Liquid crystal element and emulsion composition

Abstract

A liquid crystal element provided with two transparent conductive film-attached substrates in which transparent conductive films are disposed so as to face each other, and a liquid crystal-polymer composite film sandwiched between the two transparent conductive film-attached substrates, the liquid crystal-polymer composite film containing an alkynol.

Description

Technical Field

[0001] The present invention relates to a liquid crystal element and an emulsion composition. Specifically, it relates to a liquid crystal element capable of switching between a transparent state and a scattering state, and an emulsion composition that can be used in the formation of the liquid crystal element. This application claims priority based on Japanese Patent Application No. 2022-170454 filed on October 25, 2022, and incorporates its content herein. Background Art

[0002] In recent years, the demand for smart glass that can electrically switch the transparency has been increasing. As a dimming material for smart glass, a liquid crystal method, an electrochromic method, an SPD (Suspend Particle Device) method, etc. have been proposed. Among them, the liquid crystal method has attracted much attention because of its extremely short response time and no stress on users.

[0003] In the liquid crystal method, PDLC (Polymer Dispersed Liquid Crystals) is well-known (Non-Patent Document 1). PDLC has a structure in which a liquid crystal-polymer composite film formed by dispersing particulate liquid crystals in a polymer matrix is sandwiched between two transparent conductive substrates.

[0004] Among PDLCs, normal mode driving is the most common. For PDLCs driven in the normal mode, in the state where no voltage is applied, liquid crystal molecules are oriented along the wall surface of the polymer matrix, and a refractive index mismatch occurs between the liquid crystal region and the polymer matrix. Due to this mismatch, light scattering occurs and whitening occurs, thus functioning as a shade. On the other hand, when a voltage is applied to the PDLC, the liquid crystal molecules are oriented along the electric field direction, so that the refractive indices in the liquid crystal region and the polymer matrix are the same, and light is transmitted and becomes transparent.

[0005] PDLC has been put into practical use as a dimming shutter for vehicles such as trains and cars, and for windows, doors, partitions, etc. in buildings such as commercial buildings and hospitals, for the purpose of design and privacy protection. In addition, it is also used as a display device for displaying characters and graphics.

[0006] Since PDLC has flexibility due to the structure of the aforementioned liquid crystal-polymer composite film, it can be made into a film element. Moreover, the film element can be cut and formed. Utilizing such characteristics, users can simply paste it on glass for construction.

[0007] In recent years, due to the improvement of energy conservation awareness, attempts have been made to reduce the air conditioning load by using smart glass on windows and controlling the amount of solar radiation entering the room. However, in the case of PDLC, although it is possible to switch between the presence and absence of light scattering, the scattering is basically forward scattering, resulting in a light transmission element. Therefore, it is almost impossible to control the amount of transmitted light and it cannot contribute to energy conservation.

[0008] Patent Document 1 discloses a liquid crystal element that uses a liquid crystal component having a prescribed dielectric anisotropy and refractive index anisotropy as the liquid crystal component in a liquid crystal composition containing a liquid crystal component and a dichroic dye. By increasing its NI point (nematic-isotropic phase transition temperature), the change amplitude (dynamic range) of the visible light transmittance is high, and the dynamic range can be maintained even after driving at a high temperature. Prior Art Documents Patent Documents

[0009] Patent Document 1: Pamphlet of International Publication No. 2022 / 186062 Non-Patent Documents

[0010] Non-Patent Document 1: D.A. Higgins, Advanced Materials 2000, 12, No. 4 Summary of the Invention Problems to be Solved by the Invention

[0011] PDLC can be considered for use in applications that require durability at high temperatures, such as in-vehicle smart windows, and there is a need to improve durability at high temperatures. However, the liquid crystal elements of Patent Document 1 and Non-Patent Document 1 are not sufficiently durable at high temperatures. Technical Solution for Solving the Problem

[0012] The present inventors found that by containing alkynol in a liquid crystal-polymer composite film, the durability of the liquid crystal element at high temperatures is improved, and thus the present invention was completed. That is, the gist of the present invention is as follows.

[0013] [1] A liquid crystal element, comprising: two substrates with transparent conductive films disposed opposite to each other, and a liquid crystal-polymer composite film sandwiched between the two substrates with transparent conductive films, wherein the liquid crystal-polymer composite film contains alkynol. [2] The liquid crystal element according to [1], wherein the liquid crystal-polymer composite film can switch between a transparent state and a scattering state by applying a voltage. [3] The liquid crystal element according to [1] or [2], wherein the liquid crystal-polymer composite film contains a polymer matrix and a liquid crystal composition, and the liquid crystal composition is present in the polymer matrix. [4] The liquid crystal element according to any one of [1] to [3], wherein the liquid crystal composition contains a nematic liquid crystal or a chiral nematic liquid crystal as a liquid crystal component. [5] The liquid crystal element according to [3] or [4], wherein the polymer constituting the polymer matrix contains at least one selected from polyurethanes, polyacrylic acids, polyvinyl alcohols, and modified products thereof. [6] The liquid crystal element according to any one of [3] to [5], wherein the liquid crystal composition contains a dichroic dye. [7] The liquid crystal element according to [6], wherein the dichroic dye contains at least one selected from anthraquinone dyes and azo dyes. [8] The liquid crystal element according to [6] or [7], wherein, based on 100% by mass of the liquid crystal composition, the content of the dichroic dye is 0.1% by mass or more and 20% by mass or less. [9] The liquid crystal element according to any one of [1] to [8], wherein the alkynol includes alkynediol.

[10] The liquid crystal element according to any one of [1] to [9], wherein the HLB value of the alkynol is 5 to 15.

[11] The liquid crystal element according to any one of [1] to

[10] , wherein the liquid crystal-polymer composite film contains a surfactant other than the alkynol.

[12] The liquid crystal element according to

[11] , wherein the HLB value of the mixture of the alkynol and the surfactant is 5 to 15.

[13] The liquid crystal element according to any one of [1] to

[12] , wherein the substrate with a transparent conductive film is a resin substrate.

[14] An emulsion composition in which a liquid crystal composition is dispersed in a medium containing water, wherein the medium disperses or dissolves a polymer and an alkynol.

[15] The emulsion composition according to

[14] , wherein the liquid crystal composition contains a dichroic dye.

[16] The emulsion composition according to

[15] , wherein the dichroic dye contains at least one selected from anthraquinone dyes and azo dyes.

[17] The emulsion composition according to

[15] or

[16] , wherein, based on 100% by mass of the liquid crystal composition, the content of the dichroic dye is 0.1% by mass or more and 20% by mass or less.

[18] The emulsion composition according to any one of

[14] to

[17] , wherein the alkynol includes alkynediol.

[19] The emulsion composition according to any one of

[14] to

[18] , wherein the HLB value of the alkynol is 5 to 15.

[20] The emulsion composition according to any one of

[14] to

[19] , wherein the medium contains a surfactant other than the alkynol.

[21] The emulsion composition according to

[20] , wherein the HLB value of the mixture of the alkynol and the surfactant is 5 to 15.

[22] The emulsion composition according to any one of

[14] to

[21] , wherein the polymer contains at least one selected from polyurethanes, polyacrylic acids, polyvinyl alcohols, and modified products thereof.

[23] A vision shielding element that uses the liquid crystal element according to any one of [1] to

[13] or the emulsion composition according to any one of

[14] to

[22] .

[0014] The present invention also has the following aspects.

[0015] [1] A liquid crystal-polymer composite film containing an alkynol. [2] The liquid crystal-polymer composite film according to [1], wherein the liquid crystal-polymer composite film contains a liquid crystal composition and a polymer matrix. [3] The liquid crystal-polymer composite film according to [1] or [2], wherein the alkynol is a compound represented by Formula 1 or Formula 2. [4] The liquid crystal-polymer composite film according to any one of [1] to [3], wherein, based on the mass of the liquid crystal-polymer composite film, the content of the alkynol is preferably 1% by mass or more and 5% by mass or less, more preferably 2% by mass or more and 4% by mass or less. [5] The liquid crystal-polymer composite film according to any one of [1] to [4], which contains a liquid crystal composition, and based on the mass of the liquid crystal-polymer composite film, the content of the liquid crystal composition is preferably 40% by mass or more and 70% by mass or less, more preferably 45% by mass or more and 60% by mass or less. [6] The liquid crystal-polymer composite film according to any one of [1] to [5], which contains a liquid crystal composition containing a liquid crystal component, and based on the mass of the liquid crystal-polymer composite film, the content of the liquid crystal component is preferably 25% by mass or more and 60% by mass or less, more preferably 40% by mass or more and 55% by mass or less. [7] The liquid crystal-polymer composite film according to any one of [1] to [6], which contains a liquid crystal composition containing a chiral reagent, and based on the mass of the liquid crystal-polymer composite film, the content of the chiral reagent is preferably 0.04% by mass or more and 4% by mass or less, more preferably 0.1% by mass or more and 2.5% by mass or less. [8] The liquid crystal-polymer composite film according to any one of [1] to [7], which contains a liquid crystal composition containing a dichroic pigment, and the content of the dichroic pigment is preferably 0.2% by mass or more and 10% by mass or less, more preferably 1.5% by mass or more and 6% by mass or less, based on the mass of the liquid crystal-polymer composite film. [9] The liquid crystal-polymer composite film according to any one of [1] to [8], which contains a polymer matrix, and the content of the polymer matrix is preferably 15% by mass or more and 45% by mass or less, more preferably 25% by mass or more and 40% by mass or less, based on 100% by mass of the liquid crystal-polymer composite film.

[10] The liquid crystal-polymer composite film according to any one of [1] to [9], which contains a liquid crystal composition and a polymer matrix, and the mass ratio represented by [liquid crystal composition] / [polymer matrix] of the total mass of the liquid crystal composition to the total mass of the polymer matrix is preferably 0.5 or more and 4 or less, more preferably 1 or more and 3 or less.

[11] An emulsion composition containing an alkynol.

[12] The emulsion composition according to

[11] , wherein the emulsion composition contains a liquid crystal composition, a polymer, and an aqueous medium.

[13] The emulsion composition according to

[11] or

[12] , wherein the alkynol is a compound represented by Formula 1 or Formula 2.

[14] The emulsion composition according to any one of

[11] to

[13] , and the content of the alkynol is preferably 0.4% by mass or more and 5% by mass or less, more preferably 0.9% by mass or more and 4.5% by mass or less, based on the mass of the emulsion composition.

[15] The emulsion composition according to any one of

[11] to

[14] , which contains a liquid crystal composition, and the content of the liquid crystal composition is preferably 15% by mass or more and 40% by mass or less, more preferably 20% by mass or more and 35% by mass or less, based on the mass of the emulsion composition.

[16] The emulsion composition according to any one of

[11] to

[15] , which contains a liquid crystal composition containing a liquid crystal component, and the content of the liquid crystal component is preferably 14% by mass or more and 36% by mass or less, more preferably 19% by mass or more and 32% by mass or less, based on the mass of the emulsion composition.

[17] The emulsion composition according to any one of

[11] to

[16] , which contains a liquid crystal composition containing a chiral reagent, and the content of the chiral reagent is preferably 0.01% by mass or more and 2.2% by mass or less, more preferably 0.02% by mass or more and 1.8% by mass or less, based on the mass of the emulsion composition.

[18] The emulsion composition according to any one of

[11] to

[17] contains a liquid crystal composition containing a dichroic pigment. The content of the dichroic pigment is preferably 0.8% by mass or more and 4% by mass or less, more preferably 1.1% by mass or more and 3.6% by mass or less, based on the mass of the emulsion composition.

[19] The emulsion composition according to any one of

[11] to

[18] contains a polymer. The content of the polymer is preferably 9% by mass or more and 30% by mass or less, more preferably 12% by mass or more and 23% by mass or less, based on 100% by mass of the emulsion composition.

[20] The emulsion composition according to any one of

[11] to

[19] contains a liquid crystal composition and a polymer. The mass ratio represented by [liquid crystal composition] / [polymer] of the total mass of the liquid crystal composition to the total mass of the polymer is preferably 0.5 or more and 4 or less, more preferably 1 or more and 3 or less.

[21] The emulsion composition according to any one of

[11] to

[20] contains an aqueous medium. The content of the aqueous medium is preferably 42% by mass or more and 59% by mass or less, more preferably 45% by mass or more and 56% by mass or less, based on the mass of the emulsion composition.

[22] The emulsion composition according to any one of

[11] to

[21] contains an aqueous medium. The content of water is preferably 42% by mass or more and 52% by mass or less, more preferably 44% by mass or more and 50% by mass or less, based on the mass of the emulsion composition.

[23] In the emulsion composition according to any one of

[11] to

[22] , the viscosity of the emulsion composition at 25°C is preferably 10 mPa·s or more and 10000 mPa·s or less, more preferably 100 mPa·s or more and 2000 mPa·s or less.

[24] A liquid crystal-polymer composite film formed from the emulsion composition according to any one of

[11] to

[22] .

[25] A liquid crystal element includes: two substrates each with a transparent conductive film disposed opposite to each other, and the liquid crystal-polymer composite film according to any one of [1] to

[10] and

[24] sandwiched between the two substrates with transparent conductive films.

[26] A light-shielding element using the liquid crystal element described in

[25] . Advantages of the Invention

[0016] According to the present invention, a liquid crystal element with improved durability at high temperatures can be provided.

[0017] Due to the above characteristics, the liquid crystal element of the present invention can be used for windows, screens, displays, etc. For example, as a vision shielding element, it can be used for windows and partitions of buildings and vehicles. In addition, it can also be used as displays such as advertising boards, display windows, computer terminals, and projections. Detailed Embodiments

[0018] Hereinafter, the present invention will be described in detail. The following description is only an example of the embodiments of the present invention. The present invention is not limited to the following description as long as it does not exceed its gist, and can be arbitrarily modified and implemented within the scope not departing from the gist of the present invention.

[0019] 《Liquid Crystal-Polymer Composite Film》 The liquid crystal-polymer composite film of the present invention contains alkynol. The liquid crystal-polymer composite film of the present invention may be the same composite film as the liquid crystal-polymer composite film in the liquid crystal element described later.

[0020] 《Liquid Crystal Element》 The liquid crystal element of the present invention is a liquid crystal element including: two substrates with transparent conductive films arranged opposite to each other, and a liquid crystal-polymer composite film sandwiched between the two substrates with transparent conductive films, wherein the liquid crystal-polymer composite film contains alkynol.

[0021] [Mechanism] In the liquid crystal element of the present invention, by including alkynol in the above liquid crystal-polymer composite film, the surface tension of the liquid crystal composition decreases and the stability increases, and it is possible to suppress the coalescence of the liquid crystal composition (that is, the particles of the liquid crystal composition aggregate and integrate) in a high-temperature environment, and the durability of the liquid crystal element at high temperatures can be improved. In addition, alkynol can also act as an antifoaming agent in the emulsion composition, so it is possible to improve the stability and film-forming property of the emulsion composition.

