ADHESIVE PARTICLES, ADHESIVE AND LIGHT CONTROL LAMINATE

Abstract

Provided are adhesive particles for which dripping during heating is suppressed, adhesion is increased, and the occurrence of light leakage is suppressed.　Adhesive particles according to the present invention each comprise a base particle and a covering portion disposed on the surface of the base particle; the base particle is a black particle; and the covering portion contains a thermosetting resin.

Description

[Technical Field]

[0001] The present invention relates to adhesive particles. The present invention also relates to an adhesive and a light-control laminate using the adhesive particles. [Background technology]

[0002] Light-controlling materials such as light-controlling glass and light-controlling films are often used in display devices such as liquid crystal displays and in-vehicle displays. Light-controlling materials have the property of changing their light transmittance depending on whether or not an electric field is applied, making it possible to adjust the amount of incident light.

[0003] A liquid crystal display element is constructed by disposing a liquid crystal between two glass or film substrates, and an adhesive is used to bond the two glass or film substrates together.

[0004] In recent years, with the trend toward larger screens and more flexible display devices, there has been an increasing need for adhesives with higher adhesive properties. To further enhance the adhesive properties of adhesives, adhesive particles may be incorporated into the adhesive. Furthermore, to prevent light from passing through the particles in the adhesive, the particles may be colored in a dark color.

[0005] Patent Document 1 below discloses a particle comprising a base particle and a coating portion disposed on the surface of the base particle. In this particle, the base particle contains a colorant, and the material of the coating portion is a compound having a specific structure. Patent Document 1 also discloses that the material of the coating portion is a thermoplastic resin. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-132740 Summary of the Invention [Problem to be solved by the invention]

[0007] In the case of colored base particles whose surfaces are coated with a thermoplastic resin, it is sometimes difficult to provide a sufficient thickness for the coating layer, resulting in difficulty in sufficiently enhancing the adhesiveness of the particles. Furthermore, the thermoplastic resin in the coating layer may melt when heated, causing dripping, resulting in reduced adhesiveness. Furthermore, if dripping occurs, when the liquid crystal display element is turned on and operated, light from the backlight may pass through the molten resin (light leakage), resulting in problems such as a decrease in the contrast of the liquid crystal display element and a reduction in display quality known as white spots.

[0008] An object of the present invention is to provide adhesive particles that can suppress dripping during heating, improve adhesion, and suppress the occurrence of light leakage. Another object of the present invention is to provide an adhesive and a light-control laminate using the adhesive particles. [Means for solving the problem]

[0009] According to a broad aspect of the present invention, there is provided an adhesive particle comprising a base particle and a coating portion disposed on a surface of the base particle, the base particle being a black particle and the coating portion including a thermosetting resin.

[0010] In a specific aspect of the adhesive particle according to the present invention, the ratio of the thickness of the coating portion to the particle diameter of the adhesive particle exceeds 0.01.

[0011] In a specific aspect of the adhesive particles according to the present invention, the thermosetting resin is an epoxy resin, and the coating portion contains an amine curing agent.

[0012] In a specific aspect of the adhesive particle according to the present invention, the 10% K value of the base particle is 10 N / mm 2 More than 7000N / mm 2 The following is the result.

[0013] According to a broad aspect of the present invention, there is provided an adhesive comprising the adhesive particles described above and a binder.

[0014] According to a broad aspect of the present invention, there is provided a photochromic stack comprising a first substrate, a second substrate, and a photochromic layer disposed between the first substrate and the second substrate, wherein the material of the photochromic layer comprises the adhesive particles described above. [Effects of the Invention]

[0015] The adhesive particle according to the present invention comprises a base particle and a coating portion disposed on the surface of the base particle, the base particle being a black particle, and the coating portion including a thermosetting resin. Because the adhesive particle according to the present invention has the above-described configuration, it is possible to suppress dripping during heating, improve adhesion, and suppress light leakage. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a cross-sectional view showing an adhesive particle according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view showing an example of a PDLC-type light-control laminate using adhesive particles according to the first embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view showing an example of an SPD-type light-control laminate using adhesive particles according to the first embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described in detail below.

[0018] <Adhesive particles> The adhesive particle according to the present invention includes a base particle and a coating portion disposed on the surface of the base particle. In the adhesive particle according to the present invention, the base particle is a black particle. In the adhesive particle according to the present invention, the coating portion includes a thermosetting resin.

[0019] The adhesive particles according to the present invention have the above-described configuration, so that the thickness of the coating can be sufficiently ensured, resulting in sufficiently enhanced adhesiveness. Furthermore, the adhesiveness of an adhesive containing the adhesive particles according to the present invention can be enhanced. Adhesion can be achieved by thermally curing the thermosetting resin. Furthermore, dripping during heating can be suppressed. As a result, adhesiveness can be further enhanced, and light leakage can be suppressed. Furthermore, contamination due to dripping can be prevented. By suppressing light leakage, a decrease in the contrast of a liquid crystal display element can be prevented, and a deterioration in display quality can be prevented.

[0020] The adhesive particles can be suitably used in adhesives. The adhesive particles can also be used in light-control materials, light-control layers, and light-control laminates. The adhesive particles can be used as spacers for light-control glass or light-control films. The adhesive particles can also be adhesive particles for light-control laminates.

[0021] The shape of the adhesive particles is not particularly limited. The shape of the adhesive particles may be spherical, or may be a shape other than spherical, such as flat. Note that the spherical shape is not limited to a perfect sphere, but also includes a nearly spherical shape, and also includes a shape having an aspect ratio (major axis / minor axis) of 1.5 or less, for example.

[0022] FIG. 1 is a cross-sectional view showing an adhesive particle according to a first embodiment of the present invention.

