JP5387793B2 - Liquid crystal alignment agent - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent used in a method for manufacturing a liquid crystal display element of a vertical alignment method manufactured by irradiating ultraviolet rays with a voltage applied to liquid crystal molecules.

  In a liquid crystal display element that responds by an electric field to liquid crystal molecules that are aligned perpendicular to the substrate (also referred to as a vertical alignment method), ultraviolet light is applied while applying a voltage to the liquid crystal molecules during the manufacturing process. Some include processes. In such a liquid crystal display element, it is common to add a photopolymerizable compound to the liquid crystal composition in advance. Usually, the direction in which the liquid crystal molecules tilt in response to an electric field is controlled by protrusions provided on the substrate or slits provided on the display electrode, but a photopolymerizable compound is added to the liquid crystal composition. In the liquid crystal display element after the above process, the polymer structure in which the direction in which the liquid crystal molecules are tilted is formed on the liquid crystal alignment film. It is said that the response speed of the liquid crystal display element is faster than the method of controlling the direction (see, for example, Patent Document 1).

  In addition, recently, the response speed of the liquid crystal display element is increased through the above steps even when the photopolymerizable compound is not added to the liquid crystal composition but is added to the liquid crystal alignment film. Has been reported (for example, see Non-Patent Document 1).

  As a technique different from the above, there is a photo-alignment technique for controlling the direction in which liquid crystal molecules are tilted by ultraviolet irradiation (see, for example, Patent Document 2). However, in the case of the photo-alignment technique, the anisotropy of polarized ultraviolet rays is used to give anisotropy to the liquid crystal alignment film in advance, and the direction of the actually tilted liquid crystal molecules as described above is used. It is completely different from the technique to memorize.

JP 2003-307720 A JP 2003-114437 A

SID 09 Digest 45.1

  An object of the present invention is to add a photopolymerizable compound in a liquid crystal composition or a liquid crystal alignment film in a vertical alignment type liquid crystal display device produced by irradiating ultraviolet rays while applying voltage to liquid crystal molecules. However, an object of the present invention is to provide a liquid crystal aligning agent used in a method for producing a liquid crystal display element that can increase the response speed.

（Ｒ^６は−ＣＨ_２−、−Ｏ−、−ＣＯＯ−、−ＮＨＣＯ−、−ＮＨ−、−ＣＨ_２Ｏ−、−Ｎ（ＣＨ_３）−、−ＣＯＮ（ＣＨ_３）−、又は−Ｎ（ＣＨ_３）ＣＯ−を表す。Ｒ^７は炭素原子数１〜２０の直鎖状アルキレン（アルキレンは非置換でもフッ素原子によって置換されていてもよい。）を表し、さらにアルキレンの任意の−ＣＨ_２−は、−ＣＦ_２−、−ＣＨ＝ＣＨ−、又は下記の置換基（これらの置換基は隣り合わない。）で置き換えられていてもよい。
置換基：−Ｏ−、−ＣＯＯ−、−ＮＨＣＯ−、−ＮＨ−、炭素環基、又は複素環基。
Ｒ^８は−ＣＨ_２−、−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＮＨＣＯ−、−ＮＨ−、−Ｎ（ＣＨ_３）−、−ＣＯＮ（ＣＨ_３）−、−Ｎ（ＣＨ_３）ＣＯ−、炭素環基、又は複素環基を表し、Ｒ^９が、ビニルフェニル基、−ＣＲ^１０＝ＣＨ_２基、炭素環基、複素環基、又は以下の式で表される基を表し、Ｒ^１０は水素原子又はフッ素原子で置換されていてもよいメチル基を表す。但し、Ｒ^８が−ＯＣＯ−、−ＮＨＣＯ−又は−Ｎ（ＣＨ_３）ＣＯ−であってＲ^９が−ＣＨ＝ＣＨ_２又は−Ｃ（ＣＨ_３）＝ＣＨ_２であるものを除く。） The present invention is characterized by the following configuration.
[1] A liquid crystal alignment layer is formed by applying a liquid crystal alignment agent on two substrates,
Two substrates are arranged so that the liquid crystal alignment layer faces each other,
A liquid crystal layer is sandwiched between the two substrates,
A liquid crystal aligning agent for use in a method for manufacturing a liquid crystal display element of a vertical alignment method that irradiates ultraviolet rays while applying a voltage to a liquid crystal layer,
The polyamic acid according to claim 1 having a side chain (A) for vertically aligning liquid crystal and a photoreactive side chain (B) represented by the following formula (b), and obtained by imidizing the polyamic acid. A liquid crystal aligning agent comprising at least one selected from the group consisting of polyimides.

(R ⁶ is —CH ₂ —, —O—, —COO—, —NHCO—, —NH—, —CH ₂ O—, —N (CH ₃ ) —, —CON (CH ₃ ) —, or —N Represents (CH ₃ ) CO—, R ⁷ represents a linear alkylene having 1 to 20 carbon atoms (the alkylene may be unsubstituted or substituted by a fluorine atom), and any —CH of alkylene ₂ — may be replaced by —CF ₂ —, —CH═CH—, or the following substituents (these substituents are not adjacent to each other).
Substituent: —O—, —COO—, —NHCO—, —NH—, a carbocyclic group, or a heterocyclic group.
R ⁸ represents —CH ₂ —, —O—, —COO—, —OCO—, —NHCO—, —NH—, —N (CH ₃ ) —, —CON (CH ₃ ) —, —N (CH ₃ ). CO— represents a carbocyclic group or a heterocyclic group, and R ⁹ represents a vinylphenyl group, —CR ¹⁰ ═CH ₂ group, a carbocyclic group, a heterocyclic group, or a group represented by the following formula: R ¹⁰ represents a hydrogen atom or a methyl group which may be substituted with a fluorine atom. However, except that R ⁸ is —OCO—, —NHCO— or —N (CH ₃ ) CO—, and R ⁹ is —CH═CH ₂ or —C (CH ₃ ) ═CH ₂ . )

[2] The polyamic acid reacts a diamine component containing a diamine having a side chain (A) and a photoreactive side chain (B) that aligns the liquid crystal vertically with a tetracarboxylic dianhydride component. The liquid crystal aligning agent according to the above [1], which is a polyamic acid obtained by causing the reaction to occur.

（Ｒ^６は−ＣＨ_２−、−Ｏ−、−ＣＯＯ−、−ＮＨＣＯ−、−ＮＨ−、−ＣＨ_２Ｏ−、−Ｎ（ＣＨ_３）−、−ＣＯＮ（ＣＨ_３）−、又は−Ｎ（ＣＨ_３）ＣＯ−を表す。Ｒ^７は炭素原子数１〜２０の直鎖状アルキレン（アルキレンは非置換でもフッ素原子によって置換されていてもよい。）を表し、さらにアルキレンの任意の−ＣＨ_２−は、−ＣＦ_２−、−ＣＨ＝ＣＨ−、又は下記の置換基（これらの置換基は隣り合わない。）で置き換えられていてもよい。
置換基：−Ｏ−、−ＣＯＯ−、−ＮＨＣＯ−、−ＮＨ−、炭素環基、又は複素環基。
Ｒ^８は−ＣＨ_２−、−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＮＨＣＯ−、−ＮＨ−、−Ｎ（ＣＨ_３）−、−ＣＯＮ（ＣＨ_３）−、又は−Ｎ（ＣＨ_３）ＣＯ−を表し、Ｒ¹¹は、ビニルフェニル基、−ＣＨ＝ＣＨ_２、−Ｃ（ＣＨ_３）＝ＣＨ_２、又は下記のいずれかの基を表す。但し、式（２）のＲ^８が−ＯＣＯ−、−ＮＨＣＯ−又は−Ｎ（ＣＨ_３）ＣＯ−であってＲ^１１が−ＣＨ＝ＣＨ_２又は−Ｃ（ＣＨ_３）＝ＣＨ_２であるものを除く。）

[3] The liquid crystal aligning agent according to [2], wherein the diamine having the photoreactive side chain (B) is represented by the following formula (2).

(R ⁶ is —CH ₂ —, —O—, —COO—, —NHCO—, —NH—, —CH ₂ O—, —N (CH ₃ ) —, —CON (CH ₃ ) —, or —N Represents (CH ₃ ) CO—, R ⁷ represents a linear alkylene having 1 to 20 carbon atoms (the alkylene may be unsubstituted or substituted by a fluorine atom), and any —CH of alkylene ₂ — may be replaced by —CF ₂ —, —CH═CH—, or the following substituents (these substituents are not adjacent to each other).
Substituent: —O—, —COO—, —NHCO—, —NH—, a carbocyclic group, or a heterocyclic group.
R ⁸ represents —CH ₂ —, —O—, —COO—, —OCO—, —NHCO—, —NH—, —N (CH ₃ ) —, —CON (CH ₃ ) —, or —N (CH ₃ ) CO— and R ¹¹ represents a vinylphenyl group, —CH═CH ₂ , —C (CH ₃ ) ═CH ₂ , or any of the following groups. However, ^{R 8} is -OCO of formula (2) -, - NHCO- or -N _(CH 3) CO- is a by ^{R 11} is -CH = CH ₂ or -C _(CH 3) = ones is CH ₂ except for. )

（式（ａ）中ｌ、ｍ及びｎはそれぞれ独立に、０又は１の整数を表す。Ｒ^１は炭素原子数２〜６のアルキレン基、−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＮＨＣＯ−、−ＣＯＮＨ−、又は炭素原子数１〜３のアルキレン−エーテル基を表す。Ｒ^２、Ｒ^３及びＲ^４は、それぞれ独立に、フェニレン基又はシクロアルキレン基を表す。Ｒ^５は水素原子、炭素原子数５〜１８の直鎖状アルキル基若しくはフッ素含有アルキル基、又は芳香環基、脂肪族環基、複素環基若しくはそれらからなる大環状基を表す。） [4] The liquid crystal aligning agent according to the above [2] or [3], wherein the diamine having a side chain (A) for vertically aligning the liquid crystal is represented by the following formula (1).

