KR20140095004A - Liquid crystal aligning agent for psa mode liquid crystal display device, liquid crystal alignment film for psa mode liquid crystal display device, and the psa mode liquid crystal display device and manufacturing method thereof - Google Patents

Abstract

Provided is a liquid crystal display device in a PSA mode with fast response speed capable of showing a proper pretilt angle with small optical irradiation amount and maintaining a high voltage maintenance ratio after optical irradiation. A liquid crystal alignment agent for forming a liquid crystal alignment film in the liquid crystal display device in the PSA mode comprises: a compound (A) having a structure (a) capable of performing one or more functions among a radical generation function which generates radical by the optical irradiation and an optical increase function which shows an increase action by the optical irradiation.

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal alignment agent for a liquid crystal display element, a liquid crystal alignment layer for a liquid crystal display element, a liquid crystal alignment element for a liquid crystal display element, and a method of manufacturing the liquid crystal display element. CRYSTAL DISPLAY DEVICE, AND THE PSA MODE LIQUID CRYSTAL DISPLAY DEVICE AND MANUFACTURING METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal aligning agent and a liquid crystal alignment film for a PSA mode liquid crystal display element, a PSA mode liquid crystal display element and a manufacturing method thereof, and more particularly to a technique for reducing a light irradiation amount during PSA processing .

BACKGROUND ART [0002] Conventionally, various driving methods have been developed as liquid crystal display elements, which have different electrode structures and physical properties of liquid crystal molecules to be used. For example, an MVA (Multi-Domain Vertical Alignment) type panel conventionally known as a vertical alignment mode is intended to enlarge the viewing angle by regulating the tilting direction of the liquid crystal molecules by protrusions formed in the liquid crystal panel. However, according to this method, insufficient transmittance and contrast derived from projections are inevitable, and the response speed of liquid crystal molecules tends to be slow.

Recently, in order to solve the problems of the MVA type panel, a PSA (Polymer Sustained Alignment) mode has been proposed as a new driving mode for controlling the orientation of liquid crystal molecules. In the PSA mode, the liquid crystal cell is irradiated with light while a voltage is applied between a pair of electrodes sandwiching the liquid crystal layer, the photopolymerizable monomer is incorporated into the liquid crystal material, And controlling the molecular orientation of the liquid crystal molecules by polymerization. According to this technique, there is an advantage that the viewing angle can be enlarged and high-speed response can be achieved. In recent years, further rapid response of PSA type liquid crystal panels has been studied. As a technique, a monofunctional liquid crystal compound having any one of an alkenyl group and a fluoroalkenyl group (hereinafter also referred to as " alkenyl liquid crystal " (See, for example, Patent Documents 1 to 3).

Japanese Patent Application Laid-Open No. 2010-285499 Japanese Patent Application Laid-Open No. 9-104644 Japanese Patent Application Laid-Open No. 6-108053

According to the PSA mode, it is possible to enlarge the viewing angle and to achieve a high-speed response. On the other hand, a large amount of ultraviolet irradiation is required for the polymerization reaction of the photopolymerizable monomer, and the display quality of the panel is deteriorated due to the ultraviolet irradiation . In addition, when the light irradiation amount is insufficient, unreacted photopolymerizable monomer remains in the liquid crystal layer, and burn-in (after-image) of the image is liable to occur due to the unreacted monomer. In this regard, in the PSA mode, the photopolymerizable monomer can be polymerized with as little light irradiation as possible, and furthermore, unreacted monomers must be reduced as much as possible.

In addition, in the liquid crystal display device using the alkenyl-based liquid crystal, the response speed can be increased. On the other hand, the light irradiation for the polymerization of the photopolymerizable monomer causes the voltage It is clear that the lowering of the maintenance rate becomes larger. From the viewpoint of further improving the display quality of the liquid crystal display element, it is necessary to maintain a high voltage holding ratio after the light irradiation for polymerization of the photopolymerizable monomer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a PSA mode liquid crystal display device capable of maintaining an appropriate pretilt angle at a low light irradiation amount and maintaining a high voltage holding ratio after light irradiation, And a liquid crystal aligning agent for a mode liquid crystal display element.

DISCLOSURE OF THE INVENTION The present inventors have intensively studied in order to achieve the above-mentioned problems of the prior art, and as a result, they found that the above problems can be solved by forming a liquid crystal alignment film using a liquid crystal aligning agent containing a specific compound, I have come to completion. Specifically, a liquid crystal aligning agent, a liquid crystal alignment film, a liquid crystal display element, and a manufacturing method thereof for PSA mode liquid crystal display elements described below are provided by the present invention.

In one aspect of the present invention, there is provided a compound (a) having a structure (a) capable of expressing at least any one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting an increase sensitization by light irradiation (A) for a PSA mode liquid crystal display device.

According to another aspect of the present invention, there is provided a liquid crystal display device comprising a first step of coating a liquid crystal aligning agent of the present invention on a conductive film of a pair of substrates each having a conductive film and then heating the same to form a coated film, A second step of arranging a pair of substrates provided with a pair of substrates facing each other through a liquid crystal layer containing a liquid crystal compound so as to face each other so as to construct a liquid crystal cell; And a third step of irradiating the liquid crystal cell with light in a state where the liquid crystal cell is irradiated with light.

In another aspect, the present invention provides a liquid crystal alignment film for a PSA mode liquid crystal display element formed using the liquid crystal aligning agent of the present invention, and a PSA mode liquid crystal display element comprising the liquid crystal alignment film.

The PSA mode liquid crystal display device manufactured using the liquid crystal aligning agent of the present invention can display an appropriate pretilt angle at a small light irradiation amount by containing the compound (A) in the liquid crystal alignment film. Further, a liquid crystal display element having a high voltage holding ratio and a fast response speed can be obtained.

Particularly, by forming a liquid crystal alignment film of a liquid crystal display element having a liquid crystal layer containing an alkenyl-based liquid crystal using the liquid crystal aligning agent of the present invention, it is possible to improve the response speed of the liquid crystal display element, It is possible to appropriately suppress the decrease of the voltage holding ratio accompanying the light irradiation due to the addition.

1 is a view showing electrode patterns of a transparent electrode film used in Examples and Comparative Examples.
2 is a view showing an electrode pattern of a transparent electrode film used in Examples and Comparative Examples.
3 is a view showing an electrode pattern of a transparent electrode film used in Examples and Comparative Examples.

(Mode for carrying out the invention)

Hereinafter, each component contained in the liquid crystal aligning agent for PSA mode liquid crystal display element of the present invention (hereinafter simply referred to as a liquid crystal aligning agent), and other components arbitrarily blended as necessary, will be described.

≪ Compound (A) >

The liquid crystal aligning agent of the present invention is preferably a compound (A) capable of exhibiting at least any one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a depressing action by light irradiation , &Quot; specific structure "). Here, the " photo-sensitization function " refers to a function of quickly causing an inter-crossover transition to a triplet excited state after becoming a singlet excited state by irradiation of light. When it collides with another molecule in this triplet excited state, it changes its partner into an excited state and returns to its base state by itself. This photo-sensitization function may coexist with a radical generating function of generating a radical by light irradiation.

The specific structure of the compound (A) is preferably a structure capable of exhibiting at least a photosensitivity function, that is, a structure capable of expressing only a photosensitization function or a structure capable of exhibiting a photosensitivity function and a radical generation function.

The compound (A) may be a relatively low molecular weight compound having no repeating unit, or may be a polymer. The compound (A) may be used alone or in combination of two or more.

The compound (A) as a low molecular compound preferably has a molecular weight of 1,000 or less, more preferably 800 or less. Specific examples of the compound (A) in the case of a low molecular weight compound include compounds having an acetophenone structure such as acetophenone, acetophenone benzyl ketal, 2,2-dimethoxy-2-phenylacetophenone, compound;

Hydroxybenzophenone, 4-methylbenzophenone, 3,4-dimethylbenzophenone, 3- (4-benzoyl-phenoxy) propyl, 4 A compound having a benzophenone structure such as chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, and 4,4'-bis (dimethylamino) benzophenone ;

A nitroaryl structure such as 3,5-dinitrobenzene, 4-methyl-3,5-dinitrobenzene, 3- (3,5-dinitrophenoxy) ≪ / RTI > In addition to,

(9,10-dioxo-9,10-dihydroanthracene-2-yl) propyl, 3- (4,5-dimethoxy-3,6-dioxo Cyclohexa-1,4-dienyl) propyl, 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) Benzoin ethyl ether, benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane 2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2- chlorothioxanthone, 2- 2, 4-trimethylbenzoyldiphenylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2, 4,4-trimethylpentylphosphine oxide, and the like.

The compound (A) as the polymer may have any of the above-described specific structures in the main chain and side chain of the polymer. However, it can be easily controlled in the amount of introduction, and the point , It is preferable that the polymer has a side chain of the polymer.

Examples of the main skeleton of the polymer having the specific structure (hereinafter also referred to as "polymer (A)") include polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, polyorganosiloxane, A skeleton composed of a cellulose derivative, a polyacetal derivative, a polystyrene derivative, a poly (styrene-phenylmaleimide) derivative, and a poly (meth) acrylate derivative. As the polymer (A), at least one polymer having a skeleton selected therefrom can be suitably selected and used according to the use of the liquid crystal display element and the like. Further, (meth) acrylate means that it includes acrylate and methacrylate.

As the polymer (A), those having a skeleton selected from polyamic acid, polyimide, polyamic acid ester, polyorganosiloxane and poly (meth) acrylate are preferable, and polyamic acid, polyimide, It is more preferable to have a skeleton selected from polyorganosiloxane.

