JPWO2018139457A1 - Liquid crystal element, manufacturing method thereof, and display device - Google Patents

Abstract

The liquid crystal element includes a pair of substrates disposed opposite to each other, a pair of transparent electrodes disposed on surfaces of the pair of substrates opposed to each other, and a liquid crystal disposed between the pair of substrates and including a liquid crystal and a polymerizable compound. A liquid crystal layer formed by curing the composition; and a liquid crystal alignment film formed on at least one electrode arrangement surface of the pair of base materials. The liquid crystal composition contains at least one selected from the group consisting of a monofunctional (meth) acrylate compound, a polyfunctional (meth) acrylate compound, a polyfunctional thiol compound, and a styrene compound as the polymerizable compound. The liquid crystal alignment film is formed of a liquid crystal aligning agent containing poly (meth) acrylate.

Description

Cross-reference of related applications

  This application is based on the Japanese application number 2017-10532 for which it applied on January 24, 2017, and uses the description here.

  The present disclosure relates to a liquid crystal element, a manufacturing method thereof, and a display device.

  As a liquid crystal element, a polymer-dispersed liquid crystal element in which a liquid crystal layer made of a composite material of a liquid crystal and a polymer is disposed between a pair of film bases on which transparent electrodes are formed has been known in recent years. Therefore, it has been proposed to use such a polymer dispersed liquid crystal element as a light control element (see, for example, Patent Document 1 and Patent Document 2). The light control elements of Patent Document 1 and Patent Document 2 exhibit a light control function by changing the transparency by switching between voltage application and voltage non-application of the transparent electrode. In addition, it has been studied to add a new function to a show window, a smartphone, a television, a monitor, a building, furniture, or the like using such a dimming function. Known polymer-dispersed liquid crystals include, for example, PDLC (Polymer Dispersed Liquid Cristal) and PNLC (Polymer Network Liquid Cristal).

  Patent Document 3 proposes a display device in which a liquid crystal display panel is arranged on the back of a transparent display made of organic EL elements. In this display device, it has been proposed to control the light transmittance by controlling the voltage applied to the liquid crystal display panel, thereby improving the visibility of the display on the transparent display. Patent Document 4 discloses a reverse liquid crystal element in which light is transmitted and transparent when no voltage is applied between a pair of electrodes, and light is scattered and non-transparent when a voltage is applied. It is disclosed. The reverse type liquid crystal element described in Patent Document 4 has a polyimide film as an alignment film for vertically aligning liquid crystals, and the alignment state of liquid crystal molecules in the liquid crystal layer is controlled by this polyimide film.

JP 2013-3319 A JP 2013-148744 A JP 2008-083510 A International Publication No. 2015/022980

  In designing alignment film materials for liquid crystal display panels such as liquid crystal televisions, polyimide-based materials have been conventionally used effectively from the viewpoint of ensuring properties such as liquid crystal alignment and electrical characteristics. On the other hand, the priority of various characteristics required for the liquid crystal alignment film differs between the liquid crystal display panel and the light control element. For example, when used as a light control element, it is required that the liquid crystal element is excellent in thickness reduction and shape diversity rather than characteristics relating to display quality such as liquid crystal orientation and electrical characteristics.

  One way to improve the thinness of liquid crystal elements and the diversity of shapes is to reduce the thickness of the base material and widen the selection of materials. For example, applying a base material made of a polymer material Can be considered. In order to make it possible to apply a substrate made of a polymer material, the polymer used as the alignment film material is required to have excellent solubility in a low boiling point solvent. However, polyimide resins are generally difficult to dissolve in a low-boiling solvent, and there are concerns that a uniform liquid crystal alignment film cannot be obtained because the obtained coating film has many film thickness unevenness, coating unevenness, and pinholes.

  Further, a liquid crystal alignment film using a polyimide resin is easily colored, and when applied to a light control element, transparency in a light transmitting state may be a problem. Furthermore, since it is assumed that the light control element is applied to an outdoor usage, it may be necessary to have excellent weather resistance.

  The present disclosure has been made in view of the above problems, and in the case of applying a base material made of a polymer material, the liquid crystal alignment film is homogeneous and highly transparent, and has good light transmission characteristics and light scattering characteristics. The main object of the present invention is to provide a liquid crystal element that exhibits electrical characteristics sufficient for realizing a light control function and has excellent weather resistance.

  The present disclosure employs the following means in order to solve the above problems.

[1] A liquid crystal composition comprising a pair of opposed substrates, electrodes arranged on opposite surfaces of the pair of substrates, and a liquid crystal and a polymerizable compound arranged between the pair of substrates. A liquid crystal layer formed by curing the product, and a liquid crystal alignment film formed on at least one electrode arrangement surface of the pair of base materials, and the liquid crystal composition is a single compound as the polymerizable compound. The liquid crystal alignment film contains at least one selected from the group consisting of a functional (meth) acrylate compound, a polyfunctional (meth) acrylate compound, a polyfunctional thiol compound, and a styrene compound, and the liquid crystal alignment film contains poly (meth) acrylate A liquid crystal element formed of an agent.
[2] A display device comprising the liquid crystal element according to the above [1] and a transparent display that is transparent in a non-display state.
[3] A liquid crystal provided with a liquid crystal layer formed by curing a liquid crystal composition containing a liquid crystal and a polymerizable compound between a pair of substrates arranged so that electrodes provided on the respective substrate surfaces face each other. A liquid crystal aligning agent for forming a liquid crystal aligning film of an element, comprising a poly (meth) acrylate.
[4] A liquid crystal comprising a liquid crystal layer formed by curing a liquid crystal composition containing a liquid crystal and a polymerizable compound between a pair of base materials arranged so that electrodes provided on the respective base material faces each other. A method for manufacturing an element, the step of applying a liquid crystal alignment agent on at least one electrode arrangement surface of the pair of base materials to form a liquid crystal alignment film, and the pair of base materials after forming the liquid crystal alignment film A step of constructing a liquid crystal cell by arranging the electrodes so as to face each other through a layer containing the liquid crystal composition, and a step of curing the polymerizable compound after the construction of the liquid crystal cell, The liquid crystal composition includes, as the polymerizable compound, at least one selected from the group consisting of a monofunctional (meth) acrylate compound, a polyfunctional (meth) acrylate compound, a polyfunctional thiol compound, and a styrene compound, A liquid crystal aligning agent contains a poly (meth) acrylate, The manufacturing method of a liquid crystal element.

  According to the above configuration, even when a base material made of a polymer material is applied as the pair of base materials, a liquid crystal element having a uniform and highly transparent liquid crystal alignment film can be obtained. In addition, even when a base material made of a polymer material is applied, a liquid crystal having good light transmission characteristics and light scattering characteristics, sufficient electrical characteristics for realizing a dimming function, and excellent weather resistance An element can be obtained.

The figure which shows schematic structure of a liquid crystal element. 4A and 4B illustrate functions of a liquid crystal element. The figure which shows schematic structure of a display apparatus provided with a liquid crystal element and a transparent display.

  Hereinafter, embodiments will be described with reference to the drawings.

<Liquid crystal element>
As shown in FIG. 1, the liquid crystal element 10 of the present embodiment includes a pair of base materials including a first base material 11 and a second base material 12, and a first base material 11 and a second base material 12. And a liquid crystal layer 13 disposed. The liquid crystal layer 13 is a polymer-dispersed liquid crystal layer that is a polymer / liquid crystal composite material layer in which a polymer 13a and liquid crystal molecules 13b are mixed. In the present embodiment, a polymer dispersion in which a polymer network is formed in the layer. Type liquid crystal (PDLC). The liquid crystal element 10 is a dimming element that switches between a transmissive state that transmits light and a non-transmissive state that scatters light by controlling the orientation of the liquid crystal molecules 13 b existing in the polymer network by an electric field.

  The first substrate 11 and the second substrate 12 are transparent substrates made of a polymer material. Examples of the polymer material constituting the substrate include silicon, polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, polypropylene, polyvinyl chloride, aromatic polyamide, polyamideimide, polyimide, triacetyl cellulose (TAC), Examples include materials such as polymethyl methacrylate. In addition, although the 1st base material 11 and the 2nd base material 12 are good also as a glass substrate, in order to achieve thickness reduction and weight reduction of a liquid crystal element, it is especially preferable that it is a plastic substrate.

In the first base material 12 and the second base material 12, transparent electrodes 16 and 17 are arranged on the surfaces facing each other, and an electrode pair is constructed by the transparent electrodes 16 and 17. In this embodiment, the transparent electrodes 16 and 17 are transparent conductive films, for example, a NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ). An ITO film made of or a film made of a carbon material. The transparent electrodes 16 and 17 may have a predetermined pattern such as a comb shape.

  Liquid crystal alignment films 14 and 15 are formed on the electrode arrangement surfaces of the first base material 11 and the second base material 12, respectively. The liquid crystal alignment films 14 and 15 are organic thin films that regulate the alignment orientation of the liquid crystal molecules in the liquid crystal layer 13. In this embodiment, the liquid crystal alignment films 14 and 15 are formed using a polymer composition containing a polymer having a photoalignment group. A photo-alignment film. The liquid crystal alignment films 14 and 15 may be provided on at least one of the pair of substrates, but are preferably provided on both substrates from the viewpoint of alignment stability. The liquid crystal layer 13 is disposed after the liquid crystal composition is disposed in a space surrounded by a pair of base materials and a sealing agent (not shown) disposed so as to surround the outer edge portion of the electrode placement surface between the pair of base materials. It is formed by curing the liquid crystal composition. The liquid crystal composition contains a liquid crystal and a polymerizable compound.

  The liquid crystal element 10 does not include a polarizing plate on the outer surfaces of the first base material 11 and the second base material 12. Therefore, it is excellent in that light absorption loss is small and light utilization efficiency is high.

