JPWO2020045548A1 - Manufacturing method of liquid crystal alignment film, liquid crystal alignment film, and liquid crystal display element - Google Patents

Abstract

The present invention provides a simple method for manufacturing a VA mode liquid crystal display element which forms a plurality of regions having different orientation directions (orientation division) and has excellent viewing angle characteristics. The present invention contains a polymer having a photo-orientating group and a heat-crosslinkable group A as the component (A) and a solvent, and a liquid crystal aligning agent satisfying at least one of the following Z1 and Z2 is applied onto the substrate. The step of forming the cured film, the first irradiation step of irradiating the cured film with ultraviolet rays from an oblique direction, and the ultraviolet irradiation of the cured film after the ultraviolet irradiation from a direction different from that of the first irradiation step. A method for producing a multi-domain liquid crystal alignment film, which comprises a second irradiation step in this order, and at least one of the irradiation steps is performed through a mask including a light-shielded region and a non-light-shielded region. Z1: The component (A) further has a thermally crosslinkable group B. Z2: A compound having a heat-crosslinkable group B is further contained as a component (B). [Selection diagram] FIG.

Description

The present invention relates to a method for producing a liquid crystal alignment film using a liquid crystal alignment agent, a liquid crystal alignment film obtained thereby, and a liquid crystal display element including the obtained liquid crystal alignment film. More specifically, even when the firing temperature is low and the firing time is short, which is obtained by using a specific liquid crystal alignment agent, the liquid crystal orientation is good, the pretilt angle expression ability is excellent, and high reliability is achieved. The present invention relates to a liquid crystal alignment film capable of overwriting the pretilt angle, a method for producing a multi-domain liquid crystal alignment film having excellent display quality, using a specific liquid crystal alignment agent, a multi-domain liquid crystal alignment film, and a liquid crystal display element.

In the liquid crystal display element, the liquid crystal alignment film plays a role of orienting the liquid crystal in a certain direction. Currently, the main liquid crystal alignment films used industrially are a polyimide-based liquid crystal alignment agent composed of a polyimide precursor polyamic acid (also called polyamic acid), a polyamic acid ester, or a polyimide solution on a substrate. It is produced by applying and forming a film.
Further, when the liquid crystal is aligned in parallel or inclined with respect to the substrate surface, the surface is stretched by rubbing after the film is formed.

On the other hand, when the liquid crystal is oriented perpendicularly to the substrate (called the vertical orientation (VA) method), a long-chain alkyl or a cyclic group or a combination of a cyclic group and an alkyl group (see, for example, Patent Document 1), a steroid skeleton (see Patent Document 1). For example, a liquid crystal alignment film in which a hydrophobic group such as (see Patent Document 2) is introduced into a side chain of polyimide is used. In this case, when a voltage is applied between the substrates and the liquid crystal molecules are tilted in the direction parallel to the substrate, it is necessary to tilt the liquid crystal molecules from the normal direction of the substrate toward one direction in the surface of the substrate. .. As a means for this, for example, a method of providing a protrusion on the substrate, a method of providing a slit in the display electrode, and a method of rubbing the liquid crystal molecules so as to be slightly tilted from the normal direction of the substrate toward one direction in the surface of the substrate ( Pretilt the liquid crystal by adding a photopolymerizable compound to the liquid crystal composition in advance and using it together with a vertically oriented film such as polyimide to irradiate the liquid crystal cell with ultraviolet rays while applying a voltage. (For example, see Patent Document 3) and the like have been proposed.

In recent years, a method (photo-orientation method) has been proposed in which projections and slits are formed in VA-type liquid crystal alignment control, and an anisotropic photochemical reaction by irradiation with polarized ultraviolet rays or the like is used as an alternative to PSA technology. That is, it is known that the tilting direction of liquid crystal molecules when a voltage is applied can be uniformly controlled by irradiating a vertically oriented polyimide film having photoreactivity with polarized ultraviolet rays to impart orientation control ability and pretilt angle development. (See Patent Document 4). In this case as well, a polyimide-based liquid crystal alignment film having excellent durability and suitable for controlling the pretilt angle of the liquid crystal is used as in the conventional alignment film. The polyimide-based liquid crystal alignment film is generally fired at a high temperature of 200 ° C. or higher.

On the other hand, studies have been energetically made to use a thin and lightweight plastic substrate for the substrate of the liquid crystal display element. In this case, since the heat resistance of the plastic substrate is low, it is necessary to perform firing at a lower temperature when producing the liquid crystal alignment film. Similarly, it is also required to reduce the energy cost in manufacturing the liquid crystal display element by lowering the firing temperature.

When firing at a low temperature, there is a problem that the curing must be completed before the alignment film material is sufficiently cured, and it is difficult to obtain a highly reliable liquid crystal display element (for example,). See Patent Document 5).

On the other hand, there is an increasing demand for a multi-domain technology for forming a plurality of regions having different orientation directions (orientation division), but in the conventional manufacturing method, exposure is performed using an exposure mask in which a plurality of openings are provided at predetermined intervals. After that, it is necessary to shift the exposure mask by a predetermined interval and re-expose, high precision is required for the alignment of the exposure mask and the formation of a plurality of openings, the manufacturing process is complicated, and improvement is required. .. Here, a method for manufacturing a multi-domain liquid crystal display element using a polymer in which a vertically oriented group is bonded to a photodegradable polyimide is known, but a very large amount of light irradiation is required and the manufacturing efficiency is poor (). For example, see Patent Documents 6, 7 and 8). Although there are further examples of methods for producing a multi-domain alignment film, it has not been clarified what kind of alignment film should be used to enable the invention (see, for example, Patent Document 9).

Japanese Unexamined Patent Publication No. 3-179323 Japanese Unexamined Patent Publication No. 4-281427 Japanese Patent No. 4504626 Japanese Patent No. 4995267 Japanese Unexamined Patent Publication No. 7-209633 JP-A-11-95224 Japanese Unexamined Patent Publication No. 2005-148442 Japanese Unexamined Patent Publication No. 2005-316827 Japanese Unexamined Patent Publication No. 2007-219191

An object of the present invention is to provide a VA mode liquid crystal display element having excellent viewing angle characteristics and a method for manufacturing the same by more easily forming a plurality of regions having different orientation directions (orientation division) with a small number of mask processing steps. do.
In addition to the above object, an object of the present invention is to provide an ECB liquid crystal display element having improved viewing angle characteristics and a liquid crystal alignment film for the element.

The present inventors have found an invention whose gist is the following <X>.
<X> As the component (A), a polymer having a photo-oriented group represented by the following formula (pa-1) and a heat-crosslinkable group A and a solvent are contained, and at least one of the following requirements Z1 and Z2 is satisfied. A process of applying the filling liquid crystal alignment agent on a substrate and forming a cured film by drying and firing.
The first irradiation step of irradiating the cured film with ultraviolet rays from an oblique direction, and
The cured film after the ultraviolet irradiation includes a second irradiation step of irradiating the cured film with ultraviolet rays from a direction different from that of the first irradiation step in this order.
A method for producing a multi-domain liquid crystal alignment film, wherein at least one of the first irradiation step and the second irradiation step is performed through a mask including a light-shielded region and a non-light-shielded region. ..
Z1: The polymer which is the component (A) further has a heat-crosslinkable group B.
Z2: As the component (B), a compound having two or more heat-crosslinkable groups B in the molecule is further contained.

In the formula, A is optionally due to a group selected from fluorine, chlorine, cyano, or an alkoxy group with 1 to 5 carbon atoms, a linear or branched alkyl residue (which is optionally one). Pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophenylene, 2,5-furanylene, substituted with a cyano group or one or more halogen atoms). Represents 1,4- or 2,6-naphthylene or phenylene, R ₁ is a single bond, oxygen atom, -COO- or -OCO-, R ₂ is a divalent aromatic group, divalent alicyclic. A group, a divalent heterocyclic group or a divalent fused ring group, R ₃ is a single bond, an oxygen atom, -COO- or -OCO-, and R ₄ is a linear chain having 1 to 40 carbon atoms. Alternatively, it is a monovalent organic group having 3 to 40 carbon atoms containing an alkyl group or an alicyclic group of a branched chain, where D is an oxygen atom, a sulfur atom or −NR _d − (where R _d is a hydrogen atom). Or an alkyl having 1 to 3 carbon atoms), a is an integer of 0 to 3, and * represents a bond position.
The thermally crosslinkable group A and the thermally crosslinkable group B are independently a carboxyl group, an amino group, an alkoxymethylamide group, a hydroxymethylamide group, a hydroxyl group, an epoxy moiety-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, wherein the thermally crosslinkable group A and the thermally crosslinkable group B are selected so as to undergo a cross-linking reaction by heat, except that the thermally crosslinkable group A and the thermally crosslinkable group A and the thermally crosslinkable group B are selected. The groups B may be the same as each other.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to more easily provide a VA mode liquid crystal display element having excellent viewing angle characteristics by forming a plurality of regions having different orientation directions (orientation division) with a small number of mask processing steps.