As the specific structure of the polymer (A), when having the specific structure in the main chain, it is preferably a benzophenone structure.

In the case of having the specific structure in the side chain, specific examples of the specific structure include a structure capable of exhibiting a radical generating function, for example, an acetophenone structure, a benzophenone structure, a quanthone structure, a fluorenone structure, a benzaldehyde structure , A fluorene structure, an anthraquinone structure, a triphenylamine structure, a carbazole structure, an alkylphenone structure, a benzoin structure, a thioxanthone structure, and an acylphosphine oxide structure;

Examples of the structure capable of exhibiting a photosensitizing function include an acetophenone structure, a benzophenone structure, an anthraquinone structure, a biphenyl structure, a carbazole structure, a nitroaryl structure (nitrobenzene structure, 1,3-dinitrobenzene structure, etc.) , A naphthalene structure, a fluorene structure, an anthracene structure, an acridine structure, an indole structure, and a 1,4-dioxocyclohexa-2,5-diene structure. Each of these structures may be substituted with one or more substituents selected from the group consisting of acetophenone, benzophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, alkylphenone, benzoin, thioxanthone, acylphosphine oxide, , A structure formed by removing one to four hydrogen atoms from nitrobenzene, 1,3-dinitrobenzene, naphthalene, anthracene, acridine, indole, and 1,4-dioxocyclohexa-2,5-diene to be.

In the case of having the specific structure in the side chain, the specific structure is preferably selected from the group consisting of an acetophenone structure, a benzophenone structure, an anthraquinone structure, a biphenyl structure, a carbazole structure, a nitroaryl structure and a naphthalene structure , And more preferably at least one selected from the group consisting of an acetophenone structure, a benzophenone structure, and a nitroaryl structure.

[Polymer (A): polyamic acid]

In the present invention, a polyamic acid (hereinafter also referred to as " polyamic acid (A) ") as the polymer (A) can be obtained by reacting, for example, tetracarboxylic acid dianhydride with a diamine having the above specific structure.

[Tetracarboxylic acid dianhydride]

Examples of the tetracarboxylic acid dianhydride used for synthesizing the polyamic acid (A) in the present invention include aliphatic tetracarboxylic acid dianhydride, alicyclic tetracarboxylic acid dianhydride, aromatic tetracarboxylic dianhydride, and the like. . Specific examples thereof include aliphatic tetracarboxylic acid dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride;

As the alicyclic tetracarboxylic acid dianhydride, for example, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,3,3a, 4, 5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2- c] furan-1,3-dione, , 5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [ (Tetrahydrofuran-2 ', 5'-dione), 5- (2,5-dioxotetrahydro-3 ' 3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane 2: 3,5: 6-2 anhydride, 2 , 4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6,8-2 anhydride, 4,9-dioxotricyclo [5.3.1.0 ^2,6 ] undecane- 5,8,10-tetraone, cyclohexanetetracarboxylic dianhydride and the like;

As the aromatic tetracarboxylic acid dianhydride, for example, pyromellitic dianhydride and the like;

Tetracarboxylic acid dianhydride described in JP-A-2010-97188, and the like can be used. The tetracarboxylic acid dianhydride may be used singly or in combination of two or more.

The tetracarboxylic acid dianhydride used for synthesizing the polyamic acid (A) preferably contains an alicyclic tetracarboxylic acid dianhydride, and 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 1,2,3 , And 4-cyclobutanetetracarboxylic acid dianhydride, and more preferably 2,3,5-tricarboxycyclopentyl acetic acid dianhydride. As the tetracarboxylic acid dianhydride used for synthesizing the polyamic acid (A), the content of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride (Total amount) is preferably 60 mol% or more, more preferably 80 mol% or more, based on the total amount of the tetracarboxylic acid dianhydride used in the synthesis.

[Diamine]

As the diamine used for synthesizing the polyamic acid in the present invention, a diamine (hereinafter also referred to as " specific diamine ") capable of imparting at least any of a radical generating function and a photosensitizing function to the polymer, . Specific examples of such specific diamines include 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, {4- [2- (3,5-diaminophenoxy) -ethoxy] -Phenyl-methanone, {4- [2 (3,5-diaminophenoxy) -ethoxy] -phenyl} -Phenyl-methanone, {4- [2- (2,4-diaminophenoxy) -ethoxy] -phenyl} -p- (4-aminophenyl) -ethoxy] -phenyl} -octolyl-methanone, 9,9-bis Oren and the like. The above-mentioned specific diamine can be used singly or in combination of two or more kinds selected from these.

As the diamine for synthesizing the polyamic acid (A) in the present invention, the above-mentioned specific diamine may be used singly, but a diamine other than the specific diamine (hereinafter also referred to as " other diamine " May be used.

Examples of the other diamines include aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoorganosiloxanes, and the like. Specific examples thereof include aliphatic diamines such as meta-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine and the like; As the alicyclic diamine, for example, 1,4-diaminocyclohexane, 4,4'-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane and the like;

As aromatic diamines, for example, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 1,5-diaminonaphthalene, 2,2'-dimethyl Diaminobiphenyl, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 2,7-diaminofluorene, 4,4'-diamino Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis [4- (4-aminophenyl) hexafluoropropane, 4,4 '- (p-phenylenediisopropylidene) bisaniline, 4,4' - (m- phenylenediisopropylidene) bisaniline, (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 2,6- diaminopyridine, 3,4-diaminopyridine, 2,4- 3,6-diamino acridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole,

N, N'-bis (4-aminophenyl) benzidine, N, N'- Aminophenyl) -N, N'-dimethylbenzidine, 1,4-bis- (4-aminophenyl) -piperazine, 3,5- diaminobenzoic acid, dodecaneoxy- Oxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecaneoxy-2,4-diaminobenzene, octadecanoxy- 2,5-diaminobenzene, pentadecaneoxy-2,5-diaminobenzene, hexadecaneoxy-2,5-diaminobenzene, octadecanoxy-2, 5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy- 2,4-diaminobenzene, 3,5-diaminobenzoic acid cholestanyl, 3,5-diaminobenzoic acid cholestenyl, 3,5-diaminobenzoic acid ranostanyl, (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 4- (4'-trifluoromethoxybenzoyloxy) cyclohexyl-3,5-diaminobenzoate, Bis (4 - ((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 1 (4'-trifluoromethylbenzoyloxy) cyclohexyl-3,5-diaminobenzoate, Heptylcyclohexane, 1,1-bis (4 - ((aminophenoxy) methyl) phenyl) -4-heptylcyclohexane, 1-bis (4 - ((aminophenyl) methyl) phenyl) -4- (4-heptylcyclohexyl) cyclohexane, 1- Aminophenyl) -2,3-dihydro-1,3,3-trimethyl-1H-inden-6-amine, 3- (3,5- Minobenzoyloxy) cholestane represented by the following formula (D-1):

^Wherein X ^I and X ^II each independently represents a single bond, -O-, -COO- or -OCO-, R ^I is an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, and n is 0 or 1, provided that a and b are not 0 at the same time.

And the like;

Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane and the like, and diamines described in JP-A-2010-97188 can be used .

Examples of the divalent group represented by "-X ^I - (R ^I -X ^II ) _n -" in the above formula (D-1) include an alkanediyl group having 1 to 3 carbon atoms, * -O-, * -COO- Or * -OC ₂ H ₄ -O- (provided that a bonding hand having "*" attached thereto is bonded to a diaminophenyl group).

Specific examples of the group "-C _c H _{2c +1} " include a methyl group, an ethyl group, a n-propyl group, an n-butyl group, an n-pentyl group, n-heptadecyl, n-heptadecyl, n-octadecyl, n-hexadecyl, n-hexadecyl, An n-nonadecyl group, and an n-eicosyl group. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or the 3,5-position with respect to the other groups.

Specific examples of the compound represented by the formula (D-1) include compounds represented by the following formulas (D-1-1) to (D-1-4).

As other diamines, these compounds may be used singly or in combination of two or more.

In the synthesis of the polyamic acid (A), the amount of the specific diamine to be used is preferably 0.1 to 80 mol%, more preferably 1 to 60 mol%, based on the total amount of the diamine used in the synthesis , More preferably from 5 to 50 mol%.

<Synthesis of polyamic acid>

The ratio of the tetracarboxylic acid dianhydride and the diamine to be used in the synthesis reaction of the polyamic acid in the present invention is such that the ratio of the acid anhydride group of the tetracarboxylic acid dianhydride to the equivalent of one equivalent of the amino group of the diamine is 0.2 to 2 equivalents , More preferably from 0.3 to 1.2 equivalents. The synthesis reaction of the polyamic acid is preferably carried out in an organic solvent. The reaction temperature at this time is preferably -20 캜 to 150 캜, more preferably 0 to 100 캜. The reaction time is preferably 0.5 to 24 hours, more preferably 2 to 10 hours.

The organic solvent to be used in the reaction is not particularly limited as long as it can dissolve the polyamic acid to be synthesized. Specific examples thereof include N-methyl-2-pyrrolidone, N-ethyl- Such as N, N-dimethylformamide, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone,? -Butyrolactone, tetramethylurea, hexamethylphosphoric triamide, (Non) protonic polar solvent; phenol-based solvents such as m-cresol, xylenol, phenol, and halogenated phenol; And the like. These organic solvents may be used singly or in combination of two or more.

