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

Abstract

The present invention provides a liquid crystal alignment agent, a liquid crystal alignment film and a liquid crystal element having excellent coating properties on a substrate. The present invention provides a liquid crystal alignment agent containing: a polymer [A] comprising a structural unit derived from a monomer having a polymerizable carbon-carbon unsaturated bond, wherein the polymer [A] accounts for 50% by mass or more of the total amount of the polymer component; and a compound [B] represented by formula (1). (In formula (1), R 1 is a linear alkyl group having 5 or more carbon atoms. 1 ‑OH…(1)

Description

Technical Field

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

[0002] In recent years, liquid crystal elements are not only used in display devices such as personal computers or liquid crystal televisions, car navigation systems, mobile phones, smart phones, and information displays, but also in various applications such as optical compensation films and dimming films. With such multi-purpose applications, liquid crystal elements are required to be further improved in quality, and improvements in driving methods or element structures, as well as improvements in liquid crystal alignment films, which are one of the components of liquid crystal elements, are being promoted.

[0003] The liquid crystal alignment film is usually formed by dissolving a polymer component in a solvent to prepare a polymer composition, applying the prepared polymer composition on a substrate, and removing the solvent. Regarding the polymer component of the liquid crystal alignment agent, polyimide and polyamic acid as its precursor have been widely used as alignment film materials since the past because they can form a liquid crystal alignment film with high heat resistance and excellent durability and have good affinity with liquid crystals (for example, refer to Patent Document 1).

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2014-112197 Summary of the invention

[0007] [Problems to be solved by the invention]

[0008] The solubility of polyimide and polyamic acid is not very good, so when using polyimide as a polymer component, protic polar solvents such as N-methyl-2-pyrrolidone (NMP) are mostly used as solvents. However, protic polar solvents generally have high boiling points and need to be calcined at a higher temperature when forming a liquid crystal alignment film. Therefore, the types of substrates that can be produced are limited or the energy cost increases. Therefore, as an alignment film material, a new material is being sought to replace polyimide.

[0009] In recent years, as liquid crystal elements have become more refined, the demand for display quality has become more stringent, and defects such as depressions and unevenness that are easily generated in contact holes formed on a substrate have also been required to be suppressed as much as possible.

[0010] The present invention has been made in view of the above-mentioned problems, and one object of the present invention is to provide a liquid crystal aligning agent having excellent coating properties on a substrate.

[0011] [Technical means to solve the problem]

[0012] The present invention adopts the following means to solve the above-mentioned problems.

[0013] <1> A liquid crystal aligning agent comprising: a polymer [A] comprising a structural unit derived from a monomer having a polymerizable carbon-carbon unsaturated bond, wherein the polymer [A] accounts for 50% by mass or more of the total amount of polymer components; and a compound [B] represented by the following formula (1).

[0014] R 1 -OH…(1)

[0015] (In formula (1), R 1 It is a straight-chain alkyl group having 5 or more carbon atoms.

[0016] <2> A liquid crystal aligning film formed using the liquid crystal aligning agent according to <1> above.

[0017] <3> A liquid crystal element comprising the liquid crystal alignment film according to <2>.

[0018] [Effects of the Invention]

[0019] According to the present invention, a liquid crystal aligning agent having excellent coating properties on a substrate can be provided. DETAILED DESCRIPTION

[0020] Hereinafter, each component contained in the liquid crystal aligning agent of this indication, and other components mix|blend arbitrarily as needed are demonstrated.

[0021] In addition, in this specification, the so-called "hydrocarbon group" refers to the meaning of chain hydrocarbon groups, alicyclic hydrocarbon groups and aromatic hydrocarbon groups. 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 in the main chain and is only composed of a chain structure. 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 alicyclic hydrocarbon as a ring structure and does not contain an aromatic ring structure. Among them, it is not necessary to be composed only of the structure of alicyclic hydrocarbons, and a group having a chain structure in a part thereof is also included. 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 be composed only of an aromatic ring structure, and a chain structure or an alicyclic hydrocarbon structure may be contained in a part thereof.

[0022] The liquid crystal aligning agent disclosed herein contains a polymer component and a solvent component, and is preferably a polymer composition in which the polymer component is dissolved in the solvent component. The liquid crystal aligning agent disclosed herein contains the polymer [A] and the compound [B] shown below.

[0023] Aggregate[A]

[0024] The liquid crystal alignment agent of the present disclosure contains a polymer [A] as a polymer component, wherein the polymer [A] contains a structural unit derived from a monomer having a polymerizable carbon-carbon unsaturated bond (hereinafter also referred to as "monomer (M)"). In addition, the polymer [A] may contain one polymer or two or more polymers.

[0025] Examples of the monomer (M) include (meth) acrylic acid compounds, aromatic vinyl compounds, conjugated diene compounds, maleimide compounds, vinyl compounds, and the like. From the perspective of obtaining an alignment film having high transparency and material strength and high affinity with liquid crystals, the polymer [A] preferably includes a structural unit derived from a (meth) acrylic acid compound, and more preferably includes a structural unit derived from a (meth) acrylic acid compound and a structural unit derived from a maleimide compound. In addition, in this specification, "(meth) acrylic acid" includes the meanings of "acrylic acid" and "methacrylic acid".

[0026] In the polymer [A], the ratio of the structural unit derived from the (meth)acrylic compound to all structural units constituting the polymer [A] contained in the liquid crystal aligning agent is preferably 25 mol% or more, more preferably 30 mol% or more, and further preferably 40 mol% or more.

[0027] The proportion of the structural unit derived from the maleimide compound relative to all structural units constituting the polymer [A] contained in the liquid crystal alignment agent is preferably 1 mol% or more, more preferably 2 mol% or more, and further preferably 5 mol% or more. In addition, the proportion of the structural unit derived from the maleimide compound relative to all structural units constituting the polymer [A] contained in the liquid crystal alignment agent is preferably 50 mol% or less, more preferably 40 mol% or less.

[0028] In addition, in the present specification, when the liquid crystal alignment agent contains two or more polymers [A], the ratio of all structural units constituting the polymer [A] contained in the liquid crystal alignment agent represents the ratio of all structural units of the two or more polymers [A]. Therefore, for example, when the polymer [A] contains a first polymer containing structural units derived from a maleimide compound at a ratio of 10 mol% and a second polymer without a maleimide compound, if the mixing ratio of the first polymer to the second polymer is 1:9, the ratio of structural units derived from the maleimide compound in the polymer [A] is (10 / 100)×(1 / 10)+(0 / 100)×(9 / 10)=0.01, i.e., 1 mol%.

[0029] As long as the polymer [A] is a polymer obtained by polymerization using a monomer (M), there is no particular limitation on the monomer composition. If it is considered to impart good liquid crystal orientation to the liquid crystal alignment film, the liquid crystal alignment agent of the present invention preferably comprises a polymer having at least one selected from the group consisting of a light-aligning group, a liquid crystal alignment group, and a liquid crystal side chain (hereinafter also referred to as a "specific structure") as the polymer [A]. The polymer [A] having a specific structure (hereinafter also referred to as "polymer [A1]") tends to have low solubility due to its rigid structure. In contrast, according to the liquid crystal alignment agent of the present invention using compound [B] as at least a part of the solvent component, even if the polymer [A] has a specific structure, the polymer [A] can be fully dissolved, and a liquid crystal alignment agent with excellent coating properties can be obtained, which is preferred in this respect.

[0030] Photo-orientation group

[0031] As the photo-alignment group contained in the polymer [A], a functional group that can be used to impart anisotropy to the film by photoisomerization reaction based on light irradiation, photodimerization reaction, photo-induced Fries rearrangement reaction or photolysis reaction can be used. As a specific example of the photo-alignment group, for example, it can be listed: a group containing azobenzene containing azobenzene or its derivatives as a basic skeleton, a group containing cinnamic acid structure containing cinnamic acid structure containing cinnamic acid structure containing cinnamic acid structure containing cinnamic acid structure containing chalcone or its derivatives as a basic skeleton, a group containing benzophenone containing benzophenone containing benzoic acid phenyl ester or its derivatives as a basic skeleton, a group containing benzoic acid phenyl ester containing benzoic acid phenyl ester containing benzoic acid phenyl ester containing benzoic acid phenyl ester containing coumarin containing coumarin containing cyclobutane or its derivatives as a basic skeleton containing cyclobutane structure etc.. Among them, in terms of high sensitivity to light and easy introduction to the side chain of the polymer, the photo-alignment group is particularly preferably a group containing cinnamic acid structure. The group containing a cinnamic acid structure is preferably a group represented by the following formula (5) containing a cinnamic acid structure as a basic skeleton.