It is a schematic diagram which shows the irradiation process of this invention. Θ represents the irradiation angle in the first irradiation step, Φ represents the irradiation angle in the second irradiation step, and Ψ represents the tilt angle.

The method for producing a multi-domain liquid crystal alignment film of the present invention contains a polymer having a photo-oriented group represented by the above formula (pa-1) and a thermally crosslinkable group A as a component (A), and a solvent. A step of applying a liquid crystal alignment agent satisfying at least one of the following requirements Z1 and Z2 onto a substrate and forming a cured film by drying and firing.
The first irradiation step of irradiating the cured film with ultraviolet rays from an oblique direction, and
The cured film after the ultraviolet irradiation includes a second irradiation step of irradiating the cured film with ultraviolet rays from a direction different from that of the first irradiation step in this order.
A method for producing a multi-domain liquid crystal alignment film, wherein at least one of the first irradiation step and the second irradiation step is performed through a mask including a light-shielded region and a non-light-shielded region. ..
Z1: The polymer which is the component (A) further has a heat-crosslinkable group B.
Z2: As the component (B), a compound having two or more heat-crosslinkable groups B in the molecule is further contained.
The thermally crosslinkable group A and the thermally crosslinkable group B are independently a carboxyl group, an amino group, an alkoxymethylamide group, a hydroxymethylamide group, a hydroxyl group, an epoxy moiety-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, wherein the thermally crosslinkable group A and the thermally crosslinkable group B are selected so as to undergo a cross-linking reaction by heat, except that the thermally crosslinkable group A and the thermally crosslinkable group A and the thermally crosslinkable group B are selected. The groups B may be the same as each other.

Here, "two or more in the molecule" means that two or more groups of the same type are contained in the molecule, for example, two or more epoxy groups, or a combination of an epoxy group and a thiirane group. In addition, it is intended to include a case where a total of two or more different types of groups are contained in the molecule. "Two or more in the molecule" preferably contains two or more groups of the same type in the molecule.

Since the polymer which is the component (A) contained in the liquid crystal alignment agent of the present invention has high sensitivity to light, the orientation control ability can be exhibited even when irradiated with polarized ultraviolet rays having 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) is formed even when the firing time of the liquid crystal alignment agent is short. A cross-linking reaction containing the polymer is possible. As a result, when the photo-aligned portion develops anisotropy due to a photoreaction, the anisotropy tends to remain (memory) in the liquid crystal alignment film, so that the liquid crystal orientation is enhanced and the pretilt angle of the liquid crystal is expressed. It becomes possible to do.

The site having a photo-oriented group represented by the above formula (pa-1) (for example, the group represented by the formula (a-1) described later), the thermally crosslinkable group A and the thermally crosslinkable group B are Since any of these can be a side chain in a polymer, it can be paraphrased as a "side chain" if necessary.
Hereinafter, each constituent requirement of the present invention will be described in detail.

<Component (A): Specific polymer>
[Photo-oriented group represented by the formula (pa-1)]
In the present invention, the site having photoorientation 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 include, but is not limited to, a structure derived from a monomer represented by the following formula (a-1-m). In the formula, _Ia is a monovalent organic group represented by the following formula (pa-1).

In formula (pa-1), A is optionally due to a group selected from fluorine, chlorine, cyano, or an alkoxy group with 1 to 5 carbon atoms, a linear or branched alkyl residue (which is: Pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophenylene, which is optionally substituted with one cyano group or one or more halogen atoms), 2 , 5-Flanylene, 1,4- or 2,6-naphthylene or phenylene, R ₁ is a single bond, oxygen atom, -COO- or -OCO-, R ₂ is a divalent aromatic group, 2 It is a valent alicyclic group, a divalent heterocyclic group or a divalent fused ring group, R ₃ is a single bond, an oxygen atom, -COO- or -OCO-, and R ₄ is 1 carbon number. It is a monovalent organic group having 3 to 40 carbon atoms including an alkyl group or an alicyclic group having a linear or branched chain of ~ 40, and D is an oxygen atom, a sulfur atom or −NR _d − (here, R). _d represents a hydrogen atom or an alkyl having 1 to 3 carbon atoms), a is an integer of 0-3, * represents a bonding position to _{S a.}

In the formula (a-1) or (a-1-m), S a represents a spacer unit, linking groups of the left _{S a} is the backbone of the first and second specific polymer, optionally Is shown to be bonded via a spacer.

S _a can be represented for example by the structure of the following formula (Sp).

In formula (Sp),
The left bond of W ₁ represents the bond to _{M b.}
The right bond of W ₃ represents the bond to _{I a}
W ₁ , W ₂ and W ₃ are independently single-bonded, divalent heterocycles, − (CH ₂ ) _n − (in the equation, 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- but 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- (in the formula, R independently represents hydrogen or a linear or branched alkyl group having 1 to 5 carbon atoms). Can be done
A ₁ and A ₂ are independently 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 the formula (a-1-m), Ma _{represents a} polymerizable group. Examples of the polymerizable group include (meth) acrylate, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, norbornene, radically polymerizable groups of (meth) acrylamide and its derivatives, and siloxane. can. Preferably, it is (meth) acrylate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, or acrylamide.
r is an integer that satisfies 1 ≦ r ≦ 3.

In the formula (a-1-m), M _b is a single bond, a (r + 1) -valent heterocycle, a linear or branched alkyl group having 1 to 10 carbon atoms, an (r + 1) -valent aromatic group, ( It is a group selected from r + 1) valent alicyclic groups, each group being unsubstituted or having one or more hydrogen atoms substituted with a fluorine atom, a chlorine atom, a cyano group, a methyl group or a methoxy group. Is also good.

The aromatic group of A _{1, A 2,} and _{M b,} for example, benzene, biphenyl, an aromatic hydrocarbon having 6 to 18 carbon atoms such as naphthalene. The alicyclic group of A _{1, A 2,} and M _b, can be mentioned such as cyclohexane, an alicyclic hydrocarbon having 6 to 12 carbon atoms such as bicyclohexane. The heterocyclic ring in A _{1, A 2,} and M _b, may include, for example, pyridine, piperidine, nitrogen-containing heterocyclic ring piperazine. Examples of the alkyl group in A ₁ and A ₂ include a linear or branched alkyl group having 1 to 10 carbon atoms.

From the viewpoint of exhibiting good vertical orientation control ability and stable pretilt angle, the structure of (a-1) is the group represented by the above (pa-1) or the following (pa-1-a). The groups represented can be mentioned. Further, the site may include, but is not limited to, a structure derived from a monomer represented by the following formula (pa-1-ma).

Wherein (pa-1-a) or _(pa-1-ma), M a, M b, and _{S a} are the same as defined above.
Z is an oxygen atom or a sulfur atom.
X _a and X _b are independently hydrogen atoms, fluorine atoms, chlorine atoms, cyano groups, or alkyl groups 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 containing an alkyl group or an alicyclic group, straight or branched chain of 1 to 40 carbon atoms.
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.

Wherein (pa-1-a) or (pa-1-ma), as a linear or branched alkylene group having 1 to 10 carbon atoms _{S a,} linear or branched alkylenes having 1 to 8 carbon atoms It is preferably a group, for example, a methylene group, an ethylene group, an n-propylene group, an n-butylene group, a t-butylene group, an n-pentylene group, an n-hexylene group, an n-heptylene group, and an n-octylene group. ..

As the divalent aromatic group of S _a, for example, 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 2,3,5,6 Fluoro-1,4-phenylene groups and the like can be mentioned.

As divalent alicyclic group S _a, for example, trans-1,4-cyclohexylene, trans - it can be exemplified trans-1,4-bi-cyclohexylene and the like.

