TWI745537B - Liquid crystal element, its manufacturing method, and display device - Google Patents

Abstract

The liquid crystal element includes: a pair of substrates arranged in opposite directions; electrodes arranged on the faces of the pair of substrates facing each other; a liquid crystal layer arranged between the pair of substrates and is made of The liquid crystal composition is cured and formed; and the liquid crystal alignment film is formed on the electrode arrangement surface. 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 alignment agent containing a polymer component. Regarding the liquid crystal alignment agent, the content ratio of the structural unit derived from the monomer having a specific side chain structure is 10 mol% or less relative to the total amount of all the structural units of the polymer component, and it is selected from the group consisting of silane compounds and polysilicon At least one compound in the group consisting of oxanes.

Description

Liquid crystal element, its manufacturing method, and display device [Cross-reference of related applications]

This application is based on the Japanese application number 2017-19833 filed on February 6, 2017, and its contents are cited in this application.

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 has been known in recent years. The polymer-dispersed liquid crystal element is provided with a composite material containing a liquid crystal and a polymer between a pair of film substrates on which a transparent electrode is formed. A liquid crystal layer, and it has been proposed to use the polymer dispersed liquid crystal element as a dimming element (for example, refer to Patent Document 1 or Patent Document 2). The dimming elements of Patent Document 1 and Patent Document 2 exhibit a dimming function by changing the transparency of the transparent electrode by switching between voltage application and no voltage application. In addition, studies have been conducted to use the dimming function to provide new functions to shop windows, smart phones, televisions, monitors, buildings, furniture, and the like. As a polymer dispersed liquid crystal, for example, a polymer dispersed liquid crystal (Polymer Dispersed Liquid Cristal, PDLC) or a polymer network liquid crystal (Polymer Network Liquid Cristal, PNLC), etc. are known.

Patent Document 3 proposes a method containing organic electroluminescence A display device in which a liquid crystal display panel is arranged on the back of a transparent display (electroluminescence, EL) element. It is proposed that in the display device, the light transmittance is controlled by controlling the voltage applied to the liquid crystal display panel, thereby improving the visibility of the display of the transparent display. In addition, Patent Document 4 discloses an inverted type liquid crystal element in which light passes through without applying a voltage between a pair of electrodes and becomes a transparent state, and when a voltage is applied, light is scattered and becomes a non-transparent state. . The inverted 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 the polyimide film.

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2013-3319

[Patent Document 2] Japanese Patent Laid-Open No. 2013-148744

[Patent Document 3] Japanese Patent Laid-Open No. 2008-083510

[Patent Document 4] International Publication No. 2015/022980

It is envisaged that the dimming element is used for outdoor use, so it is required to be excellent in weather resistance. In addition, the dimming element is supposed to be used in various environments with the expansion of its use, and therefore it is required to be excellent in high temperature and high humidity resistance. However, the weather resistance of the conventional reverse-type liquid crystal element having the alignment film for vertically aligning the liquid crystal is not sufficient. In addition, if exposed to a high temperature and high humidity environment, the alignment film is easily peeled from the substrate, and the resistance is high. The temperature and humidity are not sufficient. Therefore, it is required to develop a liquid crystal element with good light transmission characteristics and light scattering characteristics, high humidity and high temperature resistance, and weather resistance.

The present disclosure is made in view of the above-mentioned problems, and its main purpose is to provide a liquid crystal element having high high temperature and high humidity resistance, excellent adhesion to a substrate, excellent weather resistance, and excellent light transmission characteristics and light scattering characteristics.

The present disclosure adopts the following means in order to solve the above-mentioned problems.

[1] A liquid crystal element, comprising: a pair of substrates arranged oppositely; electrodes, respectively arranged on the surfaces of the pair of substrates facing each other; a liquid crystal layer arranged between the pair of substrates , And formed by curing a liquid crystal composition containing a liquid crystal and a polymerizable compound; and a liquid crystal alignment film formed on the electrode arrangement surface of at least one of the pair of base materials; the polymerizable compound contains selected from At least one of a monofunctional (meth)acrylate compound, a multifunctional (meth)acrylate compound, a multifunctional thiol compound, and a styrenic compound; the liquid crystal alignment film uses a polymer containing Component of the liquid crystal alignment agent. Regarding the liquid crystal alignment agent, the polymer component is derived from a monomer having at least one structure selected from the group consisting of the following (a) to (e) The content ratio of the structural unit relative to the total amount of all the structural units of the polymer component is 10 mol% or less, and it contains at least one compound selected from the group consisting of silane compounds and polysiloxanes, (a ) Alkyl or alkoxy with 8-22 carbons, (b) fluoroalkyl or fluoroalkoxy with 6-18 carbons, (c) A monovalent group formed by bonding any one of a benzene ring, a cyclohexane ring, and a heterocyclic ring to an alkyl group, alkoxy group, fluoroalkyl group, or fluoroalkoxy group having 1 to 20 carbon atoms, (d) A total of two or more at least one ring selected from the group consisting of a benzene ring, a cyclohexane ring, and a heterocyclic ring, and the plurality of rings are directly or via a divalent linking group. Valence group, (e) a monovalent group with 17 to 51 carbon atoms having a steroid skeleton.

[2] A display device, comprising: the liquid crystal element described in [1]; and a transparent display that is transparent in a non-display state.

[3] A liquid crystal alignment agent for forming a liquid crystal alignment film of a liquid crystal element, the liquid crystal element is provided between a pair of substrates arranged in such a way that electrodes provided on each substrate surface are opposed to each other. A liquid crystal layer formed by curing a liquid crystal composition of a polymerizable compound, and a structure derived from a monomer having at least one structure selected from the group consisting of (a) to (e) in the polymer component The content ratio of the unit is 10 mol% or less with respect to the total amount of all the structural units of the polymer component, and it contains at least one compound selected from the group consisting of silane compounds and polysiloxanes.

[4] A method of manufacturing a liquid crystal element, which is a method of manufacturing a liquid crystal element including a liquid crystal element and A liquid crystal layer formed by curing a liquid crystal composition of a polymerizable compound, and the method for manufacturing the liquid crystal element includes: coating a liquid crystal alignment agent on the electrode arrangement surface of at least one of the pair of base materials to form a liquid crystal alignment Film step; after forming the liquid crystal alignment film, the pair of substrates are passed through the package The step of constructing a liquid crystal cell by arranging the layer containing the liquid crystal composition in such a manner that the electrodes are opposed to each other; and a step of hardening the polymerizable compound after constructing the liquid crystal cell; the polymerizable compound contains an option At least one of the group consisting of a monofunctional (meth)acrylate compound, a multifunctional (meth)acrylate compound, a multifunctional thiol compound, and a styrenic compound. Regarding the liquid crystal alignment agent, the The content ratio of the structural unit derived from the monomer having at least one structure selected from the group consisting of (a) to (e) in the material component relative to the total of all the structural units of the polymer component The amount is 10 mol% or less, and contains 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 humidity, excellent adhesion to the substrate, and excellent weather resistance can be obtained. In addition, a liquid crystal element excellent in light transmission characteristics and light scattering characteristics can be obtained.

10: Liquid crystal element

11: The first substrate

12: The second substrate

13: liquid crystal layer

14, 15: Liquid crystal alignment film

16, 17: transparent electrode

20: display device

30: Transparent display

Fig. 1 is a diagram showing a schematic configuration of a liquid crystal element.

Fig. 2(a) is a diagram showing a liquid crystal element in a state where no voltage is applied between transparent electrodes.

Fig. 2(b) is a diagram showing a liquid crystal element in a state where a voltage is applied between transparent electrodes.

Fig. 3 is a diagram showing a schematic configuration of a display device including a liquid crystal element and a transparent display.

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

<Liquid crystal element>

The liquid crystal element 10 of this embodiment, as shown in FIG. 1, includes a pair of substrates including a first substrate 11 and a second substrate 12, and a liquid crystal layer disposed between the first substrate 11 and the second substrate 12 13. The liquid crystal layer 13 is a polymer-dispersed liquid crystal layer that is a polymer/liquid crystal composite layer having a polymer matrix and liquid crystals. In this embodiment, it is a polymer-dispersed liquid crystal (PDLC ). The liquid crystal element 10 is a dimming element that switches between the transmission state of transmitted light and the non-transmission state of scattering light by using an electric field to control the alignment of liquid crystal molecules present in the polymer network.

The first substrate 11 and the second substrate 12 are transparent substrates containing a polymer material. Examples of polymer materials constituting the base material include: silicon, polyethylene terephthalate, polybutylene terephthalate, polyether agglomerate, polycarbonate, polypropylene, polyvinyl chloride, aromatics Polyamide, polyamide imide, polyimide, triacetyl cellulose (Triacetyl Cellulose, TAC), polymethyl methacrylate and other materials. Furthermore, the first base material 11 and the second base material 12 may also be glass substrates, and in order to realize the thinning and weight reduction of the liquid crystal element, plastic substrates are particularly preferred.

In the first base material 11 and the second base material 12, a transparent electrode 16 and a transparent electrode 17 are respectively arranged on surfaces facing each other, and an electrode pair is constructed by the transparent electrode 16 and the transparent electrode 17. In this embodiment, the transparent electrode 16 and the transparent electrode 17 are transparent conductive films, such as _{NESA film containing tin oxide (SnO 2} ) (registered trademark of PPG in the United States), and indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) indium tin oxide (Indium Tin Oxid, ITO) film, or a film containing a carbon material. In addition, the transparent electrode 16 and the transparent electrode 17 may have predetermined patterns, such as a strip|belt shape, a comb tooth shape, etc., for example.

A liquid crystal alignment film 14 and a liquid crystal alignment film 15 are formed on the respective electrode arrangement surfaces of the first substrate 11 and the second substrate 12. The liquid crystal alignment film 14 and the liquid crystal alignment film 15 are organic thin films that define the alignment direction of liquid crystal molecules in the liquid crystal layer 13 and are formed using a polymer composition containing a polymer and a solvent. Furthermore, the liquid crystal alignment film 14 and the liquid crystal alignment film 15 only need to be provided on at least one of a pair of substrates, but from the viewpoint of alignment stability, they are preferably provided on two substrates. The liquid crystal layer 13 is formed by arranging a liquid crystal composition in a space surrounded by a pair of substrates and a sealant (not shown), and then curing the liquid crystal composition. The sealant surrounds the electrode between the pair of substrates. Arrange the outer edge of the surface.

