WO2018143017A1

WO2018143017A1 - Liquid crystal element and production method therefor, and display device

Info

Publication number: WO2018143017A1
Application number: PCT/JP2018/002007
Authority: WO
Inventors: 幸志樫下; 内山　克博
Original assignee: Jsr株式会社
Priority date: 2017-02-06
Filing date: 2018-01-23
Publication date: 2018-08-09
Also published as: TWI745537B; JPWO2018143017A1; TW201835317A; CN110168439A; CN110168439B; JP6766894B2

Abstract

This liquid crystal element is provided with: a pair of substrates that are disposed to face each other; electrodes that are disposed on the opposed surfaces of the pair of substrates; a liquid crystal layer which is interposed between the pair of substrates and which is formed by curing a liquid crystal composition comprising liquid crystal and a polymerizable compound; and a liquid crystal alignment film that is formed on the surfaces on which the electrodes are disposed. The polymerizable compound contains a monofunctional (meth)acrylate compound, a polyfunctional (meth)acrylate compound, and the like. The liquid crystal alignment film is formed using a liquid crystal aligning agent containing a polymer component. The liquid crystal aligning agent contains at least one type of compound which is selected from the group consisting of silane compounds and polysiloxanes and in which the content ratio of a structural unit derived from a monomer having a specific side-chain structure is 10 mol% or less with respect to the total amount of all structural units of the polymer component.

Description

Liquid crystal element, manufacturing method thereof, and display device

Cross-reference of related applications

This application is based on Japanese Application No. 2017-19833 filed on Feb. 6, 2017, the contents of which are incorporated herein by reference.

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 PDLC (Polymer Dispersed Liquid Crystal) 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

Since the dimmer element is assumed to be used for outdoor use, it is required to have excellent weather resistance. In addition, the dimmer element is assumed to be used in various environments as its usage is expanded, and therefore, it is required to have excellent high temperature and high humidity resistance. However, the conventional reverse type liquid crystal element having an alignment film for vertically aligning the liquid crystal has insufficient weather resistance, and when exposed to a high-temperature and high-humidity environment, the alignment film is easily peeled off and has high-temperature and high-humidity resistance. not enough. Therefore, development of a liquid crystal element having good light transmission characteristics and light scattering characteristics, and also having high humidity and high temperature resistance and good weather resistance is required.

The present disclosure has been made in view of the above problems, and provides a liquid crystal device that has high temperature and high humidity resistance and excellent adhesion to a substrate, excellent weather resistance, and excellent light transmission characteristics and light scattering characteristics. The main purpose is to do.

This 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 an object, and a liquid crystal alignment film formed on at least one electrode arrangement surface of the pair of substrates, wherein the polymerizable compound is a monofunctional (meth) acrylate compound, Including at least one selected from the group consisting of a polyfunctional (meth) acrylate compound, a polyfunctional thiol compound, and a styrene compound, and the liquid crystal alignment film is formed using a liquid crystal alignment agent including a polymer component, The liquid crystal aligning agent has a content ratio of a structural unit derived from a monomer having at least one structure selected from the group consisting of the following (a) to (e) in the polymer component: A liquid crystal device, which is 10 mol% or less based on the total amount of all structural units of the polymer component, and contains at least one compound selected from the group consisting of silane compounds and polysiloxanes.
(A) an alkyl group or alkoxy group having 8 to 22 carbon atoms;
(B) a C6-C18 fluoroalkyl group or fluoroalkoxy group.
(C) A monovalent group in which any one of a benzene ring, a cyclohexane ring and a heterocyclic ring is bonded to an alkyl group, alkoxy group, fluoroalkyl group or fluoroalkoxy group having 1 to 20 carbon atoms.
(D) It has a total of two or more of at least one ring selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, and these plural rings are bonded directly or via a divalent linking group. Monovalent group.
(E) a monovalent group having 17 to 51 carbon atoms and having a steroid skeleton.
[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 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 the base material faces each other A liquid crystal aligning agent for forming a liquid crystal alignment film, wherein the polymer component is a structural unit derived from a monomer having at least one structure selected from the group consisting of (a) to (e). The liquid crystal aligning agent whose content rate is 10 mol% or less with respect to the total amount of all the structural units of the said polymer component, and contains at least 1 type of compound chosen from the group which consists of a silane compound and polysiloxane.
[4] 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 the base material surfaces face each other. A method of forming a liquid crystal alignment film by applying a liquid crystal aligning agent on at least one electrode arrangement surface of the pair of base materials, and forming the pair of base materials after forming the liquid crystal alignment film. A step of constructing a liquid crystal cell by placing 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 functional compound includes 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, and the liquid crystal aligning agent is contained in the polymer component. The content ratio of the structural unit derived from the monomer having at least one structure selected from the group consisting of the above (a) to (e) is 10 mol with respect to the total amount of all the structural units of the polymer component. %, And at least one compound selected from the group consisting of silane compounds and polysiloxanes.

According to the above configuration, a liquid crystal element having high resistance to high temperature and high humidity, excellent adhesion to a substrate, and excellent weather resistance can be obtained. In addition, a liquid crystal element having excellent light transmission characteristics and light scattering characteristics 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 having a polymer matrix and a liquid crystal. In this embodiment, a polymer-dispersed liquid crystal (polymer dispersed liquid crystal in which a polymer network is formed in the layer ( 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 liquid crystal molecules present in the polymer network with 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.

Transparent electrodes

16 and 17 are respectively arranged on surfaces of the first base material 12 and the second base material 12 that face each other, and an electrode pair is constructed by the

transparent electrodes

16 and 17. In the present 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 band shape or a comb shape.