Examples of the divalent heterocyclic group of S _a include 1,4-pyridylene group, 2,5-pyridylene group, 1,4-furanylene group, 1,4-piperazine group, 1,4-piperidin group and the like. 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, more preferably may be from an alkylene group having 1 to 4 carbon atoms.

As the divalent aromatic group R _2, for example, 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 2,3,5,6 Fluoro-1,4-phenylene group, naphthylene group and the like can be mentioned.

As divalent alicyclic group R _2, for example, trans-1,4-cyclohexylene, trans - it can be exemplified trans-1,4-bi-cyclohexylene and the like.

Examples of the divalent heterocyclic group of R ₂ include a 1,4-pyridylene group, a 2,5-pyridylene group, a 1,4-furanylene group, a 1,4-piperazine group, a 1,4-piperidin group and the like. be able to.

R ₂ is 1,4-phenylene group, trans 1,4-cyclohexylene, trans - may be from trans-1,4-bi-cyclohexylene.

The linear or branched alkyl group having 1 to 40 carbon atoms of R _4, for example, can be cited a straight chain or branched chain alkyl group having 1 to 20 carbon atoms, a part of the hydrogen atoms of the alkyl group Alternatively, all of them may be substituted with fluorine atoms. 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, 2- (perfluorodecyl) ethyl group and the like.

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) (in the formula, in the formula, R ₇ is a hydrogen atom, a fluorine atom or an alkyl group having 1 to 20 carbon atoms, respectively, and the alkyl group having 1 to 20 carbon atoms may be substituted with a fluorine atom, and * indicates a bond position). The groups represented can be mentioned.

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" indicates that it is an E form, and "t" indicates that the cyclohexyl group is a trans form.

[Thermal crosslinkable group A and the thermocrosslinkable group B]
The thermally crosslinkable group A and the thermally crosslinkable group B are independently a carboxyl group, an amino group, an alkoxymethylamide group, a hydroxymethylamide group, a hydroxyl group, an epoxy moiety-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, wherein the thermally crosslinkable group A and the thermally crosslinkable group B are selected so as to undergo a cross-linking reaction by heat, except that the thermally crosslinkable group A and the thermally crosslinkable group A and the thermally crosslinkable group B are selected. The groups B may be the same as each other.

As for the combination of such a thermally crosslinkable group A and the thermally 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 a hydroxy group. Is a blocked isocyanate group, one is a phenolic hydroxy group and the other is an epoxy, oxetanyl or tiylanyl group, one is a carboxyl group and the other is a blocked isocyanate group, one is amino A combination in which the group is a blocked isocyanate group and 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 heat-crosslinkable group A into the polymer which is the component (A), the monomer having the heat-crosslinkable group A may be copolymerized.

Further, when the liquid crystal alignment agent used in the present invention satisfies the requirement Z1, when the polymer which is the component (A) is produced, the monomer having a thermally crosslinkable group A and the monomer having a thermally crosslinkable group B are used. Both may be copolymerized.

Examples of the monomer having a thermocrossable group include acrylic acid, methacrylic acid, crotonic acid, mono- (2- (acryloyloxy) ethyl) phthalate, mono- (2- (methacryloyloxy) ethyl) phthalate, and N-(. Monomers with carboxyl groups such as carboxyphenyl) maleimide, N- (carboxyphenyl) methacrylamide, and 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- Monotyls having a hydroxy group such as acryloyloxy-6-hydroxynorbornene-2-carboxylic-6-lactone and 5-methacryloyloxy-6-hydroxynorbornen-2-carboxylic-6-lactone;

Monomonics with phenolic hydroxy groups such as hydroxystyrene, N- (hydroxyphenyl) methacrylamide, N- (hydroxyphenyl) acrylamide, N- (hydroxyphenyl) maleimide, and N- (hydroxyphenyl) maleimide;

Monomers having an amino group such as aminoethyl acrylate, aminoethyl methacrylate, aminopropyl acrylate, and aminopropyl methacrylate;

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

Allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, 2-methyl glycidyl methacrylate, glycidyl α-ethyl acrylate, glycidyl α-n-propyl acrylate, glycidyl α-n-butyl acrylate, 3,4-acrylic acid Epoxybutyl, 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl acrylate, 6,7-epoxyheptyl methacrylate, 6,7-epoxyheptyl α-ethylacrylic acid, 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 with epoxy site-containing groups such as hexene, 1,7-octadiene monoepoxiside;

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, Acryloic acid esters such as 2,4-trifluorooxetane, 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-trifluoromethylo Xetane, 3- (2-methacryloyloxyethyl) -2-pentafluoroethyloxetane, 3- (2-methacryloyloxyethyl) -2-phenyloxetane, 3- (2-methacryloyloxyethyl) -2,2-difluorooxetane , 3- (2-Methylloyloxyethyl) -2,2,4-trifluorooxetane, 3- (2-methacryloyloxyethyl) -2,2,4,4-tetrafluorooxetane and other monomers having an oxetane group;

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 thiylanyl group such as 2- or 3- or 4- (β-epithiopropylthio) styrene, 2- or 3- or 4- (β-epithiopropyloxy) styrene;

2- (0- (1'-methylpropyridaneamino) carboxyamino) ethyl acrylate, 2- (3,5-dimethylpyrazolyl) carbonylamino) ethyl acrylate, 2- (0- (1'-methyl) methacrylate Monomer having a blocked isocyanate group such as propylideneamino) carboxyamino) ethyl, 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 a specific copolymer is obtained, a monomer having a photo-orientating group represented by the above formula (a-1-m), a thermally crosslinkable group A, and, if necessary, a thermally crosslinkable property. In addition to the monomers having a group B, other monomers copolymerizable with these monomers can also be used in combination.

Specific examples of such other monomers include acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylonitrile, maleic acid anhydrides, styrene compounds, vinyl compounds, N-methoxymethyl (meth) acrylamide, and 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 the acrylic acid ester compound include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl acrylate, anthryl methyl acrylate, phenyl acrylate, 2,2,2-trifluoroethyl acrylate, and 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, anthryl methyl methacrylate, phenyl methacrylate, and 2,2,2-tri. 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, 8-ethyl-8-tricyclodecyl methacrylate and the like.

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, vinylnaphthalene, vinylcarbazole, allylglycidyl ether, and 3-ethenyl-7-oxabicyclo [4.1.0] heptane.

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

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

The nitrogen-containing aromatic heterocycle has 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). It is preferable that the aromatic cyclic hydrocarbon contains at least one, preferably 1 to 4 of the above.

Specifically, an oxazole ring, a thiazole ring, a pyridine ring, a pyrimidine ring, a quinoline ring, a 1-pyrazoline ring, an isoquinoline ring, a thiadiazole ring, a pyridazine ring, a triazine ring, a pyrazine ring, a phenanthroline ring, a quinoxalin ring, a benzothiazole ring, Examples thereof include an oxadiazole ring and an aclysine ring. Further, 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 and 2- (3-pyridylcarbonyloxy) ethyl (meth) acrylate, 2 -(4-Pyridylcarbonyloxy) ethyl (meth) acrylate, etc. may be mentioned.

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

The photoreactive site represented by the above formula (pa-1) contained in the polymer of the present invention may be used alone or in combination of two or more kinds.
The photoreactive site represented by the above formula (pa-1) is contained in a proportion of 5 to 50 mol%, 10 to 40 mol%, or 15 to 35 mol% of all repeating units of the polymer which is the component (A). It is preferable to be done.

The site having a heat-crosslinkable group contained in the polymer of the present invention may be a heat-crosslinkable group A alone, or a combination of two or more kinds of parts including the heat-crosslinkable group A and the heat-crosslinkable group B. May be used.
The amount of the site having a thermally crosslinkable group introduced is preferably 50 to 95 mol%, 60 to 90 mol%, or 65 to 85 mol% of all the repeating units of the polymer which is 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 all the repeating units of the polymer which is the component (A).

<Manufacturing method of 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-oriented group represented by the above formula (pa-1) and a monomer having the above-mentioned heat-crosslinkable group A. , And, if desired, obtained by copolymerizing the above-mentioned monomer having a heat-crosslinkable group B. In addition, it can be copolymerized with the above other monomers.

