WO2020145175A1

WO2020145175A1 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element

Info

Publication number: WO2020145175A1
Application number: PCT/JP2019/051064
Authority: WO
Inventors: 祐太飯塚; 耕平後藤
Original assignee: 日産化学株式会社
Priority date: 2019-01-08
Filing date: 2019-12-26
Publication date: 2020-07-16
Also published as: KR20210112333A; JPWO2020145175A1; TW202039601A; TWI816960B; CN113272729A; JP7424318B2

Abstract

The present invention provides: a liquid crystal alignment film that has excellent display reliability with less changes in a pretilt angle even after being driven for a long time, has high voltage holding characteristics, and is capable of reducing charge buildup; a liquid crystal display element comprising the same; and a liquid crystal alignment agent that provides the same. The present invention provides a liquid crystal alignment agent that comprises, as component (A), a polymer having a photo-alignment group represented by formula (pa-1) (in the formula, A is phenylene or the like, R₁ is a single bond, oxygen atom, or the like, R₂ is a divalent aromatic group or the like, R₃ is a single bond, oxygen atom, or the like, R₄ is a linear or branched alkyl group having 1 to 40 carbon atoms or a monovalent organic group having 3 to 40 carbon atoms and including an alicyclic group, D is an oxygen atom, sulfur atom, or -NR_d-, a is an integer of 0 to 3, and * is a binding site) and a thermal crosslinking group A, and as component (B), a polymer selected from polyimide that has a radical generating group that generates a radical due to irradiation with light and a precursor thereof, and a solvent.

Description

Liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display device

The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film obtained by the liquid crystal aligning agent, and a liquid crystal display device including the obtained liquid crystal aligning film. More specifically, the present invention relates to a liquid crystal aligning agent capable of providing a liquid crystal aligning film having excellent liquid crystal aligning property, excellent pretilt angle expressing ability, and high reliability, and a liquid crystal display device having excellent display quality.

In the liquid crystal display element, the liquid crystal alignment film plays a role of aligning the liquid crystal in a certain direction. Currently, the main liquid crystal alignment film used industrially is a polyimide precursor polyamic acid (also called polyamic acid), polyamic acid ester, or a polyimide-based liquid crystal aligning agent consisting of a solution of polyimide, on the substrate. It is manufactured by applying and forming a film.
Further, when the liquid crystal is aligned parallel or inclined with respect to the substrate surface, after film formation, surface stretching treatment by rubbing is further performed.

On the other hand, when the liquid crystal is aligned vertically to the substrate (called vertical alignment (VA) system), long-chain alkyl or cyclic group or a combination of cyclic group and alkyl group (see, for example, Patent Document 1), steroid skeleton (refer to Patent Document 1). For example, a liquid crystal alignment film in which a hydrophobic group such as that of Patent Document 2) is introduced into a side chain of polyimide is used. In this case, when a voltage is applied between the substrates to tilt the liquid crystal molecules in a direction parallel to the substrates, the liquid crystal molecules need to be tilted from the substrate normal direction to one direction in the substrate surface. .. As means for this, for example, a method of providing a protrusion on the substrate, a method of providing a slit on the display electrode, and rubbing the liquid crystal molecules slightly from the substrate normal direction toward one direction in the substrate surface ( Pretilt), or by pre-tilting the liquid crystal by irradiating ultraviolet rays while applying a voltage to the liquid crystal cell by adding a photopolymerizable compound to the liquid crystal composition in advance and using it together with a vertical alignment film such as polyimide. There has been proposed a method (see, for example, Patent Document 3) for doing so. Such a technique is called PSA (Polymer Sustained Alignment).

In recent years, a method (photo-alignment method) that utilizes an anisotropic photochemical reaction due to polarized UV irradiation or the like has been proposed as an alternative to the formation of protrusions and slits in liquid crystal alignment control of the VA method and PSA technology. That is, it is known that the tilt direction of liquid crystal molecules when a voltage is applied can be uniformly controlled by irradiating a vertically aligned polyimide film having photoreactivity with polarized ultraviolet light and imparting alignment regulating ability and pretilt angle expressing property. (See Patent Document 4).

VA liquid crystal display elements are used in TVs and in-vehicle displays because of their high contrast and wide viewing angle. A liquid crystal display device for TV uses a backlight that generates a large amount of heat in order to obtain high brightness, and a liquid crystal display device used for in-vehicle applications, such as a car navigation system or a meter panel, is exposed to a high temperature environment for a long time. It may be used or left unused. Under such severe conditions, when the pretilt angle gradually changes, problems such as the initial display characteristics not being obtained and display unevenness occur. In addition, when the liquid crystal is driven, the voltage holding characteristics and charge storage characteristics are also affected by the liquid crystal alignment film, and when the voltage holding ratio is low, the contrast of the display screen decreases, and when the charge accumulation with respect to the DC voltage is large. Causes a phenomenon that the display screen is burned.

Here, by using a polyimide precursor having a repeating unit having a photo-alignable group and a repeating unit having a polymerization initiator structure as the liquid crystal alignment layer, PSA treatment is performed to share it with the alignment sustaining layer. It is known to form a bond and increase the stability of the tilt angle (Patent Document 5). It is also known that the stability of the tilt angle is enhanced by an alignment layer obtained from a polymer having a photoalignable group and an alignment sustaining layer formed using a monomer that generates radicals by absorbing light (Patent Reference 6). However, in the PSA treatment after the photo-alignment treatment, the reverse reaction of the photo-alignment group may proceed and the photo-alignment property may be impaired.

JP-A-3-179323 JP-A-4-281427 Japanese Patent No. 4504626 Japanese Patent No. 4995267 International publication WO2011/001579 International publication WO2013/002084

The present invention has been made in view of the above circumstances, and its problem is that the change in the pretilt angle is small even after driving for a long time, the display reliability is excellent, the voltage holding characteristic is high, and the charge accumulation is reduced. A liquid crystal alignment film which can be used, a liquid crystal display device having the liquid crystal alignment film, and a liquid crystal alignment agent for providing the same.

The present inventors have found an invention based on the following <X>.
<X> A polymer having a photoalignable group represented by the following formula (pa-1) and a thermally crosslinkable group A as the component (A), and a radical-generating group that generates a radical by light irradiation as the component (B). A liquid crystal aligning agent containing a polymer and a solvent selected from a polyimide having the above and a precursor thereof.

In the formula, A is optionally a group selected from fluorine, chlorine, cyano, or an alkoxy group having 1 to 5 carbon atoms, a linear or branched alkyl residue (which may be one Substituted with a cyano group or with one or more halogen atoms), pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophenylene, 2,5-furanylene, Represents 1,4- or 2,6-naphthylene or phenylene, R ₁ is a single bond, an oxygen atom, —COO— or —OCO—, and R ₂ is a divalent aromatic group or a divalent alicyclic group Group, a divalent heterocyclic group or a divalent condensed cyclic group, R ₃ is a single bond, an oxygen atom, —COO— or —OCO—, and R ₄ is a straight chain having 1 to 40 carbon atoms. Or a monovalent organic group having 3 to 40 carbon atoms including a branched alkyl group or an alicyclic group, D is an oxygen atom, a sulfur atom or —NR _d — (wherein R _d is a hydrogen atom) Or represents an alkyl having 1 to 3 carbon atoms, a is an integer of 0 to 3, and * represents a bonding position.

According to the present invention, the liquid crystal orientation is good, the pretilt angle expressing ability is excellent, the change in the pretilt angle is small even after driving for a long time, the display reliability is high, the voltage holding characteristic is high, and the charge accumulation is high. A liquid crystal aligning film and a liquid crystal aligning agent that can be reduced can be provided.
In addition, the liquid crystal display device manufactured by the method of the present invention has excellent display characteristics.

The liquid crystal aligning agent of the present invention is a polymer having a photo-aligning group represented by the following formula (pa-1) and a heat-crosslinkable group A as the component (A), and a radical as a component (B) upon irradiation with light. It contains a polymer and a solvent selected from a polyimide having a radical-generating group to be generated and a precursor thereof.

The liquid crystal aligning agent may be a polymer in which the component (A) further has a thermally crosslinkable group A, and may satisfy at least one of the following requirements Z1 and Z2.
The polymer which is the Z1:(A) component further has a thermally crosslinkable group B.
Z2: A compound having two or more heat-crosslinkable groups B in the molecule is further contained as the component (C).
The heat-crosslinkable group A and the heat-crosslinkable group B are each independently a carboxyl group, an amino group, an alkoxymethylamide group, a hydroxymethylamide group, a hydroxyl group, an epoxy group-containing group, an oxetanyl group, a thiylanyl group, an isocyanate group and a block. An organic group selected from the group consisting of isocyanate groups, which is selected so that the heat-crosslinkable group A and the heat-crosslinkable group B undergo a crosslinking reaction by heat, provided that the heat-crosslinkable group A and the heat-crosslinkable group are The groups B may be the same as each other.

Here, "two or more in the molecule" means, for example, a case where two or more groups of the same kind such as two or more epoxy groups are contained in the molecule, or a combination of an epoxy group and a thiirane group. In addition, the case where two or more different groups are contained in the molecule is meant to be included. “Two or more in the molecule” preferably contains two or more groups of the same kind in the molecule.

The polymer which is the component (A) contained in the liquid crystal aligning agent of the present invention has high sensitivity to light, and therefore can exhibit the alignment control ability even in the irradiation of polarized ultraviolet rays with a low exposure amount.
Further, since the polymer as the component (A) contains the heat-crosslinkable group A and further contains the heat-crosslinkable group B in the component, the component (A) can be obtained even when the firing time of the liquid crystal aligning agent is short. A cross-linking reaction involving the polymer As a result, when the photo-alignment site exhibits anisotropy due to photoreaction, anisotropy is likely to remain (memory) in the liquid crystal alignment film, so that the liquid crystal alignment is enhanced and the pretilt angle of the liquid crystal is exhibited. It becomes possible to do.

Further, the liquid crystal aligning agent of the present invention can be suitably used particularly when the PSA treatment is carried out by using the liquid crystal composition containing the alkenyl-based liquid crystal by containing the polymer as the component (B). Therefore, it is possible to improve the durability of the pretilt angle by the PSA process.

The photo-alignable group represented by the above formula (pa-1), the heat-crosslinkable group A and the heat-crosslinkable group B are all capable of forming a side chain in the polymer. In other words, it can be referred to as a "side chain".
Hereinafter, each constituent element of the present invention will be described in detail.

<(A) component: specific polymer>
[Photo-Orienting Group Represented by Formula (pa-1)]
In the present invention, the site having the photo-alignment property represented by the above formula (pa-1) in the molecule can be represented by, for example, the following formula (a-1). Further, the site may have a structure derived from a monomer represented by the following formula (a-1-m), but is not limited thereto. In the formula, Ia is a monovalent organic group represented by the following formula (pa-1).

In formula (pa-1), A is a group optionally selected from fluorine, chlorine, cyano, or an alkoxy group having 1 to 5 carbon atoms, a linear or branched alkyl residue (this is Optionally substituted with one cyano group or one or more halogen atoms), pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophenylene, 2 , 5-furanylene, 1,4- or 2,6-naphthylene or phenylene, R ₁ is a single bond, an oxygen atom, —COO— or —OCO—, and R ₂ is a divalent aromatic group, 2 A divalent alicyclic group, a divalent heterocyclic group or a divalent condensed cyclic group, R ₃ is a single bond, an oxygen atom, —COO— or —OCO—, and R ₄ is a carbon number of 1 A monovalent organic group having 3 to 40 carbon atoms including a linear or branched alkyl group having 40 to 40 carbon atoms or an alicyclic group, and D is an oxygen atom, a sulfur atom or —NR _d — (wherein R is _d represents a hydrogen atom or alkyl having 1 to 3 carbon atoms, a is an integer of 0 to 3, and * represents a bonding position.

In the above formula (a-1) or (a-1-m), S _a represents a spacer unit, and the bonding group on the left of S _a is bonded to the main chain of the specific polymer via a spacer. Indicates that
S _a can be represented by, for example, a structure represented by the following formula (Sp).

