TW202144878A - Liquid crystal element and method for producing same - Google Patents

Abstract

This liquid crystal element 10 is provided with: a first base material 11 that is provided with a first electrode; a second base material 12 that is provided with a second electrode, while being arranged so as to face the first base material 11; and a liquid crystal layer 13 that is formed by curing a liquid crystal composition containing a liquid crystal and a polymerizable compound, while being arranged so as to be adjacent to the first base material 11 and the second base material 12. With respect to this liquid crystal element 10, if the liquid crystal layer 13 is removed from at least one of the first base material 11 and the second base material 12, and the base material from which the liquid crystal layer 13 has been removed, is immersed in hexane at 23 DEG C for 30 seconds and is subsequently dried, the base material surface on the side from which the liquid crystal layer has been removed has a silicon atom ratio of from 0.05% to 10% relative to the total amount of carbon atoms, oxygen atoms and silicon atoms as determined by X-ray photoelectron spectroscopy.

Description

Liquid crystal element and method of manufacturing the same

[Cross-reference to related applications] This application is based on Japanese Patent Application No. 2020-89042 for which it applied on May 21, 2020, and the description is incorporated herein by reference.

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

As a liquid crystal element, a polymer-dispersed liquid crystal element in which a liquid crystal layer containing a composite material of liquid crystal and a polymer is arranged between a pair of film substrates on which transparent electrodes are formed is known. In recent years, it has been proposed to use a polymer-dispersed liquid crystal element as a light control element (for example, refer to Patent Document 1 or Patent Document 2). The light-adjusting elements of Patent Document 1 and Patent Document 2 exhibit a light-adjusting function by changing the transparency by switching between voltage application and non-voltage application of the transparent electrode. In addition, research is underway to provide new functions such as display windows, smartphones, TVs, monitors, buildings, and furniture by utilizing the dimming function of polymer-dispersed liquid crystal elements. As the polymer-dispersed liquid crystal, a polymer dispersed liquid crystal (PDLC), a polymer network liquid crystal (PNLC), and the like are known.

As a polymer-dispersed liquid crystal element, it has previously been proposed to inject a constituent material of a polymer/liquid crystal composite film into a cell together with a silane coupling agent and irradiate it with light, without forming a liquid crystal alignment film on the surfaces of a pair of substrates. Uniform and stable liquid crystal alignment state (for example, see Patent Document 3). According to the technique of this patent document 3, since the liquid crystal alignment film which controls the alignment of a liquid crystal can not be formed, the simplification of a manufacturing process can be achieved. [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. 2000-321562

[The problem to be solved by the invention] Since the liquid crystal element manufactured by the non-alignment film technique that controls the alignment of liquid crystal molecules without using a liquid crystal alignment film does not control the initial alignment of the liquid crystal by using the alignment film, it is difficult to determine the initial alignment of the liquid crystal, and it may not be possible to form a sufficient liquid crystal element. transparent state. In addition, it is assumed that the polymer-dispersed liquid crystal element is used outdoors or in a high-temperature environment. Therefore, the polymer-dispersed liquid crystal element is required to have high heat resistance, repeated driving resistance, and high optical properties after bending.

The present disclosure has been made in view of the above-mentioned problems, and its main object is to provide a liquid crystal that has high transparency and light scattering properties, and also has good heat resistance, repetitive driving resistance, and optical properties after bending without having a liquid crystal alignment film. element. [Means of Solving Problems]

The present disclosure employs the following methods in order to solve the above-mentioned problems.

<1> A liquid crystal element, comprising: a first base material provided with a first electrode; a second base material provided with a second electrode and disposed opposite to the first base material; and a liquid crystal layer provided with the first base material The base material and the second base material are arranged adjacent to each other and formed by curing a liquid crystal composition containing a liquid crystal and a polymerizable compound. The liquid crystal element does not have a liquid crystal alignment film and is formed from the first base material and the second base material. At least one of the materials peeled off the liquid crystal layer, the substrate from which the liquid crystal layer was peeled was immersed in hexane at 23° C. for 30 seconds and dried, and the surface of the substrate on the side of the peeled surface after drying was treated with The ratio of silicon atoms to the total amount of carbon atoms, oxygen atoms, and silicon atoms when measured by X-ray photoelectron spectroscopy is 0.05% or more and 10% or less. <2> A method for producing a liquid crystal element, comprising: arranging a first substrate provided with a first electrode and a second substrate provided with a second electrode to face each other through a layer containing a liquid crystal composition containing a liquid crystal and a polymerizable compound a step of constructing a liquid crystal cell; and a step of forming a liquid crystal layer by irradiating the liquid crystal cell with light to harden the liquid crystal composition, wherein the liquid crystal element does not have a liquid crystal alignment film, and is formed from the first substrate and at least one of the second substrates to peel off the liquid crystal layer, immerse the substrate from which the liquid crystal layer was peeled at 23° C. in hexane for 30 seconds, and then dry it. The ratio of silicon atoms to the total amount of carbon atoms, oxygen atoms, and silicon atoms when the surface of the substrate is measured by X-ray photoelectron spectroscopy is 0.05% or more and 10% or less. <3> A method for producing a liquid crystal element, comprising: arranging a first substrate provided with a first electrode and a second substrate provided with a second electrode to face each other through a layer containing a liquid crystal composition containing a liquid crystal and a polymerizable compound The step of constructing a liquid crystal cell; and the step of curing the liquid crystal composition by irradiating the liquid crystal cell with light, the liquid crystal cell does not have a liquid crystal alignment film, and by irradiating the liquid crystal cell with more than ^{50 mW/cm 2} The liquid crystal composition is cured by irradiating light with a wavelength of 313 nm for 150 seconds or less or irradiating light with a wavelength of 365 nm for 150 seconds or less at an irradiation amount of ^{150 mW/cm 2 or more.} [Effect of invention]

According to such a structure, even if a liquid crystal alignment film is not provided on a base material, transparency and light-scattering property are high, and a liquid crystal element with good heat resistance, repeated driving resistance, and optical characteristics after bending can be obtained.

Hereinafter, matters related to the aspect of the present disclosure will be described in detail. (first embodiment) ＜Liquid crystal element＞ The liquid crystal element of the present embodiment is a polymer-dispersed liquid crystal element. As shown in FIG. 1 , the liquid crystal element 10 includes a pair of substrates including a first substrate 11 and a second substrate 12 , and a liquid crystal layer 13 disposed between the first substrate 11 and the second substrate 12 . The liquid crystal element 10 is a dimming element that uses an electric field to control the alignment of the liquid crystal molecules 13b present in the polymer network 13a formed in the liquid crystal layer 13, thereby switching the transmission state of transmitted light and the non-transmission state of scattered light.

The first base material 11 and the second base material 12 are transparent base materials made of glass or resin material. Examples of the resin material constituting the base material include silicon, polyethylene terephthalate, polybutylene terephthalate, polyether, polycarbonate, polypropylene, polyvinyl chloride, aromatic polyamide Acetamide, polyamide imide, polyimide, triacetyl cellulose (Triacetyl Cellulose, TAC), polymethyl methacrylate and other materials. The first base material 11 and the second base material 12 can be glass substrates, and are preferably plastic substrates in terms of realizing thinning and weight reduction of the liquid crystal element 10 .

In the first base material 11 and the second base material 12 , the transparent electrodes 16 and the transparent electrodes 17 are respectively arranged on the surfaces facing each other, and the electrode pairs are constituted by the transparent electrodes 16 and the transparent electrodes 17 . The transparent electrode 16 and the transparent electrode 17 are transparent conductive films, for example, a Nessa (NESA) film (registered trademark of PPG, USA) _{containing tin oxide (SnO 2 ), a film containing indium oxide-tin oxide (In 2} O ₃ -SnO _{2 )} ) of indium tin oxide (Indium Tin Oxide, ITO) films, or films containing carbon materials. The transparent electrode 16 and the transparent electrode 17 may have a predetermined pattern such as a comb-like shape.

The liquid crystal layer 13 is formed by curing a liquid crystal composition containing a liquid crystal and a polymerizable compound. The liquid crystal layer 13 is a polymer/liquid crystal composite material layer in which a polymer and liquid crystal molecules 13b coexist, and a polymer network 13a formed by polymerizing a polymerizable compound is constructed in the liquid crystal layer 13 . In the liquid crystal element 10 , a liquid crystal alignment film for aligning the liquid crystal molecules 13 b in the liquid crystal layer 13 is not formed on the first substrate 11 and the second substrate 12 . Furthermore, the liquid crystal element 10 does not include polarizers on the outer surfaces of the first substrate 11 and the second substrate 12 . Therefore, it is excellent in that the absorption loss of light is small and the utilization efficiency of light is high.

FIGS. 2( a ) and 2 ( b ) are diagrams for explaining the function of the liquid crystal element 10 . FIG. 2( a ) shows a state in which no voltage is applied between the transparent electrodes 16 and 17 , and FIG. ) represents a state in which a voltage is applied between the transparent electrode 16 and the transparent electrode 17 . The liquid crystal element 10 is a reverse polymer dispersion type liquid crystal element.

In the liquid crystal element 10, in a state where no voltage is applied between the transparent electrodes 16 and the transparent electrodes 17, the long axis direction of the liquid crystal molecules 13b becomes a direction perpendicular to the substrate surface, whereby incident light is transmitted from one of the pair of substrates. One becomes transparent by passing through the other. On the other hand, when a voltage is applied between the transparent electrode 16 and the transparent electrode 17, the alignment state of the liquid crystal molecules 13b changes, and the liquid crystal molecules 13b rotate in a direction parallel to the substrate surface. Thereby, the incident light is scattered and becomes an opaque state. The liquid crystal element 10 exhibits a dimming function by switching between application and non-application of such a voltage. The liquid crystal element 10 has, for example, a film shape or a plate shape. In addition, the light transmittance of the liquid crystal element 10 may be changed according to the applied voltage.

In the liquid crystal element 10, the liquid crystal layer 13 was peeled off from at least one of the first substrate 11 and the second substrate 12, and the substrate from which the liquid crystal layer 13 was peeled was immersed in hexane at 23° C. for 30 seconds and dried , the ratio of silicon atoms to the total amount of carbon atoms, oxygen atoms, and silicon atoms when measured by X-ray Photoelectron Spectroscopy (XPS) on the surface of the substrate on the peeled side after drying ( Hereinafter, also referred to as "silicon surface coverage") is 0.05% or more and 10% or less. If the silicon surface coverage is less than 0.05%, the initial alignment of the liquid crystal cannot be determined, the transparency cannot be sufficiently ensured, or the effect of improving heat resistance, repetitive driving resistance, bending resistance, and optical properties after bending cannot be sufficiently obtained. . From this viewpoint, the silicon surface coverage is preferably 0.06% or more, more preferably 0.08% or more, and still more preferably 0.10% or more. In addition, when the silicon surface coverage is more than 10%, the repetitive driving resistance, bending resistance, and optical properties after bending of the liquid crystal element 10 tend to decrease. Therefore, the silicon surface coverage is preferably 8.0% or less, more preferably 7.5% or less, and still more preferably 5.0% or less.

