WO2018016263A1

WO2018016263A1 - Method for manufacturing liquid crystal element

Info

Publication number: WO2018016263A1
Application number: PCT/JP2017/023099
Authority: WO
Inventors: 雄介井上; 孝人加藤
Original assignee: Jsr株式会社
Priority date: 2016-07-19
Filing date: 2017-06-22
Publication date: 2018-01-25
Also published as: TW201804552A

Abstract

In the present invention, a liquid crystal element is manufactured by a method including a film formation step for applying a liquid crystal alignment agent on each of a first substrate and a second substrate and forming a coating film, a contact step for bringing the coating film formed on only one of the first substrate and the second substrate into contact with a solvent or bringing the coating film formed on each of the first substrate and the second substrate into contact with a solvent under different conditions for each substrate, and a step for arranging the first substrate and the second substrate so that the coating films face each other after the contact step and constructing a liquid crystal cell.

Description

Manufacturing method of liquid crystal element

The present disclosure relates to a method for manufacturing a liquid crystal element.

As the liquid crystal element, in addition to a horizontal alignment mode liquid crystal element using a nematic liquid crystal having a positive dielectric anisotropy, such as a TN (Twisted Nematic) type and an STN (Super Twisted Nematic) type, a negative dielectric different Various liquid crystal elements are known, such as a VA (Vertical Alignment) type liquid crystal element in a vertical (homeotropic) alignment mode using a nematic liquid crystal having a directivity. These liquid crystal elements include a liquid crystal alignment film having a function of aligning liquid crystal molecules in a certain direction. As the material constituting the liquid crystal alignment film, polyamic acid, polyimide, polyamic acid ester, polyamide, polyester, polyorganosiloxane, and the like are known, and in particular, the liquid crystal alignment film made of polyamic acid or polyimide is heat resistant, mechanical It has been used preferably for a long time because of its excellent mechanical strength and affinity with liquid crystal molecules (see Patent Documents 1 to 3).

Further, as an alignment treatment method, a PSA (Polymer Sustained Alignment) method is known. In the PSA method, a pre-tilt angle characteristic is obtained by allowing a liquid crystal layer provided in a gap between a pair of substrates to contain a polymerizable compound and irradiating ultraviolet rays with a voltage applied between the substrates to polymerize the polymerizable compound. This is a technique that attempts to control the orientation direction of the liquid crystal. According to this technique, it is possible to increase the viewing angle and speed up the liquid crystal molecule response, and it is possible to solve the problem of lack of transmittance and contrast that is inevitable in the MVA panel. In the PSA system, in recent years, a polymerizable compound is contained in a liquid crystal alignment film, and the alignment direction of the liquid crystal is controlled by irradiating ultraviolet rays with a voltage applied between the substrates.

Also, in recent years, with the expansion of the use of liquid crystal panels, development of liquid crystal panels with complicated shapes such as curved displays with curved display surfaces has been promoted. A curved display is generally manufactured by bonding a pair of substrates so that a liquid crystal layer is disposed between the substrates to form a liquid crystal cell, and then bending the liquid crystal cell. However, by bending the liquid crystal cell to manufacture a curved display, a region in which a pretilt angle shifts between one substrate and the other substrate in a pair of substrates may occur. In this case, there is a concern that the image quality is degraded.

Taking these points into consideration, by producing a curved display using a liquid crystal cell constructed by laminating these substrates by differentiating the pretilt angle between the liquid crystal alignment film of one substrate and the liquid crystal alignment film of the other substrate, It has been proposed to suppress the shift of the pretilt angle between the substrates when the liquid crystal cell is bent (see Patent Document 4). In this patent document 4, as a method for making the pretilt angle different between substrates, among the liquid crystal alignment films formed on the substrate, a method of irradiating only the liquid crystal alignment film of one substrate with ultraviolet irradiation, and at the time of film formation A method of varying the bake temperature between substrates is disclosed.

JP-A-4-153622 JP 56-91277 A Japanese Patent Laid-Open No. 11-258605 Japanese Patent Laid-Open No. 2005-26074

As in Patent Document 4, it is difficult to generate a sufficient difference in pretilt angle between one substrate and the other substrate by the method of irradiating ultraviolet rays or the method of varying the baking temperature during film formation. Therefore, there is a problem that it is difficult to ensure sufficient image quality.

The present disclosure has been made in view of the above circumstances, and one object of the present disclosure is to manufacture a liquid crystal element capable of sufficiently causing a difference in pretilt angle between one substrate and the other substrate in a pair of substrates. It is to provide a method.

According to this indication, in order to solve the above-mentioned subject, the following means are provided.
[1] A film forming step of forming a coating film by applying a liquid crystal aligning agent on each of the first substrate and the second substrate, and only one of the first substrate and the second substrate. A contact step of contacting the coating film formed thereon with a solvent, or contacting the coating film formed on each of the first substrate and the second substrate with a solvent under different conditions between the substrates; and And a step of constructing a liquid crystal cell by arranging the first substrate and the second substrate to face each other so that the coating film faces each other after the contacting step.

According to the manufacturing method of the present disclosure, a difference in pretilt angle between one substrate and the other substrate in a pair of substrates can be sufficiently generated. In addition, because of the difference in the pretilt angle between the substrates due to the difference in the contact treatment with the solvent after forming the coating film on the substrate, even when the liquid crystal alignment film is formed using the same liquid crystal alignment agent It is possible to cause a sufficient difference in pretilt angle between the substrates, and the productivity is also good.

The schematic diagram for demonstrating the orientation shift which arises in a curved-surface display. (A) is a liquid crystal cell before being bent, (b) is a liquid crystal cell after being bent, and (c) is a liquid crystal cell of one embodiment of the present disclosure.

The method for manufacturing a liquid crystal element of the present disclosure includes the following step A, step B, and step C.
Step A: a step of forming a coating film by applying a liquid crystal aligning agent on each surface of a pair of substrates including a first substrate and a second substrate.
Step B: The coating film formed on only one of the pair of substrates obtained in Step A is brought into contact with a solvent or formed on each of the first substrate and the second substrate. A step of bringing the coated film into contact with a solvent under different conditions between a pair of substrates.
Step C: After Step B, a step of constructing a liquid crystal cell by arranging the first substrate and the second substrate to face each other so that the coating films face each other.
Hereinafter, the manufacturing method of the liquid crystal element of the present disclosure will be described in detail.

