JP6551040B2 - Liquid crystal aligning agent, liquid crystal aligning film and liquid crystal display device - Google Patents

Description

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

  Liquid crystal display elements are widely used in televisions, mobile devices, various monitors, and the like. In these liquid crystal display elements, a liquid crystal alignment film is used to control the alignment of liquid crystal molecules in the liquid crystal cell. As a material of a liquid crystal aligning film, polyamic acid and a polyimide are generally used from the point which various characteristics, such as heat resistance, mechanical strength, and affinity with a liquid crystal, are favorable.

  In recent years, various liquid crystal aligning agents have been proposed in order to further improve the display performance of liquid crystal display elements (see, for example, Patent Documents 1 to 4). These Patent Documents 1 to 4 disclose that a polyamic acid or a polyimide obtained by using an amide group-containing tetracarboxylic acid dianhydride is used as a polymer component of a liquid crystal aligning agent.

International Publication No. 2013/094646 JP, 2013-241571, A International Publication No. 2013/024892 International Publication No. 2013/024893

  In recent years, a liquid crystal television with a large screen and high definition is mainly used, and a small display terminal such as a smartphone and a tablet PC is widely used, and a demand for high definition of the liquid crystal panel is further increasing. For example, accumulation of residual DC voltage inside the element is mentioned as one of the causes of display failure of the liquid crystal display element, and the liquid crystal display element is required to reduce accumulation of residual DC voltage. In addition, although liquid crystal display elements are expected to be used continuously for a long time as they become versatile, it is also required that reliability be ensured even when used for such a long time.

  The present invention has been made in view of the above problems, and provides a liquid crystal aligning agent capable of obtaining a liquid crystal display element which has good liquid crystal alignment, is less likely to accumulate residual DC voltage, and has good reliability. Is one purpose.

  The inventors of the present invention have made earnest studies to achieve the problems of the prior art as described above, and as a result, it is possible to solve the problems by producing a liquid crystal alignment film using a liquid crystal aligning agent containing a compound having a specific structure. The present invention has been completed. Specifically, the following liquid crystal aligning agent, liquid crystal alignment film, liquid crystal display element, polymer and acid dianhydride are provided.

  [1] A polymer [P] which is at least one member selected from the group consisting of polyamic acid, polyamic acid ester and polyimide and has a partial structure derived from a compound represented by the following formula (1): Liquid crystal aligning agent.

（式（１）中、Ｔ^１及びＴ^２は、それぞれ独立に３価の有機基であり、Ｒ^１及びＲ^２は、それぞれ独立に、水素原子又は炭素数１〜１０の１価の炭化水素基であり、Ａ^１及びＡ^２は、それぞれ独立に２価の芳香環基である。Ｚ^１は、炭素数１以上の２価のヘテロ原子含有基であり、Ａ^１及びＡ^２の少なくとも一方に対してヘテロ原子で結合している。）

(In Formula (1), T ¹ and T ² are each independently a trivalent organic group, and R ¹ and R ² are each independently a hydrogen atom or a monovalent hydrocarbon having 1 to 10 carbon atoms. A ¹ and A ² are each independently a divalent aromatic ring group, and Z ¹ is a divalent hetero atom-containing group having one or more carbon atoms, and at least one of A ¹ and A ² is a group Is bonded with a heteroatom.)

[2] A liquid crystal alignment film formed using the liquid crystal aligning agent of [1].
[3] A liquid crystal display device comprising the liquid crystal alignment film according to [2].
[4] A polymer having a partial structure derived from the compound represented by the above formula (1), which is at least one selected from the group consisting of polyamic acid, polyamic acid ester and polyimide.
[5] An acid dianhydride represented by the above formula (1).

  According to a liquid crystal aligning agent containing a polymer [P] having a partial structure derived from a compound represented by the above formula (1), the solubility in a solvent is good, and a liquid crystal alignment film excellent in coatability is obtained be able to. In addition, it is possible to obtain a liquid crystal display element which is excellent in liquid crystal alignment property, hardly accumulates the residual DC voltage, and is excellent in reliability.

Below, each component contained in the liquid crystal aligning agent of this indication, and the other component arbitrarily mix | blended as needed are demonstrated.
In the present specification, "hydrocarbon group" is meant to include a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. The “chain hydrocarbon group” means a straight chain 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 an alicyclic hydrocarbon structure as a ring structure and not including an aromatic ring structure. However, it does not need to be comprised only with the structure of alicyclic hydrocarbon, and the thing which has a chain-like structure in the part is also included. The "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be composed of only an aromatic ring structure, and a part thereof may contain a chain structure or an alicyclic hydrocarbon structure. “Organic group” means a group containing a carbon atom, and the structure may contain a heteroatom.

（式（１）中、Ｔ^１及びＴ^２は、それぞれ独立に３価の有機基であり、Ｒ^１及びＲ^２は、それぞれ独立に、水素原子又は炭素数１〜１０の１価の炭化水素基であり、Ａ^１及びＡ^２は、それぞれ独立に２価の芳香環基である。Ｚ^１は、炭素数１以上の２価のヘテロ原子含有基であり、Ａ^１及びＡ^２の少なくとも一方に対してヘテロ原子で結合している。） «Polymer [P]»
The liquid crystal aligning agent of this indication is at least 1 sort (s) chosen from the group which consists of a polyamic acid, a polyamic acid ester, and a polyimide, and is represented by following formula (1) (henceforth "specific acid dianhydride") A polymer [P] having a partial structure derived from the above.

(In Formula (1), T ¹ and T ² are each independently a trivalent organic group, and R ¹ and R ² are each independently a hydrogen atom or a monovalent hydrocarbon having 1 to 10 carbon atoms. A ¹ and A ² are each independently a divalent aromatic ring group, and Z ¹ is a divalent hetero atom-containing group having one or more carbon atoms, and at least one of A ¹ and A ² is a group Is bonded with a heteroatom.)

In the above formula (1), examples of the trivalent organic group of T ¹ and T ² include a trivalent hydrocarbon group and a trivalent heterocyclic group. Among them, a trivalent aromatic ring group or an alicyclic ring It is preferably a formula group. Specifically, it is preferably a group obtained by removing three hydrogen atoms from a ring portion of a substituted or unsubstituted benzene ring, naphthalene ring, cyclopentane ring or cyclohexane ring, and the ring is a benzene ring or a cyclohexane ring. The benzene ring is particularly preferable in that the improvement effect of the reliability (particularly, long-term reliability) of the liquid crystal display device obtained is more preferable. When the trivalent organic group has a ring structure, a substituent may be introduced into the ring portion. As the said substituent, a halogen atom, a hydroxyl group, a C1-C5 alkyl group, a C1-C5 alkoxy group etc. are mentioned, for example.
Examples of the monovalent hydrocarbon group for R ¹ and R ² include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, and pentyl group; alicyclic hydrocarbon groups such as cyclohexyl group and methylcyclohexyl group; Aromatic hydrocarbon groups such as phenyl group, tolyl group, benzyl group and the like can be mentioned. Among them, a hydrogen atom or an alkyl group is preferable as R ¹ and R ² , and a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is more preferable.

