high thermal leaving properties. Examples thereof include tert-butoxycarbonyl, benzyloxycarbonyl, 1,1-dimethyl-2-halogenated ethyloxycarbonyl, allyloxycarbonyl, 2-(trimethylsilyl)ethoxycarbonyl, and 9-fluorenylmethyloxycarbonyl (F-moc group). Among these, tert-butoxycarbonyl (Boc group) is particularly preferred in terms of excellent thermal leaving properties and the ability to reduce the amount of the deprotected portion remaining in the film.

[0051] In order to further improve the photoreactivity of the partial structure represented by the formula (1), X 3 An oxygen atom or a sulfur atom is preferred, and an oxygen atom is more preferred.

[0052] R 5 It is a straight-chain alkanediyl group having 1 to 12 carbon atoms, or one or more methylene groups in a straight-chain alkanediyl group having 1 to 12 carbon atoms are replaced by -O-, -COO- or -NR 8 CO-substituted and connected to X through -CH2- 3 In terms of improving the solubility of the polymer (P) and obtaining a liquid crystal element with better liquid crystal orientation, R 5 It is a straight-chain alkanediyl group having 1 to 8 carbon atoms, or one or more methylene groups in a straight-chain alkanediyl group having 1 to 8 carbon atoms are replaced by -O-, -COO- or -NR 8 CO-substituted and connected to X through -CH2- 3 The divalent group to be bonded is more preferably a straight-chain alkanediyl group having 1 to 6 carbon atoms, or a straight-chain alkanediyl group having 1 to 6 carbon atoms in which one or more methylene groups are replaced by -O-, -COO- or -NR 8 CO-substituted and connected to X through -CH2- 3 Among these, a linear alkanediyl group having 1 to 6 carbon atoms is more preferred, and an alkanediyl group having 1 to 4 carbon atoms is particularly preferred.

[0053] R 8 It is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group.

[0054] From the viewpoint of ease of introduction of the partial structure represented by the formula (1), n1 is preferably 1 or 2, and more preferably 1.

[0055] From the perspective of ensuring the solubility of the polymer (P) and facilitating the introduction of the partial structure represented by the formula (1), n2 is preferably 0 to 2, and more preferably 0 or 1.

[0056] The bond (*) in the formula (1) may be bonded to an atom constituting the main chain of the polymer or to an atom constituting a side chain. In order to achieve a better effect of improving the coating properties of the liquid crystal alignment agent and the high-temperature reliability of the liquid crystal element in a well-balanced manner, the bond (*) in the formula (1) is preferably bonded to the main chain of the polymer, and more preferably is bonded to an aromatic ring that is part of the main chain of the polymer. The aromatic ring is preferably an aromatic hydrocarbon ring, and more preferably a benzene ring.

[0057] In terms of making the liquid crystal orientation, high temperature reliability and AC afterimage characteristics of the liquid crystal element more excellent, the following combination is preferred: R in the formula (1) 2 is an (n1+1) valent alicyclic group, X 2 For single bonds, oxygen atoms, * 2 -R 6 O-, * 2 -OR 6 -, an alkanediyl group or vinylene group having 1 to 3 carbon atoms, Z 1 and Z 2 One of them is a halogen atom, a cyano group, a nitro group, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms, and the other is a hydrogen atom. Among these, the following combination is particularly preferred: R in the formula (1) 2 is an (n1+1) valent alicyclic group, X 2 For single bonds, oxygen atoms, * 2 -R 6 O-, * 2 -OR 6 - or an alkanediyl group having 1 to 3 carbon atoms, Z 2 is a halogen atom, a cyano group, a nitro group, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms, and Z 1 A hydrogen atom.

[0058] Specific examples of the partial structure represented by the formula (1) include the partial structure represented by the following formula, and a partial structure in which the terminal alkyl group, terminal alkoxy group, terminal fluoroalkyl group or terminal fluoroalkoxy group in the partial structure represented by the following formula is substituted with an alkyl group, alkoxy group, fluoroalkyl group or fluoroalkoxy group having 2 to 20 carbon atoms.

[0059] [Chemistry 4]

[0060]

[0061] [Chemistry 5]

[0062]

[0063] (wherein, “*” represents a bonding bond).

[0064] In the polymer (P), the content of the partial structure represented by the formula (1) is preferably 15 mol% or more, more preferably 20 mol% or more, and even more preferably 25 mol% or more, relative to the total amount of monomer-derived structural units contained in the polymer (P). By setting the content of the partial structure represented by the formula (1) within the above range, the coating properties of the liquid crystal aligning agent and the high-temperature reliability of the liquid crystal element can be improved in a well-balanced manner.

[0065] 〔Specific form of polymer (P)〕

[0066] The form of the polymer (P) having the partial structure represented by the formula (1) is not particularly limited. For example, the polymer (P) may have the partial structure represented by the formula (1) at the polymer terminal or in the side chain of the polymer. In order to fully obtain the effect of improving the liquid crystal orientation and reliability of the liquid crystal element and the coating properties of the liquid crystal alignment agent by introducing the partial structure represented by the formula (1), the polymer (P) preferably has the partial structure represented by the formula (1) in the side chain of the polymer, and more preferably contains a structural unit derived from a diamine (hereinafter also referred to as "specific diamine") having the partial structure represented by the formula (1).

[0067] ·Specific diamine

[0068] The specific diamine has only to have a partial structure represented by formula (1), and its structure is not particularly limited. From the perspective of ease of synthesis of the specific diamine or affinity with liquid crystals, the specific diamine is preferably an aromatic diamine. Here, the so-called aromatic diamine refers to a compound in which two primary amino groups possessed by the diamine are bonded to the same or different aromatic rings. The number of partial structures represented by formula (1) in one molecule of the specific diamine can be 1 or more, and is preferably 1 or 2.

[0069] As a preferable specific example of the specific diamine, the compound represented by any one of the following formula (2-1) to formula (2-3) can be mentioned.

[0070] [Chemistry 6]

[0071]

[0072] (In formula (2-1) to formula (2-3), R 1 、X 1 、R 2 、R 3 、X2 、R 4 、Z 1 、Z 2 、X 3 、R 5 , n1 and n2 have the same meanings as in the formula (1); R 10 、R 11 、R 12 、R 13 and R 14 are independently a substituent; n3 is an integer of 0 to 3; n4 and n5 are independently an integer of 0 to 3; n6 and n7 are independently an integer of 0 to 5; n8 and n9 are independently an integer of 0 to 4; when n3 is 2 or more, multiple R 10 Same or different, when n6 is 2 or more, multiple R 11 Same or different, when n7 is 2 or more, multiple R 12 Same or different, when n8 is 2 or more, multiple R 13 Same or different, when n9 is 2 or more, multiple R 14 same or different).

[0073] In the above formulas (2-1) to (2-3), R 10 、R 11 、R 12 、R 13 or R 14 Examples of the substituents include halogen atoms (fluorine, chlorine, bromine, iodine, etc.), cyano, nitro, alkoxy groups having 1 to 5 carbon atoms, alkyl groups having 1 to 6 carbon atoms, fluoroalkyl groups having 1 to 6 carbon atoms, hydroxyl groups, and carboxyl groups.

[0074] n3 is preferably 0 or 1.

[0075] n4 and n5 are preferably 0 to 2, more preferably 0 or 1, respectively.

[0076] n6 and n7 are preferably 0 to 2, more preferably 0 or 1, respectively.

[0077] n8 and n9 are preferably 0 or 1, respectively.

[0078] Specific examples of the specific diamine include compounds represented by the following formulas (1-1) to (1-17), and compounds in which the terminal alkyl group, terminal alkoxy group, terminal fluoroalkyl group, or terminal fluoroalkoxy group in the compounds represented by the following formulas (1-1) to (1-17) is substituted with an alkyl group having 2 to 20 carbon atoms, an alkoxy group, a cyanated alkyl group, a fluoroalkyl group, or a fluoroalkoxy group.

[0079] [Chemistry 7]

[0080]

[0081] [Chemistry 8]

[0082]

[0083] [Chemistry 9]

[0084]

[0085] The content of the structural units derived from the specific diamine in the polymer (P) is preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 50 mol% or more, relative to the total amount of the structural units derived from diamine contained in the polymer (P). By setting the content of the structural units derived from the specific diamine within this range, it is possible to achieve a balance between the coatability of the liquid crystal aligning agent and the high-temperature reliability of the liquid crystal element, and to form an organic film with excellent photo-alignment properties.

[0086] [Synthesis of specific diamines]

[0087] Specific diamines can be synthesized by appropriately combining conventional methods of organic chemistry. An example of a method for synthesizing specific diamines includes the following: first, a dinitro intermediate having a nitro group in place of the primary amino group in the target diamine is synthesized; then, the nitro group of the obtained dinitro intermediate is nitroaminated using an appropriate reduction system.

[0088] The method for synthesizing the dinitro intermediate can be appropriately selected according to the molecular structure of the target diamine. For example, the compound represented by formula (2-1) can be obtained by the following method: 5 The hydroxyl-containing compound and the group "-CZ 1 =CZ 2 -R 4 -(X 2 -R 3 ) n2 -R 2 -(X 1 -R 1 ) n1 "Carboxylic acid reaction method; having dinitrophenyl and R 5 The amine compound has a group "-CZ 1 =CZ 2 -R 4 -(X 2 -R 3 ) n2 -R 2 -(X 1 -R 1 ) n1 "Carboxylic acid reaction method; having dinitrophenyl and R5 The thiol compound has a group "-CZ 1 =CZ 2 -R 4 -(X 2 -R 3 ) n2 -R 2 -(X 1 -R 1 ) n1 Each reaction can be carried out in a suitable organic solvent in the presence of a catalyst as needed.

[0089] The reduction reaction of the dinitro intermediate can preferably be carried out in an organic solvent using a catalyst such as palladium-carbon, platinum-carbon, zinc, iron, tin, or nickel. Examples of organic solvents used herein include ethyl acetate, toluene, tetrahydrofuran, and alcohols. The synthesis method of the specific diamine is not limited to the above.