[0023] The adhesive particle 1 shown in FIG. 1 includes a base particle 2 and a coating portion 3 disposed on the surface of the base particle 2. The coating portion 3 is in contact with the surface of the base particle 2 and coats the surface of the base particle 2. The adhesive particle 1 is a coated particle in which the surface of the base particle 2 is coated with the coating portion 3. In the adhesive particle 1, the base particle 2 is a black particle. In the adhesive particle 1, the coating portion 3 contains a thermosetting resin.

[0024] The coating portion may completely cover the surface of the base particle, or may not completely cover the surface of the base particle. The base particle may have a portion that is not covered by the coating portion.

[0025] The adhesive particles 1 have excellent gap controllability because they contain the base particles 2. Therefore, the adhesive particles 1 can be suitably used as spacers for light-controlling laminates and the like. The adhesive particles 1 can be suitably used as spacers for light-controlling glass and light-controlling films. For example, in a light-controlling laminate in which the adhesive particles are disposed between substrates, the gap between the substrates can be controlled with high precision, and the thickness uniformity between the substrates can be improved. Furthermore, by suppressing peeling of the conductive film, the light-controlling performance of the light-controlling laminate can be maintained.

[0026] From the viewpoint of practicality, the average particle size of the adhesive particles is preferably 1 μm or more, more preferably 8 μm or more, even more preferably 10 μm or more, and preferably 50 μm or less, more preferably 30 μm or less, even more preferably 25 μm or less.

[0027] The particle size of the adhesive particles means the diameter if the adhesive particles are spherical, and if the adhesive particles are in a shape other than spherical, means the diameter when the adhesive particles are assumed to be spherical with a volume equivalent to the diameter of the adhesive particles.

[0028] The particle size of the adhesive particles refers to the average particle size measured by a particle size measuring device. Examples of particle size measuring devices include particle size distribution measuring devices that use principles such as laser light scattering, electrical resistance change, and image analysis after imaging. Specific methods for measuring the particle size of the adhesive particles include, for example, measuring the particle sizes of approximately 100,000 particles using a particle size distribution measuring device (Beckman Coulter's "Multisizer 4") to determine the average particle size. The average particle size refers to the number-average particle size.

[0029] From the viewpoint of further enhancing adhesiveness, the CV value of the particle diameter of the adhesive particles is preferably 10% or less, more preferably 7% or less. There is no particular upper limit to the CV value of the particle diameter of the adhesive particles. The CV value of the particle diameter of the adhesive particles may be 30% or less.

[0030] The CV value (coefficient of variation) of the particle diameter of the adhesive particles can be measured as follows.

[0031] CV value (%) = (ρ / Dn) × 100 ρ: Standard deviation of the particle diameter of the adhesive particles Dn: average particle size of the adhesive particles

[0032] The compressive elastic modulus (10% K value) of the adhesive particles when compressed by 10% at 25°C is preferably 10 N / mm 2 More preferably, 1000N / mm 2 or more, preferably 10,000 N / mm 2 Less than or equal to 7000N / mm 2 When the 10% K value is equal to or greater than the lower limit and equal to or less than the upper limit, the gap can be controlled with high precision.

[0033] The compressive elastic modulus (30% K value) of the adhesive particles when compressed 30% at 25°C is preferably 50 N / mm 2 More preferably, 2000N / mm 2 or more, preferably 20,000 N / mm 2 Less than or equal to 10,000 N / mm 2 When the 30% K value is equal to or greater than the lower limit and equal to or less than the upper limit, the gap can be controlled with high precision.

[0034] The compressive elastic modulus (10% K value and 30% K value) of the adhesive particles can be measured as follows.

[0035] Using a microcompression tester, one adhesive particle is compressed with the end face of a smooth cylindrical indenter (diameter 100 μm, made of diamond) under conditions of 25°C, a compression speed of 0.3 mN / sec, and a maximum test load of 20 mN. The load value (N) and compression displacement (mm) at this time are measured. From the obtained measured values, the compressive elastic modulus (10% K value and 30% K value) can be calculated using the following formula. As the microcompression tester, for example, the "Fisherscope H-100" manufactured by Fischer is used. The compressive elastic modulus (10% K value and 30% K value) of the adhesive particle is preferably calculated by arithmetic averaging the compressive elastic modulus (10% K value and 30% K value) of 50 arbitrarily selected adhesive particles.

[0036] 10% K value and 30% K value (N / mm 2 )=(3 / 2 1 / 2 )·F·S -3 / 2 ·R -1 / 2 F: Load value (N) when adhesive particles are compressed by 10% or 30% S: Compression displacement (mm) when adhesive particles are compressed by 10% or 30% R: Radius of adhesive particle (mm)

[0037] The compressive elastic modulus universally and quantitatively represents the hardness of the adhesive particles. By using the compressive elastic modulus, the hardness of the adhesive particles can be quantitatively and unambiguously represented.

[0038] From the viewpoint of further enhancing adhesiveness, in the following Adhesion Test A, the tensile yield stress of the adhesive particles is preferably 0.03 MPa or more, more preferably 0.05 MPa or more, and even more preferably 0.1 MPa or more. There are no particular limitations on the upper limit of the tensile yield stress of the adhesive particles. In the following Adhesion Test A, the tensile yield stress of the adhesive particles may be 0.03 MPa or less, or may be less than 0.03 MPa.

[0039] Furthermore, from the viewpoint of further enhancing adhesiveness, the tensile yield stress of the adhesive particles in the following Adhesion Test B is preferably 0.05 MPa or more, more preferably 0.07 MPa or more, and even more preferably 0.12 MPa or more. There are no particular limitations on the upper limit of the tensile yield stress of the adhesive particles. In the following Adhesion Test B, the tensile yield stress of the adhesive particles may be 0.05 MPa or less, or may be less than 0.05 MPa.