≪Process A≫
In step A, a liquid crystal aligning agent is applied on a pair of substrates including a first substrate and a second substrate, and a coating film is formed on the substrate, preferably by heating the application surface. As the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly (cycloaliphatic olefin) can be used. As the transparent conductive film provided on one surface of the substrate, a NESA film (registered trademark of US PPG) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ), etc. Can be used. In the case of manufacturing a TN type, STN type, or VA type liquid crystal element, two substrates provided with a patterned transparent conductive film are used. On the other hand, in the case of manufacturing an IPS type or FFS type liquid crystal element, a substrate provided with an electrode patterned in a comb shape and a counter substrate provided with no electrode are used. Application of the liquid crystal aligning agent to the substrate is preferably performed on the electrode forming surface by an offset printing method, a spin coating method, a roll coater method or an ink jet printing method.

After applying the liquid crystal aligning agent, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied liquid crystal aligning agent. In this case, a coating film is formed on the substrate by pre-baking. The pre-bake temperature is preferably 30 to 200 ° C., and the pre-bake time is preferably 0.25 to 10 minutes. After application on the substrate, preferably, after pre-baking, baking (post-baking) is performed for the purpose of completely removing the solvent. The firing temperature (post-bake temperature) at this time is preferably 80 to 300 ° C., and the post-bake time is preferably 5 to 200 minutes. The film thickness after post-baking is preferably 0.001 to 1 μm.

<Liquid crystal aligning agent>
Next, the liquid crystal aligning agent will be described in detail. The liquid crystal aligning agent used with the manufacturing method of this indication contains a polymer component, and also contains another component as needed.

For the polymer component in the liquid crystal aligning agent, the main skeleton of the polymer is not particularly limited. For example, polyamic acid, polyimide, polyamic acid ester, polyamide, polyorganosiloxane, polyester, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene) -Phenylmaleimide) derivatives, poly (meth) acrylates and the like as main skeletons. In the present specification, “(meth) acrylate” means to include acrylate and methacrylate. Among these, from the viewpoint of affinity with liquid crystal, mechanical strength, voltage holding ratio, heat resistance, etc., selected from the group consisting of polyamic acid, polyamic acid, polyamic acid ester, polyamide, polyorganosiloxane, and (meth) acrylate And at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and polyorganosiloxane is more preferable. In addition, as a polymer component, 1 type may be used independently and may be used in combination of 2 or more type.

Other components are not particularly limited as long as the effects of the present disclosure are not hindered. For example, a compound having at least one epoxy group in the molecule, a functional silane compound, an antioxidant, a metal chelate compound, a crosslinking agent, and a binder Examples thereof include resins, curing accelerators, surfactants, fillers, dispersants, photosensitizers, and polymerizable compounds. In addition, the mixture ratio of another component can be suitably selected according to each compound in the range which does not impair the effect of this indication.

The liquid crystal aligning agent in the production method of the present disclosure may be a one-component system, but even when the same liquid crystal aligning agent is used between the substrates, a sufficient difference in the pretilt angle between the substrates by the following contact process It is preferable that it is a multiple component system containing the 1st component and the 2nd component different from the said 1st component at the point which can produce. Particularly preferably, the liquid crystal aligning agent contains, as the first component, a compound [A] having at least one selected from the group consisting of a crosslinkable group, a photoalignable group and a radical generating group, and a polymer as the second component [P] (excluding those corresponding to the compound [A]).

(Compound [A])
The compound [A] has at least one selected from the group consisting of a crosslinkable group, a photoalignable group, and a radical generating group.
The crosslinkable group is preferably a group capable of forming a covalent bond between the same or different molecules by light or heat. As a specific example, for example, (meth) acrylic acid or a derivative thereof is used as a basic skeleton ( Examples include meth) acryl-containing groups, groups having vinyl groups (alkenyl groups, vinylphenyl groups, etc.), ethynyl groups, epoxy groups (oxiranyl groups, oxetanyl groups), and the like.

The photo-alignment group is a functional group that imparts anisotropy to the film by a photoisomerization reaction, a photodimerization reaction, or a photolysis reaction by light irradiation. Specific examples of the photo-alignment group include an azobenzene-containing group containing azobenzene or a derivative thereof as a basic skeleton, a cinnamic acid structure-containing group containing a cinnamic acid or a derivative thereof (cinnamic acid structure) as a basic skeleton, a chalcone or a derivative thereof. Chalcone-containing group including basic skeleton, benzophenone-containing group including benzophenone or a derivative thereof as basic skeleton, benzoate-containing group including benzoate or a derivative thereof as basic skeleton, coumarin-containing group including coumarin or a derivative thereof as a basic skeleton, cyclobutane or a derivative thereof Examples include a polyimide structure containing a derivative as a basic skeleton. As the photo-alignment group possessed by the compound [A], a cinnamic acid structure-containing group is particularly preferable in terms of high sensitivity to light.

The radical generating group is not particularly limited as long as it is a functional group that generates radicals by light or heat. As the radical generating group, a functional group derived from a known radical generating agent can be used. Examples of the radical generator include radical-generating group-containing compounds such as alkylphenone compounds, benzoin compounds, ketal compounds, acetophenone compounds, benzophenone compounds, thioxanthone compounds, and anthraquinone compounds.

Compound [A] is capable of more sufficiently providing a difference in pretilt angle (tilt difference) between the first substrate and the second substrate. Among these, at least one of a crosslinkable group and a photoalignable group is present. It preferably has, and more preferably has a total of at least two of at least one of a crosslinkable group and a photoalignable group. Among them, it is particularly preferable to have a (meth) acryloyl group or a cinnamic acid structure-containing group. When compound [A] has at least one of a crosslinkable group and a photoalignable group, the crosslinkable group or photoalignable group remaining in the liquid crystal alignment film interacts with the liquid crystal molecules, and the pretilt angle is stabilized. This is thought to be due to the increase in performance.

The compound [A] may be a low molecular compound (for example, a compound having a molecular weight of less than 1,000) or a polymer obtained by polymerizing monomers. The compound [A] is a crosslinkable group, a photo-alignment, in that a sufficient tilt difference is generated between the first substrate and the second substrate, and a decrease in display quality due to the inflow of impurities into the liquid crystal layer can be suppressed. A polymer having at least one selected from the group consisting of a functional group and a radical generating group is preferred. When the compound [A] is a polymer, its main skeleton is not particularly limited, but is preferably at least one of (meth) acrylate and polyorganosiloxane from the viewpoint that the effects of the present disclosure are sufficiently obtained, Of these, polyorganosiloxane is particularly preferred.

The polyorganosiloxane as the compound [A] can be synthesized according to a known method. For example, a monomer containing a hydrolyzable silane compound having an epoxy group (hereinafter also referred to as “epoxy group-containing silane compound”) is hydrolyzed and condensed to synthesize an epoxy group-containing polyorganosiloxane, The obtained epoxy group-containing polyorganosiloxane is reacted with a carboxylic acid having at least one selected from the group consisting of a crosslinkable group, a photoalignable group and a radical generating group. According to such a reaction, it is convenient, and it is easy to adjust the introduction rate of the functional group, which is preferable.