[0090] [Synthesis of polymer (P)]

[0091] The polymer (P) is based on polyamic acid, polyamic acid ester or polyimide. Such polymer (P) can be obtained, for example, by the polycondensation of tetracarboxylic acid derivatives and diamines. In addition, tetracarboxylic acid derivatives include tetracarboxylic dianhydride, tetracarboxylic acid dihalide and tetracarboxylic acid diester dihalide. Hereinafter, polyamic acid, polyamic acid ester and polyimide are described respectively.

[0092] (Polyamic acid)

[0093] When the polymer (P) is a polyamic acid, the polyamic acid (hereinafter also referred to as “polyamic acid (P)”) can be obtained by reacting tetracarboxylic dianhydride with diamine (polycondensation reaction).

[0094] Tetracarboxylic dianhydride

[0095] Examples of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid (P) include aliphatic tetracarboxylic dianhydride and aromatic tetracarboxylic dianhydride. Examples of the aliphatic tetracarboxylic dianhydride include chain tetracarboxylic dianhydride and alicyclic tetracarboxylic dianhydride.

[0096] Specific examples of tetracarboxylic dianhydrides include chain tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride and ethylenediaminetetraacetic dianhydride.

[0097] Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, and 3-oxabicyclo[3,2. 1] octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 5-(2,5-dioxotetrahydro-3-furyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic acid 2:4,6:8-dianhydride, bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic acid 2:3,5:6-dianhydride, 4,9-dioxatricyclo[5.3.1.0 2,6 ] undecane-3,5,8,10-tetraone, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, etc.;

[0098] Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, p-phenylenebis(trimellitic acid monoester anhydride), ethylene glycol bis(trimellitic anhydride ester), 1,3-propylene glycol bis(trimellitic anhydride ester), 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 4,4'-diphthalic dianhydride, 4,4'-oxydiphthalic dianhydride, and 4,4'-carbonyldiphthalic anhydride. In addition, the tetracarboxylic dianhydrides described in Japanese Patent Application Laid-Open No. 2010-97188 can also be used.

[0099] In terms of improving the solubility of the polymer (P) and obtaining a liquid crystal alignment film exhibiting good voltage holding characteristics, the tetracarboxylic dianhydride preferably contains an aliphatic tetracarboxylic dianhydride, and more preferably contains an alicyclic tetracarboxylic dianhydride. Specifically, it is preferably at least one selected from the group consisting of 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, cyclopentanetetracarboxylic dianhydride, and cyclohexanetetracarboxylic dianhydride.

[0100] In the polyamic acid (P), the content ratio of the structural units derived from alicyclic tetracarboxylic dianhydride relative to the total amount of the structural units derived from tetracarboxylic dianhydride contained in the polyamic acid (P) is preferably 20 mol% or more, more preferably 30 mol% or more, further preferably 50 mol% or more, and particularly preferably 70 mol% or more.

[0101] Diamine

[0102] When synthesizing polyamic acid (P), as diamine, only specific diamine can be used. In addition, diamines (hereinafter also referred to as "other diamines") that do not have the partial structure represented by the formula (1) can also be used together with specific diamine. In addition, by polycondensing the diamine comprising specific diamine with tetracarboxylic acid derivatives, polyamic acid, polyamic acid ester or polyimide comprising the structural unit derived from specific diamine can be obtained. In addition, by polycondensing the diamine comprising specific diamine and tetracarboxylic acid derivatives, polyamic acid, polyamic acid ester or polyimide comprising the structural unit derived from specific diamine and the structural unit derived from other diamines can be obtained.

[0103] The other diamines are not particularly limited as long as they do not have the partial structure represented by formula (1). Examples of the other diamines include aliphatic diamines, aromatic diamines, and diaminoorganosiloxanes. Examples of the aliphatic diamines include chain diamines and alicyclic diamines.

[0104] Specific examples of other diamines include chain diamines such as m-xylenediamine and hexamethylenediamine; alicyclic diamines such as 1,4-diaminocyclohexane and 4,4'-methylenebis(cyclohexylamine); and diaminoorganosiloxanes such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane.

[0105] Specific examples of the aromatic diamine include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenyl ether, 4-aminophenyl-4-aminobenzoate, 4,4'-diaminoazobenzene, 3,5-diaminobenzoic acid, 1,5-bis(4-aminophenoxy)pentane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4-aminophenoxy)propane, 1,6-bis(4-aminophenoxy)hexane, bis[2-(4-aminophenyl)ethyl]adipic acid, 1,4-bis(4-aminophenyl)-piperazine, 2,2'-dimethyl- Main-chain diamines such as 4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-(phenylenediisopropylidene)dianiline, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-[4,4'-propane-1,3-diylbis(piperidin-1,4-diyl)]dianiline, 4,4'-diaminobenzanilide, 4,4'-diaminostilbene, and 4,4'-diaminostilbeneethylurea;

[0106] Dodecyloxy-2,4-diaminobenzene, pentadecyloxy-2,4-diaminobenzene, hexadecyloxy-2,4-diaminobenzene, octadecyloxy-2,4-diaminobenzene, pentadecyloxy-2,5-diaminobenzene, octadecyloxy-2,5-diaminobenzene, cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, cholesteryloxy-3,5-diaminobenzoate, 3,5-diaminobenzoate Side chain diamines such as cholesteryl aminobenzoate, lanostanyl 3,5-diaminobenzoate, 3,6-bis(4-aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 4-(4'-trifluoromethoxybenzoyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 5ξ-cholestane-3-yl 3,5-diaminobenzoate, and a compound represented by the following formula (E-1) are also included.

[0107] [Chemistry 10]

[0108]

[0109] (In formula (E-1), X I and X II Each independently represents a single bond, -O-, *-COO- or *-OCO- (wherein "*" represents a bond to the diaminophenyl side); R Iis an alkanediyl group having 1 to 3 carbon atoms; R II is a single bond or an alkanediyl group having 1 to 3 carbon atoms; R III is an alkyl group, alkoxy group, fluoroalkyl group or fluoroalkoxy group having 1 to 20 carbon atoms; a is 0 or 1; b is an integer from 0 to 3; c is an integer from 0 to 2; d is 0 or 1; wherein 1≦a+b+c≦3).

[0110] Examples of the compound represented by formula (E-1) include compounds represented by the following formulas (E-1-1) to (E-1-4).

[0111] [Chemistry 11]

[0112]

[0113] Specific examples of diaminoorganosiloxane include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane, etc. In addition, as other diamines, diamines described in Japanese Patent Application Laid-Open No. 2010-97188 can also be used in addition to the above.

[0114] When the polymer (P) includes structural units derived from other diamines, the content ratio of the structural units derived from other diamines relative to the total amount of the structural units derived from diamines contained in the polymer (P) is preferably 1 mol% or more, more preferably 2 mol% or more, and further preferably 5 mol% or more. In addition, relative to the total amount of the structural units derived from diamines contained in the polymer (P), the content ratio of the structural units derived from other diamines is preferably 70 mol% or less, more preferably 60 mol% or less, and further preferably 50 mol% or less. By setting the content ratio of the structural units derived from other diamines to the above range, an organic film with good photo-orientation can be formed while taking into account both the coating properties of the liquid crystal alignment agent and the high temperature reliability of the liquid crystal element.

[0115] Furthermore, in order to adjust the pretilt angle of the liquid crystal molecules controlled by the liquid crystal alignment film, a diamine having a photo-alignment group and having a partial structure represented by the above formula (1) (hereinafter also referred to as "other photo-alignment diamine") can also be used as another diamine. Here, the photo-alignment group refers to a functional group that can impart anisotropy to the film through a photoreaction such as a photoisomerization reaction, a photodimerization reaction, a photoFries rearrangement reaction, or a photodecomposition reaction caused by light irradiation. Specific examples of the photo-alignment group include an azobenzene-containing group containing azobenzene or a derivative thereof as a basic skeleton, a cinnamic acid structure-containing group containing cinnamic acid or a derivative thereof (cinnamic acid structure) as a basic skeleton, a chalcone-containing group containing chalcone or a derivative thereof as a basic skeleton, a benzophenone-containing group containing benzophenone or a derivative thereof as a basic skeleton, a coumarin-containing group containing coumarin or a derivative thereof as a basic skeleton, a stilbene-containing group containing stilbene or a derivative thereof as a basic skeleton, a phenyl benzoate-containing group containing phenyl benzoate or a derivative thereof as a basic skeleton, etc. Among these, when other photo-alignment diamines are used, from the viewpoint of obtaining a liquid crystal alignment film exhibiting a desired pretilt angle, the amount of the other photo-alignment diamine used is preferably 30 mol% or less, more preferably 25 mol% or less, and even more preferably 20 mol% or less, relative to the total amount of the diamines used in the synthesis of the polymer (P).

[0116] Synthesis of polyamic acid (P)

[0117] Polyamic acid (P) can be obtained by reacting tetracarboxylic dianhydride with diamine and, if necessary, a molecular weight modifier. The ratio of tetracarboxylic dianhydride to diamine used in the synthesis reaction of polyamic acid (P) is preferably such that the anhydride group of tetracarboxylic dianhydride is 0.2 to 2 equivalents per 1 equivalent of the amino group of the diamine.

[0118] Examples of molecular weight modifiers include monoanhydrides such as maleic anhydride, phthalic anhydride, and itaconic anhydride; monoamine compounds such as aniline, cyclohexylamine, and n-butylamine; and monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. The molecular weight modifier is preferably used in an amount of 20 parts by mass or less relative to a total of 100 parts by mass of the tetracarboxylic dianhydride and diamine used.

[0119] The synthesis reaction of the polyamic acid (P) is preferably carried out in an organic solvent. The reaction temperature is preferably -20°C to 150°C, and the reaction time is preferably 0.1 hour to 24 hours.

[0120] Examples of the organic solvent used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. A particularly preferred organic solvent is preferably one or more selected from the group consisting of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphoric triamide, m-cresol, xylenol, and halogenated phenols, or a mixture of one or more of these with other organic solvents (e.g., butyl cellosolve, diethylene glycol diethyl ether, etc.). The amount (a) of the organic solvent used is preferably such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1% by mass to 50% by mass relative to the total amount (a+b) of the reaction solution.

