WO2016140302A1

WO2016140302A1 - Polyimide precursor, and liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element having precursor

Info

Publication number: WO2016140302A1
Application number: PCT/JP2016/056560
Authority: WO
Inventors: 将人長尾; 近藤　光正
Original assignee: 日産化学工業株式会社
Priority date: 2015-03-04
Filing date: 2016-03-03
Publication date: 2016-09-09
Also published as: TWI781080B; TW201702289A; KR102600209B1; CN107531904A; KR20170125923A; JP6753392B2; TW202239823A; TWI810976B; CN107531904B; JPWO2016140302A1

Abstract

The present invention provides a polyimide precursor in which the quantity of radicals generated is relatively large. Through this polyimide precursor, reaction of a polymerizable compound is accelerated, the pretilt angle in liquid crystals is efficiently set to the desired value, and a liquid crystal display element having enhanced response speed is provided. The present invention provides a polyimide precursor which uses a first photoradical generating diamine, the polyimide precursor being characterized in that the quantity of radicals generated during photoirradiation under the same conditions is greater than in a second polyimide precursor formed under the same conditions as the polyimide precursor except that the first photoradical generating diamine is replaced therein with a second photoradical generating diamine represented by formula (1).　

Description

POLYIMIDE PRECURSOR, LIQUID CRYSTAL ALIGNING AGENT, LIQUID CRYSTAL ALIGNING FILM AND LIQUID CRYSTAL DISPLAY DEVICE HAVING THE PRECURSOR

The present invention relates to a polyimide precursor having a relatively large amount of radical generation, which can be used for a vertical alignment type liquid crystal display device produced by irradiating ultraviolet rays with voltage applied to liquid crystal molecules, and the polyimide precursor. The present invention relates to a liquid crystal alignment agent having a liquid crystal alignment film, a liquid crystal alignment film formed using the liquid crystal alignment agent, and a liquid crystal display element formed using the liquid crystal alignment film.

A liquid crystal display element of a method in which liquid crystal molecules aligned perpendicular to the substrate respond by an electric field (also referred to as a vertical alignment (VA) method) is irradiated with ultraviolet rays while applying a voltage to the liquid crystal molecules in the manufacturing process. There is a thing including the process to do.
In such a vertical alignment type liquid crystal display element, a photopolymerizable compound is previously added to the liquid crystal composition, and a polyimide-based vertical alignment film is used, and ultraviolet rays are applied while applying a voltage to the liquid crystal cell. Therefore, a technique for increasing the response speed of liquid crystal (PSA (Polymer Sustained Alignment) type element, see, for example, Patent Document 1 and Non-Patent Document 1) is known.

In such a PSA device, the direction in which the liquid crystal molecules incline in response to an electric field is usually controlled by protrusions provided on the substrate or slits provided on the display electrode, but photopolymerization is performed in the liquid crystal composition. By applying UV light while applying a voltage to the liquid crystal cell and applying a voltage to the liquid crystal cell, a polymer structure in which the tilted direction of the liquid crystal molecules is memorized 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 tilt direction of the liquid crystal molecules.

On the other hand, in this PSA type liquid crystal display element, the solubility of the polymerizable compound added to the liquid crystal is low, and there is a problem that when the addition amount is increased, precipitation occurs at a low temperature, but it is good when the addition amount of the polymerizable compound is reduced. An orientation state cannot be obtained. Moreover, since the unreacted polymerizable compound remaining in the liquid crystal becomes an impurity (contamination) in the liquid crystal, there is a problem that the reliability of the liquid crystal display element is lowered. In addition, when the UV irradiation treatment necessary for the PSA method is large, components in the liquid crystal are decomposed, resulting in a decrease in reliability.
Furthermore, it has been reported that the response speed of the liquid crystal display element is increased by adding a photopolymerizable compound to the liquid crystal alignment film instead of the liquid crystal composition (SC-PVA liquid crystal display, for example, Patent Document 2).

JP 2003-307720 A

In recent years, with the improvement of the quality of liquid crystal display elements, it is desired to further increase the response speed of the liquid crystal to voltage application. For that purpose, it is necessary that the polymerizable compound reacts efficiently and exhibits the ability to fix alignment by irradiation with ultraviolet rays having a long wavelength without decomposition of components in the liquid crystal. Furthermore, it is necessary that unreacted polymerizable compound does not remain after ultraviolet irradiation and does not adversely affect the reliability of the liquid crystal display element.

An object of the present invention is to improve the response speed of a liquid crystal display device obtained by using a step of reacting a polymerizable compound in a liquid crystal and / or a liquid crystal alignment film without the above-mentioned problems of the prior art. An object of the present invention is to provide a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element that can be used.
More specifically, an object of the present invention is to provide a polyimide precursor having a relatively large amount of radical generation, and by using the polyimide precursor, the reaction of the polymerizable compound is promoted, and the pretilt angle in the liquid crystal is efficiently increased. The desired value is set to improve the response speed of the liquid crystal display element.

As a result of intensive studies, the inventors of the present invention have made a polyimide precursor a specific structure in which a radical is generated by ultraviolet irradiation and a relatively large amount of radical is generated with respect to the polymer constituting the liquid crystal aligning agent. The reaction of the polymerizable compound in the liquid crystal display device obtained by using the step of reacting the polymerizable compound in the liquid crystal and / or the liquid crystal alignment film by introducing and using the liquid crystal aligning agent having the polyimide precursor The inventors have found that the above-mentioned problems can be achieved by enhancing the properties, and have completed the invention described in detail below.

<1> A polyimide precursor using a first photoradical generating diamine, except that the first photoradical generating diamine is replaced with a second photoradical generating diamine represented by the formula (1). The said polyimide precursor characterized by having more radical generation amount at the time of light irradiation on the same conditions than the 2nd polyimide precursor formed on the same conditions as a polyimide precursor.

<2> In the above item <1>, the wavelength of light upon light irradiation is preferably 300 nm to 400 nm.
<3> In the above item <1> or <2>, the first photoradical-generating diamine may be 0.1 to 100 mol% in 100 mol% of all diamines constituting the polyimide precursor.
<4> In the above items <1> to <3>, the first photoradical-generating diamine is represented by the formula (A)
(In the formula, Ar represents an aromatic hydrocarbon group which may have a substituent,
R ¹⁰¹ represents a divalent organic group,
R ¹⁰² to R ¹⁰⁴ each independently represents a monovalent organic group)
It is good to have the following structure.

<5> In the above item <4>, -R ¹⁰¹ -is -T ₁ -ST _2-
(Where
T ₁ and T ₂ are each independently a single bond, —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, —CH ₂ O—, —N (CH ₃ ). -, -CON (CH ₃ )-, or -N (CH ₃ ) CO-,
S is a single bond or an alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted by a fluorine atom (—CH ₂ — or —CF ₂ — in an alkylene group is —CH═CH—, or A group selected from group G (wherein the groups selected from group G are not adjacent to each other) (group G: —O—, —COO—, —OCO—, —NHCO—, -CONH-, -NH-, divalent carbocycle or divalent heterocycle)))
It is good to be represented by

<6> In the above <4> or <5>, any one of R ¹⁰² to R ¹⁰⁴ is —OR ¹¹¹ (where R ¹¹¹ is an unsubstituted or substituted carbon atom having 1 to 20 carbon atoms) A linear, branched or cyclic alkyl group (wherein —CH ₂ — or —CF ₂ — in the alkyl group is —CH═CH— or a group selected from the following group G (provided that the group G is selected): Groups that are not adjacent to each other) (group G: —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, a divalent carbocycle or two Valent heterocycle)), and
The other two are each independently a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, —OR ¹¹² (R ¹¹² is an unsubstituted or substituted carbon atom having 1 to 20 carbon atoms. A linear, branched or cyclic alkyl group, or a group selected from the group consisting of optionally substituted aryl groups having 6 to 20 carbon atoms), a benzyl group, or a phenethyl group (In the case where the other two are the alkyl group or —OR ¹¹² , they may be bonded to each other to form a ring).

<7> In any one of the above items <4> to <6>, Ar may be a phenylene group.
<8> In any one of the above items <1> to <7>, the first photoradical-generating diamine is represented by the following formula (2) (wherein Ar and R ¹⁰¹ to R ¹⁰⁴ have the same definition as described above): It is good to be represented by

<9> In any one of the above items <1> to <8>, the first photoradical-generating diamine may be represented by the following formula (3).

<10> In any one of the above items <1> to <9>, the polyimide precursor may further have a side chain for vertically aligning the liquid crystal.
<11> In any one of the above items <1> to <10>, the polyimide precursor may further have a side chain including a photoreactive group in the structure.
<12>
A polyimide obtained by imidizing any of the above polyimide precursors <1> to <11>.

<13> A liquid crystal aligning agent comprising the polyimide precursor of any one of the above <1> to <11> and / or the polyimide of the above <12>.
<14> In the above <13>, a liquid crystal display element obtained by reacting the polymerizable compound by irradiating ultraviolet rays while applying a voltage, containing a polymerizable compound in the liquid crystal and / or the liquid crystal alignment film It is good to be used for manufacturing.
<15> A liquid crystal alignment film formed with the liquid crystal aligning agent according to <13> or <14>.
<16> A liquid crystal display device comprising the liquid crystal alignment film of <15>.

<17> The following formula (A)
(In the formula, Ar represents an aromatic hydrocarbon group which may have a substituent,
R ¹⁰¹ represents a divalent organic group,
R ¹⁰² to R ¹⁰⁴ each independently represents a monovalent organic group)
A diamine having a structure represented by:

<18> In the above item <17>, -R ¹⁰¹ -is -T ₁ -ST _2-
(Wherein T ₁ and T ₂ are each independently a single bond, —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, —CH ₂ O—, —N (CH ₃ ) —, —CON (CH ₃ ) —, or —N (CH ₃ ) CO—,
S is a single bond or an alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted by a fluorine atom (—CH ₂ — or —CF ₂ — in an alkylene group is —CH═CH—, or A group selected from group G (wherein the groups selected from group G are not adjacent to each other) (group G: —O—, —COO—, —OCO—, —NHCO—, -CONH-, -NH-, divalent carbocycle or divalent heterocycle)))
It is good to be represented by

<19> In the above <17> or <18>,
Any one of R ¹⁰² to R ¹⁰⁴ is —OR ¹¹¹ (wherein R ¹¹¹ is an unsubstituted or linear or branched or cyclic alkyl group having 1 to 20 carbon atoms substituted by a fluorine atom (alkyl —CH ₂ — or —CF ₂ — in the group is replaced by —CH═CH— or a group selected from the following group G (provided that the groups selected from group G are not adjacent to each other): May be substituted (group G: —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, divalent carbocycle or divalent heterocycle)) And
The other two are each independently a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, —OR ¹¹² (R ¹¹² is an unsubstituted or substituted carbon atom having 1 to 20 carbon atoms. A linear, branched or cyclic alkyl group, or a group selected from the group consisting of optionally substituted aryl groups having 6 to 20 carbon atoms), a benzyl group, or a phenethyl group (In the case where the other two are the alkyl group or —OR ¹¹² , they may be bonded to each other to form a ring).

<20> The diamine according to any one of the above <17> to <19> may be represented by the following formula (2) (Ar and R ¹⁰¹ to R ¹⁰⁴ have the same definition as described above).

<21> The diamine of any one of the above <17> to <20> has the following formula (4) (R ¹⁰³ and R ¹⁰⁴ , and R ¹¹¹ have the same definition as described above, and X ¹⁰¹ is a single bond or CO It is good to be represented by.

<22> The diamine of any of the above <17> to <21> may be selected from the group consisting of the following formulas (3) to (3) -12.

<23> The following formula (2) (wherein Ar represents an aromatic hydrocarbon group which may have a substituent, R ¹⁰¹ represents a divalent organic group, and R ¹⁰² to R ¹⁰⁴ each independently represents Represents a monovalent organic group)
Diamine represented by

<24> Diamine represented by the following formula (3).

<25> A diamine selected from the group consisting of the following formulas (3) to (3) -12.

