KR20150122585A - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display device - Google Patents

Abstract

The present invention provides a liquid crystal aligning agent which can form a liquid crystal alignment film, which has a voltage retention rate decreasing less for a long period and does not generate an afterimage even in an extreme use condition, and has excellent applicability (printability). The liquid crystal aligning agent contains polyarylene, which is a polymer having a repeating unit represented by chemical formula (P). In chemical formula (P), Ar is an n+2-valent aromatic group; n is 1 or 2; X is a single bond, an oxygen atom, a sulfur atom, a carbonyl group, an ester bond, a thioester bond, -NR-, or -CONR-, wherein R is a hydrogen atom or an alkyl group having 1-6 carbon atoms; and R^(01) is selected from a hydrogen atom, a hydroxyl group, a group having a terminal C=C double bond, a group having a triple bond between carbon atoms, a group having an epoxy group, a group with a function of aligning liquid crystal molecules, and a group which causes cross-linking reaction or isomerization reaction by light irradiation.

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. More specifically, it is possible to form a liquid crystal alignment film having excellent reliability, which does not deteriorate the voltage holding ratio over a long period of time and which does not cause after-images even under severe use conditions, .

The liquid crystal display element can be classified into various modes depending on the electrode structure and the physical properties of liquid crystal molecules used. For example, a liquid crystal alignment film is formed on the surface of a substrate on which a transparent conductive film is formed to form a substrate for a liquid crystal display device. Two liquid crystal alignment films are disposed opposite to each other to form a nematic liquid crystal layer having positive dielectric anisotropy Called Twisted Nematic (TN) type in which the long axis of the liquid crystal molecules is twisted by 90 degrees continuously from one substrate to the other substrate by using a cell having a sandwich structure.

STN (Super Twisted Nematic) type which can realize a higher duty ratio than a TN type liquid crystal display element (Patent Document 2);

A VA (Vertical Alignment) type (Patent Document 3) in which a nematic liquid crystal layer having negative dielectric anisotropy is injected into the pole gap and the liquid crystal is oriented substantially perpendicular to the substrate;

An IPS (In-Plane Switching) type (Patent Documents 4 and 5) in which comb electrodes are arranged in the form of comb teeth in a single substrate surface so that the driving direction of the liquid crystal upon application of an electric field is only in the in-plane direction of the substrate.

An FFS (Fringe Field Switching) type (Patent Document 6) in which the electrode structure of the IPS type is changed and the aperture ratio of the display element portion is increased to improve the luminance;

OCB (Optical Compensated Bend) type (Patent Document 7) which is excellent in high-speed response of an image screen while having little visual dependency,

Liquid crystal display devices are known.

As a material of the liquid crystal alignment film in these various liquid crystal display devices, resin materials such as polyamic acid, polyimide, polyamide, and polyester are known. In particular, a liquid crystal alignment film made of polyamic acid or polyimide has heat resistance, Has excellent affinity with liquid crystals, and is used in most liquid crystal display devices (Patent Document 8).

In such a liquid crystal aligning agent, improvement in the applicability (printability) and improvement in reliability (long-term stability against a severe environment) have been demanded more than ever before. The situation is as follows.

Compared to notebook personal computers and monitor displays, which are the mainstream of conventional liquid crystal display devices, liquid crystal televisions, which have recently been popular in recent years, are required to have long replacement cycles because of their long replacement cycles. For example, in the case of a liquid crystal television, etc., the liquid crystal display device is designed on the assumption that the content (usable) year number exceeds 10 years, and the liquid crystal display device is expected to be driven for a longer time than the conventional liquid crystal display device. At the same time, in order to display a liquid crystal display device with a larger size and a higher definition, the backlight tends to have higher illuminance, and a coating film of the liquid crystal aligning agent is required to be uniform over a large area.

On the other hand, in a liquid crystal display device for use in a liquid crystal projector in which the demand for a home theater is increasing in recent years, a light source having a very high irradiation intensity such as a metal halide lamp is used. In addition, since a liquid crystal display element for a mobile device such as a cellular phone or a car navigation device for a vehicle is required to increase the brightness of the backlight in order to improve visibility under sunlight including strong ultraviolet rays, Is deteriorated. When these devices are used as a display of a television game, it is assumed that they are placed under continuous driving for a very long time under the above-described conditions.

As described above, in a liquid crystal display element, exposure to a harsh environment such as high-intensity light irradiation and long-time driving, which has not been considered in the past, has been accompanied by the increase in versatility, and furthermore, will be.

Japanese Patent Application Laid-Open No. 4-153622 Japanese Patent Application Laid-Open No. 60-107020 Japanese Patent Application Laid-Open No. 11-258605 Japanese Laid-Open Patent Publication No. 56-91277 U.S. Patent No. 5,928,733 Japanese Patent Application Laid-Open No. 2002-082357 Japanese Patent Application Laid-Open No. 9-105957 Japanese Laid-Open Patent Publication No. 62-165628

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal alignment film excellent in reliability which does not deteriorate a voltage holding ratio over a long period of time, , And further to provide a liquid crystal aligning agent excellent in coating property (printing property).

According to the present invention, the above objects and advantages of the present invention are achieved by a liquid crystal aligning agent containing polyarylene. The polyarylene is preferably a polymer having a structure in which a plurality of arylene groups which may be substituted are directly bonded to each other, and more preferably a polymer having a repeating unit represented by the following formula (P)

(In the formula (P), Ar is an n + 2 valent aromatic group, n is 1 or 2,

X in each repeating unit independently represents a single bond, an oxygen atom, a sulfur atom, a carbonyl group, an ester bond, a thioester bond, -NR- or -CONR- (wherein R represents a hydrogen atom or a carbon atom Lt; / RTI > alkyl group)

R ⁰¹ in each repeating unit independently represents a group having a hydrogen atom, a hydroxyl group, a group having a terminal C═C double bond, a group having a carbon-carbon triple bond, a group having an epoxy group, A group which generates a crosslinking reaction or an isomerization reaction by light irradiation).

According to the present invention, there is provided a liquid crystal aligning agent capable of forming a liquid crystal alignment film excellent in reliability, which does not cause a reduction in the voltage holding rate over a long period of time and which does not cause afterimage even under severe use conditions. Since this liquid crystal aligning agent is excellent in coating property (printing property), the yield of the liquid crystal alignment film formation step is high and contributes to the reduction of manufacturing cost of the liquid crystal display element.

The liquid crystal display element of the present invention including the liquid crystal alignment film formed from the liquid crystal aligning agent does not deteriorate display quality over a long period of time. Therefore, the technique of the present invention can be suitably applied to applications such as a liquid crystal television, a liquid crystal projector, a mobile phone, a portable game machine, and a tablet PC, for example.

Fig. 1 is an infrared spectrum of the polyarylene obtained in Synthesis Example 1. Fig.
Fig. 2 is a schematic diagram showing an example of a pattern of electrodes in a liquid crystal cell manufactured by the embodiment. Fig.
3 is a schematic view showing another example of a pattern of electrodes in a liquid crystal cell manufactured by the embodiment.

(Mode for carrying out the invention)

As described above, the liquid crystal aligning agent of the present invention contains polyarylene.

≪ Polyarylene &

The polyarylene in the present invention may be a polyarylene having a structure in which a plurality of arylene groups are directly bonded to each other and having a structure in which a plurality of arylene groups are connected to each other by a divalent group other than an arylene group, Polyarylene ether, polyarylene sulfide, polyarylene alkenylene, and the like, and block copolymers composed of two or more of these. The above arylene group may be substituted.

The polyarylene in the present invention is preferably a polyarylene having a structure in which a plurality of arylene groups are directly bonded to each other. Particularly preferably, a polyarylene having a structure in which a plurality of naphthalene groups which may be substituted are directly bonded to each other and connected to each other is preferable, and is preferably a polyarylene having a repeating unit represented by the above formula (P). In the formula (P), n is 1 or 2, and Ar is an aromatic group of (n + 2) valences. That is, Ar is a trivalent aromatic group when n is 1 and a tetravalent aromatic group when n is 2. Ar in each repeating unit may be the same or different.

In the formula (P), each X in each repeating unit is independently a group represented by a single bond, an oxygen atom, a sulfur atom, a carbonyl group, an ester bond, a thioester bond, -NR- or -CONR-. Wherein R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

In the formula (P), R ⁰¹ in each repeating unit is, independently, a hydrogen atom, a hydroxyl group, a group having a terminal C═C double bond, a group having a carbon-carbon triple bond, a group having an epoxy group, A group having a function of orienting molecules or a group generating a crosslinking reaction or an isomerization reaction by light irradiation.

