JP5360356B2 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Abstract

The invention relates to a liquid crystal alignment agent, a liquid crystal alignment film and a liquid crystal display element. A liquid crystal alignment agent for a liquid crystal alignment film which can form great heat and light resistance, has small reduction of voltage holding ratio even in high-temperature environment under high-intensity illumination in particular, and is excellent in electrostatic leakage performance. The liquid crystal alignment agent contains epoxy with the equivalent of 50-100, and specific epoxy-containing polysiloxane with the weight average molecular weight of1000-100000, which is conversed by polystyrene determined by gel permeation chromatograph.

Description

  The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element. More specifically, the liquid crystal alignment film has a good electrostatic leakage property without impairing electrical characteristics such as voltage holding ratio even after use under a severe environment such as intense light irradiation or high temperature or after long-time driving. The present invention relates to a liquid crystal aligning agent capable of forming a liquid crystal, a liquid crystal alignment film formed therefrom, and a liquid crystal display device including the liquid crystal alignment film.

Currently, as a liquid crystal display element, a liquid crystal alignment film made of an organic resin or the like is formed on the surface of a substrate on which a transparent conductive film is provided to form a liquid crystal display element substrate. A nematic liquid crystal layer having a positive dielectric anisotropy is formed into a sandwich cell so that the long axis of the liquid crystal molecules is continuously twisted by 90 ° from one substrate to the other. A TN type liquid crystal display element having a so-called TN type (Twisted Nematic) liquid crystal cell is known (Patent Document 1). In addition, an STN (Super Twisted Nematic) type liquid crystal display element (Patent Document 2) capable of realizing a high contrast ratio as compared with a TN type liquid crystal display element, and an IPS (In-Plane Switching) type liquid crystal display with less viewing angle dependency. Element and VA (Vertical Alignment) type liquid crystal display element (Patent Document 3), an optically compensated bend (OCB) type liquid crystal display element (Non-Patent Document 1) having less viewing angle dependence and excellent high-speed response of a video screen Has been developed.
The operating principles of these various liquid crystal display elements are broadly divided into transmission types and reflection types. The transmissive liquid crystal display element performs display by using a change in intensity of transmitted light of a backlight light source from the back of the element when the element is driven. Reflective liquid crystal display elements do not use a light source for backlights, but display using changes in the intensity of reflected light from the outside, such as sunlight when the element is driven, and consume less power than transmissive displays. It is considered to be particularly advantageous for outdoor use because of its small number.

In the transmissive liquid crystal display element, the liquid crystal alignment film provided in the transmissive liquid crystal display element is exposed to light from a backlight light source for a long time. In particular, in addition to business use, in liquid crystal projector applications where demand for home theaters has been increasing in recent years, light sources with extremely high irradiation intensity such as metal halide lamps are used. Further, it is conceivable that the temperature of the liquid crystal display element itself rises during driving due to strong light irradiation.
The reflective liquid crystal display element is assumed to be used outdoors. In this case, sunlight including intense ultraviolet light is used as a light source. In the reflection type, the distance that light passes through the element is longer than the transmission type in principle.
Furthermore, both the transmission type liquid crystal display element and the reflection type liquid crystal display element tend to be widely used, for example, in an automobile for private use, and at a higher temperature than the mode conventionally considered as the mode of use of the liquid crystal display element. The usage and installation environment has become a reality.
By the way, in the manufacturing process of a liquid crystal display element, a liquid crystal dropping method, that is, an ODF (One Drop Fill) method, has started to be used from the viewpoint of process shortening and yield improvement. Unlike the conventional method in which liquid crystal is injected into an empty liquid crystal cell that has been assembled in advance using a thermosetting sealant, the ODF method is UV curable at a required location on one side substrate coated with a liquid crystal alignment film. After applying the sealing agent, the liquid crystal is dropped onto a necessary portion and the other substrate is bonded, and then the entire surface is irradiated with ultraviolet light to cure the sealing agent to produce a liquid crystal cell (Patent Document 4). The ultraviolet light irradiated at this time is usually as strong as tens of thousands of J / m ² or more. That is, when the ODF method is adopted, the liquid crystal alignment film is exposed to the strong ultraviolet light together with the liquid crystal in the manufacturing process of the liquid crystal display element.

As described above, in liquid crystal display elements, due to their high functionality, versatility, and improvement of manufacturing processes, high intensity light irradiation, high temperature environment, long time driving, etc., which were unthinkable in the past In such an environment, liquid crystal orientation, electrical characteristics such as voltage holding ratio, or display characteristics that are superior to conventional ones are required. Life expectancy has been demanded.
Conventionally, organic resins such as polyimide, polyamic acid, polyamide, and polyester are known as materials for the liquid crystal alignment film constituting the liquid crystal display element. In particular, polyimide has been used in many liquid crystal display elements because it exhibits excellent physical properties such as heat resistance, affinity with liquid crystals, and mechanical strength among organic resins (Patent Document 5). However, these organic resins are not materials developed on the assumption that they are used in harsh environments as described above, and their durability in such environments is not sufficient.
A liquid crystal aligning agent that can provide a liquid crystal aligning film having sufficient heat resistance and light resistance in an extremely harsh production environment and use environment at present, and is excellent in electrostatic leakage is not yet known.
JP-A-4-153622 JP 60-107020 A Japanese Patent Laid-Open No. 11-258605 JP-A-6-3635 Japanese Patent Publication 62-165628 JP-A-6-222366 JP-A-6-281937 JP-A-5-107544 “SID '94 Digest”, p927 (1997)

The present invention has been made in view of the circumstances as described above, and the purpose thereof is high in heat resistance and light resistance, and in particular, under a high temperature environment, there is little decrease in voltage holding ratio even by high intensity light irradiation, Another object of the present invention is to provide a liquid crystal aligning agent capable of forming a liquid crystal alignment film having excellent electrostatic leakage.
Another object of the present invention is to provide a liquid crystal alignment film having various excellent properties as described above using the liquid crystal aligning agent of the present invention.
Still another object of the present invention is to provide a liquid crystal display device excellent in heat resistance and light resistance.
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 formula (S-1)

(In Formula (S-1), X is a monovalent organic group having an epoxy group, Y is a hydroxyl group, an alkoxyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 20 carbon atoms, or 6 to 20 carbon atoms. Of the aryl group.)
At least one selected from the group consisting of a polyorganosiloxane having a repeating unit represented by the formula: the weight average molecular weight in terms of polystyrene measured by instantiation chromatography is 1,000-100,000.), and
It is achieved by a liquid crystal aligning agent containing at least one polymer selected from the group consisting of polyamic acid and polyimide .
The above objects and advantages of the present invention are, secondly,
Achieved by a liquid crystal alignment film formed from the above liquid crystal aligning agent,
This is achieved by a liquid crystal display element comprising the above liquid crystal alignment film.