The divalent aromatic ring group of A ¹ and A ² is a group in which two hydrogen atoms have been removed from the ring portion of a substituted or unsubstituted aromatic ring. Examples of the aromatic ring include monocyclic or polycyclic hydrocarbons such as benzene ring, naphthalene ring and anthracene ring; nitrogen-containing heterocycles such as pyridine ring, pyrimidine ring, pyrazine ring, quinoline ring and imidazole ring. Can be mentioned. In particular, A ¹ and A ² are preferably 1,4-phenylene groups. The ring portion of the divalent aromatic ring group may have a substituent. The above description of T ¹ and T ² can be applied to specific examples of the substituent.

The divalent hetero atom-containing group of Z ¹ means an organic group having a divalent or higher hetero atom. The hetero atom-containing group is not particularly limited as long as it is a group having 1 or more carbon atoms and being bonded to at least one of A ¹ and A ^{2 with} a hetero atom. Heteroatoms that Z ¹ has, for example, nitrogen atom, oxygen atom, sulfur atom and the like.

From the viewpoint of sufficiently reducing the residual DC voltage of the liquid crystal display element, Z ¹ preferably has at least one nitrogen atom and is bonded to A ¹ or A ² with the nitrogen atom. Specific examples of such Z ¹ include, for example, —NR ¹⁰ —CO— (R ¹⁰ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. The same shall apply hereinafter), and a nitrogen-containing heterocyclic structure. group, (provided that the nitrogen atom which nitrogen-containing heterocyclic structure is bonded to at least one of ^{a 1} and ^{a 2.) - NR 10 -R} 11 - (R 11 is 1 to 20 carbon atoms A divalent hydrocarbon group, the same shall apply hereinafter), —NR ¹⁰ —R ¹¹ —NR ¹⁰ —, —NR ¹⁰ —CO—R ¹¹ —, —NR ¹⁰ —R ¹¹ —COO— and the like.

Here, when Z ¹ is a group having a nitrogen-containing heterocyclic structure, examples of the nitrogen-containing heterocyclic structure include a nitrogen-containing heterocyclic ring such as a piperidine ring, a piperazine ring, a hexamethyleneimine ring, and an imidazole ring. The structure from which 2 hydrogen atoms are removed is mentioned. The nitrogen-containing heterocycle is preferably a piperidine ring, a piperazine ring or a hexamethyleneimine ring. Note that the nitrogen-containing heterocycle may have a substituent. The above description of T ¹ and T ² can be applied to specific examples of the substituent.
The nitrogen-containing heterocyclic structure of Z ¹ may be directly bonded to A ¹ and A ² or may be bonded to A ¹ or A ² via a divalent linking group. As a bivalent coupling group in this case, -O-, -CO-, -COO-, -NH-, -NH-CO-, a C1-C10 alkanediyl group etc. are mentioned, for example.

Among these, Z ¹ has two or more hetero atoms in that it has a high reduction effect of residual DC voltage in the obtained liquid crystal display element and high reliability (especially long-term reliability), and A ¹ and Each A ² is preferably bonded with a different hetero atom. In this case, two or more hetero atoms contained in Z ¹ may be the same or different. Specific examples of such groups include, for example, —NR ¹⁰ —R ¹¹ —NR ¹⁰ —, —B ¹ —COO— (B ¹ is a piperidine-1,4-diyl group), piperazine-1,4. -A diyl group etc. are mentioned. Among these, Z ¹ preferably has two or more nitrogen atoms and is bonded to each of A ¹ and A ² with a different nitrogen atom from the viewpoint of reduction of residual DC voltage and reliability. .

As a specific example of a specific acid dianhydride, the compound etc. which are represented, for example with each of following formula (ts-1)-a formula (ts-8) are mentioned. In addition, specific acid dianhydride can use these 1 type individually or in combination of 2 or more types.

(Synthesis of specific acid dianhydride)
The specific acid dianhydride can be synthesized by appropriately combining conventional organic chemistry methods. Examples thereof include acid monoanhydride chlorides such as trimellitic anhydride chloride and 1,3-dioxooctahydroisobenzofuran-5-carbonyl chloride, and R ¹ HN-A ¹ -Z ¹ -A ² -NHR ^2. And, optionally, in the presence of a catalyst, preferably in an organic solvent. In addition, the synthesis | combining method of specific acid dianhydride is not limited above.

<Polyamic acid>
The polyamic acid (hereinafter also referred to as “polyamic acid [P]”) as the polymer [P] can be obtained by reacting a tetracarboxylic dianhydride containing a specific acid dianhydride with a diamine. it can.
(Tetracarboxylic acid dianhydride)
The tetracarboxylic dianhydride used for the synthesis of the polyamic acid [P] may be only the specific acid dianhydride, but together with the specific acid dianhydride, tetracarboxylic dianhydrides other than the specific acid dianhydride Or the like (hereinafter also referred to as "other acid dianhydrides") may be used in combination.

Examples of other acid dianhydrides include aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, and the like. Specific examples of these include aliphatic tetracarboxylic dianhydrides such as butane tetracarboxylic dianhydride;
Examples of alicyclic tetracarboxylic acid dianhydrides include 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-dicarboxylic acid dianhydride, etc. Oxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5-dioxotetrahydrofuran-3-yl) -8 -Methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro -3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3 , 5,6-To Carboxy-2-carboxymethyl norbornane-2: 3,5: 6-dianhydride, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-di Anhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1 .0 ^2,6 ] Undecane-3,5,8,10-tetraone, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, bicyclo [2.2.2] oct-7-ene-2, 3,5,6-tetracarboxylic dianhydride, ethylenediaminetetraacetic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, ethylene glycol bis (anhydrotrimellitate), 1, 3-propylene glycol bis (anhydride Rotrimellitate);
Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride and the like; respectively, and tetracarboxylic dianhydrides described in JP 2010-97188 A can be used. Other acid dianhydrides may be used alone or in combination of two or more.

  As other acid dianhydrides used for the synthesis of polyamic acid [P], bicyclo [2.2.1] heptane-2 is preferable in that the effect of the present invention can be suitably obtained in combination with a specific acid dianhydride. 1,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5- Dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, bicyclo [3.3.0] octane-2, 4,6,8-tetracarbon 2: 4,6: 8-dianhydride, 1,2,3,4-cyclopentane tetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride and pyromellitic acid dianhydride It is preferably at least one selected from the group consisting of products.