  2A and 2B are diagrams for explaining the function of the liquid crystal element 10. FIG. 2A shows a state in which no voltage is applied between the transparent electrodes 16 and 17, and FIG. 2B shows a state between the transparent electrodes 16 and 17. The state where the voltage is applied is shown. The liquid crystal element 10 is a reverse PDLC, and in a state where no voltage is applied between the transparent electrodes 16 and 17, incident light is transmitted from one of the pair of substrates to the other to be transparent, and the transparent electrodes 16 and 17. In a state where a voltage is applied between them, the alignment state of the liquid crystal molecules 13b changes, so that incident light is scattered and becomes non-transparent. In the present embodiment, as shown in FIG. 2, in the state where no voltage is applied, the liquid crystal element 10 becomes transparent when the major axis direction of the liquid crystal molecules 13b is perpendicular to the substrate surface, and the voltage application state Then, the liquid crystal element 10 becomes non-transparent by rotating the liquid crystal molecules 13b in the direction parallel to the substrate surface. The liquid crystal element 10 exhibits a dimming function by switching between application / non-application of voltage. The liquid crystal element 10 has, for example, a film shape or a plate shape. In addition, the liquid crystal element 10 may change the light transmittance according to the applied voltage.

<Liquid crystal composition>
Next, a liquid crystal composition used for forming the liquid crystal layer 13 will be described. The liquid crystal composition contains a liquid crystal and a polymerizable compound. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal.

  The polymerizable compound is preferably a compound exhibiting radical polymerizability, and is at least selected from the group consisting of monofunctional (meth) acrylate compounds, polyfunctional (meth) acrylate compounds, polyfunctional thiol compounds, and styrene compounds. It is particularly preferable to include one kind of compound (hereinafter also referred to as “specific polymerizable compound”). In the present specification, “(meth) acrylate” means containing acrylate and methacrylate.

Specific examples of the polymerizable compound include monofunctional (meth) acrylate compounds such as (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, and n-hexyl. Alkyl (meth) acrylates such as (meth) acrylate and 2-ethylhexyl (meth) acrylate; Cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate; Aryl such as benzyl (meth) acrylate (Meth) acrylates;
2-methoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, 2-phenylphenoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate , Ether-based (meth) acrylates such as ethoxylated o-phenylphenol (meth) acrylate, ethyldiethylene glycol (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate;
Alcohol-based (meth) acrylates such as 2-hydroxyethyl (meth) acrylate; Carboxylic acid-based (meth) acrylates such as 2- (meth) acryloyloxyethyl succinic acid and 2- (meth) acryloyloxyethyl hexahydrophthalic acid Nitrogen-containing unsaturated compounds such as acrylamide, (meth) acryloylmorpholine, isobutoxymethyl (meth) acrylamide, vinylcaprolactam, N-vinyl-2-pyrrolidone; tetrabromophenyl (meth) acrylate, pentachlorophenyl (meth) acrylate Halogenated (meth) acrylates such as; 3- (meth) acryloxypropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and the like;

Examples of polyfunctional (meth) acrylate compounds include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and neopentyl glycol di (Meth) acrylate, (meth) acryloyloxypivalyl (meth) acryloyloxypivalate, 2-hydroxy-3-acryloyloxypropyl (meth) acrylate, tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) ) Acrylate, 1,9-nonanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, pentaerythritol Tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, trimethylolpropane (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, urethane (meth) acrylate compound (for example, Phenyl glycidyl ether (meth) acrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol tri (meth) acrylate hexamethylene diisocyanate urethane prepolymer, dipentaerythritol penta (meth) acrylate hexamethylene diisocyanate), etc .;

Examples of the polyfunctional thiol compound include 1,3-propanedithiol, 1,4-butanedithiol, 1,6-hexanedithiol, 2,5-hexanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, 3,7-dithia-1,9-nonanedithiol, 1,4-bis (3-mercaptobutyryloxy) butane, tetraethylene glycol bis (3-mercaptopropionate), dimercaptobenzene, 1,2-di (Mercaptomethyl) benzene, 1,3-di (mercaptomethyl) benzene, 1,4-di (mercaptomethyl) benzene, 1,3-dimercapto-5-methyl-benzene, 4,5-dimercapto-1,3 4-thiadiazole, 1,4-bis (2-mercaptoethyl) benzene, thiol group-containing carboxylic acid and 2 Dithiol compounds such esters with alcohols;
Isocyanuric acid, trimercaptobenzene, 2,4,6-trimercapto-1,3,5-triazine, 1,3,5-tris (3-mercaptobutyryloxyethyl) -1,3,5-triazine-2 , 4,6 (1H, 3H, 5H) -trione, trimethylolpropane tris (3-mercaptobutyrate), trimethylolpropane tris (3-mercaptopropionate), tris-[(3-mercaptopropionyloxy)- Ethyl] -isocyanurate, trimethylolethane tris (3-mercaptobutyrate), pentaerythritol tetrakis (3-mercaptobutyrate), pentaerythritol tetrakis (3-mercaptopropionate), dipentaerythritol hexakis (3-mercapto) Propionate), thiol A polyfunctional polymer (for example, under the trade name, Thiocol LP (registered trademark), polythiol (registered trademark) (manufactured by Toray Fine Chemical Co., Ltd.)), a polyester of a thiol group-containing carboxylic acid and a polyhydric alcohol Examples of the thiol compound include styrene, methylstyrene, and the like.

  Although a polymeric compound may be used individually by 1 type, it is preferable to use in combination of 2 or more type from a viewpoint of making an optical characteristic favorable. Specifically, the liquid crystal composition preferably contains a monofunctional (meth) acrylate compound and a polyfunctional (meth) acrylate compound as the polymerizable compound. The monofunctional (meth) acrylate compound and the polyfunctional (meth) acrylate are preferable. It is more preferable to contain a compound and a polyfunctional thiol compound. Moreover, it is particularly preferable that a urethane (meth) acrylate compound is contained as at least a part of the monofunctional (meth) acrylate compound and the polyfunctional (meth) acrylate compound.

The content ratio of the polymerizable compound in the liquid crystal composition is appropriately selected according to the type of the compound. For example, the content ratio of the monofunctional (meth) acrylate compound is preferably 10 to 300 parts by mass and more preferably 20 to 200 parts by mass with respect to a total of 100 parts by mass of the liquid crystal. The content ratio of the polyfunctional (meth) acrylate compound is preferably 1 to 200 parts by mass and more preferably 5 to 100 parts by mass with respect to 100 parts by mass of the total liquid crystal.
Moreover, when making a urethane (meth) acrylate compound contain, it is preferable to set it as 1-150 mass parts with respect to the total 100 mass parts of a liquid crystal, and it is more preferable to set it as 5-100 mass parts. .
The content ratio of the polyfunctional thiol compound is preferably 0.5 to 50 parts by mass, and more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the total liquid crystal. The blending ratio of the styrene compound is preferably 0.1 to 30 parts by mass, and more preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the total liquid crystal.
The content ratio of the polymerizable compound in the liquid crystal composition (the total amount when two or more are included) is preferably 1 to 90% by mass with respect to the total amount of the liquid crystal and the polymerizable compound. It is more preferable to set it as -80 mass%, and it is still more preferable to set it as 10-75 mass%.

  The use ratio of the specific polymerizable compound is preferably 70% by mass or more, more preferably 80% by mass or more, and 90% by mass or more with respect to the entire polymerizable compound to be contained in the liquid crystal composition. More preferably. The polymerizable compound contained in the liquid crystal composition is particularly preferably composed of a specific polymerizable compound.

  The liquid crystal composition may contain other components other than the liquid crystal and the polymerizable compound. From the viewpoint of further enhancing the polymerizability of the polymerizable compound and promoting the formation of a polymer network in the liquid crystal layer 13 (preferably over the entire liquid crystal layer 13), a polymerization initiator is contained as another component. Is preferred.

  The polymerization initiator contained in the liquid crystal composition is a compound (photoinitiator) capable of initiating polymerization of a polymerizable compound by irradiation with radiation such as visible light, ultraviolet light, far ultraviolet light, electron beam, and X-ray. preferable. The photoinitiator is preferably a radical polymerization initiator capable of generating radicals by light irradiation, and specific examples thereof include acetophenone, benzophenone, 2-benzoylbenzoic acid, 4,4′-bis (diethylamino), for example. Benzophenone, 2-methoxy-2-phenylacetophenone, 2-isobutoxy-2-phenylacetophenone, 2- (1,3-benzodioxol-5-yl) -4,6-bis (trichloromethyl) -1,3 , 5-triazine, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, Benzaldehyde, fluorene, anthraquinone, tri Phenylamine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, 4,4′-diaminobenzophenone, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methyl Propan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-isopropylthioxanthone, 2-chlorothioxanthone, diphenyl (2,4,6-trimethoxybenzoyl) phosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, 2-hydroxy-1- [4- [4- (2-hydroxy-2-methylpropionyl) benzyl] phenyl] -2- Methylpropan-1-one, 2-ben Dil-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 1,2-octanedione, 1- [4- (phenylthio) -, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime), 4 , 4′-bis (diethylamino) benzophenone, 4- (diethylamino) benzophenone, 2-hydroxy-2-phenylacetophenone, 4,4′-dimethoxybenzyl, diphenylethanedione, 2-benzyl-2- (dimethylamino) -1 -[4- (morpholino) phenyl] -1-butanone and the like can be mentioned.

  The content ratio of the polymerization initiator in the liquid crystal composition is a component other than the solvent contained in the liquid crystal composition from the viewpoint of promptly performing a curing reaction and suppressing a decrease in curability due to addition of an excessive amount. It is preferable to set it as 0.1-10 mass% with respect to the total mass of (solid content), It is more preferable to set it as 0.5-8 mass%, It is still more preferable to set it as 1-7 mass%. In addition, a polymerization initiator can be used individually by 1 type or in combination of 2 or more types.

