WO2018155675A1

WO2018155675A1 - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element

Info

Publication number: WO2018155675A1
Application number: PCT/JP2018/006890
Authority: WO
Inventors: 祐太飯塚; 隆之根木; 耕平後藤
Original assignee: 日産化学株式会社
Priority date: 2017-02-27
Filing date: 2018-02-26
Publication date: 2018-08-30
Also published as: KR20190124743A; JPWO2018155675A1; JP7106059B2; KR102573453B1; TW201900855A; CN110546560B; TWI805572B; CN110546560A

Abstract

The present invention provides: a liquid crystal alignment film which exhibits good liquid crystal aligning properties even if the firing time thereof is shortened, while achieving excellent pretilt angle imparting ability and high reliability; and a liquid crystal aligning agent. The present invention provides: a liquid crystal aligning agent which contains a solvent and a component (A) that is a polymer having structures (A-1) and (A-2), and wherein the polymer additionally has a structure (A-3) that has at least one functional group selected from among an oxetanyl group, an oxiranyl group, a group represented by formula (3), a group represented by formula (4), a group represented by formula (5) and a thiirane group; and/or the liquid crystal aligning agent which additionally contains a component (B) other than the component (A), and wherein the component (B) is a compound that has two or more groups in each molecule, said groups being selected from the group consisting of an epoxy group, a thiirane group, a hydroxyalkylamide group, and a benzyl alcohol group. (A-1) A structure that has at least one functional group in each molecule, said functional group being selected from among a carboxyl group, an amino group and a hydroxyl group. (A-2) A structure that is represented by formula (pa-1) (wherein the symbols are as defined in the description).

Description

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

The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film obtained thereby, and a liquid crystal display element comprising the obtained liquid crystal alignment film. More specifically, even when the firing temperature is low and the firing time is short, the liquid crystal aligning agent can provide a liquid crystal aligning film that has good liquid crystal orientation, excellent pretilt angle development ability, and high reliability. And a liquid crystal display element having excellent display quality.

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

On the other hand, when the liquid crystal is aligned perpendicularly to the substrate (referred to as a vertical alignment (VA) method), a long chain alkyl, a cyclic group, or a combination of a cyclic group and an alkyl group (see, for example, Patent Document 1), a steroid skeleton ( For example, a liquid crystal alignment film in which a hydrophobic group is introduced into a side chain of polyimide such as Patent Document 2) is used. In this case, when a voltage is applied between the substrates to incline the liquid crystal molecules in a direction parallel to the substrate, the liquid crystal molecules need to be inclined from the substrate normal direction toward one direction in the substrate surface. . 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, or a liquid crystal molecule is slightly tilted from the normal direction of the substrate toward one direction in the substrate surface by rubbing ( Pretilt method, and also pre-tilt the liquid crystal by adding a photopolymerizable compound to the liquid crystal composition in advance and using it with a vertical alignment film such as polyimide and irradiating ultraviolet rays while applying voltage to the liquid crystal cell The method (for example, refer patent document 3) etc. to make are proposed.

Recently, as a substitute for the formation of protrusions and slits in the VA liquid crystal alignment control and the PSA technique, a method using an anisotropic photochemical reaction such as irradiation with polarized ultraviolet rays (photo-alignment method) has also been proposed. In other words, it is known that the tilt direction of liquid crystal molecules during voltage application can be uniformly controlled by irradiating polarized UV light to a photo-reactive vertical alignment polyimide film and imparting alignment regulating ability and pretilt angle expression. (See Patent Document 4). In this case as well, a polyimide-based liquid crystal alignment film that is excellent in durability and suitable for controlling the pretilt angle of the liquid crystal is used as in the case of conventional alignment films.

On the other hand, as a solvent for a liquid crystal alignment treatment agent using a polyimide polymer, a highly polar solvent such as N-methyl-2-pyrrolidone (also referred to as NMP) is used because the solvent solubility of these polyimide polymers is low. in use. These highly polar solvents have high boiling points. For example, NMP has a boiling point of 200 ° C. or higher. Therefore, in order to produce a liquid crystal alignment film using a liquid crystal alignment treatment agent using NMP as a solvent, in order to eliminate NMP remaining in the liquid crystal alignment film, at a high temperature of about 200 ° C. near the boiling point of NMP. Need to be fired.

On the other hand, when a plastic substrate that is thin and lightweight but has low heat resistance is used as the substrate of the liquid crystal display element, it is necessary to perform firing at the time of producing the liquid crystal alignment film at a lower temperature. Similarly, it is also required to reduce the energy cost in manufacturing the liquid crystal display element by lowering the baking temperature.

When firing at a low temperature, there is a problem that curing must be terminated in a state where the alignment film material is not sufficiently cured, and it has been difficult to obtain a highly reliable liquid crystal display element (for example, (See Patent Document 5).

Japanese Patent Laid-Open No. 3-179323 JP-A-4-281427 Japanese Patent No. 4504626 Japanese Patent No. 4996267 JP-A-7-209633

As a result of investigations by the inventors, it was found that when the liquid crystal alignment film was produced by lowering the baking temperature and shortening the baking time, the liquid crystal alignment property was significantly impaired in addition to the above.
It is an object of the present invention to provide a liquid crystal alignment film and a liquid crystal aligning agent that have good liquid crystal orientation, excellent pretilt angle development ability, and high reliability even when the baking time is shortened. .

The inventors have found an invention having the following <X> as a gist.
<X> Component (A): a polymer having the following structures (A-1) and (A-2); and a liquid crystal aligning agent containing a solvent,
The polymer is (A-3) an oxetanyl group, an oxiranyl group, a group represented by the following formula (3), a group represented by the following formula (4), a group represented by the following formula (5), and thiirane. A structure having at least one functional group selected from a group (hereinafter also referred to as “thermally crosslinkable group”); and / or the component (B) other than the component (A), wherein the liquid crystal aligning agent is The component (B) is a compound containing two or more groups selected from the group consisting of epoxy groups, thiirane groups, hydroxyalkylamide groups, and benzyl alcohol groups in the molecule. Liquid crystal aligning agent.

(A-1) A structure having at least one functional group selected from a carboxyl group, an amino group and a hydroxyl group in the molecule (hereinafter also referred to as “polar group”).
(A-2) A structure represented by the following formula (pa-1) (hereinafter also referred to as “photo-alignable group”).

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

According to the present invention, it is possible to provide a liquid crystal alignment film and a liquid crystal aligning agent that have good liquid crystal alignment, excellent pretilt angle development ability, and high reliability even when the baking time is shortened.
Moreover, the liquid crystal display element manufactured by the method of the present invention has excellent display characteristics.

The liquid crystal aligning agent of the present invention contains (A) component: a polymer having the following structures (A-1) and (A-2); and a solvent.
Moreover, the liquid crystal aligning agent of this invention has the following 1st aspects; and / or a 2nd aspect further.
That is, in the liquid crystal aligning agent of the first aspect of the present invention, the polymer is represented by (A-3) an oxetanyl group, an oxiranyl group, a group represented by the above formula (3), or a above formula (4). And a structure having at least one functional group selected from the group represented by the above formula (5) and a thiirane group (hereinafter also referred to as “thermally crosslinkable group”).
The liquid crystal aligning agent of the second aspect of the present invention further has a component (B) other than the component (A), and the component (B) has two or more epoxy groups, thiirane groups, It is a compound containing a group selected from the group consisting of a hydroxyalkylamide group and a benzyl alcohol group.
The component (B) is a compound containing two or more epoxy groups or thiirane groups in the molecule, or the component (B) is a compound having two or more hydroxyalkylamide groups and benzyl in the molecule. It is a compound containing a group selected from the group consisting of alcohol groups.
Here, “two or more in a molecule” means, for example, a combination of an epoxy group and a thiirane group, in addition to the case where two or more of the same kind of groups such as two or more epoxy groups are contained in the molecule. In addition, even if they are different from each other, it is intended to include the case where two or more groups selected from the group consisting of epoxy groups, thiirane groups, hydroxyalkylamide groups, and benzyl alcohol groups are contained in the molecule. “Two or more in a molecule” preferably contains two or more of the same kind of groups in the molecule.

The liquid crystal aligning agent of the first aspect of the present invention contains a polymer having the structure of (A-1) to (A-3) (hereinafter also referred to as “first specific polymer”) and a solvent. .
In addition, the liquid crystal aligning agent of the second aspect of the present invention is a polymer having the structures (A-1) and (A-2) (hereinafter also referred to as “second specific polymer”), (B ) Contains components and solvent.
Here, since either of the three structures of the first specific polymer or the two structures of the second specific polymer can be a side chain in the polymer, the “side chain” Can also be rephrased.
Hereinafter, each constituent element of the present invention, particularly the first and second aspects of the present invention, will be described in detail.

<(A) component: 1st specific polymer>
The first specific polymer of the present invention is represented by the following formula (I).

In the formula, S _a , S _b , and S _c each represent an independent spacer unit;
I _a1 has the same definition as in formula (a-1-m) described later,
I _b is a group represented by the formula (pa-1),
I _c is selected from the group consisting of an oxetanyl group, an oxiranyl group, a group represented by the formula (3), a group represented by the formula (4), a group represented by the formula (5), and a thiirane group. Represents a monovalent organic group having at least one functional group.
M _a , M _c , M _d , M _e , r ¹ , and r ² are definitions defined in formula (a-1-m), formula (b-1-m), and formula (c-1-m) described later. It is the same.

Further, x, y, and z are not particularly limited, but, for example, x, y, and z can independently take values of 0.01 or more and 0.89 or less.
The formulas (I) to (II) mean that each side chain is present in a ratio of x, y, and z, and in the polymer, a block copolymer in which each side chain is blocked. It does not mean coalescence.

<(A) component: 2nd specific polymer>
The second specific polymer used in the second aspect of the present invention is represented by the following formula (I ′).

In formula (I ′), S _a , S _b , I _a1 , I _b , M _a , M _c , M _d , r ¹ , and r ² have the same definition as above.
Further, in the formula (I ′), x and y are not particularly limited, but for example, x and y can independently take a value of 0.05 or more and 0.95 or less.
The formula (I ′) means that each side chain exists in a ratio of x and y, and in the polymer means a block copolymer in which each side chain is blocked. is not.

Since the 1st and 2nd specific polymer contained in the liquid crystal aligning agent of this invention has a high sensitivity with respect to light, it can express alignment control ability also in polarized-ultraviolet irradiation of a low exposure amount.
The first specific polymer can undergo a cross-linking reaction in the first specific polymer even when the firing time of the liquid crystal aligning agent is short due to the reaction of the thermally crosslinkable group with an amino group and a hydroxyl group or a carboxyl group. . Thereby, when the photo-alignment part of the first specific polymer exhibits anisotropy by photoreaction, the anisotropy easily remains (memory) in the liquid crystal alignment film. In addition, the pretilt angle of the liquid crystal can be expressed.
The amino group, carboxyl group and hydroxyl group of the first and second specific polymers react with a group selected from the group consisting of the epoxy group, thiirane group, hydroxyalkylamide group and benzyl alcohol group of the component (B). By doing so, even when the firing time of the liquid crystal aligning agent is short, the crosslinking reaction in the first and second specific polymers becomes possible. As a result, when the photo-alignment sites of the first and second specific polymers exhibit anisotropy due to a photoreaction, anisotropy tends to remain (memory) in the liquid crystal alignment film. And the pretilt angle of the liquid crystal can be expressed.

