KR101536009B1 - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display device - Google Patents

Abstract

An object of the present invention is to provide a liquid crystal aligning agent capable of forming a liquid crystal alignment film having a high heat resistance and a high light resistance, a reduced voltage holding ratio even under a high temperature environment and a high intensity of light irradiation,

The liquid crystal aligning agent contains a specific polyorganosiloxane having an epoxy equivalent of 50 to 10,000 g / mol, and a weight average molecular weight of 1,000 to 100,000 as measured by gel permeation chromatography, in terms of polystyrene.

A liquid crystal aligning agent, a liquid crystal alignment film, a liquid crystal display element, a polyorganosiloxane

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal alignment material, a liquid crystal alignment film, and a liquid crystal display device,

The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film and a liquid crystal display element. More particularly, the present invention relates to a liquid crystal aligning agent capable of forming a liquid crystal alignment film having excellent electrostatic leakage property without deteriorating electric characteristics such as voltage holding ratio even after use in a severe environment such as high-intensity light irradiation or high temperature or long- A liquid crystal alignment film formed therefrom, and a liquid crystal display device including the liquid crystal alignment film.

As a liquid crystal display element, a liquid crystal alignment layer containing 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 substrate for a liquid crystal display element. Two liquid crystal alignment layers are disposed opposite to each other, TN type liquid crystal having a so-called TN type (Twisted Nematic) liquid crystal cell in which a nematic liquid crystal layer having a nematic liquid crystal layer is formed as a cell having a sandwich structure and the long axis of the liquid crystal molecule is twisted by 90 degrees continuously from one substrate toward the other substrate Display devices are known (see Patent Document 1 below). In addition, a liquid crystal display device such as an STN (Super Twisted Nematic) type liquid crystal display device (Patent Document 2) capable of realizing a higher contrast ratio than a TN type liquid crystal display device, an IPS (In-Plane Switching) An optical compensating bend (OCB) type liquid crystal display device (hereinafter referred to as non-patent document 1) has been developed which has a small VA (Vertical Alignment) type liquid crystal display device (Patent Document 3) have.

The operation principle of such various liquid crystal display elements is largely classified into a transmission type and a reflection type. In the transmissive liquid crystal display element, display is performed using the change in the intensity of light transmitted through the backlight source from the back surface of the element when the element is driven. The reflection type liquid crystal display device performs display by using a change in the intensity of reflected light from the outside such as sunlight at the time of device driving without using a backlight source and consumes less power than the transmission type, Which is particularly advantageous for use.

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 the backlight source for a long time. Particularly, in a liquid crystal projector application in which demand for a home theater is increasing not only for a business purpose but also a metal halide lamp or the like, a highly illuminated light source is used. It is also conceivable that the temperature of the liquid crystal display element itself rises at the time of driving according to light irradiation with high intensity.

The reflection type liquid crystal display device is supposed to be used outdoors, and in this case, sunlight including strong ultraviolet light becomes a light source. Further, in the reflective type, the distance through which the light passes through the element becomes longer in comparison with the transmissive type in principle.

In addition, both transmissive liquid crystal display elements and reflection type liquid crystal display elements tend to be installed in, for example, automobiles, and the use of liquid crystal display elements is lowered compared with a conventionally conceived mode, This is becoming reality.

However, in the manufacturing process of a liquid crystal display device, liquid crystal dropping method, that is, ODF (One Drop Fill) method, has begun to be used in view of process shortening and improvement of yield. The ODF method differs from the conventional method in which liquid crystal is injected into an empty liquid crystal cell assembled using a thermosetting sealant in advance. After applying an ultraviolet-curable sealant to a necessary portion of a substrate on which a liquid crystal alignment film is applied , The liquid crystal is dropped to a necessary portion and the other substrate is bonded, and ultraviolet light is irradiated to the entire surface to cure the sealing agent to manufacture a liquid crystal cell (Patent Document 4). The ultraviolet light irradiated at this time is usually tensile J / m < 2 > or more and strong. That is, in the case of using the ODF method, 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, the liquid crystal display device is exposed to harsh environments such as high-intensity light irradiation, high-temperature environment, and long-time driving that can not be conventionally expected due to its high performance, versatility, and improved manufacturing process. It has been demanded that electric characteristics such as orientation, voltage retention and the like, or display characteristics are further superior to those of the prior art, and longer life of the liquid crystal display device is required.

Conventionally, organic resins such as polyimide, polyamic acid, polyamide, and polyester have been known as materials of the liquid crystal alignment film constituting the liquid crystal display element. In particular, polyimide is 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, since these organic resins are not materials developed on the assumption of use in such a severe environment as described above, durability under such an environment is not sufficient.

At present, a liquid crystal aligning agent capable of providing a liquid crystal alignment film having a very harsh manufacturing environment, sufficient heat resistance and light resistance in a use environment, and having excellent electrostatic leakage property is not yet known.

[Patent Document 1] JP-A-4-153622

[Patent Document 2] Japanese Unexamined Patent Publication (Kokai) No. 60-107020

[Patent Document 3] JP-A-11-258605

[Patent Document 4] JP-A-6-3635

[Patent Document 5] JP-A-62-165628

[Patent Document 6] JP-A-6-222366

[Patent Document 7] JP-A-6-281937

[Patent Document 8] JP-A-5-107544

[Non-Patent Document 1] "SID '94 Digest", p. 927 (1997)

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to provide a liquid crystal alignment film excellent in heat resistance and light resistance, particularly in a high temperature environment, And to provide a liquid crystal aligning agent capable of being obtained.

Another object of the present invention is to provide a liquid crystal alignment film having excellent properties as described above using the liquid crystal aligning agent of the present invention.

It is still another object of the present invention to provide a liquid crystal display element excellent in heat resistance and light resistance.

Other objects and advantages of the present invention will be apparent from the following description.

According to the present invention, the above objects and advantages of the present invention are achieved by firstly,

A polyorganosiloxane having a repeating unit represented by the following formula (S-1), a hydrolyzate thereof and a condensate of a hydrolyzate (provided that the epoxy equivalent thereof is 50 to 10,000 g / mol, And a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography is 1,000 to 100,000).

[S-1]

(In the formula (S-1), X is a monovalent organic group having an epoxy group and Y is an hydroxyl group, an alkoxyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms)

The above objects and advantages of the present invention are secondly,

Is achieved by the liquid crystal alignment layer formed of the above-mentioned liquid crystal aligning agent, and thirdly,

And a liquid crystal display element having the above-described liquid crystal alignment film.

The use of the liquid crystal aligning agent of the present invention makes it possible to provide a liquid crystal alignment film which exhibits excellent heat resistance and light resistance compared with the conventional alignment film and a liquid crystal alignment film which does not deteriorate voltage holding ratio characteristics even when irradiated with light of high intensity under high temperature, Can be obtained. Therefore, this liquid crystal alignment film can be suitably applied to various liquid crystal display devices.

The liquid crystal display element of the present invention including the liquid crystal alignment layer formed of the liquid crystal alignment agent of the present invention can be used in various applications such as a tabletop calculator, a wristwatch, a desk clock, a coefficient display board, a word processor, a personal computer, a car navigation system, .

The liquid crystal aligning agent of the present invention comprises at least one member 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 a hydrolyzate (hereinafter referred to as " Quot; polyorganosiloxane ").

<Polyorganosiloxane Having Epoxy Group>

The polyorganosiloxane having an epoxy group contained in the liquid crystal aligning agent of the present invention is 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 a hydrolyzate It is more than one kind.

The epoxy group contained in X in the above-mentioned polyorganosiloxane having epoxy group means oxirane group or 1,2-epoxy group. X is preferably a group represented by the following formula (X-1) or (X-2).