[0040] (Adhesion Test A) Glass substrates are prepared as the first and second substrates. Adhesive particles are deposited on the surface of the first substrate at a density of 10 particles / mm 2 Then, spray at 5 kgf / cm according to the method of JIS K6850. 2 The adhesive particles are adhered to the first and second substrates at a pressure of 100°C for 60 minutes to prepare a test specimen (test sample). The adhesive strength of the resulting test specimen is measured at 23°C using a Tensilon universal testing machine at a tensile speed of 20 mm / min and a load cell rating of 1000 N. This measured value is the tensile yield stress of the adhesive particles.

[0041] (Adhesion test B) Glass substrates are prepared as the first and second substrates. Adhesive particles are deposited on the surface of the first substrate at a density of 10 particles / mm 2 Then, spray at 5 kgf / cm according to the method of JIS K 6850. 2 The adhesive particles are adhered to the first and second substrates at a pressure of 1000 kJ / min and heated at 130°C for 60 minutes to prepare a test specimen (test sample). The adhesive strength of the resulting test specimen is measured at 23°C using a Tensilon universal testing machine at a tensile speed of 20 mm / min and a load cell rating of 1000 N. This measured value is the tensile yield stress of the adhesive particles.

[0042] The glass substrate may be, for example, "S-7213" manufactured by Matsunami Glass Industry Co., Ltd. The Tensilon universal material testing machine may be, for example, "RTI-1310" manufactured by A&D Co., Ltd.

[0043] Other details of the adhesive particles will be described below. In this specification, "(meth)acrylate" means one or both of "acrylate" and "methacrylate," and "(meth)acrylic" means one or both of "acrylic" and "methacrylic."

[0044] (base material particles) The base particles are black particles. The adhesive particles according to the present invention have the above-described structure, and therefore can suppress the occurrence of light leakage.

[0045] The material of the base particles is not particularly limited, and may be an organic material or an inorganic material.

[0046] Examples of the organic material include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate; polycarbonate, polyamide, phenol-formaldehyde resin, melamine-formaldehyde resin, benzoguanamine-formaldehyde resin, urea-formaldehyde resin, phenolic resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide, polyacetal, polyimide, polyamide-imide, polyether ether ketone, polyether sulfone, and divinylbenzene polymer. The divinylbenzene polymer may be a divinylbenzene copolymer. Examples of the divinylbenzene copolymer include a divinylbenzene-styrene copolymer and a divinylbenzene-(meth)acrylic acid ester copolymer. From the viewpoint of easily controlling the hardness of the adhesive particles and the base particles within a suitable range, it is preferable that the material of the base particles is a polymer obtained by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group.

[0047] When the base particle is obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, the polymerizable monomer having an ethylenically unsaturated group may be a non-crosslinkable monomer or a crosslinkable monomer.

[0048] Examples of the non-crosslinkable monomer include vinyl compounds such as styrene monomers, α-methylstyrene, and chlorostyrene; vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; acid vinyl ester compounds such as vinyl acetate, vinyl butyrate, vinyl laurate, and vinyl stearate; halogen-containing monomers such as vinyl chloride and vinyl fluoride; and (meth)acrylic compounds such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, and cyclohexyl (meth)acrylate. Examples of suitable (meth)acrylate compounds include alkyl (meth)acrylate compounds such as (meth)acrylate and isobornyl (meth)acrylate; oxygen-containing (meth)acrylate compounds such as 2-hydroxyethyl (meth)acrylate, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate, and glycidyl (meth)acrylate; nitrile-containing monomers such as (meth)acrylonitrile; halogen-containing (meth)acrylate compounds such as trifluoromethyl (meth)acrylate and pentafluoroethyl (meth)acrylate; α-olefin compounds such as diisobutylene, isobutylene, linearene, ethylene, and propylene; and conjugated diene compounds such as isoprene and butadiene.

[0049] Examples of the crosslinkable monomer include vinyl compounds such as vinyl monomers like divinylbenzene, 1,4-divinyloxybutane, and divinylsulfone; (meth)acrylic compounds such as polyfunctional (meth)acrylate compounds like tetramethylolmethane tetra(meth)acrylate, polytetramethylene glycol diacrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, glycerol tri(meth)acrylate, glycerol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, and 1,4-butanediol di(meth)acrylate; and allyl compounds. Examples of silane compounds include triallyl (iso) cyanurate, triallyl trimellitate, diallyl phthalate, diallyl acrylamide, and diallyl ether; examples of silane compounds include silane alkoxide compounds such as tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, isopropyltrimethoxysilane, isobutyltrimethoxysilane, cyclohexyltrimethoxysilane, n-hexyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, trimethoxysilylstyrene, γ-(meth)acryloxypropyltrimethoxysilane, 1,3-divinyltetramethyldisiloxane, methylphenyldimethoxysilane, and diphenyldimethoxysilane;Examples of suitable silane alkoxides include polymerizable double bonds such as vinyltrimethoxysilane, vinyltriethoxysilane, dimethoxymethylvinylsilane, dimethoxyethylvinylsilane, diethoxymethylvinylsilane, diethoxyethylvinylsilane, ethylmethyldivinylsilane, methylvinyldimethoxysilane, ethylvinyldimethoxysilane, methylvinyldiethoxysilane, ethylvinyldiethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane; cyclic siloxanes such as decamethylcyclopentasiloxane; modified (reactive) silicone oils such as single-end-modified silicone oil, double-end-modified silicone oil, and side-chain silicone oil; and carboxyl group-containing monomers such as (meth)acrylic acid, maleic acid, and maleic anhydride.

[0050] From the viewpoint of increasing the blackness and suppressing the occurrence of light leakage, the base particle preferably contains a colorant. The base particle can be obtained by uniformly mixing and dispersing the colorant in the polymerizable monomer having an ethylenically unsaturated group, followed by polymerization.

[0051] From the viewpoint of increasing the blackness and suppressing the occurrence of light leakage, the colorant is preferably a pigment or a dye, and is preferably a black pigment or a black dye. The colorant may be used alone or in combination of two or more kinds.

