JP6561475B2 - Liquid crystal aligning agent, liquid crystal aligning film and method for producing the same, liquid crystal display element, retardation film and method for producing the same - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film and a manufacturing method thereof, a liquid crystal display element, a retardation film and a manufacturing method thereof.

  Conventionally, as a liquid crystal display element, various drive systems having different electrode structures, properties of liquid crystal molecules to be used, manufacturing processes, and the like have been developed. For example, a TN (Twisted Nematic) type and an STN (Super Twisted Nematic) type have been developed. Various liquid crystal display elements such as VA (Vertical Alignment), IPS (In-Plane Switching), and FFS (fringe field switching) are known. These liquid crystal display elements have a liquid crystal alignment film for aligning liquid crystal molecules. As a material for the liquid crystal alignment film, polyimide or a precursor thereof is generally used because various properties such as heat resistance, mechanical strength, and affinity with liquid crystal are good.

  In recent years, large-screen high-definition liquid crystal televisions are mainly used, and small display terminals such as smartphones and tablet PCs are widely used, and the demand for high-definition liquid crystal panels is increasing. Based on such a background, various liquid crystal aligning agents have been proposed in order to improve the display quality and reliability of the liquid crystal panel (see, for example, Patent Document 1 and Patent Document 2). In Patent Document 1, a polymer obtained by reacting a tetracarboxylic dianhydride, a diamine, and a diol such as 2,2-bis (4-hydroxyphenyl) propane is used as a polymer component of a liquid crystal aligning agent. It is disclosed to use. Patent Document 2 discloses that a liquid crystal alignment film is formed by heating a biphenyl type epoxy resin using a catechol novolac resin as a curing agent.

  In addition, various optical materials are used for liquid crystal display elements. Above all, retardation films eliminate the object of viewing color dependency and the viewing angle dependency that the display color and contrast ratio change depending on the visual direction. It is used for the purpose. As such retardation films, those having a liquid crystal alignment film formed on the surface of a substrate such as a TAC film and a liquid crystal layer formed by curing a polymerizable liquid crystal on the surface of the liquid crystal alignment film are known. ing. In recent years, a liquid crystal alignment film in a retardation film has been produced by using a photo-alignment method that imparts liquid crystal alignment ability by irradiating a radiation-sensitive organic thin film formed on the substrate surface with polarized or non-polarized radiation. Various liquid crystal aligning agents for retardation films for producing a liquid crystal aligning film by such a method have been proposed (for example, see Patent Document 3).

JP-A-9-304777 JP-A-10-330756 JP 2012-37868 A

  A liquid crystal display is manufactured by disposing a pair of substrates on which a liquid crystal alignment film is formed facing each other and disposing a liquid crystal between the pair of facing substrates. In this case, the pair of substrates is sealed with an epoxy resin or the like. It is pasted using an agent. Here, in touch panel type display panels represented by smartphones and tablet PCs, attempts have been made to narrow the frame in order to make the movable area of the touch panel wider and to make the liquid crystal panel more compact. On the other hand, with the narrowing of the frame of the liquid crystal panel, display unevenness may be visually recognized around the sealant, and there is a concern that the display quality may be affected. In order to increase the definition of the liquid crystal display, a liquid crystal display element in which display unevenness around the sealant is hardly visible (bezel unevenness resistance is high) is required.

  In addition, with the recent high definition of liquid crystal panels, the demand for display quality has become increasingly severe, and it is desirable that the afterimage characteristics and reliability of the liquid crystal display elements be excellent. Furthermore, when a retardation film is produced using a liquid crystal aligning agent, it is required that the adhesiveness to the substrate can withstand long-term use (adhesion reliability).

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal aligning agent capable of obtaining a liquid crystal display device having little display unevenness around the sealant and having excellent afterimage characteristics and reliability. To do. Another object of the present invention is to provide a liquid crystal aligning agent capable of obtaining a retardation film having good adhesion reliability.

  The inventors of the present invention diligently studied to solve the problems of the prior art as described above, and when a compound having a specific structure is contained in the liquid crystal aligning agent, display unevenness around the sealing agent can be reduced, and afterimage characteristics. And it discovered that the liquid crystal display element excellent in reliability could be obtained, and came to complete this invention. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal alignment film and method for producing the same, liquid crystal display element, retardation film and method for producing the same.

[1] An aromatic polyvalent hydroxy compound (A) having a partial structure (b) in which two or more hydrogen atoms bonded to an aromatic ring are substituted with a hydroxy group (however, the aromatic polyvalent hydroxy compound (A) Is a polymer, the aromatic polyvalent hydroxy compound (A) is at least one selected from the group consisting of a polyimide precursor, polyimide, polysiloxane, poly (meth) acrylate, and polyester). Liquid crystal aligning agent.
[2] A liquid crystal alignment film formed using the liquid crystal aligning agent of [1].
[3] A liquid crystal alignment film obtained by applying the liquid crystal aligning agent of [1] to a substrate to form a coating film, and irradiating the coating film with light.
[4] A liquid crystal alignment film obtained by applying the liquid crystal aligning agent of [1] to a substrate and then rubbing.
[5] Manufacture of a liquid crystal alignment film comprising: a step of applying the liquid crystal aligning agent of [1] above onto a substrate to form a coating film; and a step of irradiating the coating film with light to impart liquid crystal alignment ability. Method.
[6] A liquid crystal display device comprising the liquid crystal alignment film according to any one of [3] to [5].
[7] A retardation film comprising the liquid crystal alignment film of [2] or [3].
[8] A step of coating the liquid crystal aligning agent according to [1] on a substrate to form a coating film, a step of irradiating the coating film with light, and a polymerization property on the coating film after the light irradiation. And a step of applying and curing a liquid crystal.

  According to the liquid crystal aligning agent containing the aromatic polyvalent hydroxy compound (A), it is possible to reduce display unevenness around the sealing agent while improving the afterimage characteristics and reliability of the liquid crystal display element. Furthermore, a retardation film having good adhesion reliability to the substrate can be obtained.

The schematic block diagram of a FFS type liquid crystal display element. The plane schematic diagram of the top electrode used for manufacture of a rubbing alignment type liquid crystal display element. (A) is a top view of a top electrode, (b) is the elements on larger scale of a top electrode. The figure which shows the drive electrode of 4 systems. The plane schematic diagram of the top electrode used for manufacture of a photo-alignment type liquid crystal display element. (A) is a top view of a top electrode, (b) is the elements on larger scale of a top electrode.

  The liquid crystal aligning agent of the present invention is a liquid polymer composition in which a polymer component is preferably dissolved or dispersed in an organic solvent. Below, each component contained in the liquid crystal aligning agent of this invention and the other component arbitrarily mix | blended as needed are demonstrated.

<Aromatic polyvalent hydroxy compound (A)>
The liquid crystal aligning agent of the present invention contains an aromatic polyvalent hydroxy compound (A) having a partial structure (b) in which two or more hydrogen atoms bonded to an aromatic ring are substituted with a hydroxy group.
Examples of the aromatic ring in the partial structure (b) include a benzene ring, a naphthalene ring, and an anthracene ring. Among these, as the aromatic ring, a benzene ring is preferable. Moreover, the number of the hydroxy groups couple | bonded with an aromatic ring should just be 2 or more, Preferably it is 2-4, More preferably, it is 2 or 3, More preferably, it is two. The bonding position of the hydroxy group is not particularly limited. For example, when the aromatic ring is a benzene ring and there are two hydroxy groups bonded to the benzene ring, the positional relationship between the ortho position, the meta position, and the para position is Any of them may be used, but the ortho position or the para position is preferable.
The aromatic ring in the partial structure (b) may have a substituent other than a hydroxy group. Examples of the substituent include a fluoro group, a chloro group, a bromo group, an iodo group, a cyano group, an alkyl group, and an alkoxy group.

（式（１）中、Ｒ^１は１価の有機基であり、ｎは１〜３の整数であり、ｍは０〜２の整数である。ただし、ｎ＋ｍ≦３である。「＊」は結合手であることを示す。） When the aromatic ring of the partial structure (b) is a benzene ring, specific examples of the partial structure (b) include a structure represented by the following formula (1).

(In Formula (1), R ¹ is a monovalent organic group, n is an integer of 1 to 3, m is an integer of 0 to 2. However, n + m ≦ 3. Shows that it is a bond.)

Examples of R ^{1 in the} above formula (1) include a fluoro group, a chloro group, a bromo group, an iodo group, a cyano group, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. n is preferably 1 or 2, and more preferably 1. m is preferably 0 or 1, more preferably 0. In addition, about two "*" in the said Formula (1), the case where at least one of these bond hands couple | bonds with a hydrogen atom is included.

  The aromatic polyvalent hydroxy compound (A) may be a polymer, or may be an additive component blended separately from the polymer component of the liquid crystal aligning agent.

When the aromatic polyvalent hydroxy compound (A) is a polymer The aromatic polyvalent hydroxy compound (A) is a polymer having the partial structure (b) (hereinafter also referred to as “polymer (A)”). In this case, the polymer (A) has at least one selected from the group consisting of a polyimide precursor, polyimide, polysiloxane, poly (meth) acrylate, and polyester as a main skeleton. Here, examples of the polyimide precursor include polyamic acid and polyamic acid ester. Among these, the polymer (A) is at least one polymer (A1) selected from the group consisting of a polyimide precursor and a polyimide from the viewpoints of heat resistance, mechanical strength, affinity with liquid crystal, and the like. Is preferred. In addition, the polymer used for preparation of a liquid crystal aligning agent may be only 1 type, and 2 or more types may be sufficient as it.

  The polymer (A) may have the partial structure (b) in the main chain of the polymer or in the side chain of the polymer. Here, the “main chain” of the polymer in the present specification refers to a “trunk” portion composed of the longest chain of atoms in the polymer. It is allowed that the “trunk” portion includes a ring structure. Therefore, “having partial structure (b) in the main chain” means that this structure constitutes a part of the main chain. The “side chain” of the polymer refers to a portion branched from the “trunk” of the polymer. In addition, when a polymer (A) has the said partial structure (b) in a principal chain, it does not exclude that the said structure exists also in a side chain.

[Polyamic acid]
The polyamic acid as the polymer (A) can be obtained, for example, by reacting tetracarboxylic dianhydride with diamine. The polyamic acid can be obtained by polymerization in which the monomer composition contains at least one of a tetracarboxylic dianhydride having the partial structure (b) and a diamine having the partial structure (b). It is preferable to use a diamine having the partial structure (b) (hereinafter also referred to as “specific diamine”) in terms of a high degree of freedom in selecting a compound.

(Tetracarboxylic dianhydride)
Examples of tetracarboxylic dianhydrides used for the synthesis of polyamic acid include aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, and the like. it can. Specific examples of these include aliphatic tetracarboxylic dianhydrides such as butane tetracarboxylic dianhydride;
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-di 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-carboxymethylnorbornane-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-cyclohexane tetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene -2, 3,5,6-tetracarboxylic dianhydride, ethylenediaminetetraacetic acid dianhydride, cyclopentanetetracarboxylic dianhydride, ethylene glycol bis (anhydro trimellitate), 1,3-propylene glycol bis (anhydro Trimellitate ) Etc .;

  Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride, and the like, respectively, and JP 2010-97188 A The tetracarboxylic dianhydride described in 1. can be used. In addition, as tetracarboxylic dianhydride used for the synthesis | combination of a polyamic acid, these 1 type can be used individually or in combination of 2 or more types.

  As tetracarboxylic dianhydride, among others, bicyclo [2.2.1] heptane-2,3,5,6-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-tetracarboxylic acid 2: 4,6: 8-dianhydride, cyclohexanetetracarboxylic dianhydride And pyromellitic dianhydride Preferably contains at least one compound selected from the group consisting of. The amount of these preferred compounds used (the total amount when two or more are used) is preferably 5 mol% or more based on the total amount of tetracarboxylic dianhydride used for the synthesis of polyamic acid. It is more preferable to set it as 10 mol% or more, and it is more preferable to set it as 20 mol% or more.