In formula (Sp),
The bond on the left of W ₁ represents the bond to M _b ,
The bond on the right of W ₃ represents the bond to I _a ,
W ₁ , W ₂ and W ₃ are each independently a single bond, a divalent heterocycle, —(CH ₂ ) _n — (in the formula, n represents 1 to 20), —OCH ₂ —, — Represents CH ₂ O—, —COO—, —OCO—, —CH═CH—, —CF═CF—, —CF ₂ O—, —OCF ₂ —, —CF ₂ CF ₂ — or —C≡C— However, one or more non-adjacent CH ₂ groups in these substituents are independently —O—, —CO—, —CO—O—, —O—CO—, —Si(CH ₃ ) ₂ — O-Si(CH ₃ ) ₂ -, -NR-, -NR-CO-, -CO-NR-, -NR-CO-O-, -OCO-NR-, -NR-CO-NR-, -CH ═CH—, —C≡C— or —O—CO—O— (wherein R independently represents hydrogen or a linear or branched alkyl group having 1 to 5 carbon atoms). Can
A ₁ and A ₂ are each independently a group selected from a single bond, a divalent alkyl group, a divalent aromatic group, a divalent alicyclic group, or a divalent heterocyclic group. , Each group may be unsubstituted or one or more hydrogen atoms may be substituted with a fluorine atom, a chlorine atom, a cyano group, a methyl group or a methoxy group.

In formula (a-1-m), M _a represents _a polymerizable group. Examples of the polymerizable group include (meth)acrylate, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, norbornene, radical-polymerizable groups of (meth)acrylamide and its derivatives, and siloxane. it can. Preferred are (meth)acrylate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide and acrylamide.
r is an integer that satisfies 1≦r≦3.
M _b is selected from a single bond, a (r+1)-valent heterocycle, a linear or branched alkyl group having 1 to 10 carbon atoms, a (r+1)-valent aromatic group, and a (r+1)-valent alicyclic group. Each of the groups may be unsubstituted or one or more hydrogen atoms may be substituted with a fluorine atom, a chlorine atom, a cyano group, a methyl group or a methoxy group.

Examples of the aromatic group for A ₁ , A _2, and M _b include aromatic hydrocarbons having 6 to 18 carbon atoms such as benzene, biphenyl, and naphthalene. Examples of the alicyclic group for A ₁ , A _2, and M _b include alicyclic hydrocarbons having 6 to 12 carbon atoms such as cyclohexane and bicyclohexane. Examples of the heterocycle in A ₁ , A ₂ and M _b include nitrogen-containing heterocycles such as pyridine, piperidine and piperazine. Examples of the alkyl group for A ₁ and A ₂ include a linear or branched alkyl group having 1 to 10 carbon atoms.

The group represented by the above (pa-1) is preferably a group represented by the following (pa-1-a) from the viewpoint of exhibiting excellent vertical alignment control ability and stable pretilt angle. The site may have a structure derived from a monomer represented by the following formula (pa-1-ma), but is not limited thereto.

In formula (pa-1-a) or (pa-1-ma), M _a , M _b , and S _a have the same definitions as described above.
Z is an oxygen atom or a sulfur atom.
X _a and X _b are each independently a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group or an alkyl group having 1 to 3 carbon atoms.
R ₁ is a single bond, an oxygen atom, —COO— or —OCO—.
R ₂ is a divalent aromatic group, a divalent alicyclic group, or a divalent heterocyclic group.
R ₃ is a single bond, an oxygen atom, —COO— or —OCO—.
R ₄ is a monovalent organic group having 3 to 40 carbon atoms including a linear or branched alkyl group having 1 to 40 carbon atoms or an alicyclic group.
R ₅ is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine atom or a cyano group, preferably a methyl group, a methoxy group or a fluorine atom.
a is an integer of 0 to 3 and b is an integer of 0 to 4.

In formula (pa-1-a) or (pa-1-ma), the straight-chain or branched-chain alkylene group having 1 to 10 carbon atoms of S _a is a straight-chain or branched-chain alkylene group having 1 to 8 carbon atoms. It is preferably a group, for example, a methylene group, ethylene group, n-propylene group, n-butylene group, t-butylene group, n-pentylene group, n-hexylene group, n-heptylene group, n-octylene group. ..
Examples of the divalent aromatic group of S _a include 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 2,3,5,6-tetra Fluoro-1,4-phenylene group and the like can be mentioned.

In the formula (pa-1-a) or (pa-1-ma), as the divalent alicyclic group for S _a , for example, trans-1,4-cyclohexylene, trans-trans-1,4-bicyclohexyl Examples thereof include siren.
Examples of the divalent heterocyclic group for S _a include a 1,4-pyridylene group, a 2,5-pyridylene group, a 1,4-furanylene group, a 1,4-piperazine group, and a 1,4-piperidine group. be able to.
S _a is preferably an alkylene group having 1 to 8 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms, and further preferably an alkylene group having 1 to 4 carbon atoms.

Examples of the divalent aromatic group of R ₂ include 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 2,3,5,6-tetra Examples thereof include a fluoro-1,4-phenylene group and a naphthylene group.
Examples of the divalent alicyclic group for R ₂ include trans 1,4-cyclohexylene and trans-trans-1,4-bicyclohexylene.
Examples of the divalent heterocyclic group for R ₂ include 1,4-pyridylene group, 2,5-pyridylene group, 1,4-furanylene group, 1,4-piperazine group and 1,4-piperidine group. be able to.
R ₂ is preferably a 1,4-phenylene group, trans 1,4-cyclohexylene, trans-trans-1,4-bicyclohexylene.

Examples of the linear or branched alkyl group having 1 to 40 carbon atoms of R ₄ include a linear or branched alkyl group having 1 to 20 carbon atoms, and a part of hydrogen atoms of the alkyl group. Alternatively, all of them may be substituted with a fluorine atom. Examples of such alkyl groups include, for example, methyl group, ethyl group, n-propyl, n-butyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n -Nonyl group, n-decyl group, n-lauryl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n -Nonadecyl group, n-eicosyl group, 4,4,4-trifluorobutyl group, 4,4,5,5,5-pentafluoropentyl, 4,4,5,5,6,6,6-heptafluoro Hexyl group, 3,3,4,4,5,5,5-heptafluoropentyl group, 2,2,2-trifluoroethyl group, 2,2,3,3,3-pentafluoropropyl group, 2- Examples thereof include (perfluorobutyl)ethyl group, 2-(perfluorooctyl)ethyl group, and 2-(perfluorodecyl)ethyl group.

Examples of the monovalent organic group having 3 to 40 carbon atoms including the alicyclic group of R ₄ include a cholestenyl group, a cholestanyl group, an adamantyl group, the following formula (Alc-1) or (Alc-2) (wherein R ₇ is a hydrogen atom, a fluorine atom or an alkyl group having 1 to 20 carbon atoms, and the alkyl group having 1 to 20 carbon atoms may be substituted with a fluorine atom, and * represents a bonding position). Examples thereof include groups represented.

Examples of the monomer represented by the above formula (pa-1-ma) include, but are not limited to, the structures represented by the formulas (paa-1-ma1) to (paa-1-ma18). In the formula, "E" represents the E form, and "t" represents the cyclohexyl group is trans type.

[Thermal Crosslinkable Group A and Thermally Crosslinkable Group B]
The heat-crosslinkable group A and the heat-crosslinkable group B are each independently a carboxyl group, an amino group, an alkoxymethylamide group, a hydroxymethylamide group, a hydroxyl group, an epoxy group-containing group, an oxetanyl group, a thiylanyl group, an isocyanate group and a block. An organic group selected from the group consisting of isocyanate groups, which is selected so that the heat-crosslinkable group A and the heat-crosslinkable group B undergo a crosslinking reaction by heat, provided that the heat-crosslinkable group A and the heat-crosslinkable group are The groups B may be the same as each other.

As the combination of the heat-crosslinkable group A and the heat-crosslinkable group B, one is a carboxyl group and the other is an epoxy group, an oxetanyl group or a thiylanyl group, and one is a hydroxy group and the other is Is a blocked isocyanate group, one is a phenolic hydroxy group, the other is an epoxy group, a combination that is an oxetanyl group or thiyanyl group, one is a carboxyl group, the other is a blocked isocyanate group, one is an amino A group in which the other is a blocked isocyanate group, a combination in which both are N-alkoxymethylamides, and the like. More preferable combinations are a carboxyl group and an epoxy group, a hydroxy group and a blocked isocyanate group, and the like.

In order to introduce the thermally crosslinkable group A into the polymer as the component (A), a monomer having the thermally crosslinkable group A may be copolymerized.

In addition, when the liquid crystal aligning agent of the present invention satisfies the requirement Z1, both of the monomer having the heat-crosslinkable group A and the monomer having the heat-crosslinkable group B are used in the production of the polymer as the component (A). It may be copolymerized.

Examples of the monomer having a heat-crosslinkable group include, for example,
Acrylic acid, methacrylic acid, crotonic acid, mono-(2-(acryloyloxy)ethyl)phthalate, mono-(2-(methacryloyloxy)ethyl)phthalate, N-(carboxyphenyl)maleimide, N-(carboxyphenyl)methacryl Amide, and a monomer having a carboxyl group such as N-(carboxyphenyl)acrylamide;

2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 2,3-dihydroxypropyl acrylate, 2,3-dihydroxypropyl Methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, caprolactone 2-(acryloyloxy)ethyl ester, caprolactone 2-(methacryloyloxy)ethyl ester, poly(ethylene glycol)ethyl ether acrylate, poly(ethylene glycol)ethyl ether methacrylate, 5- Acryloyloxy-6-hydroxynorbornene-2-carboxylic-6-lactone, 5-methacryloyloxy-6-hydroxynorbornene-2-carboxylic-6-lactone, and other monomers having a hydroxy group;

Monomers having a phenolic hydroxy group such as hydroxystyrene, N-(hydroxyphenyl)methacrylamide, N-(hydroxyphenyl)acrylamide, N-(hydroxyphenyl)maleimide, and N-(hydroxyphenyl)maleimide;

Amino group-containing monomers such as aminoethyl acrylate, aminoethyl methacrylate, aminopropyl acrylate, and aminopropyl methacrylate;

Substituted with a hydroxymethyl group or an alkoxymethyl group such as N-hydroxymethyl(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-ethoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide (meth) ) Acrylamide compounds;

Allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, 2-methyl glycidyl methacrylate, α-ethyl glycidyl acrylate, α-n-propyl glycidyl acrylate, α-n-butyl glycidyl acrylate, 3,4-acrylic acid Epoxybutyl, 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl acrylate, 6,7-epoxyheptyl methacrylate, α-ethylacrylic acid-6,7-epoxyheptyl, o-vinylbenzyl glycidyl ether, m-Vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, 3,4-epoxycyclohexylmethyl methacrylate, 3-ethenyl-7-oxabicyclo[4.1.0]heptane, 1,2-epoxy-5- Monomers having epoxy moiety-containing groups such as hexene and 1,7-octadiene monoepoxide;