More preferably 5 or more (preferably 10 or more) of the repeating units represented by the above formula (P) are directly bonded and connected to each other,

And most preferably a polyarylene comprising only repeating units represented by the above formula (P).

At least one of R ⁰¹ in each repeating unit is a group having a hydroxyl group, a group having a terminal C═C double bond, a group having a carbon-carbon triple bond, a group having an epoxy group, a group having a function of orienting liquid crystal molecules, A group which generates a crosslinking reaction or an isomerization reaction by irradiation is preferable.

Specific examples of R in the -NR- and -CONR- include a methyl group, an ethyl group and a propyl group.

When R ⁰¹ is a group having a terminal C═C double bond, examples of the substituent -XR ⁰¹ in the formula (P) include an allyloxy group and a (meth) acryloxy group.

When R ⁰¹ is a group having an epoxy group, examples of the substituent -XR ⁰¹ in the formula (P1) include a glycidyloxy group, a 2,3-cyclohexyl epoxy group and a 3,4-cyclohexyl epoxy group. have.

The liquid crystal aligning group is a group having a function of aligning a group of liquid crystal molecules in a certain direction. Examples of such a liquid crystal aligning group include groups represented by the following formula (D) and the like:

(Wherein R < ¹ > is an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, a cyano group, a fluorine atom, or a hydrocarbon group having 17 to 51 carbon atoms and having a steroid skeleton;

Z ^I is a single bond, + -O-, + -COO- or + -OCO- (provided that the bond with "+" is R ¹ );

R ^II is a cyclohexylene group or a phenylene group, provided that the cyclohexylene group or the phenylene group may be substituted by a cyano group, a fluorine atom, a trifluoromethyl group or an alkyl group having 1 to 3 carbon atoms;

n1 is 1 or 2,

Provided that when n1 is 2, two R < 11 ^> may be the same or different from each other;

n2 is 0 or 1;

^Ⅱ Z is a single bond, -O- +, + or -COO- + -OCO- (However, the "+" attached to the coupling hand R ^Ⅰ cheukim shown below);

n3 is an integer of 0 to 2;

n4 is 0 or 1; And

&Quot; * " indicates a combined hand).

The alkyl group having 1 to 40 carbon atoms in R ¹ in the formula (D) is preferably a straight chain, and specific examples thereof include a methyl group, ethyl group, n-propyl group, n-butyl group, , n-hexyl group, n-octyl group, n-decyl group, n-dodecyl group, n-hexadecyl group and stearyl group;

The fluoroalkyl group having 1 to 40 carbon atoms is preferably a straight chain, and specific examples thereof include 3-trifluoromethylpropyl group, 4-trifluoromethylbutyl group, 6-trifluoromethylhexyl group, Pentafluoroethylpropyl group, a 4-pentafluoroethylbutyl group, an 8-pentafluoroethyloctyl group, a 3,3,4,4,5,5,5- Heptafluoropentyl group, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl group, 3,3,4,4,5,5 , 6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl group and the like;

Examples of the hydrocarbon group having 17 to 51 carbon atoms having the above steroid skeleton include 3-cholestanyl group, 3-cholestenyl group, 3-lanostanyl group, 3-colloranyl group, 3- A 3-estranyl group, and the like.

When R ^I is an alkyl group and both of n2 and n4 are 0, the alkyl group of R ^I is preferably a straight chain alkyl group having 4 to 40 carbon atoms.

Examples of the divalent group represented by - ( ^RII ) _n1- in the formula (D) include a case where n1 is 1, for example, 1,4-phenylene group, 1,4-cyclohexylene group and the like;

Examples of the case where n1 is 2 include, for example, 4,4'-biphenylene group, 4,4'-bicyclohexylene group, groups represented by each of the following formulas, and the like.

(In the above formula, the combined hands marked with " + " are on the R ^I side;

In the formula (D), n3 is preferably 2;

In the formula (D), or n2 is 1, or also preferred that n2 is 0 and R ^Ⅰ a hydrocarbon group of a carbon number of 17-51 with a steroid skeleton).

The photoreactive group is a group capable of generating a crosslinking reaction or an isomerization reaction by light irradiation. Examples of such a photoreactive group include a divalent group represented by the following formula (E) and the like:

(In the formula (E), d is 0 or 1;

A ¹ and A ² each represent an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom or a cyano group;

e and f are each an integer of 0 to 4; And

Quot; and " * " each indicate a combined hand).

Each of A ¹ and A ² in the formula (E) is preferably an alkoxy group having 1 to 6 carbon atoms. e and f are each preferably 0.

The group represented by the formula (E) is preferably present in the side chain of the polyarylene. In this case, a hydrogen atom or a monovalent organic group (preferably, the above-mentioned liquid crystal aligning group) is bonded to the other side of the bonding hands of the formula (E), a monovalent group in the whole of the formula (E) To the backbone of the polyarylene. Specific examples of such groups include groups represented by each of the following formulas:

(Wherein R ¹ is a hydrogen atom, a monovalent organic group having 3 to 40 carbon atoms and an alicyclic group, an alkyl group having 1 to 40 carbon atoms, or a fluorinated alkyl group having 1 to 40 carbon atoms;

v is an integer from 1 to 10;

&Quot; * " indicates a combined hand).

When the polyarylene has at least one kind of group selected from the group consisting of a group having a terminal C = C double bond and an epoxy group, the liquid crystal aligning agent containing the polyarylene exhibits a particularly low residual DC voltage , And is suitable for application to an FFS type liquid crystal display device. In order to effectively exhibit this function,

When the polyarylene has a group having a terminal C = C double bond, the content ratio of the terminal C = C double bond in the polyarylene is preferably 0.0001 mol / g-polymer or more, 0.025 mol / g-polymer is more preferable;

When the polyarylene has an epoxy group, the epoxy equivalent of the polyarylene is preferably 10,000 g / mol or less, and more preferably 40 to 2,000 g / mol. The case where the polyarylene has a group having a terminal C = C double bond and an epoxy group in the above-described ranges in a superimposed manner is also suitable for use in an FFS type liquid crystal display element.

When the polyarylene has a liquid crystal aligning group, the liquid crystal aligning agent containing the polyarylene can be suitably applied to the production of a vertically aligned liquid crystal display element. In order to effectively exhibit this function, the content ratio of the liquid crystal aligning group in the polyarylene is preferably 0.0001 mol / g-polymer or more, more preferably 0.0005 to 0.025 mol / g-polymer.

When the polyarylene has a photoreactive group, the liquid crystal aligning agent containing the polyarylene can be preferably applied to a liquid crystal alignment film formed by the photo alignment method. In order to effectively exhibit this function, the content ratio of the photoreactive group in the polyarylene is preferably 0.0001 mol / g-polymer or more, more preferably 0.0005 to 0.025 mol / g-polymer.

The polyarylene contained in the liquid crystal aligning agent of the present invention may have two or more kinds of the above groups in a superimposed manner.

The polyarylene in the present invention is preferably a polymer having at least one repeating unit selected from the repeating units represented by the following formulas (P-1) and (P-2)

(In the formulas (P-1) and (P-2), X and R ⁰¹ are the same as those in the formula (P)).

In the polyarylene, there is a plurality of at least one kind of repeating unit selected from the repeating units represented by the above formulas (P-1) and (P-2), but the substituent -XR ⁰¹ May be the same or different.

With respect to the polyarylene contained in the liquid crystal aligning agent of the present invention, the weight average molecular weight Mw in terms of polystyrene measured by gel permeation chromatography is preferably 500 to 1,000,000, more preferably 1,000 to 500,000.

The polyarylene as described above can be synthesized by a known method.

For example, the polyarylene comprising the repeating unit represented by the above formula (P-1) can be obtained by using a naphthalene dihalide having the desired substituent -XR ⁰¹ as a starting material and using a transition metal complex (for example, ) In the presence of a chain transfer agent;

Chain chain growth reaction in which one of the halogen atoms of the naphthalene dihalide having the desired substituent -XR ⁰¹ is converted to a Grignard group and then the other is carried out in the presence of a nickel (II) complex;

A naphthalene dihalide having the desired substituent -XR ⁰¹ ,

A compound in which naphthalene is introduced with two trialkyltin groups (R ₃ Sn-, R is an alkyl group) or a dialkoxyboron group ((RO) ₂ B- and R is an alkyl group) Polymer chain growth reaction carried out in the presence of a palladium complex;

Can be synthesized by an appropriate method such as a chain-growth reaction in which dihydroxynaphthalene having a desired substituent -XR ⁰¹ is used as a raw material in the presence of a copper (II) complex.