（式（２−１）及び式（２−２）中、Ｒ^２、Ｒ^３及びＲ^４は、それぞれ独立に単結合又は２価の有機基である。ｎは１〜３の整数であり、ｒ１は０〜３の整数であり、ｒ２は０〜２の整数である。ただし、ｎ＋ｒ１≦４、ｎ＋ｒ２≦３である。Ｒ^１は上記式（１）と同義である。） (Diamine)
As long as the specific diamine has the partial structure (b), the remaining structure is not particularly limited. For example, the specific diamine is represented by the following formula (2-1) and the following formula (2-2). And the like.

(In Formula (2-1) and Formula (2-2), R ² , R ³ and R ⁴ are each independently a single bond or a divalent organic group. N is an integer of 1 to 3, r1 is an integer of 0 to 3, r2 is an integer of 0-2. However, n + r1 ≦ 4, n + r2 ≦ 3 a is .R ¹ is as defined in the above formula (1).)

In the above formulas (2-1) and (2-2), examples of the divalent organic group represented by R ² , R ^3, and R ⁴ include a divalent hydrocarbon group having 1 to 30 carbon atoms and the hydrocarbon. At least one methylene group of the group is —O—, —S—, —CO—, —COO—, —COS—, —NR ⁵ —, —CONR ⁵ —, —CO—NR ⁵ —CO— (provided that R ⁵ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.) And a group substituted with a divalent functional group. The hydrogen atom which the hydrocarbon group of R ² , R ³ and R ⁴ has may be substituted with, for example, a halogen atom.
For R ¹ and n, the description of the above formula (1) can be applied.

  Here, in the present specification, the “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 that are composed only of a chain structure without including a cyclic structure in the main chain. However, it may be saturated or unsaturated. The “alicyclic hydrocarbon group” means a hydrocarbon group that includes only an alicyclic hydrocarbon structure as a ring structure and does not include an aromatic ring structure. However, it is not necessary to be comprised only by the structure of an alicyclic hydrocarbon, The thing which has a chain structure in the part is also included. “Aromatic hydrocarbon group” means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be composed only of an aromatic ring structure, and a part thereof may include a chain structure or an alicyclic hydrocarbon structure.

Specific examples of the divalent hydrocarbon group in R ² , R ³ and R ⁴ include a chain hydrocarbon group such as a methylene group, ethylene group, propanediyl group, butanediyl group, pentanediyl group, hexane Alkanediyl groups such as diyl group, heptanediyl group, octanediyl group, nonanediyl group, and decandiyl group; alkenediyl groups such as vinylene group, propenediyl group, butenediyl group, pentenediyl group, and hexenediyl group; Or branched. Further, examples of the alicyclic hydrocarbon group include a cyclohexylene group, and examples of the aromatic hydrocarbon group include a phenylene group, a biphenylene group, and a naphthylene group.

Specific examples of the specific diamine include compounds represented by the following formulas (2-1-1) to (2-1-2) as the compounds represented by the formula (2-1). Examples of the compound represented by the formula (2-2) include compounds represented by the following formulas (2-2-1) to (2-2-2), respectively. In addition, specific diamine can be used individually by 1 type or in combination of 2 or more types.

  Although the specific diamine may be sufficient as the diamine used for the synthesis | combination of the polyamic acid as a polymer (A), other diamines other than a specific diamine may be used together.

  Examples of other diamines include aliphatic diamines, alicyclic diamines, aromatic diamines, and diaminoorganosiloxanes. Specific examples of these include aliphatic diamines such as m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and 1,3-bis (aminomethyl) cyclohexane. An alicyclic diamine such as 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine);

（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−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配向性基含有ジアミン： 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 are each independently a single bond, —O—, —COO— or —OCO—, and 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 an integer of 0 to 2, c is an integer of 1 to 20, and d is 0 or 1, provided that a and b are not 0 at the same time.)
Oriented group-containing diamine such as a compound represented by:

p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylamine, 4,4′-diaminodiphenyl sulfide, 4-aminophenyl-4′-aminobenzoate, 4,4′-diaminoazobenzene, 1 , 5-bis (4-aminophenoxy) pentane, 1,7-bis (4-aminophenoxy) heptane, bis [2- (4-aminophenyl) ethyl] hexanedioic acid, N, N-bis (4-amino) Phenyl) methylamine, 1,5-diaminonaphthalene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl, 4,4 '-Diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophen Fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 '-(p-phenylenediisopropyl Riden) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diamino Acridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N, N′-bis (4-aminophenyl) -benzidine, N, N′-bis (4-aminophenyl) -N, N′-dimethylbenzidine, 1,4-bis- (4-aminophenyl) -piperazine, 3,5-diaminobenzoic acid and the like;
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— (however, a bond marked with “*” is bonded to a diaminophenyl group) is preferred. 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-position or 3,5-position with respect to other groups.

なお、ポリアミック酸の合成に使用するその他のジアミンとしては、これらの化合物の１種を単独で又は２種以上を適宜選択して使用することができる。 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). .

In addition, as another diamine used for the synthesis | combination of a polyamic acid, 1 type of these compounds can be used individually or in combination of 2 or more types as appropriate.

  When the liquid crystal aligning agent in the present invention is applied to a liquid crystal aligning agent for a TN type, STN type or vertical alignment type liquid crystal display element, a group capable of imparting liquid crystal aligning ability to the coating film on the side chain of the polyamic acid ( It is preferable to introduce a liquid crystal alignment group). Here, the liquid crystal aligning group is a group capable of imparting liquid crystal aligning property to the coating film without depending on light irradiation, and specifically, for example, an alkyl group having 4 to 20 carbon atoms, or 4 to 20 carbon atoms. Examples thereof include a fluoroalkyl group, an alkoxy group having 4 to 20 carbon atoms, a group having a steroid skeleton having 17 to 51 carbon atoms, and a group having a polycyclic structure. The polyamic acid having a liquid crystal aligning group can be obtained, for example, by polymerization containing the above aligning group-containing diamine in the monomer composition. When using an orientation group-containing diamine, the blending amount is preferably 3 mol% or more, based on the total diamine used for synthesis, from the viewpoint of developing good liquid crystal orientation, and is 5 to 70 mol. % Is more preferable.

  The use ratio of the specific diamine is preferably 0.5 mol% or more, preferably 1 mol% or more, based on the total amount of diamine used for the synthesis of the polyamic acid, from the viewpoint of sufficiently obtaining the effects of the present invention. More preferably, it is more preferably 5 mol% or more. Moreover, the upper limit of the use ratio of the specific diamine is not particularly limited, but is preferably 80 mol% or less, more preferably 70 mol% or less, and further preferably 60 mol% or less. preferable.

（式（４）中、Ｘ^３は、硫黄原子、酸素原子又は−ＮＨ−である。「＊」はそれぞれ結合手を示す。但し、２つの「＊」のうち少なくとも一つは芳香環に結合している。）
で表される部分構造を基本骨格として含有するエステル基含有構造、等が挙げられる。 When providing the liquid crystal aligning ability with the photo-alignment method with respect to the coating film formed with the liquid crystal aligning agent, you may use the polymer which has a photo-alignment structure as at least one part of a polymer (A). As a specific example of the photoalignment structure, a group exhibiting photoalignment by photoisomerization, photodimerization, photolysis, or the like can be employed. Specifically, for example, an azo-containing group containing an azo compound or derivative thereof as a basic skeleton, a cinnamic acid-containing group containing cinnamic acid or a derivative thereof as a basic skeleton, or a chalcone-containing group containing chalcone or a derivative thereof as a basic skeleton A benzophenone-containing group containing benzophenone or a derivative thereof as a basic skeleton, a coumarin-containing group containing coumarin or a derivative thereof as a basic skeleton, a cyclobutane-containing structure containing cyclobutane or a derivative thereof as a basic skeleton, bicyclo [2.2.2 ] Bicyclo [2.2.2] octene-containing structure containing octene or a derivative thereof as a basic skeleton, the following formula (4)

(In Formula (4), X ³ is a sulfur atom, an oxygen atom or —NH—. “*” Represents a bond, respectively, provided that at least one of two “*” is bonded to an aromatic ring. doing.)
An ester group-containing structure containing a partial structure represented by the above as a basic skeleton, and the like.

  The polyamic acid having a photoalignment structure can be obtained, for example, by polymerization containing at least one of a tetracarboxylic dianhydride having a photoalignment structure and a diamine having a photoalignment structure as a raw material. In this case, from the viewpoint of photoreactivity, the proportion of the monomer having a photo-alignment structure is preferably 20 mol% or more with respect to the total amount of monomers used for polymer synthesis, and is 30 to 80 mol. % Is more preferable.

(Synthesis of polyamic acid)
The polyamic acid can be obtained by reacting the above tetracarboxylic dianhydride and diamine together with a molecular weight adjusting agent as necessary. 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 an equivalent is preferable, and the ratio which becomes 0.3-1.2 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. 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 polyamic acid synthesis reaction 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 from 0.1 to 24 hours, more preferably from 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 of organic solvents 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. And at least one selected from the group consisting of halogenated phenols is used as a solvent, or a mixture of one or more of these and another organic solvent is preferably used in the above range. The amount (x) of the organic solvent used is such that the total amount (y) of tetracarboxylic dianhydride and diamine is 0.1 to 50% by weight with respect to the total amount (x + y) of the reaction solution. Is preferred.

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid was purified. You may use for preparation of a liquid crystal aligning agent. When polyamic acid is dehydrated and cyclized into a polyimide, the above reaction solution may be directly subjected to dehydration and cyclization reaction, or may be subjected to dehydration and cyclization reaction after isolating the polyamic acid contained in the reaction solution. Alternatively, the isolated polyamic acid may be purified and then subjected to a dehydration ring closure reaction. Isolation and purification of the polyamic acid can be performed according to known methods.

[Polyamic acid ester]
Examples of the polyamic acid ester as the polymer (A) include [I] a method of reacting the polyamic acid obtained by the above synthesis reaction with an esterifying agent, and [II] a method of reacting a tetracarboxylic acid diester and diamine. [III] A method of reacting a tetracarboxylic acid diester dihalide with a diamine, and the like.
In this specification, “tetracarboxylic acid diester” means a compound in which two of the four carboxyl groups of tetracarboxylic acid are esterified and the remaining two are carboxyl groups. “Tetracarboxylic acid diester dihalide” means a compound in which two of the four carboxyl groups of tetracarboxylic acid are esterified and the remaining two are halogenated.

  Examples of the esterifying agent used in Method [I] include a hydroxyl group-containing compound, an acetal compound, a halide, an epoxy group-containing compound, and the like. Specific examples thereof include hydroxyl group-containing compounds such as alcohols such as methanol, ethanol and propanol; phenols such as phenol and cresol; and acetal compounds such as N, N-dimethylformamide diethyl acetal, N, N-diethylformamide diethyl acetal and the like; halides such as methyl bromide, ethyl bromide, stearyl bromide, methyl chloride, stearyl chloride, 1,1,1-trifluoro-2-iodoethane and the like; epoxy group-containing Examples of the compound include propylene oxide.

  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. The tetracarboxylic acid derivative used in method [II] may be only a tetracarboxylic acid diester, but may also be used in combination with tetracarboxylic dianhydride. Examples of the diamine used in Method [II] include the diamines exemplified in the synthesis of polyamic acid. 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 a polyamic acid 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 to 150 ° C, 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. The tetracarboxylic acid derivative used in the method [III] may be only a tetracarboxylic acid diester dihalide, or a tetracarboxylic dianhydride may be used in combination. Examples of the diamine used in Method [III] include the diamines exemplified in the synthesis of polyamic acid. 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 to 150 ° C, 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 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. In addition, the reaction solution formed by dissolving the polyamic acid ester may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid ester contained in the reaction solution. Alternatively, the isolated polyamic acid ester may be purified and then used for the preparation of the liquid crystal aligning agent. Isolation and purification of the polyamic acid ester can be performed according to a known method.

[Polyimide]
The polyimide as the polymer (A) can be obtained, for example, by dehydrating and ring-closing imidizing the polyamic acid having the partial structure (b) synthesized as described above.

  The polyimide may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure possessed by the polyamic acid that is the precursor, and only a part of the amic acid structure may be dehydrated and cyclized. It may be a partially imidized product in which a ring structure coexists. The polyimide used for the reaction 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, a part of the imide ring may be an isoimide ring.

