CN110546560B

CN110546560B - Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element

Info

Publication number: CN110546560B
Application number: CN201880026904.8A
Authority: CN
Inventors: 饭塚祐太; 根木隆之; 后藤耕平
Original assignee: Nissan Chemical Corp
Current assignee: Nissan Chemical Corp
Priority date: 2017-02-27
Filing date: 2018-02-26
Publication date: 2022-08-19
Anticipated expiration: 2038-02-26
Also published as: KR20190124743A; JPWO2018155675A1; WO2018155675A1; JP7106059B2; CN110546560A; KR102573453B1; TWI805572B; TW201900855A

Abstract

The invention provides a liquid crystal alignment film and a liquid crystal alignment agent, which have good liquid crystal alignment performance and excellent pretilt angle expression capability even though the firing time is short, and can obtain high reliability. The invention provides a liquid crystal aligning agent, which contains the following components (A): a polymer having the following structures (A-1) and (A-2); and a solvent, wherein the polymer further has (A-3) a structure having at least one functional group selected from the group consisting of an oxetanyl group, an oxirane 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 a thiiranyl group; and/or the liquid crystal aligning agent further comprises a component (B) other than the component (A), wherein the component (B) is a compound having 2 or more groups selected from the group consisting of an epoxy group, a thiiranyl group, a hydroxyalkylamide group and a benzyl alcohol group in a molecule, and (A-1) has at least one functional group selected from the group consisting of a carboxyl group, an amino group and a hydroxyl group in a molecule; (A-2) a structure represented by the following formula (pa-1) (wherein the symbols are as defined in the specification).

Description

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

Technical Field

The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film obtained therefrom, and a liquid crystal display element provided with the liquid crystal alignment film obtained therefrom. More specifically, the present invention relates to a liquid crystal aligning agent which can provide a liquid crystal alignment film having good liquid crystal alignment properties, excellent pretilt angle expressibility, and high reliability even when the firing temperature is low and the firing time is short, and a liquid crystal display element having excellent display quality.

Background

In a liquid crystal display element, a liquid crystal alignment film plays a role of aligning liquid crystal in a constant direction. A liquid crystal alignment film that is mainly used in industry is produced by applying a polyimide-based liquid crystal alignment agent containing a solution of polyamic acid (also referred to as polyamic acid) that is a polyimide precursor, polyamic acid ester, and polyimide onto a substrate to form a film.

In addition, when the liquid crystal is aligned in parallel or obliquely with respect to the substrate surface, after the film formation, a surface stretching treatment is further performed by rubbing.

On the other hand, in the case of vertically aligning liquid crystals with respect to a substrate (also referred to as a Vertical Alignment (VA) system), a liquid crystal alignment film is used in which a long-chain alkyl group, a cyclic group, or a combination of a cyclic group and an alkyl group (for example, see patent document 1), a steroid skeleton (for example, see patent document 2), or other hydrophobic groups are introduced into side chains of polyimide. In this case, when a voltage is applied between the substrates and the liquid crystal molecules are tilted in a direction parallel to the substrates, the liquid crystal molecules need to be tilted in a direction within the substrate plane from the substrate normal direction. As means therefor, for example, a method of providing a protrusion on a substrate; a method of providing a slit in a display electrode; a method of slightly tilting (pre-tilting) the liquid crystal molecules from the substrate normal direction to one direction in the substrate plane by friction; and a method in which a photopolymerizable compound is added to a liquid crystal composition in advance, the mixture is used together with a vertical alignment film such as polyimide, and ultraviolet rays are irradiated to the liquid crystal cell while applying a voltage, thereby pretilt the liquid crystal (see, for example, patent document 3).

In recent years, as a technique for replacing the formation of projections and slits and PSA technique in VA-mode liquid crystal alignment control, a method (photo-alignment method) has been proposed which utilizes anisotropic photochemical reaction by polarized ultraviolet irradiation or the like. That is, it is known that the tilt direction of liquid crystal molecules at the time of voltage application can be uniformly controlled by applying polarized ultraviolet rays to a polyimide film having photoreactive vertical alignment properties to impart alignment controllability and pretilt angle expressiveness (see patent document 4). In this case, as in the case of the conventional alignment film, a polyimide-based liquid crystal alignment film is used which has excellent durability and is suitable for controlling the pretilt angle of the liquid crystal.

On the other hand, among solvents for liquid crystal aligning agents using polyimide polymers, highly polar solvents such as N-methyl-2-pyrrolidone (also referred to as NMP) are used because of low solubility of these polyimide polymers in solvents. These highly polar solvents have a high boiling point, for example NMP has a boiling point of 200 ℃. Therefore, in order to produce a liquid crystal alignment film using a liquid crystal alignment treatment agent using NMP as a solvent and remove NMP remaining in the liquid crystal alignment film, it is necessary to perform firing at a high temperature of about 200 ℃.

In contrast, when a plastic substrate having low heat resistance, which is thin and lightweight, is used as a substrate of a liquid crystal display element, it is necessary to perform firing at a lower temperature in the production of a liquid crystal alignment film. Similarly, it is also required to reduce energy cost in manufacturing a liquid crystal display element by lowering the firing temperature.

When firing is performed at a low temperature, there is a problem that curing has to be completed in a state where the alignment film material is not sufficiently cured, and it is difficult to obtain a liquid crystal display element with high reliability (for example, see patent document 5).

Documents of the prior art

Patent literature

Patent document 1: japanese laid-open patent publication No. 3-179323

Patent document 2: japanese patent laid-open publication No. 4-281427

Patent document 3: japanese patent No. 4504626

Patent document 4: japanese patent No. 4995267

Patent document 5: japanese laid-open patent publication No. 7-209633

Disclosure of Invention

Problems to be solved by the invention

As a result of the studies, the inventors have found that the liquid crystal alignment film is produced by lowering the firing temperature and shortening the firing time, and as a result, the liquid crystal alignment properties are significantly impaired in addition to the above.

The purpose of the present invention is to provide a liquid crystal alignment film and a liquid crystal alignment agent that have good liquid crystal alignment properties, excellent pretilt angle expression ability, and high reliability even when the firing time is short.

Means for solving the problems

The present inventors have found the following < X >.

< X > a liquid crystal aligning agent comprising a solvent, and (A) a component: a polymer having the following structures (A-1) and (A-2),

the polymer also has (A-3) a structure having at least one functional group selected from the group consisting of an oxetanyl group, an oxirane 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 a thiiranyl group (hereinafter, also referred to as a "thermally crosslinkable group"); and/or

The liquid crystal aligning agent further contains a component (B) other than the component (A), wherein the component (B) is a compound having 2 or more groups selected from the group consisting of an epoxy group, a thiiranyl group, a hydroxyalkylamide group, and a benzyl alcohol group in the molecule.

(A-1) has a structure having at least one functional group selected from the group consisting of 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-alignment group").

Wherein A represents pyrimidine-2, 5-diyl, pyridine-2, 5-diyl, 2, 5-thiophenylene, 2, 5-furanylene, 1, 4-or 2, 6-naphthylene or phenylene which is optionally substituted with a group selected from fluorine, chlorine and a cyano group, or with an alkoxy group having 1 to 5 carbon atoms, a linear or branched alkyl residue which is optionally substituted with 1 cyano group or 1 or more halogen atoms, and R is ₁ Is a single bond, an oxygen atom, -COO-or-OCO-, R ₂ Is a 2-valent aromatic group, a 2-valent alicyclic group, a 2-valent heterocyclic group or a 2-valent condensed ring group, R ₃ Is a single bond, an oxygen atom, -COO-or-OCO-, R ₄ Is a C1-40 linear or branched alkyl group or a C3-40 1-valent organic group containing an alicyclic group, D represents an oxygen atom, a sulfur atom or-NR _d - (in addition, R) _d Represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms), a is an integer of 0 to 3, and a represents a bonding position.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention can provide a liquid crystal alignment film and a liquid crystal alignment agent which have good liquid crystal alignment properties, excellent pretilt angle expression ability, and high reliability even when the firing time is short.

In addition, the liquid crystal display element manufactured by the method of the present invention has excellent display characteristics.

Detailed Description

The liquid crystal aligning agent of the present invention comprises a solvent and a component (A): a polymer having the following structures (A-1) and (A-2).

The liquid crystal aligning agent of the present invention further has the following embodiment 1; and/or manner 2.

That is, the polymer of the liquid crystal aligning agent according to embodiment 1 of the present invention further has a structure (a-3) having at least one functional group selected from an oxetanyl group, an oxirane group, a group represented by formula (3), a group represented by formula (4), a group represented by formula (5), and a thiiranyl group (hereinafter, also referred to as a "thermally crosslinkable group").

The liquid crystal aligning agent according to embodiment 2 of the present invention further comprises a component (B) other than the component (a), wherein the component (B) is a compound having 2 or more groups selected from the group consisting of an epoxy group, a thiiranyl group, a hydroxyalkylamide group, and a benzyl alcohol group in a molecule.

(B) Component (B) is a compound containing 2 or more groups selected from the group consisting of hydroxyalkylamide groups and benzyl alcohol groups in the molecule.

Here, "2 or more in the molecule" means that, for example, 2 or more groups of the same kind such as 2 or more epoxy groups are contained in the molecule, and also means that, for example, 2 or more groups selected from the group consisting of epoxy groups, thiiranyl groups, hydroxyalkylamide groups, and benzyl alcohol groups are contained in the molecule even if the groups are different, such as a combination of an epoxy group and a thiiranyl group. The "number of groups in a molecule" is preferably 2 or more, and preferably 2 or more groups of the same kind are contained in the molecule.

The liquid crystal aligning agent of embodiment 1 of the present invention contains a polymer having the structures (A-1) to (A-3) (hereinafter, also referred to as "specific polymer 1") and a solvent.

The liquid crystal aligning agent according to embodiment 2 of the present invention contains a polymer having the structures of (A-1) and (A-2) (hereinafter, also referred to as "specific polymer 2"), a component (B), and a solvent.

Here, the 3 structures of the 1 st specific polymer or the 2 structures of the 2 nd specific polymer can be formed as side chains in the polymer, and may be also referred to as "side chains" as needed.

The respective constitutional requirements of the present invention, particularly, the 1 st and 2 nd aspects of the present invention will be described in detail below.

< component (A): specific Polymer No. 1

The 1 st specific polymer of the present invention is represented by the following formula (I).

In the formula, S _a 、S _b And S _c Represent each independently a spacer group (spacer) unit,

I _a1 as defined in the formula (a-1-m) described later,

I _b is a group represented by the aforementioned formula (pa-1),

I _c represents a 1-valent organic group having at least one functional group selected from the group consisting of an oxetanyl group, an oxirane group, a group represented by the formula (3), a group represented by the formula (4), a group represented by the formula (5), and a thiiranyl group,

M _a 、M _c 、M _d 、M _e 、r ¹ 、r ² the same as defined in the formula (a-1-m), the formula (b-1-m) and the formula (c-1-m) described later.

X, y, and z are not particularly limited, and may be, for example, 0.01 to 0.89 independently of each other.

The expressions (I) to (II) indicate that the side chains are present at a ratio of x, y, and z, and do not indicate that the side chains are blocked in the polymer.

< component (A): specific Polymer No. 2

The 2 nd specific polymer used in the 2 nd embodiment of the present invention is represented by the following formula (I').

In the formula (I'), S _a 、S _b 、I _a1 、I _b 、M _a 、M _c 、M _d 、r ¹ And r ² Have the same definitions as above.

In formula (I'), x and y are not particularly limited, and x and y may be, for example, each independently a value of 0.05 to 0.95.

In the formula (I'), the presence of each side chain at a ratio of x and y is referred to, and the formula does not mean a block copolymer in which each side chain is blocked in a polymer.

The specific polymers 1 and 2 contained in the liquid crystal aligning agent of the present invention have high sensitivity to light, and therefore can exhibit alignment controllability even under irradiation of polarized ultraviolet rays with a low exposure amount.

The 1 st specific polymer can undergo a crosslinking reaction in the 1 st specific polymer by the reaction of the thermally crosslinkable group with the amino group and the hydroxyl group or the carboxyl group even when the baking time of the liquid crystal aligning agent is short. Accordingly, when the photoalignment site of the 1 st specific polymer exhibits anisotropy by photoreaction, the anisotropy is likely to remain (store) in the liquid crystal alignment film, and thus the liquid crystal alignment property can be improved and the pretilt angle of the liquid crystal can be exhibited.