[0121] The reaction solution formed by dissolving polyamic acid (P) is obtained in the described manner. The reaction solution can be directly supplied to the preparation of liquid crystal alignment agent, and the polyamic acid (P) contained in the reaction solution can also be separated and then supplied to the preparation of liquid crystal alignment agent, or the separated polyamic acid (P) can also be refined and then supplied to the preparation of liquid crystal alignment agent. In the case where polyamic acid (P) is dehydrated and ring-closed to form polyimide, the reaction solution can be directly supplied to dehydration ring-closed reaction, and the polyamic acid (P) contained in the reaction solution can also be separated and then supplied to dehydration ring-closed reaction, or the separated polyamic acid (P) can also be refined and then supplied to dehydration ring-closed reaction. The separation and purification of polyamic acid (P) can be carried out according to known methods.

[0122] (Polyamic acid ester)

[0123] The polyamic acid ester (hereinafter also referred to as "polyamic acid ester (P)") as a polymer (P) can be obtained, for example, by the following methods: [I] a method of reacting the polyamic acid (P) obtained by the above-mentioned synthesis reaction with an esterifying agent; [II] a method of reacting a tetracarboxylic acid diester with a diamine; [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine.

[0124] In this specification, the term "tetracarboxylic acid diester" refers to a compound in which two of the four carboxyl groups of a tetracarboxylic acid are esterified and the remaining two are carboxyl groups. The term "tetracarboxylic acid diester dihalide" refers to a compound in which two of the four carboxyl groups of a tetracarboxylic acid are esterified and the remaining two are halogenated.

[0125] Examples of the esterifying agent used in method [I] include hydroxyl-containing compounds, acetal compounds, halides, and epoxy-containing compounds. Specific examples of these include alcohols such as methanol, ethanol, and propanol, and phenols such as phenol and cresol. Examples of acetal compounds include N,N-dimethylformamide diethyl acetal and N,N-diethylformamide diethyl acetal. Examples of halides include methyl bromide, ethyl bromide, octadecane bromide, methyl chloride, octadecane chloride, and 1,1,1-trifluoro-2-iodoethane. Examples of epoxy-containing compounds include propylene oxide.

[0126] The tetracarboxylic acid diester used in method [II] can be obtained, for example, by ring-opening the tetracarboxylic dianhydride exemplified in the description of the synthesis of polyamic acid (P) using an alcohol such as methanol or ethanol. Furthermore, the tetracarboxylic acid derivative used in method [II] may be solely a tetracarboxylic acid diester, or may be used in combination with a tetracarboxylic dianhydride.

[0127] The tetracarboxylic acid diester dihalide used in method [III] can be obtained, for example, by reacting the tetracarboxylic acid diester obtained in the above manner with an appropriate chlorinating agent such as thionyl chloride. Furthermore, the tetracarboxylic acid derivative used in method [III] may be solely the tetracarboxylic acid diester dihalide, but tetracarboxylic dianhydride may also be used in combination.

[0128] The polyamic acid ester (P) contained in the liquid crystal alignment agent may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist. The reaction solution formed by dissolving the polyamic acid ester (P) can be directly used for the preparation of the liquid crystal alignment agent, or the polyamic acid ester (P) contained in the reaction solution can be separated and then used for the preparation of the liquid crystal alignment agent, or the separated polyamic acid ester (P) can be refined and then used for the preparation of the liquid crystal alignment agent. The separation and purification of the polyamic acid ester (P) can be carried out according to known methods.

[0129] (Polyimide)

[0130] The polyimide (hereinafter also referred to as “polyimide (P)”) as the polymer (P) can be obtained, for example, by subjecting the polyamic acid (P) synthesized in the above manner to dehydration ring closure and imidization.

[0131] The polyimide (P) may be a fully imidized product obtained by dehydrating and ring-closing all the amic acid structures of the polyamic acid (P) as its precursor, or a partially imidized product obtained by dehydrating and ring-closing only a portion of the amic acid structure so that the amic acid structure and the imide ring structure coexist. The imidization rate of the polyimide (P) is preferably 20% or more, more preferably 30% to 99%. The imidization rate is a percentage representing the ratio of the number of imide ring structures to the total number of amic acid structures and the number of imide ring structures of the polyimide (P). Here, a portion of the imide ring may be an isoimide ring.

[0132] The dehydration ring-closure of the polyamic acid (P) is preferably carried out by heating the polyamic acid (P) or by dissolving the polyamic acid (P) in an organic solvent, adding a dehydrating agent and a dehydration ring-closure catalyst to the solution, and heating as needed.

[0133] In the method of adding a dehydrating agent and a dehydration ring-closure catalyst to a solution of polyamic acid (P), anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used as the dehydrating agent. The amount of the dehydrating agent used is preferably set to 0.01 mol to 20 mol relative to 1 mol of the amic acid structure of polyamic acid (P). As a dehydration ring-closure catalyst, for example, tertiary amines such as pyridine, collidine, dicollidine, triethylamine, and 1-methylpiperidine can be used. The amount of the dehydration ring-closure catalyst used is preferably set to 0.01 mol to 10 mol relative to 1 mol of the dehydrating agent used. As the organic solvent used in the dehydration ring-closure reaction, the organic solvents exemplified as the organic solvents used in the synthesis of polyamic acid (P) can be cited. The reaction temperature of the dehydration ring-closure reaction is preferably 0°C to 180°C, more preferably 10°C to 150°C. The reaction time is preferably 1.0 hour to 120 hours, more preferably 2.0 hour to 30 hours.

[0134] A reaction solution containing polyimide (P) is obtained in the described manner. The reaction solution can be directly used for the preparation of a liquid crystal alignment agent, or it can be used for the preparation of a liquid crystal alignment agent after removing a dehydrating agent and a dehydration ring-closure catalyst from the reaction solution, or it can be used for the preparation of a liquid crystal alignment agent after separating the polyimide (P), or it can be used for the preparation of a liquid crystal alignment agent after refining the separated polyimide (P). These refining operations can be carried out according to known methods. In addition, polyimide (P) can also be obtained by imidization of polyamic acid ester (P).

[0135] The polymer (P) obtained in the above manner preferably has a solution viscosity of 20 mPa·s to 1,800 mPa·s, more preferably 50 mPa·s to 1,500 mPa·s, when prepared as a 15% by mass solution. The solution viscosity (mPa·s) of the polymer (P) is a value measured at 25°C using an E-type rotational viscometer on a 15% by mass solution of the polymer (P) prepared in a good solvent (e.g., γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).

[0136] The weight average molecular weight (Mw) of the polymer (P) measured by gel permeation chromatography (GPC) in terms of polystyrene is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. Furthermore, the molecular weight distribution (Mw / Mn) of the polymer (P), represented by the ratio of Mw to the number average molecular weight (Mn) in terms of polystyrene measured by GPC, is preferably 8 or less, more preferably 7 or less. When the Mw and Mw / Mn of the polymer (P) are within these ranges, good liquid crystal orientation of the liquid crystal cell can be ensured.

[0137] The content of the polymer (P) in the liquid crystal aligning agent is preferably 2% by mass or more, more preferably 5% by mass or more, and even more preferably 7% by mass or more relative to the total amount of solid components contained in the liquid crystal aligning agent (i.e., the total mass of the components of the liquid crystal aligning agent excluding the solvent).

[0138] [Other ingredients]

[0139] The liquid crystal aligning agent of the present disclosure may further contain components other than the polymer (P) (hereinafter also referred to as "other components"). Examples of other components include a polymer different from the polymer (P) (hereinafter also referred to as "polymer (Q)"), a crosslinking agent, and a solvent.

[0140] Polymer (Q)

[0141] Polymer (Q) is a polymer that does not have the partial structure represented by the formula (1). The main skeleton of polymer (Q) is not particularly limited. As polymer (Q), for example, polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyenamine, polyurea, polyamide, polyamideimide, polybenzoxazole precursor, polybenzoxazole, cellulose derivative, polyacetal, addition polymer, etc. can be listed. As addition polymer, for example, (meth) acrylic acid polymer, styrene polymer, maleimide polymer, (meth) acrylic acid-styrene copolymer, (meth) acrylic acid-maleimide copolymer, (meth) acrylic acid-styrene-maleimide copolymer and styrene-maleimide copolymer, etc. can be listed.

[0142] When used together with the polymer (P), in terms of exhibiting good liquid crystal orientation and voltage retention characteristics, the polymer (Q) is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane and addition polymer.

[0143] When the liquid crystal aligning agent contains a polymer (Q), the content of the polymer (Q) is preferably 10% by mass or more, more preferably 20% by mass or more, and further preferably 50% by mass or more, relative to the total amount of the polymer (P) and the polymer (Q). Furthermore, the content of the polymer (Q) is preferably 98% by mass or less, more preferably 95% by mass or less, and further preferably 93% by mass or less, relative to the total amount of the polymer (P) and the polymer (Q).

[0144] Cross-linking agent

[0145] The liquid crystal alignment agent disclosed herein may also contain a cross-linking agent. By also containing a cross-linking agent, the high-temperature reliability of the liquid crystal element can be further improved, or the generation of AC residual images can be further reduced. As the cross-linking agent, the following compounds can be listed, wherein the compound has two or more groups selected from the group consisting of a cyclic ether group, a cyclic thioether group, an isocyanate group, a protected isocyanate group, a hydroxymethyl group, a protected hydroxymethyl group, a cyclic carbonate group, a group containing a polymerizable carbon-carbon bond, a protected amino group, a hydroxyalkylamide group, a protected hydroxyalkylamide group, a silanol group, and an alkoxysilane group.

[0146] From the perspective of sufficiently achieving improved AC afterimage characteristics and high-temperature reliability of the liquid crystal element, the number of crosslinkable groups contained in one molecule of the crosslinking agent is preferably 2 to 10, more preferably 2 to 6. Furthermore, the molecular weight of the crosslinking agent is preferably 100 to 1,000, more preferably 100 to 800, and even more preferably 100 to 700.

