JP5854205B2 - Liquid crystal alignment agent - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent. More specifically, the present invention relates to a liquid crystal aligning agent that can exhibit a good pretilt angle by irradiating polarized or non-polarized ultraviolet rays and can provide a liquid crystal alignment film having a high degree of ultraviolet resistance.

As a liquid crystal display element, a horizontal alignment mode using a nematic liquid crystal having a positive dielectric anisotropy represented by a TN (Twisted Nematic) type, a STN (Super Twisted Nematic) type, an IPS (In Plane Switching) type, etc. In addition to the above liquid crystal display elements, a vertical alignment mode VA (Vertical Alignment) type liquid crystal display element using nematic liquid crystal having negative dielectric anisotropy is known.
Such a liquid crystal display element includes a liquid crystal alignment film having a function of aligning liquid crystal molecules in a certain direction. As the material constituting the liquid crystal alignment film, polyamic acid, polyimide, polyamide, polyester, polyorganosiloxane, and the like are known. In particular, the liquid crystal alignment film made of polyamic acid or polyimide has heat resistance, mechanical strength, liquid crystal It has been used preferably for a long time because of its excellent affinity with molecules (Patent Documents 1 to 3).
Patent Document 4 discloses a liquid crystal aligning agent containing a polyorganosiloxane obtained by reacting a mixture of trifunctional and tetrafunctional hydrolyzable silane compounds in the presence of oxalic acid and alcohol. It is described that a liquid crystal alignment film formed from a liquid crystal aligning agent is excellent in vertical alignment and heat resistance.
Further, as a method for imparting liquid crystal alignment ability to an organic film, the photo-alignment method has been put into practical use in place of the rubbing method that has been conventionally employed. Although the proposal of this technology itself belongs to the old days, research and development of liquid crystal alignment film materials for photo-alignment methods has been progressing. For example, Patent Document 5 discloses that a polyimide thin film having a cinnamate structure is polarized or non-polarized. There has been proposed a technique for imparting a desired pretilt angle expression property by utilizing the rotation of molecules by photoisomerization of the cinnamate structure. However, according to the technique of Patent Document 5, it is necessary to irradiate a considerable amount of ultraviolet rays in order to give a desired pretilt angle expression, and the tact time at the time of manufacturing a liquid crystal display element becomes long or intense ultraviolet rays are emitted. For this reason, the electrical characteristics of the liquid crystal alignment film formed, in particular, the adverse effect such as the loss of the voltage holding ratio has occurred.

In recent years, as a new liquid crystal alignment film material that can exhibit good liquid crystal alignment performance with a very small radiation dose when the photo alignment method is applied, it consists of polyamic acid or polyimide with a specific photosensitive site introduced in the molecule Materials have been reported (Patent Documents 10 to 12). The liquid crystal aligning agent described in these documents is an extremely excellent material capable of forming a liquid crystal alignment film exhibiting good liquid crystal alignment properties by irradiation with radiation of about 500 to 3,000 J / m ² .
By the way, the progress of liquid crystal display devices has been remarkable in recent years, and high-definition display capable of high-definition display and high-speed video response has become possible. In addition to television, in-vehicle display devices, game machines, portable video playback As is well known, it is widely applied to machines. In addition, as the display with high brightness becomes possible, the number of scenes in which the liquid crystal display element as described above is used outdoors in the daytime increases, so that the liquid crystal display element and the liquid crystal alignment film included in the liquid crystal display element have been conventionally used. It has been exposed to strong ultraviolet rays for a long time that could not be considered in the usage mode. For this reason, the conventionally known liquid crystal alignment film materials do not have ultraviolet resistance that can be adapted to the current use mode, and it is desired to improve the ultraviolet resistance of the liquid crystal alignment film.
As described above, with the change in the usage of liquid crystal display elements and the development of new manufacturing methods, there is an increasing demand for improving the ultraviolet resistance of liquid crystal alignment film materials, and an urgent countermeasure is eagerly desired.

JP-A-4-153622 JP 56-91277 A Japanese Patent Laid-Open No. 11-258605 JP-A-9-281502 US Patent Application Publication No. 2009/0325453 JP-A-6-222366 JP-A-6-281937 JP-A-5-107544 JP 2010-97188 A International Publication No. 09/025386 Pamphlet International Publication No. 2009/25385 Pamphlet International Publication No. 2009/25388 Pamphlet

T. T. et al. J. et al. Scheffer et. al. , J .; Appl. Phys. vol. 48, p1783 (1977) F. Nakano et. al. , JPN. J. et al. Appl. Phys. vol. 19, p2013 (1980)

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal alignment film that can exhibit a good pretilt angle by irradiating polarized or non-polarized ultraviolet rays and has high ultraviolet resistance. It is in providing the liquid crystal aligning agent to give.

According to the present invention, the above-mentioned problems of the present invention are as follows.
It is achieved by a liquid crystal aligning agent comprising (I) a polyorganosiloxane having a group having a polymerizable double bond and (II) a polyorganosiloxane having a group having a cinnamic acid structure.
Secondly, the above problems of the present invention are as follows.
(III) It is achieved by a liquid crystal aligning agent comprising a polyorganosiloxane having a group having a polymerizable double bond and a group having a cinnamic acid structure.

The liquid crystal aligning agent of this invention can give the liquid crystal aligning film which has favorable pretilt angle expression property, and also has high ultraviolet-ray tolerance by irradiating a polarized or non-polarized ultraviolet-ray.
Since the liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention has a high UV resistance, the liquid crystal display device having such a liquid crystal alignment film should be used for a long time under strong UV irradiation conditions, for example, outdoors in the daytime. However, the display quality does not deteriorate.

The liquid crystal aligning agent of the present invention is as described above.
Have a group having (I) a polymerizable double bond, polyorganosiloxanes having no group having a cinnamic acid structure (hereinafter. Referred to as "polyorganosiloxane (I)") and,
(II) a polyorganosiloxane having a group having a cinnamic acid structure (hereinafter referred to as “polyorganosiloxane (II)”);
Or (III) a polyorganosiloxane having a group having a polymerizable double bond and a group having a cinnamic acid structure (hereinafter referred to as “polyorganosiloxane (III)”. ) ")
And containing at least one polyorganosiloxane.
In addition to the group having a polymerizable double bond, the polyorganosiloxane (I) is optionally a group having a function of aligning liquid crystal molecules (hereinafter referred to as “liquid crystal aligning group”), a photosensitizing function. (Hereinafter referred to as “photosensitizing group”) and the like. In addition to the group having a cinnamic acid structure, the polyorganosiloxane (II) optionally has a group having a protected carboxy group (hereinafter referred to as “latent acidic group”), an epoxy group, and the like. May be. The polyorganosiloxane (III) may optionally have an epoxy group in addition to the group having a polymerizable double bond and the group having a cinnamic acid structure.
The group having a cinnamic acid structure may include a part having a function of aligning liquid crystal molecules in a part of the group.

The liquid crystal aligning agent of the present invention is
A polyorganosiloxane (II) or a polyorganosiloxane (III) having a group having a cinnamic acid structure including a portion having a function of aligning liquid crystal molecules when the polyorganosiloxane (I) having a liquid crystal aligning group is contained When it contains, this liquid crystal aligning agent can be applied suitably for a VA type liquid crystal display element. In other cases, the liquid crystal aligning agent can be suitably applied to a TN type, STN type, or IPS type liquid crystal display element.
In this specification, the “liquid crystal alignment group” means an alkyl group having 4 to 30 carbon atoms, a fluoroalkyl group having 1 to 30 carbon atoms, a hydrocarbon group having 17 to 51 carbon atoms having a steroid skeleton, and a carbon number. It is a concept including an alkoxyphenyl group having 2 to 24 alkoxy groups, a hydrocarbon group having 12 to 30 carbon atoms having a bicyclohexane skeleton, and the like.

<Polyorganosiloxane>
Polyorganosiloxanes (I) and a group having a polymerizable double bond in (III) is lower following formula (A)

(In the formula (A), R ¹⁵ is a hydrogen atom or a methyl group,
X ^I and X ^II are each a 1,4-phenylene group, a methylene group or an alkylene group having 2 to 8 carbon atoms,
Z is an oxygen atom, -COO- ^* or -OCO- ^* (However, bond marked with "*" is ^{X II} side.)
a, b, c and d are each 0 or 1,
However, when c is is a 0 d is ^{1, X II} is a 1,4-phenylene group,
When b is 0, d is 0. )
In Ru groups der represented.