3-(acryloyloxymethyl)oxetane, 3-(acryloyloxymethyl)-2-methyloxetane, 3-(acryloyloxymethyl)-3-ethyloxetane, 3-(acryloyloxymethyl)-2-trifluoromethyloxetane, 3-(acryloyloxymethyl)-2-pentafluoroethyloxetane, 3-(acryloyloxymethyl)-2-phenyloxetane, 3-(acryloyloxymethyl)-2,2-difluorooxetane, 3-(acryloyloxymethyl) -2,2,4-trifluorooxetane, 3-(acryloyloxymethyl)-2,2,4,4-tetrafluorooxetane, 3-(2-acryloyloxyethyl)oxetane, 3-(2-acryloyloxyethyl) )-2-Ethyloxetane, 3-(2-acryloyloxyethyl)-3-ethyloxetane, 3-(2-acryloyloxyethyl)-2-trifluoromethyloxetane, 3-(2-acryloyloxyethyl)-2 -Pentafluoroethyl oxetane, 3-(2-acryloyloxyethyl)-2-phenyloxetane, 3-(2-acryloyloxyethyl)-2,2-difluorooxetane, 3-(2-acryloyloxyethyl)-2, Acrylic esters such as 2,4-trifluorooxetane and 3-(2-acryloyloxyethyl)-2,2,4,4-tetrafluorooxetane; 3-(methacryloyloxymethyl)oxetane, 3-(methacryloyloxymethyl) )-2-Methyloxetane, 3-(methacryloyloxymethyl)-3-ethyloxetane, 3-(methacryloyloxymethyl)-2-trifluoromethyloxetane, 3-(methacryloyloxymethyl)-2-pentafluoroethyloxetane, 3-(methacryloyloxymethyl)-2-phenyloxetane, 3-(methacryloyloxymethyl)-2,2-difluorooxetane, 3-(methacryloyloxymethyl)-2,2,4-trifluorooxetane, 3-(methacryloyl) Oxymethyl)-2,2,4,4-tetrafluorooxetane, 3-(2-methacryloyloxyethyl)oxetane, 3-(2-methacryloyloxyethyl)-2-ethyloxetane, 3-(2-methacryloyloxyethyl )-3-Ethyloxetane, 3-(2-methacryloyloxyethyl)-2-trifluoromethyl Oxetane, 3-(2-methacryloyloxyethyl)-2-pentafluoroethyloxetane, 3-(2-methacryloyloxyethyl)-2-phenyloxetane, 3-(2-methacryloyloxyethyl)-2,2-difluorooxetane Monomers having an oxetanyl group, such as 3-(2-methacryloyloxyethyl)-2,2,4-trifluorooxetane and 3-(2-methacryloyloxyethyl)-2,2,4,4-tetrafluorooxetane;

2,3-epithiopropyl acrylate or methacrylate, and 2- or 3- or 4-(β-epithiopropylthiomethyl)styrene, 2- or 3- or 4-(β-epithiopropyloxymethyl)styrene, Monomers having a thiiranyl group such as 2- or 3- or 4-(β-epithiopropylthio)styrene, 2- or 3- or 4-(β-epithiopropyloxy)styrene;

2-(0-(1'-methylpropylideneamino)carboxyamino)ethyl acrylate, 2-(3,5-dimethylpyrazolyl)carbonylamino)ethyl acrylate, 2-(0-(1'-methyl)methacrylate Monomers having a blocked isocyanate group such as propylideneamino)carboxyamino)ethyl and 2-(3,5-dimethylpyrazolyl)carbonylamino)ethyl methacrylate; and the like. In addition, (meth)acrylamide means both acrylamide and methacrylamide.

Further, in the present invention, when the specific copolymer is obtained, the monomer having the photo-alignment group represented by the formula (a-1-m), the heat-crosslinkable group A, and optionally the heat-crosslinkable group are used. In addition to the monomer having the group B, other monomers copolymerizable with these monomers can be used in combination.

Specific examples of such other monomers include acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylonitrile, maleic anhydride, styrene compounds, vinyl compounds, N-methoxymethyl (meth)acrylamide, N-butoxymethyl. Examples thereof include acrylamide compounds such as (meth)acrylamide and acrylamide, and monomers having a nitrogen-containing aromatic heterocyclic group and a polymerizable group.

Examples of acrylic acid ester compounds include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl acrylate, anthrylmethyl acrylate, phenyl acrylate, 2,2,2-trifluoroethyl acrylate, tert-butyl. Acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 2-methyl-2-adamantyl acrylate, 2- Examples thereof include propyl-2-adamantyl acrylate, 8-methyl-8-tricyclodecyl acrylate, and 8-ethyl-8-tricyclodecyl acrylate.

Examples of the methacrylic acid ester compound include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, hexadecyl methacrylate, octadecyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthryl methacrylate, anthrylmethyl methacrylate, phenyl methacrylate, 2,2,2-trimethacrylate. Fluoroethyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl methacrylate, 2-methyl- Examples thereof include 2-adamantyl methacrylate, 2-propyl-2-adamantyl methacrylate, 8-methyl-8-tricyclodecyl methacrylate and 8-ethyl-8-tricyclodecyl methacrylate.

Examples of the (meth)acrylic acid amide compound include acrylamide, methacrylamide, N-methylacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide and the like.

Examples of the vinyl compound include methyl vinyl ether, benzyl vinyl ether, vinyl naphthalene, vinyl carbazole, allyl glycidyl ether, and 3-ethenyl-7-oxabicyclo[4.1.0]heptane.

Examples of the styrene compound include styrene, methylstyrene, chlorostyrene, and bromostyrene.

Examples of the maleimide compound include maleimide, N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide.

The nitrogen-containing aromatic heterocycle is a structure selected from the group consisting of the following formulas [Na] to [Nb] (in the formula, Z ₂ is a linear or branched alkyl group having 1 to 5 carbon atoms). Is an aromatic cyclic hydrocarbon containing at least 1, preferably 1 to 4.

Specifically, oxazole ring, thiazole ring, pyridine ring, pyrimidine ring, quinoline ring, 1-pyrazoline ring, isoquinoline ring, thiadiazole ring, pyridazine ring, triazine ring, pyrazine ring, phenanthroline ring, quinoxaline ring, benzothiazole ring, Examples thereof include an oxadiazole ring and an acridine ring. Furthermore, the carbon atom of these nitrogen-containing aromatic heterocycles may have a substituent containing a heteroatom. Among these, for example, a pyridine ring can be mentioned.

Examples of the monomer having a nitrogen-containing aromatic heterocyclic group and a polymerizable group include 2-(2-pyridylcarbonyloxy)ethyl (meth)acrylate, 2-(3-pyridylcarbonyloxy)ethyl (meth)acrylate, and 2 Examples include -(4-pyridylcarbonyloxy)ethyl(meth)acrylate.

The other monomers used in the present invention may be used alone or in a combination of two or more kinds.

The photoreactive moiety represented by the above formula (pa-1) contained in the polymer as the component (A) of the liquid crystal aligning agent of the present invention may be used alone or in combination of two or more moieties. May be used in combination.

The photoreactive moiety represented by the above formula (pa-1) is contained in a proportion of 5 to 95 mol%, 10 to 60 mol%, or 15 to 50 mol% of all repeating units of the polymer as the component (A). Preferably.

The site having a heat-crosslinkable group to be contained in the polymer of the present invention may be the heat-crosslinkable group A alone, or a combination of two or more sites containing the heat-crosslinkable group A and the heat-crosslinkable group B. You may use it.
The introduction amount of the site having a heat-crosslinkable group is preferably 5 to 95 mol%, 40 to 90 mol%, or 50 to 85 mol% of all repeating units of the polymer as the component (A).

The content of the structure derived from the other monomer is preferably 0 to 40 mol %, 0 to 30 mol %, or 0 to 20 mol% of the total repeating units of the polymer as the component (A).

<Method for producing specific polymer>
The specific polymer of the component (A) contained in the liquid crystal aligning agent of the present invention is a monomer having a photo-alignable group represented by the above formula (pa-1), a monomer having the above-mentioned heat-crosslinkable group A. , And optionally, the above-mentioned monomer having a heat-crosslinkable group B is copolymerized. Further, it can be copolymerized with the above-mentioned other monomers.

The method for producing the specific polymer of the component (A) in the present invention is not particularly limited, and a general method industrially handled can be used. Specifically, it can be produced by cationic polymerization, radical polymerization or anionic polymerization using a vinyl group of a monomer. Of these, radical polymerization is particularly preferable from the viewpoint of easy reaction control.
As the polymerization initiator for radical polymerization, known compounds such as radical polymerization initiators and reversible addition-cleavage chain transfer (RAFT) polymerization reagents can be used.

Radical thermal polymerization initiators are compounds that generate radicals when heated above the decomposition temperature. Examples of such radical thermal polymerization initiators include ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), diacyl peroxides (acetyl peroxide, benzoyl peroxide, etc.), hydroperoxides (peroxides). Hydrogen, tert-butyl hydroxide peroxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyketals (dibutylperoxycyclohexane) Etc.), alkyl peresters (peroxy neodecanoic acid-tert-butyl ester, peroxypivalic acid-tert-butyl ester, peroxy 2-ethylcyclohexanoic acid-tert-amyl ester, etc.), persulfates (potassium persulfate, Sodium persulfate, ammonium persulfate, etc.) and azo compounds (azobisisobutyronitrile, 2,2′-di(2-hydroxyethyl)azobisisobutyronitrile, etc.) can be mentioned.

Such radical thermal polymerization initiators may be used alone or in combination of two or more.

The radical photopolymerization initiator is not particularly limited as long as it is a compound that initiates radical polymerization by light irradiation. Examples of such radical photopolymerization initiators include known compounds such as benzophenone, Michler's ketone, 4,4′-bis(diethylamino)benzophenone, xanthone, thioxanthone, and isopropylxanthone. These compounds may be used alone or in a mixture of two or more.
The radical polymerization method is not particularly limited, and emulsion polymerization method, suspension polymerization method, dispersion polymerization method, precipitation polymerization method, bulk polymerization method, solution polymerization method and the like can be used.

The solvent used for the polymerization reaction of the specific polymer of the component (A) is not particularly limited as long as it can dissolve the generated polymer. Specific examples thereof include the solvents described in the section <solvent> below, for example, N-alkyl-2-pyrrolidones, dialkylimidazolidinones, lactones, carbonates, ketones, and formula (Sv-1). Examples thereof include the compound represented by the formula (Sv-2), tetrahydrofuran, 1,4-dioxane, dimethyl sulfone and dimethyl sulfoxide.
These solvents may be used alone or in combination. Further, even a solvent that does not dissolve the produced polymer may be used as a mixture with the above-mentioned solvent as long as the produced polymer does not precipitate.
Further, in the radical polymerization, oxygen in the solvent causes a hindrance to the polymerization reaction, and therefore it is preferable to use an organic solvent that is degassed to the extent possible.

The polymerization temperature during radical polymerization can be selected from any temperature of 30 to 150° C., but is preferably in the range of 50 to 100° C. The reaction can be carried out at any concentration, but the monomer concentration is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction can be performed at a high concentration in the initial stage, and then an organic solvent can be added.
In the above radical polymerization reaction, when the ratio of the radical polymerization initiator is large relative to the monomer, the molecular weight of the obtained polymer becomes small, and when it is small, the molecular weight of the obtained polymer becomes large. It is preferably 0.1 to 10 mol% with respect to the monomer to be polymerized. Moreover, various monomer components, a solvent, an initiator, etc. can also be added at the time of superposition|polymerization.

[Recovery of polymer]
When the generated polymer is recovered from the reaction solution obtained by the above reaction, the reaction solution may be poured into a poor solvent to precipitate the polymers. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, heptane, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, water and the like. The polymer precipitated by pouring it into a poor solvent can be collected by filtration, and then dried at room temperature or under normal pressure or reduced pressure by heating. Further, by repeating the operation of re-dissolving the polymer recovered by precipitation and re-precipitating and recovering it in an organic solvent twice to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons, and the like, and it is preferable to use three or more kinds of poor solvents selected from these, because the purification efficiency is further improved.

The molecular weight of the specific polymer of the component (A) is a weight average measured by GPC (Gel Permeation Chromatography) method, taking into consideration the strength of the resulting coating film, workability during coating film formation, and uniformity of the coating film. The molecular weight is preferably 2,000 to 1,000,000, more preferably 5,000 to 100,000.

<(B) component>
The component (B) contained in the liquid crystal aligning agent of the present invention is a polymer selected from a polyimide having a radical-generating group that generates a radical upon irradiation with light and a precursor thereof.

Examples of such a radical generating group include organic groups represented by the following structures [X-1] to [X-18], [W], [Y], and [Z].

In formulas [X-1] to [X-18], * represents a binding site to a portion other than the polymerizable reactive group of the compound molecule, and S ¹ and S ² are independently -O- and -NR-. , —S—, R is a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, and R ¹ and R ² are each independently a hydrogen atom or a halogen atom. Represents an alkyl group having 1 to 4 carbon atoms.

In formulas [W], [Y], and [Z], * represents a binding site to a portion other than the polymerizable reactive group of the compound molecule, and Ar may have an organic group and/or a halogen atom as a substituent. A good aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylene is shown, and R ⁹ and R ¹⁰ are each independently an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. In the case where R ⁹ and R ¹⁰ are alkyl groups, they may be bonded to each other at the ends to form a ring structure. Q represents the following structure.