[0147] Specific examples of crosslinking agents include compounds having a cyclic ether group or a cyclic thioether group, such as ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, triglycidyl isocyanurate, glycerol polyglycidyl ether, pentaerythritol tetraglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, N,N',N',N'-tetraglycidyl glycoluril, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromocyanurate, Pentanediol diglycidyl ether, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N-diglycidyl-benzylamine, N,N-diglycidyl-aminomethylcyclohexane, N,N-diglycidyl-cyclohexylamine, epoxidation reaction products of 2,2'-diallylbisphenol A diallyl ether using hydrogen peroxide, etc.

[0148] Examples of the compound having an isocyanate group or a protected isocyanate group include tolylene diisocyanate, xylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, or compounds in which the isocyanate groups of these compounds are protected with 3,6-dimethylpyrazole, methyl ethyl ketoxime, diethyl malonate, or ε-caprolactam; and compounds represented by the following formula (d1-1).

[0149] Examples of the compound having a hydroxymethyl group or a protected hydroxymethyl group include compounds represented by the following formulae (d2-1) to (d2-10).

[0150] Examples of the compound having a cyclic carbonate group include compounds represented by the following formula (d3-1) and formula (d3-2).

[0151] Examples of compounds having a group containing a polymerizable carbon-carbon bond include compounds having a (meth)acryloyl group, a maleimide group, an alkenyl group, a vinylphenyl group, a vinyl ether group, or a 3-methylenetetrahydrofuran-2(3H)-one-5-yl group. Specific examples thereof include ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, pentaerythritol tri(meth)acrylate, and compounds represented by the following formulas (d4-1) to (d4-7), respectively.

[0152] Examples of the compound having a protected amino group include compounds represented by the following formula (d5-1) to formula (d5-5).

[0153] Examples of the compound having a hydroxyalkylamide group or a protected hydroxyalkylamide group include compounds represented by the following formula (d6-1) to formula (d6-7), and the like.

[0154] Examples of the compound having a silanol group or an alkoxysilane group include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, and vinyltriethoxysilane.

[0155] [Chemistry 12]

[0156]

[0157] [Chemistry 13]

[0158]

[0159] (In formula (d2-4), Ac is an acetyl group).

[0160] [Chemistry 14]

[0161]

[0162] [Chemistry 15]

[0163]

[0164] [Chemistry 16]

[0165]

[0166] [Chemistry 17]

[0167]

[0168] [Chemistry 18]

[0169]

[0170] In the case of making the liquid crystal alignment agent of the present invention contain a cross-linking agent, from the perspective of improving the mechanical strength of the liquid crystal alignment film and achieving improved reliability of the liquid crystal element or further reducing the AC residual image, the content of the cross-linking agent is preferably 0.5 parts by mass or more relative to 100 parts by mass of the total amount of the polymer components contained in the liquid crystal alignment agent (that is, the total amount of polymer (P) and polymer (Q)). From the perspective of the above, the content of the cross-linking agent is more preferably 1 part by mass or more, and further preferably 2 parts by mass or more, relative to 100 parts by mass of the total amount of the polymer components. In addition, from the perspective of obtaining a liquid crystal element with good liquid crystal orientation and electrical properties, and from the perspective of making the storage stability of the liquid crystal alignment agent good, the content of the cross-linking agent is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and further preferably 10 parts by mass or less, relative to 100 parts by mass of the total amount of the polymer components.

[0171] Solvent

[0172] The liquid crystal aligning agent disclosed herein is prepared in the form of a liquid composition, wherein the liquid composition is prepared by dispersing or dissolving a polymer (P) and optionally used components in an appropriate solvent.

[0173] Examples of the organic solvent include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethylene carbonate, and propylene carbonate.

[0174] Other components, in addition to those mentioned above, include antioxidants, metal chelate compounds, curing accelerators, surfactants, fillers, dispersants, photosensitizers, acid generators, base generators, and free radical generators. The proportions of these components can be appropriately selected for each compound within a range that does not impair the effects of the present disclosure.

[0175] The solid content concentration in the liquid crystal alignment agent (the ratio of the total mass of the components of the liquid crystal alignment agent other than the solvent to the total mass of the liquid crystal alignment agent) can be appropriately selected considering viscosity, volatility, etc., preferably in the range of 1% by mass to 10% by mass. That is, the liquid crystal alignment agent is applied to the substrate surface as described later, preferably heated, thereby forming a coating film as a liquid crystal alignment film or a coating film as a liquid crystal alignment film. At this time, when the solid content concentration is 1% by mass or more, the film thickness of the coating film can be fully ensured, and there is a tendency to easily obtain a good liquid crystal alignment film. When the solid content concentration is 10% by mass or less, the film thickness of the coating film will not become too large. In addition, the viscosity of the liquid crystal alignment agent can be suppressed from increasing, and there is a tendency to make the coating property good.

[0176] The range of particularly preferred solid content concentration varies depending on the purpose of the liquid crystal aligning agent or the method used when applying the liquid crystal aligning agent to the substrate. For example, with respect to the liquid crystal aligning agent for liquid crystal display elements, when applied to the substrate by a spinner method, the solid content concentration (the ratio of the total mass of all components in the liquid crystal aligning agent except the solvent to the total mass of the liquid crystal aligning agent) is particularly preferably in the range of 1.5% by mass to 4.5% by mass. In the case of using a printing method, it is particularly preferred to set the solid content concentration to the range of 3% by mass to 9% by mass, thereby setting the solution viscosity to the range of 12mPa·s to 50mPa·s. In the case of using an inkjet method, it is particularly preferred to set the solid content concentration to the range of 1% by mass to 5% by mass, thereby setting the solution viscosity to the range of 3mPa·s to 15mPa·s. The temperature when preparing the liquid crystal aligning agent is preferably 10°C to 50°C, more preferably 20°C to 30°C. In addition, regarding the liquid crystal aligning agent for retardation film, from the viewpoint of making the coating property of the liquid crystal aligning agent and the film thickness of the formed coating film appropriate, the solid content concentration of the liquid crystal aligning agent is preferably in the range of 0.2% by mass to 10% by mass, and more preferably in the range of 3% by mass to 10% by mass.

[0177] The reason why the coating properties of the liquid crystal alignment agent and the high-temperature reliability of the liquid crystal element can be achieved by using the liquid crystal alignment agent containing the polymer (P) is not certain, but it is speculated that the substituted cinnamate structure in the formula (1) (in the formula (1), "-CO-CZ 1 =CZ 2 -R 4 -" partial structure) and shorten the wavelength of light absorption, thereby improving high temperature reliability, and the alkyl spacer structure (R in the formula (1) 5 ) and the melting point of the polymer (P) is lowered, thereby improving the solubility of the polymer (P), and these work in conjunction with each other. However, the above speculation does not limit the present invention.

[0178] Liquid crystal alignment film and liquid crystal element

[0179] The liquid crystal alignment film of the present invention can be formed by a liquid crystal alignment agent prepared in the manner described. In addition, the liquid crystal element of the present invention has a liquid crystal alignment film formed using the liquid crystal alignment agent described in the above. The action mode of the liquid crystal in the liquid crystal element is not particularly limited, for example, it can be applied to twisted nematic (TN) type, super twisted nematic (STN) type, vertical alignment (VA) type (including vertical alignment-multi-domain vertical alignment (VA-MVA) type, vertical alignment-patterned vertical alignment (VA-PVA) type, etc.), in-plane switching (IPS) type, fringe field switching (FFS) type, optically compensated bend (OCB) type, polymer stabilized alignment (PSA) type and other modes. The liquid crystal element can be produced, for example, by a method including the following steps 1 to 3. In step 1, the substrate used varies depending on the desired operation mode. Steps 2 and 3 are common to each operation mode.

[0180] <Step 1: Coating Film Formation>

[0181] First, a liquid crystal alignment agent is applied to a substrate, and the coated surface is preferably heated to form a coating film on the substrate. As a substrate, for example, a transparent substrate comprising the following materials can be used: glass such as float glass and soda glass; resins such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly(alicyclic olefin). In the case of manufacturing a TN type, STN type, or VA type liquid crystal element, two substrates provided with patterned transparent conductive films are used. On the other hand, in the case of manufacturing an IPS type or FFS type liquid crystal element, a substrate provided with electrodes patterned into a comb shape and an opposing substrate without electrodes are used. As a transparent conductive film, a NESA film (registered trademark of PPG Corporation, USA) containing tin oxide (SnO2) and an indium tin oxide (ITO) film containing indium oxide-tin oxide (In2O3-SnO2) can be used. The liquid crystal alignment agent is preferably applied to the substrate surface by offset printing, flexographic printing, spin coating, roll coater coating, or inkjet printing. The liquid crystal alignment agent disclosed herein can easily form a uniform film even by inkjet coating, and is therefore suitable for inkjet coating.

[0182] After applying the liquid crystal alignment agent, it is preferred to perform preheating (prebaking) for the purpose of preventing the applied liquid crystal alignment agent from sagging. The prebaking temperature is preferably 30°C to 200°C, and the prebaking time is preferably 0.25 minutes to 10 minutes. Thereafter, a calcination (post-baking) process is performed for the purpose of removing the solvent in the applied liquid crystal alignment agent. The calcination temperature (post-baking temperature) at this time is preferably 80°C to 250°C, more preferably 80°C to 200°C. The post-baking time is preferably 5 minutes to 200 minutes. The thickness of the film formed in this way is preferably 0.001 μm to 1 μm.

[0183] <Step 2: Orientation Treatment>

[0184] In the case of manufacturing TN type, STN type, IPS type or FFS type liquid crystal elements, a process (orientation treatment) for imparting liquid crystal orientation ability to the coating film formed in the process 1 is implemented. Thus, the orientation ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. As an orientation treatment, the following treatments can be used: a friction treatment in which a roller wound with a cloth containing fibers such as nylon, rayon, and cotton is rubbed in a certain direction against the coating film formed on the substrate; a light orientation treatment in which the coating film formed on the substrate is irradiated with light and the coating film is imparted with liquid crystal orientation ability. On the other hand, in the case of manufacturing a vertically aligned (VA) type liquid crystal element, the coating film formed in the process 1 can be directly used as a liquid crystal alignment film. In addition, in order to further improve the liquid crystal orientation ability, an orientation treatment can also be applied to the coating film. The liquid crystal alignment film preferred for a vertically aligned liquid crystal element is also preferred for a PSA type liquid crystal element.