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

The radical thermal polymerization initiator is a compound that generates radicals by heating to a temperature higher than 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.), and hydroperoxides (peroxidation). Hydrogen, tert-butylhydroxide, cumenehydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyketals (dibutylperoxycyclohexane, etc.) Etc.), alkyl peresters (peroxyneodecanic acid-tert-butyl ester, peroxypivalic acid-tert-butyl ester, peroxy2-ethylcyclohexanoic acid-tert-amyl ester, etc.), persulfates (potassium persulfate, etc.) Examples thereof include sodium persulfate, ammonium persulfate, etc.) and azo radical compounds (azobisisobutyronitrile, and 2,2'-di (2-hydroxyethyl) azobisisobutyronitrile, etc.).
Such a radical thermal polymerization initiator 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 admixture of two or more.
The radical polymerization method is not particularly limited, and an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method, a precipitation polymerization method, a massive polymerization method, a 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 the produced polymer dissolves. Specific examples include the solvents described in the section <Solvent> described later, for example, N-alkyl-2-pyrrolidones, dialkylimidazolidinones, lactones, carbonates, ketones, and formula (Sv-1). Examples thereof include the compound represented and the compound represented by the formula (Sv-2), tetrahydrofuran, 1,4-dioxane, dimethyl sulfoxide, dimethyl sulfoxide and the like.
These solvents may be used alone or in combination. Further, even if the solvent does not dissolve the produced polymer, it may be mixed with the above-mentioned solvent and used as long as the produced polymer does not precipitate.
Further, in radical polymerization, oxygen in the solvent causes an inhibition of the polymerization reaction, so it is preferable to use an organic solvent degassed to the extent possible.

The polymerization temperature at the time of 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 initial reaction can be carried out at a high concentration and then an organic solvent can be added.
In the above-mentioned radical polymerization reaction, when the ratio of the radical polymerization initiator is large with respect to the monomer, the molecular weight of the obtained polymer is small, and when the ratio of the radical polymerization initiator is small, the molecular weight of the obtained polymer is large. It is preferably 0.1 to 10 mol% with respect to the monomer to be polymerized. Further, various monomer components, solvents, initiators and the like can be added at the time of polymerization.

[Recovery of polymer]
When the produced polymer is recovered from the reaction solution obtained by the above reaction, the reaction solution may be put into a poor solvent to precipitate the polymers. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, heptane, butyl cellsolve, heptane, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, water and the like. The polymer which has been put into a poor solvent and precipitated can be collected by filtration and then dried at normal temperature or by heating under normal pressure or reduced pressure. Further, when the operation of redistributing the polymer recovered by precipitation in an organic solvent and repeating the operation of recovering the precipitation 2 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 the weight average measured by the GPC (Gel Permeation Chromatography) method in consideration of the strength of the obtained coating film, the workability at the time of forming the coating film, and the uniformity of the coating film. The molecular weight is preferably 2000 to 10000, more preferably 5000 to 100,000.

<Ingredient (B)>
When the liquid crystal alignment agent used in the present invention satisfies the requirement Z2, it contains a cross-linking agent as the component (B). Examples of the component (B) include a cross-linking agent having two or more thermally cross-linkable groups B.

Examples of the cross-linking agent as the component (B) include an epoxy compound, a compound having two or more amino groups, a methylol compound, an isocyanate compound, a phenoplast compound, a low molecular weight compound such as a blocked isocyanate compound, and a polymer of N-alkoxymethylacrylamide. , Polymers of compounds having an epoxy group, polymers of compounds having an isocyanate group, and the like.

Specific examples of the above-mentioned epoxy compounds include 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-xylene diamine, 1,3-bis (N, N-diglycidyl aminomethyl) cyclohexane, and N, N, N', N'-tetraglycidyl-4, 4'-diaminodiphenylmethane And so on.

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

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

Examples of aromatic-aliphatic diamines include 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 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 glycol uryl, alkoxymethylated benzoguanamine, and alkoxymethylated melamine.

Specific examples of alkoxymethylated glycol uryl include 1,3,4,6-tetrax (methoxymethyl) glycol uryl, 1,3,4,6-tetrax (butoxymethyl) glycol uryl, 1,3,4. , 6-Tetrax (hydroxymethyl) glycoluryl, 1,3-bis (hydroxymethyl) urea, 1,1,3,3-tetrakis (butoxymethyl) urea, 1,1,3,3-tetrakis (methoxymethyl) Examples thereof 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 compounds manufactured by Mitsui Cytec Co., Ltd. (trade name: Cymel (registered trademark) 1170, powder link (registered trademark) 1174), 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 manufactured by DIC Co., Ltd. (high condensation type, trade name: Beccamin () Registered trademarks) J-300S, P-955, N) and the like.

Specific examples of the alkoxymethylated benzoguanamine include tetramethoxymethylbenzoguanamine and the like. As commercial products, Mitsui Cytec Co., Ltd. (trade name: Cymel (registered trademark) 1123), Sanwa Chemical Co., Ltd. (trade name: Nicarac (registered trademark) BX-4000, BX-37, BL- 60, BX-55H) and the like.

Specific examples of the alkoxymethylated melamine include hexamethoxymethylmelamine and the like. Commercially available products include methoxymethyl type melamine compounds manufactured by Mitsui Cytec Co., Ltd. (trade name: Cymel (registered trademark) 300, 301, 303, 350), butoxymethyl type melamine compound (trade name: Mycoat (registered trademark)). ) 506, 508), Sanwa Chemical's methoxymethyl type melamine compound (trade name: Nicarac (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: Nicarac (registered trademark) MX-45, MX-410, MX-302) and the like.

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

Specific examples of the isocyanate compound include, for example, VESTANAT B1358 / 100, VESTAGON BF 1540 (above, isocyanurate-type modified polyisocyanate, manufactured by Degussa Japan Co., Ltd.), Takenate (registered trademark) B-882N, B-7075 (these are registered trademarks). As mentioned above, isocyanurate-type modified polyisocyanate, manufactured by Mitsui Kagaku Co., Ltd. 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 molecular terminals 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 (all manufactured by Nippon Polyurethane Industry Co., Ltd.), Takenate B-830, B-815N, and the like. Examples thereof include B-820NSU, B-842N, B-846N, B-870N, B-874N, and B-882N (all manufactured by Mitsui Chemicals, Inc.).

Further, 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). ) Examples thereof include polymers produced by using an acrylamide compound or a methacrylicamide compound substituted with a hydroxymethyl group such as acrylamide or an alkoxymethyl group.

Specific examples of such polymers include poly (N-butoxymethylacrylamide), N-butoxymethylacrylamide and styrene copolymers, N-hydroxymethylmethacrylamide and methylmethacrylate copolymers, and N. Examples thereof include a copolymer of -ethoxymethylmethacrylamide and benzylmethacrylate, and a copolymer of N-butoxymethylacrylamide, benzylmethacrylate and 2-hydroxypropylmethacrylate. The weight average molecular weight of such a polymer is 1,000 to 200,000, more preferably 3,000 to 150,000, and even more preferably 3,000 to 50,000.

Examples of the polymer of the compound having an epoxy group include a polymer produced by using a compound having an epoxy group such as glycidyl methacrylate, 3,4-epoxycyclohexylmethylmethacrylate, and 3,4-epoxycyclohexylmethylmethacrylate. Be done.

Specific examples of such polymers include poly (3,4-epoxycyclohexylmethylmethacrylate), poly (glycidylmethacrylate), copolymers of glycidylmethacrylate and methylmethacrylate, and 3,4-epoxycyclohexylmethylmethacrylate. 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 even more preferably 3,000 to 50,000.

Examples of the polymer of the above-mentioned compound having an isocyanate group include 2-isocyanatoethyl methacrylate (Kalens MOI [registered trademark], manufactured by Showa Denko Co., Ltd.) and 2-isocyanatoethyl acrylate (Kalens AOI [registered trademark]. , Showa Denko Co., Ltd., etc., or a compound having an isocyanate group, or 2- (0- [1'-methylpropylideneamino] carboxyamino) ethyl methacrylate (Karenzu MOI-BM [registered trademark], Showa Denko Co., Ltd. ), 2-[(3,5-Dimethylpyrazolyl) carbonylamino] ethyl methacrylate (Carens MOI-BP [registered trademark], manufactured by Showa Denko Co., Ltd.), etc. Examples of the polymer to be used.

Specific examples of such polymers include 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 even more preferably 3,000 to 50,000.

These cross-linking agents can be used alone or in combination of two or more.

When the liquid crystal alignment agent used in the present invention contains the cross-linking agent of the component (B), the content is preferably 1 part by mass to 100 parts by mass based on 100 parts by mass of the resin which is the component (A). , More preferably 1 part by mass to 80 parts by mass.