When the liquid crystal aligning agent of the present invention is used, the liquid crystal alignment film having excellent heat resistance and light resistance as compared with the conventional alignment film, particularly, the voltage holding ratio characteristic is deteriorated even by high-intensity light irradiation in a high temperature environment. It is possible to obtain a liquid crystal alignment film having no electrostatic leakage and excellent electrostatic leakage. Therefore, this liquid crystal alignment film can be suitably applied to various liquid crystal display elements.
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 is a device such as a desk calculator, a wristwatch, a table clock, a counting display board, a word processor, a personal computer, a car navigation system, a liquid crystal television, etc. Is preferably used.

The liquid crystal aligning agent of the present invention is at least one selected from the group consisting of a polyorganosiloxane having a repeating unit represented by the above formula (S-1), a hydrolyzate thereof and a condensate of the hydrolyzate (hereinafter, "Polyorganosiloxane having an epoxy group") , and
At least one polymer selected from the group consisting of polyamic acid and polyimide .
<Polyorganosiloxane having epoxy group>
The polyorganosiloxane having an epoxy group contained in the liquid crystal aligning agent of the present invention is a polyorganosiloxane having a repeating unit represented by the above formula (S-1), a hydrolyzate thereof, and a condensate of the hydrolyzate. Is at least one selected from the group consisting of
The epoxy group contained in X in the above polyorganosiloxane having an epoxy group means an oxiranyl group or a 1,2-epoxy group. X is a 3-glycidoxypropyl group or the following formula ( X-2)

The group represented by these is preferable.
Examples of the alkoxy group having 1 to 20 carbon atoms of Y include a methoxyl group, an ethoxyl group, and an octadecyloxy group;
Examples of the alkyl group having 1 to 20 carbon atoms include 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-lauryl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n- Nonadecyl group, n-eicosyl group, etc .;
Examples of the aryl group having 6 to 20 carbon atoms include a phenyl group and a butyloxyphenyl group.
The polyorganosiloxane having an epoxy group has an epoxy equivalent of 50 to 10,000 g / mol, preferably 50 to 5,000 g / mol, more preferably 100 to 1,000, and further 150 to 500 g. / Mol is preferred.
The polyorganosiloxane having an epoxy group has a polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography (GPC) of 1,000 to 100,000, preferably 1,500 to 50,000. More preferably, it is 2,000-10,000.
Such polyorganosiloxane having an epoxy group is preferably 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. It can be synthesized by hydrolysis or hydrolysis / condensation below.
Examples of the silane compound having an epoxy group include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropylmethyldiethoxy. Silane, 3-glycidoxypropyldimethylmethoxysilane, 3-glycidoxypropyldimethylethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxy Examples include silane.

  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- (perfluorosilane Fluoro-n-octyl) ethyltri-i-propoxysilane, 2- (Perful Olo-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- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloxypropyltri-n-propoxysilane, 3- (meth) acryloxypropyltri-i-propoxysilane, 3- (meth) acryloxypropyltri-n-butoxysilane, 3- (meth) acryloxypropyltri-sec-butoxysilane, 3-mercaptopropyltri Chlorosilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltri-n-propoxysilane, 3-mercaptopropyltri-i-propoxysilane, 3-mercaptopropyltri-n-butoxysilane , -Mercaptopropyltri-sec-butoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri-n-propoxysilane, vinyltri-i-propoxysilane, Vinyltri-n-butoxysilane, vinyltri-sec-butoxysilane, allyltrichlorosilane, allyltrimethoxysilane, 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, methyldichlorosilane, methyldimethoxysilane, methyldiethoxysilane, methyldi-n-propoxysilane, methyldi-i-propoxysilane, Methyldi-n-butoxysilane, methyldi-sec-butoxysilane, dimethyldichlorosilane, dimethyldimethoxysilane, dimethyldiethoxysilane, 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 (above, 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);
FZ3711, FZ3722 (above, manufactured by Nippon Unicar Co., Ltd.);
DMS-S12, 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 (manufactured by Chisso Corporation);
Methyl silicate MS51, Methyl silicate MS56 (above, manufactured by Mitsubishi Chemical Corporation);
Ethyl silicate 28, ethyl silicate 40, ethyl silicate 48 (above, manufactured by Colcoat Co., Ltd.);
Partial condensates such as GR100, GR650, GR908, and GR950 (manufactured by Showa Denko KK) can be given.

Among these other silane compounds, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane , Vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltri Methoxysilane, mercaptomethyltriethoxysilane, dimethyldimethoxysilane or dimethyldiethoxysilane is preferred.
Since the polyorganosiloxane having an epoxy group used in the present invention has an epoxy equivalent as described above, in the synthesis of a polyorganosiloxane having an epoxy group, use of a silane compound having an epoxy group and another silane compound is used. The proportion should be set by adjusting the resulting polyorganosiloxane epoxy equivalent in the above range.

Examples of the organic solvent that can be used for synthesizing the polyorganosiloxane having an epoxy group include hydrocarbons, ketones, esters, ethers, and alcohols.
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, and acetic acid. Examples of the ethers such as i-amyl, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, and ethyl lactate include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, tetrahydrofuran, and dioxane. Examples of the alcohol include 1-hexanol, 4-methyl-2-pentanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono- - propyl ether, ethylene glycol monobutyl -n- butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol mono -n- propyl ether, and respectively. 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 10,000 parts by weight, more preferably 50 to 1,000 parts by weight with respect to 100 parts by weight of the total silane compounds.
The amount of water used in producing the polyorganosiloxane having an epoxy group is preferably 0.5 to 100 times mol, more preferably 1 to 30 times mol, based on all silane compounds.

