JP2021103205A - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal element - Google Patents

Abstract

To provide a liquid crystal alignment agent capable of obtaining a liquid crystal element excellent in coating properties and electrical properties.SOLUTION: A liquid crystal alignment agent comprises: a polymer [P] having at least one kind selected from a group consisting of an amide group, a protected amide group, an urea group and a protected urea group; an annular carbonate compound; and di-alkylene glycol monoalkyl ether.SELECTED DRAWING: None

Description

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal element.

In recent years, liquid crystal elements are used not only in display devices such as personal computers, liquid crystal televisions, car navigation systems, mobile phones, smartphones, and information displays, but also in various applications such as optical compensation films and dimming films. Has been done. Along with such versatility, further improvement in quality of liquid crystal elements is required, and along with improvements in drive systems and element structures, improvements in liquid crystal alignment films, which are one of the constituent members of liquid crystal elements, are being promoted. ing.

For the purpose of further improving the performance of the liquid crystal element, it has been proposed to use a polyimide having a nitrogen-containing structure such as an amide group (-NH-CO-) as an alignment film material (see, for example, Patent Document 1). In Patent Document 1, a tetracarboxylic dianhydride containing 1,2,3,4-cyclobutanetetracarboxylic dianhydride is reacted with a diamine compound containing a diamine having an amide group (-NH-CO-). It is disclosed that the polyamic acid thus obtained is contained in the liquid crystal aligning agent.

JP-A-2009-294274

The amide group has a high polarity, and the solubility of the liquid crystal aligning agent in the solvent component is not so good. Therefore, a liquid crystal alignment agent containing a polymer having a nitrogen-containing structure such as an amide group is inferior in coatability to a substrate, and the thickness of the alignment film formed by using the liquid crystal alignment agent may not be uniform. ..

The liquid crystal alignment film is generally formed by applying a liquid crystal alignment agent containing a polymer component and a solvent on a substrate on which a color filter or a transparent conductive film is laminated, and removing the solvent from the coating film. At this time, the solvent component in the liquid crystal alignment agent permeates into the lower layer, so that the low molecular weight component contained in the lower layer (for example, the colored cured film) is eluted and may be mixed in the liquid crystal alignment film or the liquid crystal layer. In this case, there is a concern that the eluate from the lower layer may cause deterioration of the electrical characteristics of the liquid crystal element.

The present invention has been made in view of the above problems, and one object of the present invention is to provide a liquid crystal aligning agent capable of obtaining a liquid crystal element having excellent coatability and good electrical characteristics.

The present invention employs the following means to solve the above problems.

<1> A polymer [P] having at least one selected from the group consisting of an amide group, a protected amide group, a urea group and a protected urea group, a cyclic carbonate compound, and a dialkylene glycol monoalkyl ether. And, a liquid crystal alignment agent containing.
<2> The liquid crystal alignment agent of <1> above, which further contains a dialkylene glycol dialkyl ether.
<3> A liquid crystal alignment film formed by using the liquid crystal alignment agent of <1> or <2> above.
<4> A liquid crystal element provided with the liquid crystal alignment film of <3> above.

The liquid crystal alignment agent of the present invention can obtain a liquid crystal element having excellent coatability and good electrical characteristics.

Hereinafter, each component contained in the liquid crystal alignment agent of the present disclosure, and other components optionally blended will be described. The liquid crystal aligning agent is a liquid polymer composition containing a polymer component and a solvent component, preferably in which the polymer component is dissolved in the solvent component.

In addition, in this specification, a "hydrocarbon group" means a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. The "chain hydrocarbon group" means a linear hydrocarbon group and a branched hydrocarbon group which do not contain a cyclic structure in the main chain and are composed only of a chain structure. However, it may be saturated or unsaturated. The "alicyclic hydrocarbon group" means a hydrocarbon group containing only the alicyclic hydrocarbon structure as the ring structure and not containing the aromatic ring structure. However, it does not have to be composed only of the alicyclic hydrocarbon structure, and some of them have a chain structure. The "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it does not have to be composed of only an aromatic ring structure, and a chain structure or an alicyclic hydrocarbon structure may be included in a part thereof.

（式（１）中、Ｒ^１及びＲ^２は、それぞれ独立に水素原子又は１価の有機基である。ｍは０又は１である。「＊」は、炭化水素基に結合する結合手であることを表す。） ≪Polymer component≫
<Polymer [P]>
The liquid crystal alignment agent of the present disclosure has a weight having at least one partial structure (hereinafter, also referred to as "specific structure") selected from the group consisting of an amide group, a protected amide group, a urea group and a protected urea group. Contains coalescence [P]. The specific structure of the polymer [P] is represented by, for example, the following formula (1).

(In the formula (1), R ¹ and R ² are independently hydrogen atoms or monovalent organic groups. M is 0 or 1. “*” Is a bond that binds to a hydrocarbon group. Indicates that there is.)

In the above formula (1), ^{as the monovalent organic group of R 1} and R ^2, a monovalent hydrocarbon group having 1 to 20 carbon atoms or a protecting group is preferable. Examples of the monovalent hydrocarbon group include a monovalent chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group, among which an alkyl group having 1 to 3 carbon atoms, a cyclohexyl group or a cyclohexyl group is used. A phenyl group is preferred. Here, the protecting group is a functional group that makes the group represented by the above formula (1) an inactive group. A "protected amide group" is a group that produces a group "* ^1- CO-NH- * ¹ " (where * ¹ represents a bond with a hydrocarbon group) by elimination of the protecting group. is there. In addition, the "protected urea group" ^{generates a group "* 2-} NH-CO-NH- * ² " (where * ² represents a bond with a hydrocarbon group) by desorbing the protecting group. Is the basis for

The protecting group in the above formula (1) is preferably a monovalent protecting group desorbed by heat or light, for example, a carbamate-based protecting group, an amide-based protecting group, an imide-based protecting group, a sulfonamide-based protecting group, or the like. Can be mentioned. Of these, carbamate-based protecting groups are preferable because they are highly desorbable by heat, and specific examples thereof include tert-butoxycarbonyl group, benzyloxycarbonyl group, and 1,1-dimethyl-2-haloethyloxycarbonyl. Examples include a group, an allyloxycarbonyl group, a 2- (trimethylsilyl) ethoxycarbonyl group and the like. Of these, the tert-butoxycarbonyl group is particularly preferable because it is excellent in desorption by heat and the residual amount in the film of the deprotected portion can be reduced.
R ¹ and R ² are preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or a protecting group, and particularly preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or a tert-butoxycarbonyl group.

Examples of the polymer [P] include polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyenamine, polyester, polyamide, polyamideimide, polybenzoxazole precursor, polybenzoxazole, cellulose derivative, polyacetal, and polymerizable unsaturated bond. Examples thereof include a polymer having a polymer having a structural unit derived from the contained monomer (hereinafter, also referred to as “polymer Q”) as a main skeleton. The polymer [P] is a polyamic acid, a polyamic acid ester, a polyimide, a polyorganosiloxane, a polyamide, and a polymer in that a liquid crystal alignment film having high affinity with a liquid crystal, high mechanical strength, and high reliability can be formed. It is preferable to contain at least one selected from the group consisting of Q, and it is particularly preferable to contain at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide.

The polymer [P] may have a specific structure in either the main chain or the side chain. From the viewpoint of improving the electrical characteristics of the liquid crystal element, the polymer [P] preferably has a specific structure in the main chain. In addition, "having a specific structure in the main chain" means a case where only the main chain has a specific structure and a case where the main chain and the side chain have a specific structure. Here, the "main chain" refers to the part of the "stem" composed of the longest chain of atoms in the polymer. It is permissible for this "trunk" portion to include a ring structure. Therefore, "having a specific structure in the main chain" means that the specific structure constitutes a part of the main chain. The "side chain" refers to a portion of the polymer branched from the "stem".

Examples of the method for obtaining a polymer having a specific structure include a method of polymerizing using a monomer having a specific structure. In this case, in the polymer [P], the content of the structural unit derived from the monomer having a specific structure is 5 mol% or more with respect to the total amount of the monomer units contained in the polymer [P]. It is preferably 10 mol% or more, more preferably 15 mol% or more, and particularly preferably 20 mol% or more. The content of the structural unit derived from the monomer having a specific structure is preferably 90 mol% or less, preferably 80 mol% or less, based on the total amount of the monomer unit contained in the polymer [P]. Is more preferable, and 70 mol% or less is further preferable.

・ Specific group A
The polymer [P] is at least one group selected from the group consisting of a group having a polymerizable carbon-carbon unsaturated bond, a photoinitiator group and a photooriented group (hereinafter, also referred to as “specific group A”). It is preferable to have more. Having such a specific group A is preferable in that a more stable liquid crystal alignment film can be formed and a liquid crystal alignment film capable of obtaining a liquid crystal element exhibiting excellent electrical characteristics can be formed.

Among the specific groups A, the group having a polymerizable carbon-carbon unsaturated bond is preferably a functional group that can be polymerized by heat or light. Specific examples of the group having a polymerizable carbon-carbon unsaturated bond include (meth) acryloyl group, vinyl group, allyl group, vinylphenyl group, maleimide group, vinyloxy group, ethynyl group and the like. Of these, a (meth) acryloyl group, a vinyl group, an allyl group, an ethynyl group or a vinylphenyl group is preferable, and a (meth) acryloyl group is more preferable, because the reactivity with heat is high.

In the polymer [P], the content of the group having a polymerizable carbon-carbon unsaturated bond is preferably 1 mol% or more, preferably 5 mol%, based on the total amount of the monomer units of the polymer [P]. The above is more preferable, and 10 mol or more is further preferable. The content of the group having a polymerizable carbon-carbon unsaturated bond is preferably 60 mol% or less, more preferably 50 mol% or less, based on the total amount of the monomer units of the polymer [P].

The photoinitiator group is a site in which polymerization initiation ability is generated by light or a site having a photosensitizing action, and is a group having a structure in which one or a plurality of hydrogen atoms are removed from the photoinitiator. Here, the photoinitiator is a compound capable of initiating the polymerization of a polymerizable component by irradiation with radiation such as visible light, ultraviolet rays, far ultraviolet rays, electron beams, and X-rays. The photoinitiator group contained in the polymer [P] is preferably a group having a structure in which a hydrogen atom is removed from a radical polymerization initiator capable of generating radicals by light irradiation, and specifically, an acetophenone structure, an oxime ester structure, and the like. A group having a dibenzoyl structure, a benzoin structure, a benzophenone structure, an alkylphenone structure or an acylphosphine oxide structure is preferable. Among these, the photoinitiator group is preferably a group having an alkylphenone structure or an acetophenone structure.