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

Figures 2(a) and 2(b) are diagrams for explaining the function of the liquid crystal element 10. Figure 2(a) shows a state where no voltage is applied between the transparent electrode 16 and the transparent electrode 17, and Figure 2(b) shows A state in which a voltage is applied between the transparent electrode 16 and the transparent electrode 17. The liquid crystal element 10 is an inverted PDLC. In the state where no voltage is applied between the transparent electrode 16 and the transparent electrode 17, the incident light passes through one of the pair of substrates and is transparent to the transparent electrode. 16. Voltage applied between transparent electrodes 17 In the state, as the alignment state of the liquid crystal changes, the incident light is scattered and becomes a non-transparent state. In this embodiment, the liquid crystal in the liquid crystal layer 13 is in a state of being twisted in the long axis direction (for example, 270 degrees Super Twisted Nematic (STN) or 90 degrees) when no voltage is applied between the electrodes. Twisted Nematic (TN)), the twist disappears by applying a voltage between the electrodes. Due to the switching of the application/non-application of the 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 a film shape or a plate shape, for example. The liquid crystal element 10 may have a variable light transmittance in accordance with an applied voltage. Furthermore, the alignment state of the liquid crystal when no voltage is applied is not limited to the twist alignment, and may be a homogeneous alignment.

<Liquid crystal composition>

Next, the liquid crystal composition used in the formation of the liquid crystal layer 13 will be described. The liquid crystal composition contains a liquid crystal and a polymerizable compound.

Examples of the liquid crystal include nematic liquid crystal and discotic liquid crystal, and among them, nematic liquid crystal is preferred. In addition, cholesteric liquid crystals, palm-type reagents, strong electrosensitive liquid crystals, etc. can also be added to these liquid crystals and used.

The polymerizable compound is preferably a compound exhibiting radical polymerizability, and more preferably includes a compound selected from a monofunctional (meth)acrylate compound, a polyfunctional (meth)acrylate compound, a polyfunctional thiol compound, and benzene At least one compound in the group consisting of vinyl compounds (hereinafter also referred to as "specific polymerizable compound") is particularly preferably a polyfunctional (meth)acrylate compound. In addition, in this specification, "(meth)acrylate" means acrylate and methacrylate are included.

As the polymerizable compound, a polymerizable compound exhibiting optical anisotropy (hereinafter, also referred to as a "polymerizable liquid crystal compound") can be preferably used. Examples of polymerizable liquid crystal compounds include ULC-001, ULC-001-K1, ULC-008, ULC-011 (above, manufactured by DIC Co., Ltd.), RM257, and RM8 (above, by Merck) Manufacturing) and so on. Regarding the combination of a liquid crystal material and a polymerizable liquid crystal compound, the refractive index of MLC6080 (manufactured by Merck) as a liquid crystal material and ULC-001-K1 as a polymerizable liquid crystal compound are approximately the same, and it shows when no voltage is applied. The high light transmission state is therefore preferable.

The content ratio of the polymerizable compound (the total amount when two or more are contained) is preferably 1% by mass to 95% by mass relative to the total amount of the liquid crystal and the polymerizable compound in the liquid crystal composition. It is more preferable to set it as 5 mass%-90 mass %, and it is more preferable to set it as 10 mass%-90 mass %.

The content ratio of the polymerizable liquid crystal compound in the liquid crystal composition is preferably 1% by mass to 95% by mass relative to the total amount of the polymerizable liquid crystal compound and the liquid crystal, and more preferably 3% by mass to 90% by mass. It is more preferable to set it as 5 mass%-90 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 improving the polymerizability of the polymerizable compound and promoting the formation of the polymer network in the liquid crystal layer 13 (preferably on the whole of the liquid crystal layer 13), it is preferable to contain a polymerization initiator as Other ingredients.

The polymerization initiator contained in the liquid crystal composition is preferably a compound (photopolymerization initiator) that can start the polymerization of the polymerizable compound by irradiation of visible rays, ultraviolet rays, extreme ultraviolet rays, electron beams, X-rays, etc. . As photopolymerization The initiator is preferably a radical polymerization initiator capable of generating free 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-methylpropane-1-one, 2-hydroxy-1-[ 4-[4-(2-Hydroxy-2-methylpropanyl)benzyl]phenyl]-2-methylpropane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinylphenyl)-butanone-1, 2,4,6-trimethylbenzyl-diphenylphosphine oxide, 1,2-octanedione, 1-(4-(benzene Thio)-, 2-(O-benzyl oxime)], ethyl ketone, 1-[9-ethyl-6-(2-methylbenzyl)-9H-carbazole-3- Yl)-,1-(O-acetyloxime), 4,4'-bis(diethylamino)benzophenone, 2-hydroxy-2-phenylacetophenone, 2-benzyl- 2-(Dimethylamino)-1-[4-(morpholinyl)phenyl]-1-butanone and the like.

From the standpoint of rapidly advancing the curing reaction and suppressing the decrease in curability caused by the addition of an excess amount, the content of the polymerization initiator in the liquid crystal composition is preferably other than the solvent contained in the liquid crystal composition. The total mass of the components (solid content) of is 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 8% by mass, and still more preferably 1% by mass to 7% by mass. In addition, the polymerization initiator may be used singly or in combination of two or more.

As other components blended in the liquid crystal composition, dyes can also be used. By using a 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, when the dye is dispersed in the liquid crystal layer 13, the change in light-shielding property/transmittance caused by the switching between voltage application and non-application is also clear. In addition, when driving repeatedly Durability is also good, which is better in this respect.

As the dye, a dichroic dye can be preferably used. The dichroic dye used is not particularly limited, and known compounds can be suitably used. Examples thereof include polyiodine, azo compounds, anthraquinone compounds, and dioxazine compounds. Among these, in terms of excellent light resistance and high dichroic ratio, at least one selected from the group consisting of azo compounds and anthraquinone compounds is preferred, and azo compounds are particularly preferred. In addition, one kind of coloring matter may be used alone, or two or more kinds may be combined.

The blending ratio of the pigment (the total amount in the case of blending two or more) is preferably 0.05% to 5% by mass relative to the total mass of the solid content in the liquid crystal composition, more preferably 0.1 Mass%~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 of mixing these components may be performed at room temperature, or may be performed while raising the temperature. In addition, each component may be dissolved in an appropriate organic solvent, and then the solvent may be removed by, for example, a distillation operation.

<Liquid crystal alignment agent>

Next, the liquid crystal alignment agent used to form the liquid crystal alignment film 14 and the liquid crystal alignment film 15 will be described. The liquid crystal alignment agent contains at least one compound selected from the group consisting of silane compounds and polysiloxanes (hereinafter, also referred to as "silicon-containing compounds"). Among these, in terms of the improvement effect of the weather resistance of the liquid crystal element 10 and the further lowering of the post-baking temperature, polysiloxane is particularly preferable. In addition, it is preferable to contain a silane compound in terms of further improving the adhesion to the substrate.

(Polysiloxane)

Polysiloxanes can be hydrolyzed, for example, by hydrolyzing silane compounds. Obtained by condensation. Examples of hydrolyzable silane compounds include tetraalkoxysilane compounds such as tetramethoxysilane and tetraethoxysilane; methyltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxy Alkoxysilane compounds containing alkyl or aryl groups such as silane and dimethyldiethoxysilane; sulfur-containing alkoxy groups such as 3-mercaptopropyltriethoxysilane and mercaptomethyltriethoxysilane Silane compounds; glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxy Silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3 , 4-epoxycyclohexyl) ethyl triethoxy silane and other epoxy-containing alkoxy silane compounds; 3-(meth) propylene oxy propyl trimethoxy silane, 3-(methyl) ) Acrylic oxygen propyl methyl dimethoxy silane, 3-(meth) acryl oxy propyl methyl diethoxy silane, vinyl triethoxy silane and other alkoxy containing unsaturated bonds Silane compound; 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxy silane, 2-aminopropyl trimethoxy silane, 2-aminopropyl triethoxy silane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-urea Trimethoxysilane, 3-ureidopropyltriethoxysilane, N-methylcarbonyloxyethyl-N'-trimethoxysilylpropyl ethylenediamine, N-ethoxycarbonyl Nitrogen-containing alkoxysilane compounds such as -3-aminopropyltrimethoxysilane; Trimethoxysilylpropyl succinic anhydride and other acid anhydride group-containing alkoxysilane compounds. The hydrolyzable silane compound may be used singly or in combination of two or more. Furthermore, "(meth)acrylic acid~" means to include "acrylic acid~" and "methacrylic acid~".

The hydrolysis. The condensation reaction is performed by reacting one or two or more of the above-mentioned hydrolyzable silane compounds with water, preferably in the presence of a suitable catalyst and organic solvent. During the reaction, the use ratio of water is preferably 1 mol to 30 mol with respect to 1 mol of the hydrolyzable silane compound (total amount). Examples of the catalyst used include acids, alkali metal compounds, organic bases, titanium compounds, zirconium compounds, and the like. The amount of the catalyst used depends on the type of catalyst, temperature and other reaction conditions, and should be appropriately set. For example, relative to the total amount of the silane compound, it is preferably 0.01 times mol to 3 times mol. Examples of the organic solvent used include hydrocarbons, ketones, esters, ethers, alcohols, etc. Among these, it is preferable to use a water-insoluble or poorly water-soluble organic solvent. The use ratio of the organic solvent is preferably 10 parts by mass to 10,000 parts by mass with respect to 100 parts by mass of the total of the silane compounds used in the reaction.

The hydrolysis. The condensation reaction is preferably carried out by heating in an oil bath or the like, for example. At this time, the heating temperature is preferably 130°C or lower, and the heating time is preferably 0.5 to 12 hours. After the reaction is completed, the organic solvent layer separated from the reaction solution is dried with a desiccant as necessary, and then the solvent is removed, thereby obtaining the target polysiloxane. Furthermore, the synthesis method of polysiloxane is not limited to the hydrolysis. The condensation reaction can also be carried out, for example, by a method of reacting a hydrolyzable silane compound in the presence of oxalic acid and alcohol.

