JP7453608B2 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Description

The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film obtained using the same, and a liquid crystal display element equipped with the obtained liquid crystal aligning film. More specifically, the present invention relates to a liquid crystal aligning agent that can provide a liquid crystal aligning film that has good liquid crystal alignment, excellent pretilt angle expression ability, and high reliability, and a liquid crystal display element that has excellent display quality.

In a liquid crystal display element, a liquid crystal alignment film plays the role of aligning liquid crystal in a certain direction. Currently, the main liquid crystal alignment films used industrially are polyimide precursors such as polyamic acid (also called polyamic acid), polyamic acid esters, and polyimide-based liquid crystal alignment agents made of polyimide solutions, which are applied to a substrate. It is manufactured by coating and forming a film.
In addition, when the liquid crystal is aligned parallel or oblique to the substrate surface, a surface stretching process by rubbing is further performed after the film is formed.

On the other hand, when aligning liquid crystal perpendicularly to the substrate (referred to as vertical alignment (VA) method), long-chain alkyls, cyclic groups, or combinations of cyclic groups and alkyl groups (for example, see Patent Document 1), steroid skeletons ( For example, a liquid crystal alignment film is used in which a hydrophobic group such as (see Patent Document 2) is introduced into the side chain of polyimide. In this case, when applying a voltage between the substrates and tilting the liquid crystal molecules in a direction parallel to the substrates, it is necessary to make sure that the liquid crystal molecules tilt from the normal direction of the substrates to one direction within the plane of the substrates. . Methods for this purpose include, for example, providing protrusions on the substrate, providing slits in the display electrodes, and rubbing to slightly tilt the liquid crystal molecules from the normal direction of the substrate toward one direction within the substrate surface. Furthermore, the liquid crystal can be pretilted by adding a photopolymerizable compound to the liquid crystal composition in advance, using it together with a vertical alignment film such as polyimide, and irradiating the liquid crystal cell with ultraviolet rays while applying a voltage. A method (for example, see Patent Document 3) has been proposed.

In recent years, as an alternative to the formation of protrusions and slits in VA liquid crystal alignment control, and the PSA technique, methods (photoalignment methods) that utilize anisotropic photochemical reactions such as polarized ultraviolet irradiation have also been proposed. In other words, it is known that by irradiating a photoreactive, vertically aligned polyimide film with polarized ultraviolet rays to impart alignment regulation ability and pretilt angle development ability, it is possible to uniformly control the tilt direction of liquid crystal molecules when voltage is applied. (See Patent Document 4).

VA type liquid crystal display elements are used in TVs and car displays because of their high contrast and wide viewing angle. LCD display elements for TVs use backlights that generate a large amount of heat in order to achieve high brightness, and LCD display elements used in automobiles, such as car navigation systems and instrument panels, cannot be used in high-temperature environments for long periods of time. It may be used or left alone. Under such severe conditions, if the pretilt angle changes gradually, problems such as initial display characteristics not being obtained or display unevenness occur. Furthermore, when driving the liquid crystal, the voltage retention characteristics and charge accumulation characteristics are also affected by the liquid crystal alignment film, and if the voltage retention rate is low, the contrast of the display screen will decrease, and if the charge accumulation with respect to the DC voltage is large. The phenomenon of burn-in of the display screen occurs. In particular, in order to increase transmittance, it is required to provide a relatively large tilt angle of 3° or more from the vertical. Until now, there has been no material that can maintain a stable tilt angle.

Japanese Patent Application Publication No. 3-179323 Japanese Patent Application Publication No. 4-281427 Patent No. 4504626 Patent No. 4995267

As a result of the authors' studies, it was not possible to stably generate a tilt angle exceeding 87° simply by adjusting the amount of the photo-alignable group. An object of the present invention is to provide a liquid crystal aligning film and a liquid crystal aligning agent that can stably generate a tilt angle of more than 87° and have high reliability.

式中、Ａは場合によりフッ素、塩素、シアノから選択される基によるか、又は炭素数１～５のアルコキシ基、直鎖状若しくは分岐鎖状のアルキル残基（これは、場合により１個のシアノ基又は１個以上のハロゲン原子で置換されている）で置換されている、ピリミジン－２，５－ジイル、ピリジン－２，５－ジイル、２，５－チオフェニレン、２，５－フラニレン、１，４－若しくは２，６－ナフチレン又はフェニレンを表し、Ｒ_１は単結合、酸素原子、－ＣＯＯ－または－ＯＣＯ－であり、Ｒ_２は２価の芳香族基、２価の脂環式基、２価の複素環式基または２価の縮合環式基であり、Ｒ_３は単結合、酸素原子、－ＣＯＯ－または－ＯＣＯ－であり、Ｒ_４は炭素数１～４０の直鎖又は分岐鎖のアルキル基または脂環式基を含む炭素数３～４０の１価の有機基であり、Ｄは、酸素原子、硫黄原子又は－ＮＲ_ｄ－（ここで、Ｒ_ｄは、水素原子又は炭素数１～３のアルキルを表す）を表し、ａは０～３の整数であり、＊は結合位置を表す。
（Ａ－３）オキセタニル基、オキシラニル基、下記式（３）で表される基、下記式（４）で表される基、下記式（５）で表される基及びチイラン基から選択される少なくとも１種の官能基を有する構造（以下、「熱架橋性基」とも称する）。

The present inventors have discovered the invention whose gist is <1> below.
<1> A liquid crystal aligning agent containing the following component (A) and a solvent.
Component (A): A polymer having the following structures (A-1) to (A-3).
(A-1) A structure having an isocyanate group and/or a blocked isocyanate group.
(A-2) A structure represented by the following formula (pa-1) (hereinafter also referred to as a "photoalignable group").

In the formula, A is optionally a group selected from fluorine, chlorine, cyano, or an alkoxy group having 1 to 5 carbon atoms, a linear or branched alkyl residue (which can optionally be one pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophenylene, 2,5-furanylene, substituted with a cyano group or one or more halogen atoms); Represents 1,4- or 2,6-naphthylene or phenylene, R ₁ is a single bond, oxygen atom, -COO- or -OCO-, and R ₂ is a divalent aromatic group, a divalent alicyclic group group, a divalent heterocyclic group, or a divalent fused cyclic group, R ₃ is a single bond, an oxygen atom, -COO- or -OCO-, and R ₄ is a straight chain having 1 to 40 carbon atoms. or a monovalent organic group having 3 to 40 carbon atoms containing a branched alkyl group or alicyclic group, and D is an oxygen atom, a sulfur atom, or -NR _d - (where R _d is a hydrogen atom or represents an alkyl having 1 to 3 carbon atoms), a is an integer of 0 to 3, and * represents a bonding position.
(A-3) selected from oxetanyl group, oxiranyl group, group represented by the following formula (3), group represented by the following formula (4), group represented by the following formula (5), and thiirane group A structure having at least one functional group (hereinafter also referred to as a "thermally crosslinkable group").

ADVANTAGE OF THE INVENTION By this invention, provision of the tilt angle exceeding 87 degrees is possible, and the liquid crystal aligning film and liquid crystal aligning agent from which high reliability can be obtained can be provided.
Furthermore, the liquid crystal display element manufactured by the method of the present invention has excellent display characteristics.

式中、
Ｓ_ａ、Ｓ_ｂ、及びＳ_ｃは、それぞれ独立したスペーサー単位を表し、
Ｉ_ａは、後述する式（ａ－１－ｍ）においてする定義と同義であり、
Ｉ_ｂは、前記式（ｐａ－１）で表される基であり、
Ｉ_ｃは、オキセタニル基、オキシラニル基、前記式（３）で表される基、前記式（４）で表される基、前記式（５）で表される基及びチイラン基からなる群から選択される少なくとも１種の官能基を有する１価の有機基を表す。
Ｍ’_ａ、Ｍ’_ｃ、Ｍ’_ｅは、それぞれに後述するＭ_ａ、Ｍ_ｃ、Ｍ_ｅ、に由来する主鎖の構造を表し、Ｍ_ｂ、Ｍ_ｄ、ｃ、ｒ^２は、後述する式（ａ－１―ｍ）、式（ｂ－１－ｍ）及び式（ｃ－１－ｍ）においてする定義と同様である。
またｘ、ｙ、ｚは特に限定はないが、例えば、ｘ、ｙ、ｚはそれぞれ独立して、０．０１以上、０．８９以下の値をとることができる。 The liquid crystal aligning agent of the present invention contains a liquid crystal aligning agent containing a polymer having the structures (A-1) to (A-3) above (hereinafter also referred to as "specific polymer") and a solvent. Each component of the present invention will be explained in detail below.
<(A) component: specific polymer>
The specific polymer of the present invention is represented by the following formula (I).

During the ceremony,
S _a , S _b , and S _c each represent an independent spacer unit,
I _a has the same meaning as the definition in formula (a-1-m) described below,
I _b is a group represented by the above formula (pa-1),
_Ic is selected from the group consisting of an oxetanyl group, an oxiranyl group, a group represented by the formula (3), a group represented by the formula (4), a group represented by the formula (5), and a thiirane group. represents a monovalent organic group having at least one functional group.
M' _a , M' _c , and M' _e represent main chain structures derived from M _a , M _c , and M _e , which will be described later, respectively, and M _b , M _d , c, and r ² will be described later. The definitions are the same as those in formula (a-1-m), formula (b-1-m), and formula (c-1-m).
Further, x, y, and z are not particularly limited, but, for example, x, y, and z can each independently take a value of 0.01 or more and 0.89 or less.

In addition, formula (I) means that each side chain is present in the proportions of x, y, and z, and in the polymer, it means a block copolymer in which each side chain is blocked. It's not a thing.

Since the specific polymer contained in the liquid crystal aligning agent of the present invention has high sensitivity to light, it can exhibit alignment control ability even when irradiated with polarized ultraviolet light at a low exposure dose. Further, due to the reaction between the thermally crosslinkable group and the amino group and the hydroxyl group or carboxyl group, the specific polymer can undergo a crosslinking reaction within the specific polymer even when the baking time of the liquid crystal aligning agent is short. This makes it easier for the anisotropy to remain (memory) in the liquid crystal alignment film when the photoalignment site of the specific polymer develops anisotropy due to a photoreaction, thereby increasing the liquid crystal alignment and improving the liquid crystal alignment. It becomes possible to express a pretilt angle.

<<(A-1) Site having isocyanate group and/or blocked isocyanate group>>
The (A-1) isocyanate group and/or blocked isocyanate group-containing site in component (A) of the present invention is preferably represented by the following formula (1).
Further, the site is preferably derived from a monomer of the following formula (1m).