Further specific examples of the photoinitiator group include, for example, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-. Phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one, phenyl2- (meth) acryloyloxy-2-one Propyl Ketone, 4-Isopropylphenyl 2- (Meta) Acryloyloxy-2-Propyl Ketone, 4- (2- (Meta) Acryloyloxyethoxy) -Benzoine, 4- (Meta) Acryloyloxyphenyl 2- (Meta) Acryloyloxy Examples thereof include a group having a structure in which a hydrogen atom is removed from -2-propyl ketone, 4- (meth) acryloyloxybenzophenone and the like.

In the polymer [P], the content of the photoinitiator group is preferably 1 mol% or more, more preferably 3 mol% or more, and 5 mol, based on the total amount of the monomer units contained in the polymer [P]. The above is more preferable. The content of the photoinitiator group is preferably 50 mol% or less, more preferably 40 mol% or less, based on the total amount of the monomer units of the polymer [P].

（式（６）中、Ｒ^２１及びＲ^２２は、それぞれ独立して水素原子、フッ素原子、シアノ基、炭素数１〜３のアルキル基、又は炭素数１〜３のフルオロアルキル基であり、Ｒ^２３は、炭素数１〜１０のアルキル基、アルコキシ基、フルオロアルキル基若しくはフルオロアルコキシ基、フッ素原子又はシアノ基である。ｋは０〜４の整数である。ｋが２以上の場合、複数のＲ^２３は同一の基又は異なる基である。「＊」は結合手であることを表す。） The photo-oriented group is a functional group that imparts anisotropy to the film by a photoisomerization reaction, a photodimerization reaction, a photodecomposition reaction, or a photofries rearrangement reaction by light irradiation. Specific examples of the photoorientating group include an azobenzene-containing group containing azobenzene or a derivative thereof as a basic skeleton, a lauric acid structure-containing group containing katsura acid or a derivative thereof as a basic skeleton, and a chalcone containing chalcone or a derivative thereof as a basic skeleton. Examples thereof include a containing group, 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, and a cyclobutane-containing structure containing cyclobutane or a derivative thereof as a basic skeleton. Among these, a cinnamic acid structure-containing group is preferable in terms of high sensitivity to light, and examples thereof include a group having a partial structure represented by the following formula (6).

In formula (6), R ²¹ and R ²² are independently hydrogen atoms, fluorine atoms, cyano groups, alkyl groups having 1 to 3 carbon atoms, or fluoroalkyl groups having 1 to 3 carbon atoms, respectively, and R ^{Reference numeral 23} denotes an alkyl group having 1 to 10 carbon atoms, an alkoxy group, a fluoroalkyl group or a fluoroalkoxy group, a fluorine atom or a cyano group. K is an integer of 0 to 4. When k is 2 or more, a plurality of R ²³ is the same group or a different group. “*” Indicates that it is a bonder.)

In the structure represented by the above formula (6), R ²¹ and R ²² are both hydrogen atoms or one is a hydrogen atom and the other (preferably R) in that the photoreactivity can be made higher. ²² ) is preferably an alkyl group having 1 to 3 carbon atoms. R ²³ is preferably a fluorine atom, a cyano group or an alkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom, a cyano group or an alkyl group having 1 to 3 carbon atoms. k is preferably 0 to 2, more preferably 0 or 1.

One of the two bonding hands "*" in the above formula (6) is an alkyl group or an alkoxy group having 3 to 20 carbon atoms, in that the pretilt angle of the obtained liquid crystal element can be controlled more preferably. It is preferably bonded to a fluoroalkyl group, a fluoroalkoxy group, a cyano group-containing alkyl group, a cyano group-containing alkoxy group, or a group having at least one of a benzene ring and a cyclohexane ring.

In the polymer [P], the content of the photooriented group is preferably 1 mol% or more, more preferably 5 mol% or more, and 10 mol, based on the total amount of the monomer units of the polymer [P]. The above is more preferable. The content of the photo-oriented group is preferably 60 mol% or less, more preferably 50 mol% or less, based on the total amount of the monomer units of the polymer [P].

・ Specific group B
The polymer [P] further has at least one group (hereinafter also referred to as “specific group B”) selected from the group consisting of a tertiary amine structure, a protected amino group and a nitrogen-containing aromatic heterocyclic group. Is preferable. Having such a specific group B is preferable in that a liquid crystal element exhibiting more excellent electrical characteristics can be obtained.

（式（７）中、Ｒ^５１は２価の炭化水素基である。Ｒ^５２及びＲ^５３は、Ｒ^５２が２価の炭化水素基であってＲ^５３が１価の炭化水素基であるか、又はＲ^５２とＲ^５３とが互いに合わせられてＲ^５１及びＲ^５２が結合する窒素原子と共に構成される環構造を表す。「＊」は結合手であることを示す。） Of the specific group B, the tertiary amine structure is preferably a partial structure represented by the following formula (7).

(In the formula (7), R ⁵¹ is a divalent hydrocarbon group. In R ⁵² and R ^53, is R ^{52 a} divalent hydrocarbon group and R ^{53 a} monovalent hydrocarbon group? , Or a ^{ring structure in which R 52} and R ⁵³ are combined with each other ^{and composed of a nitrogen atom to which R 51} and R ⁵² are bonded. “*” Indicates a bond.)

In the above formula (7), ^{examples of the divalent hydrocarbon group of R 51} and R ⁵² include an alkanediyl group, a cyclohexylene group, and a phenylene group. Examples of the monovalent hydrocarbon group of R ⁵³ include an alkyl group, a cyclohexyl group, a phenyl group and the like. R ⁵² and R ⁵³ and are are combined with each other as the ring structure formed together with the nitrogen atom to which R ⁵² and R ⁵³ are attached, piperidine structure, piperazine structures, pyrrolidine structure, hexamethyleneimine structures, and the like.

In the protected amino group, the amino group is protected by a protecting group, and the protecting group is preferably removed by heat to form a primary amino group or a secondary amino group. The primary amino group or the secondary amino group generated by the elimination of the protecting group is bonded to the hydrocarbon group. The protecting group is preferably a group that is desorbed by heat, and examples thereof include a carbamate-based protecting group, an amide-based protecting group, an imide-based protecting group, and a sulfonamide-based protecting group. Of these, the tert-butoxycarbonyl group is preferable because it has high heat-removability and the residual amount in the film of the deprotected portion can be reduced.

The nitrogen-containing aromatic heterocyclic group is an n-valent group obtained by removing n hydrogen atoms from the ring portion of the nitrogen-containing aromatic heterocycle. The nitrogen-containing aromatic heterocycle may be an aromatic ring containing one or more nitrogen atoms in the ring skeleton. Further, the hetero atom may contain only a nitrogen atom, or may contain a nitrogen atom and a hetero atom other than the nitrogen atom (oxygen atom, sulfur atom, etc.).

Specific examples of the heterocycle constituting the nitrogen-containing aromatic heterocyclic group include, for example, a pyrrole ring, an imidazole ring, a pyrazole ring, a triazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, an indol ring, a benzimidazole ring, and the like. Purine ring, quinoline ring, isoquinoline ring, naphthylidine ring, quinoxaline ring, phthalazine ring, triazine ring, azepine ring, diazepine ring, aclydin ring, phenazine ring, phenanthrolin ring, oxazole ring, thiazole ring, carbazole ring, thiazazole ring, benzothiazole Examples thereof include a ring, a phenothiazine ring, and an oxadiazole ring. In the nitrogen-containing aromatic heterocyclic group, a substituent may be introduced into the ring portion. Examples of the substituent include a halogen atom, an alkyl group, an alkoxy group and the like. Among these, the nitrogen-containing aromatic heterocyclic group is preferably a group obtained by removing a hydrogen atom from the pyrrole ring, the imidazole ring, the pyrazole ring, the triazole ring, the pyridine ring, the pyrimidine ring, the pyridazine ring, or the ring portion of the pyrazine ring.

In the polymer [P], the content of the characteristic group B is preferably 1 mol% or more, more preferably 5 mol% or more, and 10 mol or more, based on the total amount of the monomer units of the polymer [P]. Is even more preferable. The content of the photo-oriented group is preferably 60 mol% or less, more preferably 50 mol% or less, based on the total amount of the monomer units of the polymer [P]. The characteristic group B contained in the polymer [P] may be only one type or two or more types.

Next, a preferable example of the polymer [P] will be described in detail.
<Polyamic acid>
When the polymer [P] is a polyamic acid, the polyamic acid (hereinafter, also referred to as “polyamic acid [P]”) can be obtained by reacting a tetracarboxylic dianhydride with a diamine compound. As a method for obtaining a polymer having a specific structure, (1) a method of polymerizing using a tetracarboxylic acid anhydride having a specific structure, and (2) a diamine having a specific structure (hereinafter, also referred to as "specific diamine") are used. And the like. Of these, the method (2) is preferable in that the degree of freedom in selecting the monomer is high.

(Tetracarboxylic dianhydride)
Examples of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid [P] include an aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, and an aromatic tetracarboxylic dianhydride. be able to. Specific examples of these include 1,2,3,4-butanetetracarboxylic dianhydride as the aliphatic tetracarboxylic dianhydride;
As the alicyclic tetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2-2,3,4-cyclobutanetetracarboxylic dianhydride, 2 , 3,5-tricarboxycyclopentyl acetate dianhydride, 5- (2,5-dioxotetrakidian-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1, 3-dione, 5- (2,5-dioxotetrakidian-3-yl) -8-methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 2 , 4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, etc .; As aromatic tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4'-(hexafluoroisopropydian) diphthalic acid anhydride, ethylene glycol bisanehydrotrimate, 4,4'-(hexafluoroisopropi) Liden) Diphthalic acid dianhydride, 4,4'-carbonyldiphthalic acid dianhydride and the like can be mentioned, respectively; and the tetracarboxylic dianhydride described in JP-A-2010-97188 can be used. As the tetracarboxylic dianhydride, one type can be used alone or two or more types can be used in combination.

