JP2014186301A - Composition for liquid crystal display element, and liquid crystal display element and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display element having a good fast responsiveness and voltage retention characteristic.SOLUTION: A composition for a liquid crystal display element is provided, to be used for forming at least one of a liquid crystal layer and a liquid crystal alignment layer of a liquid crystal display element. The composition includes a compound (A) having a structure that can develop a chain-transfer function.

Description

  The present invention relates to a composition for a liquid crystal display element, a liquid crystal display element and a method for producing the same.

  In general, a liquid crystal display element includes a liquid crystal layer including liquid crystal molecules between a pair of substrates arranged opposite to each other, and a liquid crystal alignment layer (liquid crystal alignment film) that is disposed so as to sandwich the liquid crystal layer and controls the liquid crystal molecules to a desired alignment state. ). Conventionally, as a liquid crystal display element, various drive systems having different electrode structures and physical properties of liquid crystal molecules to be used have been developed. For example, an MVA (Multi-Domain Vertical Alignment) type panel conventionally known as a vertical alignment mode is intended to expand the viewing angle by regulating the tilting direction of liquid crystal molecules by projections formed in the liquid crystal panel. . However, according to this method, there are problems that the transmittance and contrast due to the protrusions are unavoidable and the response speed of the liquid crystal molecules is slow.

  In recent years, in order to solve the problems of the MVA panel, a PSA (Polymer Sustained Alignment) mode has been proposed as a new driving mode for controlling the alignment of liquid crystal molecules. In the PSA mode, a photopolymerizable monomer is mixed in a liquid crystal material, a liquid crystal cell is assembled, and then light is applied to the liquid crystal cell with a voltage applied between a pair of electrodes sandwiching the liquid crystal layer. This is a technique for controlling the molecular orientation of liquid crystal molecules by polymerizing polymerizable monomers. According to this technique, there is an advantage that the viewing angle can be increased and the response speed can be increased. In recent years, further rapid response of PSA type liquid crystal panels has been studied. As such a technique, a monofunctional liquid crystal compound having one of an alkenyl group and a fluoroalkenyl group (hereinafter referred to as “alkenyl”). Attempts have been made to introduce a liquid crystal layer into a liquid crystal layer (see, for example, Patent Documents 1 to 3).

JP 2010-285499 A JP-A-9-104644 JP-A-6-108053

  Since the liquid crystal display element is used as a display device such as a liquid crystal television, there is a high demand for high-speed response. From the viewpoint of further improving the quality of the liquid crystal display element, a material for obtaining a liquid crystal display element having better high-speed response than conventional ones is desired.

  In addition, in a liquid crystal display element using alkenyl liquid crystals, the response speed can be increased, but by irradiating light during polymerization of the photopolymerizable monomer, the liquid crystal cell does not contain the alkenyl liquid crystals. It has become clear that the decrease in the voltage holding ratio is greater than that. 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 even after light irradiation.

  The present invention has been made in view of the above problems, and a main object of the present invention is to provide a composition for a liquid crystal display element capable of obtaining a liquid crystal display element having good high-speed response and voltage holding characteristics.

  As a result of intensive studies to achieve the above-described problems of the prior art, the present inventors have incorporated a compound capable of expressing a specific function into at least one of the liquid crystal alignment layer and the liquid crystal layer of the liquid crystal display element. It has been found that the above problems can be solved, and the present invention has been completed. Specifically, the present invention provides the following composition for a liquid crystal display element, a liquid crystal display element and a method for producing the same, and a liquid crystal alignment film.

  In one aspect, the present invention provides a composition for a liquid crystal display element for forming at least one of a liquid crystal layer and a liquid crystal alignment layer of a liquid crystal display element, which has a structure capable of developing a chain transfer function (A The composition for liquid crystal display elements containing this is provided. As a preferred embodiment of the composition, a liquid crystal aligning agent containing a compound (A) having a structure capable of developing a chain transfer function is provided. As another preferred embodiment of the composition, a liquid crystal composition comprising a liquid crystal compound, a photopolymerizable compound, and a compound (A) having a structure capable of developing a chain transfer function is provided. These liquid crystal display element compositions can be preferably applied to PSA mode liquid crystal display elements.

  In another aspect of the present invention, the liquid crystal display element composition is applied onto the conductive film of a pair of substrates having a conductive film, and then heated to form a coating film; A step of constructing a liquid crystal cell by arranging a pair of substrates on which the coating film is formed so that the coating film faces each other through a liquid crystal layer containing a liquid crystalline compound, and between the conductive films of the pair of substrates And a step of irradiating a liquid crystal cell with light while a voltage is applied to the liquid crystal display element. In addition, a liquid crystal aligning agent is applied to each of the conductive films of a pair of substrates having a conductive film and then heated to form a coating film, and the pair of substrates on which the coating film is formed is chain-transferred. A step of constructing a liquid crystal cell by arranging the coating film so as to face each other through a liquid crystal layer containing a compound (A) having a structure capable of expressing a function and a liquid crystalline compound, and the pair of substrates And a step of irradiating light to a liquid crystal cell in a state where a voltage is applied between conductive films.

  In another aspect, the present invention provides a liquid crystal alignment film formed using the liquid crystal display element composition. In addition, a pair of substrates opposed to each other with a predetermined interval, a liquid crystal alignment layer formed on the surfaces of the pair of substrates facing each other, and a liquid crystal disposed between the two liquid crystal alignment layers And a liquid crystal display element containing a compound (A) having a structure capable of developing a chain transfer function in at least one of the liquid crystal alignment layer and the liquid crystal layer.

  The liquid crystal display element manufactured using the composition for liquid crystal display elements of this invention is excellent in high-speed responsiveness by including a compound (A) in at least any one of a liquid crystal layer and a liquid crystal aligning layer. In addition, when applied to a liquid crystal display element containing an alkenyl-based liquid crystal in the liquid crystal layer, it is possible to suitably suppress a decrease in voltage holding ratio caused by light irradiation due to the addition of the alkenyl-based liquid crystal while increasing the response speed. can do.

The figure which shows the electrode pattern of the transparent electrode film used in the Example and the comparative example. The figure which shows the electrode pattern of the transparent electrode film used in the Example and the comparative example. The figure which shows the electrode pattern of the transparent electrode film used in the Example and the comparative example.

  The composition for a liquid crystal display element of the present invention is used for forming at least one of a liquid crystal layer and a liquid crystal alignment layer of a liquid crystal display element, and comprises a compound (A) having a structure capable of developing a chain transfer function. contains. Preferable specific examples of the liquid crystal display element composition include [I] a liquid crystal aligning agent containing the above compound (A), and [II] a liquid crystal composition containing the liquid crystalline compound and the above compound (A). Can be mentioned. Each will be described in turn below.

[Liquid crystal aligning agent]
The liquid crystal aligning agent of this invention contains the said compound (A), and contains another component as needed.
<Compound (A)>
The “chain transfer function” in the compound (A) refers to a function of changing the type of chain transmitter in the course of the chain reaction. Examples of the structure capable of expressing the function (hereinafter also referred to as “chain transfer structure”) include, for example, thiol groups, polysulfide groups, vinyl ether groups, halogenated alkyl groups, thionoester groups (—C (═S) —O—). ), Allyl sulfide structure, allyl sulfonate structure, allyl halide structure, allyl phosphate structure, allyl silane structure, and the like. The polysulfide group includes a sulfide group (—S—), a disulfide group (—S—S—), a trisulfide group, a tetrasulfide group, and the like. In addition, each structure of allyl sulfide structure, allyl sulfonate structure, allyl halide structure, allyl phosphate structure and allyl silane structure is at least one hydrogen atom from allyl sulfide, allyl sulfonate, allyl halide, allyl phosphate ester, allyl silane structure. Means a structure comprising a group obtained by removing

  The form which makes the liquid crystal aligning agent of this invention contain the said compound (A) is not specifically limited. For example, a form in which the compound (A) is contained in a liquid crystal aligning agent as an additive, a form in which the compound (A) is contained in a liquid crystal aligning agent as at least a part of a polymer component of the liquid crystal aligning agent, and a compound as an additive The form etc. which use together (A) and the compound (A) as a polymer component are mentioned.

As the compound (A) as an additive, those known as chain transfer agents can be used. Specific examples thereof include alkylthiols such as n-butyl mercaptan, n-pentyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-lauryl mercaptan; thiophenol, m-bromothiophenol Thiophenols such as p-bromothiophenol, m-toluenethiol and p-toluenethiol; mercaptoalcohols such as 2-mercaptoethanol and 2,3-dimercapto-1-propanol; thiosalicylic acid, mercaptoacetic acid, 3- Mercaptocarboxylic acids such as mercaptopropionic acid; methyl mercaptoacetate, methyl 3-mercaptopropionate, 2-ethylhexyl 3-mercaptopropionate, n-octyl 3-mercaptopropionate, 3-mercap Methoxybutyl propionate, mercaptocarboxylic acid esters, such as 3-mercaptopropionic acid stearyl; t-butyl sulfide, monosulfide, such as allyl sulfide; disulfides diphenyl disulfide and the like; formula (v-1) ~ (v-7)
(In the formula, Me represents a methyl group, Et represents an ethyl group, and Ph represents a phenyl group.)