式（１）又は（ａ－１－ｍ）中、Ｓａはスペーサー単位を表し、Ｓａの左の結合子は特定重合体の主鎖に、任意にスペーサーを介して結合することを示し、Ｉａはイソシアネート基又はブロック化されたイソシアネート基である。
また、式（ａ－１－ｍ）中、Ｍａは第１の重合性基を表す。該第１の重合性基して、（メタ）アクリレート、フマレート、マレエート、α－メチレン－γ－ブチロラクトン、スチレン、ビニル、マレイミド、ノルボルネン、（メタ）アクリルアミド及びその誘導体のラジカル重合性基、及びシロキサンを挙げることができる。好ましくは（メタ）アクリレート、α－メチレン－γ－ブチロラクトン、スチレン、ビニル、マレイミド、アクリルアミドであるのがよい。
ｃは１から３の整数であり、好ましくは１または２である。
Ｍｂは、単結合、２価の複素環、３価の複素環、４価の複素環、置換又は非置換の分岐である炭素数１～１０のアルキル基、２価の芳香族基、３価の芳香族基、４価の芳香族環、２価の脂環式基、３価の脂環式基、４価の脂環式基、２価の縮合環式基、３価縮合環式基または４価の縮合環式基であり、それぞれの基は無置換であるか又は一個以上の水素原子がフッ素原子、塩素原子、シアノ基、メチル基又はメトキシ基によって置換されていてもよい。

In formula (1) or (a-1-m), Sa represents a spacer unit, the left bond of Sa indicates that it is bonded to the main chain of the specific polymer, optionally via a spacer, and Ia is It is an isocyanate group or a blocked isocyanate group.
Further, in formula (a-1-m), Ma represents the first polymerizable group. The first polymerizable group includes radically polymerizable groups of (meth)acrylate, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, norbornene, (meth)acrylamide and its derivatives, and siloxane. can be mentioned. Preferred are (meth)acrylate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, and acrylamide.
c is an integer from 1 to 3, preferably 1 or 2.
Mb represents a single bond, a divalent heterocycle, a trivalent heterocycle, a tetravalent heterocycle, a substituted or unsubstituted branched alkyl group having 1 to 10 carbon atoms, a divalent aromatic group, and a trivalent heterocycle. aromatic group, tetravalent aromatic ring, divalent alicyclic group, trivalent alicyclic group, tetravalent alicyclic group, divalent fused cyclic group, trivalent fused cyclic group Alternatively, it is a tetravalent fused cyclic 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.

Sa is preferably derived from the following formula (2).

The left bond of W ₁ represents the bond to Mb, the right bond of W ₃ represents the bond to Ia, and W ₁ , W ₂ and W ₃ each independently represent a single bond or a divalent heterocycle. , -(CH ₂ )n- (wherein n is an integer from 1 to 20), -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -CH=CH-, - CF=CF-, -CF ₂ O-, -OCF ₂ -, -CF ₂ CF ₂ - or -C≡C-, but one or more of the non-adjacent CH ₂ groups in these substituents are independently -O-, -CO-, -CO-O-, -O-CO-, -Si(CH ₃ ) ₂ -O-Si(CH ₃ ) ₂ -, -NR-, -NR-CO-, -CO-NR-, -NR-CO-O-, -OCO-NR-, -NR-CO-NR-, -CH=CH-, -C≡C- or -O-CO-O- (in the formula , R independently represents hydrogen or an alkyl group having 1 to 5 carbon atoms).
A ₁ and A ₂ are each independently a divalent aromatic group, a divalent alicyclic group, a divalent heterocyclic group, or a divalent fused cyclic group, and each group is It may be substituted or one or more hydrogen atoms may be replaced by a fluorine atom, a chlorine atom, a cyano group, a methyl group or a methoxy group.

As described above, Ia is an isocyanate group and/or a blocked isocyanate group.
The blocked isocyanate group is an isocyanate group in which an isocyanate group (-NCO) is blocked with an appropriate protecting group (BL), and can be represented by the following formula (5), for example.
In the liquid crystal aligning agent of the present invention, the protective group (block portion) of the blocked isocyanate group is thermally dissociated and removed by heating and baking during formation of the liquid crystal aligning film, and a reactive isocyanate group is generated. A crosslinking reaction proceeds between the generated isocyanate groups and the polymer constituting the liquid crystal alignment film. Further, the isocyanate group reacts with a compound having two or more functional groups of one or more selected from the group consisting of amino groups and hydroxyl groups in the molecule.

A blocked isocyanate group can be obtained by allowing a suitable blocking agent to act on a compound having an isocyanate group.
Examples of blocking agents include alcohols such as methanol, ethanol, isopropanol, n-butanol, 1-methoxy-2-propanol, 2-ethoxyhexanol, 2-N,N-dimethylaminoethanol, 2-ethoxyethanol, and cyclohexanol. ; Phenols such as phenol, o-nitrophenol, p-chlorophenol, o-, m- or p-cresol; Lactams such as ε-caprolactam; Acetone oxime, methyl ethyl ketone oxime, methyl isobutyl ketone oxime, cyclohexanone oxime, acetophenone Oximes such as oxime and benzophenone oxime; pyrazoles such as pyrazole, 3,5-dimethylpyrazole and 3-methylpyrazole; thiols such as dodecanethiol and benzenethiol; carboxylic acid esters such as diethyl malonate; etc. It will be done. Preferred are ethanol, isopropanol, 1-methoxy-2-propanol, 3,5-dimethylpyrazole, γ-caprolactam, and methyl ethyl ketone oxime.

BL-1 to BL-7 are shown below as preferred specific structures of BL, but the structure is not limited thereto. Note that the broken line connector indicates the bonding site with the carbonyl carbon in formula (5), and R ₆ in formula BL-7 is a straight or branched alkyl group having 1 to 10 carbon atoms (provided that non-adjacent One or more of the CH ₂ groups may be independently replaced by an oxygen atom).

Examples of Ia include, but are not limited to, the following Ia-1 to Ia-8. In the formula, the broken line represents the bond to Sa in the above formula (1), and R ₆ is a linear or branched alkyl group having 1 to 10 carbon atoms (however, one or more of the non-adjacent CH ₂ groups is an independent may be replaced with an oxygen atom).

When (A-1) contains an isocyanate group, that is, an unblocked isocyanate group, the isocyanate group has two or more functional groups selected from the group consisting of amino groups and hydroxyl groups in the molecule. Since it exhibits excellent reactivity with the above-mentioned compounds, it is possible to carry out the crosslinking reaction efficiently even during firing at low temperatures.

The reaction temperature between the isocyanate group and the amino group or hydroxyl group is preferably from 50°C to 200°C, more preferably from 80°C to 200°C, and even more preferably from 80°C to 180°C.

Isocyanate groups have excellent reactivity with amino groups and hydroxyl groups, especially amino groups, and crosslinking reactions may proceed even at low temperatures, resulting in poor storage stability of the liquid crystal aligning agent. Therefore, when storing a liquid crystal aligning agent for a long period of time, blocked isocyanate groups may be used.

When the blocked isocyanate group is at a high temperature such as the temperature of heating and baking during formation of a liquid crystal alignment film, thermal dissociation of the block portion occurs and a crosslinking reaction proceeds via the isocyanate group. It is preferable that the blocked isocyanate group is one in which crosslinking by the isocyanate group does not proceed under the low temperature conditions in which the liquid crystal aligning agent is stored. In order to achieve such thermal reactivity, the blocked isocyanate compound is preferably one whose thermal dissociation temperature of the block portion is considerably higher than that during storage of the liquid crystal aligning agent, for example, 50 ° C. to 230 ° C. , 60°C to 150°C is more preferable.

(A-1) The site having an isocyanate group and/or a blocked isocyanate group is preferably derived from a monomer represented by the above formula (a-1-m), as described above. Examples of the monomer represented by the formula (a-1-m) include, but are not limited to, the following.

(A-1) The amount of introduced portions having isocyanate groups and/or blocked isocyanate groups is preferably 5 to 90 mol, and 5 to 85 mol% of the specific polymer as component (A). is more preferable, and even more preferably 15 to 80 mol%.

<(A-2) Structure having photoalignment property>
The specific polymer contained in the liquid crystal aligning agent of the present invention has a structure having a photoalignment property represented by the above formula (pa-1) in the molecule, preferably in the side chain.
By setting the structure of the portion having photoalignment to the above structure, the vertical alignment control ability can be stably maintained for a long period of time even when exposed to external stress such as heat. Furthermore, since it has high sensitivity to light, it can exhibit alignment control ability even when irradiated with polarized ultraviolet light at a low exposure dose, which is preferable from the viewpoint of simplifying the manufacturing process of a liquid crystal alignment film.

式中、Ｉ_ｂは、下記式（ｐａ－１）で表される１価の有機基である。

式中、Ａは場合によりフッ素、塩素、シアノから選択される基によるか、又は炭素数１～５のアルコキシ基、直鎖状若しくは分岐鎖状のアルキル残基（これは、場合により１個のシアノ基又は１個以上のハロゲン原子で置換されている）で置換されている、ピリミジン－２，５－ジイル、ピリジン－２，５－ジイル、２，５－チオフェニレン、２，５－フラニレン、１，４－若しくは２，６－ナフチレン又はフェニレンを表し、Ｒ_１は単結合、酸素原子、－ＣＯＯ－または－ＯＣＯ－であり、Ｒ_２は２価の芳香族基、２価の脂環式基、２価の複素環式基または２価の縮合環式基であり、Ｒ_３は単結合、酸素原子、－ＣＯＯ－または－ＯＣＯ－であり、Ｒ_４は炭素数１～４０の直鎖又は分岐鎖のアルキル基または脂環式基を含む炭素数３～４０の１価の有機基であり、Ｄは、酸素原子、硫黄原子又は－ＮＲ_ｄ－（ここで、Ｒ_ｄは、水素原子又は炭素数１～３のアルキルを表す）を表し、ａは０～３の整数であり、＊は結合位置を表す。 In the present invention, the site in the molecule having photoalignment properties represented by the above formula (pa-1) can be represented by, for example, the following formula (b-1). Further, the site can include, but is not limited to, a structure derived from a monomer represented by the following formula (b-1-m).

In the formula, I _b is a monovalent organic group represented by the following formula (pa-1).

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

式（Ｓｐ）中、
Ｗ_１の左の結合はＭ_ｄへの結合を表し、
Ｗ_３の右の結合はＩ_ｂへの結合を表し、
Ｗ_１、Ｗ_２及びＷ_３は、それぞれ独立して、単結合、二価の複素環、－（ＣＨ_２）_ｎ－（式中、ｎは１～２０を表す）、－ＯＣＨ_２－、－ＣＨ_２Ｏ－、―ＣＯＯ－、－ＯＣＯ－、－ＣＨ＝ＣＨ－、－ＣＦ＝ＣＦ－、－ＣＦ_２Ｏ－、－ＯＣＦ_２－、－ＣＦ_２ＣＦ_２－又は－Ｃ≡Ｃ－を表すが、これらの置換基において非隣接のＣＨ_２基の一つ以上は独立して、－Ｏ－、－ＣＯ－、－ＣＯ－Ｏ－、－Ｏ－ＣＯ－、－Ｓｉ（ＣＨ_３）_２－Ｏ－Ｓｉ（ＣＨ_３）_２―、－ＮＲ－、－ＮＲ－ＣＯ－、－ＣＯ－ＮＲ－、－ＮＲ－ＣＯ－Ｏ－、－ＯＣＯ－ＮＲ－、－ＮＲ－ＣＯ－ＮＲ－、－ＣＨ＝ＣＨ－、－Ｃ≡Ｃ－又は－Ｏ－ＣＯ－Ｏ－（式中、Ｒは独立して水素又は炭素原子数１から５の直鎖又は分岐鎖のアルキル基を表す）で置換することができ、
Ａ_１及びＡ_２は、それぞれ独立して、単結合、２価のアルキル基、２価の芳香族基、２価の脂環式基、又は２価の複素環式基から選ばれる基であり、それぞれの基は無置換であるか又は一個以上の水素原子がフッ素原子、塩素原子、シアノ基、メチル基又はメトキシ基によって置換されていても良い。
式（ｂ－１－ｍ）中、Ｍ_ｃは第２の重合性基を表す。該第２の重合性基として、 （メタ）アクリレート、フマレート、マレエート、α－メチレン－γ－ブチロラクトン、スチレン、ビニル、マレイミド、ノルボルネン、（メタ）アクリルアミド及びその誘導体のラジカル重合性基、及びシロキサンを挙げることができる。好ましくは（メタ）アクリレート、α－メチレン－γ－ブチロラクトン、スチレン、ビニル、マレイミド、アクリルアミドであるのがよい。 In the above formula (b-1) or (b-1-m), S _b represents a spacer unit, and the left bond of S _b is bonded to the main chain of the specific polymer, optionally via a spacer. Show that.
S _b can be represented, for example, by the structure of the following formula (Sp).