In the above formula, R ¹¹ represents —CH ₂ —, —NR—, —O—, or —S—, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and * represents Q of the compound molecule. The binding sites with other parts are shown.
R ¹² represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms.

The method for producing a polyimide precursor having a radical generating group and a polyimide obtained by imidizing the polyimide precursor is not particularly limited. For example, a method of polymerizing a diamine component containing a diamine having a radical generating group and a tetracarboxylic acid dianhydride, a method of polymerizing a diamine component containing a diamine having a radical generating group and a tetracarboxylic acid diester, containing a radical generating group. Method of polymerizing tetracarboxylic dianhydride component containing tetracarboxylic dianhydride and diamine compound, polymerizing tetracarboxylic dianhydride and diamine, and then polymerizing compound containing radical generating group by some reaction And the like. Among them, a method of polymerizing a diamine component containing a diamine having a radical generating group and a tetracarboxylic acid dianhydride or a tetracarboxylic acid diester is preferable from the viewpoint of ease of production.

The diamine having a radical-generating group is specifically a diamine having a side chain capable of generating a radical and polymerizing, and examples thereof include a diamine represented by the following general formula (6). It is not limited to.

In Formula (6), R ⁶ is a single bond, —CH ₂ —, —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, —CH ₂ O—, —N( Represents CH ₃ )-, -CON(CH ₃ )-, or -N(CH ₃ )CO-,
R ⁷ represents a single bond, or an alkylene group having 1 to 20 carbon atoms, which is unsubstituted or substituted with a fluorine atom, and any one or more of —CH ₂ — or —CF ₂ — of the alkylene group is independently. May be substituted with a group selected from —CH═CH—, a divalent carbocycle, and a divalent heterocycle, and further, any of the following groups, namely —O—, —COO— , -OCO-, -NHCO-, -CONH-, or -NH- may be substituted with these groups provided that they are not adjacent to each other;
R ⁸ is a group selected from the above formulas [X-1] to [X-18].

The bonding positions of the two amino groups (—NH ₂ ) in formula (6) are not limited. Specifically, with respect to the side-chain linking group, 2,3 positions, 2,4 positions, 2,5 positions, 2,6 positions, 3,4 positions on the benzene ring, 3,4 positions, 3, 5 positions. Above all, from the viewpoint of reactivity when synthesizing the polyamic acid, the 2,4 position, the 2,5 position, or the 3,5 position is preferable. Considering the ease of synthesizing the diamine, the positions 2, 4 or 3, 5 are more preferable.

Specific examples of the diamine having a photoreactive group containing at least one selected from the group consisting of a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group and a cinnamoyl group are as follows. Compounds include, but are not limited to.

In the above formula, J ¹ is a single bond, a bonding group selected from —O—, —COO—, —NHCO—, or —NH—, and J ² is a single bond or unsubstituted or substituted with a fluorine atom. Represents an alkylene group having 1 to 20 carbon atoms.

Examples of the diamine having a side chain that is a site that is decomposed by ultraviolet irradiation to generate a radical include, but are not limited to, the diamine represented by the following general formula (7).

In formula (7), T ¹ and T ² are each independently a single bond, —O—, —S—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, —CH. ₂ O—, —N(CH ₃ )—, —CON(CH ₃ )—, or —N(CH ₃ )CO—,
S represents a single bond or an alkylene group having 1 to 20 carbon atoms, which is unsubstituted or substituted by a fluorine atom, and any one or more of —CH ₂ — or —CF ₂ — of the alkylene group is independently. It may be substituted with a group selected from —CH═CH—, a divalent carbocycle, and a divalent heterocycle, and further, any of the following groups, namely —O—, —COO—, -OCO-, -NHCO-, -CONH-, or -NH- may be substituted with these groups provided that they are not adjacent to each other,
J is a group selected from the above formulas [W], [Y] and [Z].

The bonding positions of the two amino groups (—NH ₂ ) in the above formula (7) are not limited. Specifically, with respect to the side-chain linking group, 2,3 positions, 2,4 positions, 2,5 positions, 2,6 positions, 3,4 positions on the benzene ring, 3,4 positions, 3, 5 positions. Above all, from the viewpoint of reactivity when synthesizing the polyamic acid, the 2,4 position, the 2,5 position, or the 3,5 position is preferable. Considering the ease of synthesizing the diamine, the positions 2, 4 or 3, 5 are more preferable.

The structure represented by the following formula is most preferable in view of ease of synthesis, high versatility, characteristics, etc., but not limited to these. In the following formula, n is an integer of 2-8.

The above diamines may be used either individually or in combination of two or more, depending on the liquid crystal alignment property of the liquid crystal alignment film, the sensitivity in the polymerization reaction, the voltage holding property, and the accumulated charge.

Such a diamine having a radical-generating group is preferably used in an amount of 5 to 50 mol% of the total diamine component used in the synthesis of a polymer selected from a polyimide having a radical-generating group and a precursor thereof, and more preferably Is 10 to 40 mol %, particularly preferably 15 to 30 mol %.

Incidentally, when obtaining a polymer selected from the polyimide having a radical-generating group used in the present invention and a precursor thereof, unless diminishing the effect of the present invention, other diamines other than the diamine having a radical-generating group, other diamine It can be used together as a diamine component. Specifically, for example, p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl- m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2, 4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl , 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-biphenyl, 3,3' -Trifluoromethyl-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 4,4'- Diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminodiphenylmethane, 2,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether , 3,4′-diaminodiphenyl ether, 2,2′-diaminodiphenyl ether, 2,3′-diaminodiphenyl ether, 4,4′-sulfonyldianiline, 3,3′-sulfonyldianiline, bis(4-aminophenyl) Silane, bis(3-aminophenyl)silane, dimethyl-bis(4-aminophenyl)silane, dimethyl-bis(3-aminophenyl)silane, 4,4′-thiodianiline, 3,3′-thiodianiline, 4,4 '-Diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl(4,4'-diaminodiphenyl)amine , N-methyl(3,3'-diaminodiphenyl)amine, N-methyl(3,4'-diaminodiphenyl)amine, N-methyl(2,2'-diaminodiphenyl)amine, N-methyl(2,3 '-Diaminodiphenyl)amine, 4,4'-diamino Benzophenone, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 1,4-diaminonaphthalene, 2,2′-diaminobenzophenone, 2,3′-diaminobenzophenone, 1,5-diaminonaphthalene, 1, 6-diaminonaphthalene, 1,7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2 -Bis(4-aminophenyl)ethane, 1,2-bis(3-aminophenyl)ethane, 1,3-bis(4-aminophenyl)propane, 1,3-bis(3-aminophenyl)propane, 1 ,4-bis(4aminophenyl)butane, 1,4-bis(3-aminophenyl)butane, bis(3,5-diethyl-4-aminophenyl)methane, 1,4-bis(4-aminophenoxy) Benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-amino) Benzyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4′-[1,4-phenylenebis(methylene)]dianiline, 4,4′-[1,3-phenylenebis(methylene) ] Dianiline, 3,4'-[1,4-phenylenebis(methylene)]dianiline, 3,4'-[1,3-phenylenebis(methylene)]dianiline, 3,3'-[1,4-phenylene Bis(methylene)]dianiline, 3,3′-[1,3-phenylenebis(methylene)]dianiline, 1,4-phenylenebis[(4-aminophenyl)methanone], 1,4-phenylenebis[(3 -Aminophenyl)methanone], 1,3-phenylenebis[(4-aminophenyl)methanone], 1,3-phenylenebis[(3-aminophenyl)methanone], 1,4-phenylenebis(4-aminobenzoate ), 1,4-phenylenebis(3-aminobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), bis(4-aminophenyl)terephthalate, Bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate, N,N'-(1,4-phenylene)bis(4-aminobenzamide ), N,N′-(1,3-phenylene)bis(4-aminobenzamide), N,N′-(1,4-phenylene)bis(3-aminobenzamide), N,N′-(1, 3-phenylene)bis(3-aminobenzamide), N,N'-bis(4-aminophenyl)terephthalamide, N,N'-bis(3-aminophenyl)terephthalamide, N,N'-bis(4 -Aminophenyl)isophthalamide, N,N'-bis(3-aminophenyl)isophthalamide, 9,10-bis(4-aminophenyl)anthracene, 4,4'-bis(4-aminophenoxy)diphenylsulfone, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-amino Phenyl)hexafluoropropane, 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2'-bis(4 -Aminophenyl)propane, 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane, trans-1,4-bis(4-aminophenyl) ) Cyclohexane, 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, bis(4-aminophenoxy)methane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4-amino) Phenoxy)propane, 1,3-bis(3-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,4-bis(3-aminophenoxy)butane, 1,5-bis(4 -Aminophenoxy)pentane, 1,5-bis(3-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,6-bis(3-aminophenoxy)hexane, 1,7 -Bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane, 1 ,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy)decane 1,11-bis(4-aminophenoxy)undecane, 1,11-bis(3-amino Aromatic diamines such as phenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane; bis(4-aminocyclohexyl)methane, bis(4-amino-) Alicyclic diamines such as 3-methylcyclohexyl)methane; 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1 ,8-Diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane and other aliphatic diamines; 1,3-bis[2-(p-amino Diamine having urea structure such as phenyl)ethyl]urea and 1,3-bis[2-(p-aminophenyl)ethyl]-1-tert-butyloxycarbonylurea; Np-aminophenyl-4-p- Amine having a nitrogen-containing unsaturated heterocyclic structure such as aminophenyl(tert-butyloxycarbonyl)aminomethylpiperidine; N-tert-butoxycarbonyl-N-(2-(4-aminophenyl)ethyl)-N-(4 Examples thereof include diamines having an N-Boc group such as -aminobenzyl)amine.

The above-mentioned other diamines may be used alone or in combination of two or more, depending on the liquid crystal alignment property of the liquid crystal alignment film, the sensitivity in the polymerization reaction, the voltage holding property, the accumulated charge and the like. ..

The tetracarboxylic dianhydride to be reacted with the above diamine component is not particularly limited. Specifically, pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2, 3,6,7-anthracene tetracarboxylic acid, 1,2,5,6-anthracene tetracarboxylic acid, 3,3′,4,4′-biphenyl tetracarboxylic acid, 2,3,3′,4′-biphenyl Tetracarboxylic acid, bis(3,4-dicarboxyphenyl) ether, 3,3',4,4'-benzophenone tetracarboxylic acid, bis(3,4-dicarboxyphenyl) sulfone, bis(3,4-di) Carboxyphenyl)methane, 2,2-bis(3,4-dicarboxyphenyl)propane, 1,1,1,3,3,3-hexafluoro-2,2-bis(3,4-dicarboxyphenyl) Propane, bis(3,4-dicarboxyphenyl)dimethylsilane, bis(3,4-dicarboxyphenyl)diphenylsilane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis(3,4) -Dicarboxyphenyl)pyridine, 3,3',4,4'-diphenylsulfone tetracarboxylic acid, 3,4,9,10-perylene tetracarboxylic acid, 1,3-diphenyl-1,2,3,4- Cyclobutanetetracarboxylic acid, oxydiphthaltetracarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid Acid, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,3-dimethyl -1,2,3,4-Cyclobutanetetracarboxylic acid, 1,2,3,4-cycloheptanetetracarboxylic acid, 2,3,4,5-tetrahydrofuran tetracarboxylic acid, 3,4-dicarboxy-1- Cyclohexyl succinic acid, 2,3,5-tricarboxycyclopentyl acetic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid, bicyclo[3,3,0]octane-2 ,4,6,8-Tetracarboxylic acid, bicyclo[4,3,0]nonane-2,4,7,9-tetracarboxylic acid, bicyclo[4,4,0]decane-2,4,7,9 -Tetracarboxylic acid, bicyclo[4,4,0]decane-2,4,8,10-tetracarboxylic acid, tricyclo[6.3.0.0<2,6>] Undecane-3,5,9,11-tetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4 -Tetrahydrinaphthalene-1,2-dicarboxylic acid, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic acid, 5-(2,5-dioxotetrahydrofuryl) -3-Methyl-3-cyclohexane-1,2-dicarboxylic acid, tetracyclo[6,2,1,1,0<2,7>]dodeca-4,5,9,10-tetracarboxylic acid, 3 5,5,6-tricarboxynorbornane-2:3,5:6 dicarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid and other carboxylic acid dianhydrides.