As the organic solvent to be used in the reaction, a poor solvent of the polyamic acid may be used in combination within a range in which the synthesized polyamic acid is not precipitated. Examples of such a poor solvent include alcohols such as methanol, ethanol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, and ethylene glycol monomethyl ether; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; Esters such as ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, diethyl oxalate, and isoamyl propionate; Ethers such as diethyl ether, ethylene glycol methyl ether, ethylene glycol propyl ether, ethylene glycol butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, tetrahydrofuran and diisopentyl ether; Halogenated hydrocarbons such as dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, and trichloroethane; And hydrocarbons such as hexane, heptane, octane, benzene, toluene and xylene. These poor solvents may be used singly or in combination of two or more.

When a poor solvent of the polyamic acid is used as the organic solvent used in the reaction, the use ratio thereof is preferably 50% by weight or less, more preferably 40% by weight or less based on the total amount of the organic solvent used in the synthesis % Or less, and more preferably 30 wt% or less.

The amount (x) of the organic solvent used is preferably such that the total amount (y) of the tetracarboxylic acid dianhydride and the diamine is 0.1 to 50 wt% with respect to the total amount (x + y) By weight to 30% by weight.

As described above, a reaction solution obtained by dissolving the polyamic acid (A) is obtained. The reaction solution may be provided as it is in the preparation of a liquid crystal aligning agent. Alternatively, the polyamic acid (A) contained in the reaction solution may be isolated and then supplied to the preparation of a liquid crystal aligning agent, or the polyamic acid (A) Or may be provided for the preparation of a liquid crystal aligning agent. When the polyamic acid (A) is subjected to dehydration ring closure to form polyimide, the reaction solution may be directly supplied to the dehydration ring-closing reaction. Alternatively, the polyamic acid (A) contained in the reaction solution may be isolated, , Or may be subjected to a dehydration ring-closing reaction after the isolated polyamic acid (A) is purified. The polyamic acid (A) can be isolated and purified by a known method.

&Lt; Polymer (A): polyimide >

In the present invention, the polyimide (hereinafter also referred to as &quot; polyimide (A) &quot;) as the polymer (A) can be obtained by, for example, imidizing the polyamic acid (A) have.

The polyimide (A) may be a complete imide cargo which is subjected to dehydration ring closure of all of the arboric acid structure of the polyamic acid (A) which is a precursor thereof, and the dehydration ring closure of only a part of the arboric acid structure, It may be a partially imide cargo. The polyimide (A) in the present invention preferably has an imidization ratio of 40% or more, more preferably 50 to 99%. The imidization rate is a percentage of the ratio of the number of imide ring structures to the sum of the number of amide structure and the number of imide ring structure of polyimide. A part of the imide ring may be an isoimide ring.

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

In the above method (i), the reaction temperature is preferably 50 to 200 캜, and more preferably 60 to 170 캜. If the reaction temperature is less than 50 ° C, the dehydration ring-closure reaction does not proceed sufficiently, and if the reaction temperature exceeds 200 ° C, the molecular weight of the obtained polyimide (A) may be lowered. The reaction time is preferably 0.5 to 48 hours, more preferably 2 to 20 hours.

On the other hand, in the method (ii), examples of the dehydrating agent include acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride. The amount of the dehydrating agent to be used is preferably 0.01 to 20 mol based on 1 mol of the acid structural unit. As the dehydration cyclization catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, triethylamine and N-methylpiperidine can be used. The amount of the dehydration ring-closing catalyst to be used is preferably 0.01 to 10 mol based on 1 mol of the dehydrating agent to be used. As the organic solvent used in the dehydration ring-closure reaction, a solvent exemplified as an organic solvent used for the synthesis of the polyamic acid (A) can be mentioned. The reaction temperature of the dehydration cyclization reaction is preferably 0 to 180 캜, more preferably 10 to 150 캜. The reaction time is preferably 0.5 to 20 hours, more preferably 1 to 8 hours.

The polyimide (A) obtained by the above method (i) may be directly supplied to the preparation of the liquid crystal aligning agent, or may be provided in the preparation of the liquid crystal aligning agent after the obtained polyimide (A) is purified. On the other hand, in the above method (ii), a reaction solution containing the polyimide (A) is obtained. This reaction solution may be supplied directly to the preparation of a liquid crystal aligning agent or may be provided in the preparation of a liquid crystal aligning agent after removal of the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution, for example, by solvent substitution, (A) may be isolated and then supplied to the preparation of the liquid crystal aligning agent, or the polyimide (A) which has been isolated may be purified and then provided in the preparation of the liquid crystal aligning agent. The polyimide (A) can be isolated and purified by a known method.

&Lt; Polymer (A): polyamic acid ester &

The polyamic acid ester (hereinafter also referred to as &quot; polyamic acid ester (A) &quot;) as the polymer (A) in the present invention can be obtained, for example, Reacting an acid dianhydride with another diamine to obtain a polyamic acid, and then reacting the obtained polyamic acid with a compound having the specific structure and an epoxy group. The polyamic acid ester (A) may have only an amide ester structure, or may be a partial esterified product in which an amide structure and an amide ester structure coexist.

The polyamic acid (A), the polyamic acid ester (A) and the polyimide (A) obtained as described above preferably have a solution viscosity of 10 to 800 mPa · s when the solution is a 10 wt% And more preferably a solution viscosity of 15 to 500 mPa · s. The solution viscosity (mPa 占 퐏) of the polymer was determined by using a solution of these polymers (for example,? -Butyrolactone, N-methyl-2-pyrrolidone and the like) % Of the polymer solution at 25 占 폚 using an E-type rotational viscometer. The polyamic acid (A), the polyamic acid ester (A) and the polyimide (A) preferably have a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) of 500 to 300,000, More preferably 1,000 to 200,000.

[Polymer (A): polyorganosiloxane]

The polyorganosiloxane (hereinafter also referred to as &quot; polyorganosiloxane (A) &quot;) as the polymer (A) can be synthesized by suitably combining organic chemical methods. As an example thereof, there can be mentioned, for example, a polymer (hereinafter referred to as &quot; an epoxy group-containing polyorganosiloxane &quot;) obtained by hydrolysis and condensation of a hydrolyzable silane compound (s1) having an epoxy group or a mixture of the silane compound Siloxane "), and then reacting the obtained epoxy group-containing polyorganosiloxane with the carbonic acid (c1) having the specific structure.

The silane compound (s1) is not particularly limited as long as it is a hydrolyzable silane compound having an epoxy group. Specific examples thereof include, for example, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropyl 3-glycidyloxypropyldimethylethoxysilane, 2-glycidyloxyethyltrimethoxysilane, 2-glycidyloxyethyltriethoxysilane, 3-glycidyloxypropyldimethylethoxysilane, 2-glycidyloxyethylmethyldimethoxysilane, 2-glycidyloxyethylmethyldiethoxysilane, 2-glycidyloxyethyldimethylmethoxysilane, 2-glycidyloxyethyldimethylethoxysilane , 4-glycidyloxybutyltrimethoxysilane, 4-glycidyloxybutyltriethoxysilane, 4-glycidyloxybutylmethyldimethoxysilane, 4-glycidyloxybutylmethyldiethoxysilane, 4 -Glycidyloxybutyldimethylmethoxysilane, 4-glycidyloxybutyldimethylethoxysilane, 2- (3,4-epoxycyclohexyl) (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3- (3,4-epoxycyclohexyl) propyltrimethoxysilane, 3- (3,4-epoxy Cyclohexyl) propyltriethoxysilane and the like. As the silane compound (s1), one kind or a mixture of two or more kinds of them can be used.

Examples of other silane compounds that can be optionally used in the synthesis of the epoxy group-containing polyorganosiloxane include methyltrichlorosilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrichlorosilane, phenyl But are not limited to, trimethoxysilane, trimethoxysilane, phenyltriethoxysilane, methyldichlorosilane, methyldimethoxysilane, methyldiethoxysilane, dimethyldichlorosilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldichlorosilane, But are not limited to, diphenyldiethoxysilane, chlorodymethylsilane, methoxydimethylsilane, ethoxydimethylsilane, chlorotrimethylsilane, bromotrimethylsilane, iodotrimethylsilane, methoxytrimethylsilane, ethoxytrimethylsilane, tetramethoxysilane, tetra Ethoxysilane, octadecyltrichlorosilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, 3- (meth) acryloxy A ropil trichlorosilane, 3- (meth) acryloxy propyl trimethoxy silane, 3- (meth) acryloxy-propyltriethoxysilane, and the like silane. As the other silane compounds, one kind or a mixture of two or more kinds of them may be used. Further, in the present specification, "(meth) acryloxy" means acryloxy and methacryloxy.

The silane compound used in the synthesis of the polyorganosiloxane (A) preferably contains the silane compound (s1) in an amount of 10 to 100 mol%, more preferably 20 to 100 mol%, based on the total amount of the silane compound . When the other silane compound is used, the content thereof is preferably 30 mol% or less, more preferably 10 mol% or less, based on the total amount of the silane compound used in the synthesis.

The hydrolysis / condensation reaction of the silane compound in the above can be carried out by reacting one or more silane compounds as described above with water, preferably in the presence of a suitable catalyst and an organic solvent. In the hydrolysis-condensation reaction, the use ratio of water is preferably 0.5 to 100 moles, more preferably 1 to 30 moles, per 1 mole of the silane compound (total amount).