<(A-1) Structure having polar group in molecule>
The first and second specific polymers contained in the liquid crystal aligning agent of the present invention are at least one selected from polar groups, that is, carboxyl groups, amino groups and hydroxyl groups in the molecule, preferably in the side chain. It has a structure having a functional group of
Since this structure enables a crosslinking reaction in the specific polymer even when the baking time of the liquid crystal aligning agent obtained from the first and second specific polymers of the present invention is shortened, the liquid crystal alignment obtained The liquid crystal orientation of the film can be improved and the pretilt angle of the liquid crystal can be expressed.

In the present invention, the structure having a polar group in the molecule can be represented, for example, by the following formula (a-1). Examples of the structure include a structure derived from a monomer represented by the following formula (a-1-m), but are not limited thereto.

In the formula, I _a1 is a monovalent organic group selected from a carboxyl group, a hydroxyl group, a group having at least one partial structure of the following formula (a2), or a primary amino group. However, the following formula (a2) represents a group other than the primary amino group, and r ¹ is 1 or 2. In the formula, * indicates a bond.

S _a represents a single bond or a divalent linking group.
In I _a1 , examples of the group having a partial structure of the above formula (a2) include a 5-membered or 6-membered nitrogen-containing heterocycle, and examples thereof include piperidine and morpholine. Each of these groups may be unsubstituted or one or more hydrogen atoms may be replaced by fluorine, chlorine, cyano, methyl or methoxy groups. Preferable examples of I _a1 include a monovalent organic group selected from a carboxyl group and a hydroxyl group.

M _a represents a first polymerizable group. Examples of the first polymerizable group include radical polymerizable groups of the following formulas (M _a -1) to (M _a -2), α-methylene-γ-butyrolactone, maleimide, norbornene and derivatives thereof, and siloxane. it can. Preferred are formulas (M _a -1) to (M _a -2), and α-methylene-γ-butyrolactone maleimide.
In the formula, R ₁ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and * represents a bond.

Examples of the divalent linking group in S _a of the formula (a-1-m) include, for example, an alkanediyl group having 1 to 10 carbon atoms (preferably 1 to 6), 6 to 20 carbon atoms (preferably 6 to 6 carbon atoms). 14) an arylene group, a (* A) —CONH—R ₆ — (* B) group, a (* A) —COO—R ₇ — (* B) group, and the like. Here, R ₆ and R ₇ are each independently a single bond, an alkanediyl group having 1 to 12 (preferably 1 to 6) carbon atoms, or an arylene having 6 to 20 (preferably 6 to 14) carbon atoms. Group, an alkyleneoxyarylene group, and any carbon-carbon bond of the alkanediyl group may have an —O— bond, and (* A) is a bond bonded to a carbon atom having an unsaturated bond It indicates that indicates that (* B) is a bond that binds to the I _a1. Examples of the alkanediyl group include methylene group, ethylene group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-1,3-diyl group, Propane-2,2-diyl group, butane-1,2-diyl group, butane-1,3-diyl group, butane-1,4-diyl group, pentane-1,4-diyl group, pentane-1,5 -Diyl group, hexane-1,5-diyl group, hexane-1,6-diyl group and the like can be mentioned. Examples of the arylene group include a phenylene group, a naphthylene group, a biphenylene group, and an anthrylene group. Examples of the alkyleneoxyarylene group include an ethyleneoxyphenylene group, a hexyleneoxyphenylene group, a hexyleneoxybiphenyl group, and the like. Among them, the divalent linking group for _{S a,} alkanediyl group having 1 to 10 carbon atoms (preferably 1-6), an arylene group having 6 to 20 carbon atoms (preferably 6 ~ 14), (* A) A —COO—R ₇ — (* B) group is preferred, and R ₇ is preferably an alkanediyl group having 2 to 6 carbon atoms.

Specific examples of the above formula (a-1-m) having a carboxyl group include, for example, (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, crotonic acid, isocrotonic acid, α-ethylacrylic And acid, β-ethylacrylic acid, β-propylacrylic acid, β-isopropylacrylic acid, itaconic acid, fumaric acid, vinylbenzoic acid and the like. Specific examples of the above formula (a-1-m) having an amino group include t-butylaminoethyl (meth) acrylate. Specific examples of the above formula (a-1-m) having a hydroxyl group include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl. Hydroxyalkyl (meth) acrylates such as (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate; Examples thereof include ethyl (meth) acrylamide, (4-hydroxymethylcyclohexyl) methyl acrylate, N-methylol (meth) acrylamide, N-hydroxy (meth) acrylamide and the like.
Specific examples of the formula (a-1-m) having a group having a partial structure of the formula (a2) include 2,2,6,6-tetramethyl-4-piperidyl methacrylate and the like. .

The site | part which has a polar group in the molecule | numerator contained in the polymer of this invention may be used individually by 1 type, and may be used combining 2 or more types of site | parts.
The portion having a polar group in the molecule is contained in a proportion of 5 to 94 mol%, 20 to 94 mol%, or 20 to 88 mol%, or 25 to 80 mol% of the first specific polymer (component (A)). It is preferred that Alternatively, the site having a polar group in the molecule is 5 to 95 mol%, or 20 to 90 mol%, or 30 to 85 mol%, 20 to 80 mol%, or 50 to 50 mol% of the second specific polymer (component (A)). It is preferable to contain in the ratio of 85 mol%.

<(A-2) Structure having photo-alignment>
The first and second specific polymers contained in the liquid crystal aligning agent of the present invention have a structure having a photo-alignment property represented by the above formula (pa-1) in the molecule, preferably in the side chain. Have.
By making the structure of the portion having photo-alignment property the above structure, the vertical alignment control ability can be stably maintained for a long time even when exposed to external stress such as heat. Moreover, since it has high sensitivity to light, it is preferable from the viewpoint of simplifying the manufacturing process of the liquid crystal alignment film because it can exhibit alignment control ability even when irradiated with polarized UV light at a low exposure amount.

In the present invention, the site having photo-alignment property represented by the above formula (pa-1) in the molecule can be represented, for example, by the following formula (b-1). Examples of the site include a structure derived from a monomer represented by the following formula (b-1-m), but are not limited thereto. In the formula, I _b is a monovalent organic group represented by the following formula (pa-1).

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

In the above formula (b-1) or (b-1-m), S _b represents a spacer unit, and the left connector of S _b is optional in the main chain of the first and second specific polymers. It shows that it couple | bonds via a spacer.
S _b 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 _d ,
The right bond of W ₃ represents the bond to I _b
W ₁ , W ₂ and W ₃ each independently represent a single bond, a divalent heterocyclic ring, — (CH ₂ ) _n — (wherein n represents 1 to 20), —OCH ₂ —, — CH ₂ O—, —COO—, —OCO—, —CH═CH—, —CF═CF—, —CF ₂ O—, —OCF ₂ —, —CF ₂ CF ₂ — or —C≡C— is represented. However, one or more of the non-adjacent CH ₂ groups in these substituents are independently —O—, —CO—, —CO—O—, —O—CO—, —Si (CH ₃ ) ₂ —. O—Si (CH ₃ ) ₂ —, —NR—, —NR—CO—, —CO—NR—, —NR—CO—O—, —OCO—NR—, —NR—CO—NR—, —CH ═CH—, —C≡C— or —O—CO—O— (wherein R independently represents hydrogen or a linear or branched alkyl group having 1 to 5 carbon atoms) Rukoto can,
A ₁ and A ₂ are each independently a group selected from a single bond, a divalent alkyl group, a divalent aromatic group, a divalent alicyclic group, or a divalent heterocyclic group. Each group may be unsubstituted or one or more hydrogen atoms may be substituted with a fluorine atom, a chlorine atom, a cyano group, a methyl group or a methoxy group.

In formula (b-1-m), M _c represents a second polymerizable group. Examples of the second polymerizable group include (meth) acrylate, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, norbornene, radical polymerizable groups of (meth) acrylamide and derivatives thereof, and siloxane. Can be mentioned. (Meth) acrylate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide and acrylamide are preferred.

r ² is an integer satisfying 1 ≦ r ² ≦ 3.

In formula (b-1-m), M _d represents a single bond, a (r ² +1) -valent heterocyclic ring, a linear or branched alkyl group having 1 to 10 carbon atoms, and a (r ² +1) -valent aromatic. Group, a group selected from (r ² +1) -valent alicyclic group, each group is unsubstituted or one or more hydrogen atoms are fluorine atom, chlorine atom, cyano group, methyl group or methoxy group It may be substituted by a group.

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

From the viewpoint of exhibiting good vertical alignment controllability and a stable pretilt angle, the structure of (b-1) is represented by the group represented by (pa-1) above or the following (pa-1-a): The groups represented can be mentioned. Examples of the site include a structure derived from a monomer represented by the following formula (pa-1-ma), but are not limited thereto.

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

In the formula (pa-1-a) or (pa-1-ma), the linear or branched alkylene group having 1 to 10 carbon atoms of S _{b is used} as the linear or branched alkylene group having 1 to 8 carbon atoms. 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 S _b, for example 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 2,3,5,6 A fluoro-1,4-phenylene group can be exemplified.

Formula (pa-1-a) or (pa-1-ma), examples divalent alicyclic group _{S b,} for example trans-1,4-cyclohexylene, trans - trans-1,4-Bishikuroheki Examples include silene.
Examples of the divalent heterocyclic group for S _b include 1,4-pyridylene group, 2,5-pyridylene group, 1,4-furylene group, 1,4-piperazine group, 1,4-piperidine group, and the like. be able to.
S _b is preferably an alkylene group having 1 to 8 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms, and still more preferably an alkylene group having 1 to 4 carbon atoms.

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

Examples of the linear or branched alkyl group having 1 to 40 carbon atoms of R ₄ include a linear or branched alkyl group having 1 to 20 carbon atoms, and a part of hydrogen atoms of the alkyl group. Or all may be substituted by the fluorine atom. Examples of such alkyl groups include, for example, methyl, ethyl, n-propyl, n-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, 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- (Perfluorobutyl) Methyl group, 2- (perfluorooctyl) ethyl group and a 2- (perfluorodecyl) ethyl group or 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) (wherein R ₇ is a hydrogen atom, a fluorine atom or an alkyl group which may be substituted with a fluorine atom having 1 to 20 carbon atoms, and * represents a bonding position. .

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

One type of photoreactive site contained in the polymer of the present invention may be used alone, or two or more types may be used in combination.
The photoreactive site is contained in a proportion of 5 to 94 mol%, 10 to 80 mol%, or 15 to 70 mol%, 10 to 50 mol%, or 15 to 50 mol% of the first specific polymer (component (A)). It is preferred that
Alternatively, the photoreactive site is 5 to 95 mol%, 10 to 80 mol%, or 15 to 70 mol%, or 15 to 60 mol%, or 15 to 50 mol% of the second specific polymer (component (A)). It is preferable to contain by a ratio.