Of course, the tetracarboxylic dianhydride may be used alone or in combination of two or more depending on the liquid crystal alignment property of the liquid crystal alignment film, the sensitivity in the polymerization reaction, the voltage holding property, the accumulated charge and the like. ..

In the synthesis when the polymer is a polyamic acid ester, the structure of the tetracarboxylic acid dialkyl ester to be reacted with the diamine component is not particularly limited, but specific examples thereof are given below.
Specific examples of the aliphatic tetracarboxylic acid diester include 1,2,3,4-cyclobutane tetracarboxylic acid dialkyl ester, 1,2-dimethyl-1,2,3,4-cyclobutane tetracarboxylic acid dialkyl ester, and 1 ,3-Dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2, 3,4-Cyclopentanetetracarboxylic acid dialkyl ester, 2,3,4,5-tetrahydrofuran tetracarboxylic acid dialkyl ester, 1,2,4,5-cyclohexanetetracarboxylic acid dialkyl ester, 3,4-dicarboxy-1 -Cyclohexyl succinic acid dialkyl ester, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid dialkyl ester, 1,2,3,4-butane tetracarboxylic acid dialkyl ester, bicyclo[3 ,3,0] Octane-2,4,6,8-tetracarboxylic acid dialkyl ester, 3,3',4,4'-dicyclohexyltetracarboxylic acid dialkyl ester, 2,3,5-tricarboxycyclopentyl acetic acid dialkyl ester , Cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic acid dialkyl ester, tricyclo[4.2.1.0<2,5>]nonane-3, 4,7,8-Tetracarboxylic acid-3,4:7,8-dialkyl ester, hexacyclo[6.6.0.1<2,7>. 0<3,6>. 1<9,14>. 0<10,13>] hexadecane-4,5,11,12-tetracarboxylic acid-4,5,11,12-dialkyl ester, 4-(2,5-dioxotetrahydrofuran-3-yl)-1, 2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dialkyl ester and the like can be mentioned.

Examples of the aromatic tetracarboxylic acid dialkyl ester include pyromellitic acid dialkyl ester, 3,3′,4,4′-biphenyltetracarboxylic acid dialkyl ester, 2,2′,3,3′-biphenyltetracarboxylic acid dialkyl ester, 2,3,3′,4-biphenyltetracarboxylic acid dialkyl ester, 3,3′,4,4′-benzophenone tetracarboxylic acid dialkyl ester, 2,3,3′,4′-benzophenone tetracarboxylic acid dialkyl ester, Bis(3,4-dicarboxyphenyl)ether dialkyl ester, bis(3,4-dicarboxyphenyl)sulfone dialkyl ester, 1,2,5,6-naphthalenetetracarboxylic acid dialkyl ester, 2,3,6,7 -Naphthalene tetracarboxylic acid dialkyl ester and the like.

The component (B) polymer of the present application is preferably a component having a surface energy close to that of the component (A) polymer. The acrylic component such as the component (A) basically has low polarity and low surface energy. On the other hand, the polyimide component has high polarity and high surface energy. However, if the difference in the surface energy between these two components is too large, they do not mix well and agglomeration occurs, resulting in a film with irregularities, and cratering and unevenness, which narrows the process margin. Such problems may occur. Therefore, by lowering the polarity of the polyimide component, the surface energy can be controlled to a value that is higher than that of the acrylic component but has a small difference. As a method of reducing the polarity of the polyimide component, there are a method of mixing with the component (A) after chemical imidization and a method of introducing a side chain.

As such a polymer, a polymer obtained by polymerizing a tetracarboxylic acid derivative such as a known tetracarboxylic dianhydride and a diamine component containing a diamine having a radical generating group, and then chemically imidizing the polymer. , A polyimide precursor obtained by using a diamine component containing a diamine having a side chain together with a diamine having a radical generating group, a polyimide obtained by imidizing it, a tertiary butoxycarbonyloxy group together with a diamine having a radical generating group. Examples thereof include a polyimide precursor obtained by using the diamine, and a polyimide obtained by imidizing it. By such a side chain or chemical imidization, the surface energy can be brought close to that of the acrylic polymer which is the component (A). Therefore, when a cured film is formed by coating and baking a liquid crystal aligning agent, aggregation or the like may occur. A flat cured film can be provided without causing this. Examples of the diamine having a side chain include diamines represented by the formulas (2), (3), (4) and (5) described in paragraphs [0023] to [0039] of International Patent Application Publication WO2016/125870 and Specific examples thereof include diamines represented by the formulas [A-1] to [A-32]. Examples of the diamine having a tertiary butoxycarbonyloxy group include compounds represented by the formulas [A-1], [A-2] and [A-3] described in paragraphs [0011] to [0034] of International Patent Application Publication WO2017/119461. The diamine which has a structure and the diamine illustrated as the specific example are mentioned.

The content ratio of the polymer as the component (A) and the polymer as the component (B) in the liquid crystal aligning agent of the present invention is such that the mass ratio of the component (A) to the component (B) is 5:95 to 95:5. Is more preferable, 10:90 to 90:10 is more preferable, and 20:80 to 60:40 is further preferable.

<(C) component>
When the liquid crystal aligning agent used in the present invention satisfies the requirement Z2, it contains a crosslinking agent as the component (C). Examples of the component (C) include crosslinking agents having two or more heat-crosslinkable groups B.

As the cross-linking agent which is the component (C), epoxy compounds, compounds having two or more amino groups, methylol compounds, isocyanate compounds, phenoplast compounds, low molecular compounds such as blocked isocyanate compounds, and polymers of N-alkoxymethyl acrylamide. , A polymer of a compound having an epoxy group, a polymer of a compound having an isocyanate group, and the like.

Specific examples of the epoxy compound described above, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N,N', N',-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, and N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane Etc.

Examples of the compound having two or more amino groups include diamines such as alicyclic diamine, aromatic diamine, aromatic-aliphatic diamine, and aliphatic diamine.

Examples of the alicyclic diamines include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4′-diaminodicyclohexylmethane, 4,4′-diamino-3,3′-dimethyldicyclohexylamine and isophorone. Diamine and the like can be mentioned.

Examples of aromatic diamines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, 3,5-diaminotoluene, 1,4-diamino. Examples include 2-methoxybenzene, 2,5-diamino-p-xylene and 1,3-diamino-4-chlorobenzene.

Examples of aromatic-aliphatic diamines are 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, 4-amino-N-methylbenzylamine, 3-aminophenethylamine, 4- Aminophenethylamine, 3-amino-N-methylphenethylamine, 4-amino-N-methylphenethylamine, 3-(3-aminopropyl)aniline, 4-(3-aminopropyl)aniline, 3-(3-methylaminopropyl) Aniline, 4-(3-methylaminopropyl)aniline, 3-(4-aminobutyl)aniline, 4-(4-aminobutyl)aniline, 3-(4-methylaminobutyl)aniline, 4-(4-methyl Aminobutyl)aniline, 3-(5-aminopentyl)aniline, 4-(5-aminopentyl)aniline, 3-(5-methylaminopentyl)aniline, 4-(5-methylaminopentyl)aniline, 2-( Examples thereof include 6-aminonaphthyl)methylamine, 3-(6-aminonaphthyl)methylamine, 2-(6-aminonaphthyl)ethylamine and 3-(6-aminonaphthyl)ethylamine.

Examples of the aliphatic diamines are 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane and 1,7-diaminoheptane. , 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,3-diamino-2,2-dimethylpropane, 1,6-diamino-2,5-dimethylhexane, 1,7 -Diamino-2,5-dimethylheptane, 1,7-diamino-4,4-dimethylheptane, 1,7-diamino-3-methylheptane, 1,9-diamino-5-methylheptane and the like can be mentioned.

Specific examples of the methylol compound include compounds such as alkoxymethylated glycoluril, alkoxymethylated benzoguanamine, and alkoxymethylated melamine.

Specific examples of the alkoxymethylated glycoluril include 1,3,4,6-tetrakis(methoxymethyl)glycoluril, 1,3,4,6-tetrakis(butoxymethyl)glycoluril, 1,3,4. ,6-Tetrakis(hydroxymethyl)glycoluril, 1,3-bis(hydroxymethyl)urea, 1,1,3,3-tetrakis(butoxymethyl)urea, 1,1,3,3-tetrakis(methoxymethyl) Examples include urea, 1,3-bis(hydroxymethyl)-4,5-dihydroxy-2-imidazolinone, and 1,3-bis(methoxymethyl)-4,5-dimethoxy-2-imidazolinone. As commercially available products, compounds such as glycoluril compound (trade name: Cymel (registered trademark) 1170, powder link (registered trademark) 1174) manufactured by Mitsui Cytec Co., Ltd., methylated urea resin (trade name: UFR (registered trademark) 65) ), butylated urea resin (trade name: UFR (registered trademark) 300, U-VAN10S60, U-VAN10R, U-VAN11HV), urea/formaldehyde resin (high condensation type, trade name: Beckamine (trade name) manufactured by DIC Corporation. Registered trademark) J-300S, same P-955, same N) and the like.

Specific examples of alkoxymethylated benzoguanamine include, for example, tetramethoxymethyl benzoguanamine and the like. Commercially available products include Mitsui Cytec Co., Ltd. (trade name: Cymel (registered trademark) 1123), Sanwa Chemical Co., Ltd. (trade names: Nicalac (registered trademark) BX-4000, BX-37, and BL- 60, BX-55H) and the like.

Specific examples of alkoxymethylated melamine include hexamethoxymethylmelamine. As commercially available products, Mitsui Cytec Co., Ltd. methoxymethyl type melamine compound (trade name: Cymel (registered trademark) 300, 301, 303, 350), butoxymethyl type melamine compound (trade name: Mycoat (registered trademark) 506, 508), methoxymethyl type melamine compound manufactured by Sanwa Chemical Co., Ltd. (trade name: Nicalac (registered trademark) MW-30, MW-22, MW-11, MS-001, MX-002, the same) MX-730, MX-750, MX-035), butoxymethyl type melamine compound (trade name: Nicalac (registered trademark) MX-45, MX-410, MX-302) and the like.

Further, it may be a compound obtained by condensing a melamine compound, a urea compound, a glycoluril compound and a benzoguanamine compound in which a hydrogen atom of such an amino group is substituted with a methylol group or an alkoxymethyl group. Examples include high molecular weight compounds prepared from melamine compounds and benzoguanamine compounds described in US Pat. No. 6,323,310. Examples of commercial products of the melamine compound include trade name: Cymel (registered trademark) 303 (manufactured by Mitsui Cytec Co., Ltd.) and the like, and commercial products of the benzoguanamine compound include trade name: Cymel (registered trademark) 1123 ( Mitsui Cytec Co., Ltd., etc. may be mentioned.

Specific examples of the isocyanate compound are, for example, VESTANAT B1358/100, VESTAGON BF 1540 (above, isocyanurate type modified polyisocyanate, manufactured by Degussa Japan Co., Ltd.), Takenate (registered trademark) B-882N, and B-7075 (the same). Above, isocyanurate-type modified polyisocyanate, manufactured by Mitsui Chemicals, Inc. and the like can be mentioned.

Specific examples of the phenoplast compound include the following compounds, but the phenoplast compound is not limited to the following compound examples.

Specific examples of the compound having two or more hydroxyalkylamide groups at the terminal of the molecule include the following compounds, Primid XL-552, and Primid SF-4510.

Examples of the blocked isocyanate compound include Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (above, manufactured by Nippon Polyurethane Industry Co., Ltd.), Takenate B-830, B-815N, Examples thereof include B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (above, manufactured by Mitsui Chemicals, Inc.).

Furthermore, examples of the above-mentioned N-alkoxymethylacrylamide polymer include N-hydroxymethyl(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-ethoxymethyl(meth)acrylamide, and N-butoxymethyl(meth). ) A polymer produced by using an acrylamide compound or a methacrylamide compound substituted with a hydroxymethyl group or an alkoxymethyl group such as acrylamide.