Furthermore, the silicon surface coverage can be determined by the content of the silicon-containing compound in the liquid crystal composition, the ratio of silicon atoms contained in the silicon-containing compound, and the amount of silicon-containing groups (such as alkoxysilyl groups) contained in the silicon-containing compound. structure, etc. By XPS-based surface analysis, information about elements present at a depth of several nm from the surface can be obtained. Therefore, the amount of silicon atoms (more specifically, the amount of the silicon-containing compound) present in the boundary portion between the substrate and the liquid crystal layer 13 in the liquid crystal element 10 can be grasped from the silicon surface coverage.

<Liquid crystal composition> Next, the liquid crystal composition for forming the liquid crystal layer 13 of the liquid crystal element 10 will be described. The liquid crystal composition contains a liquid crystal and a polymerizable compound. In addition, the liquid crystal composition contains a silicon-containing compound.

(liquid crystal) Examples of the liquid crystal include low molecular weight compounds having a liquid crystal phase, such as nematic liquid crystals and smectic liquid crystals. The liquid crystal used is preferably a low molecular liquid crystal, more preferably a nematic liquid crystal. In addition, in this specification, the "low molecular weight liquid crystal" means a liquid crystal compound which does not have a molecular weight distribution and a molecular weight is 2000 or less. The low-molecular-weight liquid crystal is preferably a liquid crystal compound having a total of 2 to 10 ring structures including at least any one of a substituted or unsubstituted benzene ring and a cyclohexane ring. The number of rings which the low-molecular-weight liquid crystal has is more preferably 2 to 8, further preferably 2 to 5.

The liquid crystal preferably contains a liquid crystal selected from the group consisting of a cyclohexyl cyano group-containing liquid crystal and a diphenylacetylene structure-containing liquid crystal, in terms of realizing the improvement of optical properties in a liquid crystal element without a liquid crystal alignment film. At least one compound (hereinafter, also referred to as "specific liquid crystal"). The specific liquid crystal preferably has a negative dielectric constant anisotropy.

（式（1）及式（2）中，R¹ ～R³ 及Y¹ ～Y⁴ 分別獨立地為鹵素原子、氰基或碳數1～10的一價有機基，R⁴ 為碳數1～10的一價有機基。a1、a2、b1及b2分別獨立地為0～4的整數）As a specific example of a specific liquid crystal, the compound etc. which are represented by following formula (1) are mentioned as a cyclohexylcyano group containing liquid crystal, and the compound etc. which are represented by following formula (2) are mentioned as a diphenylacetylene structure-containing liquid crystal. [hua 1]

(In formula (1) and formula (2), R ¹ to R ³ and Y ¹ to Y ⁴ are each independently a halogen atom, a cyano group or a monovalent organic group having 1 to 10 carbon atoms, and R ⁴ is a carbon number of 1 A monovalent organic group of ~10. a1, a2, b1 and b2 are each independently an integer of 0 to 4)

In the above formulas (1) and (2), the ^{monovalent organic groups of R 1} to R ⁴ are preferably a monovalent hydrocarbon group having 1 to 12 carbon atoms, a hydrocarbon group having 1 to 12 carbon atoms, and an oxygen atom bonded to each other. The monovalent group of , or a group in which at least one hydrogen atom of a hydrocarbon group having 1 to 12 carbon atoms is substituted with a fluorine atom or a cyano group. As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, Preferably it is a fluorine atom. From the viewpoint of further increasing the refractive index anisotropy as R ¹ to R ⁴ , among them, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms are preferred. A fluoroalkyl group having ∼10 carbon atoms, a fluoroalkoxy group having 1 to 10 carbon atoms, a cyano group-containing alkyl group having 2 to 11 carbon atoms, or a cyano group-containing alkoxy group having 2 to 11 carbon atoms. The ^{monovalent organic group of Y 1} to Y ⁴ is preferably an alkyl group or an alkoxy group having 1 to 3 carbon atoms. As Y ¹ to Y ⁴ , a fluorine atom, a cyano group, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms is preferable.

More specifically, the compound represented by the formula (1) is a compound having a 1,2-diphenylacetylene skeleton. In the above formula (1), R ¹ and R ^{2 are more} preferably an alkyl group or an alkoxy group having 1 to 10 carbon atoms, and still more preferably an alkyl group or an alkoxy group having 1 to 8 carbon atoms. Among these, R ^{1 is} preferably an alkyl group having 1 to 8 carbon atoms, and R ^{2 is} preferably an alkoxy group having 2 to 8 carbon atoms. Y ¹ and Y ^{2 are} preferably a halogen atom or a methyl group, more preferably a fluorine atom. a1 and b1 are preferably 0 to 2, and more preferably 0 or 1. It is preferable that the compound represented by the said formula (1) is a neutral liquid crystal whose dielectric constant anisotropy is almost zero, or has a negative dielectric constant anisotropy.

The compound represented by the formula (2) is a compound having a bicyclohexylcyano skeleton. In the above formula (2), R ³ and R ^{4 are more} preferably an alkyl group or an alkoxy group having 2 to 10 carbon atoms. The total carbon number of R ³ and R ⁴ is preferably 4-15, more preferably 6-12. Y ³ and Y ^{4 are} preferably a halogen atom or a methyl group, more preferably a fluorine atom or a methyl group. a2 and b2 are preferably 0 to 2, more preferably 0 or 1. It is preferable that the compound represented by the said formula (2) has negative dielectric constant anisotropy.

[化3]

As a specific example of the specific liquid crystal, the compound represented by the formula (1) includes, for example, compounds represented by the following formulae (1-1) to (1-11), and the like; the compound represented by the formula (2) Examples of the compound include compounds represented by the following formulae (2-1) to (2-10), for example. As the specific liquid crystal, one type may be used alone, or two or more types may be used in combination. [hua 2]

[hua 3]

The liquid crystal composition may further contain liquid crystals (hereinafter, also referred to as "other liquid crystals") different from the specific liquid crystals. Examples of other liquid crystals include nematic liquid crystals, smectic liquid crystals, and the like, and among these, nematic liquid crystals are also preferred.

Specific examples of other liquid crystals include liquid crystal compounds having positive dielectric anisotropy, for example, biphenyl-based liquid crystals, phenylcyclohexane-based liquid crystals, ester-based liquid crystals, terphenyl-based liquid crystals, and biphenylcyclohexane-based liquid crystals. liquid crystals, pyrimidine-based liquid crystals, dioxane-based liquid crystals, bicyclooctane-based liquid crystals, cubane-based liquid crystals, etc.; liquid crystal compounds having negative dielectric anisotropy include, for example, dicyanobenzene-based liquid crystals , Pyridazine liquid crystal, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, terphenyl liquid crystal, dicyanophenyl ester liquid crystal Liquid crystal, alkenyl liquid crystal, etc. In addition, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonanoate, and cholesteryl carbonate can also be added as liquid crystals to nematic liquid crystals; Ferroelectric liquid crystals such as methyl-p-amino-2-methylbutylcinnamate (p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate) are used. As other liquid crystals, one type of liquid crystal may be used alone or two or more types of liquid crystals may be used in combination according to various physical property values such as dielectric anisotropy and birefringence. The other liquid crystals are preferably negative-type liquid crystals having negative dielectric constant anisotropy, more preferably negative-type liquid crystals having negative dielectric constant anisotropy.

The content ratio of the specific liquid crystal is preferably 1 mass % or more, more preferably 5 mass % or more, and still more preferably 10 mass % or more with respect to the total amount of the specific liquid crystal and other liquid crystals in the liquid crystal composition. In addition, the content ratio of the specific liquid crystal is preferably 80 mass % or less, more preferably 70 mass % or less, and still more preferably 60 mass % or less with respect to the total amount of the specific liquid crystal and other liquid crystals in the liquid crystal composition. By making the content ratio of the specific liquid crystal within the above-mentioned range, the haze value of the liquid crystal element 10 when no voltage is applied can be made lower, and the haze value when a voltage is applied can be made higher, and the contrast characteristics can be improved. In terms of better.

Furthermore, according to the specific liquid crystal, it is considered that the refractive index anisotropy of the liquid crystal molecules in the liquid crystal layer increases due to the main skeleton (1,2-diphenylacetylene skeleton, bicyclohexyl cyano skeleton) possessed by the specific liquid crystal, thereby increasing the refractive index anisotropy of the liquid crystal molecules in the liquid crystal layer. In this way, the haze value when no voltage is applied can be made lower, and the haze value when voltage is applied can be made higher, and a liquid crystal element showing favorable optical characteristics can be obtained.

(Polymerizable compound) A polymerizable compound is a low molecular weight compound which can form a polymer by at least any one of light and heat. The polymerizable compound is not particularly limited as long as it is soluble in a liquid crystal, but a compound showing radical polymerizability is preferred. The radical polymerizable group is preferably selected from the group consisting of a (meth)acryloyl group, a vinyl group, a vinyloxy group, a vinylphenyl group (—C ₆ H ₅ -CH=CH ₂ ), allyl group, maleimide group and at least one of the group consisting of itaconic anhydride group, particularly preferably (meth)acryloyl group. In addition, in this specification, "(meth)acrylate" means that an acrylate and a methacrylate are included. The "low molecular weight compound" is a compound having no molecular weight distribution, and its molecular weight is preferably 1,000 or less, more preferably 800 or less.

As a polymerizable compound, a monofunctional (meth)acrylate compound, a polyfunctional (meth)acrylate compound, and a styrene-type compound are mentioned, for example. As the polymerizable compound, a liquid crystal compound having one or two or more radically polymerizable groups (hereinafter, also referred to as a "polymerizable liquid crystal compound") can be preferably used. By using the polymerizable liquid crystal compound, the liquid crystal alignment of the liquid crystal element 10 can be further improved, which is preferable in this respect.

The polymerizable liquid crystal compound is preferably a compound having at least one of a total of two or more substituted or unsubstituted aromatic rings and aliphatic rings. In addition, the aromatic ring includes an aromatic hydrocarbon ring and an aromatic heterocyclic ring. The aromatic ring which the polymerizable liquid crystal compound has is preferably an aromatic hydrocarbon ring, and examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, and the like. Among these, a benzene ring is particularly preferable. As an aliphatic ring which a polymerizable liquid crystal compound has, a cyclohexane ring, a dodecylcyclohexane ring, etc. are mentioned, Preferably it is a cyclohexane ring. The substituent which the aromatic ring or aliphatic ring may have is preferably a fluorine atom, a cyano group, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, a fluoroalkyl group, or a cyano group-containing alkyl group.

