JP5708957B2 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element.

Until now, a nematic liquid crystal having positive dielectric anisotropy has been sandwiched with a substrate with a transparent electrode having a liquid crystal alignment film, and the major axis of liquid crystal molecules is continuously 0 to 360 ° between the substrates as necessary. TN (Twisted Nematic) type and STN (Super Twisted Nematic) type that are twisted to IPS, an IPS (In Plane Switching) type that forms an electrode only on one side of the substrate and applies an electric field in a direction parallel to the substrate, negative There are known liquid crystal display elements having various liquid crystal cells such as VA (Vertical Alignment) type using nematic liquid crystal having dielectric anisotropy (see Patent Documents 1 to 4). Among the above, a liquid crystal display element having an IPS type liquid crystal cell is known as a horizontal electrolysis type liquid crystal display element.
In such a liquid crystal cell, a liquid crystal alignment film is provided on the substrate surface in order to align liquid crystal molecules in a predetermined direction with respect to the substrate surface. This liquid crystal alignment film is usually formed by a method of rubbing the organic film surface formed on the substrate surface in one direction with a cloth material such as rayon (rubbing method) in TN type, STN type and IPS type liquid crystal cells. Is done. However, if the liquid crystal alignment film is formed by rubbing treatment, dust and static electricity are likely to be generated during the rubbing process, so that dust adheres to the alignment film surface and causes display defects. In the case of a substrate having a (Thin Film Transistor) element, there is also a problem that the circuit damage of the TFT element occurs due to the generated static electricity, which causes a decrease in product yield. Furthermore, in liquid crystal display elements, which are becoming increasingly high-definition in the future, uniform rubbing treatment is becoming difficult due to unevenness that inevitably occurs on the substrate surface as the density of pixels increases.

Thus, as another means for aligning liquid crystals in a liquid crystal cell, a photo-alignment method has been proposed in which liquid crystal alignment ability is imparted by irradiating a photosensitive organic thin film formed on a substrate surface with polarized or non-polarized radiation ( (See Patent Documents 5 to 15). According to this technology, uniform liquid crystal alignment can be realized without generating static electricity or dust. This technique can be applied to VA type liquid crystal cells in addition to TN type, STN type, and IPS type liquid crystal cells.
In recent years, it has been reported that by using a specific azo compound in a liquid crystal aligning agent used in a TN type liquid crystal cell, a liquid crystal alignment film having good electrical characteristics can be obtained by a photo-alignment method (Patent Document 16). However, according to this technique, since a high integrated exposure amount of 10,000 J / m ² or more is necessary for forming the liquid crystal alignment film, the degree of damage with time of the exposure apparatus is large, and the liquid crystal alignment film manufacturing cost is low. Including soaring problems.
In this regard, it has been reported that a liquid crystal aligning agent containing a polymer having a specific long chain structure or cyclic structure gives a liquid crystal alignment film having excellent liquid crystal alignment and electrical properties by a photo-alignment method with a small exposure amount ( Patent Documents 17 to 19). This technique is an excellent technique that can easily and inexpensively form a liquid crystal alignment film having a desired performance when applied to a liquid crystal display element having a VA type liquid crystal cell. Alternatively, when applied to a liquid crystal display element having an IPS liquid crystal cell, the liquid crystal orientation is not necessarily sufficient.
When applied to a liquid crystal display element having a TN type, STN type or IPS type liquid crystal cell, particularly an IPS type liquid crystal display element, a liquid crystal alignment film excellent in liquid crystal alignment and electrical characteristics by a photo-alignment method with a small exposure amount The liquid crystal aligning agent which can be given is not yet known.

JP 56-91277 A JP-A-1-120528 US Pat. No. 5,928,733 Japanese Patent Laid-Open No. 11-258605 JP-A-6-287453 JP-A-10-251646 Japanese Patent Laid-Open No. 11-2815 JP-A-11-152475 JP 2000-144136 A JP 2000-319510 A JP 2000-281724 A JP-A-9-297313 JP 2003-307736 A JP 2004-163646 A JP 2002-250924 A JP 2007-138138 A International Publication No. 2009/025385 Pamphlet International Publication No. 2009/025386 Pamphlet International Publication No. 2009/025388 Pamphlet JP-A 63-291922

Chemical Reviews, 95, p1409 (1995)

The present invention has been made in view of the above circumstances, and the object thereof is good by a photo-alignment method with a small exposure amount when applied to a liquid crystal display element having a TN type, STN type or IPS type liquid crystal cell. An object of the present invention is to provide a liquid crystal aligning agent that can form a liquid crystal alignment film that exhibits excellent liquid crystal alignment ability and is excellent in various properties such as electrical characteristics. Another object of the present invention is to provide a liquid crystal alignment film and a liquid crystal display device having the excellent characteristics as described above.
Still other objects and advantages of the present invention will become apparent from the following description.

In accordance with the present invention, the above objects and advantages of the present invention are primarily as follows:
The following formulas (A1 ′) and (A2 ′)

(In the formula (A1 ′), R is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fluorine atom or a cyano group, and R ¹ is a phenylene group or a cyclohexylene group, provided that the phenylene group or the cyclohexylene group. A part or all of the hydrogen atoms may be substituted with a fluorine atom or a cyano group, and R ² represents a single bond, a methylene group, an alkylene group having 2 or 3 carbon atoms, an oxygen atom, a sulfur atom, —CH═CH—. Or —NH—, a is an integer of 0 to 3, and when a is 2 or 3, a plurality of R ¹ and R ² may be the same or different, and R ³ is a fluorine atom or a cyano group, b is an integer of 0 to 4, and “*” indicates a bond;
In the formula (A2 ′), R ′ is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fluorine atom or a cyano group, and R ⁴ is a phenylene group or a cyclohexylene group, provided that the phenylene group or the cyclohexylene group. A part or all of the hydrogen atoms may be substituted with a fluorine atom or a cyano group, and R ⁵ is a single bond, a methylene group, an alkylene group having 2 or 3 carbon atoms, an oxygen atom, a sulfur atom or —NH—. , C is an integer of 1 to 3, and when c is 2 or 3, a plurality of R ⁴ and R ⁵ may be the same or different, and R ⁶ is a fluorine atom or cyano. D is an integer of 0 to 4, R ⁷ is an oxygen atom, -COO- ⁺ or -OCO- ⁺ (in the above, a bond marked with "+" is bonded to R ⁸ ). And R ⁸ is a divalent aromatic group, a divalent alicyclic group, a divalent heterocyclic group or a divalent condensed cyclic group, R ⁹ is a single bond, ⁺ —OCO— (CH ₂ ) _f - or _{^{+ -O- (CH 2) g -}} ( provided that a bond marked with "+" in the above _{^{- (R 7 -R 8) e}} - is a side, f and g are each 1 to 10 E) is an integer of 0 to 3, and “*” indicates a bond. )
A radiation-sensitive polyorganosiloxane having at least one group selected from the group consisting of groups represented by each of the above, and a group consisting of a polyorganosiloxane other than the above-mentioned radiation-sensitive polyorganosiloxane, polyamic acid, and polyimide This is achieved by a liquid crystal aligning agent containing at least one selected polymer.
Secondly, the above objects and advantages of the present invention are achieved by a liquid crystal alignment film formed from the above liquid crystal aligning agent,
Thirdly, this is achieved by a liquid crystal display device having the above-described liquid crystal alignment film.

When the liquid crystal aligning agent of this invention is applied to the liquid crystal display element which has a TN type, STN type, or IPS type liquid crystal cell, especially the horizontal electrolysis type liquid crystal display element which has an IPS type liquid crystal cell, it is by a small exposure amount. A liquid crystal alignment film that exhibits good liquid crystal alignment ability and excellent performance such as electrical characteristics can be formed by the photo-alignment method.
Since the liquid crystal display element of the present invention comprising the liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention can display high quality and is inexpensive, it can be effectively applied as various display devices. Can do.

The liquid crystal aligning agent of the present invention includes a radiation-sensitive polyorganosiloxane having at least one group selected from the group consisting of groups represented by the above formulas (A1 ′) and (A2 ′), and the above-mentioned sensitivity. It contains at least one polymer selected from the group consisting of polyorganosiloxanes other than radioactive polyorganosiloxanes, polyamic acids, and polyimides.
<Radiation sensitive polyorganosiloxane>
The radiation-sensitive polyorganosiloxane contained in the liquid crystal aligning agent of the present invention has at least one group selected from the group consisting of groups represented by the above formulas (A1 ′) and (A2 ′). Is.
The alkyl group having 1 to 3 carbon atoms of R in the above formula (A1 ′) and R ′ in the above formula (A2 ′) is preferably a methyl group, an ethyl group or an n-propyl group. The phenylene group and the cyclohexylene group of R ¹ in the above formula (A1 ′) and R ⁴ in the above formula (A2 ′) are each a 1,4-phenylene group or a 1,4-cyclohexylene group. preferable.
R ² in the above formula (A1 ′) is preferably a single bond, an oxygen atom or —CH═CH—.
Examples of the divalent aromatic group represented by R ⁸ in the above formula (A2 ′) include a 1,4-phenylene group or a 4,4′-biphenylene group;
Examples of the divalent alicyclic group include 1,4-cyclohexylene group and 4,4′-bicyclohexylene group;
Examples of the divalent heterocyclic group include a furan-2,5-diyl group, a thiophene-2,5-diyl group, a 2,2′-bithiophene-5,5′-diyl group;
Examples of the divalent condensed cyclic group include anthraquinone-2,6-diyl group, naphthalene-1,4-diyl group, naphthalene-1,5-diyl group, naphthalene-2,6-diyl group, and naphthalene-2. , 7-diyl group, anthracene-9,10-diyl group, carbazole-3,6-diyl group, dibenzothiophene-2,8-diyl group and the like. In the above formula (A2 ′), e is preferably 0.
Specific examples of the group possessed by the radiation-sensitive polyorganosiloxane contained in the liquid crystal aligning agent of the present invention include, for example, the following formula (A1 ′) as a group represented by the following formula (A1 ′):

(However, in the above, “*” indicates a bond.)
A group represented by each of the following:
As the group represented by the above formula (A2 ′), for example, the following formula

(However, in the above, “*” indicates a bond.)
And groups represented by each of the above.
The content ratio of at least one group selected from the group consisting of groups represented by each of the above formulas (A1 ′) and (A2 ′) in the radiation-sensitive polyorganosiloxane contained in the liquid crystal aligning agent of the present invention. Is preferably 0.2 to 6 mmol / g-polymer, more preferably 0.3 to 5 mmol / g-polymer.
The radiation-sensitive polyorganosiloxane contained in the liquid crystal aligning agent of the present invention is in addition to at least one group selected from the group consisting of groups represented by the above formulas (A1 ′) and (A2 ′). Further, it preferably has an epoxy group. In this case, the epoxy equivalent of the radiation-sensitive polyorganosiloxane is preferably 150 g / mol or more, more preferably 200 to 10,000 g / mol, and further preferably 200 to 2,000 g / mol. By using a radiation-sensitive polyorganosiloxane having an epoxy equivalent in such a proportion, the liquid crystal aligning agent of the present invention is superior in liquid crystal aligning property and excellent in afterimage characteristics without impairing the storage stability of the liquid crystal aligning agent. An alignment film can be formed, which is preferable.
Regarding the radiation-sensitive polyorganosiloxane contained in the liquid crystal aligning agent of the present invention, the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography is preferably 1,000 to 200,000, and 2,000. Is more preferably from 100,000 to 100,000, and particularly preferably from 3,000 to 30,000.