[0052] Examples of the pigment include carbon black, titanium black, aniline black, iron oxide, lamp black, graphite, copper-chromium composite oxide, copper-chromium-zinc composite oxide, etc. From the viewpoint of increasing the blackness and suppressing the occurrence of light leakage, the pigment is preferably carbon black.

[0053] Examples of the dyes include pyrazole azo dyes, anilino azo dyes, triphenylmethane dyes, anthraquinone dyes, anthrapyridone dyes, benzylidene dyes, oxol dyes, pyrazolotriazole azo dyes, pyridone azo dyes, cyanine dyes, phenothiazine dyes, pyrrolopyrazole azomethine dyes, xathene dyes, phthalocyanine dyes, benzopyran dyes, indigo dyes, pyrromethene dyes, triarylmethane dyes, azomethine dyes, perylene dyes, perinone dyes, quatarylene dyes, and quinophthalone dyes. The dyes may be black dyes obtained by mixing two or more of acid dyes, direct dyes, basic dyes, mordant dyes, acid mordant dyes, azoic dyes, disperse dyes, oil-soluble dyes, food dyes, and derivatives thereof.

[0054] The polymerization method is not particularly limited, and examples thereof include known methods such as radical polymerization, ionic polymerization, polycondensation (condensation polymerization, polycondensation), addition condensation, living polymerization, and living radical polymerization. Other polymerization methods include suspension polymerization and dispersion polymerization in the presence of a radical polymerization initiator.

[0055] Examples of the inorganic material include silicate glass, borosilicate glass, lead glass, soda-lime glass, alumina, and alumina silicate glass.

[0056] The base particle may be formed solely from the organic material, solely from the inorganic material, or both from the organic material and the inorganic material. The base particle is preferably formed solely from the organic material. In this case, the particle can have an appropriate hardness and can more effectively function as a spacer.

[0057] The base particles may be organic-inorganic hybrid particles. The base particles may be core-shell particles. When the base particles are organic-inorganic hybrid particles, examples of inorganic materials for the base particles include silica, alumina, barium titanate, zirconia, and silicone. The inorganic material is preferably not a metal. The base particles formed from silica are not particularly limited, but examples include base particles obtained by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, followed by firing as necessary. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed from a crosslinked alkoxysilyl polymer and an acrylic resin.

[0058] The organic-inorganic hybrid particles are preferably core-shell organic-inorganic hybrid particles having a core and a shell disposed on the surface of the core. The core is preferably an organic core. The shell is preferably an inorganic shell. From the viewpoint of enabling the particles to more effectively function as spacers, the base particles are preferably organic-inorganic hybrid particles having an organic core and an inorganic shell disposed on the surface of the organic core.

[0059] Examples of the material for the organic core include the organic materials described above.

[0060] Examples of materials for the inorganic shell include the inorganic substances listed as materials for the base particle described above. The material for the inorganic shell is preferably silica. The inorganic shell is preferably formed by forming a shell-like substance from a metal alkoxide on the surface of the core by a sol-gel method and then firing the shell-like substance. The metal alkoxide is preferably a silane alkoxide. The inorganic shell is preferably formed from a silane alkoxide.

[0061] From the viewpoint of practicality, the particle diameter of the base particles is preferably 0.9 μm or more, more preferably 7.9 μm or more, even more preferably 9.9 μm or more, and preferably 49 μm or less, more preferably 29 μm or less, even more preferably 24.5 μm or less.

[0062] The particle size of the base particle means the diameter when the base particle is spherical, and when the base particle has a shape other than spherical, means the diameter when the base particle is assumed to be a true sphere of a volume equivalent to the particle size.

[0063] The particle size of the base particles refers to the average particle size measured by a particle size measuring device. Examples of particle size measuring devices include particle size distribution measuring devices that use principles such as laser light scattering, electrical resistance change, and image analysis after imaging. Specific methods for measuring the particle size of the base particles include, for example, measuring the particle sizes of approximately 100,000 particles using a particle size distribution measuring device (Beckman Coulter's "Multisizer 4") to determine the average particle size. The average particle size refers to the number-average particle size.

[0064] From the viewpoint of further improving adhesiveness, the CV value of the particle diameter of the base particles is preferably 10% or less, more preferably 7% or less. There is no particular upper limit to the CV value of the particle diameter of the base particles. The CV value of the particle diameter of the base particles may be 30% or less.

[0065] The CV value (coefficient of variation) of the particle diameter of the base particles can be measured as follows.

[0066] CV value (%) = (ρ / Dn) × 100 ρ: Standard deviation of the particle size of the base material particles Dn: average particle size of the above base material particles

[0067] The compressive modulus of elasticity (10% K value) of the base particle when compressed by 10% at 25°C is preferably 10 N / mm 2 More preferably, 1000N / mm 2or more, preferably 10,000 N / mm 2 Less than or equal to 7000N / mm 2 When the 10% K value is equal to or greater than the lower limit and equal to or less than the upper limit, the gap can be controlled with high precision.

[0068] The compressive modulus of elasticity of the base particle when compressed by 30% at 25°C (30% K value) is preferably 50 N / mm 2 More preferably, 2000N / mm 2 or more, preferably 20,000 N / mm 2 Less than or equal to 10,000 N / mm 2 When the 30% K value is equal to or greater than the lower limit and equal to or less than the upper limit, the gap can be controlled with high precision.

[0069] The compressive elastic modulus (10% K value and 30% K value) of the base particle can be measured as follows.

[0070] Using a microcompression tester, one base particle is compressed with the end face of a smooth cylindrical indenter (diameter 100 μm, made of diamond) under conditions of 25°C, a compression speed of 0.3 mN / sec, and a maximum test load of 20 mN. The load value (N) and compression displacement (mm) at this time are measured. From the obtained measured values, the compressive elastic modulus (10% K value and 30% K value) can be calculated using the following formula. As the microcompression tester, for example, the "Fisherscope H-100" manufactured by Fischer is used. The compressive elastic modulus (10% K value and 30% K value) of the base particle is preferably calculated by arithmetic averaging the compressive elastic modulus (10% K value and 30% K value) of 50 arbitrarily selected base particles.