Specific examples of the group represented by the above formula (A) include, for example, vinyl group, allyl group, p-styryl group, (meth) acryloxymethyl group, 2-((meth) acryloxy) ethyl group, 3- ( (Meth) acryloxy) propyl group, 4-((meth) acryloxy) butyl group, 5-((meth) acryloxy) pentyl group, 6-((meth) acryloxy) hexyl group, 7-((meth) acryloxy) heptyl Group, 8-((meth) acryloxy) octyl group, 9-((meth) acryloxy) nonyl group, 10-((meth) acryloxy) decyl group, 4- (2-((meth) acryloxy) ethyl) phenyl group 2-((4- (meth) acryloxy) phenyl) ethyl group, 4-((meth) acryloxymethyl) phenyl group, 4- (meth) acryloxyphenylmethyl group, 4 (3-((meth) acryloxy) propyl) phenyl group, 3- (4- (meth) acryloxyphenyl) propyl group, 4-((meth) acryloxymethoxy) phenyl group, 4- (2-((meta ) Acryloxy) ethoxy) phenyl group, 4- (3-((meth) acryloxy) propoxy) phenyl group, (meth) acryloxymethoxymethyl group, 2-((meth) acryloxymethoxy) ethyl group, 2- (2 -((Meth) acryloxy) ethoxy) ethyl group, 2- (2- (2-((meth) acryloxy) ethoxy) ethoxy) ethyl group, 3- (3-((meth) acryloxy) propoxy) propyl group, acryl Roxymethyl group etc. can be mentioned, It can be 1 or more types selected from these. Among these, vinyl group, allyl group, p-styryl group, (meth) acryloxymethyl group, 2-((meth) acryloxy) ethyl group and 3-((meth) acryloxy) propyl group may be mentioned as preferable groups. it can.
The group represented by the above formula (A) may be directly bonded to the Si atom of the polyorganosiloxane (I) or may be bonded via a divalent linking group.

The polyorganosiloxane (I) is selected from a group containing a polymerizable carbon-carbon double bond, preferably a group represented by the above formula (A), more preferably a specific group exemplified above. One or more groups are preferably in a proportion of 0.01 to 0.60 mol, more preferably 0.02 to 0.50 mol, relative to 1 mol of silicon atoms contained in polyorganosiloxane (I). It is contained in a proportion, more preferably in a proportion of 0.02 to 0.30 mol. The polyorganosiloxane (III) is selected from a group containing a polymerizable carbon-carbon double bond, preferably a group represented by the above formula (A), more preferably a specific group exemplified above. One or more groups are preferably in a proportion of 0.01 to 0.60 mol, more preferably 0.02 to 0.50 mol, relative to 1 mol of silicon atoms contained in polyorganosiloxane (I). It is contained in a proportion, more preferably in a proportion of 0.02 to 0.30 mol.
Examples of the group having a cinnamic acid structure in the polyorganosiloxane (II) or polyorganosiloxane (III) include, for example, the following formula (B0-1)

(In the formula (B0-1), R ¹ is a monovalent organic group having 3 to 40 carbon atoms including an alkyl group having 1 to 40 carbon atoms or an alicyclic group, provided that one of hydrogen atoms of the alkyl group. Part or all may be substituted with a fluorine atom, R ² is a single bond, an oxygen atom, —COO— or —OCO—, and R ³ is a divalent aromatic group or a divalent alicyclic group. A divalent heterocyclic group or a divalent condensed cyclic group, provided that part or all of the hydrogen atoms of the divalent aromatic group may be substituted with fluorine atoms, and R ⁴ is a single group. A bond, an oxygen atom, —COO— or —OCO—, R ⁵ is a single bond, a methylene group, an alkylene group having 2 to 10 carbon atoms or a divalent aromatic group, and R ⁷ is a fluorine atom or a methyl group. Or a cyano group, f is an integer of 0 to 3, and g is an integer of 0 to 4.)
A group represented by formula (B0-2)

(In the formula (B0-2), R ⁸ is an alkyl group having 1 to 40 carbon atoms or a monovalent organic group having 3 to 40 carbon atoms including an alicyclic group or an aromatic group, provided that the alkyl group is Part or all of the hydrogen atoms may be substituted with fluorine atoms, R ⁹ is a single bond, oxygen atom, —COO— or —OCO—, R ¹⁰ is a methylene group, alkylene having 2 to 10 carbon atoms A divalent aromatic group, a divalent alicyclic group, a divalent heterocyclic group, or a divalent condensed cyclic group, provided that a part of hydrogen atoms of the divalent aromatic group or All may be substituted with fluorine atoms, R ¹¹ is a single bond, —OCO— (CH ₂ ) _e —, —COO— (CH ₂ ) _k — or —O— (CH ₂ ) _i —; However e, k and i is an integer of from 1 to 10, ^{respectively, R 13} is fluorine atom, methylcarbamoyl A group or a cyano group, h is an integer of 0 to 3, j is an integer of 0-4.)
The group etc. which are represented by these can be mentioned.

Examples of the monovalent organic group having 3 to 40 carbon atoms including the alicyclic group of R ¹ in the above formula (B0-1) and R ⁸ in (B0-2) include a cholestenyl group, a cholestanyl group, an adamantyl group and the like. Can be mentioned. Examples of the alkyl group having 1 to 40 carbon atoms of R ¹ and R ⁸ include, for example, an alkyl group having 1 to 20 carbon atoms, provided that part or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms. It may be a group. Such a (fluorinated) alkyl group is preferably a straight chain group having 5 to 20 carbon atoms, such as an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, n-decyl group, n-lauryl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, 4,4,4-trifluorobutyl group, 4,4,5,5,5-pentafluoropentyl group, 4,4,5,5,6,6,6-heptafluorohexyl group, 3,3,4,4,5,5,5-heptafluoropentyl group, 2,2,2-trifluoroethyl group, 2,2,3,3,3-pentafluoropropyl group, 2- (perfluoro Butyl) ethyl group, 2- Perfluorooctyl) ethyl group, 2- (including perfluoro decyl) ethyl can be cited, can be at one or more of these.

Examples of the divalent aromatic group represented by R ³ in the above formula (B0-1) and R ¹⁰ in (B0-2) include a 1,4-phenylene group, a 2-fluoro-1,4-phenylene group, 3 -Fluoro-1,4-phenylene group, 2,3,5,6-tetrafluoro-1,4-phenylene group and the like;
Examples of the alicyclic group for R ³ and R ¹⁰ include a 1,4-cyclohexylene group;
Examples of the divalent heterocyclic group represented by R ³ and R ¹⁰ include a 1,4-pyridylene group, a 2,5-pyridylene group, a 1,4-furanylene group;
Examples of the divalent condensed cyclic group represented by R ³ and R ¹⁰ include a naphthylene group.
Examples of the group represented by the above formula (B0-1) include the description represented by each of the following formulas (B0-1-1) to (B0-1-3);
Examples of the group represented by the formula (B0-2) include groups represented by the following formulas (B0-2-1) to (B0-2-3), respectively. The group obtained by removing the hydrogen atom of a carboxy group from the carboxylic acid described in Japanese Patent Application No. 2010-1111836 can be mentioned.

(R ¹ in the above formulas (B0-1-1) to (B0-1-3) has the same meaning as in the above formula (B0-1);
R ⁸ in the above formulas (B0-2-1) to (B0-2-3) has the same meaning as in the above formula (B0-2), and u is an integer of 1 to 10. )
The group represented by the above formula (B0-1) or (B0-2) may be directly bonded to the Si atom of the polyorganosiloxane (II) or polyorganosiloxane (III), or a divalent group. It may be bonded via a linking group.
The polyorganosiloxane (II) is a group having a cinnamic acid structure, preferably one or more selected from the groups represented by the above formulas (B0-1) and (B0-2), more preferably One or more groups selected from the exemplified specific groups are preferably in a ratio of 0.01 to 0.60 moles with respect to 1 mole of silicon atoms contained in the polyorganosiloxane (II). More preferably, it is contained in a proportion of 0.02 to 0.50 mol, and more preferably in a proportion of 0.02 to 0.30 mol. The polyorganosiloxane (III) is a group having a cinnamic acid structure, preferably at least one selected from the groups represented by the formulas (B0-1) and (B0-2), more preferably Preferably at least one group selected from the exemplified specific groups is in a proportion of 0.01 to 0.60 moles per mole of silicon atoms contained in the polyorganosiloxane (III), More preferably, it is contained in a proportion of 0.02 to 0.50 mol, and more preferably in a proportion of 0.02 to 0.30 mol.

