JP6451941B2 - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent. In detail, a liquid crystal alignment film excellent in applicability (printability) that can form a highly reliable liquid crystal alignment film that has little decrease in voltage holding ratio over a long period of time, does not cause an afterimage even under severe use conditions. It relates to an alignment agent.

Liquid crystal display elements can be classified into various modes depending on the electrode structure and the physical properties of the liquid crystal molecules used. For example,
For example, a liquid crystal alignment film is formed on the surface of a substrate provided with a transparent conductive film to form a substrate for a liquid crystal display element, and two of them are arranged to face each other and a nematic liquid crystal layer having positive dielectric anisotropy in the gap A so-called TN (Twisted Nematic) type (Patent Document 1) in which the long axis of liquid crystal molecules is continuously twisted by 90 ° from one substrate toward the other substrate.
STN (Super Twisted Nematic) type (Patent Document 2) capable of realizing a high duty ratio as compared with a TN type liquid crystal display element;
A VA (Vertical Alignment) type (Patent Document 3) in which a layer of nematic liquid crystal having negative dielectric anisotropy is injected into the gap and the liquid crystal is aligned substantially perpendicular to the substrate (Patent Document 3);
An IPS (In-Plane Switching) type in which the driving direction of the liquid crystal when the electric field is applied is only in the in-plane direction of the substrate by arranging the electrode pairs in a comb-like shape on one substrate surface (Patent Documents 4 and 5) ;
FFS (Fringe Field Switching) type (Patent Document 6) in which luminance is improved by changing the electrode structure of the IPS type to increase the aperture ratio of the display element portion;
OCB (Optical Compensated Bend) type that has low viewing angle dependency and excellent high-speed response of the video screen (Patent Document 7)
Such liquid crystal display devices are known.

As materials for the liquid crystal alignment film in these various liquid crystal display elements, 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 and mechanical strength. Because of its excellent affinity with liquid crystals, it is used in many liquid crystal display elements (Patent Document 8).
In such a liquid crystal aligning agent, in recent years, improvement in applicability (printability) and improvement in reliability (long-term stability against harsh environments) have been increasingly demanded. The circumstances are as follows.
Compared to notebook computers, monitor displays, and the like, which have been the main applications of conventional liquid crystal display elements, liquid crystal televisions, which have become increasingly popular in recent years, have a long replacement cycle and are originally required to have a long life. For example, in the case of a liquid crystal television application and the like, it is designed on the assumption that the service life exceeds 10 years, and driving for an extremely long time is planned compared with the use of a conventional liquid crystal display element. At the same time, in order to increase the size of the liquid crystal display element and display with high definition, the illumination intensity of the backlight tends to be high, and the 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 element for use in a liquid crystal projector, which has been increasingly demanded as a home theater in recent years, a light source having a very high irradiation intensity such as a metal halide lamp is used. In addition, liquid crystal display elements for mobile devices such as mobile phones and in-vehicle car navigation systems need to increase the brightness of the backlight in order to improve the visibility under sunlight including strong ultraviolet rays, so that the deterioration is further accelerated. Is concerned. When these devices are used as a display for a video game, it is assumed that they are placed under continuous driving for an extremely long time under the above-described conditions.
As described above, liquid crystal display devices are exposed to harsh environments such as high-intensity light irradiation and long-time driving, which have not been conceived in the past, due to versatility. There is a demand for uniform film thickness and long life.

JP-A-4-153622 JP 60-107020 A Japanese Patent Laid-Open No. 11-258605 JP 56-91277 A US Pat. No. 5,928,733 JP 2002-082357 A JP-A-9-105957 Japanese Patent Laid-Open No. 62-165628

  The present invention has been made in view of the above circumstances, and its purpose is to provide a highly reliable liquid crystal alignment film that has little decrease in voltage holding ratio over a long period of time and does not cause an afterimage even under severe use conditions. Another object of the present invention is to provide a liquid crystal aligning agent that can be formed and is excellent in applicability (printability).

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 includes a structure in which a plurality are linked directly bonded arylene group that is replacement, is a polymer having a repeating unit represented by the following formula (P).

(In the formula (P), Ar is an n + divalent aromatic group, n is 1 or 2,
X in each repeating unit is independently 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 a carbon atom of 1 to 6). Is an alkyl group of
R ⁰¹ in each repeat unit are independently a hydrogen atom, end end C = C group having a double bond, a group having a carbon-carbon triple bond, a group having an epoxy group, a function of aligning liquid crystal molecules And a group that causes a crosslinking reaction or an isomerization reaction upon irradiation with light. )

According to the present invention, there is provided a liquid crystal aligning agent capable of forming a liquid crystal alignment film excellent in reliability, in which there is little decrease in voltage holding ratio over a long period of time and no afterimage is generated even under severe use conditions. Since this liquid crystal aligning agent is excellent also in applicability | paintability (printability), the yield of a liquid crystal aligning film formation process is high, and it contributes to reduction of a liquid crystal display element manufacturing cost.
The liquid crystal display element of the present invention having a liquid crystal alignment film formed from the above liquid crystal aligning agent does not deteriorate display quality over a long period of time. Therefore, the technology 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.

2 is an infrared spectrum of polyarylene obtained in Synthesis Example 1. It is the schematic which shows an example of the pattern of the electrode in the liquid crystal cell manufactured in the Example. It is the schematic which shows another example of the pattern of the electrode in the liquid crystal cell manufactured in the Example.

As described above, the liquid crystal aligning agent of the present invention contains polyarylene.
<Polyarylene>
The polyarylene in the present invention is mainly composed of a polyarylene having a structure in which a plurality of arylene groups are directly bonded and connected, and a divalent group other than the arylene group is bonded and connected between the plurality of arylene groups. It is a concept including a chain structure such as polyarylene ether, polyarylene sulfide, polyarylene alkenylene, and a block copolymer composed of two or more of these. The arylene group in the above 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 and linked. Particularly preferably, it is a polyarylene having a structure in which a plurality of optionally substituted naphthalene groups are directly bonded and connected, and in particular, a polyarylene having a repeating unit represented by the above formula (P). preferable. In the above formula (P), n is 1 or 2, and Ar is an (n + 2) -valent aromatic group. That is, Ar is a trivalent aromatic group when n is 1, and is a tetravalent aromatic group when n is 2. Moreover, Ar in each repeating unit may be the same or different.
In the above formula (P), X in each repeating unit is independently a single bond, oxygen atom, sulfur atom, carbonyl group, ester bond, thioester bond, -NR- or -CONR-. is there. Here, R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Further, in the above formula (P), R ⁰¹ in each repeating unit having each independently hydrogen atom, end end C = C group having a double bond, a group having a carbon-carbon triple bond, an epoxy group A group having a function of aligning liquid crystal molecules, or a group that causes a crosslinking reaction or an isomerization reaction by light irradiation.
More preferably, it is a polyarylene having a structure in which 5 or more (preferably 10 or more) of repeating units represented by the above formula (P) are directly bonded and linked,
Most preferably, it is a polyarylene consisting only of the repeating unit represented by the above formula (P).

At least one of R ⁰¹ in each repeat unit, a group having an end edge C = C double bonds, groups having carbon-carbon triple bond, a group having an epoxy group, a group having a function of aligning liquid crystal molecules and Ru is selected from the group caused a crosslinking reaction or isomerization reaction by the light irradiation.
Specific examples of R in the above -NR- and -CONR- include a methyl group, an ethyl group, a propyl group, and the like.
When R ⁰¹ is a group having a terminal C═C double bond, examples of the substituent —X—R ⁰¹ in the above 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 —X—R ⁰¹ in the above formula (P1) include a glycidyloxy group, a 2,3-cyclohexyl epoxy group, and a 3,4-cyclohexyl epoxy group. Can be mentioned.
The liquid crystal alignment 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 orientation group include a group represented by the following formula (D).