(In the formula (a), l, m and n each independently represents an integer of 0 or 1. R ¹ represents an alkylene group having 2 to 6 carbon atoms, —O—, —COO—, —OCO—, — NHCO-, -CONH-, or an alkylene-ether group having 1 to 3 carbon atoms, R ² , R ³ and R ⁴ each independently represents a phenylene group or a cycloalkylene group, and R ⁵ is a hydrogen atom. And represents a linear alkyl group having 5 to 18 carbon atoms or a fluorine-containing alkyl group, or an aromatic ring group, an aliphatic ring group, a heterocyclic group, or a macrocyclic group composed thereof.

[5] A diamine having a side chain (A) for vertically aligning the liquid crystal is represented by the formula (1), l, m and n are all 1, R ² is phenylene, R ³ is phenylene or cyclohexylene, R ⁴ is cyclohexylene, R ⁵ is an alkyl group having 2 to 24 carbon atoms, or l, m, and n are all 0, and R ⁵ is The liquid crystal aligning agent as described in [9] above, which is a diamine which is an alkyl group having 12 to 22 carbon atoms.

〔７〕上記〔１〕〜〔６〕のいずれかに記載の液晶配向剤を用いて得られる液晶配向層。 [6] The liquid crystal aligning agent according to any one of [1] to [5], wherein the diamine having a side chain (A) for vertically aligning the liquid crystal is a diamine having any one of the following structures.

[7] A liquid crystal alignment layer obtained using the liquid crystal aligning agent according to any one of [1] to [6].

According to the present invention, there is provided a liquid crystal display element capable of increasing the response speed (shortening the response time) without adding a photopolymerizable compound to the liquid crystal composition or the liquid crystal alignment film.
In addition, the liquid crystal aligning agent of the present invention can be used in a liquid crystal display element of a vertical alignment method produced by irradiating ultraviolet rays while applying a voltage to liquid crystal molecules, so that light can be emitted into a liquid crystal composition or liquid crystal alignment film. Even without adding a polymerizable compound, it is possible to obtain a liquid crystal display element in which the response speed of the liquid crystal is increased (response time is short).

<Side chains that align liquid crystal vertically>
A side chain that aligns liquid crystal vertically (also referred to as side chain A) is a side chain that has the ability to orient liquid crystal molecules perpendicular to the substrate, and the structure is not limited as long as it has this ability. .
As the side chain A, for example, a long-chain alkyl group, a long-chain fluoroalkyl group, a cyclic group having an alkyl group or a fluoroalkyl group at the terminal, a steroid group, or the like is known, and is preferably used in the present invention. It is done. These groups may be directly bonded to the main chain of polyamic acid or polyimide as long as they have the above-mentioned ability, and may be bonded via an appropriate bonding group.

  As said side chain A, what is represented by a following formula (a) can be illustrated.

R ¹ in the formula (a) is an alkylene group having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, —O—, —COO—, —OCO—, —NHCO—, —CONH—, or a carbon atom. Represents an alkylene-ether group (—C—C—O—) having a number of 1 to 3. Among these, from the viewpoint of ease of synthesis, —O—, —COO—, —CONH—, or an alkylene-ether group having 1 to 3 carbon atoms is preferable.

R ² , R ³ and R ⁴ each independently represent a phenylene group or a cycloalkylene group. The combination of l, m, n, R ² , R ³ and R ⁴ shown in the following table is preferable from the viewpoint of ease of synthesis and the ability to align the liquid crystal vertically.

R ⁵ represents a hydrogen atom, an alkyl group having 2 to 24 carbon atoms, preferably 5 to 8 carbon atoms or a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, or a macrocyclic group composed thereof. When at least one of l, m, and n is 1, the structure of R ⁵ is preferably a hydrogen atom, an alkyl group having 2 to 14 carbon atoms, or a fluorine-containing alkyl group having 2 to 14 carbon atoms. More preferably a hydrogen atom, an alkyl group having 2 to 12 carbon atoms, preferably 2 to 10 carbon atoms, or a fluorine-containing alkyl group.
When l, m, and n are all 0, the structure of R ⁵ is preferably an alkyl group having 12 to 22 carbon atoms, preferably 12 to 20 carbon atoms, or a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring. , A heterocyclic ring, or a macrocyclic group comprising them, more preferably an alkyl group having 12 to 20 carbon atoms, preferably 12 to 18 carbon atoms, or a fluorine-containing alkyl group.

  The ability to align the liquid crystal vertically varies depending on the structure of the side chain A, but generally, the ability to align the liquid crystal vertically increases as the amount of the side chain A contained in the polymer increases, and decreases as the amount decreases. . Further, the side chain A containing a cyclic structure tends to align the liquid crystal vertically even with a small content as compared with the side chain A of the long-chain alkyl group.

  The abundance of the side chain A in the polyamic acid or polyimide used in the present invention is not particularly limited as long as the liquid crystal alignment film can align the liquid crystal vertically, but it is 5 to the total amount of diamine used. 50 mol% is preferable and 10-30 mol% is more preferable. As for the amount of side chain A present, however, in the liquid crystal display device having the liquid crystal alignment film, if it is desired to increase the response speed of the liquid crystal, the presence of side chain A is within the range where vertical alignment can be maintained. The amount is preferably as small as possible.

<Photoreactive side chain>
The photoreactive side chain (also referred to as side chain B) is a side chain having a functional group capable of forming a covalent bond by causing a photoreaction upon irradiation with ultraviolet rays, and this side chain B is represented by the following formula ( b).

上記式（ｂ）中のＲ^６は、−ＣＨ_２−、−Ｏ−、−ＮＨ−、−Ｎ（ＣＨ_３）−、−ＣＯＮＨ−、−ＮＨＣＯ−、−ＣＨ_２Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮ（ＣＨ_３）−、又は−Ｎ（ＣＨ_３）ＣＯ−を表す。Ｒ^６は、通常の有機合成的手法で形成させることができるが、合成の容易性の観点から、−ＣＨ_２−、−Ｏ−、−ＣＯＯ−、−ＮＨＣＯ−、−ＮＨ−、又は−ＣＨ_２Ｏ−が好ましい。

R ⁶ in the above formula (b) is —CH ₂ —, —O—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —CH ₂ O—, —COO—, _{-OCO -, - CON (CH 3} ) -, or an -N _(CH 3) CO-. R ⁶ can be formed by an ordinary organic synthetic method, but from the viewpoint of ease of synthesis, —CH ₂ —, —O—, —COO—, —NHCO—, —NH—, or —CH ₂ O- is preferred.

R ⁷ in the above formula (b) represents a linear alkylene having 1 to 20 carbon atoms (the alkylene may be unsubstituted or substituted by a fluorine atom), and any —CH _{2 of} alkylene - _{is, -CF 2 -, - CH =} CH-, or the following substituents (. nonadjacent these substituents) may be replaced by.
Substituents: —O—, —COO—, —NHCO—, —NH—, carbocyclic group, heterocyclic group.
Specific examples of the carbocyclic group and heterocyclic group include the following structures, but are not limited thereto.

Alkylene R ⁷ represents, for faster response speed, reaction efficiency of a flexible spacer (group linking the R ⁶ and R ⁸⁾ provided, photoreactive groups between R ⁶ and R ⁸ And R ⁷ is preferably a linear alkylene having 1 to 20 carbon atoms, preferably 2 to 8 carbon atoms.

R ⁸ in the above formula (b) is —CH ₂ —, —O—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —CH ₂ O—, —COO—, _{-OCO -, - CON (CH 3} ) -, - N (CH 3) CO-, represents a carbocyclic group, or a heterocyclic group. Among these, from the viewpoint of easy synthesis, —CH ₂ —, —O—, —COO—, —OCO—, NHCO—, —NH—, a carbocyclic group, or a heterocyclic group is preferable. Specific examples of the carbocyclic group and the heterocyclic group are as described above. R ⁸ is more preferably —CH ₂ —, —O—, —COO—, —OCO—, NHCO—, or —NH— from the viewpoint of response speed.
^{R 9} in the above formula (b), the ^{R 9} represents vinyl phenyl ^{group, -CR} 10 = CH _2, carbocyclic, heterocyclic, or a group represented by the following ^{formula, R 10} is hydrogen It represents a methyl group which may be substituted with an atom or a fluorine atom. However, when R ⁸ in formula (b) is —OCO—, —NHCO—, or —N (CH ₃ ) CO—, R ⁹ becomes —CH═CH ₂ or —C (CH ₃ ) ═CH _2. There is nothing.

Among these, R ⁹ is more preferably a vinylphenyl group, —CH═CH ₂ , —C (CH ₃ ) ═CH ₂ or the following group from the viewpoint of photoreactivity.

From the viewpoint of response speed, R ⁹ is particularly preferably a vinyl group, —C (CH ₃ ) ═CH ₂ or the following group.

  The amount of the side chain B in the polyamic acid or polyimide used in the present invention is not particularly limited as long as it can increase the response speed of the liquid crystal in the liquid crystal display element, but is 10% relative to the total amount of diamine used. -95 mol% is preferable and 60-95 mol% is more preferable. The amount of the side chain B is preferably as large as possible within a range that does not affect other characteristics when it is desired to increase the response speed of the liquid crystal in the liquid crystal display element.

<Polyamic acid>
In the present invention, the polyamic acid having the side chain A and the side chain B is obtained by reacting the diamine having the side chain A and / or the diamine having the side chain B with tetracarboxylic dianhydride, or the diamine, By reaction with a tetracarboxylic dianhydride having a chain A and / or a tetracarboxylic dianhydride having a side chain B, a diamine having a side chain A and / or a diamine having a side chain B and a side chain A Can be obtained by a reaction with a tetracarboxylic dianhydride having a side chain B and / or a tetracarboxylic dianhydride having a side chain B.
Among these, it is preferable to obtain by the reaction of a diamine having a side chain A and / or a diamine having a side chain B with a tetracarboxylic dianhydride in view of easiness of raw material synthesis.

<Diamine compound having side chain A>
As a diamine compound having a side chain A (hereinafter also referred to as diamine A), the diamine side chain has an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, or a macrocyclic substituent composed thereof. A diamine can be mentioned as an example. Specific examples include diamines having a side chain represented by the formula (a). More specifically, for example, diamines represented by the following formula (1), (3), (4), or (5) can be exemplified, but the invention is not limited thereto.