Specific examples of such a polymer include, for example, poly(N-butoxymethylacrylamide), a copolymer of N-butoxymethylacrylamide and styrene, a copolymer of N-hydroxymethylmethacrylamide and methylmethacrylate, and N. Examples thereof include a copolymer of ethoxymethyl methacrylamide and benzyl methacrylate, and a copolymer of N-butoxymethyl acrylamide, benzyl methacrylate and 2-hydroxypropyl methacrylate. The weight average molecular weight of such a polymer is 1,000 to 200,000, more preferably 3,000 to 150,000, and further preferably 3,000 to 50,000.

Examples of the polymer of the compound having an epoxy group include polymers produced by using a compound having an epoxy group such as glycidyl methacrylate, 3,4-epoxycyclohexylmethyl methacrylate and 3,4-epoxycyclohexylmethyl methacrylate. To be

Specific examples of such a polymer include poly(3,4-epoxycyclohexylmethyl methacrylate), poly(glycidyl methacrylate), a copolymer of glycidyl methacrylate and methyl methacrylate, and 3,4-epoxycyclohexylmethyl methacrylate. Examples thereof include a copolymer with methyl methacrylate and a copolymer with glycidyl methacrylate and styrene. The weight average molecular weight of such a polymer is 1,000 to 200,000, more preferably 3,000 to 150,000, and further preferably 3,000 to 50,000.

Examples of the polymer of the compound having an isocyanate group described above include 2-isocyanatoethyl methacrylate (Karenz MOI [registered trademark], Showa Denko KK), 2-isocyanatoethyl acrylate (Karenzu AOI [registered trademark]). , Showa Denko KK, etc., or a compound having an isocyanate group, or 2-(0-[1′-methylpropylideneamino]carboxyamino)ethyl methacrylate (Karenz MOI-BM [registered trademark], Showa Denko KK )), 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate (Karenz MOI-BP [registered trademark], Showa Denko KK) and other compounds having a blocked isocyanate group. Polymers that are used.

Specific examples of such a polymer include, for example, poly(2-isocyanatoethyl acrylate), poly(2-(0-[1′-methylpropylideneamino]carboxyamino)ethyl methacrylate), 2-isocyanatoethyl. Examples thereof include a copolymer of methacrylate and styrene, a copolymer of 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate and methyl methacrylate, and the like. The weight average molecular weight of such a polymer is 1,000 to 200,000, more preferably 3,000 to 150,000, and further preferably 3,000 to 50,000.

These crosslinking agents can be used alone or in combination of two or more kinds.

When the cross-linking agent of the component (C) is contained in the liquid crystal aligning agent used in the present invention, the content is preferably 1 part by mass to 100 parts by mass based on 100 parts by mass of the resin as the component (A). , And more preferably 1 to 80 parts by mass.

[Preparation of liquid crystal aligning agent]
The liquid crystal aligning agent used in the present invention is preferably prepared as a coating liquid so as to be suitable for forming a liquid crystal aligning film. That is, the liquid crystal aligning agent of the present invention is preferably prepared as a solution in which a resin component for forming a resin film is dissolved in an organic solvent. Here, the resin component is the specific polymer which is the component (A) and the polymer which is the component (B) which have already been described. At that time, the total content of the specific polymer as the component (A) and the content of the polymer as the component (B) is preferably 0.5 to 20% by mass, and more preferably the total amount of the liquid crystal aligning agent. Is preferably 1 to 20% by mass, more preferably 1 to 15% by mass, and particularly preferably 1 to 10% by mass.

<Solvent>
The solvent contained in the liquid crystal aligning agent used in the present invention is not particularly limited as long as it is a solvent capable of dissolving the component (A), the component (B) and optionally the component (C). The solvent contained in the liquid crystal aligning agent may be one kind or a mixture of two or more kinds. Further, even if it is not a solvent that dissolves the component (A) or the component (B), it can be used in combination with a solvent that dissolves the component (A) or the component (B). In this case, when the surface energy of the solvent that does not dissolve the component (A) or the component (B) is lower than that of the solvent that dissolves the component (A) or the component (B), the coatability of the liquid crystal aligning agent on the substrate is improved. It is preferable because it is possible.

Specific examples include water, N-alkyl-2-pyrrolidones such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylcaprolactam. , Tetramethylurea, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, 1,3-dimethyl-2-imidazo Dialkyl imidazolidinones such as ridinone, lactones such as γ-butyrolactone, γ-valerolactone and δ-valerolactone, carbonates such as ethylene carbonate and propylene carbonate, methanol, ethanol, propanol, isopropanol, 3-methyl- Ketones such as 3-methoxybutanol, ethylamylketone, methylnonylketone, methylethylketone, isoamylmethylketone, methylisopropylketone, diisobutylketone, cyclohexanone, cyclopentanone, methylisobutylketone, 4-hydroxy-4-methyl-2-pentanone , Compounds represented by the following formula (Sv-1) and compounds represented by the following formula (Sv-2), 4-methyl-2-pentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, 2-Methylcyclohexyl acetate, butyl butyrate, isoamyl butyrate, diisobutyl carbinol, diisopentyl ether and the like can be mentioned.

In formulas (Sv-1) to (Sv-2), Y ₁ and Y ₂ are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, and X ₁ is an oxygen atom or —COO— And X2 is a single bond or a carbonyl group, and R ₁ is an alkanediyl group having 2 to 4 carbon atoms. n ₁ is an integer of 1 to 3. When n ₁ is 2 or 3, plural R ₁ may be the same or different. Z ₁ is a divalent hydrocarbon group having 1 to 6 carbon atoms, and Y ₃ and Y ₄ are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms).

In formula (Sv-1), examples of the monovalent hydrocarbon group of 1 to 6 carbon atoms for Y ₁ and Y ₂ include a monovalent chain hydrocarbon group of 1 to 6 carbon atoms and a monovalent hydrocarbon group of 1 to 6 carbon atoms. Examples thereof include a monovalent alicyclic hydrocarbon group and a monovalent aromatic hydrocarbon group having 1 to 6 carbon atoms. Examples of the monovalent chain hydrocarbon group having 1 to 6 carbon atoms include an alkyl group having 1 to 6 carbon atoms. The alkanediyl group of R ₁ may be linear or branched.

In formula (Sv-2), examples of the divalent hydrocarbon group having 1 to 6 carbon atoms represented by Z ₁ include an alkanediyl group having 1 to 6 carbon atoms.
Examples of the monovalent hydrocarbon group having 1 to 6 carbon atoms of Y ₃ and Y ₄ include a monovalent chain hydrocarbon group having 1 to 6 carbon atoms and a monovalent alicyclic hydrocarbon group having 1 to 6 carbon atoms. And a monovalent aromatic hydrocarbon group having 1 to 6 carbon atoms. Examples of the monovalent chain hydrocarbon group having 1 to 6 carbon atoms include an alkyl group having 1 to 6 carbon atoms.

Specific examples of the solvent represented by the formula (Sv-1) include, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol monobutyl ether ( Butyl cellosolve), ethylene glycol monohexyl ether, ethylene glycol dimethyl ether, ethylene glycol monoacetate, ethylene glycol diacetate, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether Ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monomethyl ether, propylene glycol diacetate, ethylene Glycol, 1,4-butanediol, 3-methoxybutyl acetate, 3-ethoxybutyl acetate, etc.;
Specific examples of the solvent represented by (Sv-2) include methyl glycolate, ethyl glycolate, butyl glycolate, ethyl lactate, butyl lactate, isoamyl lactate, ethyl-3-ethoxypropionate, methyl-3. Examples thereof include methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate and butyl 3-methoxypropionate.

The solvent preferably has a boiling point of 80 to 200°C. More preferably, it is 80° C. to 180° C., and as a preferable solvent, N,N-dimethylformamide, tetramethylurea, 3-methoxy-N,N-dimethylpropanamide, propanol, isopropanol, 3-methyl-3-methoxy Butanol, ethyl amyl ketone, methyl ethyl ketone, isoamyl methyl ketone, methyl isopropyl ketone, diisobutyl ketone, cyclohexanone, cyclopentanone, methyl isobutyl ketone, 4-hydroxy-4-methyl-2-pentanone, 4-methyl-2-pentyl acetate, 2-ethylbutyl acetate, cyclohexyl acetate, 2-methylcyclohexyl acetate, butyl butyrate, isoamyl butyrate, diisobutylcarbinol, diisopentyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, ethylene glycol -I-Propyl ether, ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol monoacetate, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene Glycol monoethyl ether acetate, propylene glycol monobutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monomethyl ether, 3-methoxybutyl acetate, methyl glycolate, ethyl glycolate, butyl glycolate, ethyl lactate, butyl lactate, isoamyl lactate, Examples thereof include ethyl-3-ethoxypropionate, methyl-3-methoxypropionate, ethyl 3-methoxypropionate, and the like.
The boiling point in this range is particularly preferable when the liquid crystal aligning agent containing the solvent is applied on the plastic substrate described later.

<Other ingredients>
The liquid crystal aligning agent used in the present invention may contain a component other than the component (A), the component (B) and, if necessary, the component (C). Such other components include a crosslinking catalyst, a compound that improves the film thickness uniformity and surface smoothness when a liquid crystal alignment agent is applied, a compound that improves the adhesion between the liquid crystal alignment film and the substrate, and the like. However, the present invention is not limited to this.

<Crosslinking catalyst>
A cross-linking catalyst may be added to the liquid crystal aligning agent used in the present invention for the purpose of promoting the reaction between the heat-crosslinkable group A and the heat-crosslinkable group B. Examples of such a crosslinking catalyst include p-toluenesulfonic acid, camphorsulfonic acid, trifluoromethanesulfonic acid, p-phenolsulfonic acid, 2-naphthalenesulfonic acid, mesitylenesulfonic acid, p-xylene-2-sulfonic acid, m- Xylene-2-sulfonic acid, 4-ethylbenzenesulfonic acid, 1H,1H,2H,2H-perfluorooctanesulfonic acid, perfluoro(2-ethoxyethane)sulfonic acid, pentafluoroethanesulfonic acid, nonafluorobutane-1- Examples thereof include sulfonic acids such as sulfonic acid and dodecylbenzenesulfonic acid, hydrates and salts thereof. Examples of the compound that generates an acid by heat include bis(tosyloxy)ethane, bis(tosyloxy)propane, bis(tosyloxy)butane, p-nitrobenzyl tosylate, o-nitrobenzyl tosylate, 1,2,3- Phenylene tris (methyl sulfonate), p-toluenesulfonic acid pyridinium salt, p-toluenesulfonic acid morphonium salt, p-toluenesulfonic acid ethyl ester, p-toluenesulfonic acid propyl ester, p-toluenesulfonic acid butyl ester, p- Toluenesulfonic acid isobutyl ester, p-toluenesulfonic acid methyl ester, p-toluenesulfonic acid phenethyl ester, cyanomethyl p-toluenesulfonate, 2,2,2-trifluoroethyl p-toluenesulfonate, 2-hydroxybutyl p-toluenesulfonate , N-ethyl-p-toluenesulfonamide and the like.

[Compound that improves film thickness uniformity and surface smoothness]
Examples of the compound that improves the uniformity of the film thickness and the surface smoothness include a fluorine-based surfactant, a silicone-based surfactant and a nonion-based surfactant.
Specifically, for example, F-top (registered trademark) 301, EF303, EF352 (manufactured by Tochem Products), Megafac (registered trademark) F171, F173, R-30 (manufactured by DIC), Florard FC430, FC431 ( Sumitomo 3M), Asahi Guard (registered trademark) AG710 (manufactured by Asahi Glass Co., Ltd.), Surflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by AGC Seimi Chemical). ..
The amount of these surfactants used is preferably 0.01 parts by mass to 2 parts by mass, more preferably 0.01 parts by mass to 1 part by mass with respect to 100 parts by mass of the resin component contained in the polymer composition. Parts by mass.