<Synthesis of radiation-sensitive polyorganosiloxane>
The radiation-sensitive polyorganosiloxane contained in the liquid crystal aligning agent of the present invention may be synthesized by any method as long as it is as described above. As a method for synthesizing the radiation-sensitive polyorganosiloxane contained in the liquid crystal aligning agent of the present invention, for example, at least one selected from the group consisting of groups represented by the above formulas (A1 ′) and (A2 ′), for example. A method of hydrolyzing and condensing a hydrolyzable silane compound having a seed group, or a mixture of the hydrolyzable silane compound and another hydrolyzable silane compound;
Polyorganosiloxane having an epoxy group and the following formulas (A1) and (A2)

(R, R ¹ , R ² , R ³ , a and b in formula (A1) have the same meanings as in formula (A1 ′);
R ′, R ⁴ , R ⁵ , R ⁶ , R ⁸ , R ⁹ , c, d and e in the formula (A2) have the same meanings as in the above formula (A2 ′). )
Or a method of reacting with at least one selected from the group consisting of compounds represented by the above.
Of these, the latter method is preferred from the viewpoints of ease of synthesis of the raw material compound, ease of reaction, and the like.
Hereinafter, polyorganosiloxane having an epoxy group, which is a preferred method for synthesizing the radiation-sensitive polyorganosiloxane contained in the liquid crystal aligning agent of the present invention, and each of the above formulas (A1) and (A2) The reaction method with at least 1 sort (s) selected from the group which consists of said compound is demonstrated.

[Polyorganosiloxane having epoxy group]
The epoxy group in the polyorganosiloxane having an epoxy group is bonded to a silicon atom through an ethylene oxide skeleton or a 1,2-epoxycycloalkane skeleton either directly or through an alkylene which may be interrupted by an oxygen atom. It is preferable that it exists in polyorganosiloxane as what is contained in the group (group which has an epoxy group). Examples of the group having such an epoxy group include the following formula (EP-1) or (EP-2)

(In formulas (EP-1) and (EP-2), “*” indicates a bond).)
The group represented by these can be mentioned.
The epoxy equivalent of the polyorganosiloxane having an epoxy group is preferably 100 to 10,000 g / mol, and more preferably 150 to 1,000 g / mol.
About the polyorganosiloxane having an epoxy group, the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography is preferably 500 to 100,000, more preferably 1,000 to 10,000, In particular, it is preferably 1,000 to 5,000.
Such polyorganosiloxane having an epoxy group is, for example, a silane compound having an epoxy group or a mixture of a silane compound having an epoxy group and another silane compound, preferably in the presence of a suitable organic solvent, water and a catalyst. Can be synthesized by hydrolysis and condensation.
Examples of the silane compound having an epoxy group include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropylmethyldiethoxy. Silane, 3-glycidyloxypropyldimethylmethoxysilane, 3-glycidyloxypropyldimethylethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxy A silane etc. can be mentioned.

  Examples of the other silane compounds include tetrachlorosilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, trichlorosilane, Trimethoxysilane, triethoxysilane, tri-n-propoxysilane, tri-i-propoxysilane, tri-n-butoxysilane, tri-sec-butoxysilane, fluorotrichlorosilane, fluorotrimethoxysilane, fluorotriethoxysilane, Fluorotri-n-propoxysilane, fluorotri-i-propoxysilane, fluorotri-n-butoxysilane, fluorotri-sec-butoxysilane, methyltrichlorosilane, methyltrimethoxysilane, Rutriethoxysilane, methyltri-n-propoxysilane, methyltri-i-propoxysilane, methyltri-n-butoxysilane, methyltri-sec-butoxysilane, 2- (trifluoromethyl) ethyltrichlorosilane, 2- (trifluoromethyl) ) Ethyltrimethoxysilane, 2- (trifluoromethyl) ethyltriethoxysilane, 2- (trifluoromethyl) ethyltri-n-propoxysilane, 2- (trifluoromethyl) ethyltri-i-propoxysilane, 2- (tri Fluoromethyl) ethyltri-n-butoxysilane, 2- (trifluoromethyl) ethyltri-sec-butoxysilane, 2- (perfluoro-n-hexyl) ethyltrichlorosilane, 2- (perfluoro-n-hexyl) ethyltri Methoxy Lan, 2- (perfluoro-n-hexyl) ethyltriethoxysilane, 2- (perfluoro-n-hexyl) ethyltri-n-propoxysilane, 2- (perfluoro-n-hexyl) ethyltri-i-propoxysilane 2- (perfluoro-n-hexyl) ethyltri-n-butoxysilane, 2- (perfluoro-n-hexyl) ethyltri-sec-butoxysilane, 2- (perfluoro-n-octyl) ethyltrichlorosilane, 2 -(Perfluoro-n-octyl) ethyltrimethoxysilane, 2- (perfluoro-n-octyl) ethyltriethoxysilane,

2- (perfluoro-n-octyl) ethyltri-n-propoxysilane, 2- (perfluoro-n-octyl) ethyltri-i-propoxysilane, 2- (perfluoro-n-octyl) ethyltri-n-butoxysilane 2- (perfluoro-n-octyl) ethyltri-sec-butoxysilane, hydroxymethyltrichlorosilane, hydroxymethyltrimethoxysilane, hydroxyethyltrimethoxysilane, hydroxymethyltri-n-propoxysilane, hydroxymethyltri-i- Propoxysilane, hydroxymethyltri-n-butoxysilane, hydroxymethyltri-sec-butoxysilane, 3- (meth) acryloxypropyltrichlorosilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meta Acryloxypropyltriethoxysilane, 3- (meth) acryloxypropyltri-n-propoxysilane, 3- (meth) acryloxypropyltri-i-propoxysilane, 3- (meth) acryloxypropyltri-n-butoxy Silane, 3- (meth) acryloxypropyltri-sec-butoxysilane, 3-mercaptopropyltrichlorosilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltri-n-propoxysilane 3-mercaptopropyltri-i-propoxysilane, 3-mercaptopropyltri-n-butoxysilane, 3-mercaptopropyltri-sec-butoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltrieth Sisilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri-n-propoxysilane, vinyltri-i-propoxysilane, vinyltri-n-butoxysilane, vinyltri-sec-butoxysilane, allyltrichlorosilane, allyltri Methoxysilane, allyltriethoxysilane, allyltri-n-propoxysilane, allyltri-i-propoxysilane, allyltri-n-butoxysilane, allyltri-sec-butoxysilane, phenyltrichlorosilane, phenyltrimethoxysilane, phenyltriethoxysilane, Phenyltri-n-propoxysilane, phenyltri-i-propoxysilane, phenyltri-n-butoxysilane, phenyltri-sec-butoxysilane, methyl Dichlorosilane, methyldimethoxysilane, methyldiethoxysilane, methyldi-n-propoxysilane, methyldi-i-propoxysilane, methyldi-n-butoxysilane, methyldi-sec-butoxysilane, dimethyldichlorosilane, dimethyldimethoxysilane, dimethyldi Ethoxysilane, dimethyldi-n-propoxysilane, dimethyldi-i-propoxysilane, dimethyldi-n-butoxysilane, dimethyldi-sec-butoxysilane,

(Methyl) [2- (perfluoro-n-octyl) ethyl] dichlorosilane, (methyl) [2- (perfluoro-n-octyl) ethyl] dimethoxysilane, (methyl) [2- (perfluoro-n- Octyl) ethyl] dimethoxysilane, (methyl) [2- (perfluoro-n-octyl) ethyl] di-n-propoxysilane, (methyl) [2- (perfluoro-n-octyl) ethyl] di-i -Propoxysilane, (methyl) [2- (perfluoro-n-octyl) ethyl] di-n-butoxysilane, (methyl) [2- (perfluoro-n-octyl) ethyl] di-sec-butoxysilane, (Methyl) (3-mercaptopropyl) dichlorosilane, (methyl) (3-mercaptopropyl) dimethoxysilane, (methyl) (3-mercapto Propyl) diethoxysilane, (methyl) (3-mercaptopropyl) di-n-propoxysilane, (methyl) (3-mercaptopropyl) di-i-propoxysilane, (methyl) (3-mercaptopropyl) di-n -Butoxysilane, (methyl) (3-mercaptopropyl) di-sec-butoxysilane, (methyl) (vinyl) dichlorosilane, (methyl) (vinyl) dimethoxysilane, (methyl) (vinyl) diethoxysilane, (methyl ) (Vinyl) di-n-propoxysilane, (methyl) (vinyl) di-i-propoxysilane, (methyl) (vinyl) di-n-butoxysilane, (methyl) (vinyl) di-sec-butoxysilane, Divinyldichlorosilane, divinyldimethoxysilane, divinyldiethoxysilane, divinyldi-n- Lopoxysilane, divinyldi-i-propoxysilane, divinyldi-n-butoxysilane, divinyldi-sec-butoxysilane, diphenyldichlorosilane, diphenyldimethoxysilane, diphenyldiethoxysilane, diphenyldi-n-propoxysilane, diphenyldi-i-propoxy Silane, diphenyldi-n-butoxysilane, diphenyldi-sec-butoxysilane, chlorodimethylsilane, methoxydimethylsilane, ethoxydimethylsilane, chlorotrimethylsilane, bromotrimethylsilane, iodotrimethylsilane, methoxytrimethylsilane, ethoxytrimethylsilane, n-propoxytrimethylsilane, i-propoxytrimethylsilane, n-butoxytrimethylsilane, sec-butoxytrimethylsilane, t-butoxytrimethylsilane, (chloro) (vinyl) dimethylsilane, (methoxy) (vinyl) dimethylsilane, (ethoxy) (vinyl) dimethylsilane, (chloro) (methyl) diphenylsilane, (methoxy) (methyl) diphenylsilane In addition to silane compounds having one silicon atom such as (ethoxy) (methyl) diphenylsilane,