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, there are tertiary organic amines such as triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine, 4-dimethylaminopyridine, and quaternary organic amines such as tetramethylammonium hydroxide. preferable.
As a catalyst for producing 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 / condensation rate without causing side reactions such as ring opening of the epoxy group. This is preferable.
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. For example, the amount is preferably 0.01 to 3 moles relative to the total silane compound, More preferably, it is 0.05-1 times mole.

The hydrolysis or hydrolysis / condensation reaction in producing an epoxy group-containing polyorganosiloxane is carried out by dissolving an epoxy group-containing silane compound and, if necessary, another silane compound in an organic solvent, and dissolving the solution in an organic base. It is preferable to carry out by mixing with water and heating with, for example, an oil bath.
During the hydrolysis / 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 heating, the mixture may be stirred or placed under reflux.
After completion of the reaction, the organic solvent layer separated from the reaction solution 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).

<Other ingredients>
The liquid crystal aligning agent of the present invention contains the polyorganosiloxane having an epoxy group as described above as an essential component, but may contain other components as long as the advantages and effects of the present invention are not impaired. Examples of such other components include polymers other than polyorganosiloxane having an epoxy group (hereinafter referred to as “other polymer”), compounds having at least one epoxy group in the molecule (however, having an epoxy group) Excluding polyorganosiloxane, hereinafter referred to as “epoxy compound”), functional silane compounds and the like.
[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, polyamic acid ester, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, and poly (styrene-phenylmaleimide) derivative. And poly (meth) acrylate. Among these, at least one polymer selected from the group consisting of polyamic acid and polyimide is essential .

The polyamic acid can be synthesized by reacting tetracarboxylic dianhydride with diamine.
-Tetracarboxylic dianhydride-
Examples of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1, 2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4- Cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclo Ntylacetic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic 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- 5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro- 5-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro -7-methyl-5- (tetrahydro-2,5 -Dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-ethyl-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, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5- (tetrahydro- 2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5 (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2- ] -Furan-1,3-dione, 5- (2,5-dioxotetrahydrofuranyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, bicyclo [2.2.2] -oct -7-ene-2,3,5,6-tetracarboxylic dianhydride, 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-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy- 2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, Formulas (TI) and (T-II)

(In the formulas (T-I) and (T-II), R ¹ and R ³ are each a divalent organic group having an aromatic ring, and R ² and R ⁴ are each a hydrogen atom or an alkyl group. And a plurality of R ² and R ⁴ may be the same or different.)
An aliphatic or alicyclic tetracarboxylic dianhydride such as tetracarboxylic dianhydride represented by each of
Pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 1,4,5, 8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bis ( 3,4-dicar Boxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidene diphthalic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2 , 2 ′, 3,3′-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis ( Triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4′-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4′-diphenylmethane dianhydride, ethylene glycol-bis ( Anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anhydrotrimellitate) Retate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis ( Anhydrotrimellitate), 2,3,2 ′, 3′-biphenyltetracarboxylic dianhydride, the following formulas (T-1) to (T-4)

An aromatic tetracarboxylic dianhydride such as a compound represented by each of the above can be exemplified. These can be used singly or in combination of two or more.
Among the above, the tetracarboxylic dianhydrides used to synthesize the polyamic acid include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3- Dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic 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, 1,3,3a , 4, 5, b-Hexahydro-5,8-dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2.2.2] -Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 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-1,2-dicarboxylic anhydride, 3,5,6-tri Carboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone , Pyromellitic dianhydride, 3,3 ′, 4,4′-be Zophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 1,4,4 5,8-Naphthalenetetracarboxylic dianhydride, among the compounds represented by the above formula (TI), the following formulas (T-5) to (T-7)

And the following formula (T-8) among the compounds represented by formula (T-II):

で表される化合物よりなる群から選択される少なくとも一種（以下、「特定テトラカルボン酸二無水物」という。）を含むものであることが好ましい。
特定テトラカルボン酸二無水物としては、特に２，３，５−トリカルボキシシクロペンチル酢酸二無水物、１，３，３ａ，４，５，９ｂ−ヘキサヒドロ−５−（テトラヒドロ−２，５−ジオキソ−３−フラニル）−ナフト［１，２−ｃ］フラン−１，３−ジオン、１，３，３ａ，４，５，９ｂ−ヘキサヒドロ−８−メチル−５−（テトラヒドロ−２，５−ジオキソ−３−フラニル）−ナフト［１，２−ｃ］フラン−１，３−ジオン、３−オキサビシクロ［３．２．１］オクタン−２，４−ジオン−６−スピロ−３’−（テトラヒドロフラン−２’，５’−ジオン）、５−（２，５−ジオキソテトラヒドロ−３−フラニル）−３−メチル−３−シクロヘキセン−１，２−ジカルボン酸無水物、３，５，６−トリカルボキシ−２−カルボキシノルボルナン−２：３，５：６−二無水物、４，９−ジオキサトリシクロ［５．３．１．０^２，６］ウンデカン−３，５，８，１０−テトラオンおよび２，３，２’，３’−ビフェニルテトラカルボン酸二無水物よりなる群から選ばれる少なくとも一種であることが好ましい。
上記ポリアミック酸を合成するために用いられるテトラカルボン酸二無水物は、上記の如き特定テトラカルボン酸二無水物を、全テトラカルボン酸二無水物に対して、５０モル％以上含むものであることが好ましく、６０モル％以上含むものであることがより好ましく、特に７５モル％以上含むものであることが好ましい。

It is preferable that it contains at least one selected from the group consisting of compounds represented by the following (hereinafter referred to as “specific tetracarboxylic dianhydride”).
Specific tetracarboxylic dianhydrides include, in particular, 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-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy -2-Carboxylnorbol Down -2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^{2, 6]} undecane -3,5,8,10- tetraone and 2,3, It is preferably at least one selected from the group consisting of 2 ′, 3′-biphenyltetracarboxylic dianhydride.
The tetracarboxylic dianhydride used to synthesize the polyamic acid preferably contains 50 mol% or more of the specific tetracarboxylic dianhydride as described above with respect to the total tetracarboxylic dianhydride. , 60 mol% or more is more preferable, and 75 mol% or more is particularly preferable.