Examples of the liquid crystal orientation group that the polyorganosiloxane (I) can optionally have include, for example, an alkyl group having 4 to 30 carbon atoms, a fluoroalkyl group having 1 to 30 carbon atoms, and 17 to 51 carbon atoms having a steroid skeleton. A hydrocarbon group having 2 to 24 carbon atoms, an alkoxyphenyl group having 2 to 24 carbon atoms, a hydrocarbon group having 12 to 30 carbon atoms having a bicyclohexane skeleton, and the like.
As said C4-C30 alkyl group, a linear thing is preferable, for example, n-hexyl group, n-heptyl group, n-octyl group, n-dodecyl group, n-octadecyl group etc. can be mentioned. . Examples of the C1-C30 fluoroalkyl group include 3,3,3-trifluoropropyl group, 3,3,4,4,5,5,5-heptafluoropentyl group, 3,3,4, 4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl group, 3,3,4,4,5,5,6,6,7,7,8,8, A 9,9,10,10,10-heptadecafluorodecyl group and the like;
Examples of the hydrocarbon group having 17 to 51 carbon atoms and having the steroid skeleton include, for example, 3-cholestanyl group, 3-cholestenyl group, 3-lanostanyl group, 3-colanyl group, 3-pregnal group, 3-androstanyl group, 3 -Estranyl group etc. can be mentioned, respectively. The alkoxyphenyl group having an alkoxy group having 2 to 24 carbon atoms is preferably a 4-alkoxyphenyl group having a linear alkoxy group having 2 to 18 carbon atoms, such as a 4-n-pentoxyphenyl group. 4-n-hexyloxyphenyl group, 4-n-octyloxyphenyl group, 4-n-dodecyloxyphenyl group, and the like. Examples of the hydrocarbon group having 12 to 30 carbon atoms having a bicyclohexane skeleton include 4-n-pentylbicyclohexyl group, 4-n-heptylbicyclohexyl group, 4-n-propylbicyclohexyl group and the like. it can.

The liquid crystal alignment group as exemplified above may be directly bonded to the Si atom of the polyorganosiloxane (I) or may be bonded via a divalent linking group.
The proportion of the liquid crystal alignment group in the polyorganosiloxane (I) is preferably 0.7 mol or less with respect to 1 mol of silicon atoms contained in the polyorganosiloxane (I). The ratio is more preferably less than or equal to mol, and particularly preferably the ratio of 0.1 to 0.5 mol.

Examples of the photosensitizing group that polyorganosiloxane (I) can optionally have include, for example, an acetophenone structure, a benzophenone structure, an anthraquinone structure, a biphenyl structure, a carbazole structure, a nitroaryl structure, a fluorene structure, a naphthalene structure, an anthracene structure, Examples thereof include a group having one or more of structures selected from an acridine structure and an indole structure. Each of the above structures is a structure comprising groups obtained by removing 1 to 4 hydrogen atoms from acetophenone, benzophenone, anthraquinone, biphenyl, carbazole, nitrobenzene or dinitrobenzene, naphthalene, fluorene, anthracene, acridine or indole. It is. The acetophenone structure, carbazole structure and indole structure are each preferably a structure comprising groups obtained by removing 1 to 4 hydrogen atoms of the benzene ring of acetophenone, carbazole or indole.
Among these, the photosensitizing group is a group having at least one structure selected from the group consisting of an acetophenone structure, a benzophenone structure, an anthraquinone structure, a biphenyl structure, a carbazole structure, a nitroaryl structure, and a naphthalene structure. And a group having at least one structure selected from the group consisting of an acetophenone structure, a benzophenone structure, and a nitroaryl structure is particularly preferable.
Examples of photosensitizing groups include the following formulas (D0-3-1) to (D0-3-10).

And groups represented by each of the above.
The photosensitizing group as exemplified above may be directly bonded to the Si atom of the polyorganosiloxane (I) or may be bonded via a divalent linking group.
The proportion of the photosensitizing group in the polyorganosiloxane (I) is preferably 0.3 mol or less with respect to 1 mol of silicon atoms contained in the polyorganosiloxane (I). The ratio is more preferably less than or equal to a mole, and particularly preferably less than or equal to 0.1 mole. It is preferable that the polyorganosiloxane (I) does not have a photosensitizing group.

Examples of the latent acidic group that the polyorganosiloxane (II) can optionally have include those described in Japanese Patent Application No. 2011-202073. Examples of the latent acidic group in the present invention include 1-ethoxyethoxycarbonyl group, 1-n-propoxyethoxycarbonyl group, 1-cyclohexyloxyethoxycarbonyl group, 2-tetrahydropyranyloxycarbonyl group, 2-tetrahydropyranyloxycarbonyl. One or more selected from the group consisting of a group, 1-methyl-1-methoxyethoxycarbonyl group, 1-methyl-1-cyclohexyloxyethoxycarbonyl group, t-butoxycarbonyl group and t-amyloxycarbonyl group Is preferred.
The latent acidic group as exemplified above may be directly bonded to the Si atom of the polyorganosiloxane (I) or may be bonded via a divalent linking group.
The proportion of latent acidic groups in the polyorganosiloxane (II) is preferably 0.3 mol or less with respect to 1 mol of silicon atoms contained in the polyorganosiloxane (II). The ratio is more preferably less than or equal to a mole, and particularly preferably less than or equal to 0.1 mole. It is preferable that the polyorganosiloxane (I) does not have a photosensitizing group.

Examples of the epoxy group that the polyorganosiloxane (II) and (III) can optionally have include an oxiranyl group (1,2-epoxy group), a 3,4-epoxycyclohexyl group, and the like. It can be one or more selected from among them.
These epoxy groups may be directly bonded to Si atoms of polyorganosiloxane (II) or polyorganosiloxane (III), or may be bonded via a divalent linking group.
The proportion of the epoxy group present in the polyorganosiloxane (II) is preferably 0.7 mol or less with respect to 1 mol of the silicon atom contained in the polyorganosiloxane (II). More preferably, the ratio is 0.5 mol, and particularly preferably 0.1 to 0.3 mol. The proportion of the epoxy group in the polyorganosiloxane (III) is preferably 0.7 mol or less with respect to 1 mol of the silicon atom contained in the polyorganosiloxane (III), and 0.05 to 0 More preferably, the ratio is 0.5 mol, and particularly preferably 0.1 to 0.3 mol.

For the polyorganosiloxanes (I), (II) and (III), the polystyrene-equivalent weight average molecular weights measured by gel permeation chromatography are preferably 500 to 1,000,000, respectively. More preferably, it is ˜100,000, more preferably 1,000 to 50,000.
Such polyorganosiloxanes (I), (II) and (III) may be produced by any method as long as they have the above-mentioned characteristics. It can be obtained by such a method.

The above polyorganosiloxane (I) is, for example, a hydrolyzable silane compound having a polymerizable double bond (hereinafter referred to as “silane compound (a1)”) or a silane compound (a1) and other hydrolyzable compounds. It can be obtained by a method through a step of polycondensing a mixture with a silane compound. In synthesizing the polyorganosiloxane (I), one or more groups selected from a liquid crystal aligning group and a photosensitizing group can be obtained in addition to a group having a polymerizable double bond by performing the following operation. The polyorganosiloxane (I) can be obtained. Ie;
In the polycondensation of the silane compound, another hydrolyzable silane compound is used in combination, and at least a part of the other hydrolyzable silane compound has an epoxy group (hereinafter referred to as “silane compound (a2)”. First, a polyorganosiloxane having a group having a polymerizable double bond and an epoxy group (hereinafter referred to as “precursor (I)”) is synthesized, and then the precursor (I) is synthesized. A carboxylic acid having a liquid crystal alignment group (hereinafter referred to as “carboxylic acid (2)”) and a carboxylic acid having a photosensitizing group (hereinafter referred to as “carboxylic acid (3)”). In addition to a group having a polymerizable double bond, a polyol having at least one group selected from a liquid crystal aligning group and a photosensitizing group is reacted with one or more compounds selected from It can be obtained Ganoderma siloxane (I). In addition, in the polycondensation of the silane compound, another hydrolyzable silane compound is used in combination, and at least a part of the other hydrolyzable silane compound has a liquid crystal alignment group (hereinafter referred to as “silane”). By using the compound (a3) "), a polyorganosiloxane (I) having a liquid crystal aligning group in addition to a group having a polymerizable double bond can be obtained.