(In the formula (D), ^{R I} is the carbonization of 17-51 carbon atoms and having an alkyl group of 1 to 40 carbon atoms, fluoroalkyl group having 1 to 40 carbon atoms, or a cyano group or a fluorine atom, or a steroid skeleton A hydrogen group;
Z ^I represents a single ^bond, + ^-O-, + -COO- or ⁺ -OCO- (where bond marked with "+" is ^{R I} side.); And
R ^II represents a cyclohexylene group or a phenylene group, provided that the cyclohexylene group or phenylene group may be substituted with 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, the two R ^IIs may be the same or different from each other;
n2 is 0 or 1;
Z ^II is a single ^bond, + ^-O-, + -COO- or ⁺ -OCO- (where bond marked with "+" is ^{R I} side.); And
n3 is an integer from 0 to 2;
n4 is 0 or 1; and “*” represents a bond. )

Examples of the alkyl group having 1 to 40 carbon atoms of R ^I in formula (D), is preferably a straight-chain, specifically, for example, methyl group, ethyl group, n- propyl group, n- butyl radical, n -Pentyl group, n-hexyl group, n-octyl group, n-decyl group, n-dodecyl group, n-hexadecyl group, stearyl group and the like;
As a C1-C40 fluoroalkyl group, a linear thing is preferable, and specifically, for example, 3-trifluoromethylpropyl group, 4-trifluoromethylbutyl group, 6-trifluoromethylhexyl group, 10- Trifluoromethyldecyl group, 3-pentafluoroethylpropyl group, 4-pentafluoroethylbutyl group, 8-pentafluoroethyloctyl group, 3,3,4,4,5,5,5-heptafluoropentyl group, 3 , 3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl group, 3,3,4,4,5,5,6,6,7,7 , 8, 8, 9, 9, 10, 10, 10-heptadecafluorodecyl group and the like;
Examples of the 17-51 hydrocarbon group having a steroid skeleton include, for example, 3-cholestanyl group, 3-cholestenyl group, 3-lanostanyl group, 3-colanyl group, 3-pregnal group, 3-androstanyl group, and 3-estranyl. Each group can be mentioned.

When R ^I is an alkyl group and both n2 and n4 are 0, the R ^I alkyl group is preferably a linear alkyl group having 4 to 40 carbon atoms.
In the formula (D), as the divalent group represented _by- (R ^II ) _n1- , when n1 is 1, for example, a 1,4-phenylene group, a 1,4-cyclohexylene group and the like;
As a case where n1 is 2, for example, a 4,4′-biphenylene group, a 4,4′-bicyclohexylene group, a group represented by each of the following formulas, and the like can be mentioned as preferable examples.

(In the above formula, a bond marked with "+" is R ^I side.
In the above formula (D), n3 is preferably 2.
In the above formula (D), n2 it is preferred either a 1 or n2 is a 0 ^{R I} is a hydrocarbon group having 17 to 51 carbon atoms having a steroid skeleton.
The photoreactive group is a group that causes 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).

(In the formula (E), d is 0 or 1;
A ¹ and A ² are each 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 “*” represents a bond. )
A ¹ and A ² in the above formula (E) are each preferably an alkoxy group having 1 to 6 carbon atoms. e and f are each preferably 0.
The group represented by the above 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 one of the bonds in the formula (E) to form a monovalent group as a whole. Further, it is preferable to bond to the main chain skeleton of polyarylene by another bond. Specific examples of such groups include groups represented by the following formulas, for example.

(In the above formula, R ¹ is a hydrogen atom, a monovalent organic group having 3 to 40 carbon atoms including 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;
“*” Represents a bond. )
When the polyarylene has at least one 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. Therefore, it is suitable for application to an FFS type liquid crystal display element. In order to express this function effectively,
When the polyarylene has a group having a terminal C═C double bond, the content of the terminal C═C double bond 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 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. Also when the polyarylene has a group having a terminal C═C double bond and an epoxy group in an overlapping manner within the above range, it is also suitable for use in an FFS type liquid crystal display device.
When the polyarylene has a liquid crystal alignment group, the liquid crystal aligning agent containing the polyarylene can be preferably applied to the production of a vertical alignment type liquid crystal display element. In order to effectively express this function, the content ratio of the liquid crystal aligning group in the polyarylene is preferably 0.0001 mol / g-polymer or more, and is preferably 0.0005 to 0.025 mol / g-. More preferably, it is a polymer.
Further, 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 a photoalignment method. In order to effectively express this function, the content ratio of the liquid photoreactive group in the polyarylene is preferably 0.0001 mol / g-polymer or more, preferably 0.0005 to 0.025 mol / g. -More preferably a polymer.
The polyarylene contained in the liquid crystal aligning agent of the present invention may have two or more 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 repeating units represented by the following formulas (P-1) and (P-2).

(In the formulas (P-1) and (P-2), X and R ⁰¹ have the same meanings as in the above formula (P).)
In the polyarylene, there are a plurality of repeating units selected from the repeating units represented by each of the formulas (P-1) and (P-2). The substituents —X—R ^{01 in} may be the same or different.
For 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 1,000. 500,000.

The polyarylene as described above can be synthesized by a known method.
For example, polyarylene composed of a repeating unit represented by the above formula (P-1) is made from naphthalene dihalide having a desired substituent —XR ⁰¹ as a raw material, and the presence of a transition metal complex (for example, a zerovalent nickel complex). Polymer chain growth reaction performed below;
Polymer chain growth reaction carried out in the presence of a divalent nickel complex after one of the halogen atoms of naphthalene dihalide having the desired substituent —XR ⁰¹ is Grignated;
Naphthalene dihalide having the desired substituent -XR ¹ ;
Starting from a compound in which two of a trialkyltin group (R ₃ Sn-, R is an alkyl group) or a dialkoxyboron group ((RO) ₂ B-, R is an alkyl group) is introduced into the naphthalene And a polymer chain growth reaction carried out in the presence of a zerovalent palladium complex;
It can be synthesized by an appropriate method such as a polymer chain growth reaction performed using dihydroxynaphthalene having a desired substituent —XR ¹ as a raw material in the presence of a copper (II) complex.
A polyarylene having a main chain structure having a divalent group other than an arylene group is, for example, other co-polymers that give a divalent group other than an arylene group during the polymer chain growth reaction. It can be produced in the presence of a polymerizable monomer.
For the polyarylene obtained by any of the above methods, a reaction in which this is chemically converted using the reactivity of the substituent can be preferably applied.
For example, a polyarylene having a hydroxyl group as a substituent can be obtained by reacting with a halogenated hydrocarbon compound having a desired group after the hydroxyl group is converted to an alkali metal salt. . By this method, for example, a polyarylene having an allyloxy group as a substituent can be obtained. A polyarylene having a group having a C═C double bond as a substituent can be obtained by oxidizing the C═C double bond with, for example, a peracid to obtain a polyarylene having an epoxy group. A polyarylene having a desired group can also be obtained by further reacting the polyarylene having an epoxy group with a carboxylic acid or the like.
Those skilled in the art can easily set preferable conditions for the above reaction by a few preliminary experiments.