[0071] 10% K value and 30% K value (N / mm 2 )=(3 / 2 1 / 2 )·F·S -3 / 2 ·R -1 / 2 F: Load value (N) when the base particle is compressed by 10% or 30% S: Compression displacement (mm) when the base particle is compressed by 10% or 30% R: Radius of base particle (mm)

[0072] The compressive modulus universally and quantitatively represents the hardness of the base particle. The compressive modulus can be used to quantitatively and unambiguously represent the hardness of the base particle.

[0073] The content of the base particles in 100% by weight of the adhesive particles is preferably 13% by weight or more, more preferably 37% by weight or more, even more preferably 63% by weight or more, and is preferably 99% by weight or less, more preferably 94% by weight or less, even more preferably 87% by weight or less. When the content of the base particles is equal to or more than the above lower limit and equal to or less than the above upper limit, adhesiveness can be further improved and dripping during heating can be more effectively suppressed.

[0074] From the viewpoint of suppressing light leakage and increasing the strength of the base particle, the content of the colorant in 100% by weight of the base particle is preferably 1% by weight or more, more preferably 3% by weight or more, even more preferably 5% by weight or more, and is preferably 20% by weight or less, more preferably 15% by weight or less, even more preferably 10% by weight or less. When the base particle contains multiple colorants, the content of the colorant means the total content of the multiple colorants.

[0075] (Covered part) In the adhesive particle according to the present invention, the coating portion is disposed on the surface of the base particle. The coating portion includes a thermosetting resin. The coating portion is a thermosetting resin portion. The thermosetting resin portion is formed from a thermosetting resin and includes a thermosetting resin. Since the adhesive particle according to the present invention has the above configuration, it is possible to ensure a sufficient thickness of the coating portion, and as a result, it is possible to sufficiently improve adhesion. In addition, it is possible to suppress dripping during heating. As a result, it is possible to further improve adhesion and suppress the occurrence of light leakage. By suppressing the occurrence of light leakage, it is possible to prevent a decrease in contrast of a liquid crystal display element and to prevent a deterioration in display quality.

[0076] The coating may be formed of one layer. The coating may be formed of multiple layers. That is, the coating may have a laminated structure of two or more layers. When the coating is formed of multiple layers, it is preferable that the outermost layer contains a thermosetting resin.

[0077] Examples of the thermosetting resin include epoxy resin, vinyl ester resin, unsaturated polyester resin, etc. The thermosetting resin may be used alone or in combination of two or more.

[0078] Examples of the epoxy resin include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, phenol novolac type epoxy resins, biphenyl type epoxy resins, biphenyl novolac type epoxy resins, biphenol type epoxy resins, naphthalene type epoxy resins, fluorene type epoxy resins, phenol aralkyl type epoxy resins, naphthol aralkyl type epoxy resins, dicyclopentadiene type epoxy resins, anthracene type epoxy resins, epoxy resins having an adamantane skeleton, epoxy resins having a tricyclodecane skeleton, and epoxy resins having a triazine nucleus in the skeleton.

[0079] Examples of the vinyl ester resin include bis-based vinyl ester resins and novolac-based vinyl ester resins.

[0080] Examples of the unsaturated polyester resin include resins obtained by polycondensation of an α,β-unsaturated dicarboxylic acid or its acid anhydride with a glycol.

[0081] From the viewpoint of improving adhesiveness at low temperatures, the thermosetting resin is preferably an epoxy resin. From the viewpoint of improving adhesiveness at low temperatures, the thermosetting resin preferably contains an epoxy resin.

[0082] When an epoxy resin is used as the material for the adhesive particles, the epoxy resin is preferably a polyfunctional epoxy resin. Examples of the polyfunctional epoxy resin include bifunctional epoxy resins such as bisphenol A epoxy resins and bisphenol F epoxy resins, trifunctional epoxy resins such as triazine epoxy resins and glycidylamine epoxy resins, and tetrafunctional epoxy resins such as tetrakisphenolethane epoxy resins and glycidylamine epoxy resins. The epoxy resins may be used alone or in combination of two or more.

[0083] Furthermore, when an epoxy resin is used as the material for the adhesive particles, it is preferable to use a curing agent together with the epoxy resin. The curing agent thermally cures the epoxy resin. The curing agent is not particularly limited. Examples of the curing agent include imidazole curing agents, amine curing agents, phenolic curing agents, thiol curing agents such as polythiol curing agents, and acid anhydride curing agents. Only one type of curing agent may be used, or two or more types may be used in combination. From the viewpoint of easily controlling the compression characteristics of the adhesive particles within a suitable range, it is preferable that the curing agent be an amine curing agent.

[0084] The imidazole curing agent is not particularly limited. Examples of the imidazole curing agent include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine and 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-methyl-4- ... Examples of the imidazole compound include imidazole compounds in which the hydrogen atom at the 5-position of 1H-imidazole is substituted with a hydroxymethyl group and the hydrogen atom at the 2-position is substituted with a phenyl group or a toluyl group, such as imidazole, 2-phenyl-4-benzyl-5-hydroxymethylimidazole, 2-para-toluyl-4-methyl-5-hydroxymethylimidazole, 2-meta-toluyl-4-methyl-5-hydroxymethylimidazole, 2-meta-toluyl-4,5-dihydroxymethylimidazole, and 2-para-toluyl-4,5-dihydroxymethylimidazole.

[0085] The thiol curing agent is not particularly limited, and examples of the thiol curing agent include trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate.