A dye may be used as the other component blended in the liquid crystal composition. By using the dye, the liquid crystal element 10 in which the dye is dispersed in the liquid crystal layer 13 can be obtained. In addition, according to the liquid crystal element 10 of the present disclosure, even when a pigment is dispersed in the liquid crystal layer 13, the change in light shielding property / light transmittance due to switching between application / non-application of voltage is clear, and It is preferable in that it has good durability when it is repeatedly driven.
A dichroic dye can be preferably used as the dye. The dichroic dye to be used is not particularly limited, and known compounds can be used as appropriate, and examples thereof include polyiodine, azo compounds, anthraquinone compounds, dioxazine compounds and the like. Among these, at least one selected from the group consisting of an azo compound and an anthraquinone compound is preferable, and an azo compound is particularly preferable in terms of excellent light resistance and a high dichroic ratio. In addition, a pigment | dye may be used individually by 1 type and may combine 2 or more types.

  The blending ratio of the dye (the total amount when two or more are blended) is preferably 0.05 to 5% by mass relative to the total mass of the solid content in the liquid crystal composition. It is more preferable to set it as 1-3 mass%.

  A liquid crystal composition is prepared by mixing a liquid crystal, a polymerizable compound, and other components added as necessary. The treatment for mixing these components may be performed at room temperature or while raising the temperature. It is also possible to dissolve each component in a suitable organic solvent and then remove the solvent, for example, by distillation.

<Liquid crystal aligning agent>
Next, a liquid crystal aligning agent used for forming the liquid crystal alignment films 14 and 15 will be described. The liquid crystal aligning agent contains poly (meth) acrylate as a polymer component. In the present specification, “poly (meth) acrylate” includes polyacrylate and polymethacrylate.

(Poly (meth) acrylate)
Examples of the poly (meth) acrylate include a method in which a monomer having a (meth) acryloyl group (hereinafter also referred to as “(meth) acrylic monomer”) is reacted in the presence of a polymerization initiator. . In the poly (meth) acrylate used for preparing the liquid crystal aligning agent, the use ratio of the (meth) acrylic monomer with respect to the total amount of the monomer used for polymerization is preferably 20% by mass or more, more preferably. Is 30% by mass or more, more preferably 40% by mass or more, and particularly preferably 50% by mass or more.

The (meth) acrylic monomer used for the polymerization is not particularly limited, and examples thereof include unsaturated carboxylic acids such as (meth) acrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, vinylbenzoic acid and the like. Acid: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, allyl (meth) acrylate, cyclohexyl (meth) acrylate, tricyclo (meth) acrylate [5.2.1.0 ^2,6 ] dec-8-yl, dicyclopentanyl (meth) acrylate, benzyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylic acid Lauryl, trimethoxysilylpropyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3 (meth) acrylic acid , 3,3-pentafluoropropyl, methoxyethyl (meth) acrylate, (N) N-dimethylaminoethyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, ( 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxybutyl (meth) acrylate, 4-hydroxybutyl glycidyl ether acrylate, etc. Unsaturated carboxylic acid esters: maleic anhydride, itaconic anhydride, unsaturated polycarboxylic acid anhydrides such as cis-1,2,3,4-tetrahydrophthalic anhydride, and the like. In addition, a (meth) acrylic-type monomer can be used individually by 1 type or in combination of 2 or more types.

  The (meth) acrylic monomer used for polymerization has an epoxy group from the viewpoint of improving the liquid crystal orientation and electrical properties of the obtained liquid crystal element 10 and the adhesion of the liquid crystal alignment film to the substrate (meta ) It preferably contains an acrylic monomer. The ratio of the (meth) acrylic monomer having an epoxy group is preferably 1% by mass or more, more preferably 5% by mass or more, based on the total amount of monomers used for polymerization. More preferably, the content is 10% by mass or more.

  In the polymerization, a monomer other than the (meth) acrylic monomer may be used. Examples of other monomers include conjugated diene compounds such as 1,3-butadiene and 2-methyl-1,3-butadiene; aromatic vinyl compounds such as styrene, methylstyrene and divinylbenzene; and maleimide group-containing compounds. Can be mentioned. The ratio of other monomers is preferably 80% by mass or less, more preferably 70% by mass or less, based on the total amount of monomers used for the synthesis of poly (meth) acrylate, More preferably, it is 60 mass% or less.

The poly (meth) acrylate contained in the liquid crystal aligning agent has a side chain structure (hereinafter also referred to as “specific side chain structure”) included in the group consisting of (a) to (e) shown below. Preferably not.
(A) an alkyl group having 8 to 22 carbon atoms (b) a fluorine-containing alkyl group having 6 to 18 carbon atoms (c) any one of a benzene ring, a cyclohexane ring and a heterocyclic ring; A group to which an alkyl group or a fluorine-containing alkyl group is bonded (d) a group having at least two rings selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring (e) having a steroid skeleton Groups having 17 to 51 carbon atoms

（式（５）中、Ａ^１〜Ａ^３は、それぞれ独立に、フェニレン基又はシクロへキシレン基であり、環部分に置換基を有していてもよい。Ｒ^２１は、水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、少なくとも１個の水素原子がフッ素原子で置換された炭素数１〜２０のフッ素含有アルキル基、少なくとも１個の水素原子がフッ素原子で置換された炭素数１〜２０のフッ素含有アルコキシ基、又はフッ素原子であり、Ｒ^２２及びＲ^２３は、それぞれ独立に、単結合、−Ｏ−、−ＣＯＯ−、−ＯＣＯ−又は炭素数１〜３のアルカンジイル基である。ｋ、ｍ及びｎは、１≦ｋ＋ｍ＋ｎ≦４を満たす０以上の整数である。Ｒ^２１が水素原子、炭素数１〜３のアルキル基又はフッ素原子の場合、ｋ＋ｍ＋ｎ≧２を満たす。「＊」は結合手を示す。）Specific examples of the specific side chain structure include (a) alkyl groups such as n-octyl group, n-nonyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n -A heptadecyl group, an n-octadecyl group, etc .; as the fluorine-containing alkyl group in (b), for example, a group in which at least one hydrogen atom of the alkyl group in (a) is substituted with a fluorine atom; Examples of the group and the group (d) include a group represented by the following formula (5); examples of the group (e) include a cholestanyl group, a cholesteryl group, and a lanostannyl group.

(In Formula (5), A ^{1 to} A ³ each independently represents a phenylene group or a cyclohexylene group, and may have a substituent in the ring portion. R ²¹ represents a hydrogen atom or a carbon number. An alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a fluorine-containing alkyl group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, and at least one hydrogen atom being a fluorine atom; A substituted fluorine-containing alkoxy group having 1 to 20 carbon atoms or a fluorine atom, and R ²² and R ²³ are each independently a single bond, —O—, —COO—, —OCO—, or C 1 to C 3 is an alkanediyl group of 3. k, m, and n are integers of 0 or more that satisfy 1 ≦ k + m + n ≦ 4, and when R ²¹ is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a fluorine atom, k + m + n It satisfies ≧ 2. * "Indicates a bond.)

（式中、「＊」は結合手を示す。）Specific examples of the group represented by the above formula (5) include groups represented by the following formulas (5-1) to (5-10), but are not limited thereto. is not. Examples of the substituent that A ^{1 to} A ³ may have in the ring portion include a fluorine atom, an alkyl group having 1 to 3 carbon atoms, and an alkoxy group having 1 to 3 carbon atoms. k + m + n is preferably an integer of 2 to 4.

(In the formula, “*” indicates a bond.)

  The polymerization reaction using the (meth) acrylic monomer is preferably performed by radical polymerization. Examples of the polymerization initiator used in the polymerization reaction include 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4 Azo compounds such as -methoxy-2,4-dimethylvaleronitrile); organic peroxides such as benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1'-bis (t-butylperoxy) cyclohexane; Hydrogen oxide; a redox initiator composed of these peroxides and a reducing agent can be used. Of these, azo compounds are preferred. These polymerization initiators can be used alone or in combination of two or more. The use ratio of the polymerization initiator is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 40 parts by mass with respect to 100 parts by mass of the total amount of monomers used for the reaction.

  The polymerization reaction of the (meth) acrylic monomer is preferably performed in an organic solvent. Examples of the organic solvent used in the reaction include alcohols, ethers, ketones, amides, esters, hydrocarbon compounds, and the like. Among these, it is preferable to use at least one selected from the group consisting of alcohols and ethers, and it is more preferable to use partial ethers of polyhydric alcohols. Preferred examples thereof include diethylene glycol methyl ethyl ether and propylene glycol monomethyl ether acetate. In addition, as an organic solvent, these 1 type can be used individually or in combination of 2 or more types.

  In the polymerization reaction of the (meth) acrylic monomer, the reaction temperature is preferably 30 to 120 ° C, more preferably 60 to 110 ° C. The reaction time is preferably 1 to 36 hours, and more preferably 2 to 24 hours. The amount of organic solvent used (a) is such that the total amount (b) of monomers used in the reaction is 0.1 to 50% by mass relative to the total amount (a + b) of the reaction solution. An amount is preferred. The reaction solution containing poly (meth) acrylate may be used for the preparation of the liquid crystal alignment agent as it is, or may be used for the preparation of the liquid crystal alignment agent after isolating the poly (meth) acrylate contained in the reaction solution. Good.

  For poly (meth) acrylate, the polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC) improves the liquid crystal alignment of the liquid crystal alignment film to be formed, and the liquid crystal alignment From the viewpoint of ensuring stability over time, it is preferably 250 to 500,000, more preferably 500 to 100,000, and still more preferably 1,000 to 50,000.

  The content ratio of the poly (meth) acrylate in the liquid crystal aligning agent is sufficient from the viewpoint of obtaining the liquid crystal element 10 having sufficiently high transparency while sufficiently obtaining the coating property improvement effect when the low boiling point solvent is used. It is preferable that it is 3-99 mass% with respect to the total amount of the polymer component of an aligning agent. The lower limit of the content ratio is more preferably 5% by mass or more, further preferably 20% by mass, and particularly preferably 50% by mass. Moreover, about the upper limit of the content rate of poly (meth) acrylate, when obtaining the improvement effect of the various characteristics by the polymer different from poly (meth) acrylate, More preferably, it is 95 mass% or less, More preferably, it is 90 mass % Or less. In addition, poly (meth) acrylate may be used individually by 1 type, and may be used in combination of 2 or more type.