Examples of naphthalene derivatives having a phenolic hydroxyl group for giving a repeating unit represented by the above formula (P-1) include 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-methyl-1-hydroxynaphthalene, and 6-phenyl. 2-hydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2, Examples include 8-dihydroxynaphthalene and 3-methyl-2,6-dihydroxynaphthalene. The naphthalene derivative having a phenolic hydroxyl group may be used alone or in combination of two or more.
Moreover, as a compound for giving the repeating unit represented by the said Formula (P-2), a phenol, p-isopropenyl phenol, an ethynyl styrene, and phenylacetylene are mentioned, for example. These may be used alone or in combination of two or more.
Other copolymerizable monomers for providing the other divalent group other than the arylene group include, for example, propargyl acid, 6-hexynoic acid, 2-propyn-1-ol, 1-butyne-3- Mention may be made of all, 3-butyn-3-ol, 1-pentyn-3-ol, 4-pentyn-1-ol, 3-ethynylaniline and 4-ethynylaniline. Other copolymerizable monomers may be used alone or in combination of two or more.
The content ratio of the repeating unit of the other divalent group in the polyarylene is preferably 0 to 30 mol%, more preferably 0 to 20 mol%, still more preferably 0 to 10 mol%, based on all repeating units. is there.

<Other ingredients>
The liquid crystal aligning agent of the present invention contains the polyarylene as described above as an essential component, and is preferably constituted as a solution composition in which these are dissolved in a solvent described later, but other components may be added as necessary. Furthermore, you may contain. Examples of the other components include other polymers, compounds having at least one epoxy group in the molecule (hereinafter referred to as “epoxy compound”), and functional silane compounds.
The other polymer is a polymer having no structure represented by the above formula (1), and is used for improving the solution property (coating property) and electrical property of the liquid crystal aligning agent of the present invention. Can do. Examples of other polymers include polyamic acid, imidized polymer of the polyamic acid, polyamic acid ester, polyester, polyamide, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly A (meth) acrylate etc. can be mentioned and 1 or more types selected from these can be used. The other polymer is preferably at least one selected from the group consisting of a polyamic acid, an imidized polymer of the polyamic acid, a polyamic acid ester, and a polyorganosiloxane.
The use ratio of the other polymer is preferably 60 parts by weight or less, based on 100 parts by weight of the total of the polymers (meaning the total of polyarylene and other polymers, the same shall apply hereinafter), and 40% by weight. It is more preferable that the amount is not more than parts. When using other polymers, the effect of using other polymers is preferably expressed by setting the content ratio to 10 parts by weight or more with respect to 100 parts by weight of the total amount of the polymers.

The epoxy compound and the functional silane compound can each be contained in the liquid crystal aligning agent of the present invention in order to further improve the adhesion between the obtained liquid crystal aligning 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, and 1,6-hexane. Diol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3 -Bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylme Emissions, N, N-diglycidyl - benzylamine, N, N-diglycidyl - aminomethyl cyclohexane, N, N-diglycidyl - cyclohexyl amine may be mentioned as preferred.
The compounding ratio of these epoxy compounds is preferably 40 parts by weight or less, more preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the total amount of the polymer.

Examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl)- 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyl Trimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4 7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9- Triethoxysilyl-3,6-diazanonyl acetate, methyl 9-trimethoxysilyl-3,6-diazananoate, methyl 9-triethoxysilyl-3,6-diazananoate, N-benzyl-3-aminopropyltri Examples include methoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and N-phenyl-3-aminopropyltriethoxysilane.
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 with respect to 100 parts by weight of the total amount of the polymer.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention is constituted by dissolving the polyarylene as described above and other additives optionally blended as required, preferably in an organic solvent.
Examples of the organic solvent that can be used in the liquid crystal aligning agent of the present invention include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4. -Methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, Ethylene glycol-i-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, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, Examples thereof include 2-methoxyethanol and 1-methoxypropyl-2-acetate. These can be used alone or in admixture of two or more.

The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, and the like. The range is preferably 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface as described later, and preferably, when heated, a coating film that becomes a liquid crystal aligning film is formed, but the solid content concentration is less than 1% by weight. In this case, the film thickness of the coating film becomes too small to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes excessive. Thus, a good liquid crystal alignment film cannot be obtained, and the viscosity of the liquid crystal aligning agent increases, resulting in poor coating properties.
The particularly preferable range of the solid content concentration varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spinner method is used, the solid content concentration is particularly preferably in the range of 1.5 to 4.5% by weight. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.
The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 10-50 degreeC, More preferably, it is 20-30 degreeC.

<Liquid crystal alignment film>
A liquid crystal alignment film can be formed from the liquid crystal aligning agent of the present invention as described above.
The liquid crystal alignment film can be formed, for example, by a method of (1) forming a coating film on a substrate (coating film forming process) and (2) applying a liquid crystal alignment process in this order. However, when the liquid crystal aligning agent of the present invention is applied to a vertical alignment mode liquid crystal display element such as a VA type or an MVA type, (2) the liquid crystal alignment imparting step is an optional step, and this is not necessary. Also good.
Hereinafter, each of the steps for forming the liquid crystal alignment film will be described.

(1) Coating film formation process In a coating film formation process, the liquid crystal aligning agent of this invention is apply | coated on a board | substrate, Preferably a coating film is formed by heating this after that.
Examples of the substrate include glass such as float glass and soda glass;
A transparent substrate made of a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, or polycarbonate can be used.
When the liquid crystal aligning agent of the present invention is applied to a vertical electric field type liquid crystal display device such as a TN type, STN type, VA type, MVA type, PSA type, etc., two substrates provided with a patterned transparent conductive film As a pair, the liquid crystal aligning agent of this invention is apply | coated on each transparent conductive film formation surface, and a coating film is formed. On the other hand, when the liquid crystal aligning agent of the present invention is applied to a lateral electric field type liquid crystal display element such as an IPS type or FFS type, a pair of electrodes in which a transparent conductive film or a metal film is patterned in a comb shape on one side. A coating film is formed by applying the liquid crystal aligning agent of the present invention to the surface on which the comb-like electrode is formed and one surface of the counter substrate, respectively. . As the transparent conductive film, for example, an ITO film made of In ₂ O ₃ —SnO _{2 or} a NESA (registered trademark) film made of SnO ₂ can be used. As the metal film, for example, a film made of a metal such as chromium can be used. For patterning the transparent conductive film and the metal film, for example, a method of forming a pattern by a photo-etching method or a sputtering method after forming a transparent conductive film without a pattern, or having a desired pattern when forming the transparent conductive film For example, a method using a mask can be used.

The liquid crystal aligning agent of this invention is apply | coated on the above substrates, Preferably this is heated after that and a coating film is formed. At the time of application, in order to further improve the adhesion between the substrate and the electrode and the coating film, a pretreatment for heating after applying a functional silane compound, titanate compound or the like on the substrate and the electrode in advance is performed. It may be left.
The liquid crystal aligning agent can be applied onto the substrate by an appropriate application method such as an offset printing method, a spin coating method, a roll coater method, or an ink jet printing method. Preferably, after coating, the coated surface can be preheated (prebaked) and then fired (postbaked) to form a coating film. The prebaking condition is, for example, a heating time of 0.1 to 5 minutes at a heating temperature of 40 to 120 ° C., and the postbaking condition is, for example, a heating temperature of 120 to 300 ° C., preferably 150 to 250 ° C. The heating time is 5 to 200 minutes, preferably 10 to 100 minutes.
The film thickness of the coating film after post-baking is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm. The liquid crystal aligning agent of the present invention is VA type, MVA type, PSA. When applied to a vertical alignment type liquid crystal display element such as a (Polymer Stabilized Alignment) type, the coating film formed as described above can be used as a liquid crystal alignment film as it is. However, even in this case, the following (2) liquid crystal orientation imparting step may optionally be performed.