The liquid crystal aligning agent may also contain a polysiloxane having a functional group such as a photo-alignment group or a pretilt angle imparting group in the side chain as the polysiloxane. The functional group-containing polysiloxane can be obtained, for example, by polymerizing at least a part of the raw material with an epoxy group-containing hydrolyzable silane compound to synthesize a side chain having an epoxy group Polysiloxane, in turn, reacts polysiloxane having epoxy group with carboxylic acid having functional group. Alternatively, a method in which a hydrolyzable silane compound having a functional group is used for polymerization in a monomer can also be adopted.

The reaction of epoxy-containing polysiloxane and carboxylic acid is preferably carried out in the presence of a catalyst and an organic solvent. The use ratio of the carboxylic acid is preferably 5 mol% or more, and more preferably 10 mol% to 80 mol% relative to the epoxy groups of the epoxy group-containing polysiloxane. As the catalyst, for example, a compound known as an organic base or a so-called hardening accelerator that promotes the reaction of an epoxy compound can be used. The use ratio of the catalyst is preferably 100 parts by mass or less with respect to 100 parts by mass of epoxy group-containing polysiloxane.

Preferred specific examples of the organic solvent 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 becomes 5 to 50% by mass. The reaction temperature in the reaction is preferably 0°C to 200°C, and the reaction time is preferably 0.1 hour to 50 hours. After the reaction is completed, the organic solvent layer separated from the reaction solution is dried with a desiccant as needed, and then the solvent is removed, thereby obtaining a polysiloxane with functional groups.

Regarding polysiloxane, it is a weight average of polystyrene conversion measured by Gel Permeation Chromatography (GPC) The molecular weight is preferably 500 to 1,000,000, more preferably 1,000 to 100,000, and still more preferably 1,000 to 50,000. Furthermore, polysiloxanes may be used singly or in combination of two or more.

(Silane compound)

The silane compound contained in the liquid crystal alignment agent is an organosilicon compound having a carbon-silicon bond, and specific examples thereof include hydrolyzable silane compounds exemplified as silane compounds used in the synthesis of polysiloxanes. The silane compound preferably 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 Rs may be the same or different from each other)), It is more preferably an alkoxysilane compound having at least one functional group selected from the group consisting of an epoxy group, an amine group, and a thiol group, and particularly preferably an epoxy group-containing alkoxysilane compound. Furthermore, a silane compound may be used individually by 1 type, and may be used in combination of 2 or more types. In addition, as a silicon-containing compound, polysiloxane and a silane compound may be used in combination.

The silicon-containing compound in the liquid crystal alignment agent can be appropriately selected according to the compound used. For example, in the case of containing polysiloxane as the silicon-containing compound, from the viewpoint of sufficiently improving the weather resistance of the obtained liquid crystal element 10, the content of polysiloxane in the liquid crystal alignment agent is preferably relative to the liquid crystal The total amount of the polymer components in the aligning agent is 1% by mass or more, more preferably 2% by mass or more, and still more preferably 5% by mass or more. In addition, the upper limit of the content of polysiloxane is preferably set to 97% by mass or less, and more preferably set to 90% by mass or less.

In addition, when the silane compound is formulated as the silicon-containing compound in the liquid crystal alignment agent, the adhesion to the substrate and the weather resistance of the liquid crystal element 10 are sufficiently improved. From the viewpoint of good effects, the blending ratio of the silane compound is preferably 0.5 parts by mass or more with respect to 100 parts by mass of the total polymer components in the liquid crystal alignment agent, more preferably 1 part by mass to 30 parts by mass .

Regarding the liquid crystal alignment agent of this embodiment, among the polymer components contained in the liquid crystal alignment agent, it is derived from having at least one side chain structure selected from the group consisting of the following (a) to (e) (Hereinafter, it is also referred to as "specific group") The content ratio of the structural unit of the monomer is 10 mol% or less with respect to the total amount of all the structural units of the polymer component.

(a) Alkyl or alkoxy having 8 to 22 carbon atoms.

(b) Fluoroalkyl or fluoroalkoxy having 6 to 18 carbon atoms.

(c) A monovalent group formed by bonding any one of a benzene ring, a cyclohexane ring, and a heterocyclic ring to an alkyl group, alkoxy group, fluoroalkyl group, or fluoroalkoxy group having 1 to 20 carbon atoms.

(d) A total of two or more at least one ring selected from the group consisting of a benzene ring, a cyclohexane ring, and a heterocyclic ring, and the plurality of rings are directly or via a divalent linking group. Price base.

(e) A monovalent group with 17 to 51 carbon atoms having a steroid skeleton.

Here, in this specification, the "side chain structure" in the "monomer having a side chain structure" refers to the case where the part introduced into the main chain of the polymer in the structural formula of the monomer is used as the main skeleton A partial structure bonded to the main skeleton directly or via a linking group. That is, the "side chain structure" of the monomer is introduced into the side chain of the polymer obtained by the polymerization when the monomer is used for polymerization. Furthermore, the so-called "main chain" of a polymer refers to the longest atom contained in the polymer The "dry" part of the chain. The "dry" part is allowed to include a ring structure. The so-called "side chain" of the polymer refers to the part branched from the "dry" of the polymer. Therefore, for example, in the case of a diamine used in the synthesis of polyamide acid or polyimide, a skeleton containing two primary amine groups is set as the main skeleton, and the skeleton is bonded to the main skeleton directly or via a linking group. Part of the structure on the skeleton is equivalent to the "side chain structure". Furthermore, regarding the side chain structure having a cyano group, the liquid crystal molecules are aligned horizontally due to the side chain structure. In the case where the liquid crystal molecules in the liquid crystal layer 13 are vertically aligned, the specific group preferably does not contain a cyano group.

The phrase "the content ratio of the structural unit derived from the monomer having a specific group is 10 mol% or less relative to the total amount of all the structural units of the polymer component" refers to the case where the liquid crystal alignment agent contains two or more polymers Below, the total number of moles obtained by multiplying the number of moles of the structural unit derived from a monomer having a specific group in each polymer and the mass mixing ratio of the polymer. Therefore, for example, in the case where the liquid crystal alignment agent contains two polymers of polymer 1 and polymer 2 in a mass ratio of 60:40, if the number of structural units derived from a monomer having a specific group in polymer 1 is 0%. % And the number of structural units derived from a monomer having a specific group in polymer 2 is 20 mol%, then the "content ratio of structural units derived from a monomer having a specific group" of the liquid crystal alignment agent becomes 60 parts by mass×0 mol%+40 parts by mass×20 mol%=8 mol%. Therefore, in this case, the requirement that 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. Furthermore, the above-mentioned requirement is satisfied even when the polymer component does not contain a specific group.

On the other hand, regarding the polymer comprising the polymer 1 and polymer 2 Ingredients, when the blending ratio of polymer 1 and polymer 2 is 20:80 by mass, the "containment ratio of the structural unit derived from the monomer having a specific group" of the liquid crystal alignment agent is 20 parts by mass× 0 mol%+80 parts by mass×20 mol%=16 mol%. Therefore, in this case, the requirement that "the content ratio 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" is not satisfied.

As specific examples of the specific group, the alkyl group and alkoxy group of (a) include, for example, n-octyl, n-nonyl, n-decyl, n-dodecyl, n-tridecyl, n-tetradecyl Linear alkyl groups such as alkyl group, n-heptadecyl group, n-octadecyl group, and linear alkoxy groups formed by bonding these linear alkyl groups with oxygen atoms; (b) fluoroalkyl group Examples of the fluoroalkoxy group include linear fluoroalkyl groups and fluoroalkoxy groups in which at least one hydrogen atom of the alkyl group and alkoxy group of (a) is substituted with a fluorine atom; the group of (c) Examples of the group (d) include a group represented by the following formula (5); examples of the group (e) include a cholesteryl group, a cholesterol group, and a lanostyl group.

(In formula (5), A ¹ to A ³ are each independently a phenylene group or a cyclohexene group, and may have a substituent in the ring part. R ²¹ is a hydrogen atom, an alkyl group with 1 to 20 carbons, and a carbon number Alkoxy with 1-20, fluoroalkyl with 1-20, fluoroalkoxy with 1-20, cyano-containing alkyl with 1-20, cyano-containing with 1-20 R ²² and R ²³ are each independently a single bond, -O-, -COO-, -OCO- or an alkanediyl group having 1 to 3 carbon atoms. k, m, and n is an integer of 0 or more satisfying 1≦k+m+n≦4. Where R ²¹ is a hydrogen atom, an alkyl group with 1 to 3 carbons, a cyano group-containing alkyl group with 1 to 20 carbons, and a carbon number of 1. In the case of ~20 cyano group-containing alkoxy, fluorine atom, or cyano group, k+m+n≧2. "*" indicates a bonding bond)

As a specific example of the group represented by the said formula (5), the group etc. which are represented by the following formula are mentioned, for example, but it is not limited to these. Examples of substituents 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 2~4. R ²¹ preferably has a carbon number of 3 or more, more preferably 4 or more, and still more preferably 7 or more.

(In the formula, "*" represents the bonding key)

Among the polymer components contained in the liquid crystal alignment agent, from the viewpoint of obtaining a liquid crystal element with higher weather resistance and high temperature and humidity resistance, the content ratio of the structural unit derived from a monomer having a specific group is preferably The total amount of all structural units in the polymer component is 8 mol% or less, more preferably 5 mol% or less, and still more preferably 2 mol% Less than ear%. In addition, in this specification, when at least a part of the partial structure of (a) to (e) constitutes a part of the photoalignment group shown below, or the part of (a) to (e) When the structure is bonded to the photo-alignment group, the above-mentioned (a) to (e) also correspond to the specific group.

(Polymer component)

The polymer component contained in the liquid crystal alignment agent can be only the polysiloxane, or a polymer different from polysiloxane (hereinafter, also referred to as "other polymer"), or polysiloxane A mixture of alkanes and other polymers. In the case where only the silane compound is contained as the silicon-containing compound, the liquid crystal alignment agent contains other polymers shown below as the polymer component.