[0185] In the photo-alignment treatment, light irradiation can be performed by the following methods, etc.: a method of irradiating the coating film after the post-baking process; a method of irradiating the coating film after the pre-baking process and before the post-baking process; a method of irradiating the coating film during the heating process of the coating film in at least any one of the pre-baking process and the post-baking process. As the radiation irradiated to the coating film, for example, ultraviolet rays and visible light containing light with a wavelength of 150nm to 800nm ​​can be used. Preferably, ultraviolet rays containing light with a wavelength of 200nm to 400nm are used. When the radiation is polarized, it can be linearly polarized or partially polarized. When the radiation used is linearly polarized or partially polarized, irradiation can be performed from a direction perpendicular to the substrate surface, from an oblique direction, or a combination of these directions. The irradiation direction in the case of non-polarized radiation is set to an oblique direction.

[0186] Examples of the light source include low-pressure mercury lamps, high-pressure mercury lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps, and excimer lasers. The radiation dose to the substrate surface is preferably 400 J / m 2 ~50,000J / m 2 , more preferably 1,000 J / m 2 ~20,000J / m 2 After the light irradiation for imparting alignment ability, the substrate surface may be cleaned using water, an organic solvent (e.g., methanol, isopropyl alcohol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.), or a mixture thereof, or the substrate may be heated.

[0187] <Step 3: Liquid Crystal Cell Construction>

[0188] Prepare two substrates with liquid crystal alignment films formed in the manner described above, and manufacture a liquid crystal cell by configuring a liquid crystal adjacent to the liquid crystal alignment film between the two substrates. When manufacturing a liquid crystal cell, for example, the following method can be cited: two substrates are arranged oppositely across a gap in a manner in which the liquid crystal alignment films face each other, the peripheral portions of the two substrates are bonded together using a sealant, and a method of injecting a filling liquid crystal into the cell gap surrounded by the substrate surface and the sealant and sealing the injection hole; a method based on a liquid crystal droplet (One Drop Fill, ODF) method, etc. As a sealant, an epoxy resin containing a hardener and an alumina ball as a spacer can be used. As a liquid crystal, nematic liquid crystal and smectic liquid crystal can be listed, wherein nematic liquid crystal is preferably used. In the PSA mode, the following treatment is performed: a liquid crystal and a photopolymerizable compound are arranged between two substrates, thereby constructing a liquid crystal cell, and after constructing the liquid crystal cell, the liquid crystal cell is irradiated with light while a voltage is applied between the conductive films possessed by a pair of substrates.

[0189] Next, for each mode of liquid crystal cell, a polarizing plate is attached to the outer surface of the liquid crystal cell as needed to produce a liquid crystal element. Examples of polarizing plates include those made by sandwiching a polarizing film called "H film" made by stretching and aligning polyvinyl alcohol while allowing it to absorb iodine, between cellulose acetate protective films, or those consisting solely of the H film.

[0190] The liquid crystal element disclosed herein can be effectively applied to various applications. Specifically, it can be applied to various display devices such as watches, portable game consoles, word processors, notebook personal computers, car navigation systems, camcorders, personal digital assistants (PDAs), digital cameras, mobile phones, smartphones, various monitors, liquid crystal televisions, and information displays, as well as to light-adjusting films and phase difference films.

[0191] The present disclosure described above includes the following aspects [1] to

[14] .

[0192] [1] A liquid crystal aligning agent comprising a polymer (P), wherein the polymer (P) is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, and has a partial structure represented by the formula (1).

[0193] [2] The liquid crystal alignment agent according to [1], wherein R in the formula (1) 2 It is a (n1+1)-valent alicyclic group.

[0194] [3] The liquid crystal alignment agent according to [1] or [2], wherein X in the formula (1) 2 For single bonds, oxygen atoms, * 2 -R 6 O-, * 2 -OR 6 - or an alkanediyl group having 1 to 3 carbon atoms.

[0195] [4] The liquid crystal alignment agent according to any one of [1] to [3], wherein Z in the formula (1) 1 and Z 2 One of them is a halogen atom, a cyano group, a nitro group, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms, and the other is a hydrogen atom.

[0196] [5] The liquid crystal aligning agent according to [1], wherein in the formula (1), R 2 is an (n1+1) valent alicyclic group, X 2 For single bonds, oxygen atoms, * 2 -R 6 O-, * 2 -OR 6 - or an alkanediyl group having 1 to 3 carbon atoms, Z 1 and Z 2 One of them is a halogen atom, a cyano group, a nitro group, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms, and the other is a hydrogen atom.

[0197] [6] The liquid crystal aligning agent according to any one of [1] to [5], wherein the polymer (P) contains a structural unit derived from a diamine having a partial structure represented by the formula (1).

[0198] [7] The liquid crystal aligning agent according to [6], wherein the diamine is represented by any one of the formulas (2-1) to (2-3).

[0199] [8] The liquid crystal aligning agent according to [6] or [7], wherein the polymer (P) further includes a structural unit derived from a diamine that does not have the partial structure represented by the formula (1).

[0200] [9] The liquid crystal aligning agent according to any one of [1] to [8], further comprising a polymer (Q) not having a partial structure represented by the formula (1).

[0201]

[10] The liquid crystal alignment agent according to any one of [1] to [9] further contains the following compound, which has two or more groups selected from the group consisting of a cyclic ether group, a cyclic thioether group, an isocyanate group, a protected isocyanate group, a hydroxymethyl group, a protected hydroxymethyl group, a cyclic carbonate group, a group containing a polymerizable carbon-carbon bond, a protected amino group, a silanol group and an alkoxysilyl group in the molecule.

[0202]

[11] A liquid crystal alignment film formed using the liquid crystal alignment agent according to any one of [1] to

[10] .

[0203]

[12] A liquid crystal element comprising the liquid crystal alignment film according to

[11] .

[0204]

[13] A polymer, which is any one of a polyamic acid, a polyamic acid ester, and a polyimide, and contains a structural unit derived from a diamine having a partial structure represented by the formula (1).

[0205]

[14] A compound represented by any one of the above formulas (2-1) to (2-3).

[0206] [Example]

[0207] Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples.

[0208] In the following examples, the weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw / Mn) of the polymer were measured by the following methods.

[0209] <Weight average molecular weight, number average molecular weight, and molecular weight distribution>

[0210] Mw and Mn were measured by gel permeation chromatography (GPC) under the following conditions. In addition, the molecular weight distribution (Mw / Mn) was calculated from the obtained Mw and Mn.

[0211] Device: Showa Denko's "GPC-101"

[0212] GPC columns: Combination of GPC-KF-801, GPC-KF-802, GPC-KF-803, and GPC-KF-804 manufactured by Shimadzu GLC Co., Ltd.

[0213] Mobile phase: tetrahydrofuran (THF) or N,N-dimethylformamide solution containing lithium bromide and phosphoric acid

[0214] Column temperature: 40°C, flow rate: 1.0 mL / min, sample concentration: 1.0 mass%, sample injection volume: 100 μL, detector: differential refractometer, standard substance: monodisperse polystyrene

[0215] The compounds used in the following examples are shown below. In addition, for convenience, the "compound represented by formula (X)" may be simply expressed as "compound (X)".

[0216] [Chemistry 19]

[0217] Photo-aligning diamine

[0218]

[0219] [Chemistry 20]

[0220]

[0221] Tetracarboxylic dianhydride

[0222] [Chemistry 21]

[0223]

[0224] ·Diamines other than photo-aligning diamines

[0225] [Chemistry 22]

[0226]

[0227] Cross-linking agent

[0228] [Chemistry 23]

[0229]

[0230] 1. Synthesis of diamine [Synthesis Example 1-1]

[0231] The compound (PRDA-1) was synthesized according to the following scheme.

[0232] [Chemistry 24]

[0233]

[0234] Synthesis of compound (PRDA-1-1)

[0235] 82.2 g (540 mmol) of methyl 4-hydroxybenzoate, 166 g (1.20 mmol) of potassium carbonate, and 500 mL of N,N-dimethylacetamide were added, and the mixture was stirred at room temperature for 1 hour. 95.2 g (400 mmol) of 4,4,4-trifluoro-1-iodobutane was added. After stirring at room temperature for 5 hours, 400 mL of water was added, and the resulting precipitate was filtered. 32.0 g of sodium hydroxide and 400 mL of water were added to the precipitate, and the mixture was refluxed for 4 hours. After neutralization with hydrochloric acid, the resulting precipitate was recrystallized from ethanol to obtain 84.1 g of compound (PRDA-1-1).

[0236] Synthesis of compound (PRDA-1-2)

[0237] Thionyl chloride (50 mL) and a catalytic amount of dimethylformamide (DMF) were added to 7.45 g (30.0 mmol) of compound (PRDA-1-1). After stirring at 60° C. for 2 hours, thionyl chloride was distilled off under reduced pressure.

[0238] A flask separate from the container containing compound (PRDA-1-1) was prepared, and 5.19 g (30.0 mmol) of 4-bromophenol and 10 mL of triethylamine were dissolved in 100 mL of THF, followed by cooling to 0°C in an ice bath. A THF solution (100 mL) of the reaction product of compound (PRDA-1-1) and thionyl chloride was added dropwise. After reacting at room temperature overnight, the reaction solution was washed with 1N hydrochloric acid and water, and the organic layer was recovered and distilled off under reduced pressure to obtain 10.7 g of compound (PRDA-1-2).

[0239] Synthesis of compound (PRDA-1-3)

[0240] Add compound (PRDA-1-2) 20.2g (50.0mmol), crotonic acid 12.9g (150.0mmol), P (o-tolyl) 3 1.52g (5.00mmol), iPr2NEt 25.9mL (150mmol), palladium acetate 561mg (2.50mmol), DMF 250mL, fully replace with nitrogen, heat to 100 ° C and stir for 6 hours, cool to room temperature, add ethyl acetate 200mL, filter and remove the precipitate. Add hexane 200mL to the filtrate and wash in the order of 1N hydrochloric acid, water, and saturated brine. Dry the organic layer with sodium sulfate, remove the solvent by reduced pressure distillation using a rotary evaporator, and dry the precipitated solid to obtain 2.33g of compound (PRDA-1-3).