[0022] The liquid crystal element of the present invention can switch between a transparent state and a scattering state by applying a voltage. By switching between the transparent state and the scattering state, the transmittance of light can be controlled.

[0023] By making the dielectric anisotropy (Δε) of the liquid crystal component used in the present invention positive, the obtained liquid crystal-polymer composite film is in a transparent state when a voltage is applied and in a scattering state when no voltage is applied, but it can also have a memory property that only requires a voltage to be applied when switching between the transparent state and the scattering state.

[0024] In the present invention, the voltage refers to a DC voltage, an AC voltage, a pulse voltage, or a combination thereof having an effective value above a threshold. In the present invention, the transparent state refers to the state of the liquid crystal-polymer composite film when the above-mentioned voltage is applied or not applied. Among when the voltage is applied and when the voltage is not applied, the state with a smaller haze value of the liquid crystal-polymer composite film is taken as the transparent state. In addition, in the present invention, the scattering state refers to the state of the liquid crystal-polymer composite film when the above-mentioned voltage is applied or not applied. Among when the voltage is applied and when the voltage is not applied, the state with a larger haze value of the liquid crystal-polymer composite film is taken as the scattering state. In the scattering state, it becomes an opaque state in contrast to the transparent state. The haze value in this specification is measured by the method specified in JIS K7136. In addition, the total light transmittance in this specification is measured by the method of JIS K7361-1. In this specification, light means visible light (wavelength 380 nm to 780 nm), and the total light transmittance is measured in the visible light region.

[0025] The haze value of the above-mentioned transparent state in the liquid crystal element of the present invention is preferably 0% or more and less than 50%, more preferably 0% or more and 40% or less, further preferably 0% or more and 20% or less, and particularly preferably 0% or more and 10% or less. If the haze value of the transparent state is within the above range, it is preferable from the viewpoint of excellent transparency.

[0026] The haze value of the above-mentioned scattering state in the liquid crystal element of the present invention is preferably 50% or more, more preferably 60% or more, further preferably 80% or more, and particularly preferably 90% or more. There is no particular limitation on the upper limit, and it can be 100%. Specifically, the haze value of the scattering state in the liquid crystal element of the present invention is preferably 50% or more and 100% or less, more preferably 60% or more and 100% or less, further preferably 80% or more and 100% or less, and particularly preferably 90% or more and 100% or less. If the haze value of the scattering state is within the above range, it is preferable from the viewpoint of excellent visibility shielding.

[0027] The haze difference (dynamic range) between the above-mentioned scattering state and the above-mentioned transparent state in the liquid crystal element of the present invention is represented by [haze value of the scattering state] - [haze value of the transparent state], and is preferably 40% or more, more preferably 60% or more, further preferably 80% or more, and particularly preferably 85% or more. There is no particular limitation on the upper limit, and it is usually 98% or less. Specifically, the haze difference (dynamic range) between the scattering state and the transparent state in the liquid crystal element of the present invention is preferably 40% or more and 98% or less, more preferably 60% or more and 98% or less, further preferably 80% or more and 98% or less, and particularly preferably 85% or more and 98% or less. If the haze difference between the scattering state and the transparent state is within the above range, the angle based on excellent dimming function and suitable for use as a dimming blind is preferred.

[0028] The change range of the haze value of the scattering state after heat treatment at 110 °C for 100 hours and the haze value of the scattering state before heat treatment in the liquid crystal element of the present invention is represented by [haze value of the scattering state after heat treatment] - [haze value of the scattering state before heat treatment], preferably 0% or more and 10% or less, more preferably 0% or more and 8% or less, still more preferably 0% or more and 5% or less, and particularly preferably 0% or more and 3% or less.

[0029] When the liquid crystal composition does not contain the dichroic pigment described below, the total light transmittance of the above transparent state in the liquid crystal element of the present invention is preferably 50% or more and 100% or less, more preferably 60% or more and 100% or less, still more preferably 80% or more and 100% or less, and particularly preferably 90% or more and 100% or less. If the total light transmittance of the transparent state when the dichroic pigment is not contained is within the above range, it is preferred from the viewpoints of transparency and brightness.

[0030] In addition, when the liquid crystal composition contains the dichroic pigment described below, the total light transmittance of the above transparent state in the liquid crystal element of the present invention is preferably 15% or more and 70% or less, more preferably 20% or more and 65% or less, still more preferably 30% or more and 60% or less, and particularly preferably 35% or more and 55% or less. If the total light transmittance of the transparent state when the dichroic pigment is contained is within the above range, it is preferred from the viewpoints of transparency and brightness.

[0031] When the liquid crystal composition does not contain the dichroic pigment described below, the total light transmittance of the above scattering state in the liquid crystal element of the present invention is preferably 50% or more and 100% or less, more preferably 60% or more and 100% or less, still more preferably 80% or more and 100% or less, and particularly preferably 90% or more and 100% or less. If the total light transmittance of the scattering state when the dichroic pigment is not contained is within the above range, it is preferred from the viewpoints of shielding property and brightness.

[0032] In addition, when the liquid crystal composition contains the dichroic pigment described below, the total light transmittance of the above scattering state in the liquid crystal element of the present invention is preferably 0% or more and 20% or less, more preferably 0% or more and 15% or less, still more preferably 0% or more and 10% or less, and particularly preferably 0% or more and 5% or less. If the total light transmittance of the scattering state when containing dichroic pigment is within the above range, the angle based on the shielding property and darkness is preferable.

[0033] The difference in the total light transmittance between the above-mentioned scattering state and the above-mentioned transparent state in the liquid crystal element of the present invention is represented by [total light transmittance of the scattering state value] - [total light transmittance difference of the transparent state], and is preferably 0% or more and 10% or less, more preferably 0% or more and 8% or less, still more preferably 0% or more and 5% or less, and particularly preferably 0% or more and 3% or less.

[0034] The change range of the total light transmittance value after heat treatment at 110 °C for 100 hours and before heat treatment in the above-mentioned scattering state in the liquid crystal element of the present invention is represented by [total light transmittance after heat treatment] - [total light transmittance before heat treatment], and is preferably 0% or more and 10% or less, more preferably 0% or more and 8% or less, still more preferably 0% or more and 5% or less, and particularly preferably 0% or more and 3% or less.

[0035] "Liquid Crystal-Polymer Composite Film" The liquid crystal-polymer composite film contained in the liquid crystal element of the present invention (hereinafter, sometimes referred to as "the liquid crystal-polymer composite film of the present invention") contains alkynol. Alkynol refers to a compound having a carbon-carbon triple bond and a hydroxyl group in each molecule.

[0036] <Alkynol> As long as the alkynol contained in the liquid crystal-polymer composite film of the present invention can be uniformly dispersed in water as a dispersion medium, it can be an asymmetric structure, a symmetric structure, a structure having only 1 hydroxyl group, or a compound having 2 or more hydroxyl groups. Among them, a compound having a plurality of hydrophilic groups and a plurality of hydrophobic groups is preferable; a compound having a gemini structure is more preferable, and the gemini structure has a plurality of hydrophilic groups and a plurality of hydrophobic groups via a carbon-carbon triple bond in each molecule; the gemini structure is still more preferably the target structure.

[0037] As the alkynol having the above asymmetric structure, the structure of the following formula 1 can be cited.

[0038] [Chemical Formula 1]

[0039] (In formula 1, R 11 and R 12 each independently represent a hydrocarbon group having a linear or branched structure and having 1 or more and 8 or less carbon atoms, and A 11 represents a single bond, an oxyalkylene group having a repeating unit number of 1, or a polyoxyalkylene group having a repeating unit number of 2 or more and 30 or less.)

[0040] As a compound having two or more hydroxyl groups, for example, an acetylenic diol represented by the structure of the following formula 2 can be cited.

[0041] [Chemical formula 2]

[0042] (In formula 2, R 21 , R 22 , R 23 and R 24 each independently represent a hydrocarbon group having 1 or more and 8 or less carbon atoms with a straight-chain or branched structure, and A 21 and A 22 each independently represent a single bond, an oxyalkylene group with a repeating unit number of 1, or a polyoxyalkylene group with a repeating unit number of 2 or more and 30 or less.)

[0043] Among them, acetylenic diol is preferred from the perspective of having a high orientation in the liquid crystal composition and obtaining a more excellent stabilization effect because it has multiple hydrophilic groups and multiple hydrophobic groups via an ethynyl group in each molecule, that is, it has a gemini structure.

[0044] In formula 1 and formula 2, R 11 , R 12 , R 21 , R 22 , R 23 and R 24 each independently represent a hydrocarbon group having 1 or more and 8 or less carbon atoms with a straight-chain or branched structure; preferably a hydrocarbon group having 1 or more and 6 or less carbon atoms with a straight-chain or branched structure; more preferably, R 11 , R 21 and R 23 are each independently a hydrocarbon group having 1 or more and 3 or less carbon atoms with a straight-chain or branched structure, and R 12 , R 22 and R 24 are each independently a hydrocarbon group having 4 or more and 6 or less carbon atoms with a straight-chain or branched structure.

[0045] In addition, in formula 1 and formula 2, from the viewpoint of stabilizing the liquid crystal composition, it is preferred that the ethynyl group and the hydroxyl group are bonded to the same carbon atom, and A 11 , A 21 and A 22 are preferably single bonds.

[0046] On the other hand, from the viewpoint of dispersibility in water as a dispersion medium, A 11 , A 21 and A 22 are preferably polyoxyalkylene groups. A 11 , A 21 and A 22When it is a polyoxyalkylene group, A 11 、A 21 and A 22 The number of repeating units of is preferably 2 or more, more preferably 4 or more. As the upper limit, it is preferably 24 or less, more preferably 12 or less, and further preferably 8 or less. Specifically, when A 11 、A 21 and A 22 are polyoxyalkylene groups, A 11 、A 21 and A 22 The number of repeating units of is preferably 2 or more and 24 or less, more preferably 4 or more and 12 or less, and further preferably 4 or more and 8 or less. It should be noted that the number of repeating units refers to n when representing -(OA) n - represents an oxyalkylene group or a polyoxyalkylene group, and (OA) represents an oxyalkylene unit.

[0047] As the oxyalkylene group of A 11 、A 21 and A 22 The number of carbon atoms is preferably 1 or more, more preferably 2 or more. As the upper limit of the number of carbon atoms, it is preferably 12 or less, more preferably 8 or less, and further preferably 4 or less. The above oxyalkylene group can be linear or branched. Specifically, as the oxyalkylene group of A 11 、A 21 and A 22 The number of carbon atoms is preferably 1 or more and 12 or less, more preferably 2 or more and 8 or less, and further preferably 2 or more and 4 or less. In addition, when the number of repeating units of A 11 、A 21 and A 22 is 2 or more, multiple A 11 、A 21 and A 22 can be the same or different. When the number of repeating units of A 21 and A 22 is 1, A 21 and A 22 can be the same or different.

[0048] As the alkynol, examples include: 1-pentyn-3-ol, 2-butyne-1,4-diol, 4,6-nonadecadiyn-1-ol, 2,5,8,11-tetramethyl-6-dodecadiyn-5,8-diol, 5,8-dimethyl-6-dodecadiyn-5,8-diol, 2,4,7,9-tetramethyl-5-dodecadiyn-4,7-diol, 8-hexadecadiyn-7,10-diol, 7-tetradecadiyn-6,9-diol, 2,3,6,7-tetramethyl-4-octadiyn-3,6-diol, 3,6-diethyl-4-octadiyn-3,6-diol, 2,5-dimethyl-3-hexadiyn-2,5-diol, etc. In addition, alkylene oxide derivatives of the above alkynols, etc.

[0049] The alkynol can be used alone or in combination of two or more. From the viewpoint of the stability of the liquid crystal composition, a mixture of a monohydric alcohol and a dihydric alcohol of the alkynol is also preferred.

[0050] The HLB value (i.e., Hydrophile-Lipophile Balance) of the alkynol contained in the liquid crystal-polymer composite film of the present invention is preferably 5 or more and 15 or less. If the HLB value is 5 or more and 15 or less, the dispersibility of the liquid crystal composition in the emulsion composition is excellent, the haze of the scattering state becomes large, and it tends to be easy to obtain a liquid crystal element with excellent visibility shielding. At the same time, from the viewpoint of stabilizing the liquid crystal compound in the liquid crystal-polymer composite film and obtaining a liquid crystal element with excellent heat resistance, the HLB value is more preferably 6 or more and 14 or less, and further preferably 7 or more and 13 or less.

[0051] The liquid crystal-polymer composite film of the present invention may contain a surfactant other than the above alkynol (hereinafter, also referred to as "other surfactant"). In the present invention, the surfactant composed only of alkynol and the mixture of the surfactant other than alkynol and alkynol are collectively referred to as "acetylene-based surfactant".

[0052] As examples of the above other surfactants, the following surfactants, etc. can be cited. Anionic surfactants such as carboxylates, sulfonates, sulfates, and phosphates; Cationic surfactants such as amine salts and quaternary ammonium salts; Amphoteric surfactants such as alkyl amino fatty acid salts, alkyl amine oxides, betaines, sulfobetaines, amide sulfobetaines, carboxybetaines, and imidazolines; Ether types such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene aralkyl ethers, polyoxyethylene aralkyl aryl ethers, polyoxyethylene-polyoxypropylene block adducts, alkyl glucosides, and polyether-modified silicone; ester types such as glycerol fatty acid esters, sorbitan fatty acid esters, and sucrose fatty acid esters; ester / ether types such as polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxyethylene sucrose fatty acid esters; acetyl types such as acetyl-modified polyvinyl alcohol; and nonionic surfactants such as fatty acid alkanolamides.

[0053] Among these, from the perspective of high water solubility and dispersion stability, anionic surfactants are preferred, and sulfonates are particularly preferred. In addition, nonionic surfactants tend to be preferred as they can improve the electrical reliability of liquid crystal elements. Among them, ether types or ester types are preferred, and polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene aralkyl ethers, polyoxyethylene aralkyl aryl ethers, polyoxyethylene-polyoxypropylene block adducts, etc. are particularly preferred.

[0054] When containing the above other surfactants, the content is not particularly limited, but relative to 100% by mass of the mixture of the above alkyne alcohol and the above surfactant, the content of the other surfactant is preferably 20 to 80% by mass, more preferably 20 to 75% by mass. If it is above the lower limit value, the affinity of the alkyne alcohol in water can be improved to enhance dispersibility, and if it is below the upper limit, the heat resistance tends to be excellent.