<(A-3) Thermally crosslinkable group-containing site>
The first specific polymer contained in the liquid crystal aligning agent of the present invention has a site having a thermally crosslinkable group, that is, an oxetanyl group (1,2-epoxy structure), an oxiranyl group (1,3- An epoxy structure), a group represented by the following formula (3), a group represented by the following formula (4), a group represented by the following formula (5) and a thiirane group. It has a part to have. In other words, the first specific polymer is represented by an oxetanyl group, an oxiranyl group, a group represented by the following formula (3), a group represented by the following formula (4), and the following formula (5) in the molecule. And at least one functional group selected from a thiirane group in the side chain. In formulas (3) to (5), * represents a bond.

The site having the thermally crosslinkable group (A-3) can form a crosslinking reaction with the amino group, the hydroxyl group, or the carboxyl group, which are the polar groups, and the above ( The liquid crystal alignment ability of the portion having the photo-alignment property A-2) is stabilized, and a liquid crystal alignment film having excellent pretilt angle expression ability can be obtained.

In the present invention, the site having a thermally crosslinkable group can be represented by, for example, the following formula (c-1). Examples of the site include a structure derived from a monomer represented by the following formula (c-1-m).

In formula (c-1) or (c-1-m), I _c represents an oxetanyl group, an oxiranyl group, a group represented by the above formula (3), or a group represented by the above formula (4) in the molecule. And a monovalent organic group selected from the group represented by the above formula (5) and a thiirane group. _Sc represents a single bond or a divalent linking group.
In the formula (c-1-m), M e represents the third polymerizable groups. Examples of the third polymerizable group include radical polymerizable groups of the following formulas (M _c -1) to (M _c -2), α-methylene-γ-butyrolactone, maleimide, norbornene and derivatives thereof, and siloxane. it can.

In the formulas (M _c -1) to (M _c -2), Rc represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and * represents a bonding position.
_Me is preferably a formula (M _c -1) to (M _c -2), α-methylene-γ-butyrolactone maleimide.

The divalent linking group of _{S c} of the formula (c-1-m), for example, alkanediyl group having 1 to 10 carbon atoms (preferably 1 to 6), 6 to 20 carbon atoms (preferably 6 to 14) an arylene group, a (* A) —CONH—R ₆ — (* B) group, a (* A) —COO—R ₇ — (* B) group, and the like. Here, R ₆ and R ₇ are each independently a single bond, an alkanediyl group having 1 to 12 (preferably 1 to 6) carbon atoms, or an arylene having 6 to 20 (preferably 6 to 14) carbon atoms. Group, an alkyleneoxyarylene group, and any carbon-carbon bond of the alkanediyl group may have an —O— bond or an —S— bond, and (* A) is bonded to a carbon atom having an unsaturated bond. (* B) indicates that it is a bond that bonds to _Ia1 . Examples of the alkanediyl group include methylene group, ethylene group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-1,3-diyl group, Propane-2,2-diyl group, butane-1,2-diyl group, butane-1,3-diyl group, butane-1,4-diyl group, pentane-1,4-diyl group, pentane-1,5 -Diyl group, hexane-1,5-diyl group, hexane-1,6-diyl group and the like can be mentioned. Examples of the arylene group include a phenylene group, a naphthylene group, a biphenylene group, and an anthrylene group. Examples of the alkyleneoxyarylene group include an ethyleneoxyphenylene group, a hexyleneoxyphenylene group, a hexyleneoxybiphenyl group, and the like. Among them, the divalent linking group for _{S a,} alkanediyl group having 1 to 10 carbon atoms (preferably 1-6), an arylene group having 6 to 20 carbon atoms (preferably 6 ~ 14), (* A) A —COO—R ₇ — (* B) group is preferred, and R ₇ is preferably an alkanediyl group having 2 to 6 carbon atoms. In each group, 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.

Specific examples of the formula (c-1-m) having an oxiranyl group include, for example, allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, 2-methylglycidyl methacrylate, glycidyl α-ethyl acrylate, α-n-propyl. Glycidyl acrylate, α-n-butyl glycidyl acrylate, 3,4-epoxybutyl acrylate, 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl acrylate, 6,7-epoxyheptyl methacrylate, α -Ethylacrylic acid-6,7-epoxyheptyl, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, 3,4-epoxycyclohexylmethyl methacrylate, 3-ethenyl-7- Oxabicyclo [4 1.0] heptane, 1,2-epoxy-5-hexene, 1,7-cyclooctadiene monoepoxide, and the like. Among these, glycidyl methacrylate, 2-methylglycidyl methacrylate, -6,7-epoxyheptyl methacrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, 3, methacrylate 4-Epoxycyclohexyl is preferred from the viewpoint of improving the copolymerization reactivity and the orientation of the liquid crystal alignment film.

Specific examples of the formula (c-1-m) having an oxetanyl group include, for example, 3- (acryloyloxymethyl) oxetane, 3- (acryloyloxymethyl) -2-methyloxetane, and 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) oxe 3- (2-acryloyloxyethyl) -2-ethyloxetane, 3- (2-acryloyloxyethyl) -3-ethyloxetane, 3- (2-acryloyloxyethyl) -2-trifluoromethyloxetane, 3 -(2-acryloyloxyethyl) -2-pentafluoroethyloxetane, 3- (2-acryloyloxyethyl) -2-phenyloxetane, 3- (2-acryloyloxyethyl) -2,2-difluorooxetane, 3- Acrylic acid esters such as (2-acryloyloxyethyl) -2,2,4-trifluorooxetane and 3- (2-acryloyloxyethyl) -2,2,4,4-tetrafluorooxetane; 3- (methacryloyloxy Methyl) oxetane, 3- (methacryloyloxymethyl) -2-me Luoxetane, 3- (methacryloyloxymethyl) -3-ethyloxetane, 3- (methacryloyloxymethyl) -2-trifluoromethyloxetane, 3- (methacryloyloxymethyl) -2-pentafluoroethyloxetane, 3- (methacryloyloxy Methyl) -2-phenyloxetane, 3- (methacryloyloxymethyl) -2,2-difluorooxetane, 3- (methacryloyloxymethyl) -2,2,4-trifluorooxetane, 3- (methacryloyloxymethyl) -2 , 2,4,4-tetrafluorooxetane, 3- (2-methacryloyloxyethyl) oxetane, 3- (2-methacryloyloxyethyl) -2-ethyloxetane, 3- (2-methacryloyloxyethyl) -3-ethyl Oxetane, 3 -(2-methacryloyloxyethyl) -2-trifluoromethyloxetane, 3- (2-methacryloyloxyethyl) -2-pentafluoroethyloxetane, 3- (2-methacryloyloxyethyl) -2-phenyloxetane, 3- (2-methacryloyloxyethyl) -2,2-difluorooxetane, 3- (2-methacryloyloxyethyl) -2,2,4-trifluorooxetane, 3- (2-methacryloyloxyethyl) -2,2,4 And methacrylates such as 4-tetrafluorooxetane.
Specific examples of the formula (c-1-m) having a thiirane group include compounds represented by the following formula (S),

In the formula, X represents O (CH ₂ ) _n , S (CH ₂ ) _n , or (CH ₂ ) _n , and n represents an integer of 0 to 6. Y represents an acryloyl group, a methacryloyl group, an allyl group, or a vinyl group. ), Or 2,3-epithiopropyl acrylate or methacrylate, and 2- or 3- or 4- (β-epithiopropylthiomethyl) styrene, 2- or 3- or 4- (β-epithiopropyloxymethyl) And styrene, 2- or 3- or 4- (β-epithiopropylthio) styrene, 2- or 3- or 4- (β-epithiopropyloxy) styrene, and the like.

The site | part which has a heat crosslinkable group contained in the polymer of this invention may be used individually by 1 type, and may be used in combination of 2 or more types.
The introduction amount of the site having a thermally crosslinkable group is 1 to 40 mol%, or 1 to 30 mol%, or 5 to 30 mol%, or 2 to 30 mol%, or 5 of the first specific polymer (component (A)). It is preferably ˜25 mol%.

<(B) Compound containing two or more groups selected from the group consisting of an epoxy group, a thiirane group, a hydroxyalkylamide group, and a benzyl alcohol group in the molecule>
The component (B) used in the liquid crystal aligning agent of the second aspect of the present invention is a group selected from the group consisting of two or more epoxy groups, thiirane groups, hydroxyalkylamide groups, and benzyl alcohol groups in the molecule. It is a compound which has this. With such a configuration, an epoxy group or a thiirane group can be unevenly distributed in the upper layer portion of the liquid crystal alignment film, and the polar group (A-1) contained in the first and second specific polymers can be obtained. The cross-linking reaction with the amino group or carboxyl group is promoted, and the cross-linking density of the film surface layer component is increased. Therefore, since the anisotropy due to the photoreaction (A-2) is likely to remain (memory) in the film, the liquid crystal alignment ability can be stabilized, and the liquid crystal excellent in liquid crystal alignment and pretilt angle expression ability. An alignment film can be obtained.

The compound having two or more epoxy groups or thiirane groups in the molecule is not particularly limited as long as it has two or more epoxy groups or thiirane groups at the molecular ends. Examples of the compound having two or more epoxy groups at the molecular terminal include an epoxy compound having at least one tertiary nitrogen atom in the molecule and an epoxy compound having no nitrogen compound in the molecule. .
Specific examples of the epoxy compound having at least one tertiary nitrogen atom in the molecule include epoxy compounds having a structure represented by the following formulas (Ep-1) to (Ep-11) and aliphatic diamines. Examples thereof include an epoxy compound containing a nitrogen atom as a nucleus. Among these, from the viewpoint of reactivity and availability, epoxy compounds having a structure represented by (Ep-4) to (Ep-9), epoxy compounds containing nitrogen atoms having an aliphatic diamine as a parent nucleus, and the like are preferable.

X represents a single bond, an aliphatic group having 1 to 6 carbon atoms, or an aromatic group, and Y represents a methylene group, an ethylene group, a trimethylene group, an ethylidene group, an isopropylidene group, a vinylene group, a vinylidene group, or an oxy group. , An imino group, a thio group, or a sulfonyl group, R ₁ to R ₃ represent a hydrogen atom or an aliphatic group having 1 to 6 carbon atoms, and j represents an integer of 0 to 4.
Among epoxy compounds having at least one tertiary nitrogen atom in the molecule, a compound in which the tertiary nitrogen atom is bonded to at least one of an aliphatic group or an alicyclic group can shorten the firing time. It is suitable.