Examples of the epoxy group-containing silane compound include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2- (3,4-epoxycyclohexyl) ethyl. Examples include triethoxysilane. These may be used individually by 1 type and may be used in combination of 2 or more type.

In the synthesis of the epoxy group-containing polyorganosiloxane, other silane compounds may be used together with the epoxy group-containing silane compound. Examples of the other silane compounds include alkoxysilane compounds such as tetramethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and dimethyldiethoxysilane;
Nitrogen / sulfur-containing alkoxysilane compounds such as 3-mercaptopropyltriethoxysilane, mercaptomethyltriethoxysilane, 3-aminopropyltrimethoxysilane, N- (3-cyclohexylamino) propyltrimethoxysilane; 3- (meth) acryl Roxypropyltrimethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxypropylmethyldiethoxysilane, 3- (meth) acryloxyoctyltrimethoxysilane, vinyltriethoxysilane, p- Examples include unsaturated bond-containing alkoxysilane compounds such as styryltrimethoxysilane; trimethoxysilylpropyl succinic anhydride and the like. “(Meth) acryloxy” means “acryloxy” and “methacryloxy”. The proportion of other silane compounds used is preferably 70 mol% or less, more preferably 50 mol% or less, based on the total amount of silane compounds used for polymerization.

The hydrolysis / condensation reaction is carried out by reacting one or more of the above silane compounds with water, preferably in the presence of a suitable catalyst and organic solvent. In the reaction, the amount of water used is preferably 1 to 30 mol with respect to 1 mol of the silane compound (total amount). Examples of the catalyst to be used include acids, alkali metal compounds, organic bases, titanium compounds, zirconium compounds and the like. The amount of catalyst used varies depending on the type of catalyst, reaction conditions such as temperature, and the like, and should be set appropriately. For example, the amount is 0.01 to 3 times the total amount of the silane compound. Examples of the organic solvent to be used include hydrocarbons, ketones, esters, ethers, alcohols, and the like, and among these, it is preferable to use a water-insoluble or slightly water-soluble organic solvent. The organic solvent is used in an amount of preferably 10 to 10,000 parts by mass with respect to 100 parts by mass in total of the silane compounds used in the reaction.

The above hydrolysis / condensation reaction is preferably carried out by heating with, for example, an oil bath. At that time, the heating temperature is preferably 130 ° C. or less, and the heating time is preferably 0.5 to 12 hours. After completion of the reaction, the organic solvent layer separated from the reaction solution is dried with a desiccant as necessary, and then the solvent is removed to obtain the desired polyorganosiloxane. The method for synthesizing the polyorganosiloxane is not limited to the hydrolysis / condensation reaction described above, and may be performed by, for example, a method in which a hydrolyzable silane compound is reacted in the presence of oxalic acid and alcohol.

The reaction between the epoxy group-containing polyorganosiloxane and the carboxylic acid is preferably carried out in an organic solvent in the presence of a suitable catalyst. In the reaction of the epoxy group-containing polyorganosiloxane with the carboxylic acid, the carboxylic acid is preferably used in an amount of 1 to 70 mol% based on the epoxy group of the epoxy group-containing polyorganosiloxane. % Is more preferable.

In the above reaction, for example, a catalyst generally used as an epoxy group curing accelerator can be used as the catalyst. Examples of the catalyst include tertiary amines, imidazole derivatives, organic phosphorus compounds, quaternary phosphonium salts, diazabicycloalkenes, organometallic compounds, quaternary ammonium halides, metal halide compounds, and latent curing accelerators. The ratio of the catalyst used is preferably 0.01 to 100 parts by mass, more preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the epoxy group-containing polyorganosiloxane.

Examples of the organic solvent used in the above reaction include ketones, ethers, esters, amides, alcohols and the like. The proportion of the organic solvent used is preferably such that the total mass of components other than the organic solvent in the reaction solution is 0.1 to 50% by mass as the proportion of the total amount of the reaction solution. It is more preferable to set the ratio to be%. The reaction temperature of the above reaction is preferably −20 ° C. to 200 ° C., more preferably 0 ° C. to 160 ° C. The reaction time is preferably 1 hour to 48 hours, more preferably 2 hours to 12 hours. The resulting reaction solution may be used for preparing a liquid crystal aligning agent after isolating the polyorganosiloxane contained in the reaction solution using a known isolation method.

Regarding the polyorganosiloxane as the compound [A], the weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) is preferably in the range of 1,000 to 50,000, More preferably, it is in the range of 200 to 10,000. In addition, compound [A] may be used individually by 1 type, and may be used in combination of 2 or more type.

(Polymer [P])
The polymer [P] is a polymer different from the compound [A], that is, a polymer having no crosslinkable group, photoalignable group, or radical generating group. When the compound [A] is a polymer, the polymer [P] is preferably a polymer having a main chain different from that of the compound [A]. From the viewpoint of affinity with liquid crystal, mechanical strength, and voltage holding ratio, the polymer [P] is more preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide. Among these, a combination in which the compound [A] is polyorganosiloxane and the polymer [P] is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide is particularly preferable.

(Polyamic acid, polyamic acid ester and polyimide)
The polyamic acid, polyamic acid ester and polyimide contained in the liquid crystal aligning agent can be synthesized according to a conventionally known method. For example, polyamic acid can be obtained by reacting tetracarboxylic dianhydride and diamine. The polyamic acid ester can be obtained by, for example, a method of reacting the polyamic acid obtained above with an esterifying agent (for example, methanol, ethanol, N, N-dimethylformamide diethyl acetal, or the like). The polyimide can be obtained, for example, by dehydrating and ring-closing the polyamic acid obtained above to imidize. With respect to the polyimide to be used, the imidation ratio is preferably 20 to 95%, more preferably 30 to 90%. 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.