  In the synthesis of the polyamic acid [P], the ratio of use of the specific acid dianhydride (the total amount of two or more when used) is a synthesis from the viewpoint of sufficiently obtaining the improvement effect by the use of the specific acid dianhydride. It is preferable to set it as 1 mol% or more with respect to the whole quantity of the tetracarboxylic dianhydride used for this, It is more preferable to set it as 5 mol% or more, It is further more preferable to set it as 10 mol% or more. Further, the upper limit value of the use ratio of the specific acid dianhydride is not particularly limited, but from the viewpoint of enhancing the reliability of the liquid crystal display element obtained and the improvement effect of the residual DC voltage, the specific acid dianhydride and the other It is preferable to use an acid dianhydride in combination. Specifically, the data ratio of the specific acid dianhydride is preferably 80 mol% or less, more preferably 70 mol% or less, with respect to the total amount of tetracarboxylic acid dianhydride used in the synthesis. Preferably, it is more preferably 60 mol% or less.

(Diamine)
Examples of the diamine used for the synthesis of the polyamic acid [P] include aliphatic diamine, alicyclic diamine, aromatic diamine, and diaminoorganosiloxane. Specific examples thereof include aliphatic diamines such as metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis (aminomethyl) cyclohexane; As alicyclic diamines, for example, 1,4-diaminocyclohexane, 4,4'-methylenebis (cyclohexylamine) and the like;

（式（Ｅ−１）中、Ｘ^I及びＸ^IIは、それぞれ独立に、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。）
で表される化合物などの側鎖導入型のジアミン： Examples of aromatic diamines include dodecanoxydiaminobenzene, tetradecanoxydiaminobenzene, pentadecanoxydiaminobenzene, hexadecanoxydiaminobenzene, octadecanoxydiaminobenzene, cholestanyloxydiaminobenzene, and cholesteryloxydiaminobenzene. Cholestanyl diaminobenzoate, cholesteryl diaminobenzoate, lanostannyl diaminobenzoate, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 1,1-bis (4 -((Aminophenyl) methyl) phenyl) -4-butylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((amino Phenoxy Methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4- (4-heptylcyclohexyl) cyclohexane, N- (2,4-diaminophenyl) -4 -(4-Heptylcyclohexyl) benzamide, the following formula (E-1)

(In formula (E-1), X ^I and X ^II each independently represent a single bond, -O-, * -COO- or * -OCO- (wherein "*" represents a bond to X ^I 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, and b is 0 And c is an integer of 1 to 20, and d is 0 or 1. However, a and b can not be 0 simultaneously.)
Side chain introduction type diamines such as compounds represented by:

のそれぞれで表される化合物などの側鎖非導入型のジアミン、などを；
ジアミノオルガノシロキサンとして、例えば、１，３−ビス（３−アミノプロピル）−テトラメチルジシロキサンなどを；それぞれ挙げることができるほか、特開２０１０−９７１８８号公報に記載のジアミンを用いることができる。 p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 4-aminophenyl-4′-aminobenzoate, 4,4′-diaminoazobenzene, 1,5-bis (4-amino) Phenoxy) pentane, 1,7-bis (4-aminophenoxy) heptane, bis [2- (4-aminophenyl) ethyl] hexanedioic acid, N, N-bis (4-aminophenyl) methylamine, 3,5 -Diaminobenzoic acid, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 1,5-diaminonaphthalene, 2,2'-dimethyl-4, 4'-diaminobiphenyl, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, 2,7-diaminofluorene, 4,4'- Diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] Hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1 , 4-Bis (4-amino phenoxy) benzene, 4, 4'- bis (4- amino phenoxy) biphenyl, a following formula (N-1-1)-a formula (N-1-7)

A side chain non-introducing diamine, such as a compound represented by each of
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane; and the diamines described in JP-A 2010-97188 can be used.

Examples of the divalent group represented by “—X ^I — (R ^I —X ^II ) _d —” in the above formula (E-1) include alkanediyl groups having 1 to 3 carbon atoms, * —O—, * -COO- or _{* -O-C 2 H 4 -O-} ( where bond marked with "*" is bonded to the diamino phenyl group.) is preferably. Examples of the group “—C _c H _{2c + 1} ” include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a tridecyl group, and a tetradecyl group. Group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group and the like, and these are preferably linear. The two amino groups in the diaminophenyl group are preferably in the 2,4- or 3,5-position relative to the other group.

Specific examples of the compound represented by the formula (E-1) include, for example, compounds represented by the following formulas (E-1-1) to (E-1-4). .

  Among these, aromatic diamines can be preferably used as the diamine. The proportion of the aromatic diamine used is preferably 40 mol% or more, more preferably 50 mol% or more, and more preferably 70 mol% or more, based on the total amount of diamine used in the synthesis of the polyamic acid [P]. It is further preferred that In addition, a diamine can be used individually by 1 type or in combination of 2 or more types.

(Synthesis of polyamic acid)
The polyamic acid can be obtained by reacting the above-mentioned tetracarboxylic acid dianhydride and diamine with a molecular weight modifier as required. The ratio of the tetracarboxylic dianhydride and the diamine used in the polyamic acid synthesis reaction is 0.2 to 2 for the tetracarboxylic dianhydride acid anhydride group to 1 equivalent of the amino group of the diamine. The ratio which becomes equivalent is preferable, and the ratio which becomes 0.8 to 1.2 equivalent is more 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 phenyl isocyanate and naphthyl isocyanate. It can be mentioned. The use ratio of the molecular weight modifier is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less with respect to 100 parts by weight of the total of the tetracarboxylic dianhydride and diamine used.

  The synthesis reaction of polyamic acid is preferably carried out in an organic solvent. The reaction temperature at this time is preferably -20 ° C to 150 ° C, more preferably 0 to 100 ° C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.

  Examples of the organic solvent used in the reaction include aprotic polar solvents, phenol solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like. Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and a phenolic solvent (first group organic solvent), or one or more selected from the first group organic solvent And a mixture of at least one selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (second-group organic solvent). In the latter case, the proportion of the second group organic solvent used is preferably 50% by weight or less, more preferably 40% by weight, based on the total amount of the first group organic solvent and the second group organic solvent. Or less, more preferably 30% by weight or less.

  Particularly preferred organic solvents are N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol. At least one selected from the group consisting of halogenated phenols and specific solvents shown below is used as a solvent, or a mixture of one or more of these and another organic solvent is used in the above ratio It is preferable to do. The amount (a) of the organic solvent used is such that the total amount (b) of the tetracarboxylic acid dianhydride and the diamine is 0.1 to 50% by weight with respect to the total amount (a + b) of the reaction solution. Is preferred.