[Compound that improves the adhesion between the liquid crystal alignment film and the substrate]
Specific examples of the compound that improves the adhesion between the liquid crystal alignment film and the substrate include the functional silane-containing compounds shown below.
For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane , N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy Carbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl- 1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxy Examples thereof include amino-based silane-containing compounds such as silane and N-bis(oxyethylene)-3-aminopropyltriethoxysilane.
When a compound that improves the adhesion to the substrate is used, its amount is preferably 0.1 part by mass to 30 parts by mass with respect to 100 parts by mass of the resin component contained in the polymer composition, It is more preferably 1 part by mass to 20 parts by mass.

In an embodiment, a photosensitizer can be used as an additive for improving the photoreactivity of the photoalignable group. Specific examples thereof include aromatic 2-hydroxyketone (benzophenone), coumarin, ketocoumarin, carbonylbiscoumarin, acetophenone, anthraquinone, xanthone, thioxanthone, and acetophenone ketal.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal aligning agent of the present invention may be applied on a substrate and baked, and then subjected to an alignment treatment such as rubbing treatment or light irradiation, or in some vertical alignment applications, a liquid crystal alignment film may be formed without the alignment treatment. it can. Examples of the substrate include glass such as float glass and soda glass; polyethylene terephthalate, polybutylene terephthalate, polypropylene, polystyrene, polyether sulfone, polycarbonate, poly(alicyclic olefin), polyvinyl chloride, polyvinylidene chloride, polyether ether. A transparent substrate made of a plastic such as a ketone (PEEK) resin film, polysulfone (PSF), polyether sulfone (PES), polyamide, polyimide, acrylic and triacetyl cellulose can be used.
As the transparent conductive film provided on one surface of the substrate, a NESA film made of tin oxide (SnO ₂ ) (registered trademark of PPG Co., USA), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ) and the like are used. Can be used.

<Coating film forming step>
The method for applying the liquid crystal aligning agent of the present invention is not particularly limited, but there are screen printing, flexographic printing, offset printing, inkjet, dip coating, roll coating, slit coating, spin coating and the like, and these may be used depending on the purpose. Good. After coating on the substrate by these methods, the solvent can be evaporated by a heating means such as a hot plate to form a coating film.

Firing after applying the liquid crystal aligning agent can be performed at any temperature of 40 to 300° C., preferably 40° C. to 250° C., more preferably 40° C. to 230° C.
The thickness of the coating film formed on the substrate is preferably 5 to 1,000 nm, more preferably 10 to 500 nm or 10 to 300 nm. This firing can be performed with a hot plate, a hot air circulation furnace, an infrared furnace, or the like.
Rayon cloth, nylon cloth, cotton cloth or the like can be used for the rubbing treatment.

<Light irradiation process>
Alignment treatment by light irradiation may be performed in an embodiment, for example, a step of forming a coating film by applying the above liquid crystal aligning agent on a substrate, or in a state where the coating film is not in contact with the liquid crystal layer, or The step of irradiating the coating film with light while being in contact with the liquid crystal layer may be included.

The light irradiated by the alignment treatment by light irradiation can be, for example, ultraviolet rays containing a light with a wavelength of 150 to 800 nm or visible light. Among these, ultraviolet rays containing light with a wavelength of 300 to 400 nm are preferable. The irradiation light may be polarized light or non-polarized light. It is preferable to use light including linearly polarized light as the polarized light.

When the light used is polarized light, the light irradiation may be performed from a direction perpendicular to the substrate surface, an oblique direction, or a combination thereof. When irradiating non-polarized light, it is preferable to perform irradiation from a direction oblique to the surface of the substrate.
The dose of light is preferably set to 0.1 mJ / cm ² or more 1,000 mJ / cm less than ^2, more preferably, to 1 ~ 500 mJ / cm ^2, it is 2 ~ 200 mJ / cm ² further preferable.

<Liquid crystal display element>
The liquid crystal display element of the present invention is provided with two substrates arranged to face each other, a liquid crystal layer provided between the substrates, and between the substrate and the liquid crystal layer, and is formed by the liquid crystal aligning agent of the present invention. A vertical alignment type liquid crystal display device including a liquid crystal cell having the formed liquid crystal alignment film. Specifically, the liquid crystal alignment agent of the present invention is applied onto two substrates and baked to form a liquid crystal alignment film, and the two substrates are arranged so that the liquid crystal alignment films face each other. This is a vertical alignment type liquid crystal display device having a liquid crystal cell produced by sandwiching a liquid crystal layer composed of liquid crystal between these two substrates and irradiating with ultraviolet rays.
As described above, by using the liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention and irradiating the liquid crystal alignment film and the liquid crystal layer with ultraviolet rays, an interaction occurs between the liquid crystal and the liquid crystal alignment film of the present invention. However, the liquid crystal residual DC is small, and it is considered that the liquid crystal display element is less likely to cause burn-in.

The substrate used for the liquid crystal display element of the present invention is not particularly limited as long as it is a highly transparent substrate, but is usually a substrate on which transparent electrodes for driving liquid crystals are formed. As a specific example, the same substrates as those described above for the liquid crystal alignment film can be mentioned.
The liquid crystal display device of the present invention may use a substrate provided with a conventional electrode pattern or protrusion pattern, but by having a liquid crystal alignment film formed using the liquid crystal aligning agent of the present invention, It is possible to operate by using a substrate with a line/slit electrode pattern of 1 to 10 μm formed on one side and a structure with no slit pattern or protrusion pattern formed on the opposite substrate, which simplifies the manufacturing process of the device. And high transmittance can be obtained.

Also, for high-performance devices such as TFT-type devices, those in which devices such as transistors are formed between the electrodes for driving the liquid crystal and the substrate are used.

In the case of a transmissive liquid crystal display element, it is common to use the above substrate, but in a reflective liquid crystal display element, an opaque substrate such as a silicon wafer can be used if only one substrate is used. is there. At that time, a material such as aluminum that reflects light may be used for the electrodes formed on the substrate.

The liquid crystal alignment film is formed by applying the liquid crystal aligning agent of the present invention on this substrate and then firing it, and the details are as described above.

A nematic liquid crystal having a negative dielectric anisotropy can be used as the liquid crystal composition used in the liquid crystal display device of the present invention. For example, dicyanobenzene-based liquid crystals, pyridazine-based liquid crystals, Schiff-based liquid crystals, azoxy-based liquid crystals, biphenyl-based liquid crystals, phenylcyclohexane-based liquid crystals, terphenyl-based liquid crystals and the like can be used. Further, it is preferable to use an alkenyl liquid crystal together. As such an alkenyl-based liquid crystal, a conventionally known one can be used. For example, the compound represented by the following formula can be exemplified, but the invention is not limited thereto.

The liquid crystal composition forming the liquid crystal layer of the liquid crystal display device of the present invention is not particularly limited as long as it is a liquid crystal material used in the vertical alignment method. For example, MLC-6608, MLC-6609 and the like, which are liquid crystal compositions having negative dielectric anisotropy manufactured by Merck & Co., Inc. can be used. Furthermore, MLC-3022, MLC-3023 (including a photopolymerizable compound (RM)) manufactured by Merck Ltd., which is a liquid crystal composition containing an alkenyl-based liquid crystal and having a negative dielectric anisotropy, can be used. ..

As a method for sandwiching this liquid crystal layer between two substrates, a known method can be mentioned. For example, a pair of substrates on which a liquid crystal alignment film is formed is prepared, spacers such as beads are scattered on the liquid crystal alignment film on one substrate, and an adhesive is applied to the periphery of the substrate to form the liquid crystal alignment film. There is a method in which the other substrate is bonded so that the surface on the side where the light is applied becomes the inside, and liquid crystal is injected under reduced pressure to seal the liquid crystal.
In addition, a pair of substrates on which a liquid crystal alignment film is formed is prepared, spacers such as beads are sprinkled on the liquid crystal alignment film on one substrate and then liquid crystal is dropped, and then the side where the liquid crystal alignment film is formed. The liquid crystal cell can also be produced by a method in which the other substrate is attached and sealed so that the surface of the liquid crystal layer faces the inside. At this time, the thickness of the spacer is preferably 1 to 30 μm, more preferably 2 to 10 μm.

The step of producing a liquid crystal cell by irradiating the liquid crystal alignment film and the liquid crystal layer with ultraviolet rays may be any time after the liquid crystal is sealed. The irradiation amount of the ultraviolet rays is, for example, 1 to 60 J/cm ² , preferably 40 J/cm ² or less, and the smaller the irradiation amount of the ultraviolet rays is, the more the reduction in reliability caused by the destruction of the members constituting the liquid crystal display element can be suppressed.
The wavelength of ultraviolet rays used is preferably 300 to 500 nm, more preferably 300 to 400 nm. The wavelength of ultraviolet rays used in the step of producing the liquid crystal cell is preferably different from the wavelength of ultraviolet rays used in the light irradiation step. Above all, that the wavelength of the ultraviolet ray used in the step of forming the liquid crystal cell is longer than the wavelength of the ultraviolet ray used in the light irradiation step, that the reverse reaction of the light irradiation step proceeds in the step of forming the liquid crystal cell. From the viewpoint of preventing
For example, it is preferable that the wavelength of ultraviolet rays used in the light irradiation step is 300 to 350 nm, and the wavelength of ultraviolet rays used in the step of forming a liquid crystal cell is 350 to 400 nm. By doing so, it is possible to avoid the problem that in the PSA treatment after the photo-alignment treatment, the reverse reaction of the photo-alignment group proceeds to impair the photo-alignment property.

Further, the liquid crystal alignment film and the liquid crystal layer may be irradiated with ultraviolet rays while applying a voltage and maintaining this electric field. Here, the voltage applied between the electrodes is, for example, 5 to 30 Vp-p, preferably 5 to 20 Vp-p.

In the case of the PSA method in which the liquid crystal contains a polymerizable compound, when the liquid crystal alignment film and the liquid crystal layer are irradiated with ultraviolet rays, the polymerizable compound reacts with each other to form a polymer, and the polymer causes the liquid crystal molecules to tilt. By being stored, the response speed of the obtained liquid crystal display element can be increased.

The liquid crystal aligning agent of the present invention contains at least one polymer selected from a polyimide having a radical generating group and a precursor thereof, and is therefore suitable for use in the PSA system. That is, in the photo-alignment step, the photo-alignment group of the polymer as the component (A) is photo-reacted to give a tilt angle. After that, at the time of PSA treatment, radicals are generated from the polymer of the component (B) and the alkenyl liquid crystal in the liquid crystal composition is polymerized, whereby the imparted tilt angle can be fixed. As a result, the durability of the tilt angle of the obtained liquid crystal display element can be improved.

Further, the above liquid crystal aligning agent is not only useful as a liquid crystal aligning agent for producing a vertical alignment type liquid crystal display device such as a PSA type liquid crystal display or an SC-PVA type liquid crystal display, but also by a rubbing treatment or an optical alignment treatment. It can also be suitably used for producing a liquid crystal alignment film to be formed.

The abbreviations used in the examples are as follows.
<Methacrylic monomer>
(Photo-alignable monomer)
MA-p-1: A compound represented by the following formula (MA-p-1).
In the formula (MA-p-1), the steric double bond represents the E form.