Product names such as KC-89, KC-89S, X-21-3153, X-21-5841, X-21-5842, X-21-5843, X-21-5844, X-21-5845, X -21-5848, X-21-5847, X-21-5848, X-22-160AS, X-22-170B, X-22-170BX, X-22-170D, X-22-170DX, X-22 -176B, X-22-176D, X-22-176DX, X-22-176F, X-40-2308, X-40-2651, X-40-2655A, X-40-2671, X-40-2672 , X-40-9220, X-40-9225, X-40-9227, X-40-9246, X-40-9247, X-40-9250, X-40-9323, X-41-10 3, X-41-1056, X-41-1805, X-41-1810, KF6001, KF6002, KF6003, KR212, KR-213, KR-217, KR220L, KR242A, KR271, KR282, KR300, KR311, KR401N, KR500, KR510, KR5206, KR5230, KR5235, KR9218, KR9706 (manufactured by Shin-Etsu Chemical Co., Ltd.); glass resin (manufactured by Showa Denko KK); SH804, SH805, SH806A, SH840, SR2400, SR2402, SR2405, SR2406, SR2410, SR2411, SR2416, SR2420 (above, manufactured by Toray Dow Corning Co., Ltd.); FZ3711, FZ3722 (above, manufactured by Nihon Unicar Co., Ltd.); DMS-S1 , DMS-S15, DMS-S21, DMS-S27, DMS-S31, DMS-S32, DMS-S33, DMS-S35, DMS-S38, DMS-S42, DMS-S45, DMS-S51, DMS-227, PSD -0332, PDS-1615, PDS-9931, XMS-5025 (above, manufactured by Chisso Corporation); Methyl silicate MS51, Methyl silicate MS56 (above, manufactured by Mitsubishi Chemical Corporation); Ethyl silicate 28, Ethyl silicate 40, Examples include partial condensates such as ethyl silicate 48 (above, Colcoat Co., Ltd.); GR100, GR650, GR908, GR950 (above, Showa Denko Co., Ltd.), and one or more of these are used. can do.

Among other silane compounds, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltri Ethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, mercapto It is preferable to use one or more selected from the group consisting of methyltrimethoxysilane, mercaptomethyltriethoxysilane, dimethyldimethoxysilane and dimethyldiethoxysilane.
In synthesizing the polyorganosiloxane having an epoxy group in the present invention, the use ratio of the silane compound having an epoxy group and the other silane compound is set so that the epoxy equivalent of the obtained polyorganosiloxane is within the above preferred range. It is preferable to prepare and set.
Examples of the organic solvent that can be used for synthesizing the polyorganosiloxane having an epoxy group include hydrocarbons, ketones, esters, ethers, alcohols, and the like.

Examples of the hydrocarbon include toluene and xylene; examples of the ketone include methyl ethyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, diethyl ketone, and cyclohexanone;
Examples of the ester include ethyl acetate, n-butyl acetate, i-amyl acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, and ethyl lactate;
Examples of the ether include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, tetrahydrofuran, dioxane and the like;
Examples of the alcohol include 1-hexanol, 4-methyl-2-pentanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, propylene glycol monomethyl. Examples include ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, and the like. Of these, water-insoluble ones are preferred.
These organic solvents can be used alone or in admixture of two or more.
The amount of the organic solvent used is preferably 10 to 10 parts by weight based on 100 parts by weight of the total of silane compounds (the total of silane compounds having an epoxy group and other silane compounds optionally used). 1,000 parts by weight, and more preferably 50 to 1,000 parts by weight.

The amount of water used when synthesizing the polyorganosiloxane having an epoxy group is preferably 0.5 to 100 mol, more preferably 1 to 30 mol, relative to a total of 1 mol of the silane compound.
As said catalyst, an acid, an alkali metal compound, an organic base, a titanium compound, a zirconium compound etc. can be used, for example.
Examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide and the like.
Examples of the organic base include primary and secondary organic amines such as ethylamine, diethylamine, piperazine, piperidine, pyrrolidine and pyrrole; triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine, 4-dimethylaminopyridine, Examples thereof include tertiary organic amines such as diazabicycloundecene; quaternary organic amines such as tetramethylammonium hydroxide, and the like. Among these organic bases, tertiary organic amines such as triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine and 4-dimethylaminopyridine; quaternary organic amines such as tetramethylammonium hydroxide preferable.

As a catalyst for synthesizing a polyorganosiloxane having an epoxy group, an alkali metal compound or an organic base is preferable. By using an alkali metal compound or organic base as a catalyst, the desired polyorganosiloxane can be obtained at a high hydrolysis and condensation rate without causing side reactions such as ring opening of the epoxy group. This is preferable. In addition, the liquid crystal aligning agent of the present invention containing a reaction product of a polyorganosiloxane having an epoxy group synthesized using an alkali metal compound or an organic base as a catalyst and a cinnamic acid derivative is extremely excellent in storage stability, which is advantageous. It is. The reason is that, as pointed out in Non-Patent Document 1 (Chemical Reviews, 95, p1409 (1995)), when an alkali metal compound or an organic base is used as a catalyst in hydrolysis and condensation reactions, a random structure, a ladder type It is presumed that this is because a polyorganosiloxane having a structure or a cage structure and having a low silanol group content is obtained. Since the content ratio of silanol groups is small, the condensation reaction between silanol groups is suppressed, and when the liquid crystal aligning agent of the present invention contains other polymers described later, the silanol groups and other polymers Since the condensation reaction is suppressed, it is assumed that the storage stability is excellent.
As the catalyst, an organic base is particularly preferable. The amount of the organic base used varies depending on the reaction conditions such as the type of organic base and temperature, and should be set as appropriate. Yes, more preferably 0.05 to 1 mol.

The hydrolysis and condensation reaction when synthesizing the polyorganosiloxane having an epoxy group is carried out by dissolving the silane compound having an epoxy group and, if necessary, another silane compound in an organic solvent, and dissolving this solution with an organic base and water. It is preferably carried out by mixing and heating using a suitable heating device such as an oil bath.
In the hydrolysis and condensation reaction, the heating temperature is preferably 130 ° C. or lower, more preferably 40 to 100 ° C., and preferably 0.5 to 12 hours, more preferably 1 to 8 hours. During the heating, the mixed solution may be stirred or may not be stirred, or the mixed solution may be placed under reflux.
After completion of the reaction, the organic solvent layer separated from the reaction mixture is preferably washed with water. In this washing, washing with water containing a small amount of salt, for example, an aqueous ammonium nitrate solution of about 0.2% by weight is preferred because the washing operation is facilitated. Washing is carried out until the aqueous layer after washing becomes neutral, and then the organic solvent layer is dried with an appropriate desiccant such as anhydrous calcium sulfate or molecular sieves as necessary, and then the solvent is removed to remove the solvent. A polyorganosiloxane having an epoxy group can be obtained.
In the present invention, a commercially available polyorganosiloxane having an epoxy group may be used. Examples of such commercially available products include DMS-E01, DMS-E12, DMS-E21, and EMS-32 (manufactured by Chisso Corporation).

[Compounds Represented by the Formulas (A1) and (A2)]
Specific examples of the compound represented by each of the above formulas (A1) and (A2) include a bond of the group exemplified above as the group represented by each of the above formulas (A1 ′) and (A2 ′). Mention may be made of carboxylic acids formed by bonding hydrogen atoms.

[Synthesis of radiation-sensitive polyorganosiloxane]
The radiation-sensitive polyorganosiloxane contained in the liquid crystal aligning agent of the present invention preferably comprises a polyorganosiloxane having an epoxy group as described above and a compound represented by each of the above formulas (A1) and (A2). It can be easily obtained by reacting at least one selected from the group, preferably in the presence of a catalyst and an organic solvent.
Here, at least one selected from the group consisting of the compounds represented by each of the above formulas (A1) and (A2) preferably has a total of 1 mol of the epoxy group of the polyorganosiloxane. It is used in a proportion of 0.001 to 10 mol, more preferably 0.01 to 5 mol, further preferably 0.05 to 2 mol, particularly preferably 0.05 to 0.8 mol.
As said catalyst, a well-known compound can be used as what is called a hardening accelerator which accelerates | stimulates reaction with an organic base or an epoxy compound, and an acid anhydride.
Examples of the organic base include primary and secondary organic amines such as ethylamine, diethylamine, piperazine, piperidine, pyrrolidine, and pyrrole;
Tertiary organic amines such as triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine, 4-dimethylaminopyridine, diazabicycloundecene;
A quaternary organic amine such as tetramethylammonium hydroxide can be used. Of these organic bases, tertiary organic amines such as triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine, 4-dimethylaminopyridine;
Quaternary organic amines such as tetramethylammonium hydroxide are preferred.