[Chemical Formula X-1]

[Formula X-2]

As the alkoxyl group having 1 to 20 carbon atoms for Y, for example, methoxyl group, ethoxyl group, octadecyloxyl group and the like;

Examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, a n-hexyl group, n-heptadecyl group, n-heptadecyl group, n-octadecyl group, n-hexadecyl group, n-hexadecyl group, N-nonadecyl, n-eicosyl and the like;

Examples of the aryl group having 6 to 20 carbon atoms include a phenyl group, a butyloxyphenyl group and the like.

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 g / mol, and preferably 150 to 500 g / mol More preferable.

The polyorganosiloxane having an epoxy group has a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) of 1,000 to 100,000, preferably 1,500 to 50,000, more preferably 2,000 to 10,000 .

The polyorganosiloxane having an epoxy group is preferably obtained by subjecting a silane compound having an epoxy group or a mixture of a silane compound having an epoxy group and another silane compound to hydrolysis or hydrolysis in the presence of an appropriate organic solvent, And can be synthesized by condensation.

Examples of the silane compound having an epoxy group include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyl 3-glycidoxypropyldimethylethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4 &lt; -Epoxycyclohexyl) ethyltriethoxysilane, and the like.

Examples of the other silane compounds include tetrachlorosilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, tetra-n-butoxysilane, tetra- -Butoxysilane, trichlorosilane, trimethoxysilane, triethoxysilane, tri-n-propoxysilane, tri-i-propoxysilane, tri-n-butoxysilane, tri- , Fluorotrichlorosilane, fluorotrimethoxysilane, fluorotriethoxysilane, fluorotri-n-propoxysilane, fluorotri-i-propoxysilane, fluorotri-n-butoxysilane, fluorotri-sec -Methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-i-propoxysilane, methyltri-n-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriethoxysilane, methyltri- Tri-sec-butoxy silane, 2- (trifluoromethyl) ethyl trichlorosilane, 2- (triple 2- (trifluoromethyl) ethyl triethoxysilane, 2- (trifluoromethyl) ethyl tri-n-propoxysilane, 2- (trifluoromethyl) ethyl tri (trifluoromethyl) ethyl tri-n-butoxysilane, 2- (trifluoromethyl) ethyl tri-sec-butoxysilane, 2- (perfluoro- N-hexyl) ethyltriethoxysilane, 2- (perfluoro-n-hexyl) ethyltrimethoxysilane, 2- (perfluoro- (Perfluoro-n-hexyl) ethyltri-n-butoxysilane, 2- (perfluoro-n-hexyl) ethyltri- Octyl) ethyltrichlorosilane, 2- (perfluoro-n-octyl) ethyl tri-sec-butoxysilane, 2- (perfluoro- Methoxy silane, 2- (perfluoro-n-octyl) ethyl triethoxy silane, 2- (perfluoro-n-octyl) ethyl tri- N-pentylsilane, 2- (perfluoro-n-octyl) ethyltri-i-propoxysilane, 2- (perfluoro- Octyl) ethyl tri-sec-butoxysilane, hydroxymethyl trichlorosilane, hydroxymethyltrimethoxysilane, hydroxyethyltrimethoxysilane, hydroxymethyltri-n-propoxysilane, hydroxymethyltri- i-propoxysilane, hydroxymethyltri-n-butoxysilane, hydroxymethyltri-sec-butoxysilane,

(Meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- Propoxy silane, propoxy silane, 3- (meth) acryloxypropyltri-i-propoxy silane, 3- (meth) acryloxypropyltri-n-butoxysilane, 3- Silane, 3-mercaptopropyltrichlorosilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltri-n-propoxysilane, 3- mercaptopropyltrimethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltrimethoxysilane, Vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri-n-propoxysilane, vinyltri-i-propoxysilane, vinyltri-n-butoxysilane But are not limited to, vinyltrimethoxy silane, allyltrimethoxysilane, allyltriethoxysilane, allyltri-n-propoxysilane, allyltri-i-propoxysilane, allyltri-n Butoxysilane, phenyltri-sec-butoxysilane, phenyltrichlorosilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltri-n-propoxysilane, phenyltri-i-propoxysilane, phenyl Butoxysilane, methyldimethoxysilane, methyldiethoxysilane, methyldi-n-propoxysilane, methyldi-i-propoxysilane, methyldi-i-propoxysilane, methyldi- Di-n-propoxysilane, dimethyl di-i-propoxysilane, dimethyl di-sec-butoxysilane, dimethyldichlorosilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyl di- Di-n-butoxy silane, dimethyl di-sec-butoxysilane,

(Perfluoro-n-octyl) ethyl] dimethoxysilane, (methyl) [2- (perfluoro-n-octyl) ethyl] dichlorosilane, (Methyl) [2- (perfluoro-n-octyl) ethyl] di-n-propoxysilane, (Methyl) [2- (perfluoro-n-octyl) ethyl] di-n-butoxysilane, (Methyl) (3-mercaptopropyl) dimethoxysilane, (methyl) (3-mercaptopropyl) dichlorosilane, Propoxysilane, (methyl) (3-mercaptopropyl) di-n-propoxysilane, (methyl) (3-mercaptopropyl) di- (Methyl) (vinyl) dimethoxysilane, (methyl) (vinyl) dichlorosilane, (methyl) (vinyl) dimethoxysilane, ) Diethoxysilane, (methyl) (vinyl) di-n- (Methyl) (vinyl) di-sec-butoxysilane, divinyldichlorosilane, (vinyl) di-n-butoxysilane, , Divinyldimethoxysilane, divinyldiethoxysilane, divinyldi-n-propoxysilane, divinyldi-i-propoxysilane, divinyldi-n-butoxysilane, divinyldi-sec- Diphenyldimethoxysilane, diphenyldiethoxysilane, diphenyldi-n-propoxysilane, diphenyldi-i-propoxysilane, diphenyldi-n-butoxysilane, Methoxydimethylsilane, ethoxydimethylsilane, chlorotrimethylsilane, bromotrimethylsilane, iodotrimethylsilane, methoxytrimethylsilane, ethoxytrimethylsilane, n-butoxytrimethylsilane, n- Propoxytrimethylsilane, n-butoxytrimethylsilane, sec-butoxytrimethylsilane, t-butoxytrimethylsilane, (chloro) (vinyl) dime (Methyl) diphenylsilane, (ethoxy) (methyl) diphenylsilane, (methoxy) (vinyl) dimethylsilane, (ethoxy) In addition to the silane compound having one silicon atom such as diphenylsilane,

X-21-5841, X-21-5842, X-21-5843, X-21-5844, X-21-5845, K- X-22-170BX, X-22-170D, X-22-170DX, X-22-170B, X-21-5846, X- X-22-176D, X-22-176F, X-40-2308, X-40-2651, X-40-2655A, X-40-2671, X- 2672, X-40-9220, X-40-9225, X-40-9227, X-40-9246, X-40-9247, X-40-9250, X-40-9323, X- KR-200, KR-213, KR-217, KR220L, KR242A, KR271, KR282, KR300, KR311, KR401N, KR500, KR- KR510, KR5206, KR5230, KR5235, KR9218, KR9706 (manufactured by Shinetsu Chemical Industry Co., Ltd.);

Glass resin (manufactured by Showa Denko K.K.); SH804, SH805, SH806A, SH840, SR2400, SR2402, SR2405, SR2406, SR2410, SR2411, SR2416, SR2420 (manufactured by Toray Dow Corning Co., Ltd.);

FZ3711, FZ3722 (manufactured by Nippon Unicar Co., Ltd.);

DMS-S12, DMS-S15, DMS-S21, DMS-S27, DMS-S31, DMS-S32, DMS-S33, DMS-S35, DMS- 227, PSD-0332, PDS-1615, PDS-9931 and XMS-5025 (manufactured by Chisso Corporation);

Methyl silicate MS51, methyl silicate MS56 (manufactured by Mitsubishi Chemical Corporation);

Ethyl silicate 28, ethyl silicate 40, ethyl silicate 48 (trade name, manufactured by Colcoat Co., Ltd.);

GR100, GR650, GR908, and GR950 (manufactured by Showa Denko K.K.).