As the tetracarboxylic dianhydride used for the synthesis of polyamic acid [P], an aliphatic tetracarboxylic dianhydride and a fat can be obtained in that a polymer [P] having higher solubility in a solvent can be obtained. It is preferable to contain at least one compound selected from the group consisting of cyclic tetracarboxylic dianhydride, more preferably to contain alicyclic tetracarboxylic dianhydride, and more than cyclobutane ring, cyclopentane ring and cyclohexane ring. It is more preferable to contain an alicyclic tetracarboxylic dianhydride having at least one ring structure selected from the above group. The ratio of aliphatic tetracarboxylic dianhydride and alicyclic tetracarboxylic dianhydride used (total amount when two or more types are included) is the tetracarboxylic dianhydride used for the synthesis of polyamic acid [P]. It is preferably 20 mol% or more, more preferably 40 mol% or more, and further preferably 50 mol% or more, based on the total amount of the above.

（式（５Ａ）中、Ｒ^１０、Ｒ^１１及びＲ^１２は、それぞれ独立して、単結合、炭素数１〜２０の２価の炭化水素基、又は炭素−炭素結合間に−Ｏ−を有する炭素数２〜２０の２価の基である。ｊは１〜３の整数である。ただし、ｊ＝２又は３の場合、Ｒ^１１は単結合にはならない。Ｒ^１３及びＲ^１４は、それぞれ独立して炭素数１〜５の１価の有機基である。ｐ１及びｐ２は、それぞれ独立して０〜２の整数である。Ｒ^１、Ｒ^２及びｍは、上記式（１）と同義である。）

（式（５Ｂ）中、Ｌ^３は単結合又は２価の連結基であり、Ｒ^１７は炭素数１〜４０の１価の有機基である。ｍ１及びｍ２は、それぞれ独立して０又は１である。ただし、ｍ１及びｍ２は同時に０にならない。Ｒ^１及びＲ^２は、上記式（１）と同義である。） (Diamine compound)
-Specific diamine Examples of the diamine compound used for the synthesis of polyamic acid include aliphatic diamines, alicyclic diamines, aromatic diamines, and diaminoorganosiloxane. The specific diamine is preferably an aromatic diamine, and specific examples thereof include a compound represented by the following formula (5A) and a compound represented by the following formula (5B).

(In formula (5A), R ¹⁰ , R ¹¹ and R ¹² each independently have a single bond, a divalent hydrocarbon group having 1 to 20 carbon atoms, or -O- between carbon-carbon bonds. It is a divalent group with 2 to 20 carbon atoms. J is an integer of 1 to 3. However, when j = 2 or 3, R ¹¹ is not a single bond. R ¹³ and R ¹⁴ are respectively. .p1 and p2 is a monovalent organic group of 1 to 5 carbon atoms independently may ^.R 1, ^{R 2} and m are each independently an integer of 0 to 2, the same as defined for the formula (1) Is.)

(In formula (5B), L ³ is a single bond or a divalent linking group, R ¹⁷ is a monovalent organic group having 1 to 40 carbon atoms, and m1 and m2 are independently 0 or 1 respectively. it. However, .R ¹ and ^{R 2} m1 and m2 not 0 at the same time is as defined in the above formula (1).)

In the above formula (5A), the ^{divalent hydrocarbon groups of R 10} , R ¹¹ and R ¹² are divalent chain hydrocarbon groups or alicyclic hydrocarbons from the viewpoint of improving the electrical characteristics of the liquid crystal element. It is preferably a hydrogen group, more preferably a divalent chain hydrocarbon group, and even more preferably an alcandiyl group. If a divalent hydrocarbon group R ^{10, R 11} and ^{R 12} are alkanediyl ^group, the carbon number of R ^{10, R 11} and ^{R 12,} 1 to 10 are preferred, 1-6 is more preferable. R ^{10, R 11} and ^{R 12,} carbon - if a divalent group having 2 to 20 carbon atoms having a -O- between carbon bond, said divalent ^{group, -R} 15 - (O-R ¹⁶ ) It is preferable that r- (where R ¹⁵ and R ¹⁶ are independently alkanediyl groups, and r is an integer of 1 to 3).
R ¹³ and R ¹⁴ are preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group or an ethyl group. P1 and p2 are preferably 0 or 1. j is preferably 1 or 2.

In the above formula (5B), 2 divalent linking group of L ³ is preferably an alkanediyl group of 1 to 5 carbon atoms, more preferably an alkanediyl group having 1 to 3 carbon atoms. Examples of the monovalent organic group of R ¹⁷ include a monovalent hydrocarbon group having 1 to 40 carbon atoms, a group containing a hetero atom between carbon-carbon bonds of the hydrocarbon group, and a group having a heterocyclic group. Be done. Of these, R ¹⁷ is preferably a monovalent group having a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms or a nitrogen-containing aromatic heterocycle.

（式中、「ＴＭＳ」はトリメトキシシリル基を表す。）

As a specific example of the specific diamine, as the compound represented by the above formula (5A), a compound represented by each of the following formulas (5-1) to (5-17); Examples of the represented compound include compounds represented by the following formulas (5-18) to (5-31). In addition, it is specified by using the compound represented by each of the following formulas (5-18) to (5-22), formula (5-28), formula (5-29) and formula (5-31). A polymer [P] having a nitrogen-containing aromatic heterocyclic group as the group B can be obtained.

(In the formula, "TMS" represents a trimethoxysilyl group.)

-Other diamines The diamine compound used for the synthesis of polyamic acid [P] may be only a specific diamine, but together with the specific diamine, a diamine different from the specific diamine (hereinafter, also referred to as "other diamine") is used. You may use it. Examples of other diamines include aliphatic diamines, alicyclic diamines, aromatic diamines, and diaminoorganosiloxane.

（式（Ｅ−１）中、Ｘ^I及びＸ^IIは、それぞれ独立して、単結合、−Ｏ−、＊−ＣＯＯ−又は＊−ＯＣＯ−（ただし、「＊」はＸ^Ｉとの結合手を示す。）であり、Ｒ^Ｉは炭素数１〜３のアルカンジイル基であり、Ｒ^ＩＩは単結合又は炭素数１〜３のアルカンジイル基であり、ａは０又は１であり、ｂは０〜２の整数であり、ｃは１〜２０の整数であり、ｄは０又は１である。但し、ａ及びｂが同時に０になることはない。）
で表される化合物等の側鎖型ジアミン等が挙げられる。上記式（Ｅ−１）で表される化合物としては、例えば下記式（Ｅ−１−１）〜式（Ｅ−１−４）のそれぞれで表される化合物等が挙げられる。

Specific examples of other diamines include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 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] hexanedioic acid, 4,4'-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis (4-) Aminophenyl) Hexafluoropropane, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'-diaminodiphenylamine, 1,5-bis (4-) Aminophenyl) pentane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, 4,4'-(phenylenediisopropyridene) ) Main chain diamines such as bisaniline, 1,3-bis (3-aminopropyl) -tetramethyldisiloxane, m-xylylene diamine, hexamethylenediamine, 4,4'-methylenebis (cyclohexylamine);
Dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy-2,4-diaminobenzene, pentadecanoxy-2,5-diaminobenzene, octadecanoxy-2,5 -Diaminobenzene, cholestanoloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2,4-diaminobenzene, 3, Cholestanyl 5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanostanyl 3,5-diaminobenzoate, 3,6-bis (4-aminobenzoyloxy) cholesterol, 3,6-bis (4-aminophenoxy) Cholestan, 4- (4'-trifluoromethoxybenzoyloxy) cyclohexyl-3,5-diaminobenzoate, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 3,5 -Diaminobenzoic acid = 5ξ-cholestane-3-yl, the following formula (E-1)

(In the formula (E-1), X ^I and X ^II are independently single-bonded, -O-, * -COO- or * -OCO- (where "*" is a bond with ^{X I.} a shown.), ^{R I} is 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, a is 0 or 1, b is It is an integer of 0 to 2, c is an integer of 1 to 20, d is 0 or 1. However, a and b cannot be 0 at the same time.)
Examples thereof include side chain diamines such as compounds represented by. Examples of the compound represented by the above formula (E-1) include compounds represented by the following formulas (E-1-1) to (E-1-4).

（式中、Ｌ^２は２価の連結基である。）

（式中、Ｒ^４０は炭素数１〜２０のアルキル基である。Ｌ^１は２価の連結基である。）

A polyamic acid [P] having a specific group A can be produced by using a diamine having a specific group A as another diamine, and a polyamic acid having a specific group B can be produced by using a diamine having a specific group B. [P] can be produced. Specific examples of the diamine having the specific group A include compounds represented by the following formulas (a-1) to (a-11). Specific examples of the diamine having the specific group B include 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, and N-methyl-3,6-diaminocarbazole. , N-Ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, 3,6-diaminoacridine, the above formulas (5-18) to (5-22), formula (5-28). ), Compounds represented by the formulas (5-29) and (5-31), compounds represented by the following formulas (b-1) to (b-18), and the like.

(In the formula, L ² is a divalent linking group.)

(In the formula, R ⁴⁰ is an alkyl group having 1 to 20 carbon atoms. L ¹ is a divalent linking group.)

In the synthesis of polyamic acid [P], the ratio of the specific diamine used is that the applicability of the liquid crystal alignment agent and the electrical characteristics of the liquid crystal element can be improved in a well-balanced manner. It is preferably 5 mol% or more, more preferably 10 mol% or more, further preferably 15 mol% or more, and particularly preferably 20 mol% or more, based on the total amount of the above. The proportion of the specific diamine used is preferably 90 mol% or less, more preferably 80 mol% or less, and more preferably 70 mol% or less, from the viewpoint of obtaining the effect of improving the performance by the combined use of other diamines. It is more preferable to have. As the specific diamine, one type can be used alone or two or more types can be used in combination.

(Synthesis of polyamic acid)
The polyamic acid [P] can be obtained by reacting the above-mentioned tetracarboxylic dianhydride with a diamine compound, if necessary, with a molecular weight regulator. In the synthesis reaction of polyamic acid [P], the ratio of the tetracarboxylic dianhydride and the diamine compound used was 0. The acid anhydride group of the tetracarboxylic dianhydride was 0. A ratio of 2 to 2 equivalents is preferable. Examples of the molecular weight modifier include acid monoanhydrides such as maleic anhydride, phthalic anhydride, and itaconic anhydride, monoamine compounds such as aniline, cyclohexylamine, and n-butylamine, and monoisocyanate compounds such as phenylisocyanate and naphthylisocyanate. Can be mentioned. The ratio of the molecular weight adjusting agent used is preferably 20 parts by mass or less with respect to 100 parts by mass in total of the tetracarboxylic dianhydride and the diamine compound used.