式（１）中のｌ、ｍ、ｎ、及びＲ^１〜Ｒ^５の定義については、前記式（ａ）と同じである。

The definitions of l, m, n, and R ^{1 to} R ⁵ in Formula (1) are the same as those in Formula (a).

In Formula (3) and Formula (4), A ₁₀ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or —NH—. , A ₁₁ represents a single bond or a phenylene group. a represents a side chain A, and a ′ represents an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, or a macrocyclic group composed of these groups. )

In the formula (5), A ₁₄ represents an alkyl group having 3 to 20 carbon atoms which may be substituted with a fluorine atom, and A ₁₅ represents a 1,4-cyclohexylene group or 1,4-phenylene. Represents a group. A ₁₆ represents an oxygen atom or —COO— * (where a bond marked with “*” is bonded to A ₃ ), and A ₁₇ represents an oxygen atom or —COO— * (where “*”) Represents a bond with (CH ₂ ) a ₂ ). A ₁ is an integer of 0 or 1, a ₂ is an integer of ₂ to 10, and a ₃ is an integer of 0 or 1.

The bonding position of the two amino groups (—NH ₂ ) in the formula (1) is not limited. Specifically, with respect to the linking group of the side chain, 2, 3 position, 2, 4 position, 2, 5 position, 2, 6 position, 3, 4 position on the benzene ring, 3, 4 position, 5 positions. Among these, from the viewpoint of reactivity when synthesizing a polyamic acid, positions 2, 4, 2, 5, or 3, 5 are preferable. Considering the ease in synthesizing the diamine compound, the positions 2, 4 or 3, 5 are more preferable.
Specific examples of the structure of the formula (1) include diamines represented by the following formulas [A-1] to [A-24], but are not limited thereto.

式［Ａ−１］〜式［Ａ−５］中、Ａ_１は、炭素原子数２〜２４のアルキル基又はフッ素含有アルキル基である。

In Formula [A-1] to Formula [A-5], A ₁ is an alkyl group having 2 to 24 carbon atoms or a fluorine-containing alkyl group.

式［Ａ−６］及び式［Ａ−７］中、Ａ_２は、−Ｏ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＯＯＣＨ_２−、又は−ＣＨ_２ＯＣＯ−を示し、Ａ_３は炭素子数１〜２２のアルキル基、アルコキシ基、フッ素含有アルキル基又はフッ素含有アルコキシ基である。

In Formula [A-6] and Formula [A-7], A ₂ represents —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ —, or —CH ₂ OCO—, and A ₃ Is an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group.

式［Ａ−８］〜式［Ａ−１０］中、Ａ_４は、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、−ＮＨＣＯ−、−ＣＯＯＣＨ_２−、−ＣＨ_２ＯＣＯ−、−ＣＨ_２Ｏ−、−ＯＣＨ_２−、又は−ＣＨ_２−を表す。Ａ_５は炭素子数１〜２２のアルキル基、アルコキシ基、フッ素含有アルキル基又はフッ素含有アルコキシ基を表す。

In Formula [A-8] to Formula [A-10], A ₄ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O. -, - OCH ₂ -, or -CH ₂ - represents a. A ₅ represents an alkyl group, alkoxy group, fluorine-containing alkyl group or fluorine-containing alkoxy group Tansoko number 1 to 22.

式［Ａ−１１］及び式［Ａ−１２］中、Ａ_６は、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、−ＮＨＣＯ−、−ＣＯＯＣＨ_２−、−ＣＨ_２ＯＣＯ−、−ＣＨ_２Ｏ−、−ＯＣＨ_２−、−ＣＨ_２−、−Ｏ−、又は−ＮＨ−を表し、Ａ_７はフッ素基、シアノ基、トリフルオロメチル基、ニトロ基、アゾ基、ホルミル基、アセチル基、アセトキシ基、又は水酸基を表す。

In Formula [A-11] and Formula [A-12], A ₆ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O. —, —OCH ₂ —, —CH ₂ —, —O—, or —NH—, and A ₇ represents fluorine group, cyano group, trifluoromethyl group, nitro group, azo group, formyl group, acetyl group, acetoxy Represents a group or a hydroxyl group.

式［Ａ−１３］及び式［Ａ−１４］中、Ａ_８は、炭素原子数３〜１２のアルキル基を表し、１,４-シクロヘキシレンのシス−トランス異性は、それぞれトランス異性体である。

In Formula [A-13] and Formula [A-14], A ₈ represents an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer. .

式［Ａ−１５］及び式［Ａ−１６］中、Ａ_９は、炭素原子数３〜１２アルキル基を表し、１,４-シクロヘキシレンのシス−トランス異性は、それぞれトランス異性体である。

In Formula [A-15] and Formula [A-16], A ₉ represents an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer.

  Specific examples of the diamine represented by the formula (3) include diamines represented by the following formulas [A-25] to [A-30], but are not limited thereto.

In Formula [A-25] to Formula [A-30], A ₁₂ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or — NH— represents A ₁₃ represents an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.

  Specific examples of the diamine represented by the formula (4) include diamines represented by the following formulas [A-31] to [A-32], but are not limited thereto.

Of these, [A-1], [A-2], [A-3], [A-4], [A-5], [A-5], [A-5], [A-5], [A-5], [A-5], [A-5], [A-5], [A-5] A-25], [A-26], [A-27], [A-28], [A-29], and [A-30] are preferable.
The above diamine compounds can be used alone or in combination of two or more depending on the liquid crystal alignment properties, pretilt angle, voltage holding characteristics, accumulated charge and the like when the liquid crystal alignment film is formed.

  In order to achieve the object of the present invention, it is preferable that 5 to 50 mol% of the diamine component used for the synthesis of the polyamic acid is diamine A. Furthermore, it is preferable that 5-30 mol% of a diamine component is diamine A, Most preferably, it is 5-15 mol%.

<Diamine compound having side chain B>
Examples of the diamine compound having a side chain B (also referred to as diamine B) include diamines having a side chain represented by the formula (b). More specifically, for example, diamines represented by the following general formula (2) can be mentioned.

式（２）中、Ｒ^６は−ＣＨ_２−、−Ｏ−、−ＣＯＯ−、−ＮＨＣＯ−、−ＮＨ−、−ＣＨ_２Ｏ−、−Ｎ（ＣＨ_３）−、−ＣＯＮ（ＣＨ_３）−、又は−Ｎ（ＣＨ_３）ＣＯ−を表す。Ｒ^７は、炭素原子数１〜２０の直鎖状アルキレン（アルキレンは非置換でもフッ素原子によって置換されていてもよい。）を表し、さらにアルキレンの任意の−ＣＨ_２−は、−ＣＦ_２−、−ＣＨ＝ＣＨ−、又は下記の置換基（これらの置換基は隣り合わない。）で置き換えられていてもよい。
置換基：−Ｏ−、−ＣＯＯ−、−ＮＨＣＯ−、−ＮＨ−、炭素環基、又は複素環基。
Ｒ^８は−ＣＨ_２−、−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＮＨＣＯ−、−ＮＨ−、−Ｎ（ＣＨ_３）−、−ＣＯＮ（ＣＨ_３）−、又は−Ｎ（ＣＨ_３）ＣＯ−を表し、Ｒ¹¹はビニルフェニル基、−ＣＨ＝ＣＨ_２、−Ｃ（ＣＨ_３）＝ＣＨ_２、又は下記のいずれかの基を表す。但し、式（２）のＲ^８が−ＯＣＯ−、−ＮＨＣＯ−又は−Ｎ（ＣＨ_３）ＣＯ−である場合、Ｒ^１１は−ＣＨ＝ＣＨ_２又は−Ｃ（ＣＨ_３）＝ＣＨ_２となることはない。

In formula (2), R ⁶ represents —CH ₂ —, —O—, —COO—, —NHCO—, —NH—, —CH ₂ O—, —N (CH ₃ ) —, —CON (CH ₃ ). - or a -N _(CH 3) CO-. R ⁷ represents a linear alkylene having 1 to 20 carbon atoms (the alkylene may be unsubstituted or substituted by a fluorine atom), and any —CH ₂ — in the alkylene is —CF ₂ —. , -CH = CH-, or the following substituents (these substituents are not adjacent to each other).
Substituent: —O—, —COO—, —NHCO—, —NH—, a carbocyclic group, or a heterocyclic group.
R ⁸ represents —CH ₂ —, —O—, —COO—, —OCO—, —NHCO—, —NH—, —N (CH ₃ ) —, —CON (CH ₃ ) —, or —N (CH ₃ ) CO—, R ¹¹ represents a vinylphenyl group, —CH═CH ₂ , —C (CH ₃ ) ═CH ₂ , or any of the following groups. However, when R ⁸ in the formula (2) is —OCO—, —NHCO—, or —N (CH ₃ ) CO—, R ¹¹ becomes —CH═CH ₂ or —C (CH ₃ ) ═CH _2. There is nothing.

The bonding position of the two amino groups (—NH ₂ ) in the formula (2) is not particularly limited. Specifically, with respect to the linking group of the side chain, 2, 3 position, 2, 4 position, 2, 5 position, 2, 6 position, 3, 4 position on the benzene ring, 3, 4 position, 5 positions. Among these, from the viewpoint of reactivity when synthesizing a polyamic acid, positions 2, 4, 2, 5, or 3, 5 are preferable. Considering the ease in synthesizing the diamine compound, the positions 2, 4 or 3, 5 are more preferable.
Specific examples include the following compounds, but are not limited thereto.

In the formula, X independently represents a linking group selected from the group consisting of —C—, —O—, —NHCO—, —CONH—, —COO—, —OCO—, and —NH—; m and n each independently represents an integer of 0 to 20.
One or two of the above diamine compounds may be used depending on the liquid crystal alignment properties, the pretilt angle, the voltage holding characteristics, the accumulated charge characteristics, and the response speed of the liquid crystal when the liquid crystal display element is used. A mixture of more than one can also be used.

  In order to achieve the object of the present invention, it is preferable that 10 to 95 mol% of the diamine component used for the synthesis of the polyamic acid is diamine B. Furthermore, 40 to 95 mol% of the diamine component is more preferably diamine B, and particularly preferably 70 to 95 mol%.