[0086] The amine curing agent is not particularly limited, and examples of the amine curing agent include ethylenediamine, hexamethylenediamine, octamethylenediamine, decamethylenediamine, 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraspiro[5.5]undecane, bis(4-aminocyclohexyl)methane, phenylenediamine, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, metaphenylenediamine, diaminodiphenylmethane, diaminophenyl ether, metaxylenediamine, diaminonaphthalene, bisaminomethylcyclohexane, and diaminodiphenylsulfone. The amine curing agent is preferably ethylenediamine, hexamethylenediamine, octamethylenediamine, 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane, metaphenylenediamine, dianodiphenylmethane, diaminodiphenylsulfone, phenylenediamine, or 2,2-bis[4-(4-aminophenoxy)phenyl]propane. The use of these preferred amine curing agents can improve adhesion at low temperatures. From the perspective of improving adhesion at low temperatures, the amine curing agent is more preferably ethylenediamine, 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane, diaminodiphenylmethane, phenylenediamine, or 2,2-bis[4-(4-aminophenoxy)phenyl]propane.

[0087] The acid anhydride curing agent is not particularly limited, and any acid anhydride that is used as a curing agent for thermosetting compounds such as epoxy compounds can be widely used. Examples of the acid anhydride curing agent include phthalic anhydride, tetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride, anhydrides of phthalic acid derivatives, maleic anhydride, nadic anhydride, methylnadic anhydride, glutaric anhydride, succinic anhydride, glycerin bistrimellitic anhydride monoacetate, and ethylene glycol bistrimellitic anhydride, bifunctional acid anhydride curing agents such as trimellitic anhydride, and tetrafunctional or higher acid anhydride curing agents such as pyromellitic anhydride, benzophenonetetracarboxylic anhydride, methylcyclohexenetetracarboxylic anhydride, and polyazelaic anhydride.

[0088] The surface area covered by the coating portion (coverage rate) of the total surface area (100%) of the base particle is preferably 20% or more, more preferably 50% or more, even more preferably 80% or more, and particularly preferably 85% or more. There are no particular limitations on the upper limit of the coverage rate. The coverage rate may be 100% or less, or may be 99% or less. When the coverage rate is equal to or greater than the lower limit, the adhesiveness can be further improved. Furthermore, when the adhesive particles are used as a gap material, the gap can be controlled with even greater precision.

[0089] The surface area covered by the coating portion (coverage rate) of the total surface area of ​​the base particle (100%) is determined by observing the adhesive particle with an electron microscope or optical microscope and calculating the percentage of the surface area covered by the coating portion relative to the projected area of ​​the base particle.

[0090] From the viewpoint of further enhancing adhesiveness, the thickness of the coating is preferably 0.1 μm or more, more preferably 0.5 μm or more, even more preferably 1 μm or more, and is preferably 10 μm or less, more preferably 7 μm or less, even more preferably 5 μm or less. When the coating is formed of multiple layers, the thickness of the coating means the thickness of the entire coating.

[0091] The thickness of the coating portion can be calculated from the difference between the particle diameter of the base particle and the particle diameter of the particle.

[0092] The ratio of the thickness of the coating portion to the particle diameter of the adhesive particle (thickness of coating portion / particle diameter of adhesive particle) is defined as ratio A. From the viewpoint of further enhancing adhesion and suppressing the occurrence of light leakage, the ratio A is preferably greater than 0.01, more preferably 0.02 or more, even more preferably 0.03 or more, particularly preferably 0.05 or more, and is preferably 0.30 or less, more preferably 0.25 or less, even more preferably 0.20 or less, particularly preferably 0.15 or less.

[0093] The content of the thermosetting resin is preferably 1 part by weight or more, more preferably 6 parts by weight or more, and even more preferably 13 parts by weight or more, and is preferably 87 parts by weight or less, more preferably 63 parts by weight or less, and even more preferably 57 parts by weight or less, relative to 100 parts by weight of the base particles. When the content of the thermosetting resin is equal to or more than the lower limit and equal to or less than the upper limit, adhesiveness can be further improved and dripping during heating can be more effectively suppressed.

[0094] The content of the curing agent relative to 100 parts by weight of the base particles is preferably 0.1 parts by weight or more, more preferably 1 part by weight or more, and even more preferably 2 parts by weight or more, and is preferably 40 parts by weight or less, more preferably 35 parts by weight or less, and even more preferably 30 parts by weight or less. When the content of the curing agent is equal to or more than the lower limit and equal to or less than the upper limit, adhesion at low temperatures can be improved and aggregation can be suppressed.

[0095] The content of the curing agent in the adhesive particles is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, even more preferably 15 parts by weight or more, and is preferably 40 parts by weight or less, more preferably 30 parts by weight or less, and even more preferably 25 parts by weight or less, relative to 100 parts by weight of the thermosetting resin in the adhesive particles. When the content of the curing agent is equal to or more than the lower limit and equal to or less than the upper limit, adhesion at low temperatures can be improved and aggregation can be suppressed.

[0096] <Adhesive> The adhesive according to the present invention includes the adhesive particles and a binder. The adhesive particles are preferably dispersed in the binder and used as an adhesive. The adhesive is preferably used in a light-control layer and a light-control laminate. Only one type of binder may be used, or two or more types may be used.

[0097] The binder is not particularly limited. Generally, an insulating resin is used as the binder. Examples of the binder resin include vinyl resin, thermoplastic resin, curable resin, thermoplastic block copolymer, and elastomer. Only one type of the binder resin may be used, or two or more types may be used in combination.

[0098] Examples of the vinyl resin include vinyl acetate resin, acrylic resin, and styrene resin. Examples of the thermoplastic resin include polyolefin resin, ethylene-vinyl acetate copolymer, and polyamide resin. Examples of the curable resin include epoxy resin, urethane resin, polyimide resin, and unsaturated polyester resin. The curable resin may be a room temperature curable resin, a thermosetting resin, a photocurable resin, or a moisture curable resin. The curable resin may be used in combination with a curing agent. Examples of the thermoplastic block copolymer include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, a hydrogenated product of styrene-butadiene-styrene block copolymer, and a hydrogenated product of styrene-isoprene-styrene block copolymer. Examples of the elastomer include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.