Among these other silane compounds, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltri But are not limited to, ethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, dimethyldimethoxysilane, or dimethyldiethoxysilane are preferable.

Since the polyorganosiloxane having an epoxy group used in the present invention has an epoxy equivalent as described above, when the polyorganosiloxane having an epoxy group is synthesized, the use ratio of the silane compound having an epoxy group and the other silane compound is The polyorganosiloxane epoxy equivalent should be adjusted and set to the above-mentioned range.

Examples of the organic solvent that can be used in 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 Examples of the ethers include ethyleneglycol dimethylether, ethyleneglycol diethylether, tetraethyleneglycol diethylether, tetraethyleneglycol diethylether, and the like. Examples of the ethers include ethyl acetate, n-butyl acetate, i-amyl acetate, propylene glycol monomethyl ether acetate, 3- Examples of the alcohols include 1-hexanol, 4-methyl-2-pentanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene Propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether and the like, Can each. Of these, non-water-soluble ones are preferable. These organic solvents may be used alone or in combination of two or more.

The amount of the organic solvent to be used is preferably 10 to 10,000 parts by weight, more preferably 50 to 1,000 parts by weight, based on 100 parts by weight of the total silane compound.

The amount of water used when preparing the polyorganosiloxane having an epoxy group is preferably from 0.5 to 100 times, more preferably from 1 to 30 times, moles based on the total amount of the silane compound.

As the catalyst, for example, an acid, an alkali metal compound, an organic base, a titanium compound, a zirconium compound and the like can be used.

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- Tertiary organic amines such as butylamine, pyridine, 4-dimethylaminopyridine and diazabicyclo-undecene, and quaternary organic amines such as tetramethylammonium hydroxide. Among these organic bases, tertiary organic amines such as triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine and 4-dimethylaminopyridine, quaternary organics such as tetramethylammonium hydroxide Amines are preferred.

As the catalyst for producing the polyorganosiloxane having an epoxy group, an alkali metal compound or an organic base is preferable. By using an alkali metal compound or an organic base as a catalyst, it is possible to obtain a desired polyorganosiloxane at a high hydrolysis / condensation rate without side reactions such as ring-opening of epoxy groups and the like, .

As the catalyst, an organic base is particularly preferable. The amount of the organic base to be used differs depending on the kind of the organic base, the reaction conditions such as the temperature, and the like, and should be appropriately set. For example, it is preferably 0.01 to 3 moles per mole of the total silane compound, more preferably 0.05 to 1 It is a bait.

The hydrolysis or hydrolysis and condensation reaction in the production of a polyorganosiloxane having an epoxy group can be carried out by dissolving an epoxy group-containing silane compound and, if necessary, another silane compound in an organic solvent, mixing the solution with an organic base and water For example, by heating with an oil bath or the like.

In the hydrolysis and condensation reaction, the heating temperature is preferably 130 占 폚 or lower, more preferably 40 to 100 占 폚, preferably 0.5 to 12 hours, and more preferably 1 to 8 hours . During the heating, the mixed solution may be stirred or may be placed under reflux.

After completion of the reaction, it is preferable to wash the organic solvent layer collected from the reaction solution with water. At the time of this cleaning, it is preferable that the cleaning operation is facilitated by washing with water containing a small amount of salt, for example, an aqueous solution of ammonium nitrate of about 0.2 wt%. The washing is carried out until the water layer after the washing becomes neutral. Thereafter, the organic solvent layer is dried with an appropriate drying agent such as calcium sulfate anhydride or molecular sieve, if necessary, and then the solvent is removed to obtain a polyorganosiloxane having a desired epoxy group Siloxane 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 a 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 a polymer other than a polyorganosiloxane having an epoxy group (hereinafter referred to as "another polymer"), a compound having at least one epoxy group in the molecule (except for a polyorganosiloxane having an epoxy group Hereinafter referred to as "epoxy compound"), and a functional silane compound.

[Other Polymers]

The other polymer can be used to further improve the solution characteristics of the liquid crystal aligning agent of the present invention and the electrical characteristics of the resulting liquid crystal alignment film. Examples of such another polymer 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, poly (styrene-phenylmaleimide ) Derivatives, and poly (meth) acrylates. Of these, at least one polymer selected from the group consisting of polyamic acid and polyimide is preferable.

The polyamic acid can be synthesized by reacting a tetracarboxylic dianhydride with a diamine.

- tetracarboxylic dianhydride -

Examples of the tetracarboxylic acid dianhydride used in the synthesis of the polyamic acid include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2-dimethyl- 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dichloro- 3,4-cyclobutane tetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,2,3,4-cyclo Pentane tetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ', 4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5 - tricarboxycyclopentyl acetic acid dianhydride, 3,5,6-tricarboxy norbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic acid dianhydride, 1,3,3a , 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [l, 2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro- 3-dione, 1,3,3a, 4,5,9b-hexahydro-5-ethyl-5- (tetra 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 [ , 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2- c] , 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [ Dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [ 1,2-c] -furan-1,3-dione, 5- (2,5-dioxotetrahydrofuranyl) -3-methyl-3-cyclohexene- Tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dicarboxylic acid anhydride, bicyclo [2.2.2] (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene- Dicarboxylic acid 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, tetracarboxylic acid dianhydride represented by each of the following formulas TI and T-II, aliphatic or alicyclic tetracarboxylic acid dianhydride;

[Chemical formula I-I]

[Chemical Formula T-II]

(In the formulas TI and T-II, R ¹ and R ³ are each a divalent organic group having an aromatic ring, R ² and R ⁴ are each a hydrogen atom or an alkyl group, and a plurality of R ² and R ^4, Or may be different)

Pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenylsulfonetetracarboxylic acid dianhydride, 1,4,5 , 8-naphthalene tetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyl ether tetracarboxylic dianhydride, 3,3 ', 4,4'-dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3', 4,4'-tetraphenylsilane tetracarboxylic dianhydride, 1,2,3,4-furan tetracarboxyl Acid dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4 , 4'-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ', 4,4'-perfluoroisopropylidene diphthalic acid dianhydride, 3,3' '- biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4'-diphenyl ether dianhydride, bis (triphenylphthalic acid) dianhydride, m-phenylene- (Anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anhydroglycidyl) Bis (4-hydroxyphenyl) propane-1,6-hexanediol-bis (anhydrotrimellitate) Aromatic tetracarboxylic acids such as bis (anhydrotrimellitate), 2,3,2 ', 3'-biphenyltetracarboxylic dianhydride and compounds represented by the following formulas T-1 to T-4 You can call it water. These may be used singly or in combination of two or more.

[Chemical formula (T-1)

[Chemical Formula T-2]

[Chemical Formula T-3]

[Chemical Formula T-4]

The tetracarboxylic acid dianhydride used for synthesizing the polyamic acid may be selected from the group consisting of butanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3- Dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [ , 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [ 1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) , 2-c] furan-1,3-dione, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, 3-oxabicyclo [3.2. 1] octane-2,4-dione-6-spiro-3 '- (tetrahydrofuran-2', 5'- Furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3,5,6-tricarboxy-2-carboxy norbornane- 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, pyromellitic acid dianhydride, 3,3 ' -Benzophenone tetracarboxylic acid dianhydride, 3,3 ', 4,4'-biphenylsulfonetetracarboxylic acid dianhydride, 2,2', 3,3'-biphenyltetracarboxylic acid dianhydride, 1 , 4,5,8-naphthalenetetracarboxylic acid dianhydride, the compound represented by each of the following formulas T-5 to T-7 in the compound represented by the formula TI and the compound represented by the formula T-II (Hereinafter referred to as "specific tetracarboxylic acid dianhydride") selected from the group consisting of compounds represented by the general formula (T-8).