The synthetic reaction of the polyamic acid [P] is preferably carried out in an organic solvent. The reaction temperature at this time is preferably −20 ° C. to 150 ° C., and the reaction time is preferably 0.1 to 24 hours. Examples of the organic solvent used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons and the like. Specific examples include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol and One or more selected from the group consisting of halogenated phenol may be used as the reaction solvent, or a mixture of one or more of these with another organic solvent (for example, butyl cellosolve, diethylene glycol diethyl ether, etc.) may be used. preferable. The amount of the organic solvent used (a) shall be such that the total amount (b) of the tetracarboxylic dianhydride and the diamine is 0.1 to 50% by mass with respect to the total amount (a + b) of the reaction solution. Is preferable.
As described above, a polymer solution obtained by dissolving the polyamic acid [P] is obtained. This polymer solution may be used as it is for the preparation of the liquid crystal alignment agent, or the polyamic acid [P] contained in the polymer solution may be isolated and then used for the preparation of the liquid crystal alignment agent.

<Polyamic acid ester>
When the polymer [P] is a polyamic acid ester, the polyamic acid ester (hereinafter, also referred to as “polyamic acid ester [P]”) reacts, for example, [I] polyamic acid [P] with an esterifying agent. It can be obtained by a method, a method of reacting a tetracarboxylic acid diester with a diamine compound, a method of reacting a tetracarboxylic acid diester dihalide with a diamine compound, or the like. The polyamic acid ester [P] may have only an amic acid ester structure, or may be a partial esterified product in which an amic acid structure and an amic acid ester structure coexist. In the above [II] and [III], it is preferable to react the tetracarboxylic acid derivative with the diamine compound containing the specific diamine. The reaction solution obtained by dissolving the polyamic acid ester [P] may be used as it is for the preparation of the liquid crystal alignment agent, or the polyamic acid ester [P] contained in the reaction solution is isolated and then the liquid crystal alignment agent is prepared. May be offered to.

<Polyimide>
When the polymer [P] is a polyimide, the polyimide (hereinafter, also referred to as “polyimide [P]”) is obtained by, for example, dehydrating and ring-closing the polyamic acid [P] synthesized as described above to imidize it. Obtainable. The polyimide [P] may be a completely imidized product in which all of the amic acid structure possessed by the precursor polyamic acid [P] is dehydrated and ring-closed, and only a part of the amic acid structure is dehydrated and ring-closed. , It may be a partially imidized product in which an amic acid structure and an imide ring structure coexist. The polyimide [P] preferably has an imidization ratio of 20 to 99%, more preferably 30 to 90%. The imidization ratio is the ratio of the number of imide ring structures to the total of the number of amic acid structures and the number of imide ring structures of polyimide expressed as a percentage. Here, a part of the imide ring may be an isoimide ring.

The dehydration ring closure of the polyamic acid [P] is preferably carried out by dissolving the polyamic acid [P] in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to this solution, and heating as necessary. In this method, as the dehydrating agent, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used. The amount of the dehydrating agent used is preferably 0.01 to 20 mol with respect to 1 mol of the amic acid structure of the polyamic acid [P]. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collagen, lutidine, and triethylamine can be used. The amount of the dehydration ring closure catalyst used is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent used. Examples of the organic solvent used for the dehydration ring closure reaction include organic solvents exemplified as those used for the synthesis of polyamic acid [P]. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C. The reaction time is preferably 1.0 to 120 hours. The reaction solution containing the polyimide [P] may be used as it is for the preparation of the liquid crystal alignment agent, or the polyimide [P] may be isolated and then used for the preparation of the liquid crystal alignment agent.

The solution viscosity of the polymer [P] used for preparing the liquid crystal aligning agent preferably has a solution viscosity of 10 to 800 mPa · s when a solution having a concentration of 10% by mass is used, and is preferably 15 to 500 mPa · s. It is more preferable that the solution has the viscosity of. The solution viscosity (mPa · s) is E for a polymer solution having a concentration of 10% by mass prepared using a good solvent of the polymer [P] (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is a value measured at 25 ° C. using a mold rotational viscometer.

The polystyrene-equivalent weight average molecular weight (Mw) of the polymer [P] measured by gel permeation chromatography (GPC) is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. Is. The molecular weight distribution (Mw / Mn) represented by the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 7 or less, more preferably 5 or less. In preparing the liquid crystal alignment agent, one type of polymer [P] may be used alone, or two or more types may be used in combination.

The liquid crystal alignment agent of the present disclosure may contain a polymer other than the polymer [P] (hereinafter, also referred to as “other polymer”) as a polymer component. The other polymer may be a polymer having no specific structure, and the main skeleton is not particularly limited. Other polymers include, for example, polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyenamine, polyurea, polyamide, polyamideimide, polybenzoxazole precursor, polybenzoxazole, cellulose derivative, polyacetal, polymerizable. Examples thereof include a polymer having a structural unit derived from an unsaturated bond-containing monomer as a main skeleton.

For example, when the polymer [P] is at least one selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, polyorganosiloxane may be blended as another polymer. In this case, the polyorganosiloxane has by introducing a functional functional group such as a photo-oriented group or a pretilt angle-imparting group into the side chain of the polyorganosiloxane and including it in the liquid crystal aligning agent together with the polymer [P]. The functional functional group makes it possible to impart desired properties to the liquid crystal alignment film. When the other polymer is contained in the liquid crystal alignment agent, the content of the other polymer is preferably 30% by mass or less, preferably 20% by mass, based on the total amount of the polymer [P] and the other polymer. The following is more preferable. As for other polymers, one type may be used alone, or two or more types may be used in combination.

≪Solvent component≫
The liquid crystal alignment agent of the present disclosure contains a cyclic carbonate compound and a dialkylene glycol monoalkyl ether. By using a cyclic carbonate compound and a dialkylene glycol monoalkyl ether in combination as a solvent component of the liquid crystal alignment agent containing the polymer [P], a liquid crystal alignment agent showing good coatability can be obtained. Further, it is possible to obtain a liquid crystal element having a sufficiently high voltage holding ratio.

（式（２）中、Ｒ^３〜Ｒ^６は、それぞれ独立に水素原子又は炭素数１〜５の１価の炭化水素基である。ｎは１〜５の整数である。ｎが２以上の場合、式中の複数のＲ^５及び複数のＲ^６は、それぞれ独立して上記定義を有する。） <Cyclic carbonate compound>
The cyclic carbonate compound may be any compound having a carbonate structure (-O-CO-O-) in the ring skeleton, and the number of ring members, the presence or absence of a substituent, and the like are not particularly limited. As the cyclic carbonate compound, a compound represented by the following formula (2) can be preferably used.

(In the formula (2), R ^{3 to} R ⁶ are independently hydrogen atoms or monovalent hydrocarbon groups having 1 to 5 carbon atoms. N is an integer of 1 to 5. n is 2 or more. when a plurality of R ⁵ and a plurality of R ⁶ in the formula are each independently have the above definitions.)

In the above formula (2), the ^{monovalent hydrocarbon group having 1 to 5 carbon atoms of R 3 to} R ⁶ is a monovalent linear or branched chain hydrocarbon group having 1 to 5 carbon atoms. Is preferable. Specific examples thereof include alkyl groups having 1 to 5 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group and n-pentyl group; vinyl group. , An alkenyl group having 2 to 5 carbon atoms such as an allyl group; an alkynyl group having 2 to 5 carbon atoms such as an ethynyl group and a propa-2-in-1-yl group can be mentioned.
R ^{3 to} R ⁶ are preferably a hydrogen atom or a chain hydrocarbon group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a chain hydrocarbon group having 1 or 2 carbon atoms, and further preferably hydrogen. It is an atom, a methyl group, an ethyl group or a vinyl group.
n is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2.
In the compound represented by the above formula (2), the number of substituents on the ring portion (that is, the number of groups of R ^{3 to} R ⁶ which are monovalent hydrocarbon groups having 1 to 5 carbon atoms) is 0. ~ 3 is preferable, and 0 to 2 is more preferable.

Specific examples of the cyclic carbonate compound include ethylene carbonate, propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, vinylethylene carbonate, 4-propyl-1,3-dioxolane-2-one, 1,3. -Dioxane-2-one, 4-methyl-1,3-dioxane-2-one, 4-ethyl-1,3-dioxane-2-one, 4,6-dimethyl-1,3-dioxane-2-one And so on. As the cyclic carbonate compound, one type may be used alone, or two or more types may be used in combination. The cyclic carbonate compound is selected from the group consisting of ethylene carbonate, propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, vinylethylene carbonate and 1,3-dioxane-2-one. At least one is preferable.

In the liquid crystal alignment agent, the content ratio of the cyclic carbonate compound is 0, with respect to the total amount of the solvent contained in the liquid crystal alignment agent, from the viewpoint of improving the coatability of the liquid crystal alignment agent and the electrical characteristics of the liquid crystal element in a well-balanced manner. It is preferably 5% by mass or more. The content ratio of the cyclic carbonate compound is more preferably 2% by mass or more, further preferably 3% by mass or more, and particularly preferably 5% by mass or more. From the above viewpoint, the content ratio of the cyclic carbonate compound is preferably 50% by mass or less, more preferably 40% by mass or less, further preferably 30% by mass or less, and particularly preferably 20% by mass or less.

（式（３）中、Ｒ^７は、炭素数１〜４のアルキル基である。ａ１及びａ２は、それぞれ独立して１〜４の整数である。） <Dialkylene glycol monoalkyl ether>
The dialkylene glycol monoalkyl ether can be represented by the following formula (3).

(In the formula (3), R ⁷ is an alkyl group having 1 to 4 carbon atoms. A1 and a2 are independently integers of 1 to 4).

In the above formula (3), R ⁷ is preferably linear, and particularly preferably a linear alkyl group having 1 to 3 carbon atoms. 1 to 3 are preferable, and 2 or 3 are more preferable for a1 and a2.
Specific examples of dialkylene glycol monoalkyl ether include dimethylene glycol monomethyl ether, dimethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, and dipropylene glycol. Examples thereof include monopropyl ether and dipropylene glycol mono-n-butyl ether. As the dialkylene glycol monoalkyl ether, one type can be used alone or two or more types can be used in combination.

In the liquid crystal alignment agent, the content ratio of the dialkylene glycol monoalkyl ether is based on the total amount of the solvent contained in the liquid crystal alignment agent from the viewpoint of improving the coatability of the liquid crystal alignment agent and the electrical characteristics of the liquid crystal element in a well-balanced manner. It is preferably 1% by mass or more. The content ratio of the dialkylene glycol monoalkyl ether is more preferably 5% by mass or more, further preferably 10% by mass or more, and particularly preferably 15% by mass or more. From the above viewpoint, the content ratio of the dialkylene glycol monoalkyl ether is preferably 70% by mass or less, more preferably 60% by mass or less, further preferably 50% by mass or less, and particularly preferably 40% by mass or less.