<Other diamine compounds>
The polyamic acid used in the present invention can be used in combination with other diamine compounds other than diamine A and diamine B as the diamine component as long as the effects of the present invention are not impaired. Specific examples are given below.

  p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2, 5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4 , 6-diaminoresorcinol, 4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 3,3′-dihydroxy -4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, , 3′-difluoro-4,4′-biphenyl, 3,3′-trifluoromethyl-4,4′-diaminobiphenyl, 3,4′-diaminobiphenyl, 3,3′-diaminobiphenyl, 2,2 ′ -Diaminobiphenyl, 2,3'-diaminobiphenyl, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminodiphenylmethane, 2,3'-diamino Diphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldianiline 3,3′-sulfonyldianiline, bis (4 Aminophenyl) silane, bis (3-aminophenyl) silane, dimethyl-bis (4-aminophenyl) silane, dimethyl-bis (3-aminophenyl) silane, 4,4′-thiodianiline, 3,3′-thiodianiline, 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl (4,4'-diamino Diphenyl) amine, N-methyl (3,3′-diaminodiphenyl) amine, N-methyl (3,4′-diaminodiphenyl) amine, N-methyl (2,2′-diaminodiphenyl) amine, N-methyl ( 2,3′-diaminodiphenyl) amine, 4,4′-diaminobenzophenone, 3, 3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 1,4-diaminonaphthalene, 2,2'-diaminobenzophenone, 2,3'-diaminobenzophenone, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene 1,7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6 diaminonaphthalene, 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2-bis (4- Aminophenyl) ethane, 1,2-bis (3-aminophenyl) ethane, 1,3-bis (4-aminophenyl) propane, 1,3-bis (3-aminophenyl) propane, 1,4-bis ( 4-aminophenyl) butane, 1,4-bis (3-aminophenyl) butane, bis (3,5-diethyl-4-a Nophenyl) methane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenyl) benzene, 1,3-bis (4 -Aminophenyl) benzene, 1,4-bis (4-aminobenzyl) benzene, 1,3-bis (4-aminophenoxy) benzene, 4,4 ′-[1,4-phenylenebis (methylene)] dianiline, 4,4 '-[1,3-phenylenebis (methylene)] dianiline, 3,4'-[1,4-phenylenebis (methylene)] dianiline, 3,4 '-[1,3-phenylenebis (methylene) )] Dianiline, 3,3 ′-[1,4-phenylenebis (methylene)] dianiline, 3,3 ′-[1,3-phenylenebis (methylene)] dianiline, 1,4-phenylenebis (4-aminophenyl) methanone], 1,4-phenylenebis [(3-aminophenyl) methanone], 1,3-phenylenebis [(4-aminophenyl) methanone], 1,3-phenylenebis [(3 -Aminophenyl) methanone], 1,4-phenylenebis (4-aminobenzoate), 1,4-phenylenebis (3-aminobenzoate), 1,3-phenylenebis (4-aminobenzoate), 1,3- Phenylenebis (3-aminobenzoate), bis (4-aminophenyl) terephthalate, bis (3-aminophenyl) terephthalate, bis (4-aminophenyl) isophthalate, bis (3-aminophenyl) isophthalate, N, N '-(1,4-phenylene) bis (4-aminobenzamide), N, N'-(1,3-pheny Len) bis (4-aminobenzamide), N, N ′-(1,4-phenylene) bis (3-aminobenzamide), N, N ′-(1,3-phenylene) bis (3-aminobenzamide), N, N′-bis (4-aminophenyl) terephthalamide, N, N′-bis (3-aminophenyl) terephthalamide, N, N′-bis (4-aminophenyl) isophthalamide, N, N′— Bis (3-aminophenyl) isophthalamide, 9,10-bis (4-aminophenyl) anthracene, 4,4′-bis (4-aminophenoxy) diphenylsulfone, 2,2′-bis [4- (4- Aminophenoxy) phenyl] propane, 2,2′-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2′-bis (4-aminophenyl) Hexafluoropropane, 2,2′-bis (3-aminophenyl) hexafluoropropane, 2,2′-bis (3-amino-4-methylphenyl) hexafluoropropane, 2,2′-bis (4-amino) Phenyl) propane, 2,2′-bis (3-aminophenyl) propane, 2,2′-bis (3-amino-4-methylphenyl) propane, 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid Acid, 1,3-bis (4-aminophenoxy) propane, 1,3-bis (3-aminophenoxy) propane, 1,4-bis (4-aminophenoxy) butane, 1,4-bis (3-amino) Phenoxy) butane, 1,5-bis (4-aminophenoxy) pentane, 1,5-bis (3-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) Hexane, 1,6-bis (3-aminophenoxy) hexane, 1,7-bis (4-aminophenoxy) heptane, 1,7- (3-aminophenoxy) heptane, 1,8-bis (4- Aminophenoxy) octane, 1,8-bis (3-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) nonane, 1,9-bis (3-aminophenoxy) nonane, 1,10- (4 -Aminophenoxy) decane, 1,10- (3-aminophenoxy) decane, 1,11- (4-aminophenoxy) undecane, 1,11- (3-aminophenoxy) undecane, 1,12- (4-amino Aromatic diamines such as phenoxy) dodecane, 1,12- (3-aminophenoxy) dodecane, bis (4-aminocyclohexyl) methane, bis (4-amino- Alicyclic diamine such as 3-methylcyclohexyl) methane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1 , 8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane and other aliphatic diamines.

  The above-mentioned other diamine compounds can be used alone or in combination of two or more according to properties such as liquid crystal orientation, pretilt angle, voltage holding property, and accumulated charge when the liquid crystal alignment film is formed.

<Tetracarboxylic dianhydride>
In the synthesis of the polyamic acid used in the present invention, the tetracarboxylic dianhydride to be reacted with the diamine component is not particularly limited. Specific examples of tetracarboxylic acid, which is a raw material for obtaining tetracarboxylic dianhydride, are given below.

  Pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7 Anthracene tetracarboxylic acid, 1,2,5,6-anthracene tetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4-biphenyltetracarboxylic acid, bis ( 3,4-dicarboxyphenyl) ether, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) methane, 2 , 2-bis (3,4-dicarboxyphenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (3,4-dicarboxyphenyl) propa Bis (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxyphenyl) diphenylsilane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis (3,4- Dicarboxyphenyl) pyridine, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, 1,3-diphenyl-1,2,3,4-cyclobutane Tetracarboxylic acid, oxydiphthaltetracarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2-dimethyl-1,2,3,4-cyclobuta Tetracarboxylic acid, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cycloheptanetetracarboxylic acid, 2,3,4,5-tetrahydrofurantetracarboxylic acid, 3,4-dicarboxy-1-cyclohexylsuccinic acid, 2,3,5-tricarboxycyclopentylacetic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid, bicyclo [ 3,3,0] octane-2,4,6,8-tetracarboxylic acid, bicyclo [4,3,0] nonane-2,4,7,9-tetracarboxylic acid, bicyclo [4,4,0] Decane-2,4,7,9-tetracarboxylic acid, bicyclo [4,4,0] decane-2,4,8,10-tetracarboxylic acid, tricyclo [6.3.0.0 <2,6> ] Undecane-3 , 5,9,11-tetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydrido Naphthalene-1,2-dicarboxylic acid, bicyclo [2,2,2] oct-7-ene-2,3,5,6-tetracarboxylic acid, 5- (2,5-dioxotetrahydrofuryl) -3- Methyl-3-cyclohexane-1,2-dicarboxylic acid, tetracyclo [6,2,1,1,0,2,7] dodeca-4,5,9,10-tetracarboxylic acid, 3,5,6 -Tricarboxynorbornane-2: 3,5: 6 dicarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid and the like.

  The tetracarboxylic dianhydride can be used alone or in combination of two or more depending on the liquid crystal alignment properties, voltage holding characteristics, accumulated charge, and the like when the liquid crystal alignment film is formed.

<Synthesis of polyamic acid>
In obtaining a polyamic acid by a reaction between a diamine component and tetracarboxylic dianhydride, a known synthesis method can be used. In general, the diamine component and tetracarboxylic dianhydride are reacted in an organic solvent. The reaction between the diamine component and tetracarboxylic dianhydride is advantageous in that it proceeds relatively easily in an organic solvent and no by-products are generated.

The organic solvent used in the above reaction is not particularly limited as long as the generated polyamic acid dissolves. Furthermore, even if it is an organic solvent which does not dissolve a polyamic acid, it may be mixed with the said solvent and used as long as the produced polyamic acid does not precipitate. In addition, since the water | moisture content in an organic solvent inhibits a polymerization reaction and also causes the produced polyamic acid to hydrolyze, it is preferable to use what dehydrated and dried the organic solvent.
Specific examples of the organic solvent are given below.
N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide, N-methylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 2-pyrrolidone, 1,3- Dimethyl-2-imidazolidinone, 3-methoxy-N, N-dimethylpropanamide, N-methylcaprolactam, dimethyl sulfoxide, tetramethyl urea, pyridine, dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, isopropyl alcohol, methoxymethyl Pentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, butyl cellosolve Cetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether , Propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate mono Methyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate , Tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, e Len carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, 3-ethoxypropionic acid Methyl ethyl, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 2-Ethyl-1-hexanol. These organic solvents may be used alone or in combination.

  When the diamine component and the tetracarboxylic dianhydride component are reacted in an organic solvent, the solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic dianhydride component is used as it is or in an organic solvent. A method of adding by dispersing or dissolving in a solvent, a method of adding a diamine component to a solution in which a tetracarboxylic dianhydride component is dispersed or dissolved in an organic solvent, and a tetracarboxylic dianhydride component and a diamine component. The method of adding alternately etc. is mentioned, You may use any of these methods. In addition, when the diamine component or tetracarboxylic dianhydride component is composed of a plurality of types of compounds, they may be reacted in a premixed state, may be individually reacted sequentially, or may be further reacted individually. The body may be mixed and reacted to form a high molecular weight body.