The 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 liquid crystal molecules in the liquid crystal layer 13 and are formed using a polymer composition containing a polymer and a solvent. 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 has a liquid crystal composition 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 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 changes, so that incident light is scattered and becomes non-transparent. In the present embodiment, the liquid crystal in the liquid crystal layer 13 is twisted in the major axis direction (for example, 270 ° STN alignment or 90 ° TN alignment) when no voltage is applied between the electrodes. The twist is eliminated by applying a voltage. By switching between application / non-application of voltage, the alignment state of the liquid crystal changes, and the liquid crystal element 10 exhibits a dimming function. The liquid crystal element 10 has, for example, a film shape or a plate shape. The liquid crystal element 10 may change the light transmittance according to the applied voltage. Note that the alignment state of the liquid crystal when no voltage is applied is not limited to the twisted alignment but may be a homogeneous alignment.

<Liquid crystal composition>
Next, a liquid crystal composition used for forming the liquid crystal layer 13 will be described. The liquid crystal composition includes a liquid crystal and a polymerizable compound.

Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal, and among them, nematic liquid crystal is preferable. Further, a cholesteric liquid crystal, a chiral agent, a ferroelectric liquid crystal, or the like may be added to these liquid crystals.

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 more preferable to include a kind of compound (hereinafter also referred to as “specific polymerizable compound”), and it is particularly preferable to be a polyfunctional (meth) acrylate compound. In the present specification, “(meth) acrylate” means containing acrylate and methacrylate.

As the polymerizable compound, a polymerizable compound exhibiting optical anisotropy (hereinafter also referred to as “polymerizable liquid crystal compound”) is preferably used. Examples of the polymerizable liquid crystal compound include ULC-001, ULC-001-K1, ULC-008, ULC-011 (manufactured by DIC Corporation), RM257, RM8 (manufactured by Merck), and the like. It is done. As a combination of a liquid crystal material and a polymerizable liquid crystal compound, MLC6080 (manufactured by Merck & Co., Inc.), a liquid crystal material, has almost the same refractive index as ULC-001-K1, which is a polymerizable liquid crystal compound, and has high light transmission when no voltage is applied This is preferable because it indicates the state.

The content of the polymerizable compound (the total amount when two or more are included) is preferably 1 to 95% by mass with respect to the total amount of the liquid crystal and the polymerizable compound in the liquid crystal composition. More preferably, the content is set to ˜90 mass%, and more preferably 10 to 90 mass%.
The content ratio of the polymerizable liquid crystal compound in the liquid crystal composition is preferably 1 to 95% by mass, more preferably 3 to 90% by mass with respect to the total amount of the polymerizable liquid crystal compound and the liquid crystal. More preferably, the content is 5 to 90% by mass.

The liquid crystal composition may contain other components other than the liquid crystal and the polymerizable compound. For example, 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. It is preferable to do.

The polymerization initiator contained in the liquid crystal composition is a compound (photopolymerization initiator) capable of initiating polymerization of a polymerizable compound upon irradiation with radiation such as visible light, ultraviolet light, far ultraviolet light, electron beam, and X-ray. Is preferred. The photopolymerization initiator is preferably a radical polymerization initiator capable of generating radicals by light irradiation. Specifically, for example, 4,4′-bis (diethylamino) benzophenone, 2-methoxy-2-phenylacetophenone 2-acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 1- (4-isopropylphenyl) -2-hydroxy- 2-methylpropan-1-one, 2-hydroxy-1- [4- [4- (2-hydroxy-2-methylpropionyl) benzyl] phenyl] -2-methylpropan-1-one, 2-benzyl-2 -Dimethylamino-1- (4-morpholino Benzyl) -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, 2-hydroxy- And 2-phenylacetophenone, 2-benzyl-2- (dimethylamino) -1- [4- (morpholino) phenyl] -1-butanone, and the like.

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 preferably 0.1 to 10% by mass, more preferably 0.5 to 8% by mass, and still more preferably 1 to 7% by mass with respect to the total mass of (solid content). 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. More preferably, the content is 1 to 3% by mass.

The 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 at least one compound selected from the group consisting of a silane compound and polysiloxane (hereinafter also referred to as “silicon-containing compound”). Among these, it is particularly preferable to contain polysiloxane in that the effect of improving the weather resistance of the liquid crystal element 10 is higher and the post-baking temperature can be further lowered. Moreover, it is preferable to contain 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 hydrolyzable silane compound include tetraalkoxysilane compounds such as tetramethoxysilane and tetraethoxysilane; alkyl groups or aryl groups such as methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and dimethyldiethoxysilane. Containing alkoxysilane compounds;
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 -(2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-methylcarbonyloxyethyl-N'-trimethoxysilylpropylethylenediamine, N- Nitrogen-containing alkoxysilane compounds such as ethoxycarbonyl-3-aminopropyltrimethoxysilane;
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) acrylo” means “acrylo” and “methacrylo”.

The above hydrolysis / condensation reaction is carried out by reacting one or more of the above hydrolyzable silane compounds with water, preferably in the presence of an appropriate 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 catalyst used varies depending on the type of catalyst, reaction conditions such as 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 organic solvent is used in an amount of preferably 10 to 10,000 parts by mass with respect to 100 parts by mass in total of the silane compounds used in the reaction.

The above hydrolysis / condensation reaction is preferably carried out by heating with, for example, an oil bath. At that time, the heating temperature is preferably 130 ° C. or less, and the heating time is preferably 0.5 to 12 hours. After completion of the reaction, the organic solvent layer separated from the reaction solution is dried with a desiccant as necessary, and then the solvent is removed to obtain the 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.

As the polysiloxane, the liquid crystal aligning agent may contain a polysiloxane having a functional group such as a photo-alignment group or a pretilt angle imparting group in the 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 performed in the presence of a catalyst and an organic solvent. The proportion of the carboxylic acid used 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. The organic solvent is preferably used in such a ratio 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.

For the 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. Further, it is preferably 1,000 to 50,000. 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 has an alkoxysilyl group (—Si (OR) _r R _3-r (R is an alkyl group, and r is an integer of 1 to 3. A plurality of R may be the same 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. In addition, a silane compound may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, you may use together a polysiloxane and a silane compound as a silicon-containing compound.