The polyarylene having a main chain structure having a bivalent group other than the arylene group can be produced by, for example, coexisting with other copolymerizable monomers that give a bivalent group other than an arylene group during the above-mentioned chain growth reaction .

For the polyarylene obtained by any of the above methods, a reaction for chemically converting the reactivity of the substituent by using the reactivity of the substituent can also be preferably applied.

For example, a polyarylene having a hydroxyl group as a substituent can be obtained by reacting the hydroxyl group with an alkali metal salt and then reacting with a halogenated hydrocarbon compound having a desired group. By this method, for example, a polyarylene having an aryloxy group as a substituent can be obtained. In the polyarylene having a group having a C = C double bond as a substituent, the polyarylene having an epoxy group can be obtained by oxidizing the C = C double bond by, for example, a peroxide. By reacting the polyarylene having an epoxy group with a carbonic acid or the like, a polyarylene having a desired group can be obtained.

Preferable conditions for the above reaction can be easily set by a person skilled in the art by a few preliminary experiments.

Examples of the naphthalene derivative having a phenolic hydroxyl group for imparting the repeating unit represented by the above formula (P-1) include 1-hydroxy naphthalene, 2-hydroxynaphthalene, 2-methyl- Dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, Dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,8-dihydroxynaphthalene and 3-methyl-2,6-dihydroxynaphthalene. The naphthalene derivatives having a phenolic hydroxyl group may be used singly or in combination of two or more.

Examples of the compound for imparting the repeating unit represented by the above formula (P-2) include phenol, p-isopropenylphenol, ethynylstyrene, and phenylacetylene. These may be used alone or in combination of two or more.

Examples of other copolymerizable monomers for imparting the above other divalent groups other than the arylene group include propargylic acid, 6-hexynoic acid, 2-propyn-1-ol, 3-ol, 1-pentyn-3-ol, 4-pentyn-1-ol, 3-ethynyl aniline and 4-ethynyl aniline. The other copolymerizable monomers may be used alone or in combination of two or more.

The content ratio of the repeating units of the other bivalent groups in the polyarylene is preferably 0 to 30 mol%, more preferably 0 to 20 mol%, still more preferably 0 To 10 mol%.

<Other components>

The liquid crystal aligning agent of the present invention contains the above-mentioned polyarylene as an essential component, and preferably these are constituted as a solution composition dissolved in a solvent to be described later, but if necessary further contains other components good. Examples of the other components include other polymers, compounds having at least one epoxy group in the molecule (hereinafter referred to as &quot; epoxy compound &quot;), and functional silane compounds.

The other polymer is a polymer having no structure represented by the formula (1) and can be used for improving the solution characteristics (coating properties) and electric characteristics of the liquid crystal aligning agent of the present invention. Examples of the other polymer include polyamic acid, imidized polymer of the polyamic acid, polyamic acid ester, polyester, polyamide, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide ) Derivatives, poly (meth) acrylates, and the like, and at least one selected from these may be used. The other polymer is preferably at least one selected from the group consisting of polyamic acid, imidized polymer of the polyamic acid, polyamic acid ester and polyorganosiloxane.

The use ratio of the other polymer is preferably 60 parts by weight or less, more preferably 40 parts by weight or less, based on 100 parts by weight of the total of the polymers (which means the total of polyarylene and other polymer, hereinafter the same) . When other polymers are used, the effects of using other polymers are preferably exhibited by making the content ratio thereof 10 parts by weight or more based on 100 parts by weight of the total of the polymers.

The epoxy compound and the functional silane compound may be contained in the liquid crystal aligning agent of the present invention in order to further improve the adhesion between the obtained liquid crystal alignment film and the substrate.

Examples of the epoxy compound 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, trimethylol propane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl N, N, N ', N'-bis (N, N-diglycidylaminomethyl) cyclohexane, N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N, N-diglycidylbenzylamine, N, N-diglycidylaminomethylcyclohexane, N, Cydyl-cyclohexylamine and the like are preferably used.

The mixing ratio of these epoxy compounds is preferably 40 parts by weight or less, more preferably 0.1 to 30 parts by weight, based on 100 parts by weight of the total amount of the polymers.

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-triethoxysilylpropyltriethylenetriamine, N- Trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3 , 6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, methyl 9-trimethoxysilyl-3,6-diazononanoate, Benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl- N-phenyl-3-aminopropyltriethoxysilane, and the like.

The blending ratio of these functional silane compounds is preferably 2 parts by weight or less, more preferably 0.02 to 0.2 parts by weight, 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 constituted by dissolving and containing the above-mentioned polyarylene and optionally other additives optionally mixed in an organic solvent.

Examples of the organic solvent usable in the liquid crystal aligning agent of the present invention include N-methyl-2-pyrrolidone,? -Butyrolactone,? -Butyrolactam, N, N-dimethylformamide, N, N Methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, N-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), 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 There may be mentioned di-isobutyl ketone, isoamyl propionate, isoamyl isobutyrate, di-isopentyl ether, ethylene carbonate, propylene carbonate, 2-methoxyethanol, 1-methoxy-2-propyl acetate. These may be used alone or in combination of two or more.

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 of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc., Is in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the surface of the substrate as described later, and preferably, it is heated to form a coating film which becomes a liquid crystal alignment film. When the solid concentration is less than 1% by weight, On the other hand, when the solid concentration exceeds 10% by weight, the film thickness of the coating film becomes excessively large and a good liquid crystal alignment film can not be obtained. Further, the viscosity of the liquid crystal aligning agent is increased, It becomes a fall behind.

A particularly preferable range of the solid concentration varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, in the case of the spinner method, the solid content concentration is particularly preferably in the range of 1.5 to 4.5 wt%. In the case of the printing method, it is particularly preferable that the solid concentration is in the range of 3 to 9 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 accordingly the solution viscosity is in the range of 3 to 15 mPa · s.

The temperature for preparing the liquid crystal aligning agent of the present invention is preferably 10 to 50 占 폚, more preferably 20 to 30 占 폚.

&Lt; Liquid crystal alignment film &

A liquid crystal alignment layer can be formed with the liquid crystal aligning agent of the present invention as described above.

The liquid crystal alignment film can be formed by, for example, (1) a step of forming a coating film on the substrate (coating film forming step) and (2) liquid crystal orientation imparting step in this order. However, in the case where the liquid crystal aligning agent of the present invention is applied to a liquid crystal display device of vertical alignment mode such as a VA type or MVA type, (2) the liquid crystal aligning property imparting step is optional and may not be performed.

Each of the steps for forming a liquid crystal alignment film will be described below.

(1) Coating film formation process

In the coating film forming step, a coating film is formed by applying the liquid crystal aligning agent of the present invention on a substrate, and preferably thereafter heating it.

Examples of the substrate include glass such as float glass and soda glass;

A transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, or the like can be used.

In the case where the liquid crystal aligning agent of the present invention is applied to a liquid crystal display device of the conventional system such as TN type, STN type, VA type, MVA type and PSA type, two substrates on which a patterned transparent conductive film is formed, , The liquid crystal aligning agent of the present invention is applied to each of the transparent conductive film formation surfaces to form a coating film. On the other hand, when the liquid crystal aligning agent of the present invention is applied to a liquid crystal display element of a transverse electric field system such as IPS type or FFS type, it is preferable that a transparent conductive film or a substrate having a pair of electrodes patterned in a comb- And a counter substrate on which no electrode is formed are formed as a pair, and a liquid crystal aligning agent of the present invention is applied to the surface of the comb-shaped electrode and the surface of the counter substrate, respectively, to form a coated film. As the transparent conductive film, for example, an ITO film made of In ₂ O ₃ -SnO ₂ , a NESA (registered trademark) film made of SnO ₂ , or the like can be used. As the metal film, for example, a film made of a metal such as chromium can be used. The patterning of the transparent conductive film and the metal film includes, for example, a method of forming a pattern by a photo-etching method or a sputtering method after forming a pattern-free transparent conductive film, a method of using a mask having a desired pattern in forming a transparent conductive film And so on.

The liquid crystal aligning agent of the present invention is coated on the above-described substrate, and preferably thereafter heated to form a coating film. In order to make the adhesion between the substrate and the electrode and the coating film better at the time of coating, a pretreatment is performed in which a functional silane compound, a titanate compound, You can do it.

The application of the liquid crystal aligning agent onto the substrate can be preferably carried out by an appropriate application method such as an offset printing method, a spin coating method, a roll coater method, or an inkjet printing method. Preferably, after application, the coated surface can be formed by pre-heating (pre-baking) and then baking (post baking). The prebaking condition is, for example, a heating time of 0.1 to 5 minutes at a heating temperature of 40 to 120 캜, and a post baking condition is, for example, a heating temperature of 120 to 300 캜, preferably 150 to 250 캜 For example 5 to 200 minutes, preferably 10 to 100 minutes.