[0055] In addition, when containing the above other surfactants, relative to the liquid crystal composition, the content of the other surfactant is preferably 0.1% by mass or more, more preferably 0.5% by mass or more. Furthermore, it is preferably 20% by mass or less, more preferably 10% by mass or less. By making the addition amount of the surfactant within the above range, the dispersion of the emulsion is stabilized, and at the same time, the particle size of the liquid crystal composition can tend to be controlled within the desired range. Specifically, when containing the other surfactant, relative to the liquid crystal composition, the content of the other surfactant is preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less.

[0056] Furthermore, when containing the above other surfactants, the mass ratio represented by [content of the above alkyne alcohol] / [content of the above other surfactant] is preferably 20 to 0.5, more preferably 10 to 0.8, and further preferably 5 to 1.

[0057] Relative to 100% by mass of the above acetylene-based surfactant, the content of the above alkyne alcohol is preferably 20 to 100% by mass, more preferably 20 to 100% by mass. If it is above the lower limit value, the affinity of the alkyne alcohol in water can be improved to enhance dispersibility, and if it is below the upper limit, the heat resistance tends to be excellent.

[0058] In the liquid crystal-polymer composite film, based on 100% by mass of the liquid crystal-polymer composite film, the content of the alkynol is preferably 1% by mass or more and 5% by mass or less, more preferably 2% by mass or more and 4% by mass or less. By making the content of the alkynol within the above range, the stability of the liquid crystal-polymer composite film is improved, and the stability during high-temperature storage tends to be good. In the liquid crystal-polymer composite film, based on 100% by mass of the liquid crystal-polymer composite film, the content of the acetylene-based surfactant is preferably 1% by mass or more and 10% by mass or less, more preferably 2% by mass or more and 10% by mass or less, and further preferably 4% by mass or more and 8% by mass or less. By making the content of the acetylene-based surfactant within the above range, the stability of the liquid crystal-polymer composite film is improved, and the stability during high-temperature storage tends to be good. It should be noted that, based on the mass of the acetylene-based surfactant, the total content of the alkynol and the content of the above other surfactants is not more than 100% by mass.

[0059] In addition, for the same reasons as above, the HLB value of the mixture of the alkynol and surfactants other than the alkynol is preferably 5 or more and 15 or less, more preferably 6 or more and 14 or less, and further preferably 7 or more and 13 or less. The HLB value in two or more mixtures can be calculated as the weighted average of the HLB values and weight ratios of the respective components constituting the mixture. In the present embodiment, an alkynol having an HLB value greater than 15 or an alkynol having an HLB value less than 5 can be mixed with other alkynols or surfactants other than the alkynol to make the HLB value of the mixture 5 or more and 15 or less.

[0060] It should be noted that when the above acetylene-based surfactant is a known or commercially available product, the HLB value can be a literature value or a catalog value. When the literature value or catalog value is unknown, it can be obtained by calculation. There are multiple known calculation methods for the HLB value, but in the present specification, it is set as the value obtained by the following Griffin formula. HLB value = 20 × [(molecular weight of the hydrophilic group contained in the surfactant) / (molecular weight of the surfactant)] It should be noted that the "molecular weight of the hydrophilic group" in the formula refers to the partial structure representing hydrophilicity in the alkynol compound. Specifically, for example, the hydrophilic part in the compound represented by the above formula 2 is at A 21 and A 22 is a hydroxyl group when it is a single bond (i.e., two "-OH"), and A 21 and A 22When the hydrophilic moiety is an oxyalkylene group or a polyoxyalkylene group, the hydrophilic moiety is an oxyalkylene group, a polyoxyalkylene group and a hydroxyl group.

[0061] The liquid crystal-polymer composite film of the present invention contains a polymer matrix (hereinafter sometimes referred to as "the polymer matrix of the present invention") and a liquid crystal composition (hereinafter sometimes referred to as "the liquid crystal composition of the present invention"), preferably the liquid crystal composition is present in the above polymer matrix, and more preferably the liquid crystal composition is dispersed in the polymer matrix.

[0062] The liquid crystal-polymer composite film of the present invention contains a polymer matrix and a liquid crystal composition. When the liquid crystal composition is present in the polymer matrix, the liquid crystal element exhibits flexibility. In addition, by having such a structure, even if the liquid crystal element is cut, the leakage of the liquid crystal composition is minimized. In addition, the polymer matrix protects the liquid crystal composition from deterioration factors such as oxygen or moisture, so that cutting and molding can be performed.

[0063] <Liquid crystal composition> The liquid crystal composition of the present invention can be irregularly dispersed in the polymer matrix or regularly arranged in the polymer matrix. In the liquid crystal-polymer composite film of the present invention, as the shape of the liquid crystal composition of the present invention, any one of a regular sphere, a prolate ellipsoid, a cylinder, a triangular prism, a quadrangular prism, a hexagonal prism and other prisms may be used, and these shapes can be deformed. Among these, a regular sphere, a prolate ellipsoid and a cylinder are preferred because they weaken the light scattering of the liquid crystal-polymer composite film, increase the light absorption of the dichroic pigment during coloring, and at the same time tend to reduce the haze in the transparent state.

[0064] In the liquid crystal-polymer composite film of the present invention, from the viewpoint of the transparency of the obtained liquid crystal element, when observing from the film surface of the liquid crystal-polymer composite film, the average particle size of the liquid crystal composition is preferably 2 μm or more, more preferably 5 μm or more. In addition, it is preferably 50 μm or less, more preferably 30 μm or less. By making the average particle size not less than the above lower limit value, the light scattering of the liquid crystal-polymer composite film is weakened, and the haze in the transparent state tends to become smaller. By making the average particle size not more than the above upper limit value, the granular feeling of the liquid crystal composition disappears, and the uniformity of the appearance of the liquid crystal element tends to become good. Specifically, in the liquid crystal-polymer composite film, from the viewpoint of the transparency of the obtained liquid crystal element, when observing from the film surface of the liquid crystal-polymer composite film, the average particle size of the liquid crystal composition is preferably 2 μm or more and 50 μm or less, more preferably 5 μm or more and 30 μm or less.

[0065] From the viewpoint of the light scattering property of the obtained liquid crystal element, when observing from the film surface of the liquid crystal-polymer composite film, the average particle size of the liquid crystal composition is preferably 0.01 μm or more, more preferably 0.1 μm or more. In addition, it is preferably less than 2 μm, more preferably 1 μm or less. By making the average particle size less than the above upper limit value, the light scattering of the liquid crystal-polymer composite film becomes stronger, the haze of the scattering state tends to increase, and in addition, the dynamic range (the haze difference between the scattering state and the transparent state) increases. By making the average particle size of the liquid crystal composition 0.01 μm or more, it is easy to prevent the average particle size from becoming too small (much smaller than the visible light wavelength) and the effect from weakening. Specifically, in the liquid crystal-polymer composite film, from the viewpoint of the light scattering property of the obtained liquid crystal element, when observing from the film surface of the liquid crystal-polymer composite film, the average particle size of the liquid crystal composition is preferably 0.01 μm or more and less than 2 μm, more preferably 0.1 μm or more and 1 μm or less.

[0066] The average particle size of the above liquid crystal composition is the median particle size based on the number. When observing from the film surface of the liquid crystal-polymer composite film, when the shape of the liquid crystal composition is not a circle but a polygon such as an ellipse, a triangle, a quadrilateral, a hexagon or a deformation of these shapes, the particle size can be referred to the diameter of the minimum circumscribed circle. In the above observation, if the particle size is 1 μm or more, it can be directly observed from the liquid crystal-polymer composite film surface with an optical microscope, but in the case where it is less than 1 μm, after cutting out the cross section of the liquid crystal-polymer composite film and washing away the liquid crystal with acetone or the like, conductive treatment is performed by sputtering Au or the like, and thus observation and measurement can be performed using SEM (scanning electron microscope).

[0067] (Liquid crystal component) The liquid crystal composition of the present invention preferably contains a liquid crystal component (hereinafter, sometimes referred to as "the liquid crystal component of the present invention"), and the dielectric anisotropy (Δε) of the liquid crystal component of the present invention is preferably positive. In this case, it is in the normal mode where it is in a scattering state when no voltage is applied and in a transparent state when a voltage is applied. The dielectric anisotropy (Δε) is obtained as follows: Liquid crystal is filled between substrates after alignment treatment in the horizontal or vertical direction, and the capacitance is measured using an LCR meter, so that the dielectric constant (ε / / ) of the liquid crystal component in the state after alignment treatment in the horizontal direction and the dielectric constant (ε⊥) of the liquid crystal component in the state after alignment treatment in the vertical direction can be calculated, and the difference (ε / / - ε⊥) is obtained.

[0068] The NI point (nematic-isotropic phase transition temperature) of the liquid crystal composition of the present invention is preferably 110 °C or higher and 150 °C or lower, more preferably 115 °C or higher and 145 °C or lower, and further preferably 120 °C or higher and 140 °C or lower. When the NI point is above the above lower limit, even under continuous driving at a high temperature of about 90 °C, it tends to be able to maintain the dynamic range of the transmittance change and / or the dynamic range of the haze difference between the scattering state and the transparent state. In addition, the higher the NI point, the larger the dynamic range of the transmittance change and / or the dynamic range of the haze difference between the scattering state and the transparent state tends to be. On the other hand, when the NI point rises, the lower limit temperature of the nematic phase also tends to rise. Therefore, from the viewpoint of operating at low temperatures, the NI point is preferably below the above upper limit.

[0069] The method for measuring the NI point of the liquid crystal composition is not particularly limited, and can be obtained by temporarily making the liquid crystal composition compatible and observing the phase transition or phase separation caused by temperature rise using a polarizing microscope.

[0070] The refractive index anisotropy (Δn) of the liquid crystal composition of the present invention is preferably 0.01 or more, more preferably 0.02 or more, and further preferably 0.03 or more. In addition, it is preferably 0.11 or less, more preferably 0.10 or less. By making Δn below the above upper limit value, the light scattering at the interface between the polymer matrix and the liquid crystal composition decreases, and it tends to be able to reduce the haze in the transparent state. On the other hand, by making Δn above the above lower limit value, the order parameter of the liquid crystal composition tends to become larger. Specifically, the refractive index anisotropy (Δn) of the liquid crystal composition of the present invention is preferably 0.01 or more and 0.11 or less, more preferably 0.02 or more and 0.11 or less, and further preferably 0.03 or more and 0.10 or less.

[0071] The refractive index anisotropy of the liquid crystal composition is obtained by directly obtaining the ordinary light refractive index (no) and extraordinary light refractive index (ne) of the liquid crystal composition and taking their difference (Δn = ne - no). In the case where it is difficult to directly obtain, the phase difference (retardation: R) when passing through a sample with a thickness of d can also be obtained, and it is obtained by dividing it by the thickness d (R = Δnd). The ordinary light refractive index (no) and extraordinary light refractive index (ne) can be measured by the Abbe number method.

[0072] As the liquid crystal contained in the liquid crystal composition, nematic liquid crystals, cholesteric liquid crystals, smectic liquid crystals, etc. can be used. A cholesteric liquid crystal (chiral nematic liquid crystal) can be formed by adding a chiral agent to a nematic liquid crystal. In view of being able to be used inexpensively, nematic liquid crystals or chiral nematic liquid crystals are preferred.

[0073] When using a known liquid crystalline substance as a liquid crystal component, specifically, compounds or mixtures of various low molecular systems such as biphenyl-based, phenylcyclohexane-based, and cyclohexylcyclohexane-based compounds described in "Liquid Crystal Device Handbook" edited by the 142nd Committee of the Japan Society for the Promotion of Science; Nihon Kogyo Shimbunsha (1989), pages 152 to 192 and "Liquid Crystal Handbook" edited by the Liquid Crystal Handbook Editorial Committee; Maruzen Co., Ltd. (2000), pages 260 to 330 can be used. In addition, polymer compounds or mixtures described in "Liquid Crystal Handbook" edited by the Liquid Crystal Handbook Editorial Committee; Maruzen Co., Ltd. (2000), pages 365 to 415 can also be used. As compounds constituting nematic liquid crystals, for example, the following compounds can be cited.

[0074] [Chemical formula 3]

[0075] As cholesteric liquid crystals (chiral nematic liquid crystals), for example, liquid crystals having optical activity by mixing a chiral reagent with the above-mentioned nematic liquid crystals can be used.

[0076] As nematic liquid crystals and cholesteric liquid crystals (chiral nematic liquid crystals), from the viewpoints of high-speed responsiveness of liquid crystal elements and manufacturability of emulsions, liquid crystals with low viscosity and high dielectric anisotropy are preferred.

[0077] With respect to the mass of the liquid crystal composition, the content of the above liquid crystal component is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 98.5% by mass or less. By making the content of the liquid crystal component within the above range, the responsiveness to the applied voltage tends to become good.

[0078] With respect to the mass of the liquid crystal-polymer composite film, the content of the above liquid crystal component is preferably 25% by mass or more and 60% by mass or less, more preferably 40% by mass or more and 55% by mass or less. By making the content of the liquid crystal component within the above range, the liquid crystal tends to be stably held in the polymer composite film.

[0079] (Dichroic pigment) The liquid crystal composition of the present invention may further contain a dichroic pigment in addition to the liquid crystal component. Such a liquid crystal composition is generally known as a guest-host liquid crystal.

[0080] As the dichroic pigment, any dichroic pigment compound compatible with the liquid crystal component can be used, which can be a dichroic pigment with positive Δε or a negative one. In addition, it itself can also exhibit liquid crystallinity.

[0081] As dichroic dyes, specifically, azo dyes, anthraquinone dyes, naphthoquinone dyes, perylene dyes, quinophthalone dyes, tetrazine dyes, benzothiadiazole dyes, etc. can be cited. When using well-known dichroic dyes, those described in "Liquid Crystal Device Handbook" edited by the 142nd Committee of the Japan Society for the Promotion of Science; Nihon Kogyo Shimbunsha (1989), pages 192 to 196 and pages 724 to 730, such as azo dyes, anthraquinone dyes or their mixtures can be used. Among these, those containing at least one selected from anthraquinone dyes and azo dyes are preferred because the absorption coefficient becomes larger, the solubility in the liquid crystal component becomes larger, and the light resistance tends to become higher. Here, anthraquinone dyes refer to compounds having an anthraquinone skeleton in the molecule. Azo dyes refer to compounds having an azo group (-N=N-) in the molecule. One or more dichroic dyes can be used. There is no particular limitation. When the liquid crystal composition contains a dichroic dye, preferably, in the dichroic dye, the total of at least one selected from anthraquinone dyes and azo dyes preferably contains 20% by mass or more, more preferably 50% by mass or more, based on the total mass of the dichroic dye. Specifically, when the liquid crystal composition contains a dichroic dye, the total content of anthraquinone dyes and azo dyes based on the total mass of the dichroic dye is preferably 20% by mass or more and 100% by mass or less, more preferably 50% by mass or more and 100% by mass or less, based on the total mass of the dichroic dye.