[Chemical Formula T-5]

[Chemical Formula T-6]

[Chemical Formula T-7]

[Chemical Formula T-8]

Specific examples of the tetracarboxylic acid dianhydride include 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-di 3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro- 3-dione, 3-oxabicyclo [3.2.1] octane-2,4-dione-6- Spiro-3 '- (tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) Dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] Tetraene, 2,3,5 ', 3'-biphenyltetracarboxylic dianhydride, 2,3,5'-tetraene and 2,3,2', 3'-biphenyltetracarboxylic dianhydride.

The tetracarboxylic acid dianhydride used to synthesize the polyamic acid preferably contains 50 mol% or more of the specific tetracarboxylic acid dianhydride as described above with respect to the total tetracarboxylic dianhydride, , More preferably at least 75 mol%, and still more preferably at least 75 mol%.

- 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'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfone, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, 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'-ditrifluoromethyl-4,4'-diaminobiphenyl, 5-amino- (4'-aminophenyl) -1,3,3-trimethylindane, 3,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, Diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2 , 2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, Bis (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 4 , 4'-bis (4-aminophenoxy) biphenyl, 1,3-bis (4-aminophenoxy) benzene, 1,3- -Aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 9,9- (2-chloroaniline), 2,2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino Dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 1,4,4 '- (p-phenyleneisopropylidene) bisaniline, 4 Bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4 ' Bis (trifluoromethyl) biphenyl, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] Aromatic diamines such as octafluorobiphenyl;

But are not limited to, 1,1-hexanediol diamine, 1,1-meta-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, , 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindenyldimethylenediamine, tricyclo [6.2.1.0 ^2,7 ] undecylene Aliphatic or alicyclic diamines such as dimethyldiamine, 4,4'-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane and 1,4-bis (aminomethyl) cyclohexane;

Diaminopyridine, 5, 6-diamino-2,3-dicyanopyrimidine, 5, 6-diamino-2,3-dicyanopyrimidine, Dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, Diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4- 2,4-diamino-6-methyl-s-triazine, 2,4-diamino-1,3,5-triazine, 4,6- Vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6-diaminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5- Diamino-1,2,4-triazole, 6,9-diamino-2-ethoxy acridactate, 3,8-diamino-6-phenylphenanthridine, Aminophenyl) phenylamine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl- Aminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N'-bis (4-aminophenyl) Dimethyl-benzidine, a diamine having two primary amino groups in the molecule such as a compound represented by the following formula DI and a compound represented by the following formula D-II, and a nitrogen atom other than the primary amino group;

[Formula D-I]

(In the formula (DI), R ⁵ is a monovalent organic group having a ring structure including a nitrogen atom selected from the group consisting of pyridine, pyrimidine, triazine, piperidine and piperazine, X ¹ is a divalent organic group , R ⁶ is an alkyl group having 1 to 4 carbon atoms, and a 1 is an integer of 0 to 3)

[Formula D-II]

(In the formula (D-II), R ⁷ is a divalent organic group having a ring structure including a nitrogen atom selected from the group consisting of pyridine, pyrimidine, triazine, piperidine and piperazine, and X ² is 2 A plurality of X ^{2 s} present may be the same or different, R ⁸ is each an alkyl group having 1 to 4 carbon atoms, and a 2 is an integer of 0 to 3,

A mono-substituted phenylenediamine such as a compound represented by the following formula (D-III);

[Formula D-III]

(Wherein R ⁹ is a divalent organic group selected from the group consisting of -O-, -COO-, -OCO-, -NHCO-, -CONH- and -CO-, R ¹⁰ is 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)

A diaminoorganosiloxane such as a compound represented by the following formula (D-IV);

[Formula D-IV]

(In the formula (D-IV), R ¹² represents a hydrocarbon group of 1 to 12 carbon atoms, plural R ^{12 s} present may be the same or different from each other, p is an integer of 1 to 3, and q is an integer of 1 to 20 Lt; / RTI &gt;

And compounds represented by the following formulas (D-1) to (D-5).

[Formula D-1]

[Formula D-2]

[Formula D-3]

[Formula D-4]

[Formula 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)

The benzene ring of the aromatic diamine and the compound represented by each of the formulas D-1 to D-5 may be substituted with one or more alkyl groups having 1 to 4 carbon atoms (preferably a methyl group). It is preferable that R ⁶ , R ⁸ and R ¹¹ in the above formulas DI, D-II and D-III are each a methyl group, and a1, a2 and a3 are each preferably 0 or 1, .

These diamines may be used alone or in combination of two or more.

The diamine used for synthesizing the polyamic acid may be selected from the group consisting of p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 1,5- Diminaphthalene, 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- 4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 '- (p- phenylenediisopropylidene) , 4 '- (m-phenylene diisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, Diaminocyclohexane, 4,4'-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane, 4,4'-diaminodiphenylsulfone, 2,2- (4-amino Phenoxy] phenyl] sulfone, a compound represented by each of the above formulas D-1 to D-5, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, Diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl- (4-aminophenyl) -N, N'-dimethylbenzidine, a compound represented by the following formula (DI) The compound represented by the formula D-6, the compound represented by the formula D-7 in the compound represented by the formula D-II, the compound represented by the formula D-III, the dodecanoxy- , Pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy-2,4-diaminobenzene, dodecaneoxy-2,5-diaminobenzene, Decanoxy-2,5-diaminobenzene, hexadecaneoxy-2,5-diamine Benzene, octadecaneoxy-2,5-diaminobenzene, 1,3-bis (3-aminopropyl) benzene, and 1,3-bis ) -Tetramethyldisiloxane (hereinafter referred to as "specific diamine").

[Formula D-6]

[Formula D-7]

[Formula D-8]

[Chemical formula D-9]

[Formula D-10]

[Formula D-11]

[Formula D-12]

[Formula D-13]

[Chemical Formula D-14]

[Formula D-15]

[Formula D-16]

The diamine used for synthesizing the polyamic acid preferably contains 50 mol% or more, more preferably 75 mol% or more, particularly preferably 90 mol% or more of the specific diamine as described above .

- Synthesis of polyamic acid -

The ratio of the tetracarboxylic acid dianhydride and the diamine used in the synthesis reaction of the polyamic acid is preferably such that the amount of the acid anhydride group of the tetracarboxylic dianhydride is 0.5 to 2 equivalents based on 1 equivalent of the amino group contained in the diamine, More preferably 0.7 to 1.2 equivalents.

The synthesis reaction of the polyamic acid is preferably carried out in an organic solvent at a temperature 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. The organic solvent is not particularly limited as long as it can dissolve the polyamic acid to be synthesized. Examples of the organic solvent include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, Non-protonic polar solvents such as dimethyl sulfoxide,? -Butyrolactone, tetramethyl urea, and hexamethylphosphoric triamide; m-cresol, xylenol, phenol, halogenated phenol and the like. The amount (a) of the organic solvent used is preferably such that the total amount (b) of the tetracarboxylic acid dianhydride and the diamine compound is 0.1 to 30% by weight based on the total amount (a + b) of the reaction solution. When the organic solvent is used in combination with the following poor solvent, it is to be understood that the amount (a) of the organic solvent means the total amount of the organic solvent and the poor solvent.

Alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, etc., which are poor solvents of polyamic acid, may be added to the organic solvent within a range that does not cause the production of the produced polyamic acid. Specific examples of such a poor solvent include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, Butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, di Ethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, Glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene Recycled 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, isoamyl propionate, isoamyl isobutyrate, and diisopentyl ether.

The proportion of the poor solvent to be used is preferably 80% by weight or less, more preferably 50% by weight or less, and even more preferably 40% by weight or less based on the total amount of the organic solvent and the poor solvent.