By reacting the amino group, carboxyl group and hydroxyl group of the specific polymers 1 and 2 with the group selected from the group consisting of an epoxy group, a thiiranyl group, a hydroxyalkylamide group and a benzyl alcohol group of the component (B), the crosslinking reaction can be performed in the specific polymers 1 and 2 even when the baking time of the liquid crystal aligning agent is short. Accordingly, when the photoalignment sites of the specific polymers of items 1 and 2 exhibit anisotropy by photoreaction, the anisotropy is likely to remain (store) in the liquid crystal alignment film, and thus the liquid crystal alignment properties can be improved and the pretilt angle of the liquid crystal can be exhibited.

< Structure having polar group in molecule (A-1) >

The specific polymers 1 and 2 contained in the liquid crystal aligning agent of the present invention preferably have a structure containing a polar group, i.e., a functional group selected from at least one of a carboxyl group, an amino group, and a hydroxyl group, in a side chain in a molecule.

This structure enables the crosslinking reaction to proceed in the specific polymer even when the baking time of the liquid crystal aligning agent obtained from the specific polymer of the invention 1 and 2 is shortened, and therefore, the liquid crystal alignment film obtained can exhibit the pretilt angle of the liquid crystal while improving the liquid crystal alignment property.

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

*-I _a1 (a-1)

In the formula I _a1 Is a 1-valent organic group selected from a carboxyl group, a hydroxyl group, a group having a partial structure of at least one of the following formulae (a2), or a primary amino group. Wherein the following formula (a2) represents a group other than a primary amino group, r ¹ Is 1 or 2. In the formula, denotes that atoms form bonds.

In addition, S _a Represents a single bond or a 2-valent linking group.

I _a1 In the formula (a2), examples of the group having a partial structure of the formula (a2) include a 5-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 substituted with a fluorine atom, a chlorine atom, a cyano group, a methyl group or a methoxy group. As a group I _a1 Preferable examples of the organic group include 1-valent organic groups selected from carboxyl groups and hydroxyl groups.

M _a Represents a1 st polymerizable group. The 1 st polymerizable group includes the following formula (M) _a -1)～(M _a -2), α -methylene- γ -butyrolactone, maleimide, a radical polymerizable group of norbornene and its derivatives, and siloxane. Preferably of the formula (M) _a -1)～(M _a -2), and α -methylene- γ -butyrolactone, maleimide are preferred.

In the formula, R ₁ Represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and represents an atomic bond.

S as the aforementioned formula (a-1-m) _a The linking group having a valence of 2 in (1) includes, for example, an alkanediyl group having 1 to 10 (preferably 1 to 6) carbon atoms, an arylene group having 6 to 20 (preferably 6 to 14) carbon atoms, (. alpha.) -CONH-R ₆ - (. B) radical, (. A) -COO-R ₇ - (. about.B) group, etc. Herein, R is ₆ And R ₇ Independently represents a single bond, or an alkanediyl group having 1 to 12 (preferably 1 to 6) carbon atoms, an arylene group having 6 to 20 (preferably 6 to 14) carbon atoms, or an alkyleneoxyarylene group, any carbon-carbon bond of the alkanediyl group may have an-O-bond, (. A) represents an atom bonded to a carbon atom having an unsaturated bond, and (. B) represents an atom bonded to I _a1 The bonded atoms form bonds. Examples of the alkanediyl group include a methylene group, an ethylene group, an ethane-1, 1-diyl group, a propane-1, 2-diyl group, a propane-1, 3-diyl group, a propane-2, 2-diyl group, a butane-1, 3-diyl group, a butane-1, 4-diyl group, a pentane-1, 5-diyl group, a hexane-1, 5-diyl group, and a hexane-1, 6-diyl group. Examples of the arylene group include a phenylene group, a naphthylene group, a biphenylene group, and an anthracenylene group. Examples of the alkyleneoxyarylene group include ethyleneoxyphenylene, hexyleneoxyphenylene, and hexyleneoxybiphenyl. Wherein as S _a The linking group having a valence of 2 in (A) is preferably an alkanediyl group having 1 to 10 (preferably 1 to 6) carbon atoms, an arylene group having 6 to 20 (preferably 6 to 14) carbon atoms, or an (A) -COO-R group ₇ - (. about.B) radical as R ₇ Preferably, the alkanediyl group has 2 to 6 carbon atoms.

Specific examples of the above formula (a-1-m) having a carboxyl group include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, crotonic acid, isocrotonic acid, α -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-mentioned formula (a-1-m) having a hydroxyl group include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, and 12-hydroxylauryl (meth) acrylate; hydroxyethyl (meth) acrylamide, and (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 containing the formula (a2) include 2,2,6, 6-tetramethyl-4-piperidyl methacrylate and the like.

The polar group-containing site in the molecule contained in the polymer of the present invention may be used alone in 1 kind or in combination of 2 or more kinds.

The site having a polar group in the molecule is preferably contained in a proportion of 5 to 94 mol%, 20 to 88 mol%, or 25 to 80 mol% of the specific polymer 1 ((A) component). The site having a polar group in the molecule is preferably contained in a proportion of 5 to 95 mol%, or 20 to 90 mol%, or 30 to 85 mol%, or 20 to 80 mol%, or 50 to 85 mol% of the specific polymer 2 ((A) component).

< Structure having photo-alignment Property (A-2) >

The 1 st and 2 nd specific polymers contained in the liquid crystal aligning agent of the present invention preferably have a structure having photo-alignment properties as represented by the above formula (pa-1) in a side chain in a molecule.

By forming the above structure with a structure having a portion having a photo-alignment property, the vertical alignment controllability can be stably maintained for a long period of time even when exposed to an external stress such as heat. Further, since the liquid crystal alignment film has high sensitivity to light, it can exhibit alignment controllability even when irradiated with polarized ultraviolet light of a low exposure amount, and is preferable from the viewpoint of simplifying the production process of the liquid crystal alignment film.

In the present invention, the portion having photo-alignment properties represented by the above formula (pa-1) in the molecule can be represented by, for example, the following formula (b-1). The site is not limited to the structure derived from a monomer represented by the following formula (b-1-m). In the formula I _b Is a 1-valent organic group represented by the following formula (pa-1).

-S _b -I _b (b-1)

In the formula (pa-1), A represents pyrimidine-2, 5-diyl, pyridine-2, 5-diyl, 2, 5-thiophenylene, 2, 5-furanylene, 1, 4-or 2, 6-naphthylene or phenylene which is optionally substituted with a group selected from fluorine, chlorine and cyano, or with an alkoxy group having 1 to 5 carbon atoms, a straight-chain or branched alkyl residue which is optionally substituted with 1 cyano or 1 or more halogen atoms, and R is ₁ Is a single bond, an oxygen atom, -COO-or-OCO-, R ₂ Is a 2-valent aromatic group, a 2-valent alicyclic group, a 2-valent heterocyclic group or a 2-valent condensed ring group, R ₃ Is a single bond, an oxygen atom, -COO-or-OCO-, R ₄ Is a C1-40 linear or branched alkyl group or a C3-40 1-valent organic group containing an alicyclic group, D represents an oxygen atom, a sulfur atom or-NR _d - (herein, R) _d Represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms), a is an integer of 0 to 3, and a represents a bonding position.

In the above formula (b-1) or (b-1-m), S _b Represents a spacer unit, S _b The left connecting symbol of (A) indicates that the main chain of the 1 st and 2 nd specific polymers is optionally bonded via a spacer.

S _b For example, the structure can be represented by the following formula (Sp).

----W ₁ -A ₁ -W ₂ -A ₂ -W ₃ ----- (Sp)

In the formula (Sp), the compound (A) is,

W ₁ the left key of (A) represents a pair M _d The key of (a) is selected,

W ₃ the right key of (1) represents a pair I _b The key of (a) is selected,

W ₁ 、W ₂ and W ₃ Each independently represents a single bond, a divalent heterocycle, - (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.ident.C-, in which substituents are non-adjacent CH ₂ One or more of the groups may be independently replaced by-O-, -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.ident.C-, or-O-CO-O- (wherein R independently represents hydrogen or a linear or branched alkyl group having 1 to 5 carbon atoms).

A ₁ And A ₂ Each independently is a group selected from a single bond, a 2-valent alkyl group, a 2-valent aromatic group, a 2-valent alicyclic group, or a 2-valent heterocyclic group, and each group may be unsubstituted or one or more hydrogen atoms may be substituted with a fluorine atom, a chlorine atom, a cyano group, a methyl group, or a methoxy group.

In the formula (b-1-M), M _c Represents a2 nd polymerizable group. Examples of the 2 nd polymerizable group include (meth) acrylate, fumarate, maleate, α -methylene- γ -butyrolactone, styrene, vinyl, maleimide, norbornene, radical polymerizable groups of (meth) acrylamide and its derivatives, and siloxane. Preferably (meth) acrylate, α -methylene- γ -butyrolactone, styrene, vinyl, maleimide, acrylamide.

r ² To satisfy 1 ≦ r ² An integer of 3 or less.

In the formula (b-1-M), M _d Is selected from a single bond, (r) ² +1) heterocycle, straight-chain or branched alkyl group having 1 to 10 carbon atoms, or (r) ² +1) valent aromatic group, (r) ² +1) valent alicyclic groups, eachThe group may be unsubstituted or one or more hydrogen atoms substituted with a fluorine atom, a chlorine atom, a cyano group, a methyl group or a methoxy group.

As A ₁ 、A ₂ And M _d Examples of the aromatic group in (b) include aromatic hydrocarbons having 6 to 18 carbon atoms such as benzene, biphenyl, and naphthalene. As A ₁ 、A ₂ And M _d Examples of the alicyclic group in (b) include alicyclic hydrocarbons having 6 to 12 carbon atoms such as cyclohexane and bicyclohexane. As A ₁ 、A ₂ And M _d Examples of the heterocyclic ring in (b) include nitrogen-containing heterocyclic rings such as pyridine, piperidine and piperazine. As A ₁ 、A ₂ Examples of the alkyl group in (1) include a linear or branched alkyl group 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) may be a group represented by the above-mentioned (pa-1) or a group represented by the following (pa-1-a). The site is not limited to a structure derived from a monomer represented by the following formula (pa-1-ma).

In the formula (pa-1-a) or (pa-1-ma), M _c 、M _d And S _b The definitions of (a) are the same as above.

In addition, Z is an oxygen atom or a sulfur atom.

X _a And X _b Each independently represents 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 2-valent aromatic group, a 2-valent alicyclic group, or a 2-valent heterocyclic group.

R ₃ Is a single bond, an oxygen atom, -COO-or-OCO-.

R ₄ Is a C1-40 linear or branched alkyl group or a C3-40 1-valent organic group containing 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), as S _b The C1-10 linear or branched alkylene group in (1) is preferably a C1-8 linear or branched alkylene group, and is preferably, for example, a methylene group, an ethylene group, an n-propylene group, an n-butylene group, a t-butylene group, an n-pentylene group, an n-hexylene group, an n-heptylene group, or an n-octylene group.

As S _b Examples of the aromatic group having a valence of 2 in (a) include a1, 4-phenylene group, a 2-fluoro-1, 4-phenylene group, a 3-fluoro-1, 4-phenylene group, and a2, 3,5, 6-tetrafluoro-1, 4-phenylene group.

In the formula (pa-1-a) or (pa-1-ma), as S _b Examples of the alicyclic group having a valence of 2 in (1) include trans-1, 4-cyclohexylene and trans-1, 4-bicyclohexyl.

As S _b Examples of the heterocyclic group having a valence of 2 in (1) include 1, 4-pyridylene group, 2, 5-pyridylene group, 1, 4-furylene group, 1, 4-piperazinyl group and 1, 4-piperidinyl group.

S _b Preferably an alkylene group having 1 to 8 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms, and further preferably an alkylene group having 1 to 4 carbon atoms.

As R ₂ Examples of the aromatic group having a valence of 2 in (a) include a1, 4-phenylene group, a 2-fluoro-1, 4-phenylene group, a 3-fluoro-1, 4-phenylene group, a2, 3,5, 6-tetrafluoro-1, 4-phenylene group and a naphthylene group.

As R ₂ Examples of the alicyclic group having a valence of 2 in (1) include trans-1, 4-cyclohexylene and trans-1, 4-bicyclohexyl.