(Other ingredients)

  The liquid crystal aligning agent used for forming the liquid crystal alignment films 14 and 15 is at least one selected from the group consisting of a silane compound and a polysiloxane together with poly (meth) acrylate in that the liquid crystal element 10 having high weather resistance can be obtained. It is preferable to contain. It is particularly preferable that the liquid crystal aligning agent contains polysiloxane in that the effect of improving weather resistance is high and the post-baking temperature can be further lowered. Moreover, it is preferable that a liquid crystal aligning agent contains a silane compound at the point which can make adhesiveness with respect to a base material higher.

(Polysiloxane)
Polysiloxane can be obtained, for example, by hydrolyzing and condensing a hydrolyzable silane compound. Examples of the silane compound include tetraalkoxysilane compounds such as tetramethoxysilane and tetraethoxysilane; alkyl group or aryl group-containing alkoxysilanes such as methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and dimethyldiethoxysilane. Compound;
Sulfur-containing alkoxysilane compounds such as 3-mercaptopropyltriethoxysilane and mercaptomethyltriethoxysilane;
Glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycid Epoxy group-containing alkoxysilane compounds such as xylpropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane;
Unsaturated bond-containing alkoxysilane compounds such as 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxypropylmethyldiethoxysilane, vinyltriethoxysilane ;
3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N Nitrogen-containing alkoxysilanes such as-(2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane Compound;
And acid anhydride group-containing alkoxysilane compounds such as trimethoxysilylpropyl succinic anhydride. One of these hydrolyzable silane compounds can be used alone, or two or more thereof can be used in combination. Note that “(meth) acryloxy” means “acryloxy” and “methacryloxy”.

  The hydrolysis / condensation reaction is carried out by reacting one or more of the above hydrolyzable silane compounds with water, preferably in the presence of a suitable catalyst and an organic solvent. In the reaction, the amount of water used is preferably 1 to 30 mol with respect to 1 mol of the hydrolyzable 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 the catalyst used varies depending on the reaction conditions such as the type of catalyst and temperature, and should be set appropriately. For example, the amount is preferably 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. Among these, it is preferable to use a water-insoluble or slightly water-soluble organic solvent. The use ratio of the organic solvent is 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 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 target polysiloxane. The method for synthesizing the polysiloxane is not limited to the hydrolysis / condensation reaction described above. For example, the polysiloxane may be synthesized by a method in which a hydrolyzable silane compound is reacted in the presence of oxalic acid and alcohol.

  You may make the liquid crystal aligning agent contain polysiloxane which has functional groups, such as a photo-alignment group and a pretilt angle provision group (for example, vertical alignment group shown below) in a side chain. The polysiloxane having such a functional group is obtained by, for example, synthesizing a polysiloxane having an epoxy group in a side chain by polymerization using an epoxy group-containing hydrolyzable silane compound as at least a part of the raw material, It can be obtained by reacting a polysiloxane having a functional group with a carboxylic acid having a functional group. Alternatively, a polymerization method using a hydrolyzable silane compound having a functional group as a monomer may be employed.

  The reaction between the epoxy group-containing polysiloxane and the carboxylic acid is preferably carried out in the presence of a catalyst and an organic solvent. The use ratio of the carboxylic acid is preferably 5 mol% or more, more preferably 10 to 80 mol%, based on the epoxy group of the epoxy group-containing polysiloxane. As said catalyst, a well-known compound etc. can be used as what is called a hardening accelerator which accelerates | stimulates reaction of an organic base and an epoxy compound, for example. The ratio of the catalyst used is preferably 100 parts by mass or less with respect to 100 parts by mass of the epoxy group-containing polysiloxane.

  Preferable specific examples of the organic solvent to be used include 2-butanone, 2-hexanone, methyl isobutyl ketone, cyclopentanone, cyclohexanone and butyl acetate. It is preferable to use the organic solvent in a proportion such that the solid content concentration is 5 to 50% by mass. The reaction temperature in the above reaction is preferably 0 to 200 ° C., and the reaction time is preferably 0.1 to 50 hours. After the 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 a polysiloxane having a functional group.

  The polysiloxane preferably has a group capable of vertically aligning liquid crystal molecules (hereinafter also referred to as “vertical alignment group”). Specific examples of the vertical alignment group include, for example, an alkyl group having 8 to 22 carbon atoms, a fluorine-containing alkyl group having 6 to 18 carbon atoms, a group represented by the above formula (5), and a carbon number having a steroid skeleton. 17-51 group etc. are mentioned. When polysiloxane having a vertical alignment group is contained in the liquid crystal aligning agent, the light transmittance and light scattering property of the obtained liquid crystal element can be further improved, which is preferable.

  For polysiloxane, the polystyrene-reduced weight average molecular weight measured by gel permeation chromatography (GPC) is preferably 500 to 1,000,000, more preferably 1,000 to 100,000, Furthermore, it is preferable that it is 1,000-50,000.

  The content of the polysiloxane in the liquid crystal aligning agent is 1% by mass or more based on the total amount of the polymer components in the liquid crystal aligning agent from the viewpoint of sufficiently increasing the weather resistance of the liquid crystal element 10 to be obtained. Is preferable, more preferably 2% by mass or more, and still more preferably 5% by mass or more. Further, the upper limit value of the polysiloxane content is preferably 97% by mass or less, and more preferably 90% by mass or less. In addition, polysiloxane may be used individually by 1 type and may be used in combination of 2 or more type.

(Silane compound)
The silane compound contained in the liquid crystal aligning agent is an organosilicon compound having a carbon-silicon bond, and specific examples thereof include hydrolyzable silane compounds exemplified as silane compounds used for the synthesis of polysiloxane. . The silane compound is an alkoxysilyl group (—Si (OR) _r R _3-r (where R is an alkyl group, r is an integer of 1 to _3. ) R may be the same as or different from each other. )), An alkoxysilane compound having at least one functional group selected from the group consisting of an epoxy group, an amino group and a thiol group is more preferable, and an epoxy group-containing alkoxysilane compound is particularly preferable.

  When the silane compound is blended in the liquid crystal aligning agent, the blending ratio is 0 with respect to a total of 100 parts by mass of the polymer from the viewpoint of sufficiently obtaining the effect of improving the adhesion to the substrate and the weather resistance of the liquid crystal element 10. It is preferable to set it as 5 mass parts or more, and it is more preferable to set it as 1-30 mass parts. In addition, a silane compound may be used individually by 1 type, and may be used in combination of 2 or more type.

（式（１）中、Ｒは、炭素数１〜１０のアルキル基、炭素数１〜１０のアルコキシ基、少なくとも１個の水素原子がフッ素原子で置換された炭素数１〜１０のフッ素含有アルキル基、少なくとも１個の水素原子がフッ素原子で置換された炭素数１〜１０のフッ素含有アルコキシ基、又はフッ素原子である。ａは０〜４の整数である。ａが２以上の場合、複数のＲは同一でも異なっていてもよい。「＊」は結合手を示す。）(Polymer having photo-alignment group)
It is preferable that the liquid crystal aligning agent used for formation of the liquid crystal aligning films 14 and 15 contains the polymer which has a photo-alignment group. Here, the “photo-alignable group” means a functional group that imparts anisotropy to the film by a photoisomerization reaction, a photodimerization reaction, a photolysis reaction, or a photofleece rearrangement 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 as a basic skeleton, a chalcone containing a chalcone or a derivative thereof as a basic skeleton And a benzophenone-containing group containing benzophenone or a derivative thereof as a basic skeleton, a coumarin-containing group containing coumarin or a derivative thereof as a basic skeleton, and a cyclobutane-containing structure containing cyclobutane or a derivative thereof as a basic skeleton. Among these, a cinnamic acid structure-containing group is preferable in terms of high sensitivity to light, and examples thereof include a group having a partial structure represented by the following formula (1).

(In the formula (1), R is an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a fluorine-containing alkyl having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom. A group, a fluorine-containing alkoxy group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, or a fluorine atom, a is an integer of 0 to 4. When a is 2 or more, a plurality of The Rs in each may be the same or different. “*” Represents a bond.)

（式（４）中、Ｒ^１１は、フェニレン基、ビフェニレン基、ターフェニレン基、シクロヘキシレン基又はビシクロヘキシレン基であり、環部分に、炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、少なくとも１個の水素原子がフッ素原子で置換された炭素数１〜２０のフッ素含有アルキル基、少なくとも１個の水素原子がフッ素原子で置換された炭素数１〜２０のフッ素含有アルコキシ基、又はフッ素原子を有していてもよい。Ｒ^１２は、式（１）中のベンゼン環に結合している場合には、単結合、炭素数１〜３のアルカンジイル基、酸素原子、硫黄原子、−ＣＨ＝ＣＨ−、−ＮＨ−、−ＣＯＯ−又は−ＯＣＯ−であり、式（１）中のカルボニル基に結合している場合には、単結合、炭素数１〜３のアルカンジイル基、酸素原子、硫黄原子又は−ＮＨ−である。「＊」は結合手を示す。）In the partial structure represented by the above formula (1), one of the two bonds “*” is preferably bonded to a group represented by the following formula (4). In this case, the light transmittance and light scattering property of the obtained liquid crystal element can be improved, which is preferable.

(In Formula (4), R ¹¹ is a phenylene group, a biphenylene group, a terphenylene group, a cyclohexylene group, or a bicyclohexylene group, and the ring portion includes an alkyl group having 1 to 20 carbon atoms and 1 to 20 carbon atoms. An alkoxy group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, or a fluorine containing alkoxy having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom R ¹² may have a fluorine atom or a single bond, an alkanediyl group having 1 to 3 carbon atoms, an oxygen atom when bonded to the benzene ring in formula (1), A sulfur atom, —CH═CH—, —NH—, —COO— or —OCO—, and when bonded to a carbonyl group in formula (1), a single bond, an alkane having 1 to 3 carbon atoms Diyl group, oxygen Child, a sulfur atom or -NH-. "*" Indicates a bond.)