Among the polymerizable liquid crystal compounds, those having one or more (meth)acryloyl groups and having a molecular weight of 1,000 or less are particularly preferred in terms of their high reactivity to light. compound (hereinafter, also referred to as "compound (RM)"). From the viewpoint of further improving the liquid crystal alignment in a liquid crystal element without a liquid crystal alignment film, the number of (meth)acryloyl groups contained in the compound (RM) is preferably 2 to 6, more preferably 2 to 4.

The compound (RM) preferably has a divalent aromatic ring group. The aromatic ring group possessed by the compound (RM) is a group obtained by removing two hydrogen atoms from the ring moiety of a substituted or unsubstituted aromatic ring, preferably a substituted or unsubstituted 1,4-extended phenyl. From the viewpoint of imparting favorable liquid crystal alignment, the number of the aromatic rings contained in the compound (RM) is preferably 2 to 6, more preferably 2 to 4, and particularly preferably 2 or 3. A plurality of aromatic rings are preferably bonded via a single bond or a divalent linking group. The divalent linking group is preferably -COO- from the viewpoint of improving the alignment of the liquid crystal with a rigid structure.

（式（r-1）～式（r-6）中，R^A 為氫原子或甲基。式中的多個R^A 相同或不同）Specific examples of the compound (RM) include compounds represented by the following formulae (r-1) to (r-6), for example. Moreover, as a commercial item of a compound (RM), polymerizable liquid crystals, such as LC242 (made by BASF) and RM257 (made by Merck), are mentioned. However, the compound (RM) is not limited to these compounds. [hua 4]

(In formula (r-1) to formula (r-6), R ^A is a hydrogen atom or a methyl group. ^A plurality of R A in the formula are the same or different)

In the liquid crystal composition, the compounding ratio of the polymerizable compound can be appropriately selected according to the type of the liquid crystal element to be applied. When applied to a polymer-dispersed liquid crystal element, the blending ratio of the polymerizable compound is preferably 0.05 mass % or more, more preferably 0.1 mass % with respect to the total amount of all constituent components of the liquid crystal composition. As mentioned above, it is more preferable to set it as 0.5 mass % or more. In addition, the blending ratio of the polymerizable compound is preferably 30% by mass or less, more preferably 20% by mass or less, and still more preferably 15% by mass or less with respect to the total amount of all the constituent components of the liquid crystal composition. . As the polymerizable compound, one type may be used alone, or two or more types may be used in combination.

The compounding ratio of the polymerizable liquid crystal compound is preferably 20% by mass or more, more preferably 30% by mass or more, and still more preferably 50% by mass or more with respect to the total amount of the polymerizable compound. In addition, although a polymerizable liquid crystal compound has liquid crystallinity, it is classified as a polymerizable compound in this specification. When preparing the liquid crystal composition, from the viewpoint of obtaining a liquid crystal element 10 with high transparency, and from the viewpoint of obtaining a liquid crystal element having good repetitive driving resistance and optical properties after bending, it is particularly preferable to use a polymerizable liquid crystal compound. Used in combination with specific liquid crystals.

(silicon-containing compound) The silicon-containing compound is preferably a silicon-containing polymer, more preferably a polyorganosiloxane. The polyorganosiloxane contained in the liquid crystal composition preferably contains functional groups such as a group having a function of vertically aligning liquid crystal molecules (hereinafter, also referred to as a "liquid crystal alignment group") and a polymerizable group in a side chain. Polyorganosiloxane (hereinafter, also referred to as "functional polyorganosiloxane"). Furthermore, the functional group which the functional polyorganosiloxane has may be only one kind, or two or more kinds may be sufficient. The functional polyorganosiloxane preferably has at least a liquid crystal alignment group. By forming the liquid crystal layer 13 using a liquid crystal composition containing a polyorganosiloxane having a liquid crystal alignment group, the heat resistance is high, and transparency, repetitive driving resistance, bending resistance and A liquid crystal element having high optical properties after bending is preferable in this respect.

(Liquid Crystal Alignment Group) Examples of the liquid crystal alignment group include an alkyl group having 4 to 20 carbon atoms, an alkoxy group having 4 to 20 carbon atoms, a fluoroalkyl group having 4 to 20 carbon atoms, and an alkyl group having 4 to 20 carbon atoms. Fluoroalkoxy, a group having a structure in which one ring is bonded to a chain structure having 1 to 20 carbon atoms, a group having a structure in which two or more rings are bonded directly or via a divalent linking group, a group having The base of the steroid backbone, etc. Among these, the liquid crystal alignment group is also preferably a group represented by the following formula (3). *-L ¹ -R ¹¹ -R ¹² -R ¹³ -R ¹⁴ ... (3) (In formula (3), L ¹ is a single bond, -O-, -CO-, -COO-* ¹ , -OCO- * ¹ , -NR ¹⁵ -, -NR ¹⁵ -CO-* ¹ , -CO-NR ¹⁵ -* ¹ , a hydrogen atom contained in an alkanediyl group having 1 to 6 carbon atoms and an alkanediyl group having 2 to 6 carbon atoms A divalent group substituted by a hydroxyl group, -OR ¹⁶ -* ¹ or -R ¹⁶ -O-* ¹ (wherein, R ¹⁵ is a hydrogen atom or a monovalent hydrocarbon group with 1 to 10 carbon atoms, and R ¹⁶ is a carbon number of 1 ~3 alkanediyl. "* ¹ " represents ^{a bond with R 11} ). R ¹¹ and R ¹³ are each independently a single bond, a substituted or unsubstituted phenylene, or a substituted or unsubstituted phenylene Substituted cycloextended alkyl, R ¹² is a single bond, substituted or unsubstituted phenylene, substituted or unsubstituted cycloextended alkyl, or -R ¹⁷ -B ¹ -R ¹⁸ - (wherein, R ¹⁷ and R ¹⁸ are each independently a substituted or unsubstituted phenylene or cycloalkylene, and B ¹ is a single bond, -O-, -COO-* ² , -OCO-* ² , -OCH ₂ -* ² , -CH ₂ O-* ² or an alkanediyl group having 1 to 3 carbon atoms. "* ² " represents ^{a bond with R 18} ). R ¹⁴ is a hydrogen atom, a fluorine atom, a cyano group, and a CH _{3 group.} COO-* ³ (“* ³ ” represents ^{a bond with R 13} ), an alkyl group having 1 to 18 carbon atoms, a fluoroalkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, an alkyl group having 1 to 18 carbon atoms A 1-18 fluoroalkoxy group, a C17-51 hydrocarbon group having a steroid skeleton, or a C1-18 alkyl group or a monovalent group in which a fluoroalkyl group has a hydrogen atom substituted with a cyano group. However, in the case where all of R ¹¹ , R ¹² and R ¹³ are single bonds, or the total of substituted or unsubstituted phenylene and cycloalkyl groups possessed by ^{R 11} , R ¹² and R ^{13 is one} , R ¹⁴ is an alkyl group of carbon number 4-18, a fluoroalkyl group of carbon number 4-18, an alkoxy group of carbon number 4-18, a fluoroalkoxy group of carbon number 4-18 or a carbon number having a steroid skeleton 17 to 51 hydrocarbon groups. "*" indicates a bond)

In the above formula (3), the alkanediyl group of ^{L 1 is preferably linear.} Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms in R ¹⁵ include a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group, and an alkyl group having 1 to 3 carbon atoms is preferred. R ¹⁴ is an alkyl group having 1 to 18 carbon atoms, a fluoroalkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a fluoroalkoxy group having 1 to 18 carbon atoms, or a fluoroalkoxy group having 1 to 18 carbon atoms. The monovalent group obtained by substituting the hydrogen atom of the alkyl group or the fluoroalkyl group with a cyano group is preferably a straight chain. When the liquid crystal element is a vertical alignment system, the groups preferably have 2 to 18 carbon atoms, more preferably 3 to 18 carbon atoms, and still more preferably 4 to 18 carbon atoms. As ^{a C17-C51 hydrocarbon group which has a steroid skeleton of R14} , a cholestyl group, a cholesteryl group, a lanostane group, etc. are mentioned, for example.

From the viewpoint of obtaining a liquid crystal element exhibiting good liquid crystal alignment even without a liquid crystal alignment film, the liquid crystal alignment group preferably has a total of two or more selected ^{from R 11} , R ¹² and R ^{13 .} At least one of the group consisting of substituted or unsubstituted phenylene and substituted or unsubstituted cycloalkylene, more preferably 2 to 4 pieces. Furthermore, the polyorganosiloxane having a liquid crystal alignment group may have a polymerizable group on the side chain together with the liquid crystal alignment group. In addition, the polyorganosiloxane having a polymerizable group is a different component from the polymerizable compound.

When the polyorganosiloxane contained in the liquid crystal composition has a liquid crystal alignment group, the content ratio of the liquid crystal alignment group is preferably 1 mol with respect to all the monomer units contained in the polyorganosiloxane % or more, more preferably 2 mol % or more, still more preferably 5 mol % or more. In addition, the content ratio of the liquid crystal aligning group is preferably 70 mol % or less, more preferably 50 mol % or less, and further preferably 40 mol % or less with respect to all the monomer units contained in the polyorganosiloxane. . Furthermore, the polyorganosiloxane may have only one type of liquid crystal alignment group, or may have two or more types.

(Synthesis of polyorganosiloxane) Examples of the polyorganosiloxane to be prepared in the liquid crystal composition include the following methods: (I) a method of hydrolyzing and condensing a hydrolyzable silane compound having a functional group (polymerizable group, liquid crystal alignment group, etc.); (II) ) using a hydrolyzable silane compound having an epoxy group (hereinafter, also referred to as an "epoxy-group-containing silane compound") as a monomer and performing a hydrolysis and condensation reaction to obtain a polyorganosiloxane having an epoxy group , and then, the obtained epoxy group-containing polyorganosiloxane is reacted with a carboxylic acid having a functional group, thereby introducing a functional group to the side chain of the polyorganosiloxane; (III) by A method for obtaining a target polymer by combining the method of (I) and the method of (II).

Examples of the silane compound used for the synthesis of polyorganosiloxane include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, and phenyltrimethoxysilane. Silane, phenyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane and other alkoxysilane compounds; 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane Ethoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyl Triethoxysilane, N-(3-cyclohexylamino)propyltrimethoxysilane and other alkoxysilane compounds containing nitrogen and sulfur; 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4- Epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane and other epoxy-containing silane compounds; 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldi Methoxysilane, 3-(meth)acryloyloxypropylmethyldiethoxysilane, 8-(meth)acrylooxyoctyltrimethoxysilane, vinyltrimethoxysilane, ethylene alkoxysilane compounds containing unsaturated bonds such as triethoxysilane and p-styryltrimethoxysilane; trimethoxysilylpropyl succinic anhydride, etc. The hydrolyzable silane compound may be used alone or in combination of two or more. In addition, "(meth)acryloyloxy" means a meaning including "acryloyloxy" and "methacryloyloxy".