Specific examples of the epoxy compound having at least one tertiary nitrogen atom in the molecule include N, N-diglycidylaniline, N, N-diglycidyltoluidine, N, N-diglycidylcyclohexylamine, N, N -Diglycidylmethylcyclohexylamine, N, N, N ', N'-tetraglycidyl-p-phenylenediamine, N, N, N', N'-tetraglycidyl-m-phenylenediamine, N, N, N ', N′-tetraglycidyl-o-phenylenediamine, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane, N, N, N ′, N′-tetraglycidyl-3,4′- Diaminodiphenylmethane, N, N, N ′, N′-tetraglycidyl-3,3′-diaminodiphenylmethane, N, N, N ′, N′-tetrag Sidyl-4,4′-diaminodiphenyl sulfide, N, N, N ′, N′-tetraglycidyl-1,5-diaminonaphthalene, N, N, N ′, N′-tetraglycidyl-2,7-diaminofluorene N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenyl ether, N, N, N ′, N′-tetraglycidyl-2,2-bis [4- (4-aminophenoxy) phenyl ] Propane, N, N, N ′, N′-tetraglycidyl-9,9-bis (4-aminophenyl) fluorene, N, N, N ′, N′-tetraglycidyl-2,2-bis [4- (4-Aminophenoxy) phenyl] hexafluoropropane, N, N, N ′, N′-tetraglycidyl-2,2-bis (4-aminophenyl) hexafluoropropane, N, N, N ′, N′— Tet Glycidyl-4,4 ′-(p-phenylenediisopropylidene) bisaniline, N, N, N ′, N′-tetraglycidyl-4,4 ′-(m-phenylenediisopropylidene) bisaniline, N, N, N ', N'-tetraglycidyl-1,4-bis (4-aminophenoxy) benzene, N, N, N', N'-tetraglycidyl-4,4'-bis (4-aminophenoxy) biphenyl, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine, N, N, N ′, N′-tetraglycidyl-p-xylylenediamine, 1,3-bis (N, N′-diglycidylamino) Methyl) cyclohexane, 1,4-bis (N, N′-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-1,4-cyclohexanediamine, N, N, N ′, N′-tetraglycidyl-1,3-cyclohexanediamine, N, N, N ′, N′-tetraglycidyl-4,4′-methylenebis (cyclohexylamine), N, N, N ′, N '-Tetraglycidyl-diaminoethane, N, N, N', N'-tetraglycidyl-diaminopropane, N, N, N ', N'-tetraglycidyl-diaminobutane, N, N, N', N'- Tetraglycidyl-diaminopentane, N, N, N ′, N′-tetraglycidyl-diaminohexane, N, N, N ′, N′-tetraglycidyl-diaminoheptane, N, N, N ′, N′-tetraglycidyl -Diaminooctane and the like.

Specific examples of epoxy compounds having no nitrogen compound in the molecule include trade names “Epicoat 828”, “Epicoat 834”, “Epicoat 1001”, “Epicoat 1004” manufactured by Mitsubishi Chemical Corporation, Dainippon Ink and Chemicals, Inc. Bisphenol A type epoxy compounds such as “Epicron 840”, “Epicron 850”, “Epicron 1050”, “Epicron 2055” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.
Product name “Epicron 830S” manufactured by Dainippon Ink & Chemicals, Inc. Product name “Epicoat 807” manufactured by Mitsubishi Chemical Corporation, product names “Epototo YDF-170”, “Epototo YDF-175”, “Epototo” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. Bisphenol F type epoxy compounds such as “YDF-2004”;
Bisphenol S type epoxy compounds such as Nippon Kayaku brand name “EBPS-200”, Asahi Denka Kogyo Co., Ltd. trade name “EPX-30”, Dainippon Ink Chemical Co., Ltd. trade name “Epicron EXA1514”;
Bisphenol fluorene type epoxy compounds such as “BPFG” manufactured by Osaka Gas Co., Ltd., “YL-6056”, “YL-6021”, “YX-4000”, “YX-4000H” manufactured by Mitsubishi Chemical Corporation, etc. Bixylenol type or biphenyl type epoxy compounds, or mixtures thereof;
Hydrogenated bisphenol A type epoxy compounds such as “Epototo ST-2004”, “ST-2007”, “ST-3000” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd .;
Product names “Epicoat 152” and “Epicoat 154” manufactured by Mitsubishi Chemical Corporation, product names “DEN 431” and “DEN 438” manufactured by Dow Chemical Company, Dainippon Ink and Chemicals, Inc. “Epicron N-690”, “Epicron N-695”, “Epicron N-730”, “Epicron N-770”, “Epicron N-865”, trade names “Epototo YDCN” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. -701 ”,“ Epototo YDCN-704 ”, trade names“ EPPN-201 ”,“ EOCN-1025 ”,“ EOCN-1020 ”manufactured by Nippon Kayaku Co., Ltd.,
Novolak epoxy compounds such as “EOCN-104S”, “RE-306”;
Product name “Epicoat YL-903” manufactured by Mitsubishi Chemical Corporation, product names “Epicron 152” and “Epicron 165” manufactured by Dainippon Ink and Chemicals, Inc. Product names “Epototo YDB-400” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. Brominated bisphenol A type epoxy compounds such as “Epototo YDB-500”;
Naphthalene skeletons such as trade names “ESN-190” and “ESN-360” manufactured by Nippon Steel Chemical Co., Ltd., trade names “HP-4032”, “EXA-4700”, “EXA-4750” manufactured by Dainippon Ink & Chemicals, Inc. An epoxy compound having:
Epoxy compounds having a dicyclopentadiene skeleton such as trade names “HP-7200” and “HP-7200H” manufactured by Dainippon Ink & Chemicals, Inc .;
Trishydroxyphenylmethane type epoxy compounds such as trade names “YL-933” manufactured by Mitsubishi Chemical Corporation and trade names “EPPN-501” and “EPPN-502” manufactured by Nippon Kayaku Co., Ltd .;
Alicyclic epoxy compounds such as “Celoxide 2011” manufactured by Daicel Chemical Industries, “Araldite CY175”, “Araldite CY179” manufactured by Asahi Kasei Kogyo, and “HBE-100” manufactured by Shin Nippon Chemical Co., Ltd. However, it is not limited to these. These epoxy compounds can be used alone or in combination of two or more.

The compound having two or more thiirane groups at the molecular end can be obtained, for example, by converting the epoxy group of the epoxy compound having the epoxy group into a thiirane group. As a method of converting to the thiirane group, a solution containing an epoxy compound having an epoxy group is continuously or intermittently added to a first solution containing a sulfurizing agent, and then a second solution containing a sulfurizing agent is added. The method of further adding continuously or intermittently is preferable. By this method, the epoxy group can be converted into a thiirane group.
Examples of the sulfurizing agent include thiocyanates, thioureas, phosphine sulfide, dimethylthioformamide, N-methylbenzothiazole-2-thione, and the like. Examples of the thiocyanates include sodium thiocyanate, potassium thiocyanate, and sodium thiocyanate.
By using the compound having two or more thiirane groups, the crosslinking reaction is further promoted, which is preferable in that the firing time of the liquid crystal aligning agent can be shortened.

The compound having two or more hydroxyalkylamide groups at the molecular end is not particularly limited as long as the compound has a hydroxyalkylamide group, but from the viewpoint of availability, the following formula The compound represented by (2) is one of preferred examples.

In the formula, X ₂ is an aliphatic hydrocarbon group having 1 to 20 carbon atoms or an n-valent organic group containing an aromatic hydrocarbon group, n is an integer of 2 to 6, and R ₂ and R ₃ are Each independently a hydrogen atom or an optionally substituted alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or an alkynyl group having 2 to 4 carbon atoms, and R ₂ and At least one of R ₃ represents a hydrocarbon group substituted with a hydroxy group.
Among them, atoms directly attached to the carbonyl group in X ₂ in Formula (2), it is preferable from the viewpoint of the liquid crystal orientation is a carbon atom, which do not form an aromatic ring. X ₂ in the formula (2) is preferably an aliphatic hydrocarbon group from the viewpoint of liquid crystal alignment and solubility as described above, and more preferably 1 to 10 carbon atoms.
In the formula (2), n represents an integer of 2 to 6, and n is preferably 2 to 4 from the viewpoint of solubility.
In formula (2), R ₂ and R ₃ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or the number of carbon atoms 2 to 4 alkynyl groups, at least one of R ₂ and R ₃ represents a hydrocarbon group substituted by a hydroxy group. Among them, at least one of R ₂ and R ₃ is preferably a structure represented by the following formula (3a) from the viewpoint of reactivity, and more preferably a structure represented by the following formula (4a). .

In formula (3a), R ₄ to R ₇ each independently represents a hydrogen atom, a hydrocarbon group, or a hydrocarbon group substituted with a hydroxy group.

Specific examples of the compound having two or more hydroxyalkylamide groups at the molecular ends include the following compounds.

If the amount of the compound having a hydroxyalkylamide group is too large, unreacted components are eluted in the liquid crystal, which may reduce reliability. Therefore, the addition amount of the compound having a hydroxyalkylamide group is preferably 0.1 to 40% by mass, and more preferably 1 to 30% by mass with respect to the polymer of component (A).

Examples of the compound having two or more benzyl alcohol groups at the molecular ends include those having a benzyl alcohol group in which a hydroxyl group is bonded to an aromatic ring with a methyl group in between. Among these, at least one compound selected from the group consisting of a compound represented by the following formula [1] and a compound represented by the formula [2] is preferable.

In the formula, Y ₁ , Y ₂ and Y ₃ each independently represent an aromatic ring. Any hydrogen atom of the aromatic ring may be substituted with a hydroxyl group, an alkyl group having 1 to 3 carbon atoms, a halogen atom, an alkoxy group having 1 to 3 carbon atoms, or a vinyl group. Z ₁ is a divalent saturated hydrocarbon group having 1 to 10 carbon atoms which may be bonded to form a cyclic structure by a single bond or all or a part thereof, and any hydrogen atom is substituted with a fluorine atom. Or —NH—, —N (CH ₃ ) —, or a group represented by the formula [3]. t ₁ is an integer of 2 to 4, t ₂ and t ₃ are each independently an integer of 1 to 3, and a and b are each independently an integer of 1 to 3.

In formula [3], P ₁ and P ₂ are each independently an alkyl group having 1 to 5 carbon atoms, and Q ₁ represents an aromatic ring.

Specific examples thereof include benzene ring, naphthalene ring, tetrahydronaphthalene ring, azulene ring, indene ring, fluorene ring, anthracene ring, phenanthrene ring, phenalene ring, pyrrole ring, imidazole ring, oxazole ring, thiazole ring, pyrazole ring, pyridine Ring, pyrimidine ring, quinoline ring, pyrazoline ring, isoquinoline ring, carbazole ring, purine ring, thiadiazole ring, pyridazine ring, triazine ring, pyrazolidine ring, triazole ring, pyrazine ring, benzimidazole ring, benzimidazole ring, thionoline ring, phenanthroline Ring, indole ring, quinoxaline ring, benzothiazole ring, phenothiazine ring, acridine ring, oxazole ring and the like. Specific examples of more preferable aromatic rings include benzene ring, naphthalene ring, fluorene ring, anthracene ring, pyrrole ring, imidazole ring, pyrazole ring, pyridine ring, pyrimidine ring, quinoline ring, isoquinoline ring, carbazole ring, pyridazine ring, pyrazine. Ring, benzimidazole ring, benzimidazole ring, indole ring, quinoxaline ring, acridine ring and the like. More preferred are a benzene ring, a naphthalene ring, a pyridine ring and a carbazole ring, and most preferred are a benzene ring and a pyridine ring.