  The photo-alignment group may be contained in the poly (meth) acrylate, but may be contained in a polymer different from the poly (meth) acrylate. Examples of the main skeleton of the polymer having a photoalignable group include polyamic acid, polyamic acid ester, polyimide, polysiloxane, and polyamide. From the viewpoint of ensuring the reliability and weather resistance of the liquid crystal element 10, polysiloxane having a photo-alignment group can be preferably used.

  The method for synthesizing the polymer having a photoalignable group is not particularly limited, and may be appropriately selected according to the main skeleton of the polymer. As specific examples, (1) a method of polymerizing using a monomer having a photo-alignment group, (2) a polymer having a first functional group (for example, an epoxy group) in the side chain, and then the first And a method of reacting a reactive compound having a second functional group capable of reacting with the functional group (for example, a carboxyl group) and a photoalignable group with a polymer having the first functional group. When the polymer having a photo-alignment group is polysiloxane, the method (2) is preferable in that the introduction efficiency into the side chain is high.

  When the liquid crystal aligning agent contains a polymer having a photo-alignable group and a polymer having no photo-alignable group, the content ratio of the polymer having a photo-alignable group is determined using the liquid crystal aligning agent. From the viewpoint of imparting sufficient alignment ability to the formed coating film by radiation irradiation, it is preferably 1% by mass or more with respect to the total amount of the polymer components in the liquid crystal aligning agent, and 5 to 99% by mass. More preferably.

  The polymer component contained in the liquid crystal aligning agent is not limited to the above-described poly (meth) acrylate and polysiloxane, and may include other polymers. Examples of other polymers include polyamic acid, polyimide, polyamic acid ester, polyamide, polyester, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, and the like. Among these polymers, at least one selected from the group consisting of polyamic acid and polyamic acid ester is preferable, and polyamic acid is more preferable.

  The blending ratio of the other polymer is preferably 20% by mass or less, more preferably 10% by mass or less, more preferably 5% by mass or less, with respect to the total amount of the polymer components in the liquid crystal aligning agent. More preferably. In addition, another polymer can be used individually by 1 type or in combination of 2 or more types.

(Crosslinking agent)
It is preferable that a liquid crystal aligning agent contains the compound (henceforth a crosslinking agent) which has a crosslinkable group as another component. The crosslinkable group is a group capable of forming a covalent bond between the same or different molecules by light or heat. For example, a (meth) acryloyl group, a group having a vinyl group (alkenyl group, vinylphenyl group, etc.), an ethynyl group, Examples thereof include an epoxy group (oxiranyl group, oxetanyl group), a carboxyl group, and a (protected) isocyanate group. Among these, a (meth) acryloyl group is particularly preferable in terms of high reactivity. “(Meth) acrylo” means acrylo and methacrylo. The number of crosslinkable groups possessed by the crosslinking agent may be one or plural. In view of sufficiently increasing the reliability of the liquid crystal element, the number is preferably 2 or more, and more preferably 2 to 6.

Specific examples of the crosslinking agent include allyl group-containing compounds such as diallyl phthalate;
Ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol tri (meth) acrylate, ditrimethylolpropane tetra (meth) Acrylate, pentaerythritol tetra (meth) acrylate, trimethylolpropane (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ethylene glycol tri (meth) acrylate, polyether (meta ) Acrylate, ethoxylated bisphenol A di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, 2-methyl 1,8-octanediol di (meth) acrylate of (meth) acrylic compound;
Maleic acid, itaconic acid, trimellitic acid, tetracarboxylic acid, cis-1,2,3,4-tetrahydrophthalic acid, ethylene glycol bistrimate, propylene glycol bistrimate, 4,4'-oxydiphthalic acid, trimellitic anhydride Carboxylic acids such as products;
Ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2- Bis (4-hydroxyphenyl) propane diglycidyl ether, trimethylolpropane triglycidyl ether, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N-diglycidyl) Aminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane, N, N-diglycidyl-benzylamine, N, N-diglycidyl-a Bruno methylcyclohexane, N, N-diglycidyl - epoxy compounds such as cyclohexylamine;
Examples thereof include (protected) isocyanate compounds in which polyvalent isocyanates such as tolylene diisocyanate, hexamethylene diisocyanate, and diphenylmethylene diisocyanate are protected with a protecting group. Among these, a polyfunctional (meth) acrylate compound is preferable as the crosslinking agent.

  The blending ratio of the cross-linking agent is preferably 0.5 parts by mass or more with respect to 100 parts by mass of the polymer component used for the preparation of the liquid crystal aligning agent, from the viewpoint of sufficiently obtaining the effect of improving the liquid crystal alignment property and electrical characteristics. More preferably, it is 1-40 mass parts, More preferably, it is 5-30 mass parts. In addition, a crosslinking agent may be used individually by 1 type, and may be used in combination of 2 or more type.

(Antioxidant)
The liquid crystal aligning agent preferably contains an antioxidant (also referred to as a polymerization inhibitor) as another component. The antioxidant has a function of invalidating radicals and peroxides generated by energy such as ultraviolet rays and heat, and delaying or prohibiting polymerization. By including such an antioxidant in the alignment film, the polymerization reaction of the polymerizable compound in the liquid crystal composition existing in the vicinity of the alignment film surface is suppressed, and the effect of suppressing the decrease in the alignment property of the liquid crystal is obtained. This is preferable. Specific examples of the antioxidant include, for example, a compound having an amine structure (preferably a hindered amine structure), a compound having a phenol structure (preferably a hindered phenol structure), and a compound having an alkyl phosphate structure (phosphorous antioxidant). Agent), a compound having a thioether structure (sulfur-based antioxidant), and a mixture thereof (blend-based antioxidant).

Preferred examples of the antioxidant include compounds having an amine structure such as ADK STAB LA-52, LA-57, LA-63, LA-68, LA-72, LA-77, LA-81, LA-81, LA-82, LA-87, LA-402, LA-502 (Adeka) Etc .;
Examples of compounds having a phenol structure include ADK STAB AO-20, AO-30, AO-40, AO-50, AO-60, AO-80, AO-330 (above, manufactured by ADEKA), IRGANOX1010. IRGANOX 1035, IRGAOX 1076, IRGANOX 198, IRGANOX 1135, IRGANOX 1330, IRGANOX 1726, IRGANOX 1425, IRGANOX 1520, IRGANOX 245, IRGANOX 259, IRGANOX 3114, IRGANOX 3790, IRGANOB 5057, IRGANO BAX

Examples of phosphorus antioxidants include ADK STAB PEP-4C, PEP-8, PEP-36, HP-10, 2112 (above, manufactured by ADEKA), IRGAFOS168, GSY-P101 (above, manufactured by Sakai Chemical Industry), IRGAFOS168. IRGAFOS12, IRGAFOS126, IRGAFOS38, IRGAFOS P-EPQ (above, manufactured by BASF Japan) and the like;
Examples of sulfur-based antioxidants include ADK STAB AO-412, AO-503 (above, manufactured by ADEKA), IRGANOX PS 800, IRGANOX PS 802 (above, manufactured by BASF Japan) and the like;
Examples of blend antioxidants include ADK STAB A-611, A-612, A-613, AO-37, AO-15, AO-18, 328 (above, manufactured by ADEKA), TINUVIN111, TINUVIN783, TINUVIN 791 (above, manufactured by BASF Japan) and the like can be mentioned. One of these antioxidants can be used alone, or two or more can be used in combination.

  The content ratio of the antioxidant in the liquid crystal aligning agent is preferably 0.01 to 15 parts by mass, more preferably 0.01 to 100 parts by mass with respect to 100 parts by mass of the polymer component used for preparing the liquid crystal aligning agent. It is 10 mass parts, Most preferably, it is 0.1-10 mass parts.

  Examples of other components contained in the liquid crystal aligning agent include metal chelate compounds, curing accelerators, surfactants, fillers, dispersants, and photosensitizers. The blending ratio of these other components can be appropriately selected according to each compound as long as the effects of the present disclosure are not impaired.

(solvent)
The liquid crystal aligning agent is prepared as a liquid composition in which a polymer component and other components used as necessary are preferably dissolved in an appropriate 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, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl iso Examples include butyrate, diisopentyl ether, ethylene carbonate, and propylene carbonate. These can be used alone or in admixture of two or more.

  The organic solvent used for the preparation of the liquid crystal aligning agent is one of these in order to obtain a liquid crystal aligning film that exhibits good device characteristics even when the post-bake temperature is lowered (for example, 160 ° C. or lower). The compound having a boiling point at atmospheric pressure of 160 ° C. or less is preferably contained in an amount of 40% by mass or more, more preferably 50% by mass or more, and further preferably 70% by mass or more based on the total amount of the solvent.

  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 the range of 1-10 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.

<Manufacturing method of liquid crystal element>
Next, a method for manufacturing the liquid crystal element 10 will be described. The liquid crystal element 10 includes a step A in which a liquid crystal alignment film 14 and 15 is formed by applying a liquid crystal alignment agent on each electrode arrangement surface of the first base material 11 and the second base material 12, and the liquid crystal alignment films 14 and 15. A step B of constructing a liquid crystal cell by arranging a pair of substrates having a liquid crystal composition layer so that the electrode arrangement surfaces face each other, and a step C of curing the polymerizable compound after the construction of the liquid crystal cell It is preferable to manufacture by the method containing these.

(Process A)
Application of the liquid crystal aligning agent is performed on each electrode arrangement surface of the first base material 11 and the second base material 12, for example, offset printing method, spin coating method, roll coater method, ink jet printing method, bar coater method, flexographic printing. This is performed by a known coating method such as a 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. The pre-baking temperature is set according to the type of substrate, but is preferably 140 ° C. or lower, more preferably 120 ° C. or lower, and further preferably 100 ° C. or lower. About the lower limit of prebaking temperature, it is preferable to set it as 30 degreeC or more, and it is more preferable to set it as 40 degreeC or more. The pre-bake time is preferably 0.25 to 10 minutes.