Examples of the catalyst that can be used in the hydrolysis / condensation reaction include an acid, an alkali metal compound, an organic base, a titanium compound, and a zirconium compound. Specific examples of these catalysts include acids such as hydrochloric acid, sulfuric acid, nitric acid, formic acid, oxalic acid, acetic acid, trifluoroacetic acid, trifluoromethanesulfonic acid, phosphoric acid and the like as acids; As the alkali metal compound, for example, sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide and the like; Examples of the organic base include primary and secondary organic amines such as ethylamine, diethylamine, piperazine, piperidine, pyrrolidine and pyrrole: triethylamine, tri-n-propylamine, tri- Tertiary organic amines such as butylamine, pyridine, 4-dimethylaminopyridine, diazabicycloundecene, and quaternary organic amines such as tetramethylammonium hydroxide; Respectively.

As the catalyst, an alkali metal compound or an organic base is preferred among the above-mentioned catalysts in that it is possible to suppress a side reaction such as ring-opening of an epoxy group, a point at which the rate of hydrolysis and condensation can be increased, Preferred are organic bases. The organic base is preferably a tertiary organic amine or a quaternary organic amine.

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

Examples of the organic solvent that can be used in the above hydrolysis-condensation reaction include hydrocarbons, ketones, esters, ethers, and alcohols. Specific examples thereof include, for example, toluene, xylene and the like as hydrocarbons; As the ketone, for example, methyl ethyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, diethyl ketone, cyclohexanone and the like; As the ester, for example, ethyl acetate, n-butyl acetate, i-amyl acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, ethyl lactate and the like; As the ether, for example, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, tetrahydrofuran, dioxane and the like; As the alcohol, for example, 1-hexanol, 4-methyl-2-pentanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n- Propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether and the like; Respectively. Of these, it is preferable to use a water-insoluble organic solvent. These organic solvents may be used singly or in combination of two or more.

The use ratio of the organic solvent in the hydrolysis and condensation reaction is preferably 10 to 10,000 parts by weight, more preferably 50 to 1,000 parts by weight, based on 100 parts by weight of the total silane compound used in the reaction.

The hydrolysis-condensation reaction is preferably carried out by dissolving the silane compound as described above in an organic solvent, mixing the solution with an organic base and water, and heating the mixture with, for example, an oil bath. In the hydrolysis-condensation reaction, the heating temperature is preferably 130 ° C or lower, more preferably 40 to 100 ° C. The heating time is preferably 0.5 to 12 hours, more preferably 1 to 8 hours. During the heating, the mixed solution may be stirred or refluxed. After completion of the reaction, it is preferable to wash the organic solvent layer collected from the reaction solution with water. At the time of this cleaning, cleaning is preferably performed by using water containing a small amount of a salt (for example, an aqueous solution of ammonium nitrate of about 0.2 wt%) from the standpoint of facilitating the cleaning operation. The washing is carried out until the water layer after the washing becomes neutral. Thereafter, the organic solvent layer is dried with a desiccant such as anhydrous calcium sulfate and molecular sieves, if necessary, and then the solvent is removed to obtain the objective polyorganosiloxane (Epoxy group-containing polyorganosiloxane) can be obtained.

Next, the epoxy group-containing polyorganosiloxane obtained by the hydrolysis-condensation reaction is reacted with the carboxylic acid (c1) having the specific structure. Thereby, the polyorganosiloxane (A) having the specific structure in the side chain can be obtained. The carbonic acid to be used in this reaction may be carbonic acid (c1) alone, or may contain carbonic acid (c1) together with carbon having a group having a function of aligning liquid crystal molecules (hereinafter also referred to as "liquid crystal aligning group" At least one of the acid (c2) and the other carbon acid (c3) may be used.

Here, the remaining structure of the carboxylic acid (c1) is not particularly limited as long as it has the specific structure and the carboxyl group. Specific examples thereof include 3-benzoylbenzoic acid, 4-benzoylbenzoic acid, 3- (4-diethylamino-2-hydroxybenzoyl) benzoic acid, 4- (2-hydroxybenzoyl) Benzoyl-phenoxy) benzoic acid, 4- (4-methylbenzoyl) benzoic acid, 4- (3,4-dimethylbenzoyl) 3- (9,10-dioxo-9,10-dihydroanthracen-2-yl) propionic acid, 3- [ 4-dienyl) propoxy] -acetic acid, 3,5-dinitrobenzoic acid, 4-methyl-3,5-dinitrobenzoic acid, 3 Methyl-3,5-dinitrobenzoic acid, 4-phenylbenzoic acid, 11 - ((4'-nitro- [1,1'-biphenyl] -4 -Yl) oxy) undecanoic acid, and the like.

The remaining structure of the carboxylic acid (c2) is not particularly limited as long as it has a liquid crystal aligning group and a carboxyl group. Examples of the liquid crystal aligning group include an alkyl group having 4 to 20 carbon atoms, an alkoxy group or a fluoroalkyl group, a group having a steroid skeleton having 17 to 51 carbon atoms, a group having a polycyclic structure, and the like.

Specific examples of such a carboxylic acid (c2) include 4-butyloxybenzoic acid, 4-pentyloxybenzoic acid, 4-hexyloxybenzoic acid, 4-heptyloxybenzoic acid, 4-octyloxybenzoic acid, 4-undecyloxybenzoic acid, 4-undecyloxybenzoic acid, 4-tridecyloxybenzoic acid, 4-tetradecyloxybenzoic acid, 4-pentadecyloxybenzoic acid, 4-hexadecyloxybenzoic acid, 4- 4-octadecyloxybenzoic acid, 4-octadecyloxybenzoic acid, 4- (4-propylcyclohexyl) benzoic acid, 4- (4-butylcyclohexyl) benzoic acid, 4- Benzoic acid, 4- (4-heptylcyclohexyl) benzoic acid, 4- (4'-propylcyclohexyl) benzoic acid, 4- (4'-butylbicyclohexyl-4-yl) benzoic acid, 4- (4'-butylbicyclohexyl- Cyclohexyl-4-yl (4'-heptylbicyclohexyl-4-yl) benzoic acid, 4- (4- (4-pentylcyclohexyl) phenoxy) undecanoic acid and the like.

The carbonic acid (c3) is a carbonic acid other than the carbonic acid (c1) and the carbonic acid (c2). Specific examples thereof include formic acid, acetic acid, propionic acid, benzoic acid, and methylbenzoic acid.

The use ratio of the carboxylic acid (c1) is preferably 0.02 to 0.5 mole, more preferably 0.05 to 0.4 mole, and more preferably 0.05 to 0.3 mole per mole of the epoxy group of the epoxy group-containing polyorganosiloxane used in the reaction . The use ratio of the carboxylic acid (c2) is preferably 0.7 mol or less, more preferably 0.2 to 0.6 mol, per 1 mol of the epoxy group of the epoxy group-containing polyorganosiloxane used in the reaction. The use ratio of the carboxylic acid (c3) is preferably 0.3 mol or less, more preferably 0.2 mol or less, per 1 mol of the epoxy group of the epoxy group-containing polyorganosiloxane used in the reaction.

The polyorganosiloxane (A) in the present invention preferably has an epoxy equivalent of 5,000 g / mol or less, and more preferably 500 to 3,000 g / mol. Therefore, as to the use ratio of the total of the carbonic acid (c1), (c2) and (c3), it is preferable to appropriately adjust the epoxy equivalent of the polyorganosiloxane (A) to fall within the above range.

The reaction of the epoxy group of the epoxy group-containing polyorganosiloxane with the carboxylic acid can be preferably carried out in the presence of a catalyst and an organic solvent. As the catalyst used in the reaction, for example, known compounds such as so-called curing accelerators for promoting the reaction of organic bases and epoxy compounds can be used.

The organic base includes, for example, primary and secondary organic amines such as ethylamine, diethylamine, piperazine, piperidine, pyrrolidine and pyrrole; Tertiary organic amines such as triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine, 4-dimethylaminopyridine and diazabicycloundecene; Quaternary organic amines such as tetramethylammonium hydroxide; And the like. As the organic base, a tertiary organic amine or a quaternary organic amine is preferable.

Examples of the curing accelerator include tertiary amines, imidazole compounds, organic phosphorus compounds, quaternary phosphonium salts, diazabicycloalkenes, organometallic compounds, quaternary ammonium salts, boron compounds and metal halide compounds. A known one as a latent curing accelerator may be used.

The catalyst may be used in an amount of preferably 100 parts by weight or less, more preferably 0.01 to 100 parts by weight, and still more preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the polyorganosiloxane to be reacted with the carboxylic acid .

Examples of the organic solvent that can be used in the reaction between the polyorganosiloxane and the carboxylic acid include hydrocarbon, ether, ester, ketone, amide, alcohol and the like. Of these, ethers, esters and ketones are preferred from the viewpoints of solubility of the raw materials and products and ease of purification of the products. The organic solvent preferably has a solid content concentration (a ratio of the total weight of components other than the solvent in the reaction solution to the total weight of the solution) of preferably 0.1 wt% or more, more preferably 5 to 50 wt% Ratio.

The reaction temperature is preferably 0 to 200 캜, more preferably 50 to 150 캜. The reaction time is preferably 0.1 to 50 hours, more preferably 0.5 to 20 hours. Further, after completion of the reaction, it is preferable to wash the organic solvent layer collected from the reaction solution with water. After washing with water, the organic solvent layer is dried, if necessary, with a suitable drying agent, and then the solvent is removed to obtain the objective polyorganosiloxane. Further, the polyorganosiloxane (A) in a state in which it is dissolved in the reaction solution without isolating the polyorganosiloxane (A) may be directly supplied to the preparation of the next liquid crystal aligning agent.