The thickness of the coating film after post-baking is preferably 0.001 to 1 mu m, more preferably 0.005 to 0.5 mu m

When the liquid crystal aligning agent of the present invention is applied to vertically aligned liquid crystal display devices such as VA type, MVA type and PSA (Polymer Stabilized Alignment) type, the coating film formed as described above can be used as a liquid crystal alignment film as it is . Even in this case, the following (2) liquid crystal orientation imparting step may be optionally performed.

(2) Liquid crystal aligning property imparting step

When the liquid crystal aligning agent of the present invention is applied to a horizontally aligned liquid crystal display device such as a TN type, an STN type, an IPS type, an FFS type and the like, (2) after the coating film forming step (2) .

This liquid crystal orientation imparting step can be performed by performing at least one of the rubbing treatment and the light irradiation treatment.

When the polyarylene contained in the liquid crystal aligning agent of the present invention (at least one of polyarylene and other polymer in the presence of other polymer) has a photoreactive group, the light irradiation treatment It is preferable to perform the rubbing treatment as the liquid crystal aligning property imparting step.

The rubbing treatment can be carried out by rubbing the surface of the coating film formed on the substrate in a predetermined direction with a roll of cloth made of, for example, nylon, rayon, cotton or the like.

As the light to be irradiated in the light irradiation treatment, for example, ultraviolet light or visible light including light having a wavelength of 150 to 800 nm can be used. Ultraviolet rays containing light having a wavelength of 200 to 400 nm are preferred. As the light source to be used, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an Hg-Xe lamp and an excimer laser can be used. The ultraviolet ray of the above-mentioned preferable wavelength range can be obtained by a means for using the light source together with a filter, a diffraction grating, or the like.

When the light used for light irradiation is polarized (linearly polarized light or partial polarized light), the light may be irradiated from a direction perpendicular to the coated film surface in an oblique direction. On the other hand, in the case of irradiating non-polarized light, it is preferable that the irradiation is performed in an oblique direction with respect to the coated film surface.

The irradiation dose or exposure dose of light is preferably 50 to 40,000 J / m 2, and more preferably 100 to 20,000 J / m 2.

<Liquid crystal display element>

A liquid crystal display device can be manufactured using the substrate having the liquid crystal alignment film formed as described above.

A pair of substrates on which a liquid crystal alignment film is formed as described above is prepared, and a liquid crystal cell having a configuration in which liquid crystal is sandwiched between the pair of substrates is manufactured. To produce a liquid crystal cell, for example, the following two methods can be used.

As a first method, a pair of substrates are disposed to face each other with a space (cell gap) interposed therebetween so that the respective liquid crystal alignment films face each other, and peripheral portions of the pair of substrates are bonded to each other using a sealant, A liquid crystal is injected and filled in a cell gap defined by the liquid crystal cell, and then the liquid crystal cell is manufactured by sealing the injection port.

As a second method, for example, an ultraviolet curable sealant is applied to a predetermined place on one of the two substrates on which a liquid crystal alignment film is formed, and further liquid crystal is dropped to a predetermined number of places on the liquid crystal alignment film surface A liquid crystal cell is manufactured by joining the other substrate so that the liquid crystal alignment film is opposed to the liquid crystal alignment film and spreading the liquid crystal on the entire surface of the substrate and then irradiating the entire surface of the substrate with ultraviolet light to cure the sealant ODF (One Drop Fill) method).

In any of the above methods, it is preferable that the liquid crystal cell using the liquid crystal cell is heated to a temperature at which the liquid crystal using isotropic phase is gradually cooled to room temperature to remove the flow alignment at the time of filling the liquid crystal.

As the liquid crystal, for example, a nematic liquid crystal, a smectic liquid crystal or the like can be used.

In the case of producing a horizontally aligned liquid crystal display element, nematic liquid crystals having positive dielectric anisotropy are preferable, and examples thereof include biphenyl liquid crystal, phenyl cyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, Hexane-based liquid crystals, pyrimidine-based liquid crystals, fluorinated benzene-based liquid crystals, dioxane-based liquid crystals, bicyclooctane-based liquid crystals, quaternary type liquid crystals and the like. A cholesteric liquid crystal, a chiral agent, a ferroelectric liquid crystal, or the like may be added to these liquid crystals and used.

On the other hand, when a vertically aligned liquid crystal display device is manufactured, a nematic liquid crystal having a negative dielectric anisotropy is preferable. For example, a dicyanobenzene liquid crystal, a pyridazine liquid crystal, a cypher base liquid crystal, Biphenyl-based liquid crystal, phenylcyclohexane-based liquid crystal, and the like.

In the case of manufacturing a PSA type liquid crystal display element, a step of irradiating the liquid crystal cell with light is performed in a state in which a voltage is applied between the conductive films of a pair of liquid crystal substrates obtained as described above. The voltage to be applied here may be DC or AC of 5 to 50 V, for example. As the light to be irradiated, the same light as the light used in the liquid crystal orientation imparting step in the formation of the liquid crystal alignment film can be used. The dose of light is preferably 1,000 J / m 2 or more and less than 100,000 J / m 2, and more preferably 1,000 to 50,000 J / m 2.

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

As the polarizing plate used for the outside of the liquid crystal cell, a polarizing plate in which a polarizing film called &quot; H film &quot; in which iodine is absorbed while polyvinyl alcohol is oriented in a stretched orientation is sandwiched by a cellulose acetate protective film or a polarizing plate made of H film itself have.

(Example)

&Lt; Synthesis Example of Specific Polymer &

In the following Synthesis Examples, the synthesis operations of the respective polymers were repeated as necessary with the scales described below to ensure the required amount of polymer in the following Synthesis Examples.

Synthesis Example 1

A 500 mL three-necked flask equipped with a three-way cock equipped with a nitrogen inlet tube and a stirrer was charged with 20.00 g (0.125 mol) of 2,6-dihydroxynaphthalene, 0.58 g (0.125 mmol) of bis [(N, N, N ', N'-tetramethylethylenediamine) copper (II)] chloride and 380 mL of 2-methoxyethanol were introduced and stirring was started. Subsequently, 13.7 g of 31% by weight aqueous hydrogen peroxide was added over 2 hours, and the reaction was carried out at 25 DEG C for 3 hours with stirring. After completion of the reaction, the reaction solution was poured into 1,000 mL of distilled water to precipitate the product. The resulting precipitate was collected by filtration, recovered, and the solvent was removed under vacuum at 80 캜 overnight to obtain a polymer (A-1) in the form of a gray powder (polymer having a repeating unit represented by the following formula (A-1)) Yield 18.76 g, yield 95%).

The polymer (A-1) obtained above had a weight average molecular weight Mw of 48,000 as measured by gel permeation chromatography in terms of polystyrene.

The polymer (A-1) obtained above was subjected to infrared spectroscopic analysis by the following procedure. The infrared spectrum is shown in Fig.

[Infrared spectroscopic analysis method]

The resulting polymer was dissolved in 2-methoxyethanol to obtain a polymer solution having a polymer concentration of 20 mass%. The solution was coated on a substrate made of polyethylene terephthalate (PET) by a doctor blade method and heated at 70 캜 for 30 minutes and at 120 캜 for 30 minutes in succession to remove the solvent to obtain a film. This film was peeled off from the PET substrate, fixed on a metal flask for infrared measurement by an adhesive tape, and then subjected to vacuum removal at 120 DEG C for 2 hours to completely remove the solvent, thereby obtaining an infrared- , And measurement was performed using the film.

Synthesis Example 2

A polymer (polymer (A-4)) having a repeating unit represented by the formula (A-4) was synthesized according to the following Reaction Scheme 1.

3.80 g of sodium hydroxide was dissolved in 250 g of distilled water in a 500 mL eggplant type flask and then 6.00 g of the polymer (A-1) obtained in the above Synthesis Example 1 was added and dissolved and stirred at room temperature (about 25 캜) A-1). A solution of 13.8 g of allyl bromide dissolved in 30 mL of ethanol was added dropwise at room temperature over 30 minutes. After completion of dropwise addition, the reaction was carried out with stirring at room temperature for 12 hours. After completion of the reaction, the reaction solution in the suspension state was subjected to suction filtration to recover the solid. The obtained solid was washed with distilled water and vacuum-dried at 50 캜 to obtain 7.6 g (yield: 85%) of a polymer having a repeating unit represented by the formula (A-4) (polymer (A-4)).

The results of ¹ H-NMR (solvent: CDCl ₃ ) measured on the polymer (A-4) were as follows.