The polyorganosiloxane (II) as described above is prepared by polycondensation of, for example, a silane compound (a2) or a mixture of a silane compound (a2) and another hydrolyzable silane compound, and then first having an epoxy group (hereinafter referred to as “polyorganosiloxane”). , "Precursor (II)"), and then the epoxy group of the precursor (II) is reacted with a carboxylic acid having a cinnamic acid structure (hereinafter referred to as "carboxylic acid (1)"). Can be synthesized. Here, by using together with the carboxylic acid (1), a carboxylic acid having a latent acidic group (hereinafter referred to as “carboxylic acid (4)”), a polyamic acid having a latent acidic group in addition to the cinnamic acid structure is used. Can be an organosiloxane (II);
Polyorganosiloxane further having an epoxy group by setting the total use ratio of the carboxylic acid (1) and the optionally used carboxylic acid (4) to an amount smaller than the amount of the epoxy group of the precursor (II) (II).

The polyorganosiloxane (III) as described above includes, for example, polycondensation of silane compounds (a1) and (a2), or a mixture of these with other hydrolyzed silane compounds, and a group having a polymerizable double bond. A polyorganosiloxane having an epoxy group (hereinafter referred to as “precursor (III)”) is synthesized, and then the epoxy group of the precursor (III) is reacted with the carboxylic acid (1). be able to. Here, by using the carboxylic acid (2) together with the carboxylic acid (1), a polyorganosiloxane (II) having a liquid crystal orientation group in addition to a group having a polymerizable double bond and a cinnamic acid structure is obtained. It is possible;
A polyorgano having an epoxy group further by setting the total use ratio of the carboxylic acid (1) and the optionally used carboxylic acid (2) to an amount smaller than the amount of the epoxy group of the precursor (III). Siloxane (III) can be used.
The polycondensation of the hydrolyzable silane compound or a mixture thereof can be performed, for example, by the method described in Japanese Patent Application No. 2011-95224. The precursors (I) and (III) thus obtained are each represented by the following formula (S-1):

(In Formula (S-1), X ¹ is a group having an epoxy group, Y ¹ is a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, an alkyl group having 1 to 20 carbon atoms, or an aryl having 6 to 20 carbon atoms. Group.)
And a repeating unit represented by the following formula (S-2)

(In the formula (S-2), A is a group represented by the formula (A), ^{Y 1} has the same meaning as ^{Y 1} in the above formula (S-1).)
It is at least one selected from the group consisting of a polyorganosiloxane having a repeating unit represented by the following formula, a hydrolyzate thereof and a condensate of the hydrolyzate, and possibly a mixture thereof. The precursor (II) is at least one selected from the group consisting of a polyorganosiloxane having a repeating unit represented by the above formula (S-1), a hydrolyzate thereof, and a condensate of the hydrolyzate, Probably a mixture of these.
By reacting the carboxylic acid (2) and optionally the carboxylic acid (3) with such an epoxy group of the precursor (I), a group having a polymerizable double bond, a liquid crystal alignment group, and an optional group Thus, polyorganosiloxane (I) having a photosensitizing group can be obtained. A polyorganosiloxane having a group having a cinnamic acid structure and optionally a photosensitizing group by reacting the carboxylic acid (1) and optionally the carboxylic acid (3) with the epoxy group of the precursor (II) (II) can be obtained. By reacting the carboxylic acid (1) and optionally the carboxylic acid (4) to the epoxy group of the precursor (III), a group having a polymerizable double bond and a group having a cinnamic acid structure and optionally Polyorganosiloxane (II) having a latent acidic group can be obtained.

The carboxylic acid (1) is a carboxylic acid having a cinnamic acid structure.
The group having a cinnamic acid structure in the carboxylic acid (1) is preferably a group represented by each of the above formulas (B0-1) and (B0-2). Accordingly, the carboxylic acid (1) in the present invention is preferably a compound in which a carboxy group is bonded to each bond of the above formulas (B0-1) and (B0-2). It is more preferable to use the compound described in Japanese Patent Application No. 2010-1111836.
The carboxylic acid (2) is a carboxylic acid having a liquid crystal alignment group. About the liquid crystal aligning group which carboxylic acid (2) has, it is the same as that of having demonstrated above about the liquid crystal aligning group which polyorganosiloxane (I) can have arbitrarily.
Examples of the carboxylic acid (2) used in the present invention include butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, stearic acid, 4-propylbenzoic acid, and 4-butyl. Benzoic acid, 4-pentylbenzoic acid, 4-hexylbenzoic acid, 4-heptylbenzoic acid, 4-octylbenzoic acid, 4-nonylbenzoic acid, 4-decylbenzoic acid, 4-dodecylbenzoic acid, 4-octadecylbenzoic acid 4-methoxybenzoic acid, 4-ethoxybenzoic acid, 4-propoxybenzoic acid, 4-butoxybenzoic acid, 4-pentyloxybenzoic acid, 4-hexyloxybenzoic acid, 4-heptyloxybenzoic acid, 4-octyloxy Benzoic acid, 4-nonyloxybenzoic acid, 4-decyloxybenzoic acid, 4-dodecyloxybenzoic acid, 4-o Tadeshiruokishi benzoate, 4-(4'-n-pentyl cyclohexyl) benzoic acid, the following formula (1) to (3)

The compound represented by each of these can be mentioned, One or more types selected from these can be used.
The carboxylic acid (3) is a carboxylic acid having a photosensitizing group.
This photosensitizing group has a function of being excited by irradiation with radiation and imparting this excitation energy to the adjacent photosensitive structure in the polymer. This excited state may be a singlet or a triplet, but is preferably a triplet because of its long lifetime and efficient energy transfer. The radiation absorbed by the photosensitizing structure is preferably ultraviolet rays or visible rays having a wavelength in the range of 150 to 600 nm. Radiation having a shorter wavelength cannot be used in a photo-alignment method because it cannot be handled by a normal optical system. On the other hand, radiation having a wavelength longer than this has low energy and hardly induces an excited state of the photosensitizing group.

Examples of the photosensitizing structure in such a photosensitizing group include acetophenone structure, benzophenone structure, anthraquinone structure, biphenyl structure, carbazole structure, nitroaryl structure, fluorene structure, naphthalene structure, anthracene structure, acridine structure, indole structure, etc. Therefore, the photosensitizing group can be a group having at least one of these structures. Each of the above structures consists of groups obtained by removing 1 to 4 hydrogen atoms from acetophenone, benzophenone, anthraquinone, biphenyl, carbazole, nitrobenzene or dinitrobenzene, naphthalene, fluorene, anthracene, acridine or indole. Refers to the structure. Here, the acetophenone structure, the carbazole structure and the indole structure are each preferably a structure composed of groups obtained by removing 1 to 4 hydrogen atoms of the benzene ring of acetophenone, carbazole or indole.
Of these, the photosensitizing structure is preferably at least one selected from the group consisting of an acetophenone structure, a benzophenone structure, an anthraquinone structure, a biphenyl structure, a carbazole structure, a nitroaryl structure, and a naphthalene structure. Particularly preferred is at least one selected from the group consisting of a benzophenone structure and a nitroaryl structure.
As carboxylic acid (3) in this invention, it is preferable that it is a compound which has a carboxyl group and a photosensitizing structure, and as a more preferable compound, for example, following formula (C-1)-(C-10)

And the like, and the like.
Carboxylic acid (4) is a carboxylic acid having a latent acidic group.
As the carboxylic acid (4), the following formula (D)
B _n R-COOH (D)
(In the formula (D), B represents the following formulas (B-1) and (B-2)

(In formula (B-1), R ¹⁶ and R ¹⁷ are each an alkyl group having 1 to 20 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or 7 carbon atoms. -10 aralkyl groups, and in formula (B-2), n1 is an integer of 2 to 10), a group having a ketal ester structure of a carboxylic acid, a 1- A group having an alkylcycloalkyl ester structure or a tertiary alkoxycarbonyl group,
n is an integer of 1 to 10,
R is a group obtained by removing (n + 1) hydrogen from a heterocyclic compound having 3 to 10 carbon atoms or an (n + 1) -valent hydrocarbon group having 1 to 18 carbon atoms. )
The compound etc. which are represented by these can be mentioned.