-Diamine-
Examples of the diamine used for the synthesis of the polyamic acid include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl sulfide, 4 , 4′-diaminodiphenylsulfone, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diaminobenzanilide, 4,4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 2,2 '-Dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl, 3,3'-ditri Fluoromethyl-4,4′-diaminobiphenyl, 5-amino-1- (4′-aminophenyl) -1,3,3-to Methylindane, 6-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 3,4′-diaminodiphenyl ether, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2- Bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4 -Aminophenoxy) biphenyl, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 9,9-bis (4-aminophenyl) fluorene 4,4′-methylene-bis (2-chloroaniline), 2,2 ′, 5,5′-tetrachloro-4,4′-diaminobiphenyl, 2,2′-dichloro-4,4′-diamino -5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 1,4,4 '-(p-phenylene isopropylidene) bisaniline, 4,4'-(m-phenylene isopropyl Redene) bisaniline, 2,2′-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′-diamino-2,2′-bis (trifluoro) Romechiru) biphenyl, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] - aromatic diamines such as octafluoro biphenyl;

1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1 , 4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene methylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyldiamine, 4 Aliphatic or cycloaliphatic diamines such as 1,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane;
2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4 -Dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,3 , 5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl -S-triazine, 2,4-diamino-1,3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6- Aminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6 Phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine, 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 '-Dimethyl-benzidine, the following formula (DI)

(In the formula (DI), R ⁵ is a monovalent organic group having a ring structure containing a nitrogen atom selected from the group consisting of pyridine, pyrimidine, triazine, piperidine and piperazine, and X ¹ is a divalent group. An organic group, R ⁶ is an alkyl group having 1 to 4 carbon atoms, and a1 is an integer of 0 to 3.)
A compound represented by formula (D-II):

(In formula (D-II), R ⁷ is a divalent organic group having a ring structure containing a nitrogen atom selected from the group consisting of pyridine, pyrimidine, triazine, piperidine and piperazine, and X ² is A plurality of X ² may be the same or different; R ⁸ is an alkyl group having 1 to 4 carbon atoms; and a2 is 0 to 3 respectively. Is an integer.)
A diamine having two primary amino groups and a nitrogen atom other than the primary amino group in a molecule such as a compound represented by:
The following formula (D-III)

(In the formula (D-III), R ⁹ is a divalent organic group selected from the group consisting of —O—, —COO—, —OCO—, —NHCO—, —CONH— and —CO—. , R ¹⁰ is a monovalent organic group having a skeleton or a group selected from the group consisting of a steroid skeleton, a trifluoromethylphenyl group, a trifluoromethoxyphenyl group and a fluorophenyl group, or an alkyl group having 6 to 30 carbon atoms. R ¹¹ is an alkyl group having 1 to 4 carbon atoms, and a3 is an integer of 0 to 3.)
Monosubstituted phenylenediamines such as compounds represented by:
The following formula (D-IV)

(In the formula (D-IV), each R ¹² represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ¹² may be the same or different from each other, and p is each , An integer of 1 to 3, and q is an integer of 1 to 20.)
Diaminoorganosiloxanes such as compounds represented by:
The following formulas (D-1) to (D-5)

(Y in the formula (D-4) is an integer of 2 to 12, and z in the formula (D-5) is an integer of 1 to 5.)
And the like, and the like.
The aromatic diamine and the benzene ring of each of the compounds represented by the formulas (D-1) to (D-5) are one or two or more alkyl groups having 1 to 4 carbon atoms (preferably a methyl group). ) May be substituted. In the above formulas (DI), (D-II) and (D-III), R ⁶ , R ⁸ and R ¹¹ are each preferably a methyl group, and a1, a2 and a3 are each 0 Or it is preferable that it is 1, and it is more preferable that it is 0.
These diamines can be used alone or in combination of two or more.
Among the above, the diamine used for synthesizing the polyamic acid is p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2 ′. -Dimethyl-4,4'-diaminobiphenyl, 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl, 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 ′-(m-phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 1,4-diaminocyclohexane, 4, 4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane, 4,4′-diaminodiphenylsulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, the above formula ( D-1) to (D-5), 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- , 6-diaminocarbazole, N, N′-bis (4-aminophenyl) -benzidine, N, N′-bis (4-aminophenyl) -N, N′-dimethylbenzidine, represented by the above formula (DI) Of the compounds represented, the following formula (D-6)

Of the compounds represented by formula (D-II), the following formula (D-7)

Of the compounds represented by formula (D-III), dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy- 2,4-diaminobenzene, dodecanoxy-2,5-diaminobenzene, pentadecanoxy-2,5-diaminobenzene, hexadecanoxy-2,5-diaminobenzene, octadecanoxy-2,5-diaminobenzene, the following formula (D-8) ~ (D-16)

And at least one selected from the group consisting of 1,3-bis (3-aminopropyl) -tetramethyldisiloxane among the compounds represented by formula (D-IV) , "Specific diamine").
The diamine used for synthesizing the polyamic acid preferably contains 50 mol% or more of the specific diamine as described above, more preferably contains 75 mol% or more, particularly 90 mol%. It is preferable to include the above.

-Synthesis of polyamic acid-
The ratio of the tetracarboxylic dianhydride and diamine used in the polyamic acid synthesis reaction is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.5 per 1 equivalent of the amino group contained in the diamine. The ratio which becomes -2 equivalent is preferable, and the ratio which becomes 0.7-1.2 equivalent is further more preferable.
The polyamic acid synthesis reaction is preferably performed in an organic solvent under a temperature condition of preferably -20 to 150 ° C, more preferably 0 to 100 ° C. The reaction time is preferably 2 to 24 hours, more preferably 2 to 12 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, dimethyl sulfoxide And aprotic polar solvents such as γ-butyrolactone, tetramethylurea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. The amount of the organic solvent used (a) is such that the total amount (b) of the tetracarboxylic dianhydride and the diamine compound is 0.1 to 30% by weight with respect to the total amount (a + b) of the reaction solution. It is preferable that In addition, when using an organic solvent together with the poor solvent demonstrated below, the usage-amount (a) of the said organic solvent should be understood as meaning the total usage-amount of an organic solvent and a poor solvent. It is.

For the organic solvent, alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon and the like, which are poor solvents for polyamic acid, can be used in combination as long as the polyamic acid to be produced does not precipitate. Specific examples of the poor solvent include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, Acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene Glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n- Chill ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1 , 4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, isoamylpropionate, isoamylisobutyrate, diisopentyl ether and the like.
The use ratio of the poor solvent is preferably 80% by weight or less, more preferably 50% by weight or less, and further preferably 40% by weight or less with respect to the total of the organic solvent and the poor solvent.