[0241] Synthesis of compound (PRDA-1-4)

[0242] 4.08 g (10.0 mmol) of compound (PRDA-1-3) and 2.12 g (10.0 mmol) of 2,4-dinitrophenylethanol were dissolved in 100 mL of dichloromethane and cooled to 0°C in an ice bath. Then, 2.30 g (12.0 mmol) of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide and 0.611 g (5.00 mmol) of 4-dimethylaminopyridine were added. The mixture was returned to room temperature and stirred overnight. The mixture was then washed with 1N hydrochloric acid and water, and the solvent was removed from the recovered organic layer by distillation using a rotary evaporator to obtain 4.89 g of compound (PRDA-1-4).

[0243] Synthesis of compound (PRDA-1)

[0244] To 6.025 g (10.0 mmol) of compound (PRDA-1-4) was added 30 mL each of THF and water, followed by 10 equivalents of tin chloride. The mixture was stirred at 60°C for 2 hours, extracted with ethyl acetate, and the organic layer was washed with water. The solvent was then removed by distillation using a rotary evaporator. The resulting solid was dissolved in 50 mL of THF, 30 mL of ethanol and 10 mL of water were added, and the solvent was slowly removed by distillation using a rotary evaporator. The precipitated solid was collected by filtration and dried to obtain 4.03 g of compound (PRDA-1).

[0245] [Synthesis Example 1-2]

[0246] Compound (PRDA-2) was synthesized according to the following scheme.

[0247] [Chemistry 25]

[0248]

[0249] Compound (PRDA-2-1) was synthesized by the same method as compound (PRDA-1-3) except that the starting materials were changed. Thereafter, compound (PRDA-2) was synthesized by the same method as compound (PRDA-1-4) and compound (PRDA-1).

[0250] [Synthesis Example 1-3]

[0251] The compound (PRDA-3) was synthesized according to the following scheme.

[0252] [Chemistry 26]

[0253]

[0254] Compound (PRDA-3-1) was synthesized by the same method as compound (PRDA-1-3) except that the starting materials were changed. Thereafter, compound (PRDA-3) was synthesized by the same method as compound (PRDA-1-4) and compound (PRDA-1).

[0255] [Synthesis Example 1-4]

[0256] Compound (PRDA-4) was synthesized according to the following scheme.

[0257] [Chemistry 27]

[0258]

[0259] Synthesis of compound (PRDA-4-1)

[0260] To 19.6 g (50.0 mmol) of 1-bromo-4-[4-pentyl[1,1'-bicyclohexyl]-4-yl]benzene and 11.3 g (60.0 mmol) of triisopropyl borate was added 30 mL of THF and cooled to -78°C. Then, n-butyllithium was slowly added dropwise and stirred for 1 hour. The solution was returned to room temperature, and 100 mL of 2N hydrochloric acid was added. Extraction was performed with ethyl acetate, and the organic phase was washed with water and dried over sodium sulfate. The solvent was then distilled off under reduced pressure to obtain compound (PRDA-4-1).

[0261] Synthesis of compound (PRDA-4-2)

[0262] To 21.4 g (60.0 mmol) of compound (PRDA-4-1) were added 4.20 g (50.0 mmol) of methyl propiolate, 13.8 g (100 mmol) of potassium carbonate, 17.4 g (75.0 mmol) of silver oxide, 561 mg (2.5 mmol) of palladium acetate, and 200 mL of acetonitrile. The mixture was stirred at 70°C for 6 hours. The precipitate was filtered and extracted with ethyl acetate. The organic phase was washed with water and dried over sodium sulfate. The solvent was removed by vacuum distillation, and the resulting solid was purified by silica gel column chromatography to obtain 8.52 g of compound (PRDA-4-2).

[0263] Synthesis of compound (PRDA-4-3)

[0264] To 11.84 g (30.0 mmol) of compound (PRDA-4-2) were added 9.52 g (75.0 mmol) of silver fluoride, 270 μg (15.0 μmol) of water, and 100 mL of acetonitrile. The mixture was stirred at 90°C for 6 hours, then extracted with ethyl acetate. The organic phase was washed with water and dried over sodium sulfate. The viscous liquid obtained by distilling the solvent under reduced pressure was dissolved in 50 mL of ethanol, 100 mL of a 40% aqueous sodium hydroxide solution was added, and the mixture was stirred at 100°C for 3 hours. The pH was then adjusted to 3 with 1N hydrochloric acid. The precipitated crystals were collected by filtration and washed with hexane to obtain 7.33 g of compound (PRDA-4-3). Subsequently, compound (PRDA-4) was synthesized using the same method as for compounds (PRDA-1-4) and (PRDA-1).

[0265] [Synthesis Example 1-5]

[0266] Compound (PRDA-5) was synthesized according to the following scheme.

[0267] [Chemistry 28]

[0268]

[0269] Compound (PRDA-5) was synthesized by the same method as compound (PRDA-1-3), compound (PRDA-1-4), and compound (PRDA-1), except that the starting materials were changed.

[0270] [Synthesis Example 1-6]

[0271] Compound (PRDA-6) was synthesized according to the following scheme.

[0272] [Chemistry 29]

[0273]

[0274] Compound (PRDA-6) was synthesized by the same method as compound (PRDA-1-2), compound (PRDA-1-3), compound (PRDA-1-4), and compound (PRDA-1), except that the starting materials were changed.

[0275] [Synthesis Example 1-7]

[0276] Compound (PRDA-7) was synthesized according to the following scheme.

[0277] [Chemistry 30]

[0278]

[0279] Compound (PRDA-7) was synthesized by the same method as compound (PRDA-1-3), compound (PRDA-1-4), and compound (PRDA-1), except that the starting materials were changed.

[0280] [Synthesis Example 1-8]

[0281] Compound (PRDA-8) was synthesized according to the following scheme.

[0282] [Chemistry 31]

[0283]

[0284] Compound (PRDA-8) was synthesized by the same method as compound (PRDA-1-3), compound (PRDA-1-4), and compound (PRDA-1), except that the starting materials were changed.

[0285] [Synthesis Example 1-9]

[0286] The compound (PRDA-9) was synthesized according to the following scheme.

[0287] [Chemistry 32]

[0288]

[0289] Compound (PRDA-9) was synthesized by the same method as compound (PRDA-1-4) and compound (PRDA-1) except that the starting materials were changed.

[0290] [Synthesis Example 1-10]

[0291] Compound (PRDA-10) was synthesized according to the following scheme.

[0292] [Chemistry 33]

[0293]

[0294] Compound (PRDA-10) was synthesized by the same method as compound (PRDA-1-4) and compound (PRDA-1) except that the starting materials were changed.

[0295] [Synthesis Example 1-11]

[0296] Compound (PRDA-11) was synthesized according to the following scheme.

[0297] [Chemistry 34]

[0298]

[0299] Synthesis of compound (PRDA-11-1)

[0300] To 21.6 g (150 mmol) of 4-nitrobenzyl bromide were added 81.0 g (375 mmol) of Michaelis' acid, 68.4 g (495 mmol) of potassium carbonate, and 200 mL of DMF, and the mixture was stirred at room temperature for 24 hours. Subsequently, 800 mL of water was added, and the precipitate was filtered. The filtered solid, after washing with water, was recrystallized from methanol / dichloromethane to obtain 56.7 g of compound (PRDA-1-1).

[0301] Synthesis of compound (PRDA-11-2)

[0302] To 8.29 g (20.0 mmol) of compound (PRDA-11-1) were added 1.68 g (40.0 mmol) of lithium hydroxide monohydrate, 100 mL of ethanol, and 50 mL of water, and the mixture was stirred at room temperature for 24 hours. Subsequently, 100 mL of 1N hydrochloric acid was added, and the precipitate was filtered. The filtered solid, after washing with water, was dried under reduced pressure to obtain 7.05 g of compound (PRDA-11-2).

[0303] Synthesis of Compound (PRDA-11-3) and Compound (PRDA-11)

[0304] To 8.29 g (20.0 mmol) of compound (PRDA-11-3) was added 100 mL of THF, cooled to 0°C in an ice bath, and then 1000 mL of a 1 M tetrahydrofuran-borane-tetrahydrofuran solution was added dropwise. After returning to room temperature and stirring for 24 hours, 30 mL of water was added dropwise, followed by 70 mL of 1N hydrochloric acid. Extraction was performed with ethyl acetate, the organic layer was washed with water, dried over sodium sulfate, and the solvent was removed by vacuum distillation to obtain 4.53 g of compound (PRDA-11-3). Subsequently, compound (PRDA-11) was synthesized using the same method as for compounds (PRDA-1-4) and (PRDA-1).

[0305] [Synthesis Example 1-12]: Synthesis of compound (PRDA-12)

[0306] The compound (PRDA-12) was synthesized according to the description of Japanese Patent Application Laid-Open No. 2022-173076.

[0307] [Synthesis Example 1-13]: Synthesis of compound (PRDA-13)

[0308] The compound (PRDA-13) was synthesized according to the description of Japanese Patent Application Laid-Open No. 2017-187600.

[0309] [Synthesis Example 1-14]: Synthesis of compound (PRDA-14)

[0310] The compound (PRDA-14) was synthesized according to Japanese Patent Application Laid-Open No. 2011-18025.

[0311] [Synthesis Example 1-15]: Synthesis of compound (PRDA-15)

[0312] The compound (PRDA-15) was synthesized according to the description of International Publication No. 2023 / 174773.

[0313] [Synthesis Example 1-16]: Synthesis of compound (PRDA-16)

[0314] 4.19 g of a compound (PRDA-16) was obtained by the same method as in Synthesis Example 1-1, except that 6-bromohexanenitrile was used instead of 4,4,4-trifluoro-1-iodobutane.