When synthesizing the polyorganosiloxane (I) by reacting the precursor (I) with a carboxylic acid, the use ratio of the carboxylic acid is as follows with respect to 1 mol of the epoxy group of the precursor (I). It is preferable that
Carboxylic acid (2): Preferably it is 0.01-0.4 mol, More preferably, it is 0.03-0.3 mol, More preferably, it is 0.05-0.2 mol.
Carboxylic acid (3): Preferably it is 0.3 mol or less, More preferably, it is 0.1 mol or less, and it is still more preferable not to contain this.
When the polyorganosiloxane (II) is synthesized by reacting the precursor (II) with a carboxylic acid, the use ratio of the carboxylic acid is as follows with respect to 1 mol of the epoxy group of the precursor (II). It is preferable that
Carboxylic acid (1) having a cinnamic acid structure: preferably 0.01 to 0.6 mol, more preferably 0.03 to 0.5 mol, still more preferably 0.05 to 0.4 mol.
Carboxylic acid (4) having a latent acidic group: preferably 0.4 mol or less, more preferably 0.01 to 0.4 mol, still more preferably 0.03 to 0.3 mol, particularly preferably 0.05. -0.2 mol.

When the polyorganosiloxane (III) is synthesized by reacting the precursor (III) with a carboxylic acid, the use ratio of the carboxylic acid is as follows with respect to 1 mol of the epoxy group of the precursor (III). It is preferable that
Carboxylic acid (1): Preferably it is 0.03-0.9 mol, More preferably, it is 0.06-0.7 mol, More preferably, it is 0.3-0.5 mol.
Carboxylic acid (2): Preferably it is 0.5 mol or less, More preferably, it is 0.01-0.3 mol, More preferably, it is 0.05-0.2 mol.
In all the cases described above, the total use ratio of the carboxylic acid is preferably 0.1 to 0.9 mol with respect to 1 mol of the epoxy group that each precursor has, More preferably, the molar amount is 0.3 to 0.5 mol.

The reaction between the precursor and the carboxylic acid is preferably carried out in the presence of a suitable catalyst and a suitable organic solvent.
As the catalyst used in the reaction between the precursor and the carboxylic acid, for example, an organic base can be suitably used, and a so-called curing accelerator that accelerates the reaction between the epoxy compound and the acid anhydride is used as a catalyst in this reaction. Can be used as Examples of the organic base include primary or secondary organic amines, tertiary organic amines, quaternary organic amine salts, and the like;
Examples of the curing accelerator include tertiary amines (excluding tertiary organic amines as organic bases), imidazole derivatives, organic phosphorus compounds, quaternary phosphonium salts, diazabicycloalkenes, organometallic compounds, and quaternary ammonium halides. , Metal halide compounds, latent curing accelerators, and the like. Examples of the latent curing accelerator include a high melting point dispersion type latent curing accelerator (for example, an amine addition type accelerator), a microcapsule type latent curing accelerator, an amine salt type latent curing accelerator, and a high temperature dissociation. Type thermal cationic polymerization type latent curing accelerator.
Of these, quaternary organic amine salts or halogenated quaternary ammonium salts are preferably used.

The use ratio of the catalyst is preferably 0.01 to 100 parts by weight, and more preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the precursor.
Examples of the organic solvent used in the reaction between the precursor and the carboxylic acid include ketones, ethers, esters, amides, and alcohols.
The proportion of the organic solvent used is preferably such that the total weight of the components other than the organic solvent in the reaction solution is 0.1 to 50% by weight as the proportion of the total amount of the reaction solution, and 5 to 50% by weight. It is more preferable to set the ratio as follows.
The reaction between the precursor and the carboxylic acid is preferably performed at a temperature of 0 to 200 ° C., more preferably 50 to 150 ° C., and preferably 0.1 to 50 hours, more preferably 0.5 to 20 hours.

The liquid crystal aligning agent of the present invention preferably contains polyorganosiloxane (I) and polyorganosiloxane (II) produced by the above method, or contains polyorganosiloxane (III).
When the liquid crystal aligning agent of this invention contains polyorganosiloxane (I) and polyorganosiloxane (II), the content rate of polyorganosiloxane (II) is 1 with respect to 100 weight part of polyorganosiloxane (I). It is preferable to set it as -20 weight part, It is more preferable to set it as 3-15 weight part, It is especially preferable to set it as 5-10 weight part.
When the liquid crystal aligning agent of this invention contains polyorganosiloxane (I) and polyorganosiloxane (II), this liquid crystal aligning agent may further contain polyorganosiloxane (III), but does not contain this. It is preferable.
When the liquid crystal aligning agent of the present invention contains polyorganosiloxane (III), the liquid crystal aligning agent may contain polyorganosiloxane (I) or polyorganosiloxane (II), or both. It is preferable not to contain both.

<Other ingredients>
The liquid crystal aligning agent of the present invention preferably contains polyorganosiloxane (I) and polyorganosiloxane (II) produced by the above method or polyorganosiloxane (III) as an essential component. As long as the effects of the invention are not diminished, other components may be contained as necessary.
Examples of such other components include polymers other than polyorganosiloxanes (I) to (III) (hereinafter referred to as “other polymers”), polymerizable unsaturated compounds, photopolymerization initiators, radical scavengers. Agents, compounds having at least one epoxy group in the molecule (except when the polyorganosiloxane has an epoxy group), functional silane compounds, surfactants, and the like. One or more selected can be used.

[Other polymers]
The above-mentioned other polymers can be used for further improving the solution characteristics of the obtained liquid crystal aligning agent and the electric characteristics and liquid crystal alignment properties of the liquid crystal alignment film to be formed. Such other polymers are polymers other than the above polyorganosiloxanes (I) to (III), for example, polyorganosiloxanes other than polyorganosiloxanes (I) to (III) (hereinafter referred to as “other polyorganosiloxanes”). ”), Polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, polysiloxane, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly (meth) acrylate, and the like. One or more selected from these can be used.
When using another polymer in this invention, it is preferable to use 1 or more types selected from the group which consists of a polyamic acid and a polyimide.
The polyamic acid can be produced, for example, by using tetracarboxylic dianhydride and diamine described in Patent Document 9 (Japanese Patent Laid-Open No. 2010-97188) and reacting them by a known method. .
The polyimide can be produced by dehydrating and ring-closing the polyamic acid by a known method to imidize.
When the liquid crystal aligning agent of this invention contains 1 or more types of polymers selected from the group which consists of a polyamic acid and a polyimide, the content rate is the sum total 100 of polyorganosiloxane (I)-(III). The total amount of polyamic acid and polyimide relative to parts by weight is preferably 60 parts by weight or less, and more preferably 30 parts by weight or less.

<Liquid crystal aligning agent>
In the liquid crystal aligning agent of the present invention, the polyorganosiloxanes (I) and (II) as described above or the polyorganosiloxane (III) and other optional components are preferably used as an organic solvent. It is constituted as a liquid composition which is dissolved and contained therein.

  Examples of the organic solvent that can be used in the liquid crystal aligning agent of the present invention include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4. -Methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl Ether, ethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol Cole monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monomethyl ether acetate , Diethylene glycol monoethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monobutyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobuty , Diisopentyl ether, ethylene carbonate, propylene carbonate, methanol, ethanol, propanol, butanol, diacetone alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, monoethylene glycol, diethylene glycol, monopropylene glycol, monohexylene glycol, propylene Glycol monomethyl ether, propylene glycol monobutyl ether, methyl acetate, ethyl acetate, ethyl lactate, dimethyl sulfoxide, tetramethylurea, hexamethylphosphotriamide, m-cresol, etc. can be mentioned, one kind selected from these It is preferable to use the above.