  As described above, a reaction solution obtained by dissolving polyamic acid [P] is obtained. The reaction solution may be used as it is for preparation of a liquid crystal aligning agent, or may be used for preparing a liquid crystal aligning agent after isolating polyamic acid contained in the reaction solution, or the isolated polyamic acid is purified. You may use for preparation of a liquid crystal aligning agent. When polyamic acid is subjected to dehydration ring closure to form a polyimide, the reaction solution may be subjected to dehydration ring closure reaction as it is, or polyamic acid contained in the reaction solution may be isolated and then subjected to dehydration ring closure reaction. Alternatively, the isolated polyamic acid may be purified and then subjected to a dehydration ring closure reaction. The isolation and purification of the polyamic acid can be carried out according to known methods.

<Polyamic acid ester>
The polyamic acid ester (hereinafter also referred to as “polyamic acid ester [P]”) as the polymer [P] includes, for example, [I] a polyamic acid [P] obtained by the above polymerization reaction and an esterifying agent. It can be obtained by a method of reacting, [II] a method of reacting a tetracarboxylic acid diester and a diamine, or [III] a method of reacting a tetracarboxylic acid diester dihalide and a diamine.

  In the present specification, the term "tetracarboxylic acid diester" means a compound in which two of four carboxyl groups possessed by a tetracarboxylic acid are esterified and the remaining two are carboxyl groups. The "tetracarboxylic acid diester dihalide" means a compound in which two of four carboxyl groups possessed by the tetracarboxylic acid are esterified and the remaining two are halogenated.

  As an esterifying agent used by method [I], a hydroxyl-containing compound, an acetal type compound, a halide, an epoxy-group containing compound etc. are mentioned, for example. Specific examples of these include hydroxyl group-containing compounds such as alcohols such as methanol, ethanol and propanol, phenols such as phenol and cresol, etc .; and acetal compounds such as N, N-dimethylformamide diethyl acetal, N, N-diethylformamide diethyl acetal and the like; as a halide, for example, methyl bromide, ethyl bromide, stearyl bromide, methyl chloride, stearyl chloride, 1,1,1-trifluoro-2-iodoethane and the like; epoxy group-containing As a compound, a propylene oxide etc. can be mentioned, for example.

The tetracarboxylic acid diester used in the method [II] can be obtained, for example, by ring-opening the tetracarboxylic dianhydride exemplified in the synthesis of the polyamic acid with alcohols such as methanol and ethanol. However, the tetracarboxylic dianhydride used includes a specific dianhydride. In the reaction, only tetracarboxylic acid diester may be used as a tetracarboxylic acid derivative, but tetracarboxylic acid dianhydride may be used in combination.
The reaction of method [II] is preferably carried out in an organic solvent in the presence of a suitable dehydration catalyst. As an organic solvent, the organic solvent illustrated as what is used for the synthesis | combination of polyamic acid [P] can be mentioned. Examples of the dehydration catalyst include 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium halide, carbonylimidazole, a phosphorus condensing agent, and the like. The reaction temperature at this time is preferably -20 ° C to 150 ° C, and more preferably 0 to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, more preferably from 0.5 to 12 hours.

The tetracarboxylic acid diester dihalide used in Method [III] can be obtained, for example, by reacting the tetracarboxylic acid diester obtained as described above with an appropriate chlorinating agent such as thionyl chloride. However, the tetracarboxylic dianhydride used includes a specific acid dianhydride. In the reaction, only tetracarboxylic acid diester dihalide may be used as the tetracarboxylic acid derivative, but tetracarboxylic acid dianhydride may be used in combination.
The reaction of Method [III] is preferably carried out in an organic solvent in the presence of a suitable base. As an organic solvent, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid can be mentioned. As the base, for example, tertiary amines such as pyridine and triethylamine; alkali metals such as sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium and potassium can be preferably used. The reaction temperature at this time is preferably -20 ° C to 150 ° C, and more preferably 0 to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, more preferably from 0.5 to 12 hours.

  The polyamic acid ester [P] to be contained in the liquid crystal aligning agent may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist. The reaction solution obtained by dissolving the polyamic acid ester [P] may be used as it is for the preparation of a liquid crystal aligning agent, and the polyamic acid ester contained in the reaction solution is isolated and then subjected to the preparation of a liquid crystal aligning agent. Alternatively, the isolated polyamic acid ester may be purified and used for the preparation of the liquid crystal aligning agent. Isolation and purification of the polyamic acid ester can be carried out according to known methods.

[Polyimide]
The polyimide as the polymer [P] (hereinafter also referred to as “polyimide [P]”) can be obtained, for example, by dehydrating and ring-closing the polyamic acid [P] synthesized as described above to imidize. it can.

  The polyimide [P] may be a completely imidized product in which all of the amic acid structure possessed by the polyamic acid [P], which is its precursor, has been subjected to dehydration ring closure, and may be a completely imidized product. A partially imidized product in which an amic acid structure and an imide ring structure coexist may be used. The polyimide to be used preferably has an imidization ratio of 20% or more, more preferably 30 to 99%, and still more preferably 40 to 99%. This imidation ratio represents the ratio of the number of imide ring structures to the total of the number of polyimide amic acid structures and the number of imide ring structures in percentage. Here, part of the imide ring may be an isoimide ring.

  The dehydration ring closure of polyamic acid is preferably performed by a method of heating polyamic acid or a method of dissolving polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to this solution, and heating as necessary. . Of these, the latter method is preferred.

  In the method of adding a dehydrating agent and a dehydrating ring-closing catalyst to a solution of polyamic acid, an acid anhydride such as acetic anhydride, propionic anhydride, trifluoroacetic anhydride and the like can be used as the dehydrating agent. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of the amic acid structure of a polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, triethylamine and the like can be used. The amount of the dehydration ring closure catalyst used is preferably 0.01 to 10 moles per mole of the dehydrating agent used. As an organic solvent used for a dehydration ring-closing reaction, the organic solvent illustrated as what is used for the synthesis | combination of polyamic acid [P] can be mentioned. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction time is preferably 1.0 to 120 hours, more preferably 2.0 to 30 hours.

  Thus, a reaction solution containing polyimide [P] is obtained. The reaction solution may be used as it is for the preparation of a liquid crystal aligning agent, or may be used for the preparation of a liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring closure catalyst from the reaction solution. It may be subjected to the preparation of the alignment agent, or it may be subjected to the preparation of the liquid crystal alignment agent after purifying the isolated polyimide. These purification operations can be performed according to known methods. In addition, a polyimide can also be obtained by imidation of polyamic acid ester [P].