[0315] 2. Synthesis of polymers

[0316] [Synthesis Example 2-1: Synthesis of Polymer (PI-1)]

[0317] Under a dry nitrogen stream, 100 parts by mole of the diamine compound (PRDA-1) was dissolved in 20 g of N-methyl-2-pyrrolidone (NMP). 100 parts by mole of the tetracarboxylic dianhydride compound (TA-1) was added to the solution, and the mixture was reacted at 40°C for 6 hours. This yielded a solution containing 20% ​​by mass of the target polyamic acid (referred to as "polymer (PI-1)").

[0318] [Synthesis Examples 2-2 to 2-16 and Comparative Synthesis Examples 1 to 4: Synthesis of Polymers (PI-2 to PI-11, PI-16 to PI-20, PI-12 to PI-15)]

[0319] Except for changing the types and amounts of tetracarboxylic dianhydride and diamine used in the polymerization as described in Table 1, polymerization was carried out in the same manner as in Synthesis Example 2-1 to obtain polymers (PI-2) to (PI-11), polymers (PI-16) to (PI-20), and polymers (PI-12) to (PI-15) as polyamic acids, respectively.

[0320]

[0321] 3. Fabrication and evaluation of vertical liquid crystal display devices

[0322] [Example 1]

[0323] (1) Preparation of liquid crystal alignment agent (AL-1)

[0324] To a mixture of 20 parts by mass of the polymer (P-1) obtained in Synthesis Example 2-1 and 100 parts by mass of the polymer (PI-18) (solid content of the polymer) were added N-methylpyrrolidone (NMP), γ-butyrolactone (GBL), diethylene glycol diethyl ether (DEDG), and diisobutyl ketone (DIBK) as solvents to prepare a solution having a solvent composition of NMP / GBL / DEDG / DIBK = 30 / 20 / 40 / 10 (mass ratio) and a solid content concentration of 4.0% by mass. The solution was filtered through a filter with a pore size of 0.5 μm to prepare a liquid crystal alignment agent (AL-1).

[0325] (2) Manufacturing of vertical liquid crystal display elements

[0326] The prepared liquid crystal alignment agent (AL-1) was applied to the transparent electrode surface of a glass substrate with a transparent electrode containing an ITO film using a spinner and pre-baked on a hot plate at 80°C for 1 minute. Thereafter, the mixture was heated at 230°C for 1 hour in an oven purged of nitrogen to form a coating film with a thickness of 0.1 μm. Subsequently, a Hg-Xe lamp and a Glan-Taylor prism were used to irradiate the coating surface with 200 J / m2 of polarized ultraviolet light containing a bright line of 313 nm from a direction inclined at 40° relative to the substrate normal. 2 Repeat the same operation to make a pair (two sheets) of substrates with liquid crystal alignment films.

[0327] Then, after applying an epoxy resin adhesive containing alumina balls with a diameter of 3.5 μm to the periphery of the surface of one of the substrates having a liquid crystal alignment film by screen printing, the liquid crystal alignment film surfaces of a pair of substrates are faced to each other, and the optical axis of the ultraviolet rays of each substrate is pressed in an antiparallel manner toward the projection direction of the substrate surface, and the adhesive is thermally cured at 150°C for 1 hour. Then, after filling the gap between the substrates with a negative liquid crystal (manufactured by Merck, MLC-6608) from the liquid crystal injection port, the liquid crystal injection port is sealed with an epoxy adhesive. Furthermore, in order to remove the flow orientation during liquid crystal injection, it is heated at 130°C and then slowly cooled to room temperature. Next, the polarizing plate is attached to the outer two surfaces of the substrate with its polarization directions orthogonal to each other and at an angle of 45° to the projection direction of the optical axis of the ultraviolet rays of the liquid crystal alignment film toward the substrate surface, thereby manufacturing a liquid crystal display element.

[0328] (3) Evaluation of liquid crystal orientation

[0329] The obtained optical vertical liquid crystal display element was observed under a microscope at 50x magnification for the presence of abnormal domains in the brightness and darkness changes when a 5V voltage was turned on and off (applied and removed). The evaluation was conducted by rating the element "good (○)" if no abnormal domains were observed and "poor (×)" if abnormal domains were observed. The results were rated "good (○)" in this example.

[0330] (4) Evaluation of AC afterimage (pretilt angle difference)

[0331] For the obtained optical vertical liquid crystal display element, the pretilt angle difference before and after the voltage application when an alternating current (AC) voltage of 7V was applied at room temperature for 20 hours was measured, and the AC residual image characteristic was evaluated based on the pretilt angle difference. The pretilt angle was determined according to the method described in the non-patent document "TJ Scheffer et al. Journal of Applied Physics. Vol. 19, p. 2013 (1980)" (TJScheffer et.al. J. Appl. Phys. vo. 19, p. 2013 (1980)) by measuring the value of the tilt angle of the liquid crystal molecules relative to the substrate surface by a crystal rotation method using a He-Ne laser, and setting it as the pretilt angle [°]. As a result, the pretilt angle difference was 0.08°. The smaller the pretilt angle difference, the less likely it is to produce a residual image caused by the application of the AC voltage after the voltage application is released, which can be said to be good. In the evaluation, a pretilt angle difference of less than 0.1° was rated as "good (○)", a pretilt angle difference of 0.1° or more and less than 0.2° was rated as "acceptable (△)", and a pretilt angle difference of 0.2° or more was rated as "poor (×)".

[0332] (5) Evaluation of Voltage Holding Ratio (VHR)

[0333] For the optical vertical liquid crystal display element obtained above, after applying a 5V voltage with an application time of 60 microseconds and a span of 167 milliseconds, the voltage holding rate was measured 167 milliseconds after the application was released. The measuring device used was a VHR measuring device "VHR-1" manufactured by Toyo Technica. At this time, if the voltage holding rate is 95% or more, it is set to "good (○)", if it is 80% or more and less than 95%, it is set to "acceptable (△)", and if it is less than 80%, it is set to "poor (×)". As a result, in the embodiment, the voltage holding rate was evaluated as "○ (good)".

[0334] (6) Evaluation of backlight reliability in high-temperature environments (high-temperature BL reliability)

[0335] For the obtained optical vertical liquid crystal display element, the reliability of backlight illumination in a high temperature environment was evaluated by the voltage holding ratio. The evaluation was carried out as follows. First, after applying a voltage of 1V for 60 microseconds to the liquid crystal unit, the voltage holding ratio (VHR1) was measured 1670 milliseconds after the application was released. Then, after irradiating the liquid crystal unit with a cold cathode fluorescent lamp (CCFL) (backlight) for one week at 60°C, it was left to stand at room temperature and naturally cooled to room temperature. After cooling, after applying a voltage of 1V for 60 microseconds to the liquid crystal unit, the voltage holding ratio (VHR2) was measured 1670 milliseconds after the application was released. The measuring device used was a VHR measuring device "VHR-1" manufactured by Toyo Technica. The rate of change of VHR at this time (ΔVHR) was calculated based on the difference between VHR1 and VHR2 (ΔVHR=VHR1-VHR2), and the reliability was evaluated based on ΔVHR. A ΔVHR of less than 5% was rated "Excellent (◎)", a ΔVHR of 5% or more and less than 10% was rated "Good (○)", a ΔVHR of 10% or more and less than 20% was rated "Acceptable (△)", and a ΔVHR of more than 20% was rated "Poor (×)". As a result, the reliability of the backlight illumination in a high-temperature environment in the above-described example was rated "Excellent (○)".

[0336] (7) Evaluation of film uniformity by inkjet coating (IJ coating uniformity)

[0337] The prepared liquid crystal alignment agent (AL-1) was applied to the transparent electrode surface of a glass substrate with a transparent electrode using an inkjet coater (manufactured by Shibaura Mechatronics). The coating conditions were 2,500 strokes / (nozzle, minute) at a spray rate of 250 mg / 10 seconds, with two reciprocating strokes (a total of four strokes). Furthermore, the substrate for coating the liquid crystal alignment agent was a glass substrate with an ITO transparent electrode, which had been heated on a 200°C hot plate for 1 minute and then cleaned with ultraviolet light / ozone to reduce the water contact angle on the transparent electrode surface to 10° or less.

[0338] After coating, let it stand for 1 minute, pre-bake it at 80°C for 1 minute, and then bake it at 200°C for 40 minutes in a clean oven under a nitrogen environment. Then, use a 20x microscope to observe the peripheral and central parts of the liquid crystal alignment film. At this time, the situation where there are no pinholes and uneven coating (uneven film thickness, etc.) is evaluated as "excellent (◎)", the situation where the total number of pinholes and uneven coating sites is 1 or more and less than 3 is evaluated as "good (○)", and the situation where the total number of pinholes and uneven coating sites is 3 or more is evaluated as "poor (×)". In addition, if the solubility of the polymer is good, the uniformity of the film based on inkjet coating also tends to be improved. As a result, the IJ coating uniformity of the liquid crystal alignment agent of the embodiment is evaluated as "excellent (◎)".

[0339] [Example 2 to Example 16 and Comparative Examples 1 to 4]

[0340] A liquid crystal aligning agent was prepared in the same manner as in Example 1, except that the composition of the liquid crystal aligning agent was changed as shown in Table 2. Furthermore, a photo-vertical liquid crystal display element was produced in the same manner as in Example 1 using the obtained liquid crystal aligning agent, and various evaluations were performed. The results are shown in Table 2.

[0341]

[0342] In Table 2, the abbreviations of the solvents represent the following compounds.