Chemical shift σ: 7.8~6.9ppm (benzene ring, a _{hydrogen, 4H), 6.0~5.6ppm (CH 2} = C H -CH 2 -O, 2H), 5.3~4.8ppm (C H 2 = CH-CH 2 - O, 4H), 4.8~4.3ppm (CH 2 = CH-C H 2 -O, 4H)

Synthesis Example 3

(Polymer (A-2)) having a repeating unit represented by the formula (A-2) was synthesized according to the following Reaction Scheme 2:

(In Scheme 2, mCPBA is m-chloro and benzoic acid).

In a 500 mL eggplant-shaped flask, 6.88 g of the polymer (A-4) obtained in Synthesis Example 2 was dissolved in 200 g of tetrahydrofuran. While cooling the resulting solution to 0 占 폚, 36.5 g of m-chloro and benzoic acid (content 69 wt%) were added in small portions over 30 minutes. After completion of the addition, the mixture was stirred at the same temperature for 1 hour, then heated to room temperature and further stirred for 1 hour, then heated to 50 ° C, and the reaction was continued at the same temperature for 8 hours with stirring. Thereafter, the temperature of the reaction mixture was cooled, and the solvent was distilled off under reduced pressure at 30 캜. 30 g of tetrahydrofuran was added to the residue to dissolve the solution, and the resulting solution was poured into 500 ml of methanol to reprecipitate the product. The solid recovered by suction filtration was washed with methanol and dried under vacuum at 50 캜 to obtain 5.1 g of a polymer having a repeating unit represented by the formula (A-2) (polymer (A-2)) (yield: 64% .

The results of ¹ H-NMR (solvent: CDCl ₃ ) measured on the polymer (A-2) were as follows.

Chemical shift σ: 7.8~6.9ppm (benzene ring, a _{hydrogen, 4H), 6.0~5.6ppm (CH 2} = C H -CH 2 -O, XH), 5.3~4.8ppm (C H 2 = CH-CH 2 - O, 2XH), 4.8~4.3ppm (CH 2 = CH-C H2 -O, 2XH), 4.4~4.0ppm (CH 2 ▽ CH-C H 2 -O, 4YH), 3.2~1.8ppm (C H 2 C H -CH ₂ -O, 6YH)

The above X and Y values were determined from the peak area obtained by the ¹ H-NMR, and as a result, X = 0.58 and Y = 0.42. Thus, the epilization ratio of the allyl group contained in the polymer (A-4) used as the raw material was 42%.

Synthesis Example 4

17.8 g of the polymer (A-2) obtained in Synthesis Example 3, 28 g of methyl isobutyl ketone, 2.1 g of 4-octyloxybenzoic acid and 4 g of UCAT18X (trade name, manufactured by SANA PRO Co., ), And the reaction was carried out at 80 占 폚 for 12 hours with stirring. After completion of the reaction, the reaction mixture was poured into methanol, and the resulting precipitate was collected. The resulting precipitate was dissolved in ethyl acetate to prepare a solution. The solution was washed with water three times and then the solvent was distilled off under reduced pressure, whereby 10% of the epoxy groups contained in the polymer (A-2) To obtain 18.8 g of a polymer (polymer (A-3)) modified with cyclohexylbenzoic acid.

Synthesis Example 5

A 500 mL three-necked flask equipped with a three-way cock equipped with a nitrogen-introducing tube and a stirrer was charged with 27.79 g (0.125 mol) of 1,4-dibutoxybenzene, 0.1 g of di- 0.58 g (0.125 mmol) of bis [(N, N, N ', N'-tetramethylethylenediamine) copper (II)] chloride and 380 mL of 2-methoxyethanol were introduced and stirring was started. Subsequently, 13.7 g of a 31 wt% aqueous hydrogen peroxide solution was added dropwise over 2 hours, and the reaction was carried out at 25 DEG C for 3 hours. After completion of the reaction, the reaction solution was poured into 1,000 mL of distilled water, and the resulting precipitate was collected by filtration. The recovered precipitate was vacuum-dried overnight at 80 캜 to obtain 20.22 g (yield: 73%) of a polymer (A-5) as a gray powder (polymer having a repeating unit represented by the following formula (A-5)).

&Lt; Synthesis Example of Monomer &

Synthesis Example m1

Compound (m-1) was synthesized according to the following reaction scheme m1.

11.0 g of hydroquinone, 55.3 g of 11-bromododecanol, 30.4 g of potassium carbonate and 300 mL of N, N-dimethylacetamide were placed in a 500 mL three-necked flask equipped with a thermometer, reflux tube and nitrogen inlet tube, The reaction was carried out for 5 hours. After completion of the reaction, 300 mL of ethyl acetate and 300 mL of tetrahydrofuran were added to the reaction mixture, and the mixture was washed three times with 1 M hydrochloric acid and three times with water. The organic layer after the washing was concentrated to 100 mL, and then the solution was poured into 1 L of ethanol and precipitated. The precipitate was collected by filtration, and the solvent was removed under reduced pressure to obtain 36.0 g of the compound (m-1a).

Then, 36.0 g of the compound (m-1a) obtained above, 400 mL of tetrahydrofuran and 17.8 g of triethylamine were placed in a 1 L three-necked flask equipped with a thermometer, a dropping funnel and a nitrogen inlet tube, did. Then, a solution obtained by dissolving 18.4 g of methacryloyl chloride in 100 mL of tetrahydrofuran was added dropwise over 1 hour, the temperature of the reaction solution was returned to room temperature, and the reaction was carried out for 2 hours. After completion of the reaction, 400 mL of ethyl acetate was added to the reaction mixture, and the mixture was washed three times with saturated aqueous sodium carbonate solution and three times with water. To the organic layer after washing, 0.04 g of 2,6-di-t-butyl-4-methylphenol was added and the mixture was concentrated to 150 ml. The residue was purified by column chromatography (adsorbent = silica, developing solvent = mixed solvent consisting of hexane and ethyl acetate = 7: 3 (weight ratio)), and the obtained distillate was concentrated under reduced pressure. The precipitated crystals were collected by filtration and the solvent was removed under reduced pressure to obtain 32.9 g of the compound (m-1).

Synthesis Example m2

Compound (m-2) was synthesized according to the following reaction scheme m2.

29.4 g of 4- (4-n-pentylcyclohexyl) cyclohexanecarboxylic acid, 300 mL of thionyl chloride and 0.3 mL of N, N-dimethylformamide were placed in a 500 mL eggplant type flask equipped with a reflux condenser and a nitrogen inlet tube , And the reaction was carried out under reflux for 1 hour. After completion of the reaction, the solvent was removed by an aspirator, and the obtained solid was dissolved in 200 mL of tetrahydrofuran to obtain Solution A.

On the other hand, 22.5 g of the compound (m-1a) obtained in the same manner as in the above step of Synthesis Example m1, 200 mL of tetrahydrofuran, and 10.6 g of tetraethylamine were placed in a 1 L three- g, and the mixture was ice-cooled to 5 DEG C or less. After the solution A adjusted as described above was dropped over 1 hour, the temperature of the reaction solution was returned to room temperature and the reaction was carried out for 2 hours. After completion of the reaction, 400 mL of ethyl acetate was added to the reaction solution, and the solution was washed three times with water. The solution was concentrated under reduced pressure, and the precipitated crystals were collected by filtration and the solvent was removed under reduced pressure to obtain white crystals of the compound (m- 43.9 g.

&Lt; Synthesis Example of Specific Polymer &

Synthesis Example 6

A polymer (polymer (A-6)) having two kinds of repeating units represented by the formula (A-6) was synthesized according to the following Reaction Scheme 3:

(R &lt; ¹ &gt; and R &lt; ² &gt; in the formula (3)

(&Quot; * &quot; in the above formula represents a combined hand)).

(M-1) obtained in Synthesis Example m1 and 4.1 g of the compound (m-1) obtained in Synthesis Example m1 (m-2) obtained in Synthesis Example m1 were added to a 200 ml three-necked flask equipped with a stirrer, ), 0.046 g of di-? -Hydroxy-bis [(N, N, N ', N'-tetramethylethylenediamine) copper (II)] chloride and 70 mL of 2-methoxyethanol, did. Subsequently, 2.2 g of 31% by weight hydrogen peroxide solution was added thereto over 2 hours, and the reaction was carried out at 25 DEG C for 3 hours. After completion of the reaction, the reaction solution was poured into 700 mL of distilled water, and the resulting precipitate was collected by filtration. The collected precipitate was vacuum-dried at 80 占 폚 overnight to obtain 4.8 g of a polymer (A-6) as a gray powder.