[Preparation of liquid crystal alignment agent]
The liquid crystal alignment agent used in the present invention is preferably prepared as a coating liquid so as to be suitable for forming a liquid crystal alignment film. That is, the liquid crystal alignment 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 a specific polymer which is the component (A) already described. At that time, the content of the specific polymer is preferably 0.5 to 20% by mass, more preferably 1 to 20% by mass, still more preferably 1 to 15% by mass, and particularly preferably 1 with respect to the entire liquid crystal alignment agent. It is preferably 10% by mass.

<Solvent>
The solvent contained in the liquid crystal alignment agent used in the present invention is not particularly limited as long as it is a solvent that dissolves the component (A) and, if necessary, the component (B). The solvent contained in the liquid crystal alignment agent may be one type or a mixture of two or more types. 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, if 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 coating property of the liquid crystal alignment agent on the substrate is improved. It is preferable because it can be used.

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-imidazole Dialkylimidazolidinones such as lydinone, lactones such as γ-butyrolactone, γ-valerolactone, δ-valerolactone, carbonates such as ethylene carbonate and propylene carbonate, methanol, ethanol, propanol, isopropanol, 3-methyl- Ketones such as 3-methoxybutanol, ethylamyl ketone, methylnonyl ketone, methyl ethyl ketone, isoamyl methyl ketone, methyl isopropyl ketone, diisobutyl ketone, cyclohexanone, cyclopentanone, methyl isobutyl ketone, 4-hydroxy-4-methyl-2-pentanone Classes, 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, Examples thereof include 2-methylcyclohexyl acetate, butyl butyrate, isoamyl butyrate, diisobutylcarbinol, diisopentyl ether and the like.

In formulas (Sv-1) to (Sv-2), Y ₁ and Y ₂ are independently hydrogen atoms or monovalent hydrocarbon groups having 1 to 6 carbon atoms, and X ₁ is an oxygen atom or −COO−. in it, X2 is a single bond or a carbonyl group, R ₁ is alkanediyl group having 2 to 4 carbon atoms. n ₁ is an integer from 1 to 3. If n ₁ is 2 or 3, a plurality of 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 independently hydrogen atoms or monovalent hydrocarbon groups having 1 to 6 carbon atoms).

In the formula (Sv-1) _{, examples of the monovalent hydrocarbon group having 1 to 6 carbon atoms of Y 1} and Y ₂ include a monovalent chain hydrocarbon group having 1 to 6 carbon atoms and 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 the formula (Sv-2), examples of the divalent hydrocarbon group having 1 to 6 carbon atoms of _{Z 1 include an alkanediyl group having 1 to 6 carbon atoms.}
The _{monovalent hydrocarbon groups having 1 to 6 carbon atoms of Y 3} and Y ₄ are monovalent chain hydrocarbon groups having 1 to 6 carbon atoms and monovalent alicyclic hydrocarbons having 1 to 6 carbon atoms. Examples thereof include groups and monovalent aromatic hydrocarbon groups 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 ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, and 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 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, and methyl-3. -Methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate and the like can be mentioned, respectively.

The solvent preferably has a boiling point of 80 to 200 ° C. More preferably, it is 80 ° C. to 180 ° C., and as preferable solvents, N, N-dimethylformamide, tetramethylurea, 3-methoxy-N, N-dimethylpropanamide, propanol, isopropanol, 3-methyl-3-methoxy. Butanol, ethylamyl 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, Ethyl-3-ethoxypropionate, methyl-3-methoxypropionate, ethyl 3-methoxypropionate, etc. can be mentioned.
It is particularly preferable that the boiling point is in this range when the liquid crystal alignment agent containing the solvent is applied onto a plastic substrate described later.

<Other ingredients>
The liquid crystal alignment agent used in the present invention may contain components other than the above components (A) and (B). Examples of such other components include a cross-linking catalyst, a compound that improves 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, it is not limited to this.

<Crosslink catalyst>
A cross-linking catalyst may be added to the liquid crystal alignment agent used in the present invention for the purpose of accelerating the reaction between the heat-crosslinkable group A and the heat-crosslinkable group B. Examples of such a cross-linking catalyst include p-toluene sulfonic acid, campha sulfonic acid, trifluoromethane sulfonic acid, p-phenol sulfonic acid, 2-naphthalene sulfonic acid, mesitylen sulfonic acid, p-xylene-2-sulfonic acid, m-. Xylene-2-sulfonic acid, 4-ethylbenzene sulfonic acid, 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid, perfluoro (2-ethoxyethane) sulfonic acid, pentafluoroethane sulfonic acid, nonafluorobutane-1- Examples thereof include sulfonic acids such as sulfonic acids and dodecylbenzene sulfonic acids, or hydrates and salts thereof. Examples of compounds that generate acid by heat include bis (tosyloxy) ethane, bis (tosyloxy) propane, bis (tosyloxy) butane, p-nitrobenzyl tosylate, o-nitrobenzyl tosylate, 1,2,3-. P-toluenetris (methylsulfonate), 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-toluenesulfoneamide and the like.

[Compounds that improve film thickness uniformity and surface smoothness]
Examples of the compound for improving 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, Ftop (registered trademark) 301, EF303, EF352 (manufactured by Tochem Products), Megafuck (registered trademark) F171, F173, R-30 (manufactured by DIC), Florard FC430, FC431 (manufactured by DIC). Sumitomo 3M Ltd.), Asahi Guard (registered trademark) AG710 (Asahi Glass Co., Ltd.), Surflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, SC106 (made by AGC Seimi Chemical Co., Ltd.) and the like. ..
The ratio of these surfactants used is preferably 0.01 parts by mass to 2 parts by mass, and 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. It is a mass part.

[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 following functional silane-containing compounds.
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 silane-containing compounds such as silane and N-bis (oxyethylene) -3-aminopropyltriethoxysilane.
When a compound that improves adhesion to a substrate is used, the amount used 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. More preferably, it is 1 part by mass to 20 parts by mass.

In certain embodiments, a photosensitizer can also be used as an additive to improve the photoreactivity of the photooriented group. Specific examples include aromatic 2-hydroxyketone (benzophenone), coumarin, ketocoumarin, carbonyl biscumarin, acetophenone, anthraquinone, xanthone, thioxanthone, and acetophenone ketal.

In the liquid crystal alignment agent used in the present invention, all of the above-mentioned resin components may be the above-mentioned specific polymers, but other polymers (hereinafter, also referred to as “other polymers”) may be used. It may be mixed. At that time, as the content of the other polymer in the resin component, 5 to 95 parts by mass or 10 to 90 parts by mass can be mentioned with respect to 100 parts by mass in total of the component (A) and the other polymer. ..
Examples of such other polymers include poly (meth) acrylates, polyamic acids, polyamic acid esters, polyimides, and the like, and polymers that do not satisfy at least one of the constituent requirements of the specific polymer. Can be mentioned.

The other polymer is preferably a polyimide or a precursor thereof (hereinafter, also referred to as a polyimide component), which has a surface energy close to that of the polymer which is the component (A). 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 surface energy between these two components is too large, they will not be compatible well and agglomeration will occur, resulting in the formation of an uneven film, and the occurrence of cissing and unevenness, resulting in a narrow process margin. There is a risk of causing problems such as. Therefore, by lowering the polarity of the polyimide component, the surface energy can be controlled to a value higher than that of the acrylic component but with a small difference. As a method of lowering the polarity of the polyimide component, there are a method of chemically imidizing and then mixing with the component (A), and a method of introducing a side chain.