  Then, it is preferable that a baking (post-baking) process is implemented for the purpose of removing a solvent completely and accelerating | stimulating a crosslinking reaction as needed. The firing temperature (post-bake temperature) at this time is preferably 160 ° C. or lower, more preferably 150 ° C. or lower, particularly 110 ° C. or lower, when using a base material made of a polymer material. preferable. By making at least a part of the polymer component of the liquid crystal aligning agent poly (meth) acrylate, the solubility in a low boiling point solvent can be improved, and even when the post-baking temperature is lowered, it is homogeneous. An alignment film can be obtained, and the liquid crystal orientation and voltage holding ratio of the liquid crystal element 10 can be ensured. The post-bake time is preferably 5 to 200 minutes, more preferably 10 to 120 minutes.

(Photo-alignment treatment)
The coating film formed using the liquid crystal aligning agent is preferably imparted with a liquid crystal aligning ability by performing a rubbing treatment, a photo-alignment treatment or the like. In the present embodiment, a photo-alignment treatment that imparts liquid crystal alignment ability by light irradiation is performed.

  In the photo-alignment treatment, the coating film may be irradiated with light such as ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm. The radiation may be polarized or non-polarized, or may be irradiated in combination. The exposure method is not particularly limited, and examples thereof include a method of irradiating linearly polarized light from a direction perpendicular to the substrate surface or an oblique direction, and a method of irradiating non-polarized light from an oblique direction.

As a light source to be used, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, or the like can be used. Ultraviolet rays in a preferable wavelength region can be obtained by means of using a light source in combination with, for example, a filter or a diffraction grating. The radiation dose is preferably 10 to 50,000 J / m ² , more preferably 20 to 10,000 J / m ² . Light irradiation for photo-alignment treatment is a method of irradiating the coating film after the post-baking process, a method of irradiating the coating film after the pre-baking process and before the post-baking process, a pre-baking process and a post-baking process. In at least one of the methods, it can be carried out by a method of irradiating the coating film during heating.

(Process B)
In Step B, two base materials having a liquid crystal alignment film are prepared, and a liquid crystal composition layer containing a liquid crystal and a polymerizable compound is provided between the two base materials facing each other so that the liquid crystal alignment films face each other. A liquid crystal cell is manufactured by arranging. Specifically, the peripheral portions of the first base material 11 and the second base material 12 are bonded together with a sealing agent, and the liquid crystal composition is injected and filled into the cell gap defined by the base material surface and the sealing agent, and then injected. A method of sealing the holes; after applying a sealing agent to the periphery of one substrate on the liquid crystal alignment film side and further dropping the liquid crystal composition at predetermined locations on the surface of the liquid crystal alignment film, the liquid crystal alignment film The other base material is bonded so as to face each other, and the liquid crystal is spread over the entire surface of the base material, and then the sealing agent is cured (ODF method). As the sealant, for example, an epoxy resin containing a hardener and aluminum oxide spheres as a spacer can be used.

(Process C)
In step C, the liquid crystal composition is cured by performing at least one treatment selected from heating and light irradiation. The heating temperature during the curing reaction is appropriately selected depending on the type of polymerizable compound and liquid crystal to be used, and is heated at a temperature in the range of 40 to 80 ° C., for example. The heating time is preferably 0.5 to 5 minutes. When curing by light irradiation, unpolarized ultraviolet rays having a wavelength in the range of 200 to 500 nm can be preferably used as the irradiation light. The irradiation dose of light, preferably in the 50~10,000mJ / cm ^2, and more preferably a 100~5,000mJ / cm ^2.

  The liquid crystal element 10 can be applied to various uses. For example, a building window, an indoor / outdoor partition (partition), a show window, a vehicle (automobile, aircraft, ship, railway, etc.) window, and various indoor and outdoor advertisements. It can be effectively used as various light control elements such as information signs, home appliances, mobile phones, smartphones, various monitors, watches, portable games, personal computers, glasses, sunglasses, medical equipment, furniture, and the like. The liquid crystal element 10 may be used as it is, depending on the thickness, hardness, shape, application, etc. of the element, or may be used by being attached to glass or a transparent resin.

(Liquid crystal device)
A display device of the present disclosure includes the above-described liquid crystal element and a transparent display that is transparent in a non-display state. Specifically, as shown in FIG. 3, the display device 20 has a structure in which the liquid crystal element 10 is disposed on the back surface of the transparent display 30, and the liquid crystal element 10 functions as a dimming element, thereby being transparent. The visibility of display on the display 30 changes.

  The transparent display 30 is, for example, an organic electroluminescence element (organic EL element), and is formed between a pair of glass substrates, an anode electrode and a cathode electrode formed of a transparent electrode material, and the anode electrode and the cathode electrode. A hole transport layer and a light emitting layer. The transparent display 30 is transparent in the non-display state in which no voltage is applied. When a voltage is applied, the pixels to which the voltage is applied emit light, and characters, images, and the like are displayed.

  In the display device 20 of FIG. 3, the entire surface of the display device 20 is transparent when the liquid crystal element 10 and the transparent display 30 are in a state where no voltage is applied. Therefore, for example, when the display device 20 is applied as a front glass or a rear glass of a show window, it is possible to visually check the products displayed in the showcase and the inside of the store from the outside. In addition, when a voltage is applied to the transparent display 30 while the liquid crystal element 10 is not applied with voltage, characters, images, and the like displayed on the transparent display 30 are displayed in a state of being raised on the glass. Become.

  On the other hand, the back surface of the transparent display 30 is shielded from light when a voltage is applied to the liquid crystal element 10. In this case, it is possible to prevent the characters, images, and the like displayed on the display device 20 from overlapping with objects behind the display device 20, and the display on the transparent display 30 is easy to see. In addition, the decorativeness can be improved. Or it is good also as a structure which makes variable the degree of permeation | transmission of the light from the front surface of the display apparatus 20 by controlling the applied voltage of the liquid crystal element 10 according to the brightness of the front surface of the display apparatus 20, or a back surface. .

  In addition, in the display apparatus 20 of FIG. 3, it is good also as a structure which arrange | positions the light control element 10 only to the one part area | region of the transparent display 30. FIG. Or it is good also as a structure which can change the transmittance | permeability for every display area by dividing | segmenting the display area of the transparent display 30 into several, and arrange | positioning a light control element for every display area.

  In the above-described embodiment, the liquid crystal alignment films 14 and 15 are the photo-alignment films, but may not be subjected to the photo-alignment process. Also in this case, when a base material made of a polymer material is used as the base material of the liquid crystal element 10, the liquid crystal alignment film is homogeneous, the liquid crystal alignment film is highly transparent, and has light transmission characteristics and light scattering characteristics. Therefore, a liquid crystal element that exhibits electrical characteristics sufficient for realizing the light control function and excellent weather resistance can be obtained.

  Hereinafter, the contents of the present disclosure will be described more specifically with reference to examples. However, the contents of the present disclosure are not limited to these examples.

  In the following examples, the weight average molecular weight Mw, the number average molecular weight Mn and the epoxy equivalent of the polymer, and the solution viscosity of the polymer solution were measured by the following methods. The required amounts of raw material compounds and polymers used in the following examples were ensured by repeating the synthesis on the synthesis scale shown in the following synthesis examples as necessary.

[Weight average molecular weight Mw and number average molecular weight Mn of the polymer]
Mw and Mn are polystyrene equivalent values measured by GPC under the following conditions.
Column: Tosoh Co., Ltd., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²
[Epoxy equivalent]
The epoxy equivalent was measured by the hydrochloric acid-methyl ethyl ketone method described in JIS C 2105.
[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.

  The relationship between the abbreviations of the compounds used in the following examples and the structural formulas is as follows. Hereinafter, for convenience, the “compound represented by the formula (X)” is simply referred to as “compound (X)”.

(carboxylic acid)

(Polymerizable compound)

(Photoinitiator)

(Crosslinking agent)

(Silane compound)

(Antioxidant)

(Dichroic dye)

<Synthesis of poly (meth) acrylate>
[Synthesis Example 1]
A flask equipped with a condenser and a stirrer was charged with 1.2 parts by mass of 2,2′-azobisisobutyronitrile and 200 parts by mass of propylene glycol monomethyl ether acetate. Subsequently, after 80 parts by mass of glycidyl methacrylate and 20 parts by mass of styrene were charged and purged with nitrogen, stirring was started gently. The solution temperature was raised to 95 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing a polymer (Pac-1). In addition, the monomer consumption rate after completion | finish of reaction computed from the measurement result of solid content concentration of a polymer solution was 99%.

[Synthesis Example 2]
A flask equipped with a condenser and a stirrer was charged with 1.2 parts by mass of 2,2′-azobisisobutyronitrile and 200 parts by mass of propylene glycol monomethyl ether acetate. Subsequently, 50 parts by mass of glycidyl methacrylate and 50 parts by mass of tricyclo [5.2.1.0 ^2,6 ] dec-8-yl methacrylate were charged, purged with nitrogen, and then gently stirred. The solution temperature was raised to 95 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing a polymer (Pac-2). In addition, the monomer consumption rate after completion | finish of reaction computed from the measurement result of solid content concentration of a polymer solution was 99%.

<Synthesis of epoxy group-containing polysiloxane>
[Synthesis Example 3]
In a reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser, 100.0 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (ECETS), 500 g of methyl isobutyl ketone and 10.0 g of triethylamine were added. Charged and mixed at room temperature. Next, 100 g of deionized water was dropped from the dropping funnel over 30 minutes, and the mixture was reacted at 80 ° C. for 6 hours while mixing under reflux. After completion of the reaction, the organic layer is taken out and washed with a 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 obtain a polysiloxane having an epoxy group. Was obtained as a viscous transparent liquid. When ¹ H-NMR analysis was performed on the polysiloxane having an epoxy group, a peak based on the epoxy group was obtained in the vicinity of chemical shift (δ) = 3.2 ppm, and side reaction of the epoxy group occurred during the reaction. Not confirmed. The weight average molecular weight (Mw) of the polysiloxane having an epoxy group (SEp-1) obtained in Synthesis Example 3 was Mw = 2,200, and the epoxy equivalent was 186 g / mol.