Examples of the tetracarboxylic dianhydride used for the polymerization include aliphatic tetracarboxylic dianhydrides such as butanetetracarboxylic dianhydride and ethylenediaminetetraacetic acid dianhydride; 2,3,5-tricarboxycyclopentylacetic acid Dianhydride, 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2, 5-Dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 2,4,6,8-tetracarboxy Bicyclo [3.3.0] octane-2: 4,6: 8-dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, etc. Rubonic acid dianhydride; pyromellitic dianhydride, 4,4 '-(hexafluoroisopropylidene) diphthalic anhydride, p-phenylenebis (trimellitic acid monoester anhydride), ethylene glycol bis (anhydrotri) And aromatic tetracarboxylic dianhydrides such as 1,3-propylene glycol bis (anhydrotrimellitate) and the like, and tetracarboxylic acids described in JP 2010-97188 A A dianhydride can be used. In addition, tetracarboxylic dianhydride may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the diamine used in the polymerization include aliphatic diamines such as ethylenediamine and tetramethylenediamine; alicyclic diamines such as p-cyclohexanediamine and 4,4′-methylenebis (cyclohexylamine); hexadecanoxy Diaminobenzene, cholestanyloxydiaminobenzene, cholestanyl diaminobenzoate, cholesteryl diaminobenzoate, lanostannyl diaminobenzoate, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 2,5-diamino-N, N-diallylaniline, the following formulas (8-1) to (8-3) )

A side chain type aromatic diamine such as a compound represented by each of the following: p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylamine, 4-aminophenyl-4′-aminobenzoate, 4 , 4'-diaminoazobenzene, 3,5-diaminobenzoic acid, 1,5-bis (4-aminophenoxy) pentane, bis [2- (4-aminophenyl) ethyl] hexanedioic acid, bis (4-aminophenyl) ) Amine, N, N-bis (4-aminophenyl) methylamine, N, N′-bis (4-aminophenyl) -benzidine, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2 '-Bis (trifluoromethyl) -4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl ether, 2,2-bis [4- (4- Minophenoxy) phenyl] propane, 4,4 ′-(phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4- (4-aminophenoxycarbonyl) -1- (4-aminophenyl) ) Non-side chain aromatic diamines such as piperidine, 4,4 ′-[4,4′-propane-1,3-diylbis (piperidine-1,4-diyl)] dianiline; 1,3-bis (3 In addition to diaminoorganosiloxane such as -aminopropyl) -tetramethyldisiloxane, diamines described in JP 2010-97188 A can be used. In addition, a diamine may be used individually by 1 type and may be used in combination of 2 or more type.

For the polyamic acid, polyamic acid ester and polyimide contained in the liquid crystal aligning agent, the weight average molecular weight (Mw) in terms of polystyrene measured by GPC is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. The molecular weight distribution (Mw / Mn) is preferably 7 or less, more preferably 5 or less. In addition, the polyamic acid, polyamic acid ester, and polyimide which are contained in the liquid crystal aligning agent may be only one kind, or may be a combination of two or more kinds.

The compounding ratio of the compound [A] and the polymer [P] is such that the compound [A] is contained in 100 parts by mass of the polymer [P] contained in the liquid crystal aligning agent from the viewpoint of sufficiently producing a tilt difference. The blending ratio is preferably 1 to 100 parts by mass, more preferably 3 to 50 parts by mass, and even more preferably 5 to 40 parts by mass.

(solvent)
The liquid crystal aligning agent is prepared as a solution composition in which a polymer component and other components optionally blended as necessary are preferably dissolved or dispersed in an organic solvent. Examples of the organic solvent used include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,2-dimethyl-2-imidazolidinone, γ-butyrolactone, γ-butyrolactam, and 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 Ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, A propylene carbonate etc. can be mentioned. These can be used individually by 1 type or in mixture of 2 or more types.

The solid content concentration in the liquid crystal aligning agent (the ratio of the total mass of components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc. It is in the range of 1 to 10% by mass. When the solid content concentration is less than 1% by mass, the film thickness of the coating film becomes too small, and it becomes difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by mass, it is difficult to obtain a good liquid crystal alignment film because the film thickness is excessive, and the viscosity of the liquid crystal aligning agent increases and the applicability decreases. There is a tendency.

≪Process B≫
Next, step B will be described. Step B is a step of causing a tilt difference between the substrates by making the contact mode with the solvent different from the coating film formed on each substrate. Specifically, (1) one of the first substrate and the second substrate is not subjected to the treatment of bringing the coating film into contact with the solvent, and only the other substrate is brought into contact with the coating film with the solvent. And a process of bringing the coating film and the solvent into contact with each other on both the first substrate and the second substrate. The conditions for contacting the solvent are the same as those of the first substrate. And a method (hereinafter, also referred to as “second method”) under different conditions between the first substrate and the second substrate.

As the solvent used for contact with the coating film in the first method, an organic solvent or an alkaline aqueous solution is preferably used. The organic solvent is preferably at least one selected from the group consisting of alcohols, ethers, ketones and hydrocarbons. Specific examples thereof include alcohols such as ethanol, propanol, isopropyl alcohol, 1-methoxy-2-propanol, diacetone alcohol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, butyl cellosolve (ethylene glycol monobutyl ether), propylene glycol. Monoethyl ether, ethyl lactate, 1-hexanol, 4-methyl-2-pentanol, etc .;

Examples of ethers include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol mono-n-butyl ether acetate, propylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether. Acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monopropyl ether acetate, tetra Dorofuran, methyl 3-methoxy propionate, di isopentyl ether and the like;
Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, and methyl isoamyl ketone;
Examples of the hydrocarbon include hexane, heptane, octane, benzene, toluene, xylene, mesitylene, and cyclohexane; These organic solvents can be used individually by 1 type or in combination of 2 or more types. In addition, you may use, for example, adding water and surfactant suitably to these organic solvents.

Among these, the organic solvent is preferably at least one selected from the group consisting of alcohol and ketone, and is selected from the group consisting of ethanol, propanol, isopropanol, acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclopentanone. It is more preferable to use at least one type, and it is particularly preferable to use at least one of isopropanol and acetone.

Examples of the alkaline aqueous solution include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanol. Amine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5,4,0] -7-undecene, 1,5-diazabicyclo- [4 An alkaline aqueous solution in which 3,0] -5-nonane and the like are dissolved may be mentioned. In addition, you may add alcohol, such as methanol and ethanol, and surfactant suitably to these alkaline aqueous solution, for example.

As a solvent used for contact with the coating film, it is preferable to use a solvent having different solubility in the first component and different solubility in the second component in the liquid crystal aligning agent. Particularly preferably, the solvent used for contact with the coating film is a good solvent for the first component and a poorly or insoluble solvent for the second component. By using such a solvent, when a coating film is formed on each of the pair of substrates using the liquid crystal aligning agent containing the first component and the second component, the tilt difference between the substrates can be sufficiently reduced by a simple method. Can be generated. Whether to use an organic solvent or an alkaline aqueous solution as the solvent used for contact with the coating film may be selected in consideration of the solubility of the first component.