The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, and the like. The range is preferably 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface as described later, and preferably, when heated, a coating film that becomes a liquid crystal aligning film is formed, but the solid content concentration is less than 1 wt% In this case, the film thickness of the coating film becomes too small to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes excessive. Therefore, a good liquid crystal alignment film cannot be obtained.
The particularly preferable solid content concentration range varies depending on the method used when applying the liquid crystal aligning agent to the substrate. For example, when the spinner method is used, a solid content concentration of 1.5 to 7.5% by weight is particularly preferable. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 6 to 15% by weight, and thereby the solution viscosity is in the range of 8 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 3 to 10% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.
The temperature for preparing the liquid crystal aligning agent of the present invention is preferably 10 ° C. to 50 ° C., more preferably 20 ° C. to 30 ° C.

<Method for forming liquid crystal alignment film>
The liquid crystal aligning agent of this invention can be used conveniently in order to form a liquid crystal aligning film by the photo-alignment method.
As a method for forming the liquid crystal alignment film, for example, the liquid crystal alignment film of the present invention is applied to a substrate to form a coating film, and then the coating film is irradiated with polarized or non-polarized radiation to further enhance the liquid crystal alignment ability. The method of giving can be mentioned.
First, the liquid crystal aligning agent of this invention is apply | coated to the transparent conductive film side of the board | substrate with which the pattern-shaped transparent conductive film was provided, for example by appropriate coating methods, such as a roll coater method, a spinner method, a printing method, an inkjet method. . Then, the coated surface is preheated (prebaked) and then baked (postbaked) to form a coating film. The pre-bake conditions are, for example, 0.1 to 5 minutes at 40 to 120 ° C., and the post-bake conditions are preferably 120 to 300 ° C., more preferably 150 to 250 ° C., preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The film thickness of the coating film after post-baking is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.
Examples of the substrate include glass such as float glass and soda glass, and a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and cyclic olefin resin.
As the transparent conductive film, a NESA (registered trademark) film made of SnO ₂ , an ITO film made of In ₂ O ₃ —SnO _2, or the like can be used. A known method is used for patterning these transparent conductive films.
When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate or the transparent conductive film and the coating film, a functional silane compound, titanate compound or the like is previously applied on the substrate and the transparent conductive film. May be.

Next, the coating film is given a liquid crystal alignment ability by irradiating linearly polarized light, partially polarized radiation or non-polarized radiation. Here, as the radiation, for example, ultraviolet rays including light having a wavelength of 150 nm to 800 nm and visible light can be used, but ultraviolet rays including light having a wavelength of 300 nm to 400 nm are preferable. When the radiation used is linearly polarized or partially polarized, irradiation may be performed from a direction perpendicular to the substrate surface, or from an oblique direction to give a pretilt angle, or a combination thereof. May be. When irradiating non-polarized radiation, the direction of irradiation needs to be an oblique direction.
The irradiation dose of radiation, preferably less than 1 J / ^{m 2} or more 10,000 J / ^{m 2,} more preferably from 10~3,000J / ^{m 2.} In addition, when providing the liquid crystal aligning ability by the photo-alignment method to the coating film formed from the conventionally known liquid crystal aligning agent, the irradiation dose of 10,000 J / m < ² > or more was required. However, when the liquid crystal aligning agent of the present invention is used, a good liquid crystal aligning ability is imparted even when the radiation irradiation amount in the photo-alignment method is 3,000 J / m ² or less, and further 1,000 J / m ² or less This contributes to the reduction of the manufacturing cost of the liquid crystal display element.

<Method for manufacturing liquid crystal display element>
The liquid crystal display element of this invention comprises the liquid crystal aligning film formed from the liquid crystal aligning agent of this invention. The liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention is preferable because it can exhibit its advantageous effects to the maximum when applied to a vertical alignment type liquid crystal display element.
The liquid crystal display element of this invention can be manufactured as follows, for example.
A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above, and disposing a liquid crystal between the two substrates. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example.
In the first method, first, two substrates are arranged to face each other through a gap (cell gap) so that the liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded together using a sealant, In this method, liquid crystal is injected and filled in the cell gap defined by the substrate surface and the sealing agent, and then the injection hole is sealed, whereby a liquid crystal cell can be manufactured.
The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet light curable sealing material is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is dropped on the liquid crystal alignment film surface. The other substrate is bonded so as to face each other, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, whereby a liquid crystal cell can be manufactured.
In any case, it is desirable to remove the flow alignment at the time of filling the liquid crystal by heating the liquid crystal cell to a temperature at which the liquid crystal used takes an isotropic phase and then gradually cooling to room temperature.

And the liquid crystal display element of this invention can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell. Here, when the liquid crystal alignment film is vertically aligned, the cell is configured so that the directions of easy alignment axes of the two substrates on which the liquid crystal alignment film is formed are parallel, and a polarizing plate is attached to the cell. A liquid crystal display element having a vertical alignment type liquid crystal cell can be obtained by bonding so that the polarization direction forms an angle of 45 ° with the easy alignment axis.
As the sealing agent, for example, an aluminum oxide sphere as a spacer and an epoxy resin containing a curing agent can be used.
As the liquid crystal, for example, nematic liquid crystal, smectic liquid crystal and the like can be preferably used.
In the case of a vertically aligned liquid crystal cell, a nematic liquid crystal having negative dielectric anisotropy is preferable, for example, dicyanobenzene liquid crystal, pyridazine liquid crystal, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenyl cyclohexane liquid crystal. Etc. are used.
The polarizing plate used outside the liquid crystal cell is composed of a polarizing film called “H film” in which polyvinyl alcohol is stretched and oriented while absorbing iodine and sandwiched between cellulose acetate protective films, or the H film itself. A polarizing plate etc. can be mentioned.
The liquid crystal display element of the present invention thus produced is excellent in various performances such as display characteristics and long-term reliability.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
In the following, the weight average molecular weight of the polyorganosiloxane and the solution viscosity of the polyamic acid were measured by the following methods.
[Weight average molecular weight]
The weight average molecular weight of the polyorganosiloxane was determined as a polystyrene equivalent value using monodisperse polystyrene as a standard substance from the result of measurement by gel permeation chromatography under the following conditions using the following apparatus.
Measuring device: Model “8120-GPC” manufactured by Tosoh Corporation
Column: “TSKgelGRCXLII” manufactured by Tosoh Corporation
Solvent: Tetrahydrofuran Sample concentration: 5% by weight
Sample injection volume: 100 μL
Column temperature: 40 ° C
Column pressure: 68 kgf / cm ²
[Solution viscosity of polyamic acid]
The solution viscosity (mPa · s) of the polyamic acid was measured at 25 ° C. using an E-type rotational viscometer for each polymer solution.

<Synthesis of polyorganosiloxane (I)>
Synthesis Example A-1
To a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser, 13.9 g of oxalic acid and 19.5 g of ethanol were added and stirred to prepare an ethanol solution of oxalic acid. Next, this solution was heated to 70 ° C. in a nitrogen atmosphere, and then a mixture composed of 15.1 g of tetraethoxysilane and 1.6 g of vinyltriethoxysilane as a raw material silane compound was added dropwise thereto. After completion of the dropping, a polycondensation reaction was carried out while maintaining a temperature of 70 ° C. for 6 hours. After completion of the reaction, the solution was cooled to 25 ° C., and 40.0 g of butyl cellosolve was added to obtain a solution containing polyorganosiloxane (A-1) which is polyorganosiloxane (I).
The weight average molecular weight Mw of the polyorganosiloxane (A-1) contained in this solution was 12,000.

Synthesis Examples A-2 to A-10
In Synthesis Example A-1, the kind and amount of the silane compound used as a raw material and the amounts of oxalic acid and ethanol used were the same as those in Synthesis Example A-1, except that the amounts were as described in Table 1 Then, solutions containing polyorganosiloxane (A-2) to (A-10), which are polyorganosiloxane (I), were prepared.
In Synthesis Examples A-7 and A-8, two types of silane compounds (a2-3) were used.
The weight average molecular weight Mw of each polyorganosiloxane contained in each solution is shown in accordance with 1 in Table 1.