In the formula (Sp),
The left bond of W ₁ represents the bond to M _d ,
The right bond of W ₃ represents the bond to I _b ,
W ₁ , W ₂ and W ₃ each independently represent a single bond, a divalent heterocycle, -(CH ₂ ) _n - (in the formula, n represents 1 to 20), -OCH ₂ -, - Represents CH ₂ O-, -COO-, -OCO-, -CH=CH-, -CF=CF-, -CF ₂ O-, -OCF ₂ -, -CF ₂ CF ₂ - or -C≡C- However, in these substituents, one or more non-adjacent CH ₂ groups are independently -O-, -CO-, -CO-O-, -O-CO-, -Si(CH ₃ ) ₂ - O-Si(CH ₃ ) ₂ -, -NR-, -NR-CO-, -CO-NR-, -NR-CO-O-, -OCO-NR-, -NR-CO-NR-, -CH Substitution with =CH-, -C≡C- or -O-CO-O- (wherein R independently represents hydrogen or a straight or branched alkyl group having 1 to 5 carbon atoms) is possible,
A ₁ and A ₂ are each independently a group selected from a single bond, a divalent alkyl group, a divalent aromatic group, a divalent alicyclic group, or a divalent heterocyclic group; , each group may be unsubstituted or one or more hydrogen atoms may be substituted with a fluorine atom, chlorine atom, cyano group, methyl group or methoxy group.
In formula (b-1-m), M _c represents a second polymerizable group. As the second polymerizable group, radically polymerizable groups of (meth)acrylate, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, norbornene, (meth)acrylamide and its derivatives, and siloxane are used. can be mentioned. Preferred are (meth)acrylate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, and acrylamide.

r ² is an integer satisfying 1≦r ² ≦3.
In formula (b-1-m), M _d is a single bond, a (r ² +1)-valent heterocycle, a linear or branched alkyl group having 1 to 10 carbon atoms, or an (r ² +1)-valent aromatic group. A group selected from group groups, (r ² +1)-valent alicyclic groups, and each group is unsubstituted or one or more hydrogen atoms are a fluorine atom, a chlorine atom, a cyano group, a methyl group, or a methoxy group. It may be substituted with a group.

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

式中、Ｍ_ｃ、Ｍ_ｄ、Ｓ_ｂ及びｑは、上述と同じ定義である。
また、Ｚは酸素原子、または硫黄原子である。
Ｘ_ａ及びＸ_ｂは、それぞれ独立して水素原子、フッ素原子、塩素原子、シアノ基又は炭素数１～３のアルキル基である。
Ｒ_１は単結合、酸素原子、－ＣＯＯ－または－ＯＣＯ－である。
Ｒ_２は２価の芳香族基、２価の脂環式基、又は２価の複素環式基である。
Ｒ_３は単結合、酸素原子、－ＣＯＯ－または－ＯＣＯ－である。
Ｒ_４は炭素数１～４０の直鎖又は分岐鎖のアルキル基または脂環式基を含む炭素数３～４０の１価の有機基である。
Ｒ_５は炭素数１～３のアルキル基、炭素数１～３のアルコキシ基、フッ素原子またはシアノ基、好ましくはメチル基、メトキシ基又はフッ素原子である。
ａは０～３の整数であり、ｂは０～４の整数である。 From the viewpoint of achieving good vertical alignment control ability and a stable pretilt angle, the structure of (b-1) is a group represented by the above (pa-1) or the following (pa-1-a). Mention may be made of the groups represented. Further, the site may include, but is not limited to, a structure derived from a monomer represented by the following formula (pa-1-ma).

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

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

In formula (pa-1-a) or (pa-1-ma), the divalent alicyclic group of S _b is, for example, trans-1,4-cyclohexylene, trans-trans-1,4-bicyclohexylene, Examples include silene and the like.
Examples of the divalent heterocyclic group of S _b include 1,4-pyridylene group, 2,5-pyridylene group, 1,4-furanylene group, 1,4-piperazine group, 1,4-piperidine group, etc. be able to.
S _b is preferably an alkylene group having 1 to 8 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms, and even more preferably an alkylene group having 1 to 4 carbon atoms.

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

Examples of the straight-chain or branched alkyl group having 1 to 40 carbon atoms for R ₄ include straight-chain or branched alkyl groups having 1 to 20 carbon atoms, and some of the hydrogen atoms of this alkyl group Alternatively, all of them may be substituted with fluorine atoms. Examples of such alkyl groups include methyl group, ethyl group, n-propyl, n-butyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n- -nonyl group, n-decyl group, n-lauryl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n -nonadecyl group, n-eicosyl group, 4,4,4-trifluorobutyl group, 4,4,5,5,5-pentafluoropentyl, 4,4,5,5,6,6,6-heptafluoro Hexyl group, 3,3,4,4,5,5,5-heptafluoropentyl group, 2,2,2-trifluoroethyl group, 2,2,3,3,3-pentafluoropropyl group, 2- Examples include (perfluorobutyl)ethyl group, 2-(perfluorooctyl)ethyl group, and 2-(perfluorodecyl)ethyl group.
Examples of the monovalent organic group having 3 to 40 carbon atoms containing an alicyclic group for R ₄ include a cholestenyl group, a cholestanyl group, an adamantyl group, and the following formula (Alc-1) or (Alc-2) (in the formula, R ₇ is a hydrogen atom, a fluorine atom, or an alkyl group optionally substituted with a fluorine atom having 1 to 20 carbon atoms, and examples include a group represented by *indicates a bonding position). .

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

The photoreactive sites contained in the polymer of the present invention may be used alone or in combination of two or more types.
Further, the photoreactive site is preferably contained in a proportion of 5 to 50 mol%, 10 to 50 mol%, or 15 to 50 mol% of the specific polymer (component (A)).

上記式（３）～（５）中、＊は結合手を示す。 <(A-3) Site having thermally crosslinkable group>
The specific polymer contained in the liquid crystal aligning agent of the present invention has a site having a thermally crosslinkable group, that is, an oxetanyl group (1,2-epoxy structure) and an oxiranyl group (1,3-epoxy structure) in the molecule. , a moiety having at least one functional group selected from a group represented by the following formula (3), a group represented by the following formula (4), a group represented by the following formula (5), and a thiirane group. have In other words, the specific polymer contains an oxetanyl group, an oxiranyl group, a group represented by the following formula (3), a group represented by the following formula (4), a group represented by the following formula (5), and The side chain has a site having at least one functional group selected from thiirane groups.

In the above formulas (3) to (5), * represents a bond.

The site having a thermally crosslinkable group in (A-3) above can form a crosslinking reaction with the polar groups such as amino groups, hydroxyl groups, and carboxyl groups, and even when the baking time of the liquid crystal aligning agent is shortened, the above (A-3) A-2) It is possible to stabilize the liquid crystal alignment ability of the site having photoalignment properties and obtain a liquid crystal alignment film that is excellent in the ability to express a pretilt angle.

式（ｃ－１）又は（ｃ－１－ｍ）中、Ｉ_ｃは、分子内にオキセタニル基、オキシラニル基、上記式（３）で表される基、上記式（４）で表される基、上記式（５）で表される基及びチイラン基から選択される１価の有機基である。Ｓ_ｃは、単結合又は２価の連結基を表す。 In the present invention, the site having a thermally crosslinkable group can be represented by the following formula (c-1), for example. Furthermore, the site can include a structure derived from a monomer represented by the following formula (c-1-m).

In formula (c-1) or (c-1-m), I _c represents an oxetanyl group, an oxiranyl group, a group represented by the above formula (3), a group represented by the above formula (4) in the molecule. , a monovalent organic group selected from a group represented by the above formula (5) and a thiirane group. S _c represents a single bond or a divalent linking group.

式（Ｍ_ｃ－１）～（Ｍ_ｃ－２）中、Ｒｃは水素原子又は炭素数１～５のアルキル基を表し、＊は結合位置を示す。
Ｍ_ｅとして好ましくは、式（Ｍ_ｃ－１）～（Ｍ_ｃ－２）、α－メチレン－γ－ブチロラクトンマレイミドであるのがよい。 Furthermore, in formula (c-1-m), M _e represents a third polymerizable group. Examples of the third polymerizable group include the following formulas (M _c -1) to (M _c -2), radically polymerizable groups of α-methylene-γ-butyrolactone, maleimide, norbornene and its derivatives, and siloxane. can.

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

Examples of the divalent linking group in S _c of formula (c-1-m) include alkanediyl groups having 1 to 10 carbon atoms (preferably 1 to 6 carbon atoms), and alkanediyl groups having 6 to 20 carbon atoms (preferably 6 to 6 carbon atoms). 14) arylene group, (*A)-CONH-R ₆ -(*B) group, (*A)-COO-R ₇ -(*B) group, and the like. Here, R ₆ and R ₇ are each independently a single bond, an alkanediyl group having 1 to 12 carbon atoms (preferably 1 to 6 carbon atoms), or an arylene group having 6 to 20 carbon atoms (preferably 6 to 14 carbon atoms). group, alkyleneoxyarylene group, any carbon-carbon bond of the alkanediyl group may have an -O- bond or -S- bond, and (*A) is a bond with a carbon atom having an unsaturated bond. (*B) indicates a bond that binds to _Ia1 . Examples of alkanediyl groups include methylene group, ethylene group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-1,3-diyl group, Propane-2,2-diyl group, butane-1,2-diyl group, butane-1,3-diyl group, butane-1,4-diyl group, pentane-1,4-diyl group, pentane-1,5 -diyl group, hexane-1,5-diyl group, hexane-1,6-diyl group, etc. Furthermore, examples of the arylene group include a phenylene group, a naphthylene group, a biphenylene group, an anthrylene group, and the like. Examples of the alkyleneoxyarylene group include ethyleneoxyphenylene group, hexyleneoxyphenylene group, and hexyleneoxybiphenyl group. Among them, the divalent linking group in S _a includes an alkanediyl group having 1 to 10 carbon atoms (preferably 1 to 6 carbon atoms), an arylene group having 6 to 20 carbon atoms (preferably 6 to 14 carbon atoms), (*A) A -COO-R ₇ -(*B) group is preferred, and R ₇ is preferably an alkanediyl group having 2 to 6 carbon atoms. In addition, one or more hydrogen atoms in 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 formula (c-1-m) having an oxiranyl group include allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, 2-methylglycidyl methacrylate, α-ethyl glycidyl acrylate, α-n-propyl Glycidyl acrylate, α-n-butyl glycidyl acrylate, 3,4-epoxybutyl acrylate, 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl acrylate, 6,7-epoxyheptyl methacrylate, α -6,7-epoxyheptyl ethyl acrylate, o-vinylbenzylglycidyl ether, m-vinylbenzylglycidyl ether, p-vinylbenzylglycidyl ether, 3,4-epoxycyclohexylmethyl methacrylate, 3-ethenyl-7- Examples include oxabicyclo[4.1.0]heptane, 1,2-epoxy-5-hexene, and 1,7-octadiene monoepoxide. Among these, glycidyl methacrylate, 2-methylglycidyl methacrylate, 6,7-epoxyheptyl methacrylate, o-vinylbenzylglycidyl ether, m-vinylbenzylglycidyl ether, p-vinylbenzylglycidyl ether, methacrylic acid 3, 4-epoxycyclohexyl is preferred from the viewpoint of improving copolymerization reactivity and alignment of the liquid crystal aligning film.