As R ₂ Examples of the heterocyclic group having a valence of 2 include 1, 4-pyridylene group, 2, 5-pyridylene group, 1, 4-furanylene group, 1, 4-piperazinyl group, and 1, 4-piperidyl group.

R ₂ 1, 4-phenylene, trans-1, 4-cyclohexylene and trans-1, 4-bicyclohexyl are preferred.

AsR ₄ Examples of the C1-40 linear or branched alkyl group include C1-20 linear or branched alkyl groups, and some or all of the hydrogen atoms of the alkyl group may be substituted with fluorine atoms. Examples of the above alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-lauryl group, an n-dodecyl group, an n-tridecyl group, and an n-tetradecyl group, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, 4,4, 4-trifluorobutyl, 4,4,5,5, 5-pentafluoropentyl, 4,4,5,5,6,6, 6-heptafluorohexyl, 3,3,4,4,5, 5-heptafluoropentyl, 2,2, 2-trifluoroethyl, 2,2,3,3, 3-pentafluoropropyl, 2- (perfluorobutyl) ethyl, 2- (perfluorooctyl) ethyl, 2- (perfluorodecyl) ethyl and the like.

As R ₄ Examples of the C3-40 organic group having a valence of 1 containing an alicyclic group include a cholesteryl group, a cholestanyl group, an adamantyl group, and the following formulas (Alc-1) and (Alc-2) (wherein R is ₇ Hydrogen atom, fluorine atom, or C1-20 alkyl group which may be substituted with fluorine atom, and represents a bonding position), and the like.

The monomers represented by the above formula (pa-1-ma) include, but are not limited to, those represented by the formulae (paa-1-ma1) to (paa-1-ma 18). In the formula, "E" represents an E-isomer, and "t" represents a trans-form of a cyclohexyl group.

The photoreactive site contained in the polymer of the present invention may be used alone or in combination of 1 or more than 2 kinds.

The photoreactive site is preferably contained in a ratio 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 specific polymer 1 ((A) component).

The photoreactive site is preferably contained in a ratio of 5 to 95 mol%, 10 to 80 mol%, 15 to 70 mol%, 15 to 60 mol%, or 15 to 50 mol% of the specific polymer 2 ((A) component).

(A-3) site having thermally crosslinkable group

The 1 st specific polymer contained in the liquid crystal aligning agent of the present invention has a site containing a thermally crosslinkable group, that is, a site containing at least one functional group selected from an oxetanyl group (1, 2-epoxy structure), an oxirane group (1, 3-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 thiiranyl group in a molecule. In other words, the 1 st specific polymer has a site having at least one functional group selected from an oxetanyl group, an oxirane 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 a thiiranyl group in a molecule in a side chain. In the formulae (3) to (5), a indicates that an atom forms a bond.

The site having a thermally crosslinkable group of the above (A-3) can form a crosslinking reaction with the amino group, the hydroxyl group and the carboxyl group as the polar group, and the liquid crystal alignment film having excellent pretilt angle expression ability can be obtained while stabilizing the liquid crystal alignment ability of the site having photo-alignment properties of the above (A-2) even when the baking time of the liquid crystal alignment agent is shortened.

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

-S _c -I _c (c-1)

M _e -S _c -I _c (c-1-m)

In the formula (c-1) or (c-1-m), I _c Is a 1-valent organic group selected from the group consisting of an oxetanyl group, an oxirane group, a group represented by the formula (3), a group represented by the formula (4), a group represented by the formula (5), and a thiiranyl group. S _c Represents a single bond or a 2-valent linking group.

In addition, in the formula (c-1-M), M _e Represents a3 rd polymerizable group. Examples of the 3 rd polymerizable group include the following formula (M) _c -1)～(M _c -2), α -methylene- γ -butyrolactone, maleimide, radical polymerizable groups of norbornene and its derivatives, and siloxanes.

Formula (M) _c -1)～(M _c In-2), Rc represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and represents a bonding site.

As M _e Preferably of the formula (M) _c -1)～(M _c -2), α -methylene- γ -butyrolactone, maleimide are preferred.

S as the aforementioned formula (c-1-m) _c The linking group having a valence of 2 in (1) includes, for example, an alkanediyl group having 1 to 10 (preferably 1 to 6) carbon atoms, an arylene group having 6 to 20 (preferably 6 to 14) carbon atoms, (. alpha.) -CONH-R ₆ - (. B) radical, (. A) -COO-R ₇ - (. about.B) group, etc. Herein, R is ₆ And R ₇ Independently represents a single bond, or an alkanediyl group having 1 to 12 (preferably 1 to 6) carbon atoms, an arylene group having 6 to 20 (preferably 6 to 14) carbon atoms, or an alkyleneoxyarylene group, any carbon-carbon bond of the alkanediyl group may have an-O-bond or an-S-bond, (. lambda.A) represents a bond to a carbon atom having an unsaturated bond, and (. beta.B) represents a bond to I _a1 The bonded atoms form bonds. Examples of the alkanediyl group include a methylene group, an ethylene group, an ethane-1, 1-diyl group, a propane-1, 2-diyl group, a propane-1, 3-diyl group, a propane-2, 2-diyl group and a butane-1, 2-diyl groupA base, a butane-1, 3-diyl group, a butane-1, 4-diyl group, a pentane-1, 5-diyl group, a hexane-1, 6-diyl group and the like. Examples of the arylene group include a phenylene group, a naphthylene group, a biphenylene group, and an anthracenylene group. Examples of the alkyleneoxyarylene group include an ethyleneoxyphenylene group, a hexyleneoxyphenylene group, and a hexyleneoxybiphenyl group. Wherein as S _a The linking group having a valence of 2 in (A) is preferably an alkanediyl group having 1 to 10 (preferably 1 to 6) carbon atoms, an arylene group having 6 to 20 (preferably 6 to 14) carbon atoms, or an (A) -COO-R group ₇ - (. about.B) radical as R ₇ Preferably, the alkanediyl group has 2 to 6 carbon atoms. One or more hydrogen atoms of each group 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 oxirane group include allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, 2-methylglycidyl methacrylate,. alpha. -ethylglycidyl acrylate,. alpha. -n-propylglycidyl acrylate,. alpha. -n-butylglycidyl acrylate, 3, 4-epoxybutyl methacrylate, 6, 7-epoxyheptyl acrylate, 6, 7-epoxyheptyl methacrylate,. alpha. -ethylglycidyl acrylate, 6, 7-epoxyheptyl acrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, n-vinylbenzyl glycidyl ether, p-n-vinylbenzyl glycidyl ether, p-and n-vinylbenzyl glycidyl ether, 3, 4-epoxycyclohexylmethyl methacrylate, 3-vinyl-7-oxabicyclo [4.1.0] heptane, 1, 2-epoxy-5-hexene, 1, 7-octadiene monoepoxide, and the like. Among them, glycidyl methacrylate, 2-methylglycidyl methacrylate, 6, 7-epoxyheptyl methacrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether and 3, 4-epoxycyclohexyl methacrylate are preferable from the viewpoint of improving the copolymerization reactivity, the alignment property of the liquid crystal alignment film and the like.

Specific examples of the oxetanyl group-containing formula (c-1-m) include, for example, 3- (acryloyloxymethyl) oxetane, 3- (acryloyloxymethyl) -2-methyloxetane, 3- (acryloyloxymethyl) -3-ethyloxetane, 3- (acryloyloxymethyl) -2-trifluoromethyloxetane, 3- (acryloyloxymethyl) -2-pentafluoroethyloxetane, 3- (acryloyloxymethyl) -2-phenyloxetane, 3- (acryloyloxymethyl) -2, 2-difluorooxetane, 3- (acryloyloxymethyl) -2,2, 4-trifluorooxetane, and, 3- (acryloyloxymethyl) -2,2,4, 4-tetrafluorooxetane, 3- (2-acryloyloxyethyl) oxetane, 3- (2-acryloyloxyethyl) -2-ethyloxetane, 3- (2-acryloyloxyethyl) -3-ethyloxetane, 3- (2-acryloyloxyethyl) -2-trifluoromethyloxetane, 3- (2-acryloyloxyethyl) -2-pentafluoroethyloxetane, 3- (2-acryloyloxyethyl) -2-phenyloxetane, 3- (2-acryloyloxyethyl) -2, 2-difluorooxetane, 3- (2-acryloyloxyethyl) -2, acrylates such as 2, 4-trifluorooxetane and 3- (2-acryloyloxyethyl) -2,2,4, 4-tetrafluorooxetane; 3- (methacryloxymethyl) oxetane, 3- (methacryloxymethyl) -2-methyloxetane, 3- (methacryloxymethyl) -3-ethyloxetane, 3- (methacryloxymethyl) -2-trifluoromethyloxetane, 3- (methacryloxymethyl) -2-pentafluoroethyloxetane, 3- (methacryloxymethyl) -2-phenyloxetane, 3- (methacryloxymethyl) -2, 2-difluorooxetane, 3- (methacryloxymethyl) -2,2, 4-trifluorooxetane, 3- (methacryloxymethyl) -2,2,4, 4-tetrafluorooxetane, 3- (2-methacryloyloxyethyl) oxetane, 3- (2-methacryloyloxyethyl) -2-ethyloxetane, 3- (2-methacryloyloxyethyl) -3-ethyloxetane, 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, and methacrylates such as 2, 4-trifluorooxetane and 3- (2-methacryloyloxyethyl) -2,2,4, 4-tetrafluorooxetane.

Specific examples of the formula (c-1-m) having a thienylpropyl group include compounds represented by the following formula (S)

(wherein 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 acryloyl, methacryloyl, allyl, or vinyl), or 2, 3-epithiopropyl acrylate or methacrylate, and 2-or 3-or 4- (. beta. -epithiopropylthiomethyl) styrene, 2-or 3-or 4- (. beta. -epithiopropyloxymethyl) styrene, 2-or 3-or 4- (. beta. -epithiopropylthio) styrene, 2-or 3-or 4- (. beta. -epithiopropyloxy) styrene, and the like.

The site having a thermally crosslinkable group contained in the polymer of the present invention may be used alone in 1 kind or in combination of 2 or more kinds.

The amount of the site having a thermally crosslinkable group introduced is preferably 1 to 40 mol%, or 1 to 30 mol%, or 5 to 30 mol%, or 2 to 30 mol%, or 5 to 25 mol% of the specific polymer 1 ((A) component).

(B) Compound having 2 or more groups selected from the group consisting of epoxy group, thiiranyl group, hydroxyalkylamide group and benzyl alcohol group in the molecule >

The component (B) used in the liquid crystal aligning agent according to embodiment 2 of the present invention is a compound having 2 or more groups selected from the group consisting of epoxy groups, thiiranyl groups, hydroxyalkylamide groups, and benzyl alcohol groups in the molecule. By forming such a structure, it is possible to promote the crosslinking reaction between the epoxy group or the thiirane group unevenly present in the upper layer portion of the liquid crystal alignment film and the amino group or the carboxyl group as the polar group (a-1) contained in the specific polymers of the above-mentioned 1 st and 2 nd, and to increase the crosslinking density of the film surface layer component. Accordingly, the anisotropy achieved by the photoreaction of (a-2) is likely to remain (be stored) in the film, and thus the liquid crystal alignment ability can be stabilized, and a liquid crystal alignment film excellent in liquid crystal alignment properties and pretilt angle expressive ability can be obtained.

The compound having 2 or more epoxy groups or thiirane groups in the molecule is not particularly limited as long as it has 2 or more epoxy groups or thiirane groups at the molecular terminal. Examples of the compound having 2 or more epoxy groups at the molecular end include an epoxy compound having at least 1 or more tertiary nitrogen atoms in the molecule, an epoxy compound having no nitrogen compound in the molecule, and the like.

Specific examples of the epoxy compound having at least 1 or more tertiary nitrogen atoms in the molecule include epoxy compounds having a structure represented by the following formulae (Ep-1) to (Ep-11), and epoxy compounds containing a nitrogen atom as a core of an aliphatic diamine. Among them, epoxy compounds having structures represented by (Ep-4) to (Ep-9), epoxy compounds containing a nitrogen atom with an aliphatic diamine as a core, and the like are preferable from the viewpoint of reactivity and availability.

X is a single bond, an aliphatic group having 1 to 6 carbon atoms, or an aromatic group, Y is any of methylene, ethylene, trimethylene, ethylidene, isopropylidene, vinylidene, oxy, imino, thio, or sulfonyl, R is a hydrogen atom, and ₁ ～R ₃ represents 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 1 or more tertiary nitrogen atoms in the molecule, compounds in which a tertiary nitrogen atom is bonded to at least 1 of an aliphatic group or an alicyclic group are preferable from the viewpoint that the firing time can be shortened.