The polyorganosiloxane (A) contained in the liquid crystal aligning agent of the present invention preferably has a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) of 500 to 100,000, preferably 1,000 to 30,000 More preferable.

When the polymer (A) in the present invention is a main skeleton of a poly (meth) acrylate derivative, it can be synthesized, for example, as follows. First, a monomer material containing an epoxy group-containing monomer is polymerized to synthesize a poly (meth) acrylate derivative having an epoxy group, and then the derivative and a compound having the specific structure and a carboxyl group (for example, c1). Thus, a poly (meth) acrylate derivative having the specific structure in the side chain can be obtained.

The compound (A) contained in the liquid crystal aligning agent of the present invention may be used alone or in combination of two or more species selected from the group consisting of the low-molecular compound and the polymer (A). The liquid crystal aligning agent of the present invention is a liquid crystal aligning agent which can appropriately control the liquid crystal alignment on the film surface of the liquid crystal alignment film and reduce the decrease in the voltage holding ratio due to the light irradiation during the PSA treatment, It is preferable to include at least the polymer (A), the compound (A) is more preferably the polymer (A), and the polymer (A) having the specific structure in the side chain is particularly preferable.

&Lt; Polymer (B) >

When the liquid crystal aligning agent of the present invention contains only a low molecular compound as the compound (A), the liquid crystal aligning agent contains the polymer (B) having no specific structure as the polymer component together with the compound (A) . Examples of the polymer (B) that can be used as the main skeleton include polyamic acids, polyimides, polyamic acid esters, polyesters, polyamides, polyorganosiloxanes, cellulose derivatives, polyacetal derivatives, polystyrene derivatives, (Meth) acrylate derivatives, and the like. As the polymer (B), one or more kinds of polymers having a skeleton selected therefrom can be suitably selected and used.

The polymer (B) is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide and polyorganosiloxane, and is preferably at least one selected from the group consisting of polyamic acid, polyimide and polyorganosiloxane More preferably at least one selected.

The polymer (B) can be synthesized by appropriately combining the methods of organic chemistry. For example, a polyamic acid as the polymer (B) can be obtained by reacting a tetracarboxylic acid dianhydride exemplified as a compound used in the synthesis of the polyamic acid (A) with another diamine. The polyimide as the polymer (B) can be obtained by subjecting the polyamic acid as the polymer (B) to dehydration ring closure, and the polyamic acid ester can be obtained by esterifying the polyamic acid. Further, the polyorganosiloxane can be obtained by hydrolysis and condensation of at least one member selected from the group consisting of the silane compound (s1) and the other silane compounds. As for the reaction conditions of the respective polymers, the description of the polymer (A) can be applied.

When the compound (A) contained in the liquid crystal aligning agent of the present invention is a low molecular compound, the content of the compound (A) is preferably from 100 parts by weight of the polymer contained in the liquid crystal aligning agent Preferably 0.1 to 20 parts by weight, more preferably 0.5 to 15 parts by weight.

In the case where the liquid crystal aligning agent of the present invention contains the polymer (A) as the compound (A), in order to improve the solution characteristics and electric characteristics, the polymer (A) Polymer (B) may also be used. In this case, the content of the polymer (A) is preferably 1% by weight or more, more preferably 5 to 50% by weight based on the total amount of the polymer contained in the liquid crystal aligning agent.

As preferred embodiments of the liquid crystal aligning agent of the present invention, the polymer component includes (I) a polyorganosiloxane (A) alone; (II) an embodiment comprising at least one member selected from the group consisting of a polyamic acid (A) and a polyimide (A); (III) an embodiment comprising at least one member selected from the group consisting of a polyorganosiloxane (A), a polyamic acid (A) and a polyimide (A); (B) is at least one selected from the group consisting of a polyamic acid and a polyimide which does not have the specific structure (IV), and the polyorganosiloxane (A) and the other polymer (B) Sun; (B) is at least one selected from the group consisting of (V) a polyamic acid (A) and a polyimide (A), and the other polymer (B) At least one member selected from the group consisting of polyorganosiloxane, polyamic acid and polyimide; And the like. The blending ratios of the polyorganosiloxane, the polyamic acid and the polyimide in each mode can be arbitrarily set according to the application of the liquid crystal display element to be applied.

Among them, an aspect containing at least one of polyamic acid and polyimide is preferable in terms of mechanical strength, electrical characteristics, affinity with liquid crystal, etc., and the aspects of (II) and (IV) , And the embodiment of (IV) is particularly preferable.

The ratio of the polyorganosiloxane (A) to the polyamic acid and the polyimide (total) in the embodiment of the above (IV) is preferably 100 parts by weight or more based on the total amount of the polyorganosiloxane (A), the polyamic acid and the polyimide It is preferable that the polyorganosiloxane (A) is contained in an amount of 1 to 50 parts by weight, more preferably 2 to 40 parts by weight, and still more preferably 3 to 30 parts by weight.

The polymer (A) preferably contains 0.5 to 5 mmol / g, more preferably 1 to 4 mmol / g, of the specific structure as a whole of the polymer component in the liquid crystal aligning agent.

Further, in the present invention, by forming a liquid crystal alignment film using the liquid crystal aligning agent containing the compound (A), the reaction of the photopolymerizable compound (photopolymerizable monomer) contained in the liquid crystal layer during the light irradiation during the PSA treatment It can be deduced that it can help from the liquid crystal alignment film side. Thus, it can be deduced that a sufficient pretilt angle can be given even with a small light irradiation amount, and a decrease in the voltage holding ratio and a decrease in the response speed due to light irradiation can be suppressed.

<Other components>

The liquid crystal aligning agent of the present invention may contain other components as required. Such other components include, for example, a compound having at least one epoxy group in the molecule (hereinafter referred to as an &quot; epoxy group-containing compound &quot;) and a functional silane compound.

[Epoxy Compound]

The epoxy compound can be used to improve the adhesion to the substrate surface and electric characteristics in the liquid crystal alignment film. 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 ether N, N, N ', N'-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N, N-diglycidyl-benzylamine, N, N-diglycidylaminomethylcyclohexane, N, N -Diglycidyl-cyclohexylamine, and the like. When these epoxy compounds are added to the liquid crystal aligning agent, the blending ratio thereof 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 contained in the liquid crystal aligning agent.

[Functional silane compound]

The functional silane compound can be used for the purpose of improving the printability of a liquid crystal aligning agent. Examples of such a 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-triethoxysilylpropyl triethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 9-tri Methoxysilyl-3,6-diazanonyl acetate, methyl 9-trimethoxysilyl-3,6-diazanonanoate, N-benzyl-3-aminopropyltrimethoxysilane, Trimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane and the like, Can.

When these functional silane compounds are added to the liquid crystal aligning agent, the blending ratio thereof is preferably 2 parts by weight or less, more preferably 0.02 to 0.2 parts by weight per 100 parts by weight of the total amount of the polymers.

In addition to the above-exemplified compounds, compounds having at least one oxetanyl group in the molecule, an antioxidant, and the like may be used as the other components.

<Solvent>

The liquid crystal aligning agent of the present invention is constituted by dissolving a polymer component and optionally other optional components, if necessary, in an organic solvent.

Examples of the solvent used in the preparation of the liquid crystal aligning agent of the present invention include N-methyl-2-pyrrolidone,? -Butyrolactone,? -Butyrolactam, N, N-dimethylformamide, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, Propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol diisopropyl ether, diethylene glycol diisopropyl ether, Ethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether There may be mentioned the lactate, dipropylene glycol monomethyl ether (DPM), di-isobutyl ketone, isoamyl propionate, isoamyl isobutyrate, di-isopentyl ether, ethylene carbonate, propylene carbonate, and the like. 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 is heated to form a coating film which becomes a liquid crystal alignment film or a liquid crystal alignment film. At this time, when the solid concentration is less than 1% by weight, the film thickness of the coating film becomes too small to obtain a good liquid crystal alignment film. On the other hand, when the solid concentration exceeds 10% by weight, the film thickness of the coating film becomes excessively large, and it becomes difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal aligning agent is increased and the coating property is poor.

Particularly preferable range of the solid concentration varies depending on the method of applying the liquid crystal aligning agent to the substrate. For example, in the case of the spinner method, it is particularly preferable that the solid concentration is in the range of 1.5 to 4.5% by weight. In the case of the printing method, it is particularly preferable to set the solid concentration in the range of 3 to 9% by weight and the solution viscosity in the range of 12 to 50 mPa · s accordingly. In the case of the inkjet method, it is particularly preferable that the solid concentration is in the range of 1 to 5 wt%, and the solution viscosity is in the range of 3 to 15 mPa · s. 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.

<Liquid Crystal Alignment Film and Liquid Crystal Display Device>

The liquid crystal alignment film of the present invention is formed by the liquid crystal aligning agent prepared as described above and is used as a liquid crystal alignment film of a PSA mode liquid crystal display device. Further, the PSA mode liquid crystal display element of the present invention comprises the liquid crystal alignment film. (I) to (iii) below;

(i) a first step of applying the liquid crystal aligning agent of the present invention onto a conductive film of a pair of substrates each having a conductive film, and then heating the liquid crystal aligning agent to form a coated film,

(Ii) a second step of arranging a pair of substrates on which the coating film is formed, with the coating film facing each other via a liquid crystal layer containing a liquid crystalline compound,

(Iii) a third step of irradiating the liquid crystal cell with light while applying a voltage between the conductive films of the pair of substrates. Hereinafter, each of these steps will be described in detail.