Vinyl ethers such as compounds represented by each of these; alkyl halides such as carbon tetrachloride, carbon tetrabromide, trichlorobromomethane, and trichloromethane; allyls such as allyl sulfonate, allyl halide, allyl phosphate, and allylsilane compounds Compounds; thionoesters such as benzyl thionobenzoate; and α-methylstyrene dimer.
From the viewpoint of chain transfer performance and industrial availability, compound (A) as an additive includes alkylthiols, thiophenols, mercaptoalcohols, mercaptocarboxylic acids, mercaptocarboxylic acid esters, monosulfides, disulfides. And at least one selected from the group consisting of vinyl ethers and alkyl halides. In addition, the compound (A) as an additive can be used individually by 1 type in the above or in combination of 2 or more types.

When the compound (A) is at least a part of the polymer component of the liquid crystal aligning agent, the compound (A) is a polymer having the chain transfer structure. The said polymer may have the said chain transfer structure in any of the principal chain and side chain of a polymer. From the viewpoint of easy control of the introduction amount of the chain transfer structure, it is preferable to have the chain transfer structure in the side chain of the polymer.
Examples of the main skeleton of the polymer having the chain transfer structure (hereinafter, also referred to as “polymer (A)”) include, for example, polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, polyorganosiloxane, cellulose derivative, Examples include skeletons composed of polyacetal derivatives, polystyrene derivatives, poly (styrene-phenylmaleimide) derivatives, poly (meth) acrylate derivatives, and the like. As the polymer (A), one or more polymers having a skeleton selected from these can be appropriately selected and used depending on the use of the liquid crystal display element. In addition, (meth) acrylate means containing an acrylate and a methacrylate.
Among the above, the polymer (A) preferably has a skeleton selected from polyamic acid, polyimide, polyamic acid ester, polyorganosiloxane and poly (meth) acrylate, and polyamic acid, polyimide, polyamic acid ester and More preferably, it has a skeleton selected from polyorganosiloxanes.

  When the polymer (A) has the chain transfer structure in the main chain, the structure is preferably a sulfide group, a disulfide group, or a trisulfide group from the viewpoint of ease of introduction. On the other hand, when the chain transfer structure is present in the side chain, it must be a thiol group, polysulfide group, vinyl ether group, thionoester group, allyl sulfide structure, allyl sulfonate structure, allyl halide structure, allyl phosphate structure, allyl silane structure. Are preferable, and a thiol group, a sulfide group, a disulfide group, or a vinyl ether group is more preferable.

[Polymer (A): Polyamic acid]
In the present invention, the polyamic acid (hereinafter also referred to as “polyamic acid (A)”) as the polymer (A) reacts, for example, a tetracarboxylic dianhydride with a diamine having the chain transfer structure. Can be obtained.

[Tetracarboxylic dianhydride]
Examples of the tetracarboxylic dianhydride used for synthesizing the polyamic acid (A) in the present invention include an aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, and an aromatic tetracarboxylic dianhydride. An anhydride etc. can be mentioned. Specific examples thereof include aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride;
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4, 5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane -2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene- No 1,2-dicarboxylic acid Product, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride, 4,9-di Oxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, 1,2,4,5-cyclohexanetetracarboxylic dianhydride and the like;
Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride;
In addition to the above, tetracarboxylic dianhydrides described in JP 2010-97188 A can be used. In addition, the said tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

The tetracarboxylic dianhydride used for synthesizing the polyamic acid (A) is an alicyclic tetracarboxylic dianhydride in that the solubility of the polymer, the orientation of the liquid crystal, the voltage holding property, etc. can be improved. In particular, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetra Carboxylic 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, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3 Furanyl) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride , Bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride and 1,2,4,5-cyclohexanetetracarboxylic dianhydride It is more preferable that the specific tetracarboxylic dianhydride which is at least 1 type chosen from the group which consists of comprises.
As tetracarboxylic dianhydride used for synthesizing polyamic acid (A), the content (total amount) of the specific tetracarboxylic dianhydride is the total amount of tetracarboxylic dianhydride used for synthesis. On the other hand, it is preferably 50 mol% or more, more preferably 70 mol% or more.

[Diamine]
As the diamine used for synthesizing the polyamic acid in the present invention, a diamine (hereinafter also referred to as “specific diamine”) that can impart a chain transfer function to the polymer by having the chain transfer structure. Can be mentioned. Specific examples of such specific diamines include, for example, 4,4'-thiodianiline, 2,2'-thiodianiline, 4,4'-dithiodianiline, 2,2'-dithiodianiline, 4,4'-diamino. Examples thereof include diphenyl sulfide. The said specific diamine can be used individually by 1 type or in combination of 2 or more types.

As the diamine for synthesizing the polyamic acid (A) in the present invention, the specific diamine may be used alone, but together with the specific diamine, a diamine other than the specific diamine (hereinafter referred to as “other diamine”). May be used).
Examples of the other diamines include aliphatic diamines, alicyclic diamines, aromatic diamines, and diaminoorganosiloxanes. Specific examples thereof include aliphatic diamines such as metaxylylenediamine, 1,3-propanediamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, and the like; alicyclic diamines such as 1,4- Diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane and the like;

  Examples of aromatic diamines include p-phenylenediamine, 4,4′-diaminodiphenylmethane, 1,5-diaminonaphthalene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diamino-2, 2′-bis (trifluoromethyl) biphenyl, 2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [ 4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-( m-phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4, '-Bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl- 3,6-diaminocarbazole,

N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N′-bis (4-aminophenyl) -benzidine, N, N′-bis (4-aminophenyl)- N, N′-dimethylbenzidine, 1,4-bis- (4-aminophenyl) -piperazine, 3,5-diaminobenzoic acid, dodecanoxy-2,4-diaminobenzene, tetradecanoxy-2,4-diaminobenzene, pentadecanoxy -2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy-2,4-diaminobenzene, dodecanoxy-2,5-diaminobenzene, tetradecanoxy-2,5-diaminobenzene, pentadecanoxy-2,5- Diaminobenzene, hexadecanoxy-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-diaminobenzoate cholestanyl, 3,5-diaminobenzoate cholestenyl, 3,5-diaminobenzoate lanostannyl, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis ( 4-Aminophenoxy) cholestane, 4- (4′-trifluoromethoxybenzoyloxy) cyclohexyl-3,5-diaminobenzoate, 4- (4′-trifluoromethylbenzoyloxy) cyclohexyl-3,5-diaminobenzoate 1,1-bis (4-((aminopheny ) Methyl) phenyl) -4-butylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenoxy) methyl) phenyl ) -4-heptylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4- (4-heptylcyclohexyl) cyclohexane, 1- (4-aminophenyl) -2,3-dihydro- 1,3,3-trimethyl-1H-indene-5-amine, 1- (4-aminophenyl) -2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine, 4-amino Phenyl-4′-aminobenzoate, 3- (3,5-diaminobenzoyloxy) cholestane, and the following formula (D-1)

(In Formula (D-1), X ^I and X ^II each independently represent a single bond, —O—, * —COO—, * —OCO— or * —NH—CO— (where “*” is The bond is attached to the diaminophenyl group.), 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. However, a and b are not 0 at the same time, and when X ^I is * —NH—CO—, n is 0. )
A compound represented by:
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane, and the like, and diamines described in JP 2010-97188 A can be used.

Examples of the divalent group represented by “—X ^I — (R ^I —X ^II ) _n —” in the formula (D-1) include an alkanediyl group having 1 to 3 carbon atoms, * —O—, * —COO—, * —O—C ₂ H ₄ —O—, or * —NH—CO— (however, a bond marked with “*” is bonded to a diaminophenyl group) are preferred.
Specific examples of the group “—C _c H _{2c + 1} ” include, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group. Group, n-nonyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group Group, n-eicosyl group and the like. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or 3,5-position with respect to 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-1-6).
In addition, as another diamine, 1 type of these compounds can be used individually or in combination of 2 or more types.

  What is necessary is just to set suitably the usage-amount of the said specific diamine in the synthesis | combination of the said polyamic acid (A) according to the quantity of the chain transfer structure made to exist in a liquid crystal aligning agent, but with respect to the whole quantity of the diamine used for a synthesis | combination. 0.1 to 80 mol% is preferable, 1 to 60 mol% is more preferable, and 3 to 50 mol% is still more preferable.

<Synthesis of polyamic acid>
The ratio of the tetracarboxylic dianhydride and the diamine used in the polyamic acid synthesis reaction in the present invention is such that the acid anhydride group of the tetracarboxylic dianhydride is 0. A ratio of 2 to 2 equivalents is preferable, and a ratio of 0.3 to 1.2 equivalents is more preferable. The synthesis reaction of polyamic acid is preferably performed in an organic solvent. The reaction temperature at this time is preferably -20 ° C to 150 ° C, more preferably 0 to 100 ° C. The reaction time is preferably 0.5 to 24 hours, and more preferably 2 to 10 hours.

  Here, the organic solvent used for the reaction is not particularly limited as long as it can dissolve the synthesized polyamic acid. Specifically, for example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N, N Aprotic polar solvents such as dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide; m-cresol And phenol solvents such as xylenol, phenol and halogenated phenol; These organic solvents can be used individually by 1 type or in mixture of 2 or more types.