Specific examples of the epoxy compound having at least 1 or more tertiary nitrogen atoms 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 '-tetraglycidyl-3, 3' -diaminodiphenylmethane, N, N, N ', N' -tetraglycidyl-4, 4 '-diaminodiphenylsulfide, N, N, N', N '-tetraglycidyl-1, 5-diaminonaphthalene, N, N, N', N '-tetraglycidyl-2, 7-diaminofluorene, N, N, N', N '-tetraglycidyl-4, 4' -diaminodiphenylether, 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-4, 4 '-diaminodiphenylether, 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-4, 5-diaminodiphenylether, N, N', N '-tetraglycidyl-4, N, N, N' -tetraglycidyl-diaminodiphenyl ether, N, N, N ', N' -tetraglycidyl-4, N, N, N ', N' -tetraglycidyl-4, N, 2, N, N, N, 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 ' -tetraglycidyl-4, 4 ' - (p-phenylenediisopropylidene) dianiline, N, N, N ', N ' -tetraglycidyl-4, 4 ' - (m-phenylenediisopropylidene) dianiline, 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 ' -diglycidylaminomethyl) 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 '-tetraglycidyl-diaminopropane, N' -tetraglycidyl-diaminobutane, N '-tetraglycidyl-diaminopentane, N' -tetraglycidyl-diaminohexane, N '-tetraglycidyl-diaminoheptane, N' -tetraglycidyl-diaminooctane, and the like.

Specific examples of the epoxy compound having no nitrogen compound in the molecule include bisphenol a type epoxy compounds such as trade names "Epikote 828", "Epikote 834", "Epikote 1001", "Epikote 1004", and "Epiclon 840", "Epiclon 850", "Epiclon 1050", "Epiclon 2055", and "Epikote 128" manufactured by mitsubishi chemical corporation, mitsubishi chemical corporation;

bisphenol F-type epoxy compounds such as "Epiclon 830S" manufactured by DAINIPPON INK AND CHEMICALS, INCORPORATED, "Epikote 807" manufactured by Mitsubishi chemical Co., Ltd., and "Epotote YDF-170", "Epotote YDF-175", "Epotote YDF-2004" manufactured by Nissan iron chemical Co., Ltd.;

bisphenol S type epoxy compounds such as "EBPS-200" manufactured by Japan chemical industry, "EPX-30" manufactured by Asahi Denka Co., Ltd., and "Epiclon EXA 1514" manufactured by DAINIPPON INK AND CHEMICALS, INCORPORATED;

bisphenol fluorene type epoxy compounds such as "BPFG" manufactured by Osaka Gas co., ltd., and bixylenol type or biphenyl type epoxy compounds such as "YL-6056", "YL-6021", "YX-4000H" manufactured by mitsubishi chemical corporation, or mixtures thereof;

hydrogenated bisphenol A type epoxy compounds such as "Epotote ST-2004", "ST-2007", "ST-3000" and the like, trade names of New Zealand iron and gold chemical Co., Ltd;

novolac type epoxy compounds such as "Epikote 152", "Epikote 154", trade name "D.E.N.431", "D.E.N.438" manufactured by Mitsubishi Chemical Company, trade name "Epiclon N-690" manufactured by DAINIPPON INK AND CHEMICALS, INCORPORATED "," Epiclon N-695 "," Epiclon N-730 "," Epiclon N-770 "," Epiclon N-865 ", trade name" Epotote YDCN-701 "," Epotote YDCN-704 "manufactured by Nippon Chemical Company, trade name" EPPN-201 "," EOCN-1025 "," EOCN-1020 "," EOCN-104S "," RE-306 "manufactured by Nippon Chemical Company;

brominated bisphenol A type epoxy compounds such as "Epikote YL-903" manufactured by Mitsubishi chemical corporation, "Epiclon 152" and "Epiclon 165" manufactured by DAINIPPON INK AND CHEMICALS, INCORPORATED, and "Epotote YDB-400" and "Epotote YDB-500" manufactured by Nissan Tekko chemical corporation;

epoxy compounds having a naphthalene skeleton such as trade names "ESN-190", "ESN-360" manufactured by Nippon chemical Co., Ltd., trade names "HP-4032", "EXA-4700", "EXA-4750" manufactured by DAINIPPON INK AND CHEMICALS, INCORPORATED;

epoxy compounds having a dicyclopentadiene skeleton such as "HP-7200" and "HP-7200H" manufactured by DAINIPPON INK AND CHEMICALS, INCORPORATED;

trihydroxyphenyl methane-type epoxy compounds such as "YL-933" manufactured by Mitsubishi chemical corporation, and "EPPN-501" and "EPPN-502" manufactured by Nippon chemical corporation;

alicyclic epoxy compounds such as "Celoxide 2011" manufactured by Dailuo chemical industries, the "Araldite CY 175" manufactured by Asahi Kasei Chemicals, the "Araldite CY 179" manufactured by Asahi Kasei Chemicals, and the "HBE-100" manufactured by Nippon Hizikia chemical industries, but the present invention is not limited thereto. These epoxy compounds may be used alone or in combination of 2 or more.

The compound having 2 or more thietanyl groups at the molecular terminals is obtained, for example, by converting the epoxy group of the epoxy compound having an epoxy group into a thietanyl group. The method for converting to a thiiranyl group is preferably a method in which a solution containing the epoxy compound having an epoxy group is continuously or intermittently added to a1 st solution containing a vulcanizing agent, and then a2 nd solution containing a vulcanizing agent is further continuously or intermittently added. By this method, the epoxy group can be converted into a thiiranyl group.

Examples of the vulcanizing agent include thiocyanates, thioureas, phosphine sulfides, dimethylthiocarboxamide, and N-methylbenzothiazole-2-thione. Examples of the thiocyanate include sodium thiocyanate, potassium thiocyanate, and sodium thiocyanate.

The use of the compound having 2 or more thiiranyl groups is preferable from the viewpoint that the firing time of the liquid crystal aligning agent can be shortened because the crosslinking reaction is further promoted.

The compound having 2 or more hydroxyalkylamide groups at the molecular end is not particularly limited with respect to other structures if the compound has a hydroxyalkylamide group, but a compound represented by the following formula (2) is one of preferable examples from the viewpoint of availability and the like.

In the formula, X ₂ Is an n-valent organic group containing an aliphatic hydrocarbon group or an aromatic hydrocarbon group having 1 to 20 carbon atoms, n is an integer of 2 to 6, R ₂ And R ₃ Each independently represents a hydrogen atom, or an 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 which may have a substituent, R ₂ And R ₃ At least 1 of them represents a hydrocarbon group substituted with a hydroxyl group.

Wherein X in the formula (2) ₂ The atom (b) in (c) is preferably a carbon atom which is not bonded to a carbonyl group and forms an aromatic ring from the viewpoint of liquid crystal alignment properties. In addition, X in the formula (2) ₂ The aliphatic hydrocarbon group is preferably one having 1 to 10 carbon atoms from the viewpoint of liquid crystal alignment properties and solubility, as described above.

In the formula (2), n represents an integer of 2 to 6, but n is preferably 2 to 4 from the viewpoint of solubility.

In the formula (2), R ₂ And R ₃ Each independently represents a hydrogen atom, or an 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 which may have a substituent, R ₂ And R ₃ At least 1 of (a) represents a hydrocarbon group substituted with a hydroxyl group. Wherein R is ₂ And R ₃ At least 1 of them is preferably, more preferably a structure represented by the following formula (4a) from the viewpoint of reactivity。

In the formula (3a), R ₄ ～R ₇ Each independently represents any of a hydrogen atom, a hydrocarbon group, or a hydrocarbon group substituted with a hydroxyl group.

Specific examples of the compound having 2 or more hydroxyalkylamide groups at the molecular end include the following compounds.

If the amount of the compound having a hydroxyalkylamide group is too large, unreacted components may be eluted into the liquid crystal, and reliability may be lowered. Therefore, the amount of the compound having a hydroxyalkylamide group to be added is preferably 0.1 to 40% by mass, more preferably 1 to 30% by mass, based on the polymer of the component (A).

Examples of the compound having 2 or more silanol groups at the molecular end include compounds having a silanol group in which a methyl group is sandwiched between hydroxyl groups and which is bonded to an aromatic ring. Among them, at least one compound selected from the group consisting of the compound represented by the following formula [1] and the compound represented by the following formula [2] is preferable.

In the formula, Y ₁ 、Y ₂ And Y ₃ Each independently represents 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 single bond, and all or a part of them may be bonded to form a cyclic structureA 2-valent saturated hydrocarbon group having 1 to 10 carbon atoms, wherein any hydrogen atom may be substituted with a fluorine atom, -NH-, -N (CH) ₃ ) -, formula [3]The radicals shown. t is t ₁ Is an integer of 2 to 4, t ₂ And t ₃ Each independently an integer of 1 to 3, and a and b each independently an integer of 1 to 3.

-P ₁ -Q ₁ -P ₂ - [3]

Formula [3]In, P ₁ And P ₂ Each independently an alkyl group having 1 to 5 carbon atoms, Q ₁ Represents an aromatic ring.

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

The hydrogen atoms of these aromatic rings may be substituted by 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.

Formula [2]]T in (1) ₂ And t ₃ More preferably an integer of 1 or 2. Further, a and b are more preferably 1 or 2.

Formula [2]]Z in ₁ In the case of a 2-valent saturated hydrocarbon group having 1 to 10, preferably 1 to 5 carbon atoms, all or a part of which may be bonded to form a cyclic structure, any hydrogen atom contained therein may be substituted with a fluorine atom.

As Z ₁ Examples of (3) include an alkylene group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, and a group having 1 to 10 carbon atoms, which is a combination of the alkylene group and the alicyclic hydrocarbon group. Further, there may be mentioned those in which any hydrogen atom of the above-mentioned groups is substituted with a fluorine atom.

Formula [ 3]]In (1) Q ₁ Specific examples of the aromatic ring include a benzene ring, a naphthalene ring, a tetrahydronaphthalene ring, an azulene ring, an indene ring, a fluorene ring, an anthracene ring, a phenanthrene ring, a phenalene ring, a pyrrole ring, an imidazole ring, an oxazole ring, a thiazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a quinoline ring, a pyrazoline ring, an isoquinoline ring, a carbazole ring, a purine ring, a thiadiazole ring, a pyridazine ring, a triazine ring, a pyrazolidine ring, a triazole ring, a pyrazine ring, a benzimidazole ring, a quinoline 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 rings, naphthalene rings, fluorene rings, anthracene rings, pyrrole rings, imidazole rings, pyrazole rings, pyridine rings, pyrimidine rings, quinoline rings, isoquinoline rings, carbazole rings, pyridazine rings, pyrazine rings, benzimidazole rings, indole rings, quinoxaline rings, acridine rings, and the like. Further preferable examples include a benzene ring, a naphthalene ring, a pyridine ring, a carbazole ring, and a fluorene ring.

Examples of the compound having 2 or more silanol groups at the molecular end include compounds [ P1] to [ P45], but are not limited thereto.

The compound having 2 or more benzyl alcohol groups at the molecular end is preferably a compound represented by [ P13], [ P15], [ P18], [ P20] or [ P26], and more preferably a compound represented by [ P13], [ P18] or [ P20 ].

(B) The amount of the component (B) is preferably 0.1 to 40 parts by mass, more preferably 0.5 to 20 parts by mass, based on 100 parts by mass of the 1 st and/or 2 nd specific polymer contained in the liquid crystal aligning agent.

The component (B) may be used alone or in combination of 2 or more compounds.

< solvent >

The solvent used in the liquid crystal aligning agent of the present invention is not particularly limited as long as it dissolves the 1 st and 2 nd specific polymers.

Specific examples thereof include water, N-alkyl-2-pyrrolidones such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, dialkyl imidazolinones such as N, N-dimethylformamide, N-dimethylacetamide, N-methylcaprolactam, tetramethylurea, 3-methoxy-N, N-dimethylpropanamide, 3-ethoxy-N, N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropanamide and 1, 3-dimethyl-2-imidazolidinone, lactones such as γ -butyrolactone, γ -valerolactone and δ -valerolactone, carbonates such as ethylene carbonate and propylene carbonate, carbonates such as propylene carbonate, and the like, Methanol, ethanol, propanol, isopropanol, 3-methyl-3-methoxybutanol, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, isoamyl methyl ketone, methyl isopropyl ketone, diisobutyl ketone, cyclohexanone, methyl isobutyl ketone, 4-hydroxy-4-methyl-2-pentanone, and other ketones, the compound represented by the following formula (Sv-1) and the compound represented by the following formula (Sv-2), 4-methyl-2-pentyl acetate, 2-ethyl butyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, 2-methyl cyclohexyl acetate, butyl butyrate, isoamyl butyrate, diisobutyl methanol, diisoamyl ether, and the like.