In this way, a reaction solution obtained by dissolving polyamic acid is obtained. The reaction solution may be used as it is for preparing a liquid crystal aligning agent. Alternatively, the polyamic acid contained in the reaction solution may be isolated and used for the preparation of a liquid crystal aligning agent, or after the isolated polyamic acid is purified, . The isolation of the polyamic acid can be carried out 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 a method of distilling off the reaction solution under reduced pressure using an evaporator. Alternatively, the polyamic acid can be purified by a method of dissolving the polyamic acid in an organic solvent, followed by precipitation with a poor solvent, or a step of distillation under reduced pressure using an evaporator once or several times.

- Synthesis of polyimide -

The polyimide can be synthesized by dehydration ring closure of the polyamic acid obtained as described above. At this time, all of the amic acid structures may be fully imidized by dehydration ring closure, or only a part of the amic acid structures may be dehydrated and cyclized to form partial imide cargoes in which the amic acid structure and the imide structure coexist. The imidization ratio of the polyimide is preferably 40% or more, and more preferably 80% or more. As used herein, the term "imidization rate" refers to a numerical value, expressed as a percentage, of the ratio of the number of imide ring structures to the sum of the number of amic acid structures and the number of imide ring structures in the polyimide. At this time, a part of the imide ring may be an isoimide ring.

The dehydration ring closure reaction of polyamic acid can be carried out by a method comprising the steps of (i) heating polyamic acid, or (ii) dissolving polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring- .

The reaction temperature in the method of heating the polyamic acid of (i) is preferably 50 to 200 占 폚, more preferably 60 to 170 占 폚. If the reaction temperature is less than 50 캜, the dehydration ring-closure reaction does not proceed sufficiently, and if the reaction temperature exceeds 200 캜, the molecular weight of the obtained polyimide may be lowered. 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 of adding the dehydrating agent and dehydrating ring-closing catalyst to the solution of the polyamic acid of the above (ii), for example, an acid anhydride such as acetic anhydride, propionic anhydride or trifluoroacetic anhydride can be used. The amount of the dehydrating agent to be used is preferably 0.01 to 20 mol based on 1 mol of the polyamic acid structural unit. As the dehydration cyclization catalyst, for example, tertiary amines such as pyridine, collidine, lutidine and triethylamine can be used. However, it is not limited thereto. The amount of the dehydration ring-closing catalyst to be used is preferably 0.01 to 10 mol based on 1 mol of the dehydrating agent to be used. Examples of the organic solvent used in the dehydration ring-closure reaction include organic solvents exemplified for use in the synthesis of polyamic acid. The reaction temperature of the dehydration ring-closing 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) can be used as it is for the production of a liquid crystal aligning agent, or after the obtained polyimide is purified, it can be used for the production of a liquid crystal aligning agent. On the other hand, in the method (ii), a reaction solution containing polyimide is obtained. This reaction solution can be used as it is for the production of a liquid crystal aligning agent or after the dehydrating agent and the dehydration ring-closing catalyst are removed from the reaction solution, it can be used for the preparation of a liquid crystal aligning agent, or after the polyimide is isolated, Or may be used in the production of a liquid crystal aligning agent after purification of 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 substitution can be applied. Isolation and purification of polyimide can be carried out by performing the same operation as described above as a method for isolating and purifying polyamic acid.

- Polymers of terminal modified type -

The polyamic acid and the polyimide may be polymers of terminal modified types each having a controlled molecular weight. Such a terminal modified polymer can be synthesized by adding an appropriate molecular weight control agent such as anhydride monoacid, monoamine compound or monoisocyanate compound to the reaction system when synthesizing a polyamic acid. Examples of the acid anhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-undecylsuccinic anhydride, n-tetradecylsuccinic anhydride, and n-hexadecylsuccinic anhydride. . Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, Octadecylamine, n-octadecylamine, n-octadecylamine, n-hexadecylamine, n-hexadecylamine, Silane and the like. 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 amount of the tetracarboxylic acid dianhydride and diamine used in the synthesis of the polyamic acid.

- the ratio of use of other polymers -

When the liquid crystal aligning agent of the present invention contains a polymer other than the polyorganosiloxane having an epoxy group, the proportion of the other polymer to be used is preferably 50,000 parts by weight or less based on 100 parts by weight of the polyorganosiloxane having an epoxy group, More preferably 1,000 to 20,000 parts by weight, particularly preferably 2,000 to 10,000 parts by weight.

[Epoxy Compound]

The epoxy compound can be contained in the liquid crystal aligning agent of the present invention from the viewpoint of further improving the adhesiveness of the formed liquid crystal alignment film to the substrate surface. 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 different from the polyorganosiloxane having an epoxy group in that the molecular weight is less than 1,000.

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, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5, Tetraglycidyl-2,4-hexanediol, N, N, N ', N'-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl ) Cyclohexane, N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N, N-diglycidyl- -Aminomethylcyclohexane and the like can be preferably used. The compounding ratio of these epoxy group-containing compounds is preferably 40 parts by weight or less based on 100 parts by weight of the sum of the polymers (the sum of the polyorganosiloxane having an epoxy group and other polymers, and the same applies hereinafter) 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-ureidopropyltriethoxy Silane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyl triethylenetriamine, N- 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- Aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane and the like.

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, based on 100 parts by weight of the total of the polymers.

<Liquid Crystal Aligner>

The liquid crystal aligning agent of the present invention is preferably prepared in the form of a solution in which the polyorganosiloxane having an epoxy group as described above and optionally other components are dissolved in an appropriate organic solvent.

Examples of the organic solvent that can be used in the liquid crystal aligning agent of the present invention include the solvents exemplified for use in the synthesis reaction of polyamic acid. Here, the poor solvents exemplified as those that can be used in the synthesis reaction of the polyamic acid can also be suitably selected and used in combination. The preferred organic solvent for use in the liquid crystal aligning agent of the present invention is one obtained by combining one or more of the above organic solvents. In the following preferable solid concentration, each component contained in the liquid crystal aligning agent is not precipitated, The surface tension of the aligning agent is in the range of 20 to 50 mN / m.

The solid 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. The preferred solid concentration is in the range of 1 to 20% by weight. In other words, the liquid crystal aligning agent of the present invention forms a coating film which is coated on the substrate surface to become a liquid crystal alignment film, but when the solid concentration is less than 1% by weight, the film thickness of the coating film becomes too small to obtain a good liquid crystal alignment film, When the concentration is more than 20% by weight, the film thickness of the coating film becomes too large, so that it is difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal aligning agent is increased and the coating property is lowered.

Particularly preferable ranges of the solid concentration are different depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, in the case of using the spinner method, the range of 1.5 to 6.0 wt% is particularly preferable. In the case of the printing method, it is particularly preferable that the solid concentration is in the range of 3 to 20 wt%, and the solution viscosity is in the range of 12 to 50 mPa · s accordingly. In the case of the ink-jet method, it is particularly preferable that the solid concentration is in the range of 1 to 5 wt% and the solution viscosity is in the range of 3 to 15 mPa · s accordingly.

The temperature at which the liquid crystal aligning agent of the present invention is produced is preferably 0 to 200 캜, more preferably 20 to 60 캜.

<Liquid crystal display element>

The liquid crystal display element of the present invention comprises the liquid crystal alignment layer formed of 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 coated on a pair of substrates, and the solvent is removed to form a coating film. In the case where 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 each provided with a transparent conductive film patterned on one side are used as a pair of substrates use. On the other hand, when the liquid crystal display element to be manufactured is a transverse electric field system known as an IPS system, a substrate provided with a transparent conductive film having a comb-like pattern and a substrate having no transparent conductive film are used as a pair of substrates .