Examples of the curing accelerator include tertiary amines such as benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, cyclohexyldimethylamine, and triethanolamine; 2-methylimidazole, 2-n-heptylimidazole 2-n-undecylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 2- Ethyl-4-methylimidazole, 1- (2-cyanoethyl) -2-methylimidazole, 1- (2-cyanoethyl) -2-n-undecylimidazole, 1- (2-cyanoethyl) -2-phenylimidazole, 1 -(2-cyanoethyl) -2-ethyl 4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-di (hydroxymethyl) imidazole, 1- (2-cyanoethyl) -2-phenyl-4,5- Di [(2′-cyanoethoxy) methyl] imidazole, 1- (2-cyanoethyl) -2-n-undecylimidazolium trimellitate, 1- (2-cyanoethyl) -2-phenylimidazolium trimellitate, 1- (2-cyanoethyl) -2-ethyl-4-methylimidazolium trimellitate, 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)] ethyl-s-triazine, 2,4 -Diamino-6- (2'-n-undecylimidazolyl) ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl-4'-me Louisimidazolyl- (1 ′)] ethyl-s-triazine, isocyanuric acid adduct of 2-methylimidazole, isocyanuric acid adduct of 2-phenylimidazole, 2,4-diamino-6- [2′-methylimidazolyl- ( 1 ′)] imidazole compounds such as isocyanuric acid adducts of ethyl-s-triazine;
Organophosphorus compounds such as diphenylphosphine, triphenylphosphine, triphenyl phosphite;

Benzyltriphenylphosphonium chloride, tetra-n-butylphosphonium bromide, methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, n-butyltriphenylphosphonium bromide, tetraphenylphosphonium bromide Ethyltriphenylphosphonium iodide, ethyltriphenylphosphonium acetate, tetra-n-butylphosphonium, o, o-diethylphosphorodithionate, tetra-n-butylphosphonium benzotriazolate, Tetra-n-butylphosphonium tetrafluoroborate, tetra-n-butylphosphonium tetraphenylborate, tetraphenylphosphonium tetraphenylborate Such as over preparative quaternary phosphonium salts;
Diazabicycloalkenes such as 1,8-diazabicyclo [5.4.0] undecene-7 and organic acid salts thereof;
Organometallic compounds such as zinc octylate, tin octylate, aluminum acetylacetone complex;
Quaternary ammonium salts such as tetraethylammonium bromide, tetra-n-butylammonium bromide, tetraethylammonium chloride, tetra-n-butylammonium chloride;
Boron compounds such as boron trifluoride and triphenyl borate;
Metal halides such as zinc chloride and stannic chloride;
High melting point dispersion type latent curing accelerators such as amine addition accelerators such as dicyandiamide and adducts of amine and epoxy resin;
A microcapsule-type latent curing accelerator in which the surface of a curing accelerator such as the imidazole compound, organic phosphorus compound or quaternary phosphonium salt is coated with a polymer;
Examples include amine salt type latent curing accelerators; latent curing accelerators such as high temperature dissociation type thermal cationic polymerization type latent curing accelerators such as Lewis acid salts and Bronsted acid salts.

Of these, quaternary ammonium salts such as tetraethylammonium bromide, tetra-n-butylammonium bromide, tetraethylammonium chloride, and tetra-n-butylammonium chloride are preferable. The catalyst is used in an amount of preferably 100 parts by weight or less, more preferably 0.01 to 100 parts by weight, and still more preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the polyorganosiloxane having an epoxy group. .
The reaction between the polyorganosiloxane having an epoxy group and at least one selected from the group consisting of the compounds represented by formulas (A1) and (A2) is carried out in the presence of an organic solvent as necessary. It can be carried out. Examples of such organic solvents include hydrocarbons, ethers, esters, ketones, amides, alcohols and the like. Of these, ethers, esters or ketones are preferred from the viewpoints of solubility of raw materials and products and ease of purification of the products. The solvent is used in such a ratio that the solid content concentration (the ratio of the weight of components other than the solvent in the reaction solution to the total weight of the solution) is preferably 0.1% by weight or more, more preferably 5 to 50% by weight. Is done.
The reaction temperature is preferably 0 to 200 ° C, more preferably 50 to 150 ° C. The reaction time is preferably 0.1 to 50 hours, more preferably 0.5 to 20 hours. The radiation-sensitive polyorganosiloxane as described above is synthesized from the group consisting of the groups represented by the above formulas (A1 ′) and (A2 ′) by the ring-opening addition of the epoxy of the polyorganosiloxane having an epoxy group. It is a method for introducing at least one selected group. This synthesis method is simple and can increase the introduction rate of at least one group selected from the group consisting of the groups represented by the formulas (A1 ′) and (A2 ′). This is a very suitable method.

<Other ingredients>
The liquid crystal aligning agent of this invention contains the above radiation sensitive polyorganosiloxane. In addition to the radiation-sensitive polyorganosiloxane as described above, the liquid crystal aligning agent of the present invention may further contain other components as long as the effects of the present invention are not impaired. Examples of such other components include polymers other than radiation-sensitive polyorganosiloxane (hereinafter referred to as “other polymers”), curing agents, curing catalysts, curing accelerators, and at least one epoxy in the molecule. Compounds having a group (excluding those corresponding to radiation-sensitive polyorganosiloxane; hereinafter referred to as “epoxy compounds”), functional silane compounds (however, excluding those corresponding to radiation-sensitive polyorganosiloxane). ), And surfactants. However, at least one polymer selected from the group consisting of polyorganosiloxanes other than the radiation-sensitive polyorganosiloxane, polyamic acid, and polyimide is essential.

[Other polymers]
Said other polymer can be used in order to improve the solution characteristic of the liquid crystal aligning agent of this invention, and the electrical property of the liquid crystal aligning film obtained. Examples of such other polymers include at least one polymer selected from the group consisting of polyamic acid and polyimide, and polyorganosiloxanes other than the radiation-sensitive polyorganosiloxane (hereinafter referred to as “other polyorganosiloxanes”). .), Polyamic acid ester, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly (meth) acrylate, and the like.

{Polyamic acid}
The polyamic acid can be obtained by reacting tetracarboxylic dianhydride and diamine.
Examples of the tetracarboxylic dianhydride used for synthesizing the polyamic acid in the present invention include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride and the like. Can be mentioned. Specific examples thereof include aliphatic tetracarboxylic dianhydrides such as butane tetracarboxylic dianhydride;
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4, 5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane -2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene- No 1,2-dicarboxylic acid 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2 : 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone and the like;
As aromatic tetracarboxylic dianhydride, for example, pyromellitic dianhydride can be mentioned, respectively,
Tetracarboxylic dianhydrides described in Patent Documents 17 to 19 can be used.

Among these, the tetracarboxylic dianhydride used for synthesizing the polyamic acid preferably includes an alicyclic tetracarboxylic dianhydride, and 2,3,5-tricarboxycyclopentyl. It is preferable that it contains at least one selected from the group consisting of acetic dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride, in particular 2,3,5-tricarboxycyclopentyl acetic acid dianhydride It is preferable that a thing is included.
The tetracarboxylic dianhydride used to synthesize the polyamic acid comprises 2,3,5-tricarboxycyclopentylacetic acid dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride. It is preferable that at least one selected from the group contains 10 mol% or more, more preferably 20 mol% or more, more preferably 2,3,5-tricarboxyl, based on the total tetracarboxylic dianhydride. Most preferably, it is composed of at least one selected from the group consisting of cyclopentylacetic acid dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride.

Examples of the diamine used for synthesizing the polyamic acid include aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoorganosiloxanes, and the like. Specific examples thereof include aliphatic diamines such as 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine and the like;
Examples of alicyclic diamines include 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane, and the like;

Examples of aromatic diamines include p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl ] Propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenyle Diisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4 -Diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole N, N′-bis (4-aminophenyl) -benzidine, N, N′-bis (4-aminophenyl) -N, N′-dimethylbenzidine, 1,4-bis- (4-aminophenyl)- Piperazine, 3,5-diaminobenzoic acid, dodecanoxy-2,4-diaminobenzene, tetradecanoxy-2,4-diamino Benzene, Pentadekanokishi 2,4-diaminobenzene, Hekisadekanokishi 2,4-diaminobenzene, Okutadekanokishi 2,4-diaminobenzene, dodecanoxy-2,5-diaminobenzene, Tetoradekanokishi 2,5-diaminobenzene,

Pentadecanoxy-2,5-diaminobenzene, hexadecanoxy-2,5-diaminobenzene, octadecanoxy-2,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, choles Tanyloxy-2,4-diaminobenzene, cholestenyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanostannyl 3,5-diaminobenzoate, 3, 6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 4- (4′-trifluoromethoxybenzoyloxy) cyclohexyl-3,5-diaminobenzoate, 4- ( 4'-trifluoromethylbenzoiro C) cyclohexyl-3,5-diaminobenzoate, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl ) -4-heptylcyclohexane, 1,1-bis (4-((aminophenoxy) methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4- (4-Heptylcyclohexyl) cyclohexane and the following formula (D-1)

(In the formula (D-1), ^{X I} is an alkyl group having 1 to 3 carbon ^atoms, * ^-O-, * -COO- or ^* -OCO- (where bond marked with "*" is diaminophenyl group And h is 0 or 1, i is an integer from 0 to 2, and j is an integer from 1 to 20.)
A compound represented by:
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane, respectively.
Diamines described in Patent Documents 17 to 19 can be used.
The ^{X I} in the above formula (D-1) an alkyl group having 1 to 3 carbon ^atoms, * -O- or ^* -COO- (provided that a bond marked with "*" is bonded to the diamino phenyl group.) In Preferably there is. Specific examples of the group C _j H _{2j + 1} — include, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n -Nonyl group, n-decyl 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 -An eicosyl group etc. can be mentioned. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or 3,5-position with respect to the other groups.
Specific examples of the compound represented by the above formula (D-1) include, for example, the following formulas (D-1-1) to (D-1-4):

And the like can be mentioned.
In the above formula (D-1), it is preferable that h and i are not 0 at the same time.
These diamines can be used alone or in combination of two or more. The proportion of tetracarboxylic dianhydride and diamine used in the polyamic acid synthesis reaction is 0.2 eq. Of tetracarboxylic dianhydride acid anhydride group with respect to 1 equivalent of amino group contained in the diamine compound. The ratio which becomes -2 equivalent is preferable, More preferably, it is the ratio which becomes 0.3-1.2 equivalent.
The polyamic acid synthesis reaction is preferably performed in an organic solvent, preferably at a temperature of −20 to 150 ° C., more preferably at a temperature of 0 to 100 ° C., preferably 0.5 to 24 hours, more preferably 2 to 10 Done for hours. Here, the organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, N, Aprotic polar solvents such as N-dimethylimidazolidinone, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide;
Mention may be made of phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. The amount (a) of the organic solvent used is such that the total amount (b) of tetracarboxylic dianhydride and diamine compound is preferably 0.1 to 50% by weight, more preferably 5 to 5%, based on the total amount (a + b) of the reaction solution. The amount is 30% by weight.