  Moreover, as an organic solvent used for reaction, you may use together the poor solvent of this polyamic acid within the range which the polyamic acid synthesize | combined does not precipitate. Examples of such poor solvents 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; ethyl lactate, Esters such as butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, diethyl oxalate, isoamylpropionate; 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 Ethers such as tetrahydrofuran and diisopentyl ether; halogenated hydrocarbons such as dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane and trichloroethane; hydrocarbons such as hexane, heptane, octane, benzene, toluene and xylene Can be mentioned. These poor solvents can be used individually by 1 type or in mixture of 2 or more types.

When using the poor solvent of the said polyamic acid as an organic solvent used for reaction, the use ratio is preferably 50% by weight or less, more preferably 40% by weight with respect to the total amount of the organic solvent used for synthesis. % Or less, more preferably 30% by weight or less.
The amount of organic solvent used (a) is such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1 to 50% by weight based on the total amount (a + b) of the reaction solution. The amount is preferably 5 to 30% by weight, and more preferably.

  As described above, a reaction solution obtained by dissolving the polyamic acid (A) is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid (A) contained in the reaction solution, or the isolated polyamic You may use for preparation of a liquid crystal aligning agent, after refine | purifying an acid (A). Moreover, when polyamic acid (A) is dehydrated and cyclized into a polyimide, the above reaction solution may be subjected to a dehydration and cyclization reaction as it is, and after the polyamic acid (A) contained in the reaction solution is isolated. You may use for a dehydration ring closure reaction, or you may use for a dehydration ring closure reaction after refine | purifying the isolated polyamic acid (A). Isolation and purification of the polyamic acid (A) can be performed according to a known method.

<Polymer (A): Polyimide>
In the present invention, the polyimide as the polymer (A) (hereinafter also referred to as “polyimide (A)”) is imidized by, for example, dehydrating and ring-closing the polyamic acid (A) synthesized as described above. Can be obtained.

  The polyimide (A) may be a completely imidized product obtained by dehydrating and ring-closing all of the amic acid structure of the polyamic acid (A) as a precursor, and only a part of the amic acid structure may be dehydrating and ring-closing. Alternatively, it may be a partially imidized product in which an amic acid structure and an imide ring structure coexist. The imidation ratio of the polyimide (A) in the present invention is preferably 40% or more, and more preferably 50 to 99%. This imidation ratio represents the ratio of the number of imide ring structures to the total of the number of polyimide amic acid structures and the number of imide ring structures in percentage. Note that a part of the imide ring may be an isoimide ring.

  The dehydration ring closure of the polyamic acid (A) is performed by [i] a method of heating the polyamic acid (A) or [ii] dissolving the polyamic acid (A) in an organic solvent, and the dehydrating agent and dehydration ring closure catalyst in this solution. It can carry out by the method of adding and heating as needed.

In the method [i] above, the reaction temperature is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. When the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and when the reaction temperature exceeds 200 ° C., the molecular weight of the resulting polyimide (A) may decrease. The reaction time is preferably 0.5 to 48 hours, more preferably 2 to 20 hours.
On the other hand, in the above method [ii], as the dehydrating agent, for example, acid anhydrides such as acetic anhydride, propionic anhydride, trifluoroacetic anhydride and the like can be used. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of an amic acid structural unit. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, N-methyl piperidine, can be used, for example. It is preferable that the usage-amount of a dehydration ring-closing catalyst shall be 0.01-10 mol with respect to 1 mol of dehydrating agents to be used. Examples of the organic solvent used for the dehydration ring-closing reaction include the solvents exemplified as the organic solvent used for the synthesis of the polyamic acid (A). The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. 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 used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after purifying the obtained polyimide (A). . On the other hand, in the said method [ii], the reaction solution containing a polyimide (A) is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, for example, after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution by a method such as solvent substitution. The polyimide (A) may be isolated and used for the preparation of the liquid crystal aligning agent, or the isolated polyimide (A) may be purified and then used for the preparation of the liquid crystal aligning agent. The operation of isolating and purifying the polyimide (A) can be performed according to a known method.

<Polymer (A): Polyamic acid ester>
The polyamic acid ester (hereinafter also referred to as “polyamic acid ester (A)”) as the polymer (A) in the present invention is, for example, a tetracarboxylic acid exemplified as a compound used for the synthesis of the polyamic acid (A). After reacting dianhydride and other diamine to obtain a polyamic acid, it can be synthesized by reacting the obtained polyamic acid with the compound having the chain transfer structure and epoxy group. . The polyamic acid ester (A) may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist.

  The polyamic acid (A), polyamic acid ester (A), and polyimide (A) obtained as described above have a solution viscosity of 10 to 800 mPa · s when this is a 10% by weight solution. Preferably, it has a solution viscosity of 15 to 500 mPa · s. In addition, the solution viscosity (mPa · s) of the above polymer is based on a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). The value measured at 25 ° C. using an E-type rotational viscometer. The polyamic acid (A), polyamic acid ester (A), and polyimide (A) preferably have a polystyrene equivalent weight average molecular weight of 500 to 300,000 as measured by gel permeation chromatography (GPC). More preferably, it is 1,000 to 200,000.

[Polymer (A): Polyorganosiloxane]
The polyorganosiloxane (hereinafter also referred to as “polyorganosiloxane (A)”) as the polymer (A) can be synthesized by appropriately combining organic chemistry methods. For example, for example,
[I] Hydrolyzable silane compound (s1) having an epoxy group or a mixture of the silane compound (s1) and another silane compound is subjected to hydrolysis condensation to form a polymer (hereinafter referred to as “epoxy group-containing polyorgano”). A method of reacting the obtained epoxy group-containing polyorganosiloxane with the carboxylic acid (c1) having the above chain transfer structure;
[II] Hydrolyzable condensation of the hydrolyzable silane compound (s2) having the above chain transfer structure or a mixture of the silane compound (s2) and other silane compounds.

<About Method [I]>
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-glycidyloxypropylmethyldiethoxysilane, 3- Glycidyloxypropyldimethylmethoxysilane, 3-glycidyloxypropyldimethylethoxysilane, 2-glycidyloxyethyltrimethoxysilane, 2-glycidyloxyethyltriethoxysilane, 2-glycidyloxyethylmethyldimethoxysilane, 2- Glycidyloxyethylmethyldiethoxysilane, 2-glycidyloxyethyldimethylmethoxysilane, 2-glycidyloxyethyldimethylethoxysilane, 4-glycidyloxybutyltrimethoxysilane, 4-glycidyloxybutyl Riethoxysilane, 4-glycidyloxybutylmethyldimethoxysilane, 4-glycidyloxybutylmethyldiethoxysilane, 4-glycidyloxybutyldimethylmethoxysilane, 4-glycidyloxybutyldimethylethoxysilane, 2- (3 4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (3,4-epoxycyclohexyl) propyltrimethoxysilane, 3- (3,4-epoxycyclohexyl) And propyltriethoxysilane. As the silane compound (s1), one of these can be used alone, or two or more can be mixed and used.

  In the synthesis of the epoxy group-containing polyorganosiloxane, other silane compounds that can be used as necessary include, for example, methyltrichlorosilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrichlorosilane, phenyltrimethoxysilane, Phenyltriethoxysilane, methyldichlorosilane, methyldimethoxysilane, methyldiethoxysilane, dimethyldichlorosilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldichlorosilane, diphenyldimethoxysilane, diphenyldiethoxysilane, chlorodimethylsilane, methoxydimethyl Silane, ethoxydimethylsilane, chlorotrimethylsilane, bromotrimethylsilane, iodotrimethylsilane, methoxytrimethylsilane , Ethoxytrimethylsilane, tetramethoxysilane, tetraethoxysilane, octadecyltrichlorosilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, 3- (meth) acryloxypropyltrichlorosilane, 3- (meth) acryloxypropyltrimethoxysilane , 3- (meth) acryloxypropyltriethoxysilane and the like. As other silane compounds, one of these may be used alone or in admixture of two or more. In the present specification, “(meth) acryloxy” includes acryloxy and methacryloxy.

  The silane compound used in the synthesis of the polyorganosiloxane (A) preferably contains 10 to 100 mol% of the silane compound (s1) with respect to the total amount of the silane compound, and 20 to 100 mol%. More preferred. When using the said other silane compound, it is preferable that the content rate is 30 mol% or less with respect to the whole quantity of the silane compound used for a synthesis | combination, and it is more preferable that it is 10 mol% or less.

  The hydrolysis / condensation reaction of the silane compound in the above can be performed by reacting one or more of the above silane compounds with water, preferably in the presence of an appropriate catalyst and an organic solvent. In the hydrolysis / condensation reaction, the proportion of water used is preferably 0.5 to 100 mol, more preferably 1 to 30 mol, per 1 mol of the silane compound (total amount).

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

Examples of the catalyst include alkali metal compounds or organic bases, in that side reactions such as ring opening of epoxy groups can be suppressed, hydrolysis condensation rate can be increased, and storage stability is excellent. An organic base is particularly preferable. The organic base is preferably a tertiary organic amine or a quaternary organic amine.
The amount of the organic base used varies depending on the reaction conditions such as the type of organic base and temperature, and should be set appropriately. For example, the amount is preferably 0.01 to 3 moles relative to all silane compounds. More preferably, it is 0.05-1 times mole.