The polyamic acid is preferably dehydrated and closed by heating the polyamic acid, or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to the solution, and heating the solution as necessary. .
In the method of adding a dehydrating agent and a dehydrating ring-closing catalyst to a polyamic acid solution, as the dehydrating agent, for example, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. 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. It is preferable that the usage-amount of a dehydration ring-closing catalyst shall be 0.01-10 mol with respect to 1 mol of dehydrating agents to be used. Examples of the organic solvent used in the dehydration ring-closing reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. 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.

  In this way, a reaction solution containing polyimide is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, and the liquid crystal after isolating the polyimide. You may use for preparation of an aligning agent, or you may use for preparation of a liquid crystal aligning agent, after purifying the isolated polyimide. These purification operations can be performed according to known methods. In addition, polyimide can also be obtained by imidation of polyamic acid ester.

The polyamic acid, polyamic acid ester, and polyimide obtained as described above preferably have a solution viscosity of 20 to 1,800 mPa · s when this is made into a solution having a concentration of 15% by weight. More preferably, it has a solution viscosity of ˜1,500 mPa · s. 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 polystyrene equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of the polyamic acid, polyamic acid ester and polyimide is preferably 1,000 to 500,000, more preferably 2,000. ~ 300,000. 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.

[Polysiloxane]
The polysiloxane as the polymer (A) can be obtained, for example, by hydrolyzing and condensing a hydrolyzable silane compound. Specifically, the following [1] or [2]
[1] A hydrolyzable silane compound having an epoxy group (ms-1) or a mixture of the silane compound (ms-1) and another silane compound is hydrolyzed to synthesize an epoxy group-containing polysiloxane. Then, a method of reacting the obtained epoxy group-containing polysiloxane with the carboxylic acid having the partial structure (b) (hereinafter also referred to as “specific carboxylic acid”),
[2] A hydrolyzable silane compound (ms-2) having the partial structure (b) or a method of hydrolytic condensation of a mixture of the silane compound (ms-2) and other silane compounds. It is done. Among these, the method [1] is preferable because it is simple and can increase the introduction rate of the specific structure in the polymer (A).

  Specific examples of the silane compound (ms-1) include, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropyl. Methyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (3,4-epoxycyclohexyl) propyltrimethoxysilane, etc. Can be mentioned. As the silane compound (ms-1), one of these can be used alone, or two or more can be used in combination.

Other silane compounds are not particularly limited as long as they are hydrolyzable silane compounds. For example, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, dimethyl Alkoxysilanes such as diethoxysilane;
3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (3-cyclohexylamino) propyltri Nitrogen / sulfur-containing alkoxysilanes such as methoxysilane and N-2- (aminoethyl) -3-aminopropyltrimethoxysilane;
3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropyltriethoxysilane, 6- (meth) acryloyloxyhexyltrimethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, 3- (Meth) acryloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, alkoxysilanes containing unsaturated bonds such as p-styryltrimethoxysilane; in addition to trimethoxysilylpropyl succinic anhydride Can be mentioned. Other silane compounds can be used alone or in combination of two or more.

The hydrolysis / condensation reaction of the silane compound is carried out by reacting one or more of the above silane compounds with water, preferably in the presence of an appropriate catalyst and an organic solvent.
In the method of [1] above, from the viewpoint of suppressing side reactions caused by an excessive amount of epoxy groups while allowing the partial structure (b) to be sufficiently introduced into the polymer, The epoxy equivalent of the polysiloxane is preferably 100 to 10,000 g / mol, and more preferably 150 to 1,000 g / mol. Therefore, in synthesizing the epoxy group-containing polysiloxane, it is preferable to adjust the usage ratio of the silane compound (ms-1) so that the epoxy equivalent of the obtained polysiloxane is in the above range. In the hydrolysis / condensation reaction, the proportion of water used is preferably 0.5 to 100 mol, more preferably 1 to 30 mol, per 1 mol of the silane compound (total amount).

Examples of the catalyst used in the hydrolysis / condensation reaction include acids, alkali metal compounds, organic bases, titanium compounds, zirconium compounds and the like. The amount of catalyst used varies depending on the type of catalyst, reaction conditions such as temperature, and should be set as appropriate. For example, it is preferably 0.01 to 3 times the total amount of the silane compound. More preferably, it is 0.05-1 times mole.
Examples of the organic solvent used in the above hydrolysis / condensation reaction include hydrocarbons, ketones, esters, ethers, alcohols and the like. Among these, it is preferable to use a water-insoluble or poorly water-soluble organic solvent. The use ratio of the organic solvent is preferably 10 to 10,000 parts by weight, and more preferably 50 to 1,000 parts by weight with respect to a total of 100 parts by weight of the silane compounds used in the reaction.

  The hydrolysis / condensation reaction is preferably carried out by heating with, for example, an oil bath. In the hydrolysis / condensation reaction, the heating temperature is preferably 130 ° C. or lower, more preferably 40 to 100 ° C. The heating time is preferably 0.5 to 12 hours, and more preferably 1 to 8 hours. During heating, the mixture may be stirred or placed under reflux. Moreover, after completion | finish of reaction, it is preferable to wash | clean the organic-solvent layer fractionated from the reaction liquid with water. In this washing, washing with water containing a small amount of salt (for example, an aqueous ammonium nitrate solution of about 0.2% by weight) is preferable in that the washing operation is facilitated. Washing is performed until the aqueous layer after washing becomes neutral, and then the organic solvent layer is dried with a desiccant such as anhydrous calcium sulfate or molecular sieve as necessary, and then the solvent is removed to remove the solvent. The polysiloxane can be obtained. The method for synthesizing the polysiloxane is not limited to the hydrolysis / condensation reaction described above. For example, the polysiloxane may be synthesized by a method in which a hydrolyzable silane compound is reacted in the presence of oxalic acid and alcohol.

なお、特定カルボン酸は、１種を単独で又は２種以上を組み合わせて使用することができる。 In the method [1], the epoxy group-containing polysiloxane obtained by the above reaction is then reacted with a specific carboxylic acid. Thereby, the epoxy group which epoxy group-containing polysiloxane has, and carboxylic acid react, and polysiloxane which has the said partial structure (b) can be obtained. The specific carboxylic acid is not particularly limited as long as it has the partial structure (b), and examples thereof include compounds represented by the following formulas (5-1) to (5-3).

In addition, specific carboxylic acid can be used individually by 1 type or in combination of 2 or more types.

In the synthesis of the polysiloxane as the polymer (A), the carboxylic acid used for the reaction with the epoxy group-containing polysiloxane may be only the specific carboxylic acid, but other carboxylic acids other than the specific carboxylic acid are used in combination. May be.
The other carboxylic acid is not particularly limited as long as it does not have the partial structure (b), and examples thereof include carboxylic acids having the liquid crystal alignment group. Other carboxylic acids can be used alone or in combination of two or more.

  The proportion of the carboxylic acid to be reacted with the epoxy group-containing polysiloxane is preferably 0.001 to 1.5 mol with respect to 1 mol in total of the epoxy groups of the polysiloxane, 0.01 to 1.0 More preferably, it is a mole. The use ratio of the specific carboxylic acid is preferably 5 mol% or more, and more preferably 10 mol% or more with respect to the total amount of carboxylic acid to be reacted with the epoxy group-containing polysiloxane.

  The reaction between the epoxy group-containing polysiloxane and the carboxylic acid can be preferably carried out in the presence of a catalyst and an organic solvent. As said catalyst, a well-known compound etc. can be used as what is called a hardening accelerator which accelerates | stimulates reaction of an organic base and an epoxy compound, for example. Of these, tertiary organic amines or quaternary organic amines are preferred. The ratio of the catalyst used is preferably 100 parts by weight or less, more preferably 0.01 to 100 parts by weight, and still more preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the epoxy group-containing polysiloxane.

  Examples of the organic solvent used in the above reaction include hydrocarbons, ethers, esters, ketones, amides, alcohols and the like. Among these, from the viewpoints of solubility of raw materials and products, and ease of purification of the product, it is preferably at least one selected from the group consisting of ethers, esters and ketones, and specific examples of particularly preferred solvents Examples thereof include 2-butanone, 2-hexanone, methyl isobutyl ketone, and butyl acetate. The organic solvent is preferably used in such a ratio that the solid content concentration (the ratio of the total weight of components other than the solvent in the reaction solution to the total weight of the solution) is 0.1% by weight or more, It is more preferable to use it at a ratio of 5 to 50% by weight.

  The reaction temperature in the above reaction is preferably 0 to 200 ° C, more preferably 50 to 150 ° C. The reaction time is preferably 0.1 to 50 hours, more preferably 0.5 to 20 hours. Moreover, after completion | finish of reaction, it is preferable to wash | clean the organic-solvent layer fractionated from the reaction liquid with water. After washing with water, the organic solvent layer is dried with an appropriate desiccant as required, and then the solvent is removed to obtain the desired polysiloxane.

  Regarding the polysiloxane as the polymer (A), the polystyrene-reduced weight average molecular weight (Mw) measured by GPC is preferably in the range of 100 to 50,000, and preferably in the range of 200 to 10,000. More preferred. When the weight average molecular weight of the polysiloxane is in the above range, it is easy to handle when producing a liquid crystal alignment film, and the obtained liquid crystal alignment film has sufficient material strength and characteristics.

[Poly (meth) acrylate]
The poly (meth) acrylate as the polymer (A) is, for example, a (meth) acrylic monomer (ma-1) having an epoxy group, or the (meth) acrylic monomer (ma-1). After polymerizing a mixture with other (meth) acrylic monomers in the presence of a polymerization initiator, the resulting polymer (hereinafter also referred to as “epoxy group-containing poly (meth) acrylate”), It can be obtained by a method of reacting with a specific carboxylic acid.

  Examples of the (meth) acrylic monomer (ma-1) include unsaturated carboxylic acid esters having an epoxy group. Specific examples thereof include, for example, glycidyl (meth) acrylate, glycidyl α-ethyl acrylate, glycidyl α-n-propyl acrylate, glycidyl α-n-butyl acrylate, 3,4-epoxybutyl (meth) acrylate. Α-ethyl acrylate 3,4-epoxybutyl, (meth) acrylate 3,4-epoxycyclohexylmethyl, (meth) acrylate 6,7-epoxyheptyl, α-ethyl acrylate 6,7-epoxyheptyl, Examples include 4-hydroxybutyl glycidyl ether of acrylic acid, (meth) acrylic acid (3-ethyloxetane-3-yl) methyl, and the like. In addition, a (meth) acrylic-type monomer (ma-1) can be used individually by 1 type in the above or in combination of 2 or more types.

  Other (meth) acrylic monomers include, for example, (meth) acrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, vinyl benzoic acid and other unsaturated carboxylic acids: (meth) acrylic Methyl methacrylate, ethyl (meth) acrylate, propyl (meth) acrylate, allyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, (meth) acrylate-2-ethylhexyl, (meth ) Lauryl acrylate, (meth) acrylic acid trimethoxysilylpropyl, (meth) acrylic acid methoxyethyl, (meth) acrylic acid-N, N-dimethylaminoethyl, (meth) acrylic acid methoxypolyethylene glycol, (meth) acrylic Tetrahydrofurfuryl acid, 2-hydroxyethyl (meth) acrylate, (meth Unsaturated carboxylic acid esters such as glycidyl acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxybutyl (meth) acrylate, 4-hydroxybutyl glycidyl ether: maleic anhydride, anhydrous And unsaturated polyvalent carboxylic acid anhydrides such as itaconic acid and cis-1,2,3,4-tetrahydrophthalic anhydride. In addition, the other (meth) acrylic monomers can be used alone or in combination of two or more.

In the synthesis of poly (meth) acrylate, the total amount (number of moles) of epoxy groups per gram of epoxy group-containing poly (meth) acrylate is preferably 5.0 × 10 ⁻⁵ or more, and 1.0 × 10 ^{-4 to} 1.0 × 10 ⁻² mol / g is more preferable, and 5.0 × 10 ^{−4 to} 5.0 × 10 ⁻³ mol / g is still more preferable. Therefore, the use ratio of the (meth) acrylic monomer (m-1) can be adjusted so that the total number of moles of epoxy groups per 1 g of the epoxy group-containing poly (meth) acrylate is within the above range. preferable.
In the polymerization, a monomer other than the (meth) acrylic monomer may be used. Examples of other monomers include conjugated diene compounds such as 1,3-butadiene and 2-methyl-1,3-butadiene; aromatic vinyl compounds such as styrene, methylstyrene, and divinylbenzene. The proportion of other monomers used is preferably 30 mol% or less, more preferably 20 mol% or less, based on the total amount of monomers used for the synthesis of poly (meth) acrylate.