  The temperature at the time of making a diamine component and a tetracarboxylic dianhydride component react can select arbitrary temperatures, for example, -20 degreeC-150 degreeC, Preferably it is the range of -5 degreeC-100 degreeC. Moreover, reaction can be performed by arbitrary density | concentrations, for example, 1-50 mass%, Preferably it is 5-30 mass%.

  The ratio of the total number of moles of the tetracarboxylic dianhydride component with respect to the total number of moles of the diamine component in the polymerization reaction can be selected according to the molecular weight of the polyamic acid to be obtained. Similar to the normal polycondensation reaction, the molecular weight of the polyamic acid produced increases as the molar ratio approaches 1.0. If it shows a preferable range, it is 0.8 to 1.2.

  The method for synthesizing the polyamic acid used in the present invention is not limited to the above-described method, and in the same manner as the general polyamic acid synthesis method, instead of the tetracarboxylic dianhydride, a tetracarboxylic acid having a corresponding structure is used. The corresponding polyamic acid can also be obtained by reacting by a known method using a tetracarboxylic acid derivative such as acid or tetracarboxylic acid dihalide.

<Polyimide>
Examples of the method for imidizing the polyamic acid to form a polyimide include thermal imidization in which a polyamic acid solution is heated as it is, and catalytic imidization in which a catalyst is added to the polyamic acid solution.
In the polyimide used in the present invention, the imidization ratio from polyamic acid to polyimide is not necessarily 100%.

  The temperature at which the polyamic acid is thermally imidized in the solution is 100 ° C. to 400 ° C., preferably 120 ° C. to 250 ° C., and a method in which water generated by the imidation reaction is removed from the system is preferable.

  The catalytic imidation of the polyamic acid can be performed by adding a basic catalyst and an acid anhydride to the polyamic acid solution and stirring at -20 to 250 ° C, preferably 0 to 180 ° C. The amount of the basic catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times of the amidic acid group, and the amount of the acid anhydride is 1 to 50 mol times, preferably 3 to 30 mol of the amido acid group. Is double. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Among them, pyridine is preferable because it has an appropriate basicity for proceeding with the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Among them, use of acetic anhydride is preferable because purification after completion of the reaction is facilitated. The imidization rate by catalytic imidation can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

  When recovering the produced polyamic acid or polyimide from the reaction solution of polyamic acid or polyimide, the reaction solution may be poured into a poor solvent and precipitated. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and water. The polymer precipitated in a poor solvent and collected by filtration can be dried by normal temperature or reduced pressure at room temperature or by heating. Moreover, when the polymer which carried out precipitation collection | recovery is re-dissolved in an organic solvent and the operation which carries out reprecipitation collection | recovery is repeated 2 to 10 times, the impurity in a polymer can be decreased. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons and the like, and it is preferable to use three or more kinds of poor solvents selected from these because purification efficiency is further improved.

<Liquid crystal aligning agent>
A liquid crystal aligning agent is a coating liquid for forming a liquid crystal aligning film, and is a solution in which a resin component for forming a liquid crystal aligning film is dissolved in an organic solvent. Here, the resin component is a resin component containing at least one polymer selected from the group consisting of the polyamic acid and the polyimide. In that case, the content of the resin component is preferably 1% by mass to 20% by mass, more preferably 3% by mass to 15% by mass, and particularly preferably 3% by mass to 10% by mass.

  In the liquid crystal aligning agent used in the present invention, the above resin components may all be polyamic acid having side chain A and side chain B, or polyimide obtained by imidizing it, and these polyamic acid and polyimide. The other polymer may be mixed. In that case, 0.5 mass%-15 mass% are preferable, and, as for content of this other polymer in a resin component, More preferably, they are 1 mass%-10 mass%. Examples of such other polymers include polyamic acid or polyimide that does not have side chain A and side chain B at the same time.

  The molecular weight of the polymer of the above resin component is the weight measured by the GPC (Gel Permeation Chromatography) method in consideration of the strength of the coating film obtained therefrom, workability at the time of coating film formation, and uniformity of the coating film. The average molecular weight is preferably 5,000 to 1,000,000, and more preferably 10,000 to 150,000.

The organic solvent used for the liquid crystal aligning agent used for this invention will not be specifically limited if it is an organic solvent in which the resin component mentioned above is dissolved. This organic solvent may be one type of solvent or a mixed solvent of two or more types. If the specific example of an organic solvent is given dare, the organic solvent illustrated by the said polyamic acid synthesis can be mentioned. Among them, N-methyl-2-pyrrolidone, γ-butyrolactone, N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N, N-dimethylpropanamide and the like are resin components. It is preferable from the viewpoint of solubility.
Moreover, since the solvent as shown below improves the uniformity and smoothness of the coating film, it is preferable to use the solvent by mixing it with a solvent having high solubility of the resin component. For example, isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, Ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol Cole monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol Monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate , Butyl butyrate Butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene acetate Glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxy Propyl propionate, butyl 3-methoxypropionate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol Monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, methyl lactate Examples include esters, lactate ethyl esters, lactate n-propyl esters, lactate n-butyl esters, lactate isoamyl esters, and 2-ethyl-1-hexanol. A plurality of these solvents may be mixed. When using these solvents, it is preferable that it is 5-80 mass% of the whole solvent contained in a liquid crystal aligning agent, More preferably, it is 20-60 mass%.

  The liquid crystal aligning agent may contain components other than those described above. Examples thereof include compounds that improve the film thickness uniformity and surface smoothness when a liquid crystal aligning agent is applied, and compounds that improve the adhesion between the liquid crystal aligning film and the substrate.

  Examples of compounds that improve film thickness uniformity and surface smoothness include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants. More specifically, for example, F-top EF301, EF303, EF352 (manufactured by Tochem Products), MegaFuck F171, F173, R-30 (manufactured by Dainippon Ink), Florard FC430, FC431 (manufactured by Sumitomo 3M) ), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.). When using these surfactants, the use ratio thereof is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 with respect to 100 parts by mass of the resin component contained in the liquid crystal aligning agent. Part by mass.

Specific examples of the compound that improves the adhesion between the liquid crystal alignment film and the substrate include a functional silane-containing compound and an epoxy group-containing compound. 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-tri Toxisilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxy Silane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyl Trimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, poly Lopylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl -2,4-hexanediol, N, N, N ′, N ′,-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′ , N ′,-tetraglycidyl-4, 4′-diaminodiphenylmethane, 3- (N-allyl-N-glycidyl) aminopropyltrimethoxysilane, 3- (N, N-diglycidyl) aminopropyltrimethoxysilane and the like. It is done.
In order to further increase the rubbing resistance of the liquid crystal alignment film obtained by using the liquid crystal aligning agent of the present invention, 2,2′-bis (4-hydroxy-3,5-dihydroxymethylphenyl) propane, tetra (methoxymethyl) A phenol compound such as bisphenol may be added. When using these compounds, it is preferable that it is 0.1-30 mass parts with respect to 100 mass parts of the resin component contained in a liquid crystal aligning agent, More preferably, it is 1-20 mass parts.
In addition to the above, the liquid crystal aligning agent used in the present invention is a dielectric or conductive material for the purpose of changing the electrical properties such as the dielectric constant and conductivity of the liquid crystal alignment film as long as the effects of the present invention are not impaired. Substances may be added.

Among the above liquid crystal aligning agents, among {polyamic acid obtained by reacting diamine component containing diamine A and diamine B and tetracarboxylic dianhydride} and {polyimide obtained by imidizing it} A liquid crystal aligning agent containing at least one kind, wherein diamine B is a diamine represented by the formula (2), and R ^{8 in the} formula (2) is —CH ₂ —, —O—, —COO—. , —OCO—, —NHCO— or —NH—, wherein R ¹¹ is —CR ¹⁰ ═CH ₂ group, and R ¹⁰ is a methyl group optionally substituted with a hydrogen atom or a fluorine atom. Is a liquid crystal aligning agent newly provided by the present invention (also referred to as the liquid crystal aligning agent of the present invention).
The liquid crystal aligning agent of the present invention is not only useful as a liquid crystal aligning agent for producing the liquid crystal display element of the present invention, but can also be suitably used for a liquid crystal aligning film produced by rubbing treatment or photo-alignment treatment.

<Liquid crystal alignment film>
The liquid crystal aligning agent of the present invention can be used as a liquid crystal aligning film after being applied and baked on a substrate and then subjected to alignment treatment by rubbing treatment, light irradiation or the like, or without alignment treatment in vertical alignment applications. In this case, the substrate to be used is not particularly limited as long as it is a highly transparent substrate, and a glass substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, or the like can be used. In addition, it is preferable to use a substrate on which an ITO electrode or the like for driving liquid crystal is formed from the viewpoint of simplifying the process. In the reflective liquid crystal display element, an opaque material such as a silicon wafer can be used as long as only one substrate is used. In this case, a material that reflects light, such as aluminum, can also be used.

  The application method of the liquid crystal aligning agent is not particularly limited, but industrially, a method of screen printing, offset printing, flexographic printing, ink jet, or the like is common. Other coating methods include dip, roll coater, slit coater, spinner and the like, and these may be used depending on the purpose.

Although baking after apply | coating a liquid crystal aligning agent can be performed at 100-350 degreeC arbitrary temperatures, Preferably it is 120 to 300 degreeC, More preferably, it is 150 to 250 degreeC. This baking can be performed with a hot plate, a hot-air circulating furnace, an infrared furnace, or the like.
Although the thickness of the film after baking is not specifically limited, Preferably it is 5-300 nm, More preferably, it is 10-100 nm.
When the liquid crystal is aligned horizontally or tilted, the fired coating film is treated with rubbing or irradiation with polarized ultraviolet rays.

<Liquid crystal display element>
The liquid crystal display element of the present invention is selected from the group consisting of a polyamic acid having a side chain (A) for vertically aligning liquid crystals and a photoreactive side chain (B) and a polyimide obtained by imidizing it. Two substrates having a liquid crystal alignment layer formed from a liquid crystal alignment agent containing at least one kind,
A liquid crystal cell having a liquid crystal layer sandwiched between the two substrates arranged so that the liquid crystal alignment layers face each other;
Means for irradiating ultraviolet rays while applying a voltage to the liquid crystal layer;
It is characterized by having.