&Lt; Synthesis of other polymer >

[Synthesis of polyamic acid]

Synthesis Example PA-1

In a 100 mL four-necked flask equipped with a three-way cock equipped with a nitrogen inlet tube and a stirrer, 4.98 g (50 mol parts) of 4,4'-diaminodiphenylamine as diamine and 4.96 g g (50 moles), 66.35 g of N-methyl-2-pyrrolidone (NMP) was added thereto and stirred while dissolving nitrogen to obtain a diamine solution. While stirring the diamine solution, 9.315 g (95 molar parts) of 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride as a tetracarboxylic acid dianhydride was added, and the reaction was carried out at room temperature for 2 hours with stirring. After completion of the reaction, NMP was added so that the polymer concentration became 15% by weight, and the mixture was stirred at room temperature for 24 hours to obtain a solution containing polyamic acid (PA-1).

The viscosity of the solution containing the polyamic acid (PA-1) obtained above was 910 mPa ((measurement temperature: 25 캜).

Synthesis Example PA-2

In a 100 mL four-necked flask equipped with a three-way cock equipped with a nitrogen inlet tube and a stirrer, 7.60 g (100 mol parts) of 3,5-diaminobenzoic acid as a diamine was charged, 50.71 g of NMP was added thereto, Followed by stirring and dissolution to obtain a diamine solution. While this diamine solution was stirred, 10.361 g (95 molar parts) of pyromellitic dianhydride as tetracarboxylic dianhydride was added and the reaction was carried out at room temperature for 2 hours with stirring. After completion of the reaction, NMP was added to adjust the polymer concentration to 15 wt%, and the mixture was stirred at room temperature for 24 hours to obtain a solution containing polyamic acid (PA-2).

The viscosity of the solution containing the polyamic acid (PA-2) obtained above was 720 mPa · s (measurement temperature: 25 ° C).

Synthesis Example PA-3

0.64 g of 3,5-diaminobenzoic acid 6-methacryloxyhexyl as the diamine, 0.19 g of octadecyloxy-2,4-diaminobenzene, and 1,2,3,4-cyclobutane tetra 0.49 g of carboxylic acid dianhydride was dissolved in 5.26 g of N-methyl-2-pyrrolidone (NMP), and the reaction was carried out at room temperature for 16 hours to obtain a solution containing polyamic acid (PA-3).

[Synthesis of imidized polymer]

Synthesis Example PI-1

2.283 g (50 moles) of 4,4'-diaminodiphenylamine as diamine and 2.271 g (50 moles) of 4,4'-diaminodiphenylmethane as a diamine, and bicyclo [3.3.0] octane -2,4,6,8-tetracarboxylic acid 2: 4, 5.446 g (95 molar parts) of 6,6: 8-2 anhydride was dissolved in 40 g of NMP and the reaction was carried out at room temperature for 6 hours with stirring to obtain a polyamic acid- Solution.

Subsequently, 50 g of NMP was added to the obtained solution, and then 2.52 g of pyridine (1.5 molar parts with respect to one molar part of the polyamic acid) and 3.26 g of acetic anhydride (1.5 molar parts with copper) were added. The reaction was carried out. After completion of the reaction, the reaction mixture was poured into a large excess of methanol to precipitate the reaction product. The recovered precipitate was washed with methanol, and the solvent was removed under reduced pressure at 40 占 폚 for 15 hours to obtain an imidized polymer (PI-1) having an imidization rate of 50%.

This imidized polymer (PI-1) was provided as an NMP solution having a concentration of 15% by weight in the preparation of a liquid crystal aligning agent described later. The viscosity of the NMP solution (concentration 15% by weight) was 350 mPa · s (measurement temperature: 25 ° C).

Synthesis Example PI-2

In the reaction vessel, 8.93 g of 4,4'-diaminodiphenylamine as a diamine and 2.22 g of 4,4'-diaminodiphenylmethane were placed and dissolved in 108.54 g of N-methyl-2-pyrrolidone. To this was added 13.52 g of bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic dianhydride as tetracarboxylic acid dianhydride and further adding N-methyl-2-pyrrolidone To give a monomer concentration of 12% by weight. This solution was reacted at 50 占 폚 overnight with stirring to obtain a solution containing polyamic acid.

To the solution was added 4.04 g of pyridine (1.0 molar parts with respect to one molar part of the polyamic acid acid) and 5.21 g of acetic anhydride (1.0 molar equivalents with copper), followed by dehydration ring closure reaction at 110 DEG C for 4 hours. After completion of the reaction, the reaction mixture was poured into a large excess of methanol to precipitate the reaction product. The recovered precipitate was washed with methanol, and the solvent was removed under reduced pressure at 40 占 폚 for 15 hours to obtain an imidized polymer (PI-2) having an imidation rate of 50%.

[Synthesis of polyamic acid ester]

Synthesis Example PE-1

0.71 g (50 moles) of 4,4'-diaminodiphenylamine and 0.72 g (50 moles) of 4,4'-diaminodiphenylmethane as diamine, 1.4 ml of pyridine as a base and 71 ml of NMP as a solvent were dissolved and dissolved , To obtain a diamine solution. 2.08 g (97 molar parts) of dimethyl-1,3-bis (chlorocarbonyl) cyclobutane-2,4-carboxylate was added to this solution while stirring with water, and further a solid content concentration of 5 wt% NMP was added so as to conduct the reaction under stirring with water for 4 hours. After completion of the reaction, the reaction solution was poured into 250 g of water, and the precipitated polymer was recovered by suction filtration. The recovered polymer was washed one time with 250 mL of water and three times with 63 g of methanol, and then dried for 5 hours under a reduced pressure of 40 DEG C to obtain 2.8 g of a polyamic acid ester (PE-1) in powder form. The polyamic acid ester (PE-1) had a weight average molecular weight Mw of 23,000.

This polyamic acid ester (PE-1) was provided as an NMP solution having a concentration of 15% by weight in the preparation of the liquid crystal aligning agent described later.

[Synthesis of polyorganosiloxane]

Synthesis Example PS-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 added dropwise over 30 minutes from the dropping funnel, 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 an aqueous 0.2 wt% 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 To give a crude transparent liquid. As a result of ¹ H-NMR analysis of the polyorganosiloxane, it was confirmed that a peak based on the epoxy group was obtained in the vicinity of the chemical shift (?) = 3.2 ppm as the theoretical intensity, and no side reaction of the epoxy group occurred during the reaction . The polyorganosiloxane thus obtained had a weight average molecular weight Mw of 3,500 and an epoxy equivalent of 180 g / mol.

Then, 10.0 g of the above-obtained polyorganosiloxane having an epoxy group, 30.28 g of methyl isobutyl ketone, 3.98 g of 4-dodecyloxybenzoic acid and UCAT 18X (trade name, manufactured by SANA PRO Co., Ltd.) were added to a 200 mL three- , And the reaction was carried out at 100 占 폚 for 48 hours with stirring. After completion of the reaction, ethyl acetate was added to the reaction mixture, which was then washed with water three times. The organic layer was dried over magnesium sulfate and then the solvent was distilled off to obtain 9.0 g of a polyorganosiloxane (PS-1). The weight average molecular weight Mw of the obtained polyorganosiloxane (PS-1) was 9,900.

&Lt; Preparation and evaluation of liquid crystal aligning agent >

Example 1

[Preparation of liquid crystal aligning agent]

The polymer (A-1) obtained in Synthesis Example 1 was dissolved in 2-methoxyethanol as a solvent to prepare a solution having a polymer concentration of 5% by weight. This solution was filtered with a filter having a pore diameter of 0.2 탆 to prepare a liquid crystal aligning agent.

[Evaluation of liquid crystal aligning agent]

1. Evaluation of applicability

The liquid crystal aligning agent prepared above was coated on a glass substrate using a spinner and prebaked on a hot plate at 80 DEG C for 1 minute and then heated in an oven at 200 DEG C in which the inside of the chamber was replaced by nitrogen for 1 hour ) To form a coating film having an average film thickness of 1,000 ANGSTROM. The coating film was observed with an atomic force microscope (AFM) to measure the center average roughness (Ra).

When the Ra value is less than 1.0 nm, the coating property of the liquid crystal aligning agent is "good". When the Ra value is less than 1.0 nm, the coating property is "possible" when the Ra value is less than 1.0 nm and less than 5.0 nm.

The evaluation results are shown in Table 1.