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 hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, diethyl ketone and cyclohexanone; esters such as ethyl acetate and n-acetate. Butyl, i-amyl acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, ethyl lactate and the like; ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, tetrahydrofuran and dioxane; alcohols such as 1-hexanol 4-methyl-2-pentanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n- propyl ether, ethylene glycol monobutyl -n- butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono -n- propyl ether and the like; may be mentioned, respectively. Of these, it is preferable to use a water-insoluble organic solvent. In addition, these organic solvents can be used individually by 1 type or in mixture of 2 or more types.
The use ratio of the organic solvent in the hydrolytic condensation reaction is preferably 10 to 10,000 parts by weight, more preferably 50 to 1,000 parts by weight with respect to 100 parts by weight of the total silane compounds 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 solution in an oil bath, for example. 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, and more preferably 1 to 8 hours. During heating, the mixture may be stirred or placed under reflux. Moreover, it is preferable to wash | clean the organic-solvent layer fractionated from the reaction liquid with water after completion | finish of reaction. In this washing, washing with water containing a small amount of salt (for example, an aqueous ammonium nitrate solution of about 0.2% by weight) is preferable in that the washing operation is facilitated. Washing is performed until the aqueous layer after washing becomes neutral, and then the organic solvent layer is dried with a desiccant such as anhydrous calcium sulfate or molecular sieve as necessary, and then the solvent is removed to remove the solvent. The 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 chain transfer structure. Thereby, the polyorganosiloxane (A) which has the said chain transfer structure in a side chain can be obtained. The carboxylic acid used in this reaction may be carboxylic acid (c1) alone, or a group having a function of aligning liquid crystal molecules together with carboxylic acid (c1) (hereinafter also referred to as “liquid crystal alignment group”). And / or other carboxylic acids (c3) other than these carboxylic acids may be used.

  Here, as long as carboxylic acid (c1) has the said chain transfer structure and a carboxyl group, the remaining structure is not specifically limited. Specifically, 3-mercaptopropionic acid, thiosalicylic acid, mercaptoacetic acid, dithioglycolic acid, 3,3′-dithiopropionic acid, 4-mercaptobutanoic acid, mercaptosuccinic acid, 4-mercaptobenzoic acid, 3-mercaptobenzoic acid An acid, 2-methoxy-4-mercaptobenzoic acid, 4- (methylthio) benzoic acid, etc. can be mentioned.

  As long as the said carboxylic acid (c2) has a liquid crystal aligning group and a carboxyl group, the remaining structure is not specifically limited. 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, and a group having a polycyclic structure. Specific examples of the carboxylic acid (c2) include, for example, 4-butoxyoxybenzoic acid, 4-octyloxybenzoic acid, 4-dodecaloxybenzoic acid, 4-hexadecoxyoxybenzoic acid, 4-icosaloxybenzoic acid, 4- (4- Pentylcyclohexyl) benzoic acid, 4- (4-octylcyclohexyl) benzoic acid, 4- (4′-pentylbicyclohexyl-4-yl) benzoic acid, 4- (4′-heptylbicyclohexyl-4-yl) benzoic acid And succinic acid = 5ξ-cholestan-3-yl. Specific examples of the carboxylic acid (c3) include formic acid, acetic acid, propionic acid, benzoic acid, methylbenzoic acid and the like.

The use ratio of the carboxylic acid (c1) is preferably 0.005 to 0.5 mol with respect to 1 mol of the epoxy group of the epoxy group-containing polyorganosiloxane used for the reaction, 0.01 to 0.4 More preferably, the molar amount is 0.02 to 0.3 mol. Moreover, it is preferable to set it as 0.7 mol or less with respect to 1 mol of epoxy groups of the epoxy group containing polyorganosiloxane used for reaction, and the usage-amount of carboxylic acid (c2) shall be 0.6 mol or less. Is more preferable. The proportion of the carboxylic acid (c3) used is preferably 0.3 mol or less, more preferably 0.2 mol or less, based on 1 mol of the epoxy group of the epoxy group-containing polyorganosiloxane used in the reaction. preferable.
The polyorganosiloxane (A) in the present invention preferably has an epoxy equivalent of 1000 g / mol or less, more preferably 100 to 700 g / mol. Therefore, it is preferable that the total use ratio of the carboxylic acids (c1), (c2), and (c3) is appropriately adjusted so that the epoxy equivalent of the polyorganosiloxane (A) is within the above range.

The reaction between the epoxy group of the epoxy group-containing polyorganosiloxane and the carboxylic acid can be preferably carried out in the presence of a catalyst and an organic solvent. Here, as the catalyst used for the reaction, for example, a compound known as a so-called curing accelerator that accelerates the reaction of an organic base or an epoxy compound can be used.
Examples of the organic base include primary and secondary organic amines such as ethylamine, diethylamine, piperazine, piperidine, pyrrolidine and pyrrole; triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine, 4-dimethylaminopyridine, And tertiary organic amines such as diazabicycloundecene; quaternary organic amines such as tetramethylammonium hydroxide; and the like. Of these, tertiary organic amines or quaternary organic amines are preferred as the organic base.
Examples of the curing accelerator include tertiary amines, imidazole compounds, organic phosphorus compounds, quaternary phosphonium salts, diazabicycloalkenes, organometallic compounds, quaternary ammonium salts, boron compounds, metal halogen compounds, and the like. In addition to the above, those known as latent curing accelerators can be used.
The catalyst is preferably 100 parts by weight or less, more preferably 0.01 to 100 parts by weight, still more preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the polyorganosiloxane to be reacted with the carboxylic acid. Can be used.

Examples of the organic solvent that can be used in the reaction between the polyorganosiloxane and the carboxylic acid include hydrocarbons, ethers, esters, ketones, amides, alcohols, and the like. Of these, ethers, esters, and ketones are preferable from the viewpoints of solubility of raw materials and products and ease of purification of the products. The organic solvent preferably has a solid content concentration (the ratio of the total weight of components other than the solvent in the reaction solution to the total weight of the solution) of 0.1% by weight or more, more preferably 5 to 50% by weight. % Used.
The reaction temperature is preferably 0 to 200 ° C, more preferably 50 to 150 ° C. The reaction time is preferably 0.1 to 50 hours, more preferably 0.5 to 20 hours. Moreover, after completion | finish of reaction, it is preferable to wash | clean the organic-solvent layer fractionated from the reaction liquid with water. After washing with water, the organic solvent layer is dried with an appropriate desiccant as required, and then the solvent is removed to obtain the desired polyorganosiloxane. Note that the polyorganosiloxane (A) dissolved in the reaction solution may be used as it is for the preparation of the next liquid crystal aligning agent without performing the isolation operation of the polyorganosiloxane (A).

<About Method [II]>
The remaining structure of the silane compound (s2) used in the method [II] is not particularly limited as long as it is a hydrolyzable silane compound having the chain transfer structure. Specific examples include 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, and the like. As a silane compound (s2), 1 type can be used individually or in mixture of 2 or more types. Moreover, as another silane compound used by method [II], the silane compound (s1) demonstrated by said method [I], another silane compound, etc. are mentioned.
The silane compound used in the synthesis preferably contains 1 mol% or more of the silane compound (s2) with respect to the total amount of the silane compound, and more preferably contains 3 to 50 mol%. The content ratio of the other silane compounds is preferably 10 to 99 mol%, more preferably 20 to 97 mol%, based on the total amount of silane compounds used in the synthesis.
The hydrolysis / condensation reaction of the silane compound in Method [II] is carried out by dissolving the silane compound as described above in an organic solvent, mixing this solution with an organic base and water, and heating the solution in an oil bath, for example. Is preferred. For the details of the reaction conditions at that time, the explanation of the above [I] can be applied.

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

Moreover, when the polymer (A) in this invention uses a poly (meth) acrylate derivative as a main skeleton, it is compoundable as follows, for example. First, a monomer raw material containing a monomer having an epoxy group is polymerized to synthesize a poly (meth) acrylate derivative having an epoxy group, and then the derivative, a compound having the chain transfer structure and a carboxyl group (for example, the above) Carboxylic acid (c1)) is reacted. Thereby, the poly (meth) acrylate derivative which has the said chain transfer structure in a side chain can be obtained.
As said compound (A) contained in the liquid crystal aligning agent of this invention, it is preferable that a polymer (A) is included, and it is more preferable that the said compound (A) is a polymer (A).

Although content of the said compound (A) in the liquid crystal aligning agent of this invention should just be adjusted suitably with the form to contain, from a viewpoint which obtains the effect of this invention suitably, it is the polymer component in a liquid crystal aligning agent. The chain transfer structure is preferably included in an amount of 0.5 to 100 mmol / g, and more preferably 1 to 50 mmol / g. Therefore, when the liquid crystal aligning agent is prepared, the polymer (A) and the amount of the compound (A) used as an additive are used so that the content of the chain transfer structure in the liquid crystal aligning agent is in the above range. Is preferably adjusted as appropriate.
Specifically, in the case where the liquid crystal aligning agent of the present invention contains the compound (A) in the form of an additive separately from the polymer component, from the viewpoint of sufficiently exhibiting the chain transfer function in the liquid crystal aligning film. The total amount of the polymer components of the liquid crystal aligning agent is preferably 0.05 parts by weight or more, more preferably 0.1 parts by weight or more, and 0.5 parts by weight or more. More preferably. Further, from the viewpoint of suppressing a decrease in voltage holding ratio and a decrease in response speed due to addition of an excessive amount, it is preferably 50 parts by weight or less, more preferably 30 parts by weight or less, and 20 parts by weight or less. More preferably.