[0099] The adhesive and the binder preferably contain a thermoplastic component or a thermosetting component. The adhesive and the binder may contain a thermoplastic component or a thermosetting component.

[0100] In addition to the adhesive particles and the binder, the adhesive may contain various additives such as fillers, extenders, softeners, plasticizers, polymerization catalysts, curing catalysts, colorants, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, lubricants, antistatic agents, and flame retardants.

[0101] The content of the binder in 100% by weight of the adhesive is preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, particularly preferably 70% by weight or more, and is preferably 99.99% by weight or less, more preferably 99.9% by weight or less. When the content of the binder is equal to or more than the lower limit and equal to or less than the upper limit, the adhesiveness can be further improved.

[0102] The content of the adhesive particles in 100% by weight of the adhesive is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and is preferably 80% by weight or less, more preferably 60% by weight or less, even more preferably 40% by weight or less, particularly preferably 20% by weight or less, and most preferably 10% by weight or less. When the content of the adhesive particles is equal to or more than the lower limit and equal to or less than the upper limit, the adhesiveness is improved and the gap can be controlled with high precision.

[0103] <Light-control laminate> The photochromic stack according to the present invention includes a first substrate, a second substrate, and a photochromic layer disposed between the first substrate and the second substrate, wherein the material of the photochromic layer contains the adhesive particles described above.

[0104] FIG. 2 is a cross-sectional view showing an example of a PDLC-type light-control laminate using adhesive particles according to the first embodiment of the present invention.

[0105] The PDLC-type light-control laminate 51 includes a first substrate 52, a second substrate 53, and a light-control layer 54. The light-control layer 54 is disposed between the first substrate 52 and the second substrate 53. A sealant may be disposed between the first substrate 52 and the second substrate 53 around the light-control layer 54.

[0106] The light-controlling layer 54 includes liquid crystal capsules 54A, a binder 54B, and a plurality of adhesive particles 1. The liquid crystal capsules 54A are dispersed in the binder 54B. The liquid crystal capsules 54A are held in a capsule-like state in the binder 54B. The liquid crystal material may be dispersed in the binder in a capsule-like state, or the liquid crystal material may be dispersed in the binder as a continuous phase.

[0107] The adhesive particles 1 are spherical adhesive particles. In the PDLC-type light-control laminate 51, the thermosetting resin portion of the adhesive particles 1 is thermally cured.

[0108] FIG. 3 is a cross-sectional view showing an example of an SPD-type light-control laminate using adhesive particles according to the first embodiment of the present invention.

[0109] The SPD-type light-switching stack 61 includes a first substrate 62, a second substrate 63, and a light-switching layer 64. The light-switching layer 64 is disposed between the first substrate 62 and the second substrate 63. A sealant may be disposed between the first substrate 62 and the second substrate 63 around the light-switching layer 64.

[0110] The material of the light-control layer 64 contains a plurality of adhesive particles 1. The adhesive particles 1 are spherical adhesive particles. In the SPD-type light-control laminate 61, the thermosetting resin portion of the adhesive particles 1 is thermally cured.

[0111] The light control layer 64 includes droplets 64A of a light control suspension and a resin matrix 64B. The droplets 64A of the light control suspension are dispersed in the resin matrix 64B. The droplets 64A of the light control suspension are held in a droplet state in the resin matrix 64B.

[0112] Transparent electrodes may be formed on the surfaces of the first substrate and the second substrate, and examples of materials for the transparent electrodes include indium tin oxide (ITO).

[0113] The light-controlling layer has a light-controlling property. The light-controlling property is a property that allows the visible light transmittance to be changed depending on whether or not an electric field is applied, thereby adjusting the amount of incident light. Examples of mechanisms for changing the visible light transmittance include the PDLC (Polymer Dispersed Liquid Crystal) system, the SPD (Suspended Particle Device) system, a guest-host liquid crystal system using liquid crystal, the TN (Twisted Nematic) system, the VA (Vertical Alignment) system, and the IPS (In-Plane-Switching) system. The material of the light-controlling layer is not particularly limited, and any material having a light-controlling property may be used.

[0114] The light-controlling laminate is preferably a PDLC-type light-controlling laminate or an SPD-type light-controlling laminate.

[0115] [PDLC method] The light-modulating layer preferably further contains a binder and a liquid crystal material dispersed in the binder.

[0116] The liquid crystal material is not particularly limited. The liquid crystal material preferably has a property of changing its orientation upon application of an electric field. The liquid crystal material may be dispersed in the binder as a continuous phase, or may be dispersed in the binder in the form of liquid crystal droplets or liquid crystal capsules. Examples of the liquid crystal material include nematic liquid crystals and cholesteric liquid crystals.

[0117] Examples of the nematic liquid crystal material include cyanobiphenyls, phenyl esters, azoxybenzenes, fluorine-containing biphenyls, carbonate esters, Schiff bases, etc. The nematic liquid crystal material may be used alone or in combination of two or more.

[0118] Examples of the cholesteric liquid crystal material include nematic liquid crystals and smectic liquid crystals such as steroid cholesterol derivatives, Schiff bases, azos, azoxys, benzoates, biphenyls, terphenyls, cyclohexylcarboxylates, phenylcyclohexanes, biphenylcyclohexanes, pyrimidines, dioxanes, cyclohexylcyclohexane esters, cyclohexylethanes, cyclohexanes, tolanes, alkenyls, stilbenes, and condensed polycyclics, as well as mixtures of these liquid crystals with the addition of chiral components of optically active materials such as Schiff bases, azos, esters, and biphenyls. Only one type of cholesteric liquid crystal material may be used, or two or more types may be used in combination.