The polymerization reaction using the (meth) acrylic monomer is preferably performed by radical polymerization. Examples of the polymerization initiator used in the polymerization reaction include initiators usually used in radical polymerization. For example, 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4 -Dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) and other azo compounds; benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1′-bis ( Examples thereof include organic peroxides such as t-butylperoxy) cyclohexane; hydrogen peroxide; redox initiators composed of these peroxides and reducing agents. Of these, azo compounds are preferable, and 2,2′-azobis (isobutyronitrile) is more preferable. As a polymerization initiator, these can be used individually by 1 type or in combination of 2 or more types.
The use ratio of the polymerization initiator is preferably 0.01 to 50 parts by weight, and more preferably 0.1 to 40 parts by weight with respect to 100 parts by weight of all monomers used in the reaction.

  The polymerization reaction of the (meth) acrylic monomer is preferably performed in an organic solvent. Examples of the organic solvent used in the reaction include alcohols, ethers, ketones, amides, esters, hydrocarbon compounds, and the like. Among these, it is preferable to use at least one selected from the group consisting of alcohols and ethers, and it is more preferable to use partial ethers of polyhydric alcohols. Preferred examples thereof include diethylene glycol methyl ethyl ether and propylene glycol monomethyl ether acetate. In addition, as an organic solvent, these can be used individually by 1 type or in combination of 2 or more types.

  In the polymerization reaction of the (meth) acrylic monomer, the reaction temperature is preferably 30 to 120 ° C, more preferably 60 to 110 ° C. The reaction time is preferably 1 to 36 hours, and more preferably 2 to 24 hours. The amount of organic solvent used (a) is such that the total amount (y) of monomers used in the reaction is 0.1 to 50% by weight with respect to the total amount (x + y) of the reaction solution. It is preferable to do.

The epoxy group-containing poly (meth) acrylate obtained by the above reaction is then reacted with a specific carboxylic acid. The description of polysiloxane can be applied to the specific carboxylic acid. In the reaction, the specific carboxylic acid may be used alone, or other carboxylic acid other than the specific carboxylic acid may be used in combination.
The use ratio of the carboxylic acid to be reacted with the epoxy group-containing poly (meth) acrylate may be 0.001 to 0.95 mol with respect to a total of 1 mol of epoxy groups contained in the epoxy group-containing poly (meth) acrylate. preferable. More preferably, it is 0.01-0.9 mol, and it is still more preferable to set it as 0.05-0.8 mol.

  The reaction between the epoxy group-containing poly (meth) acrylate and the carboxylic acid can be preferably carried out in the presence of a catalyst and an organic solvent. Here, as a catalyst used for reaction, the compound illustrated as a catalyst which can be used by the synthesis | combination of polysiloxane can be mentioned, for example. Among these, a quaternary ammonium salt is preferable. The amount of the catalyst used is preferably 100 parts by weight or less, more preferably 0.01 to 100 parts by weight, and still more preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the epoxy group-containing poly (meth) acrylate. It is.

  As the organic solvent used in the reaction, examples of the organic solvent that can be used in the polymerization of the (meth) acrylic monomer can be applied, and among them, an ester is preferable. The organic solvent is preferably used in such a ratio that the solid content concentration (the ratio of the total weight of components other than the solvent in the reaction solution to the total weight of the solution) is 0.1% by weight or more, It is more preferable to use it at a ratio of 5 to 50% by weight. The reaction temperature is preferably 0 to 200 ° C, more preferably 50 to 150 ° C. The reaction time is preferably 0.1 to 50 hours, more preferably 0.5 to 20 hours.

In this way, a solution containing poly (meth) acrylate as the polymer (A) can be obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, may be used for the preparation of the liquid crystal aligning agent after isolating the poly (meth) acrylate contained in the reaction solution, or the isolated poly You may use for preparation of a liquid crystal aligning agent, after refine | purifying (meth) acrylate. Isolation and purification of poly (meth) acrylate can be performed according to known methods.
In addition, the synthesis | combining method of poly (meth) acrylate as a polymer (A) is not limited to the said method. For example, a (meth) acrylic monomer having the partial structure (b) or a mixture of the (meth) acrylic monomer and another (meth) acrylic monomer is present in the presence of a polymerization initiator. It can also be obtained by a method of polymerizing with, for example.

  For poly (meth) acrylate, the polystyrene-equivalent number average molecular weight (Mn) measured by GPC improves the liquid crystal alignment of the liquid crystal alignment film to be formed and ensures the stability of the liquid crystal alignment over time. In view of the above, it is preferably 250 to 500,000, more preferably 500 to 100,000, and still more preferably 1,000 to 50,000.

[polyester]
The polyester as the polymer (A) can be obtained, for example, by reacting the dicarboxylic acid having the partial structure (b) with a diepoxy compound.
Examples of the diepoxy compound to be reacted with the dicarboxylic acid having the partial structure (b) include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6 In addition to hexanediol diglycidyl ether, diepoxy compounds described in JP2013-113937A and the like can be mentioned.
The use ratio of the diepoxy compound and dicarboxylic acid compound used in the polyester synthesis reaction is preferably 0.2 to 2 equivalents of the epoxy group of the diepoxy compound with respect to 1 equivalent of the carboxy group contained in the dicarboxylic acid compound. .3 equivalents to 1.2 equivalents are more preferred.

  The reaction between the dicarboxylic acid and the diepoxy compound is preferably performed in the presence of an organic solvent. Examples of the organic solvent include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, N, N-dimethylimidazolidinone, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexa Examples include aprotic polar solvents such as methyl phosphortriamide; phenol solvents such as m-cresol, xylenol, phenol, and halogenated phenol. The reaction temperature is preferably 0 ° C to 250 ° C, more preferably 50 ° C to 180 ° C. The reaction time is preferably 0.5 hours to 24 hours, and more preferably 2 hours to 12 hours.

  Thus, a solution containing the polyester as the polymer (A) can be obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyester contained in the reaction solution, or after the isolated polyester is purified. It may be used for the preparation of a liquid crystal aligning agent. Isolation and purification of the polyester can be performed according to a known method.

The polyester obtained as described above preferably has a solution viscosity of 20 to 1,800 mPa · s when it is made into a solution having a concentration of 15% by weight, and has a viscosity of 50 to 1,500 mPa · s. More preferably, it has a solution viscosity. In addition, the solution viscosity (mPa · s) of polyester is E for a polymer solution having a concentration of 15% by weight prepared using a good solvent for the polymer (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is a value measured at 25 ° C. using a mold rotational viscometer.
In addition, for polyester, the polystyrene-equivalent number average molecular weight (Mn) measured by GPC improves the liquid crystal alignment of the liquid crystal alignment film to be formed, and ensures the stability of the liquid crystal alignment over time. Therefore, it is preferably 250 to 500,000, more preferably 500 to 100,000, and still more preferably 1,000 to 50,000.

When the aromatic polyvalent hydroxy compound (A) is an additive When the aromatic polyvalent hydroxy compound (A) is used as at least part of the additive component, the compound (A) has the above partial structure (b ) Having a molecular weight of 500 or less (hereinafter also referred to as “compound (Ad)”). The molecular weight of the compound (Ad) is more preferably 450 or less, and still more preferably 400 or less.
As long as the compound (Ad) has the partial structure (b), the remaining structure is not particularly limited. In addition, the compound (Ad) may have only one partial structure (b) or a plurality of the partial structures (b). Preferably it is 1-4, More preferably, it is 1 or 2.

  In addition to the partial structure (b), the compound (Ad) has a functional group (hereinafter also referred to as “specific functional group”) that interacts with the functional group of the polymer component in the liquid crystal aligning agent. Is preferred. Here, the term “interaction” refers to an intermolecular force that forms a covalent bond between molecules or is weaker than a covalent bond (eg, ion-dipole interaction, dipole-dipole interaction, hydrogen bond, It means the formation of electromagnetic force between molecules such as van der Waals force. By having such a functional group, it is possible to suppress the elution of the compound (Ad) from the liquid crystal alignment film, thereby suppressing the deterioration of the reliability and afterimage characteristics of the liquid crystal display element, and the partial structure (b). This is preferable in that an introduction effect can be obtained.

The said specific functional group can be suitably selected according to the functional group which a polymer component has. For example, in the case of a liquid crystal aligning agent containing polyimide or a precursor thereof as a polymer component, the specific functional group is preferably a functional group that interacts with a carboxyl group or an imide group. Group, amino group, carboxyl group, alkoxysilyl group and the like . The number of the specific functional groups possessed by the aromatic polyvalent hydroxy compound (A) is preferably 1 or more, more preferably 1 to 4, and even more preferably 1 or 2. .

（式（Ａｄ−１）中、Ａ^１は（ｔ＋１）価の有機基であり、Ａ^２は上記特定官能基であり、ｔは１〜４の整数である。） Examples of the compound (Ad) include compounds represented by the following formula (Ad-1).

(In the formula (Ad-1), A ¹ is a (t + 1) -valent organic group, A ² is the specific functional group, and t is an integer of 1 to 4.)

なお、化合物（Ａｄ）としては１種を単独で又は２種以上を組み合わせて使用することができる。 In the above formula (Ad-1), the (t + 1) -valent organic group of A ¹ has, for example, 1 to 30 carbon atoms, and preferably 1 to 20 carbon atoms. A ² is preferably an epoxy group, an amino group, a carboxyl group or an alkoxysilyl group. t is preferably 1 or 2. Examples of the bonding position of two hydroxyl groups in the formula (Ad-1) include 2,3-position, 2,4-position, 2,5-position, and 3,4-position with respect to other groups. .
Specific examples of the compound (Ad) include, for example, the compounds represented by the above formulas (5-1) to (5-3) and the following formulas (5-4) to (5-9), respectively. The compound etc. which are represented by these are mentioned.

In addition, as a compound (Ad), 1 type can be used individually or in combination of 2 or more types.

The compounding ratio of the compound (A) is preferably selected as appropriate depending on whether the compound (A) is a polymer or an additive. When the compound (A) is a polymer, the compounding ratio of the compound (A) is preferably 5 parts by weight or more with respect to 100 parts by weight of the total polymer components contained in the liquid crystal aligning agent. More preferably, it is more preferably 30 parts by weight or more. If the ratio is less than 5 parts by weight, unevenness around the sealant tends to occur, and the afterimage characteristics and reliability tend to be inferior.
Moreover, when using the compound (Ad) as an additive, it is preferable that the mixture ratio shall be 0.05 weight part or more with respect to a total of 100 weight part of a polymer component, 0.1 weight part or more More preferably, it is more preferably 0.2 parts by weight or more. Further, the upper limit of the compounding ratio of the compound (Ad) is preferably 50 parts by weight or less, more preferably 30 parts by weight or less, and more preferably 20 parts by weight or less with respect to 100 parts by weight of the total of the polymer components. More preferably. When the content ratio of the compound (Ad) is less than 0.05 parts by weight, it is difficult to obtain the effect of reducing unevenness around the sealant, the afterimage characteristics, and the effect of improving the reliability. It tends to decrease.

  In addition, by using a liquid crystal aligning agent containing the compound having the partial structure (b), it is possible to suppress display unevenness around the sealant and to maintain afterimage characteristics (particularly “DC caused by residual charges accumulated by application of a DC voltage”. The reason why both the image sticking property called “afterimage” and the reliability of the liquid crystal display element can be achieved is not clear, but the hydroxyl group of the partial structure (b) increases the adhesion between the substrate and the alignment film, thereby One reason is considered to have contributed to the improvement of characteristics.