When the liquid crystal aligning agent of this invention contains a polymer (A) as said compound (A), it is good also considering the whole polymer component contained in the said liquid crystal aligning agent as a polymer (A), or solution characteristics or In order to improve electrical characteristics, the polymer (A) may have a polymer (B) that does not have the chain transfer structure. When only the polymer (A) is contained as the compound (A), the content ratio of the polymer (A) is preferably 1% by weight or more based on the total amount of the polymer contained in the liquid crystal aligning agent, More preferably, the content is 3% by weight or more.
The mode of the liquid crystal display element to which the liquid crystal aligning agent is applied is not particularly limited, but can be preferably applied to a PSA mode liquid crystal display element. In the present invention, a liquid crystal alignment film of a PSA mode liquid crystal display element is formed using the liquid crystal aligning agent containing the compound (A), so that a photopolymerizable compound (photopolymerizable compound) can be formed upon light irradiation to the liquid crystal cell. As a result of being assisted from the liquid crystal alignment film side so that the photopolymerization reaction of the monomer) is not hindered, it is presumed that the polymerization reaction of the photopolymerizable monomer can sufficiently proceed and various characteristics can be improved.

<Polymer (B)>
The polymer (B) in the present invention includes, for example, polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, polyorganosiloxane, cellulose derivative, polyacetal derivative, polystyrene derivative, poly (styrene-phenylmaleimide) derivative as the main skeleton. And polymers having a skeleton composed of a poly (meth) acrylate derivative and the like. As the polymer (B), one or more polymers having a skeleton selected from these can be appropriately selected and used.
Among these, the polymer (B) is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide and polyorganosiloxane, and is composed of polyamic acid, polyimide and polyorganosiloxane. More preferably, at least one selected from the group consisting of polyamic acid and polyimide is more preferable. When the liquid crystal aligning agent of the present invention does not contain the polymer (A) as the compound (A), that is, when the compound (A) is used only in the form of an additive, the liquid crystal aligning agent is the polymer. (B) is included as an essential component.

  The polymer (B) can be synthesized by appropriately combining organic chemistry methods. For example, the polyamic acid as the polymer (B) can be obtained by reacting the tetracarboxylic dianhydride exemplified as the compound used for the synthesis of the polyamic acid (A) with another diamine. The polyimide as the polymer (B) can be obtained by dehydrating and ring-closing the polyamic acid as the polymer (B), and the polyamic acid ester can be obtained by esterifying the polyamic acid. The polyorganosiloxane can be obtained by using an epoxy group-containing polyorganosiloxane or hydrolyzing and condensing other silane compounds exemplified in the above method [I]. In addition, about the reaction conditions of each polymer, the description of the said polymer (A) is applicable.

As a preferred embodiment of the liquid crystal aligning agent of the present invention, the polymer component is
(I) A mode consisting of at least one selected from the group consisting of polyamic acid (A) and polyimide (A);
(II) at least one selected from the group consisting of polyamic acid (A) and polyimide (A), and an embodiment consisting of polyorganosiloxane (A);
(III) an embodiment consisting only of polyorganosiloxane (A);
(IV) A mode comprising a polyorganosiloxane (A) and a polymer (B), and the polymer (B) is at least one selected from the group consisting of a polyamic acid and a polyimide having no chain transfer structure. ;
(V) an embodiment consisting of only the polymer (B) and the polymer (B) being at least one selected from the group consisting of polyamic acid and polyimide having no chain transfer structure;
And so on. Of the above preferred embodiments, (I) to (IV) may contain the compound (A) as an additive, and (v) contains the compound (A) as an essential component. The blending ratio of polyamic acid, polyimide, and polyorganosiloxane in each embodiment can be arbitrarily set according to the use of the liquid crystal display element.

  Among these, in terms of mechanical strength, electrical characteristics, affinity with liquid crystal, and the like, an embodiment containing at least one of polyamic acid and polyimide is preferable. Specifically, the above (I), (II), The embodiment of (IV) or (v) is more preferred, and the embodiment of (I), (II) or (IV) is more preferred. The ratio of the polyorganosiloxane, polyamic acid and polyimide (total) used in the above aspect (II) or (IV) is based on 100 parts by weight of the total amount of polyorganosiloxane, polyamic acid and polyimide. Is preferably 1 to 50 parts by weight, more preferably 2 to 40 parts by weight, and even more preferably 3 to 30 parts by weight.

<Other ingredients>
The liquid crystal aligning agent of this invention may contain the other component as needed. Examples of such other components include compounds having at least one epoxy group in the molecule (hereinafter referred to as “epoxy group-containing compound”), functional silane compounds, and the like.

[Epoxy compound]
Epoxy compounds can be used to improve the adhesion and electrical properties of the liquid crystal alignment film with the substrate surface. Here, as the epoxy compound, for example, 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, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N, N, N ', N'-tetraglycidyl-m-xylenediamine, 1 , 3-Bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodipheny Methane, N, N-diglycidyl - benzylamine, N, N-diglycidyl - aminomethyl cyclohexane, N, N-diglycidyl - may be mentioned as being preferred and cyclohexylamine. When these epoxy compounds are added to the liquid crystal aligning agent, the blending ratio is preferably 40 parts by weight or less, and 0.1 to 30 parts by weight with respect to a total of 100 parts by weight of the polymer contained in the liquid crystal aligning agent. More preferred.

[Functional silane compounds]
The functional silane compound can be used for the purpose of improving the printability of the liquid crystal aligning agent. Examples of such functional silane compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl). ) -3-Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3- Aminopropyltrimethoxysilane, N-triethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-trimethoxysilyl -3,6- Methyl azananoate, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycid And xylpropyltrimethoxysilane. When these functional silane compounds are added to the liquid crystal aligning agent, the blending ratio is preferably 2 parts by weight or less, more preferably 0.02 to 0.2 parts by weight with respect to 100 parts by weight of the total amount of the polymer.
As the other components, in addition to the compounds exemplified above, compounds having at least one oxetanyl group in the molecule, antioxidants, and the like can be used.

<Solvent>
The liquid crystal aligning agent of the present invention is preferably constituted by dissolving a polymer component and other components optionally blended as necessary, in an organic solvent.
Here, examples of the solvent used for preparing the liquid crystal aligning agent of the present invention include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol Dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether (DPM), diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, di Examples include isopentyl ether, ethylene carbonate, and propylene carbonate. These can be used alone or in admixture of two or more.

  The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, and the like. The range is preferably 1 to 10% by weight. That is, the liquid crystal aligning agent of this invention is apply | coated to a substrate surface so that it may mention later, Preferably the coating film which becomes a liquid crystal aligning film or a coating film used as a liquid crystal aligning film is formed by heating. At this time, when the solid content concentration is less than 1% by weight, the film thickness of the coating film is too small to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, it is difficult to obtain a good liquid crystal alignment film due to excessive film thickness, and the viscosity of the liquid crystal aligning agent increases, resulting in poor coating characteristics. It becomes.

  The particularly preferable solid content concentration range varies depending on the method of applying the liquid crystal aligning agent to the substrate. For example, when the spinner method is used, the solid content concentration is particularly preferably in the range of 1.5 to 4.5% by weight. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s. The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 10-50 degreeC, More preferably, it is 20-30 degreeC.

[Liquid crystal composition]
The liquid crystal composition of the present invention contains the liquid crystalline compound and the compound (A), and further contains other components as necessary. By forming a liquid crystal layer using the liquid crystal composition, the compound (A) can be contained in the liquid crystal layer. The mode of the liquid crystal display element to which the liquid crystal composition is applied is not particularly limited, but can be preferably applied to a PSA mode liquid crystal display element. When the liquid crystal composition of the present invention is used for the production of a PSA mode liquid crystal display device, it can assist the photopolymerization reaction of the photopolymerizable compound during the light irradiation to the liquid crystal cell, and the polymerization reaction of the photopolymerizable monomer. It is speculated that it can be sufficiently advanced.

  Examples of the compound (A) to be contained in the liquid crystal composition of the present invention include the compounds exemplified as additives among the above-mentioned compound (A) that can be contained in the liquid crystal aligning agent of the present invention. The compounding ratio of the compound (A) may be appropriately set according to the type of the compound (A), the liquid crystal compound, the polymerizable compound, etc. to be used. It is preferable to set it as 0.5 weight%, and it is more preferable to set it as 0.05-0.3 weight%.

As the liquid crystalline compound, nematic liquid crystal having negative dielectric anisotropy can be preferably used. For example, dicyanobenzene liquid crystal, pyridazine liquid crystal, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenyl cyclohexane liquid crystal, A terphenyl liquid crystal or the like can be used. Further, as the liquid crystalline compound, it is preferable to use an alkenyl liquid crystal in combination in that the response speed of the PSA mode liquid crystal display element can be further increased. A conventionally well-known thing can be used as the said alkenyl type liquid crystal, For example, the compound etc. which are represented with each of the following formula (L1-1)-a formula (L1-10) can be mentioned. As the liquid crystalline compound, one kind can be used alone, or two or more kinds can be used in combination.