Specific examples of formula (c-1-m) having an oxetanyl group include 3-(acryloyloxymethyl)oxetane, 3-(acryloyloxymethyl)-2-methyloxetane, 3-(acryloyloxymethyl)-3 -Ethyloxetane, 3-(acryloyloxymethyl)-2-trifluoromethyloxetane, 3-(acryloyloxymethyl)-2-pentafluoroethyloxetane, 3-(acryloyloxymethyl)-2-phenyloxetane, 3-( acryloyloxymethyl)-2,2-difluorooxetane, 3-(acryloyloxymethyl)-2,2,4-trifluorooxetane, 3-(acryloyloxymethyl)-2,2,4,4-tetrafluorooxetane, 3-(2-acryloyloxyethyl)oxetane, 3-(2-acryloyloxyethyl)-2-ethyloxetane, 3-(2-acryloyloxyethyl)-3-ethyloxetane, 3-(2-acryloyloxyethyl) -2-trifluoromethyloxetane, 3-(2-acryloyloxyethyl)-2-pentafluoroethyloxetane, 3-(2-acryloyloxyethyl)-2-phenyloxetane, 3-(2-acryloyloxyethyl)- 2,2-difluorooxetane, 3-(2-acryloyloxyethyl)-2,2,4-trifluorooxetane, 3-(2-acryloyloxyethyl)-2,2,4,4-tetrafluorooxetane, etc. Acrylic acid ester; 3-(methacryloyloxymethyl)oxetane, 3-(methacryloyloxymethyl)-2-methyloxetane, 3-(methacryloyloxymethyl)-3-ethyloxetane, 3-(methacryloyloxymethyl)-2-tri Fluoromethyloxetane, 3-(methacryloyloxymethyl)-2-pentafluoroethyloxetane, 3-(methacryloyloxymethyl)-2-phenyloxetane, 3-(methacryloyloxymethyl)-2,2-difluorooxetane, 3-( methacryloyloxymethyl)-2,2,4-trifluorooxetane, 3-(methacryloyloxymethyl)-2,2,4,4-tetrafluorooxetane, 3-(2-methacryloyloxyethyl)oxetane, 3-(2 -methacryloyloxyethyl)-2-ethyloxetane, 3-(2-methacryloyloxyethyl)-3-ethyloxetane, 3-(2-methacryloyloxyethyl)-2-trifluoromethyloxetane, 3-(2-methacryloyloxy) ethyl)-2-pentafluoroethyloxetane, 3-(2-methacryloyloxyethyl)-2-phenyloxetane, 3-(2-methacryloyloxyethyl)-2,2-difluorooxetane, 3-(2-methacryloyloxyethyl) )-2,2,4-trifluorooxetane, 3-(2-methacryloyloxyethyl)-2,2,4,4-tetrafluorooxetane, and other methacrylic acid esters.

式中、ＸはＯ（ＣＨ_２）_ｎ、Ｓ（ＣＨ_２）_ｎ、または（ＣＨ_２）_ｎを示し、ｎは０から６の整数を示す。Ｙはアクリロイル基、メタクリロイル基、アリル基、またはビニル基を示す。）、又は２，３－エピチオプロピルアクリレートまたはメタクリレート、及び２－または３―または４－（β－エピチオプロピルチオメチル）スチレン、２－または３―または４－（β－エピチオプロピルオキシメチル）スチレン、２－または３―または４－（β－エピチオプロピルチオ）スチレン、２－または３―または４－（β－エピチオプロピルオキシ）スチレン等を挙げることができる。 Specific examples of the formula (c-1-m) having a thiirane group include compounds represented by the following formula (S),

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

One type of moiety having a thermally crosslinkable group to be contained in the polymer of the present invention may be used alone, or two or more types of moieties may be used in combination.
The amount of the site having a thermally crosslinkable group introduced is preferably 5 to 45 mol%, 5 to 40 mol%, or 5 to 35 mol% of the specific polymer (component (A)).

式中、Ｉ_ｘ１は、カルボキシ基、水酸基、下記式（ｘ２）の少なくとも一つの部分構造を有する基または１級アミノ基から選ばれる１価の有機基である。但し、下記式（ｘ２）は１級アミノ基以外の基を示し、ｒ^１は、１又は２である。

式中、＊は結合手を示す。
また、Ｓ_ｘは、単結合又は２価の連結基を表す。 <(A-4) Structure having a polar group in the molecule>
The specific polymer contained in the liquid crystal aligning agent of the present invention may have a structure having a polar group in the molecule, that is, at least one functional group selected from a carboxy group, an amino group, and a hydroxyl group. .
This structure makes it possible to improve the liquid crystal orientation of the obtained liquid crystal alignment film and to express the pretilt angle of the liquid crystal even when the baking time of the liquid crystal aligning agent obtained from the specific polymer of the present invention is shortened. .
In the present invention, a structure having a polar group in the molecule can be represented by the following formula (x-1), for example. Further, the structure can include, but is not limited to, a monomer-derived structure represented by the following formula (x-1-m).

In the formula, I _x1 is a monovalent organic group selected from a carboxy group, a hydroxyl group, a group having at least one partial structure of the following formula (x2), or a primary amino group. However, the following formula (x2) represents a group other than a primary amino group, and r ¹ is 1 or 2.

In the formula, * indicates a bond.
Moreover, S _x represents a single bond or a divalent linking group.

In I _x1 , examples of the group having the partial structure of formula (x2) include a 5- or 6-membered nitrogen-containing heterocycle, such as piperidine and morpholine. Each of these groups may be unsubstituted, or one or more hydrogen atoms may be substituted with a fluorine atom, chlorine atom, cyano group, methyl group, or methoxy group. A preferable example of I _x1 is a monovalent organic group selected from a carboxy group and a hydroxyl group.

式中、Ｒ_１は水素原子又は炭素数１～５のアルキル基を表し、＊は結合手を示す。 M _x represents the fourth polymerizable group. Examples of the fourth polymerizable group include the following formulas (M _x -1) to (M _x -2), radically polymerizable groups of α-methylene-γ-butyrolactone, maleimide, norbornene and its derivatives, and siloxane. can. Preferred are formulas (M _x -1) to (M _x -2) and α-methylene-γ-butyrolactone maleimide.

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

Examples of the divalent linking group in _S 14) arylene group, (*A)-CONH-R ₆ -(*B) group, (*A)-COO-R ₇ -(*B) group, and the like. Here, R ₆ and R ₇ are each independently a single bond, an alkanediyl group having 1 to 12 carbon atoms (preferably 1 to 6 carbon atoms), or an arylene group having 6 to 20 carbon atoms (preferably 6 to 14 carbon atoms). group, alkyleneoxyarylene group, any carbon-carbon bond of the alkanediyl group may have an -O- bond, and (*A) is a bond bonding to a carbon atom having an unsaturated bond. This shows that (*B) is a bond that binds to I _x1 . Examples of alkanediyl groups include methylene group, ethylene group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-1,3-diyl group, Propane-2,2-diyl group, butane-1,2-diyl group, butane-1,3-diyl group, butane-1,4-diyl group, pentane-1,4-diyl group, pentane-1,5 -diyl group, hexane-1,5-diyl group, hexane-1,6-diyl group, etc. Furthermore, examples of the arylene group include a phenylene group, a naphthylene group, a biphenylene group, an anthrylene group, and the like. Examples of the alkyleneoxyarylene group include ethyleneoxyphenylene group, hexyleneoxyphenylene group, and hexyleneoxybiphenyl group. Among them, as the divalent linking group in _S A -COO-R ₇ -(*B) group is preferred, and R ₇ is preferably an alkanediyl group having 2 to 6 carbon atoms.

Specific examples of the above formula (x-1-m) having a carboxyl group include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, crotonic acid, isocrotonic acid, α-ethyl acrylic acid, β-ethyl acrylic acid, β-propylacrylic acid, β-isopropylacrylic acid, itaconic acid, fumaric acid, vinylbenzoic acid and the like. Further, as a specific example of the above formula (x-1-m) having an amino group, t-butylaminoethyl (meth)acrylate and the like can be mentioned. Specific examples of the above formula (x-1-m) having a hydroxyl group include 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, 12-hydroxylauryl (meth)acrylate and other hydroxyalkyl (meth)acrylates; hydroxy Other examples include ethyl (meth)acrylamide, (4-hydroxymethylcyclohexyl)methyl acrylate, N-methylol (meth)acrylamide, and N-hydroxy (meth)acrylamide.

Specific examples of the above formula (x-1-m) having a group having the partial structure of the above formula (x2) include 2,2,6,6-tetramethyl-4-piperidyl methacrylate. .

The moiety having a polar group in the molecule contained in the polymer of the present invention may be used singly, or two or more moieties may be used in combination.
In addition, when a moiety having a polar group is contained in the molecule, the content thereof is 5 to 85 mol%, 5 to 80 mol%, or 5 to 65 mol% of the specific polymer (component (A)). It is preferable that

<Solvent>
The solvent used for the liquid crystal aligning agent of the present invention is not particularly limited as long as it is a solvent that dissolves the specific polymer.
Specific examples include water, N-alkyl-2-pyrrolidones such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylcaprolactam. , tetramethylurea, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, 1,3-dimethyl-2-imidazo Dialkyl imidazolidinones such as lysinone, lactones such as γ-butyrolactone, γ-valerolactone, and δ-valerolactone, carbonates such as ethylene carbonate and propylene carbonate, methanol, ethanol, propanol, isopropanol, 3-methyl- Ketones such as 3-methoxybutanol, 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 the following formula: Compounds represented by (Sv-1) and compounds represented by the following formula (Sv-2), 4-methyl-2-pentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, 2-methyl acetate Examples include cyclohexyl, butyl butyrate, isoamyl butyrate, diisobutyl carbinol, diisopentyl ether, and the like.

式（Ｓｖ－１）～（Ｓｖ－２）中、Ｙ_１及びＹ_２はそれぞれ独立に水素原子又は炭素数１～６の１価の炭化水素基であり、Ｘ_１は酸素原子又は－ＣＯＯ－であり、Ｘ２は単結合又はカルボニル基であり、Ｒ_１は炭素数２～４のアルカンジイル基である。ｎ_１は１～３の整数である。ｎ_１が２又は３の場合、複数のＲ_１は同じでも異なっていてもよい。Ｚ_１は炭素数１～６の２価の炭化水素基であり、Ｙ_３及びＹ_４はそれぞれ独立に水素原子又は炭素数１～６の１価の炭化水素基である）等が挙げられる。
式（Ｓｖ－１）中、Ｙ_１及びＹ_２の炭素数１～６の１価の炭化水素基として、例えば炭素数１～６の１価の鎖状炭化水素基、炭素数１～６の１価の脂環式炭化水素基及び炭素数１～６の１価の芳香族炭化水素基などが挙げられる。炭素数１～６の１価の鎖状炭化水素基としては、炭素数１～６のアルキル基等を挙げることができる。Ｒ_１のアルカンジイル基は直鎖状でも分岐状でもよい。
式（Ｓｖ－２）中、Ｚ_１の炭素数１～６の２価の炭化水素基として、例えば炭素数１～６のアルカンジイル基等を挙げることができる。Ｙ_３及びＹ_４の炭素数１～６の１価の炭化水素基としては、炭素数１～６の１価の鎖状炭化水素基、炭素数１～６の１価の脂環式炭化水素基及び炭素数１～６の１価の芳香族炭化水素基などが挙げられる。炭素数１～６の１価の鎖状炭化水素基としては炭素数１～６のアルキル基などが挙げられる。

In formulas (Sv-1) to (Sv-2), Y ₁ and Y ₂ are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, and X ₁ is an oxygen atom or -COO- , X2 is a single bond or a carbonyl group, and R ₁ is an alkanediyl group having 2 to 4 carbon atoms. n ₁ is an integer from 1 to 3. When n ₁ is 2 or 3, a plurality of R ₁ may be the same or different. Z ₁ is a divalent hydrocarbon group having 1 to 6 carbon atoms, and Y ₃ and Y ₄ are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms.
In formula (Sv-1), the monovalent hydrocarbon group having 1 to 6 carbon atoms in Y ₁ and Y ₂ may be, for example, a monovalent chain hydrocarbon group having 1 to 6 carbon atoms, or a monovalent hydrocarbon group having 1 to 6 carbon atoms. Examples include a monovalent alicyclic hydrocarbon group and a monovalent aromatic hydrocarbon group having 1 to 6 carbon atoms. Examples of the monovalent chain hydrocarbon group having 1 to 6 carbon atoms include an alkyl group having 1 to 6 carbon atoms. The alkanediyl group for R ₁ may be linear or branched.
In formula (Sv-2), examples of the divalent hydrocarbon group having 1 to 6 carbon atoms in Z ₁ include alkanediyl groups having 1 to 6 carbon atoms. The monovalent hydrocarbon group having 1 to 6 carbon atoms for Y ₃ and Y ₄ includes a monovalent chain hydrocarbon group having 1 to 6 carbon atoms, and a monovalent alicyclic hydrocarbon group having 1 to 6 carbon atoms. and a monovalent aromatic hydrocarbon group having 1 to 6 carbon atoms. Examples of the monovalent chain hydrocarbon group having 1 to 6 carbon atoms include an alkyl group having 1 to 6 carbon atoms.