<Other ingredients>
The liquid crystal aligning agent in this invention contains a polymer component with the aromatic polyvalent hydroxy compound (A) as an additive, when an aromatic polyvalent hydroxy compound (A) is contained as an additive component. As the polymer component, a polymer having the partial structure (b), a polymer not having the partial structure (b) (hereinafter referred to as “other polymer”), or a mixture thereof is used. Can do.
The main skeleton of the other polymer is not particularly limited. For example, polyamic acid, polyimide, polyamic acid ester, polysiloxane, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly ( Main skeletons such as (meth) acrylate may be mentioned. In addition, (meth) acrylate means containing an acrylate and a methacrylate.
Among these, the polymer is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyamide, polyorganosiloxane, poly (meth) acrylate, and polyester, polyamic acid, More preferably, it is at least one selected from the group consisting of polyamic acid esters and polyimides. In addition, another polymer may be used individually by 1 type, and may be used in combination of 2 or more type.

  When the liquid crystal aligning agent in this invention contains a polymer (A), the said other polymer may be included with the said polymer (A). When other polymers are blended in the liquid crystal aligning agent, the blending ratio is preferably 30 parts by weight or less with respect to a total of 100 parts by weight of the polymer contained in the liquid crystal aligning agent. It is more preferable to set it as 20 weight part, and it is still more preferable to set it as 0.3-10 weight part.

  In addition, the liquid crystal aligning agent in this invention may contain components other than the above as needed. Examples of the component include a compound having at least one epoxy group in the molecule, a compound having at least one oxetanyl group in the molecule, a functional silane compound, a metal chelate compound, a curing accelerator, a surfactant, and an antioxidant. , Sensitizers, preservatives and the like. These blending ratios can be appropriately selected according to various compounds within a range that does not impair the effects of the present invention.

<Solvent>
The liquid crystal aligning agent in the present invention is prepared as a liquid composition in which the aromatic polyvalent hydroxy compound (A) and other components used as necessary are preferably dispersed or dissolved in an appropriate solvent. The

  Examples of the organic solvent to be used include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, Ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-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 Recall 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. be able to. These can be used alone or in admixture of two or more.

  The solid content concentration in the liquid crystal aligning agent (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, etc. It is in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent is applied to the substrate surface as will be described later, and preferably heated to form a coating film that is a liquid crystal alignment film or a coating film that becomes a liquid crystal alignment film. 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, it is difficult to obtain a good liquid crystal alignment film because the film thickness is excessive, and the viscosity of the liquid crystal aligning agent increases and the applicability decreases. There is a tendency.

  The particularly preferable solid content concentration range varies depending on the use of the liquid crystal aligning agent and the method used when the liquid crystal aligning agent is applied to the substrate. For example, when a liquid crystal aligning agent for a liquid crystal display element is applied to a substrate by a spinner method, the solid content concentration (the ratio of the total weight of all components other than the solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) 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 when preparing the liquid crystal aligning agent is preferably 10 to 50 ° C, more preferably 20 to 30 ° C. Moreover, about the liquid crystal aligning agent for retardation films, the solid content density | concentration of a liquid crystal aligning agent is 0.2 to 10 weight% from a viewpoint which makes the applicability | paintability of a liquid crystal aligning agent, and the film thickness of the coating film formed moderate. It is preferable that it is the range of 3-10 weight%.

<Liquid crystal display element and retardation film>
A liquid crystal alignment film can be manufactured by using the liquid crystal aligning agent described above. Moreover, the liquid crystal aligning film formed using the said liquid crystal aligning agent can be preferably applied to the liquid crystal aligning film for liquid crystal display elements, and the liquid crystal aligning film for retardation films. Below, a liquid crystal display element and retardation film are demonstrated.

[Liquid crystal display element]
The liquid crystal display element in this invention comprises the liquid crystal aligning film formed using the said liquid crystal aligning agent. The operation mode of the liquid crystal display element is not particularly limited. For example, various operation modes such as a TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), IPS type, FFS type, OCB type, etc. Can be applied to.

  A liquid crystal display element can be manufactured by the method of including the following processes (1-1)-processes (1-3), for example. In the step (1-1), the substrate to be used differs depending on the desired operation mode. Step (1-2) and step (1-3) are common to each operation mode.

[Step (1-1): 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.
(1-1A) When manufacturing a TN-type, STN-type, or VA-type liquid crystal display element, for example, first, a pair of two substrates on which patterned transparent conductive films are provided, and each transparent conductive film is formed. A liquid crystal aligning agent is preferably applied onto the surface by an offset printing method, a spin coating method, a roll coater method or an ink jet printing method. As the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly (cycloaliphatic 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, after forming a transparent conductive film without a pattern, a method of forming a pattern by photo-etching; a method of using a mask having a desired pattern when forming a transparent conductive film; And so on. 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 applying the liquid crystal aligning agent, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied liquid crystal aligning agent. The pre-baking 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, and more preferably 0.5 to 5 minutes. Then, a baking (post-baking) process is implemented for the purpose of removing a solvent completely and heat imidating the amic acid structure which exists in a polymer as needed. The firing temperature (post-bake 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 thickness of the film thus formed is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

  (1-1B) When manufacturing an IPS type or FFS type liquid crystal display element, an electrode forming surface of a substrate provided with an electrode made of a transparent conductive film or a metal film patterned in a comb shape, and an electrode are provided. A liquid crystal aligning agent is apply | coated to one surface of the counter substrate which is not formed, respectively, Then, each coating surface is heated, and a coating film is formed. Regarding the material used for the substrate and the transparent conductive film, the coating method, the heating conditions after coating, the patterning method for the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferred film thickness of the coating film to be formed The same as (1-1A). As the metal film, for example, a film made of a metal such as chromium can be used.

  In both cases (1-1A) and (1-1B), after applying a liquid crystal aligning agent on the substrate, the organic solvent is removed to form a liquid crystal alignment film or a liquid crystal alignment film. The At this time, when at least one of polyamic acid, polyamic acid ester and polyimide is blended in the liquid crystal aligning agent, the polyamic acid and polyamic acid blended in the liquid crystal aligning agent are further heated after the coating film is formed. It is good also as a coating film made more imidized by advancing the dehydration ring-closing reaction of ester and polyimide.

[Step (1-2): Orientation ability imparting treatment]
When manufacturing a TN type, STN type, IPS type, or FFS type liquid crystal display element, the process which provides liquid crystal aligning ability to the coating film formed at the said process (1-1) is implemented. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. Examples of the orientation-imparting treatment include rubbing treatment in which the 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. On the other hand, when manufacturing a VA type liquid crystal display element, the coating film formed in the above step (1-1) can be used as it is as a liquid crystal alignment film. May be.

In the photo-alignment treatment, 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, for example. When the radiation is polarized light, it may be linearly polarized light or partially polarized light. 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 non-polarized radiation is irradiated, the irradiation direction 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 rays in a preferable wavelength region can be obtained by means of using a light source in combination with, for example, a filter or a diffraction grating. The radiation dose is preferably 100 to 50,000 J / m ² , more preferably 300 to 20,000 J / m ² . Moreover, you may perform light irradiation with respect to a coating film, heating a coating film, in order to improve the reactivity. The temperature at the time of heating is 30-250 degreeC normally, Preferably it is 40-200 degreeC, More preferably, it is 50-150 degreeC.

  In addition, the liquid crystal alignment film after the rubbing treatment is further subjected to a process for changing the pretilt angle of a part of the liquid crystal alignment film by irradiating a part of the liquid crystal alignment film with ultraviolet rays or a surface of the liquid crystal alignment film. A resist film is formed on the part, and a rubbing process is performed in a direction different from the previous rubbing process, followed by a process of removing the resist film, so that the liquid crystal alignment film has 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. A liquid crystal alignment film suitable for a VA liquid crystal display element can also be suitably used for a PSA (Polymer sustained alignment) type liquid crystal display element.

[Step (1-3): Construction of liquid crystal cell]
(1-3A) Two substrates on which the liquid crystal alignment film is formed as described above are prepared, and a liquid crystal cell is manufactured by disposing a liquid crystal between the two substrates facing 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. First, two substrates are arranged opposite to each other through a gap (cell gap) so that the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded together using a sealant, and the substrate surface and the sealant are bonded. A liquid crystal cell can be manufactured by injecting and filling liquid crystal into the cell gap partitioned by the step, and then sealing the injection hole. The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet light curable sealant is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is dropped to a predetermined location on the liquid crystal alignment film surface. After that, 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, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, thereby manufacturing a liquid crystal cell. can do. Regardless of which method is used, the liquid crystal cell produced as described above is further heated to a temperature at which the used liquid crystal takes an isotropic phase, and then slowly cooled to room temperature, thereby removing the flow alignment at the time of filling the liquid crystal. It is desirable to do.

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 nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferable. For example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl. Cyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. Further, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck & Co., Inc.). A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.

(1-3B) When manufacturing a PSA type liquid crystal display element, a liquid crystal cell is constructed in the same manner as in the above (1-3A) except that a photopolymerizable compound is injected or dropped together with liquid crystal. Thereafter, the liquid crystal cell is irradiated with light while 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, 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. In addition, the ultraviolet rays in the above preferable wavelength region can be obtained by means of using a light source in combination with, for example, a filter diffraction grating. The irradiation dose of light, preferably 1,000~200,000J / ^{m 2,} more preferably from 1,000~100,000J / ^{m 2.}

  (1-3C) When a coating film is formed on a substrate using a liquid crystal aligning agent containing a compound (polymer or additive) having a photopolymerizable group, a liquid crystal cell is formed in the same manner as (1-3A) above. Then, a method of manufacturing a liquid crystal display element may be adopted by performing a step of irradiating light to the liquid crystal cell in a state where a voltage is applied between the conductive films of the pair of substrates. According to this method, the PSA mode can be realized with a small amount of light irradiation. The applied voltage can be, for example, 0.1 to 30 V direct current or alternating current. The description of (1-3B) above can be applied to the conditions of light to be irradiated.

  And a liquid crystal display element can be obtained by sticking a polarizing plate on the outer surface of a liquid crystal cell. As a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film itself in which a polarizing film called an “H film” in which iodine is absorbed while stretching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films The polarizing plate which consists of can be mentioned.

[Phase difference film]
Next, a method for producing a retardation film using a liquid crystal aligning agent will be described. In the production of the retardation film, it is possible to form a uniform liquid crystal alignment film while suppressing the generation of dust and static electricity during the process, and by using a suitable photomask during radiation irradiation, the substrate It is preferable to use a photo-alignment method in that a plurality of regions having different liquid crystal alignment directions can be formed arbitrarily. Specifically, it can be produced through the following steps (2-1) to (2-3).

[Step (2-1): Formation of coating film by liquid crystal aligning agent]
First, a liquid crystal aligning agent is apply | coated on a board | substrate and a coating film is formed. As the substrate used here, a transparent substrate made of a synthetic resin such as triacetyl cellulose (TAC), polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polyamide, polyimide, polymethyl methacrylate, polycarbonate, etc. is preferably exemplified. Can do. Of these, TAC is generally used as a protective layer for a polarizing film in a liquid crystal display device. In addition, polymethyl methacrylate can be preferably used as a substrate for a retardation film in that the hygroscopicity of the solvent is low, the optical properties are good, and the cost is low. In addition, for the substrate used for the application of the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the coating film, a conventionally known pretreatment is performed on the surface of the substrate surface on which the coating film is formed. May be implemented.

  In many cases, the retardation film is used in combination with a polarizing film. At this time, it is necessary to attach the retardation film by precisely controlling the angle with respect to the polarization axis of the polarizing film in a specific direction so that the desired optical characteristics can be exhibited. Accordingly, by forming a liquid crystal alignment film having a liquid crystal alignment ability in a predetermined angle direction on a substrate such as a TAC film or polymethyl methacrylate, the angle of the retardation film is controlled on the polarizing film. The step of bonding can be omitted. Thereby, it can contribute to the improvement of productivity of a liquid crystal display element. In order to form a liquid crystal alignment film having a liquid crystal alignment ability in a predetermined angle direction, it is preferable to carry out by a photo-alignment method using a liquid crystal alignment agent.

The liquid crystal aligning agent can be applied onto the substrate by an appropriate application method such as a roll coater method, a spinner method, a printing method, an ink jet method, a bar coater method, an extrusion die method, a direct gravure coater method, a chamber. Doctor coater method, offset gravure coater method, single roll kiss coater method, reverse kiss coater method using small diameter gravure roll, 3 reverse roll coater method, 4 reverse roll coater method, slot die method, air doctor coater method A positive rotation roll coater method, a blade coater method, a knife coater method, an impregnation coater method, an MB coater method, an MB reverse coater method, and the like can be employed.
After coating, the coated surface is heated (baked) to form a coating film. The heating temperature at this time is preferably 40 to 150 ° C, more preferably 80 to 140 ° C. The heating time is preferably 0.1 to 15 minutes, and more preferably 1 to 10 minutes. The film thickness of the coating film formed on the substrate is preferably 1 to 1,000 nm, more preferably 5 nm to 500 nm.