The silicon-containing compound in the liquid crystal aligning agent can be appropriately selected according to the compound to be used. For example, when polysiloxane is contained as the silicon-containing compound, the content of the polysiloxane in the liquid crystal aligning agent is such that the polymer component in the liquid crystal aligning agent has a sufficiently high weather resistance from the viewpoint of sufficiently increasing the weather resistance of the liquid crystal element 10 to be obtained. It is preferable to set it as 1 mass% or more with respect to a total amount, It is more preferable to set it as 2 mass% or more, It is further more preferable to set it as 5 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.
Further, when a silane compound is blended in the liquid crystal aligning agent as a silicon-containing compound, the blending ratio is the weight in the liquid crystal aligning agent 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. The total amount is preferably 0.5 parts by mass or more, more preferably 1 to 30 parts by mass with respect to 100 parts by mass of the combined components.

The liquid crystal aligning agent of the present embodiment includes at least one side chain structure (hereinafter referred to as “specific group”) selected from the group consisting of the following (a) to (e) in the polymer component contained in the liquid crystal aligning agent. The content ratio of the structural unit derived from the monomer having) is 10 mol% or less with respect to the total amount of all the structural units of the polymer component.
(A) an alkyl group or alkoxy group having 8 to 22 carbon atoms;
(B) a C6-C18 fluoroalkyl group or fluoroalkoxy group.
(C) A monovalent group in which any one of a benzene ring, a cyclohexane ring and a heterocyclic ring is bonded to an alkyl group, alkoxy group, fluoroalkyl group or fluoroalkoxy group having 1 to 20 carbon atoms.
(D) It has a total of two or more of at least one ring selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, and these plural rings are bonded directly or via a divalent linking group. Monovalent group.
(E) a monovalent group having 17 to 51 carbon atoms and having a steroid skeleton.

Here, in the present specification, the “side chain structure” in the “monomer having a side chain structure” means that the main skeleton is the portion introduced into the main chain of the polymer in the structural formula of the monomer. In some cases, it means a partial structure bonded to the main skeleton directly or via a linking group. That is, the “side chain structure” possessed by the monomer is introduced into the side chain of the polymer obtained by the polymerization when the monomer is used for polymerization. The “main chain” of the polymer refers to a “trunk” portion composed of the longest chain of atoms in the polymer. It is permissible for this “trunk” part to contain a ring structure. The “side chain” of the polymer refers to a portion branched from the “trunk” of the polymer. Therefore, for example, in the case of a diamine used for the synthesis of polyamic acid or polyimide, a skeleton containing two primary amino groups is a main skeleton, and a partial structure bonded to the main skeleton directly or via a linking group is “side”. Corresponds to “chain structure”. In the side chain structure having a cyano group, the liquid crystal molecules are horizontally aligned by this side chain structure. When the liquid crystal molecules in the liquid crystal layer 13 are vertically aligned, the specific group preferably has no cyano group.

“The content of the structural unit derived from the monomer having a specific group is 10 mol% or less with respect to the total amount of all the structural units of the polymer component” means that the liquid crystal alignment agent is a polymer of two or more types. Is included, it means the total number of mole parts obtained by multiplying the number of moles of the structural unit derived from the monomer having a specific group and the mass mixing ratio of the polymer. Therefore, for example, when the liquid crystal aligning agent contains two types of polymers, polymer 1 and polymer 2, at a mass ratio of 60:40, the number of structural units derived from the monomer having a specific group in polymer 1 Is 0 mol% and the number of structural units derived from the monomer having the specific group in the polymer 2 is 20 mol%, the “structure derived from the monomer having the specific group” of this liquid crystal aligning agent The “unit content ratio” is 60 parts by mass × 0 mol% + 40 parts by mass × 20 mol% = 8 mol%. Therefore, in this case, the requirement “the content ratio of the structural unit derived from the monomer having the specific group is 10 mol% or less with respect to the total amount of all the structural units of the polymer component” is satisfied. This requirement is also satisfied when the polymer component does not have a specific group.

On the other hand, when the blending ratio of the polymer 1 and the polymer 2 is a mass ratio of 20:80 with respect to the polymer component composed of the polymer 1 and the polymer 2, the “single group having a specific group” of the liquid crystal aligning agent The “content ratio of the structural unit derived from the monomer” is 20 parts by mass × 0 mol% + 80 parts by mass × 20 mol% = 16 mol%. Therefore, in this case, the requirement “the content ratio of the structural unit derived from the monomer having the specific group is 10 mol% or less with respect to the total amount of all the structural units of the polymer component” is not satisfied.

Specific examples of the specific group include (a) alkyl group and alkoxy group such as n-octyl group, n-nonyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group. A linear alkyl group such as n-heptadecyl group and n-octadecyl group and a linear alkoxy group in which these linear alkyl group and an oxygen atom are bonded; the fluoroalkyl group and the fluoroalkoxy group in (b) For example, a linear fluoroalkyl group and a fluoroalkoxy group in which at least one hydrogen atom of the alkyl group and alkoxy group in the above (a) is substituted with a fluorine atom; a group in (c) and a group in (d) For example, the group represented by the following formula (5); and the group (e) include, for example, a cholestanyl group, a cholesteryl group, a lanostannyl group, and the like. Door can be.

(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 fluoroalkyl group having 1 to 20 carbon atoms, a fluoroalkoxy group having 1 to 20 carbon atoms, a cyano group-containing alkyl group having 1 to 20 carbon atoms, a carbon number A cyano group-containing alkoxy group having 1 to 20 carbon atoms, a fluorine atom or a cyano group, wherein R ²² and R ²³ are each independently a single bond, —O—, —COO—, —OCO— or a group having 1 to 3 carbon atoms. K, m, and n are integers of 0 or more that satisfy 1 ≦ k + m + n ≦ 4, R ²¹ represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a cyano group having 1 to 20 carbon atoms. Contains alkyl group, 1-20 carbon atoms (In the case of a cyano group-containing alkoxy group, a fluorine atom or a cyano group, k + m + n ≧ 2 is satisfied. “*” Indicates a bond.)