（式（４）中、Ｒ^８及びＲ^９は、それぞれ独立して、炭素数１〜４のアルキル基である。ｂ１及びｂ２は、それぞれ独立して１〜４の整数である。） <Dialkylene glycol dialkyl ether>
The liquid crystal alignment agent of the present disclosure preferably contains a dialkylene glycol dialkyl ether together with a cyclic carbonate compound and a dialkylene glycol monoalkyl ether. By using dialkylene glycol dialkyl ether in combination, the coatability (printability) of the liquid crystal alignment agent can be made more excellent, and the effect of suppressing intermixing with the lower layer of the liquid crystal alignment film is high. It is preferable in that the electrical characteristics of the liquid crystal element can be improved. The dialkylene glycol dialkyl ether can be represented by the following formula (4).

(In the formula (4), R ⁸ and R ⁹ are independently alkyl groups having 1 to 4 carbon atoms. B1 and b2 are independently integers of 1 to 4).

In the above formula (4), R ⁸ and R ⁹ are preferably linear, more preferably a linear alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group or an ethyl group. b1 and b2 are preferably 1 to 3, more preferably 2 or 3.
Specific examples of dialkylene glycol dialkyl ether include dimethylene glycol dimethyl ether, dimethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, and dipropylene glycol methyl ethyl ether. Examples thereof include dipropylene glycol diethyl ether, dipropylene glycol dipropyl ether and dipropylene glycol din-butyl ether. As the dialkylene glycol dialkyl ether, one type can be used alone or two or more types can be used in combination.

The content ratio of the dialkylene glycol dialkyl ether is 1% by mass or more with respect to the total amount of the solvent contained in the liquid crystal alignment agent from the viewpoint of improving the coatability of the liquid crystal alignment agent and the electrical characteristics of the liquid crystal element in a well-balanced manner. It is preferable to have. The content ratio of the dialkylene glycol dialkyl ether is more preferably 5% by mass or more, further preferably 10% by mass or more, and particularly preferably 15% by mass or more. From the above viewpoint, the content ratio of the dialkylene glycol dialkyl ether is preferably 70% by mass or less, more preferably 60% by mass or less, further preferably 50% by mass or less, and particularly preferably 40% by mass or less.

When a dialkylene glycol monoalkyl ether and a dialkylene glycol dialkyl ether are used as the solvent component, the ratio (D1 / D2) of the dialkylene glycol dialkyl ether (D1) to the dialkylene glycol dialkyl ether (D2) is the coatability. From the viewpoint of further enhancing the effect of improving the above, the mass ratio is preferably in the range of 80/20 to 20/80, more preferably in the range of 70/30 to 30/70, and even more preferably in the range of 65/35 to 35/65. , 60/40 to 40/60 is particularly preferred.

As the solvent, only the cyclic carbonate compound and the dialkylene glycol monoalkyl ether may be used, or only the cyclic carbonate compound, the dialkylene glycol monoalkyl ether and the dialkylene glycol dialkyl ether may be used, but a mixture thereof. The solvent may further contain a solvent different from the cyclic carbonate compound, the dialkylene glycol monoalkyl ether and the dialkylene glycol dialkyl ether (hereinafter, also referred to as “other solvent”). As another solvent, a known solvent used for preparing the liquid crystal alignment agent can be used. Specific examples of other solvents include a solvent capable of improving the solubility and leveling property of the polymer (hereinafter, also referred to as “first solvent”), and a solvent having good wettability and spreadability (hereinafter, “second solvent”). ”).

Specific examples of these include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, as the first solvent. 4-Hydroxy-4-methyl-2-pentanone, diisobutylketone, 1,3-dimethyl-2-imidazolidinone, etc.;
As the second solvent, methanol, ethanol, propanol, butanol, pentanol, 3-methyl-1-butanol, 1-hexanol, 2-hexanol, heptanol, phenol, cyclohexanol, methylcyclohexanol, diacetone alcohol, propane-1 , 2-diol, 3-methoxy-1-butanol and other alcohol solvents;
Ethylene glycol monomethyl ether, ethylene glycol monobutyl ether (butyl cellosolve), propylene glycol monobutyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol dimethyl ether, propylene glycol Ether-based solvents such as monomethyl ether (PGME) and diisopentyl ether;
Methyl acetate, ethyl acetate, propyl acetate, n-butyl acetate, i-butyl acetate, sec-butyl acetate, t-butyl acetate, 3-methoxybutyl acetate, methyl acetoacetate, ethyl acetoacetate, ethyl propionate, n propionate -Butyl, methyl lactate, ethyl lactate, n-butyl lactate, methylmethoxypropionate, ethylethoxypropionate, ethylene glycol ethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol diethyl ether acetate, Ester solvents such as propylene glycol monomethyl ether acetate (PGMEA), isoamyl propionate, isoamyl isobutyrate, propylene glycol diacetate;
Acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, di-n-butyl ketone, methyl-i-butyl ketone, methyl-n-pentyl ketone, ethyl-n-butyl ketone, methyl-n-hexyl Examples thereof include ketone solvents such as ketone, diisobutyl ketone, trimethylnonanone, cyclobutanone, cyclopentanone, cyclohexanone, and cycloheptanone. As the other solvent, one type may be used alone, or two or more types may be mixed and used.

As the other solvent, it is preferable to use at least one selected from the group consisting of alcohol-based solvents and ether-based solvents. Further, the liquid crystal alignment agent of the present disclosure preferably contains substantially no first solvent from the viewpoint of heating at the lowest possible temperature during film formation. Specifically, the content ratio of the first solvent is preferably 5% by mass or less, more preferably 1% by mass or less, and 0. It is more preferably 5% by mass or less, and particularly preferably 0% by mass.

When another solvent is used as the solvent, the content ratio of the other solvent (the total amount when two or more kinds are used) is preferably 90% by mass or less with respect to the total amount of the solvent contained in the liquid crystal aligning agent. , 80% by mass or less is more preferable, 70% by mass or less is further preferable, 60% by mass or less is further preferable, and 50% by mass or less is particularly preferable.

≪Other ingredients≫
The liquid crystal alignment agent may contain other components in addition to the polymer component and the solvent component, if necessary.

<Crosslinkable group-containing compound>
The liquid crystal alignment agent of the present disclosure may further contain a compound having a crosslinkable group (hereinafter, also referred to as a “crosslinkable group-containing compound”). When a crosslinkable group-containing compound is contained, it is preferable in that a liquid crystal element having excellent electrical characteristics can be obtained. The crosslinkable group contained in the crosslinkable group-containing compound comprises a cyclic ether group, a cyclic carbonate group, an isocyanate group, a protected isocyanate group, an oxazoline group, a β-hydroxyalkylamide group, a merdamic acid group, a methylol group and an alkylmethylol group. It is preferably a compound having at least one selected from the group and having a molecular weight of 1000 or less. The number of crosslinkable groups contained in one molecule of the crosslinkable group-containing compound is preferably 2 or more, and more preferably 3 or more. The crosslinkable group-containing compound 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 methylol group and an alkylmethylol group, and the protected isocyanate is preferable. A compound having at least one selected from the group consisting of a group, a β-hydroxyalkylamide group, a methylol group and an alkylmethylol group is more preferable.

Specific examples of the crosslinkable group-containing compound include compounds having a cyclic ether group, such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropantriglycidyl ether, and N. , N, N', N'-tetraglycidyl-m-xylene diamine, 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, etc .; as compounds having a cyclic carbonate group, for example, N, N, N' , N'-tetra [(2-oxo-1,3-dioxolan-4-yl) ethyl] -4,4'-diaminodiphenylmethane, etc.;
Compounds having an isocyanate group or a protected isocyanate group include, for example, tolylene diisocyanate, xylylene diisocyanate, chlorophenylenedi isocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, and polyhydric isocyanates thereof. Protected isocyanate compounds protected with a protective group; examples of compounds having an oxazoline group include 2,2'-bis (4-propyl-2-oxazoline) and 2,2'-bis (4-phenyl-2-oxazoline). ), 1,2-Bis (2-oxazolin-2-yl) ethane, 1,4-bis (2-oxazolin-2-yl) cyclohexane, 1,3-bis (2-oxazolin-2-yl) benzene, 1,3-Bis (4,5-dihydro-2-oxazolyl) benzene, 1,3-bis (4-methyl-2-oxazoline-2-yl) benzene, etc.; as compounds having a β-hydroxyalkylamide group For example, N, N, N', N'-tetrax (2-hydroxyethyl) adipamide and the like; as a compound having a methylol group or an alkylmethylol group, for example, trimethylpropane, 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 and the like can be mentioned, respectively. As the crosslinkable group-containing compound, one type may be used alone, or two or more types may be used in combination.

When a crosslinkable group-containing compound is used, the content ratio of the crosslinkable group-containing compound in the liquid crystal alignment agent is from the viewpoint of forming a stable liquid crystal alignment film and further enhancing the effect of enhancing the electrical characteristics of the obtained liquid crystal element. , 0.5 parts by mass or more is preferable, and 1 part by mass or more is more preferable with respect to 100 parts by mass of the total amount of the polymer [P]. The content ratio of the crosslinkable group-containing compound is preferably 40 parts by mass or less with respect to 100 parts by mass of the total amount of the polymer component in the liquid crystal aligning agent from the viewpoint of suppressing performance deterioration due to addition of an excessive amount. , 30 parts by mass or less is more preferable. As the crosslinkable group-containing compound, one type can be used alone or two or more types can be used in combination.

In addition to the above, other components contained in the liquid crystal alignment agent include, for example, antioxidants, metal chelate compounds, curing accelerators, surfactants, fillers, dispersants, photosensitizers and the like. The blending ratio of the other components can be appropriately selected according to each compound as long as the effects of the present invention are not impaired.

The solid content concentration in the liquid crystal alignment agent (the ratio of the total mass of the components other than the solvent of the liquid crystal alignment agent to the total mass of the liquid crystal alignment agent) is appropriately selected in consideration of viscosity, volatility, etc., but is preferable. It is in the range of 1 to 10% by mass. When the solid content concentration is 1% by mass or more, a sufficient film thickness of the coating film can be secured, and a liquid crystal alignment film showing good liquid crystal orientation can be easily obtained. On the other hand, when the solid content concentration is 10% by mass or less, the coating film can be made to have an appropriate thickness, a liquid crystal alignment film showing good liquid crystal alignment can be easily obtained, and the viscosity of the liquid crystal alignment agent is appropriate. There is a tendency that the coatability can be improved.