[Step (2-2): Light irradiation step]
Next, the coating film formed on the substrate as described above is irradiated with light, thereby imparting liquid crystal alignment ability to the liquid crystal alignment film. The description of the photo-alignment process in the step (1-2) can be applied to the type of light to be irradiated, the wavelength, the irradiation direction, and the light source. The dose of light is preferably in a 0.1~1,000mJ / cm ^2, more preferably to 1 to 500 mJ / cm ^2, and more preferably be 2~200mJ / cm ^2.

[Step (2-3): Formation of Liquid Crystal Layer]
Next, a polymerizable liquid crystal is applied and cured on the coating film after the light irradiation as described above. Thereby, the coating film (liquid crystal layer) containing a polymerizable liquid crystal is formed. The polymerizable liquid crystal used here is a liquid crystal compound or a liquid crystal composition that is polymerized by at least one treatment of heating and light irradiation. As such a polymerizable liquid crystal, a conventionally known liquid crystal can be used. Specifically, for example, Non-Patent Document 1 (“UV curable liquid crystal and its application”, Liquid Crystal, Vol. 3, No. 1 (1999). Year), pp 34-42). Further, cholesteric liquid crystal; discotic liquid crystal; twisted nematic alignment type liquid crystal to which a chiral agent is added may be used. The polymerizable liquid crystal may be a mixture of a plurality of liquid crystal compounds. The polymerizable liquid crystal may further be a composition containing a known polymerization initiator, an appropriate solvent, and the like.
In order to apply the polymerizable liquid crystal as described above on the formed liquid crystal alignment film, for example, an appropriate application method such as a bar coater method, a roll coater method, a spinner method, a printing method, or an ink jet method can be employed. .

Next, the coating film of the polymerizable liquid crystal formed as described above is subjected to at least one treatment selected from heating and light irradiation to cure the coating film to form a liquid crystal layer. It is preferable to perform these treatments in a superimposed manner because good alignment can be obtained.
The heating temperature of the coating film is appropriately selected depending on the type of polymerizable liquid crystal used. For example, when using RMS03-013C manufactured by Merck, it is preferable to heat at a temperature in the range of 40 to 80 ° C. The heating time is preferably 0.5 to 5 minutes.
As irradiation light, non-polarized ultraviolet rays having a wavelength in the range of 200 to 500 nm can be preferably used. The irradiation dose of light, preferably in the 50~10,000mJ / cm ^2, and more preferably a 100~5,000mJ / cm ^2.
The thickness of the liquid crystal layer to be formed is appropriately set depending on desired optical characteristics. For example, when manufacturing a half-wave plate in visible light having a wavelength of 540 nm, a thickness is selected such that the retardation of the formed retardation film is 240 to 300 nm. The thickness is selected such that the phase difference is 120 to 150 nm. The thickness of the liquid crystal layer from which the desired retardation is obtained varies depending on the optical characteristics of the polymerizable liquid crystal used. For example, when RMS03-013C manufactured by Merck is used, the thickness for manufacturing a quarter-wave plate is in the range of 0.6 to 1.5 μm.

  The retardation film obtained as described above can be preferably applied as a retardation film of a liquid crystal display element. The liquid crystal display element to which the retardation film manufactured using the liquid crystal aligning agent of the present invention is applied is not limited in its operation mode. For example, TN type, STN type, IPS type, FFS type, VA type and the like are known. It can be applied to various modes. The retardation film is used by attaching the substrate-side surface of the retardation film to the outer surface of the polarizing plate disposed on the viewing side of the liquid crystal display element. Therefore, it is preferable that the retardation film substrate is made of TAC or an acrylic base, and the retardation film substrate also functions as a protective film for the polarizing film.

  Here, there is a roll-to-roll method as a method for producing a retardation film on an industrial scale. In this method, a film is unwound from a wound body of a long base film, a liquid crystal alignment film is formed on the unwound film, and a polymerizable liquid crystal is applied and cured on the liquid crystal alignment film. It is the method of performing the process and the process which laminates | stacks a protective film as needed in the continuous process, and collect | recovering the film after passing through these processes as a wound body. The retardation film formed using the liquid crystal aligning agent in the present invention has good adhesion to the substrate, and the liquid crystal alignment film and the substrate are hardly peeled even when stored as a wound body. Therefore, it is possible to suppress a decrease in product yield when producing a retardation film by a roll-to-roll method, which is preferable from the viewpoint of productivity.

  The liquid crystal display element of the present invention can be effectively applied to various devices, such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, The present invention can be used for various display devices 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 polymer weight average molecular weight Mw, imidization rate, epoxy equivalent, and solution viscosity of the polymer solution were measured by the following methods. Hereinafter, the compound represented by Formula X may be simply referred to as “Compound X”.
[Weight average molecular weight Mw of polymer]
Mw is a polystyrene equivalent value measured by GPC under the following conditions.
Column: Tosoh Co., Ltd., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²
[Imidation rate of polymer]
A solution containing polyimide is poured into pure water, and the resulting precipitate is sufficiently dried at room temperature under reduced pressure, then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR is measured at room temperature using tetramethylsilane as a reference substance. did. From the obtained ¹ H-NMR spectrum, the imidation ratio was determined using the following formula (EX-1).
Imidation ratio (%) = (1-A ¹ / A ² × α) × 100 (EX-1)
(In Formula (EX-1), A ¹ is a peak area derived from protons of NH groups appearing near a chemical shift of 10 ppm, A ² is a peak area derived from other protons, and α is a precursor of a polymer ( It is the number ratio of other protons to one NH group proton in the polyamic acid).
[Epoxy equivalent]
The epoxy equivalent was measured by the hydrochloric acid-methyl ethyl ketone method described in JIS C 2105.
[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.

<Synthesis of compounds>
[Synthesis Example 1-1; Synthesis of Compound (X-1)]
Compound (X-1) was synthesized according to the following scheme 1.

[Synthesis Example 1-2; Synthesis of Compound (X-2)]
Compound (X-2) was synthesized according to the following scheme 2.

[Synthesis Example 1-3; Synthesis of Compound (X-3)]
Compound (X-3) was synthesized according to the following scheme 3.

<Synthesis of polymer>
[Synthesis Example 2-1; Synthesis of Polymer (PA-1)]
Pyromellitic dianhydride as tetracarboxylic dianhydride 11.01 g (93 mol parts with respect to 100 mol parts of the total amount of diamine used in the synthesis), and 0.66 g of compound (X-1) as the diamine compound (5 mol parts), 16.70 g (80 mol parts) of bis [2- (4-aminophenyl) ethyl] hexanedioic acid, and 1.62 g (15 mol parts) of 4,4′-diaminodiphenylamine. The mixture was dissolved in a mixed solvent of 85 g of N-methyl-2-pyrrolidone (NMP) and 85 g of γ-butyrolactone (GBL) and reacted at 30 ° C. for 6 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The recovered precipitate was washed with methanol and then dried under reduced pressure at 40 ° C. for 15 hours to obtain 28.9 g of polyamic acid (hereinafter referred to as polymer (PA-1)). The obtained polymer (PA-1) was prepared so that it might become 15 weight% in the solvent composition of NMP: GBL = 50: 50, and when the viscosity of this solution was measured, it was 366 mPa * s. Further, when this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

[Synthesis Example 2-2 to Synthesis Example 2-6]
A polyamic acid was obtained in the same manner as in Synthesis Example 2-1, except that the types and amounts of tetracarboxylic dianhydride and amine compound used in the reaction were changed as shown in Table 1 below. When each of the polymer solutions obtained in Synthesis Examples 2-2 to 2-6 was allowed to stand at 20 ° C. for 3 days, none of them was gelled, and the storage stability was good.

The numerical values in Table 1 indicate, for tetracarboxylic dianhydrides, the usage ratio (mol%) relative to the total amount of tetracarboxylic dianhydrides used for the reaction, and for diamines, the total amount of diamine used for the reaction. The ratio of use (mol%) to the amount is shown.
Abbreviations of tetracarboxylic dianhydride and diamine in Table 1 are as follows.
(Tetracarboxylic dianhydride)
AN-1; 1,2,3,4-cyclobutanetetracarboxylic dianhydride AN-2; pyromellitic dianhydride AN-3; 2,3,5-tricarboxycyclopentylacetic dianhydride AN-4; 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione AN-5; 5- (2,5 -Dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione AN-6; bicyclo [3.3.0] Octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride (diamine compound)
DA-1; Compound DA-2 represented by Formula (X-1); Compound DA-3 represented by Formula (X-2); Compound DA- represented by Formula (X-3) 4, 1,5-bis (4-aminophenoxy) pentane DA-5; bis [2- (4-aminophenyl) ethyl] hexanedioic acid DA-6; 4,4′-diaminodiphenylamine DA-7; 5-diaminobenzoic acid DA-8; N- (2,4-diaminophenyl) -4- (4-heptylcyclohexyl) benzamide DA-9; 4- (tetradecaoxy) benzene-1,3-diamine DA-10 3,5-diaminobenzoic acid cholestanyl DA-11; 4,4′-diaminodiphenylmethane The polymer (PA-4) is particularly suitable for a TN-type liquid crystal display device, and the polymer (PA-5) is particularly preferred. VA liquid crystal display Suitable for element.

[Synthesis Example 3-1; Synthesis of Polymer (PI-1)]
21.49 g of bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride as tetracarboxylic dianhydride (amine compound used in the synthesis) 98 mol parts per 100 mol parts in total), and 3.05 g (10 mol parts) of the compound (X-3) as a diamine compound, bis [2- (4-aminophenyl) ethyl] hexanedioic acid 20.22 g (60 mole parts) and 5.24 g of 4,4′-diaminodiphenylamine (30 mole parts) were dissolved in 200 g of NMP and reacted at room temperature for 6 hours. Next, 250 g of NMP was added, 6.79 g of pyridine and 8.77 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 100 ° C. for 5 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The recovered precipitate was washed with methanol, and then dried at 40 ° C. under reduced pressure for 15 hours to obtain polyimide (PI-1) having an imidization ratio of about 50%. The obtained polyimide (PI-1) was prepared so that it might become 15 weight% with NMP. The viscosity of this solution was measured and found to be 625 mPa · s. Moreover, when the obtained polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

[Synthesis Example 4-1; Synthesis of Polymer (p-1)]
A polymer (p-1) was obtained in the same manner as described in JP-A-9-304777. Pyromellitic dianhydride 21.81 g (0.10 mol), 2,2-bis [4- (4-aminophenoxy) phenyl] propane 36.95 g (0.09 mol), and 2,2-bis ( 2.28 g (0.01 mol) of 4-hydroxyphenyl) propane was dissolved in 549 g of N-methyl-2-pyrrolidone and reacted at room temperature for 24 hours. Next, the reaction solution was poured into a large excess of pure water to precipitate the reaction product. Thereafter, the precipitate was separated, washed with pure water, and dried at 40 ° C. under reduced pressure for 15 hours to obtain 54.9 g of a polymer (p-1) having a logarithmic viscosity (ηln) of 1.16 dl / g. .
[Synthesis Example 5-1; Synthesis of Polymer (p-2)]
A polymer (p-2) was obtained in the same manner as described in JP-A-10-330756. 5 g of biphenyl type epoxy resin (Epicoat YL-6121, manufactured by Yuka Shell Epoxy Co., Ltd.), 50 g of catechol novolak resin (Epicoat YLH-600, manufactured by Yuka Shell Epoxy Co., Ltd.), imidazole derivative (2E4MZ-CNS, 1 g of Shikoku Kasei Co., Ltd.), 1430 g of NMP, and 100 g of butyl cellosolve were placed in a flask and stirred under a nitrogen atmosphere to obtain a uniform brown transparent liquid. Next, the reaction solution was poured into a large excess of pure water to precipitate the reaction product. Thereafter, the precipitate was separated, washed with pure water, and dried at 40 ° C. under reduced pressure for 15 hours to obtain 49 g of a polymer (p-2).