The hydrolysis and condensation reactions can be carried out by reacting one or two or more of the above-mentioned silane compounds with water, preferably in the presence of a suitable catalyst and an organic solvent. In the hydrolysis and condensation reactions, the use ratio of water is preferably 0.5 mol to 100 mol, more preferably 1 mol to 30 mol, relative to 1 mol of the silane compound (total amount).

Examples of catalysts used in the hydrolysis and condensation reactions include acids, alkali metal compounds, organic bases, titanium compounds, and zirconium compounds. The amount of the catalyst used varies depending on the type of catalyst, reaction conditions such as temperature, etc., and should be appropriately set. For example, relative to the total amount of the silane compound, it is preferably 0.01 to 3 moles, more preferably 0.05 moles. Molar to 1 times Molar. Examples of the organic solvent used in the hydrolysis and condensation reactions include hydrocarbons, ketones, esters, ethers, alcohols, and the like. 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 from 10 parts by mass to 10,000 parts by mass, more preferably from 50 parts by mass to 1,000 parts by mass, with respect to 100 parts by mass of the total silane compound used in the reaction.

The hydrolysis and condensation reactions are preferably carried out by heating with an oil bath or the like. In the case of hydrolysis and condensation reaction, the heating temperature is preferably 130°C or lower, and more preferably 40°C to 100°C. The heating time is preferably 0.5 hours to 12 hours, and more preferably 1 hour to 8 hours. During the heating process, the mixed solution can be stirred or placed under reflux. Moreover, after completion|finish of reaction, it is preferable to wash|clean the organic solvent layer extracted from the reaction liquid with water. At the time of said washing, it is preferable in this respect that washing operation is facilitated by washing with water containing a small amount of salt (for example, an aqueous ammonium nitrate solution of about 0.2 mass %, etc.). Washing is performed until the water layer after washing becomes neutral, after that, after drying the organic solvent layer with a desiccant such as anhydrous calcium sulfate, molecular sieve, etc. as necessary, the solvent is removed, whereby the target polyorganic organic solvent can be obtained. Siloxane. In addition, the synthesis method of the polyorganosiloxane is not limited to the above-mentioned hydrolysis and condensation reaction, and may be carried out by, for example, a method such as the following: reacting a hydrolyzable silane compound in the presence of oxalic acid and alcohol.

In the condensation reaction, a polyorganosiloxane having an epoxy group in a side chain can be obtained by using an epoxy group-containing silane compound for at least a part of the raw material. In addition, a polyorganosiloxane having a functional group in a side chain can be obtained by reacting the obtained epoxy group-containing polyorganosiloxane with a functional group-containing carboxylic acid.

The reaction between the epoxy group-containing polyorganosiloxane and the carboxylic acid is preferably carried out in an organic solvent in the presence of a catalyst if necessary. As an organic solvent to be used, alcohol, ether, ketone, amide, ester, hydrocarbon compound etc. are mentioned, for example. As the catalyst, organic bases such as tertiary organic amines and quaternary organic amines, quaternary ammonium salts, and the like can be used. The reaction temperature of the reaction is preferably 30°C to 120°C, and the reaction time is preferably 1 hour to 24 hours. About the reaction solution which melt|dissolved the target polymer, the polymer contained in a reaction solution can be isolate|separated using a well-known isolation|separation method, and it can be used for preparation of a liquid crystal aligning agent.

The polyorganosiloxane has a polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC), preferably in the range of 100 to 50,000, more preferably in the range of 500 In the range of -20,000, it is more preferable to exist in the range of 1000-10,000, and it is still more preferable to exist in the range of 1200-10,000.

In the liquid crystal composition, the compounding ratio of the silicon-containing compound is appropriately set according to the type of the silicon-containing compound. When the silicon-containing compound is a polyorganosiloxane, the content of the polyorganosiloxane is preferably 0.0001 mass % or more with respect to the total amount of the liquid crystal composition. When the content ratio of the polyorganosiloxane is 0.0001 mass % or more, the silicon content in the boundary portion between the liquid crystal layer 13 and the substrate can be sufficiently increased, and the adhesion between the liquid crystal layer 13 and the substrate and the adhesion of the liquid crystal element 10 can be sufficiently obtained. The effect of improving heat resistance, repeated driving resistance, bending resistance, and optical properties after bending is preferable in this respect. From such a viewpoint, the content ratio of the polyorganosiloxane is more preferably 0.0005 mass % or more, and further preferably 0.001 mass % or more with respect to the total amount of the liquid crystal composition. In addition, from the viewpoint of favorably maintaining the quality of the liquid crystal element 10 , the content of the polyorganosiloxane is preferably 20 mass % or less, more preferably 15 mass % or less, with respect to the total amount of the liquid crystal composition.

The liquid crystal composition of the present embodiment may contain other components in addition to the above-mentioned components as necessary.

<Polymerization initiator> The liquid crystal composition may further contain a polymerization initiator. As the polymerization initiator, a photoradical polymerization initiator that generates radicals by light can be preferably used. As a photoradical polymerization initiator, an O-acyl oxime compound, an acetophenone compound, a biimidazole compound, etc. are mentioned, for example.

As specific examples of these, the O-acyl oxime compound includes, for example, 1,2-octanedione 1-[4-(phenylthio)-2-(O-benzyl oxime)], ethyl ketone -1-[9-Ethyl-6-(2-methylbenzyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), ethanone-1-[9 -Ethyl-6-(2-methyl-4-tetrahydrofuranylmethoxybenzyl)-9.H.-carbazol-3-yl]-1-(O-acetyloxime) or ethyl Keto-1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxolane)methoxybenzyl}-9 .H.-carbazol-3-yl]-1-(O-acetyl oxime), etc.;

For example, the acetophenone compound is preferably an α-amino ketone compound, and in particular, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butane-1- Ketone, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, 2-methyl-1 -(4-Methylthiophenyl)-2-morpholinopropan-1-one, etc.; As a biimidazole compound, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole etc. are mentioned, for example.

The polymerization initiator contained in the liquid crystal composition of the present disclosure can be appropriately selected from conventionally known compounds and used in terms of curing progresses to the inside of the liquid crystal layer 13 and improving durability, and bending the liquid crystal element. From the viewpoint of good adhesion between the subsequent substrate and the liquid crystal layer, it is preferable to use a polymerization initiator selected from the group consisting of acylphosphine oxide-based polymerization initiators, α-aminophenalkyl ketone-based polymerization initiators, and α-hydroxybenzene At least one polymerization initiator (hereinafter, also referred to as "specific initiator") in the group consisting of an acetone-based polymerization initiator and an oxime ester-based polymerization initiator. In addition, only one type of specific starter to be used may be used, and two or more types may be mixed. Furthermore, a specific initiator and a photopolymerization initiator different from the specific initiator may be used in combination.

Examples of the acylphosphine oxide-based polymerization initiator include: bis(2,4,6-trimethylbenzyl)-phenyl-phosphine oxide (eg, trade name: Irgacure 819 , BASF (BASF) company), bis(2,6-dimethoxybenzyl)-2,4,4-trimethyl-pentylphenylphosphine oxide, 2,4,6-trimethyl benzalyl-diphenyl-phosphine oxide (trade name: Lucirin, TPO: manufactured by BASF, etc.) and the like. Examples of the α-aminophenalkyl ketone-based polymerization initiator include 2-methyl-2-morpholino-1-(4-methylthiophenyl)propan-1-one, 2-dimethylene amino-2-benzyl-1-(4-morpholinylphenyl)butan-1-one and the like. As an α-hydroxyacetophenone-based polymerization initiator, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, etc. are mentioned. As the oxime ester-based polymerization initiator, 1,2-octanedione, 1-[4-(phenylthio)phenyl]-,2-(O-benzyl oxime), ethyl ketone, 1-[9-ethyl-6-(2-methylbenzyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime) and the like.

The ratio of the polymerization initiator in the liquid crystal composition is preferably 0.001 mass % or more, more preferably 0.005 mass % or more, with respect to the total amount of the liquid crystal composition. In addition, the ratio of the polymerization initiator is preferably 7.0 mass % or less, more preferably 5.0 mass % or less, with respect to the total amount of the liquid crystal composition. By setting the ratio of the polymerization initiator to be within the above-mentioned range, the polymerization of the polymerizable compound can be accelerated even if the exposure amount is reduced when the liquid crystal element is irradiated with light, and the alignment controllability of the liquid crystal molecules can be further improved. In terms of better. In addition, as a polymerization initiator, 1 type may be used individually, and 2 or more types may be used in combination.

<Polymerization inhibitor> The liquid crystal composition may further contain a polymerization inhibitor. The polymerization inhibitor can be used to adjust the light sensitivity of the liquid crystal composition, for example. As the polymerization inhibitor to be used, for example, phenol, hydroquinone, p-methoxyphenol, benzoquinone, methoxybenzoquinone, 1,2-naphthoquinone, cresol, p-tert-butyl phthaloquinone can be mentioned. Catechols such as diphenols, alkylphenols, alkylbisphenols, phenothiazine, 2,5-di-tert-butylhydroquinone, 2,6-di-tert-butylphenol , octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N,N'-hexamethylene bis(3,5-di-tert-butyl) yl-4-hydroxy-hydrocinnamamide), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 4,4'-methylenebis(2,6- Di-tert-butylphenol), 4,4'-butylene bis(3-methyl-6-tert-butylphenol), 2,6-bis(2'-hydroxy-3'-tert-butyl) -5'-methylbenzyl)4-methylphenol, 1,1,3-tris(2'-methyl-5'-tert-butyl-4'-hydroxyphenyl)butane, 1,3 ,5-trimethyl-2,4,6-tris(3'-5'-di-tert-butyl-4'-hydroxybenzyl)benzene, triethylene glycol bis[3-(3-tertiary Butyl-5-methyl-4-hydroxyphenyl)propionate], pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2-th Tributyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenylacrylate, 2,4-dimethyl-6-tert-butylphenol , and phenols such as 2-tert-butyl-4-methoxyphenol, 6-tert-butyl-m-cresol, 2,6-di-tert-butyl-p-cresol, 2-tert-butyl-p-cresol Hydroquinone, methylene blue, copper dimethyl dithiocarbamate, copper diethyl dithiocarbamate, copper dipropyl dithiocarbamate, dibutyl dithiocarbamate At least one of copper carbamate, copper dibutyldithiocarbamate, copper salicylate, thiodipropionate, mercaptobenzimidazole, and phosphite. Moreover, an oxygen-containing gas (air etc.) may be used together.

The usage ratio of the polymerization inhibitor is not particularly limited, but is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, based on the total amount of the liquid crystal composition. In addition, the use ratio of the polymerization inhibitor is preferably 7.0% by mass or less, more preferably 5.0% by mass or less. A polymerization inhibitor can be used individually by 1 type or in combination of 2 or more types.