2. Production of liquid crystal cell (Production of FFS type liquid crystal cell)

A glass substrate (electrode substrate) on which electrodes of two systems (electrode A 101 and electrode B 102) made of chromium having a comb-like pattern shown in Fig. 2 are formed and a glass substrate (Opposite substrate) was used as a pair of substrates, and the liquid crystal aligning agent was applied to one surface of the electrode-formed surface of the electrode substrate and one surface of the opposite substrate using a spinner and heated at 80 DEG C for 1 minute ) And 230 DEG C for 1 hour (post-baking) to form a coating film having a thickness of 1,000 ANGSTROM. Each of these coating films was subjected to a rubbing treatment with a rubbing machine having a roll covered with rayon cloth at a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / sec, and a hair pressing indentation length of 0.1 mm. Thereafter, ultrasonic cleaning was performed for 1 minute in ultrapure water, and then dried in a 100 占 폚 clean oven for 10 minutes to obtain two substrates having a liquid crystal alignment film.

Next, after the liquid crystal injection hole was left on the outer peripheral edge of the liquid crystal alignment film formation surface of the counter substrate, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 占 퐉 was screen-printed and then the liquid crystal alignment film formation surface was opposed, A pair of substrates were superimposed on each other so as to coincide with the projection direction of the substrate to the substrate surface, and the substrates were heated and pressed at 150 DEG C for 1 hour to thermally cure the adhesive.

Subsequently, a nematic liquid crystal (MLC-6221, manufactured by Merck Ltd.) was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to eliminate the flow orientation at the time of injecting the liquid crystal, the liquid crystal cell was heated to 150 DEG C and gradually cooled to room temperature to produce an FFS type liquid crystal cell.

Three liquid crystal cells are manufactured in total, one of which is referred to as "(1) evaluation of liquid crystal orientation property" and "(2) evaluation of residual DC voltage (normal condition) Evaluation of Residual DC Voltage (Critical Condition) &quot;, and the other one in "(4) Evaluation of Voltage Conservation Rate" and "(5) Evaluation of Reliability", respectively.

3. Evaluation of Liquid Crystal Cell

(1) Evaluation of liquid crystal alignment property

With respect to the liquid crystal cell prepared above, the presence or absence of an abnormal domain when a voltage of 5 V AC was turned on / off (applied / released) was observed with a polarizing microscope.

When the abnormal domain was not observed, the liquid crystal alignment property was evaluated as &quot; good &quot;, and when the abnormal domain was observed in any of the display areas, the liquid crystal alignment property was evaluated as & .

(2) Evaluation of residual DC voltage (normal condition)

A rectangular wave of 30 Hz, 3 V, in which DC 10 V was superimposed on the liquid crystal cell prepared above was applied for 20 hours at an environmental temperature of 25 캜 and the voltage remaining in the liquid crystal cell immediately after the DC voltage was cut off was measured by a flicker elimination method The residual DC voltage was found to be 120..

When the evaluation value of the residual DC voltage is 300 volts or less, the residual DC voltage in the normal condition of the liquid crystal cell is &quot; good &quot;, and when the value exceeds 300 volts and less than 500 volts, , And the residual DC voltage under normal conditions when it is 500 ㎷ or more can be considered as &quot; defective &quot;.

(3) Evaluation of residual DC voltage (severe condition)

Except that the voltage of the superposing direct current and the application temperature and time of the direct current superimposed rectangular wave are set to 20V, 100 ° C, and 500 hours, respectively, in the above "(2) Evaluation of Residual DC Voltage (Normal Condition) In the same manner, the residual DC voltage was found to be 200..

When the evaluation value of the residual DC voltage is equal to or less than 300 volts, the residual DC voltage in a severe condition of the liquid crystal cell is &quot; good &quot;. When the voltage exceeds 300 volts and less than 500 volts, , And the residual DC voltage in the severe condition when it is 500 ㎷ or more can be considered as &quot; defective &quot;.

(4) Evaluation of Voltage Conservation Rate

A voltage of 5 V was applied to the liquid crystal cell manufactured in the above-described manner at an application time of 60 microseconds and a span of 167 milliseconds, and the voltage maintenance ratio (initial voltage maintenance ratio VHR _BF ) after 167 milliseconds after the application was released was 92 %. As the measuring apparatus, &quot; VHR-1 &quot; manufactured by Toyo Technica Co., Ltd. was used.

When the value of the initial voltage holding ratio VHR _BF is 95% or more, the voltage holding ratio of the liquid crystal cell is "good", the voltage holding ratio is "possible" when the initial voltage holding ratio is 90% or more and less than 95% .

(5) Evaluation of reliability

The liquid crystal cell after the measurement of the initial voltage holding ratio was kept in an oven at 100 캜 for 300 hours. Thereafter, the liquid crystal display element was allowed to stand at room temperature and allowed to cool to room temperature. Thereafter, the voltage holding ratio was measured in the same manner as in "(4) Evaluation of voltage holding ratio" (voltage holding ratio after stress application VHR _AF ).

Then, the stress-applied voltage holding ratio VHR _AF and the initial voltage holding ratio VHR _BF were substituted into the following equation (2), and the rate of change of the voltage holding ratio (VHR (%)) was determined.

VHR (%) = ((VHR _BF - VHR _AF ) / VHR _BF ) 100 (2)

When the value of DELTA VHR is 10% or less, the reliability of the liquid crystal cell is "good". When the value of DELTA VHR is 10% or less, the reliability is "possible" when it is more than 10% and 20% or less.

The evaluation results are shown in Table 2.

Example 2

Except that propylene glycol-1-monomethyl ether-2-acetate was used as a solvent and the polymer (A-2) obtained in Synthesis Example 3 was used as a polymer in the preparation of the liquid crystal aligning agent of Example 1, A liquid crystal aligning agent was prepared in the same manner as in Example 1, and various evaluations were carried out.

The evaluation results are shown in Table 1 and Table 2.

Example 3

[Preparation of liquid crystal aligning agent]

The polymer (A-3) obtained in Synthesis Example 4 was dissolved in a mixed solvent (NMP: BC = 50: 50 (weight ratio)) consisting of NMP and butyl cellosolve (BC) did. This solution was filtered with a filter having a pore size of 0.2 탆 to prepare a liquid crystal aligning agent.

[Evaluation of liquid crystal aligning agent]

1. Evaluation of applicability

Quot; 1 &quot; Evaluation of Coating Properties &quot;, the coating properties of the liquid crystal aligning agent were evaluated.

The evaluation results are shown in Table 1.

2. Production of liquid crystal cell (Production of TN type liquid crystal cell)

The liquid crystal aligning agent prepared above was coated on the transparent electrode surface of a glass substrate having a transparent electrode made of an ITO film by using a liquid crystal alignment film printing machine (manufactured by Nippon Sha Sein Insights Co., Ltd.) After the solvent was removed by heating (prebaking) for a minute, the film was heated on a hot plate at 150 ° C for 10 minutes (post baking) to form a coating film having a thickness of 1,000 Å. The coating film was subjected to a rubbing treatment with a rubbing machine having a roll covered with a rayon cloth at a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / sec, and a piercing indentation length of 0.1 mm. Thereafter, the substrate was ultrasonically cleaned in ultrapure water for 1 minute and then dried in a 100 ° C clean oven for 10 minutes to obtain a substrate having a rubbed coating film. This operation was repeated to obtain a pair of substrates (two pieces) each having a rubbed coating film.

Next, after an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 占 퐉 was applied to the outer edge of the surface having one rubbed coating film out of the above-described pair of substrates, They were superposed and squeezed, and the adhesive was cured. Then, a nematic liquid crystal (MLC-6221, manufactured by Merck Ltd.) was filled between a pair of substrates from the liquid crystal injection port, and then a liquid crystal injection hole was sealed with an acrylic photo-curable adhesive to produce a TN type liquid crystal cell.

3. Evaluation of Liquid Crystal Cell

The liquid crystal cell prepared above was subjected to various evaluations in the same manner as in Example 1.

The evaluation results are shown in Table 2.

Example 4

[Preparation of liquid crystal aligning agent]

The polymer (A-4) obtained in Synthesis Example 2 was dissolved in a mixed solvent (NMP: BC = 50: 50 (weight ratio)) consisting of NMP and butyl cellosolve (BC) did. This solution was filtered with a filter having a pore size of 0.2 탆 to prepare a liquid crystal aligning agent.

[Evaluation of liquid crystal aligning agent]

1. Evaluation of applicability

Quot; 1 &quot; Evaluation of Coating Properties &quot;, the coating properties of the liquid crystal aligning agent were evaluated.

The evaluation results are shown in Table 1.

2. Production of liquid crystal cell (Production of VA type liquid crystal cell)

2 &quot; (Manufactured by Merck Co., Ltd., MLC-6608 (manufactured by Mitsubishi Kagaku Kogyo Co., Ltd.) as the liquid crystal aligning agent, without using the rubbing treatment after the coating film formation and using the liquid crystal aligning agent prepared above as the liquid crystal aligning agent ), A VA type liquid crystal cell was produced in the same manner as in Example 3. [

3. Evaluation of Liquid Crystal Cell

The liquid crystal cell prepared above was subjected to various evaluations in the same manner as in Example 1.