（式（２）及び式（３）中、Ｔ^１、Ｔ^２、Ｒ^１、Ｒ^２、Ａ^１、Ａ^２及びＺ^１は、それぞれ上記式（１）と同義である。Ｒ^３及びＲ^４は、それぞれ独立に、水素原子又は１価の有機基である。） The polymer [P] obtained as described above is at least one selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, and has a partial structure represented by the following formula (2) and the following formula ( And at least one selected from the group consisting of the partial structures represented by 3).

(In Formula (2) and Formula (3), T ¹ , T ² , R ¹ , R ² , A ¹ , A ² and Z ¹ each have the same meaning as in Formula (1) above) R ³ and R ⁴ Are each independently a hydrogen atom or a monovalent organic group.)

For specific examples and preferred examples of the above formula (2) and ^{T 1,} T ² in the formula (3), ^R 1, R ^2, A 1, ^{A 2} and ^{Z 1} are the description of the above formula (1) It can apply.
The monovalent organic group of R ³ and R ^4, for example, monovalent hydrocarbon group having 1 to 10 carbon atoms, and the like groups having the cinnamic acid structure.
In the polymer [P], the content ratio of the partial structure represented by the above formula (1) is the total amount of structural units constituting the polymer [P] (the monomer used in the synthesis of the polymer [P]). The total amount is preferably 0.5 to 40 mol%, more preferably 2.5 to 35 mol%, and still more preferably 5 to 30 mol%.

The polymer [P] to be contained in the liquid crystal aligning agent preferably has a solution viscosity of 10 to 800 mPa · s, when it is made into a solution having a concentration of 10% by weight, and a solution of 15 to 500 mPa · s. More preferably, it has a viscosity. In addition, the solution viscosity (mPa · s) of the above polymer is based on a polymer solution having a concentration of 15% by weight prepared using a good solvent for the polymer (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). The value measured at 25 ° C. using an E-type rotational viscometer.
The weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) of the polymer [P] is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. It is. Moreover, the molecular weight distribution (Mw / Mn) represented by the ratio between Mw and the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. By being in such a molecular weight range, it is possible to ensure good orientation and stability of the liquid crystal display element.

«Other ingredients»
The liquid crystal aligning agent of this indication may contain other components other than the said polymer [P] in the range which does not prevent the objective and effect of this indication.
<Other polymers>
Examples of the other components include polymers other than the polymer [P] (hereinafter, also referred to as "other polymers") and the like. Other polymers can be used to improve solution properties and electrical properties. Specific examples of the other polymer include, for example, a polyamic acid obtained by reacting the other acid dianhydride with a diamine, an imidized polymer of the polyamic acid, an esterified polymer of the polyamic acid, Polysiloxane, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly (meth) acrylate and the like can be mentioned.
When other polymers are blended in the liquid crystal aligning agent, the blending ratio is 50 parts by weight or less with respect to a total of 100 parts by weight of the polymer [P] and the other polymers contained in the liquid crystal aligning agent. Preferably, it is 40 parts by weight or less, more preferably 30 parts by weight or less.

  As other components, other than the above, for example, a compound having at least one epoxy group in the molecule, a functional silane compound, a surfactant, a filler, a pigment, an antifoamer, a sensitizer, a dispersant, an antioxidant Agents, adhesion aids, antistatic agents, leveling agents, antibacterial agents and the like. In addition, these compounding ratios can be suitably set in the range which does not prevent the effect of this invention according to each compound to mix | blend.

<Solvent>
The liquid crystal aligning agent of the present disclosure is prepared as a liquid composition in which the polymer [P] and other components optionally used are preferably dispersed or dissolved in an appropriate organic solvent.

  As the solvent to be used, for example, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene Glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol i-propyl ether, Ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol Diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, etc. It can be mentioned. These can be used individually by 1 type or in mixture of 2 or more types.

  The solid concentration in the liquid crystal aligning agent of the present disclosure (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility and the like. The range is preferably 1 to 10% by weight. That is, the liquid crystal aligning agent of this indication is apply | coated to the substrate surface so that it may mention later, Preferably the coating film which becomes a liquid crystal aligning film or a coating film used as a liquid crystal aligning film is formed by heating. At this time, when the solid content concentration is less than 1% by weight, the film thickness of the coating film becomes too small, and it becomes difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes too large to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases and the coatability decreases. There is a tendency.

  The particularly preferable solid content concentration range varies depending on the method of applying the liquid crystal aligning agent to the substrate. For example, in the case of the spinner method, the solid content concentration is particularly preferably in the range of 1.5 to 4.5% by weight. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s. The temperature at the time of preparing the liquid crystal aligning agent of this indication becomes like this. Preferably it is 10-50 degreeC, More preferably, it is 20-30 degreeC.

≪Liquid crystal alignment film and liquid crystal display element≫
The liquid crystal alignment film of the present disclosure is formed by the liquid crystal aligning agent prepared as described above. Moreover, the liquid crystal display element of this indication comprises the liquid crystal aligning film formed using the said liquid crystal aligning agent. The driving mode of the liquid crystal display element is not particularly limited, and can be applied to various driving modes such as TN type, STN type, IPS type, FFS type, VA type, MVA type, and PSA type.

  The liquid crystal display element of this indication can be manufactured by the method of including the following processes 1-3, for example. In step 1, the substrate to be used varies depending on the desired drive mode. Step 2 and step 3 are common to each drive mode.

<Step 1: Formation of Coating Film>
First, a liquid crystal aligning agent is apply | coated on a board | substrate, Then, a coating film is formed on a board | substrate by heating an application surface.
(1-1) When manufacturing a TN type, STN type, VA type, MVA type or PSA type liquid crystal display element, a pair of substrates each provided with a patterned transparent conductive film is used as a pair. The liquid crystal aligning agent is preferably applied on the formation surface of the transparent conductive film by an offset printing method, a spin coating method, a roll coater method or an ink jet printing method. Here, as the substrate, for example, glass such as float glass and soda glass; transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate and poly (alicyclic olefin) can be used. As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. Can be used. In order to obtain a patterned transparent conductive film, for example, a method of forming a pattern by photo-etching after forming a transparent conductive film without a pattern, a method of using a mask having a desired pattern when forming a transparent conductive film, etc. be able to. In applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound or a functional titanium compound is formed on the surface of the substrate surface on which the coating film is formed. It is also possible to perform a pretreatment to apply the above in advance.