[0032] [Chemistry 1]

[0033]

[0034] (In formula (5), X 11 and X 12 R are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 5 carbon atoms, or a fluoroalkyl group having 1 to 5 carbon atoms. 10 is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a fluorine atom, or a cyano group. a is an integer of 0 to 4. When a is 2 or more, a plurality of R10 are the same group or different groups. “*” indicates a bonding bond. )

[0035] In the above formula (5), examples of the substituents possessed by the substituted alkyl group having 1 to 10 carbon atoms and the substituted alkoxy group having 1 to 10 carbon atoms include a fluorine atom and a cyano group.

[0036] Examples of the group represented by the formula (5) include a monovalent group obtained by removing one hydrogen atom from a carboxyl group of cinnamic acid, or a group in which a substituent is introduced into the benzene ring of the monovalent group (hereinafter also referred to as a "cis-cinnamate group"), and a monovalent group in which a carboxyl group of cinnamic acid is esterified and a divalent organic group is bonded to the benzene ring, or a group in which a substituent is introduced into the benzene ring of the monovalent group (hereinafter also referred to as a "reverse-cinnamate group").

[0037] In the formula (5), X 11 and X 12 It is preferably a hydrogen atom, a fluorine atom, a cyano group or an alkyl group having 1 to 3 carbon atoms. a is preferably 0 or 1, and 0 is particularly preferred.

[0038] The cis-cinnamate group can be represented by, for example, the following formula (5-1), and the trans-cinnamate group can be represented by, for example, the following formula (5-2).

[0039] [Chemistry 2]

[0040]

[0041] (In formula (5-1), R 14 R is a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a cyano group. 15 A is a phenylene group, a biphenylene group, a terphenylene group or a cyclohexylene group, or a group in which at least a part of the hydrogen atoms possessed by these groups are substituted by a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a monovalent group in which at least a part of the hydrogen atoms of the alkoxy group are substituted by a halogen atom. 1 is a single bond, an oxygen atom, a sulfur atom, an alkanediyl group having 1 to 3 carbon atoms, -CH=CH-, -NH-, * 1 -COO-,* 1 -OCO-,* 1 -NH-CO-,* 1 -CO-NH-,* 1 -CH2-O- or * 1 -O-CH2-(“* 1 " indicates that the 15 b is 0 or 1.

[0042] In formula (5-2), R 16It is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent group in which at least a part of the hydrogen atoms in the hydrocarbon group is substituted with an alkoxy group, a halogen atom or a cyano group.

[0043] X in formula (5-1) and formula (5-2) 11 , X 12 , R 10 and a has the same meaning as in the above formula (5). "*" represents a bonding bond.)

[0044] Liquid crystal orientation group

[0045] The liquid crystal orientation group is a group having the function of vertically or horizontally aligning liquid crystal molecules independently of light irradiation. Examples of the liquid crystal orientation group include: an alkyl group having 4 to 20 carbon atoms, an alkoxy group having 4 to 20 carbon atoms, a fluoroalkyl group having 4 to 20 carbon atoms, a fluoroalkoxy group having 4 to 20 carbon atoms, a group having a structure formed by bonding a ring to a chain structure having 1 to 20 carbon atoms, a group having a structure formed by bonding two or more rings directly or via a divalent linking group, a group having a steroid skeleton, etc. Among them, the liquid crystal orientation group is preferably a group represented by the following formula (6).

[0046] *-L 31 -R 31 -R 32 -R 33 -R 34 …(6)

[0047] (In formula (6), L 31 Single bond, -O-, -CO-, -COO-* 1 、-OCO-* 1 、-NR 35 -、-NR 35 -CO-* 1 、-CO-NR 35 -* 1 , an alkanediyl group having 1 to 6 carbon atoms, a divalent group in which a hydrogen atom possessed by an alkanediyl group having 2 to 6 carbon atoms is substituted with a hydroxyl group, -OR 36 -* 1 or -R 36 -O-* 1 (Among them, R 35 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, R 36 It is an alkanediyl group having 1 to 3 carbon atoms. 1 " indicates that the 31 The bonding bond of R 31 and R 33 are each independently a single bond, a substituted or unsubstituted phenylene group, or a substituted or unsubstituted cycloalkylene group, R 32is a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted cycloalkylene group, or -R 37 -B 31 -R 38 (Among them, R 37 and R 38 are independently substituted or unsubstituted phenylene or cycloalkylene), B 31 Single bond, -O-, -COO-* 2 、-OCO-* 2 、-OCH2-* 2 、-CH2O-* 2 , or an alkanediyl group having 1 to 3 carbon atoms. 2 " indicates that the 38 The bonding bond of R 34 A hydrogen atom, a fluorine atom, a cyano group, CH3COO-* 3 (“* 3 " indicates that the 33 ), an alkyl group having 1 to 18 carbon atoms, a fluoroalkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a fluoroalkoxy group having 1 to 18 carbon atoms, a hydrocarbon group having 17 to 51 carbon atoms having a steroid skeleton, or a monovalent group in which a hydrogen atom possessed by an alkyl group or a fluoroalkyl group having 1 to 18 carbon atoms is replaced by a cyano group. 31 , R 32 and R 33 All single bonds, or R 31 , R 32 and R 33 When the total number of substituted or unsubstituted phenylene groups and cycloalkylene groups is one, R 34 It is an alkyl group having 4 to 18 carbon atoms, a fluoroalkyl group having 4 to 18 carbon atoms, an alkoxy group having 4 to 18 carbon atoms, a fluoroalkoxy group having 4 to 18 carbon atoms, or a hydrocarbon group having 17 to 51 carbon atoms and having a steroid skeleton. "*" indicates a bonding bond. )

[0048] In the formula (6), L 31 The alkanediyl group is preferably straight-chain. 35 The monovalent hydrocarbon group having 1 to 10 carbon atoms includes a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group, and is preferably an alkyl group having 1 to 3 carbon atoms.

[0049] About R 34, an alkyl group having 1 to 18 carbon atoms, a fluoroalkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a fluoroalkoxy group having 1 to 18 carbon atoms, or a monovalent group formed by replacing a hydrogen atom possessed by an alkyl group or a fluoroalkyl group having 1 to 18 carbon atoms with a cyano group is preferably a straight chain. When the liquid crystal element is set to a vertical alignment type, these groups preferably have 2 to 18 carbon atoms, more preferably 3 to 18 carbon atoms, and even more preferably 4 to 18 carbon atoms. As R 34 Examples of the hydrocarbon group having 17 to 51 carbon atoms and having a steroid skeleton include cholesteryl, cholesterol, and lanostanyl.

[0050] From the viewpoint of obtaining a liquid crystal element showing good liquid crystal orientation, the liquid crystal orientation group is preferably R 31 , R 32 and R 33 The group preferably has a total of two or more substituted or unsubstituted phenylene groups and at least one of cycloalkylene groups, and more preferably has a total of 2 to 4 of the substituted or unsubstituted phenylene groups.

[0051] As a specific example of a liquid crystal orientation group, the group represented by following formula (6-1) - formula (6-10) is mentioned, for example.

[0052] [Chemistry 3]

[0053]

[0054] (In formula (6-1) to formula (6-10), R 20 X is a fluorine atom, a cyano group, an alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a fluoroalkoxy group having 1 to 20 carbon atoms. 21 It is -O-, -COO- or an alkanediyl group having 1 to 3 carbon atoms. "*" indicates a bonding bond. )

[0055] Liquid crystal side chain

[0056] The liquid crystal side chain is a side chain structure that allows the polymer [A] to exhibit liquid crystallinity within a predetermined temperature range (preferably a temperature range of 100° C. to 300° C.) Specific examples of the liquid crystal side chain include partial structures represented by the following formulae (7-1) to (7-8), respectively.

[0057] [Chemistry 4]

[0058]

[0059] (In formula (7-1) to formula (7-8), A 2 and A 5 are independently a single bond, -O-, -CH2-, -COO-, -CONH-, or -CH=CH-CO-O-. 3A is a monovalent group having a ring structure. 4 X is a hydrogen atom, a nitro group, a cyano group, -CH=C(CN)2, -CH=CH-CN, a halogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent heterocyclic group, or an alkoxy group having 1 to 20 carbon atoms. 3 is a single bond, -CO-, -CH2O-, -CH=N-, or -CF2-. One of a1 and a2 is 0, and the other is 1. c1 is an integer of 0 to 3. b1 is an integer of 1 to 12. In formula (7-2) and formula (7-3), the total of c1 is 2 or more. In formula (7-4) and formula (7-5), the total of c1 is 1 or more. "*" represents a bonding bond. )

[0060] The polymer [A1] can be obtained, for example, by polymerizing a monomer having a specific structure. Examples of monomers having a specific structure include (meth) acrylic acid compounds, styrene compounds, maleimide compounds, and the like. In the polymer [A1], the content of the structural unit having the specific structure is preferably set to 1 mol% or more, more preferably 2 mol% or more, and further preferably 5 mol% or more, relative to all the structural units constituting the polymer [A1]. In addition, the content of the structural unit having the specific structure is preferably set to 50 mol% or less, and more preferably 40 mol% or less, relative to all the structural units constituting the polymer [A1].