<Synthesis of polysiloxane having functional group>
[Synthesis Example 4]
In a 100 mL three-necked flask, 18.4 g of the polysiloxane having an epoxy group obtained in Synthesis Example 3 (SEp-1), 70.8 g of methyl isobutyl ketone, 3.45 g of cinnamic acid derivative (CA-1) (polyorganosiloxane ( SEp-1) 15 mol parts per 100 mol epoxy groups), cinnamic acid derivative (CA-2) 6.21 g (polysiloxane (SEp-1) 100 mol parts epoxy groups 25 mol) Part) and 1.03 g of tetrabutylammonium bromide were added and stirred at 80 ° C. for 12 hours. After completion of the reaction, 40 g of diethylene glycol diethyl ether and 60 g of cyclohexane were added. This solution was washed with water six times by liquid separation washing, and then 100 g of diethylene glycol diethyl ether was further added, and the solvent was distilled off so that the solid content concentration was 10% by mass. did. As a result, a diethylene glycol diethyl ether solution having a solid content concentration of 10% by mass containing the polymer (S-1) which is a polysiloxane having a functional group was obtained. The weight average molecular weight Mw of the polymer (S-1) was 17,000.

[Synthesis Example 5 and Synthesis Example 6]
Except having changed the kind and quantity of carboxylic acid used for reaction as described in the following Table 1, it synthesize | combined similarly to the synthesis example 4, polymer (S-2), (S -3) was obtained. In addition, the number in Table 1 represents the number of moles relative to 100 parts by mole of the epoxy group that polysiloxane (SEp-1) has.

<Synthesis of polyamic acid>
[Synthesis Example 7]
121,35 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride (90 mol parts with respect to 100 mol parts of the total amount of diamine used in the synthesis), and 3,5 as diamine compounds -94.34 g (30 mole parts) of diaminobenzoate and 84.3 g (70 mole parts) of 4,4′-diaminodiphenyl ether were dissolved in 1200 g of N-methyl-2-pyrrolidone (NMP), and 30 ° C. The reaction was carried out 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 under reduced pressure at 40 ° C. for 15 hours to obtain 290 g of polyamic acid (hereinafter referred to as polymer (PA-1)). The obtained polymer (PA-1) was prepared to be 20% by mass with NMP, and the viscosity of this solution was measured to be 1310 mPa · s. Further, when this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

<Synthesis of polyimide>
[Synthesis Example 8]
2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride 3.19 g (12.8 mmol) as a tetracarboxylic dianhydride, and a diamine compound 1,5-diamino-4- [4- (trans-4-n-heptylcyclohexyl) phenoxymethyl] benzene 4.59 g (11.6 mmol) and 3,5-diaminobenzoic acid 2.16 g (14.2 mmol) Is dissolved in 24.9 g of NMP and reacted at 80 ° C. for 5 hours, and then 2.50 g (12.8 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride, And 12.4 g of NMP were added and reacted at 40 ° C. for 8 hours to obtain a polyamic acid solution having a polymer concentration of 25% by mass. NMP was added to 30.0 g of the obtained polyamic acid solution to dilute it to 6% by mass, and then 3.95 g of acetic anhydride and 2.40 g of pyridine were added and reacted at 50 ° C. for 2 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 100 ° C. under reduced pressure to obtain polyimide (hereinafter referred to as polymer (PI-1)). The imidation ratio of the obtained polyimide was 55%, and the weight average molecular weight was 48,000.

<Preparation of liquid crystal composition>
1. Preparation of Liquid Crystal Composition I 1.20 g of liquid crystal (MLC-6608, manufactured by Merck & Co.), 1.20 g of compound (R-1) as a polymerizable compound, 0.60 g of compound (R-2), and compound (R -3) 0.12 g, compound (R-4) 0.36 g, and compound (P-1) 0.012 g as a photoinitiator were mixed, heated, cooled to 25 ° C., and then liquid crystal Composition I was obtained.
2. Preparation of liquid crystal composition II 1.20 g of liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.), 0.024 g of dichroic dye shown below, 1.20 g of compound (R-1) as a polymerizable compound, compound ( 0.62 g of R-2), 0.12 g of compound (R-3) and 0.36 g of compound (R-4), and 0.012 g of compound (P-1) as a photoinitiator And heated to 25 ° C. to obtain a liquid crystal composition II.
(Dichroic dye)
A mixture of 6.0 parts by mass of the compound (m-1), 2.0 parts by mass of the compound (m-2), and 2.0 parts by mass of the compound (m-3) was used.

[Example 1]
<Preparation of liquid crystal aligning agent>
As a polymer component, the amount corresponding to 20 parts by mass of the diethylene glycol diethyl ether solution containing the polymer (S-1) obtained in Synthesis Example 4 in terms of the polymer (S-1), and Synthesis Example 1 The solution containing the polymer (PAc-1) obtained in 1 above was mixed with an amount corresponding to 80 parts by mass in terms of the polymer (PAc-1), and 5 parts by mass of the compound (add-2). As a solvent, propylene glycol monomethyl ether (PGME), diethylene glycol diethyl ether (DEDG), propylene glycol monomethyl ether acetate (PGMEA) is added, the solid content concentration is 4% by mass, and the weight ratio of each solvent is PGME: DEDG: PGMEA = It was prepared to be 30:20:50. Subsequently, this obtained solution was filtered with a filter having a pore size of 0.2 μm to prepare a liquid crystal aligning agent (A-1).

<Evaluation of liquid crystal aligning agent and liquid crystal element>
1. Evaluation of coating property The liquid crystal aligning agent (A-1) prepared above is applied using a bar coater on the electrode arrangement surface of a PET film substrate (PET-ITO substrate) having an ITO electrode on the substrate surface. Then, after pre-baking for 1 minute on a hot plate at 80 ° C., the coating was heated for 2 minutes (post-bake) in a 120 ° C. oven in which the interior was replaced with nitrogen to form a coating film having an average film thickness of 0.1 μm. . This coating film was observed visually and with a microscope having a magnification of 100 times to examine the presence or absence of film thickness unevenness, coating unevenness, and pinholes. Evaluation is “good” when no film thickness unevenness, coating unevenness and pinholes are observed even when observed visually and with a 100 × microscope, and pinholes are observed with a 100 × microscope. However, when the coating unevenness on the coating film surface was not observed visually, the coating property was “OK”, and when the coating thickness was visually observed at least one of film thickness unevenness, coating unevenness and pinholes. The coating property was evaluated as “bad”. In this example, no film thickness unevenness, coating unevenness and pinholes were observed even with visual observation and a 100 × magnification microscope, and the coating property was “good”.

2. Evaluation of transparency of coating film Using the spectrophotometer (150-20 type double beam manufactured by Hitachi, Ltd.), the transparency of the coating film was evaluated by the light transmittance (%) at a wavelength of 400 nm. In the evaluation, when the light transmittance was 97% or more, the transparency was “good”, and when it was less than 97%, the transparency was “bad”. As a result, the light transmittance of this coating film was 98.1%, and the transparency was “good”.

3. Manufacture of liquid crystal element Using a Hg-Xe lamp and a Grand Taylor prism, the surface of the coating film prepared in step 1 is irradiated with polarized ultraviolet light 20 mJ / cm ² containing a 313 nm emission line from a direction inclined by 20 ° from the normal to the liquid crystal alignment film. Obtained. By repeating the same operation, a pair (two) of substrates having a liquid crystal alignment film was prepared. Next, a 6 μm spacer was applied to the surface of one substrate having the liquid crystal alignment film, and then the liquid crystal composition I prepared above was dropped onto the liquid crystal alignment film surface to which the spacer was applied. Next, the two substrates were bonded together with a sealant so that the liquid crystal alignment film surface of the other substrate faced to obtain a liquid crystal cell. This liquid crystal cell was irradiated with ultraviolet rays under the conditions of a wavelength of 365 nm, an ultraviolet intensity of 15 mW / cm ² , an irradiation time of 15 seconds, and a substrate surface temperature of 20 ° C. using an ultraviolet irradiation device having an ultraviolet light emitting diode as a light source. The product I was cured to obtain the liquid crystal element 10 shown in FIG.

4). Evaluation of Light Transparency Transparency when no voltage was applied was evaluated by measuring the haze (HAZE) of the liquid crystal element when no voltage was applied. The measurement was performed using a spectroscopic haze meter (manufactured by Tokyo Denshoku). A lower haze value means better transparency. As a result, in this example, the haze value was 2%, and the transparency when no voltage was applied was excellent.
5). Evaluation of light scattering property The light scattering property at the time of voltage application was evaluated by measuring the (HAZE) of the liquid crystal element in the voltage application state. The measurement is performed in the above 3. 20V is applied to the liquid crystal element manufactured in step 4 by alternating current drive, and the above 4. In the same manner as described above, a spectroscopic haze meter (manufactured by Tokyo Denshoku) was used. A higher haze value means better light scattering properties. As a result, in this example, the haze value was 92%, and the light scattering property was excellent when a voltage was applied.

6). Evaluation of voltage holding ratio 3. After applying a voltage of 5 V at 23 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, the voltage holding ratio (VHR _BF ) after 1670 milliseconds after the application release was measured. However, the voltage holding ratio was 80.4%. In addition, as a measuring apparatus, Toyo Technica Co., Ltd. make and VHR-1 were used.

7). Evaluation of weather resistance 3. The xenon lamp light (illuminance: 250 W / m ² (300-800 nm)) was irradiated for 200 hours to the liquid crystal element manufactured in (1) using a light resistance tester (SUNTEST CPS +: manufactured by Toyo Seiki Co., Ltd.). For the liquid crystal element after light irradiation, 6. The voltage holding ratio was measured by the same method. This value was defined as a voltage holding ratio (VHR _AFXe ) after light irradiation. The decrease rate ΔVHR _Xe (%) of the voltage holding rate was obtained from the following formula (EX-1), and the weather resistance was evaluated based on the decrease rate ΔVHR _Xe .
ΔVHR _Xe = ((VHR _BF −VHR _AFXe ) ÷ VHR _BF ) × 100 (EX-1)
When ΔVHR _Xe was less than 5%, the weather resistance was judged as “good”, when it was 5% or more but less than 10%, “good”, and when it was 10% or more, it was judged as “bad”. As a result, ΔVHR _Xe of the liquid crystal element of this example was 3.5%, and the weather resistance was “good”.
For the liquid crystal element after 200 hours of light irradiation, the above 4. The haze value in the state where no voltage was applied was measured by the same method as above, and the weather resistance was evaluated based on the haze value. As a result, in the liquid crystal element of this example, the haze value was 2% even after the light irradiation, and the transparency did not change before and after the light irradiation.