Specific examples of the group represented by the above formula (5) include, but are not limited to, a group represented by the following formula. 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 2 to 4. R ²¹ is preferably 3 or more carbon atoms, more preferably 4 or more, more preferably 7 or more.

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

In the polymer component contained in the liquid crystal aligning agent, the content ratio of the structural unit derived from the monomer having a specific group is selected from the viewpoint of obtaining a liquid crystal element having higher weather resistance and high temperature and high humidity resistance. It is preferably 8 mol% or less, more preferably 5 mol or less, and even more preferably 2 mol or less, based on the total amount of all structural units. In the present specification, when at least a part of the partial structures (a) to (e) constitutes a part of the photoalignable group shown below, or the above (a) to (e) In the case where the partial structure is bonded to the photoalignable group, the above (a) to (e) also correspond to the specific group.

(Polymer component)
The polymer component contained in the liquid crystal aligning agent may be only the above-described polysiloxane, but may be a polymer different from polysiloxane (hereinafter also referred to as “other polymer”), It may be a mixture with other polymers. When only the silane compound is contained as the silicon-containing compound, the liquid crystal aligning agent contains the other polymer shown below as the polymer component.

The main skeleton of the other polymer is not particularly limited. For example, polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly (meth) acrylate, etc. The main skeleton is mentioned. Among these, it is at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and poly (meth) acrylate from the viewpoint of heat resistance, mechanical strength, affinity with liquid crystal, and the like. preferable. In addition, only 1 type may be sufficient as another polymer, and 2 or more types may be sufficient as it. (Meth) acrylate is meant to include acrylate and methacrylate.

When the liquid crystal aligning agent contains polysiloxane, the blending ratio of the other polymer is preferably 1 to 95% by mass with respect to the total amount of the polymer components in the liquid crystal aligning agent, and 5 to 95% by mass. %, More preferably 10 to 90% by mass. In addition, another polymer can be used individually by 1 type or in combination of 2 or more types.

(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, or 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 represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a fluoroalkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom. A fluoroalkoxy 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 R May be the same or different. “*” Represents a bond.)

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

The photo-alignment group may be contained in polysiloxane, but may be contained in a polymer different from polysiloxane. From the viewpoint of ensuring the reliability and weather resistance of the liquid crystal element 10, a polysiloxane having a photoalignable group can be preferably used as the polymer having a photoalignable group.

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 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 is 5 to 99% by mass. More preferably.

(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. The number of crosslinkable groups possessed by the crosslinking agent may be one or more. 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. The amount is more preferably 1 to 40 parts by mass, still more preferably 5 to 30 parts by mass. 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. The inclusion of such an antioxidant in the alignment film is preferable in that the transparency of the liquid crystal element when no voltage is applied can be improved. This effect is presumed to be due to the presence of the antioxidant suppressing the polymerization reaction of the polymerizable compound in the liquid crystal composition existing in the vicinity of the alignment film surface and suppressing the decrease in the alignment of the liquid crystal. Is done.
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 (above, manufactured by ADEKA), CHIMASSORB119, CHIMASSORB2020, CHIMASSORB944, TINUVIN622, TINUVIN123, TINUVIN144, TINUVIN765, TINUVIN770, TINUVIN111, TINUVIN79, TINUV3111, TINUV3 Etc .;
As a compound having a phenol structure, for example, 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 of the antioxidant in the liquid crystal aligning agent is preferably 0.01 to 15 parts by mass, more preferably 0.01 to 15 parts by mass with respect to 100 parts by mass of the polymer component used for preparing the liquid crystal aligning agent. The amount is 10 parts by mass, and particularly preferably 0.1 to 10 parts by mass.

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 components used as necessary are dissolved in a suitable 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, 150 ° C. or lower). The compound having a boiling point at atmospheric pressure of 150 ° C. or less is preferably 40% by mass or more, more preferably 50% by mass or more, and still more 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 in the range of 1 to 10% by mass. When the solid content concentration is less than 1% by mass, the film thickness of the coating film becomes too small, and it becomes difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by mass, it is difficult to obtain a good liquid crystal alignment film because the film thickness is excessive, and the viscosity of the liquid crystal aligning agent increases and the applicability decreases. There is a tendency.

<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 And can be manufactured by a method including:

(Process A)
Application of the liquid crystal aligning agent is, for example, a known method such as an offset printing method, a spin coating method, a roll coater method, an ink jet printing method, or a bar coater method on each electrode arrangement surface of the first substrate 11 and the second substrate 12. The coating method is used. 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. The lower limit of the pre-bake temperature is preferably 30 ° C or higher, and more preferably 40 ° C or higher. The prebake time is preferably 0.25 to 10 minutes.

Thereafter, it is preferable to carry out a baking (post-bake) step for the purpose of completely removing the solvent and, if necessary, promoting the crosslinking reaction. 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. The post-bake time is preferably 5 to 200 minutes, more preferably 10 to 120 minutes.

The coating film formed using the liquid crystal aligning agent is subjected to a treatment for imparting liquid crystal alignment ability (alignment treatment). Examples of the alignment treatment include a rubbing treatment in which a coating film is rubbed in a fixed direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton, and a photo-alignment treatment in which the coating film is irradiated with polarized or non-polarized radiation. Is mentioned.

(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 for the curing reaction is appropriately selected depending on the type of the polymerizable compound and the liquid crystal to be used. For example, the heating temperature is 40 to 80 ° C. The heating time is preferably 0.5 to 5 minutes. In the case of curing by light irradiation, non-polarized ultraviolet rays having a wavelength in the range of 200 to 500 nm can be preferably used as the irradiation light. The amount of light irradiation is preferably 50 to 10,000 mJ / cm ² , more preferably 100 to 5,000 mJ / 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 shown in FIG. 3, when the liquid crystal element 10 and the transparent display 30 are not applied with voltage, the entire surface of the display device 20 is transparent. 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 a voltage, characters, images, and the like displayed on the transparent display 30 are displayed in a state of being raised on the glass. .