[Synthesis Example 6-1; Synthesis of Polymer (PSi-1)]
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser was charged with 100.0 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 500 g of methyl isobutyl ketone and 10.0 g of triethylamine, and room temperature. And mixed. 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and the reaction was carried out at 80 ° C. for 6 hours while mixing under reflux. After completion of the reaction, the organic layer is taken out, washed with 0.2 wt% ammonium nitrate aqueous solution until the water after washing becomes neutral, and then the solvent and water are distilled off under reduced pressure to have an oxiranyl group. Polyorganosiloxane was obtained as a viscous transparent liquid. When ¹ H-NMR analysis was performed on the polyorganosiloxane having an oxiranyl group, a peak based on the oxiranyl group was obtained in the vicinity of the chemical shift (δ) = 3.2 ppm according to the theoretical intensity. It was confirmed that no side reaction occurred. The epoxy equivalent of the polyorganosiloxane having an oxiranyl group was measured and found to be 186 g / equivalent.
Next, in a 100 mL three-necked flask, 9.3 g of the polyorganosiloxane having the oxiranyl group obtained above, 26 g of methyl isobutyl ketone, 3 g of 4-phenoxycinnamic acid and UCAT 18X (trade name, manufactured by San Apro Co., Ltd.) 0.10 g Was reacted at 80 ° C. for 12 hours with stirring. After completion of the reaction, the reaction mixture was poured into methanol to collect a precipitate, which was dissolved in ethyl acetate to form a solution. The solution was washed with water three times, and then the solvent was distilled off to remove the oxiranyl group. 6.3 g of polyorganosiloxane (PSi-1) having a cinnamic acid structure was obtained as a white powder. The weight average molecular weight Mw in terms of polystyrene measured by GPC for this polyorganosiloxane (PSi-1) was 3,500.

<Preparation and evaluation of liquid crystal aligning agent>
[Example 1: rubbing alignment FFS type liquid crystal display element]
(1) Preparation of liquid crystal aligning agent The polymer (PA-1) obtained in Synthesis Example 2-1 as a polymer was obtained from γ-butyrolactone (GBL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC). In a mixed solvent (GBL: NMP: BC = 40: 40: 20 (weight ratio)) to obtain a solution having a solid content concentration of 3.5% by weight. The liquid crystal aligning agent (R-1) was prepared by filtering this solution through a filter having a pore diameter of 0.2 μm.

(2) Evaluation of applicability The liquid crystal aligning agent (R-1) prepared above was applied on a glass substrate using a spinner, prebaked on a hot plate at 80 ° C. for 1 minute, and then the interior was filled with nitrogen. By heating (post-baking) in a substituted 200 ° C. oven for 1 hour, a coating film having an average film thickness of 1,000 mm was formed. This coating film was observed with a microscope having a magnification of 100 times and 10 times to examine the presence or absence of film thickness unevenness and pinholes. Evaluation is that the film thickness unevenness and the pinhole are not observed even when observed with a 100 × microscope, the coating property is “good”, and the 100 × microscope observes at least one of the film thickness unevenness and the pinhole. However, when both the film thickness unevenness and the pinhole were not observed with a 10 × microscope, the coating property was “OK”. At least one of the film thickness unevenness and the pinhole was clearly observed with a 10 × microscope. The case was evaluated as “bad” coating property. In this example, neither film thickness unevenness nor pinhole was observed even with a 100 × microscope, and the coating property was “good”.
(3) Evaluation of rubbing resistance The coating film obtained above was rubbed at a roll rotation speed of 1000 rpm, a stage moving speed of 20 cm / sec, and a hair foot indentation length of 0.4 mm by a rubbing machine having a roll wrapped with a cotton cloth. The treatment was performed 7 times. Foreign matter (a piece of coating film) due to rubbing scraping on the obtained substrate was observed with an optical microscope, and the number of foreign matters in a 500 μm × 500 μm region was measured. In the evaluation, the rubbing resistance was “good” when the number of foreign materials was 3 or less, and the rubbing resistance “good” when 4 or more and 7 or less, and the rubbing resistance “bad” when 8 or more. As a result, the rubbing resistance of this coating film was “good”.

(4) Manufacture of FFS type liquid crystal display element by rubbing process The FFS type liquid crystal display element 10 shown in FIG. 1 was produced. First, a glass substrate 11a having an electrode pair on one side of which a bottom electrode 15 having no pattern, a silicon nitride film as an insulating layer 14, and a top electrode 13 patterned in a comb shape are formed in this order, and an electrode The liquid crystal aligning agent (R-1) prepared in the above (1) is paired with the opposite glass substrate 11b not provided with the glass substrate 11a, and the surface of the glass substrate 11a having the transparent electrode and one surface of the opposite glass substrate 11b. The coating film was formed by coating using a spinner. Next, this coating film was pre-baked for 1 minute on a hot plate at 80 ° C., and then heated (post-baked) at 230 ° C. for 15 minutes in an oven in which the inside of the chamber was replaced with nitrogen, so that the average film thickness was 1,000 mm. A coating film was formed. A schematic plan view of the top electrode 13 used here is shown in FIG. 2A is a top view of the top electrode 13, and FIG. 2B is an enlarged view of a portion C1 surrounded by a broken line in FIG. 2A. In this example, the line width d1 of the electrodes was 4 μm, and the distance d2 between the electrodes was 6 μm. Further, as the top electrode 13, four types of drive electrodes of electrode A, electrode B, electrode C, and electrode D were used. FIG. 3 shows the configuration of the drive electrode used. In this case, the bottom electrode 15 functions as a common electrode that acts on all of the four drive electrodes, and each of the four drive electrode regions serves as a pixel region.

  Subsequently, the surface of the coating film formed on the glass substrates 11 a and 11 b was rubbed with cotton to form the liquid crystal alignment film 12. In FIG.2 (b), the rubbing direction with respect to the coating film formed on the glass substrate 11a is shown by the arrow. Next, after applying the product name “XN-21-S” (manufactured by Mitsui Chemicals) as a sealant to the outer edge of the surface having the liquid crystal alignment film in one of the pair of substrates, Then, the substrates were bonded together via a spacer having a diameter of 3.5 μm so that the rubbing directions of the substrates 11a and 11b were antiparallel, and the sealant was cured. Next, liquid crystal MLC-6221 (manufactured by Merck & Co., Inc.) was injected between the pair of substrates through the liquid crystal injection port to form the liquid crystal layer 16. Furthermore, the liquid crystal display element 10 was produced by bonding a polarizing plate (not shown) on both outer surfaces of the substrates 11a and 11b so that the polarization directions of the two polarizing plates were orthogonal to each other.

(5) Evaluation of liquid crystal orientation For the FFS type liquid crystal display device manufactured as described above, the presence or absence of abnormal domains in the change in brightness when a voltage of 5 V is turned ON / OFF (applied / released) is observed with a microscope at a magnification of 50 times. did. In the evaluation, when the abnormal domain was not observed, the liquid crystal alignment was “good”, and when the abnormal domain was observed, the liquid crystal alignment was “bad”. In this liquid crystal display element, the liquid crystal orientation was “good”.
(6) Evaluation of voltage holding ratio For the FFS type liquid crystal display device manufactured as described above, a voltage of 5 V was applied at 23 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and 167 milliseconds after the release of application. When the voltage holding ratio (VHR) of was measured, it was 98.1%. In addition, as a measuring apparatus, Toyo Technica Co., Ltd. make and VHR-1 were used.

(7) Evaluation of afterimage characteristics (DC afterimage evaluation)
The liquid crystal display element produced above was placed in an environment of 25 ° C. and 1 atmosphere. The bottom electrode was set as a common electrode for all four drive electrodes, and the potential of the bottom electrode was set to 0 V potential (ground potential). The electrode B and the electrode D were short-circuited with the common electrode to be in a 0 V application state, and a composite voltage composed of an AC voltage of 3.5 V and a DC voltage of 1 V was applied to the electrodes A and C for 2 hours. Immediately after 2 hours, an AC voltage of 1.5 V was applied to all of the electrodes A to D. Then, from the start of applying an AC voltage of 1.5 V to all drive electrodes, a drive stress application region (pixel region of electrode A and electrode C) and a drive stress non-application region (pixel region of electrode B and electrode D) The time until the difference in brightness with the eye could not be visually confirmed was measured, and this was defined as the afterimage erasing time. Note that the shorter this time, the less likely an afterimage is generated. The case where the afterimage erasing time was less than 30 seconds was evaluated as “good”, the case where it was 30 seconds or more and less than 120 seconds was evaluated as “good”, and the case where it was 120 seconds or more was evaluated as “bad”. The afterimage erasing time of the liquid crystal display element was 2 seconds, and the afterimage characteristics were evaluated as “good”.
(8) per FFS type liquid crystal display device manufactured in light resistance above, to measure the voltage holding ratio similarly to the above (6), and its value as an initial VHR _{(VHR BF).} Next, the liquid crystal display element after the initial VHR measurement was allowed to stand in an 80 ° C. oven under LED lamp irradiation for 200 hours, and then allowed to stand at room temperature and naturally cooled to room temperature. With respect to the liquid crystal cell after light irradiation, the voltage holding ratio was measured again by the same method as described above. This value was defined as a voltage holding ratio (VHR _AFBL ) after light irradiation. The decrease amount ΔVHR _BL (%) of the voltage holding ratio was obtained from the following formula (EX-2) and evaluated as light resistance.
ΔVHR _BL = ((VHR _BF −VHR _AFBL ) ÷ VHR _BF ) × 100 (EX−2)
When ΔVHR was less than 3%, the light resistance was judged as “good”, when it was 3% or more but less than 5%, “good”, and when it was 5% or more, “bad”. As a result, ΔVHR _BL of the liquid crystal display element of this example was 1.2%, and the heat resistance was “good”.

(9) Unevenness around sealant (bezel unevenness resistance)
The FFS type liquid crystal display device manufactured above was stored for 30 days under conditions of 25 ° C. and 50% RH, and then driven with an AC voltage of 5 V to observe the lighting state. The evaluation is “good” if the luminance difference (more black or more white) is not visually recognized around the sealant, but “good” if the luminance difference disappears within 20 minutes after lighting, 20 minutes. A case where the luminance difference was visually recognized even after a lapse was defined as “defective”. As a result, the luminance difference of the liquid crystal display element was not visually recognized, and was judged as “good”.

[Examples 2 to 7 and Comparative Examples 1 to 4]
In Example 1 above, the liquid crystal aligning agent is prepared in the same manner as in Example 1 except that the type and amount of solids (polymer and additive) contained in the liquid crystal aligning agent are changed as shown in Table 2 below. At the same time, FFS type liquid crystal display elements were manufactured by a rubbing method and various evaluations were performed. The evaluation results are shown in Table 2 below. In Examples 4 to 6 and Comparative Example 4, an additive was blended in the liquid crystal aligning agent. In Table 2, the numerical value of the additive indicates the blending ratio (part by weight) of the additive with respect to 100 parts by weight of the polymer component.

In Table 2, the abbreviations of the additives are as follows.
A-1: Compound represented by the above formula (5-4) A-2; Compound represented by the above formula (5-1) A-3; Compound represented by the above formula (5-7) a- 1; Phenol

  As shown in Table 2, in Examples 1 to 7, all the coating properties of the liquid crystal aligning agent and the rubbing resistance, and the liquid crystal alignment properties, voltage holding ratio, afterimage characteristics, light resistance, and bezel unevenness resistance of the liquid crystal display element are “ The result was “good” or “good”, and various characteristics were balanced. On the other hand, in Comparative Examples 1-4, it was a result inferior to an Example in several evaluation items among liquid crystal orientation, a voltage holding ratio, an afterimage characteristic, light resistance, and bezel unevenness tolerance. In particular, in Comparative Example 2, the liquid crystal alignment was poor, and the evaluation of afterimage characteristics and bezel unevenness resistance, which are characteristics requiring visibility in the subsequent characteristic evaluation, could not be performed. In Comparative Example 1, the afterimage characteristics and the bezel unevenness resistance were inferior to those of the Examples.