As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid was purified. You may use for preparation of a liquid crystal aligning agent.
When polyamic acid is dehydrated and cyclized into a polyimide, the above reaction solution may be directly subjected to dehydration and cyclization reaction, or may be subjected to dehydration and cyclization reaction after isolating the polyamic acid contained in the reaction solution. Alternatively, the isolated polyamic acid may be purified and then subjected to a dehydration ring closure reaction.
The polyamic acid is isolated by pouring the reaction solution into a large amount of poor solvent to obtain a precipitate, and drying the precipitate under reduced pressure, or by distilling off the organic solvent in the reaction solution under reduced pressure using an evaporator. Etc. The polyamic acid can be purified by a method in which the polyamic acid is dissolved again in an organic solvent and then precipitated with a poor solvent, or a method in which the step of distilling off under reduced pressure with an evaporator is performed once or several times.

{Polyimide}
The polyimide can be synthesized by dehydrating and ring-closing the amic acid structure of the polyamic acid obtained as described above. At this time, all of the amic acid structure may be dehydrated and closed to completely imidize, or only a part of the amic acid structure may be dehydrated and closed to form a partially imidized product in which the amic acid structure and the imide structure coexist. Also good. The polyamic acid is dehydrated and closed by (i) a method of heating the polyamic acid, or (ii) dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to this solution, and heating as necessary. It can be done by a method.
The reaction temperature in the method of heating the polyamic acid (i) is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. If the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and if the reaction temperature exceeds 200 ° C., the molecular weight of the resulting polyimide may decrease. The reaction time in the method of heating the polyamic acid is preferably 0.5 to 48 hours, more preferably 2 to 20 hours.
On the other hand, in the method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride is used as the dehydrating agent. Can do. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of a polyamic acid structural unit. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, can be used, for example. However, it is not limited to these. It is preferable that the usage-amount of a dehydration ring-closing catalyst shall be 0.01-10 mol with respect to 1 mol of dehydrating agents to be used. Examples of the organic solvent used in the dehydration ring-closing reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C., more preferably 10 to 150 ° C., and the reaction time is preferably 0.5 to 20 hours, more preferably 1 to 8 hours.

  The polyimide obtained in the above method (i) may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after purifying the obtained polyimide. On the other hand, in the above method (ii), a reaction solution containing polyimide is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution. It may be used for the preparation of a liquid crystal aligning agent or may be used for the preparation of a liquid crystal aligning agent after purifying the isolated polyimide. In order to remove the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution, for example, a method such as solvent replacement can be applied. The isolation and purification of the polyimide can be performed by performing the same operation as described above as the isolation and purification method of the polyamic acid.

{Other polyorganosiloxanes}
The other polyorganosiloxane in the present invention is a polyorganosiloxane other than the above-mentioned radiation-sensitive polyorganosiloxane. Such other polyorganosiloxane is, for example, at least one silane compound selected from the group consisting of an alkoxysilane compound and a halogenated silane compound (hereinafter also referred to as “raw silane compound”), preferably an appropriate organic solvent. In which it can be synthesized by hydrolysis and condensation in the presence of water and a catalyst.

Examples of the raw material silane compound used here include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, and tetra-tert. -Butoxysilane, tetrachlorosilane; methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-iso-propoxysilane, methyltri-n-butoxysilane, methyltri-sec-butoxysilane, methyltri-tert-butoxy Silane, methyltriphenoxysilane, methyltrichlorosilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri-n-propoxysilane, ethyltri-iso-propoxy Lan, ethyltri-n-butoxysilane, ethyltri-sec-butoxysilane, ethyltri-tert-butoxysilane, ethyltrichlorosilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrichlorosilane; dimethyldimethoxysilane, dimethyldiethoxysilane, Examples include dimethyldichlorosilane; trimethylmethoxysilane, trimethylethoxysilane, trimethylchlorosilane, and the like, and it is preferable to use one or more of these, particularly tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyl Triethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxy It is preferred to use at least one selected from the run and the group consisting of trimethyl silane. Other polyorganosiloxanes in the present invention can be synthesized in the same manner as described above as a method for synthesizing a polyorganosiloxane having an epoxy group, except that the raw material silane compound as described above is used.
For other polyorganosiloxanes, the polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography is preferably 1,000 to 100,000, more preferably 5,000 to 50,000.

{Use ratio of other polymers}
When the liquid crystal aligning agent of the present invention contains another polymer together with the above-mentioned radiation-sensitive polyorganosiloxane, the use ratio of the other polymer is based on 100 parts by weight of the radiation-sensitive polyorganosiloxane. It is preferably 10,000 parts by weight or less. The more preferable usage rate of the other polymer varies depending on the type of the other polymer.
In the case where the liquid crystal aligning agent of the present invention contains at least one polymer selected from the group consisting of radiation-sensitive polyorganosiloxane and polyamic acid and polyimide, a more preferable use ratio of both is radiation-sensitive. The total amount of polyamic acid and polyimide with respect to 100 parts by weight of the functional polyorganosiloxane is 100 to 5,000 parts by weight, and more preferably 200 to 2,000 parts by weight.
On the other hand, in the case where the liquid crystal aligning agent of the present invention contains a radiation-sensitive polyorganosiloxane and another polyorganosiloxane, the more preferable use ratio of both is other than 100 parts by weight of the radiation-sensitive polyorganosiloxane. The amount of polyorganosiloxane is 100 to 2,000 parts by weight.
When the liquid crystal aligning agent of the present invention contains another polymer together with the radiation-sensitive polyorganosiloxane, the type of the other polymer is at least one selected from the group consisting of polyamic acid and polyimide. Preferably, the polymer or other polyorganosiloxane or both.

[Curing agent and curing catalyst]
The curing agent and the curing catalyst can be contained in the liquid crystal aligning agent of the present invention for the purpose of further strengthening the crosslinking reaction of the radiation-sensitive polyorganosiloxane, and the curing accelerator accelerates the curing reaction controlled by the curing agent. Therefore, it can be contained in the liquid crystal aligning agent of the present invention.
As the curing agent, a curable compound having an epoxy group or a curing agent generally used for curing a curable composition containing a compound having an epoxy group can be used. An acid anhydride and polyhydric carboxylic acid can be illustrated.
Examples of the polyvalent carboxylic acid anhydride include cyclohexanetricarboxylic acid anhydride and other polyvalent carboxylic acid anhydrides. Specific examples of the cyclohexanetricarboxylic acid anhydride include, for example, cyclohexane-1,3,4-tricarboxylic acid-3,4-anhydride, cyclohexane-1,3,5-tricarboxylic acid-3,5-anhydride, cyclohexane- 1,2,3-tricarboxylic acid-2,3-acid anhydride, and the like. Examples of other polyvalent carboxylic acid anhydrides include 4-methyltetrahydrophthalic acid anhydride, methylnadic acid anhydride, Dodecenyl succinic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, trimellitic anhydride, formula (CA-1)

(In formula (CA-1), k is an integer of 1 to 20.)
Diels-Alder reaction of maleic anhydride with cycloaliphatic compounds having conjugated double bonds such as α-terpinene and allocymene, in addition to tetracarboxylic dianhydrides generally used for the synthesis of compounds and polyamic acids Products and their hydrogenated products can be mentioned.
As the curing catalyst, for example, an antimony hexafluoride compound, a phosphorus hexafluoride compound, aluminum trisacetylacetonate, or the like can be used. These catalysts can catalyze the cationic polymerization of epoxy groups by heating.
Examples of the curing accelerator include imidazole compounds;
Quaternary phosphorus compounds;
Quaternary amine compounds;
Diazabicycloalkenes such as 1,8-diazabicyclo [5.4.0] undecene-7 and organic acid salts thereof; organometallic compounds such as zinc octylate, tin octylate and aluminum acetylacetone complex;
Boron compounds such as boron trifluoride and triphenyl borate; metal halides such as zinc chloride and stannic chloride;
High melting point dispersion type latent curing accelerators such as dicyandiamide, amine addition type accelerators such as adducts of amine and epoxy resin;
A microcapsule type latent curing accelerator whose surface is covered with a polymer such as a quaternary phosphonium salt;
An amine salt type latent curing accelerator;
And high temperature dissociation type thermal cationic polymerization type latent curing accelerators such as Lewis acid salts and Bronsted acid salts.

[Epoxy compound]
The said epoxy compound can be contained in the liquid crystal aligning agent of this invention from a viewpoint of improving the adhesiveness with respect to the substrate surface of the liquid crystal aligning film formed. Examples of such epoxy compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexane. Diol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N′— Tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-dia Bruno diphenylmethane, N, N-diglycidyl - benzylamine, N, N-diglycidyl - aminomethyl cyclohexane, may be mentioned as being preferred.
When the liquid crystal aligning agent of the present invention contains an epoxy compound, the content is preferably 100 parts by weight with respect to the total of 100 parts by weight of the radiation-sensitive polyorganosiloxane and other polymers optionally used. Is 40 parts by weight or less, more preferably 0.1 to 30 parts by weight.
In addition, when the liquid crystal aligning agent of this invention contains an epoxy compound, you may use together basic catalysts, such as 1-benzyl-2-methylimidazole, in order to raise | generate the crosslinking reaction efficiently.

[Functional silane compounds]
The said functional silane compound can be used in order to improve the adhesiveness with the board | substrate of the liquid crystal aligning film obtained. Examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, and N- (2-aminoethyl) -3. -Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltri Methoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7 Triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl- 3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene ) -3-Aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane And the patent text 20 such as those described in (JP 63-291922 JP), may be used reaction products of a silane compound having a tetracarboxylic dianhydride and an amino group.
When the liquid crystal aligning agent of this invention contains a functional silane compound, as the content rate, it is with respect to a total of 100 weight part of said radiation sensitive polyorganosiloxane and the other polymer arbitrarily used. , Preferably 50 parts by weight or less, more preferably 20 parts by weight or less.