When a solvent having different solubility in the first component and in the second component in the liquid crystal aligning agent is used for contact with the coating film, it is sufficient that a sufficient tilt difference can be generated between the substrates. The solvent used for the contact with the 1st component and 2nd component in an agent, and a coating film is not specifically limited. In a preferred embodiment, the first component is polyorganosiloxane, the second component is at least one selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, and the solvent used for contact with the coating film is alcohol or ketone A combination of at least one selected from the group consisting of

It should be noted that the difference in tilt between the substrates caused by different contact modes of the solvent with the solvent between the substrates is that the surface of the coating film is washed by contact with the solvent, and the components of the surface of the coating film between the substrates. It is thought that this is caused by the difference. For example, when the first component is polyorganosiloxane and the second component is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, in the substrate not subjected to contact treatment with a solvent, the polyorganosiloxane is By remaining in the film, it is considered that a pretilt angle is developed under the influence of polyorganosiloxane (that is, compound [A]). On the other hand, in the substrate subjected to the contact treatment with the solvent, the polyorganosiloxane is eluted by the contact treatment, and a pretilt angle derived from polyamic acid, polyamic acid ester or polyimide (that is, polymer [P]) is expressed. Conceivable. Thereby, it is estimated that the tilt difference between the first substrate and the second substrate is increased. However, this is just a guess, and does not limit the content of the present disclosure.

In the second method, the “contact with the solvent under different conditions between the substrates” may be any as long as it can cause a tilt difference between the first substrate and the second substrate. For example, changing the composition of the solvent used for contact with the coating film between a pair of substrates, changing the contact time between the coating film and the solvent between a pair of substrates, changing the contact temperature between the coating film and the solvent, Or the method etc. which perform these combining 2 or more types are mentioned. Among these, the method of making each coating film of a 1st board | substrate and a 2nd board | substrate contact the solvent from which a solvent composition differs between board | substrates is preferable. Here, “the solvent compositions are different” means that at least one of the types and component ratios of the components constituting the solvent to be brought into contact with the coating film is different. Specifically, (i) a method in which the type of solvent to be brought into contact with the coating film is different between the first substrate and the second substrate, and (ii) a component ratio of a plurality of components contained in the solvent to be brought into contact with the coating film. Examples thereof include a method of making the first substrate different from the second substrate.

As these preferable specific examples, in the method (i), one of the first substrate and the second substrate is brought into contact with the solvent exemplified in the first method, and the other coating is applied to the liquid crystal. The first component and the second component in the alignment agent are brought into contact with a poorly soluble or insoluble solvent. In the above method (ii), the solvent exemplified in the first method is a poorly soluble or insoluble solvent (for example, water) with respect to the first component and the second component in the liquid crystal aligning agent. This is done by adjusting the density. From the viewpoint of increasing the tilt difference between the first substrate and the second substrate, among these, the method (i) is more preferable.

In the second method, it is preferable that one of the first substrate and the second substrate is brought into contact with a solvent having different solubility for the first component and different solubility for the second component. In this case, a sufficient tilt difference between the pair of substrates can be generated by a simple method with respect to the coating film formed using the liquid crystal aligning agent containing the first component and the second component. Specifically, for example, when the first component in the liquid crystal aligning agent is polyorganosiloxane and the second component is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, The coating film of one of the two substrates is brought into contact with at least one selected from the group consisting of alcohol and ketone, and the coating film of the other substrate is made to the first component and the second component in the liquid crystal aligning agent. The method of making it contact with poorly soluble or insoluble solvents (water etc.) etc. are mentioned.

The method for bringing the solvent into contact with the coating film on the substrate is not particularly limited, and examples thereof include spraying treatment, shower treatment, immersion treatment, liquid piling treatment, and the like. Preferably, it is spraying treatment, showering treatment or immersion treatment, and spraying treatment is particularly preferred. The spray treatment is preferable in that a tilt difference can be sufficiently generated while minimizing the amount of the solvent brought into contact with the coating film. In contacting the coating film with the solvent, a part of the coating film may be brought into contact with the solvent, but it is preferable to bring the entire surface of the coating film into contact with the solvent. At this time, in order to sufficiently bring the coating film and the solvent into contact with each other, for example, a series of treatments for supplying and contacting the solvent to the coating film on the substrate are performed a plurality of times, or in the case of immersion treatment, the solvent is stirred. Alternatively, shaking is also effective.

The contact treatment between the coating film and the solvent may be performed at a timing after pre-baking and before post-baking, or may be performed at a timing after post-baking. From the viewpoint of increasing the cleaning efficiency due to contact with the solvent and causing a sufficient difference in pretilt angle between the substrates, it is preferable to carry out at a timing after pre-baking and before post-baking. The temperature when contacting with the solvent is preferably 10 to 50 ° C., more preferably 20 to 30 ° C. The contact time with the solvent is preferably 5 seconds to 30 minutes, more preferably 5 seconds to 15 minutes. The amount of the solvent to be brought into contact with the coating film is appropriately selected in consideration of the contact method and the like. After the contact between the coating film and the solvent, the solvent may be completely removed from the coating film by further heating or the like. In the contact treatment, the contact time and the contact temperature with the solvent may be the same or different between the substrates.

≪Process C≫
In Step C, two substrates having a coating film formed using a liquid crystal aligning agent are prepared, and a liquid crystal cell is manufactured by disposing a liquid crystal between the two substrates disposed to face each other. At this time, the liquid crystal cell may be constructed using the substrate after the coating film is brought into contact with the solvent as it is, or before or after the coating film is brought into contact with the solvent, rubbing treatment or light on the coating film surface as necessary. A liquid crystal cell may be constructed after performing the alignment treatment.

In order to manufacture a liquid crystal cell, for example, two substrates are arranged to face each other with a gap so that the liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded together using a sealant, Examples thereof include a method in which a liquid crystal layer is formed by injecting and filling a liquid crystal in a cell gap surrounded by a sealing agent, and then the injection hole is sealed, a method using an ODF method, and the like. As the sealant, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include nematic liquid crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferable. After the construction of the liquid crystal cell, the liquid crystal cell may be subjected to light irradiation in a state where a voltage is applied between the conductive films of the pair of substrates.

In the case of manufacturing a PSA liquid crystal element, a liquid crystal compound and a photopolymerizable compound are present in a liquid crystal layer, and a voltage is applied between conductive films of a pair of substrates after the liquid crystal cell is constructed. In this state, the liquid crystal cell is irradiated with light. As the photopolymerizable compound, for example, a compound having a functional group capable of radical polymerization such as a (meth) acryloyl group and a vinyl group is used. The blending ratio of the photopolymerizable compound is preferably 0.1 to 0.5% by mass with respect to the total amount of the liquid crystal compound to be used.

As the liquid crystal compound, nematic liquid crystal having negative dielectric anisotropy can be preferably used. The liquid crystalline compound preferably contains an alkenyl liquid crystal in that the response speed of the PSA liquid crystal element can be further increased. As the alkenyl-based liquid crystal, conventionally known ones can be used, and among them, those including a monofunctional alkenyl-based liquid crystal having one of an alkenyl group and a fluoroalkenyl group are preferable. Specific examples of the alkenyl liquid crystal include compounds represented by the following formulas (L1-1) to (L1-9). The blending ratio of the alkenyl-based liquid crystal is preferably 0.1 to 10% by mass with respect to the total amount of the liquid crystal compound to be used.