  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. Polyamic acid can be 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 the reaction solution under reduced pressure using an evaporator. it can. Further, the polyamic acid can be purified by a method of dissolving the polyamic acid again in an organic solvent and then precipitating with a poor solvent, or a method of performing the step of distilling under reduced pressure with an evaporator once or several times.

-Synthesis of polyimide-
The polyimide can be synthesized by dehydrating and ring-closing 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 imidation ratio of polyimide is preferably 40% or more, and more preferably 80% or more. Here, the “imidation ratio” refers to a numerical value representing the ratio of the number of imide ring structures to the total of the number of amic acid structures and the number of imide ring structures in polyimide as a percentage. At this time, a part of the imide ring may be an isoimide ring.
The polyamic acid dehydration cyclization reaction is carried out 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 closure 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. When the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and when 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, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride is used as the dehydrating agent. Can do. The amount of the dehydrating agent used is preferably 0.01 to 20 mol with respect to 1 mol of the 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. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent 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 a liquid crystal aligning agent, or may be used for the preparation of a 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 dehydrating 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.

-End-modified polymer-
Each of the polyamic acid and the polyimide may be a terminal-modified polymer having a controlled molecular weight. Such a terminal-modified polymer can be synthesized by adding an appropriate molecular weight regulator such as acid monoanhydride, monoamine compound, monoisocyanate compound to the reaction system when synthesizing the polyamic acid. . Here, as the acid monoanhydride, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride , N-hexadecyl succinic anhydride and the like. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n -Dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine . Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.
The use ratio of the molecular weight regulator is preferably 5% by weight or less, more preferably 2% by weight or less, based on the total of tetracarboxylic dianhydride and diamine used when synthesizing the polyamic acid. is there.
-Ratio of other polymers used-
When the liquid crystal aligning agent of the present invention contains another polymer in addition to the polyorganosiloxane having an epoxy group, the proportion of the other polymer used is 100 parts by weight of the polyorganosiloxane having an epoxy group. 50,000 parts by weight or less, more preferably 200 to 50,000 parts by weight, still more preferably 1,000 to 20,000 parts by weight, and particularly preferably 2,000 to 10,000. It is preferably 000 parts by weight.

[Epoxy compound]
The said epoxy compound can be contained in the liquid crystal aligning agent of this invention from a viewpoint which improves the adhesiveness with respect to the substrate surface of the liquid crystal aligning film formed. The polyorganosiloxane having an epoxy group is also a compound having at least one epoxy group in the molecule, but the epoxy compound referred to here is a polyorganosiloxane having an epoxy group in that the molecular weight is less than 1,000. Different.
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 - such as aminomethyl cyclohexane may be mentioned as preferred. The blending ratio of these epoxy group-containing compounds is preferably 40 parts by weight or less with respect to 100 parts by weight of the total of the polymers (the total of the polyorganosiloxane having epoxy groups and other polymers). More preferably, it is 0.1 to 30 parts by weight.

Examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl)- 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyl Trimethoxysilane, 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 ( Examples thereof include oxyethylene) -3-aminopropyltrimethoxysilane and N-bis (oxyethylene) -3-aminopropyltriethoxysilane.
The blending ratio of these functional silane compounds is preferably 2 parts by weight or less, more preferably 0.2 parts by weight or less, with respect to 100 parts by weight of the total polymer.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention is preferably prepared as a solution state in which the polyorganosiloxane having an epoxy group as described above and other components optionally used are dissolved in a suitable organic solvent.
Liquid crystal aligning agent of this invention As an organic solvent which can be used for the liquid crystal aligning agent of this invention, the solvent illustrated as what is used for the synthesis reaction of a polyamic acid can be mentioned, for example. Here, the poor solvent illustrated as what can be used together in the synthesis reaction of a polyamic acid can also be selected suitably, and can be used together. A preferable organic solvent used in the liquid crystal aligning agent of the present invention is obtained by combining one or two or more of the above organic solvents, and each component contained in the liquid crystal aligning agent at the following preferable solid content concentration. It does not precipitate, and the surface tension of the liquid crystal aligning agent is in the range of 20 to 50 mN / m.
The solid content concentration of the liquid crystal aligning agent of the present invention (the ratio of the total weight of 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, and the like. A preferable solid content concentration is in the range of 1 to 20% by weight. That is, 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 alignment film. When the solid content concentration is less than 1% by weight, the coating film thickness is When the solid content concentration exceeds 20% by weight, it is difficult to obtain a good liquid crystal alignment film, and it is difficult to obtain a good liquid crystal alignment film. The viscosity of the aligning agent increases, resulting in poor coating properties.
The particularly preferable solid content concentration range varies depending on the method used when applying the liquid crystal aligning agent to the substrate. For example, when the spinner method is used, the range of 1.5 to 6.0% 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 20% 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 at which the liquid crystal aligning agent of the present invention is prepared is preferably 0 ° C to 200 ° C, more preferably 20 ° C to 60 ° C.

<Liquid crystal display element>
The liquid crystal display element of the present invention comprises a liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention as described above.
The liquid crystal display element of the present invention can be produced, for example, by the following method.
(1) First, the liquid crystal alignment film of the present invention is applied onto a pair of substrates, and the solvent is removed to form a coating film. Here, when the display mode of the liquid crystal display element to be manufactured is a vertical electric field system such as a TN type, an STN type, or a VA type, two substrates on which a transparent conductive film patterned on one side is provided. Are used as a pair of substrates. On the other hand, when the display mode of the liquid crystal display element to be manufactured is a lateral electric field method known as an IPS method, the liquid crystal display element has a substrate provided with a transparent conductive film having a comb-like pattern and a transparent conductive film. A pair of substrates is used as a pair.
In any of the above cases, the liquid crystal aligning agent is applied onto the substrate (on the surface having the transparent conductive film of the substrate when the substrate has a transparent conductive film). As the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly (cycloaliphatic olefin) can be used. Examples of the transparent conductive film provided on one surface of the substrate include an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), and the like. Can be used. In addition, in order to obtain these patterned transparent conductive films, a method of forming a pattern by a photo-etching method after forming a transparent conductive film without a pattern, and a mask having a desired pattern when forming the transparent conductive film. For example, a method of directly forming a patterned transparent conductive film can be employed.
The liquid crystal aligning agent is applied onto the substrate by an appropriate application method such as a roll coater method, a spinner method, a printing method, or an ink jet method. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound, a functional titanium compound, or the like is applied in advance to the coated surface of the substrate. You may keep it.
After application, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied alignment agent. The pre-baking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The pre-bake time is preferably 1 to 15 minutes, more preferably 1 to 10 minutes. Thereafter, a post-heating (post-baking) step is performed for the purpose of completely removing the solvent. The post-bake temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-bake time is preferably 5 to 120 minutes, more preferably 10 to 60 minutes.