[0061] The liquid crystal alignment agent of the present disclosure may also include a polymer having no specific structure (hereinafter also referred to as polymer [A2]) as polymer [A]. In terms of improving the solubility of compound [B] and further improving the coating properties of the liquid crystal alignment agent, it is particularly preferred that polymer [A] includes polymer [A1] having a specific structure and polymer [A2] having no specific structure.

[0062] When the liquid crystal alignment agent contains polymer [A1] and polymer [A2], from the viewpoint of obtaining a liquid crystal alignment film having good liquid crystal orientation, the content of polymer [A1] is preferably set to 1% by mass or more, and more preferably set to 2% by mass or more, relative to the total amount of polymer [A] contained in the liquid crystal alignment agent. In addition, from the viewpoint of suppressing the reduction of coating properties, the content of polymer [A1] is preferably set to 40% by mass or less, and more preferably set to 30% by mass or less, relative to the total amount of polymer [A] contained in the liquid crystal alignment agent.

[0063] Cross-linking group

[0064] At least a part of the polymer [A] contained in the liquid crystal aligning agent may have a crosslinking group. When using the polymer [A] having a crosslinking group, it is suitable in that the coating property of the liquid crystal aligning agent and the electrical properties of the liquid crystal element can be improved in a well-balanced manner.

[0065] As crosslinking groups, for example, epoxy groups, cyclic carbonate groups, isocyanate groups, protected isocyanate groups, oxazoline groups, β-hydroxyalkylamide groups, Meldrum's acid groups, methylol groups, alkyl methylol groups, hydroxyl groups, protected hydroxyl groups, carboxyl groups, protected carboxyl groups (hereinafter also referred to as "protected carboxyl groups"), amino groups, protected amino groups, vinyl groups, allyl groups, (meth) acryloyl groups, alkoxysilyl groups, etc. can be listed. In addition, in the present specification, epoxy groups include oxetane groups and oxetane groups. Among them, in terms of high reactivity based on heat and good storage stability, the crosslinking group is preferably selected from at least one of the group consisting of epoxy groups, protected isocyanate groups, oxazoline groups, methylol groups, carboxyl groups, and protected carboxyl groups, and particularly preferably includes epoxy groups.

[0066] Only polymer [A1] may have a crosslinkable group, only polymer [A2] may have a crosslinkable group, or both polymer [A1] and polymer [A2] may have a crosslinkable group. In terms of the high effect of improving coating properties and optimizing electrical properties exerted by the introduction of a crosslinkable group, it is preferred that at least polymer [A1] has a crosslinkable group, and it is more preferred that both polymer [A1] and polymer [A2] have a crosslinkable group.

[0067] The polymer [A] having a crosslinkable group can be obtained, for example, by polymerizing a monomer having a crosslinkable group. In the polymer [A], the content ratio of the structural unit having a crosslinkable group is preferably 10 mol% or more, more preferably 20 mol% or more, and further preferably 30 mol% or more, relative to all the structural units constituting the polymer [A] contained in the liquid crystal alignment agent. In addition, the content ratio of the structural unit having a crosslinkable group is preferably 99 mol% or less, more preferably 95 mol% or less, relative to all the structural units constituting the polymer [A] contained in the liquid crystal alignment agent.

[0068] A preferred embodiment when the polymer [A] has a crosslinking group is that the polymer [A] contains at least one ring structure Q of an oxetane ring and an oxirane ring in the same polymer or in a different polymer, and a functional group that reacts with the ring structure Q by heating. In this case, the coating property of the liquid crystal alignment agent can be improved while maintaining the voltage holding rate of the liquid crystal element high, which is suitable in this respect.

[0069] The ring structure of the polymer [A] is preferably an oxetane ring in terms of high reactivity, and is preferably an oxirane ring in terms of high freedom of selection of monomers.

[0070] Examples of the functional group that reacts with the ring structure Q include a carboxyl group, a hydroxyl group, an isocyanate group, and an amino group, and groups in which the groups are protected by a protective group, an alkoxymethyl group, etc. Among them, the functional group that reacts with the ring structure Q is preferably at least one selected from the group consisting of a carboxyl group and a protected carboxyl group, in terms of making the storage stability of the liquid crystal aligning agent good and having high reactivity with the oxetane ring and the oxirane ring under heating.

[0071] Only polymer [A1] may have a ring structure Q, only polymer [A2] may have a ring structure Q, or both polymer [A1] and polymer [A2] may have a ring structure Q. In addition, the same is true for the functional group that reacts with the ring structure Q. Only polymer [A1] may have a functional group that reacts with the ring structure Q, only polymer [A2] may have a functional group that reacts with the ring structure Q, or both polymer [A1] and polymer [A2] may have a functional group that reacts with the ring structure Q. In terms of improving the voltage holding ratio, it is preferred that at least polymer [A2] has a ring structure Q and a functional group that reacts with the ring structure Q, and it is more preferred that both polymer [A1] and polymer [A2] have a ring structure Q and a functional group that reacts with the ring structure Q.

[0072] Specific examples of the monomer having a ring structure Q include: (meth)acrylic acid compounds such as glycidyl (meth)acrylate, α-ethyl acrylate glycidyl, α-n-propyl acrylate glycidyl, α-n-butyl acrylate glycidyl, (meth)acrylate 3,4-epoxybutyl, α-ethyl acrylate 3,4-epoxybutyl, (meth)acrylate 3,4-epoxycyclohexylmethyl, (meth)acrylate 6,7-epoxyheptyl, α-ethyl acrylate 6,7-epoxyheptyl, acrylate 4-hydroxybutyl glycidyl ether, (meth)acrylate (3-ethyloxetan-3-yl)methyl ester; and styrene compounds such as 4-vinyl-1-glycidyloxymethylbenzene and 3-vinyl-1-glycidyloxymethylbenzene. As the monomer having a ring structure Q, one of these may be used alone, or two or more of them may be used in combination.

[0073] Specific examples of monomers having a functional group that reacts with the ring structure Q include: compounds containing a carboxyl group, such as (meth)acrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, vinylbenzoic acid, crotonic acid, citraconic acid, itaconic acid, 3-maleimidobenzoic acid, and 3-maleimidopropionic acid; unsaturated polycarboxylic acid anhydrides, such as maleic anhydride; compounds containing a protected carbonyl group, respectively represented by the following formulas (m-1) to (m-7); and the like.

[0074] [Chemistry 5]

[0075]

[0076] (In formula (m-1) to formula (m-7), R is a hydrogen atom or a methyl group.)

[0077] As the monomers, one kind may be used alone or two or more kinds may be used in combination.

[0078] In the polymer [A], the content ratio of the structural unit derived from the monomer having the ring structure Q is preferably 1 mol % to 90 mol %, more preferably 5 mol % to 90 mol %, and further preferably 10 mol % to 80 mol % relative to all the structural units constituting the polymer [A] contained in the liquid crystal aligning agent.

[0079] The content ratio of the structural unit derived from the monomer having a functional group reactive with the ring structure Q is preferably 1 mol % to 90 mol %, more preferably 5 mol % to 90 mol %, and further preferably 10 mol % to 80 mol % relative to all structural units constituting the polymer [A] contained in the liquid crystal aligning agent.

[0080] The polymer [A] may have a structural unit derived from a monomer having no specific structure or crosslinking group (hereinafter also referred to as "other monomer") as the monomer [M], within the range not impairing the effects of the present disclosure. Specific examples of other monomers include (meth)acrylic acid compounds such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, phenyl (meth)acrylate, and unsaturated carboxylic acid esters such as benzyl (meth)acrylate;

[0081] Examples of aromatic vinyl compounds include styrene, methylstyrene, divinylbenzene, etc.; examples of conjugated diene compounds include 1,3-butadiene, 2-methyl-1,3-butadiene, etc.; examples of maleimide compounds include maleimide, N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, etc.; examples of vinyl compounds include methyl vinyl ether, benzyl vinyl ether, etc. In addition, as the monomer [M], one kind may be used alone, or two or more kinds may be used in combination.

[0082] The polymer [A] can be obtained, for example, by polymerizing the monomer [M] in the presence of a polymerization initiator using an existing method such as free radical polymerization. The polymerization initiator used is preferably an azo compound such as 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile). The proportion of the polymerization initiator used is preferably 0.01 to 30 parts by mass relative to 100 parts by mass of the total amount of the monomers used in the reaction.