(2) Liquid crystal orientation imparting step When the liquid crystal aligning agent of the present invention is applied to a horizontal alignment type liquid crystal display element such as a TN type, STN type, IPS type, or FFS type, the above (1) coating film formation (2) Liquid crystal orientation provision process is performed after a process.
This liquid crystal orientation imparting step can be performed by performing at least one of a rubbing treatment and a light irradiation treatment.
When the polyarylene contained in the liquid crystal aligning agent of the present invention (when other polymer is present, at least one of the polyarylene and the other polymer) has a photoreactive group. Is preferably subjected to a light irradiation treatment as a liquid crystal orientation imparting step, and otherwise is preferably subjected to a rubbing treatment as a liquid crystal orientation impartation step.
The rubbing treatment can be performed by rubbing the surface of the coating film formed on the substrate with a roll around which a cloth made of fibers such as nylon, rayon, and cotton is wound.
As 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 light containing light having a wavelength of 200 to 400 nm is preferable. As a light source to be used, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an Hg-Xe lamp, an excimer laser, or the like can be used. The ultraviolet rays in the preferable wavelength region can be obtained by means of using the light source in combination with, for example, a filter, a diffraction grating, or the like.
When the light used for light irradiation is polarized (linearly polarized light or partially polarized light), the light may be irradiated from a direction perpendicular to the coating surface or from an oblique direction. On the other hand, when irradiating non-polarized light, the irradiation is preferably performed from an oblique direction with respect to the coating surface.
The light irradiation amount or the exposure amount is preferably 50 to 40,000 J / m ² , more preferably 100 to 20,000 J / m ² .

<Liquid crystal display element>
A liquid crystal display element can be manufactured using the substrate having the liquid crystal alignment film formed as described above.
A pair of substrates on which the liquid crystal alignment film is formed as described above is prepared, and a liquid crystal cell having a configuration in which the liquid crystal is sandwiched between the pair of substrates is manufactured. In order to manufacture a liquid crystal cell, the following two methods can be mentioned, for example.
As a first method, a pair of substrates are arranged to face each other through a gap (cell gap) so that the liquid crystal alignment films face each other, and the peripheral portions of the pair of substrates are bonded together using a sealant, and the substrate surface and A method of manufacturing a liquid crystal cell can be mentioned by injecting and filling liquid crystal into a cell gap partitioned by an appropriate sealing agent, and then sealing the injection hole.
As a second method, for example, an ultraviolet light curable sealing material is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and further, a predetermined number of locations on the surface of the liquid crystal alignment film. After the liquid crystal is dropped on the liquid crystal, the other substrate is bonded so that the liquid crystal alignment film faces, and the liquid crystal is spread over the entire surface of the substrate. A method for manufacturing a cell (ODF (One Drop Fill) method) can be given.
In any of the above methods, it is preferable that the liquid crystal cell is then heated to a temperature at which the used liquid crystal takes an isotropic phase, and then slowly cooled to room temperature, thereby removing the flow alignment at the time of filling the liquid crystal.
As the liquid crystal, for example, nematic liquid crystal, smectic liquid crystal, or the like can be used.

When producing a horizontal alignment type liquid crystal display element, a nematic type liquid crystal having positive dielectric anisotropy is preferable, for example, biphenyl liquid crystal, phenyl cyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl cyclohexane liquid crystal, Pyrimidine liquid crystals, fluorinated benzene liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like are used. A cholesteric liquid crystal, a chiral agent, a ferroelectric liquid crystal, or the like may be added to these liquid crystals.
On the other hand, when manufacturing a vertical alignment type liquid crystal display element, a nematic liquid crystal having negative dielectric anisotropy is preferable, for example, dicyanobenzene liquid crystal, pyridazine liquid crystal, Schiff base liquid crystal, azoxy liquid crystal, biphenyl type. A liquid crystal, a phenylcyclohexane type liquid crystal, or the like can be used.
In the case of manufacturing a PSA type liquid crystal display element, a step of irradiating light to a liquid crystal cell is performed in a state where a voltage is applied between conductive films of a pair of liquid crystal substrates obtained as described above. . The voltage applied here can be, for example, 5 to 50 V direct current or alternating current. As the light to be irradiated, the same light as that used in the liquid crystal alignment imparting step in the formation of the liquid crystal alignment film can be used. The amount of light irradiation is preferably 1,000 J / m ² or more and less than 100,000 J / m ² , more preferably 1,000 to 50,000 J / m ² .
And the liquid crystal display element of this invention can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell in a predetermined direction.
The polarizing plate used outside the liquid crystal cell is composed of a polarizing film called “H film” in which polyvinyl alcohol is stretched and oriented while absorbing iodine and sandwiched between cellulose acetate protective films, or the H film itself. A polarizing plate etc. can be mentioned.

Of the following examples, Example 1 is Reference Example 2.
<Example of synthesis of specific polymer>
In the following synthesis examples, the required amount of polymer in the subsequent synthesis examples was secured by repeating the synthesis operation of each polymer as necessary on the scale described below.
Synthesis example 1
The inside of a 500 mL three-necked flask equipped with a three-way cock equipped with a nitrogen introduction tube and a stirrer was made into a nitrogen atmosphere, where 20.00 g (0.125 mol) of 2,6-dihydroxynaphthalene, di-μ-hydroxo- Bis [(N, N, N ′, N′-tetramethylethylenediamine) copper (II)] chloride (0.58 g, 0.125 mmol) and 2-methoxyethanol (380 mL) were charged and stirring was started. Subsequently, 13.7 g of 31% by weight hydrogen peroxide solution was added over 2 hours, and the reaction was carried out at 25 ° C. with stirring for 3 hours. 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 and placed under vacuum at 80 ° C. overnight to remove the solvent, thereby removing the gray powder polymer (A-1) (in the formula (A-1) below). The polymer having the repeating unit represented was obtained (yield 18.76 g, yield 95%).

The polystyrene equivalent weight average molecular weight Mw of the polymer (A-1) obtained above measured by gel permeation chromatography was 48,000.
Infrared spectroscopic analysis of the polymer (A-1) obtained above was performed by the following method. The infrared spectrum is shown in FIG.
[Infrared spectroscopy analysis method]
The obtained polymer was dissolved in 2-methoxyethanol to obtain a polymer solution having a polymer concentration of 20% by mass. The solution was applied onto a substrate made of polyethylene terephthalate (PET) by a doctor blade method, and heated at 70 ° C. for 30 minutes and 120 ° C. for 30 minutes in order to remove the solvent to obtain a film. After peeling this film from the PET substrate and fixing it to a metal frame for infrared measurement with an adhesive tape, the film was placed under vacuum at 120 ° C. for 2 hours to completely remove the solvent. Measurement was performed using the film.

Synthesis example 2
According to the following scheme 1, the polymer (polymer (A-4)) having a repeating unit represented by the formula (A-4) was synthesized.

In a 500 mL eggplant-shaped flask, 3.80 g of sodium hydroxide was dissolved in 250 g of distilled water, and then 6.00 g of the polymer (A-1) obtained in Synthesis Example 1 was added and dissolved, and room temperature (about 25 C.) to obtain a sodium salt of the polymer (A-1). A solution prepared by dissolving 13.8 g of allyl bromide in 30 mL of ethanol was added dropwise thereto at room temperature over 30 minutes. After completion of the dropwise addition, the reaction was performed at room temperature with stirring for 12 hours. After completion of the reaction, the suspension-like reaction liquid was suction filtered to recover a solid. The obtained solid was washed with distilled water and then vacuum dried at 50 ° C. to obtain 7.6 g of a polymer having a repeating unit represented by formula (A-4) (polymer (A-4)). Obtained (yield 85%).
The results of ¹ H-NMR (solvent: CDCl ₃ ) measured for the polymer (A-4) were as follows.
Chemical shifts σ: 7.8~6.9ppm (benzene ring on _{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
According to the following scheme 2, the polymer (polymer (A-2)) having a repeating unit represented by the formula (A-2) was synthesized.