<26> A polyimide precursor using the diamine according to any one of the above items <17> to <25>.
<27> In the above item <26>, the diamine of any one of the above items <17> to <25> may be 0.1 to 100 mol% in 100 mol% of all diamines constituting the polyimide precursor.
<28> The polyimide precursor according to <26> or <27> may further include a side chain for vertically aligning the liquid crystal.
<29> In the above item <28>, the side chain for vertically aligning the liquid crystal has the following formula [II-1] (in the formula [II-1], X ¹ represents a single bond, — (CH ₂ ) _a — ( a represents an integer of 1 to 15), —O—, —CH ₂ O—, —COO— or OCO—, X ² is a single bond or (CH ₂ ) _b — (b is 1 to 15 X ³ represents a single bond, — (CH ₂ ) _c — (c is an integer of 1 to 15), —O—, —CH ₂ O—, —COO— or OCO—. represents .X ⁴ is a benzene ring, a cyclohexane ring, and represents a divalent cyclic group selected from heterocyclic, any hydrogen atom in these cyclic groups, an alkyl group having 1 to 3 carbon atoms, 1 to 3 carbon atoms An alkoxyl group, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxyl group having 1 to 3 carbon atoms, or a fluorine atom May be conversion, further, X ⁴ is may be a divalent organic group selected from an organic group having a carbon number of 17 to 51 having a steroid skeleton .X ⁵ is a benzene ring, cyclohexane ring and heterocyclic And an arbitrary hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, or a fluorine-containing alkyl group having 1 to 3 carbon atoms. Group, a fluorine-containing alkoxyl group having 1 to 3 carbon atoms or a fluorine atom, n represents an integer of 0 to 4. X ⁶ is an alkyl group having 1 to 18 carbon atoms, 1 to 18 carbon atoms And a fluorine-containing alkyl group having 1 to 18 carbon atoms or a fluorine-containing alkoxyl group having 1 to 18 carbon atoms.)
And [II-2]
(In the formula [II-2], X ⁷ represents a single bond, —O—, —CH ₂ O—, —CONH—, —NHCO—, —CON (CH ₃ ) —, —N (CH ₃ ) CO— And represents —COO— or OCO—, wherein X ⁸ represents an alkyl group having 8 to 22 carbon atoms or a fluorine-containing alkyl group having 6 to 18 carbon atoms.)
It is good that it is at least one selected from.

<30> The polyimide precursor according to any one of the above <26> to <29> may further have a side chain containing a photoreactive group in the structure.
<31> In the above <30>, a side chain containing a photoreactive group in the structure thereof,
The following formula [III]
(In the formula [III], R ⁸ represents a single bond, —CH ₂ —, —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, —CH ₂ O—, — Represents N (CH ₃ ) —, —CON (CH ₃ ) —, or —N (CH ₃ ) CO—, wherein R ⁹ is a single bond, alkylene having 1 to 20 carbon atoms which may be substituted with a fluorine atom The alkylene group —CH ₂ — may be optionally substituted with —CF ₂ — or —CH═CH—, and if any of the following groups are not adjacent to each other, these groups are substituted: —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, a divalent carbocyclic or heterocyclic ring, R ¹⁰ is a group represented by the following formula R ¹⁰ −1 to It represents a photoreactive group selected from the group consisting of R ^{10 -7.)}
Or formula (IV)
(Y ₁ represents —CH ₂ —, —O—, —CONH—, —NHCO—, —COO—, —OCO—, —NH—, or —CO—. Y ₂ has 1 to 30 carbon atoms. An alkylene group, a divalent carbocycle or a heterocycle, and one or more hydrogen atoms of the alkylene group, divalent carbocycle or heterocycle may be substituted with a fluorine atom or an organic group. _{In the case of 2} , when the following groups are not adjacent to each other, —CH ₂ — may be substituted by these groups; —O—, —NHCO—, —CONH—, —COO—, —OCO—, — NH—, —NHCONH—, —CO— Y ₃ represents —CH ₂ —, —O—, —CONH—, —NHCO—, —COO—, —OCO—, —NH—, —CO—, or represents a bond .Y ₄ is .Y ₅ is a single bond representing a cinnamoyl group, 1 to 3 carbon atoms An alkylene group, a divalent carbocycle or a heterocycle, and one or more hydrogen atoms of the alkylene group, divalent carbocycle or heterocycle may be substituted with a fluorine atom or an organic group. In Y ₅ , when the following groups are not adjacent to each other, —CH ₂ — may be substituted with these groups; —O—, —NHCO—, —CONH—, —COO—, —OCO—, —NH—, —NHCONH—, —CO—, wherein Y ₆ represents a photopolymerizable group which is an acryl group or a methacryl group.
It is good to be represented by

<31> A polyimide obtained by imidizing any of the polyimide precursors of <26> to <30>.
<32> A liquid crystal aligning agent comprising the polyimide precursor of any one of the above <26> to <31> and / or the polyimide of the above <31>.
<33> In the above <32>, a liquid crystal display element obtained by reacting the polymerizable compound by irradiating ultraviolet rays while applying a voltage, containing a polymerizable compound in the liquid crystal and / or the liquid crystal alignment film It is good to be used for manufacturing.
<34> A liquid crystal alignment film formed with the liquid crystal aligning agent according to <32> or <33>.
<35> A liquid crystal display device comprising the liquid crystal alignment film of <34>.

According to the present invention, a polyimide precursor having a relatively large amount of radical generation can be provided.
Further, according to the present invention, by using a liquid crystal aligning agent having the polyimide precursor and / or a liquid crystal aligning film formed with the liquid crystal aligning agent, even if the irradiation amount of ultraviolet rays is relatively low, A desired pretilt angle can be obtained in the liquid crystal, and accordingly, a vertical alignment type liquid crystal display element, particularly a PSA type liquid crystal display element, having a high response speed can be provided.

The present invention relates to a polyimide precursor having a relatively large amount of radical generation, a diamine constituting the polyimide, a liquid crystal alignment agent having the polyimide precursor, a liquid crystal alignment film formed using the liquid crystal alignment agent, and the A liquid crystal display element is provided. Hereinafter, this will be described in order.
<Polyimide precursor with a relatively large amount of radical generation>
The present invention provides a polyimide precursor having a relatively large amount of radical generation.
Specifically, the present invention provides a polyimide precursor using a first photoradical-generating diamine.
The polyimide precursor using the first photoradical diamine was formed under the same conditions except that the first photoradical diamine was replaced with the second photoradical diamine represented by formula (1). The amount of radical generation upon light irradiation under the same conditions is larger than that of the second polyimide precursor.
Here, the wavelength of light “when irradiated with light under the same conditions” may be 300 to 400 nm, preferably 310 to 380 nm, more preferably 350 to 370 nm.

In the present specification, the “polyimide precursor” means a product obtained by reacting a diamine component with a tetracarboxylic dianhydride component.
Further, in the present specification, “to a polyimide precursor using a diamine” or “a polyimide precursor is formed using a to diamine” means “to diamine” as a raw material for the polyimide precursor. It means being used. Here, the “diamine” includes a case where it is a part or the whole of a raw material.
In the present specification, “a ˜diamine constituting a polyimide precursor” means “a ˜diamine” is used as a raw material for the polyimide precursor to form the polyimide precursor. Here, the “diamine” includes a case where it is a part or the whole of a raw material.

In the polyimide precursor of the present invention, the first photo radical generating diamine is 0.1 to 100 mol%, preferably 10 to 80 mol%, more preferably 30 out of 100 mol% of the total diamine constituting the polyimide precursor. It should be ˜50 mol%.

The first photoradical-generating diamine has the formula (A)
(In the formula, Ar represents an aromatic hydrocarbon group which may have a substituent,
R ¹⁰¹ represents a divalent organic group,
R ¹⁰² to R ¹⁰⁴ each independently represents a monovalent organic group)
It is good to have the following structure.

-R ¹⁰¹ - _is, -T 1 _{-S-T 2} - it is a group represented by.
Here, T ₁ and T ₂ are each independently a single bond, —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, —CH ₂ O—, —N ( CH ₃ ) —, —CON (CH ₃ ) —, or —N (CH ₃ ) CO—,
S is a single bond or an alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted by a fluorine atom (—CH ₂ — or —CF ₂ — in an alkylene group is —CH═CH—, or A group selected from group G (wherein the groups selected from group G are not adjacent to each other) (group G: —O—, —COO—, —OCO—, —NHCO—, -CONH-, -NH-, divalent carbocycle or divalent heterocycle)).

Any one of R ¹⁰² to R ¹⁰⁴ is —OR ¹¹¹ (wherein R ¹¹¹ is an unsubstituted or linear or branched or cyclic alkyl group having 1 to 20 carbon atoms substituted by a fluorine atom (alkyl —CH ₂ — or —CF ₂ — in the group is replaced by —CH═CH— or a group selected from the following group G (provided that the groups selected from group G are not adjacent to each other): May be substituted (group G: —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, divalent carbocycle or divalent heterocycle)) And
The other two are each independently a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, —OR ¹¹² (R ¹¹² is an unsubstituted or substituted carbon atom having 1 to 20 carbon atoms. A linear, branched or cyclic alkyl group, or a group selected from the group consisting of optionally substituted aryl groups having 6 to 20 carbon atoms), a benzyl group, or a phenethyl group (In the case where the other two are the alkyl group or —OR ¹¹² , they may be bonded to each other to form a ring).

Ar is preferably a group selected from phenylene, naphthylene and biphenylene.
Since Ar to which carbonyl is bonded is involved in the absorption wavelength of ultraviolet rays, a structure having a long conjugate length such as naphthylene or biphenylene is preferable when the wavelength is increased. Ar may be substituted with a substituent, and such a substituent is preferably an electron-donating organic group such as an alkyl group, a hydroxyl group, an alkoxy group, and an amino group.
However, when Ar has a structure such as naphthylene or biphenylene, the solubility becomes poor and the difficulty of synthesis increases. Therefore, a phenyl group is most preferred because sufficient characteristics can be obtained with a phenyl group when the wavelength of ultraviolet rays is in the range of 300 nm to 400 nm, preferably 310 to 380 nm.

The first photoradical-generating diamine is preferably represented by the following formula (2) (Ar and R ¹⁰¹ to R ¹⁰⁴ have the same definition as described above). The diaminobenzene may have a structure of any of o-phenylenediamine, m-phenylenediamine, and p-phenylenediamine. However, in terms of reactivity with acid dianhydride, diaminobenzene may be m-phenylenediamine or p-phenylenediamine. Phenylenediamine is preferred.

In particular, the first photoradical-generating diamine is represented by the following formula (4) (R ¹⁰³ and R ¹⁰⁴ , and R ¹¹¹ have the same definition as described above, and X ¹⁰¹ represents a single bond or CO). Preferably it is a diamine.

Specifically, examples of the first photoradical-generating diamine include, but are not limited to, the following formulas (3) to (3) -12. The first photoradical-generating diamine is particularly preferably a diamine represented by the formula (3).

<Side chains that align liquid crystal vertically>
The polyimide precursor of the present invention preferably further has a side chain for vertically aligning the liquid crystal.
The side chain for vertically aligning the liquid crystal is represented by the following formula [II-1] or [II-2].
In the formula [II-1], X ¹ to X ⁶ and n are as defined above. In the formula [II-2], X ⁷ and X ⁸ are as defined above.

Among these, X ¹ is a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 15), —O—, —CH ₂ O, from the viewpoint of availability of raw materials and ease of synthesis. -Or COO- is preferred, and more preferred is a single bond,-(CH ₂ ) _a- (a is an integer of 1 to 10), -O-, -CH ₂ O- or COO-. Among these, X ² is preferably a single bond or (CH ₂ ) _b — (b is an integer of 1 to 10). X ³ is preferably a single bond, — (CH ₂ ) _c — (c is an integer of 1 to 15), —O—, —CH ₂ O— or COO— from the viewpoint of ease of synthesis. A single bond, — (CH ₂ ) _c — (c is an integer of 1 to 10), —O—, —CH ₂ O— or COO— is preferable.

Among these, X ⁴ is preferably an organic group having 17 to 51 carbon atoms having a benzene ring, a cyclohexane ring or a steroid skeleton from the viewpoint of ease of synthesis. X ⁵ is preferably a benzene ring or a cyclohexane ring. In particular, n is preferably 0 to 3 and more preferably 0 to 2 in view of availability of raw materials and ease of synthesis.
X ⁶ is preferably an alkyl group having 1 to 18 carbon atoms, a fluorine-containing alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 18 carbon atoms, or a fluorine-containing alkoxyl group having 1 to 10 carbon atoms. More preferably, it is an alkyl group having 1 to 12 carbon atoms or an alkoxyl group having 1 to 12 carbon atoms. Particularly preferred is an alkyl group having 1 to 9 carbon atoms or an alkoxyl group having 1 to 9 carbon atoms.