The hydrogen atoms of these aromatic rings may be substituted with a hydroxyl group, an alkyl group having 1 to 3 carbon atoms, a halogen atom, an alkoxy group having 1 to 3 carbon atoms, or a vinyl group.
T ₂ and t ₃ in the formula [2] are more preferably integers of 1 or 2. Moreover, a and b are more preferably 1 or 2.
Z ₁ in the formula [2] is a divalent saturated hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, which may be bonded to all or part of it to form a cyclic structure. Any hydrogen atom that it has may be substituted with a fluorine atom.

Examples of Z ₁ include an alkylene group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, a combination of an alkylene group and an alicyclic hydrocarbon group, and 1 carbon atom. ˜10 groups. In addition, a group in which any hydrogen atom of the above-described group is substituted with a fluorine atom is exemplified.

Q ₁ in the formula [3] is an aromatic ring, and specific examples thereof include benzene ring, naphthalene ring, tetrahydronaphthalene ring, azulene ring, indene ring, fluorene ring, anthracene ring, phenanthrene ring, phenalene ring, pyrrole. Ring, imidazole ring, oxazole ring, thiazole ring, pyrazole ring, pyridine ring, pyrimidine ring, quinoline ring, pyrazoline ring, isoquinoline ring, carbazole ring, purine ring, thiadiazole ring, pyridazine ring, triazine ring, pyrazolidine ring, triazole ring, Examples include a pyrazine ring, a benzimidazole ring, a benzimidazole ring, a thionoline ring, a phenanthroline ring, an indole ring, a quinoxaline ring, a benzothiazole ring, a phenothiazine ring, an acridine ring, and an oxazole ring. Specific examples of more preferable aromatic rings include benzene ring, naphthalene ring, fluorene ring, anthracene ring, pyrrole ring, imidazole ring, pyrazole ring, pyridine ring, pyrimidine ring, quinoline ring, isoquinoline ring, carbazole ring, pyridazine ring, pyrazine. Ring, benzimidazole ring, benzimidazole ring, indole ring, quinoxaline ring, acridine ring and the like. More preferably, a benzene ring, a naphthalene ring, a pyridine ring, a carbazole ring, a fluorene ring, etc. are mentioned.

Examples of the compound having two or more benzyl alcohol groups at the molecular end include compounds [P1] to [P45], but are not limited thereto.
The compound having two or more benzyl alcohol groups at the molecular end is preferably a compound represented by [P13], [P15], [P18], [P20], [P26], among them, [P13], The compounds represented by [P18] and [P20] are more preferable.

The amount of component (B) used is preferably 0.1 to 40 parts by weight, more preferably 100 parts by weight of the first and / or second specific polymer contained in the liquid crystal aligning agent. Is 0.5 to 20 parts by mass.
Moreover, (B) component may be used individually by 1 type of compound, and may be used in combination of 2 or more type of compound.

<Solvent>
The solvent used for the liquid crystal aligning agent of this invention will not be specifically limited if it is a solvent which dissolves the 1st and 2nd specific polymer.
Specific examples include water, N-alkyl-2-pyrrolidones such as N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylcaprolactam. Tetramethylurea, 3-methoxy-N, N-dimethylpropanamide, 3-ethoxy-N, N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropanamide, 1,3-dimethyl-2-imidazo Dialkylimidazolidinones such as ridinone, lactones such as γ-butyrolactone, γ-valerolactone and δ-valerolactone, carbonates such as ethylene carbonate and propylene carbonate, methanol, ethanol, propanol, isopropanol, 3-methyl- 3-methoxybutanol, ethyl Ketones such as milketone, methylnonylketone, methylethylketone, isoamylmethylketone, methylisopropylketone, diisobutylketone, cyclohexanone, methylisobutylketone, 4-hydroxy-4-methyl-2-pentanone, represented by the following formula (Sv-1) And a compound represented by the following formula (Sv-2), 4-methyl-2-pentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, 2-methylcyclohexyl acetate, butyl butyrate, isoamyl butyrate , Diisobutyl carbinol, diisopentyl ether and the like.

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

In the formula (Sv-1), examples of the monovalent hydrocarbon group having 1 to 6 carbon atoms represented by Y ₁ and Y ₂ include, for example, a monovalent chain hydrocarbon group having 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.
Examples of the monovalent hydrocarbon group having 1 to 6 carbon atoms of Y ₃ and Y ₄ include a monovalent chain hydrocarbon group having 1 to 6 carbon atoms and a monovalent alicyclic hydrocarbon group having 1 to 6 carbon atoms. And 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, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol monobutyl ether ( Butyl cellosolve), ethylene glycol monohexyl ether, ethylene glycol dimethyl ether, ethylene glycol monoacetate, ethylene glycol diacetate, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether Ether acetate, die Lenglycol 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, for example, methyl glycolate, ethyl glycolate, butyl glycolate, ethyl lactate, butyl lactate, isoamyl lactate, ethyl-3-ethoxypropionate, methyl-3 -Methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate and the like.

The solvent preferably has a boiling point of 80 to 200 ° C. More preferably, it is 80 ° C. to 180 ° C., and preferred solvents include N, N-dimethylformamide, tetramethylurea, 3-methoxy-N, N-dimethylpropanamide, propanol, isopropanol, 3-methyl-3-methoxy. Butanol, ethyl amyl ketone, methyl ethyl ketone, isoamyl methyl ketone, methyl isopropyl ketone, diisobutyl ketone, cyclohexanone, 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, diisobutyl carbinol, diisopentyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ester Tellurium, 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, glycol Lumpur butyl, ethyl lactate, butyl lactate, isoamyl, ethyl 3-ethoxypropionate, methyl 3-methoxy propionate, 3-methoxy ethyl propionate, and the like.
The boiling point within this range is particularly preferred when the liquid crystal aligning agent containing the solvent is applied onto a plastic substrate described later.

<Method for producing specific polymer>
The first and second specific polymers contained in the liquid crystal aligning agent of the present invention are (A-1) a monomer having at least one functional group selected from a carboxyl group, an amino group and a hydroxyl group in the molecule (A-1). And (b) a monomer having a photo-alignment site and (c) a monomer having a thermally crosslinkable group for the first specific polymer. Moreover, it can copolymerize with other monomers other than the above. Examples of other monomers include industrially available monomers capable of radical polymerization reaction.

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

Examples of the acrylic 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, 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- Propyl-2-adamantyl acrylate, 8-methyl-8-tricyclodecyl acrylate, Beauty, etc. 8-ethyl-8-tricyclodecyl acrylate.

Examples of the methacrylic acid ester compound include alkyl group-containing methacrylates such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, hexadecyl methacrylate, octadecyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthryl methacrylate, anthryl methyl methacrylate, phenyl methacrylate, 2 , 2,2-trifluoroethyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl Methacrylate, 2-methyl 2-adamantyl methacrylate, 2-propyl-2-adamantyl methacrylate, 8-methyl-8-tricyclodecyl methacrylate, and, 8-ethyl-8-tricyclodecyl methacrylate.

Examples of the vinyl compound include vinyl ether, methyl vinyl ether, benzyl vinyl ether, 2-hydroxyethyl vinyl ether, phenyl vinyl ether, and propyl vinyl ether.
Examples of the styrene compound include styrene, methylstyrene, chlorostyrene, bromostyrene, and the like.
The nitrogen-containing aromatic heterocyclic ring is a structure selected from the group consisting of the following formulas [Na] to [Nb] (wherein Z ₂ is a linear or branched alkyl group having 1 to 5 carbon atoms) It may be an aromatic cyclic hydrocarbon containing at least 1, preferably 1 to 4.

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

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

As the acrylamide compound, the above-mentioned N-methoxymethyl (meth) acrylamide,
Other than N-butoxymethyl (meth) acrylamide and acrylamide, methacrylamide, N-methylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N-methylmethacrylamide, N, N-dimethylmethacrylamide, N , N-diethylmethacrylamide, and the like.

Other monomers used in the present invention may be used alone or in combination of two or more monomers.
The content of the other monomer is 0 to 60 mol%, 0 to 40 mol%, or 1 to 40 mol%, or 5 to 40 mol%, 60 to 99 mol% of the first specific polymer (component (A)), or It is preferably contained in 60 to 95 mol%, 60 to 99 mol%, or 60 to 95 mol%, 0 to 20 mol%, or 1 to 20 mol%, or 5 to 20 mol%. In this case, the total of the part having a polar group in the molecule, the photoreactive part, and the part having thermal crosslinkability is 40 to 100 mol%, 60 to 100 mol% of the first specific polymer (A) component. 80 to 100 mol%, or 80 to 99 mol%, or 80 to 95 mol% is preferable.
Alternatively, the content of other monomers is preferably 0 to 60 mol%, 0 to 40 mol%, 1 to 40 mol%, or 5 to 40 mol% of the second specific polymer (component (A)). In this case, the total of the site having a polar group in the molecule and the photoreactive site is 40 to 100 mol%, 60 to 100 mol%, or 60 to 99 mol% of the second specific polymer (component (A)). %, Or 60 to 95 mol% is preferable.

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

The radical thermal polymerization initiator is a compound that generates radicals by heating to a decomposition temperature or higher. Examples of such radical thermal polymerization initiators include ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), diacyl peroxides (acetyl peroxide, benzoyl peroxide, etc.), hydroperoxides (peroxidation). Hydrogen, tert-butyl hydride peroxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyketals (dibutyl peroxycyclohexane) Etc.), alkyl peresters (peroxyneodecanoic acid-tert-butyl ester, peroxypivalic acid-tert-butyl ester, peroxy 2-ethylcyclohexa Acid-tert-amyl ester), persulfates (potassium persulfate, sodium persulfate, ammonium persulfate, etc.), azo compounds (azobisisobutyronitrile, and 2,2′-di (2-hydroxyethyl) And azobisisobutyronitrile).
Such radical thermal polymerization initiators can be used singly 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 combination of two or more.
The radical polymerization method is not particularly limited, and an emulsion polymerization method, suspension polymerization method, dispersion polymerization method, precipitation polymerization method, bulk polymerization method, solution polymerization method and the like can be used.

The solvent used for the polymerization reaction of the first and second specific polymers is not particularly limited as long as the produced polymer is soluble. Specific examples include the above solvents, for example, N-alkyl-2-pyrrolidones, dialkylimidazolidinones, lactones, carbonates, ketones, compounds represented by the above formula (Sv-1) and the above formulas. Examples include compounds represented by (Sv-2), tetrahydrofuran, 1,4-dioxane, dimethyl sulfone, dimethyl sulfoxide, hexamethyl sulfoxide, and the like.
These solvents may be used alone or in combination. Furthermore, even if it is a solvent which does not dissolve the produced | generated polymer | macromolecule, you may mix and use it for the above-mentioned solvent in the range which the produced | generated polymer does not precipitate.
In radical polymerization, oxygen in the solvent causes the polymerization reaction to be hindered. Therefore, it is preferable to use an organic solvent that has been deaerated to the extent possible.

The polymerization temperature at the time of radical polymerization can be arbitrarily selected from 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 stage of the reaction is carried out at a high concentration, and then an organic solvent can be added.
In the above-mentioned radical polymerization reaction, the molecular weight of the obtained polymer is decreased when the ratio of the radical polymerization initiator is large relative to the monomer, and the molecular weight of the obtained polymer is increased when the ratio is small, the ratio of the radical initiator is The content 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 during the polymerization.