Specific examples of the solvent represented by formula (Sv-1) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol monobutyl ether ( butyl cellosolve), ethylene glycol monohexyl ether, ethylene glycol dimethyl ether, ethylene glycol monoacetate, ethylene glycol diacetate, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl Ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monomethyl ether, propylene glycol diacetate, ethylene Glycol, 1,4-butanediol, 3-methoxybutyl acetate, 3-ethoxybutyl acetate, etc.;

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

The solvent preferably has a boiling point of 80 to 200°C. More preferably, it is 80 to 180°C. Preferred solvents 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-ethylbutyl acetate, cyclohexyl acetate, 2-methylcyclohexyl acetate, butyl butyrate, isoamyl butyrate, diisobutyl carbinol, diisopentyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, Examples of the solvent include ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol monoacetate, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monomethyl ether, 3-methoxybutyl acetate, methyl glycolate, ethyl glycolate, butyl glycolate, ethyl lactate, butyl lactate, isoamyl lactate, ethyl-3-ethoxypropionate, methyl-3-methoxypropionate, and ethyl 3-methoxypropionate. The boiling point in this range is particularly preferred when the liquid crystal alignment agent containing the solvent is applied to a plastic substrate, which will be described later.

<Method for producing specific polymer>
The specific polymer contained in the liquid crystal aligning agent of the present invention includes (A-1) a monomer having at least one selected from (a) an isocyanate group and/or a blocked isocyanate group in the molecule; It is obtained by polymerizing (b) a monomer having a photo-alignable site, (c) a monomer having a thermally crosslinkable group, and optionally (d) a monomer having a polar group. Moreover, it can be copolymerized with other monomers other than those mentioned above. Other monomers include, for example, industrially available monomers capable of radical polymerization.

Specific examples of other monomers include acrylic ester compounds, methacrylic ester compounds, maleimide compounds, acrylonitrile, maleic anhydride, styrene compounds, and vinyl compounds containing nitrogen-containing aromatic heterocyclic groups and polymerizable groups. Examples include monomers.

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

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

Examples of the vinyl compound include vinyl ether, methyl vinyl ether, benzyl vinyl ether, 2-hydroxyethyl vinyl ether, phenyl vinyl ether, and propyl vinyl ether.

Examples of styrene compounds include styrene, methylstyrene, chlorostyrene, and bromostyrene.

具体的には、オキサゾール環、チアゾール環、ピリジン環、ピリミジン環、キノリン環、１－ピラゾリン環、イソキノリン環、チアジアゾール環、ピリダジン環、トリアジン環、ピラジン環、フェナントロリン環、キノキサリン環、ベンゾチアゾール環、オキサジアゾール環、アクリジン環などを挙げることができる。さらに、これら窒素含有芳香族複素環の炭素原子には、ヘテロ原子を含む置換基を有していてもよい。これらのうち、例えば、ピリジン環が挙げられる。
窒素含有芳香族複素環基及び重合性基を有するモノマーとして、例えば、２－（２－ピリジルカルボニルオキシ）エチル（メタ）アクリレート、２－（３－ピリジルカルボニルオキシ）エチル（メタ）アクリレート、２－（４－ピリジルカルボニルオキシ）エチル（メタ）アクリレート、等が挙げられる。 The nitrogen-containing aromatic heterocycle has a structure selected from the group consisting of the following formulas [N-a] to [N-b] (wherein Z ₂ is a straight chain or branched alkyl group having 1 to 5 carbon atoms) It is preferable that the aromatic cyclic hydrocarbon contains at least one, preferably one to four.

Specifically, oxazole ring, thiazole ring, pyridine ring, pyrimidine ring, quinoline ring, 1-pyrazoline ring, isoquinoline ring, thiadiazole ring, pyridazine ring, triazine ring, pyrazine ring, phenanthroline ring, quinoxaline ring, benzothiazole ring, Examples include an oxadiazole ring and an acridine ring. Furthermore, the carbon atoms of these nitrogen-containing aromatic heterocycles may have a substituent containing a heteroatom. Among these, for example, a pyridine ring can be mentioned.
Examples of monomers having a nitrogen-containing aromatic heterocyclic group and a polymerizable group include 2-(2-pyridylcarbonyloxy)ethyl (meth)acrylate, 2-(3-pyridylcarbonyloxy)ethyl (meth)acrylate, 2- (4-pyridylcarbonyloxy)ethyl (meth)acrylate, and the like.

The other monomers used in the present invention may be used alone or in combination of two or more types.
The content of the other monomers is preferably 0 to 20 mol%, 1 to 20 mol%, or 5 to 20 mol% of the specific polymer (component (A)). In this case, the total of the site having an isocyanate group and/or a blocked isocyanate group, the photoreactive site, and the thermally crosslinkable site in the molecule is 80 to 100 mol of the specific polymer (A) component. %, or 80 to 99 mol%, or 80 to 95 mol%.

The method for producing the specific polymer in the present invention is not particularly limited, and general industrially used methods can be used. Specifically, it can be produced by cationic polymerization, radical polymerization, or anionic polymerization using vinyl groups of monomers. Among these, radical polymerization is particularly preferred from the viewpoint of ease of reaction control.

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.
A radical thermal polymerization initiator is a compound that generates radicals when heated above the decomposition temperature. Such radical thermal polymerization initiators include, for example, ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), diacyl peroxides (acetyl peroxide, benzoyl peroxide, etc.), hydroperoxides (peroxide Hydrogen, tert-butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyketals (dibutyl peroxycyclohexane) ), alkyl peresters (peroxyneodecanoic acid tert-butyl ester, peroxypivalic acid tert-butyl ester, peroxy 2-ethylcyclohexanoic acid tert-amyl ester, etc.), persulfates (potassium persulfate, sodium persulfate, ammonium persulfate, etc.), and azo compounds (azobisisobutyronitrile, 2,2'-di(2-hydroxyethyl)azobisisobutyronitrile, etc.). Such radical thermal polymerization initiators can be used alone or in combination of two or more.

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

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

The solvent used in the polymerization reaction of the specific polymer is not particularly limited as long as it dissolves the produced polymer. Specific examples include the above solvents, such as N-alkyl-2-pyrrolidones, dialkylimidazolidinones, lactones, carbonates, ketones, compounds represented by the above formula (Sv-1), and the above formula Examples include the compound represented by (Sv-2), tetrahydrofuran, 1,4-dioxane, dimethylsulfone, dimethylsulfoxide, hexamethylsulfoxide, and the like.
These solvents may be used alone or in combination. Furthermore, even if the solvent does not dissolve the polymer to be produced, it may be used by mixing it with the above-mentioned solvent.
Further, in radical polymerization, oxygen in the solvent becomes a cause of inhibiting the polymerization reaction, so it is preferable to use an organic solvent that has been degassed to the extent possible.

The polymerization temperature during radical polymerization can be selected from any temperature in the range of 30 to 150°C, but is preferably in the range of 50 to 100°C. Further, the monomer concentration is preferably 1 to 50% by weight, more preferably 5 to 30% by weight. The initial stage of the reaction can be carried out at a high concentration, and then an organic solvent can be added.
In the above radical polymerization reaction, the ratio of the radical initiator to the monomer to be polymerized is preferably 0.1 to 10 mol%. Furthermore, various monomer components, solvents, initiators, etc. can be added during polymerization.

[Recovery of polymer]
When recovering produced polymers from the reaction solution obtained by the above-described reaction, the reaction solution may be poured into a poor solvent to precipitate the polymers. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, heptane, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, water, and the like. The polymer precipitated in a poor solvent can be collected by filtration and then dried under normal pressure or reduced pressure, at room temperature or by heating. Furthermore, by repeating the procedure of redissolving the precipitated and collected polymer in an organic solvent and re-precipitating and collecting it 2 to 10 times, the amount of impurities in the polymer can be reduced. Examples of the poor solvent in this case include alcohols, ketones, hydrocarbons, etc. It is preferable to use three or more types of poor solvents selected from these, since the efficiency of purification will further increase.

The molecular weight of the polymer of the present invention is determined by the weight average molecular weight measured by GPC (Gel Permeation Chromatography) method, considering the strength of the resulting coating film, workability during coating film formation, and uniformity of the coating film. It is preferably 2,000 to 1,000,000, more preferably 5,000 to 100,000.

[Preparation of liquid crystal alignment agent]
It is preferable that the liquid crystal alignment agent (namely, polymer composition) used for this invention is prepared as a coating liquid so that it may become suitable for formation of a liquid crystal alignment film. That is, the liquid crystal aligning agent of the present invention is preferably prepared as a solution in which a resin component for forming a resin film is dissolved in an organic solvent. Here, the resin component is the specific polymer (component (A)) described above. At that time, the content of the resin component is preferably 0.5 to 20% by mass, more preferably 1 to 15% by mass, particularly preferably 1 to 10% by mass based on the entire liquid crystal aligning agent.

In the polymer composition of this embodiment, all of the above-mentioned resin components have a site having the above-mentioned isocyanate group and/or blocked isocyanate group, a site having photo-alignment property, and a thermally crosslinkable group. However, other polymers other than these (hereinafter also referred to as "other polymers") may be mixed. At that time, the content of other polymers in the resin component may be 5 to 95 parts by mass, or 10 to 90 parts by mass, based on a total of 100 parts by mass of component (A) and other polymers. .

Such other polymers include, for example, poly(meth)acrylate, polyamic acid ester, polyimide, etc., and have the moieties (A-1) to (A-3) that the specific polymer of the present invention has. Examples include polymers that are not

<Other ingredients>
The liquid crystal aligning agent of the present invention may contain other components than the above-mentioned characteristic polymer component. Such other components include polymers selected from polyimides and their precursors, which have at least one group selected from vertical alignment groups and tert-butoxycarbonyl groups, or which have been chemically imidized. (hereinafter also referred to as component (B)), compounds containing two or more epoxy groups or thiirane groups in the molecule, and other crosslinkable compounds (hereinafter collectively referred to as "component (B)"). Compounds that improve film thickness uniformity and surface smoothness when a liquid crystal alignment agent is applied, compounds that improve the adhesion between the liquid crystal alignment film and the substrate, etc. Yes, but not limited to this.