(2) When the display mode of the liquid crystal display element to be manufactured is the VA type, the coating film formed as described above can be used as a liquid crystal alignment film as it is. The rubbing process described may be performed. On the other hand, when the display mode of the liquid crystal display element to be manufactured is a vertical electric field method other than the VA type or a horizontal electric field method, a rubbing process is performed on the formed coating film surface.
The rubbing treatment can be performed by a method of rubbing in a certain direction with a roll around which a cloth made of fibers such as nylon, rayon, and cotton is wound. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. Furthermore, a part of the liquid crystal alignment film as shown in, for example, Patent Document 6 (Japanese Patent Laid-Open No. 6-222366) or Patent Document 7 (Japanese Patent Laid-Open No. 6-281937) is applied to the coating film after the rubbing treatment. Or a part of the surface of the liquid crystal alignment film as disclosed in Patent Document 8 (Japanese Patent Laid-Open No. 5-107544) By forming a resist film on the top and performing a rubbing treatment in a direction different from the previous rubbing treatment, and then removing the resist film so that the liquid crystal alignment film has different liquid crystal alignment capabilities for each region, It is possible to improve the visibility characteristics of the obtained liquid crystal display element.

(3) A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above, and disposing a liquid crystal between the two substrates opposed to each other. Here, when the rubbing process is performed on the coating film, the two substrates are disposed to face each other so that the rubbing directions in the respective coating films are at a predetermined angle, for example, orthogonal or antiparallel.
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 step, 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.
Regardless of which method is used, the liquid crystal cell produced as described above is further heated to a temperature at which the liquid crystal used takes an isotropic phase, and then gradually cooled to room temperature, so that the flow alignment during liquid crystal injection is achieved. It is desirable to remove.
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, as the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used.
As the liquid crystal, for example, a nematic liquid crystal, a smectic liquid crystal, or the like can be used. When manufacturing a liquid crystal display element having a TN liquid crystal cell, an STN liquid crystal cell or an IPS liquid crystal cell, a nematic liquid crystal having positive dielectric anisotropy is preferable. For example, a biphenyl liquid crystal or a phenylcyclohexane liquid crystal , Ester liquid crystals, terphenyl liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, and cubane liquid crystals. For example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names C-15 and CB-15 (manufactured by Merck); A ferroelectric liquid crystal such as p-amino-2-methylbutyl cinnamate may be further added and used.
On the other hand, in the case of a VA type liquid crystal cell, a nematic type liquid crystal having negative dielectric anisotropy is preferable, and this is generally called a negative type liquid crystal. For example, dicyanobenzene liquid crystal, pyridazine liquid crystal, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, and phenylcyclohexane liquid crystal are used.
As a polarizing plate bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film in which a polarizing film called an “H film” that absorbs iodine while stretching and aligning polyvinyl alcohol is sandwiched between protective films of cellulose acetate The polarizing plate which consists of itself can be mentioned.

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 Mw of the polyorganosiloxane having an epoxy group in the following synthesis examples is a polystyrene conversion value measured by gel permeation chromatography under the following conditions.
Column: Tosoh Corporation, TSK-GEL
Solvent: Tetrahydrofuran Column temperature: 40 ° C
Pressure: 80 kgf / cm ²
The epoxy equivalent was measured by the hydrochloric acid-methyl ethyl ketone method described in JIS C 2105.
The solution viscosity of the polyamic acid solution and the polyimide solution is a value measured at 25 ° C. using an E-type viscometer for the polymer solution indicated in each synthesis example.
The imidation ratio of polyimide was determined by the following formula (1) from ¹ H-NMR measured at room temperature using tetramethylsilane as a reference substance after each polyimide was dried under reduced pressure at room temperature and then dissolved in deuterated dimethyl sulfoxide.

Imidation rate (%) = (1-A ¹ / A ² × α) × 100 (1)

(In Formula (1), A ¹ is a peak area derived from protons of NH groups appearing near a chemical shift of 10 ppm, A ² is a peak area derived from other protons, and α is a precursor of the polyimide (polyamic acid) The number ratio of other protons to one proton of NH group in)
Determined by

<Synthesis of polyorganosiloxane having epoxy group>
Synthesis example 1
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 stirring under reflux. After completion of the reaction, the organic layer is taken out and washed with a 0.2 wt% ammonium nitrate aqueous solution until the water after washing becomes neutral, and then the solvent and water are distilled off under reduced pressure, whereby a polyorgano having an epoxy group is obtained. Siloxane (EPS-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 weight-average molecular weight Mw and epoxy equivalent of the polyorganosiloxane (EPS-1) having this epoxy group.
Synthesis Examples 2-3
Polyorganosiloxanes (EPS-2) and (EPS-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 weight average molecular weight 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 of polyamic acid>
Synthesis example 4
20 g (0.1 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 21 g of 2,2′-dimethyl-4,4′-diaminobiphenyl as diamine (0. 1 mol) is dissolved in a mixed solvent consisting of 37 g of N-methyl-2-pyrrolidone and 330 g of γ-butyrolactone, and reacted at 40 ° C. for 3 hours, thereby containing 10% by weight of polyamic acid (A-1). About 400 g was obtained. The solution viscosity of this solution was 160 mPa · s.
Synthesis example 5
9.8 g (0.05 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 11 g (0.05 mol) of pyromellitic dianhydride and 4,4 as diamine 20 g (0.1 mol) of 4′-diaminodiphenylmethane was dissolved in a mixed solvent consisting of 23 g of N-methyl-2-pyrrolidone and 210 g of γ-butyrolactone, reacted at 40 ° C. for 3 hours, and then 135 g of γ-butyrolactone was added. By adding, about 390 g of a solution containing 10% by weight of polyamic acid (A-2) was obtained. The solution viscosity of this solution was 125 mPa · s.
Synthesis Example 6
Pyromellitic anhydride 28 g (0.09 mol) and 1,2,3,4-cyclobutanetetracarboxylic dianhydride 2.8 g (0.01 mol) as tetracarboxylic dianhydride and p-phenylene as diamine By dissolving 3.0 g (0.02 mol) of diamine and 23 g (0.08 mol) of 4,4′-diaminodiphenyl ether in 323 g of N-methyl-2-pyrrolidone and reacting at 40 ° C. for 3 hours, About 380 g of a solution containing 15% by weight of acid (A-3) was obtained. The solution viscosity of this solution was 380 mPa · s.