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, 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 the display device 20 of FIG. 3, the light control element 10 may be arranged only in a partial region of the transparent display 30. 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.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is 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, the imidation ratio of the polyimide, 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 or N, N-dimethylformamide solution containing lithium bromide and phosphoric acid 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.
[Imidation rate of polyimide]
The polyimide solution was poured into pure water, and the resulting precipitate was sufficiently dried at room temperature under reduced pressure, then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. From the obtained ¹ H-NMR spectrum, the imidation ratio [%] was determined by the following formula (1).
Imidation ratio [%] = (1- (A ¹ / (A ² × α))) × 100 (1)
(In Formula (1), A ¹ is a peak area derived from protons of NH groups appearing near a chemical shift of 10 ppm, A ² is a peak area derived from other protons, and α is a precursor of a polymer ( It is the number ratio of other protons to one NH group proton in the polyamic acid).
[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)” may be simply referred to as “compound (X)”.

(carboxylic acid)

(Additive)

(Antioxidant)

(Dichroic dye)

<Synthesis of polyimide>
[Synthesis Example 1]
16.5 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride (98 mol parts with respect to 100 mol parts of the total amount of diamine used in the synthesis), and paraphenylenediamine as diamine compound 8.0 g (99.5 mol parts) and 0.2 g (0.5 mol parts) cholestenyloxy-2,4-diaminobenzene were dissolved in 225 g of N-methyl-2-pyrrolidone (NMP). Reaction was performed at 60 degreeC for 1 hour. Thereafter, 250 g of NMP, 29.11 g of pyridine, and 22.54 g of acetic anhydride were added, and a dehydration ring-closing reaction was performed at 110 ° C. for 5 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 43 g of polyimide (hereinafter referred to as polymer (PI-1)) having an imidation ratio of about 90%. The obtained polymer (PI-1) was prepared to be 10% by mass with NMP, and the viscosity of this solution was measured to be 410 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. For polymer (PI-1), the content ratio β of structural units derived from the monomer having a specific group to all the structural units of the polymer (in the case of polyimide and polyamic acid, the monomer used for polymerization) The use amount Q2) of the monomer having a specific group with respect to the total amount Q1 is 0.25 mol%.
Content ratio β [mol%] = (Q2 / Q1) × 100

[Synthesis Example 2]
2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride 3.19 g (12.8 mmol) as tetracarboxylic dianhydride, and 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) Was dissolved in 24.9 g of NMP and reacted at 80 ° C. for 5 hours. 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 dried at 100 ° C. under reduced pressure to obtain polyimide (hereinafter referred to as polymer (PI-2)). The imidation ratio of the obtained polyimide was 55%, and the weight average molecular weight was 48,000. In the polymer (PI-2), the content ratio β is 22.6 mol%.

[Synthesis Example 3]
Dissolve 32.39 g of pyromellitic dianhydride as tetracarboxylic dianhydride (98 mol parts with respect to 100 mol parts of the total amount of diamine used in the synthesis) and 17.60 g of hexamethylenediamine as diamine compounds in 200 g of NMP. And reacted at 60 ° C. for 1 hour. Thereafter, 250 g of NMP, 23.5 g of pyridine and 30.4 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 80 ° C. for 2 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The collected precipitate was washed with methanol and then dried under reduced pressure at 40 ° C. for 15 hours to obtain a polyimide (hereinafter referred to as polymer (PI-3)). In the polymer (PI-3), the content ratio β is 0 mol%.

<Synthesis of polyamic acid>
[Synthesis Example 4-1]
136.7 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride (90 mol parts with respect to 100 mol parts of diamine used for synthesis), 2,2′-dimethyl as diamine 163.3 g of -4,4′-diaminobiphenyl was dissolved in 1700 g of NMP and reacted at 40 ° C. for 3 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The recovered precipitate was washed with methanol and then dried at 40 ° C. under reduced pressure for 15 hours to obtain 290 g of polyamic acid (hereinafter referred to as polymer (PAA-1)). The obtained polymer (PAA-1) was prepared to be 10% by mass with NMP, and the viscosity of this solution was measured to be 80 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. In the polymer (PAA-1), the content ratio β is 0 mol%.

[Synthesis Example 4-2]
26. As a tetracarboxylic dianhydride, 25.0 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (45 mol parts with respect to 100 mol parts of diamine used in the synthesis) and pyromellitic dianhydride 8 g (45 parts by mole with respect to 100 parts by mole of the diamine used in the synthesis), 4- {4- [2- (4′-pentyl-1,1′-bicyclohexyl) ethyl] phenoxy} benzene-1, 2-diamine 27.6 g, 3,5-diaminobenzoic acid 8.2 g, 4- (4 aminophenoxycarbonyl) -1- (4-aminophenyl) piperidine 17.7 g, and bis [2- (4-aminophenyl) ) Ethyl] hexane diacid (43.6 g) was dissolved in NMP (850 g) and reacted at 40 ° C. for 6 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The recovered precipitate was washed with methanol and then dried at 40 ° C. under reduced pressure for 15 hours to obtain 140 g of polyamic acid (hereinafter referred to as polymer (PAA-2)). The obtained polymer (PAA-2) was prepared to be 10% by mass with NMP, and the viscosity of this solution was measured to be 90 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. In the polymer (PAA-2), the content ratio β is 11 mol%.