<(B) component>
The liquid crystal aligning agent of the present invention is a polymer selected from polyimide and its precursor as component (B), and has at least one group selected from a vertical alignment group and a tert-butoxycarbonyl group, or The polymer may contain at least one of a polymer that has been selectively imidized.

The polymer of component (B) is a polyimide and its precursor (hereinafter also referred to as a polyimide component), and has a surface energy close to that of the polymer of component (A). Acrylic components such as component (A) basically have low polarity and low surface energy. On the other hand, polyimide components have high polarity and high surface energy. However, if the difference in surface energy between these two components is too large, they will not mix well and agglomeration will occur, resulting in an uneven film, repelling, and unevenness, which will narrow the process margin. Problems such as this may occur. Therefore, by lowering the polarity of the polyimide component, the surface energy can be controlled to a value that is higher than that of the acrylic component but has a small difference. Methods for lowering the polarity of the polyimide component include a method of chemically imidizing it and then mixing it with component (A), and a method of introducing a side chain.

Such polymers include polymers obtained by chemically imidizing a tetracarboxylic acid derivative such as a known tetracarboxylic dianhydride and a known diamine, and a diamine having a side chain. Examples thereof include the resulting polyimide precursor, a polyimide obtained by imidizing the same, a polyimide precursor obtained using a diamine having a tert-butoxycarbonyloxy group, and a polyimide obtained by imidizing the same. Due to such side chains and chemical imidization, the surface energy can be brought close to that of the acrylic polymer, which is component (A), so when a liquid crystal aligning agent is applied and baked to form a cured film, agglomeration etc. This does not occur and a flat cured film can be provided. Examples of diamines having side chains include diamines represented by formulas (2), (3), (4), and (5) described in paragraphs [0023] to [0039] of International Patent Application Publication WO2016/125870; Specific examples include diamines represented by formulas [A-1] to [A-32]. Examples of diamines having a tertiary-butoxycarbonyloxy group include formulas [A-1], [A-2], and [A-3] described in paragraphs [0011] to [0034] of International Patent Application Publication WO2017/119461. Diamines having this structure and specific examples thereof include the diamines exemplified.

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

<Crosslinking agent component>
1. Compounds containing two or more epoxy groups or thiirane groups in the molecule With such a structure, the polar groups of (A-1), such as amino groups, hydroxyl groups, carboxyl groups, and The crosslinking reaction with hydroxyl groups is further promoted, and it becomes possible to obtain a liquid crystal aligning film having excellent pretilt angle expression ability even during short-time baking. The compound having two or more epoxy groups or thiirane groups in the molecule is not particularly limited as long as it has two or more epoxy groups or thiirane groups at the end of the molecule. Examples of compounds having two or more epoxy groups at the end of the molecule include epoxy compounds having at least one tertiary nitrogen atom in the molecule, and epoxy compounds having no nitrogen compound in the molecule. .

Specifically, epoxy compounds having at least one tertiary nitrogen atom in the molecule include epoxy compounds with structures represented by the following formulas (Ep-1) to (Ep-11) and aliphatic diamines. Examples include epoxy compounds containing a nitrogen atom as a nucleus.

Ｘはそれぞれ、単結合または炭素数１～６の脂肪族基、または芳香族基を表し、Ｙはメチレン基、エチレン基、トリメチレン基、エチリデン基、イソプロピリデン基、ビニレン基、ビニリデン基、オキシ基、イミノ基、チオ基、スルホニル基のいずれかを表し、Ｒ_１～Ｒ_３は水素原子または、炭素数１～６の脂肪族基を表し、ｊは０～４の整数を表す。

X represents a single bond, an aliphatic group having 1 to 6 carbon atoms, or an aromatic group, and Y represents a methylene group, ethylene group, trimethylene group, ethylidene group, isopropylidene group, vinylene group, vinylidene group, or oxy group. , an imino group, a thio group, or a sulfonyl group, R ₁ to R ₃ represent a hydrogen atom or an aliphatic group having 1 to 6 carbon atoms, and j represents an integer of 0 to 4.

Among epoxy compounds having at least one tertiary nitrogen atom in the molecule, compounds in which the tertiary nitrogen atom is bonded to at least one aliphatic group or alicyclic group can shorten the firing time. It is suitable for

Specific examples of epoxy compounds having at least one tertiary nitrogen atom in the molecule include N,N-diglycidylaniline, N,N-diglycidyltoluidine, N,N-diglycidylcyclohexylamine, and N,N-diglycidylaniline. - diglycidylmethylcyclohexylamine, N,N,N',N'-tetraglycidyl-p-phenylenediamine, N,N,N',N'-tetraglycidyl-m-phenylenediamine, N,N,N', N'-tetraglycidyl-o-phenylenediamine, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-3,4'- Diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-3,3'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl sulfide, N,N, N',N'-tetraglycidyl-1,5-diaminonaphthalene, N,N,N',N'-tetraglycidyl-2,7-diaminofluorene, N,N,N',N'-tetraglycidyl-4 ,4'-diaminodiphenyl ether, N,N,N',N'-tetraglycidyl-2,2-bis[4-(4-aminophenoxy)phenyl]propane, N,N,N',N'-tetraglycidyl -9,9-bis(4-aminophenyl)fluorene, N,N,N',N'-tetraglycidyl-2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, N,N , N',N'-tetraglycidyl-2,2-bis(4-aminophenyl)hexafluoropropane, N,N,N',N'-tetraglycidyl-4,4'-(p-phenylenediisopropylidene) ) bisaniline, N,N,N',N'-tetraglycidyl-4,4'-(m-phenylenediisopropylidene)bisaniline, N,N,N',N'-tetraglycidyl-1,4-bis( 4-aminophenoxy)benzene, N,N,N',N'-tetraglycidyl-4,4'-bis(4-aminophenoxy)biphenyl, N,N,N',N'-tetraglycidyl-m-xyly Diamine, 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,N,N',N'-tetraglycidyl -diaminopropane, N,N,N',N'-tetraglycidyl-diaminobutane, N,N,N',N'-tetraglycidyl-diaminopentane, N,N,N',N'-tetraglycidyl-diamino Examples include hexane, N,N,N',N'-tetraglycidyl-diaminoheptane, N,N,N',N'-tetraglycidyl-diaminooctane, and the like.

Specific examples of epoxy compounds that do not have a nitrogen compound in the molecule include the product names "Epikoat 828", "Epikoat 834", "Epicoat 1001", and "Epicoat 1004" manufactured by Mitsubishi Chemical Corporation, and Dainippon Ink & Chemicals Co., Ltd. Bisphenol A type epoxy compounds such as "Epiclon 840", "Epiclon 850", "Epiclon 1050", "Epiclon 2055" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., and "Epototh 128" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.;
Dainippon Ink and Chemicals' product name "Epicron 830S", Mitsubishi Chemical's product name "Epicote 807", Nippon Steel & Sumikin Chemical Co., Ltd.'s product name "Epotote YDF-170", "Epotote YDF-175", "Epotote" Bisphenol F-type epoxy compounds such as “YDF-2004”;
Bisphenol S-type epoxy compounds such as Nippon Kayaku's trade name "EBPS-200", Asahi Denka Kogyo's trade name "EPX-30", Dainippon Ink and Chemicals Co., Ltd.'s trade name "Epiclon EXA1514";
Bisphenol fluorene type epoxy compounds such as "BPFG" manufactured by Osaka Gas Co., Ltd., "YL-6056", "YL-6021", "YX-4000", "YX-4000H" manufactured by Mitsubishi Chemical Corporation, etc. Bixylenol-type or biphenyl-type epoxy compounds, or mixtures thereof;
Hydrogenated bisphenol A type epoxy compounds such as "Epotote ST-2004", "ST-2007", "ST-3000" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.;
Product names “Epicote 152” and “Epicote 154” manufactured by Mitsubishi Chemical Company, “D.E.N.431” and “D.E.N.438” manufactured by Dow Chemical Company, Dainippon Ink & Chemicals Co., Ltd. "Epicron N-690", "Epicron N-695", "Epicron N-730", "Epicron N-770", "Epicron N-865" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., "Epototh YDCN" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. -701'', ``Epotote YDCN-704'', Nippon Kayaku Co., Ltd. product name ``EPPN-201'', ``EOCN-1025'', ``EOCN-1020'',
Novolac type epoxy compounds such as "EOCN-104S" and "RE-306";
Mitsubishi Chemical Corporation's product name "Epicort YL-903", Dainippon Ink and Chemicals' product names "Epicron 152" and "Epicron 165", Nippon Steel & Sumikin Chemical Co., Ltd.'s product name "Epotote YDB-400", " Brominated bisphenol A type epoxy compounds such as “Epotote YDB-500”;
Naphthalene skeletons such as product names “ESN-190” and “ESN-360” manufactured by Nippon Steel Chemical Co., Ltd. and product names “HP-4032”, “EXA-4700” and “EXA-4750” manufactured by Dainippon Ink and Chemicals Co., Ltd. an epoxy compound having;
Epoxy compounds having a dicyclopentadiene skeleton, such as product names "HP-7200" and "HP-7200H" manufactured by Dainippon Ink and Chemicals;
Tris-hydroxyphenylmethane type epoxy compounds such as the product name "YL-933" manufactured by Mitsubishi Chemical Corporation and the product names "EPPN-501" and "EPPN-502" manufactured by Nippon Kayaku Co., Ltd.;
Alicyclic epoxy compounds such as "Celoxide 2011" manufactured by Daicel Chemical Industries, Ltd., "Araldite CY175" and "Araldite CY179" manufactured by Asahi Kasei Corporation, and "HBE-100" manufactured by Shin Nippon Chemical Co., Ltd. etc., but are not limited to these. These epoxy compounds can be used alone or in combination of two or more.

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

The amount of two or more components used in the molecule is preferably 0.1 parts by mass to 40 parts by mass, more preferably 0.5 parts by mass, based on 100 parts by mass of the resin component contained in the polymer composition. Parts by mass to 30 parts by mass.

2. Other crosslinkable compounds Other crosslinkable compounds include compounds having an isocyanate group, an oxetane group, or a cyclocarbonate group, or a hydroxy group described in paragraphs [0109] to [0113] of International Publication Publication WO2016/047771. In addition to compounds having at least one group selected from the group consisting of , hydroxyalkyl groups, and lower alkoxyalkyl groups, examples include compounds having blocked isocyanate groups.
Examples of the blocked isocyanate compound include Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (manufactured by Nippon Polyurethane Industry Co., Ltd.), Takenate B-830, B-815N, Examples include B-820NSU, B-842N, B-846N, B-870N, B-874N, and B-882N (all manufactured by Mitsui Chemicals, Inc.).

The amount of these crosslinking agent components used is preferably 0.1 parts by mass to 40 parts by mass, more preferably 1 part by mass to 30 parts by mass, based on 100 parts by mass of the resin component contained in the polymer composition. Department.

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

[Compound that improves adhesion between liquid crystal alignment film and substrate]
Specific examples of compounds that improve the adhesion between the liquid crystal alignment film and the substrate include the following functional silane-containing compounds. For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane , N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy Carbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl- 1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxy Examples include amino-based silane-containing compounds such as silane and N-bis(oxyethylene)-3-aminopropyltriethoxysilane.

When using a compound that improves adhesion to the substrate, the amount used is preferably 0.1 parts by mass to 30 parts by mass based on 100 parts by mass of the resin component contained in the polymer composition. More preferably, it is 1 part by mass to 20 parts by mass.