The substrate used in the liquid crystal display element of the present invention is not particularly limited as long as it is a highly transparent substrate, but is usually a substrate on which a transparent electrode for driving liquid crystal is formed. Specific examples include the same substrates as those described in the above <Liquid crystal alignment film>. In the liquid crystal display element of the present invention, a substrate provided with a conventional electrode pattern or protrusion pattern may be used. However, the liquid crystal display of the present invention can be operated even in a structure in which a line / slit electrode pattern of 1 to 10 μm is formed on one side substrate and no slit pattern or projection pattern is formed on the opposite substrate. The liquid crystal display can simplify the manufacturing process and obtain high transmittance.
As a high-performance element such as a TFT type element, an element in which an element such as a transistor is formed between an electrode for driving a liquid crystal and a substrate is used.
In the case of a transmissive liquid crystal element, it is common to use a substrate as described above. However, in a reflective liquid crystal display element, an opaque substrate such as a silicon wafer can be used if only one substrate is used. It is. At that time, a material such as aluminum that reflects light may be used for the electrode formed on the substrate.

  The liquid crystal alignment layer is a resin film for aligning liquid crystals perpendicularly to the substrate, and is formed using the liquid crystal aligning agent. For the step of forming the liquid crystal alignment layer on the substrate, the coating method described in <Liquid crystal alignment film> and the baking method after coating can be applied.

  As a method for sandwiching a liquid crystal layer between two substrates, a known method for producing a liquid crystal cell can be exemplified. As an example of liquid crystal cell production, prepare a pair of substrates on which a liquid crystal alignment layer is formed, spray spacers on the liquid crystal alignment layer of one substrate, and place the other side so that the liquid crystal alignment layer surface is on the inside. And a method of sealing the substrate by injecting liquid crystal under reduced pressure, or a method of sealing the substrate by bonding the liquid crystal after dropping the liquid crystal on the liquid crystal alignment layer surface on which spacers are dispersed. The thickness of the spacer at this time is preferably 1 to 30 μm, more preferably 2 to 10 μm.

  The liquid crystal used in the liquid crystal display element of the present invention can increase the response speed of the liquid crystal even if it is a liquid crystal to which no photopolymerizable compound is added. It doesn't matter.

The step of applying a voltage to the liquid crystal layer and irradiating ultraviolet rays while forming an electric field is performed by applying a voltage between the electrodes installed on the substrate, for example, by applying a voltage to the liquid crystal layer and maintaining this voltage. A method of irradiating with ultraviolet rays is mentioned. Here, a function generator can be used as means for applying a voltage to the liquid crystal layer, and an existing apparatus such as a high-pressure mercury lamp can be used as means for irradiating ultraviolet rays. The voltage applied between the electrodes is, for example, 5 to 30 Vp-p, preferably 5 to 20 Vp-p. The wavelength of the ultraviolet light is preferably 250 to 400 nm, more preferably 300 to 400 nm. The ultraviolet irradiation amount is, for example, 1 to 60 J / cm ² , preferably 40 J / cm ² or less, and the smaller the ultraviolet irradiation amount, the lowering of reliability due to the destruction of the members constituting the liquid crystal display can be suppressed, and It is preferable because the production efficiency is increased by reducing the ultraviolet irradiation time.

  Through the above steps, the photoreactive group of the side chain B reacts and the direction in which the liquid crystal molecules are tilted is stored, so that the response speed of the liquid crystal display element is increased.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention should not be construed as being limited thereto.
[Synthesis of polyamic acid]
Abbreviations of compounds such as tetracarboxylic dianhydride used are shown below.
(Tetracarboxylic dianhydride)
C-1: 1,2,3,4-cyclobutanetetracarboxylic dianhydride (diamine compound)
DA-6: p-phenylenediamine DA-7: 1,3-diamino-4-octadecyloxybenzene DA-8: 1,3-diamino-4- [4- (trans-4-n-heptylcyclohexyl) Phenoxy] benzene DA-9: 1,3-diamino-4- {4- [trans-4- (trans-4-n-pentylcyclohexyl) cyclohexyl] phenoxy} benzene

(Organic solvent)
NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve Among the above diamine compounds, DA-2 and DA-3 were obtained as in Reference Synthesis Examples described below.

(Reference Synthesis Example 1) Synthesis of DA-2 To a 500 mL (milliliter) three-necked flask, 5.94 g of tetramethylene glycol monovinyl ether, 5.70 g of triethylamine, and 30 mL of toluene were added. The system was heated to 100 ° C., 10 g of 2,4-dinitrofluorobenzene dissolved in 20 mL of toluene was added dropwise, and the mixture was stirred at 100 ° C. for 6 hours. After completion of the reaction, 50 mL of pure water was added and stirred, and then ethyl acetate was added to extract the organic layer. Anhydrous magnesium sulfate was added to the organic layer, dehydrated and dried, filtered, and then the solvent was distilled off using a rotary evaporator. The residue was recrystallized using a mixed solvent of ethyl acetate / hexane = 7/3 (volume ratio, the same applies hereinafter), and 13.2 g of 2,4-dinitro-1- (4-vinyloxy) butoxybenzene. (Yield 90%).

To a 500 mL three-necked flask, 2.12 g of the above dinitro compound, 20 mL of toluene, and 80 mL of a 10% by mass ammonium chloride aqueous solution were added. The system was heated to 70 ° C., 4.2 g of iron (electrolytic iron) was added, and the mixture was stirred at 70 ° C. for 2.5 hours. After completion of the reaction, 30 mL of 5% by mass aqueous sodium hydrogen carbonate solution was added, and the precipitate was filtered and washed with toluene. The filtrate was extracted with ethyl acetate, anhydrous magnesium sulfate was added to the organic layer, dehydrated and dried. After filtration, the solvent was distilled off using a rotary evaporator. The residue was recrystallized using a mixed solvent of ethyl acetate / hexane = 7/3 to obtain 0.59 g of the desired product (yield 38%). The results measured by ¹ H-NMR of desired product are shown below. From this result, it was confirmed that the obtained solid was the target diamino compound, that is, 4- (4- (vinyloxy) butoxy) benzene-1,3-diamine.
¹ H NMR (400 MHz, CDCl ₃ ): δ = 6.60-6.62 (d, 1H), 6.44-6.51 (m, 1H), 6.13-6.14 (d, 1H ), 6.03-6.07 (m, 1H), 4.14-4.21 (d, 1H), 3.96-4.00 (d, 1H), 3.92-3.96 (t , 2H), 3.73-3.73 (m, 4H), 3.34 (s, 2H) 1.85-1.87 (m, 4H)

(Reference Synthesis Example 2) Synthesis of DA-3 To a 300 mL three-necked flask, 5.11 g of 10-undecen-1-ol, 2.37 g of pyridine, and 100 mL of tetrahydrofuran were added. The system was cooled to 0 ° C. with ice cooling, 8.3 g of 3,5-dinitrobenzoyl chloride was added, and the mixture was stirred at room temperature for 2 hours. After completion of the reaction, 20 mL of pure water was added and stirred, and then ethyl acetate was added to extract the organic layer. Anhydrous magnesium sulfate was added to the organic layer, dehydrated and dried, filtered, and then the solvent was distilled off using a rotary evaporator. The residue was recrystallized using a mixed solvent of ethyl acetate / hexane = 7/3 to obtain 6.9 g of undec-10-enyl-3,5-dinitrobenzoate (yield 63%).

To the 300 mL three-necked flask, 6.55 g of the above dinitro compound, 50 mL of tetrahydrofuran and 50 mL of pure water were added, the system was stirred, 17.06 g of tin chloride was added, and the mixture was stirred at 60 ° C. for 2 hours. After completion of the reaction, 400 ml of 5% by mass sodium hydrogen carbonate was added to adjust the pH to 7-8. Thereafter, 160 ml of ethyl acetate was added, the white precipitate was removed by filtration, and the organic layer was extracted with ethyl acetate. The organic layer was dehydrated and dried by adding anhydrous magnesium sulfate, filtered, and then the solvent was distilled off using a rotary evaporator. The residue was recrystallized using a mixed solvent of ethyl acetate / hexane = 7/3 to obtain 4.5 g of the desired product (yield 82%). The results measured by ¹ H-NMR of desired product are shown below. From this result, it was confirmed that the obtained solid was the target diamino compound, that is, undec-10-enyl-3,5-diaminobenzoate.
¹ H NMR (400 MHz, [D ₆ ] -DMSO): δ = 6.41 (s, 2H), 6.01 (s, 1H), 5.73-5.84 (m, 1H), 4. 91-5.01 (m, 6H), 4.13-4.16 (t, 2H), 1.98-2.02 (m, 2H), 1.60-1.67 (m, 2H), 1.27-1.37 (m, 12H)

<Molecular weight measurement of polyamic acid and polyimide>
The molecular weight of the polyamic acid in the following synthesis examples is as follows using a normal temperature gel permeation chromatography (GPC) apparatus (GPC-101) manufactured by Showa Denko KK and a column (KD-803, KD-805) manufactured by Shodex. The measurement was performed as described above.
Column temperature: 50 ° C
Eluent: N, N′-dimethylformamide (as additives, lithium bromide-hydrate (LiBr · H ₂ O) is 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) is 30 mmol / L, Tetrahydrofuran (THF) 10ml / L)
Flow rate: 1.0 ml / min Standard sample for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight: about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation, and polyethylene glycol (molecular weight manufactured by Polymer Laboratories) About 12,000, 4,000, 1,000).

<Synthesis Example 1>
As tetracarboxylic dianhydride, 0.71 g (3.96 mmol) of C-1 was used as a diamine component, 0.85 g (3.20 mmol) of DA1 and 0.30 g (0.80 mmol) of DA-7 were used, The reaction was performed in 7.69 g of NMP at room temperature for 16 hours to obtain a solution having a polyamic acid (PAA-1) concentration of 20% by mass. 8.0 g of this polyamic acid solution (PAA-1) is diluted with 12.0 g of NMP and 5.3 g of BCS, 6 mass% of polyamic acid (PAA-1), 74 mass% of NMP, and 20 mass of BCS. % Liquid crystal aligning agent (A1) was obtained. The number average molecular weight of PAA-1 was 20,500, and the weight average molecular weight was 63,000.