In the formulae (Sv-1) to (Sv-2), Y ₁ And Y ₂ Each independently is a hydrogen atom or a C1-6 hydrocarbon group, X ₁ Is an oxygen atom or-COO-, X ₂ Is a single bond or a carbonyl group, R ₁ Is C2-4 alkaneA hydrocarbon diradical. n is ₁ Is an integer of 1 to 3. n is ₁ In the case of 2 or 3, a plurality of R ₁ May be the same or different. Z is a linear or branched member ₁ Is a C1-6 2-valent hydrocarbon group, Y ₃ And Y ₄ Each independently includes a hydrogen atom or a 1-valent hydrocarbon group having 1 to 6 carbon atoms).

In the formula (Sv-1), as Y ₁ And Y ₂ Examples of the 1-valent hydrocarbon group having 1 to 6 carbon atoms include a 1-valent chain hydrocarbon group having 1 to 6 carbon atoms, a 1-valent alicyclic hydrocarbon group having 1 to 6 carbon atoms, and a 1-valent aromatic hydrocarbon group having 1 to 6 carbon atoms. Examples of the 1-valent chain hydrocarbon group having 1 to 6 carbon atoms include alkyl groups having 1 to 6 carbon atoms. R is ₁ The alkanediyl group (b) may be linear or branched.

In the formula (Sv-2), as Z ₁ Examples of the C1-6 2-valent hydrocarbon group include C1-6 alkanediyl groups.

As Y ₃ And Y ₄ Examples of the 1-valent hydrocarbon group having 1 to 6 carbon atoms include a 1-valent chain hydrocarbon group having 1 to 6 carbon atoms, a 1-valent alicyclic hydrocarbon group having 1 to 6 carbon atoms, and a 1-valent aromatic hydrocarbon group having 1 to 6 carbon atoms. Examples of the 1-valent chain hydrocarbon group having 1 to 6 carbon atoms include alkyl groups having 1 to 6 carbon atoms.

Specific examples of the solvent represented by the formula (Sv-1) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-isopropyl 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 acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl 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, propylene glycol diacetate, ethylene glycol, propylene glycol, ethylene glycol, 1, 4-butanediol, ethylene glycol, propylene glycol monomethyl ether, propylene glycol diacetate, propylene glycol, ethylene glycol, propylene glycol ether, propylene glycol ether, propylene glycol ether, 3-ethoxybutyl acetate and the like;

specific examples of the solvent represented by (Sv-2) include methyl glycolate, ethyl glycolate, butyl glycolate, ethyl lactate, butyl lactate, isoamyl lactate, ethyl-3-ethoxypropionate, methyl-3-methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, and the like.

The solvent preferably has a boiling point of 80 to 200 ℃. More preferably from 80 ℃ to 180 ℃, and preferable examples of the solvent include N, N-dimethylformamide, tetramethylurea, 3-methoxy-N, N-dimethylpropanamide, propanol, isopropanol, 3-methyl-3-methoxybutanol, 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-ethyl butyl acetate, cyclohexyl acetate, 2-methyl cyclohexyl acetate, butyl butyrate, isoamyl butyrate, diisobutyl methanol, diisoamyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-N-propyl ether, methyl isopropyl ketone, diisobutyl ketone, cyclohexanone, methyl isobutyl ketone, 4-hydroxy-4-methyl-2-pentanone, 4-methyl-2-pentyl acetate, 2-ethyl butyl acetate, cyclohexyl acetate, 2-methyl cyclohexyl acetate, butyl butyrate, isoamyl butyrate, diisobutyl methanol, diisoamyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-N-propyl ether, and the like, Ethylene glycol-isopropyl 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 acetate, propylene glycol monobutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monomethyl ether, 3-methoxybutyl acetate, methyl glycolate, ethyl glycolate, butyl glycolate, ethyl lactate, butyl lactate, isoamyl lactate, ethyl-3-ethoxypropionate, methyl-3-methoxypropionate, ethyl 3-methoxypropionate, and the like.

The boiling point is preferably in this range, particularly when the liquid crystal aligning agent containing the solvent is applied to a plastic substrate described later.

< Process for producing specific Polymer >

The specific polymers 1 and 2 contained in the liquid crystal aligning agent of the present invention are obtained by polymerizing the above-mentioned (a-1) monomer having at least 1 functional group selected from a carboxyl group, an amino group and a hydroxyl group in the molecule, (b) monomer containing a site having photo-alignment properties, and (c) monomer having a thermally crosslinkable group with respect to the specific polymer 1. In addition, it may be copolymerized with other monomers than those described above. Examples of the other monomers include industrially available monomers capable of radical polymerization.

Specific examples of the other monomer include an acrylate compound, a methacrylate compound, a maleimide compound, acrylonitrile, maleic anhydride, a styrene compound, a vinyl compound, and the like, an acrylamide compound such as N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, and the like, and a monomer containing a nitrogen-containing aromatic heterocyclic group and a polymerizable group.

Examples of the acrylate compound include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl methyl acrylate, phenyl acrylate, 2,2, 2-trifluoroethyl acrylate, t-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, and 8-ethyl-8-tricyclodecyl acrylate.

Examples of the methacrylate compound include alkyl-containing methacrylates such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, hexadecyl methacrylate and octadecyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthryl 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, and mixtures thereof, 2-propyl-2-adamantyl methacrylate, 8-methyl-8-tricyclodecyl methacrylate, and 8-ethyl-8-tricyclodecyl methacrylate, and the like.

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, and bromostyrene.

The nitrogen-containing aromatic heterocycle is a nitrogen-containing aromatic heterocycle having a structure selected from the group consisting of the following formula [ N-a]～[N-b](in the formula, Z ₂ A linear or branched alkyl group having 1 to 5 carbon atoms) and preferably 1 to 4.

Specific examples thereof include an oxazole ring, a thiazole ring, a pyridine ring, a pyrimidine ring, a quinoline ring, a 1-pyrazoline ring, an isoquinoline ring, a thiadiazole ring, a pyridazine ring, a triazine ring, a pyrazine ring, a phenanthroline ring, a quinoxaline ring, a benzothiazole ring, an oxadiazole ring and an acridine ring. Further, the carbon atom of the nitrogen-containing aromatic heterocyclic ring may have a substituent containing a hetero atom. Among them, for example, a pyridine ring is exemplified.

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

Examples of the acrylamide compound include, in addition to the above-mentioned N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide and acrylamide, methacrylamide, N-methacrylamide, N-dimethylacrylamide, N-diethylacrylamide, N- (meth) methacrylamide, N- (dimethyl) methacrylamide, N- (diethyl) methacrylamide and the like.

The other monomers used in the present invention may be used alone in 1 kind or in combination of 2 or more kinds.

The content of the other monomer is preferably 0 to 60 mol%, 0 to 40 mol%, or 1 to 40 mol%, or 5 to 40 mol%, 60 to 99 mol%, or 60 to 95 mol%, 0 to 20 mol%, or 1 to 20 mol%, or 5 to 20 mol% of the specific polymer 1 (component (A)). In this case, the total of the site having a polar group in the molecule, the photoreactive site and the site having thermal crosslinking properties is preferably 40 to 100 mol%, 60 to 100 mol%, 80 to 100 mol%, or 80 to 99 mol%, or 80 to 95 mol% of the component (A) of the specific polymer (1).

The content of the other monomer is preferably 0 to 60 mol%, 0 to 40 mol%, 1 to 40 mol%, or 5 to 40 mol% of the specific polymer 2 ((A) component). In this case, the total of the site having a polar group in the molecule and the photoreactive site is preferably 40 to 100 mol%, 60 to 99 mol%, or 60 to 95 mol% of the specific polymer 2 ((A) component).

The method for producing the specific polymer of the 1 st or 2 nd aspect of the present invention is not particularly limited, and a general method which is industrially practiced can be used. Specifically, the polymer can be produced by cationic polymerization, radical polymerization, or anionic polymerization of a vinyl group using a monomer. Among them, radical polymerization is particularly preferable from the viewpoint of easiness of reaction control and the like.

As the polymerization initiator for radical polymerization, known compounds such as radical polymerization initiators and reversible addition-fragmentation chain transfer (RAFT) polymerization reagents can be used.

The radical thermal polymerization initiator is a compound that generates radicals by heating to a temperature higher than the decomposition temperature. Examples of such a radical thermal polymerization initiator include ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), diacyl peroxides (acetyl peroxide, benzoyl peroxide, etc.), hydrogen peroxides (hydrogen peroxide, t-butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-t-butyl peroxide, diisopropylbenzene peroxide, dilauroyl peroxide, etc.), peroxyketals (e.g., dibutylperoxycyclohexane), alkyl peroxyesters (e.g., tert-butyl peroxyneodecanoate, tert-butyl peroxypivalate, and 2-ethylcyclohexanoate-tert-amyl peroxide), persulfates (e.g., potassium persulfate, sodium persulfate, and ammonium persulfate), azo compounds (e.g., azobisisobutyronitrile and 2, 2' -bis (2-hydroxyethyl) azobisisobutyronitrile).

Such radical thermal polymerization initiators may be used in 1 kind alone or in combination of 2 or more kinds.

The radical photopolymerization initiator is not particularly limited as long as it is a compound that initiates radical polymerization by irradiation with light. Examples of such a radical photopolymerization initiator include known compounds such as benzophenone, michler's ketone, 4' -bis (diethylamino) benzophenone, xanthone, thioxanthone, and isopropyl xanthone. These compounds may be used alone or in combination of 2 or more.

The radical polymerization method is not particularly limited, and emulsion polymerization, suspension polymerization, dispersion polymerization, precipitation polymerization, bulk polymerization, solution polymerization, and the like can be used.

The solvent used in the polymerization reaction of the specific polymers of the 1 st and 2 nd is not particularly limited as long as it is a solvent in which the formed polymer is dissolved. Specific examples thereof include the above solvents, for example, N-alkyl-2-pyrrolidones, dialkyl imidazolinones, lactones, carbonates, ketones, the compounds represented by the above formula (Sv-1) and the compounds represented by the above formula (Sv-2), tetrahydrofuran, 1, 4-dioxane, dimethyl sulfone, dimethyl sulfoxide, and hexamethylsulfoxide.

These solvents may be used alone or in admixture thereof. Further, even if the solvent does not dissolve the polymer to be produced, the solvent may be mixed and used within a range where the polymer to be produced does not precipitate.

In addition, in radical polymerization, oxygen in a solvent becomes a cause of inhibiting a polymerization reaction, and therefore, it is preferable to use an organic solvent which is degassed as much as possible.

The polymerization temperature in the radical polymerization may be any temperature of 30 to 150 ℃, but is preferably in the range of 50 to 100 ℃. The reaction may be carried out at any concentration, but the monomer concentration is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction may be carried out at a high concentration in the initial stage of the reaction and then an organic solvent may be added.

In the radical polymerization reaction, the molecular weight of the resulting polymer decreases when the proportion of the radical polymerization initiator to the monomer is large, and increases when the proportion of the radical polymerization initiator to the monomer to be polymerized is small, and therefore the proportion of the radical polymerization initiator to the monomer to be polymerized is preferably 0.1 to 10 mol%. In addition, various monomer components, solvents, initiators, and the like may be added during the polymerization.

[ recovery of Polymer ]

When the polymer produced is recovered from the reaction solution obtained by the above reaction, the reaction solution may be introduced into a poor solvent to precipitate the polymer. Examples of the poor solvent used for the precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, heptane, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, and water. The polymer precipitated by the addition of the poor solvent may be filtered and recovered, and then dried at normal pressure or reduced pressure, normal temperature or under heating. Further, the impurities in the polymer can be reduced by repeating the operation of re-dissolving the polymer recovered by precipitation in the organic solvent and re-precipitating and recovering the polymer 2 to 10 times. Examples of the poor solvent in this case include alcohols, ketones, hydrocarbons, and the like, and the use of 3 or more poor solvents selected from these is preferable because the purification efficiency is further improved.