[Examples 2 to 7 and Comparative Example 1]
Except having used each component of the kind and compounding quantity which are shown in following Table 2, it operates similarly to preparation of liquid crystal aligning agent (A-1), and each liquid crystal aligning agent (A-2)-(A-8). Prepared. Moreover, the liquid crystal element was evaluated in the same manner as in Example 1 using each of the liquid crystal alignment agents (A-2) to (A-8). The results are shown in Table 3 below.

[Example 8]
1. Production and Evaluation of Liquid Crystal Element A liquid crystal element was produced in the same manner as in Example 1 except that the liquid crystal composition II was used instead of the liquid crystal composition I. Moreover, evaluation similar to Example 1 was performed using the obtained liquid crystal element. The results are shown in Table 3 below.

In Example 8, the above 1. The following evaluations (evaluation of light transmission, evaluation of light blocking properties, and evaluation of repeated driving durability test) were further performed using the liquid crystal element manufactured in (1).
2. Evaluation of light transmittance Transparency when no voltage was applied was evaluated by measuring the transmittance of the liquid crystal element when no voltage was applied. The light transmittance was evaluated by light transmittance (%) at a wavelength of 400 nm using a spectrophotometer (150-20 type double beam manufactured by Hitachi, Ltd.). The higher the transmittance value, the better the transparency. As a result, in this example, the transmittance was 93%, and the transparency when no voltage was applied was excellent.
3. Evaluation of light blocking property The light blocking property during voltage application was evaluated by measuring the transmittance of the liquid crystal element in a voltage applied state. The measurement is as described in 1. above. 40V is applied to the liquid crystal element manufactured in step 2 by alternating current drive, and 2. In the same manner as described above, a spectrophotometer (150-20 type double beam manufactured by Hitachi, Ltd.) was used. The lower the transmittance value, the better the light blocking property. As a result, in this example, the transmittance was 5%, and the light blocking property was excellent when a voltage was applied.
4). Evaluation of Repeated Drive Durability Test A voltage of 40 V was applied to the liquid crystal element for 1 second, and then no voltage was applied for 1 second. After repeating this operation 1800 times, the above 2. And 3. The repeated driving durability test was evaluated by evaluating the light transmittance and the light blocking property in the same manner as described above. As a result, in this example, the transmittance when no voltage was applied = 93%, the transmittance when a voltage was applied = 7%, and before and after driving, no change in transmittance was observed when no voltage was applied. When voltage was applied, the increase in transmittance was only 2%. From this result, it can be said that the liquid crystal element of this example is excellent in repeated driving durability.

The numerical value of the compounding amount in Table 2 indicates the compounding ratio (parts by mass) of each compound with respect to 100 parts by mass in total of the polymer components used for preparing the liquid crystal aligning agent.
In Table 2, abbreviations are as follows: PGME: Propylene glycol monomethyl ether PGMEA: Propylene glycol monomethyl ether acetate DEDG: Diethylene glycol diethyl ether NMP: N-methyl-2-pyrrolidone GBL; γ-butyrolactone

As can be seen from Table 3, the liquid crystal alignment film containing poly (meth) acrylate is homogeneous and highly transparent even when the post-baking temperature is low (120 ° C.), and the light transmission characteristics of the liquid crystal element. And the light scattering property was good. In addition, the obtained liquid crystal element had a sufficiently high voltage holding ratio and good weather resistance. In particular, Examples 1 and 2 in which poly (meth) acrylate and polysiloxane are included in the liquid crystal alignment film and the ratio of poly (meth) acrylate is high are coating properties, light transmission properties, light scattering properties, electrical properties, and weather resistance. The properties were particularly excellent. Moreover, Example 7 which contains antioxidant in a liquid crystal aligning film WHEREIN: In the obtained liquid crystal element, haze value at the time of no voltage application and haze value after a weather resistance evaluation WHEREIN: Antioxidant is contained in a liquid crystal aligning film. It was excellent compared with Example 4 which does not contain.
In Example 8 in which a dye (dichroic dye) was dispersed in the liquid crystal layer, the voltage holding ratio of the obtained liquid crystal element was sufficiently high and the weather resistance was good. Further, even after the voltage application / non-application of the liquid crystal element was repeated, both the light blocking property and the light transmitting property were good, and the driving durability was excellent. This behavior is considered to be due to the assist from the alignment film side.
On the other hand, the comparative example 1 made into the liquid crystal aligning film which consists of polyimides was inferior to the Example in the coating property and transmittance | permeability of a coating film, and the light transmittance and weather resistance (haze value) of a liquid crystal element.

<Display test when combined with a transparent display>
[Example 9]
When a display device in which the liquid crystal element manufactured in Example 2 was superimposed on one outer surface of the transparent display was produced and displayed on the transparent display, the liquid crystal element had good transparency when no voltage was applied. The visibility of the display on the transparent display was judged as “good”.

[Comparative Example 2]
A display test was conducted in the same manner as in Example 9 except that a polarizing plate type liquid crystal element was used instead of the liquid crystal element in Example 9. As a polarizing plate type liquid crystal element, a transparent electrode and a liquid crystal alignment film are formed on each of opposing surfaces of a pair of glass substrates, a liquid crystal is filled between the pair of substrates, and a sealant is disposed around the pair of substrates. What used the polarizing plate arrange | positioned on the outer side of the glass substrate of a cell was used. As a result, in Comparative Example 2, the light transmittance of the liquid crystal element was poor, and the visibility of the display on the transparent display was determined to be “bad”. This can be said to indicate that the light transmittance of the PDLC element using an acrylic resin is good. On the other hand, in the polarizing plate type liquid crystal element, since light absorption by the polarizing plate exists, the transmittance is not theoretically 50% or more, and the visibility of the transparent display is inferior. From the above, it can be said that the liquid crystal element 10 having a liquid crystal alignment film containing poly (meth) acrylate is particularly excellent as a display element to be superimposed on a transparent display.

  Although the present disclosure has been described based on the embodiments, it is understood that the present disclosure is not limited to the above-described embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

  DESCRIPTION OF SYMBOLS 10 ... Liquid crystal element, 11 ... 1st base material, 12 ... 2nd base material, 13 ... Liquid crystal layer, 14, 15 ... Liquid crystal aligning film, 16, 17 ... Transparent electrode, 20 ... Display apparatus, 30 ... Transparent display

Claims (14)

A pair of opposed substrates,
Electrodes disposed on surfaces facing each other in the pair of substrates,
A liquid crystal layer disposed between the pair of substrates and formed by curing a liquid crystal composition containing a liquid crystal and a polymerizable compound;
A liquid crystal alignment film formed on at least one electrode arrangement surface of the pair of base materials,
The liquid crystal composition includes, as the polymerizable compound, at least one selected from the group consisting of a monofunctional (meth) acrylate compound, a polyfunctional (meth) acrylate compound, a polyfunctional thiol compound, and a styrene compound,
The liquid crystal alignment film is a liquid crystal element formed of a liquid crystal alignment agent containing poly (meth) acrylate.   2. The liquid crystal element according to claim 1, wherein the content ratio of the poly (meth) acrylate in the liquid crystal aligning agent is 3 to 99 mass% with respect to the total amount of the polymer components included in the liquid crystal aligning agent.   The liquid crystal element according to claim 1, wherein the liquid crystal aligning agent further contains polysiloxane.   The said liquid crystal aligning agent is a liquid crystal element as described in any one of Claims 1-3 containing the polymer which has a photo-alignment group.   The liquid crystal element according to claim 1, wherein the liquid crystal aligning agent further contains a silane compound.   The liquid crystal alignment element according to claim 1, wherein the liquid crystal aligning agent further contains a compound having a crosslinkable group.   The liquid crystal device according to claim 1, wherein the liquid crystal composition further contains a pigment.   The liquid crystal element according to claim 7, wherein the dye is at least one selected from the group consisting of an azo compound and an anthraquinone compound.   The liquid crystal element according to claim 1, wherein the liquid crystal composition further contains an antioxidant.   A display device comprising: the liquid crystal element according to claim 1; and a transparent display that is transparent in a non-display state.   Liquid crystal alignment of a liquid crystal element comprising a liquid crystal layer formed by curing a liquid crystal composition containing a liquid crystal and a polymerizable compound between a pair of base materials arranged so that electrodes provided on each base surface face each other A liquid crystal aligning agent for forming a film, comprising poly (meth) acrylate. A method for producing a liquid crystal device comprising a liquid crystal layer formed by curing a liquid crystal composition containing a liquid crystal and a polymerizable compound between a pair of base materials arranged so that electrodes provided on each base surface face each other Because
Applying a liquid crystal aligning agent on at least one electrode arrangement surface of the pair of base materials to form a liquid crystal alignment film;
Arranging the pair of base materials after forming the liquid crystal alignment film so that the electrodes face each other through the layer containing the liquid crystal composition;
Curing the polymerizable compound after the construction of the liquid crystal cell,
The liquid crystal composition includes, as the polymerizable compound, at least one selected from the group consisting of a monofunctional (meth) acrylate compound, a polyfunctional (meth) acrylate compound, a polyfunctional thiol compound, and a styrene compound,
The said liquid crystal aligning agent contains the poly (meth) acrylate, The manufacturing method of a liquid crystal element.   The manufacturing method of the liquid crystal element of Claim 12 which heats the liquid crystal aligning agent apply | coated on the said electrode arrangement | positioning surface at 160 degrees C or less.   The liquid crystal aligning agent is applied on at least one electrode arrangement surface of the pair of base materials to form a coating film, and the coating film is irradiated with light to impart liquid crystal alignment ability to the coating film. 14. A method for producing a liquid crystal element according to 12 or 13.

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