  After application of the liquid crystal alignment agent, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied alignment agent. The prebake temperature is preferably 30 to 200 ° C., more preferably 40 to 150 ° C., and particularly preferably 40 to 100 ° C. The pre-bake time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes. Thereafter, a firing (post-baking) step is carried out for the purpose of completely removing the solvent and, if necessary, for thermal imidization of the amic acid structure present in the polymer. The baking temperature (post-baking temperature) at this time is preferably 80 to 300 ° C., more preferably 120 to 250 ° C. The post-bake time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The film thickness of the film thus formed is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

  (1-2) In the case of producing an IPS type or FFS type liquid crystal display element, an electrode is provided on the electrode formation surface of a substrate provided with an electrode made of a transparent conductive film or a metal film patterned in a comb shape A liquid crystal aligning agent is applied to one surface of the counter substrate that is not formed, and then the coated surface is formed by heating each coated surface. The material of the substrate and the transparent conductive film used at this time, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film or metal film, the pretreatment of the substrate, and the preferred thickness of the coating film formed It is the same as (1-1). For example, a film made of a metal such as chromium can be used as the metal film.

  In both cases (1-1) and (1-2), after applying a liquid crystal aligning agent on the substrate, a coating film to be an alignment film is formed by removing the organic solvent. At this time, when the polymer contained in the liquid crystal aligning agent is a polyamic acid, a polyamic acid ester, or an imidized polymer having an imide ring structure and an amic acid structure, a film is formed. It is good also as a more imidized coating film by advancing the dehydration ring closure reaction later by further heating.

<Process 2: Orientation ability imparting treatment>
In the case of producing a TN type, STN type, IPS type or FFS type liquid crystal display element, the coating film formed in the above step 1 is subjected to a treatment for imparting liquid crystal alignment ability. Thereby, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. Examples of the alignment ability imparting treatment include a rubbing treatment in which a coating film is rubbed in a fixed direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton, and photo-alignment in which the coating film is irradiated with polarized or non-polarized radiation. Processing etc. are mentioned. On the other hand, when manufacturing a VA type liquid crystal display element, the coating film formed in the above step 1 can be used as it is as a liquid crystal alignment film, but the coating film may be subjected to alignment ability imparting treatment.

When the liquid crystal alignment ability is imparted to the coating film by the photo-alignment treatment, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used as the radiation applied to the coating film. If the radiation is polarized, it may be linearly polarized or partially polarized. When the radiation used is linearly polarized light or partially polarized light, irradiation may be performed from a direction perpendicular to the substrate surface, an oblique direction, or a combination thereof. When irradiating non-polarized radiation, the direction of irradiation is an oblique direction.
As a light source to be used, for example, 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, or the like can be used. Ultraviolet light in a preferred wavelength range can be obtained by means of using a light source in combination with, for example, a filter, a diffraction grating or the like. The dose of radiation is preferably 100 to 50,000 J / m ² , more preferably 300 to 20,000 J / m ² . In addition, light irradiation of the coating may be performed while heating the coating in order to enhance the reactivity. The temperature upon heating is usually 30 to 250 ° C, preferably 40 to 200 ° C, and more preferably 50 to 150 ° C.

  The liquid crystal alignment film after rubbing treatment is further irradiated with ultraviolet light to a part of the liquid crystal alignment film to change the pretilt angle of a part of the liquid crystal alignment film, or The resist film may be formed on the portion, and the rubbing treatment may be performed in a direction different from the rubbing treatment described above, and then the resist film may be removed to make the liquid crystal alignment film have different liquid crystal alignment capabilities for each region. . In this case, it is possible to improve the visibility characteristics of the obtained liquid crystal display element. The liquid crystal alignment film suitable for a VA type liquid crystal display element can be suitably used also for a liquid crystal display element of PSA (Polymer sustained alignment) type.

[Step 3: Construction of liquid crystal cell]
(3-1) A liquid crystal cell is manufactured by preparing two substrates on which the liquid crystal alignment film is formed as described above, and disposing a liquid crystal between two substrates disposed opposite to each other. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example.
The first method is a conventionally known method. In this method, first, two substrates are disposed opposite to each other via a gap (cell gap) such that the liquid crystal alignment films face each other. Next, the peripheral portions of the two substrates are bonded together using a sealant, and liquid crystal is injected and filled in the cell gap defined by the substrate surface and the sealant, and then the injection hole is sealed, whereby the liquid crystal cell Manufacturing.
The second method is a method called an ODF (One Drop Fill) method. In this method, for example, a UV curable sealant is applied to a predetermined place on one of the two substrates on which the liquid crystal alignment film is formed. Next, after the liquid crystal is dropped at predetermined locations on the surface of the liquid crystal alignment film, the other substrate is bonded so that the liquid crystal alignment film faces, and the liquid crystal is spread over the entire surface of the substrate. Then, the liquid crystal cell is manufactured by irradiating the entire surface of the substrate with ultraviolet light to cure the sealant.
Regardless of which method is used, the liquid crystal cell produced as described above is further heated to a temperature at which the liquid crystal used takes an isotropic phase and then gradually cooled to room temperature. It is desirable to remove.

As the sealing agent, for example, an epoxy resin containing a hardening agent and aluminum oxide spheres as a spacer can be used.
Examples of liquid crystals include nematic liquid crystals and smectic liquid crystals, among which nematic liquid crystals are preferred. For example, Schiff base liquid crystals, azoxy liquid crystals, biphenyl liquid crystals, phenylcyclohexane liquid crystals, ester liquid crystals, terphenyl liquid crystals, biphenyl A cyclohexane type liquid crystal, a pyrimidine type liquid crystal, a dioxane type liquid crystal, a bicyclooctane type liquid crystal, a cubane type liquid crystal, or the like can be used. In addition, cholesteric liquid crystals such as colestil chloride, cholesteryl nonaate, cholesteryl carbonate, and the like; and chiral agents such as those sold under the trade names "C-15" and "CB-15" (manufactured by Merck). And ferroelectric liquid crystals such as p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate may be added and used.

(3-2) When manufacturing a PSA type liquid crystal display element, a liquid crystal cell is constructed in the same manner as in the above (3-1) except that a photopolymerizable compound is injected or dropped together with a liquid crystal. After that, light is irradiated to the liquid crystal cell in a state where a voltage is applied between the conductive films of the pair of substrates. The voltage applied here can be, for example, 5 to 50 V direct current or alternating current. Moreover, as light to irradiate, the ultraviolet-ray and visible light which contain light with a wavelength of 150-800 nm can be used, for example, However, The ultraviolet-ray containing light with a wavelength of 300-400 nm is preferable. As a light source of irradiation light, 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 etc. can be used, for example. In addition, the ultraviolet-ray of said preferable wavelength area can be obtained by the means etc. which use a light source together with a filter diffraction grating etc., for example. The irradiation dose of light, preferably 1,000~200,000J / ^{m 2,} more preferably from 1,000~100,000J / ^{m 2.}

  (3-3) When a coating film is formed on a substrate using a liquid crystal aligning agent containing a compound having a photopolymerizable group, a liquid crystal cell is constructed in the same manner as the above (3-1), and then a pair of A method may be employed in which a liquid crystal display element is manufactured by subjecting a liquid crystal cell to light irradiation in a state in which a voltage is applied between conductive films of a substrate. According to this method, the PSA mode can be realized with a small amount of light irradiation. The voltage to be applied may be, for example, direct current or alternating current of 0.1 to 30 V. About the conditions of the light to irradiate, description of said (3-2) is applicable.