[Recovery of polymer]
When the produced polymer is recovered from the reaction solution obtained by the above-described reaction, the reaction solution is poured into a poor solvent to precipitate these polymers. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, heptane, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, and water. The polymer deposited in a poor solvent and precipitated can be recovered by filtration and then dried at normal temperature or under reduced pressure at room temperature or by heating. In addition, when the polymer collected by precipitation is redissolved in an organic solvent and reprecipitation and collection is repeated 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 purification efficiency is further improved.

The molecular weight of the polymer of the present invention is the weight average molecular weight measured by the GPC (Gel Permeation Chromatography) method, in consideration of the strength of the obtained coating film, the workability at the time of coating film formation, and the uniformity of the coating film. 2000 to 1000000 is preferable, and 5000 to 100,000 is more preferable.

[Preparation of liquid crystal aligning agent]
It is preferable that the liquid crystal aligning agent (namely, polymer composition) used for this invention is prepared as a coating liquid so that it may become suitable for formation of a liquid crystal aligning film. That is, the liquid crystal aligning agent of the present invention is preferably prepared as a solution in which a resin component for forming a resin film is dissolved in an organic solvent. Here, the resin component is the first and second specific polymers (component (A)) already described. In that case, the content of the first 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, particularly with respect to the entire liquid crystal aligning agent. The content is preferably 1 to 10% by mass. Alternatively, the content of the second specific polymer is preferably 0.5 to 20% by mass, more preferably 1 to 20% by mass, and particularly preferably 1 to 10% by mass with respect to the entire liquid crystal aligning agent. Is good.

In the polymer composition of the present embodiment, the above-described resin component has a part having the polar group described above, a part having photoalignment, and a thermally crosslinkable group in the case of the first specific polymer. However, other polymers (hereinafter, also referred to as “other polymers”) may be mixed. At that time, the content of the other polymer in the resin component may be 5 to 95 parts by mass, or 10 to 90 parts by mass with respect to 100 parts by mass in total of the component (A) and the other polymer. .
Such other polymer is composed of, for example, poly (meth) acrylate, polyamic acid, polyamic acid ester, polyimide, etc., and when the present invention uses one specific polymer, the first specific polymer has (A-1) to (A-3) sites, and when the present invention uses the second specific polymer, the (A-1) to (A-2) sites of the second specific polymer, In the case of the first specific polymer, only one and two sites selected from (A-1) to (A-3) are used, and in the case of the second specific polymer, Examples thereof include polymers having only one of (A-1) to (A-2).

<Other ingredients>
The liquid crystal aligning agent of this invention may contain other components other than the said characteristic polymer component. Such other components are selected from the group consisting of component (B) used in the second embodiment, that is, two or more epoxy groups, thiirane groups, hydroxyalkylamide groups, and benzyl alcohol groups in the molecule. Compound containing at least one group; and other crosslinkable compounds (hereinafter collectively referred to as “crosslinking agent components”) and liquid crystal aligning agent when applied with film thickness uniformity and surface smoothness Examples thereof include compounds that improve the adhesion, compounds that improve the adhesion between the liquid crystal alignment film and the substrate, and the like, but are not limited thereto.

<Crosslinking agent component>
1. The compound containing at least one group selected from the group consisting of two or more epoxy groups, thiirane groups, hydroxyalkylamide groups, and benzyl alcohol groups in the molecule. In the first aspect, the component (B) used in the second aspect may be included.

2. Other crosslinkable compounds As other crosslinkable compounds, compounds having an isocyanate group, an oxetane group, or a cyclocarbonate group described in paragraphs [0109] to [0113] of International Publication WO2016 / 047771, or a hydroxy group In addition to a compound having at least one group selected from the group consisting of a hydroxyalkyl group and a lower alkoxyalkyl group, a compound having a blocked isocyanate group, and the like can be mentioned.

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

Component (B) or the amount of these crosslinking agent components used is 0.1 to 40 parts by weight, preferably 0.1 to 30 parts by weight, based on 100 parts by weight of the resin component contained in the polymer composition. Part, more preferably 1 part by weight to 20 parts by weight.

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

[Compound for improving adhesion between liquid crystal alignment film and 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-to Ethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltri Methoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-amino Examples thereof include amino silane-containing compounds such as propyltrimethoxysilane and N-bis (oxyethylene) -3-aminopropyltriethoxysilane.
When using a compound that improves the adhesion to the substrate, the amount used is preferably 0.1 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 to 20 parts by mass.

In an embodiment, a photosensitizer can be used as an additive in order to improve the photoreactivity of the photoalignable group. Specific examples include aromatic 2-hydroxyketone (benzophenone), coumarin, ketocoumarin, carbonyl biscoumarin, acetophenone, anthraquinone, xanthone, thioxanthone, and acetophenone ketal.

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

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

Firing after applying the liquid crystal aligning agent can be performed at an arbitrary temperature of 40 to 300 ° C., preferably 40 to 250 ° C., more preferably 40 to 230 ° C. When a transparent substrate made of a plastic substrate is used, it 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 baking can be performed with a hot plate, a hot-air circulating furnace, an infrared furnace, or the like.
For the rubbing treatment, rayon cloth, nylon cloth, cotton cloth or the like can be used.

<Light irradiation process>
In an embodiment, alignment treatment by light irradiation may be performed, for example, a step of applying the liquid crystal aligning agent on a substrate to form a coating film, and the coating film is not in contact with the liquid crystal layer or A step of irradiating the coating film with light in contact with the liquid crystal layer.

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

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

The liquid crystal display element of the present invention can be produced by a usual method, and the production method is not particularly limited.スペーサー Preferably, the pair of substrates are opposed to each other with an appropriate gap, and a spacer is disposed between the substrates for the purpose of uniforming the thickness of the liquid crystal sandwiched between the substrates. As this spacer, a known spacer material such as a conventional scattering type spacer or a spacer formed from a photosensitive spacer forming composition can be used, and irregularities formed in a layer made of a liquid crystal cured product can be used. It can also be used as a spacer.

<Liquid crystal sandwiching process>
For example, the following two methods can be used to form a liquid crystal cell by sandwiching liquid crystal between substrates. As a first method, a pair of substrates are arranged to face 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 together using a sealant, and the substrate surface and A method of manufacturing a liquid crystal cell can be mentioned by injecting and filling liquid crystal into a 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 location on one of the two substrates on which the liquid crystal alignment film is formed, and further, a predetermined number of locations on the surface of the liquid crystal alignment film. After the liquid crystal is dropped on the liquid crystal, the other substrate is bonded so that the liquid crystal alignment film faces, and the liquid crystal is spread over the entire surface of the substrate. A method of manufacturing a cell (ODF (One Drop Fill) method) can be mentioned.

As the liquid crystal, a fluorine-based liquid crystal or a cyano-based liquid crystal having positive or negative dielectric anisotropy depending on the use, or a liquid crystal compound or liquid crystal composition that is polymerized by at least one treatment of heating and light irradiation ( Hereinafter, a polymerizable liquid crystal or a curable liquid crystal composition) may be used.
In a certain embodiment, the process of forming the coating film of the said liquid crystal aligning agent may be performed by a roll-to-roll system. When performed by the roll-to-roll method, the manufacturing process of the liquid crystal display element can be simplified, and the manufacturing cost can be reduced.
And a liquid crystal display element can be obtained by sticking a polarizing plate on both outer sides of the liquid crystal cell.

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

Monomers represented by “MA-1” and “MA-2” as monomers having a photo-alignment group (hereinafter referred to as “photo-alignment monomer”) used in the examples are monomers having a polar group (hereinafter referred to as “photo-alignment monomer”). , Referred to as “polar monomer”), a monomer represented by “MAA” or “VBA”,
A monomer represented by “GMA” as a monomer having a crosslinkable group (hereinafter referred to as “crosslinkable monomer”), and “TETRAD-C” as a compound of component (B) (hereinafter referred to as “crosslinker component”). The structures of the compounds represented by “YH-434-L” are shown below.
“MA-2” was synthesized by the synthesis method described in Synthesis Example 1 below. “MAA (methacrylic acid)”, “VBA (vinyl benzoic acid)”, “MMA”, “C18”, “TETRAD-C” and “YH-434-L” use commercially available reagents It was.
(Photo-alignment monomer)

(Polar monomer)
MAA: Methacrylic acid VBA: 4-Vinylbenzoic acid

(Crosslinkable monomer)
GMA: Glycidyl methacrylate

(Other monomers)
MMA: methyl methacrylate C12: dodecyl methacrylate C18: octadecyl methacrylate MOI-BP: 2-[(3,5-dimethylpyrazolyl) carbonylamino] ethyl methacrylate

(Crosslinking agent component)
TETRAD-C: 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane YH-434-L: N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane Primid: Β-hydroxyalkylamide represented by the formula (Primid)

In addition, the abbreviations of the reagents used in this example are shown below.
(Polymerization initiator)
AIBN: Azobisisobutyronitrile (solvent)
PGME: Propylene glycol monomethyl ether CHN: Cyclohexanone

<Measurement of ¹ HNMR>
Apparatus: Fourier transform type superconducting nuclear magnetic resonance apparatus (FT-NMR) “INOVA-400” (manufactured by Varian) 400 MHz.
Solvent: deuterated chloroform (CDCl ₃ ) or deuterated N, N-dimethyl sulfoxide ([D ₆ ] -DMSO).
Standard substance: Tetramethylsilane (TMS).

<Monomer Synthesis Example 1>
Synthesis of [MA-1]:

In a 2 L four-necked flask, 1-bromo-4- (trans-4-propylcyclohexyl) -benzene (150.0 g, 533 mmol), tert-butyl acrylate (102.5 g, 800 mmol), palladium acetate (2.39 g) , 11 mmol), tri (o-tolyl) phosphine (6.49 g, 21 mmol), tripropylamine (229.3 g, 1600 mmol) and DMAc (750 g) were added and stirred while heating to 100 ° C. After completion of the reaction, the reaction solution was filtered to remove insoluble matters, and the filtrate was poured into pure water (3.8 L) and neutralized with 12N-HCl aqueous solution. After neutralization, ethyl acetate (2.5 L) was poured and extracted. To the extracted organic layer, anhydrous magnesium sulfate was added, dehydrated and dried, and anhydrous magnesium sulfate was filtered. The obtained filtrate was evaporated using a rotary evaporator, and the crude product was repulped with cold methanol (180 g) to obtain 144.0 g of [MA-1-1] (white solid) (yield) 82%).

[MA-1-1] (144.0 g, 441 mmol) and formic acid (1000 g) were added to a 2 L four-necked flask and stirred while heating to 50 ° C. After completion of the reaction, the reaction solution was poured into pure water (3.0 L), and the precipitate was filtered. The obtained crude product was repulped with ethyl acetate (200 g) to obtain 111.1 g of [MA-1-2] (white solid) (yield 92%). The results of ¹ H-NMR of the target product are shown below. From this result, it was confirmed that the obtained solid was the target [MA-1-2].
1H NMR (400 MHz, [D6] -DMSO): δ12.34 (s, 1H), 7.53-7.60 (m, 3H), 7.25-7.27 (d, 2H), 6.44-6.48 (d, 1H), 2.45 -2.51 (t, 1H), 1.76-1.83 (t, 4H), 1.28-1.48 (m, 5H), 1.15-1.21 (m, 2H), 0.97-1.07 (m, 2H), 0.87-0.89 (t, 3H).