As preferred combinations of X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ and n in the formula [II-1], International Publication No. WO2011 / 132751 (published 2011.10.27), page 13 to The same combinations as (2-1) to (2-629) listed in Table 6 to Table 47 on page 34 can be mentioned. In each table of the International Publication, X ¹ to X ⁶ in the present invention are indicated as Y 1 to Y ^6, but Y 1 to Y ⁶ should be read as X ¹ to X ⁶ .
Further, in (2-605) to (2-629) listed in each table of the International Publication, the organic group having 17 to 51 carbon atoms having a steroid skeleton in the present invention has 12 to 20 carbon atoms having a steroid skeleton. An organic group having 12 to 25 carbon atoms having a steroid skeleton is to be read as an organic group having 17 to 51 carbon atoms having a steroid skeleton. Among them, (2-25) to (2-96), (2-145) to (2-168), (2-217) to (2-240), (2-268) to (2-315) , (2-364) to (2-387), (2-436) to (2-483), or (2-603) to (2-615) are preferred. Particularly preferred combinations are (2-49) to (2-96), (2-145) to (2-168), (2-217) to (2-240), (2-603) to (2- 606), (2-607) to (2-609), (2-611), (2-612) or (2-624).

In formula [II-2], among them, X ⁷ is preferably a single bond, —O—, —CH ₂ O—, —CONH—, —CON (CH ₃ ) — or COO—, more preferably a single bond. A bond, —O—, —CONH— or COO—; X ⁸ is preferably an alkyl group having 8 to 18 carbon atoms.

As the side chain for vertically aligning the liquid crystal, it is preferable to use a structure represented by the formula [II-1] from the viewpoint of enhancing and stabilizing the alignment of the liquid crystal.
The ability of a polyimide precursor having a side chain for vertically aligning the liquid crystal to vertically align the liquid crystal varies depending on the structure of the side chain for vertically aligning the liquid crystal. As the amount of chains increases, the ability to orient liquid crystals vertically increases and decreases as they decrease. Moreover, when it has a cyclic structure, compared with what does not have a cyclic structure, there exists a tendency for the capability to orientate a liquid crystal vertically.

<Photoreactive side chain>
The polyimide precursor of the present invention may have a photoreactive side chain. The photoreactive side chain has a functional group (also referred to as a photoreactive group in this specification) that can react by irradiation with light such as ultraviolet rays (UV) to form a covalent bond. That is, the polyimide precursor of the present invention preferably further has a side chain containing a photoreactive group in the structure.
The photoreactive side chain may be directly bonded to the main chain of the polymer, or may be bonded via a linking group. The photoreactive side chain is represented, for example, by the following formula [III].

In the formula [III], R ⁸ , R ⁹ and R ¹⁰ are as defined above. Among these, R ⁸ is preferably a single bond, —O—, —COO—, —NHCO, or —CONH—. R ⁹ can be formed by a common organic synthetic method, but from the viewpoint of ease of synthesis, a single bond or an alkylene group having 1 to 12 carbon atoms is preferable.

Specific examples of the divalent carbocycle or heterocycle for replacing any —CH ₂ — in R ⁹ include the following.

R ¹⁰ is preferably a methacryl group, an acryl group or a vinyl group from the viewpoint of photoreactivity.
The amount of the photoreactive side chain is preferably within a range in which the response speed of the liquid crystal can be increased by reacting with ultraviolet irradiation to form a covalent bond. In order to further increase the response speed of the liquid crystal It is preferable that it is as many as possible within a range that does not affect other characteristics.

<Polyimide precursor forming liquid crystal aligning agent>
The method for producing a polyimide precursor using the first photoradical-generating diamine and a polyimide obtained by imidizing the polyimide precursor is not particularly limited. Examples thereof include a method of polymerizing a first photoradical-generating diamine and tetracarboxylic dianhydride, a method of polymerizing a first photoradical-generating diamine and other diamines and tetracarboxylic dianhydride, and the like.

The same method as described above may be used for the method of producing a polyimide precursor further having a side chain and / or a photoreactive side chain for vertically aligning the liquid crystal, and a polyimide obtained by imidizing the polyimide precursor. Similarly, the preferred method also includes a first photoradical-generating diamine containing a side chain for vertically aligning liquid crystals and / or a first photoradical-generating diamine containing a photoreactive side chain, and a tetracarboxylic acid diester. A method of polymerizing the anhydride is preferred.

<Synthesis of first photoradical-generating diamine>
In the present invention, the first photo-radical-generating diamine is a dinitro compound through each step, a mononitro compound having an amino group with a protective group that can be removed in the reduction process, or a diamine, which is usually used for reduction. It can be obtained by converting the nitro group to an amino group or deprotecting the protecting group by reaction.

The method for synthesizing the first photoradical-generating diamine synthesis method of the present invention is not particularly limited. For example, the following formula (5) (in formula (5), Ar, R ¹⁰¹ to R ¹⁰⁴ are represented by the above formula (A And the same definition as in the above), and a method of synthesizing the compound by reducing the nitro group and converting it to an amino group.

The method for reducing the nitro group is not particularly limited. For example, palladium-carbon, platinum oxide, Raney nickel, platinum-carbon, rhodium-alumina, platinum sulfide carbon, reduced iron, iron chloride, tin, tin chloride, zinc Or the like as a catalyst, and a method using hydrogen gas, hydrazine, hydrogen chloride, ammonium chloride or the like.
When the structure has an unsaturated bond site, a reduction method in which the unsaturated bond is not reduced can be used.
As long as the unsaturated bond is not reduced, the reduction method is not particularly limited. For example, hydrogen gas is used using reduced iron, tin, tin chloride, poisoned palladium-carbon, poisoned platinum-carbon as a catalyst. , Hydrazine, hydrogen chloride, ammonium chloride and the like.
When the structure has a benzyl bonding site, a reduction method in which the benzyl group is not cleaved can be used.
The reduction method is not limited as long as the benzyl group is not cleaved.For example, platinum black, rhodium-alumina, platinum sulfide carbon, reduced iron, iron chloride, tin, tin chloride, zinc, etc. are used as a catalyst, hydrogen gas, There are methods using hydrazine, hydrogen chloride, ammonium chloride and the like.

As the reaction solvent, a solvent that does not affect the reaction can be used. For example, ester solvents such as ethyl acetate and methyl acetate, aromatic hydrocarbon solvents such as toluene and xylene, aliphatic hydrocarbon solvents such as n-hexane, n-heptane and cyclohexane, 1,2-dimethoxyethane, tetrahydrofuran, Ether solvents such as dioxane, alcohol solvents such as methanol and ethanol, ketone solvents such as 2-butanone and 4-methyl-2-pentanone, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl Examples include aprotic polar solvents such as -2-pyrrolidone and dimethyl sulfoxide, and water. These organic solvents can be used alone or in admixture of two or more.

The reaction temperature can be carried out at a temperature at which the reaction proceeds efficiently as long as it is below the boiling point of the solvent used without decomposition of the raw materials and products. Specifically, a temperature from −78 ° C. to the boiling point of the solvent is preferable, and a temperature from 0 ° C. to the boiling point of the solvent is more preferable from the viewpoint of simplicity of synthesis.

The method for synthesizing the compound of formula (5) is not particularly limited. For example, when R ^{102 of} formula (5) is OR ¹¹¹ (R ¹¹¹ is the same as defined in <6> above). is represented by the following formula (6) (wherein ^{^{(6), Ar, R 101}} , R 103, R 104 , the above formula (a) is the same as the respective definitions in) to synthesize a dinitro product represented by Further, a method of introducing a substituent into the OH group can be mentioned.

The method for introducing a substituent into the OH group is not particularly limited. For example, L ¹ in the following formula (7) (formula (7) is a halogen, an alkanesulfonyloxy group, or an arenesulfonyloxy group, R ¹¹¹ is the same as defined in the above <6>), and a method of reacting an alkyl halide or alkyl sulfonate ester under neutral conditions or alkaline conditions.

Although the reaction solvent and reaction temperature are the same as those described above, an alcohol solvent and water are not preferable because they may react with the raw material.
Examples of the alkyl halide include methyl iodide, ethyl iodide, n-propyl iodide, n-butyl iodide, n-octadecyl iodide, benzyl iodide, bromoethane, 1-bromopropane, 1-bromobutane and 1-bromo. Octadecane, benzyl bromide, chloroethane, 1-chloropropane, 1-chlorobutane, 1-chlorooctadecane, benzyl chloride, methyl methanesulfonate, ethyl methanesulfonate, n-propyl methanesulfonate, n-butyl methanesulfonate, methanesulfonic acid Examples thereof include n-octadecyl and benzyl methanesulfonate.

When the compound represented by the formula (5) is represented by the following formula (8), the compound represented by the above formula (6) and the vinyl ether represented by the following formula (9) are used. Examples of the synthesis method include a reaction in the presence of a catalyst or an acid catalyst.
In the formula (8), Ar, R ¹⁰¹ , R ¹⁰³ , and R ¹⁰⁴ have the same definitions as those in the formula (A), and R ²¹¹ is carbon that is unsubstituted or substituted by a fluorine atom. A linear, branched or cyclic alkyl group having 1 to 18 atoms (wherein —CH ₂ — or —CF ₂ — in the alkyl group is —CH═CH—, or a group selected from the following group G: The groups selected from Group G may not be adjacent to each other) (Group G: —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, divalent Or a divalent heterocyclic ring).
In the formula ^{(9), R 211} is, in the above formula (8) ^is the same as the definition of ^{R 211.}

Examples of the vinyl ether include ethyl vinyl ether, n-butyl vinyl ether, n-octadecyl vinyl ether, diethylene glycol monovinyl ether and the like.
Examples of the acid catalyst include p-toluenesulfonic acid, pyridinium p-toluenesulfonate, methanesulfonic acid, and the like.
The compound represented by the formula (5) is represented by the following formula (10) (in the formula (10), Ar, R ¹⁰¹ , R ¹⁰³ and R ¹⁰⁴ have the same definitions as those in the formula (A)). Is a synthesis method in which the compound represented by the above formula (6) and 3,4-dihydropyran are reacted in the absence of a catalyst or in the presence of an acid catalyst.

When the compound represented by the formula (5) is represented by the following formula (11) (in the formula (11), Ar, R ¹⁰² to R ¹⁰⁴ are the same as the respective definitions in the formula (A). And S and T ₂ are the same as defined in the above <5>), and a dinitro compound represented by the following formula (12) (in the formula (12), L ² is halogen): (13) (In the formula (13), Ar, R ¹⁰² to R ¹⁰⁴ are the same as the respective definitions in the above formula (A), and S and T ₂ are the definitions described in the above <5>. And the like, and a method of reacting an alcohol represented by the same in the presence of an alkali. The reaction solvent and reaction temperature are the same as described above, but a protic solvent such as an alcohol solvent or water can be used unless it reacts with the raw material.

Examples of the compound represented by the formula (12) include 2,4-dinitrofluorobenzene, 2,4-dinitrochlorobenzene, 2,4-dinitrobromobenzene, 2,4-dinitroiodobenzene, 3,5-dinitrochlorobenzene, Examples include 3,5-dinitroiodobenzene, 3,4-dinitrofluorobenzene, 3,4-dinitrochlorobenzene, 2,3-dinitrochlorobenzene, and the like.
There is no particular limitation on the synthesis method of the compound represented by formula (13), for example, in the case ^{where R 102} of Formula (13) is represented by ^{OR 111,} the following equation (14) (Formula (14) in , Ar, R ¹⁰³ and R ¹⁰⁴ are the same as defined in the above formula (A), and S and T ₂ are the same as defined in <5> above. There is a method in which the primary hydroxyl group is protected with a protecting group, a substituent is introduced into the remaining tertiary hydroxyl group, and then the protecting group of the primary hydroxyl group is deprotected.

Examples of the compound represented by the formula (14) include 2-hydroxy-1- (4- (hydroxymethyl) phenyl) -2-methyl-1-propanone, 1-hydroxycyclohexyl (4- (2-hydroxyethyl) phenyl )) Ketone, 1-hydroxycyclohexyl (4-hydroxyphenyl) ketone, 2-hydroxy-1- (4-((2-hydroxyethyl) thio) phenyl) -2-methyl-1-propanone, 2-hydroxy-1 -(4-hydroxyphenyl) -2-methyl-1-propanone, 2-hydroxy-1- (4- (2-hydroxyethoxy) phenyl) -2-methyl-1-propanone, 1- (3,4-dihydroxy Phenyl) -2-hydroxy-2-methyl-1-propanone, 2-hydroxy-1- (4- (2-hydroxyethyl) phenyl) -2- Chill-1-propanone, 2-hydroxy-1- (4- (3-hydroxypropyl) phenyl) -2-methyl-1-propanone and the like.
The protecting group is not particularly limited, and examples thereof include a tetrahydropyranyl group, a benzyl group, a p-methoxybenzyl group, a methoxymethyl group, a trimethylsilyl group, a t-butyldimethylsilyl group, an acetyl group, a benzoyl group, and a trityl group. Is mentioned.