  When manufacturing a PSA mode liquid crystal display element, the liquid crystal composition contains a photopolymerizable compound. As the photopolymerizable compound, a compound having a functional group capable of radical polymerization such as an acryloyl group, a methacryloyl group, and a vinyl group can be used. From the viewpoint of reactivity, polyfunctionality is preferable, and it is more preferable to have at least two of acryloyl group and methacryloyl group. From the viewpoint of stably maintaining the orientation of the liquid crystal molecules, a compound having a total of two or more of at least one of a cyclohexane ring and a benzene ring as the liquid crystal skeleton is used as the photopolymerizable compound. preferable. In addition, a conventionally well-known thing can be used as such a photopolymerizable compound. The blending ratio of the photopolymerizable compound is preferably 0.1 to 0.5% by weight with respect to the total amount of the liquid crystal compound to be used.

  In addition to the above compounds, the liquid crystal composition of the present invention may contain other components such as a polymerization initiator, an antioxidant, an ultraviolet absorber, and a stabilizer. These blending amounts can be appropriately adjusted according to the other components used.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal alignment film of the present invention is formed by the liquid crystal aligning agent prepared as described above, and the mode of the liquid crystal display element is not particularly limited, but is used as the liquid crystal alignment film of the PSA mode liquid crystal display element. Is preferred. The liquid crystal display element of the present invention includes a liquid crystal alignment film as a liquid crystal alignment layer formed on each surface of a pair of substrates, and a liquid crystal layer disposed between the two liquid crystal alignment films. The compound (A) is contained in at least one of the liquid crystal alignment film and the liquid crystal layer, and is preferably a PSA mode liquid crystal display element. The liquid crystal display element can be manufactured, for example, by the following method (X1) or (X2).
[Method (X1)]
(1-1) A step of applying the liquid crystal aligning agent of the present invention on each of the conductive films of a pair of substrates having a conductive film, and then heating this to form a coating film,
(1-2) A step of constructing a liquid crystal cell by arranging a pair of substrates on which the coating film is formed so that the coating film faces each other through a liquid crystal layer containing a liquid crystalline compound, and (1-3) a pair Irradiating the liquid crystal cell with light while applying a voltage between the conductive films of the substrate.
[Method (X2)]
(2-1) A step of applying a liquid crystal aligning agent as a composition for forming a liquid crystal alignment layer on the conductive film of a pair of substrates having a conductive film, and then heating this to form a coating film,
(2-2) A step of constructing a liquid crystal cell by arranging a pair of substrates on which a coating film is formed so that the coating film faces through a liquid crystal layer containing the compound (A) and the liquid crystalline compound, And (2-3) 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.

[Step 1: Formation of coating film]
As the substrate of the liquid crystal display element, for example, a glass such as float glass or soda glass; a transparent substrate made of a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, or poly (alicyclic olefin) can be used. . As the conductive film, it is preferable to use a transparent conductive film, for example, a NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ) or indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ). An ITO film or the like can be used. This conductive film is preferably a patterned conductive film partitioned into a plurality of regions. With such a conductive film, when a voltage is applied between the conductive films, the direction of the pretilt angle of the liquid crystal molecules can be changed for each region by applying a different voltage in each region. The characteristics can be made wider.

  In the case of the method (X1), the liquid crystal aligning agent of the present invention containing the compound (A) as one component is used as the liquid crystal aligning agent to be applied on the surface where the transparent conductive film is formed on the pair of substrates. In the case of the method (X2), the liquid crystal aligning agent of the present invention may be used, or a liquid crystal aligning agent not containing the compound (A) may be used. As a method of applying the liquid crystal aligning agent on the substrate, it can be preferably performed by an offset printing method, a spin coating method, a roll coater method or an ink jet printing method. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound or functional titanium is formed on the surface of the substrate surface on which the coating film is to be formed. You may give the pretreatment which apply | coats a compound etc. previously.

  After applying the liquid crystal aligning agent to the substrate, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied liquid crystal aligning agent. The pre-baking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The pre-bake time is preferably 0.25 to 10 minutes, and more preferably 0.5 to 5 minutes. Then, a baking (post-baking) process is implemented for the purpose of removing a solvent completely and heat imidating the amic acid structure which exists in a polymer as needed. The post-bake temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-bake time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. Thus, the film thickness of the formed film is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

By removing the organic solvent by heating after applying the liquid crystal aligning agent, a coating film to be an alignment film is formed. At this time, when the polymer contained in the liquid crystal aligning agent is a polyamic acid, a polyamic acid ester, or an imidized polymer having an imide ring structure and an amic acid structure, a coating film It is good also as a more imidized coating film by advancing the dehydration ring-closing reaction by further heating after formation.
The coating film thus formed may be used as it is for the following process, or may be subjected to the following process after rubbing the coating film surface as necessary. The rubbing treatment can be performed by rubbing the coating film surface in a certain direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton.

[Step 2: Construction of liquid crystal cell]
By preparing two substrates on which a liquid crystal alignment film is formed as described above, a liquid crystal layer is disposed between two substrates (between two liquid crystal alignment layers) arranged to face each other at a predetermined interval. Manufacture the cell. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example. The first method is a conventionally known method (vacuum injection method). First, the two substrates are arranged opposite to each other with a gap (cell gap) of, for example, 1 to 5 μm between the substrates so that the respective liquid crystal alignment films face each other, and a sealant is applied to the peripheral portion of the two substrates. The liquid crystal composition is injected and filled into the cell gap partitioned by the substrate surface and the sealing agent, and then the injection hole is sealed to manufacture a liquid crystal cell. The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet light curable sealing material is applied to a predetermined position on one of the two substrates on which the liquid crystal alignment film is formed, and a liquid crystal composition is applied to predetermined positions on the liquid crystal alignment film surface. After dropping, the other substrate is bonded so that the liquid crystal alignment film faces, and the liquid crystal composition is spread over the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealing agent, A liquid crystal cell is manufactured.
Regardless of which method is used, the liquid crystal cell produced as described above is further heated to a temperature at which the used liquid crystalline compound takes an isotropic phase, and then gradually cooled to room temperature, whereby the flow during liquid crystal filling is The orientation may be removed.

  As the liquid crystal composition to be used, in the case of the method (X1), a liquid crystal composition containing a liquid crystal compound and a photopolymerizable compound and not containing the compound (A) (hereinafter referred to as “other liquid crystal composition”). Or a liquid crystal composition of the present invention containing a liquid crystal compound, a photopolymerizable compound, and the compound (A) can be preferably used. In the case of the above method (X2), the liquid crystal composition of the present invention can be preferably used. As the liquid crystal compound and the photopolymerizable compound contained in the other liquid crystal composition, the description of the liquid crystal compound and the photopolymerizable compound contained in the liquid crystal composition of the present invention can be applied. The thickness of the liquid crystal layer is preferably 1 to 5 μm. Moreover, as a sealing agent, the epoxy resin etc. which contain the aluminum oxide sphere as a hardening | curing agent and a spacer, for example can be used.

[Step 3: Light irradiation step]
After the construction 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 applied here can be, for example, 5 to 50 V direct current or alternating current. Moreover, as light to irradiate, the ultraviolet-ray and visible light which contain light with a wavelength of 150-800 nm can be used, for example, However, The ultraviolet-ray containing light with a wavelength of 300-400 nm is preferable. As a light source of 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, an excimer laser, or the like can be used. In addition, the ultraviolet rays in the above preferable wavelength region can be obtained by means of using a light source in combination with, for example, a filter diffraction grating. The amount of light irradiation is preferably 1,000 J / m ² or more and less than 200,000 J / m ² , more preferably 1,000 to 150,000 J / m ² .

  And a liquid crystal display element can be obtained by bonding a polarizing plate on the outer surface of the liquid crystal cell after light irradiation. As a polarizing plate used here, a polarizing plate composed of a polarizing film called an “H film” in which polyvinyl alcohol is stretched and oriented while absorbing iodine and sandwiched between cellulose acetate protective films or a polarizing film made of the H film itself. Can be mentioned.