≪Liquid crystal alignment film and liquid crystal element≫
The liquid crystal alignment film of the present invention is formed by the liquid crystal alignment agent prepared as described above. Further, the liquid crystal element of the present invention includes a liquid crystal alignment film formed by using the liquid crystal alignment agent described above. The operation mode of the liquid crystal in the liquid crystal element is not particularly limited, and for example, TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), IPS (In-Plane Switching) type, FFS (Fringe). It can be applied to various modes such as Field Switching) type, OCB (Optically Compensated Bend) type, and PSA type (Polymer Sustained Alignment). The liquid crystal element can be manufactured, for example, by a method including the following steps 1 to 3. In step 1, the substrate used differs depending on the desired operation mode. Steps 2 and 3 are common to each operation mode.

<Step 1: Formation of coating film>
First, a liquid crystal alignment agent is applied onto the substrate, and preferably the coated surface is heated to form a coating film on the substrate. As the substrate, for example, glass such as float glass and soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and poly (aliphatic olefin) can be used. As the transparent conductive film provided on one surface of a substrate, NESA film (US PPG registered trademark) made of tin oxide (SnO _2), indium oxide - such as an ITO film made of tin oxide _{(In 2} O 3 -SnO ₂₎ the Can be used. When 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 in a comb tooth shape and a counter substrate not provided with electrodes are used.

The method of applying the liquid crystal alignment agent to the substrate is not particularly limited, and for example, a spin coating method, a printing method (for example, an offset printing method, a flexographic printing method, etc.), an inkjet method, a slit coating method, a bar coater method, and an extraction die. It can be performed by a method, a direct gravure coater method, a chamber doctor coater method, an offset gravure coater method, an impregnation coater method, an MB coater method, or the like.

After the liquid crystal alignment agent is applied, preheating is preferably performed for the purpose of preventing the applied liquid crystal alignment agent from dripping. The pre-baking temperature is preferably 30 to 200 ° C., and the pre-baking time is preferably 0.25 to 10 minutes. Then, a firing (post-baking) step is carried out for the purpose of completely removing the solvent and, if necessary, thermally imidizing the amic acid structure present in the polymer. The firing temperature (post-baking temperature) at this time is preferably 80 to 280 ° C, more preferably 80 to 250 ° C. The post-bake time is preferably 5 to 200 minutes. The film thickness of the film to be formed is preferably 0.001 to 1 μm.

<Step 2: Orientation treatment>
When manufacturing a TN type, STN type, IPS type or FFS type liquid crystal element, a treatment (alignment treatment) for imparting a liquid crystal alignment ability to the coating film formed in the above step 1 is performed. As a result, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. As the orientation treatment, it is preferable to use a rubbing treatment in which the surface of the coating film formed on the substrate is rubbed with cotton or the like, or a photo-alignment treatment in which the coating film is irradiated with light to impart liquid crystal alignment ability. On the other hand, in the case of manufacturing a vertically oriented liquid crystal element, the coating film formed in the above step 1 may be used as it is as a liquid crystal alignment film, and the coating film is subjected to alignment treatment in order to further enhance the liquid crystal alignment ability. May be applied.

The light irradiation for photo-orientation includes 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 pre-baking process and a post-baking process. At least one of them can be carried out by a method of irradiating the coating film while heating the coating film, or the like. As the radiation to irradiate the coating film, for example, ultraviolet rays including light having a wavelength of 150 to 800 nm and visible light can be used. Preferably, it is ultraviolet light containing light having a wavelength of 200 to 400 nm. When the radiation is polarized, it may be linearly polarized or partially polarized. When the radiation used is linearly polarized light or partially polarized light, the irradiation may be performed from a direction perpendicular to the substrate surface, may be performed from an oblique direction, or may be performed in combination thereof. In the case of unpolarized radiation, the irradiation direction is diagonal.

Examples of the light source used 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, an excimer laser, and the like. The irradiation amount of radiation is preferably 400 to 50,000 J / m ² , and more preferably 1,000 to 20,000 J / m ² . After light irradiation for imparting orientation ability, the surface of the substrate is washed with, for example, water, an organic solvent (for example, methanol, isopropyl alcohol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.) or a mixture thereof. Or a process of heating the substrate may be performed.

<Step 3: Construction of liquid crystal cell>
A liquid crystal cell is manufactured by preparing two substrates on which the liquid crystal alignment film is formed as described above and arranging the liquid crystal between the two substrates arranged opposite to each other. In order to manufacture a liquid crystal cell, for example, two substrates are arranged to face each other with a gap so that the liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded with a sealant, and the substrate surface and the sealant are attached. Examples thereof include a method of injecting and filling a liquid crystal in a cell gap surrounded by, and sealing an injection hole, a method of using an ODF method, and the like. As the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal, and among them, the nematic liquid crystal is preferable.

In the PSA mode, a polymerizable compound (for example, a polyfunctional (meth) acrylate compound, etc.) is filled in the cell gap together with the liquid crystal, and after the liquid crystal cell is constructed, a voltage is applied between the conductive films of the pair of substrates. A process of irradiating the liquid crystal cell with light is performed. In the production of the liquid crystal element in the PSA mode, the ratio of the polymerizable compound used is 0.01 to 3 parts by mass, preferably 0.1 to 1 part by mass, based on 100 parts by mass of the total amount of the liquid crystal.

When the liquid crystal element is used as a display device, a polarizing plate is subsequently attached to the outer surface of the liquid crystal cell as needed to form the liquid crystal element. Examples of the polarizing plate include a polarizing plate in which a polarizing film called "H film" in which polyvinyl alcohol is stretch-oriented and iodine is absorbed is sandwiched between a cellulose acetate protective film, or a polarizing plate made of the H film itself.

The liquid crystal device of the present invention described in detail above can be effectively applied to various applications. Specifically, for example, various display devices such as clocks, portable games, word processors, notebook computers, car navigation systems, camcoders, PDAs, digital cameras, mobile phones, smartphones, various monitors, LCD TVs, information displays, etc. It can be used as a dimmer, a retardation film, or the like.

Hereinafter, embodiments will be described in more detail based on the examples, but the present invention is not limitedly interpreted by the following examples.

In the following examples, the weight average molecular weight Mw of the polymer, the imidization ratio of the polyimide in the polymer solution, the solution viscosity of the polymer solution, and the epoxy equivalent were measured by the following methods. The required amounts of the raw material compounds and polymers used in the following examples were secured by repeating the synthesis on the synthetic scale shown in the following synthesis examples as necessary.
[Weight average molecular weight Mw of polymer]
The weight average molecular weight Mw is a polystyrene-equivalent value measured by GPC under the following conditions.
Column: Made by Tosoh Corporation, TSKgelGRCXLII
Solvent: Tetrahydrofuran (polyorganosiloxane, binder resin)
N, N-dimethylformamide solution containing lithium bromide and phosphoric acid (polyamic acid)
Temperature: 40 ° C
Pressure: 68 kgf / cm ²
[Imidization rate of polyimide]
The polyimide solution was poured into pure water, the obtained precipitate was sufficiently dried under reduced pressure at room temperature, dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. From the obtained ¹ H-NMR spectrum, the imidization rate [%] was determined by the following mathematical formula (1).
Imidization rate [%] = (1- (A ¹ / (A ² x α))) x 100 ... (1)
(In formula (1), A ¹ is the peak area derived from the proton of the NH group appearing near the chemical shift of 10 ppm, A ² is the peak area derived from other protons, and α is the precursor of the polymer (polyamic acid). ) Is the ratio of the number of other protons to one proton of the NH group.)
[Solution viscosity of polymer solution]
The solution viscosity (mPa · s) of the polymer solution was measured at 25 ° C. using an E-type rotational viscometer.
[Epoxy equivalent]
Epoxy equivalents were measured by the hydrochloric acid-methylethylketone method described in JIS C 2105.

The abbreviations of the compounds are as follows. In the following, the compound represented by the formula (X) may be simply referred to as "compound (X)".

<Synthesis of polymer>
1. 1. Synthesis of polyamic acid [Synthesis example 1]
100 mol parts of 2,3,5-tricarboxycyclopentylacetic acid dianhydride (tk-1) as tetracarboxylic dianhydride, 20 mol parts of cholestanyloxy-2,4-diaminobenzene (da-13) as diamine, 40 parts of compound (da-2) and 40 parts of 4,4'-diaminobenzanilide (da-1) were dissolved in N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours. This was carried out to obtain a solution containing 30% by mass of polyamic acid. A small amount of the obtained polyamic acid solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 20% by mass was 800 mPa · s. The reaction solution was then poured into a large excess of methanol to precipitate the reaction product. The precipitate was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain a polymer (PAA-1).
[Synthesis Examples 2 to 6]
The same operation as in Synthesis Example 1 was carried out except that the types and amounts of the tetracarboxylic dianhydrides and diamines used were changed as shown in Table 1 below, and the polyamic acids (polymers (PAA-2) to (PAA-) 6)) was obtained.

2. Synthesis of polyimide [Synthesis example 7]
2,4,6,8-Tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride (tk-2) 100 mol as tetracarboxylic dianhydride, compound as diamine 30 parts (da-14) and 70 parts of 3,5-diaminobenzoic acid (da-16) were dissolved in NMP and reacted at 60 ° C. for 6 hours to prepare a solution containing 30% by mass of polyamic acid. Obtained. A small amount of the obtained polyamic acid solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 20% by mass was 800 mPa · s.
Next, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyamic acid concentration of 7% by mass, pyridine and acetic anhydride were added, and a dehydration ring closure reaction was carried out at 110 ° C. for 4 hours. A solution containing 26% by mass of polyimide having an imidization rate of about 80% (referred to as "polymer (PI-1)") by substituting the solvent in the system with a new NMP after the dehydration ring closure reaction. Got A small amount of the obtained polyimide solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyimide concentration of 15% by mass was 120 mPa · s. The reaction solution was then poured into a large excess of methanol to precipitate the reaction product. The precipitate was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain a polymer (PI-1).