[0082] As specific examples of the dichroic dye, for example, compounds represented by the following formula can be cited.

[0083] [Chemical formula 4]

[0084] In the above formula, each X independently represents -NH- or -S-, n represents 0 or 1, and Ar represents a substituted or unsubstituted phenylene group or a substituted or unsubstituted naphthylene group. Each R independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted phenylcycloalkyl group, or a substituted or unsubstituted bicycloalkyl group. As the alkyl group, a linear or branched alkyl group having 1 to 20 carbon atoms is preferred, and a linear or branched alkyl group having 1 to 10 carbon atoms is more preferred. As the alkoxy group, a linear or branched alkoxy group having 1 to 20 carbon atoms is preferred, and a linear or branched alkoxy group having 1 to 10 carbon atoms is more preferred. As the cycloalkyl group, a cycloalkyl group having 3 to 20 carbon atoms is preferred, a cycloalkyl group having 3 to 10 carbon atoms is more preferred, and cyclohexyl is further preferred. As the phenylcycloalkyl group, it is preferably a group formed by bonding a phenyl group to a cycloalkyl group having 3 to 20 carbon atoms, more preferably a group formed by bonding a phenyl group to a cycloalkyl group having 3 to 10 carbon atoms, and still more preferably phenylcyclohexyl. As the bicycloalkyl group, it is preferably a group formed by bonding a cycloalkyl group having 3 to 20 carbon atoms to a cycloalkyl group having 3 to 20 carbon atoms (i.e., a bicycloalkyl group having 6 to 40 carbon atoms), more preferably a group formed by bonding a cycloalkyl group having 3 to 10 carbon atoms to a cycloalkyl group having 3 to 10 carbon atoms (i.e., a bicycloalkyl group having 6 to 20 carbon atoms), and still more preferably bicyclohexyl (cyclohexylhexyl). Examples of the substituent include: an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogen atom, etc.

[0085] When the liquid crystal composition contains a dichroic dye, the content of the dichroic dye is not particularly limited with respect to 100% by mass of the liquid crystal composition. It is preferably 0.1% by mass or more, more preferably 1% by mass or more, and still more preferably 3% by mass or more. In addition, with respect to 100% by mass of the liquid crystal composition, the content of the dichroic dye is preferably 20% by mass or less, more preferably 15% by mass or less, and still more preferably 10% by mass or less. By making the content of the dichroic dye be above the above lower limit value, the obtained liquid crystal element exhibits greater light absorption due to the coloring state, and the amount of transmitted light tends to become smaller. By making the content of the dichroic dye be below the above upper limit value, separation and precipitation of the dichroic dye are less likely to occur, and the reliability of the liquid crystal element tends to be improved. The above upper and lower limits can be arbitrarily combined. For example, when the liquid crystal composition contains a dichroic dye, with respect to 100% by mass of the liquid crystal composition, the content of the dichroic dye is preferably 0.1% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 15% by mass or less, still more preferably 2% by mass or more and 12% by mass or less, and particularly preferably 3% by mass or more and 10% by mass or less.

[0086] When the liquid crystal composition contains a dichroic dye, with respect to the mass of the liquid crystal-polymer composite film, the content of the dichroic dye is preferably 0.2% by mass or more and 10% by mass or less, more preferably 1.5% by mass or more and 6% by mass or less. By making the content of the dichroic dye within the above range, high contrast tends to be achieved.

[0087] In the liquid crystal composition, additives other than the liquid crystal component and the dichroic dye can be contained within a range not impairing the performance of the liquid crystal element of the present invention. Specifically, it can have a polymer precursor, a polymerization initiator, a light stabilizer, an antioxidant, a thickener, a polymerization inhibitor, a photosensitizer, an adhesive, an antifoaming agent, and a chiral agent, etc.

[0088] The chiral reagent may be any chiral compound compatible with the liquid crystal component, and may be a synthetic product or a commercially available product. In addition, it may exhibit liquid crystallinity or have a polymerizable functional group by itself. Further, it may be dextrorotatory or levorotatory, or a dextrorotatory chiral reagent and a levorotatory chiral reagent may be used in combination. In addition, as the chiral reagent, from the viewpoints of reducing the driving voltage and response speed of the liquid crystal element, a chiral reagent having a large positive value of dielectric anisotropy and low viscosity by itself is preferred, and a chiral reagent having a large helical twisting power (Helical Twisting Power), which is an index of the force for twisting the liquid crystal, is more preferred.

[0089] Examples of commercially available chiral reagents include: (R)-4-cyano-4'-(2-methyl)butylbiphenyl (trade name: CB-15, manufactured by Merck), (S)-4-cyano-4'-(2-methyl)butoxybiphenyl (trade name: C15, manufactured by Merck), (S)-4-[1-methylheptyloxy]carbonylphenyl-4-(hexyloxy)benzoate (trade name: S-811, manufactured by Merck), (R)-4-[1-methylheptyloxy]carbonylphenyl-4-(hexyloxy)benzoate (trade name: R-811, manufactured by Merck), bis[4-(4-pentylcyclohexyl)benzoic acid](S)-1-phenylethylene (trade name: S-1011, manufactured by Merck), bis[4-(4-pentylcyclohexyl)benzoic acid](R)-1-phenylethylene (trade name: R-1011, manufactured by Merck), and the like.

[0090] When the liquid crystal composition of the present invention contains a chiral reagent, its content is not particularly limited, but the reciprocal (1 / p) of the chiral pitch p [μm] determined by the ratio of the amount of the liquid crystal component used to the chiral reagent is preferably 0.01 to 0.5 [ / μm], and particularly preferably 0.01 to 0.3 [ / μm]. If the reciprocal (1 / p) of the chiral pitch is above the above lower limit value, the light scattering property in the scattering state can be improved, and if it is below the above upper limit value, the voltage rise can be suppressed. The chiral pitch can be measured by the Cano-wedge method.

[0091] When the liquid crystal composition of the present invention contains a chiral reagent, the content of the chiral reagent is preferably 0.1% by mass or more and 6% by mass or less, and more preferably 0.2% by mass or more and 3% by mass or less, based on the liquid crystal composition. By making the content of the chiral reagent within the above range, it tends to be possible to improve the contrast.

[0092] When the liquid crystal composition contains a chiral reagent, the content of the chiral reagent is preferably 0.04% by mass or more and 4% by mass or less, more preferably 0.1% by mass or more and 2.5% by mass or less, based on the mass of the liquid crystal-polymer composite film. By making the content of the chiral reagent within the above range, it tends to be possible to improve the contrast ratio.

[0093] In the liquid crystal-polymer composite film, the content of the liquid crystal composition of the present invention is preferably 40% by mass or more and 70% by mass or less, more preferably 45% by mass or more and 60% by mass or less, based on 100% by mass of the liquid crystal-polymer composite film. By making the content of the liquid crystal composition within the above range, the optical properties tend to be good and the liquid crystal can stably exist in the composite film.

[0094] In the liquid crystal composition of the present invention, the total of the liquid crystal component and other components is not more than 100% by mass, based on the mass of the liquid crystal composition. In the liquid crystal-polymer composite film of the present invention, the total of the liquid crystal component, the polymer matrix, the alkynol, and other components is not more than 100% by mass, based on the mass of the liquid crystal-polymer composite film.

[0095] <Polymer matrix> As the polymer matrix of the present invention, a hydrophilic polymer is preferably used. In this case, as long as it is hydrophilic, there is no particular limitation, but it is preferably selected so that the refractive index is consistent with the ordinary light refractive index (no) of the liquid crystal component. Typically, the no of the liquid crystal component is about 1.5, so the refractive index of the polymer matrix at a temperature of 25 °C and a wavelength of 589 nm is preferably 1.45 or more and 1.55 or less.

[0096] The weight average molecular weight (Mw) of the polymer constituting the polymer matrix is preferably 1000 or more, more preferably 10000 or more. In addition, it is preferably 1000000 or less, more preferably 100000 or less. If it is above the above lower limit value, it tends to be easy to hold the liquid crystal composition in the polymer matrix. If it is below the above upper limit value, it tends to be easy to form a film. It should be noted that the weight average molecular weight (Mw) refers to the value calculated by a conventional method using gel permeation chromatography. Specifically, the weight average molecular weight (Mw) of the polymer constituting the polymer matrix is preferably 1000 or more and 1000000 or less, more preferably 10000 or more and 100000 or less.

[0097] As the polymer constituting the polymer matrix, natural polymers such as gelatin and gum arabic can be used; synthetic polymers such as polyvinyl alcohol, polyurethane, polyurea, polyacrylic acids, polyamines, polyamides, polyethylene, polypropylene, polystyrene, and polyacrylonitrile and their modified products; copolymers such as methacrylate / acrylonitrile, urethane / acrylic ester, and acrylate / acrylonitrile, etc. In addition, a crosslinking structure can also be introduced into the polymer using a crosslinking agent.

[0098] The above polymers are preferably highly dispersible or soluble in water, and preferably gelatin, polyvinyl alcohol, polyurethane, polyurea, polyacrylic acids, polyamines, and their modified products. More preferably, it is at least one selected from polyurethane, polyacrylic acids, polyvinyl alcohol, and their modified products, and further preferably at least one selected from polyurethane, polyacrylic acids, and their modified products, and particularly preferably polyacrylic acids. These polymers can be used alone or in combination of two or more.

[0099] Polyurethane is classified according to the respective skeletons of the skeleton derived from polyisocyanate (hereinafter, also referred to as "polyisocyanate skeleton") and the skeleton derived from polyol (hereinafter, also referred to as "polyol skeleton"). As the polyisocyanate skeleton, the following can be mentioned: an aliphatic isocyanate skeleton composed of an aliphatic carbon skeleton, and an aromatic isocyanate skeleton containing an aromatic ring. Among them, from the viewpoint of high light resistance, an aliphatic isocyanate skeleton is preferred. As the polyol skeleton, the following can be mentioned: a skeleton derived from a polyether polyol having a plurality of ether bonds in each molecule, a skeleton derived from a polyester polyol having a plurality of ester bonds in each molecule, and a skeleton derived from a polycarbonate polyol having a plurality of carbonate bonds in each molecule. Among them, a skeleton derived from a polyether polyol is preferred because of good film adhesion.

[0100] Polyacrylic acids are composed of polymers of various acrylate monomers. As the acrylic monomer, compounds represented by the following formula 5 can be mentioned, etc.

[0101] [Chemical formula 5]

[0102] In the above formula 5, X 1 represents a hydrogen atom or a methyl group, and R 1 represents a hydrogen atom, a substituted or unsubstituted linear or branched alkyl group having 1 or more and 20 or less carbon atoms, a substituted or unsubstituted linear or branched alkoxy group having 1 or more and 20 or less carbon atoms, or a substituted or unsubstituted cyclic hydrocarbon group having 1 or more and 10 or less carbon atoms. As the substituent, the following can be mentioned: a halogen atom, a hydroxyl group, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms, etc.

[0103] Polyacrylic acids can also be copolymerized with monomers other than acrylates. Examples of the copolymers include: acrylate-styrene, acrylate-vinyl acetate, acrylate-acrylonitrile, acrylate-urethane, acrylate-ester, and acrylate-silicone, etc. The main chain can be composed of a copolymer of an acrylate and other monomers, or other polymers can be grafted onto the polyacrylic acid main chain.

[0104] In the polymer matrix, within the range that does not damage the performance of the liquid crystal element of the present invention, low molecular weight compounds can also be contained. Specific examples of the low molecules include: light stabilizers, antioxidants, thickeners, polymerization inhibitors, photosensitizers, adhesives, defoamers, and water-soluble pigments, etc.

[0105] In the liquid crystal-polymer composite film of the present invention, the total of the liquid crystal composition, the polymer matrix, the alkynol, and other components is not more than 100% by mass relative to the mass of the liquid crystal-polymer composite film.

[0106] In the liquid crystal-polymer composite film, relative to 100% by mass of the liquid crystal-polymer composite film, the content of the polymer matrix is preferably 15% by mass or more and 45% by mass or less, more preferably 25% by mass or more and 40% by mass or less. By making the content of the polymer matrix within the above range, the optical properties tend to be good and the liquid crystal can stably exist in the composite film.

[0107] (Ratio of liquid crystal composition to polymer matrix) In the liquid crystal-polymer composite film of the present invention, when the total mass of the polymer matrix is set to 1, the ratio of the total mass of the liquid crystal composition to the total mass of the polymer matrix is preferably 0.5 or more, more preferably 1 or more. In addition, it is preferably 4 or less, more preferably 3 or less. By making the ratio of the total mass of the liquid crystal composition to be above the above lower limit value relative to the total mass of the polymer matrix, the haze in the transparent state tends to be low and the driving voltage is low. By making the ratio of the total mass of the liquid crystal composition to be below the above upper limit value relative to the total mass of the polymer matrix, the impact resistance and adhesion of the liquid crystal-polymer composite film tend to be improved. Specifically, in the liquid crystal-polymer composite film of the present invention, the ratio of the total mass of the liquid crystal composition to the total mass of the polymer matrix, which is represented by the mass ratio [liquid crystal composition] / [polymer matrix], is preferably 0.5 or more and 4 or less, more preferably 1 or more and 3 or less.

[0108] In addition, for the purpose of increasing the relative dielectric constant of the liquid crystal-polymer composite film constituting the liquid crystal element and reducing the driving voltage, in the liquid crystal-polymer composite film of the present invention, in addition to the above polymer matrix component and the above acetylene-based surfactant component, compounds with a high dielectric constant can also be contained. Examples of the compound having a high dielectric constant include an organic compound having a polar group and inorganic particles. Examples of the organic compound having a polar group include an alcohol compound other than an alkynol, a cyano compound, a carbonyl compound, and an amino compound. In particular, the alcohol compound has high hydrophilicity and can be uniformly dispersed when mixed in the emulsion composition, and tends to improve the relative dielectric constant of the liquid crystal-polymer composite film, and thus is preferred. In particular, the liquid crystal-polymer composite film of the present invention preferably contains an alcohol having 5 or less carbon atoms. By containing the compound together with an acetylene-based surfactant, a liquid crystal element having excellent drivability at a low voltage and low power consumption can be obtained.

[0109] Examples of the alcohol having 5 or less carbon atoms include methanol, ethanol, propanol, isopropanol, butanol, pentanol, ethylene glycol, and glycerol. The alcohol having 5 or less carbon atoms may be bonded to a functional group other than a hydroxyl group. In addition, only one kind may be used, or two or more kinds may be used in combination. As the alcohol having 5 or less carbon atoms, a polyol having 2 or more hydroxyl groups is preferred. If it is a polyol, the intermolecular hydrogen bond increases and the boiling point increases, and it tends to be able to suppress the volatilization of the alcohol during film formation. From the viewpoint of viscosity, the number of hydroxyl groups possessed by the polyol is preferably 2 or more and 4 or less.