In any of the above cases, the liquid crystal aligning agent is applied on the substrate (on the side having the transparent conductive film of the substrate when the substrate has the transparent conductive film). Examples of the substrate include glass such as float glass and soda glass; A transparent substrate containing plastics such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and poly (alicyclic olefin) can be used. Examples of the transparent conductive film provided on one side of the substrate include a NESA film (a registered trademark of PPG Corporation of the US) and indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) containing tin oxide (SnO ₂ ) An ITO film or the like can be used. In order to obtain these patterned transparent conductive films, a method of forming a pattern by a photoetching method after forming a transparent conductive film without a pattern, a method of forming a patterned transparent conductive film by using a mask having a desired pattern in forming the transparent conductive film, A method of directly forming a conductive film, or the like can be used.

The application of the liquid crystal aligning agent on the substrate is carried out by a suitable application method such as a roll coater method, a spinner method, a printing method, and an ink jet method. When applying the liquid crystal aligning agent, a functional silane compound, a functional titanium compound and the like may be previously applied to the surface to be coated of the substrate in order to further improve adhesion between the substrate surface and the transparent conductive film and the coating film.

After the application, preheating (prebaking) is preferably performed for the purpose of preventing the applied alignment agent from being dropped. The prebaking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The prebaking time is preferably 1 to 15 minutes, more preferably 1 to 10 minutes. Thereafter, a post-heating (post-baking) process is performed for the purpose of completely removing the solvent and the like. The post-baking temperature is preferably 80 to 300 占 폚, more preferably 120 to 250 占 폚. The post-baking 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 produced is of the VA type, the coating film formed as described above can be used as the liquid crystal alignment film as it is, but rubbing treatment described below can be performed as necessary. On the other hand, in the case where the display mode of the liquid crystal display element to be manufactured is the vertical electric field system other than VA type or the transverse electric field system, the formed film surface is rubbed.

The rubbing treatment can be carried out by a method of rubbing the cloth in a predetermined direction with a roll wound with a cloth containing fibers such as nylon, rayon, and cotton. Accordingly, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. Further, the coating film after rubbing treatment can be applied to a coating film as described in, for example, Patent Document 6 (Japanese Patent Application Laid-Open No. 6-222366) or Patent Document 7 (Japanese Patent Application Laid-Open No. 6-281937) A process of changing a pretilt angle of a part of the liquid crystal alignment film by irradiating a part of the same liquid crystal alignment film with ultraviolet rays and a process of changing the pretilt angle of a part of the liquid crystal alignment film surface as described in Patent Document 8 (Japanese Patent Application Laid-open No. 5-107544) A rubbing process is performed in a direction different from the rubbing process performed previously and then the resist film is removed so that the liquid crystal alignment film has different liquid crystal aligning ability for each region so that the time characteristic Can be improved.

(3) A liquid crystal cell is prepared by preparing two substrates on which a liquid crystal alignment film is formed as described above, and arranging the liquid crystal between two substrates arranged opposite to each other. Here, when the coating film is subjected to the rubbing treatment, the two substrates are opposed to each other so that the rubbing directions in the respective coating films are made to have a predetermined angle, for example, orthogonal or inversely.

In order to produce a liquid crystal cell, for example, the following two methods can be mentioned.

The first method is a conventionally known method. First, two substrates are placed opposite each other with a gap (cell gap) so that the respective liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded together using a sealing agent. Then, After the liquid crystal is injected and filled in the interval, the injection hole is sealed to manufacture the liquid crystal cell.

The second method is a method called ODF (One Drop Fill) method. An ultraviolet light curable sealing material is applied to a predetermined place on one of the two substrates on which the liquid crystal alignment film is formed and the liquid crystal is dropped on the liquid crystal alignment film surface and then the other substrate is bonded so that the liquid crystal alignment film is opposed And then irradiating ultraviolet light to the entire surface of the substrate to cure the sealing agent, thereby manufacturing a liquid crystal cell.

In any method, the liquid crystal cell manufactured as described above is further heated to a temperature at which the liquid crystal used is isotropic, and then gradually cooled to room temperature to remove the flow orientation at the time of liquid crystal injection desirable.

Further, by bonding a polarizing plate to the outer surface of the liquid crystal cell, the liquid crystal display element of the present invention can be obtained.

As the sealing agent, for example, an epoxy resin containing an aluminum oxide sphere as a curing agent and a spacer can be used.

As the liquid crystal, for example, a nematic liquid crystal, a smectic liquid crystal and the like can be used. In the case of producing a liquid crystal display element having a TN type liquid crystal cell, an STN type liquid crystal cell or an IPS type liquid crystal cell, it is preferable to have a positive dielectric anisotropy in a nematic liquid crystal, and examples thereof include biphenyl type liquid crystal, phenylcyclohexane type Liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenylcyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, quartz liquid crystal and the like are used. Examples of the liquid crystal include cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonanoate, and cholesteryl carbonate; Chiral agents such as those sold under the trade names C-15 and CB-15 (Merck); and a ferroelectric liquid crystal such as p-disiloxybenzylidene-p-amino-2-methylbutyl cinnamate may be further added.

On the other hand, in the case of the VA type liquid crystal cell, it is preferable that the nematic liquid crystal has negative dielectric anisotropy, and this is sometimes called a negative type liquid crystal in general. For example, a dicyanobenzene-based liquid crystal, a pyridazine-based liquid crystal, a Schiff salt mechanical liquid crystal, an agglomerated clock liquid crystal, a biphenyl-based liquid crystal, a phenylcyclohexane-based liquid crystal and the like are used.

As the polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing plate in which a polarizing film called "H film " in which iodine is absorbed while polyvinyl alcohol is oriented in a stretched polyvinyl alcohol is sandwiched between cellulose acetate protective films or a polarizing plate made of H film itself can be given.

<Examples>

Hereinafter, the present invention will be described more specifically by way of 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 reduced value measured by gel permeation chromatography under the following conditions.

Column: TSK-GEL manufactured by TOSOH CORPORATION

Solvent: tetrahydrofuran

Column temperature: 40 DEG C

Pressure: 80 kgf / ㎠

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 was a value measured at 25 占 폚 using an E-type viscometer for the polymer solution indicated in each synthesis example.

The imidization rate of the polyimide was measured by ¹ H-NMR measurement from tetramethylsilane as a reference material at room temperature, using the following formula (1), by using the respective polyimides after drying them under reduced pressure at room temperature and then dissolving them in deuterated dimethyl sulfoxide Respectively.

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

(Wherein A ¹ is a peak area derived from a proton of an NH group appearing near 10 ppm of chemical shift, A ² is a peak area derived from other protons, and? Is a precursor of the polyimide ) &Lt; / RTI &gt; is the ratio of the number of other protons to one proton of the NH group)

&Lt; Synthesis of polyorganosiloxane having epoxy group >

Synthesis Example 1

100.0 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 500 g of methyl isobutyl ketone and 10.0 g of triethylamine were placed in a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser, , And mixed at room temperature. Subsequently, 100 g of deionized water was dropped from the dropping funnel over 30 minutes, and the reaction was carried out at 80 DEG C for 6 hours while stirring under reflux. After completion of the reaction, the organic layer was taken out and washed with a 0.2 wt% aqueous ammonium nitrate solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure to obtain a polyorganosiloxane having an epoxy group ) Was obtained as a viscous transparent liquid.

¹ H-NMR analysis was performed on the polyorganosiloxane having the epoxy group, and it was found that a peak based on the epoxy group was obtained at a theoretical intensity in the vicinity of chemical shift (?) = 3.2 ppm, and no side reaction of the epoxy group occurred during the reaction .

The weight average molecular weight Mw and the epoxy equivalent of the polyorganosiloxane (EPS-1) having the epoxy group are shown in Table 1 below.