<Synthesis of epoxy group-containing polyorganosiloxane>
[Synthesis Example 5]
In a reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser, 70.5 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 14.9 g of tetraethoxysilane, 85.4 g of ethanol and triethylamine 8.8 g was charged and mixed at room temperature. Subsequently, 70.5 g of deionized water was dropped from the dropping funnel over 30 minutes, and the mixture was reacted at 80 ° C. for 2 hours while stirring under reflux. The operation of concentrating the reaction solution and diluting with butyl acetate was repeated twice to distill off triethylamine and water to obtain a polymer solution containing polyorganosiloxane (SEp-1) having an epoxy group. ^{As a result of 1} H-NMR analysis, it was confirmed that no side reaction of the epoxy group occurred during the reaction. The polyorganosiloxane (SEp-1) had an Mw of 11,000 and an epoxy equivalent of 200 g / mol.

[Synthesis Example 6]
A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser was charged with 100.0 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 500 g of methyl isobutyl ketone and 10.0 g of triethylamine at room temperature. Mixed with. 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 give a polyorgano having an epoxy group. Siloxane (SEp-2) was obtained as a viscous transparent liquid. This polyorganosiloxane (SEp-2) was analyzed by ¹ H-NMR, and it was confirmed that no side reaction of the epoxy group occurred during the reaction. The weight average molecular weight (Mw) of the polyorganosiloxane (SEp-2) obtained in Synthesis Example 6 was 2,200, and the epoxy equivalent was 186 g / mol.

<Synthesis of polyorganosiloxane having functional group>
[Synthesis Example 7]
In a 100 mL three-necked flask, 11.3 g of polyorganosiloxane (SEp-1) obtained in Synthesis Example 5, 13.3 g of n-butyl acetate, 1.7 g of cinnamic acid derivative represented by the above formula (CA-1) ( Polyorganosiloxane (SEp-1) has 32 mol parts per 100 mol of epoxy groups), acryloyl group-containing carboxylic acid (Aronix M-5300, manufactured by Toagosei Co., Ltd.) 0.54 g (polyorganosiloxane (SEp-1) -1) was added in an amount of 8 mole parts per 100 mole parts of the epoxy group, and 0.9 g of tetrabutylammonium bromide, and the mixture was stirred at 80 ° C for 12 hours. After completion of the reaction, an additional 20 g of n-butyl acetate was added, and this solution was washed with water three times. Then, an additional 20 g of n-butyl acetate was added, and the solvent was distilled off to a solid content concentration of 10% by mass. As a result, an n-butyl acetate solution having a solid content concentration of 10% by mass containing the polymer (S-1) which is a photoalignable polyorganosiloxane was obtained. The weight average molecular weight Mw of the polymer (S-1) was 18,000. In the polymer (S-1), the content ratio β is 32 mol%.
[Synthesis Example 8]
In a 100 mL three-necked flask, 8 g of the polyorganosiloxane (SEp-2) obtained in Synthesis Example 6, 27.5 g of cyclopentanone, and 2.5 g of a cinnamic acid derivative represented by the above formula (CA-2) (polyorganosiloxane) (60 mol parts relative to 100 mol parts of epoxy group of (SEp-2)) and 0.1 g of tetrabutylammonium bromide were added and stirred at 100 ° C. for 12 hours. After completion of the reaction, 30 g of cyclohexanone was added, and this solution was washed with water by liquid separation washing 6 times. Then, 100 g of NMP was further added, and the solvent was distilled off so that the solid content concentration was 10% by mass. As a result, an NMP solution having a solid content concentration of 10% by mass containing the polymer (S-2), which is a photoalignable polyorganosiloxane, was obtained. The weight average molecular weight Mw of the polymer (S-2) was 12,000. In the polymer (S-2), the content ratio β is 60 mol%.

[Synthesis Example 9]
A polymer (S-3), which is a photoalignable polyorganosiloxane, was obtained in the same manner as in Synthesis Example 8 except that the type and amount of the carboxylic acid used in the reaction were changed as shown in Table 1 below. . In addition, the number in a table | surface represents the usage-amount (mol part) of carboxylic acid with respect to 100 mol part of epoxy groups which the used epoxy-group-containing polyorganosiloxane has. In Table 1, “M-5300” represents an acryloyl group-containing carboxylic acid (Aronix M-5300, manufactured by Toagosei Co., Ltd.). In the polymer (S-3), the content ratio β is 50 mol%.

<Synthesis of poly (meth) acrylate>
[Synthesis Example 10]
A flask equipped with a condenser and a stirrer was charged with 1 part by mass of 2,2′-azobis (isobutyronitrile) as a polymerization initiator and 180 parts by mass of diethylene glycol methyl ethyl ether as a solvent. Subsequently, 80 parts by mass of 3,4-epoxycyclohexylmethyl methacrylate and 20 parts by mass of 3-methyl-3-oxetanylmethyl methacrylate were added, and after nitrogen substitution, stirring was started gently. The solution temperature was raised to 80 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing a polymer (PAc-1) which is an epoxy group-containing polymethacrylate. In addition, the monomer consumption rate (reaction conversion) after completion | finish of reaction computed from the measurement result of solid content concentration of a polymer solution was 99%. Further, Mn of the obtained polymer (PAc-1) was 16,000.
[Synthesis Example 11]
100 parts by mass of the epoxy group-containing polymethacrylate (PAc-1) obtained in Synthesis Example 10, 30 parts by mass of acryloyl group-containing carboxylic acid (Aronix M-5300, manufactured by Toagosei Co., Ltd.), tetrabutylammonium bromide 10 as a catalyst 150 parts by mass of propylene glycol monomethyl ether acetate as a part by mass and a solvent were charged and stirred at 90 ° C. for 12 hours in a nitrogen atmosphere. After completion of the reaction, the reaction mixture was diluted with 100 parts by mass of propylene glycol monomethyl ether acetate and washed with water three times. The operation of concentrating this solution and diluting with butyl acetate was repeated twice to obtain a polymer solution containing a polymer (PAc-2) which is an acryloyl group-containing polymethacrylate. Mn of the obtained polymer was 20,000. In the polymer (PAc-2), the content ratio β is 0 mol%.