As such a polymer, a polymer obtained by polymerizing a known tetracarboxylic acid derivative such as tetracarboxylic dianhydride and a known diamine and then chemically imidizing, or a diamine having a side chain is used. Examples thereof include a obtained polyimide precursor, a polyimide obtained by imidizing the polyimide, a polyimide precursor obtained by using a diamine having a tertiary butoxycarbonyloxy group, and a polyimide obtained by imidizing the polyimide precursor. By such side chains and chemical imidization, the surface energy can be brought close to that of the acrylic polymer which is the component (A). Therefore, when a liquid crystal aligning agent is applied and fired to form a cured film, aggregation or the like occurs. It does not occur and a flat cured film can be provided. 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 WO2016 / 125870 published in International Patent Application. Specific examples thereof include diamines represented by the formulas [A-1] to [A-32]. Examples of the diamine having a tertiary butoxycarbonyloxy group include those of the formulas [A-1], [A-2], and [A-3] described in paragraphs [0011] to [0034] of International Patent Application Publication WO2017 / 119461. Examples thereof include diamines having a structure and diamines exemplified as specific examples thereof.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal alignment agent of the present invention can be applied on a substrate, fired, and then subjected to alignment treatment such as rubbing treatment or light irradiation, or in some vertical alignment applications, the liquid crystal alignment film can be formed without alignment treatment. can. As the substrate, for example, glass such as float glass and soda glass; polyethylene terephthalate, polybutylene terephthalate, polypropylene, polystyrene, polyethersulfone, polycarbonate, poly (aliphatic olefin), polyvinyl chloride, polyvinylidene chloride, polyetheretherether A transparent substrate made of a plastic such as ketone (PEEK) resin film, polysulfone (PSF), polyetherketone (PES), polyamide, polyimide, acrylic and triacetyl cellulose can be used.
As the transparent conductive film provided on one surface of a substrate, NESA film (US PPG registered trademark) made of tin oxide (SnO _2), indium oxide - such as an ITO film made of tin oxide _{(In 2} O 3 -SnO ₂₎ the Can be used.

<Coating film forming process>
The method for applying the liquid crystal alignment 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.

The firing after applying the liquid crystal alignment agent can be performed at an arbitrary temperature of 40 to 300 ° C., preferably 40 ° C. to 250 ° C., and more preferably 40 ° C. to 230 ° C. When a transparent substrate made of a plastic substrate is used, the temperature is preferably 40 to 150 ° C, more preferably 80 to 140 ° C. The firing time is preferably 0.1 to 15 minutes, more preferably 1 to 10 minutes.
The film 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 in a hot plate, a hot air circulation furnace, an infrared furnace, or the like.

<Light irradiation process>
The light irradiation step in the present invention includes a first irradiation step of irradiating the cured film obtained in the coating film forming step with ultraviolet rays from an oblique direction, and the first irradiation step of irradiating the cured film after the ultraviolet irradiation. A second irradiation step of irradiating ultraviolet rays from a direction different from the above is included in this order, and at least one of the first irradiation step and the second irradiation step includes a light-shielded region and an unshaded region. It is done through a mask.

Examples of the light irradiated by the orientation treatment by light irradiation include ultraviolet rays including light having a wavelength of 150 to 800 nm, visible light, and the like. Of these, ultraviolet rays containing light having a wavelength of 300 to 400 nm are preferable. The irradiation light may be polarized or unpolarized. As the polarized light, it is preferable to use light containing linearly polarized light.

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 to 500 mJ / cm ^2, further be 2~200mJ / cm ² preferable.

The ultraviolet irradiation direction is usually 1 ° to 89 ° with respect to the substrate normal, preferably 20 ° to 70 °, and particularly preferably 30 ° to 60 °. If this angle is too small, there is a problem that the pre-tilt angle becomes small, and if it is too large, there is a problem that it becomes difficult to design an irradiation device.

As a method of adjusting the irradiation direction to the above angle, there are a method of tilting the substrate itself and a method of tilting the light source, but tilting the light source itself is more preferable from the viewpoint of throughput.

In the present invention, by using a specific composition, the pretilt angle formed by the irradiation of ultraviolet rays from one direction can be canceled by the irradiation of ultraviolet rays from another direction, and different pretilt angles can be formed. ..
As a result, for example, after forming a pretilt angle in a specific direction by full exposure of ultraviolet rays, a plurality of regions having different orientation directions can be easily formed (orientation division) by irradiating ultraviolet rays from another direction through a mask. It is possible to efficiently manufacture a multi-domain liquid crystal display element.

In the multi-domain liquid crystal alignment film obtained by the production method of the present invention, the pre-tilt angle is a region 1 in which the pre-tilt angle is tilted from 90 ° to minus 0.1 ° to minus 10 ° as a pre-tilt angle suitable for the vertical alignment mode, and the pre-tilt angle is plus from 90 °. It is preferable to have a region 2 tilted from 0.1 ° to plus 10 °. That is, it is preferable to have a region 1 of 80 ° to 89.9 ° and a region 2 of 90.1 ° to 100 ° as pretilt angles, and a region 1 of 85 ° to 89 ° and a region 2 of 91 ° to 95 °. It is more preferable to have.

When forming the above-mentioned region 1 and region 2, the region 1 may be formed in the first irradiation step, and the region 2 may be formed in the second irradiation step, and the region 2 is formed in the first irradiation step. However, the region 1 may be formed in the second irradiation step. When the first irradiation step is performed without using a mask, it is preferable that the light irradiation amount in the second irradiation step is larger than the light irradiation amount in the first irradiation step. On the other hand, when the first irradiation step is performed through the mask, it is preferable that the light irradiation amount in the second irradiation step is smaller than the light irradiation amount in the first irradiation step.

According to the present invention, when a patterned mask is used in both the first irradiation step and the second irradiation step, even if the mask is displaced, the second irradiation region covers the first irradiation region. Since the tilt can be canceled and rewritten to the tilt angle by the second irradiation, it does not become a "dark line" when the mask shifts.

The liquid crystal display element of the present invention can be produced by a usual method using the multi-domain liquid crystal alignment film obtained in the present invention, and the production method is not particularly limited. It is preferable that the pair of substrates face each other with an appropriate gap, and spacers are arranged between the substrates for the purpose of making the thickness of the liquid crystal sandwiched between the substrates uniform. As the spacer, a known spacer material such as a conventional spray-type spacer or a spacer formed from a photosensitive spacer-forming composition can be used, and irregularities formed in a layer made of a cured liquid crystal display can be used. It can also be used as a spacer.

<LCD sandwiching process>
To form a liquid crystal cell by sandwiching the liquid crystal between the substrates, for example, the following two methods can be mentioned. As a first method, a pair of substrates are arranged facing each other through a gap (cell gap) so that the liquid crystal alignment films face each other, and the peripheral portions of the pair of substrates are bonded to each other using a sealant to form the substrate surface and the substrate surface. A method of manufacturing a liquid crystal cell can be mentioned by injecting and filling the cell gap partitioned by an appropriate sealing agent and then sealing the injection hole.

As a second method, for example, an ultraviolet light-curable sealing material is applied to a predetermined place on one of the two substrates on which the liquid crystal alignment film is formed, and further, a predetermined number of places on the liquid crystal alignment film surface. After dropping the liquid crystal on the surface, the other substrate is attached so that the liquid crystal alignment film faces each other, the liquid crystal is spread over the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the liquid crystal display. A method of manufacturing a cell (ODF (One Drop Fill) method) can be mentioned.

Examples of the liquid crystal include a fluorine-based liquid crystal and a cyano-based liquid crystal having positive or negative dielectric anisotropy depending on the application, and a liquid crystal compound or liquid crystal composition which is polymerized by at least one treatment of heating and light irradiation (a liquid crystal compound or a liquid crystal composition). Hereinafter, a polymerizable liquid crystal display or a curable liquid crystal composition) may be used.
In a certain embodiment, the step of forming the coating film of the liquid crystal alignment agent may be performed by a roll-to-roll method. When the roll-to-roll method is used, the manufacturing process of the liquid crystal display element can be simplified and the manufacturing cost can be reduced.
Then, a liquid crystal display element can be obtained by attaching polarizing plates to both outer surfaces of the liquid crystal cell.

The polarizing plate used on the outside of the liquid crystal cell is composed of a polarizing plate called "H film" in which polyvinyl alcohol is stretched and oriented while absorbing iodine, sandwiched between cellulose acetate protective films, or the H film itself. A polarizing plate and the like can be mentioned.
The liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention as described above has good liquid crystal alignment, excellent pretilt angle expression ability, and high reliability. Further, the liquid crystal display element manufactured by the method of the present invention has excellent display characteristics.

The structure of the compound used in the examples is shown below.
In the formula, "t" indicates that the cyclohexyl group is a trans type.

MA-1, MA-2, MA-3, and MA-4 are photo-oriented monomers, and CR-1, CR-2, MOI-BP, HEMA, and MAA are heat-crosslinkable monomers.

X-1, X-2, and X-3 are tetracarboxylic dianhydride monomers.

X-4 is a side chain diamine monomer, and X-5 and X-6 are other diamine monomers.