Examples of other components contained in the liquid crystal composition include, in addition to the above-mentioned components, chiral agents (eg, trade names "C-15", "CB-15" (manufactured by Merck), etc.), Antioxidants, UV absorbers, pigments, defoaming agents, photosensitizers, compatibilizers, etc. The compounding ratio of other components can be suitably selected according to each component within the range which does not impair the effect of this disclosure.

The liquid crystal composition is prepared by mixing a liquid crystal, a polymerizable compound, and optionally prepared components. The treatment of mixing these components may be performed at normal temperature, or may be performed while raising the temperature. In addition, each component may be dissolved in an organic solvent (for example, acetone, chloroform, methanol, etc.), and after that, the solvent may be removed by, for example, a distillation operation.

"Method for manufacturing a liquid crystal element" Next, the manufacturing method of the liquid crystal element 10 is demonstrated. The liquid crystal element 10 can be manufactured by a method including the following steps: Step A, a pair of substrates including the first substrate 11 and the second substrate 12 are arranged to face each other through layers including a liquid crystal composition to construct a liquid crystal cell; and In step B, light irradiation is performed to cure the liquid crystal composition after the construction of the liquid crystal cell. Furthermore, the present manufacturing method does not include the step of forming a liquid crystal alignment film.

(step A: unit construction step) In step A, two substrates having electrodes are prepared, and a liquid crystal cell is produced by disposing a layer of a liquid crystal composition between the two substrates facing each other so that the electrode formation surfaces are opposed to each other. Specifically, the following methods can be mentioned. The peripheral parts of the first base material 11 and the second base material 12 are bonded together by a sealant, and the liquid crystal composition is injected and filled in the cell gap divided by the surface of the base material and the sealant. Then, the method of sealing the injection hole; coating a sealant on the peripheral part of the liquid crystal alignment film side of one of the substrates, and then dripping the liquid crystal composition on a predetermined number of positions on the liquid crystal alignment film surface, and aligning the liquid crystal The film 14 and the liquid crystal alignment film 15 are attached to another substrate in such a way that they face each other, and the liquid crystal composition is spread on the entire surface of the substrate 11 and the substrate 12, and then the sealant is cured (One Drop Filling). , ODF) way) and so on. As a sealing agent, the epoxy resin etc. which contain a hardener and alumina balls as spacers, for example, can be used.

The obtained liquid crystal cell is preferably heated to a temperature at which the liquid crystal to be used acquires an isotropic phase and then slowly cooled to room temperature by annealing treatment to remove the flow alignment at the time of liquid crystal filling (annealing step). The heating temperature for the annealing treatment is appropriately set according to the liquid crystal to be used.

(Step B: Exposure Step) In step B, the process of hardening the liquid crystal composition is performed by performing one or more processes selected from heating and light irradiation. By the hardening reaction, the liquid crystal layer 13 in which the polymer network is formed can be obtained. In the case of hardening by heat, the heating temperature is, for example, 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 irradiation amount of light is preferably 50 mJ/cm ² or more, and more preferably 100 mJ/cm ² or more. In addition, the irradiation amount of light is preferably 10,000 mJ/cm ² or less, and more preferably 5,000 mJ/cm ² or less. By irradiating the liquid crystal composition with light, the polymerization reaction of the polymerizable compound contained in the liquid crystal composition proceeds. When the liquid crystal composition containing polyorganosiloxane is used, in the liquid crystal element 10 , the polyorganosiloxane exists in the liquid crystal layer 13 at least in the vicinity of the interface with the substrate 11 and the substrate 12 .

Light irradiation at the time of curing the liquid crystal composition, more specifically, is preferably by irradiating light with a wavelength of 313 nm or less for 150 seconds or less at an irradiation amount of ^{50 mW/cm 2 or more, or by irradiating light with a wavelength of 150 mW/cm 2} or more It was performed by irradiating light with a wavelength of 365 nm for 150 seconds or less. From the viewpoint of obtaining a liquid crystal element 10 having higher transparency and light scattering properties and better heat resistance, repetitive driving characteristics, and optical characteristics after bending, the irradiation amount when irradiating light with a wavelength of 313 nm is more preferably set to 55 mW/cm ² or more. In addition, the irradiation amount when irradiating light with a wavelength of 313 nm is preferably 300 mW/cm ² or less, more preferably 200 mW/cm ² or less, and still ^{more preferably 100 mW/cm 2} or less.

The irradiation amount when irradiating light with a wavelength of 365 nm is more preferably 155 mW/cm ² or more. In addition, from the viewpoint of improving the yield when irradiated with light having a wavelength of 365 nm, the irradiation amount is preferably 1000 mW/cm ² or less, more preferably 500 mW/cm ² or less, and still more preferably 300 mW/cm 2 or less. mW/cm ² or less.

The irradiation time when irradiating light with a wavelength of 313 nm or a wavelength of 365 nm is more preferably 1 second or more, more preferably 2 seconds or more, and particularly preferably 10 seconds or more. Moreover, the irradiation time is more preferably 120 seconds or less, more preferably 100 seconds or less, and particularly preferably 60 seconds or less. At the time of light irradiation, at least any one of the process of heating a liquid crystal cell and the process of applying a voltage between electrodes of a liquid crystal cell can be performed.

A series of processing of the said step A and the step B may be performed continuously. Therefore, for example, in the case of applying resin film substrates such as TAC films, (meth)acrylic films, and polyethylene terephthalate (PET) films as the substrates 11 and 12 of the liquid crystal element 10 , the liquid crystal element 10 can be manufactured by a roll-to-roll production method, which is preferable in this respect. As an example, in the process of rewinding the film base material wound into a roll shape, first, in the above-mentioned step A, a liquid crystal cell is produced by the ODF method, and then, in the step B, the liquid crystal cell is arranged between a pair of base materials. The liquid crystal composition was cured, and it was used as a winding body. According to this production method, the productivity on an industrial scale is high, cost reduction can be achieved, and process advantages are great.

The liquid crystal element 10 can be applied to various applications, such as windows of buildings, partitions (partitions) indoors and outdoors, display windows, windows of vehicles (cars, airplanes, ships, railways, etc.), indoor and outdoor It is used as a dimming element in various applications such as advertisements, guide signs, home appliances, mobile phones, smart phones, various monitors, clocks, portable game machines, personal computers, glasses, sunglasses, medical equipment, furniture, etc. Use effectively. The liquid crystal element 10 may be used as it is, depending on the thickness, hardness, shape, application, and the like of the element, or may be used by being attached to glass, transparent resin, or the like.

(Second Embodiment) Next, the second embodiment will be described. In addition, in this specification, in order to simplify description, it demonstrates centering on the difference from 1st Embodiment.

The liquid crystal element of this embodiment is a polymer-dispersed liquid crystal element, and includes a pair of substrates including a first substrate 11 and a second substrate 12 , and a pair of substrates disposed between the first substrate 11 and the second substrate 12 the liquid crystal layer 13 (refer to FIG. 1 ).

The liquid crystal composition for forming the liquid crystal layer 13 contains a liquid crystal and a polymerizable compound. As the liquid crystal, in addition to the liquid crystal exemplified in the first embodiment, for example, a liquid crystal composition having a negative dielectric constant anisotropy that is commercially available as a liquid crystal composition for vertical alignment (VA) mode can be used (For example, MLC-6608, MLC-6609, MLC-6610, MLC-6882, MLC-6686, MLC-7026-000, MLC-7026-100, MLC-7029, etc. manufactured by Merck) are used as Raw liquid crystal. The liquid crystal preferably has a negative dielectric constant anisotropy. Regarding the polymerizable compound, the description of the first embodiment can be applied. In addition, the liquid crystal composition preferably contains a silicon-containing compound, more preferably contains a polyorganosiloxane as the silicon-containing compound, and more preferably contains a functional polyorganosiloxane. The silicon-containing compound and the polyorganosiloxane are applicable to the description of the first embodiment.

In the second embodiment, when manufacturing a liquid crystal element, in step B, by irradiating light with a wavelength of 313 nm or less for 150 seconds or less at an irradiation dose of ^{50 mW/cm 2 or more, or irradiating with an irradiation dose of 150 mW/cm 2} or more Light irradiation at the time of curing the liquid crystal composition was performed with light having a wavelength of 365 nm for 150 seconds or less. By irradiating light under such conditions, it is possible to obtain a liquid crystal element having high transparency and light scattering properties, and good heat resistance, repetitive driving properties, and optical properties after bending. Regarding step B and other steps, the description of the first embodiment can be applied. [Example]

Hereinafter, although an Example demonstrates more concretely, this disclosure is not limited to these Examples.

In the following Examples and Comparative Examples, the weight average molecular weight and epoxy equivalent of the polymer were measured by the following methods. [Weight Average Molecular Weight of Polymer] The weight average molecular weight is a polystyrene conversion value measured by gel permeation chromatography under the following conditions. Column: Tosoh Co., Ltd., TSKgelGRCXLII Solvent: Tetrahydrofuran Temperature: 40°C Pressure: 68 kgf/cm ² [Epoxy equivalent] The epoxy equivalent is determined by Japanese Industrial Standards (JIS) C Measured by the hydrochloric acid-methyl ethyl ketone method described in 2105.

The structural formula of the compound used in this Example is shown below. In addition, below, "the compound represented by formula (X)" may be abbreviated as "compound (X)" for convenience. [hua 5]

[hua 6]

[hua 7]

[hua 8]

<Synthesis of polyorganosiloxane> [Synthesis example 1] 100 g of compound (a-1), 500 g of methyl isobutyl ketone and 10 g of triethylamine were mixed at room temperature. Then, after 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, the reaction was performed at 80° C. for 6 hours while stirring under reflux. After the reaction was completed, the organic layer was taken out and washed with a 0.2 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 viscous transparent liquid. Form to obtain reactive polyorganosiloxane (ESSQ-1). ^{The 1} H-NMR (Nuclear Magnetic Resonance, NMR) analysis of the reactive polyorganosiloxane (ESSQ-1) showed that a peak based on epoxy groups could be obtained around chemical shift (δ)=3.2 ppm. The weight average molecular weight Mw of the obtained reactive polyorganosiloxane (ESSQ-1) was 3000, and the epoxy equivalent weight was 190 g/mol.

[Synthesis Example 2] A reactive polyorganosiloxane (ESSQ-2) was synthesized in the same manner as in Synthesis Example 1 except that the types and amounts of the monomers used were changed as described in Table 1 below. In addition, in Table 1, the numerical value of a monomer column shows the ratio (mol part) of each compound with respect to 100 mol parts of the total amount of monomers used for the synthesis|combination of polyorganosiloxane. "-" in Table 1 indicates that the compound in the corresponding column is not used (the same applies to Table 2, Table 3, and Table 5).