3. 3. Synthesis of Epoxy Group-Containing Polyorganosiloxane [Synthesis Example 8]
100.0 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (compound represented by the above formula (es-1)) in a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser. , 500 g of methyl isobutyl ketone and 10.0 g of triethylamine were charged and mixed at room temperature. Then, 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and then the reaction was carried out at 80 ° C. for 6 hours while stirring under reflux. After completion of the reaction, the organic layer was taken out, washed with a 0.2 mass% ammonium nitrate aqueous solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure to carry out an epoxy group-containing polyorgano. A siloxane (referred to as "polymer (ESSQ-1)") was obtained as a viscous transparent liquid. ^{When 1} H-NMR analysis was performed on the polymer (ESSQ-1), a peak based on an epoxy group was obtained in the vicinity of chemical shift (δ) = 3.2 ppm. The weight average molecular weight Mw of the obtained polymer (ESSQ-1) was 3,500, and the epoxy equivalent was 180 g / mol.

4. Synthesis of characteristic group-containing polyorganosiloxane [Synthesis Example 9]
In a 200 mL three-necked flask, 10.0 g of the polymer (ESSQ-1), 30.28 g of methyl isobutyl ketone as the solvent, and the epoxy contained in the polymer (ESSQ-1) as the modifying component (carboxylic acid having an orientation group). The amount of compound (ca-1) corresponding to 20 mol%, the amount of compound (ca-2) corresponding to 10 mol%, and UCAT 18X (trade name, San-Apro Co., Ltd.) as a catalyst with respect to the total amount of groups. (Manufactured) 0.10 g was charged, and the reaction was carried out at 100 ° C. for 48 hours with stirring. After completion of the reaction, the solution obtained by adding ethyl acetate to the reaction mixture was washed with water three times, the organic layer was dried over magnesium sulfate, and the solvent was distilled off to obtain a polymer (PSQ-1). .. The weight average molecular weight Mw of the obtained polymer was 6,800.
[Synthesis Example 10]
The modified component to be used is an amount corresponding to 30 mol% of the compound (ca-1) and 10 mol% of the compound (ca-3) with respect to the total amount of epoxy groups contained in the polymer (ESSQ-1). A polymer (PSQ-2) was obtained by carrying out the same operation as in Synthesis Example 9 except that the amount was changed.

[Example 1]
1. 1. Preparation of liquid crystal alignment agent In 100 parts by mass of the polymer (PAA-1) obtained in Synthesis Example 1 and 5 parts by mass of the polymer (PSQ-1) obtained in Synthesis Example 9, propylene carbonate (PC) and diethylene glycol were added. Monomethyl ether (B1), diethylene glycol dimethyl ether (C1), and 3-methoxybutanol (MB) were added, the solid content concentration was 4.0% by mass, and the mixing ratio of the solvent was PC: B1: C1: MB = 15: 20 :. The solution was prepared at 30:35 (mass ratio). After sufficiently stirring this solution, a liquid crystal alignment agent (S-1) was prepared by filtering through a filter having a pore size of 0.2 μm.

2. Preparation of coloring composition (1) Preparation of pigment dispersion liquid C.I. I. Pigment Blue 15: 6 is 15 parts by mass, BYK-LPN21116 (manufactured by Big Chemie (BYK)) is 12.5 parts by mass (solid content concentration 40% by mass) as a dispersant, and propylene glycol monomethyl ether acetate is 72.5 as a solvent. A pigment dispersion (a-1) was prepared by treating with a bead mill using parts by mass.
(2) Preparation of Dye Solution A dye solution (A-1) was prepared by mixing 5 parts by mass of a colorant represented by the following formula (A-1) and 95 parts by mass of cyclohexanone as a solvent. The compound represented by the following formula (A-1) was obtained by the method described in Synthesis Example 3 of JP2013-122577A.

(3) Synthesis of Binder Resin 100 parts by mass of propylene glycol monomethyl ether acetate was charged into a flask equipped with a cooling tube and a stirrer and replaced with nitrogen. Heat to 80 ° C. and at the same temperature, 100 parts by mass of propylene glycol monomethyl ether acetate, 20 parts by mass of methacrylic acid, 10 parts by mass of styrene, 5 parts by mass of benzyl methacrylate, 15 parts by mass of 2-hydroxyethyl methacrylate, 2-ethylhexyl. A mixed solution of 23 parts by mass of methacrylate, 12 parts by mass of N-phenylmaleimide, 15 parts by mass of monobenzoate (2-acryloyloxyethyl) and 6 parts by mass of 2,2'-azobis (2,4-dimethylvaleronitrile). Was added dropwise over 1 hour, and the mixture was polymerized for 2 hours while maintaining this temperature. Then, the temperature of the reaction solution is raised to 100 ° C., and the mixture is further polymerized for 1 hour to contain a binder resin (B1) (solid content concentration 33% by mass, hereinafter referred to as "binder resin (B1) solution"). Got The obtained binder resin had Mw of 12,200 and Mn of 6,500.

(4) Preparation of coloring composition 46.0 parts by mass of pigment dispersion (a-1), 24.3 parts by mass of dye solution (A-1), 24.6 parts by mass of binder resin (B1) solution, as a cross-linking agent M-402 (mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate) manufactured by Toa Synthetic Co., Ltd. 7.1 parts by mass, 2-benzyl-2-dimethylamino-1- (4-) as a photopolymerization initiator Morphorinophenyl) butane-1-one (manufactured by Ciba Specialty Chemicals, trade name IRGACURE369) 2.1 parts by mass, Megafuck F-554 (manufactured by DIC Co., Ltd.) as a surfactant 0.05 A colored composition (G-1) having a solid content concentration of 20% by mass was prepared by mixing parts by mass and ethyl lactate as a solvent.

3. 3. Formation of Colored Hardened Film The colored composition (G-1) was applied onto a glass substrate using a spin coater, and then prebaked on a hot plate at 90 ° C. for 100 seconds to form a coating film. At the time of coating, the rotation speed of the spin coater was adjusted so that the film thickness after post-baking was 2.5 μm. Next, after cooling this substrate to room temperature, a high-pressure mercury lamp was used, and for patterning of the measurement electrode portion, 400 J of radiation containing each wavelength of 365 nm, 405 nm, and 436 nm was applied to the coating film through a photomask photomask. Exposure was performed with an exposure amount of / m ^2. Then, on this substrate, a developing solution composed of 0.04 mass% potassium hydroxide aqueous solution at 23 ° C. was applied to the unexposed portion under the conditions of a developing pressure of 110 kPa and a developing solution flow rate of 1.2 liters / minute. Shower development was performed by discharging the developer in a time corresponding to 1.5 times the time until the substrate surface disappeared and became visible. Then, this substrate was washed with ultrapure water, air-dried, and then post-baked in a clean oven at 230 ° C. for 20 minutes to form a colored cured film (thickness 2.5 μm). An ITO film (thickness: 50 nm) was formed by sputtering on the obtained colored cured film.

4. Manufacture of vertical liquid crystal display element 3. On the transparent electrode surface of the glass substrate with a transparent electrode composed of the laminated film of the colored cured film and the ITO film obtained in 1. above. The liquid crystal alignment agent (S-1) prepared in the above was applied using a spinner and prebaked on a hot plate at 80 ° C. for 1 minute. Then, the inside of the oven was heated at 230 ° C. for 1 hour in a nitrogen-substituted oven to form a coating film having a film thickness of 0.1 μm. Next, the same operation was repeated to prepare a pair (two sheets) of substrates having a colored cured film, an ITO film, and a liquid crystal alignment film.
An epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm is applied to the outer periphery of the surface of one of the substrates having the liquid crystal alignment film by screen printing, and then the liquid crystal alignment film surfaces of the pair of substrates are opposed to each other. The adhesive was heat-cured at 150 ° C. for 1 hour by pressure-bonding each substrate so that the projection directions of the optical axes of the ultraviolet rays on the substrate surface were antiparallel. Next, a negative liquid crystal (MLC-6608, manufactured by Merck Co., Ltd.) was filled in the gap between the substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to eliminate the flow orientation at the time of liquid crystal injection, this was heated at 130 ° C. and then slowly cooled to room temperature to manufacture a liquid crystal display element.

5. Evaluation of Electrical Characteristics After the produced liquid crystal display element was allowed to stand in an oven at 60 ° C., VHR was measured under the conditions of 1 V and 167 msec using a VHR measuring device manufactured by Toyo Technica. The evaluation criteria are "◎" when VHR is 100% or less and higher than 98%, "○" when 98% or less and higher than 95%, "△" when 95% or less and higher than 90%, 90. When it was less than%, it was regarded as "x". It can be said that the higher the VHR, the better the deterioration of the electrical characteristics due to the solvent in the liquid crystal alignment agent permeating into the lower layer (specifically, the colored cured film) can be suppressed. As a result, VHR was 92.0%, and the evaluation was “Δ”.

6. Evaluation of coatability (printability) An inkjet device manufactured by Shibaura was filled with a liquid crystal alignment agent (S-1), and inkjet coating was performed on a silicon wafer. Then, prebaking was performed for 1 minute on a hot plate at 80 ° C. Then, the inside of the oven was heated at 230 ° C. for 1 hour in a nitrogen-substituted oven ^{to form a coating film having a film thickness of 0.1 μm and a coating area of 100 cm 2} (= 10 cm × 10 cm). The film thickness uniformity was measured by using an alpha step in the direction orthogonal to the head traveling direction of the inkjet for a distance of 1 mm at the center of the coating film. The difference between the maximum film thickness and the minimum film thickness of the obtained film thickness profile was defined as roughness, and the quality of printability was judged. The evaluation criteria were "◎" when the roughness was 0 or more and less than 2 nm, "○" when it was 2 nm or more and less than 5 nm, "△" when it was 5 nm or more and less than 10 nm, and "×" when it was 10 nm or more. .. As a result, the roughness was 0.7 nm, and the evaluation was “⊚”.

[Examples 3 to 6, 8, 10 and Comparative Examples 1 to 4]
A liquid crystal alignment agent was prepared in the same manner as in Example 1 above, except that the composition of the liquid crystal alignment agent was changed as shown in Table 2 below. Further, using the obtained liquid crystal alignment agent, a vertical liquid crystal display element was manufactured in the same manner as in Example 1, and the electrical characteristics and coatability were evaluated. The results are shown in Table 3 below.