  And the liquid crystal display element of this indication can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell. As a polarizing plate to be bonded to the outer surface of a liquid crystal cell, the polarizing plate or H film itself is a polarizing film called “H film” which absorbs iodine while drawing and orienting polyvinyl alcohol, sandwiched by a cellulose acetate protective film The polarizing plate which consists of can be mentioned.

  The liquid crystal display device of the present disclosure can be effectively applied to various devices, and, for example, clocks, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, It can be used for various displays such as various monitors, liquid crystal televisions, and information displays.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

In the following examples, the solution viscosity of the polymer solution was measured by the following method.
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 for a solution prepared to a polymer concentration of 10% by weight using a predetermined solvent.
Hereinafter, the “compound represented by the formula (X)” may be simply abbreviated as “compound (X)”.

<Synthesis of Compound>
Example 1-1 Synthesis of Compound (ts-1)
Compound (ts-1) was synthesized according to the following scheme 1.

A solution obtained by dissolving 39.4 g of N4, N4′-bis- (4-aminophenyl) -N4, N4′-dimethylbiphenyl-4,4′-diamine in 18 mL of pyridine and 900 mL of tetrahydrofuran under a nitrogen atmosphere To 44.7 g of trimellitic anhydride chloride dissolved in 300 mL of hydrofuran was added dropwise over 30 minutes at 0 ° C. Stir at 0 ° C. for 1 hour and then at room temperature for 4 hours. After the reaction, the solvent was removed by distillation under reduced pressure to obtain a mixture of a compound (ts-1), a compound (ts-1a), and a compound (ts-1b).
Subsequently, 80 g of acetic acid and 80 g of acetic anhydride were added, and the mixture was stirred at 100 ° C. for 3 hours. The solid was thoroughly washed with acetic acid, acetic anhydride and normal hexane, and then dried under reduced pressure to obtain 71.7 g of a target compound (ts-1).

Example 1-2 Synthesis of Compound (ts-2)
Compound (ts-2) was synthesized according to the following scheme 2.

Anhydrous trimellit in which 31.1 g of 4- (4-aminophenoxycarbonyl) -1- (4-aminophenyl) piperidine is dissolved in 18 mL of pyridine and 900 mL of tetrahydrofuran and dissolved in 300 mL of tetrahydrofuran in a nitrogen atmosphere. It was dripped over 30 minutes at 0 degreeC with respect to 44.7g of acid chlorides. Stir at 0 ° C. for 1 hour and then at room temperature for 4 hours. After the reaction, the solvent was removed by distillation under reduced pressure to obtain a mixture of compound (ts-2), compound (ts-2a) and compound (ts-2b).
Subsequently, 80 g of acetic acid and 80 g of acetic anhydride were added and stirred at 100 ° C. for 3 hours. The solid was thoroughly washed with acetic acid, acetic anhydride and normal hexane, and then dried under reduced pressure to obtain 62.7 g of the compound (ts-2) as a target product.

[Example 1-3: Synthesis of compound (ts-3)]
Compound (ts-3) was synthesized according to the following scheme 3.

1,3-dioxooctahydroisobenzofuran-5-carbonyl dissolved in 2mL of 4,4'-diaminobenzanilide in 18 mL of pyridine and 900 mL of tetrahydrofuran is dissolved in 300 mL of tetrahydrofuran in a nitrogen atmosphere. It was dripped over 30 minutes with respect to 47.6g of chlorides at 0 degreeC. Stir at 0 ° C. for 1 hour and then at room temperature for 4 hours. After the reaction, the solvent was removed by distillation under reduced pressure to obtain a mixture of a compound (ts-3), a compound (ts-3a), and a compound (ts-3b).
Subsequently, 80 g of acetic acid and 80 g of acetic anhydride were added and stirred at 100 ° C. for 3 hours. The solid was thoroughly washed with acetic acid, acetic anhydride and normal hexane, and then dried under reduced pressure to obtain 54.6 g of a compound of interest (ts-3).

<Synthesis of polymer>
Example 2-1 Synthesis of Polymer (P-1)
50 mol parts of compound (ts-1) and 50 mol parts of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride, and 100 mol parts of 4,4′-ethylenedianiline as diamine Was dissolved in N-methyl-2-pyrrolidone (NMP) and reacted at room temperature for 6 hours to obtain a solution containing 20% by weight of polyamic acid. The solution viscosity measured by taking a small amount of the obtained polyamic acid (referred to as “polymer (P-1)”) solution was 450 mPa · s.

[Examples 2-2 to 2-4 and Synthesis examples 1 to 6 and 8]
A polyamic acid (polymers (P-2) to (P-4)) was prepared in the same manner as in Example 2-1 except that the types and amounts of tetracarboxylic dianhydride and diamine used were changed as shown in Table 1 below. And polymers (rP-1) to (rP-6) and (rP-8)) were synthesized.
[Synthesis Example 7]
100 mol parts of N4, N4'-bis- (4-aminophenyl) -N4, N4'-dimethylbiphenyl-4,4'-diamine is dissolved in 102 mol parts of pyridine and NMP, and 102 mol parts of trimellitic anhydride chloride Was added in several portions at 0.degree. The reaction was carried out at room temperature for 6 hours, reprecipitated with water, and then redissolved in NMP to obtain a solution containing 20% by weight of polyamideimide. The solution viscosity measured by fractionating the obtained polyamideimide solution (this is referred to as polymer “Q-7”) was 300 mPa · s.