<Synthesis of polyimide>
Synthesis example 7
2,3,5-Tricarboxycyclopentylacetic acid dianhydride 11 g (0.05 mol) and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro) as tetracarboxylic dianhydride -2,5-dioxo-3-furanyl) naphtho [1,2-c] furan-1,3-dione 16 g (0.05 mol), p-phenylenediamine 9.4 g (0.087 mol) as diamine, As 2.5 g (0.01 mol) of 1,3-bis (3-aminopropyl) tetramethyldisiloxane and 0.96 g (0.0015 mol) of 3,6-bis (4-aminobenzoyloxy) cholestane and monoamine 0.81 g (0.0030 mol) of octadecylamine is dissolved in 96 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours. A reamic acid solution was obtained. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 60 mPa · s.
Next, 270 g of NMP was added to the obtained polyamic acid solution, 40 g of pyridine and 41 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new γ-butyrolactone (by this solvent substitution operation, pyridine and acetic anhydride used in the dehydration cyclization reaction were removed from the system. The same applies hereinafter). About 240 g of a solution containing 15% by weight of polyimide (B-1) having an imidation ratio of about 95% was obtained. A small amount of this solution was collected, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 70 mPa · s.
Synthesis example 8
2,3,5-Tricarboxycyclopentyl acetic acid dianhydride 11 g (0.050 mol) as tetracarboxylic dianhydride and 4.3 g (0.040 mol) and 3 (3,5- Diaminobenzoyloxy) cholestane (5.2 g, 0.010 mol) was dissolved in NMP (83 g) and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 60 mPa · s.
Next, 190 g of NMP was added to the obtained polyamic acid solution, 4.0 g of pyridine and 5.1 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with new NMP to obtain about 120 g of a solution containing 15% by weight of polyimide (B-2) having an imidation ratio of about 50%. A small amount of this solution was collected, and NMP was added to measure the solution viscosity as a solution having a polyimide concentration of 10% by weight. The solution viscosity was 47 mPa · s.

Synthesis Example 9
2,3,5-tricarboxycyclopentylacetic acid dianhydride 11 g (0.050 mol) as tetracarboxylic dianhydride and 3.8 g (0.035 mol) p-phenylenediamine as diamine, 4,4′-diamino 2.0 g (0.01 mol) of diphenylmethane and 2.6 g (0.005 mol) of 3 (3,5-diaminobenzoyloxy) cholestane are dissolved in 80 g of NMP and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution. It was. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 60 mPa · s.
Next, 180 g of NMP was added to the obtained polyamic acid solution, 8.0 g of pyridine and 10 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 110 g of a solution containing 15% by weight of polyimide (B-3) having an imidation ratio of about 80%. A small amount of this solution was collected, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 87 mPa · s.
Synthesis Example 10
22 g (0.10 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 8.7 g (0.08 mol) of p-phenylenediamine as diamine, 4,4′-diamino Dissolve 2.0 g (0.01 mol) of diphenylmethane and 3.2 g (0.01 mol) of 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl in 256 g of NMP and dissolve at 60 ° C. for 6 hours. Reaction was performed to obtain a solution containing 10% by weight of polyamic acid. The solution viscosity of this polyamic acid solution was 40 mPa · s.
Next, 208 g of NMP was added to the obtained polyamic acid solution, 15 g of pyridine and 20 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 230 g of a solution containing 15% by weight of polyimide (B-4) having an imidation ratio of about 80%. A small amount of this solution was collected, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 57 mPa · s.

Synthesis Example 11
16.8 g (0.075 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 1,3,3a, 4,5,9b-hexahydro-5-methyl-5 ( 7.9 g (0.025 mol) of tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione and 4.3 g of p-phenylenediamine (0 0.04 mol), 11.7 g (0.04 mol) of bis [4- (4-aminophenoxy) phenyl] ether and 8.6 g (0 of 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone). .02 mol) was dissolved in 260 g of NMP and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 92 mPa · s.
Next, 350 g of NMP was added to the obtained polyamic acid solution, 40 g of pyridine and 31 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 415 g of a solution containing 11% by weight of polyimide (B-5) having an imidation ratio of about 92%. A small amount of this solution was collected, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 123 mPa · s.
Synthesis Example 12
As a tetracarboxylic dianhydride, 1,4.6 g (0.065 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5 ( Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 7.9 g (0.025 mol) and 2,3,2 ′, 3′-biphenyl 2.9 g (0.010 mol) of tetracarboxylic dianhydride, 4.3 g (0.04 mol) of p-phenylenediamine as a diamine, and 11.7 g (0 of bis [4- (4-aminophenoxy) phenyl] ether) 0.04 mol) and 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone (8.6 g, 0.02 mol) were dissolved in NMP (260 g) and reacted at 60 ° C. for 6 hours to conduct polyamidation. A succinic acid solution was obtained. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 103 mPa · s.
Next, 350 g of NMP was added to the obtained polyamic acid solution, 40 g of pyridine and 31 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 420 g of a solution containing 10% by weight of polyimide (B-6) having an imidation ratio of about 90%. The solution viscosity of this solution was 113 mPa · s.
Synthesis Example 13
Dissolve 22.4 g (0.1 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 10.8 g (0.1 mol) of p-phenylenediamine as diamine in 300 g of NMP. Then, the reaction was performed at 60 ° C. for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 103 mPa · s.
Next, 380 g of NMP was added to the obtained polyamic acid solution, 40 g of pyridine and 31 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 320 g of a solution containing 10% by weight of polyimide (B-7) having an imidization ratio of about 90%. The solution viscosity of this solution was 113 mPa · s.