  The liquid crystal display element of the present invention can be effectively applied to various devices, such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, cellular phones, smartphones, various types. It can be used for various display devices such as a monitor, a liquid crystal television, and an information display.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

The weight average molecular weight of each polymer, the epoxy equivalent, the solution viscosity of each polymer solution, and the imidization ratio of polyimide 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 equivalent value measured by gel permeation chromatography under the following conditions.
Column: Tosoh Co., Ltd., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²
[Epoxy equivalent]
The epoxy equivalent is a value measured according to the “hydrochloric acid-methyl ethyl ketone method” of JIS C2105.
[Solution viscosity of polymer solution]
The solution viscosity [mPa · s] of the polymer solution was measured at 25 ° C. using an E-type rotational viscometer for a solution prepared to a polymer concentration of 10% by weight using a predetermined solvent.
[Imidation rate of polyimide]
The polyimide solution was poured into pure water, and the resulting precipitate was sufficiently dried under reduced pressure at room temperature, then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. From the obtained ¹ H-NMR spectrum, the imidation ratio [%] was determined by the formula represented by the following formula (1).
Imidation ratio [%] = (1-A ¹ / A ² × α) × 100 (1)
(In Formula (1), A ¹ is a peak area derived from protons of NH groups appearing near a chemical shift of 10 ppm, A ² is a peak area derived from other protons, and α is a precursor of a polymer (polyamic acid). The number ratio of other protons to one proton of NH group in)

<Synthesis of polymer>
[Synthesis Example P1: Synthesis of polyamic acid (P-1)]
1,3 g (0.05 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic Acid 2: 4,6: 8-dianhydride 12.6 g (0.05 mol), and cholestanyloxy-2,4-diaminobenzene 5.02 g (0.01 mol) as diamine, N- (2, 4-Diaminophenyl) -4- (4-heptylcyclohexyl) benzamide 4.13 g (0.01 mol), 3,5-diaminobenzoic acid 6.17 g (0.04 mol), 1- (4-aminophenyl) 8.1 g (0.03 mol) of 2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine and 2.52 g (0.01 mol) of 4,4′-dithiodianiline were added to N -Methyl-2- It was dissolved in 200 g of pyrrolidone (NMP) and reacted at 60 ° C. for 6 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 at 40 ° C. under reduced pressure for 15 hours to obtain polyamic acid (P-1) as compound (A). The obtained polyamic acid (P-1) was prepared with NMP so as to be 10% by weight, and the viscosity of this solution was measured to be 930 mPa · s.

[Synthesis Example P2: Synthesis of Polyimide (P-2)]
The same operation as in Synthesis Example P1 was performed to obtain polyamic acid (P-1). After preparing the obtained polyamic acid (P-1) so as to be 10% by weight with NMP, 12.03 g of pyridine and 15.53 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 100 ° C. for 8 hours. . The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The collected precipitate was washed with methanol, and then dried at 40 ° C. under reduced pressure for 15 hours to obtain polyimide (P-2) having an imidization ratio of about 83% as compound (A). The obtained polyimide (P-2) was prepared so as to be 10% by weight with NMP. The viscosity of this solution was measured and found to be 530 mPa · s.

[Synthesis Example P3: Synthesis of Polyimide (P-3)]
11.3 g (0.05 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic Acid 2: 4,6: 8-dianhydride 12.6 g (0.05 mol), and cholestanyloxy-2,4-diaminobenzene 5.0 g (0.01 mol) as diamine, N- (2, 4-Diaminophenyl) -4- (4-heptylcyclohexyl) benzamide 4.12 g (0.01 mol), 3,5-diaminobenzoic acid 6.14 g (0.04 mol), 1- (4-aminophenyl) 10.7 g (0.04 mol) of 2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine is dissolved in 200 g of NMP, reacted at 60 ° C. for 6 hours, and contains polyamic acid That to obtain a solution. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 1,080 mPa · s.
Next, 250 g of NMP was added to the obtained polyamic acid solution, 12 g of pyridine and 15.4 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 80 ° C. for 8 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The collected precipitate was washed with methanol, and then dried at 40 ° C. under reduced pressure for 15 hours to obtain a polyimide (P-3) having an imidation ratio of about 79% as a polymer (B). The obtained polyimide (P-3) was prepared so as to be 10% by weight with NMP. It was 440 mPa * s when the viscosity of this solution was measured.

[Synthesis Example ES1: Synthesis of polyorganosiloxane (ES-1)]
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser was charged with 100.0 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 500 g of methyl isobutyl ketone and 10.0 g of triethylamine, and room temperature. Mixed. Next, 100 g of deionized water was dropped from the dropping funnel over 30 minutes, and the reaction was performed at 80 ° C. for 6 hours while mixing under reflux. After completion of the reaction, the organic layer is taken out and washed with 0.2 wt% ammonium nitrate aqueous solution until the water after washing becomes neutral, and then the solvent and water are distilled off under reduced pressure to have an epoxy group. Polyorganosiloxane (ES-1) was obtained as a viscous transparent liquid. When the obtained epoxy group-containing polyorganosiloxane (ES-1) was subjected to ¹ H-NMR analysis, a peak based on an epoxy group was obtained in the vicinity of chemical shift (δ) = 3.2 ppm according to the theoretical strength. It was confirmed that no side reaction of the epoxy group occurred during the reaction. It was 186 g / eq when the epoxy equivalent of this epoxy-group-containing polyorganosiloxane (ES-1) was measured.

[Synthesis Example S1: Synthesis of polyorganosiloxane (S-1)]
In a 200 mL three-necked flask, 37.59 g of the epoxy group-containing polyorganosiloxane (ES-1) obtained in Synthesis Example ES1, 61.28 g of methyl isobutyl ketone, 1.13 g of 3-mercaptopropionic acid (epoxy group-containing polyorganosiloxane ( ES-1) is equivalent to 5 mol% with respect to the epoxy group) and UCAT 18X (trade name, quaternary amine salt manufactured by San Apro Co., Ltd.) 1.89 g is charged and stirred at 80 ° C. for 12 hours. The reaction was performed below. After completion of the reaction, the reaction mixture was poured into methanol to collect a precipitate, which was dissolved in ethyl acetate to form a solution. The solution was washed with water three times, and the solvent was distilled off to remove the compound ( 19.2g of polyorganosiloxane (S-1) as A) was obtained as white powder. The weight average molecular weight Mw of this polyorganosiloxane (S-1) was 9,500.

[Synthesis Example S2: Synthesis of Polyorganosiloxane (S-2)]
In a 200 mL three-necked flask, 34.5 g of the epoxy group-containing polyorganosiloxane (ES-1) obtained in Synthesis Example ES1, 62.82 g of methyl isobutyl ketone, 2.68 g of 4-pentylcyclohexylbenzoic acid (epoxy group-containing polyorgano) (Equivalent to 5 mol% with respect to the epoxy group of siloxane (ES-1)) and 1.73 g of UCAT 18X were charged and reacted at 80 ° C. with stirring for 12 hours. After completion of the reaction, the reaction mixture was poured into methanol to recover the produced precipitate, which was dissolved in ethyl acetate to form a solution. The solution was washed with water three times, and then the solvent was distilled off to remove the polyorgano 19.1 g of siloxane (S-2) was obtained as a white powder. The weight average molecular weight Mw of this polyorganosiloxane (S-2) was 8,900.

<Preparation of liquid crystal composition>
[Preparation of Liquid Crystal Composition LC1]
A liquid crystal composition LC1 was obtained by adding 0.3% by weight of a photopolymerizable compound represented by the following formula (pc-1) to 10 g of nematic liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) and mixing them. .
[Preparation of Liquid Crystal Composition LC2]
5% by weight of a liquid crystalline compound represented by the above formula (L1-1) and a photopolymerizable compound represented by the following formula (pc-1) with respect to 10 g of nematic liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) A liquid crystal composition LC2 was obtained by adding 0.3% by weight and mixing.

[Example 1]
<Preparation of liquid crystal aligning agent>
As a compound (A), NMP and butyl cellosolve (BC) are added as organic solvents to the polyamic acid (P-1) obtained in Synthesis Example P1, and the solvent composition is NMP: BC = 50: 50 (weight ratio), solid content. A solution having a concentration of 6.0% by weight was obtained. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore size of 1 μm.

<Evaluation of printability>
The printability of the liquid crystal aligning agent prepared above was evaluated. First, about said liquid crystal aligning agent, it apply | coated to the transparent electrode surface of the glass substrate with a transparent electrode which consists of an ITO film | membrane using an offset type liquid crystal aligning film printer (Nissha Printing Co., Ltd.), and 80 degreeC After removing the solvent by heating (pre-baking) for 1 minute on a hot plate, heating (post-baking) for 10 minutes on a 200 ° C. hot plate and measuring with a stylus-type film thickness meter (manufactured by KLA Tencor). A coating film having an average film thickness of 600 mm was formed. This coating film was observed with a microscope having a magnification of 20 times to examine the presence or absence of printing unevenness and pinholes. In the evaluation, when the printing unevenness and the pinhole were not observed, the printing property was “good”, and when at least one of the printing unevenness and the pinhole was observed, the printing property was “bad”. As a result, neither coating unevenness nor pinhole was observed in the coating film formed using the liquid crystal aligning agent, and the printability was “good”.
<Evaluation of film thickness uniformity>
About the coating film formed above, using a stylus type film thickness meter (manufactured by KLA Tencor), the film thickness at the center of the substrate and the film thickness at the position 15 mm closer to the center from the outer edge of the substrate, respectively. It was measured. The case where the film thickness difference between the two was 20 mm or less was evaluated as film thickness uniformity “good”, and the case where the film thickness difference exceeded 20 mm was evaluated as film thickness uniformity “bad”. As a result, the coating film formed using the liquid crystal aligning agent had a film thickness uniformity of “good”.