The method for introducing a tertiary hydroxyl group after protecting the primary hydroxyl group of the compound represented by formula (14) is not particularly limited. For example, when R ^{102 in} formula (5) is OR ¹¹¹ , the formula The same conditions as in the case of synthesizing the compound represented by formula (5) from the compound represented by (6) can be used.
There is no restriction | limiting in particular about the deprotection method of each protecting group, General deprotection reaction conditions can be applied.

In the compound represented by the formula (5), the following formula (15) (in the formula (15), Ar, R ¹⁰² to R ¹⁰⁴ have the same definitions as those in the formula (A), and S, T ₂ is the same as defined in the above <5>), the following formula (16) (in formula (16), L ¹ is the same as L ^{1 in} formula (7). And a method of reacting a dinitro compound represented by the formula (13) with an alcohol represented by the formula (13) in the presence of an alkali. The reaction solvent and reaction temperature are the same as described above, but a protic solvent such as an alcohol solvent or water can be used unless it reacts with the raw material.

Examples of the compound represented by the formula (16) include 3,5-dinitrobenzyl chloride, methanesulfonic acid (3,5-dinitrobenzyl), 2,4-dinitrobenzyl chloride, methanesulfonic acid (2,4-dinitrobenzyl). ) And the like.

The compound represented by the formula (5) is represented by the following formula (17) (in the formula (17), Ar, R ¹⁰² to R ¹⁰⁴ , S, and T ₂ are the same as defined in the above <5>) Is represented by the following formula (18) (L ² in formula (18) has the same definition as L ² in formula (12)), and formula (13) Or a reaction of reacting an alcohol represented by formula (19) with an alcohol represented by formula (13) in the presence of a dehydrating condensing agent. The method etc. are mentioned. The reaction solvent and reaction temperature are the same as described above, but a protic solvent such as an alcohol solvent or water can be used unless it reacts with the raw material.

Examples of the compound represented by the formula (18) include 3,5-dinitrobenzoyl chloride.
Examples of the compound represented by the formula (19) include 3,5-dinitrobenzoic acid.
Examples of the dehydrating condensing agent include dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, diisopropylcarbodiimide, 1,1′-carbonyldiimidazole, bis (2-oxo-3-oxazolinidyl) phosphinic acid Chloride, di-2-pyridyl carbonate, triphenyl phosphite, dimethoxy-1,3,5-triazinylmethylmorpholinium, O- (benzotriazol-1-yl) -N, N, N ′, N′-tetramethyluronium tetrafluoroborate, O- (benzotriazol-1-yl) -N, N, N ′, N′-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2 -Thioxo-3-benzoxazolyl) phosphonic acid diphenyl and the like.

<Polyimide precursor having side chain for vertically aligning liquid crystal>
As a method for introducing a side chain for vertically aligning liquid crystals into the polyimide precursor, a diamine having a specific side chain structure is preferably used as a part of the diamine component. In particular, it is preferable to use a diamine represented by the following formula [2] (also referred to as a specific side chain diamine compound).

In the formula [2], X represents a structure represented by the above formula [II-1] or [II-2], n represents an integer of 1 to 4, and 1 is particularly preferable.
As the specific side chain diamine, it is preferable to use a diamine represented by the following formula [2-1] from the viewpoint that a high and stable liquid crystal vertical alignment can be obtained.

X ¹ , X ² , X ³ , X ⁴ , X ⁵ , and n in the above formula [2-1] are the same as defined in each of the above formula [II-1], and Preferable ones are also the same as defined above in Formula [II-1].
In the formula [2-1], m is an integer of 1 to 4. Preferably, it is an integer of 1.
Specific examples of the specific side chain diamine include structures represented by the following formulas [2a-1] to [2a-31].
In the formula, R ¹ represents —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ —, or CH ₂ OCO—, and R ² represents a linear or branched group having 1 to 22 carbon atoms. An alkyl group, a linear or branched alkoxyl group having 1 to 22 carbon atoms, a linear or branched alkyl group having 1 to 22 carbon atoms, or a fluorine-containing alkoxyl group.
R ³ is, -COO -, - OCO -, - CONH -, - NHCO -, - COOCH 2 -, - CH 2 OCO -, - CH 2 O -, - OCH 2 - or CH ₂ - indicates, ^{R 4} Is a linear or branched alkyl group having 1 to 22 carbon atoms, a linear or branched alkoxyl group having 1 to 22 carbon atoms, a linear or branched, fluorine-containing alkyl group having 1 to 22 carbon atoms, or It is a fluorine-containing alkoxyl group.
R ⁵ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH ₂ —, —CH ₂ —, —O—. Or NH—, and R ⁶ represents a fluorine group, a cyano group, a trifluoromethane group, a nitro group, an azo group, a formyl group, an acetyl group, an acetoxy group or a hydroxyl group.
R ⁷ is a linear or branched alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer.
R ⁸ is a linear or branched alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer.
A ₄ is a linear or branched alkyl group having 3 to 20 carbon atoms which may be substituted with a fluorine atom, A ₃ is a 1,4-cyclohexylene group or a 1,4-phenylene group, a ₂ is an oxygen atom or a COO - * (wherein "*" bond marked with binds to _{a 3)} is, _{a 1} is an oxygen atom or a COO - * (However, bond marked with "*" Is bonded to (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.

Of the above formulas [2a-1] to [2a-31], particularly preferred are formula [2a-1] to formula [2a-6], formula [2a-9] to formula [2a-13] 2a-22] to [2a-31].

Examples of the diamine having a specific side chain structure represented by the formula [II-2] include diamines represented by the following formulas [2b-1] to [2b-10].
A ¹ represents an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.

In the above formulas [2b-5] to [2b-10], A ¹ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO— or NH—. A ² represents a linear or branched alkyl group having 1 to 22 carbon atoms or a linear or branched fluorine-containing alkyl group having 1 to 22 carbon atoms.
Said diamine can also be used 1 type or in mixture of 2 or more types according to characteristics, such as a liquid crystal aligning property at the time of setting it as a liquid crystal aligning film, a pretilt angle, a voltage holding characteristic, and a stored charge.

The diamine having a side chain for vertically aligning the liquid crystal is preferably used in an amount of 5 to 50 mol% of the diamine component used for the synthesis of the polyamic acid, more preferably 10 to 40 mol% of the diamine component, and particularly preferably. Is from 15 to 30 mol%.
The use of a diamine having a side chain that vertically aligns the liquid crystal is particularly excellent in terms of improving the response speed and the ability to fix and align the liquid crystal.

<Diamine containing photoreactive side chain>
The diamine having a photoreactive side chain is, for example, a diamine having a side chain represented by the formula [3], and specifically, the following general formula [3] (R in the formula [3] ⁸ , the definitions of R ⁹ and R ¹⁰ are the same as those in the above formula [III], but are not limited thereto.

The bonding position of the two amino groups (—NH ₂ ) in the formula [3] 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, the positions 2, 4 or 3, 5 are more preferable.
Specific examples of the diamine having a photoreactive side chain include the following.
In the formula, X ⁹ and X ¹⁰ are each independently a single bond, —O—, —COO—, —NHCO—, or —NH—, a bonding group that is —NH—, and Y is a carbon atom that may be substituted with a fluorine atom Represents an alkylene group of 1 to 20.

Also, examples of the diamine having a photoreactive side chain include a diamine having a group causing a photodimerization reaction and a group causing a photopolymerization reaction represented by the following formula in the side chain.

In the above formula, Y ₁ represents —CH ₂ —, —O—, —CONH—, —NHCO—, —COO—, —OCO—, —NH—, or —CO—. Y ₂ is an alkylene group having 1 to 30 carbon atoms, a divalent carbocycle or a heterocycle, and one or more hydrogen atoms of the alkylene group, divalent carbocycle or heterocycle are fluorine atoms or organic It may be substituted with a group. In Y ₂ , when the following groups are not adjacent to each other, —CH ₂ — may be substituted with these groups; —O—, —NHCO—, —CONH—, —COO—, —OCO—, —NH—, —NHCONH—, —CO—. Y ₃ represents —CH ₂ —, —O—, —CONH—, —NHCO—, —COO—, —OCO—, —NH—, —CO—, or a single bond. Y ₄ represents a cinnamoyl group. Y ₅ is a single bond, an alkylene group having 1 to 30 carbon atoms, a divalent carbocycle or a heterocycle, and one or more hydrogen atoms of the alkylene group, divalent carbocycle or heterocycle are fluorine atoms Alternatively, it may be substituted with an organic group. In Y ₅ , when the following groups are not adjacent to each other, —CH ₂ — may be substituted with these groups; —O—, —NHCO—, —CONH—, —COO—, —OCO—, —NH—, —NHCONH—, —CO—. Y ₆ represents a photopolymerizable group which is an acrylic group or a methacryl group.

The diamine having a photoreactive side chain depends on the liquid crystal alignment property when it is used as a liquid crystal alignment film, the pretilt angle, the voltage holding property, the characteristics such as accumulated charge, the response speed of the liquid crystal when it is used as a liquid crystal display device, etc. 1 type or 2 types or more can be mixed and used.
The diamine having a photoreactive side chain is preferably used in an amount of 10 to 70 mol%, more preferably 20 to 60 mol%, particularly preferably 30 to 50 mol% of the diamine component used for the synthesis of the polyamic acid. It is.

<Other diamines>
In addition, when manufacturing a polyimide precursor and / or a polyimide, unless the effect of this invention is impaired, other diamines other than the above-mentioned diamine can be used together. Specifically, for example, 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′-diaminobiph Nyl, 3,3′-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 '-Diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'- Sulfonyl dianiline, 3,3′-sulfonyl dianiline, bis (4-aminophenyl) si Lan, 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'-diaminodiphenyl) 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-aminophenyl) 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, -Phenylenebis [(3-aminophenyl) methanone], 1,3-phenylenebis [(4-aminophenyl) methanone], 1,3-phenylenebis [(3-aminophenyl) methanone], 1,4-phenylene Bis (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-phenylene) 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, 10-bis (4-aminophenyl) anthracene, 4,4′-bis (4-aminophenoxy) diphenyl sulfone, 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-aminophene) ) Hexafluoropropane, 2,2'-bis (3-amino-4-methylphenyl) hexafluoropropane, 2,2'-bis (4-aminophenyl) propane, 2,2'-bis (3-amino) Phenyl) propane, 2,2′-bis (3-amino-4-methylphenyl) propane, 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, 1,3-bis (4-aminophenoxy) propane 1,3-bis (3-aminophenoxy) propane, 1,4-bis (4-aminophenoxy) butane, 1,4-bis (3-aminophenoxy) 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, -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, Aromatic diamines such as 11- (4-aminophenoxy) undecane, 1,11- (3-aminophenoxy) undecane, 1,12- (4-aminophenoxy) dodecane, 1,12- (3-aminophenoxy) dodecane Alicyclic diamines such as bis (4-aminocyclohexyl) methane and bis (4-amino-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-diamino Examples thereof include aliphatic diamines such as decane, 1,11-diaminoundecane, and 1,12-diaminododecane.

The above-mentioned other diamines 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>
The tetracarboxylic dianhydride component to be reacted with the diamine component is not particularly limited. Specifically, pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2, 3,6,7-anthracenetetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4-biphenyltetra Carboxylic acid, bis (3,4-dicarboxyphenyl) ether, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxy) Phenyl) methane, 2,2-bis (3,4-dicarboxyphenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (3,4-dicarboxyphenyl) Lopan, 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- Cyclobutanetetracarboxylic 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-cyclobut 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-tetra Hydrinaphthalene-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, Examples thereof include 6-tricarboxynorbornane-2: 3,5: 6 dicarboxylic acid and 1,2,4,5-cyclohexanetetracarboxylic acid. Of course, tetracarboxylic dianhydride may 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.