The main skeleton of other polymers is not particularly limited, and examples include: polyamide, polyimid, polyamide, polyester, polyamide, cellulose derivatives, polyacetal, and polystyrene Derivatives, poly(styrene-phenylmaleimide) derivatives, poly(meth)acrylates and other main skeletons. Among these, from the viewpoints of heat resistance, mechanical strength, affinity with liquid crystals, etc., it is preferably selected from the group consisting of polyamide acid, polyamide ester, polyimide, and poly(meth)acrylate. At least one polymer in the group consisting of. Furthermore, the other polymers may be only one type or two or more types. (Meth)acrylate means including acrylate and methacrylate.

In the case where the liquid crystal alignment agent contains polysiloxane, the blending ratio of other polymers is preferably 1% to 95% by mass relative to the total amount of the polymer components in the liquid crystal alignment agent, and it is more preferable to set It is 5 mass%-95 mass %, More preferably, it is 10 mass%-90 mass %. Furthermore, other polymers can be used alone or Use two or more together.

(Polymer with photo-alignment group)

The liquid crystal alignment agent used in the formation of the liquid crystal alignment film 14 and the liquid crystal alignment film 15 preferably contains a polymer having a photo-alignment group. Here, the "photoalignment group" refers to a functional group that imparts anisotropy to the film by a photoisomerization reaction, a photodimerization reaction, a photolysis reaction, and a photofries rearrangement reaction caused by light irradiation . Specific examples of the photoalignment group include, for example, an azobenzene-containing group containing azobenzene or its derivative as the basic skeleton, a cinnamic acid structure-containing group containing cinnamic acid or its derivative as the basic skeleton, A chalcone-containing group containing chalcone or its derivative as the basic skeleton, a benzophenone-containing group containing benzophenone or its derivative as the basic skeleton, and coumarin or its derivative as the basic skeleton The coumarin-containing group of the skeleton, the cyclobutane-containing structure containing cyclobutane or a derivative thereof as the basic skeleton, and the like. Among these, in terms of high sensitivity to light, a group containing a cinnamic acid structure is preferable, and examples thereof include groups having a partial structure represented by the following formula (1).

(In formula (1), R is an alkyl group with 1 to 10 carbons, an alkoxy group with 1 to 10 carbons, a fluoroalkyl group with 1 to 10 carbons in which at least one hydrogen atom is substituted by a fluorine atom, and at least one hydrogen atom A fluoroalkoxy group having 1 to 10 carbon atoms or a fluorine atom in which the atom is substituted by a fluorine atom. a is an integer of 0 to 4. When a is 2 or more, multiple Rs may be the same or different. "*" means Bonding key)

In the partial structure represented by the formula (1), one of the two bonding bonds "*" is preferably bonded to the group represented by the following formula (4). In this case, it is preferable to improve the light transmittance and light scattering properties of the obtained liquid crystal element.

[Chemistry 4]HR ¹¹ -R ¹² -＊ (4)

(In formula (4), R ¹¹ is phenylene, biphenylene, triphenylene, cyclohexylene, or biscyclohexylene, and it may also have an alkyl group with 1 to 20 carbon atoms in the ring part. Alkoxy group with 1-20, substituted alkyl with 1-20 carbons in which at least one hydrogen atom is substituted by fluorine atom or cyano group, substitution with 1-20 carbons in which at least one hydrogen atom is substituted by fluorine atom or cyano group An alkoxy group, a fluorine atom or a cyano group. When R ^{12 is} bonded to the benzene ring in the formula (1), it is a single bond, an alkanediyl group with 1 to 3 carbon atoms, an oxygen atom, a sulfur atom, and -CH= CH-, -NH-, -COO- or -OCO-, in the case of bonding to the carbonyl group in formula (1), a single bond, an alkanediyl group with 1 to 3 carbon atoms, an oxygen atom, a sulfur atom, or- NH-. "*" means bonding bond)

The photo-alignment group may be possessed by polysiloxane, or may be possessed by a polymer different from polysiloxane. From the viewpoint of ensuring the reliability and weather resistance of the liquid crystal element 10, as the polymer having an optical alignment group, a polysiloxane having an optical alignment group can be preferably used.

The method of synthesizing a polymer having a photoalignment group is not particularly limited, as long as it is appropriately selected according to the main skeleton of the polymer. As specific examples, (1) a method of polymerizing a monomer having a photo-alignment group, (2) synthesizing a polymer having a first functional group (for example, epoxy group, etc.) in the side chain, and then making it have Can be with the 1st A method of reacting a second functional group (for example, a carboxyl group, etc.) with a functional group, a reactive compound of a photo-alignment group, and a polymer having a first functional group, and the like. When the polymer having a photoalignment group is polysiloxane, it is preferable to use the method (2) in terms of high efficiency of introduction of side chains.

In the case where the liquid crystal alignment agent contains a polymer having a photo-alignment group and a polymer without a photo-alignment group, it is from the viewpoint of imparting sufficient alignment ability to the coating film formed using the liquid crystal alignment agent by radiation irradiation In other words, the content of the polymer having a photo-alignment group is preferably set to 1% by mass or more with respect to the total amount of polymer components in the liquid crystal alignment agent, and more preferably set to 5% to 99% by mass.

(Crosslinking agent)

The liquid crystal alignment agent preferably contains a compound having a crosslinkable group (hereinafter also referred to as a crosslinking agent) as another component. The crosslinkable group is a group that can form a covalent bond between the same or different molecules by light or heat. Examples include (meth)acrylic groups, groups having vinyl groups (alkenyl, vinylphenyl, etc.). Etc.), ethynyl, epoxy (oxiranyl, oxetanyl), carboxyl, (protected) isocyanate, etc. Among these, in terms of high reactivity, a (meth)acryloyl group is particularly preferable. The number of crosslinkable groups possessed by the crosslinking agent may be one or multiple. In terms of sufficiently improving the reliability of the liquid crystal element, two or more are preferable, and two to six are more preferable.

Specific examples of the crosslinking agent include, for example, allyl group-containing compounds such as diallyl phthalate; ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, diethyl Glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, pentaerythritol three (Meth)acrylate, di-trimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, trimethylolpropane (meth)acrylate, ethoxylated trimethylol Propane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene glycol tri(meth)acrylate, polyether(meth)acrylate, ethoxylated bisphenol A bis(meth)acrylate (Meth)acrylic acid esters, tricyclodecane dimethanol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate and other (meth)acrylic compounds; maleic acid , Itaconic acid, 1,2,4-benzenetricarboxylic acid, tetracarboxylic acid, cis-1,2,3,4-tetrahydrophthalic acid, ethylene glycol bis1,2,4-benzenetricarboxylic acid, Propylene glycol bis 1,2,4- trimellitic acid, 4,4'-oxydiphthalic acid, 1,2,4- trimellitic anhydride and other carboxylic acids; 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, glycerol 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-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N-di Epoxy compounds such as glycidyl-benzylamine, N,N-diglycidyl-aminomethylcyclohexane, N,N-diglycidyl-cyclohexylamine, etc.; (Protected) isocyanate compounds in which polyvalent isocyanates such as hexamethylene diisocyanate and diphenylmethylene diisocyanate are protected by a protective group. As a crosslinking agent, among these, a polyfunctional (meth)acrylate compound is preferable.

From the viewpoint of sufficiently obtaining the effect of improving liquid crystal orientation and electrical characteristics In other words, the blending ratio of the crosslinking agent is preferably 0.5 parts by mass or more relative to 100 parts by mass of the polymer component used in the preparation of the liquid crystal alignment agent, more preferably 1 part by mass to 40 parts by mass, and still more preferably 5 parts by mass ~30 parts by mass. Furthermore, a crosslinking agent may be used individually by 1 type, and may be used in combination of 2 or more types.

(Antioxidants)

The liquid crystal alignment agent preferably contains an antioxidant (also referred to as a polymerization inhibitor) as other components. Antioxidants have a function of invalidating radicals or peroxides generated by energy such as ultraviolet rays or heat to delay or prohibit polymerization. By including the antioxidant in the alignment film, the transparency of the liquid crystal element when no voltage is applied can be improved, which is preferable in this respect. Furthermore, it is presumed that the effect is caused by the presence of the antioxidant suppressing the polymerization reaction of the polymerizable compound in the liquid crystal composition present near the surface of the alignment film, and suppressing the decrease in the alignment of the liquid crystal.

As specific examples of antioxidants, 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 (phosphorus-based Antioxidants), compounds having a thioether structure (sulfur-based antioxidants), mixtures of these (mixed-based antioxidants), and the like.

As preferred examples of antioxidants, compounds having an amine structure include, for example, Adk stab LA-52, LA-57, LA-63, LA-68, LA-72, LA-77, LA-81, LA-82, LA-87, LA-402, LA-502 (the above are manufactured by ADEKA), CHIMASSORB 119, CHIMASSORB 2020, CHIMASSORB 944, TINUVIN 622, TINUVIN 123, TINUVIN 144, TINUVIN 765, TINUVIN TINUVIN 770, TINUVIN 111, TINUVIN 783, TINUVIN 791 (the above are manufactured by Japan BASF), etc.; compounds having a phenol structure can be, for example, Examples: Adk stab AO-20, Adk stab AO-30, Adk stab AO-40, Adk stab AO-50, Adk stab AO-60, Adk stab AO-80, Adk stab AO-330 (Above is ADEKA ) Manufacturing), IRGANOX 1010, IRGANOX 1035, IRGANOX 1076, IRGANOX 1098, IRGANOX 1135, IRGANOX 1330, IRGANOX 1726, IRGANOX 1425, IRGANOX 1520, IRGANOX 245, IRGANOX )259, IRGANOX 3114, IRGANOX 3790, IRGANOX 5057, IRGANOX 565, IRGANOX 295 (above Japan BASF (manufactured by Japan BASF), etc.; phosphorous antioxidants include, for example, Adk stab PEP-4C, Adk stab PEP-8, and Adk stab PEP-8. Adk stab) PEP-36, HP-10, 2112 (the above are manufactured by ADEKA), IRGAFOS 168, GSY-P101 (the above are manufactured by Sakai Chemical Industry), Yi Lu IRGAFOS 12, IRGAFOS 126, IRGAFOS 38, IRGAFOS P-EPQ (the above are made by Japan BASF), etc.; sulfur series Examples of antioxidants include: Adk stab AO-412, Adk stab AO-503 (the above are manufactured by ADEKA), and IRGANOX PS 800, IRGANOX PS 802 (the above are made by Japan BASF), etc.; mixed antioxidants include, for example: Adk stab A-611, Adk stab Adk stab A-612, Adk stab A-613, Adk stab AO-37, Adk stab AO-15, Eddie Adk stab AO-18, 328 (the above are made by ADEKA), TINUVIN 111, TINUVIN 783, TINUVIN 791 (the above are Japan BASF (Japan BASF) and so on. One of these antioxidants can be used alone or two or more of them can be used in combination.