<Synthesis of other polyorganosiloxane>
Synthesis Examples B-1 and B-2
In Synthesis Example A-1, except that the type and amount of the raw material silane compound and the amounts of oxalic acid and ethanol used were as described in 1 of Table 1, Solutions containing polyorganosiloxanes (B-1) and (B-2), which are other polyorganosiloxanes, were prepared.
The weight average molecular weight Mw of each polyorganosiloxane contained in each solution is shown in accordance with 1 in Table 1.

Abbreviations of silane compounds in 1 of Table 1 have the following meanings, respectively.
[Silane Compound (a1)]
VTES: vinyltriethoxysilane STMS: styryltrimethoxysilane ATES: allyltriethoxysilane MPTMS: 3-methacryloxypropyltrimethoxysilane APTMS: 3-acryloxypropyltrimethoxysilane [silane compound (a3)]
ODES: Octadecyltriethoxysilane DDES: Dodecyltriethoxysilane [silane compound (a4)]
TEOS: Tetraethoxysilane MTES: Methyltriethoxysilane PTES: Phenyltriethoxysilane "-" in the silane compound column of Table 1 indicates that the raw material corresponding to the column was not used.

<Synthesis of other polyorganosiloxane>
Synthesis Example G-1
In a reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser, 99 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane as a raw material silane compound, 500 g of methyl isobutyl ketone as a solvent and 10 g of triethylamine as a catalyst Were mixed at room temperature. Next, 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and then the reaction was performed for 6 hours while stirring at 80 ° C. under reflux. After completion of the reaction, the organic layer is taken out and washed with a 0.2 wt% ammonium nitrate aqueous solution until the water after washing becomes neutral, and then the solvent and water are distilled off under reduced pressure, whereby a polyorgano having an epoxy group is obtained. Siloxane was obtained as a viscous transparent liquid.
As a result of ¹ H-NMR analysis of the polyorganosiloxane having an epoxy group, a peak based on the epoxy group was obtained in the vicinity of chemical shift (δ) = 3.2 ppm according to the theoretical intensity. It was confirmed that no side reaction occurred.
Next, in a 200 mL three-necked flask, the polyorganosiloxane having an epoxy group obtained above, 30 g of methyl isobutyl ketone as a solvent, 30 g of 4-octyloxybenzoic acid as a carboxylic acid (based on the epoxy group of the polyorganosiloxane having the epoxy group) 0.10 g as a catalyst and UCAT 18X (trade name, a curing accelerator for epoxy compounds manufactured by San Apro Co., Ltd.) as a catalyst, and reacted at 100 ° C. with stirring for 48 hours. went. After completion of the reaction, the organic layer obtained by adding ethyl acetate to the reaction mixture was washed with water three times, dried using magnesium sulfate, and then the solvent was distilled off to obtain another polyorganosiloxane polyorganosiloxane ( G-1) was obtained. About this polyorganosiloxane (G-1), the weight average molecular weight Mw in terms of polystyrene measured by gel permeation chromatography was 7,200.

<Synthesis of polyorganosiloxane (I)>
Synthesis Examples C-1 to C-6
In the above Synthesis Example G-1, the same as in Synthesis Example G-1, except that the type and amount of the raw material silane compound and the type and amount of the carboxylic acid used were as described in Table 2 respectively. However, the polyorganosiloxane (C-1) which is the polyorganosiloxane (I) is prepared by adjusting the raw material silane compound concentration and the polyorganosiloxane concentration having an epoxy group in the same manner as in Synthesis Example G-1. To (C-6) were obtained. For these polyorganosiloxanes, the polystyrene-reduced weight average molecular weight Mw measured by gel permeation chromatography is shown together with 2 in Table 1.
In Synthesis Examples C-4 to C-6, two carboxylic acids were used.

Abbreviations of silane compounds and carboxylic acids in 2 of Table 1 have the following meanings, respectively.
[Silane Compound (a1)]
MPTMS: 3-methacryloxypropyltrimethoxysilane [silane compound (a2)]
ECETS: 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane [carboxylic acid (2)]
OCTBA: 4-n-octyloxybenzoic acid PCHBA: 4- (4-n-pentyl-cyclohexyl) benzoic acid SACE: Succinic acid-5ξ-cholestan-3-yl [carboxylic acid (3)]
AQCA: Anthraquinone-2-carboxylic acid DAHBBA: 2- (4-diethylamino-2-hydroxy-benzoyl) -benzoic acid “-” in the silane compound column and the carboxylic acid column in Table 2 corresponds to this column. Indicates that no ingredients were used.

<Synthesis of polyorganosiloxane (II)>
Synthesis Examples E-1 to E-5
Polyorganosiloxane having an epoxy group was obtained in the same manner as in Synthesis Example G-1. Thereafter, the polyorganosiloxane (II), a polyorganosiloxane (II), was used in the same manner as in Synthesis Example G-1, except that the type and amount of the carboxylic acid used were as described in Table 3 above. E-1) to (E-5) were obtained. For these polyorganosiloxanes, the polystyrene-reduced weight average molecular weight Mw measured by gel permeation chromatography is shown together with 3 in Table 1.
In Synthesis Examples E-1 and E-3 to E-5, two carboxylic acids were used.

The abbreviations of the silane compound (a2) and carboxylic acid in 3 of Table 1 are the following structures, respectively.
[Silane compound (a2)]
ECETS: 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane [carboxylic acid (1)]
E-1-1: Compound represented by the following formula (E-1-1) E-1-2: Compound represented by the following formula (E-1-2) E-1-3: The following formula (E -1-3) [carboxylic acid (4)]
E-4-1: 4- (t-butyloxycarbonyl) benzoic acid

“NC ₅ H ₁₁ —” in the above formula represents a linear pentyl group.
"-" In the carboxylic acid column of 3 in Table 1 indicates that the raw material corresponding to the column was not used.

<Synthesis of polyorganosiloxane (III)>
Synthesis Examples H-1 to H-5
In Synthesis Example G-1, the same as in Synthesis Example G-1, except that the type and amount of the raw material silane compound and the type and amount of the carboxylic acid used were as described in Table 4 respectively. However, the polyorganosiloxane (H-1) which is polyorganosiloxane (III) is prepared by adjusting the concentration of the raw material silane compound and the concentration of the polyorganosiloxane having an epoxy group in the same manner as in Synthesis Example G-1. To (H-5) were obtained. For these polyorganosiloxanes, the polystyrene-reduced weight average molecular weight Mw measured by gel permeation chromatography is shown in accordance with 4 in Table 1.
In Synthesis Examples H-4 and H-5, two types of carboxylic acids were used.

  The abbreviations of silane compound and carboxylic acid in 4 of Table 1 have the same meanings as the abbreviations described above.

<Synthesis of polyamic acid>
Synthesis example PA-1 to PA-3
In 135 g of N-methyl-2-pyrrolidone, the diamine and tetracarboxylic dianhydride of the type and amount shown in Table 1 were added and dissolved in this order, and the total weight of the diamine and tetracarboxylic dianhydride Is 10% by weight with respect to the total weight of the reaction solution, and this is reacted at 60 ° C. for 6 hours to contain 10% by weight of each of polyamic acids (F-1) to (F-3). 150 g of each solution was obtained. The viscosity of each solution obtained here is shown in Table 1-5.

Abbreviations of diamine and tetracarboxylic acid dihydrate in 5 in Table 1 have the following meanings, respectively.
[Diamine]
F-1-1: Compound represented by the following formula (F-1-1) F-1-2: Compound represented by the following formula (F-1-2) F-1-3: The following formula (F -1-3) Compound F-1-4: Cholestanyl 3,5-diaminobenzoate [tetracarboxylic dianhydride]
F-2-1: 2,3,5-tricarboxycyclopentyl acetic acid dianhydride

“NC ₄ H ₉ O—” and “nC ₅ H ₁₁ O—” in the above formulas represent an alkoxy group having a linear butyl group or a linear pentyl group, respectively.

Example 1
<Preparation of liquid crystal aligning agent>
In the solution containing the polyorganosiloxane (A-1) obtained in Synthesis Example A-1 as the polyorganosiloxane (I), the polyorganosiloxane obtained in Synthesis Example E-1 as the polyorganosiloxane (II) ( 5 parts by weight of E-1) was added to 100 parts by weight of polyorganosiloxane (A-1) in the above solution, and butyl cellosolve was further added to obtain a solution having a solid content concentration of 5% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 1 μm.