Synthesis Examples 2 to 3

Polyorganosiloxanes (EPS-2) and (EPS-3) each having an epoxy group were obtained in the same manner as in Synthesis Example 1, except that the starting materials were changed as shown in Table 1, respectively.

The weight average molecular weight Mw and the epoxy equivalent of the polyorganosiloxane having the epoxy group are shown in Table 1.

The abbreviations of the raw material silane compounds in Table 1 are as follows.

ECETS: 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane

MTMS: methyltrimethoxysilane

PTMS: phenyltrimethoxysilane

<Synthesis of polyamic acid>

Synthesis Example 4

20 g (0.1 mole) of 1,2,3,4-cyclobutane tetracarboxylic dianhydride as a tetracarboxylic dianhydride and 21 g (0.1 mole) of 2,2'-dimethyl-4,4'-diaminobiphenyl as a diamine (0.1 mol) was dissolved in a mixed solvent containing 37 g of N-methyl-2-pyrrolidone and 330 g of? -Butyrolactone and the reaction was carried out at 40 占 폚 for 3 hours to obtain a polyamic acid (A-1 ) Was obtained in an amount of about 400 g. The solution viscosity of this solution was 160 mPa..

Synthesis Example 5

9.8 g (0.05 mol) of 1,2,3,4-cyclobutane tetracarboxylic dianhydride and 11 g (0.05 mol) of pyromellitic dianhydride as a tetracarboxylic dianhydride, 4,4'-di 20 g (0.1 mol) of minodiphenylmethane was dissolved in a mixed solvent containing 23 g of N-methyl-2-pyrrolidone and 210 g of? -Butyrolactone, and the mixture was reacted at 40 占 폚 for 3 hours, 135 g of? -butyrolactone was added to obtain about 390 g of a solution containing 10 wt% of polyamic acid (A-2). The solution viscosity of this solution was 125 mPa s.

Synthesis Example 6

28 g (0.09 mol) of pyromellitic anhydride as tetracarboxylic dianhydride, 2.8 g (0.01 mol) of 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 3.0 g of p-phenylenediamine (0.02 mol) of 4,4'-diaminodiphenyl ether and 23 g (0.08 mol) of 4,4'-diaminodiphenyl ether were dissolved in 323 g of N-methyl-2-pyrrolidone and the reaction was carried out at 40 DEG C for 3 hours to obtain polyamic acid About 380 g of a solution containing 15% by weight of (A-3). The solution viscosity of this solution was 380 mPa s.

<Synthesis of polyimide>

Synthesis Example 7

11 g (0.05 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as a tetracarboxylic dianhydride and 13 g (0.05 mol) of 1,3,3a, 4,5,9b-hexahydro-8- 16 g (0.05 mol) of p-phenylenediamine 9.4 g (0.087 mol) as a diamine, , 2.5 g (0.01 mole) of 1,3-bis (3-aminopropyl) tetramethyldisiloxane and 0.96 g (0.0015 mole) of 3,6-bis (4-aminobenzoyloxy) cholestane as the monoamine, 0.81 g (0.0030 mol) was dissolved in 96 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 DEG C for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected and the solution viscosity was measured as a solution having a polyamic acid concentration of 10% by weight by adding NMP to be 60 mPa.s.

Then, 270 g of NMP was added to the resulting polyamic acid solution, and 40 g of pyridine and 41 g of acetic anhydride were added, followed by dehydration ring-closure reaction at 110 DEG C for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with a new? -Butyrolactone solvent (by removing the pyridine and acetic anhydride used in the dehydration ring-closure reaction from the system by the solvent substitution operation, About 240 g of a solution containing about 95% of polyimide (B-1) in an amount of 15% by weight was obtained. A small amount of this solution was collected, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight by adding? -Butyrolactone was 70 mPa 占 퐏.

Synthesis Example 8

11 g (0.050 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as a tetracarboxylic acid dianhydride, 4.3 g (0.040 mol) of p-phenylenediamine as a diamine and 3 (3,5-diaminobenzoyl Oxy) cholestane were dissolved in 83 g of NMP, and the reaction was carried out at 60 DEG C for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected and the solution viscosity was measured as a solution having a polyamic acid concentration of 10% by weight by adding NMP to be 60 mPa.s.

Then, 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 the dehydration ring-closure reaction was carried out at 110 DEG C for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with fresh NMP to obtain about 120 g of a solution containing 15% by weight of polyimide (B-2) having an imidization rate of about 50%. A small amount of this solution was collected, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight by adding NMP was 47 mPa 占 퐏.

Synthesis Example 9

11 g (0.050 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic acid dianhydride, 3.8 g (0.035 mol) of p-phenylenediamine as diamine, 4,4'-diaminodiphenyl 2.0 g (0.01 mol) of methane and 2.6 g (0.005 mol) of 3 (3,5-diaminobenzoyloxy) cholestane were dissolved in 80 g of NMP and reacted at 60 DEG C for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected and the solution viscosity was measured as a solution having a polyamic acid concentration of 10% by weight by adding NMP to be 60 mPa.s.

Subsequently, 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 the dehydration ring-closure reaction was carried out at 110 DEG C for 4 hours. After the dehydration ring-closure reaction, the solvent in the system was replaced with a fresh? -Butyrolactone solvent to obtain about 110 g of a solution containing 15% by weight of a polyimide (B-3) having an imidization rate of about 80%. A small amount of this solution was collected, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight by adding? -Butyrolactone was 87 mPa 占 퐏.

Synthesis Example 10

22 g (0.10 mole) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic acid dianhydride, 8.7 g (0.08 mole) of p-phenylenediamine as diamine, 4,4'-diaminodiphenyl 2.0 g (0.01 mole) of methane and 3.2 g (0.01 mole) of 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl were dissolved in 256 g of NMP, The reaction was carried out to obtain a solution containing 10 wt% 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 the dehydration ring-closure reaction was carried out at 110 DEG C for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with a solvent of fresh? -Butyrolactone to obtain about 230 g of a solution containing 15% by weight of polyimide (B-4) having an imidization rate of about 80%. A small amount of this solution was collected, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight by adding? -Butyrolactone was 57 mPa 占 퐏.

Synthesis Example 11

16.8 g (0.075 mol) of 2,3,5-tricarboxycyclopentylacetic dianhydride as a tetracarboxylic acid dianhydride and 13.8 g (0.075 mol) of 1,3,3a, 4,5,9b-hexahydro-5-methyl- 7.9 g (0.025 mol) of p-phenylenediamine as a diamine, 0.04 mol (0.04 mol) of p-phenylenediamine as a diamine (0.02 mol) of 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone and 11.7 g (0.04 mol) of bis [4- g, and the reaction was carried out at 60 DEG C for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected, and the solution viscosity was measured as a solution having a polyamic acid concentration of 10% by weight by adding NMP. The viscosity of the solution was 92 mPa.s.

Subsequently, 350 g of NMP was added to the obtained polyamic acid solution, and 40 g of pyridine and 31 g of acetic anhydride were added, followed by dehydration ring-closure reaction at 110 DEG C for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with a solvent of fresh? -Butyrolactone to obtain about 415 g of a solution containing 11% by weight of polyimide (B-5) having an imidization rate of about 92%. A small amount of this solution was collected, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight by adding? -Butyrolactone was 123 mPa 占 퐏.

Synthesis Example 12

As the tetracarboxylic acid dianhydride, 14.6 g (0.065 mol) of 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5 (tetrahydro 7.9 g (0.025 mol) of 2,3,5-dioxo-3-furanyl) -naphtho [1,2-c] (0.04 mole) of bis [4- (4-aminophenoxy) phenyl] ether and 0.09 mole of tetra-carboxylic acid dianhydride, 8.6 g (0.02 mol) of 2-bis [4- (4-aminophenoxy) phenyl] sulfone 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 and the solution viscosity was measured as a solution having a polyamic acid concentration of 10% by weight by adding NMP, and the solution viscosity was 103 mPa.s.