[Surfactant]
Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, silicone surfactants, polyalkylene oxide surfactants, and fluorine-containing surfactants. it can. When the liquid crystal aligning agent of this invention contains surfactant, as the content rate, Preferably it is 10 weight part or less with respect to 100 weight part of the whole liquid crystal aligning agent, More preferably, it is 1 weight part or less. is there.

<Liquid crystal aligning agent>
As described above, the liquid crystal aligning agent of the present invention contains a radiation-sensitive polyorganosiloxane as an essential component, and additionally contains other components as necessary, but preferably each component is an organic solvent. It is prepared as a dissolved solution composition.
The organic solvent that can be used for preparing the liquid crystal aligning agent of the present invention is preferably one that dissolves the radiation-sensitive polyorganosiloxane and other optional components and does not react with them.
The organic solvent that can be preferably used in the liquid crystal aligning agent of the present invention varies depending on the type of other polymer that is optionally added. When the liquid crystal aligning agent of the present invention contains at least one polymer selected from the group consisting of radiation-sensitive polyorganosiloxane and polyamic acid and polyimide, and radiation-sensitive polyorganosiloxane, polyamic acid and As the preferable organic solvent in the case where it contains another polyorganosiloxane in addition to at least one polymer selected from the group consisting of polyimides, it is exemplified above as being used for the synthesis of polyamic acid. Mention may be made of organic solvents. At this time, you may use together the poor solvent illustrated as what is used for the synthesis | combination of the polyamic acid of this invention. These organic solvents can be used alone or in combination of two or more.

  On the other hand, when the liquid crystal aligning agent of the present invention contains only a radiation-sensitive polyorganosiloxane as a polymer, or contains a radiation-sensitive polyorganosiloxane and another polyorganosiloxane, but from polyamic acid and polyimide Preferred organic solvents in the case of not containing at least one polymer selected from the group consisting of, for example, 1-ethoxy-2-propanol, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol Monobutyl ether, propylene glycol monoacetate, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol propyl ether, dipropylene glycol dimethyl ether , Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol monoamyl ether, ethylene glycol monohexyl ether, diethylene glycol, methyl cellosolve acetate, ethyl cellosolve acetate, propyl Cellosolve acetate, butyl cellosolve acetate, methyl carbitol, ethyl carbitol, propyl carbitol, butyl carbitol, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, sec-butyl acetate, n-acetate Pentyl, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutylacetate , 2-ethylhexyl acetate, benzyl acetate, n- hexyl, cyclohexyl acetate, octyl acetate, amyl acetate, isoamyl acetate, and the like. Of these, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate and the like can be mentioned.

A preferred solvent used for the preparation of the liquid crystal aligning agent of the present invention is obtained by combining one or more of the above-described organic solvents according to the presence or absence of other polymers and their types, Each component contained in the liquid crystal aligning agent does not precipitate at a preferable solid content concentration, and the surface tension of the liquid crystal aligning agent is in the range of 25 to 40 mN / m.
The solid content concentration of the liquid crystal aligning agent of the present invention, that is, the ratio of the weight of all components other than the solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent is selected in consideration of viscosity, volatility, Preferably it is the range of 1-10 weight%. The liquid crystal aligning agent of the present invention is applied to the substrate surface to form a coating film that becomes a liquid crystal aligning film. When the solid content concentration is less than 1% by weight, the film thickness of this coating film becomes too small. In some cases, it is difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, it is difficult to obtain a good liquid crystal alignment film due to excessive film thickness, and the viscosity of the liquid crystal aligning agent increases, resulting in insufficient coating characteristics. There is a case. The particularly preferable range of the solid content concentration varies depending on the method employed when the liquid crystal aligning agent is applied to the substrate. For example, when the spinner method is used, the range of 1.5 to 4.5% 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 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the ink jet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% 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 0 ° C. to 200 ° C., more preferably 0 ° C. to 40 ° C.

<Method for forming liquid crystal alignment film>
The liquid crystal aligning agent of the present invention is a liquid crystal aligning film used for a liquid crystal aligning film by a photo-alignment method, a liquid crystal display element having a TN type or STN type liquid crystal cell, or a lateral electrolysis type liquid crystal display element having an IPS type liquid crystal cell. Can be suitably used to form The liquid crystal aligning agent of the present invention is preferable because the effects of the present invention are exhibited to the maximum when applied to a liquid crystal display element having an IPS type liquid crystal cell.
In order to form a liquid crystal alignment film using the liquid crystal aligning agent of the present invention, a method of applying a liquid crystal aligning agent of the present invention on a substrate to form a coating film and irradiating the coating film with radiation Can be.
Here, when the liquid crystal aligning agent of the present invention is applied to a liquid crystal display element having a TN type or STN type liquid crystal cell, a pair of two substrates provided with a patterned transparent conductive film is used as a pair. The coating film is formed by applying the liquid crystal aligning agent of the present invention on the conductive conductive film forming surface. On the other hand, when the liquid crystal aligning agent of the present invention is applied to a liquid crystal display element having an IPS type liquid crystal cell, a substrate having an electrode in which a transparent conductive film or a metal film is patterned in a comb shape on one side, and an electrode A pair of counter substrates not provided with a coating is formed by applying the liquid crystal aligning agent of the present invention to the surface on which the comb-like electrode is formed and one surface of the counter substrate.
In any case, as the substrate, for example, a glass such as float glass or soda glass, a transparent substrate made of a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, or polycarbonate can be used. As the transparent conductive film, for example, an ITO film made of In ₂ O ₃ —SnO _{2 or} a NESA (registered trademark) film made of SnO ₂ can be used. As the metal film, for example, a film made of a metal such as chromium can be used. For patterning the transparent conductive film and the metal film, for example, a method of forming a pattern by a photo-etching method or a sputtering method after forming a transparent conductive film without a pattern, or a mask having a desired pattern when forming the transparent conductive film It is possible to use a method using

In order to further improve the adhesion between the substrate or the conductive film or the electrode and the coating film when the liquid crystal aligning agent is applied on the substrate, a functional silane compound, titanate, or the like is previously applied on the substrate and the electrode. May be.
The liquid crystal aligning agent can be applied onto the substrate by an appropriate application method such as an offset printing method, a spin coating method, a roll coater method, or an ink jet printing method, and then the application surface is preheated (prebaked). And then baking (post-baking) 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.

By irradiating the thus formed coating film with linearly or partially polarized radiation or non-polarized radiation, liquid crystal alignment ability is imparted. Here, as radiation, for example, ultraviolet rays and visible light containing light having a wavelength of 150 to 800 nm can be used, but ultraviolet rays containing light having a wavelength of 300 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.
As a light source to be used, for example, a low pressure mercury lamp, a high pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, or the like can be used. The ultraviolet rays in the preferable wavelength region can be obtained by means of using the light source in combination with, for example, a filter, a diffraction grating or the like.
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 improving the productivity of liquid crystal display elements and reducing manufacturing costs.

<Method for manufacturing liquid crystal display element>
The liquid crystal display element formed using the liquid crystal aligning agent of this invention can be manufactured as follows, for example.
First, a pair of substrates on which a liquid crystal alignment film is formed as described above is prepared, and a liquid crystal cell having a configuration in which liquid crystals are sandwiched between the pair of substrates is manufactured. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example. The first method is a conventionally known method. First, two substrates are arranged to face each other through a gap (cell gap) so that the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded using a sealant, and the substrate surface and the sealant are bonded. A liquid crystal cell can be manufactured by injecting and filling liquid crystal into the cell gap partitioned by the above, and then sealing the injection hole.
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 has an isotropic phase and then gradually cooling it 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, in the two substrates on which the liquid crystal alignment film is formed, a desired liquid crystal display element can be obtained by appropriately adjusting the angle formed by the polarization direction of the irradiated linearly polarized radiation and the angle between each substrate and the polarizing plate. Can be obtained.

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, a nematic liquid crystal, a smectic liquid crystal, or the like can be used. Those having positive dielectric anisotropy forming a nematic liquid crystal are preferred, such as biphenyl liquid crystal, phenyl cyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, Bicyclooctane liquid crystal, cubane liquid crystal, or the like is used. In addition, the liquid crystal includes, for example, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate;
Chiral agents such as those sold under the trade names “C-15” and “CB-15” (Merck)
A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be further added and 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 electrical characteristics.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
The weight average molecular weight in the following synthesis examples is a polystyrene conversion value measured by gel permeation chromatography under the following conditions.
Column: Tosoh Co., Ltd., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ^{2 In} addition, in the following synthesis examples, the required amount in the following examples was ensured by repeating the synthesis of the raw material compound and the polymer as necessary on the following synthesis scale.

<Synthesis Example of Polyorganosiloxane Having Epoxy Group>
Synthesis example ES1
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser was charged with 100.0 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 500 g of methyl isobutyl ketone and 10.0 g of triethylamine at room temperature. Mixed.
Next, 100 g of deionized water was dropped from the dropping funnel over 30 minutes, and the reaction was performed at 80 ° C. for 6 hours while mixing under reflux. After completion of the reaction, the organic layer is taken out and washed with 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 to have an epoxy group. Polyorganosiloxane (ES-1) 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. Table 1 shows the viscosity, Mw, and epoxy equivalent of the polyorganosiloxane (ES-1) having this epoxy group.