[First Step: Formation of Coating Film]

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, and poly (alicyclic olefin) can be used. As the conductive film, is preferable to use a transparent conductive film is, for example, tin oxide (SnO ₂₎ made of a NESA film (US PPG Company registered trademark), indium oxide-tin oxide consisting of (In ₂ O ₃ -SnO ₂₎ ITO film or the like can be used. The conductive film is preferably a patterned conductive film divided into a plurality of regions. With such a conductive film, it is possible to change the pretilt angle direction of the liquid crystal molecules for each region by applying a different voltage in each region when a voltage is applied between the conductive films, thereby making it possible to widen the viewing angle characteristic .

The method of applying the liquid crystal aligning agent of the present invention on the surface of the pair of substrates on which the transparent conductive film is formed can be preferably performed by an offset printing method, a spin coating method, a roll coating method, or an inkjet printing method. When applying the liquid crystal aligning agent, a functional silane compound, a functional titanium compound or the like is preferably added to the surface of the substrate on which the coating film should be formed in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film The pre-treatment for pre-coating may be carried out.

After the liquid crystal aligning agent is applied to the substrate, preheating (prebaking) is preferably performed for the purpose of preventing the liquid flow of the applied liquid crystal aligning agent and the like. The prebaking temperature is preferably 30 to 200 캜, more preferably 40 to 150 캜, particularly preferably 40 to 100 캜. The prebaking time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes. Thereafter, the solvent is completely removed, and a firing (post-baking) process is carried out in order to thermally modify the structure of the acid in the polymer as required. The post-baking temperature is preferably 80 to 300 占 폚, and more preferably 120 to 250 占 폚. The post baking time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The film thickness of the film thus formed is preferably 0.001 to 1 占 퐉, and more preferably 0.005 to 0.5 占 퐉.

After the application of the liquid crystal aligning agent, the organic solvent is removed by heating, whereby a coating film to be an alignment film is formed. At this time, when the polymer contained in the liquid crystal aligning agent of the present invention is a polyamic acid, a polyamic acid ester, or an imidized polymer having an imidazole ring structure and an arboric acid structure, the dehydration ring- , Or a more imaged coating film may be used.

The coating film thus formed may be provided to the second step as it is, or may be provided to the second step after rubbing treatment on the coating film surface as necessary. This rubbing treatment can be performed by rubbing the coating film surface in a predetermined direction with a roll of cloth made of fibers such as nylon, rayon, and cotton.

[Second Step: Construction of Liquid Crystal Cell]

Two liquid crystal alignment layers are formed as described above, and a liquid crystal layer containing a liquid crystal compound and a photopolymerizable compound is disposed between two substrates arranged opposite to each other to produce a liquid crystal cell. To produce a liquid crystal cell, for example, the following two methods can be used. The first method is a conventionally known method (vacuum injection method). First, two substrates are opposed to each other with a gap (cell gap) interposed therebetween so that the respective liquid crystal alignment films face each other. The peripheral portions of the two substrates are bonded together using a sealant, A liquid crystal compound and a photopolymerizable compound are injected and filled into the cell gap, and then the injection port is sealed to manufacture a liquid crystal cell. The second method is a method called ODF (One Drop Fill) method. For example, an ultraviolet curable sealant is applied to a predetermined position on one of the two substrates on which the liquid crystal alignment film is formed, and further a liquid crystal compound and light After the mixture with the synthetic compound is dropped, the other substrate is bonded so that the liquid crystal alignment film faces the liquid crystal compound, and the liquid crystalline compound is spread over the entire surface of the substrate. Subsequently, ultraviolet light is irradiated to the entire surface of the substrate, To thereby produce a liquid crystal cell.

Regardless of the method, the liquid crystal cell produced as described above is further heated to a temperature at which the liquid crystalline compound used takes an isotropic phase, and then gradually cooled to room temperature to remove the flow orientation at the time of filling the liquid crystal It is also good.

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

As the liquid crystalline compound, a nematic liquid crystal having a negative dielectric anisotropy can be preferably used. For example, a dicyanobenzene-based liquid crystal, a pyridazine-based liquid crystal, a hepta base-based liquid crystal, Liquid crystal, phenylcyclohexane-based liquid crystal, terphenyl-based liquid crystal, and the like. As a liquid crystal compound, an alkenyl-based liquid crystal which is a monofunctional liquid crystal compound having any one of an alkenyl group and a fluoroalkenyl group is used in combination with a point that a response speed of a PSA mode liquid crystal display element can be made faster . As such alkenyl-based liquid crystals, conventionally known ones can be used, and examples thereof include compounds represented by the following formulas (L1-1) to (L1-9).

As the photopolymerizable compound, a compound having a functional group capable of radical polymerization such as acryloyl group, methacryloyl group, vinyl group and the like can be used. From the viewpoint of reactivity, it is preferable to use a polyfunctional compound having at least two or more of acryloyl group and methacryloyl group among them. From the standpoint of stably maintaining the orientation properties of the liquid crystal molecules, it is preferable to use, as the liquid crystal skeleton, a compound having at least one ring of at least any one of cyclohexane ring and benzene ring in total. As the photopolymerizable compound, conventionally known ones can be used. The compounding ratio of the photopolymerizable compound is preferably 0.1 to 0.5 wt% with respect to the total amount of the liquid crystalline compound to be used. The thickness of the liquid crystal layer is preferably 1 to 5 mu m.

[Third step: light irradiation step]

After the formation of the liquid crystal cell, the liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates. The voltage to be applied here may be DC or AC of 5 to 50 V, for example. As the light to be irradiated, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used, but ultraviolet rays including light having a wavelength of 300 to 400 nm are preferable. As the light source of the irradiation light, 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 and an excimer laser can be used. The ultraviolet ray in the above-mentioned preferable wavelength range can be obtained by a means for using the light source together with, for example, a filter diffraction grating or the like. The irradiation dose of light is preferably 1,000 J / m 2 or more and less than 200,000 J / m 2, and more preferably 1,000 to 100,000 J / m 2.

It is also necessary to irradiate light of about 100,000 J / m 2 at the time of manufacturing a conventionally known PSA mode liquid crystal display device. However, according to the method of the present invention, the light irradiation amount is 50,000 J / M &lt; 2 &gt; or less, a desired liquid crystal display element can be obtained. Therefore, in addition to contributing to the reduction of the manufacturing cost of the liquid crystal display element, it is possible to avoid a decrease in the voltage holding ratio and a decrease in the response speed of the liquid crystal due to the strong light irradiation.

Then, the PSA mode liquid crystal display device can be obtained by bonding the polarizing plate to the outer surface of the liquid crystal cell after light irradiation. Examples of the polarizing plate used herein include a polarizing plate in which a polarizing film called "H film" in which iodine is absorbed while polyvinyl alcohol is oriented in a stretched state, a polarizing plate sandwiched by a cellulose acetate protective film, or a polarizing plate made of H film itself.

The PSA mode liquid crystal display device of the present invention can be effectively applied to various apparatuses and can be applied to various devices such as a clock, a portable game, a word processor, a notebook PC, a car navigation system, a camcorder, a PDA, A telephone, a smart phone, various monitors, a liquid crystal television, and an information display.

[Example]

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to these examples.

The weight average molecular weight, the epoxy equivalent, the solution viscosity of each polymer solution, and the imidation rate of polyimide of each polymer in each synthesis example were measured by the following methods.

[Weight average molecular weight of polymer]

The weight average molecular weight Mw of the polymer is a polystyrene reduced value measured by gel permeation chromatography under the following conditions.

Column: TSKgelGRCXLII, manufactured by Tosoh Corporation

Solvent: tetrahydrofuran

Temperature: 40 ° C

Pressure: 68kgf / ㎠

[Epoxy equivalent]

The epoxy equivalent is a value measured in accordance with the "hydrochloric acid-methyl ethyl ketone method" of JIS C2105.

[Solution viscosity of polymer solution]

The solution viscosity [mPa 占 퐏] of the polymer solution was measured at 25 占 폚 using an E-type rotational viscometer for a solution prepared by using a predetermined solvent at a polymer concentration of 10% by weight.

[Imidization Rate of Polyimide]

The polyimide solution was poured into pure water, and the obtained precipitate was sufficiently dried under reduced pressure at room temperature. The precipitate was dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference material. From the obtained ¹ H-NMR spectrum, the imidization ratio [%] was obtained from the formula shown in the following formula (1): &lt; EMI ID =

Imidization rate [%] = {(1-A ¹ ) / (A ² x?)} 100 ... (One)

(In the formula (1), A ¹ is the peak area derived from the proton of the NH group near the chemical shift of 10 ppm, A ² is the peak area derived from the other proton, and α is the peak area derived from the proton The ratio of the number of other protons to one proton in the NH group).

&Lt; Synthesis of Polymer &

[Synthesis Example P1: Synthesis of polyimide (A) (side chain introduction type)]

112 g (0.50 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride (TCA) as tetracarboxylic acid dianhydride and 49 g (0.10 mol) of cholestanyloxy-2,4-diaminobenzene as diamine, 9 (0.15 mol) of 9-bis (4-aminophenyl) fluorene, 67 g of 1- (4-aminophenyl) -2,3-dihydro-1,3,3-trimethyl- (0.25 mol) were dissolved in 750 g of N-methyl-2-pyrrolidone (NMP), and the reaction was carried out at 60 DEG C for 6 hours to obtain a solution containing polyamic acid. A small amount of the obtained polyamic acid solution was collected and NMP was added to the solution to measure a solution viscosity of 10 wt% of polyamic acid. The viscosity of the solution was 900 mPa · s.