[0083] The polymerization reaction is preferably carried out in an organic solvent. Examples of the organic solvent used in the reaction include alcohols, ethers, ketones, amides, esters, hydrocarbon compounds, and the like. The reaction temperature is, for example, 30° C. to 120° C. The reaction time is, for example, 1 hour to 36 hours. The amount (a) of the organic solvent used is preferably set to an amount such that the total amount (b) of the monomers used in the reaction is 0.1% to 60% by mass relative to the total amount (a+b) of the reaction solution.

[0084] In addition, when synthesizing a polymer having a specific structure in a side chain as the polymer [A], the synthesis method thereof is not particularly limited. As a method for synthesizing a polymer having a specific structure, for example, the following methods can be cited: a method of polymerizing using a monomer having a specific structure; a method of synthesizing a polymer having an epoxy group in a side chain using a monomer containing an epoxy group in at least a part of the raw materials, and then reacting the monomer with a carboxylic acid having a specific structure.

[0085] The weight average molecular weight (Mw) of the polymer [A] measured by gel permeation chromatography (GPC) in terms of polystyrene is preferably 1,000 to 500,000, and more preferably 2,000 to 300,000. In addition, the molecular weight distribution (Mw / Mn) 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, and more preferably 6 or less. In addition, when preparing a liquid crystal alignment agent, the polymer [A] may be used alone or in combination of two or more.

[0086] In the liquid crystal alignment agent disclosed herein, the content ratio of the polymer [A] is 50% by mass or more relative to the total amount of the polymer components contained in the liquid crystal alignment agent. The content ratio of the polymer [A] relative to the total amount of the polymer components contained in the liquid crystal alignment agent is preferably 70% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, further more preferably 95% by mass or more, and particularly preferably 99% by mass or more.

[0087] In addition, the liquid crystal alignment agent of the present disclosure may also contain polymers other than polymer [A] (hereinafter also referred to as "other polymers") as polymer components. As other polymers, for example, polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyenamine, polyurea, polyamide, polyamideimide, polybenzoxazole precursor, polybenzoxazole, cellulose derivatives, polyacetal, etc. As other polymers, one type may be included alone, or two or more types may be included.

[0088] Relative to the total amount of polymer components contained in the liquid crystal alignment agent, the content ratio of other polymers in the liquid crystal alignment agent is preferably 30 mass % or less, more preferably 20 mass % or less, further preferably 10 mass % or less, further more preferably 5 mass % or less, and particularly preferably 1 mass % or less.

[0089] <Compound [B]>

[0090] The compound [B] is a compound represented by the following formula (1). The compound [B] has a moderately low surface tension, and by using such a compound [B] as a solvent component for dissolving the polymer [A], a liquid crystal aligning agent having good coating properties on a substrate can be obtained.

[0091] R 1 -OH…(1)

[0092] (In formula (1), R 1 It is a straight-chain alkyl group having 5 or more carbon atoms.

[0093] Compound [B] is a primary alcohol or secondary alcohol having a linear alkyl chain. Here, "the alkyl chain is linear" means that there is no branch in the alkyl chain.

[0094] From the viewpoint of suppressing the generation of depressions, suppressing the decrease in wettability and spreading, and ensuring the ease of use as a solvent due to a moderately low melting point, R in the formula (1) is 1 The carbon number of the moiety is preferably 5-20, more preferably 5-15, further preferably 5-12, and particularly preferably 5-10.

[0095] As R 1Specific examples include 1-pentyl, 2-pentyl, 3-pentyl, 1-hexyl, 2-hexyl, 1-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, 1-octyl, 2-octyl, 3-octyl, 4-octyl, 1-nonyl, 2-nonyl, 1-decyl, 2-decyl, 1-undecyl, 2-undecyl, 1-dodecyl, 2-dodecyl, 1-tridecyl, 2-tridecyl, 1-tetradecyl, 2-tetradecyl, 1-pentadecyl, 2-pentadecyl, 1-hexadecyl, 2-hexadecyl, 1-heptadecyl, 2-heptadecyl, 1-octadecyl, 2-octadecyl, 1-nonadecyl, 2-nonadecyl, 1-eicosyl, 2-eicosyl, and the like.

[0096] Preferred specific examples of the compound [B] include compounds represented by the following formula (B-1) to formula (B-51), and the like.

[0097] [Chemistry 6]

[0098]

[0099] [Chemistry 7]

[0100]

[0101] [Chemistry 8]

[0102]

[0103] [Chemistry 9]

[0104]

[0105] [Chemistry 10]

[0106]

[0107] In the liquid crystal aligning agent, from the viewpoint of fully obtaining the improvement effect of the coating property of the liquid crystal aligning agent, the content ratio of compound [B] is preferably 1% by mass or more relative to the total amount of the solvent contained in the liquid crystal aligning agent. The content ratio of compound [B] is more preferably 3% by mass or more, and further preferably 5% by mass or more, and particularly preferably 10% by mass or more. In addition, relative to the total amount of the solvent contained in the liquid crystal aligning agent, compound [B] can be used in a range of 100% by mass or less. Relative to the total amount of the solvent contained in the liquid crystal aligning agent, the content ratio of compound [B] is preferably 99% by mass or less, more preferably 95% by mass or less, further preferably 90% by mass or less, further preferably 80% by mass or less, further more preferably 60% by mass or less, further more preferably 50% by mass or less, and particularly preferably 30% by mass or less. As compound [B], one may be used alone, or two or more may be used in combination.

[0108] <Compound [C]>

[0109] When preparing a liquid crystal alignment agent, only compound [B] may be used as a solvent component, but it is preferred to use compound [B] together with at least one compound [C] selected from the group consisting of a compound represented by the following formula (2), a compound represented by the following formula (3), a compound represented by the following formula (4), and a cyclic ketone having 4 to 7 carbon atoms. The combined use of compound [C] is preferred because the coating properties of the liquid crystal alignment agent on the substrate can be further improved.

[0110] R 2 -(OR 3 )n 4 …(2)

[0111] (In formula (2), R 2 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 3 It is an alkanediyl group having 2 to 4 carbon atoms. 4 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n is an integer of 0 to 3. When n is 2 or 3, the multiple R 3 are the same group or different groups. When n is 0, R 2 is an alkyl group with 3 to 5 carbon atoms, R 4 is a hydrogen atom.)

[0112] [Chemistry 11]

[0113]

[0114] (In formula (3), R 5 X is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or an alkoxyalkyl group having 2 or 3 carbon atoms. 1 is a single bond or an oxygen atom. 6 It is an alkanediyl group having 1 to 3 carbon atoms. 7 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. m is 0 or 1.

[0115] In formula (4), R 8 and R 9 Each of X is independently an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or an alkoxyalkyl group having 2 or 3 carbon atoms. 2 is a single bond or an alkanediyl group having 1 or 2 carbon atoms. )

[0116] (Compound represented by formula (2))

[0117] In the formula (2), R 2The alkyl group having 1 to 5 carbon atoms may be straight-chain or branched, and examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, and sec-pentyl. When n is 1 to 3, R 2 Preferably, it is an alkyl group having 1 to 4 carbon atoms. When n is 0, R 2 Preferred is n-propyl, n-butyl, isobutyl or isopentyl.

[0118] As R 3 The alkanediyl group having 2 to 4 carbon atoms includes ethylene, propylene, 1-methylethylene, 2-methylethylene, n-butylene, 2-methylpropylene, 2,2-dimethylethylene, and the like. 3 The carbon number is preferably 2 or 3.

[0119] As R 4 The alkyl group having 1 to 4 carbon atoms may include the above R 2 Among the alkyl groups exemplified in the description of , an alkyl group having 1 to 4 carbon atoms. 4 It is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group, and still more preferably a hydrogen atom.

[0120] Specific examples of the compound represented by the formula (2) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol monobutyl ether (butyl cellosolve), 3-methoxy-1-butanol, 1,3-butanediol, n-propyl alcohol, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol n-propyl ether, dipropylene glycol n-butyl ether, tripropylene glycol methyl ether, tripropylene glycol n-butyl ether, ethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, and the like.

[0121] (Compound represented by formula (3))

[0122] In the formula (3), R 5 , R 7 The alkyl group having 1 to 3 carbon atoms includes methyl, ethyl, n-propyl and isopropyl. 5 The alkoxy group and alkylalkoxy group include methoxy group, ethoxy group, methoxymethyl group, ethoxyethyl group, etc. 5 Preferably it is methyl or ethyl. 7 Preferred is a hydrogen atom, a methyl group or an ethyl group.

[0123] R 6 The alkanediyl group having 1 to 3 carbon atoms is preferably linear, and more preferably a methylene group or an ethylene group.