<Polymerizable compound>
The liquid crystal aligning agent of the present invention may contain a polymerizable compound having a photopolymerizable or photocrosslinkable group at two or more terminals as required. Such a polymerizable compound is a compound having two or more terminals having a group that undergoes photopolymerization or photocrosslinking. Here, the polymerizable compound having a photopolymerizable group is a compound having a functional group that causes polymerization upon irradiation with light. The compound having a photocrosslinking group is at least one selected from a polymer of a polymerizable compound, a polyimide precursor, and a polyimide obtained by imidizing the polyimide precursor by irradiating light. It is a compound having a functional group capable of reacting with the polymer and crosslinking with these polymers. A compound having a photocrosslinkable group also reacts with a compound having a photocrosslinkable group.

By using the liquid crystal aligning agent of the present invention containing the polymerizable compound in a vertical alignment type liquid crystal display element such as an SC-PVA type liquid crystal display, the side chain and the photoreactive property for aligning the liquid crystal vertically are used. Compared to the case of using a polymer having a side chain and this polymerizable compound alone, the response speed can be remarkably improved, and the response speed can be sufficiently improved even with a small amount of the polymerizable compound added. Can do.
Examples of the group that undergoes photopolymerization or photocrosslinking include monovalent groups represented by the following formula (IV).
In the formula, R ¹² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Z ¹ represents a divalent aromatic ring or heterocyclic ring which may be substituted with an alkyl group having 1 to 12 carbon atoms or an alkoxyl group having 1 to 12 carbon atoms. Z ² represents a monovalent aromatic ring or heterocyclic ring which may be substituted with an alkyl group having 1 to 12 carbon atoms or an alkoxyl group having 1 to 12 carbon atoms.

Specific examples of the polymerizable compound include a compound having a photopolymerizable group at each of two ends represented by the following formula (V), a terminal having a photopolymerizable group represented by the following formula (VI), and light. Examples thereof include a compound having a terminal having a cross-linking group and a compound having a photo-crosslinking group at each of two terminals represented by the following formula (VII).
In Formula ^{(V) ~ (VII),} R 12, Z 1 and ^{Z 2} are the same as ^R 12, ^{Z 1} and ^{Z 2} in the formula (IV), ^{Q 1} is a divalent organic group is there. Q ¹ has a ring structure such as a phenylene group (—C ₆ H ₄ —), a biphenylene group (—C ₆ H ₄ —C ₆ H ₄ —), a cyclohexylene group (—C ₆ H ₁₀ —), and the like. Preferably it is. This is because the interaction with the liquid crystal tends to increase.

Specific examples of the polymerizable compound represented by the formula (V) include a polymerizable compound represented by the following formula (R-1). In the following formula (R-1), V and W are each represented by a single bond or —R ¹ O—, and R ¹ is a linear or branched alkylene group having 1 to 10 carbon atoms, preferably , -R ¹ O-, wherein R ¹ is a linear or branched alkylene group having 2 to 6 carbon atoms. V and W may be the same or different, but synthesis is easy when they are the same.

It should be noted that even if the photopolymerization or photocrosslinking group is a polymerizable compound having an acrylate group or a methacrylate group instead of an α-methylene-γ-butyrolactone group, the acrylate group or methacrylate group is a spacer such as an oxyalkylene group. The polymerizable compound having a structure bonded to a phenylene group via a can significantly improve the response speed particularly like the polymerizable compound having α-methylene-γ-butyrolactone groups at both ends. . In addition, a polymerizable compound having a structure in which an acrylate group or a methacrylate group is bonded to a phenylene group through a spacer such as an oxyalkylene group has improved heat stability, and a high temperature, for example, a firing temperature of 200 ° C. or higher. Can withstand enough.

The manufacturing method of the said polymeric compound is not specifically limited, For example, it can manufacture according to the following synthesis example. For example, as for the polymerizable compound represented by the above formula (R-1), taraga and the like represented by the following reaction formula are proposed by P. Talaga, M. Schaeffer, C. Benezra and JLStampf, Synthesis, 530 (1990). According to the method described above, 2- (bromomethyl) propenoic acid can be synthesized by reacting with aldehyde or ketone using SnCl ₂ . Amberlyst 15 is a strongly acidic ion exchange resin manufactured by Rohm and Haas.
In the following formula, R ′ represents a monovalent organic group.

In addition, 2- (bromomethyl) acrylic acid is represented by the following reaction formula: K. Ramarajan, K. Kamalingam, DJO 'Donnell and KDBerlin, Organic Synthesis, vol.61, 56-59 (1983) Can be synthesized by the method proposed in

As a specific synthesis example, when synthesizing a polymerizable compound represented by the above formula (R-1) in which V is —R ¹ O—, W is —OR ² —, and R ¹ and R ² are the same, There are two methods represented by the following reaction formulas.

In the case of synthesizing a polymerizable compound represented by the above formula (R-1) in which R ¹ and R ² are different, a method represented by the following reaction formula can be mentioned.

In the case of synthesizing a polymerizable compound in which V and W are single bonds in the above formula (R-1), a method represented by the following reaction formula may be mentioned.

<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, a diamine component and a tetracarboxylic dianhydride component 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 is soluble. Furthermore, even if it is an organic solvent in which a polyamic acid does not melt | dissolve, you may mix and use the said solvent in the range which the produced | generated 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.

Examples of the organic solvent used in the above reaction include N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide, N-methylformamide, N-methyl-2-pyrrolidone, and N-ethyl-2. -Pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N, N-dimethylpropanamide, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethyl Sulfoxide, γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, Tilcerosolve acetate, butylcellosolve acetate, ethylcellosolve 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 monomethyl 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, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, 3-methoxypropionic acid Methyl, methyl ethyl 3-ethoxypropionate, 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 and the like. These organic solvents may be used alone or in combination.

The method of reacting a diamine component and a tetracarboxylic dianhydride component in an organic solvent is to stir a solution in which the diamine component is dispersed or dissolved in the organic solvent, and the tetracarboxylic dianhydride component as it is or an organic solvent. Dispersing or dissolving in a solution, adding a diamine component to a solution obtained by dispersing or dissolving a tetracarboxylic dianhydride component in an organic solvent, alternating tetracarboxylic dianhydride component and diamine component Any of the methods of adding to 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 reacting the diamine component and the tetracarboxylic dianhydride component is, for example, in the range of −20 ° C. to 150 ° C., preferably −5 ° C. to 100 ° C. In the reaction, for example, the total concentration of the diamine component and the tetracarboxylic dianhydride component is preferably 1 to 50% by mass, and more preferably 5 to 30% by mass with respect to the reaction solution.
The ratio of the total number of moles of the tetracarboxylic dianhydride component 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 usual polycondensation reaction, the closer the molar ratio is to 1.0, the higher the molecular weight of the polyamic acid produced, and 0.8 to 1.2 if it shows a preferred range.

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.
Examples of the method of imidizing the polyamic acid to form a polyimide include thermal imidization in which a polyamic acid solution is heated as it is, and catalytic imidation in which a catalyst is added to the polyamic acid solution. The imidation 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 is preferably carried out while removing water generated by the imidation reaction from the system.
Catalytic imidation of polyamic acid can be carried out by adding a basic catalyst and an acid anhydride to a 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 amic 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.

The polyamic acid ester is a reaction of a tetracarboxylic acid diester dichloride with a diamine similar to the synthesis of the polyamic acid, a suitable condensing agent with a diamine similar to the synthesis of the tetracarboxylic acid diester and the polyamic acid, It can be produced by reacting in the presence of a base or the like. It can also be obtained by previously synthesizing a polyamic acid by the above method and esterifying the carboxylic acid in the amic acid using a polymer reaction. Specifically, for example, tetracarboxylic acid diester dichloride and diamine in the presence of a base and an organic solvent at −20 ° C. to 150 ° C., preferably 0 ° C. to 50 ° C., for 30 minutes to 24 hours, preferably 1 hour. By reacting for ˜4 hours, a polyamic acid ester can be synthesized. The polyimide can also be obtained by heating the polyamic acid ester at a high temperature to promote dealcoholization and ring closure.

In the case where the polyimide precursor or polyimide such as polyamic acid and polyamic acid ester produced is recovered from the reaction solution, 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. Further, when the operation of re-dissolving the recovered polymer in an organic solvent and repeating the reprecipitation recovery is repeated 2 to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons and the like, and it is preferable to use three or more kinds of poor solvents selected from these because purification efficiency is further improved.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention contains the polyimide precursor, and the content of the polyimide precursor is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, and particularly preferably 3 to 10% by mass. It is. Further, when the polymerizable compound having a photopolymerizable or photocrosslinkable group at each of two or more terminals is contained, the content thereof is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the polymer. The amount is preferably 5 to 30 parts by mass.

Moreover, the liquid crystal aligning agent of this invention may contain other polymers other than the said polyimide precursor. At that time, the content of such other polymer in all the components of the polymer is preferably 0.5 to 80% by mass, more preferably 20 to 50% by mass.
The molecular weight of the polymer of the liquid crystal aligning agent is determined by GPC (Gel Permeation Chromatography) in consideration of the strength of the liquid crystal aligning film obtained by applying the liquid crystal aligning agent, the workability at the time of forming the coating film, and the uniformity of the coating film. ) The weight average molecular weight measured by the method is preferably 5,000 to 1,000,000, more preferably 10,000 to 150,000.

The solvent contained in the liquid crystal aligning agent is not particularly limited, and may be the above-described polyimide precursor and a polymerizable compound each having a photopolymerizable or photocrosslinkable group at two or more terminals contained as necessary. What is necessary is just to be able to dissolve or disperse the contained components. For example, the organic solvent which was illustrated by the synthesis | combination of said polyamic acid can be mentioned. Among them, N-methyl-2-pyrrolidone, γ-butyrolactone, N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone and 3-methoxy-N, N-dimethylpropanamide are soluble. To preferred. Of course, two or more kinds of mixed solvents may be used.

In addition, it is preferable to use a solvent that improves the uniformity and smoothness of the coating film mixed with a solvent in which the components of the liquid crystal aligning agent are highly soluble. Examples of such solvents include 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 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 acetate -Butyl, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropion Acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propano 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 Lactic acid methyl ester, lactic acid ethyl ester, lactic acid n-propyl ester, lactic acid n-butyl ester, lactic acid isoamyl ester, 2-ethyl-1-hexanol and the like. A plurality of these solvents may be mixed. These solvents are preferably 5 to 80% by mass, more preferably 20 to 60% by mass, based on the total amount of the solvent contained in the liquid crystal aligning agent.

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 (Asahi Glass Co., Ltd.) and the like. The use ratio of these surfactants is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass with respect to 100 parts by mass of the total amount of the polymer contained in the liquid crystal aligning agent. .

Specific examples of compounds that improve the adhesion between the liquid crystal alignment film and the substrate include functional silane-containing compounds and epoxy group-containing compounds. For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy Carbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-to Ethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltri Methoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-amino Propyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether , Polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetra Glycidyl-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, etc. .

In order to further increase the film strength of the liquid crystal alignment film, a phenol compound such as 2,2′-bis (4-hydroxy-3,5-dihydroxymethylphenyl) propane or tetra (methoxymethyl) bisphenol may be added. . These compounds are preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the polymer contained in the liquid crystal aligning agent.
In addition to the above, the liquid crystal aligning agent is added with a dielectric or conductive material for the purpose of changing the electrical properties such as the dielectric constant or conductivity of the liquid crystal aligning film as long as the effects of the present invention are not impaired. May be.

By applying this liquid crystal aligning agent on a substrate and baking it, a liquid crystal alignment film for vertically aligning liquid crystals can be formed. By using the liquid crystal aligning agent of this invention, the response speed of the liquid crystal display element using the liquid crystal aligning film obtained can be made quick. In addition, the polymerizable compound that has two or more terminal groups that are photopolymerized or photocrosslinked, which may be contained in the liquid crystal aligning agent of the present invention, is not contained in the liquid crystal aligning agent, or the liquid crystal aligning agent. In addition, by incorporating it in the liquid crystal, the photoreaction becomes highly sensitive even in the so-called PSA mode, and a tilt angle can be imparted even with a small amount of ultraviolet irradiation.

For example, a cured film obtained by applying the liquid crystal aligning agent of the present invention to a substrate and then drying and baking as necessary can be used as a liquid crystal aligning film as it is. In addition, the cured film is rubbed, irradiated with polarized light or light of a specific wavelength, or treated with an ion beam, or a voltage is applied to the liquid crystal display element after filling the liquid crystal as a PSA alignment film It is also possible to irradiate with UV. In particular, it is useful to use as an alignment film for PSA.