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

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal aligning agent of the present invention can be applied to a substrate, baked, and then subjected to an alignment treatment such as rubbing or light irradiation, or in some vertical alignment applications, can be made into a liquid crystal alignment film without an alignment treatment. can. Examples of substrates include glasses such as float glass and soda glass; polyethylene terephthalate, polybutylene terephthalate, polypropylene, polystyrene, polyether sulfone, polycarbonate, poly(cycloaliphatic olefin), polyvinyl chloride, polyvinylidene chloride, and polyether ether. Transparent substrates made of plastics such as ketone (PEEK) resin films, polysulfone (PSF), polyethersulfone (PES), polyamide, polyimide, acrylic, and triacetyl cellulose can be used.

The transparent conductive film provided on one surface of the substrate includes a NESA film (registered trademark of PPG, Inc., USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ), etc. Can be used.

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

The baking after applying the liquid crystal aligning agent can be carried out at any temperature from 40 to 300°C, preferably from 40 to 250°C, more preferably from 40 to 230°C. When a transparent substrate made of a plastic substrate is used, the temperature is preferably 40 to 150°C, more preferably 80 to 140°C. The firing time is preferably 0.1 to 15 minutes, more preferably 1 to 10 minutes.

The thickness of the coating film formed on the substrate is preferably 5 to 1,000 nm, more preferably 10 to 500 nm or 10 to 300 nm. This firing can be performed using a hot plate, hot air circulation furnace, infrared furnace, etc.
Rayon cloth, nylon cloth, cotton cloth, etc. can be used for the rubbing treatment.

<Light irradiation process>
In some embodiments, an alignment treatment by light irradiation may be performed, for example, a step of applying the above-mentioned liquid crystal aligning agent onto a substrate to form a coating film, and a step of applying the above-mentioned liquid crystal aligning agent onto a substrate, and a step of forming the coating film in a state where the coating film is not in contact with the liquid crystal layer, or The method may also include a step of irradiating the coating film with light while in contact with a liquid crystal layer.

Examples of the light irradiated in the alignment treatment by light irradiation include ultraviolet rays containing light with a wavelength of 150 to 800 nm, visible light, and the like. Among these, ultraviolet light containing light with a wavelength of 300 to 400 nm is preferred. The irradiation light may be polarized or non-polarized. As the polarized light, it is preferable to use light containing linearly polarized light.

When the light used is polarized light, the light irradiation may be performed from a direction perpendicular to the substrate surface, from an oblique direction, or a combination of these may be performed. When irradiating non-polarized light, it is preferable to irradiate from a direction oblique to the substrate surface.

The amount of light irradiation is preferably 0.1 mJ/cm ² or more and less than 1,000 mJ/cm ² , more preferably 1 to 500 mJ/cm ² , and even more preferably 2 to 200 mJ/cm ² . preferable.

The liquid crystal display element of the present invention can be manufactured by a conventional method, and the manufacturing method is not particularly limited. It is preferable that the pair of substrates face each other with an appropriate gap therebetween, and that a spacer is disposed between the substrates in order to make the thickness of the liquid crystal sandwiched between the substrates uniform. As this spacer, known spacer materials such as a conventional scattering type spacer and a spacer formed from a photosensitive spacer forming composition can be used, as well as unevenness formed on a layer made of a cured liquid crystal material. It is also possible to use it as a spacer.

<Liquid crystal clamping process>
For constructing a liquid crystal cell by sandwiching a liquid crystal between substrates, there are, for example, the following two methods. The first method is to place a pair of substrates facing each other with a gap (cell gap) in between so that the respective liquid crystal alignment films face each other, and then bond the peripheral parts of the pair of substrates together using a sealant. A method for producing a liquid crystal cell can be mentioned by injecting liquid crystal into a cell gap defined by a suitable sealant and then sealing the injection hole.

As a second method, for example, an ultraviolet light-curable sealing material is applied to a predetermined location on one of the two substrates on which a liquid crystal alignment film is formed, and then a sealing material that is cured by ultraviolet light is applied to several predetermined locations on the surface of the liquid crystal alignment film. After dropping the liquid crystal onto the substrate, the other substrate is attached so that the liquid crystal alignment films face each other, the liquid crystal is spread over the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to harden the sealant. A method for manufacturing cells (ODF (One Drop Fill) method) can be mentioned.

Examples of liquid crystals include fluorine-based liquid crystals and cyano-based liquid crystals that have positive or negative dielectric anisotropy depending on the application, and liquid crystal compounds or liquid crystal compositions that are polymerized by at least one of heating and light irradiation. (hereinafter also referred to as a polymerizable liquid crystal or a curable liquid crystal composition) may be used.

The step of forming the coating film of the liquid crystal aligning agent may be performed by a roll-to-roll method. If the roll-to-roll method is used, it becomes possible to simplify the manufacturing process of the liquid crystal display element and thereby reduce the manufacturing cost.

A liquid crystal display element can be obtained by attaching polarizing plates to both outer surfaces of the liquid crystal cell.
The polarizing plate used on the outside of the liquid crystal cell is either a polarizing plate in which a polarizing film called "H film", which is made by stretching and aligning polyvinyl alcohol and absorbing iodine, is sandwiched between cellulose acetate protective films, or the H film itself. Examples include polarizing plates.

The liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention as described above has good liquid crystal alignment, excellent pretilt angle expression ability, and high reliability. Furthermore, the liquid crystal display element manufactured by the method of the present invention has excellent display characteristics.

The abbreviations used in the examples are as follows.
<Methacrylic monomer>
(Photoalignable monomer)

MA-1 was synthesized by the synthesis method described in patent document (WO-2017115790).

(Epoxy group-containing monomer)
GMA: glycidyl methacrylate

(Carboxylic acid group-containing monomer)
MAA: methacrylic acid

(Isocyanate group-containing monomer)
MOI-BP: 2-[(3,5-dimethyl-1-pyrazolyl)carbonylamino]ethyl methacrylate

<Tetracarboxylic dianhydride monomer>
A1: Tetracarboxylic dianhydride represented by the following formula [A1] A2: Tetracarboxylic dianhydride represented by the following formula [A2] A3: Tetracarboxylic dianhydride represented by the following formula [A3] Product A4: Tetracarboxylic dianhydride represented by the following formula [A4] A5: Tetracarboxylic dianhydride represented by the following formula [A5] A6: Tetracarboxylic dianhydride represented by the following formula [A6] Anhydride A7: Tetracarboxylic dianhydride represented by the following formula [A7] A8: Tetracarboxylic dianhydride represented by the following formula [A8]

<Side chain diamine monomer>
B1: Side chain diamine monomer represented by the following formula [B1] B2: Side chain diamine monomer represented by the following formula [B2] B3: Side chain diamine monomer represented by the following formula [B3] B4: The following formula Side chain diamine monomer B5 represented by the following formula [B4]: Side chain diamine monomer B6 represented by the following formula [B6]: Side chain diamine monomer B7 represented by the following formula [B6]: Represented by the following formula [B7] Side chain diamine monomer B8: Side chain diamine monomer represented by the following formula [B8] B9: Side chain diamine monomer represented by the following formula [B9] B10: Side chain diamine monomer represented by the following formula [B10] B11: Side chain diamine monomer represented by the following formula [B11] B12: Side chain diamine monomer represented by the following formula [B12] B13: Side chain diamine monomer represented by the following formula [B13] B14: The following Side chain diamine monomer represented by formula [B14]

<Other diamine monomers>
C1: Other diamine monomers represented by the following formula [C1] C2: Other diamine monomers represented by the following formula [C2] C3: Other diamine monomers represented by the following formula [C3] C4: Other diamine monomers represented by the following formula [C4] Other diamine monomer C5 represented by the following formula [C5]: Other diamine monomer C6 represented by the following formula [C6]: Other diamine monomer C7 represented by the following formula [C7]: Other diamine monomer C8 represented by the following formula [C7]: Other diamine monomers represented by the following formula [C8] C9: Other diamine monomers represented by the following formula [C9] C10: Other diamine monomers represented by the following formula [C10] C11: Represented by the following formula [C11] Other diamine monomers C12: Other diamine monomers represented by the following formula [C12] C13: Other diamine monomers represented by the following formula [C13] C14: Other diamine monomers represented by the following formula [C14] C15: Other diamine monomers represented by the following formula [C14] Other diamine monomers represented by formula [C15] C16: Other diamine monomers represented by formula [C16] below C17: Other diamine monomers represented by formula [C17] below C18: Other diamine monomers represented by formula [C18] below Diamine monomer C19: Other diamine monomers represented by the following formula [C19] C20: Other diamine monomers represented by the following formula [C20]

(Crosslinking agent component)
D-1: Crosslinking agent component represented by the following formula [D1] D-2: Crosslinking agent component represented by the following formula [D2] D-3: Crosslinking agent component represented by the following formula [D3]

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

(molecular weight measurement)
The molecular weight of the polymer in the synthesis example was measured as follows using a normal temperature gel permeation chromatography (GPC) device (SSC-7200 manufactured by Senshu Kagaku Co., Ltd. and columns (KD-803, KD-805) manufactured by Shodex Co., Ltd.).
Column temperature: 50°C, eluent: DMF (as additives, lithium bromide-hydrate (LiBr H ₂ O) is 30 mmol/L, phosphoric acid anhydrous crystal (o-phosphoric acid) is 30 mmol/L, THF is 10 ml/L), flow rate: 1.0 ml/min Standard sample for creating a calibration curve: TSK standard polyethylene oxide manufactured by Tosoh Corporation (molecular weight approximately 9000,000, 150,000, 100,000, 30,000), and Polyethylene glycol manufactured by Polymer Laboratory (molecular weight approximately 12,000, 4,000, 1,000).

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

<Methacrylate polymer synthesis example 1>
MA1 (3.04 g, 6.00 mmol), GMA (0.71 g, 5.00 mmol), and MOI-BP (2.26 g, 9.00 mmol) were dissolved in NMP (24.7 g) and pumped with a diaphragm pump. After degassing, AIBN (0.16 g, 0.5 mmol) was added as a polymerization initiator, and degassing was performed again. Thereafter, the mixture was reacted at 60° C. for 13 hours to obtain a polymer solution.
Next, NMP (5.0 g) and BCS (6.0 g) were added to this polymer solution (4.0 g) and stirred at room temperature to obtain a methacrylate polymer solution (MP1).
This polymer had a number average molecular weight of 33,000 and a weight average molecular weight of 116,000.

<Methacrylate polymer synthesis examples 2 to 4>
Methacrylic polymers 2 to 4 were synthesized with the compositions shown in Table 1 using the same method as in Polymer Synthesis Example 1.

<Polyamic acid polymer synthesis example 5>
B1 (2.28 g, 3.00 mmol), C2 (1.22 g, 4.00 mmol), C7 (1.45 g, 3.00 mmol) and A1 (2.23 g, 6.00 mmol) in NMP (27.2 g) After reacting at 60°C for 5 hours, A2 (1.00g, 2.00mmol) and A4 (0.87g, 2.00mmol) and NMP (9.1g) were added and reacted at 40°C for 10 hours. A polyamic acid polymer solution (MP5) was obtained by reacting for a period of time.

<Polyamic acid polymer synthesis examples 6 to 23>
Polyamic acid polymers 6 to 23 were synthesized with the compositions shown in Table 2 using the same method as in Polymer Synthesis Example 1.

<Polyimide polymer synthesis example 24>
After adding NMP to a polyamic acid polymer solution (MP5) (50 g) and diluting it to 6.5% by mass, acetic anhydride (8.8 g) and pyridine (2.7 g) were added as an imidization catalyst, and 2. The reaction was allowed to proceed for 5 hours. This reaction solution was poured into methanol (700 ml), and the resulting precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain a polyimide polymer powder (E). The imidization rate of this polyimide polymer was 75%, the number average molecular weight was 12,400, and the weight average molecular weight was 42,500.
NMP (44.0 g) was added to the obtained polyimide powder (E) (6.0 g) and dissolved by stirring at 70° C. for 20 hours. NMP (10.0 g) and BCS (40.0 g) were added to this solution and stirred at room temperature for 5 hours to obtain a polyimide polymer solution (MP24).