Synthesis example ES2-3
Polyorganosiloxanes (ES-2) and (ES-3) having an epoxy group were obtained as viscous transparent liquids in the same manner as in Synthesis Example 1 except that the raw materials used were as shown in Table 1.
Table 1 shows the Mw and epoxy equivalent of the polyorganosiloxane having these epoxy groups. In Table 1, the abbreviations of the raw material silane compounds have the following meanings.
ECETS: 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane MTMS: methyltrimethoxysilane PTMS: phenyltrimethoxysilane

<Synthesis Example of Compound Represented by Formula (A1)>
In the following synthesis examples A1-1 to A1-4, the following formulas (A1-1) to (A1-4)

(Hereinafter referred to as “compound (A1-1)”, “compound (A1-2)”, “compound (A1-3)”, and “compound (A1-4)”), respectively. Synthesized.
Synthesis Example A1-1
A 500 mL three-necked flask equipped with a condenser is charged with 20 g of 4-bromodiphenyl ether, 0.18 g of palladium acetate, 0.98 g of tris (2-tolyl) phosphine, 32.4 g of triethylamine, and 135 mL of dimethylacetamide and mixed with the solution. did. Next, 7 g of acrylic acid was added to the above solution using a syringe and stirred, and then reacted at 120 ° C. for 3 hours with stirring. After confirming the completion of the reaction by thin layer chromatography (TLC), the reaction solution was cooled to room temperature. The insoluble material was filtered off, and the filtrate was poured into 300 mL of 1N hydrochloric acid to collect the precipitate. This precipitate was recrystallized from a mixed solvent consisting of ethyl acetate and hexane (ethyl acetate: hexane = 1: 1 (volume ratio)) to obtain 8.4 g of compound (A1-1).
Synthesis Example A1-2
A 300 mL three-necked flask equipped with a condenser is charged with 6.5 g of 4-fluorophenylboronic acid, 10 g of 4-bromocinnamic acid, 2.7 g of tetrakistriphenylphosphine palladium, 4 g of sodium carbonate, 80 mL of tetrahydrofuran and 39 mL of pure water. Then, the mixture was reacted at 80 ° C. with stirring for 8 hours. After confirming the completion of the reaction by TLC, the reaction mixture was cooled to room temperature. The reaction mixture after cooling was poured into 200 mL of 1N hydrochloric acid, and the precipitate was collected. A solution obtained by dissolving the obtained precipitate in ethyl acetate was washed successively with 100 mL of 1N hydrochloric acid, 100 mL of pure water and 100 mL of saturated brine, and dried over anhydrous magnesium sulfate, and then the solvent was distilled off. The obtained solid was vacuum-dried to obtain 9 g of compound (A1-2).

Synthesis Example A1-3
In a 200 mL three-necked flask equipped with a condenser tube, 3.6 g of 4-fluorostyrene, 6 g of 4-bromocinnamic acid, 0.059 g of palladium acetate, 0.32 g of tris (2-tolyl) phosphine, 11 g of triethylamine and 50 mL of dimethylacetamide Were mixed to obtain a solution. About this solution, it stirred at 120 degreeC for 3 hours, and reacted. After confirming the completion of the reaction by TLC, the reaction mixture was cooled to room temperature, insoluble matter was filtered off, and the filtrate was poured into 300 mL of 1N hydrochloric acid to collect a precipitate. The precipitate was recrystallized from ethyl acetate to obtain 4.1 g of Compound (A1-3).
Synthesis Example A1-4
In a 200 mL three-necked flask equipped with a condenser tube, 9.5 g of 4-vinylbiphenyl, 10 g of 4-bromocinnamic acid, 0.099 g of palladium acetate, 0.54 g of tris (2-tolyl) phosphine, 18 g of triethylamine and 80 mL of dimethylacetamide Were mixed to obtain a solution. This solution was stirred at 120 ° C. for 3 hours for reaction. After confirming the completion of the reaction by TLC, the reaction mixture was cooled to room temperature, insoluble matter was filtered off, and the filtrate was poured into 500 mL of 1N hydrochloric acid to collect a precipitate. The precipitate was recrystallized from a mixed solvent composed of dimethylacetamide and ethanol (dimethylacetamide: ethanol = 1: 1 (volume ratio)) to obtain 11 g of compound (A1-4).

<Synthesis Example of Compound Represented by Formula (A2)>
In the following synthesis examples A2-1 and A2-2, the following formulas (A2-1) and (A2-2)

(Hereinafter referred to as “compound (A2-1)” and “compound (A2-2)”), respectively.
Synthesis Example A2-1
A 200 mL three-necked flask equipped with a condenser tube was charged with 10 g of phenyl acrylate, 11.3 g of 4-bromobenzoic acid, 0.13 g of palladium acetate, 0.68 g of tris (2-tolyl) phosphine, 23 g of triethylamine and 100 mL of dimethylacetamide. Mix to make a solution. This solution was reacted with stirring at 120 ° C. for 3 hours. After confirming the completion of the reaction by TLC, the reaction mixture was cooled to room temperature, insoluble matters were filtered off, and the filtrate was poured into 500 mL of 1N hydrochloric acid to collect a precipitate. This precipitate was recrystallized from ethyl acetate to obtain 9.3 g of Compound (A2-1).

Synthesis Example A2-2
A 200 mL three-necked flask equipped with a dropping funnel was charged with 10 g of 4-cyclohexylphenol, 6.3 g of triethylamine and 80 mL of dehydrated tetrahydrofuran and mixed. This was cooled in an ice bath, and a solution consisting of 5.7 g of acryloyl chloride and 40 mL of dehydrated tetrahydrofuran was added dropwise from a dropping funnel. After completion of the dropwise addition, the mixture was further stirred in an ice bath for 1 hour, then returned to room temperature and reacted for 2 hours with stirring. After completion of the reaction, the reaction mixture was filtered to remove the produced salt. The organic layer obtained by adding ethyl acetate to the filtrate was washed with water, and then the solvent was removed under reduced pressure and dried to obtain 12.3 g of 4-cyclohexylphenyl acrylate as an intermediate.
Next, 6 g of 4-cyclohexylphenyl acrylate obtained above, 5.7 g of 2-fluoro-4-bromobenzoic acid, 0.06 g of palladium acetate, Tris (2 -Tolyl) Phosphine 0.32 g, triethylamine 11 g and dimethylacetamide 50 mL were charged and mixed to obtain a solution. This solution was reacted with stirring at 120 ° C. for 3 hours. After confirming the completion of the reaction by TLC, the reaction mixture was cooled to room temperature, insoluble matter was filtered off, and the filtrate was added to 300 mL of 1N hydrochloric acid. And the resulting precipitate was collected. This precipitate was recrystallized from ethyl acetate to obtain 3.4 g of compound (A2-2).

<Comparative synthesis example of carboxylic acid>
Synthesis example RA1
A 200 mL three-necked flask was charged with 11.21 g of 4-hydroxychalcone, 8.35 g of ethyl bromoacetate, 13.8 g of potassium carbonate, and 100 mL of dimethylacetamide and reacted at 120 ° C. with stirring for 7 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, and then 100 mL of ethyl acetate was added thereto, and the resulting organic layer was washed with water. After removing the solvent from the obtained organic layer under reduced pressure and once solidifying to dryness, recrystallization from a mixed solvent consisting of ethanol and water (ethanol: water = 4: 1 (volume ratio)) 11.4 g of a certain ethyl chalconyloxyacetate was obtained.
In a 500 mL three-necked flask equipped with a condenser, 6.2 g of the ethyl chalconyloxyacetate obtained above, 2 g of sodium hydroxide, 200 mL of ethanol, and 50 mL of water were mixed and reacted for 3 hours under reflux. went. After completion of the reaction, the reaction mixture was cooled, acidified with dilute hydrochloric acid, and extracted with 500 mL of ethyl acetate. The obtained organic layer was washed with water, and then the solvent was removed under reduced pressure to dryness, whereby the following formula (RA-1)

4.1 g of a compound represented by the formula (compound (RA-1)) was obtained.

<Synthesis example of radiation-sensitive polyorganosiloxane>
Synthesis example S1
In a 100 mL three-necked flask, 9.3 g of polyorganosiloxane (ES-1) having an epoxy group obtained in Synthesis Example ES1, 26 g of methyl isobutyl ketone, 3 g of Compound (A1-1) obtained in Synthesis Example A1-1 And 0.10 g of UCAT 18X (trade name, a quaternary amine salt manufactured by San Apro Co., Ltd.), and the reaction was carried out at 80 ° C. with stirring for 12 hours. After completion of the reaction, the reaction mixture was poured into methanol to recover the generated precipitate, which was dissolved in ethyl acetate to form a solution. The solution was washed with water three times, and then the solvent was distilled off to remove radiation. 6.3 g of a functional polyorganosiloxane (S-1) was obtained as a white powder. The radiation-sensitive polyorganosiloxane (S-1) had a weight average molecular weight Mw of 3,500.
Synthesis example S2
In Synthesis Example S1, a radiation-sensitive polyorganosiloxane was prepared in the same manner as in Synthesis Example S1, except that 3 g of Compound (A1-2) obtained in Synthesis Example A1-2 was used instead of Compound (A1-1). 7.0 g of white powder of (S-2) was obtained. This radiation-sensitive polyorganosiloxane (S-2) had a weight average molecular weight Mw of 4,900.

Synthesis example S3
In Synthesis Example S1, a radiation-sensitive polyorganosiloxane was prepared in the same manner as in Synthesis Example S1, except that 4 g of Compound (A1-3) obtained in Synthesis Example A1-3 was used instead of Compound (A1-1). 10 g of (S-3) white powder was obtained. This radiation-sensitive polyorganosiloxane (S-3) had a weight average molecular weight Mw of 5,000.
Synthesis example S4
In Synthesis Example S1, a radiation-sensitive polyorganosiloxane was prepared in the same manner as in Synthesis Example S1, except that 4 g of Compound (A1-4) obtained in Synthesis Example A1-4 was used instead of Compound (A1-1). 10 g of white powder of (S-4) was obtained. The radiation-sensitive polyorganosiloxane (S-4) had a weight average molecular weight Mw of 4,200.

Synthesis example S5
In Synthesis Example S1, 10.5 g of the epoxy group-containing polyorganosiloxane (ES-2) obtained in Synthesis Example ES2 instead of the epoxy group-containing polyorganosiloxane (ES-1) was converted into Compound (A1-1). In the same manner as in Synthesis Example S1, except that 3.35 g of Compound (A2-1) obtained in Synthesis Example A2-1 was used instead of the white color of radiation-sensitive polyorganosiloxane (S-5). 7.0 g of powder was obtained. This radiation-sensitive polyorganosiloxane (S-5) had a weight average molecular weight Mw of 5,500.
Synthesis example S6
In Synthesis Example S1, 11.4 g of the epoxy group-containing polyorganosiloxane (ES-3) obtained in Synthesis Example ES3 instead of the epoxy group-containing polyorganosiloxane (ES-1) was converted into Compound (A1-1). In the same manner as in Synthesis Example S1, except that 4.6 g of the compound (A2-2) obtained in Synthesis Example A2-3 was used instead of the white color of the radiation-sensitive polyorganosiloxane (S-6), respectively. 9.6 g of powder was obtained. The radiation-sensitive polyorganosiloxane (S-6) had a weight average molecular weight Mw of 7,400.