In this case, the substrate to be used is not particularly limited as long as it is a highly transparent substrate. Glass plate, polycarbonate, poly (meth) acrylate, polyethersulfone, polyarylate, polyurethane, polysulfone, polyether, polyetherketone , Plastic substrates such as trimethylpentene, polyolefin, polyethylene terephthalate, (meth) acrylonitrile, triacetyl cellulose, diacetyl cellulose, and acetate butyrate cellulose 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. Further, in the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used as long as the substrate is only on one side, and in this case, a material that reflects light such as aluminum can be used.

The application method of the liquid crystal aligning agent is not particularly limited, and examples thereof include screen printing, offset printing, flexographic printing, and other printing methods, ink jet methods, spray methods, roll coating methods, dip, roll coater, slit coater, spinner and the like. From the standpoint of productivity, the transfer printing method is widely used industrially, and is preferably used in the present invention.
The coating film formed by applying the liquid crystal aligning agent by the above method can be baked to obtain a cured film. The drying process after applying the liquid crystal aligning agent is not necessarily required, but if the time from application to baking is not constant for each substrate, or if baking is not performed immediately after application, the drying process is performed. It is preferable. The drying is not particularly limited as long as the solvent is removed to such an extent that the shape of the coating film is not deformed by transporting the substrate or the like. For example, a method of drying on a hot plate at a temperature of 40 ° C. to 150 ° C., preferably 60 ° C. to 100 ° C., for 0.5 minutes to 30 minutes, preferably 1 minute to 5 minutes.

The firing temperature of the coating film formed by applying the liquid crystal aligning agent is not limited, and is, for example, 100 to 350 ° C, preferably 120 to 300 ° C, and more preferably 150 ° C to 250 ° C. The firing time is 5 minutes to 240 minutes, preferably 10 minutes to 90 minutes, and more preferably 20 minutes to 90 minutes. Heating can be performed by a generally known method such as a hot plate, a hot air circulating furnace, an infrared furnace, or the like.
The thickness of the liquid crystal alignment film obtained by firing is not particularly limited, but is preferably 5 to 300 nm, more preferably 10 to 100 nm.

<Liquid crystal display element>
In the liquid crystal display element of the present invention, a liquid crystal cell can be produced by a known method after forming a liquid crystal alignment film on a substrate by the above method. Specific examples of the liquid crystal display element include two substrates disposed so as to face each other, a liquid crystal layer provided between the substrates, and a liquid crystal aligning agent provided between the substrate and the liquid crystal layer. A vertical alignment type liquid crystal display device comprising a liquid crystal cell having the above-described liquid crystal alignment film. Specifically, the liquid crystal aligning agent of the present invention is applied onto two substrates and baked to form a liquid crystal aligning film, and the two substrates are arranged so that the liquid crystal aligning films face each other. A liquid crystal layer composed of liquid crystal is sandwiched between two substrates, that is, a liquid crystal layer is provided in contact with the liquid crystal alignment film, and ultraviolet rays are applied while applying a voltage to the liquid crystal alignment film and the liquid crystal layer. This is a vertical alignment type liquid crystal display device including a liquid crystal cell to be manufactured.

The liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention is used to irradiate ultraviolet rays while applying voltage to the liquid crystal alignment film and the liquid crystal layer to polymerize the polymerizable compound, and the photoreactive property of the polymer. By reacting the side-chains or the photoreactive side chain of the polymer with the polymerizable compound, the alignment of the liquid crystal is more efficiently fixed, and the liquid crystal display device is remarkably excellent in response speed.

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. As a specific example, the thing similar to the board | substrate described with the said liquid crystal aligning film can be mentioned. A substrate provided with a conventional electrode pattern or protrusion pattern may be used. However, in the liquid crystal display element of the present invention, since the liquid crystal aligning agent of the present invention is used, a line of 1 to 10 μm, for example, is formed on one side substrate. / Slit electrode pattern is formed, and it is possible to operate even in the structure where slit pattern or projection pattern is not formed on the counter substrate. The liquid crystal display element of this structure can simplify the process at the time of manufacture and has high transmittance. Can be obtained.

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 display element, it is common to use a substrate as described above. However, in a reflective liquid crystal display element, if only one substrate is used, an opaque substrate such as a silicon wafer may be used. Is possible. At that time, a material such as aluminum that reflects light can be used for the electrode formed on the substrate.

The liquid crystal material constituting the liquid crystal layer of the liquid crystal display element of the present invention is not particularly limited, and a liquid crystal material used in a conventional vertical alignment method, for example, a negative type such as MLC-6608 or MLC-6609 manufactured by Merck & Co., Inc. Liquid crystal can be used. As the PSA mode, for example, a liquid crystal containing a polymerizable compound represented by the following formula can be used.

In the present invention, a known method can be used as a method of sandwiching the liquid crystal layer between two substrates. For example, a pair of substrates on which a liquid crystal alignment film is formed is prepared, and spacers such as beads are dispersed on the liquid crystal alignment film on one substrate so that the surface on which the liquid crystal alignment film is formed is on the inside. Then, the other substrate is bonded, and liquid crystal is injected under reduced pressure to seal. Also, a pair of substrates on which a liquid crystal alignment film is formed are prepared, and spacers such as beads are dispersed on the liquid crystal alignment film on one substrate, and then liquid crystal is dropped, and then the surface on which the liquid crystal alignment film is formed A liquid crystal cell can also be produced by a method in which the other substrate is bonded to each other so as to be inside, and sealing is performed. The thickness of the spacer is preferably 1 to 30 μm, more preferably 2 to 10 μm.

The step of producing a liquid crystal cell by irradiating ultraviolet rays while applying a voltage to the liquid crystal alignment film and the liquid crystal layer includes, for example, applying an electric field between the electrodes installed on the substrate to apply an electric field to the liquid crystal alignment film and the liquid crystal layer. And applying ultraviolet rays while maintaining this electric field. Here, the voltage applied between the electrodes is, for example, 5 to 30 Vp-p, preferably 5 to 20 Vp-p. The irradiation amount of ultraviolet rays is, for example, 1 to 60 J, preferably 40 J or less, and the smaller the irradiation amount of ultraviolet rays, the lowering of reliability caused by the destruction of the members constituting the liquid crystal display element can be suppressed, and the irradiation time of ultraviolet rays can be reduced. This is preferable because the manufacturing efficiency is increased.

As described above, when ultraviolet rays are irradiated while applying a voltage to the liquid crystal alignment film and the liquid crystal layer, the polymerizable compound reacts to form a polymer, and the direction in which the liquid crystal molecules are tilted is stored by this polymer. Thus, the pretilt angle of the obtained liquid crystal display element can be set to a desired value, and the response speed can be increased. In addition, a polyimide precursor having a side chain for vertically aligning liquid crystal and a photoreactive side chain when irradiated with ultraviolet rays while applying a voltage to the liquid crystal alignment film and the liquid crystal layer, and the polyimide precursor as an imide Since the photoreactive side chains of at least one polymer selected from the polyimide obtained by the reaction or the photoreactive side chains of the polymer react with the polymerizable compound, the liquid crystal display element obtained The response speed can be increased.

The pretilt angle of the liquid crystal display element depends on the liquid crystal alignment film used, that is, the liquid crystal aligning agent used, the polyimide precursor used, and the first photoradical-generating diamine used. As described above, by using the polyimide precursor of the present invention, particularly a polyimide precursor having a relatively large amount of radical generation, the amount of radical generation during UV irradiation increases. In addition, when the amount of radical generation increases, the reaction of the above-described polymerizable compound is promoted, so that in the case of the same wavelength, the pretilt angle of the liquid crystal display element obtained with a small irradiation amount can be set to a desired value. In addition, the response speed can be increased.
In general, the pretilt angle of a liquid crystal display element tends to be farther from 90 ° as the amount of UV irradiation in forming the liquid crystal display element increases.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples.
In the following, the abbreviations and structures of the compounds and the measuring methods of the respective properties are as follows.

(solvent)
DMF: N, N-dimethylformamide THF: Tetrahydrofuran NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve (diamine)
DA-A: 1- (4- (2- (2,4-diaminophenoxy) ethoxy) phenyl) -2-methoxy-2-methylpropan-1-one DA-1: 1- (4- (2- ( 2,4-diaminophenoxy) ethoxy) phenyl) -2-hydroxy-2-methylpropan-1-one DA-2: 4- (4- (4-heptylcyclohexyl) phenoxy) benzene-1,3-diamine 3AMPDA: 3,5-diamino-N- (pyridin-3-ylmethyl) benzamide (acid dianhydride)
BODA: Bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride (additive)
3AMP: 3-picolylamine

[ ¹ H NMR]
Apparatus: Fourier transform type superconducting nuclear magnetic resonance apparatus (FT-NMR) INOVA-400 (manufactured by Varian) 400 MHz
Solvent: deuterated chloroform (CDCl ₃ ) or deuterated dimethyl sulfoxide (DMSO-d ₆ )
Standard substance: Tetramethylsilane (TMS)
Integration count: 8 or 32.

[ ¹³ C { ¹ H} NMR]
Apparatus: Fourier transform type superconducting nuclear magnetic resonance apparatus (FT-NMR) INOVA-400 (manufactured by Varian) 100 MHz
Solvent: chloroform (CDCl _3), or deuterated dimethyl sulfoxide _(DMSO-d 6)
Standard substance: Tetramethylsilane (TMS)
Integration count: 256.

[Molecular weight]
The molecular weights of the polyimide precursor and the imidized polymer are measured by a GPC (room temperature gel permeation chromatography) apparatus, and the number average molecular weight (hereinafter also referred to as Mn) and the weight average molecular weight as polyethylene glycol and polyethylene oxide equivalent values (hereinafter also referred to as Mn). Hereinafter, it is also referred to as Mw).
GPC device: Room temperature gel permeation chromatography (GPC) device (SSC-7200) manufactured by Senshu Scientific Co., Ltd.
Column: manufactured by Shodex (series of KD803 and KD805)
Column temperature: 50 ° C
Eluent: N, N-dimethylformamide (as additives, lithium bromide-hydrate (LiBr · H ₂ O) 30 mmol / L, phosphoric acid / anhydrous crystals (o-phosphoric acid) 30 mmol / L, tetrahydrofuran) (THF) is 10 ml / L)
Flow rate: 1.0 ml / min.

Standard sample for preparing calibration curve: TSK standard polyethylene oxide (weight average molecular weight (Mw) about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation, and polyethylene glycol (peak top manufactured by Polymer Laboratories) Molecular weight (Mp) about 12,000, 4,000, 1,000). In order to avoid the overlapping of peaks, the measurement was performed by mixing four types of 900,000, 100,000, 12,000, and 1,000, and three types of 150,000, 30,000, and 4,000. Two samples of mixed samples are measured separately.

[Measurement of imidization rate]
The imidation ratio of polyimide in the synthesis example was measured as follows. 20 mg of polyimide powder was put into an NMR sample tube (NMR sampling tube standard, φ5 (manufactured by Kusano Kagaku)), and deuterated dimethyl sulfoxide (DMSO-d ₆ , 0.05% TMS (tetramethylsilane) mixed product) (1. 0 ml) was added and completely dissolved by sonication. This solution was measured for proton NMR at 500 MHz with an NMR measuring instrument (JNW-ECA500) (manufactured by JEOL Datum). The imidation rate is determined based on protons derived from structures that do not change before and after imidation as reference protons, and the peak integrated value of these protons and proton peaks derived from NH groups of amic acid that appear in the vicinity of 9.5 ppm to 10.0 ppm. It calculated | required by the following formula | equation using the integrated value.
Imidization rate (%) = (1−α · x / y) × 100
In the above formula, x is a proton peak integrated value derived from NH group of amic acid, y is a peak integrated value of reference proton, α is one NH group proton of amic acid in the case of polyamic acid (imidation rate is 0%) Is the number ratio of the reference proton to.