The abbreviations of the organic solvents used in the examples and the like are as follows.
PGME: Propylene glycol monomethyl ether CHN: Cyclohexanone The abbreviations of the polymerization initiator used in Examples and the like are as follows.
AIBN: 2,2'-azobisisobutyronitrile

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

<Reference example 1>
MA-1 (4.95 g, 12.0 mmol) and MOI-BP (7.04 g, 28.0 mmol) were dissolved in CHN (69.8 g), degassed with a diaphragm pump, and then AIBN (0). .33 g, 2.0 mmol) was added and degassing was performed again. Then, the reaction was carried out at 55 ° C. for 13 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the obtained precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure in an oven at 40 ° C. to obtain a methacrylate polymer powder (A). The number average molecular weight of this polymer was 44200 and the weight average molecular weight was 141800.
CHN (18.0 g) was added to the obtained methacrylate polymer powder (A) (1.5 g), and the mixture was dissolved by stirring at room temperature for 5 hours. CR-1 (0.15 g) and PGME (18.0 g) were added to this solution and stirred to obtain a liquid crystal alignment agent (A1).

<Example 1-0>
[Making a liquid crystal cell]
The liquid crystal alignment agent (A1) obtained in Reference Example 1 was spin-coated on the ITO surface of a glass substrate with a transparent electrode made of an ITO film, and dried on a hot plate at 40 ° C. for 300 seconds. Next, it was fired on a hot plate at 120 ° C. for 10 minutes to form a liquid crystal alignment film having a film thickness of 100 nm. Then, the coated surface of the alignment film is irradiated ^{with linearly polarized ultraviolet light of 313 nm having an irradiance intensity of 4.3 mW / cm 2 via a polarizing plate at 50 mJ / cm 2} from an angle inclined by 40 ° from the normal direction of the substrate. , A substrate with a liquid crystal alignment film was obtained. The 313 nm linearly polarized ultraviolet light to be irradiated was taken out by passing the ultraviolet light emitted from the high-pressure mercury lamp through a 313 nm bandpass filter and a Brewster polarizing plate.
Two of the above substrates were prepared, a 4 μm bead spacer was sprayed on the liquid crystal alignment film of one of the substrates, and then a sealant (Mitsui Chemicals, XN-1500T) was applied. Next, the other substrate is bonded so that the liquid crystal alignment film surfaces face each other and the irradiation direction of the incident polarized ultraviolet light is 180 ° with respect to the irradiation direction of the ultraviolet light incident on the opposite substrate. An empty cell was prepared by heat-curing the sealant at 120 ° C. for 90 minutes. A negative liquid crystal display (MLC-3022, manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method to prepare a liquid crystal cell.

[Evaluation of pre-tilt angle]
The pretilt angle of the liquid crystal cell was measured by the Mueller matrix method using "AxoScan" manufactured by Axo METRIX. The results are summarized in Table 1.

[Evaluation of liquid crystal orientation]
After the liquid crystal cell is manufactured, it is subjected to isotropic treatment at 120 ° C. for 1 hour, and then the cell is observed with a polarizing microscope. When the liquid crystal drive can be obtained, the orientation is good. The results are summarized in Table 1.

<Example 1-1>
^{In [Preparation of liquid crystal cell] of Example 1-0, after irradiating 50 mJ / cm 2 of} linearly polarized ultraviolet rays from an angle inclined by 40 ° from the normal direction of the substrate, 50 mJ from an angle inclined by 40 ° from the normal direction of the substrate. / cm ² except that irradiation was performed in the same manner as described in example 1-0, to obtain a liquid crystal cell. The first irradiation and the second irradiation were inclined by 40 ° in opposite directions from the normal direction, respectively. Moreover, the pretilt angle and the liquid crystal cell orientation were evaluated by the same method as in Example 1-0.

<Examples 1-2, 1-3>
In [Preparation of liquid crystal cell of Example 1-1, the polarized ultraviolet irradiation amount of second 100 mJ / cm ² (Example 1-2), except that the 150 mJ / cm ² (Example 1-3), A liquid crystal cell was obtained by the same method as in Example 1-1. Moreover, the pretilt angle and the liquid crystal cell orientation were evaluated by the same method as in Example 1-0.

<Reference example 2>
MA-1 (4.95 g, 12.0 mmol), MOI-BP (3.52 g, 14.0 mmol) and HEMA (1.82 g, 14.0 mmol) were dissolved in CHN (60.2 g), and a diaphragm pump was used. After degassing with, AIBN (0.33 g, 2.0 mmol) was added and degassed again. Then, the reaction was carried out at 55 ° C. for 13 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the obtained precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure in an oven at 40 ° C. to obtain a methacrylate polymer powder (B). The number average molecular weight of this polymer was 33,800 and the weight average molecular weight was 123,500.
CHN (18.0 g) was added to the obtained methacrylate polymer powder (B) (1.5 g), and the mixture was dissolved by stirring at room temperature for 5 hours. PGME (18.0 g) was added to this solution and stirred to obtain a liquid crystal alignment agent (B1).

<Reference example 3>
MA-1 (3.30 g, 8.0 mmol) and MAA (2.75 g, 32.0 mmol) were dissolved in CHN (36.2 g), degassed with a diaphragm pump, and then AIBN (0.33 g). , 2.0 mmol) and degassed again. Then, the reaction was carried out at 55 ° C. for 13 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the obtained precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure in an oven at 40 ° C. to obtain a methacrylate polymer powder (C). The number average molecular weight of this polymer was 51500 and the weight average molecular weight was 143000.
CHN (18.0 g) was added to the obtained methacrylate polymer powder (C) (1.5 g), and the mixture was dissolved by stirring at room temperature for 5 hours. CR-2 (0.45 g) and PGME (18.0 g) were added to this solution and stirred to obtain a liquid crystal alignment agent (C1).

<Reference example 4>
X-4 (2.28 g, 3.00 mmol), X-5 (1.22 g, 4.00 mmol), X-6 (1.45 g, 3.00 mmol) and X-1 (2.23 g, 6.00 mmol) ) Was dissolved in NMP (27.2 g) and reacted at 60 ° C. for 5 hours, and then NMP with X-2 (1.00 g, 2.00 mmol) and X-3 (0.87 g, 2.00 mmol). (9.1 g) was added and reacted at 40 ° C. for 10 hours to obtain a polyamic acid polymer solution.
NMP is added to a polyamic acid polymer solution (50 g) to dilute it to 6.5% by mass, acetic anhydride (8.8 g) and pyridine (2.7 g) are added as imidization catalysts, and the reaction is carried out at 75 ° C. for 2.5 hours. I let you. This reaction solution was put into methanol (700 ml), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide polymer powder. The imidization ratio of this polyimide polymer was 71%, the number average molecular weight was 13000, and the weight average molecular weight was 42000.
NMP (44.0 g) was added to the obtained polyimide powder (6.0 g), and the mixture was dissolved by stirring at 70 ° C. for 20 hours. NMP (10.0 g) and BCS (40.0 g) were added to this solution, and the mixture was stirred at room temperature for 5 hours to obtain a polyimide polymer solution (H1).
The liquid crystal alignment agent (D1) is obtained by stirring the obtained polyimide polymer solution (H1) (14.0 g) and the liquid crystal aligning agent (B1) (6.0 g) obtained in Reference Example 2 at room temperature for 5 hours. Obtained.

<Reference example 5>
The liquid crystal display was obtained by stirring the polyimide polymer solution (H1) (14.0 g) obtained in Reference Example (4) and the liquid crystal alignment agent (C1) (6.0 g) obtained in Reference Example 3 at room temperature for 5 hours. An alignment agent (E1) was obtained.

<Examples 2-0-5-3>
The test was carried out in the same manner as in Examples 1 to 1-3 except that the liquid crystal alignment agent shown in Table 1 was used instead of the liquid crystal alignment agent (A1) obtained in Reference Example 1. The evaluation results are shown in Table 1.

<Reference example 6>
MA-2 (13.74 g, 24.0 mmol) and MA-3 (7.02 g, 16.0 mmol) were dissolved in CHN (119.5 g), degassed with a diaphragm pump, and then AIBN (0). .33 g, 2.0 mmol) was added and degassing was performed again. Then, the reaction was carried out at 55 ° C. for 13 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the obtained precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure in an oven at 40 ° C. to obtain a methacrylate polymer powder (D). The number average molecular weight of this polymer was 35700 and the weight average molecular weight was 126000.
CHN (18.0 g) was added to the obtained methacrylate polymer powder (D) (1.5 g), and the mixture was dissolved by stirring at room temperature for 5 hours. CHN (18.0 g) was added to this solution and stirred to obtain a liquid crystal alignment agent (F1).