<Comparative synthesis example of radiation-sensitive polyorganosiloxane>
Synthesis example RS1
In Synthesis Example S-1, the following formula synthesized according to the method described in Patent Document 17 (International Publication No. 2009/025385 pamphlet) instead of the compound (A1-1)

In the same manner as in Synthesis Example S1 except that 4.4 g of the compound represented by formula (1) was used, 7.2 g of a white powder of radiation-sensitive polyorganosiloxane (RS-1) was obtained. The radiation-sensitive polyorganosiloxane (RS-1) had a weight average molecular weight Mw of 9,400.
Synthesis example RS2
In the same manner as in Synthesis Example S1, except that 3.52 g of Compound (RA-1) obtained in Synthesis Example RA1 was used instead of Compound (A1-1) in Synthesis Example S1, Radiation Sensitive Polyorganosiloxane 9.1g of (RS-2) white powder was obtained. This radiation-sensitive polyorganosiloxane (RS-2) had a weight average molecular weight Mw of 6,900.

<Synthesis examples of other polymers>
[Synthesis example of polyamic acid]
Synthesis example pa1
Cyclobutanetetracarboxylic dianhydride 19.61 g (0.1 mol) and 4,4′-diamino-2,2′-dimethylbiphenyl 21.23 g (0.1 mol) were combined with N-methyl-2-pyrrolidone 367. Then, the reaction was carried out at room temperature for 6 hours. The reaction mixture was poured into a large excess of methanol to precipitate the reaction product. This precipitate was washed with methanol and dried at 40 ° C. under reduced pressure for 15 hours to obtain 35 g of polyamic acid (pa-1).
Synthesis example pa2
2,3,5-tricarboxycyclopentylacetic acid dianhydride (22.4 g, 0.1 mol) and cyclohexanebis (methylamine) (14.23 g, 0.1 mol) were mixed with N-methyl-2-pyrrolidone (329.3 g). And reacted at 60 ° C. for 6 hours. The reaction mixture was poured into a large excess of methanol to precipitate the reaction product. This precipitate was washed with methanol and dried at 40 ° C. under reduced pressure for 15 hours to obtain 32 g of polyamic acid (pa-2).

[Polyimide synthesis example]
Synthesis example pi-1
17.5 g of the polyamic acid pa-2 obtained in the above synthesis example pa-2 was taken and dissolved in 232.5 g of N-methyl-2-pyrrolidone, and further 3.8 g of pyridine and 4.9 g of acetic anhydride. And a dehydration ring-closing reaction was carried out at 120 ° C. for 4 hours. After completion of the reaction, the reaction mixture was poured into a large excess of methanol to precipitate the reaction product. The precipitate was collected, washed with methanol, and dried under reduced pressure for 15 hours to obtain 15 g of polyimide (pi-1).
[Synthesis examples of other polyorganosiloxanes]
Synthesis example s1
In Synthesis Example S1, 11 g of white powder of other polyorganosiloxane (s-1) was obtained in the same manner as in Synthesis Example S1 except that 5 g of lauric acid was used instead of compound (A1-1). The other polyorganosiloxane (s-1) had a weight average molecular weight Mw of 6,000.

Example 1
<Preparation of liquid crystal aligning agent>
100 parts by weight of the radiation-sensitive polyorganosiloxane (S-1) obtained in Synthesis Example S1 as the radiation-sensitive polyorganosiloxane, and the polyamic acid (pa--) obtained in Synthesis Example pa-1 as another polymer 1) 1,000 parts by weight, and N-methyl-2-pyrrolidone and butyl cellosolve are added thereto. The solvent composition is N-methyl-2-pyrrolidone: butyl cellosolve = 50: 50 (weight ratio), solid content A solution having a concentration of 3.0% by weight was obtained. A liquid crystal aligning agent was prepared by filtering this solution through a filter having a pore diameter of 1 μm.

<Manufacture of liquid crystal display elements>
A pair of a glass substrate having a metal electrode made of chromium patterned in a comb-teeth shape on one side and a counter glass substrate on which no electrode is provided, and a surface having an electrode of the glass substrate and a surface of the counter glass substrate, respectively The liquid crystal aligning agent (LA-1) prepared above was applied using a spinner, pre-baked on an 80 ° C. hot plate for 1 minute, and then heated at 200 ° C. for 1 hour in an oven in which the inside of the cabinet was replaced with nitrogen ( A film having a thickness of 0.1 μm was formed by post-baking. Next, a pair of substrates having a liquid crystal alignment film is obtained by irradiating the surface of the coating film with polarized ultraviolet rays 300 J / m ² including a 313 nm emission line from the normal direction of the substrate using a Hg-Xe lamp and a Grand Taylor prism, respectively. It was. An epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied to the outer periphery of the surface of the substrate having the liquid crystal alignment film by screen printing, and the liquid crystal alignment film surfaces of the pair of substrates are made to face each other. The substrates were superposed and pressure-bonded so that the directions of the respective substrates were reversed when irradiated with polarized ultraviolet rays, and the adhesive was thermally cured at 150 ° C. for 1 hour. Next, a liquid crystal injection, MLC-7028, was filled into the gap between the substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Furthermore, in order to remove the flow alignment during liquid crystal injection, this was heated at 150 ° C. and then gradually cooled to room temperature. Next, a polarizing plate is bonded to both outer surfaces of the substrate so that the polarization directions thereof are orthogonal to each other and the optical axis of the polarized ultraviolet light of the liquid crystal alignment film is orthogonal to the projection direction onto the substrate surface. Manufactured.

<Evaluation method of liquid crystal display element>
The liquid crystal display element produced above was evaluated by the following method. The evaluation results are shown in Table 2.
(1) Evaluation of liquid crystal alignment The presence or absence of an abnormal domain in a change in brightness when a voltage of 5 V is turned ON / OFF (applied / released) is observed with an optical microscope for the liquid crystal display element manufactured above. The case where it was not observed was evaluated as “good” for liquid crystal alignment, and the case where an abnormal domain was observed was evaluated as “poor” for liquid crystal alignment.
(2) Evaluation of voltage holding ratio After applying a voltage of 5 V to the liquid crystal display element manufactured above at 60 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, 167 milliseconds after application cancellation The voltage holding ratio was measured. As a measuring device, VHR-1 manufactured by Toyo Corporation was used.

Examples 2-12 and Comparative Examples 1 and 2
In Example 1, a liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the types and amounts of polymers listed in Table 2 were used as the radiation-sensitive polyorganosiloxane and the other polymer. A liquid crystal display element was produced and evaluated in the same manner as in Example 1 except that the irradiation amount of polarized ultraviolet rays at the time of forming the alignment film was as shown in Table 2. The evaluation results are shown in Table 2, respectively. In Example 7, two types of polymers were used in combination as other polymers when preparing the liquid crystal aligning agent.

Claims (5)

The following formulas (A1 ′) and (A2 ′)

(In the formula (A1 ′), R is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fluorine atom or a cyano group, and R ¹ is a phenylene group or a cyclohexylene group, provided that the phenylene group or the cyclohexylene group. A part or all of the hydrogen atoms may be substituted with a fluorine atom or a cyano group, and R ² represents a single bond, a methylene group, an alkylene group having 2 or 3 carbon atoms, an oxygen atom, a sulfur atom, —CH═CH—. Or —NH—, a is an integer of 0 to 3, and when a is 2 or 3, a plurality of R ¹ and R ² may be the same or different, and R ³ is a fluorine atom or a cyano group, b is an integer of 0 to 4, and “*” indicates a bond;
In the formula (A2 ′), R ′ is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fluorine atom or a cyano group, and R ⁴ is a phenylene group or a cyclohexylene group, provided that the phenylene group or the cyclohexylene group. A part or all of the hydrogen atoms may be substituted with a fluorine atom or a cyano group, and R ⁵ is a single bond, a methylene group, an alkylene group having 2 or 3 carbon atoms, an oxygen atom, a sulfur atom or —NH—. , C is an integer of 1 to 3, and when c is 2 or 3, a plurality of R ⁴ and R ⁵ may be the same or different, and R ⁶ is a fluorine atom or cyano. D is an integer of 0 to 4, R ⁷ is an oxygen atom, -COO- ⁺ or -OCO- ⁺ (in the above, a bond marked with "+" is bonded to R ⁸ ). And R ⁸ is a divalent aromatic group, a divalent alicyclic group, a divalent heterocyclic group or a divalent condensed cyclic group, R ⁹ is a single bond, ⁺ —OCO— (CH ₂ ) _f - or _{^{+ -O- (CH 2) g -}} ( provided that a bond marked with "+" in the above _{^{- (R 7 -R 8) e}} - is a side, f and g are each 1 to 10 E) is an integer of 0 to 3, and “*” indicates a bond. )
A radiation-sensitive polyorganosiloxane having at least one group selected from the group consisting of groups represented by each of the above, and a group consisting of a polyorganosiloxane other than the above-mentioned radiation-sensitive polyorganosiloxane, polyamic acid, and polyimide A liquid crystal aligning agent comprising at least one selected polymer. The radiation sensitive polyorganosiloxane is
A polyorganosiloxane having an epoxy group;
The following formulas (A1) and (A2)

(R, R ¹ , R ² , R ³ , a and b in formula (A1) have the same meanings as in formula (A1 ′);
R ′, R ⁴ , R ⁵ , R ⁶ , R ⁸ , R ⁹ , c, d and e in the formula (A2) have the same meanings as in the above formula (A2 ′). )
The liquid crystal aligning agent of Claim 1 which is a reaction product with at least 1 sort (s) selected from the group which consists of a compound represented by each of these.
  A method for forming a liquid crystal alignment film, comprising: applying a liquid crystal alignment agent according to claim 1 on a substrate to form a coating film, and irradiating the coating film with radiation.   A liquid crystal display element comprising a liquid crystal alignment film formed from the liquid crystal aligning agent according to claim 1.   The liquid crystal display element of Claim 4 which is a horizontal electric field system.