[Table 1] polymer name Monomer (mol parts) a-1 a-2 Synthesis Example 1 ESSQ-1 100 - Synthesis Example 2 ESSQ-2 80 20

[Synthesis Example 3] Into a 500 mL three-necked flask were placed 10.0 g of reactive polyorganosiloxane (ESSQ-1), 300 g of methyl isobutyl ketone as a solvent, and 3.10 g of compound (b-1) as a modification component (relative to The number of monomer units contained in the reactive polyorganosiloxane is 20 mol parts from 100 mol parts), and 3.24 g of the compound (b-2) (relative to the monomer units contained in the reactive polyorganosiloxane) The number of body units is 100 mol parts instead of 10 mol parts), and UCAT 18X (trade name, manufactured by San-Apro Co., Ltd.) as a catalyst 0.10 g, at 100 ° C, 48 The reaction was carried out with stirring for hours. After the completion of the reaction, the solution obtained by adding ethyl acetate to the reaction mixture was washed three times with water, the organic layer was dried using magnesium sulfate, and then the solvent was distilled off to obtain a polymerizable group and an alignment group. of polyorganosiloxane (set it as polymer (PSQ-1)) 14.1 g. The weight average molecular weight Mw of the obtained polymer was 8200.

[Synthesis Example 4] A polyorganosiloxane having an alignment group was synthesized in the same manner as in Synthesis Example 3, except that the types and amounts of the reactive polyorganosiloxane and modified components used were changed as described in Table 2 below. (PSQ-2). In addition, in Table 2, the numerical value in the column of the modified component represents the usage ratio (mol ear portion).

[Table 2] polymer name reactive polymer Modified ingredients (mol parts) b-1 b-2 Synthesis Example 3 PSQ-1 ESSQ-1 20 10 Synthesis Example 4 PSQ-2 ESSQ-2 30 -

<Evaluation method of polymer-dispersed liquid crystal element> The polymer-dispersed liquid crystal cells produced in the following Examples and Comparative Examples were evaluated by the following methods. (1) Evaluation of transparency With respect to the polymer dispersion-type liquid crystal elements produced in the examples and comparative examples, the transparency when no voltage was applied was evaluated by measuring the haze (HAZE) in the state in which no voltage was applied. The measurement was performed using a spectroscopic haze meter (manufactured by Tokyo Denshoku Co., Ltd.). Regarding the evaluation, the case where the haze value was less than 3% was “good (○)”, the case where the haze value was not less than 3% and less than 10% was “acceptable (△)”, and the case where the haze value was not less than 10% was defined as “good (△)”. "Bad (×)".

(2) Evaluation of light scattering properties Regarding the polymer-dispersed liquid crystal elements produced in the Examples and Comparative Examples, the light scattering properties at the time of voltage application were evaluated by measuring the haze value in the state where the voltage was applied. The measurement was performed by applying 40 V to the polymer-dispersed liquid crystal element by AC driving and using a spectroscopic haze meter (manufactured by Tokyo Denshoku Co., Ltd.) in the same manner as in the above (1). Regarding the evaluation, the case where the haze value was more than 90% was set as "good (○)", the case where the haze value was less than 90% and more than 85% was set as "good (△)", and the case where the haze value was less than 85% was set as "defective" (×)”.

(3) Evaluation of Adhesion The tensile strength of the polymer-dispersed liquid crystal cell was measured by applying tension to the polymer-dispersed liquid crystal cell produced in the Examples and Comparative Examples until it broke, and the adhesion was evaluated based on the measured value. The measurement was performed by immobilizing one of the substrates of the polymer-dispersed liquid crystal element and applying tension to the other substrate using a small desktop tester (manufactured by Shimadzu Corporation). Regarding the evaluation, the case where the maximum stress was larger than 40 N was regarded as "good (○)", the case of 40 N or less and more than 20 N was regarded as "acceptable (△)", and the case of 20 N or less was regarded as "poor ( ×)".

(4) Evaluation of heat resistance The polymer-dispersed liquid crystal cells produced in Examples and Comparative Examples were stored in an oven at 100° C. for 200 hours. After 200 hours, the polymer-dispersed liquid crystal element was taken out, and the haze value HA1 in the state in which the voltage was not applied and the haze value HA2 in the state in which the voltage was applied were measured. Regarding the evaluation, the case where the value of ΔHZ1 obtained by the following formula (1) was less than 5% was set as “excellent (⊚)”, and the case of 5% or more and less than 7.5% was set as “good (○)” )”, the case of 7.5% or more and less than 10% was designated as “OK (△)”, and the case of 10% or more was designated as “Bad (×)”. ΔHZ1=(HB2-HB1)-(HA2-HA1)…(1) (In the formula (1), HB1 is the haze value measured in a state where no voltage is applied before heat is applied, HB2 is the haze value measured in a state where a voltage is applied before heat is applied, and HA1 is the haze value measured before heat is applied. The haze value measured in the state where no voltage is applied after that, HA2 is the haze value measured in the state where voltage is applied after applying heat)

(5) Evaluation of repetitive driving performance After applying a voltage of 40 V to the polymer-dispersed liquid crystal elements produced in the Examples and Comparative Examples for 1 hour by AC driving, the state where no voltage was applied was maintained for 1 hour. This voltage application-non-application operation was counted as one, and repeated 100 times. After that, the haze value HC1 in the state in which the voltage was not applied and the haze value HC2 in the state in which the voltage was applied were measured. Regarding the evaluation, the case where the ΔHZ2 obtained by the following formula (2) was less than 3% was set as "good (○)", and the case where it was 3% or more and less than 10% was set as "acceptable (△)" , and 10% or more were set as "defective (×)". ΔHZ2=(HB2-HB1)-(HC2-HC1)…(2) (In Equation (2), HB1 is the haze value measured in the state where no voltage is applied before repeated driving, HB2 is the haze value measured in the state where voltage is applied before repeated driving, and HC1 is the haze value measured at The haze value measured in the state of no voltage application after repeated driving, HC2 is the haze value measured in the state of voltage application after repeated driving)

(6) Evaluation of bending resistance The polymer-dispersed liquid crystal cells produced in Examples and Comparative Examples were wound around a metal rod having a diameter of 2 cm. After that, the adhesiveness was evaluated in the same manner as in the above (3). Regarding the evaluation, the case where the maximum stress was larger than 40 N was regarded as “excellent (⊚)”, the case of 40 N or less and more than 30 N was regarded as “good (○)”, and the case of 30 N or less and more than 20 N was regarded as “good (○)”. It is "acceptable (△)", and the case of 20 N or less is "defective (×)".

(7) Optical properties after bending resistance test In the same manner as in the evaluation of the bending resistance described in the above (6), after the polymer-dispersed liquid crystal element was wound on a metal rod having a diameter of 2 cm, the transparency was measured by the same operation as in the above (1) and (2). and light scattering. Regarding the evaluation, the case where the ΔHZ3 obtained by the following formula (3) was less than 5% was set as "good (○)", and the case where 5% or more and less than 10% was set as "acceptable (△)" , and 10% or more were set as "defective (×)". ΔHZ3=(HB2-HB1)-(HD2-HD1)…(3) (In Equation (3), HB1 is the haze value measured in the state where no voltage is applied before the bending resistance test, HB2 is the haze value measured in the state where the voltage is applied before the bending resistance test, HD1 is the Haze value measured in the state of no voltage applied after the bending resistance test, HD2 is the haze value measured in the state of applying voltage after the bending resistance test)

(8) Contrast evaluation A spectrophotometer (150-20 type Double Beam manufactured by Hitachi, Ltd.) was used for the liquid crystal element in which the dye was blended in the liquid crystal layer among the polymer-dispersed liquid crystal elements produced in the Examples and Comparative Examples. ) were evaluated for contrast. For evaluation, first, the light transmittance (%) was measured in a state where no voltage was applied, and the average value of the light transmittance at wavelengths of 450 nm, 550 nm, and 650 nm was calculated. Next, the light transmittance (%) was measured in a state where a voltage of 40 V was applied by AC driving, and the average value of the light transmittance at wavelengths of 450 nm, 550 nm, and 650 nm was calculated. Next, the contrast ratio (C value) was calculated according to the following formula (4). C value = light transmittance in the state where no voltage is applied / light transmittance in the state where voltage is applied ... (4) Regarding the evaluation, the case where the C value was 15% or more was set as "good (○)", and the case where it was less than 15% was set as "poor (x)". It can be judged that the higher the light transmittance in the state where no voltage is applied, the higher the light transmittance, and the lower the light transmittance during voltage driving, the higher the light blocking property, and the better the contrast.

(9) Adhesion after bending resistance test In the same manner as in the above (6) evaluation of bending resistance, after winding the polymer-dispersed liquid crystal element on a metal rod with a diameter of 2 cm, the tensile strength was measured by the same operation as in the above (3), and the adhesion was evaluated. sex. Regarding the evaluation, the case where the maximum stress was more than 30 N was set as "good (○)", the case where the maximum stress was 30 N or less and more than 20 N was set as "good (△)", and the case where the maximum stress was less than 20 N was set as "poor ( ×)".

[First Embodiment] <Manufacture and evaluation of polymer-dispersed liquid crystal element> [Example 1A] (1) Preparation of liquid crystal composition By adding compound (d-1), compound (e-1), compound (f-1), compound (RM-2) and polymer (PSQ-1) to the total of all the constituent components of the liquid crystal composition Quantitatively, the content ratios of the constituent components were 0.01 mass %, 3 mass %, 15 mass %, 3 mass %, and 1 mass %, respectively. 5) 2 g, 1 g of the liquid crystal compound (L-8), and 2 g of the liquid crystal compound (L-9) were mixed in the liquid crystal compound to obtain a liquid crystal composition (PLC-X1) (see Table 3).

(2) Manufacture of polymer-dispersed liquid crystal element A pair of PET film substrates (PET-ITO substrates) having an ITO electrode on the surface was prepared in a 10 cm square. No liquid crystal alignment films were formed on the two substrates, a spacer of 18 μm was coated on the electrode configuration surface of one of the substrates, and then the prepared liquid crystal composition (PLC- X1). Next, the two base materials were bonded together through a sealant so that the electrode arrangement surfaces of the two base materials faced each other, and a liquid crystal cell was obtained. Next, the obtained liquid crystal cell was heated on a hot plate at 80° C. (annealing step). This annealing step is a step of heating to a temperature equal to or higher than the liquid crystal transition temperature at which the liquid crystal becomes an isotropic phase. Next, after cooling the liquid crystal cell to room temperature, using an ultraviolet irradiation device equipped with a bandpass filter that transmits wavelengths around 313 nm and using a high-pressure mercury lamp as a light source, at a wavelength of 313 nm and an ultraviolet intensity of 60 mW/ The ^{liquid crystal cell was irradiated with non-polarized ultraviolet rays (exposure step) under the conditions of cm 2} and irradiation time of 30 seconds to harden the liquid crystal composition (PLC-X1) to obtain a polymer-dispersed liquid crystal cell. When irradiating the ultraviolet rays, the surface temperature of the substrate is not heated, and the ultraviolet rays are irradiated without applying a voltage to the liquid crystal cell.