<Comparative Example 1-0>
[Making a liquid crystal cell]
The liquid crystal alignment agent (F1) obtained in Reference Example 6 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 40 ° C. for 300 seconds, and the liquid crystal alignment having a film thickness of 100 nm was obtained. A film was formed. The coating film surface was irradiated with 313 nm linearly polarized ultraviolet rays having an irradiation intensity of 4.3 mW / cm ^{2 via a polarizing plate at 50 mJ / cm 2} from an angle inclined by 40 ° from the normal direction of the substrate. Then, it was fired on a hot plate at 120 ° C. for 10 minutes to obtain a substrate with a liquid crystal alignment film. The incoming linearly polarized UV was prepared by passing an ultraviolet light of a high-pressure mercury lamp through a 313 nm bandpass filter and then a 313 nm polarizing plate.
Two of the above substrates were prepared, a 4 μm bead spacer was sprayed on the liquid crystal alignment film of one of the substrates, and then a sealant (Kyoritsu Kagaku Co., Ltd., XN-1500T) was applied. Next, the other substrate was laminated so that the liquid crystal alignment film surfaces faced each other and the orientation direction was 180 °, and then the sealant was thermoset at 120 ° C. for 90 minutes to prepare an empty cell. A negative liquid crystal display (MLC-3022, manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method to prepare a liquid crystal cell.
Moreover, the pretilt angle and the liquid crystal cell orientation were evaluated by the same method as in Example 1-0.

<Comparative Example 1-1>
^{In [Preparation of liquid crystal cell] of Comparative Example 1-0, after irradiating 50 mJ / cm 2 of} linearly polarized ultraviolet rays from an angle inclined by 40 ° from the normal direction of the substrate, 50 mJ from an angle inclined by 40 ° from the normal direction of the substrate. / cm ² except that irradiation was performed in the same manner as in Comparative example 1-0, to obtain a liquid crystal cell. The first irradiation and the second irradiation were inclined by 40 ° in opposite directions from the normal direction, respectively. Moreover, the pretilt angle and the liquid crystal cell orientation were evaluated by the same method as in Example 1-0.

<Comparative Examples 1-2, 1-3>
In Comparative Example 1-0 [Preparation of LCD cell], the second polarized ultraviolet irradiation amount was changed to 100 mJ / cm ² (Comparative Example 1-2) and 150 mJ / cm ² (Comparative Example 1-3), except that the amount was changed to 100 mJ / cm 2 (Comparative Example 1-2). A liquid crystal cell was obtained by the same method as in Comparative Example 1. Moreover, the pretilt angle and the liquid crystal cell orientation were evaluated by the same method as in Example 1-0.

<Reference example 7>
MA-2 (17.18 g, 30.0 mmol) and MAA (1.72 g, 20.0 mmol) were dissolved in NMP (108.51 g), degassed with a diaphragm pump, and then AIBN (0.25 g). , 1.5 mmol) was added and degassing was performed again. Then, the reaction was carried out at 55 ° C. for 13 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the obtained precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure in an oven at 40 ° C. to obtain a methacrylate polymer powder (E). The number average molecular weight of this polymer was 22700 and the weight average molecular weight was 131000.
CHN (18.0 g) was added to the obtained methacrylate polymer powder (E) (1.5 g), and the mixture was dissolved by stirring at room temperature for 5 hours. CHN (18.0 g) was added to this solution and stirred to obtain a liquid crystal alignment agent (G1).

<Comparative Examples 2-0 to 2-3>
Using the liquid crystal alignment agent (G1) obtained in Reference Example 7, the test was carried out in the same manner as in Comparative Examples 1 to 1-3 except that the firing temperature was changed from 120 ° C. to 150 ° C.

<Reference example 8>
MA-4 (4.05 g, 8.0 mmol) and MAA (2.75 g, 32.0 mmol) were dissolved in CHN (28.5 g), degassed with a diaphragm pump, and then AIBN (0.33 g). , 2.0 mmol) and degassed again. Then, the reaction was carried out at 55 ° C. for 13 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the obtained precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure in an oven at 40 ° C. to obtain a methacrylate polymer powder (H). The number average molecular weight of this polymer was 47,000 and the weight average molecular weight was 140000.
CHN (18.0 g) was added to the obtained methacrylate polymer powder (H) (1.5 g), and the mixture was dissolved by stirring at room temperature for 5 hours. CR-2 (0.45 g) and PGME (18.0 g) were added to this solution and stirred to obtain a liquid crystal alignment agent (I1).

<Reference example 9>
The polyimide polymer solution (H1) (14.0 g) obtained in Reference Example (4) and the liquid crystal alignment agent (I1) (6.0 g) obtained in Reference Example (8) are stirred at room temperature for 5 hours. Obtained a liquid crystal alignment agent (J1).

<Examples 6-0 to 7-3>
The test was carried out in the same manner as in Examples 1 to 1-3 except that the liquid crystal alignment agent shown in Table 2 was used instead of the liquid crystal alignment agent (A1) obtained in Reference Example 1. The evaluation results are shown in Table 2.

As is clear from Tables 1 and 2, in each of the examples, the tilt angle can be rewritten by performing the second irradiation, and the liquid crystal orientation after the rewriting is also good. On the other hand, in each of the comparative examples, the tilt angle could not be rewritten.

According to the production method of the present invention, a multi-domain liquid crystal alignment film can be efficiently produced. Further, the liquid crystal display element using the obtained multi-domain liquid crystal alignment film can be suitably used for an ECB liquid crystal display element or the like.

Claims (5)

A method for producing a multi-domain liquid crystal alignment film.
A process of applying a liquid crystal alignment agent on a substrate and forming a cured film by drying and firing.
The first irradiation step of irradiating the cured film with ultraviolet rays from an oblique direction, and
The cured film after the ultraviolet irradiation obtained by the first irradiation step includes a second irradiation step of irradiating the cured film with ultraviolet rays from a direction different from the irradiation direction in the first irradiation step in this order.
At least one of the first irradiation step and the second irradiation step is performed through a mask including a light-shielded area and a non-light-shielded area.
The liquid crystal alignment agent is (A) the following formula (pa-1).

(In the formula, A may be due to 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). It may be substituted with a cyano group or one or more halogen atoms), pyrimidin-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophenylene, 2,5. -Flanylene, 1,4- or 2,6-naphthylene or phenylene, R ₁ is a single bond, oxygen atom, -COO- or -OCO-, R ₂ is a divalent aromatic group, divalent An alicyclic group, a divalent heterocyclic group or a divalent fused ring group, R ₃ is a single bond, an oxygen atom, -COO- or -OCO-, and R ₄ has 1 to 40 carbon atoms. A monovalent organic group having 3 to 40 carbon atoms containing an alkyl group or an alicyclic group having a linear or branched chain, where D is an oxygen atom, a sulfur atom or −NR _d − (where R _d is. , A hydrogen atom or an alkyl having 1 to 3 carbon atoms), where a is an integer from 0 to 3, and * represents a bond position.)
The liquid crystal alignment agent contains a polymer having a photo-orientating group represented by and a heat-crosslinkable group A and a solvent, and the liquid crystal alignment agent is
Z1: The polymer (A) further has a heat-crosslinkable group B, and / or Z2: (B) further contains a compound having two or more heat-crosslinkable groups B in the molecule (heat-crosslinkability). The group A and the heat-crosslinkable group B are independently composed of a carboxyl group, an amino group, an alkoxymethylamide group, a hydroxymethylamide group, a hydroxyl group, an epoxy moiety-containing group, an oxetanyl group, a thiylanyl group, an isocyanate group and a blocked isocyanate group. The groups selected from the above groups are selected so that the heat-crosslinkable group A and the heat-crosslinkable group B undergo a cross-linking reaction by heat, except that the heat-crosslinkable group A and the heat-crosslinkable group B are mutually exclusive. It may be the same.)
A method characterized by that. The method according to claim 1, wherein at least one of the ultraviolet rays irradiated in the first irradiation step and the second irradiation step is polarized ultraviolet rays. The method according to claim 1, wherein only the second irradiation step is performed through the mask. A multi-domain liquid crystal alignment film formed by using the method according to any one of claims 1 to 3. A liquid crystal display element comprising the multi-domain liquid crystal alignment film according to claim 4.

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