(In Scheme 2, mCPBA is m-chloroperbenzoic 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 the resulting solution was cooled to 0 ° C., 36.5 g of m-chloroperbenzoic acid (content 69% by weight) was added in small portions over 30 minutes. After completion of the addition, the mixture was stirred at the same temperature for 1 hour, then warmed to room temperature and further stirred for 1 hour, then heated to 50 ° C., and the reaction was continued with stirring at the same temperature for 8 hours. Thereafter, the temperature of the reaction mixture was cooled, and the solvent was distilled off under reduced pressure at 30 ° C. 30 g of tetrahydrofuran was added to the residue for dissolution, and the resulting solution was poured into 500 mL of methanol to reprecipitate the product. The solid recovered by suction filtration is washed with methanol and then vacuum-dried at 50 ° C., thereby obtaining 5.1 g of a polymer (polymer (A-2)) having a repeating unit represented by the formula (A-2). Obtained (yield 64%).
The results of ¹ H-NMR (solvent: CDCl ₃ ) measured for the polymer (A-2) were as follows.
Chemical shifts σ: 7.8~6.9ppm (benzene ring on _{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 H 2 -O, 2XH), 4.4~4.0ppm (CH 2 ▽ CH-C H ₂ —O, 4YH), 3.2 to 1.8 ppm (C H ₂ ▽ C H —CH ₂ —O, 6YH)
The above X and Y values were determined from the peak area obtained in the ¹ H-NMR, and X = 0.58 and Y = 0.42. Therefore, the epoxidation rate of the allyl group of the polymer (A-4) used as a raw material was 42%.

Synthesis example 4
In a 100 mL Erlenmeyer flask, 17.8 g of the polymer (A-2) obtained in Synthesis Example 3 above, 28 g of methyl isobutyl ketone, 2.1 g of 4-octyloxybenzoic acid and UCAT18X (trade name, manufactured by San Apro Co., Ltd.) The quaternary amine salt of 1.78 g was charged and reacted at 80 ° C. with stirring for 12 hours. After completion of the reaction, the reaction mixture was poured into methanol and the generated precipitate was recovered. The obtained precipitate was dissolved in ethyl acetate to form a solution, and the solution was washed with water three times, and then the solvent was distilled off under reduced pressure to obtain 10 of the epoxy groups of the polymer (A-2). 18.8 g of a polymer (polymer (A-3)) whose% was modified with 4- (n-pentyl) cyclohexylbenzoic acid was obtained.

Synthesis example 5
The inside of a 500 mL three-necked flask equipped with a three-way cock equipped with a nitrogen introduction tube and a stirrer was set to a nitrogen atmosphere, and 27.79 g (0.125 mol) of 1,4-dibutoxybenzene was added to di-μ-hydroxo. -Bis [(N, N, N ′, N′-tetramethylethylenediamine) copper (II)] chloride 0.58 g (0.125 mmol) and 2-methoxyethanol 380 mL were charged and stirring was started. Subsequently, 13.7 g of 31 wt% hydrogen peroxide water was added dropwise over 2 hours, and then reacted at 25 ° C. for 3 hours. After completion of the reaction, the reaction solution was poured into 1,000 mL of distilled water, and the generated precipitate was collected by filtration. The collected precipitate is vacuum-dried at 80 ° C. overnight to obtain 20.22 g of a gray powder polymer (A-5) (polymer having a repeating unit represented by the following formula (A-5)). (Yield 73%).

<Example of monomer synthesis>
Synthesis example m1
Compound (m-1) was synthesized according to the following scheme m1.

A 500 mL three-necked flask equipped with a thermometer, a reflux tube, and a nitrogen introduction tube was charged with 11.0 g of hydroquinone, 55.3 g of 11-bromoundecanol, 30.4 g of potassium carbonate, and 300 mL of N, N-dimethylacetamide at 100 ° C. 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 solution, and the mixture was washed one by one with 1M hydrochloric acid and three times with water. The organic layer after washing was concentrated to 100 mL, poured into 1 L of ethanol, and the deposited precipitate was collected by filtration and the solvent was removed under reduced pressure to obtain 36.0 g of compound (m-1a).
Next, 36.0 g of the compound (m-1a) obtained above, 400 mL of tetrahydrofuran and 17.8 g of triethylamine were charged into a 1 L three-necked flask equipped with a thermometer, a dropping funnel and a nitrogen introducing tube, and cooled to 5 ° C. or lower with ice. did. A solution prepared by dissolving 18.4 g of methacryloyl chloride in 100 mL of tetrahydrofuran was added dropwise thereto over 1 hour, and then the reaction solution was returned to room temperature and reacted for 2 hours. After completion of the reaction, 400 mL of ethyl acetate was added to the reaction solution, followed by separation and washing successively with a saturated aqueous sodium carbonate solution and once with water. After adding 0.04 g of 2,6-di-t-butyl-4-methylphenol to the washed organic layer and concentrating to 150 mL, column chromatography (adsorbent = silica, developing solvent = hexane and ethyl acetate) After purification with a mixed solvent (mixing ratio = 7: 3 (weight ratio)), the obtained fraction was concentrated under reduced pressure, and the precipitated crystals were collected by filtration and the solvent was removed under reduced pressure to obtain the compound ( 32.9 g of m-1) was obtained.

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

A 500 mL eggplant flask equipped with a reflux tube and a nitrogen introduction tube was charged with 29.4 g of 4- (4-n-pentylcyclohexyl) cyclohexanecarboxylic acid, 300 mL of thionyl chloride and 0.3 mL of N, N-dimethylformamide for 1 hour. The reaction was carried out under reflux. After completion of the reaction, the solid obtained by removing the solvent with an aspirator was dissolved in 200 mL of tetrahydrofuran to obtain Solution A.
On the other hand, in a 1 L three-necked flask equipped with a thermometer, a dropping funnel and a nitrogen introducing tube, 22.5 g of the compound (m-1a) obtained in the same manner as in the previous stage of Synthesis Example m1, 200 mL of tetrahydrofuran and 10% of tetraethylamine. 6 g was charged and cooled to 5 ° C. or lower with ice. The solution A prepared above was added dropwise over 1 hour, and then the temperature of the reaction solution was returned to room temperature to carry out the reaction for 2 hours. After completion of the reaction, 400 mL of ethyl acetate was added to the reaction solution, and the mixture was washed three times with water. After concentration under reduced pressure, the precipitated crystals were collected by filtration and the solvent was removed under reduced pressure to remove the compound (m- 43.9 g of white crystals of 2) were obtained.

<Example of synthesis of specific polymer>
Synthesis Example 6
According to the following scheme 3, the polymer (polymer (A-6)) having two types of repeating units represented by the formula (A-6) was synthesized.

(R ¹ and R ^{2 in} Scheme 3 are each a group represented by the following formula.

("*" In the above formula represents a bond)
The inside of a 200 mL three-necked flask equipped with a nitrogen inlet tube and a stirrer was placed in a nitrogen atmosphere. Here, 4.1 g of the compound (m-1) obtained in Synthesis Example m1 was obtained, and the compound obtained in Synthesis Example m2 2.9 g of (m-2), 0.046 g of di-μ-hydroxo-bis [(N, N, N ′, N′-tetramethylethylenediamine) copper (II)] chloride and 70 mL of 2-methoxyethanol are charged. Stirring was started at. Subsequently, 2.2 g of 31 wt% hydrogen peroxide water was added in portions over 2 hours, and then reacted at 25 ° C. for 3 hours. After completion of the reaction, the reaction solution was poured into 700 mL of distilled water, and the generated precipitate was collected by filtration. The collected precipitate was vacuum-dried at 80 ° C. overnight to obtain 4.8 g of a gray powder polymer (A-6).