<Polyimide polymer synthesis examples 25 to 42>
Using the polymer solutions obtained in Polymer Synthesis Examples 6 to 23, polyimide polymer solutions MP25 to MP42 were synthesized using the same method as in Polymer Synthesis Example 24.

(Example 1)
A liquid crystal aligning agent (PM1) was obtained by adding D3 (0.04 g) to the polymer solution (MP1) (10.0 g) obtained in methacrylate polymer synthesis example 1 and stirring at room temperature.

(Example 2)
Using the polymer solution (MP2) obtained in Polymer Synthesis Example 2, a liquid crystal aligning agent (PM2) was obtained using the same method as in Example 1.

(Example 3)
To the polymer solution (MP1) (3.0 g) obtained in methacrylate polymer synthesis example 1, added the polymer solution (MP24) (7.0 g) obtained in polyimide polymer synthesis example 24, and further added D3 (0.04 g). was added and stirred at room temperature to obtain a liquid crystal aligning agent (PM3).

(Examples 4 to 43)
Liquid crystal aligning agents (PM4) to (PM43) were obtained using the same method as in Example 1 with the compositions shown in Table 3.

(Comparative example 1)
A liquid crystal aligning agent (RPM1) was obtained by adding D3 (0.04 g) to the polymer solution (MP3) (10.0 g) obtained in methacrylate polymer synthesis example 3 and stirring at room temperature.

(Comparative example 2)
Using the polymer solution obtained in methacrylate polymer synthesis example 4, a liquid crystal aligning agent (RPM2) was obtained using the same method as in comparative example 1.

(Comparative example 3)
To the polymer solution (MP3) (3.0 g) obtained in methacrylate polymer synthesis example 3, added the polymer solution (MP5) (7.0 g) obtained in amic acid polymer synthesis example 5, and further added D3 (0.04 g). ) was added and stirred at room temperature to obtain a liquid crystal aligning agent (RPM3).

(Comparative example 4)
Using the polymer solution (MP4) obtained in methacrylate polymer synthesis example 4, a liquid crystal aligning agent (RPM4) was obtained using the same method as in comparative example 3.

(Comparative example 5)
To the polymer solution (MP3) (3.0 g) obtained in methacrylate polymer synthesis example 3, added the polymer solution (MP24) (7.0 g) obtained in polyimide polymer synthesis example 24, and further added D3 (0.04 g). was added and stirred at room temperature to obtain a liquid crystal aligning agent (RPM5).

(Comparative example 6)
Using the polymer solution (MP4) obtained in methacrylate polymer synthesis example 4, a liquid crystal aligning agent (RPM6) was obtained using the same method as in comparative example 5.

<Production of liquid crystal display element>
The liquid crystal aligning agents (PM1) to (PM43) obtained in the examples and the liquid crystal aligning agents (RPM1) to (RPM6) obtained in the comparative examples were filtered under pressure using a membrane filter with a pore diameter of 1 μm.
The obtained solution was spin-coated on the ITO surface of a glass substrate with a transparent electrode made of an ITO film, dried on a hot plate at 70°C for 90 seconds, and then baked on a hot plate at 200°C for 30 minutes to form a film with a thickness of 100 nm. A liquid crystal alignment film was formed.
Next, the coated film surface was irradiated with 50 mJ/cm2 of 313 nm linearly polarized ultraviolet light with an irradiation intensity of 4.3 mW/cm2 from an angle inclined at 40 degrees from the normal direction of the substrate through a polarizing plate to obtain a substrate with a liquid crystal alignment film. Ta. Linearly polarized ultraviolet light was prepared by passing ultraviolet light from a high-pressure mercury lamp through a 313-nm band-pass filter and then passing it through a 313-nm polarizing plate.
Two of the above substrates were prepared, and after 4 μm bead spacers were sprinkled on the liquid crystal alignment film of one substrate, a sealant (XN-1500T, manufactured by Mitsui Chemicals) was applied. Next, the other substrate was bonded together so that the liquid crystal alignment film surfaces faced each other and the alignment direction was 180°, and then the sealant was thermally cured at 120° C. for 90 minutes to prepare an empty cell. A liquid crystal (MLC-3022, manufactured by Merck & Co., Ltd.) was injected into this empty cell by a reduced pressure injection method to obtain a liquid crystal display element.

<Evaluation>
(Liquid crystal orientation)
The liquid crystal display element obtained above was subjected to isotropic phase treatment at 120° C. for 1 hour, and then the cell was observed using a polarizing microscope. A case where there was no alignment defect such as light leakage or domain generation, or a case where uniform liquid crystal driving was obtained when a voltage was applied to the liquid crystal cell was considered good. The evaluation results are shown in Table 4.

(pretilt angle)
The pretilt angle of the liquid crystal cell of the liquid crystal display element produced above was measured by the Mueller matrix method using AxoScan manufactured by Axo Metrix. The evaluation results are shown in Table 4.

As can be seen from the results in Table 4, from the comparison between Examples 1 to 43 and Comparative Examples 1 to 6, a polymethacrylate solution copolymerized with a photoreactive monomer, an epoxy group-containing monomer, and an isocyanate group-containing monomer, or The liquid crystal alignment film obtained by blending the polymethacrylate solution, polyamic acid, and polyimide solution had a higher tilt expression ability than the liquid crystal alignment film of the comparative example. Specifically, this is a comparison between Example 1 and Comparative Examples 1 and 2.

The liquid crystal aligning agent of the present invention and a liquid crystal display element using a liquid crystal aligning film obtained from the liquid crystal aligning agent can be suitably used for a liquid crystal display element that requires durability, such as for use in a vehicle.

Claims (10)

A liquid crystal aligning agent containing the following component (A) and a solvent.
(A) Component: A polymer having the following structures (A-1) to (A-3), in which the introduction ratio of the moiety having the structure (A-1) is relative to the polymer of component (A). The proportion of the moieties having the structure (A-2) is 15 to 50 mol% relative to the polymer of component (A), and the proportion of the moieties having the structure (A-3) is ( A) A polymer characterized by being 5 to 35 mol% of the component polymer .
(A-1) A structure having an isocyanate group and/or a blocked isocyanate group.
(A-2) A structure represented by the following formula (pa-1).

In the formula, A is optionally a group selected from fluorine, chlorine, cyano, or an alkoxy group having 1 to 5 carbon atoms, a linear or branched alkyl residue (which can optionally be one pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophenylene, 2,5-furanylene, substituted with a cyano group or one or more halogen atoms); Represents 1,4- or 2,6-naphthylene or phenylene, R ₁ is a single bond, oxygen atom, -COO- or -OCO-, R ₂ is a divalent aromatic group, a divalent alicyclic group group, a divalent heterocyclic group, or a divalent fused cyclic group, R ₃ is a single bond, an oxygen atom, -COO- or -OCO-, and R ₄ is a straight chain having 1 to 40 carbon atoms. or a monovalent organic group having 3 to 40 carbon atoms containing a branched alkyl group or alicyclic group, and D is an oxygen atom, a sulfur atom, or -NR _d - (where R _d is a hydrogen atom or represents an alkyl group having 1 to 3 carbon atoms), X and Y each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, or an alkyl group having 1 to 3 carbon atoms, and a is 0 to 3 is an integer, and * represents the bonding position.
(A-3) selected from oxetanyl group, oxiranyl group, group represented by the following formula (3), group represented by the following formula (4), group represented by the following formula (5), and thiirane group A structure having at least one functional group.
The liquid crystal aligning agent according to claim 1, wherein the (A-2) is derived from a monomer represented by the following formula (b-1-m).

In the formula, M _c represents a second polymerizable group, and M _d is a single bond, a (r ² +1)-valent heterocycle, a substituted or unsubstituted branched alkyl group having 1 to 10 carbon atoms, or A group selected from an unsubstituted linear alkyl group having 1 to 10 carbon atoms, an (r ² +1)-valent aromatic group, and an (r ² +1)-valent alicyclic group, and each group is an unsubstituted or one or more hydrogen atoms may be substituted with a fluorine atom, chlorine atom, cyano group, methyl group or methoxy group, and S _b is a single bond, a straight chain or branched chain having 1 to 10 carbon atoms. represents an alkylene group, a divalent aromatic group, or a divalent alicyclic group, I _b is a group represented by formula (pa-1), and r ² satisfies 1≦r ² ≦3. is an integer. The liquid crystal aligning agent according to claim 1 or 2, wherein the (A-2) is a site having photoalignment properties represented by the following formula (pa-1-a).

In the formula, S _b has the same definition as in formula (b-1-m), Z is an oxygen atom or a sulfur atom, and X _a and X _b are each independently a hydrogen atom, a fluorine atom, or a chlorine atom. 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-, and R ₂ is a divalent aromatic group or a divalent alicyclic group. is a formula group or a divalent heterocyclic group, R ₃ is a single bond, an oxygen atom, -COO- or -OCO-, and R ₄ is a linear or branched alkyl group having 1 to 40 carbon atoms. or a monovalent organic group having 3 to 40 carbon atoms 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, a is an integer from 0 to 3, and b is an integer from 0 to 4. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein the (A-1) is derived from a monomer represented by the following formula (a-1-m).

(In the formula, Ma represents the first polymerizable group,
Mb represents a single bond, a divalent heterocycle, a trivalent heterocycle, a tetravalent heterocycle, a substituted or unsubstituted branched alkyl group having 1 to 10 carbon atoms, a divalent aromatic group, and a trivalent heterocycle. aromatic group, tetravalent aromatic ring, divalent alicyclic group, trivalent alicyclic group, tetravalent alicyclic group, divalent fused cyclic group, trivalent fused cyclic group or a tetravalent fused cyclic group, each group may be unsubstituted or one or more hydrogen atoms may be substituted with a fluorine atom, chlorine atom, cyano group, methyl group or methoxy group,
Sa represents a spacer unit,
Ia is an isocyanate group or a blocked isocyanate group,
c is an integer from 1 to 3) The liquid crystal aligning agent according to any one of claims 1 to 4, wherein the (A-3) is derived from a monomer represented by the following formula (c-1-m).

In the formula, _Ic represents an oxetanyl group, an oxiranyl group, a group represented by the above formula (3), a group represented by the above formula (4), a group represented by the above formula (5), and a thiirane in the molecule. is a monovalent organic group selected from the group consisting of groups, S _c represents a single bond or a divalent linking group, and M _e represents a third polymerizable group. From claim 1, wherein the polymer of component (A) further has (A-4) a structure having in the molecule at least one functional group selected from a carboxyl group, an amino group, a hydroxyl group, and a hydroxyl group. The liquid crystal aligning agent as described in any one of Claim 5. The liquid crystal aligning agent according to any one of claims 1 to 6, wherein the weight average molecular weight of the polymer of the component (A) is 2,000 to 1,000,000. A liquid crystal aligning film formed using the liquid crystal aligning agent according to any one of claims 1 to 7. A step of applying the liquid crystal aligning agent according to any one of claims 1 to 7 on a substrate to form a coating film, and a step of forming the coating film in a state where the coating film is not in contact with the liquid crystal layer or with the liquid crystal layer. A method for producing a liquid crystal alignment film, comprising the step of irradiating the coating film with light while in contact with the coating film. A liquid crystal display element comprising the liquid crystal alignment film according to claim 8.