<Manufacture and evaluation of vertical alignment type liquid crystal display element>
[Manufacture of vertical alignment type liquid crystal display elements]
On the transparent electrode surface of the glass substrate with a transparent electrode made of an ITO film, the liquid crystal aligning agent prepared above was applied using a spinner, pre-baked on a hot plate at 80 ° C. for 1 minute, and then the interior was filled with nitrogen. A film having a thickness of 0.1 μm was formed by heating in a substituted oven at 200 ° C. for 1 hour. Next, the surface of the coating film was irradiated with polarized ultraviolet rays (p-waves) 200 J / m ² containing a 313 nm emission line from a direction inclined by 40 ° from the substrate normal using a Hg-Xe lamp and a Grand Taylor prism. An alignment film was obtained.
The same operation was repeated to manufacture a pair (two) of substrates having a liquid crystal alignment film.
An epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied to the outer periphery of the surface having one liquid crystal alignment film of the above substrates by screen printing, and the liquid crystal alignment film surfaces of a pair of substrates are opposed to each other. Then, after pressure-bonding so that the irradiation direction of polarized ultraviolet rays irradiated to each substrate was antiparallel (180 °), the adhesive was thermally cured by heating at 150 ° C. for 1 hour. Next, a negative liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) was filled in the gap between the substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive to constitute a liquid crystal cell. Furthermore, in order to remove the flow alignment during liquid crystal injection, the liquid crystal cell was heated to 150 ° C. and then gradually cooled to room temperature. Next, a vertical alignment type is formed by laminating polarizing plates on both outer surfaces of the substrate so that the polarization directions thereof are orthogonal to each other and form an angle of 45 ° with the irradiation direction of polarized ultraviolet light onto the liquid crystal alignment film surface. A liquid crystal display device was manufactured.

[Evaluation of vertical alignment liquid crystal display element]
The vertical alignment type liquid crystal display device manufactured above was evaluated as follows. The evaluation results are shown in Table 2-1.
(1) Evaluation of liquid crystal orientation The presence or absence of an abnormal domain in the change in brightness when the voltage of 5 V was turned ON / OFF (applied / released) in the liquid crystal display element manufactured above was visually observed.
In this case, light leakage is not observed when the voltage is turned off, and the drive region is displayed white when the voltage is applied, and the light is not leaked from other regions. The liquid crystal orientation was “bad”.
(2) Evaluation of pretilt angle About each liquid crystal display element manufactured above, the angle of inclination of the liquid crystal molecules from the substrate surface was measured by a crystal rotation method using He-Ne laser light, and this value was used as the pretilt angle. . The crystal rotation method is described in Non-Patent Document 1 (T. J. Scheffer et. Al., J. Appl. Phys. Vol. 48, p1783 (1977)) and Non-Patent Document 2 (F. Nakano et. Al., JPN). J. Appl.Phys.vol.19, p2013 (1980)).
(3) Evaluation of UV resistance A voltage of 1 V was applied to the liquid crystal display device manufactured above at 70 ° C. with an application time of 60 microseconds and a span of 16.67 milliseconds, and then 16.67 millimeters from the release of application. The voltage holding ratio after 2 seconds was measured, and this value was defined as the initial voltage holding ratio VHR _BI .
The liquid crystal display element after measuring the initial voltage holding ratio was irradiated with 10,000 J / m ² of ultraviolet light using a metal halide lamp with an illuminance of 800 W / m ² , and then allowed to stand at room temperature and naturally cooled to room temperature. . Subsequently, the voltage holding ratio was measured again in the same manner as described above, and this value was defined as the post-irradiation voltage holding ratio VHR _AI .
The change rate of the voltage holding ratio at this time is expressed by the following formula (1).

When this value is 95% or more, UV resistance is “excellent”, when 90% or more and less than 95% is UV resistance “good”, and when it is less than 90%, UV resistance is It was evaluated as sex “bad”.
The voltage holding ratio was manually measured using “VHR-1” manufactured by Toyo Corporation.

Examples 2-16 and Comparative Examples 1-10 and 16-22
A liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the type and amount of the polyorganosiloxane used were as described in Table 1 and evaluated by producing a liquid crystal display device. . The evaluation results are shown in Table 2-1.

Example 17
<Preparation of liquid crystal aligning agent>
100 parts by weight of polyorganosiloxane (C-1) obtained in Synthesis Example C-1 as polyorganosiloxane (I) and polyorganosiloxane (E-) obtained in Synthesis Example E-5 as polyorganosiloxane (II) 5) 5 parts by weight was dissolved in butyl cellosolve to obtain a solution having a solid content concentration of 5% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 1 μm.
<Manufacture and evaluation of vertical alignment type liquid crystal display element>
A liquid crystal display device was produced and evaluated in the same manner as in Example 1 except that the liquid crystal aligning agent prepared above was used. The evaluation results are shown in Table 2-1.
Examples 18-22 and Comparative Examples 11-15
A liquid crystal aligning agent was prepared in the same manner as in Example 17 except that the type and amount of the polyorganosiloxane used were as shown in Table 2 and evaluated. . The evaluation results are shown in Table 2-1.

Example 23
<Preparation of liquid crystal aligning agent>
The polyorganosiloxane (H-1) obtained in Synthesis Example H-1 as polyorganosiloxane (III) was dissolved in butyl cellosolve to obtain a solution having a solid content concentration of 5% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 1 μm.
<Manufacture and evaluation of vertical alignment type liquid crystal display element>
A liquid crystal display device was produced and evaluated in the same manner as in Example 1 except that the liquid crystal aligning agent prepared above was used. The evaluation results are shown in 2 of Table 2.

Examples 24-27
A liquid crystal aligning agent was prepared in the same manner as in Example 17 except that the type of polyorganosiloxane used was as described in Table 2, and a liquid crystal display device was produced and evaluated. The evaluation results are shown in 2 of Table 2.

Comparative Example 23
<Preparation of liquid crystal aligning agent>
Γ-butyrolactone (BL), propylene carbonate (PC), and N-methyl-2-pyrrolidone (NMP) are sufficiently added to the solution containing the polyamic acid (PA-1) obtained in Synthesis Example PA-1 above. The solution was stirred to obtain a solution having a solvent composition of BL: PC: NMP = 10: 40: 50 (weight ratio) and a solid content concentration of 3.6% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 1 μm.
<Manufacture and Evaluation of Optical Vertical Alignment Type Liquid Crystal Display Device>
A liquid crystal display device was produced and evaluated in the same manner as in Example 1 except that the liquid crystal aligning agent prepared above was used. The evaluation results are shown in Table 2-3.
Comparative Examples 24 and 25
A liquid crystal aligning agent was prepared in the same manner as in Comparative Example 23 except that the type of polyamic acid used was as described in Table 2-3, and a liquid crystal display device was produced and evaluated. The evaluation results are shown in Table 2-3.

Claims (5)

(I) The following formula (A)

(In the formula (A), R ¹⁵ is a hydrogen atom or a methyl group,
X ^I and X ^II are each a 1,4-phenylene group, a methylene group or an alkylene group having 2 to 8 carbon atoms,
Z is an oxygen atom, -COO- ^* or -OCO- ^* (However, bond marked with "*" is ^{X II} side.)
a, b, c and d are each 0 or 1,
However, when c is is a 0 d is ^{1, X II} is a 1,4-phenylene group,
When b is 0, d is 0. )
Have a group having in polymerizable double bond represented, polyorganosiloxanes having no group having a cinnamic acid structure, and (II) contain a polyorganosiloxane having a group having a cinnamic acid structure The liquid crystal aligning agent characterized by the above-mentioned. The above (II) polyorganosiloxane is
A polyorganosiloxane having an epoxy group;
A carboxylic acid having a cinnamic acid structure;
The liquid crystal aligning agent of Claim 1 which is obtained by making this react. The liquid crystal aligning agent of Claim 1 or 2 which is a vertical alignment type. On a substrate, a coating film formed by applying the liquid crystal aligning agent according to claim 1 or 2, characterized in that through the process of irradiating the coating film, the method of forming the liquid crystal alignment film. Characterized by comprising a liquid crystal alignment film formed from the liquid crystal aligning agent according to claim 1 or 2, the liquid crystal display device.