[0343] NMP: N-methyl-2-pyrrolidone

[0344] NEP: N-ethyl-2-pyrrolidone

[0345] GBL: gamma-butyrolactone

[0346] BC: Butyl Cellosolve

[0347] DIBK: diisobutyl ketone

[0348] DEDG: Diethylene glycol diethyl ether

[0349] DMM: Dipropylene glycol dimethyl ether

[0350] MB: 3-methoxy-1-butanol

[0351] DAA: Diacetone Alcohol

[0352] IB: Isobutyl isobutyrate

[0353] As shown in Table 2, the liquid crystal orientation, AC afterimage characteristics, voltage holding ratio, high temperature BL reliability and IJ coating uniformity of the liquid crystal alignment agents of Examples 1 to 16 containing the polymer (P) were all rated as excellent, good or acceptable, and various characteristics were improved in a well-balanced manner. Among these, when comparing Example 5 with Example 6, X in the formula (1) 2 The liquid crystal alignment agent of Example 5 having a single bond and X 2 Compared with Example 6, which has an ester bond, high-temperature BL reliability is superior. Furthermore, when comparing Example 1 with Example 9, the liquid crystal alignment agent of Example 9, in which the terminal ring structure of the partial structure represented by Formula (1) is a cyclohexane ring, exhibits reduced AC afterimages compared to Example 1, in which the terminal ring structure is a benzene ring. Furthermore, when comparing Example 7 with Example 10, Example 7, in which the substituted cinnamate structure is β-substituted, exhibits superior high-temperature BL reliability compared to Example 10, in which the substituted cinnamate structure is α-substituted.

[0354] On the other hand, the liquid crystal aligning agents of Comparative Examples 1 to 4 using only a polymer having no partial structure represented by the formula (1) instead of the polymer (P) were evaluated as poor in either high-temperature BL reliability or IJ coating uniformity.

Claims

1. A liquid crystal alignment agent comprising a polymer (P), wherein the polymer (P) is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, and has a partial structure represented by the following formula (1); In formula (1), R 1 is an alkyl group, a fluoroalkyl group or a cyanated alkyl group having 2 to 20 carbon atoms; X 1 For single bonds, oxygen atoms, * 1 -COO- or * 1 -OCO-;"* 1 "Indicates that the 1 Bond of R 2 is an (n1+1)-valent aromatic ring group, a (n1+1)-valent alicyclic group or a (n1+1)-valent heterocyclic group; R 3 is a single bond, a divalent aromatic ring group, a divalent alicyclic group or a divalent heterocyclic group; X 2 For single bonds, oxygen atoms, * 2 -COO-,* 2 -OCO-,* 2 -R 6 O-, * 2 -OR 6 -, an alkanediyl group or vinylene group having 1 to 3 carbon atoms; R 6 is an alkanediyl group having 1 to 3 carbon atoms; "* 2 " indicates that the 3 Bond of R 4 is a divalent aromatic ring group; Z 1 and Z 2 are independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms; wherein, Z 1 and Z 2 Will not become a hydrogen atom at the same time; X 3 is an oxygen atom, a sulfur atom or -NR 7 -;R 7 is a hydrogen atom or a monovalent organic group; R 5 It is a straight-chain alkanediyl group having 1 to 12 carbon atoms, or one or more methylene groups in a straight-chain alkanediyl group having 1 to 12 carbon atoms are replaced by -O-, -COO- or -NR 8 CO-substituted and connected to X through -CH2- 3 Bonding divalent group; R 8 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; n1 is an integer of 1 to 3; n2 is an integer of 0 to 3; wherein, when n1 is 2 or more, multiple X 1 Same or different, multiple R 1 Same or different; when n2 is 2 or more, multiple X 2 Same or different, multiple R 3 Same or different; "*" indicates a bond.

2. The liquid crystal aligning agent according to claim 1, wherein R in the formula (1) 2 It is a (n1+1)-valent alicyclic group.

3. The liquid crystal aligning agent according to claim 1, wherein X in the formula (1) 2 For single bonds, oxygen atoms, * 2 -R 6 O-, * 2 -OR 6 -, an alkanediyl group having 1 to 3 carbon atoms or an ethenylene group.

4. The liquid crystal alignment agent according to claim 1, wherein Z in the formula (1) 1 and Z 2 One of them is a halogen atom, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms, and the other is a hydrogen atom. The liquid crystal alignment agent according to claim 1 , wherein: In the formula (1), R 2 is an (n1+1)-valent alicyclic group, X 2 For single bonds, oxygen atoms, * 2 -R 6 O-, * 2 -OR 6 -, an alkanediyl group or vinylene group having 1 to 3 carbon atoms, Z 1 and Z 2 One of them is a halogen atom, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms, and the other is a hydrogen atom. The liquid crystal alignment agent according to claim 1 , wherein: The polymer (P) includes a structural unit derived from a diamine having a partial structure represented by the formula (1).

7. The liquid crystal alignment agent according to claim 6, wherein The diamine is represented by any one of the following formulas (2-1) to (2-3); In formula (2-1) to formula (2-3), R 1 、X 1 、R 2 、R 3 、X 2 、R 4 、Z 1 、Z 2 、X 3 、R 5 , n1 and n2 have the same meanings as in the formula (1); R 10 、R 11 、R 12 、R 13 and R 14 are independently a substituent; n3 is an integer of 0 to 3; n4 and n5 are independently an integer of 0 to 3; n6 and n7 are independently an integer of 0 to 5; n8 and n9 are independently an integer of 0 to 4; when n3 is 2 or more, multiple R 10 Same or different, when n6 is 2 or more, multiple R 11 Same or different, when n7 is 2 or more, multiple R 12 Same or different, when n8 is 2 or more, multiple R 13 Same or different, when n9 is 2 or more, multiple R 14 Same or different.

8. The liquid crystal aligning agent according to claim 6, wherein The polymer (P) further includes a structural unit derived from a diamine that does not have the partial structure represented by the formula (1). 9 . The liquid crystal aligning agent according to claim 1 , further comprising a polymer (Q) not having the partial structure represented by the formula (1).

10. The liquid crystal alignment agent according to claim 1, further comprising a compound having two or more groups in the molecule selected from the group consisting of a cyclic ether group, a cyclic thioether group, an isocyanate group, a protected isocyanate group, a hydroxymethyl group, a protected hydroxymethyl group, a cyclic carbonate group, a group containing a polymerizable carbon-carbon bond, a protected amino group, a silanol group, and an alkoxysilyl group. 11 . A liquid crystal alignment film formed using the liquid crystal alignment agent according to claim 1 . 12 . A liquid crystal element comprising the liquid crystal alignment film according to claim 11 .

13. A polymer, which is any one of polyamic acid, polyamic acid ester and polyimide, Containing a structural unit derived from a diamine having a partial structure represented by the following formula (1); In formula (1), R 1 is an alkyl group, a fluoroalkyl group or a cyanated alkyl group having 2 to 20 carbon atoms; X 1 For single bonds, oxygen atoms, * 1 -COO- or * 1 -OCO-;"* 1 " indicates that the 1 Bond of R 2 is an (n1+1)-valent aromatic ring group, a (n1+1)-valent alicyclic group or a (n1+1)-valent heterocyclic group; R 3 is a single bond, a divalent aromatic ring group, a divalent alicyclic group or a divalent heterocyclic group; X 2 For single bonds, oxygen atoms, * 2 -COO-,* 2 -OCO-,* 2 -R 6 O-, * 2 -OR 6 -, an alkanediyl group or vinylene group having 1 to 3 carbon atoms; R 6 is an alkanediyl group having 1 to 3 carbon atoms; "* 2 " indicates that the 3 Bond of R 4 is a divalent aromatic ring group; Z 1 and Z 2 are independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms; wherein, Z 1 and Z 2 Will not become a hydrogen atom at the same time; X 3 For oxygen atoms, sulfur atoms, -NR 7 -;R 7 is a hydrogen atom or a monovalent organic group; R 5 It is a straight-chain alkanediyl group having 1 to 12 carbon atoms, or one or more methylene groups in a straight-chain alkanediyl group having 1 to 12 carbon atoms are replaced by -O-, -COO- or -NR 8 CO-substituted and connected to X through -CH2- 3 Bonding divalent group; R 8 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; n1 is an integer of 1 to 3; n2 is an integer of 0 to 3; wherein, when n1 is 2 or more, multiple X 1 Same or different, multiple R 1 Same or different; when n2 is 2 or more, multiple X 2 Same or different, multiple R 3 Same or different; "*" indicates a bond.

14. A compound represented by any one of the following formulas (2-1) to (2-3); In formula (2-1) to formula (2-3), R 1 is an alkyl group, a fluoroalkyl group or a cyanated alkyl group having 2 to 20 carbon atoms; X 1 For single bonds, oxygen atoms, * 1 -COO- or * 1 -OCO-;"* 1 " indicates that the 1 Bond of R 2 is an (n1+1)-valent aromatic ring group, a (n1+1)-valent alicyclic group or a (n1+1)-valent heterocyclic group; R 3 is a single bond, a divalent aromatic ring group, a divalent alicyclic group or a divalent heterocyclic group; X 2 For single bonds, oxygen atoms, * 2 -COO-,* 2 -OCO-,* 2 -R 6 O-, * 2 -OR 6 -, an alkanediyl group or vinylene group having 1 to 3 carbon atoms; R 6 is an alkanediyl group having 1 to 3 carbon atoms; "* 2 " indicates that the 3 Bond of R 4 is a divalent aromatic ring group; Z 1 and Z 2 are independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms; wherein, Z 1 and Z 2 Will not become a hydrogen atom at the same time; X 3 For oxygen atoms, sulfur atoms, -NR 7 -;R 7 is a hydrogen atom or a monovalent organic group; R 5 It is a straight-chain alkanediyl group having 1 to 12 carbon atoms, or one or more methylene groups in a straight-chain alkanediyl group having 1 to 12 carbon atoms are replaced by -O-, -COO- or -NR 8 CO-substituted and connected to X through -CH2- 3 Bonding divalent group; R 8 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; n1 is an integer from 1 to 3; n2 is an integer from 0 to 3; R 10 、R 11 、R 12 、R 13 and R 14 are independently a substituent; n3 is an integer of 0 to 3; n4 and n5 are independently an integer of 0 to 3; n6 and n7 are independently an integer of 0 to 5; n8 and n9 are independently an integer of 0 to 4; wherein, when n1 is 2 or more, multiple X 1 Same or different, multiple R 1 Same or different; when n2 is 2 or more, multiple X 2 Same or different, multiple R 3 Same or different; when n3 is 2 or more, multiple R 10 Same or different, when n6 is 2 or more, multiple R 11 Same or different, when n7 is 2 or more, multiple R 12 Same or different, when n8 is 2 or more, multiple R 13 Same or different, when n9 is 2 or more, multiple R 14 Same or different.

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