The molecular weight of the polymer of the present invention is preferably 2000 to 1000000, more preferably 5000 to 100000, as measured by a Gel Permeation Chromatography (GPC Gel Permeation Chromatography) method, in consideration of the strength of the obtained coating film, workability at the time of forming the coating film, and uniformity of the coating film.

< production of liquid Crystal alignment agent >

The liquid crystal aligning agent (i.e., polymer composition) used in the present invention is preferably produced as a coating liquid in a manner suitable for forming a liquid crystal alignment film. That is, the liquid crystal aligning agent of the present invention is preferably produced as a solution in which a resin component for forming a resin coating is dissolved in an organic solvent. The resin component herein refers to the specific polymers ((a) component) of the 1 st and 2 nd parts already described. In this case, the content of the 1 st specific polymer is preferably 0.5 to 20% by mass, more preferably 1 to 20% by mass, further preferably 1 to 15% by mass, and particularly preferably 1 to 10% by mass, based on the total amount of the liquid crystal aligning agent. The content of the 2 nd 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 based on the whole liquid crystal aligning agent.

In the polymer composition of the present embodiment, the resin component may be a polymer including all of the above-described site having a polar group, the site having photo-alignment properties, and the site having a thermally crosslinkable group in the case of the specific polymer 1, but other polymers (hereinafter, also referred to as "other polymers") may be mixed. In this case, 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 based on 100 parts by mass of the total of the component (A) and the other polymer.

Such other polymers include, for example, poly (meth) acrylates, polyamic acids, polyamic acid esters, polyimides, and the like, and in the case of the invention using the specific polymer of item 1, examples thereof include polymers not having the sites (A-1) to (A-3) of the 1 st specific polymer, and when the 2 nd specific polymer is used in the present invention, examples thereof include polymers not having the sites (A-1) to (A-2) of the 2 nd specific polymer, and in the case of the 1 st specific polymer, examples thereof include polymers having only 1 type and 2 types of sites selected from (A-1) to (A-3), and in the case of the 2 nd specific polymer, examples thereof include polymers having only any one of (A-1) to (A-2).

< other ingredients >

The liquid crystal aligning agent of the present invention may contain other components in addition to the above-mentioned specific polymer components. Examples of such other components include the component (B) used in embodiment 2, i.e., a compound having 2 or more groups of at least 1 selected from the group consisting of an epoxy group, a thiiranyl group, a hydroxyalkylamide group, and a benzyl alcohol group in the molecule; and other crosslinkable compounds (hereinafter, these may be collectively referred to as "crosslinking agent components"), compounds that improve the uniformity of film thickness and surface smoothness when the liquid crystal alignment agent is applied, 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. A compound having 2 or more groups selected from at least 1 group consisting of an epoxy group, a thiiranyl group, a hydroxyalkylamide group and a benzyl alcohol group in a molecule

The component (B) is the above-mentioned component (B). The component (B) used in the embodiment 2 may be contained in the embodiment 1.

2. Other crosslinkable compounds

Examples of the other crosslinkable compound include a compound having an isocyanate group, an oxetanyl group or a cyclocarbonate group, a compound having at least 1 group selected from the group consisting of a hydroxyl group, a hydroxyalkyl group and a lower alkoxyalkyl group, and a compound having a blocked isocyanate group, which are described in paragraphs [0109] to [0113] of international publication No. WO 2016/047771.

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

(B) The amount of the component (a) or the crosslinking agent component (b) is preferably 0.1 to 40 parts by mass, more preferably 0.1 to 30 parts by mass, and still more preferably 1 to 20 parts by mass, based on 100 parts by mass of the resin component contained in the polymer composition.

[ Compound for improving film thickness uniformity and surface smoothness ]

Examples of the compound for improving the uniformity of the film thickness and the surface smoothness include a fluorine-based surfactant, a silicone-based surfactant, and a nonionic surfactant.

Specific examples thereof include Eftop (registered trademark) 301, EF303, EF352 (manufactured by Tohkem Products Corp.), Megaface (registered trademark) F171, F173, R-30 (manufactured by DIC), Fluorad FC430, FC431 (manufactured by Sumitomo 3M Limited), Asahiguard (registered trademark) AG710 (manufactured by Asahi Nitro corporation), Surflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, and 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, based on 100 parts by mass of the resin component contained in the polymer composition.

[ Compound for improving the adhesion between the liquid Crystal alignment film and the substrate ]

Specific examples of the compound for improving the adhesion between the liquid crystal alignment film and the substrate include the following functional silane-containing compounds.

Examples thereof include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureylpropyltrimethoxysilane, 3-ureylpropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, N-aminopropyltriethoxysilane, N-glycidyltriethoxysilane, N-hydroxyiminopropyltriethoxysilane, N-acylurea-propyltriethoxysilane, N-acylurea-propyltrimethoxysilane, N-acyltrimethoxysilane, N-isopropyltriethoxysilane, N-acyltrimethoxysilane, N-isopropyltriethoxysilane, N-methyldimethoxysilane, and the like, 10-trimethoxysilyl-1, 4, 7-triazacyclodecane, 10-triethoxysilyl-1, 4, 7-triazacyclodecane, 9-trimethoxysilyl-3, 6-diaza-nonyl acetate, 9-triethoxysilyl-3, 6-diaza-nonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, amino silane-containing compounds such as N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane and N-bis (oxyethylene) -3-aminopropyltriethoxysilane.

When a compound for improving adhesion to a substrate is used, the amount thereof is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the resin component contained in the polymer composition.

In one embodiment, a photosensitizer may be used as an additive for improving the photoreactivity of the photo-alignment group. Specific examples thereof include aromatic 2-hydroxyketones (benzophenone), coumarins, carbonylbiscoumarins, acetophenones, anthraquinones, xanthones, thioxanthones, and acetophenone ketals.

< liquid Crystal alignment film and liquid Crystal display element >

The liquid crystal aligning agent of the present invention may be applied to a substrate, fired, and then subjected to alignment treatment such as rubbing treatment or light irradiation, or may be used for forming a liquid crystal alignment film without alignment treatment in some vertical alignment applications. As the substrate, for example, glass such as float glass and soda glass; a transparent substrate formed of plastic such as polyethylene terephthalate, polybutylene terephthalate, polypropylene, polystyrene, polyethersulfone, polycarbonate, poly (alicyclic olefin), polyvinyl chloride, polyvinylidene chloride, Polyetheretherketone (PEEK) resin film, Polysulfone (PSF), Polyethersulfone (PES), polyamide, polyimide, acrylic, and triacetyl cellulose.

As the transparent conductive film provided on one surface of the substrate, tin oxide (SnO) can be used ₂ ) The formed NESA film (registered trademark of PPG corporation, USA) is made of indium oxide-tin oxide (In) ₂ O ₃ -SnO ₂ ) An ITO film formed, and the like.

< coating film Forming step >

The method for applying the liquid crystal aligning agent of the present invention is not particularly limited, and screen printing, flexo printing, offset printing, ink jet, dip coating, roll coating, slit coating, spin coating, and the like can be used as necessary. After coating on a substrate by these methods, a coating film can be formed by evaporating a solvent by a heating means such as a hot plate.

The baking after the application of the liquid crystal aligning agent may be carried out at any temperature of 40 to 300 ℃, preferably 40 to 250 ℃, more preferably 40 to 230 ℃. When a transparent substrate formed of a plastic substrate is used, the temperature is preferably 40 to 150 ℃, more preferably 80 to 140 ℃. 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 1000nm, more preferably 10 to 500nm or 10 to 300 nm. Such firing may be performed by a hot plate, a hot air circulating furnace, an infrared furnace, or the like.

The rubbing treatment may be rayon cloth, nylon cloth, cotton cloth, or the like.

< light irradiation step >

In one embodiment, the alignment treatment may be performed by light irradiation, and for example, the alignment treatment may include a step of applying the liquid crystal alignment agent onto a substrate to form a coating film, and a step of irradiating the coating film with light in a state where the coating film is not in contact with the liquid crystal layer or in contact with the liquid crystal layer.

Examples of the light irradiated in the alignment treatment by light irradiation include ultraviolet rays and visible rays containing light having a wavelength of 150 to 800 nm. Among them, ultraviolet rays containing light having a wavelength of 300 to 400nm are preferable. The illumination light may be polarized or unpolarized. As the polarized light, light containing linearly polarized light is preferably used.

When the light to be used is polarized light, the irradiation with light may be performed in a direction perpendicular to the substrate surface or in an oblique direction, or may be performed by combining these directions. When non-polarized light is irradiated, it is preferable that the irradiation be performed in an oblique direction with respect to the substrate surface.

The irradiation amount of light is preferably 0.1mJ/cm ² More than and less than 1000mJ/cm ² More preferably 1 to 500mJ/cm ² More preferably 2 to 200mJ/cm ² 。

The liquid crystal display element of the present invention can be produced by a general method, and the production method is not particularly limited. The pair of substrates face each other with an appropriate gap therebetween, and a spacer is preferably disposed between the substrates in order to make the thickness of the liquid crystal layer sandwiched between the substrates uniform. As the spacer, a known spacer material such as a conventional dispersion spacer or a spacer formed from a photosensitive spacer-forming composition can be used, and in addition, a concave-convex formed in a layer formed from a cured liquid crystal material can be used as the spacer.

< liquid Crystal holding step >

For example, the following 2 methods are used to sandwich liquid crystal between substrates to form a liquid crystal cell. As the method 1, a method is given in which a pair of substrates are opposed to each other via a gap (cell gap) so that liquid crystal alignment films are opposed to each other, peripheral portions of the pair of substrates are bonded to each other using a sealant, a liquid crystal is filled into the cell gap defined by the substrate surface and an appropriate sealant, and then the filling hole is sealed to produce a liquid crystal cell.

As the method 2, there is a method (odf (one Drop fill) method) in which an ultraviolet-curable sealing material is applied to a predetermined position on one of 2 substrates on which a liquid crystal alignment film is formed, liquid crystal is dropped onto a predetermined number of liquid crystal alignment film surfaces, then the other substrate is bonded to the liquid crystal alignment film surface, the liquid crystal is spread over the entire surface of the substrate, and then ultraviolet light is applied to the entire surface of the substrate to cure the sealing material, thereby producing a liquid crystal cell.

As the liquid crystal, a fluorine-based liquid crystal having positive and negative dielectric anisotropy, a cyano-based liquid crystal, or a liquid crystal compound or a liquid crystal composition (hereinafter, also referred to as a polymerizable liquid crystal or a curable liquid crystal composition) which is polymerized by at least 1 treatment of heating and light irradiation may be used depending on the application.

In one embodiment, the step of forming the coating film of the liquid crystal aligning agent may be performed by a Roll-to-Roll (Roll) method. The roll-to-roll method simplifies the manufacturing process of the liquid crystal display element, and thus can reduce the manufacturing cost.

Then, polarizing plates are attached to both outer sides of the liquid crystal cell, whereby a liquid crystal display element can be obtained.

Examples of the polarizing plate used outside the liquid crystal cell include a polarizing film called "H film" obtained by stretching and orienting polyvinyl alcohol and absorbing iodine, a polarizing plate obtained by sandwiching the polarizing film with a cellulose acetate protective film, and a polarizing plate formed of an H film itself.

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. In addition, the liquid crystal display element manufactured by the method of the present invention has excellent display characteristics.

Examples

The monomers having photo-alignment groups (hereinafter referred to as "photo-alignment monomers") used in examples, the monomers denoted by "MA-1" and "MA-2" are described below, the monomers denoted by "MAA" and "VBA" are described below, the monomers denoted by "crosslinkable groups (hereinafter referred to as" crosslinkable monomers "), the monomers denoted by" GMA "are described below, the compounds denoted by component (B) (hereinafter referred to as" crosslinker component "), and the structures of the compounds denoted by" tetra-C "and" YH-434-L "are described below.

"MA-2" was synthesized by the synthesis method described in synthetic example 1 below. As "MAA (methacrylic acid)", "VBA (vinylbenzoic acid)", "MMA", "C18", and "TETRAD-C" and "YH-434-L", commercially available reagents were used.

(photo-alignment monomer)

(polar monomer)

MAA: methacrylic acid (MAA)

VBA: 4-vinyl benzoic acid

(crosslinkable monomer)

GMA: glycidyl methacrylate

(other monomers)

MMA: methacrylic acid methyl ester

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: a beta-hydroxyalkylamide represented by the following formula (Primid)

Note that the reagents used in the present example are abbreviated as follows.