<Synthesis of other polymers>
[Synthesis of polyamic acid]
Synthesis example PA-1
To a 100 mL four-necked flask equipped with a three-way cock and a stirrer equipped with a nitrogen introduction tube, 4.98 g (50 mole parts) of 4,4′-diaminodiphenylamine as a diamine and 4.96 g of 4,4′-diaminodiphenylmethane ( 50 mol parts) was added, and 66.35 g of N-methyl-2-pyrrolidone (NMP) was added thereto, and dissolved by stirring while feeding nitrogen to obtain a diamine solution. While stirring this diamine solution, 9.315 g (95 parts by mole) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride was added as a tetracarboxylic dianhydride, and the reaction was allowed to stir at room temperature for 2 hours. Went. After completion of the reaction, NMP was added so that the polymer concentration was 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 · s (measurement temperature 25 ° C.).

Synthesis example PA-2
To 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 diamine was added, and NMP 50.71 g was added thereto. The mixture was dissolved by stirring while feeding nitrogen to obtain a diamine solution. While this diamine solution was stirred, 10.361 g (95 mole parts) of pyromellitic dianhydride was added as a tetracarboxylic dianhydride, and the reaction was performed with stirring at room temperature for 2 hours. After completion of the reaction, NMP was added so that the polymer concentration was 15% by weight, 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-1) obtained above was 720 mPa · s (measurement temperature 25 ° C.).

Synthesis example PA-3
0.64 g of 6,5-methacryloxyhexyl and 0.19 g of octadecyloxy-2,4-diaminobenzene as diamine and 1,2,3,4-cyclobutanetetracarboxylic as tetracarboxylic dianhydride A solution containing polyamic acid (PA-3) was obtained by dissolving 0.49 g of acid dianhydride in 5.26 g of N-methyl-2-pyrrolidone (NMP) and reacting at room temperature for 16 hours. .

[Synthesis of imidized polymer]
Synthesis example PI-1
2,4'-diaminodiphenylamine 2.283 g (50 moles) and 4,4'-diaminodiphenylamine 2.271 g (50 moles) as diamine and bicyclo [3.3.0] octane as tetracarboxylic dianhydride -2,4,6,8-tetracarboxylic acid (2): 4,6: 8-dianhydride (5,446 g, 95 mole parts) was dissolved in 40 g of NMP and reacted at room temperature with stirring for 6 hours. A solution containing was obtained.
Next, after adding 50 g of NMP to the obtained solution, 2.52 g of pyridine (1.5 mol parts with respect to 1 mol part of the amic acid unit possessed by polyamic acid) and 3.26 g of acetic anhydride (1.5 mol parts of the same) ) Was added, and dehydration ring closure reaction was performed at 70 ° C. for 6 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 then placed under reduced pressure at 40 ° C. for 15 hours to remove the solvent, thereby obtaining an imidized polymer (PI-1) having an imidization ratio of 50%.
This imidized polymer (PI-1) was subjected to preparation of a liquid crystal aligning agent described later as an NMP solution having a concentration of 15% by weight. The viscosity of the NMP solution (concentration 15% by weight) was 350 mPa · s (measurement temperature 25 ° C.).

Synthesis example PI-2
In a reaction vessel, 8.93 g of 4,4′-diaminodiphenylamine and 2.22 g of 4,4′-diaminodiphenylmethane were charged as diamines and dissolved in 108.54 g of N-methyl-2-pyrrolidone. To this, 13.52 g of bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic dianhydride was added as tetracarboxylic dianhydride, and N-methyl-2-pyrrolidone was further added. The monomer concentration was 12% by weight. By reacting this solution with stirring overnight at 50 ° C., a solution containing polyamic acid was obtained.
To the above solution, 4.04 g of pyridine (1.0 mol part with respect to 1 mol part of the amic acid unit possessed by polyamic acid) and 5.21 g of acetic anhydride (1.0 mol part) were added, and 4 at 110 ° C. A time dehydration ring closure reaction was performed. 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 then placed under reduced pressure at 40 ° C. for 15 hours to remove the solvent, thereby obtaining an imidized polymer (PI-2) having an imidation ratio of 50%.

[Synthesis of polyamic acid ester]
Synthesis example PE-1
0.74 g (50 mol parts) of 4,4′-diaminodiphenylamine as a diamine and 0.72 g (50 mol parts) of 4,4′-diaminodiphenylmethane, 1.4 mL of pyridine as a base, and 71 mL of NMP as a solvent were dissolved. A diamine solution was obtained. While stirring this solution with water, 2.08 g (97 mol parts) of dimethyl-1,3-bis (chlorocarbonyl) cyclobutane-2,4-carboxylate was added thereto, and the solid content concentration was further 5% by weight. After adding NMP so as to be, the reaction was carried out with stirring for 4 hours while cooling with water. After completion of the reaction, the reaction solution was poured into 250 g of water, and the precipitated polymer was collected by suction filtration. The recovered polymer was washed with 250 mL of water once and with 63 g of methanol three times in order, and then dried under reduced pressure at 40 ° C. for 5 hours, whereby powdered polyamic acid ester (PE-1) 2. 8 g was obtained. The weight average molecular weight Mw of this polyamic acid ester (PE-1) was 23,000.
This polyamic acid ester (PE-1) was subjected to preparation of a liquid crystal aligning agent described later as an NMP solution having a concentration of 15% by weight.

[Synthesis of polyorganosiloxane]
Synthesis example PS-1
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser was charged with 100.0 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 500 g of methyl isobutyl ketone and 10.0 g of triethylamine at room temperature. Mixed in. Next, 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and the reaction was performed at 80 ° C. for 6 hours while stirring under reflux. After completion of the reaction, the organic layer is taken out and washed with a 0.2 wt% aqueous ammonium nitrate solution until the water after washing becomes neutral, and then the solvent and water are distilled off under reduced pressure to remove a polysiloxane having an epoxy group. Organosiloxane was obtained as a viscous transparent liquid. When ¹ H-NMR analysis was performed on this polyorganosiloxane, a peak based on an epoxy group was obtained in the vicinity of chemical shift (δ) = 3.2 ppm according to the theoretical intensity, and a side reaction of the epoxy group occurred during the reaction. Not confirmed. The obtained polyorganosiloxane had a weight average molecular weight Mw of 3,500 and an epoxy equivalent of 180 g / mol.
Subsequently, 10.0 g of the polyorganosiloxane having an epoxy group obtained above and 30.28 g of methyl isobutyl ketone were added to a 200 mL three-necked flask.
-3.98 g of dodecyloxybenzoic acid and 0.10 g of UCAT 18X (trade name, quaternary amine salt manufactured by San Apro Co., Ltd.) as a catalyst were charged, and the reaction was carried out at 100 ° C. with stirring for 48 hours. After completion of the reaction, a solution obtained by adding ethyl acetate to the reaction mixture was washed with water three times, the organic layer was dried over magnesium sulfate, and then the solvent was distilled off to obtain polyorganosiloxane (PS-1) in 9. 0 g was obtained. The resulting polyorganosiloxane (PS-1) had a weight average molecular weight Mw of 9,900.

<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 obtain a solution having a polymer concentration of 5% by weight. A liquid crystal aligning agent was prepared by filtering this solution through a filter having a pore size of 0.2 μm.
[Evaluation of liquid crystal aligning agent]
1. Evaluation of coating property The liquid crystal aligning agent prepared above was coated on a glass substrate using a spinner, pre-baked for 1 minute on a hot plate at 80 ° C, and then placed in a 200 ° C oven in which the inside of the chamber was replaced with nitrogen. By heating (post-baking) for a time, a coating film having an average film thickness of 1,000 mm was formed. The coating film was observed with an atomic force microscope (AFM), and the center average roughness (Ra) was measured.
When this Ra value is less than 1.0 nm, the coating property of the liquid crystal aligning agent is “good”, when it is 1.0 nm or more and less than 5.0 nm, the coating property is “good”, and when it is 5.0 nm or more, the coating property is Can be considered “bad”.