[0110] The addition amount of the above compound is not particularly limited, but relative to 100 parts by mass of the liquid crystal composition, it is preferably 0.5 part by mass or more, more preferably 1 part by mass or more. In addition, it is preferably 40 parts by mass or less, more preferably 30 parts by mass or less. By making the addition amount of the compound within the above range, the obtained liquid crystal element tends to have excellent drivability at a low voltage.

[0111] (Substrate with a transparent conductive film) Hereinafter, a representative configuration of the substrate with a transparent conductive film of the present invention will be described, but it is not limited thereto.

[0112] Examples of the material of the substrate include inorganic transparent substances such as glass and quartz, metals, metal oxides, semiconductors, ceramics, and colorless transparent materials such as plastic plates and plastic films. These substrates can be used as single plates, or multiple substrates can be stacked and used. Among these, from the viewpoints of productivity and processability, it is preferable to use a resin substrate of a plastic plate or a plastic film. Further, among them, if it is a resin substrate using a plastic film, it is preferable from the viewpoint of being flexible and easy to construct when making a light control film. For the purpose of protecting the substrate from scratches and stains, a hard coat or a sharp cut-off layer or a band-pass layer that shields light in a specific wavelength range may be given to the substrate.

[0113] The transparent conductive film constituting the electrode is formed on the above-mentioned substrate. For example, thin films such as metal oxides, metals, semiconductors, and organic conductive substances are formed on the entire surface or a part of the surface of the substrate by known coating methods, printing methods, or vapor deposition methods such as sputtering. In addition, partial etching can also be performed after forming the conductive thin film. In particular, in order to obtain a large-area liquid crystal element, from the aspects of productivity and processability, it is desirable to use an electrode substrate formed by forming an ITO (mixture of indium oxide and tin oxide) electrode on a transparent polymer film such as PET by a vapor deposition method such as sputtering or a printing method.

[0114] Wiring for connecting between electrodes or between an electrode and the outside can also be provided on the substrate. For example, it can be an electrode substrate for segment driving, a matrix driving electrode substrate, an active matrix driving electrode substrate, etc.

[0115] Furthermore, the entire surface or a part of the electrode surface provided on the substrate can also be covered with a protective film or an alignment film formed of organic compounds such as polyimide, polyamide, silicone, and cyanide, SiO 2 , TiO 2 and ZrO 2 and other inorganic compounds or mixtures thereof.

[0116] The substrate can be subjected to an alignment treatment in such a way that the liquid crystal is aligned with respect to the substrate surface. In the case of performing the alignment treatment, for example, both substrates can be parallel alignment or perpendicular alignment, or one substrate can be parallel alignment and the other substrate can be perpendicular alignment, that is, mixed. In these alignment treatments, the electrode surface can be directly rubbed, or a common alignment film such as polyimide used in TN liquid crystal, STN liquid crystal, etc. can be used, or photo-alignment treatment can also be implemented.

[0117] The opposing substrates can appropriately have an adhesive layer containing a resin body at the peripheral portion for adhesively supporting the substrates.

[0118] The end portion or the cut surface of the liquid crystal element of the present invention can be sealed with tape-like materials such as tape, hot-press tape, and thermosetting tape, curable resin materials such as thermosetting resin, photocurable resin, moisture-curable resin, room-temperature curable adhesive, anaerobic adhesive, epoxy-based adhesive, silicone-based adhesive, fluororesin-based adhesive, polyester-based adhesive, and vinyl chloride-based adhesive, and thermoplastic resin materials, etc., thereby preventing the leakage of the internal liquid crystal composition, etc. In addition, through this sealing, there are cases where the effect of preventing the deterioration of the liquid crystal element is obtained. As a method for protecting the end surface at this time, the entire end surface can be covered, or the curable resin material or thermoplastic resin material can be allowed to flow into the liquid crystal element from the end portion and cured, or it can be covered with tape-like materials.

[0119] Between substrates with transparent conductive films disposed opposite to each other, spacers such as spherical or cylindrical glass, plastic, ceramic, or plastic films can be present. The spacers can be present in the liquid crystal-polymer composite film between the substrates by containing components of an emulsion composition (hereinafter sometimes referred to as the emulsion composition of the present invention), or can be scattered on the substrates or mixed with an adhesive and present in the adhesive layer when assembling the liquid crystal element.

[0120] The thickness of the substrate is preferably 25 μm or more and 250 μm or less, more preferably 50 μm or more and 200 μm or less. It should be noted that in this specification, the thickness can be measured by using a micrometer at any five points of the measurement object, and the average value can be calculated from the obtained values for measurement.

[0121] The thickness of the transparent conductive film is preferably 0.02 μm or more and 0.5 μm or less, more preferably 0.05 μm or more and 0.2 μm or less.

[0122] "Method for Manufacturing Liquid Crystal-Polymer Composite Film" The liquid crystal-polymer composite film of the present invention can be manufactured by coating the emulsion composition of the present invention described later on a substrate with a transparent conductive film and drying it. As the coating method, known coating methods such as bar coating, knife coating, air knife coating, die coating, screen coating, microgravure roll coating, reverse roll coating, kiss roll coating, dip roll coating, spin coating, and spray coating can be used. The substrate can be appropriately cleaned according to the properties of the substrate.

[0123] The wet film thickness during coating is preferably 10 μm or more, more preferably 20 μm or more. In addition, it is preferably 120 μm or less, more preferably 100 μm or less. By making the wet film thickness above the above lower limit value, the liquid crystal composition tends to be uniformly coated without density differences. By making the wet film thickness below the above upper limit value, the driving voltage drops to a practical value, and the haze in the transparent state tends to become lower. Specifically, the wet film thickness during coating is preferably 10 μm or more and 120 μm or less, more preferably 20 μm or more and 100 μm or less.

[0124] When coating the emulsion composition and drying, the drying temperature is preferably 40 °C or more, more preferably 50 °C or more. In addition, it is preferably 120 °C or less, more preferably 100 °C or less, and further preferably 80 °C or less. Specifically, when coating the emulsion composition and drying, the drying temperature is preferably 40 °C or more and 120 °C or less, more preferably 50 °C or more and 100 °C or less, and further preferably 60 °C or more and 80 °C or less. By setting the drying temperature to be above the above-mentioned lower limit value, the drying time is shortened to a practical time, and at the same time, the amount of residual moisture in the film tends to decrease, thereby improving the reliability of the liquid crystal element. By setting the drying temperature to be below the above-mentioned upper limit value, the emulsion composition during drying is less likely to undergo structural damage such as coalescence or phase inversion. In addition, the obtained liquid crystal-polymer composite film after coating and drying can be annealed as needed.

[0125] The film thickness of the dried liquid crystal-polymer composite film is preferably 5 μm or more and 100 μm or less, more preferably 10 μm or more and 80 μm or less, and further preferably 20 μm or more and 50 μm or less.

[0126] The liquid crystal-polymer composite film of the present invention is preferably substantially free of a water-containing medium. In the liquid crystal-polymer composite film of the present invention, the content of the water-containing medium is preferably 0% by mass or more and 1.0% by mass or less, more preferably 0% by mass or more and 0.5% by mass or less, still more preferably 0% by mass or more and 0.01% by mass or less, and further preferably 0% by mass.

[0127] "Manufacturing Method of Liquid Crystal Element" The manufacturing method of the liquid crystal element of the present invention includes sandwiching the liquid crystal-polymer composite film of the present invention between two substrates with transparent conductive films. Another substrate with a transparent conductive film can be laminated on the liquid crystal-polymer composite film formed on one of the substrates with a transparent conductive film; alternatively, the liquid crystal-polymer composite film can be sandwiched between two substrates with transparent conductive films. The manufacturing method of the liquid crystal element of the present invention preferably includes laminating these layers by further heating. The heating temperature is preferably 50°C or more and 100°C or less. The heating time is preferably 5 minutes to 1 hour. In the two substrates with transparent conductive films, the transparent conductive films are preferably arranged so as to face each other with the liquid crystal-polymer composite film sandwiched therebetween. The thickness of the liquid crystal element is preferably 150 μm or more and 500 μm or less, more preferably 200 μm or more and 400 μm or less, and further preferably 250 μm or more and 300 μm or less.

[0128] "Emulsion Composition" The emulsion composition of the present invention is an emulsion composition in which a liquid crystal composition is dispersed in a medium composition containing water, wherein the medium composition disperses or dissolves a polymer and an alkynol in a water-containing medium.

[0129] The liquid crystal composition contained in the emulsion composition of the present invention is not particularly limited, and examples thereof include the liquid crystal composition used in the liquid crystal element of the present invention described above. In addition, the aqueous medium contained in the emulsion composition is not particularly limited, and examples thereof include pure water or a mixture of water and an organic solvent.

[0130] Examples of the organic solvent include alcohols, ketones, ethers, esters, carboxylic acids, and amines. The organic solvent can be water-soluble or oil-soluble with only a small amount soluble in water, but it is preferably mixed in an amount that is uniformly soluble in water.

[0131] Relative to the mass of the emulsion composition of the present invention, the content ratio of the liquid crystal composition is preferably 15% by mass or more and 40% by mass or less, more preferably 20% by mass or more and 35% by mass or less, and still more preferably 24% by mass or more and 32% by mass or less.

[0132] Relative to the mass of the emulsion composition of the present invention, the content ratio of the liquid crystal component is preferably 14% by mass or more and 36% by mass or less, more preferably 19% by mass or more and 32% by mass or less, and still more preferably 21% by mass or more and 28% by mass or less.

[0133] When the emulsion composition of the present invention contains a dichroic pigment, relative to the mass of the emulsion composition of the present invention, the content ratio of the dichroic pigment is preferably 0.8% by mass or more and 4.0% by mass or less, more preferably 1.1% by mass or more and 3.6% by mass or less, and still more preferably 1.3% by mass or more and 3.2% by mass or less.

[0134] When the emulsion composition of the present invention contains a chiral reagent, relative to the mass of the emulsion composition of the present invention, the content ratio of the chiral reagent is preferably 0.01% by mass or more and 2.2% by mass or less, more preferably 0.02% by mass or more and 1.8% by mass or less, and still more preferably 0.04% by mass or more and 1.0% by mass or less.

[0135] In the emulsion composition of the present invention, relative to the mass of the liquid crystal composition, the content ratio of the liquid crystal component is preferably 85% by mass or more and 99% by mass or less, more preferably 88% by mass or more and 97% by mass or less, and still more preferably 90% by mass or more and 95% by mass or less.

[0136] When the emulsion composition of the present invention contains a dichroic pigment, in the emulsion composition of the present invention, relative to the mass of the liquid crystal composition, the content ratio of the dichroic pigment is preferably 1% by mass or more and 13% by mass or less, more preferably 3% by mass or more and 12% by mass or less, and still more preferably 5% by mass or more and 11% by mass or less.

[0137] When the emulsion composition of the present invention contains a chiral reagent, in the emulsion composition of the present invention, the content ratio of the chiral reagent is preferably 0.1% by mass or more and 6.0% by mass or less, more preferably 0.2% by mass or more and 3.0% by mass or less, based on the mass of the liquid crystal composition.

[0138] The content ratio of the medium composition is preferably 60% by mass or more and 85% by mass or less, more preferably 65% by mass or more and 80% by mass or less, and further preferably 68% by mass or more and 76% by mass or less, based on the mass of the emulsion composition of the present invention.

[0139] The content ratio of the polymer is preferably 9% by mass or more and 30% by mass or less, more preferably 12% by mass or more and 23% by mass or less, and further preferably 13% by mass or more and 21% by mass or less, based on the mass of the emulsion composition of the present invention.

[0140] The content ratio of the alkynol is preferably 0.4% by mass or more and 5% by mass or less, more preferably 0.9% by mass or more and 4.5% by mass or less, and further preferably 1.3% by mass or more and 4% by mass or less, based on the mass of the emulsion composition of the present invention.

[0141] The content ratio of the medium containing water is preferably 42% by mass or more and 59% by mass or less, more preferably 45% by mass or more and 56% by mass or less, and further preferably 48% by mass or more and 53% by mass or less, based on the mass of the emulsion composition of the present invention.

[0142] The content ratio of water is preferably 42% by mass or more and 52% by mass or less, more preferably 44% by mass or more and 50% by mass or less, and further preferably 46% by mass or more and 48% by mass or less, based on the mass of the emulsion composition of the present invention.

[0143] When the emulsion composition of the present invention contains an organic solvent, the content ratio of the organic solvent is preferably 0.1% by mass or more and 7% by mass or less, more preferably 1% by mass or more and 6% by mass or less, and further preferably 2% by mass or more and 5% by mass or less, based on the mass of the emulsion composition of the present invention.

[0144] In the emulsion composition of the present invention, the content ratio of the polymer is preferably 14% by mass or more and 35% by mass or less, more preferably 17% by mass or more and 30% by mass or less, and further preferably 19% by mass or more and 27% by mass or less, based on the mass of the medium composition.

[0145] In the emulsion composition of the present invention, the content ratio of the alkynol is preferably 0.5% by mass or more and 7% by mass or less, more preferably 1% by mass or more and 6% by mass or less, and still more preferably 2% by mass or more and 5% by mass or less, based on the mass of the medium composition.

[0146] In the emulsion composition of the present invention, the content ratio of the medium containing water is preferably 60% by mass or more and 80% by mass or less, more preferably 63% by mass or more and 78% by mass or less, and still more preferably 68% by mass or more and 75% by mass or less, based on the mass of the medium composition.

[0147] In the emulsion composition of the present invention, the content ratio of water is preferably 55% by mass or more and 72% by mass or less, more preferably 60% by mass or more and 70% by mass or less, and still more preferably 62% by mass or more and 68% by mass or less, based on the mass of the medium composition.

[0148] When the emulsion composition of the present invention contains an organic solvent, the content ratio of the organic solvent is preferably 0.1% by mass or more and 9% by mass or less, more preferably 1% by mass or more and 8% by mass or less, and still more preferably 1.5% by mass or more and 7% by mass or less, based on the mass of the medium composition.

[0149] Regarding the polymer dispersed or dissolved in the medium, examples include the polymers constituting the polymer matrix of the liquid crystal-polymer composite film of the present invention described above. In addition, regarding the acetylene-based surfactant dispersed or dissolved in the medium, examples also include the acetylene-based surfactant used in the liquid crystal-polymer composite film of the present invention described above.

[0150] The content ratio of the acetylene-based surfactant is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and still more preferably 1% by mass or more, based on the total mass of the emulsion composition of the present invention. Further, it is preferably 10% by mass or less, more preferably 5% by mass or less. If it is above the above lower limit, the liquid crystal composition tends to be stabilized, and if it is below the above upper limit, the alkynol can be uniformly dispersed in the emulsion composition. Specifically, the content ratio of the acetylene-based surfactant is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 8% by mass or less, and still more preferably 1% by mass or more and 5% by mass or less, based on the total mass of the emulsion composition of the present invention.