In the PSA treatment, as the light irradiated to the liquid crystal cell, for example, ultraviolet light or visible light including light having a wavelength of 150 to 800 nm can be used. Of these, ultraviolet rays containing light having a wavelength of 300 to 400 nm are preferable. As a light source for irradiation light, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, an excimer laser, or the like is used. The amount of light irradiation is preferably 1,000 to 100,000 J / m ² and more preferably 1,000 to 50,000 J / m ² . Note that as a PSA method, a liquid crystal alignment film contains a compound having a polymerizable group (low molecule or polymer), and after the liquid crystal cell is constructed, the liquid crystal is applied in a state where a voltage is applied between the conductive films of the pair of substrates. You may employ | adopt the system which performs the process which irradiates a cell with light.

When applied to a curved display, it can be manufactured by bending the liquid crystal cell obtained above. Here, when the liquid crystal cell is curved, there may occur a region where a pretilt angle shift occurs between one substrate and the other of the pair of substrates. Specifically, as shown in FIG. 1A, before the liquid crystal cell 10 is bent, the liquid crystal molecules 15 between the one substrate 11 and the other substrate 12 are aligned by the liquid

crystal alignment films

13 and 14. The liquid crystal alignment is not disturbed by the control. However, when the liquid crystal cell 10 of FIG. 1A is curved, as shown in FIG. 1B, the pretilt angle of the liquid crystal alignment film 13 formed on one substrate 11 and the other substrate 12 are A region θ in which a deviation from the pretilt angle of the formed liquid crystal alignment film 14 may occur. In this case, there is a concern that the image quality may be deteriorated.

In contrast, as shown in FIG. 1C, the liquid crystal cell 10 before being bent has a tilt angle on one of the pair of substrates 11 and 12 (substrate 12 in FIG. 1C). By making the angle almost vertical and the tilt angle on the other substrate (substrate 11 in FIG. 1C) inclined with respect to the vertical direction, that is, by causing a tilt difference between the substrates. When the liquid crystal cell 10 is curved, it is possible to prevent the pretilt angle from shifting between the substrates. In particular, according to the manufacturing method of the present disclosure, it is possible to generate a sufficient tilt difference between the substrates, and thus it is possible to sufficiently ensure image quality even when applied to a curved display. In addition, when the liquid crystal alignment film is formed on the first substrate and the second substrate, the same liquid crystal aligning agent may be used, and the above effect can be achieved by a simple method.

Subsequently, a polarizing plate is bonded to the outer surface of the liquid crystal cell as necessary to obtain a liquid crystal element. Examples of the polarizing plate include a polarizing plate comprising a polarizing film called an “H film” in which iodine is absorbed while stretching and orientation of polyvinyl alcohol is sandwiched between cellulose acetate protective films, or a polarizing plate made of the H film itself.

The liquid crystal element in the present disclosure can be effectively applied to various uses, such as a watch, a portable game, a word processor, a notebook computer, a car navigation system, a camcorder, a PDA, a digital camera, a mobile phone, a smartphone, and various types. It can be used for various display devices such as monitors, liquid crystal televisions, information displays, and light control films. Moreover, the liquid crystal element formed using the liquid crystal aligning agent of this indication can also be applied to retardation film.

Hereinafter, although it demonstrates concretely by an Example, the content of this indication is not restrict | limited to these Examples.
In this example, the weight average molecular weight Mw of the polymer and the imidization ratio of the polyimide were measured by the following methods.
[Weight average molecular weight Mw]
The weight average molecular weight Mw 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
[Imidation rate of polyimide]
The polyimide solution was poured into pure water, and the resulting precipitate was sufficiently dried at room temperature under reduced pressure, 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 imidization ratio [%] was determined by the formula shown 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)

The structural formula of the compound used in this example is as follows.

<Synthesis of polymer>
[Synthesis Example 1]
100 mol parts of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, and 70 mol parts of 4,4'-diaminodiphenyl ether and 30 mol parts of cholestanyl 3,5-diaminobenzoate as diamine Was dissolved in N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours to obtain a solution containing 10% by mass of polyamic acid (this is referred to as polymer (PA-1)). .
[Synthesis Example 2]
100 mol parts of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, and 80 mol parts of 3,5-diaminobenzoic acid and cholestanyloxy-2,4-diaminobenzene 20 as diamine A molar part was dissolved in NMP and reacted at 60 ° C. for 6 hours to obtain a solution containing 20% by mass of polyamic acid. NMP was added to the obtained polyamic acid solution to make a polyamic acid concentration of 7% by mass, and pyridine and acetic anhydride were added in an amount of 0.1-fold each with respect to the total amount of tetracarboxylic dianhydride used. Then, dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new NMP to obtain a solution containing 15% by mass of a polyimide having an imidization ratio of about 60% (this is referred to as polymer (PI-1)). Obtained.

[Synthesis Example 3]
In a reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser, 46.95 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 8-methacryloxyoctyltrimethoxysilane (the above formula (si The compound represented by -1)) 22.016 g, propylene glycol-1-monomethyl ether-2-acetate 70 g and triethylamine 6.897 g were charged and mixed at room temperature. Next, 55 g of deionized water was dropped from the dropping funnel over 30 minutes, and then the reaction was carried out at 60 ° C. for 1.5 hours while mixing under reflux. After completion of the reaction, the organic layer is taken out and washed with 0.2% by mass aqueous ammonium nitrate 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 the epoxy group was obtained in the vicinity of the chemical shift (δ) = 3.2 ppm according to the theoretical intensity. It was confirmed that no side reaction of the epoxy group occurred during the reaction.

[Synthesis Example 4]
In a 200 mL three-necked flask, 19.648 g of the epoxy group-containing polyorganosiloxane (ES-1) obtained in Synthesis Example 3, 37.28 g of propylene glycol-1-monomethyl ether-2-acetate, 4-octyloxybenzoic acid (the above formula) (Compound represented by (da-1)) 2.278 g (corresponding to 30 mol% with respect to the silicon atom contained in the epoxy group-containing polyorganosiloxane (ES-1)), and UCAT 18X (trade name, San Apro Co., Ltd.) ) Quaternary amine salt) 0.5 g was charged and reacted at 80 ° C. with stirring for 12 hours. After completion of the reaction, the reaction mixture was poured into methanol 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 9.2 g of siloxane (this is referred to as polymer (S-1)) was obtained as a white powder.

[Synthesis Example 5]
Except for using 68.966 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane as the monomer to be used, the epoxy group-containing polyorganosiloxane (ES-2) is viscous and transparent in the same manner as in Synthesis Example 3 above. Obtained as a liquid.