(polymerization initiator)

AIBN: azobisisobutyronitrile

(solvent)

PGME: propylene glycol monomethyl ether

CHN: cyclohexanone

< ¹ Measurement of HNMR>

The device comprises the following steps: fourier transform 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).

< example 1 for monomer Synthesis

Synthesis of [ MA-1 ]:

to a 2L four-necked flask, 1-bromo-4- (trans-4-propylcyclohexyl) -benzene (150.0g, 533 mmol), tert-butyl acrylate (102.5g, 800 mmol), palladium acetate (2.39g, 11 mmol), tri (o-tolyl) phosphine (6.49g, 21 mmol), tripropylamine (229.3g, 1600 mmol), and DMAc (750g) were added, and stirring was carried out while heating to 100 ℃. After completion of the reaction, the reaction mixture was filtered to remove insoluble materials, and the filtrate was poured into pure water (3.8L) and neutralized with 12N-HCl aqueous solution. After neutralization, ethyl acetate (2.5L) was injected and extracted. Anhydrous magnesium sulfate was added to the extracted organic layer to conduct dehydration and drying, and the anhydrous magnesium sulfate was filtered. The obtained filtrate was subjected to distillation to remove the solvent by a rotary evaporator, and the crude product was subjected to reslurry washing with cold methanol (180g), whereby 144.0g of [ MA-1-1] (white solid) (yield 82%) was obtained.

To a 2L four-necked flask was added [ MA-1]](144.0g, 441 mmol) and formic acid (1000g), and they were stirred while being heated to 50 ℃. After completion of the reaction, the reaction mixture was poured into pure water (3.0L), and the precipitate was filtered. The obtained crude product was subjected to repulping washing with ethyl acetate (200g), whereby [ MA-1-2 ] was obtained](white solid) 111.1g (yield 92%). Of the object ¹ The results of H-NMR are shown below. From the results, it was confirmed that [ MA-1-2 ] was used as an objective solid]。

1H NMR(400MHz,[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).

To a 2L four-necked flask was added [ MA-1-2 ]](30.0g, 110 mmol), 2-hydroxyethyl methacrylate (17.2g, 132 mmol), 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (EDC) (25.7g, 165 mmol), 4-dimethylaminopyridine (1.35g, 11 mmol) and THF (150g) and stirred at room temperature. After completion of the reaction, the reaction mixture was poured into ethyl acetate (1.0L) and extracted with pure water (800 ml). Anhydrous magnesium sulfate was added to the extracted organic layer to conduct dehydration drying, and the anhydrous magnesium sulfate was filtered. The solvent was distilled off from the obtained filtrate by using a rotary evaporator. The obtained residue was separated by silica gel column chromatography (ethyl acetate: hexane: 1:5 by volume), whereby [ MA-1] was obtained](white solid) 26.8g (yield 55%). Of the object ¹ The results of H-NMR are shown below. From the results, it was confirmed that [ MA-1] was an object of the obtained solid]。

1H NMR(400MHz,[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).

< example 2 for monomer Synthesis

Synthesis of [ MA-2 ]:

to a 2L four-necked flask, 1-bromo-4- (trans-4-pentylcyclohexyl) -benzene (150.0g, 485 mmol), tert-butyl acrylate (93.24g, 728 mmol), palladium acetate (2.18g, 9.7 mmol), tri (o-tolyl) phosphine (5.90g, 20 mmol), tripropylamine (208.5g, 1455 mmol), and DMAc (750g) were added, and stirring was performed while heating to 100 ℃. After completion of the reaction, the reaction mixture was filtered to remove insoluble materials, and the filtrate was poured into pure water (3.8L) and neutralized with 12N-HCl aqueous solution. After neutralization, ethyl acetate (2.5L) was injected and extracted. Anhydrous magnesium sulfate was added to the extracted organic layer to conduct dehydration drying, and the anhydrous magnesium sulfate was filtered. The obtained filtrate was subjected to distillation to remove the solvent by a rotary evaporator, and the crude product was subjected to repulping washing with cold methanol (190g), whereby 137.0g of [ MA-2-1] (white solid) (yield 79%) was obtained.

To a 2L four-necked flask was added [ MA-2-1]](137.0g, 384 mmol) and formic acid (1000g) were stirred while heating to 50 ℃. After completion of the reaction, the reaction mixture was poured into pure water (3.0L), and the precipitate was filtered. The obtained crude product was subjected to repulping washing with ethyl acetate (200g), whereby [ MA-2] was obtained](white solid) 111.8g (yield 96%). Of the object ¹ The results of H-NMR are shown below. From the results, it was confirmed that [ MA-2] was used as an objective solid]。

1H NMR(400MHz,[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).

To a 2L four-necked flask was added [ MA-2]](30.0g, 100 mmol), 2-hydroxyethyl methacrylate (15.6g, 119 mmol), 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (EDC) (28.7g, 150 mmol), 4-dimethylaminopyridine (1.22g, 10 mmol), THF (150g), and the mixture was stirred at room temperature. After completion of the reaction, the reaction mixture was poured into ethyl acetate (1.0L) and extracted with pure water (800 ml). Anhydrous magnesium sulfate was added to the extracted organic layer to conduct dehydration and drying, and the anhydrous magnesium sulfate was filtered. The solvent was distilled off from the obtained filtrate by using a rotary evaporator. The obtained residue was separated by silica gel column chromatography (ethyl acetate: hexane: 1:5 by volume), whereby [ MA-2] was obtained](white solid) 36.6g (yield 88%). Of the object ¹ The results of H-NMR are shown below. From the results, it was confirmed that [ MA-2] was used as a solid]。

1H NMR(400MHz,[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).

(measurement of molecular weight)

The molecular weight of the polymer in the synthesis examples was measured as follows using a Normal temperature Gel Permeation Chromatography (GPC) apparatus (SSC-7200, columns (KD-803, KD-805) manufactured by Shodex, Inc.) manufactured by Senshu Scientific co., ltd.

Column temperature: 50 deg.C

Eluent: DMF (as additive, lithium bromide-hydrate (LiBr. H) ₂ O) 30 mmol/L, phosphoric acid anhydrous crystal (orthophosphoric acid) 30 mmol/L, THF 10ml/L)

Flow rate: 1.0 ml/min

Standard curve preparation standard samples: TSK standard polyethylene oxide (molecular weight of about 9000000, 150000, 100000, 30000) manufactured by TOSOH CORPORATION, and polyethylene glycol (molecular weight of about 12000, 4000, 1000) manufactured by Polymer Laboratories Ltd.

< Synthesis example of methacrylate Polymer A1>

MA-2(2.48g, 6.01 mmol), GMA (0.14g, 1.00 mmol) and MAA (1.2g, 13.0 mmol) were dissolved in CHN (11.0g) and PGME (11.0g), and after degassing by a diaphragm pump, AIBN (0.2g, 1.0 mmol) as a polymerization initiator was added and degassing was performed again. Then reacted at 60 ℃ for 13 hours to obtain a polymer solution (MP-1).

The polymer had a number average molecular weight of 40500 and a weight average molecular weight of 138300.

< Synthesis examples of methacrylic ester polymers A2-A10 and A11-A18 >

Methacrylate polymers PA2 to PA10 and PA11 to PA18 were synthesized in the same manner as in Polymer Synthesis example A1, using the compositions shown in Table 1.

< example A1>

To 4.0g of the polymer solution (MP-1) obtained in methacrylate polymer Synthesis example A1, CHN (5.5g), PGME (5.5g) and TETRAD-C (0.03g) were added and the mixture was stirred at room temperature to obtain a liquid crystal aligning agent (PM-A1).

< examples A2 to A23 and A24 to PA40, comparative example A1>

Liquid crystal alignment agents (PM-A2) to (PM-A23) and (PM-A24) to (PM-A40) were obtained in the same manner as in example A1 and having the compositions shown in Table 2. The liquid crystal aligning agent of comparative example A1 (RPM-A1) was also produced in the same manner.

< production of liquid Crystal display element >

The liquid crystal alignment treatment agents (PM-A1) to (PM-A40) obtained in examples and the liquid crystal alignment treatment agent (RPM-A1) obtained in comparative example were subjected to pressure filtration using a membrane filter having a pore size of 1 μm.

The obtained solution was spin-coated on the ITO surface of a glass substrate having a transparent electrode made of an ITO film, dried for 120 seconds on a 50 ℃ hot plate, and then fired for 2 minutes or 20 minutes on a 120 ℃ hot plate to form a liquid crystal alignment film having a film thickness of 100 nm.

Then, the coated surface was irradiated with an irradiation intensity of 4.3mW/cm through a polarizing plate at an angle of 40 DEG from the normal direction of the substrate ² 313nm linearly polarized ultraviolet ray of 50mJ/cm ² And obtaining the substrate with the liquid crystal orientation film. The ultraviolet light of the high-pressure mercury lamp was passed through a 313nm band-pass filter and then through a 313nm polarizing plate, thereby producing linearly polarized ultraviolet light.

The substrates 2 were prepared, and a bead spacer of 4 μm was spread on the liquid crystal alignment film of one substrate, followed by applying a sealant (made by Mitsui chemical Co., Ltd., XN-1500T). Then, another substrate was bonded with the liquid crystal alignment film surface at 180 ° to the alignment direction, and the sealant was thermally cured at 120 ℃ for 90 minutes to prepare an empty cell. The empty cell was filled with liquid crystal (MLC-3022, manufactured by Merck ltd.) by a reduced pressure filling method, to obtain a liquid crystal display element.

< evaluation >

(liquid Crystal alignment Property)

The liquid crystal display element obtained above was subjected to isotropic phase treatment at 120 ℃ for 1 hour, and then cell observation was performed using a polarization microscope. It is preferable that no alignment failure such as light leakage or occurrence of domain (domain) occurs, and that uniform liquid crystal driving is obtained when a voltage is applied to the liquid crystal cell. The evaluation results are shown in table 3.

(pretilt angle)

In the liquid crystal display element produced as described above, the pretilt angle of the liquid crystal cell was measured by the mueller matrix method using an AxoScan manufactured by Axo Metrix. The evaluation results are shown in table 3.

Table 3.

No.	Liquid crystal aligning agent	Firing conditions	Liquid crystal orientation	Inclination angle (°)
					Example A1	PM-A1	120℃/20min	Good effect	89.5
Example A2	PM-A2	120℃/20min	Is good	89.6
					Example A3	PM-A3	120℃/2min	Good effect	89.2
Example A4	PM-A4	120℃/2min	Is good	89.1
					Example A5	PM-A5	120℃/2min	Good effect	88.8
Example A6	PM～A6	120℃/2min	Good effect	88.7
					Example A7	PM-A7	120℃/2min	Is good	89.3
Example A8	PM-A8	120℃/2min	Good effect	89.3
					Example A9	PM-A9	120℃/2min	Good effect	89
Example A10	PM-A10	120℃/2min	Is good	89.3
					Example A11	PM-A11	120℃/2min	Good effect	89.2
Example A12	PM-A12	120℃/2min	Is good	89.2
					Example A13	PM-A13	120℃/2min	Good effect	89.3
Example A14	PM-A14	120℃/2min	Is good	88.8
					Example A15	PM-A15	120℃/2min	Good effect	89
Example A16	PM-A16	120℃/2min	Is good	89.5
					Example A17	PM-A17	120℃/2min	Is good	89.3
Example A18	PM-A18	120℃/2min	Good effect	89.3
					Example A19	PM-A19	120℃/2min	Good effect	89.2
Example A20	PM-A20	120℃/2min	Good effect	89.2
					Example A21	PM-A21	120℃/2min	Good effect	88.9
Example A22	PM-A22	120℃/2min	Good effect	89.4
					Example A23	PM-A23	120℃/2min	Good effect	89
Example A24	PM-A24	120℃/2min	Good effect	88.6
					Example A25	PM-A25	120℃/20min	Is good	87.2
Example A26	PM-A26	120℃/2min	Is good	87.3
					Example A27	PM-A27	120℃/20min	Good effect	87.2
Example A28	PM-A28	120℃/2min	Is good	89
					Example A29	PM-A29	120℃/2min	Good effect	87.7
Example A30	PM-A30	120℃/2min	Good effect	87.9
					Example A31	PM-A31	120℃/2min	Good effect	88.6
Example A32	PM-A32	120℃/2min	Is good	88.6
					Example A33	PM-A33	120℃/2min	Is good	88.7
Example A34	PM-A34	120℃/2min	Good effect	89
					Example A35	PM-A35	180℃/20min	Is good	88
Example A36	PM-A36	180℃/20min	Good effect	87.5
					Example A37	PM-A37	120℃/2min	Good effect	89.1
Example A38	PM-A38	180℃/20min	Good effect	88
					Example A39	PM-A39	180℃/20min	Is good	88
Example A40	PM-A40	180℃/20min	Is good	88
					Comparative example A1	RPM-A1	120℃/20min	Failure of the product	89.8

From the above results, it is understood that, from the comparison between examples a1 to a2 and comparative example a1, a liquid crystal alignment film having excellent liquid crystal alignment properties and capability of expressing a pretilt angle of liquid crystal is obtained by copolymerizing a crosslinkable monomer. Further, from the comparison between example a2 and example A3, a liquid crystal alignment film having excellent liquid crystal alignment properties and excellent pretilt angle expression ability even when the firing conditions are processed in a short time is obtained by adding a crosslinking agent component.