＜ジアミン＞
ｄ−１：４，４’−エチレンジアニリン
ｄ−２：４，４’−ジアミノジフェニルエーテル
ｄ−３：４，４’−ジアミノジフェニルメタン
ｄ−４：Ｎ４，Ｎ４’−ビス−（４−アミノフェニル）−Ｎ４，Ｎ４’−ジメチルビフェニル−４，４’−ジアミン
ｄ−５：ｐ−フェニレンジアミン
ｄ−６：４，４’−ジアミノベンズアニリド In Table 1, the numerical values of the acid anhydride and the diamine represent the use ratio [mol part] of each compound to the total of 100 mol parts of the acid anhydride used in the synthesis of the polymer. The abbreviations in Table 1 have the following meanings.
<Tetracarboxylic dianhydride>
a-1: 1,2,3,4-cyclobutanetetracarboxylic dianhydride a-2: pyromellitic dianhydride a-3: 2,3,5-tricarboxycyclopentylacetic acid dianhydride a-4: Compound a-5 represented by the following formula (a-4): compound a-6 represented by the following formula (a-5): compound a-7 represented by the following formula (a-6): Compound represented by (a-7) <Acid monoanhydride chloride>
m-1: trimellitic anhydride chloride

<Diamine>
d-1: 4,4'-ethylenedianiline d-2: 4,4'-diaminodiphenyl ether d-3: 4,4'-diaminodiphenylmethane d-4: N4, N4'-bis- (4-aminophenyl) ) -N4, N4'-Dimethylbiphenyl-4,4'-diamine d-5: p-phenylenediamine d-6: 4,4'-diaminobenzanilide

Example 3-1
1. Preparation of liquid crystal aligning agent As a polymer component, NMP and butyl cellosolve (BC) are added to the solution containing the polymer (P-1) obtained in Example 2-1 above, and the mixture is sufficiently stirred. : BC = 70: 30 (weight ratio), It was set as the solution of solid content concentration 4.0 weight%. The solution was filtered using a filter with a pore diameter of 0.20 μm to prepare a liquid crystal aligning agent.

2. Manufacture of a liquid crystal cell The liquid crystal aligning agent prepared above was applied to the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film using a liquid crystal alignment film printer (Nissha Printing Co., Ltd.), and 80 ° C. After heating (pre-baking) on the hot plate for 1 minute to remove the solvent, heating (post-baking) on a hot plate at 230 ° C. for 10 minutes to form a coating film having an average film thickness of 0.10 μm. This coating film was rubbed with a rubbing machine having a roll wrapped with a rayon cloth at a roll rotation speed of 1000 rpm, a stage moving speed of 20 mm / sec, and a hair foot indentation length of 0.4 mm to give liquid crystal alignment ability. . Then, ultrasonic cleaning was performed for 90 seconds in ultrapure water, and then dried in a clean oven at 100 ° C. for 10 minutes to obtain a substrate having a liquid crystal alignment film. The above operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film.
Next, for one of the pair of substrates, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm to the outer edge of the surface having the liquid crystal alignment film, the pair of rubbing directions are orthogonal to each other. The substrates were stacked and pressure-bonded so that the liquid crystal alignment film faces each other, and the adhesive was cured. 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 acrylic photocurable adhesive to produce a liquid crystal cell. .

3. Evaluation of liquid crystal alignment The presence or absence of abnormal domains in the change in brightness when a voltage of 5 V was turned ON / OFF (applied / released) was observed with a microscope at a magnification of 50 times for the liquid crystal cell produced above. In the evaluation, the case where no abnormal domain was observed was regarded as “good” in liquid crystal alignment, and the case where an abnormal domain was observed was regarded as “defective” in liquid crystal alignment. In this liquid crystal display element, the liquid crystal alignment was "good".

4. Evaluation of long-term reliability The voltage holding ratio was measured for the liquid crystal cell manufactured above with a voltage of 1 V applied for 60 microseconds and a frame period of 16.7 msec, and this was defined as an initial value VHR _BF . Then, the liquid crystal cell was left for 50 days under backlight lighting, and the voltage retention VHR _AF after standing was measured in the same manner. A value obtained by dividing the obtained VHR _AF by VHR _BF was defined as a change rate ΔVHR (= VHR _AF / VHR _BF ), and long-term reliability was evaluated based on the change rate ΔVHR. The measuring device used was VHR-1 manufactured by Toyo Corporation. As a result, in this example, ΔVHR = 0.97, and the long-term reliability of the liquid crystal cell was good.

5. Evaluation of Residual DC Voltage A 2 V DC voltage was applied to the liquid crystal cell produced above under a temperature condition of 75 ° C. for 1 hour. After the voltage application was released, the voltage [mV] remaining in the liquid crystal cell was measured. As a result, the liquid crystal cell of this example had a residual DC voltage = 2 mV.

[Examples 3-2 to 3-5 and Comparative Examples 1 to 7]
The liquid crystal aligning agent was respectively prepared with the same solvent ratio and solid content concentration as Example 3-1 except that the type of the polymer to be used was changed as shown in Table 2 below. In addition, a liquid crystal cell was produced in the same manner as in Example 3-1, using each liquid crystal aligning agent, and various evaluations were performed in the same manner as in Example 3-1, using the obtained liquid crystal cell. The results are shown in Table 2 below.

  In Examples 3-5, two types of polymers were used. In Table 2, the numerical value in the parenthesis of the polymer indicates the use ratio of each compound to 100 parts by weight of the total amount of the polymer used for the preparation of the liquid crystal aligning agent.

  As is clear from Table 2, in all of the liquid crystal aligning agents (Example 3-1 to Example 3-5) containing the polymer [P], the solubility of the polymer in the solvent was good. In addition, the liquid crystal cell has good liquid crystal orientation, and it is difficult for the voltage holding ratio to be lowered even when placed under backlight irradiation for a long time. In addition, the residual DC voltage also showed a low value of about several to several tens of mV in the examples. On the other hand, in the liquid crystal aligning agent (comparative examples 1-7) which does not contain polymer [P], the residual DC voltage showed the value high compared with the thing of an Example. In addition, the decrease in the voltage holding ratio when the backlight was irradiated for a long time was large. Furthermore, in Comparative Examples 5 to 7, the solubility of the polymer was poor, and in Comparative Examples 3 to 5 and 7, the liquid crystal alignment was evaluated as “impossible”.

Claims (4)

Liquid crystal aligning agent containing the polymer [P] which is at least 1 type chosen from the group which consists of a polyamic acid, a polyamic acid ester, and a polyimide, and has a partial structure derived from the compound represented by following formula (1) .

(In Formula (1), T ¹ and T ² are each independently a trivalent group obtained by removing three hydrogen atoms from a benzene ring or a cyclohexane ring , and R ¹ and R ² are each independently, is hydrogen atom, a ¹ and a ² are each independently, .Z ¹ is a nitrogen atom-containing having one or more divalent atoms which is a divalent group obtained by removing two hydrogen atoms from a benzene ring And is bonded to at least one of A ¹ and A ^{2 by} a nitrogen atom.) The liquid crystal aligning agent according to claim 1, wherein Z ¹ has two or more nitrogen atoms, and is bonded to each of A ¹ and A ² by different nitrogen atoms. The liquid crystal aligning film formed using the liquid crystal aligning agent of Claim 1 or 2 . The liquid crystal display element which comprises the liquid crystal aligning film of Claim 3 .