The content ratio of the antioxidant in the liquid crystal alignment agent is preferably 0.01 parts by mass to 15 parts by mass, more preferably 0.01 parts by mass to 10 parts by mass relative to 100 parts by mass of the polymer component used in the preparation of the liquid crystal alignment agent. Preferably, it is 0.1 parts by mass to 10 parts by mass.

As other components contained in the liquid crystal alignment agent, for example, metal chelate compounds, hardening accelerators, surfactants, fillers, dispersants, optical Sensitizer etc. The blending ratio of these other components can be appropriately selected according to each compound within a range that does not impair the effect of the present disclosure.

(Solvent)

The liquid crystal alignment agent is prepared in the form of a liquid composition in which a polymer component and optional components are dissolved in an appropriate solvent.

As the organic solvent used, for example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,2-dimethyl-2-imidazolidone, γ-butanone Lactone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol mono Methyl ether, butyl lactate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene two Alcohol-isopropyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, two Ethylene 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, diiso Butyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethylene carbonate, propylene carbonate, etc. These can be used alone or in combination of two or more.

Regarding the organic solvent used in the preparation of the liquid crystal alignment agent, in order to obtain a liquid crystal alignment film that exhibits good element characteristics even when the post-baking temperature is low (for example, when the temperature is set to 150° C. or less), these With respect to the total amount of the solvent, it is preferable to include 40% by mass or more of the compound having a boiling point of 150° C. or less under 1 atmosphere, more preferably 50% by mass or more, and still more preferably 70% by mass or more.

The solid content concentration in the liquid crystal alignment agent (other than the solvent of the liquid crystal alignment agent The ratio of the total mass of the components to the total mass of the liquid crystal alignment agent) is appropriately selected in consideration of viscosity, volatility, etc., and is preferably in the range of 1% by mass 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 is difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by mass, the film thickness of the coating film becomes too large and it is difficult to obtain a good liquid crystal alignment film. In addition, the viscosity of the liquid crystal alignment agent increases and the coatability tends to decrease. .

<Method of Manufacturing Liquid Crystal Element>

Next, a method of manufacturing the liquid crystal element 10 will be described. The liquid crystal element 10 can be manufactured by a method including: coating a liquid crystal alignment agent on the respective electrode arrangement surfaces of the first substrate 11 and the second substrate 12 to form a liquid crystal alignment film 14 and a liquid crystal alignment film 15 Step A; Step B of constructing a liquid crystal cell by arranging a pair of substrates with a liquid crystal alignment film 14 and a liquid crystal alignment film 15 through the layers of the liquid crystal composition in such a way that the electrode arrangement faces each other; and Step C of hardening the polymerizable compound after the construction.

(Step A)

The liquid crystal alignment agent is applied on the respective electrode arrangement surfaces of the first substrate 11 and the second substrate 12, for example, by lithography, spin coating, roll coater, inkjet printing, and bar coater. Method and other well-known coating methods are performed. After the liquid crystal alignment agent is applied, for the purpose of preventing dripping of the applied liquid crystal alignment agent, etc., it is preferable to perform preheating (prebaking). The pre-baking temperature is set according to the type of substrate, and is preferably 140°C or lower, more preferably 120°C or lower, and still more preferably 100°C or lower. The lower limit of the pre-baking temperature is preferably 30°C or higher, and more preferably 40°C or higher. Pre-baked The time is preferably 0.25 minutes to 10 minutes.

After that, it is preferable to perform a calcination (post-baking) step for the purpose of completely removing the solvent and promoting the crosslinking reaction as necessary. In the case of using a substrate containing a polymer material, the firing temperature (post-baking temperature) at this time is preferably set to 160°C or less, more preferably 150°C or less, and particularly preferably 110°C or less . The post-baking time is preferably 5 minutes to 200 minutes, more preferably 10 minutes to 120 minutes.

The coating film formed using the liquid crystal alignment agent is subjected to a treatment (alignment treatment) for imparting liquid crystal alignment ability. As the alignment treatment, for example, a rubbing treatment in which a roll of cloth containing fibers such as nylon, rayon, and cotton yarn is used to rub the coating film in a certain direction, and an optical alignment treatment in which the coating film is irradiated with polarized or non-polarized radiation Wait.

(Step B)

In step B, two substrates with a liquid crystal alignment film are prepared, and a layer of a liquid crystal composition containing a liquid crystal and a polymerizable compound is arranged between the two substrates facing each other such that the liquid crystal alignment film faces to produce a liquid crystal cell. Specifically, it can be exemplified by bonding the peripheral portions of the first base material 11 and the second base material 12 with a sealant and injecting and filling the liquid crystal composition into the cell gap partitioned by the surface of the base material and the sealant. A method of sealing the injection hole; a sealant is applied to the periphery of the liquid crystal alignment film side of one of the substrates, and then the liquid crystal composition is dropped on a predetermined number of places on the liquid crystal alignment film surface, and the liquid crystal alignment film is opposed The method of laminating another substrate and spreading the liquid crystal on the entire surface of the substrate, and then hardening the sealant (One Drop Filling (ODF) method), etc. As a sealant, for example, a hardening agent and Alumina balls as spacers, epoxy resin, etc.

(Step C)

In step C, a treatment of hardening the liquid crystal composition by performing one or more treatments selected from heating and light irradiation is performed. The heating temperature during the curing reaction can be appropriately selected according to the type of polymerizable compound and liquid crystal used, for example, heating is performed at a temperature in the range of 40°C to 80°C. The heating time is preferably 0.5 minutes to 5 minutes. In the case of curing by light irradiation, as the irradiation light, non-polarized ultraviolet rays having a wavelength in the range of 200 nm to 500 nm can be preferably used. The amount of light irradiation is preferably 50 mJ/cm ² to 10,000 mJ/cm ² , and more preferably 100 mJ/cm ² to 5,000 mJ/cm ² .

The liquid crystal element 10 can be used in various applications, for example, it can be effectively used as windows for buildings, indoor and outdoor partitions (partitions), shop windows, windows for vehicles (cars, airplanes, ships, railways, etc.), and indoor and outdoor windows. Various dimming components for various advertisements, guide signs, home appliances, mobile phones, smart phones, various monitors, clocks, portable game consoles, computers, glasses, sunglasses, medical equipment, furniture, etc. The liquid crystal element 10 can be used as it is depending on the thickness, hardness, shape, use, etc. of the element, and it can also be used by bonding to glass, transparent resin, or the like.

(Liquid crystal device)

The display device of the present disclosure includes: the 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 a liquid crystal element 10 is arranged on the back of the transparent display 30. When the liquid crystal element 10 functions as a dimming element, the visibility of the display of the transparent display 30 is changed. change.

The transparent display 30 is, for example, an organic electroluminescence element (organic EL element), and includes: a pair of glass substrates; an anode electrode and a cathode electrode formed of a transparent electrode material; and a hole transport layer formed between the anode electrode and the cathode electrode And luminescent layer. The transparent display 30 is transparent in its entire surface in a non-display state where no voltage is applied. By applying a voltage, the pixels applied with the voltage emit light to display characters, images, and the like.

In the display device 20 of FIG. 3, the entire surface of the display device 20 is transparent when the liquid crystal element 10 and the transparent display 30 are not applied with voltage. Therefore, for example, when the display device 20 is applied as a front glass or a rear glass of a shop window, the appearance of the products displayed on the counter or the shop can be seen from outside the house. In addition, when the liquid crystal element 10 is in a state where no voltage is applied, a voltage is applied to the transparent display 30, whereby the characters, images, etc. displayed on the transparent display 30 are displayed in a state of floating on the glass.

On the other hand, in a state where a voltage is applied to the liquid crystal element 10, the back surface of the transparent display 30 is shielded from light. In this case, the characters, images, etc. displayed on the display device 20 can be prevented from overlapping with objects behind the display device 20, and the display of the transparent display 30 can be easily observed. In addition, the decoration can also be improved. Alternatively, a configuration may be adopted in which the applied voltage of the liquid crystal element 10 is controlled according to the brightness of the front or back of the display device 20, thereby changing the degree of light transmission from the front to the back of the display device 20.

Furthermore, in the display device 20 of FIG. 3, it can also be set to be used only in transparent A part of the indicator 30 is configured with a light-adjusting element 10. Alternatively, a configuration may be adopted in which the display area of the transparent display 30 is divided into a plurality and the dimming element is arranged according to the display area, so that the transmittance can be changed according to the display area.

[Example]

Hereinafter, the present invention will be further described in detail through examples, but the present invention is not limited to these examples.

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

[Weight average molecular weight Mw and number average molecular weight Mn of polymer]

Mw and Mn are polystyrene conversion values obtained by GPC measurement under the following conditions.

Column: manufactured by Tosoh Co., Ltd., TSKgelGRCXLII

Solvent: Tetrahydrofuran, or N,N-dimethylformamide solution containing lithium bromide and phosphoric acid

Temperature: 40℃

Pressure: 68kgf/cm ²

[Epoxy equivalent]

The epoxy unit weight is measured by the hydrochloric acid-methyl ethyl ketone method described in Japanese Industrial Standards (JIS) C2105.

[The imidization rate of polyimide]

The polyimide solution was poured into pure water, and the resulting precipitate was fully dried under reduced pressure at room temperature, and then dissolved in deuterated dimethyl sulfide, using tetramethyl silane as the reference substance, at room temperature ¹ H-nuclear magnetic resonance (Nuclear Magnetic Resonance, NMR) was measured. Based on the obtained ¹ H-NMR spectrum, the imidization rate [%] was determined by the following formula (1).