< Synthesis example B1 of methacrylate Polymer >

MA-2(2.5g, 6.0 mmol) and MAA (1.2g, 14.1 mmol) were dissolved in CHN (11.0g) and PGME (11.0g), degassed by a diaphragm pump, and AIBN (0.2g, 1.0 mmol) as a polymerization initiator was added to conduct degassing again. Then reacted at 60 ℃ for 13 hours to obtain a polymer (PB1) solution.

< Synthesis examples of methacrylate polymers B2-B8 and B12-B18 >

Methacrylate polymers PB2 to PB8 and PB12 to PB18 were synthesized with the compositions shown in Table 4 by the same method as in Polymer Synthesis example B1.

< example B9 for Synthesis of methacrylate Polymer >

MA2(6.19g, 15.0 mmol) and MOI-BP (8.80g, 35.0 mmol) were dissolved in CHN (61.6g), degassed by a diaphragm pump, and then added with AIBN (0.41g, 2.5 mmol) and degassed again. Then reacted at 55 ℃ for 13 hours to obtain a polymer solution of methacrylate. The polymer solution was added dropwise to a mixed solvent (1000ml) of methanol and pure water 5/5, and the resulting precipitate was filtered. The precipitate was washed with methanol and dried in an oven at 40 ℃ under reduced pressure to give a methacrylate polymer powder. The polymer had a number average molecular weight of 43600 and a weight average molecular weight of 131200.

CHN (9.0g) and PGME (9.0g) were added to the obtained methacrylate polymer powder (1.5g), and the mixture was stirred at room temperature for 5 hours to dissolve, thereby obtaining a polymer (PB9) solution.

< Synthesis examples of methacrylic acid ester polymers B10 to B11>

Methacrylate polymers PB10 to PB11 were synthesized with the compositions shown in Table 5 by the same method as in Polymer Synthesis example P1.

Table 5.

< example B1>

CHN (5.5g), PGME (5.5g) and TETRAD-C (0.02g) were added to 4.0g of the polymer solution (PB1) obtained in methacrylate polymer Synthesis example B1, and the mixture was stirred at room temperature to obtain a liquid crystal aligning agent (PM-B1).

< examples B2-B16 and comparative example B1>

Liquid crystal alignment agents (PM-B2) to (PM-B16) were prepared in the same manner as in example B1, except that the compositions shown in Table 6 were used. The liquid crystal aligning agent (RPM-B1) of comparative example B1 was also prepared in the same manner as above.

< examples B17 to B23>

Liquid crystal alignment treatment agents (PM-B17) to (PM-B23) were prepared in the same manner as in example B1, except that the components shown in Table 6 were used.

< examples B24 to B34>

Liquid crystal alignment treatment agents (PM-B24) to (PM-B34) were prepared in the same manner as in example B1, except that the components shown in Table 7 were used.

< comparative example B2>

CHN (9.0g), PGME (9.0g) and YH-434-L (0.15g) were added to the methacrylate polymer solution (PB9), and the mixture was stirred at room temperature for 5 hours to dissolve the components, thereby obtaining a liquid crystal alignment treatment agent (RPMB-2).

< production of liquid Crystal display device >

Liquid crystal display elements were produced in the same manner as described above using liquid crystal alignment agents (PM-B1) to (PM-B34) and liquid crystal alignment agents (RPM-B1) to (RPM-B2) obtained in comparative examples, instead of liquid crystal alignment agents (PM-A1) to (PM-A36) obtained in examples and liquid crystal alignment agent (RPM-A1) obtained in comparative examples.

The evaluation results obtained by similarly evaluating the liquid crystal alignment properties and the pretilt angles are shown in table 8.

Table 8.

From the above results, it is understood that the liquid crystal display element using the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the present invention, which is obtained by introducing the crosslinking agent component from the comparison of example B1 with comparative example B1, exhibits a pretilt angle even after a short time of firing. Further, from the comparison between example B1 and comparative example B2, the liquid crystal display element using the liquid crystal alignment film obtained from the liquid crystal aligning agent containing no polar group in the molecule could not obtain liquid crystal alignment properties, whereas the liquid crystal display element using the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the present invention had good liquid crystal alignment properties and exhibited a pretilt angle.

Industrial applicability

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

1. A liquid crystal aligning agent comprising a solvent and (A) a component: a polymer having the following structures (A-1) and (A-2),

the polymer also has a structure (A-3) having at least one functional group selected from the group consisting of an oxetanyl group, an oxirane 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 a thiiranyl group; and/or

The liquid crystal aligning agent further comprises a component (B) other than the component (A), wherein the component (B) is a compound having 2 or more groups selected from the group consisting of an epoxy group, a thiiranyl group, a hydroxyalkylamide group and a benzyl alcohol group in a molecule,

(A-1) a structure having at least one functional group selected from the group consisting of a carboxyl group, an amino group and a hydroxyl group in a molecule;

(A-2) a moiety having photo-alignment properties represented by the following formula (pa-1-a), wherein S _b Represents a single bond, a C1-10 linear or branched alkylene group, or a 2-valent aromatic groupA group or a 2-valent alicyclic group, Z is an oxygen atom or a sulfur atom, X _a And X _b Each independently represents 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 2-valent aromatic group, a 2-valent alicyclic group, or a 2-valent heterocyclic group, R ₃ Is a single bond, an oxygen atom, -COO-or-OCO-, R ₄ Is a C1-40 linear or branched alkyl group or a C3-40 1-valent organic group containing an alicyclic group, R ₅ 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, a is an integer of 0 to 3, b is an integer of 0 to 4,

wherein said (A-2) is derived from a monomer represented by the following formula (pa-1-ma),

in the formula (pa-1-ma), M _c Represents a2 nd polymerizable group, M _d Is selected from a single bond, (r) ² +1) valent heterocycle, substituted or unsubstituted branched alkyl group with 1-10 carbon atoms, or unsubstituted straight-chain alkyl group with 1-10 carbon atoms, (r) ² +1) valent aromatic group, (r) ² +1) valent alicyclic groups, each group being optionally unsubstituted or having one or more hydrogen atoms substituted by fluorine atom, chlorine atom, cyano group, methyl group or methoxy group, r ² To satisfy 1 ≦ r ² An integer of 3 or less, S _b 、Z、X _a 、X _b 、R ₁ 、R ₂ 、R ₃ 、R ₄ 、R ₅ A and b are as defined for formula (pa-1-a).

2. The liquid crystal aligning agent according to claim 1, wherein the component (A) has a structure in which the component (A-3) has at least one functional group selected from the group consisting of an oxetanyl group, an oxirane group, a group represented by the formula (3), a group represented by the formula (4), a group represented by the formula (5), and a thiiranyl group.

3. The liquid crystal aligning agent according to claim 1, wherein the component (A) is a polymer having the structures of the component (A-1) and the component (A-2), and the liquid crystal aligning agent further has the component (B).

4. The liquid crystal aligning agent according to claim 3, wherein the component (B) is a compound having 2 or more epoxy groups or thiiranyl groups in a molecule.

5. The liquid crystal aligning agent according to claim 3, wherein the component (B) is a compound having 2 or more hydroxyalkylamide groups or benzyl alcohol groups in a molecule.

6. The liquid crystal aligning agent according to any one of claims 3 to 5, which is obtained from the following monomer components: the monomer derived from the structure of (A-1) is contained at a ratio of 5 to 95 mol% and the monomer derived from the structure of (A-2) is contained at a ratio of 5 to 95 mol% with respect to the entire polymer of the component (A).

7. The liquid crystal aligning agent according to claim 1 or 2, which comprises 0.1 to 40 parts by mass of the component (B) per 100 parts by weight of the component (A).

8. The liquid crystal aligning agent according to claim 1 or 2, wherein the (A-1) is derived from a monomer represented by the following formula (a-1-m),

in the formula (a-1-m), I _a1 Is a 1-valent organic radical selected from carboxyl, a radical having a partial structure of at least one of the formulae (a2) described above or a primary amino radical, r ¹ Is 1 or 2, S _a Represents a single bond or a 2-valent linking group, M _a Represents a1 st polymerizable group, wherein the formula (a2) represents a group other than a primary amino group, and a bonding site is represented by formula (a 2).

9. The liquid crystal aligning agent according to claim 1 or 2, wherein the (A-3) is derived from a monomer represented by the following formula (c-1-m),

M _e -S _c -I _c (c-1-m)

in the formula (c-1-m), I _c Is a 1-valent organic group selected from the group consisting of an oxetanyl group, an oxirane group, a group represented by the formula (3), a group represented by the formula (4), a group represented by the formula (5), and a thietanyl group, S _c Represents a single bond or a 2-valent linking group, M _e Represents a3 rd polymerizable group.

10. The liquid crystal aligning agent according to claim 1 or 2, wherein the component (B) is an epoxy compound having at least 1 or more tertiary nitrogen atoms in the molecule.

11. The liquid crystal aligning agent according to claim 1 or 2, wherein the component (B) is at least one compound selected from the following formulae,

-P ₁ -Q ₁ -P ₂ - [3]

in the formula, X ₂ 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,

R ₂ and R ₃ Each independently a hydrogen atom,Or optionally substituted C1-4 alkyl, C2-4 alkenyl or C2-4 alkynyl, R ₂ And R ₃ At least 1 of (a) represents a hydrocarbon group substituted with a hydroxyl group,

Y ₁ 、Y ₂ and Y ₃ Each independently represents an aromatic ring, any hydrogen atom of the aromatic ring being optionally 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 a single bond, a saturated hydrocarbon group having 2 valences of 1 to 10 carbon atoms, all or a part of which are optionally bonded to form a cyclic structure, and any hydrogen atom is optionally substituted with a fluorine atom, -NH-, -N (CH) ₃ ) -, formula [3]The radicals shown are, for example,

t ₁ is an integer of 2 to 4, t ₂ And t ₃ Each independently an integer of 1 to 3,

a and b are each independently an integer of 1 to 3,

12. The liquid crystal aligning agent according to claim 1 or 2, which is obtained from the following monomer components: the monomer derived from the site (A-1) is contained at a ratio of 5 to 94 mol%, the monomer derived from the site (A-2) is contained at a ratio of 5 to 94 mol%, and the monomer derived from the site (A-3) is contained at a ratio of 1 to 40 mol% with respect to the entire polymer of the component (A).

13. The liquid crystal aligning agent according to claim 1 or 2, which is obtained from the following monomer components: the monomer derived from the site (A-1) is contained at a ratio of 20 to 94 mol%, the monomer derived from the site (A-2) is contained at a ratio of 5 to 50 mol%, and the monomer derived from the site (A-3) is contained at a ratio of 1 to 30 mol% with respect to the entire polymer of the component (A).

14. The liquid crystal aligning agent according to claim 1 or 2, wherein the polymer of the component (A) has a weight average molecular weight of 2000 to 1000000.

15. A liquid crystal alignment film formed by using the liquid crystal aligning agent according to any one of claims 1 to 14.

16. A method for producing a liquid crystal alignment film, comprising a step of applying the liquid crystal aligning agent according to any one of claims 1 to 14 to a substrate to form a coating film, and a step of irradiating the coating film with light in a state where the coating film is not in contact with a liquid crystal layer or in a state where the coating film is in contact with a liquid crystal layer.

17. A liquid crystal display element comprising the liquid crystal alignment film according to claim 15 or the liquid crystal alignment film obtained by the production method according to claim 16.