2. Manufacture of liquid crystal cells (manufacture of FFS type liquid crystal cells)
As a substrate, a glass substrate (electrode substrate) on which two systems of electrodes (electrode A (101) and electrode B (102)) made of chromium having a comb-like pattern shown in FIG.
A glass substrate (counter substrate) on which no electrode is formed is used as a pair of substrates, and the liquid crystal aligning agent is applied onto the electrode formation surface of the electrode substrate and one surface of the counter substrate using a spinner, respectively. Heating was carried out at 1 ° C. for 1 minute (pre-baking) and heating at 230 ° C. for 1 hour (post-baking) to form a coating film having a thickness of 1,000 mm. Each of these coating films was subjected to a rubbing treatment with a rubbing machine having a roll wound with a rayon cloth at a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / second, and a hair foot indentation length of 0.1 mm. Thereafter, ultrasonic cleaning was performed in ultrapure water for 1 minute, followed by drying in a clean oven at 100 ° C. for 10 minutes to obtain two substrates having a liquid crystal alignment film.
Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm was screen-printed and applied to the outer peripheral edge of the liquid crystal alignment film formation surface of the counter substrate, and then the liquid crystal alignment film formation surface was opposed. And a pair of board | substrates were overlap | superposed and crimped | bonded so that the projection direction to the board | substrate surface at the time of light irradiation might correspond, and it heat-cured the adhesive agent by heating at 150 degreeC for 1 hour.
Next, 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 port was sealed with an epoxy adhesive. Furthermore, in order to remove the flow alignment at the time of liquid crystal injection, this was heated to 150 ° C. and then gradually cooled to room temperature to produce an FFS type liquid crystal cell.
A total of three liquid crystal cells are manufactured, one of which is the following “(1) Evaluation of liquid crystal orientation” and “(2) Evaluation of residual DC voltage (normal conditions)”, and another one is “( “3) Evaluation of residual DC voltage (harsh conditions)” and another one were used for “(4) Voltage holding ratio” and “(5) Reliability evaluation”, respectively.

3. Evaluation of liquid crystal cell (1) Evaluation of liquid crystal alignment The liquid crystal cell produced above was observed with a polarizing microscope for the presence or absence of an abnormal domain when an AC voltage of 5 V was turned on / off (applied / released).
When the abnormal domain was not observed, the liquid crystal alignment was “good”, and when one of the abnormal domains was observed in the display region, the liquid crystal alignment was evaluated as “bad”. It was determined as “good”.
(2) Evaluation of residual DC voltage (normal conditions)
To the liquid crystal cell manufactured above, a 30 Hz, 3 V rectangular wave with 10 V DC superimposed is applied for 20 hours at an ambient temperature of 25 ° C., and the voltage remaining in the liquid crystal cell immediately after the DC voltage is cut off is flicker erased. When the residual DC voltage was determined by the method, it was 120 mV.
When the evaluation value of the residual DC voltage is 300 mV or less, the residual DC voltage in the normal condition of the liquid crystal cell is “good”, and when it exceeds 300 mV and less than 500 mV, the residual DC voltage in the normal condition is “good”, 500 mV or more The residual DC voltage under normal conditions can be considered “bad”.

(3) Evaluation of residual DC voltage (harsh conditions)
Same as above except that in “(2) Evaluation of residual DC voltage (normal conditions)”, the applied temperature and time of the superimposed DC voltage and DC superimposed rectangular wave were 20 V, 100 ° C. and 500 hours, respectively. The residual DC voltage was determined to be 200 mV.
When the value of evaluation of the residual DC voltage is 300 mV or less, the residual DC voltage in the severe condition of the liquid crystal cell is “good”, and when it exceeds 300 mV and less than 500 mV, the residual DC voltage in the severe condition is “good”, 500 mV or more The residual DC voltage under severe conditions can be considered “bad”.
(4) Evaluation of voltage holding ratio After the voltage of 5V was applied to the liquid crystal cell manufactured above with an application time of 60 microseconds and a span of 167 milliseconds, the voltage holding ratio after 167 milliseconds from the release of application. (Initial voltage holding ratio VHR _BF ) was measured and found to be 92%. As a measuring device, “VHR-1” manufactured by Toyo Corporation 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”, when the voltage holding ratio is 90% or more and less than 95%, the voltage holding ratio is “good” or less than 90% The voltage holding ratio can be considered as “bad”.

(5) Reliability Evaluation The liquid crystal cell after the initial voltage holding ratio measurement was left in an oven at 100 ° C. for 300 hours. Thereafter, the liquid crystal display element was allowed to stand at room temperature and allowed to cool to room temperature, and then the voltage holding ratio was measured in the same manner as in “(4) Evaluation of voltage holding ratio” (voltage holding ratio VHR after stress application). _AF ).
Then, the voltage holding rate VHR _AF after stress application and the initial voltage holding rate VHR _BF are substituted into the following formula (2) to obtain the rate of change in voltage holding rate (ΔVHR (%)), It was used as an index.
_{△ VHR (%) = ((} VHR BF -VHR AF) ÷ VHR BF) × 100 (2)
When the value of ΔVHR is 10% or less, the reliability of the liquid crystal cell is “good”. When the value exceeds 10% and 20% or less, the reliability is “good”. When the value is 20% or more, the reliability is “poor”. Can be considered.

Example 2
In the preparation of the liquid crystal aligning agent of Example 1 above, the polymer (A-2) obtained in Synthesis Example 2 was used as the polymer, and propylene glycol-1-monomethyl ether-2-acetate was used as the solvent. A liquid crystal aligning agent was prepared in the same manner as in Example 1, and various evaluations were performed.
The evaluation results are shown in Tables 1 and 2.

Example 3
[Preparation of liquid crystal aligning agent]
The polymer (A-3) obtained in Synthesis Example 3 was dissolved in a mixed solvent composed of NMP and butyl cellosolve (BC) (NMP: BC = 50: 50 (weight ratio)), and the polymer concentration was 6.0% by weight. Solution. A liquid crystal aligning agent was prepared by filtering this solution through a filter having a pore size of 0.2 μm.
[Evaluation of liquid crystal aligning agent]
1. Evaluation of applicability In the same manner as in “1. Evaluation of applicability” in Example 1, the applicability of the liquid crystal aligning agent was evaluated.
The evaluation results are shown in Table 1.

2. Manufacture of liquid crystal cells (Manufacture of TN liquid crystal cells)
The liquid crystal aligning agent prepared above was applied onto the transparent electrode surface of a glass substrate having a transparent electrode made of an ITO film using a liquid crystal alignment film printer (Nissha Printing Co., Ltd.), and a hot plate at 80 ° C. After removing the solvent by heating (pre-baking) for 1 minute above, it was heated (post-baking) on a hot plate at 150 ° C. for 10 minutes to form a coating film having a thickness of 1,000 mm. The coating film was rubbed with a rubbing machine having a roll wrapped with a rayon cloth at a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / sec, and a hair foot indentation length of 0.1 mm. Thereafter, ultrasonic cleaning was performed in ultrapure water for 1 minute, followed by drying 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 (two) of substrates having a rubbed coating film.
Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied to the outer edge of the surface having one of the pair of substrates that has been subjected to the rubbing treatment. The adhesive was cured by overlapping and pressing so that the film surfaces face each other. Next, a nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) is filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photo-curing adhesive, whereby a TN type liquid crystal is sealed. A cell was manufactured.
3. Evaluation of Liquid Crystal Cell The liquid crystal cell produced above was evaluated 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 4 was dissolved in a mixed solvent composed of NMP and butyl cellosolve (BC) (NMP: BC = 50: 50 (weight ratio)), and the polymer concentration was 6.0% by weight. Solution. A liquid crystal aligning agent was prepared by filtering this solution through a filter having a pore size of 0.2 μm.
[Evaluation of liquid crystal aligning agent]
1. Evaluation of applicability In the same manner as in “1. Evaluation of applicability” in Example 1, the applicability of the liquid crystal aligning agent was evaluated.
The evaluation results are shown in Table 1.
2. Manufacture of liquid crystal cells (Manufacture of VA liquid crystal cells)
In “2. Production of liquid crystal cell (production of TN liquid crystal cell)” in Example 3 above,
Using the liquid crystal aligning agent prepared above,
A VA liquid crystal cell was produced in the same manner as in Example 3 except that the rubbing treatment after the coating film formation was not performed and nematic liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) was used as the liquid crystal.
3. Evaluation of Liquid Crystal Cell The liquid crystal cell produced above was evaluated 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, the polymer (A-5) obtained in Synthesis Example 5 was used as the polymer, and the mixed solvent consisting of NMP and BC (NMP: BC = 50: 50 ( A liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the weight ratio)) was used, and various evaluations were performed.
The evaluation results are shown in Tables 1 and 2.