[Example 7]
1. 1. Preparation of liquid crystal alignment agent A liquid crystal alignment agent (S-7) was prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 2 below.
2. Manufacture and evaluation of optical vertical liquid crystal display element The composition of the liquid crystal alignment agent is changed as shown in Table 2 below, and a glass substrate with a transparent electrode made of a laminated film of a colored cured film and an ITO film is obtained in the same manner as in Example 1 above. A liquid crystal aligning agent was applied on the transparent electrode surface of the above film with a spinner, and pre-baking and post-baking were performed to form a coating film, and then the surface of the coating film was 313 nm using an Hg-Xe lamp and a Granter prism. ^{The liquid crystal alignment ability was imparted by irradiating 1,000 J / m 2} of polarized ultraviolet rays including a bright line from a direction inclined by 40 ° from the normal line of the substrate. The same operation was repeated to prepare a pair (two sheets) of substrates having a colored cured film, an ITO film, and a liquid crystal alignment film.
An epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm is applied to the outer periphery of the surface of one of the substrates having the liquid crystal alignment film by screen printing, and then the liquid crystal alignment film surfaces of the pair of substrates are opposed to each other. The adhesive was heat-cured at 150 ° C. for 1 hour by pressure-bonding each substrate so that the projection directions of the optical axes of the ultraviolet rays on the substrate surface were antiparallel. Next, a negative liquid crystal (MLC-6608, manufactured by Merck Co., Ltd.) was filled in the gap between the substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to eliminate the flow orientation at the time of liquid crystal injection, this was heated at 130 ° C. and then slowly cooled to room temperature to manufacture a liquid crystal display element. Further, the obtained liquid crystal display element was evaluated for its electrical characteristics and coatability in the same manner as in Example 1. The evaluation results are shown in Table 3 below.

[Example 2]
1. 1. Preparation of liquid crystal alignment agent A liquid crystal alignment agent (S-2) was prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 2 below.
2. Preparation of liquid crystal composition With respect to 10 g of nematic liquid crystal (MLC-6608 manufactured by Merck Co., Ltd.), 5% by mass of the liquid crystal compound represented by the following formula (L1-1) and the following formula (L2-1) are represented. The liquid crystal composition LC1 was obtained by adding 0.3% by mass of the photopolymerizable compound and mixing the compounds.

3. 3. Manufacture of PSA type liquid crystal display element 1. The liquid crystal aligning agent (S-2) prepared in 1) was applied on the transparent electrode surface of a glass substrate with a transparent electrode composed of a laminated film of a colored cured film and an ITO film using a spinner, and used on a hot plate at 80 ° C. After prebaking for 1 minute, a coating film (liquid crystal alignment film) having a film thickness of 0.08 μm was formed by heating at 200 ° C. for 1 hour in an oven replaced with nitrogen to remove the solvent. This coating film was subjected to a rubbing treatment using a rubbing machine having a roll wrapped with rayon cloth at a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / sec, and a fluff pushing length of 0.1 mm. Then, the substrate was ultrasonically cleaned in ultrapure water for 1 minute and then dried in a 100 ° C. clean oven for 10 minutes to obtain a substrate having a liquid crystal alignment film. This operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film. It should be noted that this rubbing process is a weak rubbing process performed for the purpose of controlling the collapse of the liquid crystal and performing the orientation division by a simple method.
An epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm is applied by screen printing to the outer periphery of the surface of one of the substrates having the liquid crystal alignment film, and then the liquid crystal alignment film surfaces of the pair of substrates are opposed to each other. The adhesive was heat-cured by overlapping and crimping and heating at 150 ° C. for 1 hour. Next, the liquid crystal composition LC1 is filled in the gaps between the substrates from the liquid crystal injection port, the liquid crystal injection port is sealed with an epoxy adhesive, and the liquid crystal injection port is sealed at 150 ° C. to eliminate the flow orientation during liquid crystal injection. After heating for a minute, it was slowly cooled to room temperature.
Next, an AC 10V having a frequency of 60 Hz was applied between the electrodes to the obtained liquid crystal cell, and in a state where the liquid crystal was driven, 50,000 ultraviolet rays were emitted using an ultraviolet irradiation device using a metal halide lamp as a light source. Irradiation was performed at an irradiation dose of / m ^2. It should be noted that this irradiation amount is a value measured using a photometer measured based on a wavelength of 365 nm. A liquid crystal display element was manufactured by the above method.
4. Evaluation The electrical characteristics and coatability of the PSA type liquid crystal display element manufactured above were evaluated in the same manner as in Example 1. The results are shown in Table 3 below.

[Example 9]
1. 1. Preparation of liquid crystal alignment agent A liquid crystal alignment agent (S-9) was prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 2 below.

2. Manufacture of rubbing FFS type liquid crystal display element A glass substrate in which a flat plate electrode (bottom electrode), an insulating layer and a comb-shaped electrode (top electrode) are laminated on one side in this order, and a counter glass substrate on which no electrode is provided. The coloring composition (G-1) was applied onto each surface using a spin coater, and the same operation as in “3. Formation of colored cured film” of Example 1 above was performed to form a colored cured film. Subsequently, a liquid crystal alignment agent (S-9) was applied to the formation surface side of the colored cured film on each substrate using a spinner, and heated (prebaked) on a hot plate at 80 ° C. for 1 minute. Then, the inside of the chamber was dried (post-baked) for 1 hour in a nitrogen-substituted oven at 200 ° C. to form a coating film having an average film thickness of 0.08 μm. Next, the surface of the coating film was subjected to a rubbing treatment using a rubbing machine having a roll wrapped with rayon cloth at a roll rotation speed of 500 rpm, a stage moving speed of 3 cm / sec, and a fluff pushing length of 0.4 mm. Then, the substrate was ultrasonically cleaned in ultrapure water for 1 minute and then dried in a clean oven at 100 ° C. for 10 minutes to obtain a substrate having a liquid crystal alignment film.
Next, for the pair of substrates having the liquid crystal alignment film, an epoxy resin adhesive containing an aluminum oxide ball having a diameter of 5.5 μm was screen-printed and applied, leaving a liquid crystal injection port on the edge of the surface on which the liquid crystal alignment film was formed. Then, the substrates were overlapped and crimped, and the adhesive was thermoset at 150 ° C. for 1 hour. Next, a nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to eliminate the flow orientation at the time of liquid crystal injection, this was heated at 120 ° C. and then slowly cooled to room temperature to produce a liquid crystal cell. When stacking a pair of substrates, the rubbing method of each substrate was set to be antiparallel. For the top electrode, the line width of the electrode was set to 4 μm, and the distance between the electrodes was set to 6 μm. As the top electrode, four types of driving electrodes, electrode A, electrode B, electrode C, and electrode D, were used. In this case, the bottom electrode acts as a common electrode that acts on all of the four drive electrodes, and each of the regions of the four drive electrodes becomes a pixel region.
3. 3. Evaluation The electrical characteristics and coatability of the FFS type liquid crystal display element manufactured above were evaluated in the same manner as in Example 1. The results are shown in Table 3 below.

In Table 2, the numerical values in parentheses of the polymer component and the cross-linking agent are the blending amounts of the polymers (PAA-1) to (PAA-6) and the polymer (PI-1) used for preparing the liquid crystal alignment agent 100. The mixing ratio (parts by mass) of each compound with respect to parts by mass is shown. The numerical values in parentheses of the solvent composition indicate the mixing ratio (mass ratio) of each solvent to the total amount of the solvent components used in the preparation of the liquid crystal aligning agent. Note that the dialkylene glycol dialkyl ethers, group R _4, showing the mixing ratio in the column groups R _6.
The abbreviations of the compounds are as follows.
<Solvent>
MB: 3-Methoxy-1-butanol BC: Ethylene glycol monobutylEL PB: Propylene glycol monobutylEL DAA: Diacetone alcohol NMP: N-methyl-2-pyrrolidone

As is clear from Table 3, in each of Examples 1 to 10, the roughness of the formed liquid crystal alignment film was small, and the coatability (printability) was good. Further, it was found that the voltage retention rate of the liquid crystal cell was higher than 90%, a stable liquid crystal alignment film could be formed, and the electrical characteristics were good. In particular, in Examples 1 to 9 in which the dialkylene glycol dialkyl ether was blended, the roughness of the liquid crystal alignment film was smaller than in Example 10 in which the dialkylene glycol dialkyl ether was not blended, and the liquid crystal alignment agent was applied to the substrate. The coatability and the electrical characteristics of the liquid crystal element were improved in a well-balanced manner.
On the other hand, Comparative Example 3 in which a cyclic carbonate compound was used as a solvent but no dialkylene glycol monoalkyl ether was used, and Comparative Example 2 in which a dialkylene glycol monoalkyl ether was used as a solvent but no cyclic carbonate compound was used. In Comparative Example 1 in which the polymer [P] was not used, the applicability of the liquid crystal aligning agent was evaluated as “◯” or “◎”, but the voltage retention rate of the liquid crystal cell was in the 80% range. , Inferior in electrical characteristics. Further, in Comparative Example 4 in which the cyclic carbonate compound and the dialkylene glycol monoalkyl ether were not used as the solvent, both the coatability and the electrical characteristics were inferior to those of Examples 1 to 10.

Claims (10)

A polymer [P] having at least one selected from the group consisting of an amide group, a protected amide group, a urea group and a protected urea group, and
Cyclic carbonate compound and
Dialkylene glycol monoalkyl ether and
A liquid crystal alignment agent containing. The liquid crystal alignment agent according to claim 1, further containing a dialkylene glycol dialkyl ether. The liquid crystal alignment agent according to claim 2, wherein the content ratio of the dialkylene glycol dialkyl ether is 1% by mass or more and 70% by mass or less with respect to the total amount of the solvent contained in the liquid crystal alignment agent. Any of claims 1 to 3, wherein the polymer [P] further has at least one selected from the group consisting of a group having a polymerizable carbon-carbon unsaturated bond, a photoinitiator group and a photooriented group. The liquid crystal aligning agent according to item 1. Any one of claims 1 to 4, wherein the polymer [P] further comprises at least one selected from the group consisting of a tertiary amine structure, a protected amino group and a nitrogen-containing aromatic heterocyclic group. The liquid crystal alignment agent according to. The liquid crystal alignment agent according to any one of claims 1 to 5, further comprising a compound having a crosslinkable group. The liquid crystal orientation according to any one of claims 1 to 6, wherein the content ratio of the cyclic carbonate compound is 0.5% by mass or more and 50% by mass or less with respect to the total amount of the solvent contained in the liquid crystal alignment agent. Agent. The liquid crystal according to any one of claims 1 to 7, wherein the content ratio of the dialkylene glycol monoalkyl ether is 1% by mass or more and 70% by mass or less with respect to the total amount of the solvent contained in the liquid crystal alignment agent. Orientation agent. A liquid crystal alignment film formed by using the liquid crystal alignment agent according to any one of claims 1 to 8. A liquid crystal element comprising the liquid crystal alignment film according to claim 9.