[0124] Preferred specific examples of the compound represented by the formula (3) include diacetone alcohol, 4-methoxy-4-methyl-2-pentanone, and 3-methoxy-3-methylbutyl acetate.

[0125] (Compound represented by formula (4))

[0126] In the formula (4), with respect to R 8 and R 9 Specific examples of the alkyl group having 1 to 3 carbon atoms, the alkoxy group having 1 to 3 carbon atoms, and the alkoxyalkyl group having 2 or 3 carbon atoms include R in the formula (3): 5 The bases exemplified in the description. R 8 and R 9 Preferred is a methoxy group or an ethoxy group.

[0127] Specific examples of the compound represented by the formula (4) include acetone, methyl ethyl ketone, methyl n-propyl ketone, diethyl ketone, diethyl oxalate, dimethyl dimalonate, etc. Among them, diethyl oxalate and dimethyl dimalonate are preferred.

[0128] Examples of the cyclic ketone having 4 to 7 carbon atoms include cyclobutanone, cyclopentanone, cyclohexanone, and cycloheptanone.

[0129] Among the above, the compound [C] can preferably be a compound represented by the formula (2). Among the compounds represented by the formula (2), at least one selected from the group consisting of diethylene glycol monoethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether, 3-methoxy-1-butanol, 1,3-butanediol, n-propanol, propylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-propyl ether, dipropylene glycol n-butyl ether, tripropylene glycol methyl ether, and tripropylene glycol n-butyl ether is preferred, and at least one selected from the group consisting of diethylene glycol monoethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether, 3-methoxy-1-butanol, propylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-propyl ether, and dipropylene glycol n-butyl ether is more preferred.

[0130] From the viewpoint of fully obtaining the effect of improving the coating property of the liquid crystal aligning agent on the substrate, the content ratio of compound [C] is preferably 5% by mass or more relative to the total amount of the solvent contained in the liquid crystal aligning agent. The content ratio of compound [C] is more preferably 10% by mass or more, and further preferably 20% by mass or more, and further preferably 40% by mass or more, and particularly preferably 50% by mass or more. In addition, relative to the total amount of the solvent contained in the liquid crystal aligning agent, compound [C] is preferably 99% by mass or less, more preferably 97% by mass or less, and further preferably 95% by mass or less, and further preferably 90% by mass or less. As compound [C], one may be used alone, or two or more may be used in combination.

[0131] The liquid crystal alignment agent of the present disclosure may further contain a solvent different from compound [B] and compound [C] (hereinafter also referred to as "other solvent"). As other solvents, existing solvents for preparing liquid crystal alignment agents can be used. As specific examples of other solvents, solvents for improving the solubility and leveling properties of polymers (hereinafter also referred to as "first solvent") and solvents for improving wetting and spreading properties (hereinafter also referred to as "second solvent") can be listed.

[0132] Specific examples of other solvents include, as the first solvent, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, 1,3-dimethyl-2-imidazolidinone, etc.;

[0133] Examples of the second solvent include ether solvents such as diisoamyl ether; ester solvents such as methyl acetate, ethyl acetate, propyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, tert-butyl acetate, 3-methoxybutyl acetate, methyl acetoacetate, ethyl acetoacetate, ethyl propionate, n-butyl propionate, methyl lactate, ethyl lactate, n-butyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol ethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol diethyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA), isopentyl propionate, isopentyl isobutyrate, and propylene glycol diacetate; and ketone solvents such as methyl n-butyl ketone, di-n-butyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, ethyl n-butyl ketone, methyl n-hexyl ketone, diisobutyl ketone, and trimethylnonanone. Furthermore, as other solvents, one kind may be used alone, or two or more kinds may be used as a mixture.

[0134] When other solvents are used as solvents, the content ratio of other solvents relative to the total amount of solvents contained in the liquid crystal alignment agent (the total amount when two or more solvents are used) is preferably 80 mass % or less, more preferably 50 mass % or less, further preferably 20 mass % or less, and particularly preferably 10 mass % or less.

[0135] From the perspective of achieving low temperature of the heating temperature during film formation, environmental restrictions, and health effects, the liquid crystal alignment agent of the present disclosure is preferably substantially free of N-methyl-2-pyrrolidone (NMP). Specifically, the content ratio of NMP in the liquid crystal alignment agent of the present disclosure is preferably 5% by mass or less, more preferably 1% by mass or less, relative to the total amount of the solvent contained in the liquid crystal alignment agent. It is further preferably 0.5% by mass or less.

[0136] <Other ingredients>

[0137] The liquid crystal aligning agent may further contain a component different from the above components (hereinafter also referred to as “other components”) as necessary, in addition to the components described above.

[0138] <Cross-linking agent>

[0139] The liquid crystal alignment agent disclosed in the present invention may also contain a cross-linking agent as an additive component. In the case of including a cross-linking agent, the electrical properties of the liquid crystal element can be improved, which is suitable in this respect. As a cross-linking agent, it is preferably a compound having at least one cross-linking group selected from the group consisting of a cyclic ether group, a cyclic carbonate group, an isocyanate group, a protected isocyanate group, an oxazoline group, a β-hydroxyalkylamide group, a Michaelis acid group, a hydroxymethyl group and an alkyl hydroxymethyl group and a molecular weight of 1000 or less. The number of cross-linking groups in each molecule of the cross-linking agent is preferably more than two, more preferably more than three. Among them, the cross-linking agent is preferably a compound having at least one selected from the group consisting of a cyclic ether group, a protected isocyanate group, a β-hydroxyalkylamide group, a hydroxymethyl group and an alkyl hydroxymethyl group, and more preferably a compound having at least one selected from the group consisting of a protected isocyanate group, a β-hydroxyalkylamide group, a hydroxymethyl group and an alkyl hydroxymethyl group.

[0140] Specific examples of the crosslinking agent include, as compounds having a cyclic ether group, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, N,N,N',N'-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N-diglycidyl-benzylamine, N,N-diglycidyl-aminomethylcyclohexane, and N,N-diglycidyl-cyclohexylamine. Examples of the compound having a cyclic carbonate group include, for example, N,N,N',N'-tetrakis[(2-oxo-1,3-dioxolan-4-yl)ethyl]-4,4'-diaminodiphenylmethane.

[0141] Examples of the compound having an isocyanate group or a protected isocyanate group include toluene diisocyanate, xylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, and protected isocyanate compounds obtained by protecting these polyisocyanates with a protecting group; examples of the compound having an oxazoline group include 2,2'-bis(4-propyl-2-oxazoline), 2,2'-bis(4-phenyl-2-oxazoline), 1,2-bis(2-oxazoline-2-yl)ethane, 1,4-bis(2-oxazoline-2-yl)cyclohexane, 1,3-bis(2-oxazoline-2-yl)benzene, 1,3 -bis(4,5-dihydro-2-oxazolyl)benzene, 1,3-bis(4-methyl-2-oxazolin-2-yl)benzene, etc.; as a compound having a β-hydroxyalkylamide group, for example, N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide, etc.; as a compound having a hydroxymethyl group or an alkylhydroxymethyl group, for example, trimethylolpropane, bis[2-ethyl-2,2-bis(hydroxymethyl)ethyl]ether, 2,2'-[oxybis(methylene)]bis[2-ethyl-1,3-propanediol], 2,2-bis(4-hydroxymethylphenyl)propane, 2,2-bis(2,3,4-trihydroxymethylphenyl)propane, 2,4,6-tris[bis(methoxymethyl)amino]-1,3,5-triazine, etc. As a crosslinking agent, one kind may be used alone, or two or more kinds may be used in combination.

[0142] When a cross-linking agent is used, from the viewpoint of forming a stable liquid crystal alignment film and fully obtaining the effect of improving the electrical properties of the obtained liquid crystal element, the content of the cross-linking agent in the liquid crystal alignment agent is preferably 0.5 parts by mass or more, and more preferably 1 part by mass or more, relative to 100 parts by mass of the total amount of the polymer [A]. In addition, from the viewpoint of suppressing the reduction of coating properties, the content of the cross-linking agent is preferably 40 parts by mass or less, and more preferably 30 parts by mass or less, relative to 100 parts by mass of the total amount of the polymer [A]. In addition, as a cross-linking agent, one kind may be used alone or two or more kinds may be used in combination.

[0143] As other components contained in the liquid crystal alignment agent, not only the above components can be listed, for example, antioxidants, metal chelate compounds, hardening accelerators, surfactants, fillers, dispersants, photosensitizers, etc. The proportion of other components can be appropriately selected according to each compound within the range that does not damage the effect of the present disclosure.