In a 2 L four-necked flask, [MA-1-2] (30.0 g, 110 mmol), 2-hydroxyethyl methacrylate (17.2 g, 132 mmol), 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide Hydrochloride (EDC) (25.7 g, 165 mmol), 4-dimethylaminopyridine (1.35 g, 11 mmol) and THF (150 g) were added, and the mixture was stirred at room temperature. After completion of the reaction, the reaction solution was poured into ethyl acetate (1.0 L) and extracted with pure water (800 ml). To the extracted organic layer, anhydrous magnesium sulfate was added, dehydrated and dried, and anhydrous magnesium sulfate was filtered. The obtained filtrate was evaporated by a rotary evaporator. The obtained residue was isolated by silica gel column chromatography (ethyl acetate: hexane = 1: 5 volume ratio) to obtain 26.8 g of [MA-1] (white solid) (yield 55%). . The results of ¹ H-NMR of the target product are shown below. From this result, it was confirmed that the obtained solid was the target [MA-1].
1H NMR (400 MHz, [D6] -DMSO): δ7.62-7.66 (m, 3H), 7.25-7.27 (d, 2H), 6.58-6.62 (d, 1H), 6.05 (s, 1H), 5.70 (s, 1H), 4.37-4.42 (m, 4H), 2.44-2.48 (t, 1H), 1.88 (s, 3H), 1.76-1.82 (t, 4H), 1.24-1.47 (m, 5H), 1.15 -1.21 (m, 2H), 0.96-1.06 (m, 2H), 0.85-0.89 (t, 3H).

<Monomer Synthesis Example 2>
Synthesis of [MA-2]:

In a 2 L four-necked flask, 1-? Bromo-? 4-? (Trans-? 4-pentylcyclohexyl) -benzene (150.0 g, 485 mmol), tert-butyl acrylate (93.24 g, 728 mmol), palladium acetate (2.18 g, 9.7 mmol), tri (o-tolyl) phosphine (5.90 g, 20 mmol), tripropylamine (208.5 g, 1455 mmol) and DMAc (750 g) are added and heated to 100 ° C. Stir. After completion of the reaction, the reaction solution was filtered to remove insoluble matters, and the filtrate was poured into pure water (3.8 L) and neutralized with 12N-HCl aqueous solution. After neutralization, ethyl acetate (2.5 L) was poured and extracted. To the extracted organic layer, anhydrous magnesium sulfate was added, dehydrated and dried, and anhydrous magnesium sulfate was filtered. The solvent of the obtained filtrate was distilled off with a rotary evaporator, and the crude product was repulped with cold methanol (190 g) to obtain 137.0 g of [MA-2-1] (white solid) (yield) 79%).

[MA-2-1] (137.0 g, 384 mmol) and formic acid (1000 g) were added to a 2 L four-necked flask and stirred while heating to 50 ° C. After completion of the reaction, the reaction solution was poured into pure water (3.0 L), and the precipitate was filtered. The obtained crude product was repulped with ethyl acetate (200 g) to obtain 111.8 g of [MA-2-2] (white solid) (yield 96%). The results of ¹ H-NMR of the target product are shown below. From this result, it was confirmed that the obtained solid was the target [MA-2-2].
1H NMR (400 MHz, [D ₆ ] -DMSO): δ12.34 (s, 1H), 7.53-7.60 (m, 3H), 7.25-7.27 (d, 2H), 6.44-6.48 (d, 1H), 2.45-2.51 (t, 1H), 1.77-1.83 (t, 4H), 1.38-1.48 (m, 2H), 1.17-1.34 (m, 9H), 0.97-1.07 (m, 2H), 0.87-0.89 (t , 3H).

In a 2 L four-necked flask, [MA-2-2] (30.0 g, 100 mmol), 2-hydroxyethyl methacrylate (15.6 g, 119 mmol), 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide Hydrochloride (EDC) (28.7 g, 150 mmol), 4-dimethylaminopyridine (1.22 g, 10 mmol) and THF (150 g) were added, and the mixture was stirred at room temperature. After completion of the reaction, the reaction solution was poured into ethyl acetate (1.0 L) and extracted with pure water (800 ml). To the extracted organic layer, anhydrous magnesium sulfate was added, dehydrated and dried, and anhydrous magnesium sulfate was filtered. The obtained filtrate was evaporated by a rotary evaporator. The obtained residue was isolated by silica gel column chromatography (ethyl acetate: hexane = 1: 5 volume ratio) to obtain 36.6 g of [MA-2] (white solid) (yield 88%). . The results of ¹ H-NMR of the target product are shown below. From this result, it was confirmed that the obtained solid was the target [MA-2].
1H NMR (400 MHz, [D ₆ ] -DMSO): δ7.62-7.66 (m, 3H), 7.25-7.27 (d, 2H), 6.58-6.62 (d, 1H), 6.04 (s, 1H), 5.70 (s, 1H), 4.36-4.42 (m, 4H), 2.48-2.52 (t, 1H), 1.88 (s, 3H), 1.76-1.83 (t, 4H), 1.36-1.44 (m, 2H), 1.18-1.31 (m, 9H), 1.00-1.03 (m, 2H), 0.85-0.88 (t, 3H).

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

<Methacrylate polymer synthesis example A1>
MA-2 (2.48 g, 6.01 mmol), GMA (0.14 g, 1.00 mmol) and MAA (1.2 g, 13.0 mmol) in CHN (11.0 g) and PGME (11.0 g) Then, after deaeration with a diaphragm pump, AIBN (0.2 g, 1.0 mmol) was added as a polymerization initiator, and deaeration was performed again. Thereafter, the mixture was reacted at 60 ° C. for 13 hours to obtain a polymer solution (MP-1).
The number average molecular weight of this polymer was 40500, and the weight average molecular weight was 138300.

<Methacrylate polymer synthesis examples A2 to A10 and A11 to A18>
Using the composition shown in Table 1, methacrylate polymers PA2 to PA10 and PA11 to PA18 were synthesized using the same method as in Polymer Synthesis Example A1.

<Example A1>
CHN (5.5 g), PGME (5.5 g) and TETRAD-C (0.03 g) are added to 4.0 g of the polymer solution (MP-1) obtained in methacrylate polymer synthesis example A1, and the mixture is stirred at room temperature. As a result, a liquid crystal aligning agent (PM-A1) was obtained.

<Examples A2 to A23 and A24 to PA40, Comparative Example A1>
Liquid crystal aligning agents (PM-A2) to (PM-A23) and (PM-A24) to (PM-A40) were obtained with the compositions shown in Table 2 in the same manner as in Example A1. In the same manner, a liquid crystal aligning agent (RPM-A1) of Comparative Example A1 was also prepared.

<Production of liquid crystal display element>
The liquid crystal aligning agents (PM-A1) to (PM-A40) obtained in the examples and the liquid crystal aligning agent (RPM-A1) obtained in the comparative example were pressure filtered through a membrane filter having a pore diameter of 1 μm. .
The obtained solution is 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 50 ° C. for 120 seconds, and then baked for 2 minutes or 20 minutes on a hot plate at 120 ° C. A liquid crystal alignment film having a thickness of 100 nm was formed.
Next, a 313 nm linearly polarized ultraviolet ray having an irradiation intensity of 4.3 mW / cm ^{2 is} irradiated onto the coating surface through a polarizing plate by 50 mJ / cm ² from an angle inclined by 40 ° from the normal direction of the substrate, and a substrate with a liquid crystal alignment film Got. The linearly polarized ultraviolet light was prepared by passing a 313 nm band-pass filter through the ultraviolet light of a high-pressure mercury lamp and then passing it through a 313 nm polarizing plate.
Two substrates described above were prepared, and 4 μm bead spacers were sprayed on the liquid crystal alignment film of one of the substrates, and then a sealant (XN-1500T, manufactured by Mitsui Chemicals) was applied. Next, after bonding the other substrate so that the liquid crystal alignment film faces each other and the alignment direction was 180 °, an empty cell was produced by thermosetting the sealant at 120 ° C. for 90 minutes. Liquid crystals (MLC-3022 manufactured by Merck & Co., Inc.) were injected into the empty cells by a reduced pressure injection method to obtain a liquid crystal display element.

<Evaluation>
(Liquid crystal orientation)
The liquid crystal display element obtained above was subjected to an isotropic phase treatment at 120 ° C. for 1 hour, and then observed with a polarizing microscope. The case where there was no alignment failure such as light leakage or domain generation, or the case where uniform liquid crystal driving was obtained when a voltage was applied to the liquid crystal cell was considered good. The evaluation results are shown in Table 3.

(Pretilt angle)
The pretilt angle of the liquid crystal cell was measured by the Mueller matrix method using AxoScan made by AxoMetrix. The evaluation results are shown in Table 3.

As can be seen from the above results, from the comparison between Examples A1 and A2 and Comparative Example A1, a liquid crystal alignment film excellent in liquid crystal alignment and liquid crystal pretilt angle development ability can be obtained by copolymerizing a crosslinkable monomer. It was. Furthermore, from the comparison between Example A2 and Example A3, by adding a crosslinking agent component, a liquid crystal alignment film having excellent liquid crystal alignment and excellent pretilt angle development ability even when the firing conditions are processed in a short time is obtained. It was.

<Methacrylate polymer synthesis example B1>
MA-2 (2.5 g, 6.0 mmol) and MAA (1.2 g, 14.1 mmol) are dissolved in CHN (11.0 g) and PGME (11.0 g), and deaerated with a diaphragm pump. After that, AIBN (0.2 g, 1.0 mmol) was added as a polymerization initiator, and deaeration was performed again. Then, it was made to react at 60 degreeC for 13 hours, and the polymer (PB1) solution was obtained.
The number average molecular weight of this polymer was 40500, and the weight average molecular weight was 138300.

<Methacrylate polymer synthesis examples B2 to B8 and B12 to B18>
Using the composition shown in Table 4, methacrylate polymers PB2 to PB8 and PB12 to PB18 were synthesized using the same method as in Polymer Synthesis Example B1.

<Methacrylate polymer synthesis example B9>
After MA2 (6.19 g, 15.0 mmol) and MOI-BP (8.80 g, 35.0 mmol) were dissolved in CHN (61.6 g) and deaerated with a diaphragm pump, AIBN (0.41 g , 2.5 mmol) was added and deaeration was performed again. Thereafter, the mixture was reacted at 55 ° C. for 13 hours to obtain a polymer solution of methacrylate. This polymer solution was dropped into a mixed solvent of methanol and pure water = 5/5 (1000 ml), and the resulting precipitate was filtered. This precipitate was washed with methanol and dried under reduced pressure in an oven at 40 ° C. to obtain a methacrylate polymer powder. The number average molecular weight of this polymer was 43600, and the weight average molecular weight was 131200.
CHN (9.0 g) and PGME (9.0 g) were added to the obtained methacrylate polymer powder (1.5 g), and dissolved by stirring at room temperature for 5 hours to obtain a polymer (PB9) solution.