<Preparation of liquid crystal aligning agent>
Example 1
Converted to 100 parts by weight of the polyorganosiloxane EPS-1 having an epoxy group obtained in Synthesis Example 1 and polyimide (B-1) in a solution containing the polyimide (B-1) obtained in Synthesis Example 8 Combined with the amount corresponding to 5,000 parts by weight, 500 parts by weight of N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane (molecular weight of about 400) as an epoxy compound (polymer) In addition, γ-butyrolactone (BL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC) are added thereto, and the solvent composition is added. Was a solution having BL: NMP: BC = 45: 45: 10 (weight ratio) and a solid content concentration of 4% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 1 μm.
Each evaluation was performed as follows using this liquid crystal aligning agent. The evaluation results are shown in Table 2.
<Manufacture of liquid crystal cells>
The liquid crystal aligning agent adjusted as described above is applied to the transparent electrode surface of the glass substrate with a transparent electrode made of an ITO film using a liquid crystal alignment film printer (Nissha Printing Co., Ltd.), on a hot plate at 80 ° C. After heating for 1 minute, the coating was further heated on a hot plate at 200 ° C. for 10 minutes to form a coating film having an average film thickness of 800 mm.
This coating film is rubbed with a rubbing machine having a roll wrapped with rayon cloth at a roll rotation speed of 500 rpm, a stage moving speed of 3 cm / sec, and a hair foot indentation length of 0.4 mm to form a liquid crystal alignment film. did. Next, ultrasonic cleaning was performed for 1 minute in ultrapure water, followed by drying in a 100 ° C. clean oven for 10 minutes. This operation was repeated to produce a pair (two) of substrates having a liquid crystal alignment film on the transparent electrode surface.
Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to the outer edges of the pair of substrates having the liquid crystal alignment film, the liquid crystal alignment film surfaces face each other, The adhesive was cured by overlapping and pressing so that the rubbing directions were antiparallel to each other. Next, a nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) was filled between the pair of substrates from the liquid crystal inlet, and then the liquid crystal inlet was sealed with an acrylic photo-curing adhesive to produce a liquid crystal cell. .

<Evaluation of liquid crystal cell>
The above operation was repeated to produce a plurality of liquid crystal cells. The following heat resistance evaluation and light resistance evaluation were performed using separate liquid crystal cells.
[Evaluation of voltage holding ratio]
A voltage of 5 V was applied to the liquid crystal cell produced above at 60 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage holding ratio after 167 milliseconds from release of application was measured. When this voltage holding ratio is 98% or more, it can be said that the voltage holding ratio is good.
In addition, the measuring apparatus of voltage holding ratio used VHR-1 by Toyo Corporation.
[Evaluation of heat resistance]
About the liquid crystal cell manufactured above, the voltage holding ratio was measured under the same conditions as the evaluation of the voltage holding ratio (initial voltage holding ratio). Next, this liquid crystal cell was left in a 100 ° C. oven for 1,000 hours to give a thermal stress, and then the voltage holding ratio was measured again under the same conditions (voltage holding ratio after heat stress). The change rate of the holding rate with respect to the initial voltage holding rate was examined. When this rate of change is less than ± 2%, it can be said that the heat resistance is good.
[Evaluation of light resistance]
About the liquid crystal cell manufactured above, the voltage holding ratio was measured under the same conditions as the evaluation of the voltage holding ratio (initial voltage holding ratio). Next, this liquid crystal cell was left at a distance of 5 cm under a 0 watt type white fluorescent lamp, irradiated with light for 1,000 hours to give light stress, and then the voltage holding ratio was measured again under the same conditions ( The voltage holding ratio after light stress) and the rate of change of the voltage holding ratio after light stress with respect to the initial voltage holding ratio were examined. When this rate of change is less than ± 2%, it can be said that the light resistance is good.
[Electrostatic leak measurement]
A voltage of 120 V was applied to the liquid crystal cell produced above at 25 ° C. for 5 minutes, and static electricity was accumulated in the cell. Then, the time from the cancellation of voltage application until the accumulated voltage disappeared was measured in increments of 5 minutes. When this time is within 60 minutes, it can be said that the electrostatic leakage is good.

Examples 2-18 and Comparative Examples 1-3
A liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the types and amounts of the polyorganosiloxane having an epoxy group and other polymers were set as shown in Table 2, and the liquid crystal cell was evaluated. . The evaluation results are shown in Table 2.
In addition, each of the other polymers is the polymer solution obtained in the above synthesis example and used for the preparation of the liquid crystal aligning agent, and the amount used in Table 2 is a value converted to the amount of the polymer contained in each solution. is there.
In Examples 13 to 18 and Comparative Example 2, two types of other polymers were used.

Claims (6)

The following formula (S-1)

(In Formula (S-1), X is a monovalent organic group having an epoxy group, Y is a hydroxyl group, an alkoxyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 20 carbon atoms, or 6 to 20 carbon atoms. Of the aryl group.)
At least one selected from the group consisting of a polyorganosiloxane having a repeating unit represented by the formula: the weight average molecular weight in terms of polystyrene measured by instantiation chromatography is 1,000-100,000.), and
A liquid crystal aligning agent comprising at least one polymer selected from the group consisting of polyamic acid and polyimide . X in the above formula (S-1) is a 3-glycidoxypropyl group or (X-2)

The liquid crystal aligning agent of Claim 1 which is group represented by these. At least one polymer selected from the group consisting of polyamic acid and polyimide is 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-1,2-dicarboxylic acid anhydride, 3 , 5,6- Rikarubokishi-carboxylate norbornane -2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^{2, 6]} undecane -3,5,8,10- Polyamic acid obtained by reacting tetracarboxylic dianhydride containing at least one selected from the group consisting of tetraone and 2,3,2 ′, 3′-biphenyltetracarboxylic dianhydride and diamine, and the polyamic The liquid crystal aligning agent of Claim 1 or 2 which is at least 1 type of polymer selected from the group which consists of a polyimide formed by dehydrating and ring-closing an acid. Polyorganosiloxane having at least one polymer selected from the group consisting of polyamic acid and polyimide having a repeating unit represented by the above formula (S-1), its hydrolyzate and condensation of hydrolyzate The liquid crystal aligning agent as described in any one of Claims 1-3 which is 200-50,000 weight part with respect to at least 1 type of 100 weight part selected from the group which consists of a thing. The liquid crystal aligning film formed from the liquid crystal aligning agent as described in any one of Claims 1-4 . A liquid crystal display element comprising the liquid crystal alignment film according to claim 5 .