[0144] The solid content concentration in the liquid crystal aligning agent (the total mass of the components of the liquid crystal aligning agent other than the solvent accounts for the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc., but is preferably in the range of 1% to 10% by mass. If the solid content concentration is more than 1% by mass, the film thickness of the coating can be fully ensured, and it is easy to obtain a liquid crystal alignment film showing good liquid crystal orientation. On the other hand, if the solid content concentration is less than 10% by mass, the coating can be made into a moderate thickness, and it is easy to obtain a liquid crystal alignment film showing good liquid crystal orientation. In addition, the viscosity of the liquid crystal aligning agent becomes moderate, and there is a tendency to make the coating property good.

[0145] 《Liquid crystal alignment film and liquid crystal element》

[0146] The liquid crystal alignment film of the present invention is formed by a liquid crystal alignment agent prepared in the manner described. In addition, the liquid crystal element of the present invention includes a liquid crystal alignment film formed using the liquid crystal alignment agent described above. The operating 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 manufactured, for example, by a method including the following steps 1 to 3. Regarding step 1, different substrates are used depending on the desired operation mode. Steps 2 and 3 are common to each operation mode.

[0147] <Step 1: Formation of coating film>

[0148] 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, glass such as float glass and soda glass can be used; a transparent substrate containing plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly(alicyclic olefin). As a transparent conductive film disposed on one side of the substrate, a NESA film (registered trademark of PPG, USA) containing tin oxide (SnO2) and an indium tin oxide (indium tin oxide, ITO) film containing indium oxide-tin oxide (In2O3-SnO2) can be used. In the case of manufacturing a TN type, STN type or VA type liquid crystal element, two substrates provided with a patterned transparent conductive film 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-shaped shape and an opposing substrate without an electrode are used.

[0149] The method for coating the liquid crystal alignment agent on the substrate is not particularly limited, and can be carried out by, for example, spin coating, printing (for example, offset printing, flexographic printing, etc.), inkjet, slit coating, rod coater, extrusion die, direct gravure coater, chamber doctor coater, offset gravure coater, impregnation coater, MB coater, etc.

[0150] 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. Then, a calcination (post-baking) process is performed for the purpose of completely removing the solvent. The calcination temperature (post-baking temperature) at this time is preferably 80°C to 280°C, and more preferably 80°C to 250°C. The post-baking time is preferably 5 minutes to 200 minutes. The film thickness of the formed film is preferably 0.001μm to 1μm.

[0151] <Step 2: Orientation treatment>

[0152] In the case of manufacturing TN type, STN type, IPS type or FFS type liquid crystal elements, the coating formed in the process 1 is subjected to a process (orientation treatment) of imparting liquid crystal orientation ability. Thus, the orientation ability of the liquid crystal molecules is imparted to the coating to form a liquid crystal orientation film. As an orientation treatment, it is preferred to use a friction treatment in which the surface of the coating formed on the substrate is wiped with cotton wool or the like, or to irradiate the coating with light to impart a light orientation treatment of liquid crystal orientation ability. On the other hand, in the case of manufacturing a vertically oriented liquid crystal element, the coating formed in the process 1 can be directly used as a liquid crystal orientation film, or the coating can be subjected to an orientation treatment in order to further improve the liquid crystal orientation ability.

[0153] Light irradiation for photo-orientation can be carried out by the following methods: a method of irradiating the coating after the post-baking process; a method of irradiating the coating after the pre-baking process and before the post-baking process; a method of irradiating the coating during the heating process of the coating in at least any one of the pre-baking process and the post-baking process, etc. As radiation irradiated to the coating, 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. In the case where the radiation is polarized, it can be linearly polarized or partially polarized. In the case where the radiation used is linearly polarized or partially polarized, the irradiation can be carried out from a direction perpendicular to the substrate surface, from an oblique direction, or these directions can be combined. The irradiation direction for non-polarized radiation is set to an oblique direction.

[0154] Examples of the light source include a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, and an excimer laser. The radiation dose is preferably 400 J / m 2 ~50,000J / m 2 , more preferably 1,000 J / m 2 ~20,000J / m 2 After irradiation with light for imparting alignment ability, the substrate surface may be cleaned using water, an organic solvent (e.g., methanol, isopropanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.) or a mixture thereof, or the substrate may be heated.

[0155] <Step 3: Construction of liquid crystal cell>

[0156] Prepare two substrates with liquid crystal alignment films formed in the above manner, and arrange liquid crystal between the two substrates arranged opposite to each other, thereby manufacturing a liquid crystal unit. When manufacturing a liquid crystal unit, for example, the following methods can be listed: arrange two substrates opposite to each other with a gap in a manner that the liquid crystal alignment films face each other, use a sealant to bond the peripheral portions of the two substrates, and inject the liquid crystal into the cell gap surrounded by the substrate surface and the sealant and seal the injection hole; use a method of using a liquid crystal drop (one dropfill, ODF) method, etc. As a sealant, for example, an epoxy resin containing a hardener and alumina balls as a spacer can be used. As liquid crystals, nematic liquid crystals and disc-shaped liquid crystals can be listed, among which nematic liquid crystals are preferred.

[0157] In the PSA mode, the following treatment is performed: a liquid crystal and a polymerizable compound (e.g., a multifunctional (meth)acrylate compound, etc.) are filled into a cell gap together, and after constructing a liquid crystal cell, a voltage is applied between conductive films of a pair of substrates, and the liquid crystal cell is irradiated with light. When a liquid crystal element of the PSA mode is manufactured, the polymerizable compound is used in a ratio of 0.01 to 3 parts by mass, preferably 0.1 to 1 part by mass, relative to a total of 100 parts by mass of the liquid crystal.

[0158] When the liquid crystal element is used as a display device, a polarizing plate is then attached to the outer surface of the liquid crystal unit as needed to prepare the liquid crystal element. Examples of the polarizing plate include a polarizing plate formed by sandwiching a polarizing film called "H film" between cellulose acetate protective films, or a polarizing plate composed of the H film itself, wherein the H film is formed by absorbing iodine while stretching and orienting polyvinyl alcohol.

[0159] The liquid crystal element of the present disclosure described in detail above can be effectively applied to various purposes. Specifically, for example, it can be used as various display devices or dimming devices, phase difference films, such as clocks, portable game consoles, word processors, notebook personal computers, car navigation systems, camcorders, personal digital assistants (PDAs), digital cameras, mobile phones, smart phones, various monitors, liquid crystal televisions, information displays, etc.

[0160] [Example]

[0161] Hereinafter, the embodiment will be described in more detail based on examples, but the present invention is not to be construed as being limitative by the following examples.

[0162] In the following examples, the weight average molecular weight Mw and number average molecular weight Mn of the polymer, and the solution viscosity of the polymer solution were measured by the following method. The necessary amounts of the raw material compounds and polymers used in the following examples were ensured by repeating the synthesis on the synthesis scale shown in the following synthesis examples as needed.

[0163] [Weight average molecular weight Mw and number average molecular weight Mn of polymer]

[0164] The weight average molecular weight Mw and the number average molecular weight Mn are polystyrene-equivalent values ​​measured by GPC under the following conditions.

[0165] Column: Made by Tosoh Corporation, TSKgelGRCXLII

[0166] Solvent: Tetrahydrofuran (polyorganosiloxane, binder resin)

[0167] N,N-dimethylformamide solution containing lithium bromide and phosphoric acid (polyamic acid)

[0168] Temperature: 40℃

[0169] Pressure: 68kgf / cm 2

[0170] [Solution viscosity of polymer solution]

[0171] The solution viscosity (mPa·s) of the polymer solution was measured at 25° C. using an E-type rotational viscometer.

[0172] The code numbers of the compounds are as follows: In addition, below, the compound represented by formula (X) may be simply referred to as "compound (X)".

[0173] [Chemistry 12]

[0174]

[0175] [Chemistry 13]

[0176]

[0177] [Chemistry 14]

[0178]

[0179] <Synthesis of polymer>

[0180] 1. Synthesis of polymer [A]

[0181] [Synthesis example 1]

[0182] Under nitrogen, 13.3 mmol of compound (MX-2) and 120 mmol of methyl methacrylate (MMA) as polymerization monomers, 2.4 mmol of 2,2'-azobis(2,4-dimethylvaleronitrile) as a free radical polymerization initiator, and 80 ml of tetrahydrofuran as a solvent were added to a 200 mL two-necked flask, and polymerization was carried out at 70°C for 5 hours. After reprecipitation in n-hexane, the precipitate was filtered and vacuum dried at room temperature for 8 hours to obtain the target polymer (PA-1). The weight average molecular weight Mw measured by GPC and converted to polystyrene was 45,300, and the molecular weight distribution Mw / Mn was 2.3.