<Synthesis Example 2>
As tetracarboxylic dianhydride, 0.71 g (3.96 mmol) of C-1 was used, 0.95 g (3.60 mmol) of DA1 and 0.15 g (0.40 mmol) of DA-7 were used as diamine components, The reaction was performed in 7.51 g of NMP at room temperature for 16 hours to obtain a solution having a polyamic acid (PAA-2) concentration of 20% by mass. 8.0 g of this polyamic acid solution (PAA-2) is diluted with 12.2 g of NMP and 5.3 g of BCS, 6 mass% of polyamic acid (PAA-2), 74 mass% of NMP, and 20 mass of BCS. % Liquid crystal aligning agent (A2) was obtained. PAA-2 had a number average molecular weight of 25,200 and a weight average molecular weight of 86,400.

<Synthesis Example 3>
0.41 g (2.48 mmol) of C-1 was used as a tetracarboxylic dianhydride, 0.59 g (2.25 mmol) of DA1 and 0.095 g (0.25 mmol) of DA-8 were used as diamine components, Reaction was performed in 4.70 g of NMP at room temperature for 16 hours to obtain a solution having a polyamic acid (PAA-3) concentration of 20% by mass. The polyamic acid solution (PAA-3) 4.7 g is diluted with NMP 7.8 g and BCS 3.1 g, the polyamic acid (PAA-3) is 6 mass%, the NMP is 74 mass%, and the BCS is 20 mass. % Liquid crystal aligning agent (A3) was obtained. PAA-3 had a number average molecular weight of 20,400 and a weight average molecular weight of 57,800.

<Synthesis Example 4>
0.41 g (2.48 mmol) of C-1 was used as a tetracarboxylic dianhydride, 0.59 g (2.25 mmol) of DA1 and 0.11 g (0.25 mmol) of DA-9 were used as diamine components, The reaction was performed in 4.75 g of NMP at room temperature for 16 hours to obtain a solution having a polyamic acid (PAA-4) concentration of 20% by mass. 4.7 g of this polyamic acid solution (PAA-4) is diluted with 7.9 g of NMP and 3.2 g of BCS, 6 mass% of polyamic acid (PAA-4), 74 mass% of NMP, and 20 mass of BCS. % Liquid crystal aligning agent (A4) was obtained. PAA-4 had a number average molecular weight of 19,100 and a weight average molecular weight of 55,000.

<Synthesis Example 5>
As tetracarboxylic dianhydride, 0.41 g (2.40 mmol) of C-1 was used, 0.39 g (1.75 mmol) of DA2 and 0.28 g (0.75 mmol) of DA-7 were used as diamine components, The reaction was performed in 4.57 g of NMP at room temperature for 16 hours to obtain a solution having a polyamic acid (PAA-5) concentration of 20% by mass. 4.5 g of this polyamic acid solution (PAA-5) is diluted with 7.6 g of NMP and 3.0 g of BCS, 6 mass% of polyamic acid (PAA-5), 74 mass% of NMP, and 20 mass of BCS. % Liquid crystal aligning agent (A5) was obtained. PAA-5 had a number average molecular weight of 16,700 and a weight average molecular weight of 52,900.

<Synthesis Example 6>
0.41 g (2.40 mmol) of C-1 was used as tetracarboxylic dianhydride, 0.44 g (2.00 mmol) of DA2 and 0.19 g (0.50 mmol) of DA-7 were used as the diamine component, The reaction was carried out in 4.41 g of NMP at room temperature for 16 hours to obtain a solution having a polyamic acid (PAA-6) concentration of 20% by mass. 4.4 g of this polyamic acid solution (PAA-6) is diluted with 7.3 g of NMP and 2.9 g of BCS, 6 mass% of polyamic acid (PAA-6), 74 mass% of NMP, and 20 mass of BCS. % Liquid crystal aligning agent (A6) was obtained. PAA-6 had a number average molecular weight of 24,400 and a weight average molecular weight of 93,500.

<Synthesis Example 7>
As tetracarboxylic dianhydride, 0.41 g (2.48 mmol) of C-1 was used, 0.53 g (1.75 mmol) of DA3 and 0.28 g (0.75 mmol) of DA-7 were used as diamine components, The reaction was performed in 5.20 g of NMP at room temperature for 16 hours to obtain a solution having a polyamic acid (PAA-7) concentration of 20% by mass. 5.4 g of this polyamic acid solution (PAA-7) is diluted with 9.0 g of NMP and 3.6 g of BCS, 6 mass% of polyamic acid (PAA-7), 74 mass% of NMP, and 20 mass of BCS. % Liquid crystal aligning agent (A7) was obtained. PAA-7 had a number average molecular weight of 20,900 and a weight average molecular weight of 78,900.

<Synthesis Example 8>
0.41 g (2.48 mmol) of C-1 was used as tetracarboxylic dianhydride, 0.61 g (2.00 mmol) of DA3 and 0.19 g (0.50 mmol) of DA-7 were used as the diamine component, Reaction was performed in 5.13 g of NMP at room temperature for 16 hours to obtain a solution having a polyamic acid (PAA-8) concentration of 20% by mass. This polyamic acid solution (PAA-8) 5.3 g was diluted with NMP 8.8 g and BCS 3.5 g, polyamic acid (PAA-8) 6 mass%, NMP 74 mass%, and BCS 20 mass. % Liquid crystal aligning agent (A8) was obtained. PAA-8 had a number average molecular weight of 18,800 and a weight average molecular weight of 67,300.

<Synthesis Example 9>
0.41 g (2.48 mmol) of C-1 was used as tetracarboxylic dianhydride, 0.46 g (2.00 mmol) of DA4 and 0.19 g (0.50 mmol) of DA-7 were used as the diamine component, The reaction was performed in 4.55 g of NMP at room temperature for 16 hours to obtain a solution having a polyamic acid (PAA-9) concentration of 20% by mass. 4.5 g of this polyamic acid solution (PAA-9) is diluted with 6.5 g of NMP and 3.0 g of BCS, 6 mass% of polyamic acid (PAA-9), 74 mass% of NMP, and 20 mass of BCS. % Liquid crystal aligning agent (A9) was obtained. PAA-9 had a number average molecular weight of 17,600 and a weight average molecular weight of 47,100.

<Synthesis Example 10>
As tetracarboxylic dianhydride, 0.41 g (2.48 mmol) of C-1 was used, 0.52 g (2.25 mmol) of DA4 and 0.09 g (0.25 mmol) of DA-7 were used as diamine components, The reaction was carried out at room temperature for 16 hours in 4.41 g of NMP to obtain a solution having a polyamic acid (PAA-10) concentration of 20% by mass. 4.3 g of this polyamic acid solution (PAA-10) is diluted with 6.1 g of NMP and 2.8 g of BCS, 6% by mass of polyamic acid (PAA-10), 74% by mass of NMP, and 20% of BCS. % Liquid crystal aligning agent (A10) was obtained. PAA-10 had a number average molecular weight of 19,500 and a weight average molecular weight of 55,500.

<Synthesis Example 11>
0.41 g (2.48 mmol) of C-1 was used as tetracarboxylic dianhydride, 0.82 g (2.00 mmol) of DA5 and 0.19 g (0.50 mmol) of DA-7 were used as the diamine component, The reaction was performed in 5.9 g of NMP at room temperature for 16 hours to obtain a solution having a polyamic acid (PAA-11) concentration of 20% by mass. 5.0 g of this polyamic acid solution (PAA-11) is diluted with 6.3 g of NMP and 3.3 g of BCS, 6 mass% of polyamic acid (PAA-11), 74 mass% of NMP, and 20 mass of BCS. % Liquid crystal aligning agent (A11) was obtained. PAA-11 had a number average molecular weight of 17,000 and a weight average molecular weight of 56,000.

<Synthesis Example 12>
0.49 g (2.48 mmol) of C-1 was used as tetracarboxylic dianhydride, 0.93 g (2.25 mmol) of DA5 and 0.19 g (0.25 mmol) of DA-7 were used as the diamine component, The reaction was performed in 6.03 g of NMP at room temperature for 16 hours to obtain a solution having a polyamic acid (PAA-12) concentration of 20% by mass. 5.0 g of this polyamic acid solution (PAA-12) is diluted with 6.3 g of NMP and 3.3 g of BCS, 6 mass% of polyamic acid (PAA-12), 74 mass% of NMP, and 20 mass of BCS. % Liquid crystal aligning agent (A12) was obtained. PAA-12 had a number average molecular weight of 19,500 and a weight average molecular weight of 59,000.

<Synthesis Example 13>
0.41 g (2.48 mmol) of C-1 as tetracarboxylic dianhydride, 0.64 g (2.00 mmol) of DA-10 and 0.19 g (0.50 mmol) of DA-7 as the diamine component The resulting solution was reacted in 5.26 g of NMP at room temperature for 16 hours to obtain a solution having a polyamic acid (PAA-14) concentration of 20% by mass. 5.0 g of this polyamic acid solution (PAA-14) is diluted with 6.3 g of NMP and 3.3 g of BCS, 6 mass% of polyamic acid (PAA-14), 74 mass% of NMP, and 20 mass of BCS. % Liquid crystal aligning agent (A13) was obtained. PAA-14 had a number average molecular weight of 17,500 and a weight average molecular weight of 57,000.

<Synthesis Example 14>
As tetracarboxylic dianhydride, 0.41 g (2.48 mmol) of C-1 as a diamine component, 0.72 g (2.25 mmol) of DA-10 and 0.09 g (0.25 mmol) of DA-7 as diamine components The resulting solution was reacted in 5.20 g of NMP at room temperature for 16 hours to obtain a solution having a polyamic acid (PAA-15) concentration of 20% by mass. 5.0 g of this polyamic acid solution (PAA-15) is diluted with 6.3 g of NMP and 3.3 g of BCS, 6 mass% of polyamic acid (PAA-15), 74 mass% of NMP, and 20 mass of BCS. % Liquid crystal aligning agent (A14) was obtained. The number average molecular weight of PAA-15 was 18,500, and the weight average molecular weight was 59,000.