[Example 8: Photo-alignment FFS type liquid crystal display element]
(1) Preparation of liquid crystal aligning agent The polymer (PA-2) obtained in Synthesis Example 2-2 as a polymer was obtained from γ-butyrolactone (GBL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC). In a mixed solvent (GBL: NMP: BC = 40: 40: 20 (weight ratio)) to obtain a solution having a solid content concentration of 3.5% by weight. A liquid crystal aligning agent (R-8) was prepared by filtering this solution through a filter having a pore size of 0.2 μm.

(2) Evaluation of applicability The liquid crystal aligning agent (R-8) prepared above was applied onto a glass substrate using a spinner, pre-baked for 1 minute on a hot plate at 80 ° C, and then the interior was filled with nitrogen. By heating (post-baking) in a substituted 200 ° C. oven for 1 hour, a coating film having an average film thickness of 1,000 mm was formed. The applicability was evaluated in the same manner as (2) in Example 1 above. As a result, the coating property of this coating film was “good”.
(3) Evaluation of orientation The coating film obtained above is irradiated with polarized ultraviolet rays 300 J / m ² containing a 313 nm emission line from the normal direction of the substrate using an Hg-Xe lamp and a Grand Taylor prism. Was given. The refractive index anisotropy α (nm) of this glass substrate with an alignment film was measured using a liquid crystal alignment film inspection apparatus (RayScan) manufactured by MORITEX. The evaluation was “good” when 0.020 nm or more, “good” when less than 0.020 nm and less than 0.010 nm, and “bad” when less than 0.010 nm. As a result, in this substrate, α = 0.035 nm, and the orientation was “good”.

(4) Manufacture of FFS type liquid crystal display element by photo-alignment method First, the liquid crystal aligning agent prepared by said (1) on each surface of a pair of glass substrate 11a, 11b similar to (4) of the said Example 1, respectively. (R-8) was applied using a spinner to form a coating film. Next, this coating film was pre-baked for 1 minute on a hot plate at 80 ° C., and then heated (post-baked) at 230 ° C. for 15 minutes in an oven in which the inside of the chamber was replaced with nitrogen, so that the average film thickness was 1,000 mm. A coating film was formed. A schematic plan view of the top electrode 13 used here is shown in FIG. 4A is a top view of the top electrode 13, and FIG. 4B is an enlarged view of a portion C1 surrounded by a broken line in FIG. 4A. In this example, a substrate having a top electrode having a line width d1 of electrodes of 4 μm and a distance d2 between the electrodes of 6 μm was used. As the top electrode 13, four drive electrodes of electrode A, electrode B, electrode C, and electrode D were used as in Example 1 (see FIG. 3).
Next, each surface of these coatings is irradiated with polarized ultraviolet rays 300 J / m ² including a 313 nm emission line from the normal direction of the substrate using a Hg—Xe lamp and a Grand Taylor prism, and a pair of liquid crystal alignment films are provided. A substrate was obtained. At this time, the irradiation direction of the polarized ultraviolet ray is from the normal direction of the substrate, and the polarization plane direction is set so that the direction of the line segment in which the polarization plane of the polarized ultraviolet ray is projected onto the substrate is the direction of the double-headed arrow in FIG. The light irradiation process was performed.

Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied to the outer periphery of the surface having one liquid crystal alignment film of the above substrates by screen printing, and then the liquid crystal alignment film surfaces of a pair of substrates Were placed so that the planes of polarization of polarized ultraviolet rays projected onto the substrate were parallel and pressure bonded, and the adhesive was heat cured at 150 ° C. for 1 hour. Next, liquid crystal “MLC-6221” manufactured by Merck Co., Ltd. was filled into the substrate gap from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy resin adhesive. Then, in order to remove the flow alignment at the time of liquid crystal injection, this was heated to 150 ° C. and then gradually cooled to room temperature.
Next, an FFS type liquid crystal display element was manufactured by laminating polarizing plates on both outer surfaces of the substrate. At this time, one of the polarizing plates is stuck so that the polarization direction thereof is parallel to the direction of projection of the polarization plane of the polarized ultraviolet light of the liquid crystal alignment film onto the substrate surface, and the other one has the polarization direction first. The polarizing plate was stuck so as to be orthogonal to the polarization direction of the polarizing plate.

(5) Evaluation of liquid crystal orientation About the photo-alignment FFS type liquid crystal display element manufactured above, liquid crystal orientation was evaluated like (5) of the said Example 1. FIG. As a result, this liquid crystal display element had “good” liquid crystal alignment.
(6) Evaluation of voltage holding ratio About the photo-alignment type FFS liquid crystal display element manufactured above, the voltage holding ratio (VHR) was measured in the same manner as (6) of Example 1 to evaluate the voltage holding ratio. As a result, VHR was 99.5%.
(7) Evaluation of afterimage characteristics (DC afterimage evaluation)
The afterimage characteristics of the photo-alignment type FFS liquid crystal display device manufactured above were evaluated in the same manner as in (7) of Example 1 above. As a result, the afterimage erasing time was 1 second, and the afterimage characteristics were evaluated as “good”.
(8) Light _{resistance The} voltage holding ratios (VHR _BF and VHR _AFBL ) are measured in the same manner as (8) in Example 1 above, and the light resistance of the liquid crystal display element is changed by changing the voltage holding ratio before and after applying light stress. evaluated. As a result, ΔVHR _BL was 0.5%, and the light resistance was judged as “good”.
(9) Unevenness around sealant (bezel unevenness resistance)
The bezel unevenness resistance was evaluated in the same manner as in Example 1 (9). As a result, the luminance difference of the liquid crystal display element was not visually recognized, and the bezel unevenness resistance was determined to be “good”.

[Example 9: retardation film]
(1) Preparation of liquid crystal aligning agent 100 parts by weight of the polymer (PA-3) obtained in Synthesis Example 2-3 and 5 parts by weight of the polymer (PSi-1) obtained in Synthesis Example 6-1 were mixed with propylene glycol monomethyl. Dissolved in a mixed solvent (PGMEA: NMP: BTLAC = 30: 30: 40 (weight ratio)) composed of ether acetate (PGMEA), N-methyl-2-pyrrolidone (NMP) and butyl acetate (BTLAC), and the solid content concentration Was a 4.5 wt% solution. A liquid crystal aligning agent (R-9) was prepared by filtering this solution through a filter having a pore diameter of 0.2 μm.

(2) Manufacture of retardation film The liquid crystal aligning agent (R-9) prepared above is applied to one side of a TAC film as a substrate with a bar coater, and baked in an oven at 120 ° C. for 2 minutes for film A coating film having a thickness of 100 nm was formed. Next, the surface of the coating film was irradiated perpendicularly from the substrate normal line with polarized ultraviolet rays of 10 mJ / cm ² containing an emission line of 313 nm using a Hg—Xe lamp and a Grand Taylor prism. Next, the polymerizable liquid crystal (RMS03-013C, manufactured by Merck & Co., Inc.) was filtered through a filter having a pore size of 0.2 μm, and this polymerizable liquid crystal was applied onto the coated film after light irradiation by a bar coater. A coating film was formed. After baking for 1 minute in an oven adjusted to a temperature of 50 ° C., an unpolarized ultraviolet ray containing 365 nm emission line was irradiated at 1,000 mJ / cm ² from a direction perpendicular to the coating surface using an Hg-Xe lamp. A retardation film was produced by curing a polymerizable liquid crystal to form a liquid crystal layer.

(3) Evaluation of liquid crystal orientation About the retardation film manufactured by said (2), liquid crystal orientation is observed by observing the presence or absence of an abnormal domain by visual observation under crossed Nicols and a polarizing microscope (magnification 2.5 times). evaluated. The evaluation was that the alignment was good visually and the abnormal domain was not observed with a polarizing microscope, the liquid crystal orientation was “good”, and the abnormal domain was not observed with the polarizing microscope, but the abnormal domain was observed with a polarizing microscope. The case where the liquid crystal orientation was “possible”, and the case where an abnormal domain was observed visually and with a polarizing microscope was regarded as “Poor”. As a result, this retardation film was evaluated as “good” for liquid crystal alignment.

(4) Adhesiveness Using the retardation film produced in (2) above, the adhesiveness of the coating film formed with the liquid crystal aligning agent to the substrate was evaluated. First, using an equally spaced spacer with a guide, a cutter knife was used to cut from the surface on the liquid crystal layer side of the retardation film to form 10 × 10 lattice patterns within a range of 1 cm × 1 cm. The depth of each cut was made to reach the middle of the substrate thickness from the surface of the liquid crystal layer. Next, after attaching a cellophane tape so as to cover the entire surface of the lattice pattern, the cellophane tape was peeled off. The notches in the lattice pattern after peeling were observed visually under crossed Nicols to evaluate the adhesion. The evaluation was that the adhesion was “good” when no peeling was observed at the portion along the cut line and at the intersection of the lattice pattern, and the number of lattices where peeling was observed in the above portion was the number of the entire lattice pattern. On the other hand, when the amount is less than 15%, the adhesion is “possible”, and when the number of lattices where peeling is observed in the above portion is 15% or more with respect to the total number of lattice patterns, the adhesion is “bad”. went. As a result, this retardation film had good adhesion.

  DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display element, 11a, 11b ... Glass substrate, 12 ... Liquid crystal aligning film, 13 ... Top electrode, 14 ... Insulating layer, 15 ... Bottom electrode, 16 ... Liquid crystal layer.

Claims (10)

An aromatic polyvalent hydroxy compound (A) having a partial structure (b) in which two or more hydrogen atoms bonded to an aromatic ring are substituted with a hydroxy group,
As the compound (A), at least one polymer (A1) selected from the group consisting of a polyimide precursor and polyimide, or a compound represented by the following formula (Ad-1),
The polymer (A1) is a polymer obtained by using at least one diamine selected from the group consisting of a compound represented by the following formula (2-1) and a compound represented by the following formula (2-2). A liquid crystal aligning agent.

(In Formula (2-1) and Formula (2-2), R ² , R ³ and R ⁴ are each independently a methylene group, an ethylene group, a propanediyl group, a butanediyl group, a pentanediyl group, a hexanediyl group, A pentaneyl group, an octanediyl group, a nonanediyl group, a decandiyl group, a vinylene group, a propenediyl group, a butenediyl group, a pentenediyl group, a hexenediyl group, a cyclohexylene group, a phenylene group, a biphenylene group, or a naphthylene group , n is 1 and r1 Is 0 and r2 is 0. R ¹ is a monovalent organic group.)

(In the formula (Ad-1), A ¹ is a (t + 1) -valent organic group having 1 to 20 carbon atoms , A ² is an epoxy group, an amino group, or a carboxyl group , and t is 1 or 2 . .)   The polymer (A1) is bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 1,2,3,4-cyclobutane. Tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic 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-tetracarboxylic acid 2: 4,6: 8-dianhydride, cyclohexanetetracarboxylic dianhydride and pyromerit Selected from the group consisting of acid dianhydrides At least one compound is a polymer obtained by using the reaction, the liquid crystal aligning agent of claim 1.   The liquid crystal aligning agent according to claim 1, wherein the compound (A) is an additive component having a molecular weight of 500 or less.   The liquid crystal aligning film formed using the liquid crystal aligning agent as described in any one of Claims 1-3.   The liquid crystal aligning film obtained by apply | coating the liquid crystal aligning agent as described in any one of Claims 1-3 to a board | substrate, forming a coating film, and light-irradiating this coating film.   The liquid crystal aligning film obtained by apply | coating the liquid crystal aligning agent as described in any one of Claims 1-3 to a board | substrate, and carrying out a rubbing process.   The process of apply | coating the liquid crystal aligning agent as described in any one of Claims 1-3 on a board | substrate, and forming a coating film, and the process of light-irradiating this coating film and providing liquid crystal aligning ability are included. A method for producing a liquid crystal alignment film.   A liquid crystal display element provided with the liquid crystal aligning film as described in any one of Claims 4-6.   A retardation film comprising the liquid crystal alignment film according to claim 4.   The process of apply | coating the liquid crystal aligning agent as described in any one of Claims 1-3 on a board | substrate, forming a coating film, the process of irradiating the said coating film with light, On the coating film after the said light irradiation A method for producing a retardation film, comprising: applying a polymerizable liquid crystal thereon and curing the liquid crystal.

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