[0183] [Synthesis Example 2 to Synthesis Example 7]

[0184] Except having changed the kind and amount of the monomers used as described in the following Table 1, the same operation as in Synthesis Example 1 was carried out to obtain polymers (PA-2) to (PA-7).

[0185] [Table 1]

[0186]

[0187] The numerical values ​​in Table 1 represent the usage ratio (mol %) of each monomer used in the synthesis of the polymer relative to the total amount of the monomers. In Table 1, the abbreviations of the monomers represent the following compounds.

[0188] MX-1 to MX-4: Compounds represented by the formula (MX-1) to (MX-4) respectively

[0189] MA: Methacrylic acid

[0190] GMA: Glycidyl Methacrylate

[0191] MMA: Methyl Methacrylate

[0192] PMI: N-phenylmaleimide

[0193] St:Styrene

[0194] 2. Synthesis of polyamic acid

[0195] [Synthesis example 8]

[0196] 100 mol parts of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CB) as tetracarboxylic dianhydride, 80 mol parts of 4,4'-diaminodiphenylmethane (the compound represented by the formula (DA-1)) as diamine and 20 mol parts of compound (DA-2) were dissolved in N-methyl-2-pyrrolidone (NMP), and reacted at 60°C for 6 hours to obtain a solution containing 30% by mass of polyamic acid. A small amount of the obtained polyamic acid solution was taken, and NMP was added to prepare a solution with a polyamic acid concentration of 20% by mass. The solution viscosity measured as this solution was 800 mPa·s. Subsequently, the reaction solution was injected into a large amount of excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40°C under reduced pressure for 15 hours to obtain a polymer (PB-1).

[0197] [Synthesis Example 9]

[0198] A polymer (PB-2) was obtained by the same operation as in Synthesis Example 8 except that 100 mol parts of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (tc-1) was used as tetracarboxylic dianhydride and 100 mol parts of 4,4'-diaminodiphenylmethane (da-1) was used as diamine.

[0199] <Preparation and evaluation of liquid crystal alignment agents>

[0200] [Example 1]

[0201] 1. Preparation of Liquid Crystal Alignment Agent

[0202] 2-Heptanol (B1) and diethylene glycol monoethyl ether (C1) were added to 100 parts by weight of the polymer (PA-1) obtained in Synthesis Example 1 to prepare a solution having a solid content concentration of 4.0% by weight and a solvent mixing ratio of B1:C1=20:80 (mass ratio). The solution was fully stirred and filtered using a filter with a pore size of 0.2 μm to prepare a liquid crystal aligning agent (S-1).

[0203] 2. Evaluation of coating properties

[0204] Liquid crystal alignment agent (S-1) was filled in an inkjet device manufactured by Shibaura, and inkjet coating was performed on a glass substrate having contact holes (C / H) and an ITO layer. The contact holes were formed by coating a photosensitive resin on the glass substrate to form a resin layer with a film thickness of 3.5 μm, exposing it through a mask, and then developing it to make the hole diameter 20 μm and the hole distance 200 μm. After the contact holes were formed, sputtering was performed on the contact hole formation surface of the glass substrate to form an ITO layer.

[0205] After the liquid crystal alignment agent (S-1) was applied, it was pre-baked on a heating plate at 80°C for 1 minute. Then, in an oven in which the air in the box was replaced with nitrogen, it was heated at 200°C for 1 hour to form a liquid crystal alignment film with a film thickness of 0.1 μm. 200 of the liquid crystal alignment films were visually counted at a magnification of 50 times using a scanning electron microscope (SEM), wherein the coating property was evaluated by the ratio of the contact holes that could be normally coated without depression in the contact hole portion to the whole (coating rate α[%]).

[0206] α[%] = [(number of contact holes that can be normally coated) / 200] × 100

[0207] Regarding the evaluation criteria, a coating rate α of 50% or more was considered good, and a coating rate of less than 50% was considered bad. As a result, in this example, α=72%, and the coating property was good.

[0208] 3. Manufacturing of vertical light-type liquid crystal display elements

[0209] The liquid crystal alignment agent (S-1) prepared in 1. was applied on the transparent electrode surface of the glass substrate with a transparent electrode including an ITO film using a spinner, and pre-baked on a hot plate at 80° C. for 1 minute. Then, it was heated at 200° C. for 1 hour in an oven purged with nitrogen to form a coating film with a thickness of 0.1 μm.

[0210] Then, the coating surface was irradiated with 20 J / m2 using a Hg-Xe lamp and a Glan-Taylor prism from a direction inclined at 40° from the substrate normal. 2 Polarized ultraviolet rays containing a bright line of 313 nm are used to impart liquid crystal alignment capability. The same operation is repeated to prepare a pair (two sheets) of substrates having an ITO film and a liquid crystal alignment film.

[0211] On the periphery of the surface with a liquid crystal alignment film of one of the substrates, an epoxy resin adhesive with alumina balls of 3.5 μm in diameter is applied by screen printing, and then the liquid crystal alignment film surfaces of a pair of substrates are made to face each other, and the optical axes of ultraviolet rays of each substrate are pressed in a manner that is antiparallel to the projection direction of the substrate surface, and the adhesive is thermally cured at 150°C for 1 hour. Then, after negative liquid crystal (Merck, MLC-6608) is filled in the gap between the substrates 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 to manufacture a liquid crystal display element.

[0212] 4. Evaluation of electrical properties

[0213] The liquid crystal display element manufactured in 3. above is placed in a constant temperature chamber, and a voltage holding ratio (VHR) measuring device "VHR-1" manufactured by ToyoTechnica is used to apply a voltage of 1V at 60°C with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage holding ratio (VHR) is measured 1,000 milliseconds after the application is released. Regarding the evaluation criteria, the case where the VHR is 80% or more is considered good, and the case where it is less than 80% is considered bad. As a result, in this embodiment, VHR = 81%, and the electrical characteristics are good.

[0214] [Example 2 to Example 12 and Comparative Example 1 to Comparative Example 5]

[0215] The liquid crystal alignment agent was prepared in the same manner as in Example 1 except that the composition of the liquid crystal alignment agent was changed as shown in Table 2 below. In addition, a photo-vertical liquid crystal display element was manufactured in the same manner as in Example 1 using the obtained liquid crystal alignment agent, and the coating properties and electrical properties were evaluated. The results are shown in Table 2 below.

[0216] [Example 13]

[0217] 1. Preparation of Liquid Crystal Alignment Agent

[0218] Except having changed the preparation prescription as described in the following Table 2, it carried out similarly to Example 1, and prepared a liquid crystal aligning agent (S-13).

[0219] 2. Preparation of Liquid Crystal Composition

[0220] To 10 g of nematic liquid crystal (MLC-6608, manufactured by Merck), 5% by mass of a liquid crystal compound represented by the following formula (L1-1) and 0.3% by mass of a photopolymerizable compound represented by the following formula (L2-1) were added and mixed to obtain a liquid crystal composition LC1.

[0221] [Chemistry 15]

[0222]

[0223] 3. Manufacturing of PSA type liquid crystal display elements

[0224] On the transparent electrode surface of the glass substrate with a transparent electrode including an ITO film, the liquid crystal orientation agent (S-13) prepared in 1. above is applied using a spinner, and after pre-baking on a heating plate at 80°C for 1 minute, the solvent is removed by heating at 200°C for 1 hour in an oven replaced with nitrogen, thereby forming a coating film (liquid crystal orientation film) with a film thickness of 0.08 μm. For this coating film, a friction machine having a roller wound with a rayon cloth is used, and a roller speed of 400 rpm, a platform moving speed of 3 cm / second, and a hair pressing length of 0.1 mm is used for friction treatment. Then, ultrasonic cleaning is performed in ultrapure water for 1 minute, and then dried in a clean oven at 100°C for 10 minutes, thereby obtaining a substrate with a liquid crystal orientation film. Repeat the above operation to obtain a pair (two pieces) of substrates with a liquid crystal orientation film. In addition, the friction treatment is a weak friction treatment performed for the purpose of controlling the collapse of the liquid crystal and performing orientation segmentation using a simple method.

[0225] An epoxy resin adhesive containing alumina balls with a diameter of 3.5 μm was applied to the periphery of the surface of one of the substrates having a liquid crystal alignment film by screen printing, and then the liquid crystal alignment film surfaces of a pair of substrates were made to face each other, overlapped and pressed, and heated at 150° C. for 1 hour to thermally cure the adhesive. Subsequently, after the liquid crystal composition LC1 was filled in the gap between the substrates from the liquid crystal injection port, the liquid crystal injection port was sealed with an epoxy adhesive, and then, in order to remove the flow orientation during liquid crystal injection, it was heated at 150° C. for 10 minutes and then slowly cooled to room temperature.