[Synthesis of diamine compound]
(Control Synthesis Example 1: Synthesis of aromatic diamine compound (DA-1))

Step 1: Synthesis of 1- (4- (2,4-dinitrophenoxy) ethoxy) phenyl) -2-hydroxy-2-methylpropanone Into a 2 L four-necked flask equipped with a stirrer and a nitrogen inlet tube, 2,4- 100.0 g of dinitrofluorobenzene ([Mw: 186.10 g / mol], 0.538 mol), 120.6 g of 2-hydroxy-4 ′-(2-hydroxyethoxy) -2-methylpropiophenone ([Mw : 224.25 g / mol], 0.538 mol), 81.7 g of triethylamine ([Mw: 101.19 g / mol], 0.807 mol) and 1000 g of THF were added and refluxed for 24 hours. After completion of the reaction, the mixture was concentrated on a rotary evaporator, ethyl acetate was added, and this was washed several times with pure water and physiological saline, and then dried over anhydrous magnesium sulfate.

After removing anhydrous magnesium sulfate by filtration and concentrating with a rotary evaporator, recrystallization with ethyl acetate and normal hexane gave 157.0 g of milky white solid ([Mw: 390.34 g / mol], 0.402 mol, yield) : 75%). It was confirmed by a nuclear magnetic resonance spectrum ( ¹ H-NMR spectrum) of an intramolecular hydrogen atom. The measurement data is shown below.
¹ H NMR (400 MHz, CDCl ₃ ) δ: 8.75 (Ar: 1H), 8.48-8.45 (Ar: 1H), 8.09-8.05 (Ar: 2H), 7.34 To 7.31 (Ar: 1H) 7.00 to 6.96 (Ar: 2H), 4.65 to 4.63 (-CH2-: 2H), 4.52 to 4.49 (-CH2-: 2H) ), 4.16 (—OH: 1H), 1.66 to 1.60 (—CH3 × 2, 6H) Total: 18H.

Step 2 Synthesis of 1- (4- (2,4-diaminophenoxy) ethoxy) phenyl) -2-hydroxy-2-methylpropanone (DA-1) The dinitrobenzene derivative obtained in Step 1 was added to a 1 L four-necked flask in 100. Weigh 10.0 g ([Mw: 390.34 g / mol], 0.256 mol) and 10.0 g of iron-doped platinum carbon (3 wt% manufactured by Evonic), add 500 ml of THF, and perform vacuum degassing and hydrogen replacement. Fully conducted and allowed to react for 24 hours at room temperature.

After completion of the reaction, platinum carbon was removed with a PTFE membrane filter, and the filtrate was removed with a rotary evaporator to precipitate a solid. The obtained solid was heated and washed with isopropyl alcohol, and further dried under reduced pressure, whereby 72.7 g ([Mw: 330.38 g / mol], 0.220 mol yield) of the target compound was a light pink solid. : 86%). ^{The 1} H-NMR spectrum measurement data is shown below.
¹ H NMR (400 MHz, CDCl ₃ ) δ: 8.09 to 8.05 (Ar: 2H), 7.01 to 6.97 (Ar: 2H), 6.70 to 6.68 (Ar: 1H) 6.12 (Ar: 1H), 4.36 to 4.33 (-CH2-: 2H), 4.29 to 4.27 (-OH & -CH2-: 3H), 3.7 (-NH2: 2H) ), 3.39 (—NH2: 2H), 1.64 to 1.63 (—CH3 × 2: 6H) Total: 22H.

<Synthesis Example 1>
Aromatic diamine compound (DA-A): Synthesis of 1- (4- (2- (2,4-diaminophenoxy) ethoxy) phenyl) -2-methoxy-2-methylpropan-1-one An aromatic diamine compound (DA-A) was synthesized by the following route. The aromatic diamine compound (DA-A) corresponds to the above-mentioned specific diamine compound.

First step: 2-hydroxy-2-methyl-1- (4- (2-((tetrahydro-2H-pyran-2-yl) oxy) ethoxy) phenyl) propan-1-one (DA-A-1) Synthesis of

IRGACURE 2959 (2-hydroxy-1- (4- (2-hydroxyethoxy) phenyl) -2-methylpropan-1-one, 50.0 g, 223 mmol) was dissolved in THF (200 g), and p-toluenesulfonic acid was dissolved. Monohydrate (0.424 g, 2.23 mmol) was added, and 3,4-dihydro-2H-pyran (23.4 g, 279 mmol) was added dropwise over 10 minutes and reacted at room temperature for 3 hours. Thereafter, the reaction solution is filtered, and the filtrate is concentrated to give 2-hydroxy-2-methyl-1- (4- (2-((tetrahydro-2H-pyran-2-yl) oxy) ethoxy) phenyl). A crude propan-1-one was obtained (green liquid, 73.7 g).
¹ H NMR (DMSO-d ₆ ): δ 8.22 (d, J = 9.0 Hz, 2H, C ₆ H ₄ ), 7.02 (d, J = 9.0 Hz, 2H, C ₆ H ₄ ), 5.68 (s, 1H , OH), 4.66 (t, J = 3.6 Hz, 1H, CH), 4.22 (t, J = 4.8 Hz, 2H, CH ₂ ), 4.07-3.92 (m, 1H, CH ₂ ), 3.81-3.70 (m , 2H, CH ₂ ), 3.47-3.42 (m, 1H, CH ₂ ), 1.77-1.41 (m, 6H, CH ₂ ), 1.40 (s, 6H, C (CH ₃ ) ₂ ). ¹³ C { ¹ H } NMR (DMSO-d ₆ ): δ 202.4, 162.3, 162.1, 132.9, 127.9, 114.2, 98.5, 93.9, 93.6, 77.1, 70.2, 67.8, 65.5, 63.1, 62.0, 61.7, 59.9, 30.7, 30.6, 28.6, 25.6, 25.4, 20.8, 19.5 (each s).

Second step: 2-methoxy-2-methyl-1- (4- (2-((tetrahydro-2H-pyran-2-yl) oxy) ethoxy) phenyl) propan-1-one (DA-A-2) Synthesis of

Sodium hydride (57.1 wt% purity, 15.0 g, 357 mmol) was suspended in THF (448 g) and cooled to 3 ° C., and DA-A-1 crude product (73.3 g) was dissolved in THF (138 g). The dissolved solution was added dropwise at 3 ° C. over 15 minutes. Thereafter, the mixture was stirred for 30 minutes, methyl iodide (41.0 g, 357 mmol) was added dropwise over 5 minutes, and the mixture was stirred at room temperature for 22 hours. Then, water (660 g) and toluene (586 g) were added in this order at room temperature and stirred. The aqueous layer was discarded, the organic layer was washed twice with water (650 g), and the organic layer was concentrated to give 2-methoxy. A crude product of -2-methyl-1- (4- (2-((tetrahydro-2H-pyran-2-yl) oxy) ethoxy) phenyl) propan-1-one was obtained (brown liquid, 80.1 g). .
^{_{1 H NMR (DMSO-d 6}} ): δ 8.19 (d, J = 8.8 Hz, 2H, C 6 H 4), 7.06 (d, J = 8.8 Hz, 2H, C 6 H 4), 4.66 (s, 1H , CH), 4.24-4.22 (m, 2H, CH ₂ ), 3.97-3.92 (m, 1H, CH), 3.80-3.72 (m, 2H, CH ₂ ), 3.47-3.43 (m, 1H, CH), 3.08 (s, 3H, CH ₃ ), 1.71-1.60 (m, 2H, CH ₂ ), 1.53-1.46 (m, 4H, (CH ₂ ) ₂ ), 1.41 (s, 6H, C (CH ₃ ) ₂ ) ¹³ C { ¹ H} NMR (DMSO-d ₆ ): δ 201.35, 162.6, 132.2, 127.5, 114.6, 98.5, 83.1, 67.9, 65.5, 61.7, 52.2, 30.6, 24.5, 24.9, 19.4 (each s).

Third step: Synthesis of 1- (4- (2-hydroxyethoxy) phenyl) -2-methoxy-2-methylpropan-1-one (DA-A-3)

In a solution of p-toluenesulfonic acid monohydrate (0.469 g, 2.46 mmol) dissolved in a mixed solvent of methanol (397 g) and THF (80 g), a crude product of DA-A-2 (79.4 g ) In THF (79 g) was added at room temperature over 3 minutes. Thereafter, the mixture was stirred for 2 hours, and the reaction mixture was concentrated to confirm that 20% of the raw material remained. Thereafter, THF (350 g), water (290 g), and p-toluenesulfonic acid monohydrate (2.53 g, 13.3 mmol) were added to the residue, and the mixture was stirred at room temperature for 14 hours. Thereafter, toluene (350 g) is added, and after stirring, the aqueous layer is discarded. The organic layer is washed twice with water (340 g), and the organic layer is concentrated to give 1- (4- (2-hydroxyethoxy) phenyl. ) -2-Methoxy-2-methylpropan-1-one crude was obtained (brown liquid, 50.5 g).
¹ H NMR (DMSO-d ₆ ): δ 8.20 (d, J = 9.0 Hz, 2H, C ₆ H ₄ ), 7.05 (d, J = 9.0 Hz, 2H, C ₆ H ₄ ), 4.96 (t, J = 5.4 Hz, 1H, OH), 4.10 (t, J = 4.8 Hz, 2H, CH ₂ ), 3.97-3.92 (dt, J = 5.4, 4.8 Hz, 2H, CH ₂ ), 3.09 (s, 3H, CH _{. 3), 1.42 (s,} 6H, C (CH 3) 2) 13 C {1 H} NMR (DMSO-d 6): δ 200.3, 162.8, 132.2, 127.4, 114.6, 83.1, 70.2, 59.8, 52.2, 24.9 (each s).

Fourth step: Synthesis of 1- (4- (2- (2,4-dinitrophenoxy) ethoxy) phenyl) -2-methoxy-2-methylpropan-1-one (DA-A-4)

The crude DA-A-3 (45.7 g) was dissolved in DMF (79.9 g), 1-fluoro-2,4-dinitrobenzene (35.7 g, 192 mmol), and triethylamine (29.1 g, 288 mmol) and stirred at room temperature for 24 hours. Thereafter, toluene (274 g) and water (274 g) were added and stirred, the aqueous layer was discarded, the organic layer was washed twice with water (274 g), and the organic layer was concentrated. Subsequently, the residue was purified by silica gel column chromatography (solvent: toluene / ethyl acetate = 3/1 (v / v), Rf = 0.3), and the eluate was concentrated. Then, 2-propanol (193 g) was added to the residue, and the mixture was stirred and filtered at room temperature. Again, the filtrate was added with 2-propanol (400 g), stirred and filtered at 60 ° C., and the filtrate was dried. 1- (4- (2- (2,4-dinitrophenoxy) ethoxy) phenyl) -2-methoxy-2-methylpropan-1-one (light brown solid, 29.2 g, 30% yield) (4 steps)).
¹ H NMR (DMSO-d ₆ ): δ 8.73 (d, J = 2.8 Hz, 1H, C ₆ H ₃ ), 8.50 (dd, J = 9.2, 2.8 Hz, 1H, C ₆ H ₃ ), 8.16 (d , J = 8.8 Hz, 2H, C 6 H 4), 7.65 (d, J = 9.2 Hz, 1H, C 6 H 3), 7.37 (d, J = 8.8 Hz, 2H, C 6 H 4), 4.71- 4.69 (m, 2H, CH ₂ ), 4.45-4.43 (m, 2H, CH ₂ ), 3.04 (s, 3H, CH ₃ ), 1.37 (s, 6H, C (CH ₃ ) ₂ ). ¹³ C { ¹ H} NMR (DMSO-d ₆ ): δ 201.4, 162.2, 156.0, 140.3, 139.2, 132.2, 129.7, 127.8, 121.6, 116.4, 114.7, 83.1, 69.6, 66.5, 52.2, 24.8 (each s).

Step 5: Synthesis of 1- (4- (2- (2,4-dinitrophenoxy) ethoxy) phenyl) -2-methoxy-2-methylpropan-1-one (DA-A)

DA-A-4 (10.0 g, 24.7 mmol) was dissolved in THF, 1% platinum-carbon (0.2% Fe-doped, 59.5 wt% water content, 0.62 g) was added, and the hydrogen pressure was reduced to 0. The mixture was stirred at 2 to 0.5 MPa. After 3 hours, the completion of the reaction was confirmed by HPLC, the catalyst was filtered, the filtrate was concentrated, toluene (30 g) was added, the mixture was stirred at 65 ° C. for 30 minutes, cooled to 0 ° C., and the precipitated solid was removed. Filtration and drying gave 1- (4- (2- (2,4-diaminophenoxy) ethoxy) phenyl) -2-methoxy-2-methylpropan-1-one (purple solid, 7.23 g , Yield 85%)
¹ H NMR (DMSO-d ₆ ): δ 8.20 (d, J = 9.2 Hz, 2H, C ₆ H ₄ ), 7.08 (d, J = 9.2 Hz, 2H, C ₆ H ₄ ), 6.57 (d, J = 8.4 Hz, 1H, C ₆ H ₃ ), 5.96 (d, J = 2.4 Hz, 1H, C ₆ H ₃ ), 5.77 (dd, J = 9.2, 2.8 Hz, 1H, C ₆ H ₃ ), 4.48 ( s, 2H, NH ₂ ), 4.42 (s, 2H, NH ₂ ), 4.34-4.32 (m, 2H, CH ₂ ), 4.12-4.10 (m, 2H, CH ₂ ), 3.08 (s, 3H, CH ₃ ), 1.41 (s, 6H, C (CH ₃ ) ₂ ). ¹³ C { ¹ H} NMR (DMSO-d ₆ ): δ 201.4, 162.6, 144.2, 139.6, 137.4, 132.3, 127.6, 116.3, 114.7, 102.7 , 101.8, 83.1, 68.9, 67.4, 52.2, 24.9 (each s).