Example 6
[Preparation of liquid crystal aligning agent]
The polymer obtained in Synthesis Example 1 was added to 33.3 parts by weight of the solution containing polyamic acid (PA-1) obtained in Synthesis Example PA-1 (5 parts by weight in terms of polyamic acid (PA-1)). (A-1) 95 parts by weight is added and mixed, and NMP and BC are further added and diluted, so that the total concentration of the polymer is 5% by weight and the solvent composition is NMP: BC = 50: 50 (weight ratio) ) Solution. A liquid crystal aligning agent was prepared by filtering this solution through a filter having a pore size of 0.2 μm.
[Evaluation of liquid crystal aligning agent]
Various evaluations were performed 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 Tables 1 and 2.

Example 7
[Preparation of liquid crystal aligning agent]
As a polymer, 50 parts by weight of the polymer (A-4) obtained in Synthesis Example 4 and 50 parts by weight of the imidized polymer (PI-1) obtained in Synthesis Example PI-1 are mixed with NMP and BC. It melt | dissolved in the solvent (NMP: BC = 50: 50 (weight ratio)), and it was set as the solution whose total density | concentration of a polymer is 5 weight%. A liquid crystal aligning agent was prepared by filtering this solution through a filter having a pore size of 0.2 μm.
[Evaluation of liquid crystal aligning agent]
Various evaluations were performed 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 Tables 1 and 2.
Examples 8 and 9
In the preparation of the liquid crystal aligning agent of Example 7, the liquid crystal aligning agent was prepared in the same manner as in Example 7 except that the types and amounts of polymers described in Table 1 were used, and various evaluations were performed. .
The evaluation results are shown in Tables 1 and 2.

Comparative Examples 1 and 2
[Preparation of liquid crystal aligning agent]
Using the polymer shown in Table 1 as a polymer, NMP and BC were added to the solution containing the polymer obtained in the above synthesis example and diluted to obtain a total polymer concentration of 5%. % And the solvent composition was NMP: BC = 50: 50 (weight ratio). A liquid crystal aligning agent was prepared by filtering this solution through a filter having a pore size of 0.2 μm.
[Evaluation of liquid crystal aligning agent]
Various evaluations were performed 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 Tables 1 and 2.

Comparative Examples 3-5
[Preparation of liquid crystal aligning agent]
The polymers shown in Table 1 were each dissolved in a mixed solvent composed of NMP and BC in the mixing ratio shown in Table 1 to give a solution having a total polymer concentration of 5% by weight. The solution was filtered through a filter having a pore size of 0.2 μm to prepare liquid crystal alignment agents.
[Evaluation of liquid crystal aligning agent]
Various evaluations were performed 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 Tables 1 and 2.

Examples 10-12
[Preparation of liquid crystal aligning agent]
The polymer shown in Table 1 is mixed at the weight ratio shown in Table 1 and dissolved in the solvent or mixed solvent shown in Table 1 so that the total concentration of the polymer is 5% by weight. It was. The solution was filtered through a filter having a pore size of 0.2 μm to prepare liquid crystal alignment agents.
[Evaluation of liquid crystal aligning agent]
1. Evaluation of applicability Evaluation of applicability of the liquid crystal aligning agent prepared above was performed in the same manner as in Example 1.
The evaluation results are shown in Table 1.

2. Manufacture of liquid crystal cells (Manufacture of PSA type liquid crystal cells)
The liquid phase alignment agent prepared above is patterned into a slit shape as shown in FIG. 3, and a liquid crystal alignment film printer on each electrode surface of two glass substrates each having ITO electrodes partitioned into a plurality of regions. (Prepared by Nissha Printing Co., Ltd.), heated for 1 minute on a hot plate at 80 ° C. (pre-baked) to remove the solvent, and then heated for 10 minutes on a hot plate at 150 ° C. (post-baked) Thus, a coating film having an average film thickness of 600 mm was formed. The coating film was subjected to ultrasonic cleaning for 1 minute in ultrapure water and then dried in a clean oven at 100 ° C. for 10 minutes to obtain a substrate having a liquid crystal alignment film. This operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film.
Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied to the outer edge of the surface having the liquid crystal alignment film for one of the pair of substrates. The adhesives were cured by overlapping and pressing them so that they face each other. Next, a nematic liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) is filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photo-curing adhesive, whereby a PSA type liquid crystal cell is obtained. Manufactured.

3. Evaluation of liquid crystal cell (1) Evaluation of response speed After sandwiching each liquid crystal cell produced above with two polarizing plates arranged in a crossed Nicol state, first, a visible light lamp was irradiated without applying a voltage. The luminance of light transmitted through the liquid crystal cell was measured with a photomultimeter, and this value was defined as a relative transmittance of 0%. Next, the transmittance when AC 60 V was applied between the electrodes of the liquid crystal cell for 5 seconds was measured in the same manner as described above, and this value was defined as a relative transmittance of 100%.
At this time, when 60 V AC was applied to each liquid crystal cell, the time until the relative transmittance shifted from 10% to 90% was measured, and this time was defined as the response speed and evaluated.
The evaluation results are shown in Table 3.
(2) Other evaluations Other evaluations were performed 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]
By adding and diluting NMP and BC to the solution containing the polyamic acid (PA-3) obtained in Synthesis Example PA-3, the total concentration of the polymer is 5% by weight and the solvent composition is NMP: BC = The solution was 50:50 (weight ratio). A liquid crystal aligning agent was prepared by filtering this solution through a filter having a pore size of 0.2 μm.
[Evaluation of liquid crystal aligning agent]
Various evaluations were performed 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 (4)

Following formula (P)
(In the formula (P), Ar is an n + divalent aromatic group, n is 1 or 2,
X in each repeating unit is each independently 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 a carbon atom having 1 to 6 carbon atoms). Is an alkyl group of
R ^{01 in} each repeating unit is independently a hydrogen atom, a group having a terminal C═C double bond, a group having a carbon-carbon triple bond, a group having an epoxy group, or a group having a function of aligning liquid crystal molecules. is selected from the group caused a crosslinking reaction or isomerization reaction by the light irradiation, provided that at least one of the group having a terminal C = C double bonds of R ^01, a group having a carbon-carbon triple bond, an epoxy group A group having a function of orienting liquid crystal molecules, and a group that causes a crosslinking reaction or an isomerization reaction by light irradiation,
The liquid crystal aligning agent characterized by including the polyarylene which is a polymer which has a repeating unit represented by these . The liquid crystal according to claim 1 , wherein the polyarylene is a polymer having at least one repeating unit selected from repeating units represented by the following formulas (P-1) and (P-2). Alignment agent.
(In the formulas (P-1) and (P-2), X and R ⁰¹ have the same meanings as in the above formula (P).) Liquid crystal alignment film formed from the liquid crystal aligning agent according to any one of claims 1-2. A liquid crystal display device comprising the liquid crystal alignment film according to claim 3 .