[0226] Next, an alternating current of 10 V at a frequency of 60 Hz was applied between the electrodes of the obtained liquid crystal cell, and in a state where the liquid crystal was driven, an ultraviolet irradiation device using a metal halide lamp as a light source was used at a rate of 50,000 J / m 2 The ultraviolet rays were irradiated at an irradiation amount of . The irradiation amount was a value measured using a light meter measuring at a wavelength of 365 nm. Thus, a PSA type liquid crystal display element was manufactured.

[0227] 4. Evaluation

[0228] About the liquid crystal aligning agent (S-13) and the PSA type liquid crystal display element manufactured above, coating property and electrical characteristic were evaluated in the same manner as in Example 1. These results are shown in Table 3 below.

[0229] [Comparative Example 6]

[0230] The liquid crystal alignment agent was prepared in the same manner as in Example 1 except that the composition of the liquid crystal alignment agent was changed as shown in Table 2 below. In addition, a PSA type liquid crystal display element was manufactured in the same manner as in Example 13 using the obtained liquid crystal alignment agent, and the coating properties and electrical properties were evaluated. The results are shown in Table 2 below.

[0231] [Example 14]

[0232] 1. Preparation of Liquid Crystal Alignment Agent

[0233] Except having changed the preparation prescription as described in the following Table 2, it carried out similarly to Example 1, and prepared a liquid crystal aligning agent (S-14).

[0234] 2. Manufacturing of light-level liquid crystal display elements

[0235] The liquid crystal alignment agent (S-14) prepared in 1. was applied to the transparent electrode surface of the glass substrate with a transparent electrode including an ITO film using a spinner, and pre-baked on a 50°C hot plate for 2 minutes. Then, in an oven purged with nitrogen, the coating was heated at 200°C for 30 minutes to form a film with a thickness of 0.1 μm. Subsequently, the coating surface was irradiated with 50 J / m from a direction inclined 90° from the substrate normal using a Hg-Xe lamp and a Glan-Taylor prism. 2 Polarized ultraviolet rays containing a bright line of 313 nm were irradiated, and after the polarized ultraviolet rays were irradiated, a heating treatment was performed at 150° C. for 10 minutes using a hot plate. This series of operations was repeated to prepare a pair (two sheets) of substrates having a liquid crystal alignment film.

[0236] After applying an epoxy resin adhesive with alumina balls of 3.5 μm in diameter to the periphery of the surface with a liquid crystal alignment film of one of the substrates, 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 horizontal in the projection direction of the substrate surface. The adhesive is thermally cured at 150°C for 1 hour. Then, after filling the gap between the substrates with a positive liquid crystal (Merck, MLC-7028-100) 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 to manufacture a liquid crystal display element.

[0237] 3. Evaluation

[0238] About the liquid crystal aligning agent (S-14) and the light horizontal type liquid crystal display element manufactured above, coating property and electric characteristic were evaluated in the same manner as in Example 1. The results are shown in Table 2 below.

[0239] [Table 2]

[0240]

[0241] In Table 2, two polymers were used as polymer components in Examples 10 to 14 and Comparative Examples 5 and 6. In Examples 10 to 14, A1:A2 was blended at a ratio of 10:90 (parts by mass). In Comparative Example 5, A1:other polymer was blended at a ratio of 90:10 (parts by mass), and in Comparative Example 6, A2:other polymer was blended at a ratio of 90:10 (parts by mass).

[0242] The numerical value of the column of a solvent component shows the mixing|blending ratio (mass parts) of each compound with respect to 100 mass parts of the whole amount of the solvent component used for preparation of a liquid crystal aligning agent.

[0243] In Example 11, 10 parts by mass of the cross-linking agent was blended with respect to 100 parts by mass of the total amount of the polymer components.

[0244] The compound codes are as follows.

[0245] <Solvent>

[0246] B1: 2-Heptanone

[0247] B2: 1-Dodecanol

[0248] B3: 1-Tetradecanol

[0249] C1: Diethylene glycol monoethyl ether

[0250] C2: Dipropylene glycol monomethyl ether

[0251] DIBC: Diisobutylcarbinol

[0252] 2BuOH: 2-Butanol

[0253] NMP: N-methyl-2-pyrrolidone

[0254] BC: Ethylene glycol monobutyl ether

[0255] [Chemistry 16]

[0256]

[0257] <Cross-linking agent>

[0258] D1: N,N,N',N'-Tetrakis(2-hydroxyethyl)hexanediamide

[0259] As is clear from Table 2, the liquid crystal alignment agents of Examples 1 to 14 are not prone to depression in the contact hole portion even when applied to a substrate having a contact hole, showing good coating properties. In addition, in Examples 1 to 14, the voltage retention rate of the liquid crystal display element is also high and the electrical properties are good. In particular, the liquid crystal alignment agents of Examples 7, 8, and 10 to 14 have a coating rate α of more than 80%, and excellent coating properties. In addition, if Example 8 is compared with Example 9, the liquid crystal alignment agent of Example 8 further comprising compound [C] has better coating properties than the liquid crystal alignment agent of Example 9 comprising NMP instead of compound [C].

[0260] In contrast, the coating rate α of the liquid crystal aligning agent of Comparative Examples 1 to 4, which do not contain the compound [B], is as low as about 22% to 45%, and the coating property is insufficient. In addition, the coating rate α of the liquid crystal aligning agent of Comparative Example 5, which contains the compound [B] but has a high content of polyamic acid, is 11%, which is a lower value than that of Comparative Examples 1 to 4. The coating rate α of Comparative Example 6 containing NMP is even lower, which is 7%.

[0261] From the above results, it is clear that the liquid crystal aligning agent containing the polymer [A] as the main component of the polymer component and containing the compound [B] is excellent in coating properties on the substrate.

Claims

1. A liquid crystal alignment agent, comprising: A polymer [A] comprising a structural unit derived from a monomer having a polymerizable carbon-carbon unsaturated bond, wherein the polymer [A] accounts for 95% by mass or more of the total amount of polymer components; and The compound [B] is represented by the following formula (1), and the content ratio of the compound [B] is 3% by mass or more relative to the total amount of the solvent component contained in the liquid crystal aligning agent. R 1 -OH…(1) In formula (1), R 1 It is a linear alkyl group having 5 to 20 carbon atoms.

2. The liquid crystal alignment agent according to claim 1, wherein The polymer [A] includes a polymer having at least one specific structure selected from the group consisting of a photo-alignment group, a liquid crystal alignment group, and a liquid crystal side chain.

3. The liquid crystal alignment agent according to claim 2, wherein: The polymer [A] includes a polymer having the specific structure and a polymer not having the specific structure.

4. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein The polymer [A] includes a polymer having a crosslinkable group.

5. The liquid crystal alignment agent according to any one of claims 1 to 3, wherein The polymer [A] contains at least one ring structure of an oxetane ring and an oxirane ring, and a functional group that reacts with at least one of the oxetane ring and the oxirane ring by heating in the same polymer or in different polymers.

6. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein The content ratio of the compound [B] is 3 mass % to 95 mass % with respect to the total amount of the solvent components contained in the liquid crystal aligning agent.

7. The liquid crystal aligning agent according to any one of claims 1 to 3, further comprising a compound [C], wherein the compound [C] is at least one selected from the group consisting of a compound represented by the following formula (2), a compound represented by the following formula (3), a compound represented by the following formula (4), and a cyclic ketone having 4 to 7 carbon atoms, R 2 -(O-R 3 )n-O-R 4 …(2) In formula (2), R 2 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R 3 is an alkanediyl group having 2 to 4 carbon atoms; R 4 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; n is an integer of 0 to 3; when n is 2 or 3, the multiple R 3 are the same groups or different groups; when n is 0, R 2 is an alkyl group with 3 to 5 carbon atoms, R 4 is a hydrogen atom, In formula (3), R 5 X is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or an alkoxyalkyl group having 2 or 3 carbon atoms; 1 is a single bond or an oxygen atom; R 6 is an alkanediyl group having 1 to 3 carbon atoms; R 7 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; m is 0 or 1; In formula (4), R 8 and R 9 Each of X is independently an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or an alkoxyalkyl group having 2 or 3 carbon atoms; 2 It is a single bond or an alkanediyl group having 1 or 2 carbon atoms.

8. The liquid crystal alignment agent according to claim 7, wherein: The content ratio of the compound [C] is 5 mass % to 95 mass % with respect to the total amount of the solvent component contained in the liquid crystal aligning agent. 9 . The liquid crystal aligning agent according to claim 1 , further comprising a cross-linking agent. 10 . A liquid crystal alignment film formed using the liquid crystal alignment agent according to claim 1 . A liquid crystal element comprising the liquid crystal alignment film according to claim 10 .

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