(3) Determination of surface coverage Next, regarding the obtained polymer-dispersed liquid crystal element, the liquid crystal layer was peeled off from the two PET-ITO substrates by hand, and the liquid crystal layer was peeled off from the substrate at the boundary portion between the liquid crystal layer and the substrate. On the entire surface of the ITO electrode surface of the substrate from which the liquid crystal layer was peeled off, unevenness due to the remaining of the liquid crystal layer was visually confirmed. Next, the peeled substrate was immersed in hexane at 23° C. for 30 seconds, immersed and washed, and air-dried. The surface of the ITO electrode surface of the dried substrate was subjected to elemental analysis using XPS (manufactured by Nippon Vacuum (ULVAC-PHI) Co., Ltd.), and the ratio of silicon atoms to the total of carbon atoms, oxygen atoms, and silicon atoms on the ITO electrode was calculated. (Silicon Surface Coverage). As a result, the silicon surface coverage in this example is the value on the side of the base material (liquid crystal dropping base material) on which the liquid crystal composition (PLC-X1) was dropped among the two base materials of the polymer-dispersed liquid crystal element. was 1.02%, and the value on the other substrate (opposing substrate) side was 0.96%.

(4) Evaluation of polymer-dispersed liquid crystal elements The respective evaluations of (1) to (7) and (9) in the above-mentioned <Evaluation Method of Polymer Dispersion Type Liquid Crystal Cell> were performed using the polymer-dispersed liquid crystal cell produced in the above (2). The evaluation results are shown in Table 4 below.

[Example 2A to Example 10A and Comparative Example 1A to Comparative Example 3A] Liquid crystal compositions (PLC -X2) to liquid crystal composition (PLC-X13). In addition, the numerical value in the parenthesis in Table 3 shows the compounding amount. In addition, using each of the prepared liquid crystal compositions, a polymer-dispersed liquid crystal cell was produced in the same manner as in Example 1A, and various evaluations were performed in the same manner as in Example 1A. The results of these evaluations are shown in Table 4 below. Furthermore, with regard to Example 3A, Example 4A, Example 6A, and Example 8A, and Comparative Example 2A and Comparative Example 3A, an ultraviolet irradiation device using an ultraviolet irradiation diode as a light source was used. Unpolarized ultraviolet rays were irradiated under the same conditions as in Example 1A to cure the liquid crystal composition to obtain a polymer-dispersed liquid crystal element. Regarding Example 7A, the liquid crystal composition was cured by irradiating non-polarized ultraviolet rays under the conditions of a wavelength of 365 nm, an ultraviolet intensity of 160 mW/cm ^{2 and an irradiation time of 60 seconds using an ultraviolet irradiation device using an ultraviolet irradiation diode as a light source.} Thus, a polymer-dispersed liquid crystal element was obtained. The evaluation of (9) was performed with respect to Example 9A and Example 10A.

[table 3] Composition name Liquid crystal composition Silicon surface coverage Liquid crystal (g) Polymerization inhibitor (wt%) Initiator (wt%) Compatibilizer (wt%) Polymeric compound (wt%) Silicon-containing compound (wt%) Liquid crystal drop substrate surface [%] Opposite substrate surface [%] specific liquid crystal Other LCD polymerizable liquid crystal compound other PLC-X1 L-1 (5) L-8 (1) L-5 (2) L-9 (2) - - d-1 (0.01) e-1(3) f-1 (15) RM-2 (3) - PSQ-1 (1) 1.02 0.96 PLC-X2 L-2 (4) - L-9 (3) L-10 (3) - - d-1 (0.05) e-1 (0.5) - RM-1 (1) - PSQ-1 (0.1) 0.06 0.07 PLC-X3 L-6 (5) - L-3 (1) L-4 (2) L-9 (1) L-10 (1) d-1 (0.1) e-1(5) f-1 (5) RM-2 (1) - PSQ-2 (1) 2.00 1.50 PLC-X4 L-7 (1) - L-10 (9) - - - d-1 (0.01) e-1(3) - RM-1 (1) - PSQ-1 (10) 5.20 5.30 PLC-X5 L-1 (2) - L-4 (1) L-10 (7) - - d-1 (0.01) e-1(3) f-1 (l0) RM-2 (1) - PSQ-1 (5) 4.81 4.76 PLC-X6 L-2 (2) - L-5 (2) L-9 (3) L-10 (3) - d-1 (0.01) e-1(3) f-1(3) RM-2 (3) - PSQ-2 (0.01) 0.11 0.10 PLC-X7 L-6 (3) - L-10 (7) - - - d-1 (0.01) e-1(3) f-1(1) RM-2 (3) - PSQ-1 (2) 2.14 2.22 PLC-X8 L-1 (2) L-6 (3) L-3 (2) L-10 (3) - - d-1 (0.01) e-1(3) f-1 (15) RM-2 (3) - PSQ-1 (3) 3.51 3.58 PLC-X9 L-1 (5) L-8 (1) L-5 (2) L-9 (2) - - d-1 (0.01) e-1(3) f-1 (15) - ACR-1 (5) - 0.00 0.00 PLC-X10 - - L-9 (5) L-10 (5) - - d-1 (0.01) e-1(3) f-1 (5) RM-2 (1) - TEOS (0.1) 0.04 0.04 PLC-X11 - - L-9 (5) L-10 (5) - - d-1 (0.01) e-1(3) f-1 (5) RM-2 (1) - ODTES (0.1) 0.02 0.04 PLC-X12 L-1 (5) L-8 (1) L-5 (2) L-9 (2) - - d-1 (0.01) e-2(3) f-1 (15) RM-2 (3) - PSQ-1 (1) 1.11 0.98 PLC-X13 L-1 (5) L-8 (1) L-5 (2) L-9 (2) - - d-1 (0.01) e-3(3) f-1 (15) RM-2 (3) - PSQ-1 (1) 1.07 1.01

Abbreviations in Table 3 are as follows. ACR-1: dipentaerythritol hexaacrylate TEOS: Tetraethoxysilane ODTES: n-octadecyltriethoxysilane

[Table 4] Composition name Evaluation results Transparency (haze when no voltage is applied) Light Scattering (Haze under Voltage Application) tightness heat resistance Repeat drive resistance Bending resistance Optical properties after bending resistance test Adhesion after bending resistance test Example 1A PLC-X1 ○ ○ ○ ◎ ○ ◎ ○ △ Example 2A PLC-X2 △ △ △ △ △ △ △ - Example 3A PLC-X3 ○ ○ ○ ◎ ○ ◎ ○ - Example 4A PLC-X4 △ △ △ △ △ △ △ - Example 5A PLC-X5 ○ ○ ○ ○ ○ ○ ○ - Example 6A PLC-X6 ○ ○ ○ ○ ○ ○ ○ - Example 7A PLC-X7 ○ ○ ○ ◎ ○ ◎ ○ - Example 8A PLC-X8 ○ ○ ○ ○ ○ ○ ○ - Comparative Example 1A PLC-X9 × ○ × × × × × - Comparative Example 2A PLC-X10 △ △ ○ △ △ × × - Comparative Example 3A PLC-X11 ○ △ ○ × △ × × - Example 9A PLC-X12 ○ ○ ○ ◎ ○ ◎ ○ ○ Example 10A PLC-X13 ○ ○ ○ ◎ ○ ◎ ○ ○

As shown in Table 4, according to Examples 1A to 10A, when the liquid crystal alignment film is not provided, various properties (transparency, light scattering properties, adhesion, heat resistance, repetitive driving properties, bending resistance, and bending Optical properties after the resistance test) are also "◎", "○" or "△". On the other hand, in the comparative example 1A - the comparative example 3A, it is "x" in two or more evaluation items, and it is inferior to Example 1A - Example 10A.

That is, in the examples (Comparative Examples 1A to 3A) with a silicon surface coverage of 0.04% or less, the bending resistance and the optical properties after the bending resistance test were both evaluated as "X", whereas the silicon surface was covered with In the examples (Examples 1A to 10A) with a ratio of 0.06% or more, the bending resistance and the optical properties after the bending resistance test were "⊚", "○", or "△", which were superior to the comparative examples. In addition, in the case where the silicon surface coverage was 0.06% or more, the transparency and the light scattering property were evaluated as "○" or "△", which were good as the basic characteristics of the polymer-type liquid crystal element. In addition, the evaluations regarding adhesion, heat resistance, and repetitive driving characteristics are also "⊚", "○", or "△". In particular, in the examples (Example 1A, Example 3A, Example 5A to Example 10A) in which the silicon surface coverage was in the range of 0.10% or more and 5.0% or less, any evaluation item was "◎" or "" ○”, very excellent.

In an example (Example 1A to Example 10A) in which a liquid crystal layer in a liquid crystal cell without a liquid crystal alignment film was formed using a liquid crystal composition containing a specific liquid crystal and a polymerizable liquid crystal compound, the optical properties after bending resistance and bending resistance test The characteristic is "◎", "○", or "△". In these examples, the evaluation of transparency and light-scattering property was "○" or "△", and the basic characteristics as a polymer-type liquid crystal element were also favorable. In addition, in this example, the evaluations of adhesion, heat resistance, and repetitive driving characteristics were also "⊚", "○", or "△", which were superior to Comparative Examples 1A to 3A.

In addition, from the results of Example 9A and Example 10A, it was found that by using an α-hydroxyacetophenone-based polymerization initiator or an acylphosphine oxide-based polymerization initiator, transparency, light scattering properties, and adhesiveness were maintained. , heat resistance, repeated driving characteristics, bending tolerance and optical properties after bending tolerance test, and at the same time, the adhesiveness after bending tolerance test can be improved, so that an excellent polymer-dispersed liquid crystal element can be obtained.

[Second Embodiment] <Manufacture and evaluation of polymer type liquid crystal element> In the second example, the relationship between exposure conditions and element characteristics was studied. [Example 1B] (1) Preparation of liquid crystal composition The compound (d-1), the compound (e-1), the compound (f-1), the compound (RM-1) and the polymer (PSQ-1) were calculated by the total amount with respect to all the constituent components of the liquid crystal composition. Said that the content ratio of each constituent component is 0.01 mass %, 3 mass %, 15 mass %, 5 mass %, 0.001 mass % and added to nematic liquid crystal (Merck (Merck), MLC-6608) 10 g and mixed to obtain a liquid crystal composition (PLC-1) (see Table 5).