(Thermal crosslinking monomer)
MA-B-1: Compound represented by the following formula (MA-B-1) MA-B-2: Compound represented by the following formula (MA-B-2)

<Tetracarboxylic acid dianhydride>
T-1: Tetracarboxylic acid dianhydride represented by the following formula (T-1) T-2: Tetracarboxylic acid dianhydride represented by the following formula (T-2) T-3: The following formula ( T-3) Tetracarboxylic acid dianhydride T-4: Tetracarboxylic acid dianhydride represented by the following formula (T-4)

<Alignment diamine>
DA-v-1: Oriented diamine represented by the following formula (DA-v-1) DA-v-2: Oriented diamine represented by the following formula (DA-v-2) DA-v-3: The following formula (DA -V-3) oriented diamine DA-v-4: an oriented diamine represented by the following formula (DA-v-3)

<Radical generating diamine>
DA-r-1: a diamine represented by the following formula (DA-r-1)

<Other diamines>
DA-c-1: Other diamine represented by the following formula (DA-c-1) DA-c-2: Other diamine represented by the following formula (DA-c-2)

(Crosslinking agent component)
B-1: Crosslinking agent component represented by the following formula (B-1) B-2: Crosslinking agent component represented by the following formula (B-2)

In addition, the abbreviations of the reagents used in this example are shown below.
(Polymerization initiator)
AIBN: Azobisisobutyronitrile (solvent)
NMP: N-methyl-2-pyrrolidone BCS: butyl cellosolve THF: tetrahydrofuran DMF: N,N-dimethylformamide

(Molecular weight measurement)
The molecular weight of the polymer in the synthesis example was measured using a room temperature gel permeation chromatography (GPC) device (SSC-7200, Shodex column (KD-803, KD-805) manufactured by Senshu Scientific Co., Ltd. as follows.
Column temperature: 50° C., eluent: DMF (lithium bromide-hydrate (LiBr.H ₂ O) as an additive, 30 mmol/L, phosphoric acid/anhydrous crystal (o-phosphoric acid), 30 mmol/L, THF 10 ml/L), flow rate: 1.0 ml/min Standard sample for calibration curve preparation: TSK standard polyethylene oxide manufactured by Tosoh Corporation (molecular weight of about 9,000,000, 150,000, 100,000, 30,000), and Polyethylene glycol manufactured by Polymer Laboratory (molecular weight: about 12,000, 4,000, 1,000).

(Imidization rate measurement)
The imidization ratio in the synthesis example was measured as follows. 20 mg of polyimide powder was put in an NMR sample tube (NMR sampling tube standard φ5 manufactured by Kusano Science Co., Ltd.), 1.0 ml of deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS mixture) was added, and ultrasonic waves were applied. Completely dissolved. This solution was measured for proton NMR at 500 MHz with an NMR measuring device (JNW-ECA500) manufactured by JEOL Datum. The imidization ratio is determined by using a proton derived from a structure that does not change before and after imidization as a reference proton, and the integrated value of the peak of this proton and the proton peak derived from the NH group of amic acid appearing around 9.5 to 10.0 ppm. It was calculated by the following formula using the integrated value. In the formula below, x is the proton peak integrated value derived from the NH group of the amic acid, y is the peak integrated value of the reference proton, and α is the proton of the NH group of the amic acid in the case of polyamic acid (imidization ratio is 0%). It is the ratio of the number of reference protons to one.
Imidization rate (%)=(1-α·x/y)×100

<Synthesis of polymer>
[Example of methacrylate polymer synthesis]
(Synthesis Example M-1)
MA-p-1 (10.12 g, 20.0 mmol), MA-B-1 (2.61 g, 30.0 mmol) and MA-B-2 (2.35 g, 16.5 mmol) were placed in a 4-necked flask. Weighed and added NMP so that the solid content concentration was 20 wt %. After dissolving each monomer component and performing deaeration with a diaphragm pump, AIBN (0.55 g, 3.33 mmol) was added as a polymerization initiator, and deaeration was performed again. Then, the mixture was reacted at 60° C. for 13 hours to obtain a polymer (PMA-1) solution having a polymer solid content concentration of 20 mass %.

By using the methacrylic monomer and the organic solvent shown in Table 1 below and carrying out the same procedure as in the methacrylate polymer synthesis example 1, a solution of the methacrylate polymer (PMA-2) shown in Table 1 below was obtained. In Table 1, the numerical value in parentheses indicates the compounding ratio (mol part) of each compound to 100 mol parts of the total amount of methacrylic monomer used for synthesis for the methacrylic monomer component, and the organic solvent used for synthesis. The compounding ratio (parts by weight) of each organic solvent is shown for 100 parts by weight of the total amount of the organic solvent.

[Example of polyimide polymer synthesis]
(Synthesis Example P-1)
DA-c-1 (4.56 g, 30.0 mmol), DA-c-2 (7.27 g, 30.0 mmol), DA-r-1 (3.30 g, 10.0 mmol), DA-v-1 (11.42 g, 30.0 mmol) and T-2 (5.00 g, 20.0 mmol) were weighed, NMP was added so that the reaction concentration was 18% by mass, and the mixture was reacted at 60° C. for 5 hours. Next, T-4 (4.36 g, 20.0 mmol) and T-1 (10.60 g, 54.1 mmol) were weighed and NMP was added so that the reaction concentration was 20% by mass, and at 40° C. The reaction was carried out for 10 hours to obtain a polyamic acid solution.
180.0 g of the above polyamic acid solution was taken, NMP was added so that the solid content concentration became 6.5% by mass, and the mixture was stirred for 30 minutes. To the obtained polyamic acid solution, 38.0 g of acetic anhydride and 11.5 g of pyridine were added, and heated at 70° C. for 3 hours to carry out chemical imidization. The obtained reaction liquid was poured into methanol in an amount of 3 times the mass of the reaction liquid while stirring, the deposited precipitate was filtered, and subsequently washed with methanol. The obtained resin powder was dried under reduced pressure at 100° C. to obtain a polyimide (PI-A-1) powder. The imidation ratio of this polyimide resin powder was 72%. NMP was added to the obtained polyimide (PI-A-1) so that the solid content concentration was 12%, and the mixture was stirred at 70° C. for 20 hours to obtain a polyimide (PI-A-1) having a solid content concentration of 12% by mass. A solution of

(Synthesis examples P-2 to 11)
Solutions of polyimides (PI-A-2) to (PI-A-11) having the compositions shown in Table 2 were synthesized in the same manner as in Polymer Synthesis Example P-1.

<Preparation of liquid crystal aligning agent>
(Example 1)
The polymer (PMA-1) solution obtained in Synthesis Example M-1 and the polymer (PI-A-1) solution obtained in Synthesis Example P-1 were diluted with NMP and BCS, and The compound (B-1) was added so as to be 10 parts by mass with respect to 100 parts by mass of all the polymers and stirred at room temperature. Then, the obtained solution was filtered with a filter having a pore size of 0.5 μm to give a polymer component ratio of (PMA-1):(PI-A-1)=30:70 (mass ratio in terms of solid content). A liquid crystal aligning agent (1) having a solvent composition ratio of NMP:BCS=60:40 (mass ratio) and a polymer solid content concentration of 6 mass% was obtained (Table 3 below). No abnormalities such as turbidity or precipitation were observed in this liquid crystal aligning agent, and it was confirmed to be a uniform solution.

(Examples 2-12 and Comparative Examples 1-2)
Liquid crystal aligning agents (2) to (12) and (R1) to (R2) were obtained with the composition shown in Table 3 and in the same manner as in Example 1.

<Production of liquid crystal display element>
The obtained liquid crystal aligning agent was spin-coated on the ITO surface of a glass substrate with a transparent electrode made of an ITO film, dried on a hot plate at 70° C. for 90 seconds, and then baked on a hot plate at 230° C. for 30 minutes to give a film thickness. A 100 nm liquid crystal alignment film was formed.
Then, the coated film surface was irradiated with 313 nm linearly polarized ultraviolet light having an irradiation intensity of 4.3 mW/cm ² through a polarizing plate at 50 mJ/cm ² from an angle inclined by 40° from the substrate normal direction, and a substrate with a liquid crystal alignment film was formed. Got Linearly polarized ultraviolet light was prepared by passing the ultraviolet light of a high-pressure mercury lamp through a 313 nm bandpass filter and then through a 313 nm polarizing plate.
Two of the above substrates were prepared, 4 μm of bead spacers were scattered on the liquid crystal alignment film of one substrate, and then a sealant (XN-1500T, manufactured by Mitsui Chemicals) was applied. Next, the other substrate was bonded so that the liquid crystal alignment film surfaces faced each other and the alignment direction was 180°, and then the sealant was thermally cured at 120° C. for 90 minutes. After allowing to cool at room temperature, liquid crystal (MLC-3022 manufactured by Merck & Co., Inc.) was injected by a reduced pressure injection method.
This liquid crystal cell was irradiated with 10 J/cm ^{2 of} ultraviolet light that passed through a 365 nm bandpass filter from the outside of the cell with no voltage applied, and then was irradiated for 30 minutes using a fluorescent UV lamp (FLR40SUV32/A-1). By doing so, a liquid crystal display element was obtained.

<Evaluation>
1. Liquid Crystal Alignment The pretilt angle of the liquid crystal display device produced above was measured by the Mueller matrix method using AxoScan manufactured by Axo Metrix. The evaluation results are shown in Table 4.

2. Evaluation of Change in Pretilt Angle A direct current voltage of 15 V was applied to the liquid crystal display element whose pretilt angle was measured, and after 36 hours, the pretilt angle was measured again. The amount of change in pretilt angle (Δ _pretilt ) was determined from the pretilt angle before and after applying the DC voltage. The evaluation results are shown in Table 4.

From the comparison between the above Examples and Comparative Examples, it was confirmed that by introducing a monomer having a radical initiation site into a polyimide-based polymer, a sufficient pretilt angle was exhibited even by irradiation with ultraviolet rays having a long wavelength such as 365 nm. ..

The liquid crystal aligning agent of the present invention and the liquid crystal display device using the liquid crystal aligning film obtained therefrom can be suitably used for a liquid crystal display device for which in-vehicle use or the like is required to have durability.

Claims

The following formula (pa-1) is used as the component (A).
(In the formula, A is optionally a group selected from fluorine, chlorine, cyano, or an alkoxy group having 1 to 5 carbon atoms, a linear or branched alkyl residue (this may be one Substituted with a cyano group or with one or more halogen atoms), pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophenylene, 2,5-furanylene Represents 1,4- or 2,6-naphthylene or phenylene,
R 1 is a single bond, an oxygen atom, —COO— or —OCO—,
R 2 is a divalent aromatic group, a divalent alicyclic group, a divalent heterocyclic group or a divalent condensed cyclic group,
R 3 is a single bond, an oxygen atom, —COO— or —OCO—,
R 4 is a monovalent organic group having 3 to 40 carbon atoms including a linear or branched alkyl group having 1 to 40 carbon atoms or an alicyclic group,
D represents an oxygen atom, a sulfur atom or —NR d — (wherein R d represents a hydrogen atom or alkyl having 1 to 3 carbon atoms),
a is an integer of 0 to 3, and * represents a bonding position. ) A polymer having a photo-alignment group and a heat-crosslinkable group A, a polymer and a solvent selected from a polyimide having a radical-generating group that generates a radical upon irradiation with light as a component (B) and a precursor thereof. A liquid crystal aligning agent containing.
The wavelength of light that causes a photoreaction of the photoalignable group of the component (A) and the wavelength of light that causes a radical generation reaction of the radical generating group of the component (B) are different from each other. The liquid crystal aligning agent described.
The wavelength of light causing a radical generating reaction of the radical generating group of the component (B) is longer than the wavelength of light causing a photoreaction of the photoalignable group of the component (A). The liquid crystal aligning agent according to claim 2.
Furthermore, the liquid crystal aligning agent according to any one of claims 1 to 3, which satisfies at least one of the following requirements Z1 and Z2.
The polymer which is the Z1:(A) component further has a thermally crosslinkable group B.
Z2: A compound having two or more heat-crosslinkable groups B in the molecule is further contained as the component (C).
The heat-crosslinkable group A and the heat-crosslinkable group B are each independently a carboxyl group, an amino group, an alkoxymethylamide group, a hydroxymethylamide group, a hydroxyl group, an epoxy group-containing group, an oxetanyl group, a thiylanyl group, an isocyanate group and a block. An organic group selected from the group consisting of isocyanate groups, which is selected so that the heat-crosslinkable group A and the heat-crosslinkable group B undergo a crosslinking reaction by heat, provided that the heat-crosslinkable group A and the heat-crosslinkable group are The groups B may be the same as each other.
A liquid crystal alignment film formed using the liquid crystal alignment agent according to any one of claims 1 to 4.
A step of applying a liquid crystal aligning agent according to any one of claims 1 to 4 onto a substrate to form a coating film, and a step of forming the coating film in a state where the coating film is not in contact with the liquid crystal layer or the liquid crystal layer. And a step of irradiating the coating film with light in a state of being in contact with the coating film.
A liquid crystal display device comprising the liquid crystal alignment film according to claim 5 or the liquid crystal alignment film obtained by the manufacturing method according to claim 6.