[0151] In the present invention, the dispersion of the polymer and the alkynol refers to the state in which the particles of the polymer and the alkynol are suspended in the medium, and the dissolution of the polymer and the alkynol refers to the state in which the polymer and the alkynol are sufficiently dissociated by solvation to form a homogeneous system. Regarding the dispersion and dissolution of the polymer, refer to "Journal of the Society of Dyers and Colourists", The Society of Dyers and Colourists (2004), Vol. 77, No. 4, pp. 169-176.

[0152] In the emulsion composition of the present invention, the liquid crystal composition is dispersed in a medium containing water, and it can be directly dispersed in a liquid state, or can be dispersed in the form of microcapsule liquid crystals in which the peripheral portion of the liquid crystal composition is encapsulated with a polymer, a silica compound, inorganic nanoparticles, etc. Examples of the polymer that forms the capsule of the microcapsule liquid crystal include: natural polymers such as gelatin and gum arabic; synthetic polymers such as polyvinyl alcohol, polyurethane, polyurea, polyacrylic acids, polyamines, polyamides, polyethylene, polypropylene, polystyrene, and polyacrylonitrile and their modified products; copolymers such as methacrylate / acrylonitrile, urethane / acrylic ester, and acrylate / acrylonitrile.

[0153] In the emulsion composition of the present invention, additives can also be contained within the range that does not impair the performance of the liquid crystal element manufactured using the emulsion composition. Specific examples of the additives include: emulsifiers, dispersants, anti-settling agents, film-forming aids, leveling agents, light stabilizers, antioxidants, thickeners, polymerization inhibitors, photosensitizers, adhesives, defoamers, water-soluble dyes, and chiral reagents.

[0154] Regarding the size of the liquid crystal composition in the emulsion composition of the present invention, from the viewpoint of the transparency of the obtained liquid crystal element, the average particle diameter is preferably 2 μm or more, more preferably 5 μm or more. In addition, it is preferably 50 μm or less, more preferably 30 μm or less. By making the average particle diameter above the above lower limit value, the light scattering of the obtained liquid crystal-polymer composite film becomes weaker, and the haze in the transparent state tends to become smaller. By making the average particle diameter below the above upper limit value, the granular feeling of the liquid crystal composition disappears, and the uniformity of the appearance of the obtained liquid crystal element tends to become good. Specifically, from the viewpoint of the transparency of the obtained liquid crystal element, the average particle diameter of the size of the liquid crystal composition in the emulsion composition of the present invention is preferably 2 μm or more and 50 μm or less, more preferably 5 μm or more and 30 μm or less. The size of the liquid crystal composition in the emulsion composition of the present invention can be measured by the dynamic light scattering method that can measure the particle diameter even in a relatively high concentration state.

[0155] On the other hand, from the viewpoint of the light scattering property of the obtained liquid crystal element, the average particle size of the liquid crystal composition is preferably 0.01 μm or more, more preferably 0.1 μm or more. Further, it is preferably less than 2 μm, more preferably 1 μm or less. By making the average particle size less than the above upper limit value, the light scattering of the obtained liquid crystal-polymer composite film becomes stronger, the haze of the scattering state tends to increase, and in addition, the dynamic range (the haze difference between the scattering state and the transparent state) increases. By making the average particle size of the liquid crystal composition 0.01 μm or more, it is easy to prevent the average particle size from becoming too small (much smaller than the visible light wavelength) and the effect from weakening. Specifically, from the viewpoint of the light scattering property of the obtained liquid crystal element, the average particle size of the liquid crystal composition in the emulsion composition of the present invention is preferably 0.01 μm or more and less than 2 μm, more preferably 0.1 μm or more and 1 μm or less.

[0156] The above average particle size is the median particle size based on the number. Regarding the shape and average particle size of the liquid crystal composition, the liquid crystal composition of the present invention is as described above.

[0157] In the emulsion composition of the present invention, when the total mass of the polymer and the alkynol dispersed or dissolved in the medium is set to 1, the total mass of the liquid crystal composition is preferably 0.5 or more, more preferably 1 or more. Further, it is preferably 4 or less, more preferably 3 or less. By making the total mass of the liquid crystal composition 0.5 or more with respect to the total mass of the polymer and the alkynol, the haze of the transparent state of the liquid crystal element obtained by using the emulsion composition of the present invention tends to be low, and the durability at high temperature is improved. By making the total mass of the liquid crystal composition 4 or less with respect to the total mass of the polymer and the alkynol, the impact resistance and the adhesion of the liquid crystal element obtained by using the emulsion composition of the present invention tend to be improved. Specifically, the mass ratio represented by [liquid crystal composition] / [polymer + alkynol] is preferably 0.5 or more and 4 or less, more preferably 1 or more and 3 or less.

[0158] <<Manufacturing method of emulsion composition>> The manufacturing method of the emulsion composition of the present invention is not particularly limited, and for example, it can be manufactured by the following method. Manufacturing method (1): It is a manufacturing method including the following steps: mixing a liquid crystal composition as an oil phase with a water-containing medium as an aqueous phase, and after an emulsification step, adding a liquid in which a polymer and an alkynol are dispersed or dissolved to the water-containing medium. Manufacturing method (2): It is a manufacturing method including the following steps: mixing a liquid crystal composition as an oil phase with a liquid in which a polymer and an alkynol are dispersed or dissolved in a water-containing medium as an aqueous phase, and performing an emulsification step. Manufacturing method (3): It is a manufacturing method including the following steps: Mix the powder or slurry of microcapsule liquid crystal obtained by encapsulating the peripheral part of a liquid crystal composition with a polymer, silicon oxide compound, inorganic nano-particles, etc., and a liquid containing an alkynol and a water-containing medium. After the step of dispersing the microcapsule liquid crystal, add a liquid in which a polymer is dispersed or dissolved in the water-containing medium. Manufacturing method (4): It is a manufacturing method including the following steps: Mix the powder or slurry of the microcapsule liquid crystal with a liquid in which a polymer and an alkynol are dispersed or dissolved in a liquid containing a water-containing medium, and perform the step of dispersing the microcapsule liquid crystal. Manufacturing method (5): It is a manufacturing method including the following steps: Mix a liquid crystal composition as an oil phase with a water-containing medium as a water phase and a liquid containing an alkynol. After the emulsification step, add a liquid in which a polymer is dispersed or dissolved in the water-containing medium.

[0159] Among them, manufacturing methods (1), (3), and (5) are preferred because the mixture can be emulsified or dispersed in a low-viscosity state, so they can be manufactured with low energy consumption and it is also easy to control the particle size of the liquid crystal composition.

[0160] As the liquid in which a polymer is dispersed or dissolved in a water-containing medium, a commercially available aqueous resin emulsion can be used. In addition, as the liquid in which a polymer and an alkynol are dispersed or dissolved in a water-containing medium, a product obtained by dispersing or dissolving an alkynol in a commercially available aqueous resin emulsion can be used. Specific examples of commercially available aqueous resin emulsions are shown below. Waterborne polyurethane emulsions: NeoRez R-9660, NeoRez R-972, NeoRez R-9637, NeoRez R-9679, NeoRez R-960, NeoRez R-2170, NeoRez R-966, NeoRez R-967, NeoRez R-986, NeoRez R-9603, NeoRez R-4000, NeoRez R-9404, NeoRez R-600, NeoRez R-650, NeoRez R-1010, manufactured by DSM; SuperFlex 126, SuperFlex 130, SuperFlex 150, SuperFlex 150HS, SuperFlex 170, SuperFlex 210, SuperFlex 300, SuperFlex 420, SuperFlex 420NS, SuperFlex 460, SuperFlex 460S, SuperFlex 470, SuperFlex 500M, SuperFlex 620, SuperFlex 650, SuperFlex 740, SuperFlex 820, SuperFlex 830HS, SuperFlex 860, SuperFlex 870, SuperFlex E-2000, SuperFlex E-4800, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.; NEOSTECKER 200, NEOSTECKER 400, NEOSTECKER 700, NEOSTECKER 1200, NEOSTECKER X-7096, EVAFANOL HA-107C, EVAFANOL HA-50C, EVAFANOL HA-170, EVAFANOL HA-560, EVAFANOL HA-15, EVAFANOL AP-12, EVAFANOL APC-55, manufactured by Nippon Kayaku Co., Ltd. Waterborne acrylic emulsions: NeoCryl A-633, NeoCryl A-639, NeoCryl A-655, NeoCryl A-662, NeoCryl A-1091, NeoCryl A-1092, NeoCryl A-1093, NeoCryl A-1094, NeoCryl A-2091, NeoCryl A-2092, NeoCryl A-6016, NeoCryl A-6057, NeoCryl A-6069, NeoCryl A-6092, NeoCryl A-614, NeoCryl A-550, NeoCryl A-1105, NeoCryl A-1125, NeoCryl A-1127, NeoCryl XK-12, NeoCryl XK-16, NeoCryl XK-30, NeoCryl XK-36, NeoCryl XK-52, NeoCryl XK-190, NeoCryl XK-188, NeoCryl XK-240, manufactured by DSMRIKABOND 702, RIKABOND 727, RIKABOND 743N, RIKABOND 745, RIKABOND 752, RIKABOND 801, RIKABOND 940, RIKABOND 972, RIKABOND 1711, RIKABOND 1752, RIKABOND6520, RIKABOND 6720, RIKABOND 7110, RIKABOND 7180, RIKABOND 7525, RIKABOND 7820, RIKABOND 8020, RIKABOND 8030, RIKABOND DM60, RIKABOND DM772, RIKABOND DM774, RIKABOND LDM6740, RIKABOND LDM7522, RIKABOND LDM7523, RIKABOND ES-65, RIKABONDES-90, RIKABOND ES-620, RIKABOND ET-700, RIKABOND ET-831, RIKABOND HS-5, RIKABONDHS-531, RIKABOND AP-601, RIKABOND AP-96, RIKABOND AP-620, RIKABOND AP-700, RIKABOND AP-80, RIKABOND 710A, RIKABOND 730L, RIKABOND 731L, RIKABOND 952B, RIKABOND 966A, RIKABOND 7320, RIKABOND 7400, RIKABOND FK-420, RIKABOND FK-64S, RIKABOND FK-66IS, FK-66N, FK-68H, RIKABOND FK-471, RIKABOND FK-475, RIKABOND FK-489, RIKABOND FK-284, RIKABOND FK-600S, RIKABOND FK-3830, RIKABOND FK-3840, RIKABOND FK-6100, Mowiny VDM7410, Mowiny 4061, Mowiny 4080, Mowiny 4090, Mowiny4050, Mowiny S-71, Mowiny 461, Mowiny 650, Mowiny AP-60L, Mowiny 490; manufactured by Nippon Paint Resin Co., Ltd.ThreeBond 1549, ThreeBond 1549B, ThreeBond 1555C, ThreeBond 1555D manufactured by ThreeBond Co., Ltd.;

[0161] Among them, NeoRez R-966, NeoRez R-967, NeoCryl A-1125, NeoCryl A-1127, RIKABONDFK-471, RIKABOND ES-620, RIKABOND LDM7522, Mowiny 4061, Mowiny 4080, Mowiny 4090, and ThreeBond 1549 are preferred because of their excellent dispersion stability in the oil phase.

[0162] In order to obtain a stable emulsion, a surfactant other than an alkynol (hereinafter also referred to as "other surfactant") or a dispersion stabilizer can be added at a stage before the emulsification step or the dispersion step. The other surfactant is not particularly limited and can be ionic or non-ionic, low molecular weight or high molecular weight, non-reactive or reactive.

[0163] The addition amount of the other surfactant is not particularly limited. When the emulsion composition of the present invention contains the other surfactant, the content of the other surfactant is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, based on the mass of the emulsion composition. In addition, it is preferably 20% by mass or less, more preferably 10% by mass or less. By making the addition amount of the other surfactant within the above range, the dispersion of the emulsion is stabilized, and at the same time, the particle size of the liquid crystal composition can be controlled within the desired range. Specifically, when the emulsion composition of the present invention contains the other surfactant, the content of the other surfactant is preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, based on the mass of the emulsion composition.

[0164] The above surfactant can be added to the liquid crystal composition according to its solubility, or added to a medium containing water.

[0165] Examples of the surfactant include the following surfactants and the like. Anionic surfactants such as carboxylates, sulfonates, sulfates, and phosphates; Cationic surfactants such as amine salts and quaternary ammonium salts; Amphoteric surfactants such as alkyl amino fatty acid salts, alkyl amine oxides, betaines, sulfobetaines, amide sulfobetaines, carboxybetaines, and imidazolines; Ether types such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene aralkyl ethers, polyoxyethylene aralkyl aryl ethers, polyoxyethylene polyoxypropylene block adducts, alkyl glucosides, and polyether-modified silicones; ester types such as glycerol fatty acid esters, sorbitan fatty acid esters, and sucrose fatty acid esters; ester / ether types such as polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxyethylene sucrose fatty acid esters; acetyl types such as acetyl-modified polyvinyl alcohols; and nonionic surfactants such as fatty acid alkanolamides.

[0166] Among them, from the perspective of high water solubility and dispersion stability, anionic surfactants are preferred, and sulfonates are particularly preferred. In addition, nonionic surfactants tend to improve the electrical reliability of liquid crystal elements and are preferred. Among them, ether types or ester types are preferred, and polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene aralkyl ethers, polyoxyethylene aralkyl aryl ethers, polyoxyethylene polyoxypropylene block adducts, etc. are particularly preferred.

[0167] There is no particular limitation on the dispersion stabilizer, and the following dispersion stabilizers, etc., can be cited. Polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, polyethylene glycol, polyacrylic acid, polymethacrylic acid, polyurethane, polyamine, polyamide, polyether, maleic acid copolymer, gelatin, starch, chitosan, corn starch, and their modified products; Copolymers such as methacrylate / acrylonitrile, urethane / acrylic ester, and acrylate / acrylonitrile; Particles of inorganic oxides such as silica particles, titanium oxide particles, and alumina particles: Among them, polyvinyl alcohol and its modified products, polyurethane, polyamide, etc. have high dispersion stability and are preferred. The examples of the dispersion stabilizer include the substances exemplified as the polymers constituting the polymer matrix, and when they are contained in the emulsion composition or the liquid crystal-polymer composite film, they are contained as the polymers constituting the polymer matrix.