<Preparation of liquid crystal composition>
1. Preparation of Liquid Crystal Composition I MLC6080 (manufactured by Merck) as a liquid crystal material and ULC-001-K1 (manufactured by DIC Corporation) as a polymerizable liquid crystal compound were mixed at a mass ratio of 85:15 and further photopolymerized. 1% by mass of 1-hydroxycyclohexyl phenyl ketone was added as an initiator, and the mixture was stirred while maintaining at 80 ° C. to obtain a liquid crystal composition I.
2. Preparation of Liquid Crystal Composition II MLC6080 (manufactured by Merck) as a liquid crystal material and ULC-001-K1 (manufactured by DIC Corporation) as a polymerizable liquid crystal compound were mixed at a mass ratio of 85:15. 3% by weight of dichroic dye and 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator so as to be 1% by weight and stirring while maintaining at 80 ° C. did.
(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>
A solution containing the polymer (PI-1) obtained in Synthesis Example 1 as a polymer component was added in an amount corresponding to 100 parts by mass in terms of the polymer (PI-1), and a compound (Add) as an additive. -1) is mixed in an amount of 0.5 parts by mass, and γ-butyl lactone (GBL) and butyl cellosolve (BC) are added to this as a solvent, the solid content concentration is 4.5% by mass, and the mass ratio of each solvent is GBL: A BC = 95: 5 was prepared. Next, the obtained solution was filtered through a filter having a pore size of 0.2 μm to obtain a liquid crystal aligning agent (A-1).

<Production of liquid crystal element>
The liquid crystal aligning agent (A-1) prepared above was applied on the electrode placement surface of a PET film substrate (PET-ITO substrate) having an ITO electrode on the substrate surface using a bar coater, After pre-baking with a hot plate for 1 minute, a coating film (liquid crystal alignment film) having an average film thickness of 0.1 μm was formed by heating (post-baking) for 30 minutes in an oven at 120 ° C. in which the inside of the chamber was purged with nitrogen. . The coating film was rubbed with a rubbing machine having a roll wrapped with a rayon cloth at a roll rotation speed of 1000 rpm, a stage moving speed of 25 cm / sec, and a hair foot indentation length of 0.4 mm. Then, ultrasonic cleaning was performed in ultrapure water for 1 minute, and then drying was performed in a 100 ° C. clean oven for 10 minutes to obtain a substrate having a liquid crystal alignment film. 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 a liquid crystal element.

<Evaluation>
1. 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). It means that transparency is so favorable that haze value is low. As a result, in this example, the haze value was 10%, and the transparency when no voltage was applied was excellent.
2. 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 was performed using a spectroscopic haze meter (manufactured by Tokyo Denshoku Co., Ltd.) in the same manner as in “1. 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.

3. Adhesion strength measurement test A liquid crystal element having a size of 30 × 35 mm was produced in the same manner as described above, and this liquid crystal element was fixed to a push-pull gauge (PSM-50N, manufactured by Imada Co., Ltd.) and a 90 ° peel test was performed. It was. The peel strength (N / 30 mm) was measured at two types of peel speeds (0.2 mm / sec and 5 mm / sec). As a result, a peel speed of 0.2 mm / sec showed a value of 4.8 N / 30 mm, and a peel speed of 5 mm / sec showed a value of 12.5 N / 30 mm.
4). Adhesion Reliability (High Temperature and High Humidity Resistance) Test The liquid crystal device manufactured above is placed in a high temperature and high humidity atmosphere at 85 ° C. and 85% RH for 500 hours, and then the same operation as in “3. Adhesion strength measurement test” above. The contact reliability was evaluated. As a result, a peel speed of 0.2 mm / sec showed a value of 4.3 N / 30 mm, and a peel speed of 5 mm / sec showed a value of 12.3 N / 30 mm. Therefore, in this example, the peel strength did not change much before and after exposure to high temperature and high humidity conditions, and the adhesion reliability was good.

5). Evaluation of weather resistance The liquid crystal element produced above was irradiated with xenon lamp light (illuminance 250 W / m ² (300-800 nm)) for 200 hours using a light resistance tester (SUNTEST CPS +: manufactured by Toyo Seiki Co., Ltd.). About the liquid crystal element after light irradiation, the haze value in a voltage application state was measured by the method similar to said "2. Evaluation of light scattering property", 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 92% even after the light irradiation, and the light scattering property did not change before and after the light irradiation.

[Examples 2 to 6 and Comparative Examples 1 to 3]
The liquid crystal aligning agents (A-2) to (A-9) were prepared in the same manner as in the preparation of the liquid crystal aligning agent (A-1) except that the components of the types and blending amounts shown in Table 2 were used. Prepared. In addition, 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-9). The results are shown in Table 3.

[Example 7]
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 7, 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. For the measurement, the light transmittance was evaluated by the 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 85%, 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 = 85%, the transmittance when a voltage was applied = 6%, 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 1%. From this result, it can be said that the liquid crystal element of this example is excellent in repeated driving durability.

The numerical values of the blending amounts of the polymer and additive in Table 2 indicate the blending 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. The numerical value of the compounding amount of the solvent indicates the compounding ratio (parts by mass) of each compound with respect to 100 parts by mass of the total amount of the solvent used for preparing the liquid crystal aligning agent. In Table 2, the abbreviations of the solvents are as follows.
PGME: Propylene glycol monomethyl ether PGMEA: Propylene glycol monomethyl ether acetate NMP: N-methyl-2-pyrrolidone BC; Butyl cellosolve GBL; γ-butyrolactone BA; n-butyl acetate MEK;

In addition, since the polymer contained in the liquid crystal aligning agent of Example 2 and 3 has a photo-alignment group, the result similar to the said Example 2 and 3 is obtained by performing a photo-alignment process by a well-known method. Each can be obtained.