(Examples 1 and 2)
<Synthesis of liquid crystal alignment agent>
BODA (10.01 g, 40.0 mmol), 3AMPDA (4.85 g, 20.0 mmol), DA-A (13.78 g, 40.0 mmol), DA-2 (15.22 g, 40.0 mmol) were mixed with NMP ( 166.2 g), and after reacting at 60 ° C. for 5 hours, CBDA (11.57 g, 59.0 mmol) and NMP (55.4 g) were added and reacted at 40 ° C. for 10 hours to obtain a polyamic acid solution. Obtained.
After adding NMP to this polyamic acid solution (250 g) and diluting to 6.5% by mass, acetic anhydride (45.9 g) and pyridine (14.2 g) were added as imidization catalysts, and the mixture was reacted at 70 ° C. for 3 hours. It was. This reaction solution was poured into methanol (3300 ml), and the resulting precipitate was filtered off. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (A). The imidation ratio of this polyimide was 72%, the number average molecular weight was 14,000, and the weight average molecular weight was 38000.
NMP (44.0 g) was added to the obtained polyimide powder (A) (6.0 g), and the mixture was dissolved by stirring at 70 ° C. for 20 hours. 3AMP (1 mass% NMP solution) 6.0g, NMP (4.0g), and BCS (40.0g) were added to this solution, and the liquid crystal aligning agent (A1) was obtained by stirring at room temperature for 5 hours.

<Production of liquid crystal cell>
Using the liquid crystal aligning agent (A1) obtained in Example 1, a liquid crystal cell was produced according to the procedure shown below.
The liquid crystal aligning agent (A1) obtained in 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 μm × 300 μm and a line / space of 5 μm was formed, After drying for 90 seconds on this hot plate, baking was performed in a hot air circulation oven at 200 ° C. for 30 minutes to form a liquid crystal alignment film having a thickness of 100 nm.
Moreover, after spin-coating the liquid crystal aligning agent (A1) on the ITO surface in which the electrode pattern is not formed, and drying for 90 seconds with a hot plate at 80 ° C., baking is performed in a hot air circulation oven at 200 ° C. for 30 minutes, A liquid crystal alignment film having a thickness of 100 nm was formed.
After spraying 4 μm bead spacers on the liquid crystal alignment film of one of the two substrates, a sealant (solvent type thermosetting epoxy resin) was printed thereon. Next, the surface of the other substrate on which the liquid crystal alignment film was formed was faced inward and bonded to the previous substrate, and then the sealing agent was cured to produce an empty cell. A liquid crystal cell was produced by injecting a polymerizable compound-containing liquid crystal MLC-3023 (trade name, manufactured by Merck & Co., Inc.) into the empty cell by a reduced pressure injection method.

<Measurement of pretilt angle>
<< UV irradiation: 6J / cm ² or 10J / ^cm 2 >>
In a state where a DC voltage of 15 V was applied to the obtained liquid crystal cell, the liquid crystal cell was irradiated with UV through a 365 nm bandpass filter from the outside of the liquid crystal cell at 6 J / cm ² or 10 J / cm ² . The illuminance of UV was measured using UV-MO3A manufactured by ORC. Thereafter, for the purpose of deactivating the unreacted polymerizable compound remaining in the liquid crystal cell, UV (UV lamp: FLR40SUV32 /) was used with a UV-FL irradiation apparatus manufactured by Toshiba Lighting & Technology Co., Ltd. in a state where no voltage was applied. A-1) was irradiated for 30 minutes.
Thereafter, the pretilt angle of the pixel portion of the cell after UV irradiation was measured. The pretilt angle was measured using an LCD analyzer LCA-LUV42A manufactured by Meiryo Technica. The results are shown in Table 1.

<Measurement of response speed>
First, the obtained liquid crystal cell was disposed between a pair of polarizing plates in a measuring apparatus configured in the order of a backlight, a pair of polarizing plates in a crossed Nicol state, and a light amount detector. At this time, the pattern of the ITO electrode in which the line / space was formed was set at an angle of 45 ° with respect to the crossed Nicols. Then, a rectangular wave having a voltage of ± 7 V and a frequency of 1 kHz is applied to the liquid crystal cell, and the change until the luminance observed by the light amount detector is saturated is captured by an oscilloscope, and the luminance when no voltage is applied is obtained. A voltage of 0% and ± 7 V was applied, the value of saturated luminance was taken as 100%, and the time taken for the luminance to change from 10% to 90% was taken as the response speed.

(Control Examples 1 and 2)
<Synthesis of control liquid crystal aligning agent>
In the same manner as in Example 1, except for using DA-1 (13.22 g, 40.0 mmol) instead of “DA-A (13.78 g, 40.0 mmol)” in Example 1, the control liquid crystal aligning agent ( B1) was synthesized. Specifically, the control liquid crystal aligning agent (B1) was synthesized as follows.
That is, BODA (10.01 g, 40.0 mmol), 3AMPDA (4.85 g, 20.0 mmol), DA-1 (13.22 g, 40.0 mmol), DA-2 (15.22 g, 40.0 mmol) were added. After dissolving in NMP (164.6 g) and reacting at 60 ° C. for 5 hours, CBDA (11.57 g, 59.0 mmol) and NMP (54.9 g) were added and reacted at 40 ° C. for 10 hours to polyamic acid. A solution was obtained.
After adding NMP to this polyamic acid solution (250 g) and diluting to 6.5% by mass, acetic anhydride (46.4 g) and pyridine (14.4 g) were added as an imidation catalyst, and the mixture was reacted at 70 ° C. for 3 hours. It was. This reaction solution was poured into methanol (3300 ml), and the resulting precipitate was filtered off. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (B). The imidation ratio of this polyimide was 73%, the number average molecular weight was 23000 and the weight average molecular weight was 64000.
NMP (44.0 g) was added to the obtained polyimide powder (B) (6.0 g), and the mixture was dissolved by stirring at 70 ° C. for 20 hours. 3AMP (1 mass% NMP solution) 6.0g, NMP (4.0g), and BCS (40.0g) were added to this solution, and the liquid crystal aligning agent (B1) was obtained by stirring at room temperature for 5 hours.

<Preparation of Control Liquid Crystal Cell and Measurement of Pretilt Angle and Response Speed>
A control liquid crystal cell was prepared in the same manner as in Example 1 except that the liquid crystal aligning agent (B1) was used instead of the “liquid crystal aligning agent (A1)” in Example 1.
Moreover, about the obtained control liquid crystal cell, operation similar to an Example was performed and the pretilt angle and the response speed were measured. The results are shown in Table 1.

Table 1 shows the following.
That is, the control liquid crystal cell of Control Examples 1 and 2 (using the control liquid crystal aligning agent (B1) obtained using the control diamine (DA-1)) and Examples 1 and 2 (aromatic diamine compound (DA-A)) When the liquid crystal cell of Example 1 and 2 is irradiated with the same amount of light, the pretilt angle is separated from 90 °. ing.
In addition, it can be seen that the liquid crystal cells of Examples 1 and 2 can have a desired pretilt angle and a desired response speed at a lower UV irradiation amount than the liquid crystal cells of Control Examples 1 and 2. This is because the aromatic diamine compound (DA-A) used in the liquid crystal cells of Examples 1 and 2 has a larger amount of radical generation during UV irradiation than the diamine (DA-1) used in the control liquid crystal cell. Depends on.
Since the liquid crystal cells of Examples 1 and 2 may require less UV irradiation at the same wavelength than the control liquid crystal cells of Control Examples 1 and 2, liquid crystal damage due to shortening of the UV irradiation time can be reduced. Costs can be reduced.

Claims

A polyimide precursor using a first photoradical-generating diamine,
From the second polyimide precursor formed under the same conditions as the polyimide precursor, except that the first photo radical generating diamine is replaced with the second photo radical generating diamine represented by the formula (1), the same conditions are used. The said polyimide precursor characterized by having a large amount of radical generation at the time of light irradiation below.
The polyimide precursor according to claim 1, wherein a wavelength of light upon the light irradiation is 300 nm to 400 nm.
The polyimide precursor according to claim 1 or 2, wherein the first photoradical-generating diamine is 0.1 to 100 mol% in 100 mol% of the total diamine constituting the polyimide precursor.
The first photoradical-generating diamine has the formula (A)
(In the formula, Ar represents an aromatic hydrocarbon group which may have a substituent,
R 101 represents a divalent organic group,
R 102 to R 104 each independently represents a monovalent organic group)
The polyimide precursor according to any one of claims 1 to 3, which has the following structure.
-R 101 -is -T 1 -ST 2-
(Where
T 1 and T 2 are each independently a single bond, —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, —CH 2 O—, —N (CH 3 ). -, -CON (CH 3 )-, or -N (CH 3 ) CO-,
S is a single bond or an alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted by a fluorine atom (—CH 2 — or —CF 2 — in an alkylene group is —CH═CH—, or A group selected from group G (wherein the groups selected from group G are not adjacent to each other) (group G: —O—, —COO—, —OCO—, —NHCO—, -CONH-, -NH-, divalent carbocycle or divalent heterocycle)))
The polyimide precursor of Claim 4 represented by these.
Wherein among R 102 ~ R 104, any one, -OR 111 (R 111 represents an unsubstituted or having 1 to 20 carbon atoms which is substituted by fluorine atom straight or branched chain or cyclic alkyl group ( —CH 2 — or —CF 2 — in the alkyl group is replaced by —CH═CH— or a group selected from the following group G (provided that the groups selected from group G are not adjacent to each other): May be substituted (group G: —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, a divalent carbocycle or a divalent heterocycle). ) And
The other two are each independently a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, —OR 112 (R 112 is an unsubstituted or substituted carbon atom having 1 to 20 carbon atoms. A linear, branched or cyclic alkyl group, or a group selected from the group consisting of optionally substituted aryl groups having 6 to 20 carbon atoms), a benzyl group, or a phenethyl group The polyimide precursor according to claim 4 or 5, wherein when the other two are the alkyl group or -OR 112 , they may be bonded to each other to form a ring.
The polyimide precursor according to any one of claims 4 to 6, wherein Ar is a phenylene group.
The first photoradical-generating diamine is represented by the following formula (2) (wherein Ar and R 101 to R 104 have the same definition as described above): The polyimide precursor as described.
The polyimide precursor according to any one of claims 1 to 8, wherein the first photoradical-generating diamine is represented by the following formula (3).
10. The polyimide precursor according to claim 1, further comprising a side chain for vertically aligning the liquid crystal.
The polyimide precursor according to any one of claims 1 to 10, further comprising a side chain containing a photoreactive group in the structure.
A polyimide obtained by imidizing the polyimide precursor according to any one of claims 1 to 11.
A liquid crystal aligning agent comprising the polyimide precursor according to any one of claims 1 to 11 and / or the polyimide according to claim 12.
The liquid crystal and / or the liquid crystal alignment film contains a polymerizable compound and is used for producing a liquid crystal display device obtained by reacting the polymerizable compound by irradiating ultraviolet rays while applying a voltage. The liquid crystal aligning agent of description.
A liquid crystal alignment film formed with the liquid crystal aligning agent according to claim 13 or 14.
A liquid crystal display device comprising the liquid crystal alignment film according to claim 15.
The following formula (2) (wherein Ar represents an aromatic hydrocarbon group which may have a substituent,
R 101 represents a divalent organic group,
R 102 to R 104 each independently represents a monovalent organic group)
Diamine represented by
Diamine represented by following formula (3).