[Synthesis Example 6]
In a 200 mL three-necked flask, 16.191 g of the epoxy group-containing polyorganosiloxane (ES-2) obtained in Synthesis Example 5 and 39.69 g of propylene glycol-1-monomethyl ether-2-acetate were represented by the above formula (ch-1). 4.117 g of the carboxylic acid represented (corresponding to 40 mol% with respect to the silicon atom contained in the epoxy group-containing polyorganosiloxane (ES-2)) and 0.488 g of UCAT 18X were added and stirred at 110 ° C. for 7 hours. The reaction was performed. 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 9.6 g of siloxane (referred to as polymer (S-2)) was obtained as a white powder.

[Synthesis Example 7]
A flask equipped with a condenser and a stirrer was charged with 144 parts by mass of cyclohexanone and purged with nitrogen. Heated to 80 ° C., at the same temperature, 48 parts by weight of cyclohexanone, 28.8 parts by weight of methacrylic acid, 18 parts by weight of butyl methacrylate, 18 parts by weight of methyl methacrylate, 2-ethylhexyl EO-modified acrylate (manufactured by Toagosei Co., Ltd.) , M-120) 18 parts by mass, cyclohexyl methacrylate 18 parts by mass, and glycerol methacrylate 37.2 parts by mass, and cyclohexanone 48 parts by mass and 2,2′-azobis (2,4-dimethylvaleronitrile) 8 Each 4 parts by mass of the mixed solution was added dropwise over 2 hours, and polymerization was carried out for 1 hour while maintaining this temperature. Thereafter, the temperature of the reaction solution was raised to 90 ° C., and polymerization was further performed for 1 hour. Next, this solution was cooled to room temperature, and cyclohexanone was added so that the non-volatile content was 33% by mass to obtain a solution containing a methacrylic polymer (hereinafter referred to as polymer (BP-1)). . The obtained polymer (BP-1) had Mw = 10,700, Mn = 5,600, and Mw / Mn = 1.91.
In a flask equipped with a condenser and a stirrer, the entire amount of the polymer (BP-1) solution was added and the temperature of the solution was raised to 90 ° C., and then 2-methacryloyloxyethyl isocyanate (produced by Showa Denko KK, Karenz) MOI) A mixed solution of 34.3 parts by mass (95 mol% with respect to the number of moles of glycerol methacrylate) and 0.36 parts by mass of 4-methoxyphenol was added dropwise over 15 minutes under air bubbling conditions, and this temperature was maintained. Then, the addition reaction was performed for 1.5 hours. Next, this solution was cooled to room temperature, and cyclohexanone was added so that the non-volatile content was 36% by mass to obtain a binder resin (referred to as polymer (B-1)) solution. The obtained polymer (B-1) had Mw = 12,800, Mn = 6,000, and Mw / Mn = 2.13.

<Preparation of liquid crystal aligning agent>
[Preparation Example 1]
10 parts by mass of the polymer (S-1) is added to 100 parts by mass of the polymer (PA-1) to the solution containing the polymer (PA-1), and N-methyl-2 is added as an organic solvent. -Pyrrolidone (NMP) and butyl cellosolve (BC) were added to obtain a solution having a solvent composition of NMP / BC = 42/58 (mass ratio) and a solid content concentration of 3.5 mass%. The solution was filtered through a filter having a pore size of 1 μm to prepare a liquid crystal aligning agent (AL-1).
[Preparation Examples 2 to 10]
Liquid crystal aligning agents (AL-2) to (AL-10) were respectively prepared in the same manner as in Preparation Example 1, except that the formulation was as shown in Table 1 below.

In Table 1, the abbreviations of the first component and the crosslinking agent are as follows.
A-1: Compound represented by the above formula (A-1) A-2: Irgacure 369 (manufactured by BASF, alkylphenone photopolymerization initiator)
C-1: N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane

<Preparation of liquid crystal composition>
5% by mass of the liquid crystal compound represented by the above formula (L1-1) and the photopolymerizable compound represented by the above formula (L2-1) with respect to 10 g of nematic liquid crystal (MLC-6608, manufactured by Merck) Was added and mixed to obtain a liquid crystal composition LC1.

<Manufacture and evaluation of liquid crystal elements>
[Example 1]
(1) Manufacture of liquid crystal display element The liquid crystal aligning agent (AL-1) prepared above is applied on each electrode surface of two glass substrates each having a conductive film made of an ITO electrode. The solvent was removed by heating (prebaking) for 2 minutes on a hot plate at 80 ° C. One of the two substrates obtained (referred to as “substrate A”) was pre-baked and then heated (post-baked) on a hot plate at 150 ° C. for 10 minutes to give an average film thickness of 0.06 μm. A film was formed.
Further, spray cleaning (spraying process) is performed for 90 seconds by discharging isopropanol as a cleaning liquid at a pressure of 1 kgf / cm ² (nozzle diameter 1 mm) after pre-baking to the other substrate (hereinafter referred to as “substrate B”). It was. Here, the spraying process using the cleaning liquid corresponds to the “contact process”. Then, it heated for 10 minutes on a 150 degreeC hotplate (post-baking), and formed the coating film with an average film thickness of 0.06 micrometer. By these operations, a pair (two) of substrates having a coating film was obtained. The used electrode pattern is the same type as the electrode pattern in the PSA mode.
Next, using the substrate A as the counter substrate and the substrate B as the TFT substrate among the pair of substrates, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is provided on each outer edge of the pair of substrates having the liquid crystal alignment film. After coating, the adhesive was cured by overlapping and pressing so that the liquid crystal alignment film faces each other. Next, the liquid crystal composition LC1 prepared above was filled between the pair of substrates from the liquid crystal inlet, and then the liquid crystal inlet was sealed with an acrylic photo-curing adhesive to produce a liquid crystal cell. Thereafter, an alternating current of 10 Hz is applied between the conductive films of the liquid crystal cell, and the liquid crystal is driven, and an ultraviolet irradiation device using a metal halide lamp as the light source is used, and the irradiation amount is 100,000 J / m ² . And irradiated with ultraviolet rays. In addition, this irradiation amount is the value measured using the light meter measured on the basis of wavelength 365nm.

(2) Measurement of pretilt angle The pretilt angles of the substrate A and the substrate B were measured for the liquid crystal display element obtained in (1) above. The pretilt angle is measured using a crystal using He—Ne laser light in accordance with the method described in the non-patent document “TJ Scheffer et. Al. J. Appl. Phys. Vo. 19, p. 2013 (1980)”. The value of the tilt angle of the liquid crystal molecules from the substrate surface was measured by the rotation method, and this was defined as the pretilt angle [°]. As a result, the pretilt angle of the substrate A (without cleaning) was 89 °, and the pretilt angle of the substrate B (with cleaning) was 83 °.