<Methacrylate polymer synthesis examples B10 to B11>
Using the composition shown in Table 5, methacrylate polymers PB10 to PB11 were synthesized using the same method as in Polymer Synthesis Example P1.

<Example B1>
By adding CHN (5.5 g), PGME (5.5 g) and TETRAD-C (0.02 g) to 4.0 g of the polymer solution (PB1) obtained in methacrylate polymer synthesis example B1, the mixture was stirred at room temperature. A liquid crystal aligning agent (PM-B1) was obtained.

<Examples B2 to B16, Comparative Example B1>
Liquid crystal aligning agents (PM-B2) to (PM-B16) were obtained with the compositions shown in Table 6 using the same method as in Example B1. In the same manner, a liquid crystal aligning agent (RPM-B1) of Comparative Example B1 was also prepared.

<Examples B17 to B23>
Liquid crystal aligning agents (PM-B17) to (PM-B23) were obtained with the compositions shown in Table 6 using the same method as in Example B1.

<Examples B24 to B34>
Liquid crystal aligning agents (PM-B24) to (PM-B34) were obtained with the compositions shown in Table 7 using the same method as in Example B1.

<Comparative Example B2>
CHN (9.0 g), PGME (9.0 g), and YH-434-L (0.15 g) were added to the methacrylate polymer solution (PB9) and dissolved by stirring at room temperature for 5 hours. RPMB-2) was obtained.

<Production of liquid crystal display element>
Instead of the liquid crystal aligning agents (PM-A1) to (PM-A36) obtained in the examples and the liquid crystal aligning agent (RPM-A1) obtained in the comparative examples, the liquid crystal aligning agent (PM-B1) Using (PM-B34) and the liquid crystal aligning agents (RPM-B1) to (RPM-B2) obtained in Comparative Examples, liquid crystal display elements were produced in the same manner as described above.
Similarly, Table 8 shows the evaluation results of evaluating the liquid crystal orientation and the pretilt angle.

As can be seen from the above results, from the comparison between Example B1 and Comparative Example B1, a liquid crystal display element using a liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the present invention by introducing a crosslinking agent component is short. The pretilt angle was developed even after firing for a period of time. Further, from the comparison between Example B1 and Comparative Example B2, a liquid crystal display element using a liquid crystal alignment film obtained from a liquid crystal aligning agent not containing a polar group in the molecule cannot obtain liquid crystal alignment. The liquid crystal display element using the liquid crystal alignment film obtained from the liquid crystal aligning agent of the invention had good liquid crystal alignment and also exhibited a pretilt angle.

A liquid crystal display element using a liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the present invention can be suitably used for a liquid crystal display element.

Claims

(A) component: a polymer having the following structures (A-1) and (A-2); and a liquid crystal aligning agent containing a solvent,
The polymer is (A-3) an oxetanyl group, an oxiranyl group, a group represented by the following formula (3), a group represented by the following formula (4), a group represented by the following formula (5), and thiirane. A structure having at least one functional group selected from a group; and / or a component (B) other than the component (A), and two (B) components in the molecule The above liquid crystal aligning agent, which is a compound containing a group selected from the group consisting of the above epoxy group, thiirane group, hydroxyalkylamide group, and benzyl alcohol group:
(A-1) a structure having in the molecule at least one functional group selected from a carboxyl group, an amino group, and a hydroxyl group;
(A-2) The following formula (pa-1) (wherein A is optionally a group selected from fluorine, chlorine and cyano, or an alkoxy group having 1 to 5 carbon atoms, linear or branched) A pyrimidine-2,5-diyl, pyridine-2,5-diyl, optionally substituted with an alkyl residue of (which is optionally substituted with one cyano group or one or more halogen atoms) 2,5-thiophenylene, 2,5-furylene, 1,4- or 2,6-naphthylene or phenylene, R 1 is a single bond, an oxygen atom, —COO— or —OCO—, and R 2 is A divalent aromatic group, a divalent alicyclic group, a divalent heterocyclic group or a divalent condensed cyclic group, wherein R 3 is a single bond, an oxygen atom, —COO— or —OCO—. R 4 is a linear or branched alkyl group having 1 to 40 carbon atoms. Or a monovalent organic group having 3 to 40 carbon atoms including an alicyclic group, wherein D is an oxygen atom, a sulfur atom or —NR d — (where R d is a hydrogen atom or a carbon number of 1 to A represents an integer of 0 to 3, and * represents a bonding position.
The component (A) is (A-3) an oxetanyl group, an oxiranyl group, a group represented by the formula (3), a group represented by the formula (4), a group represented by the formula (5). The liquid crystal aligning agent of Claim 1 which has a structure which has at least 1 sort (s) of functional group selected from a thiirane group.
The liquid crystal aligning agent according to claim 1, wherein the component (A) is a polymer having the structures (A-1) and (A-2), and further includes the component (B).
The liquid crystal aligning agent according to claim 3, wherein the component (B) is a compound containing two or more epoxy groups or thiirane groups in the molecule.
The liquid crystal aligning agent according to claim 3, wherein the component (B) is a compound containing two or more hydroxyalkylamide groups or benzyl alcohol groups in the molecule.
The monomer derived from the structure of (A-1) is contained in a proportion of 5 to 95 mol% with respect to the whole polymer of the component (A), and the monomer derived from the structure of (A-2) is 5 The liquid crystal aligning agent according to any one of claims 3 to 5, which is obtained from a monomer component contained in a proportion of -95 mol%.
The liquid crystal aligning agent according to any one of claims 1 to 6, comprising 0.1 to 40 parts by mass of the component (B) with respect to 100 parts by weight of the component (A).
(A-2) is represented by the following formula (b-1-m) (wherein M c represents a second polymerizable group, M d represents a single bond, a (r 2 +1) -valent heterocyclic ring, A substituted or unsubstituted branched alkyl group having 1 to 10 carbon atoms, or an unsubstituted straight chain alkyl group having 1 to 10 carbon atoms, an (r 2 +1) -valent aromatic group, and an (r 2 +1) value Each group is 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, S b represents a single bond, a linear or branched alkylene group having 1 to 10 carbon atoms, a divalent aromatic group or a divalent alicyclic group, and I b is represented by the formula (pa-1). Wherein r 2 is an integer satisfying 1 ≦ r 2 ≦ 3)). Liquid crystal aligning agent.
(A-2) is the following formula (pa-1-a) (wherein S b has the same definition as in formula (b-1-m), Z is an oxygen atom or a sulfur atom, and X a and X b are each independently a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group or an alkyl group having 1 to 3 carbon atoms, and 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, and R 3 is a single bond, an oxygen atom, —COO— or —OCO—, R 4 is a monovalent organic group having 3 to 40 carbon atoms including a linear or branched alkyl group having 1 to 40 carbon atoms or an alicyclic group, R 5 is an alkyl group having 1 to 3 carbon atoms, A C 1-3 alkoxy group, a fluorine atom or a cyano group, a is an integer of 0-3, and b is an integer of 0-4.) It is a site with photoalignable represented, the liquid crystal alignment agent according to any one of claims 1-8.
(A-1) is the following formula (a-1-m) (wherein I a1 is selected from a carboxyl group, a group having at least one partial structure of the following formula (a2), or a primary amino group) A monovalent organic group, r 1 is 1 or 2, S a represents a single bond or a divalent linking group, and M a represents a first polymerizable group, provided that the above formula ( The liquid crystal aligning agent according to any one of claims 1 to 9, which is derived from a monomer represented by a2) (wherein * represents a bonding position) represents a group other than a primary amino group). .
(A-3) is represented by the following formula (c-1-m) (wherein I c is an oxetanyl group, an oxiranyl group, a group represented by the above formula (3) in the molecule, the above formula (4) And a monovalent organic group selected from the group consisting of the group represented by the above formula (5) and the thiirane group, S c represents a single bond or a divalent linking group, M The liquid crystal according to any one of claims 1, 2, and 7 to 10, wherein e represents a third polymerizable group. Alignment agent.
The liquid crystal aligning agent according to any one of claims 1 to 11, wherein the component (B) is an epoxy compound having at least one tertiary nitrogen atom in the molecule.
Component (B) is represented by the following formula (wherein X 2 is an n-valent organic group containing an aliphatic hydrocarbon group having 1 to 20 carbon atoms or an aromatic hydrocarbon group,
n is an integer from 2 to 6,
R 2 and R 3 are each independently a hydrogen atom or an optionally substituted alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or an alkynyl group having 2 to 4 carbon atoms. And at least one of R 2 and R 3 represents a hydrocarbon group substituted with a hydroxy group.
Y 1 , Y 2 and Y 3 each independently represent an aromatic ring. Any hydrogen atom of the aromatic ring may be substituted with a hydroxyl group, an alkyl group having 1 to 3 carbon atoms, a halogen atom, an alkoxy group having 1 to 3 carbon atoms, or a vinyl group.
Z 1 is a divalent saturated hydrocarbon group having 1 to 10 carbon atoms which may be bonded to form a cyclic structure by a single bond or all or a part thereof, and any hydrogen atom is substituted with a fluorine atom. may, -NH -, - N (CH 3) -, an alkyl group of the formula [3] (P 1 and P 2 1 to 5 carbon atoms independently, Q 1 represents an aromatic ring. ).
t 1 is an integer of 2 to 4, t 2 and t 3 are each independently an integer of 1 to 3,
a and b are each independently an integer of 1 to 3. )
The liquid crystal aligning agent according to any one of claims 1 to 9, which is at least one compound selected from the group consisting of:
The monomer derived from the part (A-1) is contained in a proportion of 5 to 94 mol% with respect to the whole polymer of the component (A), and the monomer derived from the part (A-2) is 5 The present invention is characterized in that it is obtained from a monomer component containing in a proportion of ˜94 mol% and containing a monomer derived from the site (A-3) in a proportion of 1 to 40 mol%. The liquid crystal aligning agent according to any one of claims 7 to 13.
The monomer derived from the site (A-1) is contained in a proportion of 20 to 94 mol% with respect to the entire polymer of the component (A), and the monomer derived from the site (A-2) is 5 The present invention is characterized in that it is obtained from a monomer component which is contained in a proportion of ˜50 mol% and contains a monomer derived from the site (A-3) in a proportion of 1 to 30 mol%. The liquid crystal aligning agent according to any one of claims 7 to 14.
The liquid crystal aligning agent according to any one of claims 1 to 15, wherein the polymer of the component (A) has a weight average molecular weight of 2,000 to 1,000,000.
A liquid crystal alignment film formed using the liquid crystal aligning agent according to any one of claims 1 to 16.
A step of applying a liquid crystal aligning agent according to any one of claims 1 to 16 on a substrate to form a coating film, and a state in which the coating film is not in contact with the liquid crystal layer or a liquid crystal layer And a step of irradiating the coating film with light in contact with the liquid crystal alignment film.
A liquid crystal display device comprising the liquid crystal alignment film according to claim 17 or the liquid crystal alignment film obtained by the production method according to claim 18.