(2) Manufacture of polymer-dispersed liquid crystal element A pair of PET film substrates (PET-ITO substrates) having an ITO electrode on the surface was prepared in a 10 cm square. No liquid crystal alignment films were formed on the two substrates, a spacer of 18 μm was coated on the electrode configuration surface of one of the substrates, and then the prepared liquid crystal composition (PLC- 1). Next, the two base materials were bonded together through a sealant so that the electrode arrangement surfaces of the two base materials faced each other, and a liquid crystal cell was obtained. Next, the obtained liquid crystal cell was heated on a hot plate at 80° C. to a temperature equal to or higher than the liquid crystal transition temperature at which the liquid crystal became an isotropic phase (annealing step). Next, after the liquid crystal cell was lowered to room temperature, the liquid crystal cell was irradiated under the conditions of a ^{wavelength of 313 nm, an ultraviolet intensity of 60 mW/cm 2} , and an irradiation time of 30 seconds using an ultraviolet irradiation device using an ultraviolet light emitting diode as a light source. Unpolarized ultraviolet rays (exposure step) were used to harden the liquid crystal composition (PLC-1) to obtain a polymer-dispersed liquid crystal element. When irradiating the ultraviolet rays, the surface temperature of the substrate is not heated, and the ultraviolet rays are irradiated without applying a voltage to the liquid crystal cell.

(3) Evaluation of polymer-dispersed liquid crystal elements The respective evaluations of (1) to (7) and (9) described in the above-mentioned <Evaluation Method of Polymer Dispersion Type Liquid Crystal Cell> were performed using the polymer-dispersed liquid crystal cell produced in the above (2). The evaluation results are shown in Table 6 below.

[Example 2B to Example 13B and Comparative Example 1B to Comparative Example 3B] The liquid crystal composition (PLC-2) to the liquid crystal composition (PLC-6) were prepared in the same manner as in Example 1B except that the preparation recipe of the liquid crystal composition was changed as shown in Table 5 below. In addition, using each of the prepared liquid crystal compositions, a polymer-dispersed liquid crystal element was produced in the same manner as in Example 1B, and various evaluations were performed in the same manner as in Example 1B. The results of these evaluations are shown in Table 6 below. In addition, in Examples 8B to 10B, in the exposure step after the annealing step, at least one of the treatment of heating to 60° C. when irradiated with ultraviolet rays and the treatment of applying a DC voltage of 10 V were performed (see Table 1). 6). The evaluation of (9) was performed with respect to Example 13B.

In addition, in Example 12B using the liquid crystal composition (PLC-5), in the evaluation items described in the above-mentioned <Evaluation method of polymer dispersion type liquid crystal element>, "(3) Adhesion" and "(( 8) Contrast evaluation". As a result, in Example 12B, the light transmittance when no voltage was applied was 91%, the light transmittance when AC driving at 40 V was applied was 5%, the C value was 18%, and the contrast was evaluated as "good (○)" . In the same manner, the comparative example 3B was evaluated for contrast, but it was evaluated as "defective (x)".

[table 5] Composition name Raw liquid crystal Polymerization inhibitor (wt%) Initiator (wt%) Compatibilizer (wt%) Polymeric compound (wt%) Silicon-containing compound (wt%) other PLC-1 MLC-6608 d-1 (0.01) e-1(3) f-1 (15) RM-1 (5) PSQ-1 (0.001) - PLC-2 MLC-6608 d-1 (0.01) e-1(3) f-1 (20) RM-2 (0.1) PSQ-2 (0.1) - PLC-3 MLC-6608 d-1 (0.01) e-1(3) f-1 (5) RM-3 (10) PSQ-2 (1) - PLC-4 MLC-6608 d-1 (0.01) e-1(3) f-1(1) RM-4 (15) PSQ-1 (10) - PLC-5 MLC-6608 d-1 (0.01) e-1(3) f-1 (15) RM-1 (1) PSQ-1 (5) dye (3) PLC-6 MLC-6608 d-1 (0.01) e-3(3) f-1 (15) RM-1 (5) PSQ-1 (0.001) -

[Table 6] Composition name Annealing step Exposure step Evaluation results Illuminance (mW/cm ² ) Irradiation time (sec) Heating (60℃) during exposure Apply voltage during exposure Transparency (haze when no voltage is applied) Light Scattering (Haze under Voltage Application) tightness heat resistance Repeat drive resistance Bending resistance Optical properties after bending resistance test Contrast Adhesion after bending resistance test 313 nm 365 nm Example 1B PLC-1 have 60 - 30 none none ○ ○ ○ ◎ ○ ◎ ○ - △ Example 2B PLC-1 have 50 - 150 none none △ △ △ △ △ △ △ - - Example 3B PLC-1 have - 300 10 none none ○ ○ ○ △ ○ △ ○ - - Example 4B PLC-1 have - 500 2 none none ○ ○ △ ○ ○ ○ △ - - Example 5B PLC-1 none 300 - 30 none none △ ○ ○ ○ △ △ △ - - Example 6B PLC-2 have - 150 45 none none ○ ○ ○ ◎ ○ ○ ○ - - Example 7B PLC-3 have 60 - 15 none none ○ ○ ○ ◎ ○ ○ ○ - - Example 8B PLC-1 have - 160 60 have none ○ ○ ○ ○ ○ ○ ○ - - Example 9B PLC-1 have 50 - 100 none have ○ ○ ○ ○ ○ ○ ○ - - Example 10B PLC-1 have 60 - 30 have have ○ ○ ○ ◎ ○ ◎ ○ - - Example 11B PLC-4 have 60 - 30 none none △ △ △ △ △ × △ - - Example 12B PLC-5 have 60 - 30 none none - - ○ - - - - ○ - Comparative Example 1B PLC-1 have 40 - 60 none none ○ × × × × × × - - Comparative Example 2B PLC-1 have - 160 200 none none × △ △ × × × × - - Comparative Example 3B PLC-5 have - 140 60 none none - - × - - - - × - Example 13B PLC-6 have 60 - 30 none none ○ ○ ○ ◎ ○ ◎ ○ - ○

As shown in Table 6, in Example 1B to Example 11B and Example 13B, in the case of not having a liquid crystal alignment film, various properties (transparency, light scattering properties, adhesion, heat resistance, repetitive driving properties and Optical properties after bending resistance test) are also "◎", "○" or "△". On the other hand, in Comparative Example 1B and Comparative Example 2B, four or five evaluation items were "X", which were inferior to Examples 1B to 11B and Example 13B. In addition, in Example 12B which mix|blended the pigment|dye, the evaluation of the adhesiveness and contrast was "○", and the comparative example 3 was the evaluation of "X".

In addition, according to the results of Example 13B, it was found that by using the acylphosphine oxide-based polymerization initiator, the transparency, light scattering properties, adhesion, heat resistance, repetitive driving characteristics, bending resistance, and bending resistance were maintained after the test. The optical properties are improved, and the adhesion after the bending resistance test is improved, so that an excellent polymer-dispersed liquid crystal element can be obtained.

10: Liquid crystal element 11: The first substrate 12: Second substrate 13: Liquid crystal layer 13a: Polymer Networks 13b: Liquid crystal molecules 16, 17: Transparent electrodes

FIG. 1 is a diagram showing a schematic configuration of a liquid crystal element. FIG. 2( a ) and FIG. 2( b ) are diagrams for explaining the function of the liquid crystal element.

none.

Claims (11)

A liquid crystal element, comprising: a first substrate, provided with a first electrode; a second substrate provided with a second electrode and disposed opposite to the first substrate; and The liquid crystal layer is formed by being disposed adjacent to the first base material and the second base material, and by curing a liquid crystal composition containing a liquid crystal and a polymerizable compound, The liquid crystal element does not have a liquid crystal alignment film, The liquid crystal layer was peeled off from at least one of the first substrate and the second substrate, and the substrate from which the liquid crystal layer was peeled was immersed in hexane at 23° C. for 30 seconds and dried, When the base material surface on the side of the peeling surface after drying is measured by X-ray photoelectron spectroscopy, the ratio of silicon atoms is 0.05% or more and 10% or less with respect to the total amount of carbon atoms, oxygen atoms, and silicon atoms. The liquid crystal element according to claim 1, wherein the liquid crystal includes at least one selected from the group consisting of a cyclohexylcyano group-containing liquid crystal and a diphenylacetylene structure-containing liquid crystal. The liquid crystal element according to claim 1 or claim 2, wherein the liquid crystal composition contains polyorganosiloxane. The liquid crystal element according to claim 3, wherein the polyorganosiloxane has a liquid crystal alignment group. The liquid crystal element according to claim 3, wherein the polyorganosiloxane has a polymerizable group. The liquid crystal element according to claim 1 or claim 2, wherein the polymerizable compound contains a (meth)acryloyl group-containing compound having a molecular weight of 1,000 or less. The liquid crystal element according to claim 1 or claim 2, wherein the liquid crystal composition contains a polymer selected from the group consisting of acylphosphine oxide-based polymerization initiators, α-aminophenalkyl ketone-based polymerization initiators, α-hydroxyl At least one of the group consisting of an acetophenone-based polymerization initiator and an oxime ester-based polymerization initiator. A method for manufacturing a liquid crystal element, comprising: A step of constructing a liquid crystal cell by arranging the first substrate provided with the first electrode and the second substrate provided with the second electrode through a layer of a liquid crystal composition containing a liquid crystal and a polymerizable compound facing each other; and The step of forming a liquid crystal layer by curing the liquid crystal composition by irradiating the liquid crystal cell with light, The liquid crystal element does not have a liquid crystal alignment film, the liquid crystal layer is peeled off from at least one of the first substrate and the second substrate, and the substrate from which the liquid crystal layer is peeled is placed in hexane. The ratio of silicon atoms to the total amount of carbon atoms, oxygen atoms, and silicon atoms was measured by X-ray photoelectron spectroscopy on the surface of the substrate on the peeled side after drying after immersion at 23°C for 30 seconds It is 0.05% or more and 10% or less. The method for producing a liquid crystal element according to claim 8, wherein the light with a wavelength of 313 nm or less is irradiated for 150 seconds or less at an irradiation dose of ^{50 mW/cm 2 or more or 150 seconds or less at an irradiation dose of 150 mW/cm 2} or more The liquid crystal composition was cured with light having a wavelength of 365 nm. A method for manufacturing a liquid crystal element, comprising: arranging a first base material provided with a first electrode and a second base material provided with a second electrode through a layered arrangement including a liquid crystal composition containing a liquid crystal and a polymerizable compound to construct a liquid crystal cell; and by irradiating the liquid crystal cell with light to harden the liquid crystal composition, the liquid crystal cell does not have a liquid crystal alignment film, by irradiating 150 ^{mW/cm 2 or more} The liquid crystal composition is cured by irradiating light with a wavelength of 313 nm or ^{less for 150 seconds or less with an irradiation dose of 150 mW/cm 2} or more with a wavelength of 365 nm for 150 seconds or less. The method for producing a liquid crystal element according to any one of Claims 8 to 10, wherein the liquid crystal composition contains a polymer selected from the group consisting of acylphosphine oxide-based polymerization initiators and α-aminophenalkyl ketone-based polymerization initiators. At least one of the group consisting of an initiator, an α-hydroxyacetophenone-based polymerization initiator, and an oxime ester-based polymerization initiator.

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