[0168] The saponification degree of polyvinyl alcohol is preferably 80 mol% or more, more preferably 85 mol% or more. In addition, it is preferably 95 mol% or less, more preferably 91 mol% or less. By making the saponification degree within these ranges, the solubility in a water-containing medium tends to be high. Specifically, the saponification degree of polyvinyl alcohol is preferably 80 mol% or more and 95 mol% or less, more preferably 85 mol% or more and 91 mol% or less. In this specification, the saponification degree can be measured by the method described in ISO 15023-2 or Japanese Industrial Standard K6726-1994. The degree of polymerization of polyvinyl alcohol is preferably 100 or more, more preferably 300 or more. In addition, it is preferably 2500 or less, more preferably 1000 or less. By making the degree of polymerization within these ranges, the flexibility of the film tends to be excellent. Specifically, the degree of polymerization of polyvinyl alcohol is preferably 100 or more and 2500 or less, more preferably 300 or more and 1000 or less. In this specification, the degree of polymerization of polyvinyl alcohol can be measured by the method described in ISO15023-2 or Japanese Industrial Standard K6726-1994.

[0169] Specific examples of polyvinyl alcohol include: GOHSENOL GL-03, GOHSENOL GL-05, GOHSENOL GM-14L, GOHSENOL GM14, GOHSENOL GH-17, GOHSENOL GH-17R, GOHSENOL GH-20, GOHSENOL GH-23, GOHSENOL AL-06, GOHSENOL P-610, GOHSENOL C-500 manufactured by Mitsubishi Chemical Corporation; KURARAY POVAL 25-88KL, KURARAY POVAL 32-97KL, KURARAY POVAL3-86SD, KURARAY POVAL 105-88KX, KURARAY POVAL 200-88KX manufactured by Kuraray Co., Ltd.; DENKAPOVAL H-12, DENKA POVAL H-17, DENKA POVAL H-24, DENKA POVAL B-05, DENKA POVAL B-17, DENKA POVAL B-20, DENKA POVAL B-24, DENKA POVAL B-33 manufactured by Denka Company Limited, etc.

[0170] When the emulsion composition of the present invention contains a dispersion stabilizer, the content of the dispersion stabilizer is preferably 0.1% by mass or more and 3% by mass or less, more preferably 0.1% by mass or more and 2% by mass or less, based on the mass of the emulsion composition.

[0171] In the production of the emulsion composition, the emulsification method and the dispersion method are not particularly limited, and examples include: mechanical pulverization of particles using a stirrer, a homogenizer, a homogenizing mixer, a disperser, a high-pressure emulsifier, a blender, a colloid mill, or an ultrasonic disperser; a method of extruding a liquid from pores using a porous membrane, a microchannel, or an inkjet, etc.

[0172] Among the above, when manufacturing an emulsion composition having an average particle diameter of 2 μm or more and 50 μm or less for a liquid crystal composition, the method of extruding a liquid from pores using a porous membrane (membrane emulsification method) can precisely control the particle size distribution and is easy to manufacture, and thus is preferred. As the porous membrane, there is no particular limitation, but Shirasu porous glass or the like can be used.

[0173] When manufacturing an emulsion composition having an average particle diameter of 0.01 μm or more and less than 2 μm for a liquid crystal composition, first, an emulsion composition having an average particle diameter of 2 μm or more and 50 μm or less for a liquid crystal composition is manufactured using a membrane emulsification method or the like, and then when the particles are mechanically pulverized using a high-pressure emulsifier or ultrasonic waves, a uniform emulsion composition can be easily manufactured.

[0174] In the emulsion composition, in addition to the above-mentioned polymer matrix component and the above-mentioned acetylene-based surfactant component, a compound having a high dielectric constant can also be contained. By using a compound having a high dielectric constant, the relative dielectric constant of the liquid crystal-polymer composite film increases, and the driving voltage tends to decrease. As the compound having a high dielectric constant, for example, an organic compound having a polar group and inorganic particles can be cited. As the organic compound having a polar group, for example, an alcohol compound other than an alkynol, a cyano compound, a carbonyl compound, and an amino compound can be cited. In particular, the alcohol compound has high hydrophilicity and can be uniformly dispersed when mixed in the emulsion composition, and tends to be able to improve the relative dielectric constant of the liquid crystal-polymer composite film and is thus preferred. In particular, the liquid crystal-polymer composite film of the present invention preferably contains an alcohol having 5 or less carbon atoms other than an alkynol. By containing the compound together with the acetylene-based surfactant, a liquid crystal element having excellent drivability at a low voltage and low power consumption can be obtained.

[0175] As the alcohol having 5 or less carbon atoms, for example, methanol, ethanol, propanol, isopropanol, butanol, pentanol, ethylene glycol, and glycerol can be cited. The alcohol having 5 or less carbon atoms can also be bonded to a functional group other than a hydroxyl group. In addition, only one kind can be used, or two or more kinds can be mixed and used. As the alcohol having 5 or less carbon atoms, a polyhydric alcohol having 2 or more hydroxyl groups is preferred. If it is a polyhydric alcohol, the intermolecular hydrogen bond increases and the boiling point increases, and it tends to be able to suppress the volatilization of the alcohol during film formation. From the viewpoint of viscosity, the number of hydroxyl groups possessed by the polyhydric alcohol is preferably 2 or more and 4 or less. As the polyhydric alcohol, for example, ethylene glycol and glycerol can be cited, and ethylene glycol is particularly preferred.

[0176] The addition amount of the above compound is not particularly limited, but is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, relative to 100 parts by mass of the liquid crystal composition. Further, it is preferably 40 parts by mass or less, more preferably 30 parts by mass or less. By making the addition amount of the compound within the above range, the obtained liquid crystal element tends to have excellent drivability at low voltage. Specifically, when the emulsion composition of the present invention contains the compound, the content of the compound in the emulsion composition is preferably 0.5 parts by mass or more and 40 parts by mass or less, more preferably 1 part by mass or more and 30 parts by mass or less, relative to 100 parts by mass of the liquid crystal composition. When the emulsion composition of the present invention contains the compound, the content of the compound is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.2% by mass or more and 8% by mass or less, relative to the mass of the emulsion composition.

[0177] A crosslinking agent can be appropriately used in the emulsion composition. By using the crosslinking agent, the water resistance and impact resistance of the liquid crystal-polymer composite film tend to be improved.

[0178] The crosslinking agent is not particularly limited, and examples thereof include the following crosslinking agents. Epoxy compounds such as ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerol diglycidyl ether, polyglycerol polyglycidyl ether, and diglycidylaniline; Epoxysilane compounds such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyl dimethoxymethylsilane, γ-glycidoxypropyl diethoxymethylsilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltriethoxysilane; Aminosilane compounds such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane; Mercaptosilane compounds such as γ-mercaptopropyltrimethoxysilane; Hydrazide compounds such as carbohydrazide, oxalic dihydrazide, adipic dihydrazide, sebacic dihydrazide, and isophthalic dihydrazide; Semicarbazide resin; Polycarbodiimide resin; Aziridine compounds (including ethylene imino groups) such as tetramethylolmethane-tris(β-aziridinyl propionate), trimethylolpropane-tris(β-aziridinyl propionate), methylene bis[N-(1-aziridinylcarbonyl)-4-aniline], N,N'-hexamethylenebis(1-aziridinylcarboxamide), and N,N'-hexaaminoethylene-1,6-bis(1-aziridinylcarboxamide); Compounds containing acetoacetoxy groups; Compounds containing oxazoline groups; Polyethylene polyamines; Polyethyleneimine; Polyamide polyamines; Polyamide polyureas; Alkylated polyhydroxymethyl melamines; Glyoxal; Water-dispersible isocyanates; Blocked isocyanates; Compounds containing carbodiimide groups; Divinyl sulfone; Titanium lactate.

[0179] When using epoxy compounds and epoxy silane compounds, catalysts such as imidazole compounds, amine compounds, or phosphorus compounds can also be added.

[0180] Among the above, hydrazide compounds, compounds containing oxazoline groups, compounds containing carbodiimide groups, and blocked isocyanates are preferred because of their fast crosslinking speed and low toxicity.

[0181] The polymer and the crosslinking agent can be used in any combination, but the combinations of polyurethane with compounds containing oxazoline groups, polyurethane with compounds containing carbodiimide groups, polyurethane with blocked isocyanates, and polyacrylic acids with hydrazide compounds have high crosslinking reactivity and are thus preferred. In addition, from the viewpoint of the stability of the obtained emulsion composition, the combination of polyacrylic acids with compounds containing carbodiimide groups is preferred.

[0182] The addition amount of the crosslinking agent is not particularly limited, but relative to 100 parts by mass of the polymer to be crosslinked, it is preferably 0.1 part by mass or more, more preferably 1 part by mass or more. In addition, it is preferably 20 parts by mass or less, more preferably 10 parts by mass or less. By making the addition amount of the crosslinking agent within the above range, the water resistance and impact resistance of the liquid crystal-polymer composite film are improved, and flexibility tends to be maintained. Specifically, when the emulsion composition of the present invention contains a crosslinking agent, relative to 100 parts by mass of the polymer to be crosslinked, the content of the crosslinking agent in the emulsion composition is preferably 0.1 part by mass or more and 20 parts by mass or less, more preferably 1 part by mass or more and 10 parts by mass or less. When the emulsion composition of the present invention contains a crosslinking agent, relative to the mass of the emulsion composition, the content of the crosslinking agent is preferably 0.01 mass% or more and 10 mass% or less, more preferably 0.1 mass% or more and 5 mass% or less. The addition time point of the crosslinking agent can be a one-component type initially pre-added to the emulsion composition, or a two-component type added just before coating on a substrate.

[0183] The viscosity of the emulsion composition of the present invention at 25°C is preferably 10 mPa·s or more, more preferably 100 mPa·s or more. In addition, it is preferably 10,000 mPa·s or less, more preferably 2,000 mPa·s or less. By making the viscosity at 25°C within the above range, it is easy to coat the liquid crystal-polymer composite film with a uniform film thickness, and the coating speed can be increased and the productivity tends to be high. The above viscosity can be determined by a conventional method and measured using a B-type viscometer. Specifically, the viscosity of the emulsion composition of the present invention at 25°C is preferably 10 mPa·s or more and 10,000 mPa·s or less, more preferably 100 mPa·s or more and 2,000 mPa·s or less.

[0184] In order to control the viscosity of the emulsion composition of the present invention within the above range, viscosity modifiers such as thickeners, thixotropic agents, and viscosity reducers can be used.

[0185] As the viscosity modifier, there is no particular limitation, and substances exemplified as dispersion stabilizers can be cited.

[0186] Relative to 100% by mass of the emulsion composition, the content of the liquid crystal composition in the emulsion composition is preferably 20% by mass or more, more preferably 30% by mass or more. In addition, it is preferably 70% by mass or less, more preferably 65% by mass or less. By making the content of the liquid crystal composition within the above range, the shrinkage generated when coating the emulsion composition on the substrate is suppressed, and it tends to be easy to control the particle size of the liquid crystal composition and the viscosity of the emulsion composition within the above range. Specifically, relative to 100% by mass of the emulsion composition, the content of the liquid crystal composition in the emulsion composition is preferably 20% by mass or more and 70% by mass or less, more preferably 30% by mass or more and 65% by mass or less.

[0187] The particle size of the polymer in the emulsion composition is preferably 1 nm or more, more preferably 10 nm or more. In addition, it is preferably 1,000 nm or less, more preferably 200 nm or less. By being within the above range, it tends to be easy to control the viscosity of the emulsion composition within the above range. Specifically, the particle size of the polymer used in the emulsion composition is preferably 1 nm or more and 1,000 nm or less, more preferably 10 nm or more and 200 nm or less. It should be noted that the particle size can be observed and measured using SEM (scanning electron microscope) by removing moisture below the MFT (minimum film formation temperature) and conducting a conductive treatment such as sputtering Au. In addition, the dynamic light scattering method can measure the particle size even in a liquid state and at a relatively high concentration state, so it is preferred.

[0188] In addition, the weight-average molecular weight of the polymer used in the emulsion composition is preferably 1.0×10 3 or more, more preferably 1.0×10 4 or more. In addition, it is preferably 1.0×10 6 or less, more preferably 1.0×10 5 or less. By making the molecular weight of the polymer within the above range, it tends to be easy to control the viscosity of the emulsion composition within the above range. It should be noted that the weight-average molecular weight refers to the value calculated by a conventional method using gel permeation chromatography.

[0189] "View Shielding Element" An example of the view shielding element according to an embodiment of the present invention (also referred to as "this view shielding element") is a view shielding element using the liquid crystal-polymer composite film of the present invention, the liquid crystal element of the present invention, or the emulsion composition of the present invention. This view shielding element can be suitably used as a dimming shutter, for example, in vehicles such as trams and cars, and in windows, doors, and partitions of buildings such as commercial buildings and hospitals, for the purposes of adjusting light shielding and daylighting, improving the appearance design, and protecting privacy.

[0190] "Manufacturing Method of View Shielding Element" This view shielding element can be manufactured using the liquid crystal-polymer composite film of the present invention, the liquid crystal element of the present invention, or the emulsion composition of the present invention. When using the liquid crystal-polymer composite film of the present invention, this view shielding element can be manufactured by a manufacturing method including a step of molding a liquid crystal element made using the liquid crystal-polymer composite film of the present invention. When using the liquid crystal element of the present invention, this view shielding element can be manufactured by a manufacturing method including a step of molding the liquid crystal element of the present invention. Examples of the molding method include cutting molding and molding molding. When using the emulsion composition of the present invention, this view shielding element can be manufactured by a manufacturing method including steps of molding a liquid crystal-polymer composite film made using the emulsion composition of the present invention and a liquid crystal element using the liquid crystal-polymer composite film.

[0191] "Use" The alkynol-containing acetylene-based surfactant of the present invention can be used as a surfactant for dispersing a liquid crystal composition in a polymer matrix in the liquid crystal-polymer composite film of the present invention. The alkynol-containing acetylene-based surfactant of the present invention can be used as a surfactant for dispersing a liquid crystal composition in a polymer and an aqueous medium in the emulsion composition of the present invention. The alkynol-containing acetylene-based surfactant of the present invention can be used as a surfactant for dispersing a liquid crystal composition in a polymer matrix in the liquid crystal element of the present invention. The alkynol-containing acetylene-based surfactant of the present invention can be used as a surfactant for dispersing a liquid crystal composition in a polymer matrix in the viewing angle compensation element of the present invention.

[0192] The alkynol-containing acetylene-based surfactant of the present invention can be used for manufacturing the liquid crystal-polymer composite film of the present invention. The alkynol-containing acetylene-based surfactant of the present invention can be used for manufacturing the emulsion composition of the present invention. The alkynol-containing acetylene-based surfactant of the present invention can be used for manufacturing the liquid crystal element of the present invention. The alkynol-containing acetylene-based surfactant of the present invention can be used for manufacturing the viewing angle compensation element of the present invention.