The imidization rate [%]=(1-(A ¹ /(A ² ×α)))×100…(1)

(In the formula (1), A ¹ is the peak area of the proton derived from the NH group appearing near the chemical shift of 10 ppm, A ² is the peak area of the proton derived from other protons, and α is the precursor to the polymer ( (Polyamide acid) 1 NH group proton, the ratio of the number of other protons)

[Solution viscosity of polymer solution]

The solution viscosity (mPa·s) of the polymer solution was measured at 25°C using an E-type rotary viscometer.

The relationship between the abbreviations and structural formulas of the compounds used in the following examples is as follows. In addition, in the following, for convenience, the "compound represented by formula (X)" may be simply expressed as "compound (X)".

(carboxylic acid)

[化5]

(additive)

(Antioxidants)

(Dichroic pigment)

[化8]

<Synthesis of Polyimide>

[Synthesis Example 1]

16.5 g of 2,3,5-tricarboxycyclopentylacetic dianhydride as tetracarboxylic dianhydride (98 mol parts relative to 100 mol parts of the total amount of diamine used in the synthesis), and as 8.0 g of p-phenylenediamine of the diamine compound (99.5 mol parts relative to 100 mol parts of the total amount of diamine used in the synthesis) and cholestenyloxy-2,4-diaminobenzene 0.2 g (0.5 mol parts relative to 100 mol parts of the total amount of diamine used in the synthesis) was dissolved in 225 g of N-Methyl-2-pyrrolidone (NMP), The reaction was carried out at 60°C for 1 hour. Then, 250 g of NMP, 29.11 g of pyridine, and 22.54 g of acetic anhydride were added, and the dehydration ring-closure reaction was performed at 110°C for 5 hours.

Then, the reaction mixture was poured into a large amount of excess methanol to precipitate the reaction product. After washing the recovered precipitate with methanol, it was dried at 40°C under reduced pressure for 15 hours to obtain 43 g of polyimide (hereinafter referred to as polymer (PI) with an imidization rate of approximately 90% -1)). It was prepared so that the obtained polymer (PI-1) was 10% by mass in NMP, and the viscosity of the solution was measured, and the result was 410 mPa. s. In addition, the polymer solution was allowed to stand at 20°C for 3 days. As a result, gelation did not occur and the storage stability was good. Regarding the polymer (PI-1), the content ratio β of the structural unit derived from a monomer having a specific group relative to all the structural units of the polymer (in terms of polyimide and polyamide acid) In this case, the usage amount Q2) of the monomer having a specific group with respect to the total amount Q1 of the monomers used in the polymerization is 0.25 mol%.

Containing ratio β[mol%]=(Q2/Q1)×100

[Synthesis Example 2]

3.19 g (12.8 mmol) of 2,4,6,8-tetracarboxylic bicyclo[3.3.0]octane-2:4,6:8-dianhydride as tetracarboxylic dianhydride and diamine compound 1,3-diamino-4-[4-(trans-4-n-pentylcyclohexyl)phenoxymethyl]benzene 4.59g (11.6mmol) and 3,5-diaminobenzoic acid 2.16g( 14.2mmol) was dissolved in 24.9g of NMP, and after reacting at 80°C for 5 hours, 2.50g (12.8mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride was added as tetracarboxylic dianhydride And 12.4 g of NMP, and reacted at 40°C for 8 hours to obtain a polyamide acid solution with a polymer concentration of 25% by mass. After adding NMP to 30.0 g of the obtained polyamide acid solution and diluting to 6 mass %, 3.95 g of acetic anhydride and 2.40 g of pyridine were added, and the reaction was carried out at 50° C. for 2 hours. Then, the reaction mixture was poured into a large amount of excess methanol to precipitate the reaction product. After washing the collected precipitate with methanol, it was dried at 100°C under reduced pressure to obtain polyimide (hereinafter referred to as polymer (PI-2)). Of the resulting polyimide The imidization rate is 55%, and the weight average molecular weight is 48,000. In the polymer (PI-2), the content ratio β is 22.6 mol%.

[Synthesis Example 3]

32.39 g of 1,2,4,5-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 as two 17.60 g of hexamethylene diamine, which is an amine compound, was dissolved in 200 g of NMP, and the reaction was carried out at 60°C for 1 hour. Then, 250 g of NMP, 23.5 g of pyridine, and 30.4 g of acetic anhydride were added, and the dehydration ring-closure reaction was performed at 80°C for 2 hours. Then, the reaction mixture was poured into a large amount of excess methanol to precipitate the reaction product. After washing the collected precipitate with methanol, it was dried under reduced pressure at 40°C for 15 hours to obtain polyimide (hereinafter referred to as polymer (PI-3)). In the polymer (PI-3), the content ratio β is 0 mol%.

<Synthesis of polyamide acid>

[Synthesis Example 4-1]

136.7 g of 1,2,3,4-cyclobutane tetracarboxylic dianhydride as tetracarboxylic dianhydride (90 mol parts relative to 100 mol parts of diamine used in the synthesis), and as two 163.3 g of 2,2'-dimethyl-4,4'-diaminobiphenyl group of amine was dissolved in 1700 g of NMP, and the reaction was carried out at 40°C for 3 hours. Then, the reaction mixture was poured into a large amount of excess methanol to precipitate the reaction product. After washing the collected precipitate with methanol, it was dried under reduced pressure at 40°C for 15 hours to obtain 290 g of polyamide acid (hereinafter referred to as polymer (PAA-1)). The resulting polymer (PAA-1) was prepared so that it was 10% by mass in NMP, and the solubility was measured. The viscosity of the liquid was 80mPa. s. In addition, the polymer solution was allowed to stand at 20°C for 3 days. As a result, gelation did not occur and the storage stability was good. In the polymer (PAA-1), the content ratio β is 0 mol%.

[Synthesis Example 4-2]

25.0 g of 1,2,3,4-cyclobutane tetracarboxylic dianhydride as tetracarboxylic dianhydride (45 mol parts relative to 100 mol parts of diamine used in the synthesis) and 1,2 , 4,5-pyromellitic dianhydride 27.8 g (45 mol parts relative to 100 mol parts of diamine used in the synthesis), 4-{4-[2-(4'-pentane as a diamine) -1,1'-Bicyclohexyl)ethyl)phenoxy)benzene-1,3-diamine 27.6g, 3,5-diaminobenzoic acid 8.2g, 4-(4-aminophenoxy) Carbonyl)-1-(4-aminophenyl)piperidine 17.7g and bis[2-(4-aminophenyl)ethyl]hexanedioic acid 43.6g were dissolved in 850g NMP and carried out at 40°C 6 hours reaction. Then, the reaction mixture was poured into a large amount of excess methanol to precipitate the reaction product. After washing the collected precipitate with methanol, it was dried under reduced pressure at 40°C for 15 hours to obtain 140 g of polyamide acid (hereinafter referred to as polymer (PAA-2)). The resulting polymer (PAA-2) was prepared in a manner of 10% by mass in NMP, and the viscosity of the solution was measured, and the result was 90mPa. s. In addition, the polymer solution was allowed to stand at 20°C for 3 days. As a result, gelation did not occur and the storage stability was good. In the polymer (PAA-2), the content ratio β is 11 mol%.

<Synthesis of epoxy-containing polyorganosiloxane>

[Synthesis Example 5]

A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a reflux cooling tube is charged with 70.5 g of 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, 14.9 g of tetraethoxysilane, and ethanol 85.4g and 8.8g of triethylamine were mixed at room temperature. Then, after 70.5 g of deionized water was dropped from the dropping funnel for 30 minutes, the mixture was stirred under reflux and reacted at 80°C for 2 hours. The reaction solution was concentrated, diluted with butyl acetate, and this operation was repeated twice to remove triethylamine and water by distillation to obtain an epoxy-containing polyorganosiloxane (SEp-1) Polymer solution. ¹ H-NMR analysis was performed, and as a result, it was confirmed that no side reaction of the epoxy group was caused during the reaction. The Mw of the polyorganosiloxane (SEp-1) is 11,000, and the epoxy equivalent is 200 g/mole.

[Synthesis Example 6]

A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a reflux cooling tube is charged with 100.0 g of 2-(3,4-epoxycyclohexyl) ethyl trimethoxysilane, 500 g of methyl isobutyl ketone, and three Ethylamine 10.0g, mixed at room temperature. Then, after adding 100 g of deionized water dropwise for 30 minutes from the dropping funnel, the mixture was mixed under reflux and reacted at 80°C for 6 hours. After the reaction, the organic layer was taken out and washed with a 0.2% by mass ammonium nitrate aqueous solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure to obtain a polyorganic epoxy group. Silicone (SEp-2) acts as a viscous transparent liquid. ¹ H-NMR analysis was performed on the polyorganosiloxane (SEp-2), and as a result, it was confirmed that no side reaction of the epoxy group was caused 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/mole.

<Synthesis of polyorganosiloxane with functional groups>

[Synthesis Example 7]

A 100 mL three-necked flask was charged with 11.3 g of polyorganosiloxane (SEp-1) obtained in Synthesis Example 5, 13.3 g of n-butyl acetate, and 1.7 of the cinnamic acid derivative represented by the formula (CA-1). g (32 mol parts relative to 100 mol parts of epoxy groups of polyorganosiloxane (SEp-1)), acrylic acid group-containing carboxylic acid (Aronix (Aronix) M-5300, Made by Toagosei Co., Ltd.) 0.54 g (8 mol parts relative to 100 mol parts of epoxy groups of polyorganosiloxane (SEp-1)), and 0.9 g of tetrabutylammonium bromide, Stir at 80°C for 12 hours. After the completion of the reaction, 20 g of n-butyl acetate was further added, and after the solution was washed with water three times, 20 g of n-butyl acetate was further added, and the solvent was distilled off so that the solid content concentration became 10% by mass. Thereby, an n-butyl acetate solution containing a polymer (S-1) as a photo-alignable polyorganosiloxane with a solid content concentration of 10% by mass was obtained. The weight average molecular weight Mw of the polymer (S-1) was 18,000. The content ratio β in the polymer (S-1) was 32 mol%.