<Comparative Synthesis Example 1>
As tetracarboxylic dianhydride, 1.30 g (6.65 mmol) of C-1 as a diamine component, 0.68 g (6.30 mmol) of DA-6 and 0.26 g (0.7 mmol) of DA-7 as diamine components. The resulting solution was reacted at room temperature for 16 hours in 12.74 g of NMP to obtain a solution having a polyamic acid (PAA-13) concentration of 20% by mass. Dilute 10.0 g of this polyamic acid solution (PAA-13) with 16.7 g of NMP and 6.7 g of BCS, 6 mass% of polyamic acid (PAA-13), 74 mass% of NMP, and 20 mass of BCS. % Liquid crystal aligning agent (A15) was obtained. PAA-13 had a number average molecular weight of 18,700 and a weight average molecular weight of 58,000.

<Reference Example 1>
The liquid crystal aligning agent [A1] obtained in Synthesis Example 1 was spin-coated on the ITO surface of an ITO electrode substrate on which an ITO electrode pattern having a pixel size of 100 × 300 microns and a line / space of 5 microns was formed. . After drying for 90 seconds on an 80 ° C. hot plate, baking was performed for 60 minutes in a 160 ° C. hot-air circulating oven to form a liquid crystal alignment film having a thickness of 100 nm.
The liquid crystal aligning agent [A1] obtained in Synthesis Example 1 was spin-coated on the ITO surface on which no electrode pattern was formed, dried on a hot plate at 80 ° C. for 90 seconds, and then heated at 160 ° C. in a hot air circulation oven Was baked for 60 minutes to form a liquid crystal alignment film having a thickness of 100 nm. These two substrates were prepared, and a 6 μm bead spacer was sprayed on the liquid crystal alignment film surface of one of the substrates, and a sealant was printed thereon. The other substrate was bonded with the liquid crystal alignment film surface inside, and then the sealing agent was cured to produce an empty cell. Liquid crystal MLC-6608 (trade name, manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method to produce a liquid crystal cell.

  The response speed characteristics of these liquid crystal cells were measured by the method described later. Thereafter, 20 J of UV (ultraviolet rays) was irradiated from the outside of the liquid crystal cell in a state where a voltage of 20 Vp-p was applied to the liquid crystal cell. Thereafter, the response speed characteristic was measured again, and the response speed before and after UV irradiation was compared. The results are shown in Table 2.

<Reference Examples 2-4, 7, 8>, <Examples 1-4, 7, 8> and <Comparative Example 1>
As shown in Table 2, the liquid crystal aligning agent [A1] obtained in Synthesis Examples 2 to 14 and the liquid crystal aligning agent obtained in Comparative Synthetic Example 1 [Table 1] A liquid crystal cell was prepared in the same manner as in Reference Example 1 except that the change was made to A15], and the response speed was measured. The results are shown in Table 2.
As shown in Table 2, the liquid crystal alignment agents [A1] to [A4], [A9], [A10], [A13], and [A14] are Reference Examples 1 to 4, 7, 8, and 5, respectively. The liquid crystal aligning agents [A5] to [A8], [A11], and [A12] are Examples 1 to 4, 7, and 8 of the present invention, respectively.

[Response speed characteristics]
The change in luminance of the liquid crystal panel over time when a rectangular wave with a voltage of ± 4 V and a frequency of 1 kHz was applied to a liquid crystal cell to which no voltage was applied was captured with an oscilloscope. When the voltage was not applied, the luminance was 0%, a voltage of ± 4 V was applied, the saturated luminance value was 100%, and the time for the luminance to change from 10% to 90% was defined as the rising response speed.

As can be seen from Table 2, in the liquid crystal cell of the example, the response speed after UV irradiation was improved. On the other hand, in the comparative example, there was no change in response speed before and after UV irradiation. In Reference Examples 1, 2, 7, and 8 and Examples 1 to 4, 7, and 8, the degree of improvement in response speed was greater after UV irradiation when the amount of tilted side chains introduced was smaller. Further, in Reference Examples 2, 3, and 4, when the side chain having a low vertical alignment ability was used even when the amount of tilt-expressing side chain introduced was the same, the degree of improvement in the response speed after UV irradiation was large.
Similarly to the above, in Reference Examples 5 and 6, the improvement in the response speed was greater after UV irradiation when the amount of tilted side chains introduced was smaller. In addition, in Reference Examples 1 and 5 and Reference Examples 2 and 6, when DA-10 having a long alkyl spacer was used even if the amount of the introduced side chain of the tilt expression was the same and the photoreactive group was the same, Compared with the case of using DA-1, the degree of improvement in response speed after UV irradiation was large.

  The liquid crystal aligning agent of the present invention can be used for preparing a liquid crystal display element of a vertical alignment method produced by irradiating ultraviolet rays while applying a voltage to liquid crystal molecules, and is manufactured without including such steps. It can also be used for liquid crystal display elements.

Claims (7)

A liquid crystal alignment agent is applied onto two substrates to form a liquid crystal alignment layer, the two substrates are arranged so that the liquid crystal alignment layers face each other, and the liquid crystal layer is sandwiched between the two substrates. A liquid crystal aligning agent for use in a method for manufacturing a liquid crystal display element of a vertical alignment method in which ultraviolet rays are applied while applying a voltage to a liquid crystal layer,
From the group consisting of a polyamic acid having a side chain (A) for vertically aligning liquid crystal and a photoreactive side chain (B) represented by the following formula (b) and a polyimide obtained by imidizing the polyamic acid. A liquid crystal aligning agent comprising at least one selected.

(R ⁶ is —CH ₂ —, —O—, —COO—, —NHCO—, —NH—, —CH ₂ O—, —N (CH ₃ ) —, —CON (CH ₃ ) —, or —N Represents (CH ₃ ) CO—, R ⁷ represents a linear alkylene having 1 to 20 carbon atoms (the alkylene may be unsubstituted or substituted by a fluorine atom), and any —CH of alkylene ₂ — may be replaced by —CF ₂ —, —CH═CH—, or the following substituents (these substituents are not adjacent to each other).
Substituent: —O—, —COO—, —NHCO—, —NH—, a carbocyclic group, or a heterocyclic group.
R ⁸ represents —CH ₂ —, —O—, —COO—, —OCO—, —NHCO—, —NH—, —N (CH ₃ ) —, —CON (CH ₃ ) —, —N (CH ₃ ). CO— represents a carbocyclic group or a heterocyclic group, and R ⁹ represents a vinylphenyl group, —CR ¹⁰ ═CH ₂ group, a carbocyclic group, a heterocyclic group, or a group represented by the following formula: R ¹⁰ represents a hydrogen atom or a methyl group which may be substituted with a fluorine atom. However, except that R ⁸ is —OCO—, —NHCO— or —N (CH ₃ ) CO—, and R ⁹ is —CH═CH ₂ or —C (CH ₃ ) ═CH ₂ . )

  The polyamic acid is obtained by reacting a diamine component containing a diamine having a side chain (A) for vertically aligning liquid crystals and a diamine having a photoreactive side chain (B) with a tetracarboxylic dianhydride component. The liquid crystal aligning agent of Claim 1 which is a polyamic acid obtained. The liquid crystal aligning agent of Claim 2 with which the diamine which has the said photoreactive side chain (B) is represented by following formula (2).

(R ⁶ is —CH ₂ —, —O—, —COO—, —NHCO—, —NH—, —CH ₂ O—, —N (CH ₃ ) —, —CON (CH ₃ ) —, or —N Represents (CH ₃ ) CO—, R ⁷ represents a linear alkylene having 1 to 20 carbon atoms (the alkylene may be unsubstituted or substituted by a fluorine atom), and any —CH of alkylene ₂ — may be replaced by —CF ₂ —, —CH═CH—, or the following substituents (these substituents are not adjacent to each other).
Substituent: —O—, —COO—, —NHCO—, —NH—, a carbocyclic group, or a heterocyclic group.
R ⁸ represents —CH ₂ —, —O—, —COO—, —OCO—, —NHCO—, —NH—, —N (CH ₃ ) —, —CON (CH ₃ ) —, —N (CH ₃ ). CO—, a carbocyclic group, or a heterocyclic group is represented, and R ¹¹ represents a vinylphenyl group, —CH═CH ₂ , —C (CH ₃ ) ═CH ₂ , or any of the following groups. However, ^{R 8} is -OCO of formula (2) -, - NHCO- or -N _(CH 3) CO- is a by ^{R 11} is -CH = CH ₂ or -C _(CH 3) = ones is CH ₂ except for. )

The liquid crystal aligning agent of Claim 2 or 3 with which the diamine which has the side chain (A) which orientates the said liquid crystal perpendicularly is represented by following formula (1).

(In the formula (a), l, m and n each independently represents an integer of 0 or 1. R ¹ represents an alkylene group having 2 to 6 carbon atoms, —O—, —COO—, —OCO—, — NHCO-, -CONH-, or an alkylene-ether group having 1 to 3 carbon atoms, R ² , R ³ and R ⁴ each independently represents a phenylene group or a cycloalkylene group, and R ⁵ is a hydrogen atom. And represents a linear alkyl group having 5 to 18 carbon atoms or a fluorine-containing alkyl group, or an aromatic ring group, an aliphatic ring group, a heterocyclic group, or a macrocyclic group composed thereof. A diamine having a side chain (A) for vertically aligning the liquid crystal is represented by the formula (1), l, m, and n are all 1, R ² is phenylene, and R ³ is phenylene. Or cyclohexylene, R ⁴ is cyclohexylene, R ⁵ is an alkyl group having 2 to 24 carbon atoms, or l, m and n are all 0, and R ⁵ is the number of carbon atoms. The liquid crystal aligning agent of Claim 4 which is a diamine which is a 12-22 alkyl group. The liquid crystal aligning agent of Claim 2 or 3 whose diamine which has the side chain (A) which orientates the said liquid crystal vertically is a diamine which has one of the following structures.

  The liquid crystal aligning layer obtained using the liquid crystal aligning agent in any one of Claims 1-6.