<Manufacture and evaluation of liquid crystal cells>
[Manufacture of liquid crystal cells]
The liquid crystal aligning agent of Example 1 prepared above was patterned into a slit shape as shown in FIG. 1, and liquid crystal was formed on each electrode surface of two glass substrates each having an ITO electrode partitioned into a plurality of regions. It is applied using an alignment film printer (Nissha Printing Co., Ltd.), heated on a hot plate at 80 ° C. 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 mm. The coating film was subjected to ultrasonic cleaning for 1 minute in ultrapure water and then dried in a clean oven at 100 ° C. for 10 minutes to obtain a substrate having a liquid crystal alignment film. This operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film. The used electrode pattern is the same type as the electrode pattern in the PSA mode.
Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to the outer edges of the pair of substrates having the liquid crystal alignment film, the liquid crystal alignment film surfaces are overlapped and pressure-bonded so as to face each other. The adhesive was cured. Next, after filling the liquid crystal composition LC1 prepared above between a pair of substrates from the liquid crystal injection port, the liquid crystal injection port was sealed with an acrylic photo-curing adhesive to produce a liquid crystal cell.
The above operation was repeated to produce a total of five liquid crystal cells having patterned transparent electrodes. One of them was used for the evaluation of the voltage holding ratio described later. The remaining four liquid crystal cells were irradiated with light at a dose of 100,000 J / m ² with a voltage applied between the conductive films, and then subjected to evaluation of the liquid crystal cells.

[Evaluation of liquid crystal alignment]
With respect to the liquid crystal display device manufactured as described above, the presence or absence of abnormal domains in the change in brightness when a voltage of 5 V was turned ON / OFF (applied / released) was observed with a microscope with a magnification of 50 times. When the abnormal domain was not observed, the liquid crystal alignment was “good”, and when the abnormal domain was observed, the liquid crystal alignment was “bad”. The liquid crystal alignment of the liquid crystal display element was “good”. .
[Evaluation of voltage holding ratio]
For the non-light-irradiated liquid crystal cell and the liquid crystal cell with the irradiation amount of 100,000 J / m ² manufactured as described above, a voltage of 5 V was applied at 23 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and then application cancellation The voltage holding ratio (VHR) after 167 milliseconds was measured. As a result, the voltage holding ratio of the liquid crystal cell not irradiated with light was 99.2%, and the voltage holding ratio of the liquid crystal cell with an irradiation amount of 100,000 J / m ² was 98.6%. In addition, as a measuring apparatus, Toyo Technica Co., Ltd. make and VHR-1 were used.

[Evaluation of response speed of liquid crystal]
After the liquid crystal cell manufactured above is sandwiched between two polarizing plates arranged in a crossed Nicol state, the luminance of light transmitted through the liquid crystal cell by first irradiating a visible light lamp without applying a voltage is measured with a photomultimeter. The relative transmittance was 0%. Next, the transmittance when AC 5 V was applied for 5 seconds between the electrodes of the liquid crystal cell was measured in the same manner as described above, and this value was defined as a relative transmittance of 100%. When AC 5 V was applied to each liquid crystal cell, the time until the relative transmittance shifted from 10% to 90% was measured, and this time was defined as the response speed of the liquid crystal. When the response speed is less than 6 msec, it is evaluated as “good”, when it is 6 msec or more and less than 8 msec, and when it is 8 msec or more as “bad”, the response speed of this liquid crystal cell is 4.2 msec. Yes, it was judged as “good”.
[Evaluation of afterimage characteristics (evaluation of pretilt angle stability)]
The liquid crystal cells produced above are described in “T. J. Scheffer et. Al., J. Appl. Phys. Vol 48, p1783 (1977)” and “F. Nakano, et. Al., JPN. J. Appl. Phys. Vol.19, p2013 (1980) "and measured by a rotating crystal method using He-Ne laser light. The measurement was performed with respect to a pretilt angle (initial pretilt angle θini) before voltage application to the liquid crystal cell, and a pretilt angle after driving for 13 hours at AC 9 V at room temperature (pretilt angle θac after driving). Further, the pretilt angle change rate β [%] was calculated by the following mathematical formula (2). When the pretilt angle change rate β was less than 5%, it was evaluated as “good”, and when it was 5% or more as “bad”, the pretilt angle change rate of this liquid crystal cell was 2.8%. It was judged as “good”.
Pretilt angle change rate β [%] = (θac−θini) / θini × 100 (2)

<Examples 2 to 7 and Comparative Examples 1 and 2>
A liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the composition of the liquid crystal aligning agent was changed as shown in Table 1 below. In addition, a liquid crystal cell was produced using each of these liquid crystal aligning agents in the same manner as in Example 1, and the produced liquid crystal cell was evaluated. In Examples 2, 5, 7 and Comparative Example 2, the liquid crystal composition used was changed from LC1 to LC2. The evaluation results are shown in Table 2 below.

In Table 1, “parts by weight” indicates the amount of each component when the total amount of polyamic acid and polyimide in the liquid crystal aligning agent is 100 parts by weight. Abbreviations of additives have the following meanings.
A-1; tert-butyl sulfide A-2; benzylisopropenyl ether

  As shown in Table 2, in Examples 1 to 7, the evaluation of the response speed of the liquid crystal was “good” or “good”, and the afterimage characteristics were “good”. In addition, a high voltage holding ratio was exhibited even after the liquid crystal cell was irradiated with ultraviolet rays. In particular, when an alkenyl-based liquid crystal is used, the decrease in voltage holding ratio due to ultraviolet irradiation tends to be large. In Examples 2, 5, and 7, the voltage holding ratio is high even after ultraviolet irradiation, and the response speed is also good. there were. From these results, in order to achieve a high-speed response of the liquid crystal panel using alkenyl liquid crystals in the PSA mode, the voltage holding ratio of UV irradiation can be increased by allowing a compound having a chain transfer structure to be present in the liquid crystal alignment film. It has been found that a liquid crystal display element can be obtained in which the deterioration can be suppressed and the high-speed response and the afterimage characteristics are good. On the other hand, in Comparative Example 1, the afterimage characteristics and the response speed were poor. Further, in Comparative Example 2 using an alkenyl-based liquid crystal, the afterimage characteristics were poor, and a decrease in voltage holding ratio due to ultraviolet irradiation appeared remarkably.

  Furthermore, except that the ITO electrode pattern on the glass substrate was changed to a fishbone electrode pattern as shown in FIGS. A liquid crystal cell was manufactured and evaluated in the same manner as described above. Also in this case, the same effects as in Examples 1 to 7 were exhibited.

  DESCRIPTION OF SYMBOLS 1 ... ITO electrode, 2 ... Slit part, 3 ... Light-shielding film

Claims (12)

  A composition for a liquid crystal display element for forming at least one of a liquid crystal layer and a liquid crystal alignment layer of a liquid crystal display element, comprising a compound (A) having a structure capable of exhibiting a chain transfer function A composition for a liquid crystal display device.   The composition for liquid crystal display elements of Claim 1 which is an object for formation of the said liquid crystal aligning layer.   The composition for liquid crystal display elements according to claim 2, wherein the compound (A) is a polymer having a structure capable of exhibiting a chain transfer function.   The composition for liquid crystal display elements according to claim 2 or 3, wherein the compound (A) is at least one polymer selected from the group consisting of polyamic acid, polyimide, polyamic acid ester, and polyorganosiloxane.   The composition for liquid crystal display elements as described in any one of Claims 1-4 whose mode of the said liquid crystal display element is PSA mode.   The composition for liquid crystal display elements of Claim 5 which is an object for manufacture of the liquid crystal display element which contains the monofunctional liquid crystalline compound which has either one of an alkenyl group and a fluoro alkenyl group in the said liquid crystal layer. The process for apply | coating the composition for liquid crystal display elements as described in any one of Claims 2-4 on this electrically conductive film of a pair of board | substrate which has an electrically conductive film, respectively, and then heating this, and forming a coating film When,
A step of constructing a liquid crystal cell by arranging a pair of substrates on which the coating film is formed so that the coating film faces through a liquid crystal layer containing a liquid crystal compound;
Irradiating the liquid crystal cell with light while applying a voltage between the conductive films of the pair of substrates. Applying a liquid crystal aligning agent on each of the conductive films of the pair of substrates having a conductive film, and then heating the liquid crystal aligning agent to form a coating film;
A pair of substrates on which the coating film is formed are arranged so that the coating film faces each other through a liquid crystal layer containing a compound (A) having a structure capable of developing a chain transfer function and a liquid crystal compound. Building a cell;
Irradiating the liquid crystal cell with light while applying a voltage between the conductive films of the pair of substrates.   The method for producing a liquid crystal display element according to claim 7 or 8, comprising a monofunctional liquid crystalline compound having one of an alkenyl group and a fluoroalkenyl group as the liquid crystalline compound.   The liquid crystal aligning film formed using the composition for liquid crystal display elements as described in any one of Claims 2-4.   A pair of substrates opposed to each other with a predetermined interval; a liquid crystal alignment layer formed on the surface of the pair of substrates facing each other; a liquid crystal layer disposed between the two liquid crystal alignment layers; A liquid crystal display element comprising a compound (A) having a structure capable of exhibiting a chain transfer function in at least one of the liquid crystal alignment layer and the liquid crystal layer.   The liquid crystal display element according to claim 11, wherein the liquid crystal layer contains a monofunctional liquid crystalline compound having one of an alkenyl group and a fluoroalkenyl group.