[Synthesis Example 8]

A 100 mL three-necked flask was charged with 8 g of 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 formula (CA-2) ( It is 60 mol parts with respect to 100 mol parts of epoxy groups which polyorganosiloxane (SEp-2) has) and 0.1g of tetrabutylammonium bromide, and it stirred at 100 degreeC for 12 hours. After the completion of the reaction, 30 g of cyclohexanone was added, and the solution was washed with water by 6 times of liquid separation washing, and then 100 g of NMP was added, and the solvent was distilled off so that the solid content concentration became 10% by mass. Thereby, NMP with a solid content concentration of 10% by mass containing polymer (S-2) as a photo-aligned polyorganosiloxane was obtained Solution. 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]

The type and amount of carboxylic acid used in the reaction were changed as described in Table 1 below, except that the same operation as in Synthesis Example 8 was performed to obtain a polymer (S-3 ). In addition, the number in the table shows the use ratio (mole part) of carboxylic acid with respect to 100 mol parts of epoxy groups which the epoxy group-containing polyorganosiloxane used is used. "M-5300" in Table 1 represents an acrylic 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]

In a flask equipped with a cooling tube and a stirrer, 1 part by mass of 2,2'-azobis(isobutyronitrile) as a polymerization initiator and 180 parts by mass of diethylene glycol methyl ether as a solvent were charged. Then, 80 parts by mass of 3,4-epoxycyclohexyl methyl methacrylate and 20 parts by mass of 3-methyl-3-oxetanyl methyl methacrylate were added, and after nitrogen replacement, stirring was gradually started. Raise the temperature of the solution to 80°C and keep the temperature for 5 hours At this time, a polymer solution containing a polymer (PAc-1) as an epoxy group-containing polymethacrylate was obtained. In addition, the monomer consumption rate (reaction conversion) after the completion of the reaction calculated from the measurement result of the solid content concentration of the polymer solution was 99%. In addition, the Mn of the obtained polymer (PAc-1) was 16,000.

[Synthesis Example 11]

100 parts by mass of epoxy group-containing polymethacrylate (PAc-1) obtained in Synthesis Example 10, acrylic acid group-containing carboxylic acid (Aronix M-5300, Toagosei Co., Ltd.) Production) 30 parts by mass, 10 parts by mass of tetrabutylammonium bromide as a catalyst, and 150 parts by mass of propylene glycol monomethyl ether acetate as a solvent, and stirred at 90° C. for 12 hours under a nitrogen atmosphere. After the completion of the reaction, it was diluted with 100 parts by mass of propylene glycol monomethyl ether acetate, and washed with water three times. This solution was concentrated, diluted with butyl acetate, and this operation was repeated twice to obtain a polymer solution containing an acryl group-containing polymethacrylate polymer (PAc-2). The 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 1% by mass was added as The 1-hydroxycyclohexyl phenyl ketone of the photopolymerization initiator was stirred while maintaining the temperature at 80°C, and this was used as the 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, and then the following two The chromatic dye was added at 3% by mass and 1-hydroxycyclohexylphenyl ketone as a photopolymerization initiator was added at 1% by mass, and the temperature was maintained at 80°C while stirring, and this was set as liquid crystal composition II .

(Dichroic pigment)

A mixture of 6.0 parts by mass of compound (m-1), 2.0 parts by mass of compound (m-2), and 2.0 parts by mass of compound (m-3) was used.

[Example 1]

<Preparation of Liquid Crystal Alignment Agent>

The polymer (PI-1)-containing solution obtained in Synthesis Example 1 as a polymer component is converted into a polymer (PI-1) in an amount equivalent to 100 parts by mass, and a compound (Add-1) as an additive ) 0.5 parts by mass are mixed, γ-butyrolactone (GBL) and butyl cellosolve (Butyl Cellosolve, BC) are added as a solvent, and the solid content concentration is 4.5% by mass, and the mass ratio of each solvent is GBL: BC= Prepared in the manner of 95:5. Then, the resulting solution was filtered with a filter having a pore size of 0.2 μm, thereby obtaining a liquid crystal alignment agent (A-1).

<Production of Liquid Crystal Element>

Use a bar coater to coat the prepared liquid crystal alignment agent (A-1) on the polyethylene terephthalate (polyethylene terephthalate) with ITO electrodes on the surface of the substrate. Terephthalate (PET) film substrate (PET-ITO substrate) is pre-baked on the electrode arrangement surface of the substrate (PET-ITO substrate) for 1 minute on a hot plate at 80°C, and then 30 Minute heating (post-baking), thereby forming a coating film (liquid crystal alignment film) with an average film thickness of 0.1 μm. The coating film was rubbed with a rubbing machine having a roll wound with rayon cloth at a roll rotation speed of 1000 rpm, a platform moving speed of 25 cm/sec, and a bristle press length of 0.4 mm. Thereafter, ultrasonic cleaning was performed in ultrapure water for 1 minute, and then dried in a clean oven at 100° C. for 10 minutes, thereby obtaining a substrate with a liquid crystal alignment film. Repeat the same operation to prepare a pair (two pieces) of substrates with liquid crystal alignment films.

Then, a 6 μm spacer was coated on the surface of one of the substrates with the liquid crystal alignment film, and then the prepared liquid crystal composition I was dropped on the surface of the liquid crystal alignment film coated with the spacer. Then, the two substrates were bonded with the sealant so that the liquid crystal alignment film faces of the other substrate faced each other to obtain a liquid crystal cell. Using an ultraviolet irradiation device that uses an ultraviolet light-emitting diode as a light source, ^{the liquid crystal cell is irradiated with ultraviolet rays under the conditions of a wavelength of 365nm, an ultraviolet intensity of 15mW/cm 2} , an irradiation time of 15 seconds, and a substrate surface temperature of 20°C to make the liquid crystal composition The substance I is cured, thereby obtaining a liquid crystal cell.

<evaluation>

1. Evaluation of light transmittance

The transparency at the time of no voltage application was evaluated by measuring the haze (HAZE) of the liquid crystal element in a state where no voltage was applied. The measurement was performed using a spectroscopic haze meter (manufactured by Tokyo Denshoku Co., Ltd.). The lower the haze value, the better the transparency. As a result, in this example, the haze value = 10%, and the transparency in the state where no voltage is applied is excellent.

2. Evaluation of light scattering

By measuring the haze (HAZE) of the liquid crystal element in the voltage application state, the light scattering property at the time of voltage application was evaluated. The measurement was performed by applying 20 V to the liquid crystal element manufactured as described above by AC drive, and performed using a spectroscopic haze meter (manufactured by Tokyo Denshoku Co., Ltd.) in the same manner as in the "1. Evaluation of light transmittance". The higher the haze value, the better the light scattering properties. As a result, in this example, the haze value=92%, and the light scattering property in the voltage applied state was excellent.

3. Test for the determination of the adhesion strength

A liquid crystal element having a size of 30 mm×35 mm was manufactured in the same manner as described above, and the liquid crystal element was fixed on a platform of a push-pull force meter (manufactured by IMADA, PSM-50N), and a 90° peel test was performed. Furthermore, the peel strength (N/30mm) was measured at two peeling speeds (0.2mm/sec and 5mm/sec). As a result, it showed a value of 4.8 N/30 mm at a peeling speed of 0.2 mm/sec, and a value of 12.5 N/30 mm at a peeling speed of 5 mm/sec.

4. Adhesion reliability (high temperature and humidity resistance) test

The manufactured liquid crystal element was left in a high temperature and high humidity environment of 85° C. and 85% RH for 500 hours, and thereafter, the same operation as the above-mentioned "3. Adhesion Strength Measurement Test" was performed to evaluate the adhesion reliability. As a result, it showed a value of 4.3 N/30 mm at a peeling speed of 0.2 mm/sec, and a value of 12.3 N/30 mm at a peeling speed of 5 mm/sec. According to this, in the above-mentioned examples, the peel strength hardly changes before and after exposure to high temperature and high humidity conditions, and the adhesion reliability is good.

5. Evaluation of weather resistance

Using a light resistance tester (SUNTEST CPS+: manufactured by Toyo Seiki Co., Ltd.), the manufactured liquid crystal element was irradiated with a xenon lamp (illuminance 250 W/m ² (300 nm-800 nm)) for 200 hours. Regarding the liquid crystal element after light irradiation, the haze value in the voltage application state was measured by the same method as in the above-mentioned "2. Evaluation of light scattering properties", 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 also 92% after light irradiation, and the light scattering properties did not change before and after light irradiation.

[Example 2 to Example 6 and Comparative Example 1 to Comparative Example 3]

Except for using the types and blending amounts of each component shown in Table 2 below, the same operation as the preparation of the liquid crystal alignment agent (A-1) was carried out to prepare each liquid crystal alignment agent (A-2) to the liquid crystal alignment agent (A -9). In addition, using each liquid crystal alignment agent (A-2) to a liquid crystal alignment agent (A-9), the liquid crystal element was evaluated in the same manner as in Example 1. The results are shown in Table 3.

[Example 7]

1. Manufacture and evaluation of liquid crystal elements

Except that liquid crystal composition II was used instead of liquid crystal composition I, a liquid crystal element was manufactured in the same manner as in Example 1. In addition, the same evaluation as in Example 1 was performed using the obtained liquid crystal cell. The results are shown in Table 3 below.

In Example 7, the liquid crystal element manufactured in 1. above was used, and the following evaluations (evaluation of light transmittance, evaluation of light blocking properties, and evaluation of repeated drive durability test) were further performed.

2. Evaluation of light transmittance

By measuring the transmittance of the liquid crystal element in the state of no applied voltage to evaluate the non-applied Transparency when voltage is applied. The measurement was performed using a spectrophotometer (150-20 type dual electron beam manufactured by Hitachi, Ltd.), and the light transmittance was evaluated by the light transmittance (%) at a wavelength of 400 nm. The higher the transmittance value, the better the transparency. As a result, in this example, the transmittance=85%, and the transparency in the state where no voltage is applied is excellent.

3. Evaluation of light blocking properties

By measuring the transmittance of the liquid crystal element in the voltage application state, the light shielding property at the time of voltage application was evaluated. The measurement was performed by applying 40 V to the liquid crystal element manufactured in 1. above by AC drive, and using a spectrophotometer (150-20 type dual electron beam manufactured by Hitachi, Ltd.) in the same manner as in 2. The lower the transmittance value, the better the light shielding property. As a result, in this example, the transmittance=5%, and the light shielding property in the voltage applied state was excellent.