Subsequently, 350 g of NMP was added to the obtained polyamic acid solution, and 40 g of pyridine and 31 g of acetic anhydride were added, followed by dehydration ring-closure reaction at 110 DEG C for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with a solvent of fresh? -Butyrolactone to obtain about 420 g of a solution containing 10% by weight of polyimide (B-6) having an imidization rate of about 90%. The solution viscosity of this solution was 113 mPa..

Synthesis Example 13

22.4 g (0.1 mole) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 10.8 g (0.1 mole) of p-phenylenediamine as a diamine were dissolved in 300 g of NMP, For 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected and the solution viscosity was measured as a solution having a polyamic acid concentration of 10% by weight by adding NMP, and the solution viscosity was 103 mPa.s.

Then, 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 the dehydration ring-closure reaction was carried out at 110 DEG C for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with a fresh? -Butyrolactone solvent to obtain about 320 g of a solution containing 10% by weight of polyimide (B-7) having an imidization rate of about 90%. The solution viscosity of this solution was 113 mPa..

&Lt; Preparation of liquid crystal aligning agent &

Example 1

100 parts by weight of the polyorganosiloxane EPS-1 having the epoxy group obtained in Synthesis Example 1 and 5,000 parts by weight of polyimide (B-1) in terms of polyimide (B-1) And 500 parts by weight of N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenyl methane (molecular weight of about 400) as an epoxy compound (BL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC) were added thereto, To prepare a solution having a solvent composition of BL: NMP: BC = 45: 45: 10 (weight ratio) and a solid content concentration of 4% by weight. This solution was filtered using a filter having a pore size of 1 占 퐉 to prepare a liquid crystal aligning agent.

Using these liquid crystal aligning agents, each evaluation was carried out as follows. The evaluation results are shown in Table 2 below.

&Lt; Production of liquid crystal cell &

The liquid crystal aligning agent thus prepared was applied to the transparent electrode surface of a glass substrate with a transparent electrode including an ITO film using a liquid crystal alignment film printing machine (manufactured by Nippon Sha Sein Insights Co., Ltd.), and heated on a hot plate at 80 캜 for 1 minute , And further heated on a hot plate at 200 DEG C for 10 minutes to form a coating film having an average thickness of 800 ANGSTROM.

The coating film was subjected to a rubbing treatment with a rubbing machine having a roll wound with a rayon hot spring at a roll rotation speed of 500 rpm, a stage moving speed of 3 cm / sec, and a piercing press length of 0.4 mm to form a liquid crystal alignment film. Subsequently, ultrasonic cleaning was performed for 1 minute in ultrapure water, and the resultant was dried in a 100 ° C clean oven for 10 minutes. This operation was repeated to produce a pair of substrates (two substrates) having a liquid crystal alignment film on the transparent electrode surface.

Subsequently, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 占 퐉 was applied to the respective outer edge portions of the pair of substrates having the liquid crystal alignment film, and thereafter the liquid crystal alignment film surfaces faced each other, And the adhesive was cured. Subsequently, a nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection hole was sealed with an acrylic light-curing adhesive to manufacture a liquid crystal cell.

&Lt; Evaluation of liquid crystal cell &

The above operation was repeated to produce a plurality of liquid crystal cells. Evaluation of heat resistance and evaluation of light resistance were conducted using separate liquid crystal cells.

[Evaluation of voltage holding ratio]

A voltage of 5 V at 60 占 폚 was applied to the liquid crystal cell prepared above in an application time of 60 microseconds and a span of 167 milliseconds, and the voltage maintenance ratio after 167 milliseconds from the application of the release voltage was measured. When the voltage holding ratio is 98% or more, it can be said that the voltage holding ratio is good.

VHR-1 manufactured by Toyo Technica Co., Ltd. was used as a device for measuring the voltage holding ratio.

[Evaluation of heat resistance]

The voltage holding ratio of the liquid crystal cell prepared above was measured under the same conditions as the evaluation of the voltage holding ratio (initial voltage holding ratio). Then, the liquid crystal cell was placed in an oven at 100 ° C. for 1,000 hours to apply heat stress, and then the voltage holding ratio was measured under the same conditions as above (voltage holding ratio after thermal stress) to determine the initial voltage holding ratio The rate of change was examined. When the rate of change is less than ± 2%, it can be said that the heat resistance is good.

[Evaluation of light resistance]

The voltage holding ratio of the liquid crystal cell prepared above was measured under the same conditions as the evaluation of the voltage holding ratio (initial voltage holding ratio). Subsequently, the four liquid crystal cells were placed at a distance of 5 cm under a 0-watt white fluorescent lamp, irradiated with light for 1,000 hours to add optical stress, and then the voltage holding ratio was measured under the same conditions as above Retention ratio), and the rate of change of voltage retention after optical stress to initial voltage retention. When the rate of change is less than ± 2%, it can be said that the light resistance is good.

[Measurement of Electrostatic Leakage Property]

A static voltage was accumulated in the cell by applying a voltage of 120 V at 25 DEG C for 5 minutes to the liquid crystal cell manufactured as described above. Thereafter, the time from when the voltage was released to when the stored voltage was lost was measured every 5 minutes. If this time is less than 60 minutes, it can be said that the electrostatic leakage property is good.

Examples 2 to 18 and Comparative Examples 1 to 3

A liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the type and the amount of the polyorganosiloxane having an epoxy group and the other polymer were changed as shown in Table 2, respectively, and a liquid crystal cell was produced and evaluated. The evaluation results are shown in Table 2.

Further, the other polymer was used in the preparation of the liquid crystal aligning agent, and the amount of the polymer used in Table 2 was converted into the amount of the polymer contained in each solution.

In Examples 13 to 18 and Comparative Example 2, two different polymers were used, respectively.

Claims (7)

A polyorganosiloxane having a repeating unit represented by the following formula (S-1), a hydrolyzate thereof and a condensate of a hydrolyzate (provided that the epoxy equivalent thereof is 50 to 10,000 g / mol, And a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography is 1,000 to 100,000). &Lt; General Formula (S-1)

(In the formula (S-1), X is a monovalent organic group having an epoxy group and Y is an hydroxyl group, an alkoxyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms) The liquid crystal aligning agent according to claim 1, wherein X in the formula (S-1) is a group represented by the following formula (X-1) or (X-2). &Lt; General Formula (X-1)

<Formula X-2>

The liquid crystal aligning agent according to claim 1, further comprising at least one polymer selected from the group consisting of polyamic acid and polyimide. [Claim 5] The method according to claim 3, wherein the at least one polymer selected from the group consisting of polyamic acid and polyimide is 2,3,5-tricarboxycyclopentylacetic 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- Methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [l, 2-c] furan-l, 3-dione and 3-oxabicyclo [3.2. (Tetrahydrofuran-2 ', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3 -Methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: Oxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, and 2,3,2 ', 3'-biphenyltetracarboxylic dianhydride. Upon reaction of the tetracarboxylic dianhydride and the diamine containing more than two species A polyamic acid obtained, and a first liquid crystal alignment or more polymer selected from the group consisting of a polyimide obtained by dehydration ring-closure of the polyamic acid. The polyorganosiloxane according to claim 3, wherein the content ratio of at least one polymer selected from the group consisting of polyamic acid and polyimide is at least one selected from the group consisting of polyorganosiloxane having a repeating unit represented by the above formula (S-1), a hydrolyzate thereof and a hydrolyzate Water and 200 to 50,000 parts by weight based on 100 parts by weight of at least one kind selected from the group consisting of water, A liquid crystal alignment film formed from the liquid crystal aligning agent according to any one of claims 1 to 5. A liquid crystal display element comprising the liquid crystal alignment film according to claim 6.