Subsequently, 63 g of NMP was added to the obtained polyamic acid solution, 3.8 g of N-methylpiperidine and 10.6 g of acetic anhydride were added, and the dehydration ring-closure reaction was carried out at 80 DEG C for 8 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The recovered precipitate was washed with methanol and dried at 40 ° C under reduced pressure for 15 hours to obtain a polyimide (P-1) having an imidization rate of about 50% as the polymer (A). The obtained polyimide (P-1) was adjusted to 10 wt% in NMP. The viscosity of this solution was measured and found to be 330 mPa · s.

[Synthesis Example P2: Synthesis of polyimide (A) (main chain introduction type)]

The procedure of Synthesis Example P1 was repeated except that 32 g (0.15 mol) of 4,4'-diaminobenzophenone was used instead of 9,9-bis (4-aminophenyl) fluorene to give a solution containing polyamic acid . A small amount of the obtained polyamic acid solution was collected and NMP was added to the solution to measure a solution viscosity of 10 wt% of polyamic acid. The viscosity of the solution was 1,050 mPa · s. The obtained polyamic acid solution was used in the same manner as in Synthesis Example P1 to obtain a polyimide (P-2) having an imidization rate of about 50% as the polymer (A). The obtained polyimide (P-2) was adjusted to 10 wt% in NMP. The viscosity of this solution was measured and found to be 420 mPa · s.

[Synthesis Example P3: Synthesis of Polymer (B) (Synthesis of polyimide)

The procedure of Synthesis Example P1 was repeated except that 23 g (0.15 mol) of 3,5-diaminobenzoic acid was used instead of 9,9-bis (4-aminophenyl) fluorene to obtain a solution containing polyamic acid. A small amount of the obtained polyamic acid solution was collected, and NMP was added thereto. The solution viscosity was measured as a solution having a polyamic acid concentration of 10 wt%, and the solution viscosity was 2,400 mPa · s.

Subsequently, 330 g of NMP was added to the resulting polyamic acid solution, and 25 g of N-methylpiperidine and 25.5 g of acetic anhydride were added, followed by dehydration ring-closure reaction at 80 DEG C for 8 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The recovered precipitate was washed with methanol and then dried under reduced pressure at 40 占 폚 for 15 hours to obtain a polyimide (P-3) having an imidization rate of about 50% as the polymer (B). The obtained polyimide (P-3) was adjusted to 10 wt% in NMP. The viscosity of this solution was measured and found to be 340 mPa · s.

Synthesis Example S1: Synthesis of polyorganosiloxane (A)

246 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (ECETS) as a hydrolyzable silane compound and 500 g of methyl isobutyl ketone as a solvent were charged in a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser tube, And 10.0 g of triethylamine as a catalyst were added and mixed at room temperature. Subsequently, 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and the mixture was reacted under reflux at 80 DEG C for 6 hours while stirring. After completion of the reaction, the organic layer was taken out, washed with a 0.2 wt% aqueous ammonium nitrate solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure to obtain a hydrolyzed condensate (PECETS) As a viscous transparent liquid. As a result of ¹ H-NMR analysis of this hydrolysis-condensation product, it was confirmed that a peak attributed to the epoxy group was obtained in the vicinity of the chemical shift (?) = 3.2 ppm in accordance with the theoretical intensity, and no side reaction of the epoxy group occurred during the reaction .

Subsequently, in the 200 mL three-necked flask, the above-obtained hydrolyzed condensate (PECETS) having an epoxy group, 30.0 g of methyl isobutyl ketone as a solvent, and 25.0 g of 4-octyloxybenzoic acid as a carbonic acid ) And 19.9 g of 11 - ((4'-nitro- [1,1'-biphenyl] -4-yl) oxy) undecanoic acid (corresponding to 20 mol% based on the hydrolyzable silane compound used as the raw material) And 0.10 g of tetrabutylammonium bromide (TBAB, which is a curing accelerator of an epoxy compound) as a catalyst, and the reaction was carried out at 100 ° C for 2 hours with stirring. After completion of the reaction, ethyl acetate was added to the reaction mixture, and the resulting organic layer was washed with water five times, dried over magnesium sulfate and then the solvent was distilled off to obtain 251.2 g of a polyorganosiloxane (S-1) . The weight average molecular weight Mw of the polyorganosiloxane (S-1) in terms of polystyrene measured by gel permeation chromatography (GPC) was 7,200.

Synthesis Example S2: Synthesis of polyorganosiloxane (A)

The carbonic acid used was changed to 11- (4- (4-pentylcyclohexyl) phenoxy) undecanoic acid (corresponding to 20 mol% based on the hydrolyzable silane compound used as the raw material) and 4-phenylbenzoic acid (S-2), which is a polymer (A), was obtained in the same manner as in Synthesis Example S1 except that the amount of the polyorganosiloxane was changed to 10 mol% based on the decomposable silane compound. The weight average molecular weight Mw of the polyorganosiloxane (S-2) in terms of polystyrene as measured by GPC was 7,500.

The compounding amount (molar ratio) of the compound used in the synthesis of the polymer is shown in Table 1 below. The polyimide represents the ratio of each compound to the total number of moles of the tetracarboxylic acid dianhydride and diamine used in the synthesis. As for the polyorganosiloxane, the use ratio (molar ratio) of each compound to the sum of the hydrolyzable silane compounds used in the synthesis of the epoxy group-containing polyorganosiloxane is shown.

The abbreviations of the respective compounds in Table 1 are as follows.

(Diamine)

d-1; 9,9-bis (4-aminophenyl) fluorene

d-2; 4,4'-diaminobenzophenone

d-3; Cholestanyloxy-2,4-diaminobenzene

d-4; 1- (4-aminophenyl) -2,3-dihydro-1,3,3-trimethyl-1H-inden-

d-5; 3,5-diaminobenzoic acid

(Carbonic acid)

CA-1; 4-octyloxybenzoic acid

CA-2; 11 - ((4'-Nitro- [1,1'-biphenyl] -4-yl) oxy) undecanoic acid

CA-3; 11- (4- (4-pentylcyclohexyl) phenoxy) undecanoic acid

CA-4; 4-phenylbenzoic acid

&Lt; Preparation of liquid crystal composition &

[Preparation of liquid crystal composition LC1]

5 wt% of the liquid crystalline compound represented by the formula (L1-1) and 0.3 wt% of the photopolymerizable compound represented by the following formula (L2-1) were added to 10 g of a nematic liquid crystal (MLC-6608, Were added and mixed to obtain a liquid crystal composition LC1.

[Example 1]

&Lt; Preparation of liquid crystal aligning agent &

NMP and butyl cellosolve (BC) were added as an organic solvent to a solution containing the polyimide (P-1) obtained in the above Synthesis Example P1 as the compound (A), and the solvent composition was NMP: BC = 50:50 Weight ratio) and a solid concentration of 6.0 wt%. This solution was filtered using a filter having a pore diameter of 1 mu m to prepare a liquid crystal aligning agent.

&Lt; Evaluation of printability >

The printability of the liquid crystal aligning agent prepared above was evaluated. First, the aforementioned liquid crystal aligning agent was applied to the transparent electrode surface of a glass substrate with a transparent electrode formed of an ITO film using an offset type liquid crystal alignment film printing machine (manufactured by Nippon Sha Shingen Co., Ltd.) (Post-baking) on a hot plate at 200 ° C for 10 minutes to measure an average film thickness of 600 Å as measured with a contact-type film gauge (manufactured by KLA Tencor Corporation) for 1 minute on a hot plate To form a coating film. This coating film was observed under a microscope with a magnification of 20 times to examine the presence of printing unevenness and pinholes. The evaluation was made with printability &quot; good &quot; when print unevenness and pinholes were not observed, and printability &quot; poor &quot; when at least one of print unevenness and pinholes were observed. As a result, no printing unevenness or pinholes were observed in the coating film formed using the liquid crystal aligning agent prepared above, and the printability was "good".

&Lt; Evaluation of Film Thickness Uniformity &

With respect to the coating film formed above, the film thickness at the central portion of the substrate and the film thickness at the position shifted from the outer edge of the substrate by 15 mm at the center were measured using a contact type film thickness gauge (manufactured by KLA Tencor Corporation) Respectively. The film thickness uniformity was evaluated as &quot; good &quot; when the film thickness difference was 20 angstrom or less, and the film thickness uniformity was &quot; defective &quot; when the film thickness difference was more than 20 angstrom. As a result, in the coating film formed using the liquid crystal aligning agent, the difference in film thickness between the center and the end was small and the film thickness uniformity was "good".

&Lt; Production and evaluation of liquid crystal cell &

Using the liquid crystal aligning agent prepared above, the patterns (two kinds) of transparent electrodes and the ultraviolet ray irradiation amount (three levels) were changed to produce a total of six liquid crystal display elements. Various evaluations were made on the liquid crystal cells produced.

[Production of liquid crystal cell having transparent electrode without pattern]

The above liquid crystal aligning agent was coated on the transparent electrode surface of a glass substrate having a transparent electrode made of an ITO film using a liquid crystal alignment film printing machine (manufactured by Nippon Sha Sein Insights Co., Ltd.), and heated on a hot plate at 80 캜 for 1 minute (Prebaked) to remove the solvent, and then heated on a hot plate at 150 ° C for 10 minutes (post baking) to form a coating film having an average film thickness of 600 Å. The coating film was subjected to a rubbing treatment with a rubbing machine having a roll covered with a rayon hot spring 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 the substrate was dried in a 100 占 폚 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. The rubbing treatment is a weak rubbing treatment performed for the purpose of controlling the inclination of the liquid crystal and performing the orientation division by a simple and easy method.