4. Evaluation of repeated drive durability test

A voltage of 40 V was applied to the liquid crystal element for 1 second, and thereafter, it was left in a state where it was not applied for 1 second. After the operation was repeated 1800 times, the light transmittance and the light shielding property were evaluated in the same manner as in the above 2. and the above 3. to perform the evaluation of the repeated driving endurance test. As a result, in this example, the transmittance when no voltage is applied = 85%, and the transmittance when voltage is applied = 6%. Before and after driving, no change in transmittance is observed when no voltage is applied. The increase in transmittance is only 1%. From this result, it can be said that the liquid crystal element of this example is excellent in the durability of repeated driving.

The numerical values of the blending amounts of the polymers and additives in Table 2 indicate the blending ratio (parts by mass) of each compound with respect to the total of 100 parts by mass of the polymer components used in the preparation of the liquid crystal alignment agent. The numerical value of the compounding amount of the solvent represents the compounding ratio (parts by mass) of each compound with respect to 100 parts by mass of the total amount of the solvent used in the preparation of the liquid crystal alignment 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: Methyl ethyl ketone

Furthermore, the polymer contained in the liquid crystal alignment agent of Example 2 and Example 3 has a photo-alignment group. Therefore, by performing photo-alignment treatment by a known method, the same as those of Example 2 and Example 3 can be obtained, respectively. The same result.

From Table 3, it can be seen that in Examples 1 to 7, the light transmission characteristics and light scattering characteristics are good. In addition, when exposed to a high-temperature and high-humidity environment, the peel strength is also high, and the adhesion to the substrate is also excellent. In addition, the change in the haze value before and after the light stress is small is small, and the weather resistance is also excellent.

In addition, with regard to Example 6 in which an antioxidant is included in the liquid crystal alignment film, compared to Example 3 in which an antioxidant is not included in the liquid crystal alignment film, the haze value when no voltage is applied is low, and the transparency is good.

In addition, in Example 7 in which the dye (dichroic dye) was dispersed in the liquid crystal layer Among them, the adhesiveness and the weather resistance of the liquid crystal element are also good. In addition, even after repeated voltage application/non-application to the liquid crystal element, both light shielding properties and light transmittance were good, and the driving durability was excellent.

In contrast, in Comparative Example 2 using a liquid crystal alignment agent that does not contain a structural unit derived from a monomer having a specific group in the polymer component and does not contain a silicon-containing compound, the adhesion and weather resistance of the substrate are compared Example difference. In addition, in Comparative Example 1 and Comparative Example 3 in which the ratio of the structural unit derived from a monomer having a specific group was more than 10 mol %, the adhesiveness to the substrate was further lower than that in Comparative Example 2. In addition, Comparative Example 1 and Comparative Example 3 are also inferior in weather resistance compared with the Examples.

<Display test when combined with a transparent display>

[Example 8]

A display device in which the liquid crystal element manufactured in Example 3 was superimposed on one outer surface of the transparent display was produced, and the display of the transparent display was performed. As a result, it was judged that the transparency of the liquid crystal element was good, and the visibility of the transparent display was "good".

[Comparative Example 4]

The display test was performed 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 of Example 8. As the liquid crystal element of the polarizing plate method, the following is used: a transparent electrode and a liquid crystal alignment film are respectively formed on the opposing surfaces of a pair of glass substrates, liquid crystal is filled between the pair of substrates, and a sealant is arranged on the periphery The polarizing plate is arranged outside the glass substrate of the liquid crystal cell. As a result, in Comparative Example 4, the light transmittance of the liquid crystal element was poor, and it was determined that the visibility of the transparent display was "bad". It is considered that this situation is caused by the content of the specific base being 10 mol% The following PDLC elements have good light transmittance. On the other hand, in the liquid crystal element of the polarizing plate type, since light absorption in the polarizing plate exists, the transmittance does not theoretically become 50% or more, and the visibility of the transparent display deteriorates. 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.

This disclosure is described in accordance with the embodiment, but it can be understood that the disclosure is not limited to the embodiment or structure. The present disclosure also includes various modifications or modifications within an equal range. In addition, various combinations or forms, and other combinations or forms including only one element, more than one element, or less than one element in these are also included in the scope or scope of the present disclosure.

10‧‧‧Liquid crystal element

11‧‧‧The first base material

12‧‧‧Second base material

13‧‧‧Liquid crystal layer

14,15‧‧‧LCD alignment film

16,17‧‧‧Transparent electrode

Claims (10)

A liquid crystal element, comprising: a pair of substrates arranged oppositely; electrodes, respectively arranged on the faces of the pair of substrates facing each other; a liquid crystal layer arranged between the pair of substrates, and Hardening a liquid crystal composition containing a liquid crystal and a polymerizable compound to form; and a liquid crystal alignment film formed on the electrode arrangement surface of at least one of the pair of base materials; the polymerizable compound contains a monofunctional ( At least one of the group consisting of a meth)acrylate compound, a multifunctional (meth)acrylate compound, a multifunctional thiol compound, and a styrene compound; the liquid crystal alignment film uses a liquid crystal containing a polymer component Aligning agent, and the liquid crystal aligning agent contains a polymer having a photo-alignment group. Regarding the liquid crystal aligning agent, the polymer components are derived from those selected from the following (a) to (e) The content ratio of the structural unit of the monomer of at least one structure in the composition group is 10 mol% or less relative to the total amount of all the structural units of the polymer component, and it is selected from the group consisting of silane compounds and polysiloxanes At least one compound in the group consisting of (a) alkyl or alkoxy with 8-22 carbons, (b) fluoroalkyl or fluoroalkoxy with 6-18 carbons, (c) benzene ring , A cyclohexane ring and a heterocyclic ring, a monovalent group bonded to an alkyl group, alkoxy group, fluoroalkyl group or fluoroalkoxy group with 1 to 20 carbon atoms, (d) in total Two or more selected from benzene ring, cyclohexane ring and heterocyclic ring At least one ring in the group, and a plurality of the rings are bonded directly or via a divalent linking group to form a monovalent group, (e) a monovalent group with 17 to 51 carbon atoms having a steroid skeleton. The liquid crystal element according to the first item of the patent application, wherein the liquid crystal alignment agent contains a compound having a crosslinkable group. The liquid crystal element according to the first or second item of the scope of patent application, wherein the polymerizable compound is a compound that exhibits optical anisotropy. The liquid crystal element according to the first or second patent application, wherein the liquid crystal composition further contains a dye. The liquid crystal element according to claim 4, wherein the dye is at least one selected from the group consisting of azo compounds and anthraquinone compounds. The liquid crystal element described in item 1 or item 2 of the scope of patent application, wherein the liquid crystal composition further contains an antioxidant. A display device comprising: the liquid crystal element according to any one of items 1 to 6 of the scope of the patent application; and a transparent display that is transparent in a non-display state. A liquid crystal alignment agent is used to form a liquid crystal alignment film of a liquid crystal element. The liquid crystal composition is hardened to form a liquid crystal layer, and the liquid crystal alignment agent contains a polymer having a photo-alignment group, In the polymer component, the content ratio of the structural unit derived from a monomer having at least one structure selected from the group consisting of the following (a) to (e) relative to all the structural units of the polymer component The total amount of is 10 mol% or less, and contains at least one compound selected from the group consisting of silane compounds and polysiloxanes, (a) an alkyl group or alkoxy group with 8 to 22 carbon atoms, (b ) Fluoroalkyl or fluoroalkoxy with 6 to 18 carbons, (c) any one of benzene ring, cyclohexane ring and heterocyclic ring, and alkyl with 1 to 20 carbons, alkoxy, fluorine A monovalent group formed by bonding an alkyl group or a fluoroalkoxy group, (d) has a total of two or more at least one ring selected from the group consisting of a benzene ring, a cyclohexane ring, and a heterocyclic ring, and multiple The monovalent group formed by bonding the ring directly or via a divalent linking group, (e) a monovalent group having 17 to 51 carbon atoms having a steroid skeleton. A method of manufacturing a liquid crystal element, which is a method of manufacturing a liquid crystal element including a liquid crystal and a polymerizable compound between a pair of substrates arranged in such a manner that electrodes provided on each substrate surface face each other. The liquid crystal layer is formed by curing the liquid crystal composition of, and the method of manufacturing the liquid crystal element includes the step of coating a liquid crystal alignment agent on the electrode arrangement surface of at least one of the pair of substrates to form a liquid crystal alignment film After forming the liquid crystal alignment film, the step of constructing a liquid crystal cell by arranging the pair of substrates through a layer containing the liquid crystal composition in such a way that the electrodes are opposed to each other; and The step of hardening the polymerizable compound after constructing the liquid crystal cell; the polymerizable compound contains selected from a monofunctional (meth)acrylate compound, a multifunctional (meth)acrylate compound, and a multifunctional thiol compound And at least one of the group consisting of a styrene-based compound, the liquid crystal alignment agent contains a polymer having a photo-alignment group, and the liquid crystal alignment agent is derived from a polymer component selected from the group consisting of: The content ratio of the structural unit of the monomer of at least one structure in the group consisting of (a) to (e) is 10 mol% or less relative to the total amount of all the structural units of the polymer component, and contains optional At least one compound from the group consisting of free silane compounds and polysiloxanes, (a) C8-22 alkyl or alkoxy, (b) C6-18 fluoroalkyl or fluoroalkane An oxy group, (c) any one of a benzene ring, a cyclohexane ring, and a heterocyclic ring, which is bonded to an alkyl group, alkoxy group, fluoroalkyl group, or fluoroalkoxy group having 1 to 20 carbon atoms The valence group, (d) has two or more rings in total selected from the group consisting of a benzene ring, a cyclohexane ring, and a heterocyclic ring, and a plurality of the rings are bonded directly or via a divalent linking group (E) A monovalent group with 17 to 51 carbon atoms with a steroid skeleton. The method for manufacturing a liquid crystal element as described in the scope of patent application, wherein the liquid crystal alignment agent coated on the electrode arrangement surface is heated at 150°C or lower.

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