[Examples 2, 3, 6 to 14, 17, 18]
A PSA mode liquid crystal display device was produced in the same manner as in Example 1 except that the liquid crystal aligning agent used was changed as shown in Table 2 below, and the cleaning liquid used was changed as shown in Table 2 below. The corner was measured. In Example 10, after the coating film was washed with the washing liquid (D-4), it was washed in ultrapure water and then post-baked. The measurement results are shown in Tables 3 and 4 below.
[Examples 4 and 5]
A PSA type liquid crystal display device was produced in the same manner as in Example 1 except that the pre-bake conditions (PB conditions) were as shown in Table 2 below, and the pretilt angle was measured. The results are shown in Table 3 below.
[Example 15]
Substrate B was cleaned with isopropyl alcohol (corresponding to the contact process) after post-baking instead of after pre-baking and before post-baking, air-dried after cleaning with isopropyl alcohol, and then further heated at 100 ° C. for 10 minutes. A PSA mode liquid crystal display device was manufactured in the same manner as in Example 1, and the pretilt angle was measured. The results are shown in Table 4 below.
[Example 16]
A PSA mode liquid crystal display device was manufactured in the same manner as in Example 1 except that the substrate was immersed in the cleaning liquid for 1 minute instead of spraying as a cleaning method, and the pretilt angle was measured. The results are shown in Table 4 below.

[Example 19]
(1) Manufacture of liquid crystal display element By the same operation as in Example 1, application of liquid crystal aligning agent (AL-1), pre-baking and post-baking were performed in this order to obtain a substrate A having a coating film, and liquid crystal alignment Coating of the agent (AL-1), pre-baking, washing of the coating film with IPA (contact process), and post-baking were performed in this order to obtain a substrate B having a coating film. Next, of the pair of substrates obtained (substrate A and substrate B), the substrate A is used as the counter substrate, the substrate B is used as the TFT substrate, and the outer periphery of the surface having one liquid crystal alignment film of the pair of substrates. Then, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm was applied by screen printing, the liquid crystal alignment film surfaces of the pair of substrates were opposed, and the adhesive was thermally cured at 150 ° C. for 1 hour. Next, a negative liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) was filled into the gap between the substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Furthermore, in order to remove the flow alignment at the time of liquid crystal injection, this was heated at 130 ° C. and then gradually cooled to room temperature.
Next, an alternating current of 10 Hz is applied between the pair of electrodes, and the liquid crystal is driven, and an ultraviolet irradiation device using a metal halide lamp as a light source is used to achieve an irradiation dose of 100,000 J / m ^2. And irradiated with ultraviolet rays. In addition, this irradiation amount is the value measured using the light meter measured on the basis of wavelength 365nm.
(2) Measurement of pretilt angle Using the liquid crystal display element obtained above, the pretilt angle was measured in the same manner as in Example 1. As a result, the tilt angle of the substrate A that was not subjected to the cleaning treatment was 89 °. On the other hand, the tilt angle of the substrate B subjected to the cleaning treatment was 86 °, and it was confirmed that a sufficient tilt difference was generated (Table 4).

[Examples 20, 22 to 29]
A PSA mode liquid crystal is obtained by performing cleaning under the same PB conditions and cleaning manner as in cleaning the substrate B in Example 1, except that both the substrate A and the substrate B are cleaned with the cleaning liquid described in Table 2 below. A display element was manufactured and the pretilt angle was measured. In Example 24, the substrate B was post-baked after cleaning the coating film with a cleaning liquid and then cleaning in ultrapure water. The results are shown in Table 5 below.
[Example 21]
A PSA mode liquid crystal is obtained by performing cleaning under the same PB conditions and cleaning manner as in cleaning the substrate B in Example 4 except that both the substrate A and the substrate B are cleaned with the cleaning liquid described in Table 2 below. When the display element was manufactured and the pretilt angle was measured, a tilt difference of 3 ° was generated between the substrate A and the substrate B (Table 5).
[Comparative Example 1]
A PSA mode liquid crystal display device is manufactured by the same operation as in Example 1 except that both the substrate A and the substrate B are cleaned with isopropyl alcohol under the same PB conditions and cleaning mode as when the substrate B was cleaned in Example 1. When the pretilt angle was measured, there was no difference in the pretilt angle between the substrates (Table 5).

In Table 2, “Before PB” indicates that the coating film was washed with the cleaning solution after pre-bake and before post-bake, and “After PB” indicates that it was performed after post-bake. Abbreviations for the cleaning liquid are as follows.
D-1: Isopropyl alcohol (IPA)
D-2: Acetone D-3: Cyclohexane D-4: 0.7 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. D-5: Mixed solution of isopropyl alcohol and water (IPA: Water = 75: 25 (mass ratio) ))
D-6: Mixed solution of isopropyl alcohol and water (IPA: water = 50: 50 (mass ratio))

From the above results, it was confirmed that a sufficient tilt difference can be generated between the substrates according to the method of the present disclosure.

Claims

A film forming step of forming a coating film by applying a liquid crystal aligning agent on each of the first substrate and the second substrate;
The coating film formed on only one of the first substrate and the second substrate is brought into contact with a solvent or formed on each of the first substrate and the second substrate. A contact process in which the coated film is contacted with a solvent under different conditions between the substrates,
And a step of constructing a liquid crystal cell by arranging the first substrate and the second substrate to face each other so that the coating film faces each other after the contacting step.
In the contacting step, the coating film formed on only one of the first substrate and the second substrate is brought into contact with a solvent, or each of the first substrate and the second substrate is contacted. The manufacturing method of the liquid crystal element of Claim 1 which is the process of making the coating film formed on the board | substrate contact the solvent from which a solvent composition differs between board | substrates.
The liquid crystal aligning agent includes a first component and a second component different from the first component,
3. The solvent according to claim 2, wherein the solvent to be brought into contact with at least one of the first substrate and the second substrate is a solvent having different solubility in the first component and solubility in the second component. A method for manufacturing a liquid crystal element.
The liquid crystal aligning agent includes a compound [A] having at least one selected from the group consisting of a crosslinkable group, a photoalignable group, and a radical generating group, and a polymer [P] (provided that the compound [A] is included). The method for producing a liquid crystal element according to any one of claims 1 to 3, comprising:
The method for producing a liquid crystal element according to any one of claims 1 to 4, wherein the liquid crystal aligning agent contains two or more kinds of polymers having different main chains.
The method for producing a liquid crystal element according to any one of claims 1 to 5, wherein an organic solvent or an alkaline aqueous solution is used as the solvent to be brought into contact with the coating film.