The evaluation results are shown in Table 2.

Example 5

In the preparation of the liquid crystal aligning agent of Example 1, a polymer (A-5) obtained in Synthesis Example 5 was used as a polymer and a mixed solvent (NMP: BC = 50: 50 ) Was used in place of the liquid crystal aligning agent, and various evaluations were carried out.

The evaluation results are shown in Table 1 and Table 2.

Example 6

[Preparation of liquid crystal aligning agent]

(A-1) obtained in Synthesis Example 1 was added to 33.3 parts by weight (5 parts by weight in terms of polyamic acid (PA-1)) of the solution containing polyamic acid (PA-1) obtained in Synthesis Example PA- And further diluted by adding NMP and BC to obtain a solution in which the total concentration of the polymer was 5% by weight and the solvent composition was NMP: BC = 50: 50 (weight ratio). This solution was filtered with a filter having a pore size of 0.2 탆 to prepare a liquid crystal aligning agent.

[Evaluation of liquid crystal aligning agent]

Various evaluations were carried out in the same manner as in Example 1, except that the liquid crystal aligning agent prepared above was used.

The evaluation results are shown in Table 1 and Table 2.

Example 7

[Preparation of liquid crystal aligning agent]

50 parts by weight of the polymer (A-4) obtained in Synthesis Example 2 and 50 parts by weight of the imidation polymer (PI-1) obtained in Synthesis Example PI-1 were mixed in a mixed solvent of NMP and BC (NMP: BC = 50: 50 (weight ratio)) to obtain a solution having a total concentration of the polymer of 5% by weight. This solution was filtered with a filter having a pore size of 0.2 탆 to prepare a liquid crystal aligning agent.

[Evaluation of liquid crystal aligning agent]

Various evaluations were carried out in the same manner as in Example 1, except that the liquid crystal aligning agent prepared above was used.

The evaluation results are shown in Table 1 and Table 2.

Examples 8 and 9

A liquid crystal aligning agent was prepared in the same manner as in Example 7 except that a polymer of the type and the amount described in Table 1 was used in the preparation of the liquid crystal aligning agent of Example 7, and various evaluations were carried out.

The evaluation results are shown in Table 1 and Table 2.

Comparative Examples 1 and 2

[Preparation of liquid crystal aligning agent]

NMP and BC were added to a solution containing the polymer obtained in the above Synthesis Example using a polymer of the type shown in Table 1 to dilute the polymer so that the total concentration of the polymer was 5 wt% and the solvent composition was NMP: BC = 50: 50 (weight ratio). This solution was filtered with a filter having a pore size of 0.2 탆 to prepare a liquid crystal aligning agent.

[Evaluation of liquid crystal aligning agent]

Various evaluations were carried out in the same manner as in Example 1, except that the liquid crystal aligning agent prepared above was used.

The evaluation results are shown in Table 1 and Table 2.

Comparative Examples 3 to 5

[Preparation of liquid crystal aligning agent]

The polymers shown in Table 1 were dissolved in a mixed solvent of NMP and BC in the mixing ratios shown in Table 1, respectively, to obtain a solution having a total concentration of 5 wt% of the polymer. This solution was filtered with a filter having a pore size of 0.2 탆 to prepare liquid crystal aligning agents.

[Evaluation of liquid crystal aligning agent]

Various evaluations were carried out in the same manner as in Example 1, except that the liquid crystal aligning agent prepared above was used.

The evaluation results are shown in Table 1 and Table 2.

Examples 10 to 12

[Preparation of liquid crystal aligning agent]

The polymers shown in Table 1 were mixed at the weight ratios shown in Table 1 and dissolved in the solvent or mixed solvent shown in Table 1 to obtain a solution having a total polymer concentration of 5% by weight. This solution was filtered with a filter having a pore size of 0.2 탆 to prepare liquid crystal aligning agents.

[Evaluation of liquid crystal aligning agent]

1. Evaluation of applicability

The evaluation of the coatability of the liquid crystal aligning agent prepared as described above was carried out in the same manner as in Example 1.

The evaluation results are shown in Table 1.

2. Preparation of liquid crystal cell (Preparation of PSA type liquid crystal cell)

The liquid crystal aligning agent prepared above was patterned in the form of a slit as shown in Fig. 3, and a liquid crystal alignment film printer (Nippon Shishin Insetsu Co., Ltd. (Post-baking) on a hot plate at 80 DEG C for 1 minute to remove the solvent, and then heated (post baking) on a hot plate at 150 DEG C for 10 minutes to obtain a coating film having an average film thickness of 600 ANGSTROM . This coating film was ultrasonically cleaned in ultrapure water for 1 minute and then dried in a 100 ° C clean oven for 10 minutes to obtain a substrate having a liquid crystal alignment film. This operation was repeated to obtain a pair of substrates (two substrates) each having a liquid crystal alignment film.

Subsequently, with respect to one of the pair of substrates, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 mu m was applied to the outer edge of the surface having the liquid crystal alignment film, and then the liquid crystal alignment film surface was opposed to the pair of substrates And pressed to adhere to each other to cure the adhesive. Subsequently, a nematic liquid crystal (MLC-6608, manufactured by Merck Ltd.) was charged between a pair of substrates from the liquid crystal injection port, and then a liquid crystal injection hole was sealed with an acrylic-based photo-curable adhesive to produce a PSA type liquid crystal cell.

3. Evaluation of Liquid Crystal Cell

(1) Evaluation of response speed

After sandwiching each of the liquid crystal cells prepared above with two polarizing plates arranged in a cross-Nicol state, a visible light lamp was irradiated without applying a voltage at first, and the luminance of light transmitted through the liquid crystal cell was measured by a photomulti meter, This value was regarded as 0% relative transmittance. Next, the transmittance when an alternating current of 60 V was applied for 5 seconds between the electrodes of the liquid crystal cell was measured in the same manner as above, and the relative transmittance was set to 100%.

At this time, when the alternating current of 60 V was applied to each liquid crystal cell, the time until the relative transmittance was shifted to 10% to 90% was measured, and this time was defined as a response speed and evaluated.

The evaluation results are shown in Table 3.

(2) Other evaluation

Other evaluations were carried out in the same manner as in Example 1. [

The evaluation results are shown in Table 3.

Comparative Example 6

[Preparation of liquid crystal aligning agent]

NMP and BC were added to the solution containing the polyamic acid (PA-3) obtained in the above Synthesis Example PA-3 and diluted so that the total concentration of the polymer was 5% by weight and the solvent composition was NMP: BC = 50:50 Weight ratio) solution. This solution was filtered with a filter having a pore size of 0.2 탆 to prepare a liquid crystal aligning agent.

[Evaluation of liquid crystal aligning agent]

Various evaluations were carried out in the same manner as in Examples 10 to 12 except that the liquid crystal aligning agent prepared above was used.

The evaluation results are shown in Tables 1 and 3.

Claims (6)

A liquid crystal aligning agent characterized by containing polyarylene. The method according to claim 1,
Wherein the polyarylene is a polymer having a repeating unit represented by the following formula (P):

(In the formula (P), Ar is an n + 2 valent aromatic group, n is 1 or 2,
X in each repeating unit independently represents a single bond, an oxygen atom, a sulfur atom, a carbonyl group, an ester bond, a thioester bond, -NR- or -CONR- (wherein R represents a hydrogen atom or a carbon atom Lt; / RTI &gt; alkyl group)
R ⁰¹ in each repeating unit independently represents a group having a hydrogen atom, a hydroxyl group, a group having a terminal C═C double bond, a group having a carbon-carbon triple bond, a group having an epoxy group, A group which generates a crosslinking reaction or an isomerization reaction by light irradiation). 3. The method of claim 2,
Wherein the polyarylene is a polymer having at least one repeating unit selected from the repeating units represented by the following formulas (P-1) and (P-2)

(In the formulas (P-1) and (P-2), X and R ⁰¹ are the same as those in the formula (P)). 3. The method of claim 2,
In the polyarylene, at least one of R ⁰¹ is a group having a hydroxyl group, a group having a terminal C═C double bond, a group having a carbon-carbon triple bond, a group having an epoxy group, a group having a function of orienting liquid crystal molecules, Or a group which generates a crosslinking reaction or an isomerization reaction. A liquid crystal alignment film formed from the liquid crystal aligning agent according to any one of claims 1 to 4. A liquid crystal display element comprising the liquid crystal alignment film according to claim 5.

Images