[0193] The liquid crystal-polymer composite film of the present invention comprises a liquid crystal composition, a polymer matrix, and an alkynol. The liquid crystal-polymer composite film of the present invention can be used for the above-mentioned liquid crystal element. For example, the liquid crystal-polymer composite film of the present invention can be used as the liquid crystal-polymer composite film in a liquid crystal element, and the liquid crystal element includes: two substrates with transparent conductive films disposed opposite to each other and a liquid crystal-polymer composite film sandwiched between the two substrates with transparent conductive films. The liquid crystal-polymer composite film of the present invention can be used for manufacturing a liquid crystal element, and the liquid crystal element includes two substrates with transparent conductive films disposed opposite to each other and a liquid crystal-polymer composite film sandwiched between the two substrates with transparent conductive films. The liquid crystal-polymer composite film of the present invention can be used for manufacturing a viewing angle compensation element, and the viewing angle compensation element is formed from a liquid crystal element that includes two substrates with transparent conductive films disposed opposite to each other and a liquid crystal-polymer composite film sandwiched between the two substrates with transparent conductive films.

[0194] The emulsion composition of the present invention contains a liquid crystal composition, a polymer, an alkynol, and an aqueous medium. The emulsion composition of the present invention can be used for manufacturing the liquid crystal-polymer composite film in a liquid crystal element that includes two substrates with transparent conductive films and a liquid crystal-polymer composite film, and the liquid crystal element includes: two substrates with transparent conductive films disposed opposite to each other and the liquid crystal-polymer composite film sandwiched between the two substrates with transparent conductive films. The emulsion composition of the present invention can be used in the manufacture of liquid crystal elements having two substrates with transparent conductive films and a liquid crystal-polymer composite film. The liquid crystal element includes: two substrates with transparent conductive films arranged opposite to each other, and the liquid crystal-polymer composite film sandwiched between the two substrates with transparent conductive films. The emulsion composition of the present invention can be used in the manufacture of a vision shielding element in a liquid crystal element having two substrates with transparent conductive films and a liquid crystal-polymer composite film. The vision shielding element is formed by a liquid crystal element having two substrates with transparent conductive films arranged opposite to each other and the liquid crystal-polymer composite film sandwiched between the two substrates with transparent conductive films.

[0195] The liquid crystal element of the present invention can be used in the manufacture of a vision shielding element.

[0196] The liquid crystal-polymer composite film of the present invention can be used to switch between a transparent state and a scattering state by applying a voltage. The liquid crystal element of the present invention can be used to switch between a transparent state and a scattering state by applying a voltage. The vision shielding element of the present invention can be used to switch between a transparent state and a scattering state by applying a voltage.

[0197] <Explanation of Terms> In the present invention, when expressed as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, it includes the meaning of "X or more and Y or less", and also includes the meaning of "preferably greater than X" or "preferably less than Y". In addition, when expressed as "X or more" (X is an arbitrary number) or "Y or less" (Y is an arbitrary number), it also includes the meaning of "preferably greater than X" or "preferably less than Y". Examples

[0198] Hereinafter, examples and comparative examples are given to illustrate the present invention more specifically. However, the present invention is not limited by the following examples as long as it does not exceed its key points.

[0199] [Example 1] A nematic liquid crystal with Δn = 0.095 and NI point = 129.5 °C and a chiral reagent ((R)-4-cyano-4'(2-methyl)butylbiphenyl, trade name: CB-15, manufactured by Merck & Co., Inc.) were mixed in the following ratio to obtain a liquid crystal composition (L-1).

[0200] <Liquid Crystal Composition Ratio> Nematic liquid crystal: 96.8% by mass CB-15: 3.2% by mass

[0201] With respect to 45 parts by mass of the liquid crystal composition (L-1), 45 parts by mass of deionized water and 10 parts by mass of an acetylene-based surfactant (A-1: PD-002W manufactured by Nissin Chemical Industry Co., Ltd., HLB value 9-10, non-volatile content 83%; all are catalog values) were added, and emulsification was carried out through Shirasu porous glass (pore diameter 10 μm) to obtain an O / W emulsion (E-1). To 92.7% by mass of the aqueous acrylic emulsion RIKABOND LDM7522 (manufactured by Nippon Paint Resin Co., Ltd., non-volatile content 51%), 7.3% by mass of a 20% aqueous solution of GOHSENOL GH-17R of polyvinyl alcohol (manufactured by Mitsubishi Chemical Corporation) was added and stirred to obtain a white latex (W-1). To 55 parts by mass of the O / W emulsion (E-1), 45 parts by mass of the white latex (W-1) was added and stirred until homogeneous to obtain an emulsion composition (I-1).

[0202] As the substrate 1, a film having a transparent ITO electrode formed on a PET film substrate with a thickness of 125 μm was used. On the ITO electrode of this substrate, the emulsion composition (I-1) was coated by bar coating, and dried at 90 °C to form a liquid crystal-polymer composite film 1 with a film thickness of 30 μm, obtaining a laminate 1 having a liquid crystal-polymer composite film 1 formed on the substrate 1.

[0203] To the above laminate 1, the substrate 1 was further laminated in such a manner that the ITO electrodes were opposed to each other with the liquid crystal-polymer composite film 1 interposed therebetween, and heated and bonded at 80 °C to obtain a liquid crystal element (F-1).

[0204] Regarding the liquid crystal element (F-1) obtained in Example 1, before and after standing in a constant temperature bath at 110 °C for 90 hours, the haze and total light transmittance at the time of applying a voltage (rectangular wave of frequency 100 Hz·100 Vrms) ON / OFF were measured. Table 1 shows the results of the haze, total light transmittance, change amplitude of haze ΔHaze, and change amplitude of total light transmittance ΔTT of Example 1.

[0205] [Table 1]

[0206] The liquid crystal element (F-1) of Example 1 represents normal mode driving in which it is in a scattered state when the voltage is OFF and in a transparent state when the voltage is ON.

[0207] Before and after standing in a thermostat at 110 °C for 90 hours, both ΔHaze during voltage on / off and ΔTT were within 4% and within 1%, respectively.

[0208] Therefore, it can be seen that no significant reduction in optical properties was observed before and after the durability test at high temperature. It was confirmed by optical microscopy that no change in the liquid crystal diameter was observed before and after the durability test at high temperature, and the liquid crystal element has excellent durability at high temperature.

[0209] [Example 2] As the liquid crystal composition (L-2), a nematic liquid crystal with Δn = 0.096 and NI point = 143.3 °C was used without mixing a chiral agent. After passing through Shirasu porous glass (fine pore diameter 10 μm), it was emulsified with an ultrasonic disperser to obtain an O / W emulsion (E-2). In addition, as the crosslinking agent, SV-02 (containing polycarbodiimide, trade name CARBODILITE) manufactured by Nisshinbo Chemical Co., Ltd. was used. Except for this, an emulsion composition (I-2) was prepared in the same manner as in Example 1. The composition is shown in Table 2. It should be noted that the values in the table represent "parts by mass". Furthermore, a liquid crystal element (F-2) was fabricated in the same manner as in Example 1, and the optical properties (haze and total light transmittance) before and after the durability test were measured. It should be noted that the conditions of the durability test were set to stand in a thermostat at 110 °C for 100 hours. The optical properties before and after the durability test and their differences are shown in Table 3.

[0210] [Examples 3 to 7] The used liquid crystal composition and acetylene-based surfactant were replaced, and an emulsion composition was prepared in the same manner as in Example 2, a liquid crystal element was fabricated, and the optical properties before and after the durability test were measured. The composition is shown in Table 2, and the optical properties before and after the durability test and their differences are shown in Table 3. The used liquid crystal composition and acetylene-based surfactant are as follows.

[0211] [Liquid Crystal Composition] Liquid crystal composition (L-2): A nematic liquid crystal with Δn = 0.096 and NI point = 143.3 °C Liquid crystal composition (L-3): An anthraquinone-based cyan dichroic dye represented by the following (D-1), an azo-based yellow dichroic dye represented by the following (D-2), and an azo-based magenta dichroic dye NKX-3739 manufactured by Hayashibara Co., Ltd. were mixed with a nematic liquid crystal with Δn = 0.096 and NI point = 143.3 °C in the following ratio to dissolve the dichroic dye and obtain a black liquid crystal composition (L-3).

[0212] [Chemical Formula 6]

[0213] <Liquid Crystal Composition Ratio> Nematic Liquid Crystal: 93.7% by mass D-1: 4.3% by mass D-2: 0.8% by mass NKX-3739: 1.2% by mass With respect to 100% by mass of the liquid crystal composition, the content of the dichroic pigment: 6.3% by mass [Acetylene-based Surfactant] (A-1): PD-002W manufactured by Nissin Chemical Industry Co., Ltd.; an acetylene-based surfactant containing an alkynol with an HLB value of 4 and a polyoxyalkylene alkyl ether as a surfactant other than the alkynol, with an HLB value of 9 - 10 and an active ingredient of 83%; all are catalog values (A-2): SURFYNOL 465 manufactured by Nissin Chemical Industry Co., Ltd., with an HLB value of 13 and an active ingredient of 100%; all are catalog values (A-3): SURFYNOL 104PG-50 manufactured by Nissin Chemical Industry Co., Ltd., with an HLB value of 4 and an active ingredient of 50%; all are catalog values

[0214] [Comparative Example] The acetylene-based surfactant (A-1) was replaced with a non-acetylene-based surfactant (SDS: sodium dodecylbenzenesulfonate). Except for this, an emulsion composition was prepared in the same manner as in Example 2, and a liquid crystal element was fabricated. The optical properties before and after the durability test were measured. The composition is shown in Table 2, and the optical properties before and after the durability test and their differences are shown in Table 3.

[0215] [Reference Example] An attempt was made to emulsify 50 parts by mass of a liquid crystal composition (L-2) and a mixture of only 50 parts by mass of deionized water without a surfactant through Shirasu porous glass (fine pore diameter 10 μm) to prepare an O / W emulsion, but it immediately coalesced and an emulsion composition could not be obtained.

[0216] [Table 2]

[0217] [Table 3]

[0218] It was confirmed that the optical properties of Examples 1 - 7 containing alkynol hardly changed before and after the durability test, and they had excellent durability at high temperatures. Among them, Examples 1 to 6 using an acetylene-based surfactant with an HLB value of 5 to 15 have a high initial haze at the time of off (scattering state) and excellent visibility shielding property. In addition, the difference in haze values at the time of voltage on / off (dynamic range) is large, and the dimming function is particularly excellent. In addition, among them, Examples 3 to 5 using a liquid crystal composition containing a dichroic pigment have, at the time of voltage off, in addition to high haze due to light scattering caused by the liquid crystal component, a decrease in total light transmittance due to light absorption by the pigment, and particularly excellent visibility shielding property. On the other hand, Comparative Example 1 without alkynol shows a large change in ΔHaze before and after the durability test and has poor durability at high temperatures. It should be noted that in the reference example without a surfactant, since the liquid crystal compound coalesced during the production of the emulsion composition, the emulsion composition could not be coated on the substrate. In addition, even when the applied voltage is changed to 100 Hz and 50 Vrms in frequency, it is confirmed that the optical properties of Examples 2 to 7 containing alkynol hardly change before and after the durability test, and the durability at high temperatures is excellent. Among them, Examples 1 to 6 using an acetylene-based surfactant with an HLB value of 5 to 15 have a high initial haze at the time of off (scattering state) and excellent visibility shielding property. In addition, the difference in haze values at the time of voltage on / off (dynamic range) is large, and the dimming function is particularly excellent. Industrial applicability

[0219] According to the present invention, a liquid crystal element with improved durability at high temperatures can be provided.

Claims

1. A liquid crystal element, comprising: two substrates with transparent conductive films, which are arranged in a relative manner with the transparent conductive films, and a liquid crystal-polymer composite film sandwiched between the two substrates with transparent conductive films, wherein, the liquid crystal-polymer composite film contains alkynol.

2. The liquid crystal element according to claim 1, wherein, the liquid crystal-polymer composite film can switch between a transparent state and a scattering state by applying a voltage.

3. The liquid crystal element according to claim 1, wherein, the liquid crystal-polymer composite film contains a polymer matrix and a liquid crystal composition, and the liquid crystal composition exists in the polymer matrix.

4. The liquid crystal element according to claim 3, wherein, the liquid crystal composition contains nematic liquid crystal or chiral nematic liquid crystal as a liquid crystal component.

5. The liquid crystal element according to claim 3, wherein, the polymer constituting the polymer matrix contains at least one selected from polyurethane, polyacrylic acid, polyvinyl alcohol and their modified products.

6. The liquid crystal element according to claim 3, wherein, the liquid crystal composition contains a dichroic dye.

7. The liquid crystal element according to claim 6, wherein, the dichroic dye contains at least one selected from anthraquinone dyes and azo dyes.

8. The liquid crystal element according to claim 6, wherein, relative to 100% by mass of the liquid crystal composition, the content of the dichroic dye is 0.1% by mass or more and 20% by mass or less.

9. The liquid crystal element according to claim 1, wherein, alkynediol is included as the alkynol.

10. The liquid crystal element according to claim 1, wherein, the HLB value of the alkynol is 5 to 15.

11. The liquid crystal element according to claim 1, wherein, the liquid crystal-polymer composite film contains a surfactant other than the alkynol.

12. The liquid crystal element according to claim 11, wherein, the HLB value of the mixture of the alkynol and the surfactant is 5 to 15.

13. The liquid crystal element according to claim 1, wherein, the substrate with the transparent conductive film is a resin substrate.

14. An emulsion composition, which is an emulsion composition in which a liquid crystal composition is dispersed in a medium containing water, wherein, the medium disperses or dissolves a polymer and an alkynol.

15. The emulsion composition according to claim 14, wherein, the liquid crystal composition contains a dichroic dye.

16. The emulsion composition according to claim 15, wherein, the dichroic dye contains at least one selected from anthraquinone dyes and azo dyes.

17. The emulsion composition according to claim 15, wherein, relative to 100% by mass of the liquid crystal composition, the content of the dichroic dye is 0.1% by mass or more and 20% by mass or less.

18. The emulsion composition according to claim 14, wherein, alkynediol is included as the alkynol.

19. The emulsion composition according to claim 14, wherein, the HLB value of the alkynol is 5 to 15.

20. The emulsion composition according to claim 14, wherein, the medium contains a surfactant other than the alkynol.

21. The emulsion composition according to claim 20, wherein, the HLB value of the mixture of the alkynol and the surfactant is 5 to 15.

22. The emulsion composition according to claim 14, wherein, the polymer contains at least one selected from polyurethanes, polyacrylic acids, polyvinyl alcohols, and modified products thereof.

23. A vision shielding element which uses the liquid crystal element according to any one of claims 1 to 13 or the emulsion composition according to any one of claims 14 to 22.

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