As can be seen from Table 3, in Examples 1 to 7, light transmission characteristics and light scattering characteristics were good. Further, even when exposed to a high temperature and high humidity environment, the peel strength was high and the adhesion to the substrate was excellent. Moreover, the change in haze value before and after application of light stress was small, and the weather resistance was excellent.
Further, Example 6 containing an antioxidant in the liquid crystal alignment film has a lower haze value when no voltage is applied and better transparency than Example 3 which does not contain an antioxidant in the liquid crystal alignment film. Met.
In Example 7 in which a dye (dichroic dye) was dispersed in the liquid crystal layer, the adhesion and the weather resistance of the liquid crystal element were good. Furthermore, even after the voltage application / non-application of the liquid crystal element was repeated, both the light shielding properties and the light transmission properties 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, in Comparative Example 2 using a liquid crystal aligning agent that does not have a structural unit derived from a monomer having a specific group and does not contain a silicon-containing compound in the polymer component, The weather resistance was inferior to that of the examples. Further, in Comparative Examples 1 and 3 in which the proportion of the structural unit derived from the monomer having a specific group is larger than 10 mol%, the adhesion to the base material was further lowered as compared with Comparative Example 2. Moreover, the comparative examples 1 and 3 were also inferior in weather resistance compared with the Example.

<Display test when combined with a transparent display>
[Example 8]
When a display device in which the liquid crystal element manufactured in Example 3 was superposed on one outer surface of the transparent display was produced and the transparent display was displayed, the liquid crystal element had good transparency and the display of the transparent display The visibility of was judged as “good”.

[Comparative Example 4]
A display test was conducted in the same manner as in Example 8 except that a polarizing plate type liquid crystal element was used instead of the liquid crystal element in Example 8. 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 sealing agent is disposed around 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 4, 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 is considered to be due to the good light transmittance of the PDLC element having a specific group content of 10 mol% or less. 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 of the present invention is particularly excellent as a display element 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

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 substrates,
The polymerizable compound includes 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 styrenic compound,
The liquid crystal alignment film is formed using a liquid crystal alignment agent containing a polymer component,
The liquid crystal aligning agent has a content ratio of structural units derived from a monomer having at least one structure selected from the group consisting of the following (a) to (e) in the polymer component: A liquid crystal device, which is 10 mol% or less based on the total amount of all structural units, and contains at least one compound selected from the group consisting of silane compounds and polysiloxanes.
(A) an alkyl group or alkoxy group having 8 to 22 carbon atoms;
(B) a C6-C18 fluoroalkyl group or fluoroalkoxy group.
(C) A monovalent group in which any one of a benzene ring, a cyclohexane ring and a heterocyclic ring is bonded to an alkyl group, alkoxy group, fluoroalkyl group or fluoroalkoxy group having 1 to 20 carbon atoms.
(D) It has a total of two or more of at least one ring selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, and these plural rings are bonded directly or via a divalent linking group. Monovalent group.
(E) a monovalent group having 17 to 51 carbon atoms and having a steroid skeleton.
The liquid crystal element according to claim 1, wherein the liquid crystal aligning agent contains a compound having a crosslinkable group.
The liquid crystal element according to claim 1, wherein the liquid crystal aligning agent contains a polymer having a photo-alignable group.
The liquid crystal device according to any one of claims 1 to 3, wherein the polymerizable compound is a compound exhibiting optical anisotropy.
The liquid crystal element according to any one of claims 1 to 4, wherein the liquid crystal composition further contains a pigment.
The liquid crystal element according to claim 5, 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 any one of claims 1 to 6, wherein the liquid crystal composition further contains an antioxidant.
A display device comprising the liquid crystal element according to any one of claims 1 to 7 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 substrates arranged so that electrodes provided on each substrate surface face each other A liquid crystal aligning agent for forming a film,
In the polymer component, the content of the structural unit derived from the monomer having at least one structure selected from the group consisting of the following (a) to (e) is the total amount of all the structural units of the polymer component. The liquid crystal aligning agent which is 10 mol% or less and contains the at least 1 type compound chosen from the group which consists of a silane compound and polysiloxane.
(A) an alkyl group or alkoxy group having 8 to 22 carbon atoms;
(B) a C6-C18 fluoroalkyl group or fluoroalkoxy group.
(C) A monovalent group in which any one of a benzene ring, a cyclohexane ring and a heterocyclic ring is bonded to an alkyl group, alkoxy group, fluoroalkyl group or fluoroalkoxy group having 1 to 20 carbon atoms.
(D) It has a total of two or more of at least one ring selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, and these plural rings are bonded directly or via a divalent linking group. Monovalent group.
(E) a monovalent group having 17 to 51 carbon atoms and having a steroid skeleton.
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 substrates arranged so that electrodes provided on each substrate 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 polymerizable compound includes 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 styrenic compound,
The liquid crystal aligning agent is such that, in the polymer component, the content ratio of structural units derived from a monomer having at least one structure selected from the group consisting of the following (a) to (e) is The manufacturing method of a liquid crystal element which is 10 mol% or less with respect to the total amount of a structural unit, and contains the at least 1 type of compound chosen from the group which consists of a silane compound and polysiloxane.
(A) an alkyl group or alkoxy group having 8 to 22 carbon atoms;
(B) a C6-C18 fluoroalkyl group or fluoroalkoxy group.
(C) A monovalent group in which any one of a benzene ring, a cyclohexane ring and a heterocyclic ring is bonded to an alkyl group, alkoxy group, fluoroalkyl group or fluoroalkoxy group having 1 to 20 carbon atoms.
(D) It has a total of two or more of at least one ring selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, and these plural rings are bonded directly or via a divalent linking group. Monovalent group.
(E) a monovalent group having 17 to 51 carbon atoms and having a steroid skeleton.
The method for producing a liquid crystal element according to claim 10, wherein the liquid crystal aligning agent applied on the electrode arrangement surface is heated at 150 ° C. or lower.