Next, one of the pair of substrates was coated with an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 mu m on the outer edge of the surface having the liquid crystal alignment film, and then a pair of substrates was laminated on the liquid crystal alignment film surface And the adhesive was cured by pressing. Subsequently, the liquid crystal composition LC1 prepared above 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 photo-curable adhesive to produce a liquid crystal cell.

The above operation was repeated to produce three liquid crystal cells each having a pattern-free transparent electrode. One of them was provided for evaluation of the pretilt angle described later. For the remaining two liquid crystal cells, 10 V of alternating current of 60 Hz was applied between the electrodes, and in the state where the liquid crystal was driven, the light source was irradiated with ultraviolet rays using a metal halide lamp at 10,000 J / / M &lt; 2 &gt; and then provided for the evaluation of pretilt angle and voltage maintenance rate. This irradiation dose is a value measured using a photometer which is measured based on a wavelength of 365 nm.

[Evaluation of Pretilt Angle]

Using the liquid crystal cell manufactured as described above, the method described in T. J. Scheffer et al., J. Appl. Phys. vo. 19, p. 2013 (1980) ", the value of the inclination angle of the liquid crystal molecules measured from the substrate surface by the crystal rotation method using the He-Ne laser light was taken as the pretilt angle. Table 2 shows the pretilt angles of the liquid crystal cell of the tail lamp, the liquid crystal cell of the dose of 10,000 J / m 2, and the liquid crystal cell of the dose of 100,000 J / m 2.

[Evaluation of Voltage Conservation Rate]

For each of the liquid crystal cells prepared above, a voltage of 5 V was applied at 23 DEG C for an application time of 60 microseconds and a span of 167 milliseconds, and the voltage maintenance ratio after 167 milliseconds from the application of the release voltage was measured. As the measuring device, VHR-1 manufactured by Toyotecnica Co., Ltd. was used.

Table 2 shows the voltage holding ratios of the liquid crystal cell having a dose of 10,000 J / m 2 and the liquid crystal cell having a dose of 100,000 J / m 2.

[Production of liquid crystal cell having patterned transparent electrode]

The liquid crystal aligning agent prepared in the above was patterned in a slit shape as shown in Fig. 1, and on each electrode surface of two glass substrates each having ITO electrodes partitioned into a plurality of regions, a liquid crystal alignment film printing machine (Nippon Sha Shin Insetsu Ltd.) and heated on a hot plate at 80 ° C for 1 minute (prebaking) to remove the solvent. Subsequently, the film was heated (post baking) on a hot plate at 150 DEG C for 10 minutes to form 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 They were superimposed and pressed to cure the adhesive. Subsequently, the liquid crystal composition LC1 prepared above 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 photo-curable adhesive to produce a liquid crystal cell.

The above operation was repeated to produce three liquid crystal cells having patterned transparent electrodes. One of them provided the evaluation of the response speed as described below. The remaining two liquid crystal cells were irradiated with light at an irradiation dose of 10,000 J / m &lt; 2 &gt; or 100,000 J / m &lt; 2 &gt; under a voltage applied between the conductive films by the same method as in the production of the liquid crystal cell having the patternless transparent electrode. After the investigation, it was provided to the evaluation of the response speed. The electrode pattern used here is a pattern similar to the electrode pattern in the PSA mode.

[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 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 AC voltage of 10 V was applied for 5 seconds between the electrodes of the liquid crystal cell was measured in the same manner as described above, and the relative transmittance was 100%. When 10 V of AC was applied to each liquid crystal cell, the time from when the relative transmittance was changed from 10% to 90% was measured, and this time was defined as a response speed. Table 2 shows the response speeds of the liquid crystal cell of the tail lamp, the liquid crystal cell of the dose of 10,000 J / m 2 and the liquid crystal cell of the dose of 100,000 J / m 2.

[Example 2]

A liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the polyimide (P-2) obtained in Synthesis Example P2 was used as the compound (A). Various evaluations were made in the same manner as in Example 1 using this liquid crystal aligning agent. The evaluation results are shown in Table 2 above.

[Example 3]

NMP and BC as organic solvents were added to a solution containing polyimide (P-3) obtained in Synthesis Example P3 and benzophenone was further added as a compound (A) to 80 weight parts of polyimide (P-3) (6.25 parts by weight based on 100 parts by weight of polyimide (P-3)) was added to the solution, to obtain a solution having a solvent composition of NMP: BC = 50:50 (weight ratio) and a solid concentration of 6.0% by weight. This solution was filtered using a filter having a pore size of 1 탆 to prepare a liquid crystal aligning agent. Various evaluations were made in the same manner as in Example 1 using this liquid crystal aligning agent. The evaluation results are shown in Table 2 above.

[Example 4]

NMP and BC were added as organic solvents to the solution containing polyimide (P-3) obtained in Synthesis Example P3 and the polyorganosiloxane (S-1) obtained in Synthesis Example S1 as Compound (A) 5 parts by weight based on 95 parts by weight of the polyimide (P-3) were added to prepare a solution having a solvent composition of NMP: BC = 50: 50 (weight ratio) and a solid concentration of 6.0% by weight. This solution was filtered using a filter having a pore size of 1 탆 to prepare a liquid crystal aligning agent. Various evaluations were made in the same manner as in Example 1 using this liquid crystal aligning agent. The evaluation results are shown in Table 2 above.

[Example 5]

A liquid crystal aligning agent was prepared in the same manner as in Example 4, except that the polyorganosiloxane (S-2) was used instead of the polyorganosiloxane (S-1). Various evaluations were made in the same manner as in Example 1 using this liquid crystal aligning agent. The evaluation results are shown in Table 2 above.

[Comparative Example 1]

The procedure of Example 1 was repeated except that the solution containing polyimide (P-3) obtained in Synthesis Example P3 was used instead of the solution containing polyimide (P-1) To prepare a liquid crystal aligning agent. Various evaluations were made in the same manner as in Example 1 using this liquid crystal aligning agent. The evaluation results are shown in Table 2 above.

As shown in Table 2, in Examples 1 to 5, a high voltage holding ratio was maintained after ultraviolet irradiation of the liquid crystal cell, and the response speed was also good. In Examples 1 to 5, a suitable pre-tilt angle was shown at a light irradiation dose of 10,000 J / m &lt; 2 &gt;. In addition, a sufficiently fast response speed was obtained even with a small irradiation dose, and the voltage maintenance rate was also good. Particularly, when an alkenyl-based liquid crystal is used as a liquid crystal, a decrease in the voltage holding ratio due to ultraviolet irradiation tends to increase. In Examples 1 to 5, however, a high voltage holding ratio was exhibited even after ultraviolet irradiation. In addition, the printability and film uniformity of the liquid crystal aligning agent were also good. From these results, it can be said that according to the liquid crystal aligning agent of the present invention, the advantage of the PSA mode can be manifested at a light irradiation amount which is small. On the other hand, in Comparative Example 1, a proper pretilt angle was not exhibited at a light irradiation dose of 10,000 J / m 2. Also, the decrease in the voltage holding ratio due to ultraviolet irradiation was remarkable.

A liquid crystal cell was manufactured in the same manner as in Example 1 except that the pattern of the ITO electrode on the glass substrate was changed to the electrode pattern of Fig. 2 and Fig. 3, respectively, with respect to each of the liquid crystal aligning agents used in Examples 1 to 5 And various evaluations were conducted. Even in this case, the same effects as those of Examples 1 to 5 were obtained.

1: ITO electrode
2:
3:

Claims (9)

(A) having a structure (a) capable of exhibiting at least any one of a radical generating function of generating a radical by light irradiation and a photosensitizing function exhibiting a depressing action by light irradiation, and a PSA mode liquid crystal display element Liquid crystal aligning agent. The method according to claim 1,
The liquid crystal aligning agent for a PSA mode liquid crystal display element wherein the compound (A) is a polymer having the structure (a) in the side chain. The method according to claim 1,
Wherein the compound (A) is at least one polymer selected from the group consisting of polyamic acid, polyimide, polyamic acid ester and polyorganosiloxane. The method according to claim 1,
The liquid crystal aligning agent for a PSA mode liquid crystal display element wherein the compound (A) has, as the structure (a), at least a structure capable of exhibiting the photosensitizing function. The method according to claim 1,
Wherein the liquid crystal layer contains a monofunctional liquid crystal compound having one of an alkenyl group and a fluoroalkenyl group in the liquid crystal layer. A first step of applying the liquid crystal aligning agent according to any one of claims 1 to 5 onto each of the conductive films of a pair of substrates having a conductive film and then heating them to form a coated film,
A second step of constructing a liquid crystal cell by arranging a pair of substrates on which the coating film is formed so as to face each other with the liquid crystal layer containing a liquid crystal compound interposed therebetween,
A third step of irradiating the liquid crystal cell with light while a voltage is applied between the conductive films of the pair of substrates
Wherein the liquid crystal display element is a liquid crystal display element. The method according to claim 6,
Wherein the liquid crystal layer contains a monofunctional liquid crystal compound having any one of an alkenyl group and a fluoroalkenyl group as the liquid crystal compound. A liquid crystal alignment film for a PSA mode liquid crystal display element formed using the liquid crystal aligning agent according to any one of claims 1 to 5. 9. A PSA mode liquid crystal display element having the liquid crystal alignment film according to claim 8.

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