[0119] The binder holds the liquid crystal material and suppresses its flow. The binder is not particularly limited. It is preferable that the binder is insoluble in the liquid crystal material, has strength sufficient to withstand external forces, and has high transmittance to reflected and incident light. Examples of the binder material include water-soluble polymer materials such as gelatin, polyvinyl alcohol, cellulose derivatives, polyacrylic acid polymers, ethyleneimine, polyethylene oxide, polyacrylamide, polystyrene sulfonate, polyamidine, and isoprene-based sulfonic acid polymers, as well as materials that can be emulsified in water, such as fluororesins, silicone resins, acrylic resins, urethane resins, and epoxy resins. Only one type of binder material may be used, or two or more types may be used in combination.

[0120] The binder is preferably crosslinked by a crosslinking agent. The crosslinking agent is not particularly limited. The crosslinking agent preferably forms crosslinks between the binders, hardening the binder, making it difficult to dissolve, or making it insoluble. Examples of the crosslinking agent include acetaldehyde, glutaraldehyde, glyoxal, potassium alum hydrate, a polyvalent metal salt compound, adipic acid dihydrazide, melamine formalin oligomer, ethylene glycol diglycidyl ether, polyamide epichlorohydrin, and polycarbodiimide. The crosslinking agent may be used alone or in combination of two or more.

[0121] [SPD method] The light control layer preferably further includes a resin matrix and a light control suspension dispersed in the resin matrix.

[0122] The light control suspension includes a dispersion medium and light control particles dispersed in the dispersion medium.

[0123] Examples of the light control particles include carbon materials such as polyiodides and carbon black, metal materials such as copper, nickel, iron, cobalt, chromium, titanium, and aluminum, and inorganic compound materials such as silicon nitride, titanium nitride, and aluminum oxide. These materials may also be particles coated with a polymer. Only one type of the light control particles may be used, or two or more types may be used in combination.

[0124] The dispersion medium disperses the light control particles in a fluidizable state. The dispersion medium selectively adheres to and coats the light control particles, and acts to move the light control particles into the phase-separated droplet phase upon phase separation with the resin matrix. It is preferable that the dispersion medium be a material that is non-conductive and has no affinity with the resin matrix. Furthermore, the dispersion medium is preferably a liquid copolymer having a refractive index similar to that of the resin matrix when formed into a light-control laminate. The liquid copolymer is preferably a (meth)acrylic acid ester oligomer having a fluoro group or a hydroxyl group, and more preferably a (meth)acrylic acid ester oligomer having a fluoro group and a hydroxyl group. When such a copolymer is used, the monomer units with the fluoro group or hydroxyl group face the light control particles, and the remaining monomer units stabilize the droplets of the light control suspension within the resin matrix. This facilitates dispersion of the light control particles within the light control suspension, and facilitates their induction into the droplets that phase-separate upon phase separation with the resin matrix.

[0125] Examples of the (meth)acrylic acid ester oligomer having a fluoro group or a hydroxyl group include 2,2,2-trifluoroethyl methacrylate / butyl acrylate / 2-hydroxyethyl acrylate copolymer, 3,5,5-trimethylhexyl acrylate / 2-hydroxypropyl acrylate / fumaric acid copolymer, butyl acrylate / 2-hydroxyethyl acrylate copolymer, 2,2,3,3-tetrafluoropropyl acrylate / butyl acrylate / 2-hydroxyethyl acrylate copolymer, 1H,1H,5H-octafluoropentyl acrylate / butyl acrylate / 2-hydroxyethyl acrylate copolymer, and 1H,1H,5H-octafluoropentyl acrylate / butyl acrylate / 2-hydroxyethyl acrylate copolymer. , 1H,2H,2H-heptadecafluorodecyl / butyl acrylate / 2-hydroxyethyl acrylate copolymer, 2,2,2-trifluoroethyl methacrylate / butyl acrylate / 2-hydroxyethyl acrylate copolymer, 2,2,3,3-tetrafluoropropyl methacrylate / butyl acrylate / 2-hydroxyethyl acrylate copolymer, 1H,1H,5H-octafluoropentyl methacrylate / butyl acrylate / 2-hydroxyethyl acrylate copolymer, and 1H,1H,2H,2H-heptadecafluorodecyl methacrylate / butyl acrylate / 2-hydroxyethyl acrylate copolymer. It is more preferable that these (meth)acrylic acid ester oligomers have both a fluoro group and a hydroxyl group.

[0126] The weight average molecular weight of the (meth)acrylic acid ester oligomer is preferably 1,000 or more, more preferably 2,000 or more, and preferably 20,000 or less, more preferably 10,000 or less.

[0127] The light control layer can be produced using a resin material for forming the resin matrix and the light control suspension.

[0128] The resin material is preferably a resin material that is cured by irradiation with energy rays. Examples of resin materials that are cured by irradiation with energy rays include polymer compositions containing a photopolymerization initiator and a polymer compound that is cured by energy rays such as ultraviolet rays, visible light, and electron beams. Examples of the polymer composition include polymer compositions containing a polymerizable monomer having an ethylenically unsaturated group and a photopolymerization initiator. Examples of the polymerizable monomer having an ethylenically unsaturated group include non-crosslinkable monomers and crosslinkable monomers.

[0129] Examples of the non-crosslinkable monomer include vinyl compounds such as styrene monomers, α-methylstyrene, and chlorostyrene; vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; acid vinyl ester compounds such as vinyl acetate, vinyl butyrate, vinyl laurate, and vinyl stearate; halogen-containing monomers such as vinyl chloride and vinyl fluoride; and (meth)acrylic compounds such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, and cyclohexyl (meth)acrylate. Examples of suitable (meth)acrylate compounds include alkyl (meth)acrylate compounds such as (meth)acrylate and isobornyl (meth)acrylate; oxygen-containing (meth)acrylate compounds such as 2-hydroxyethyl (meth)acrylate, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate, and glycidyl (meth)acrylate; nitrile-containing monomers such as (meth)acrylonitrile; halogen-containing (meth)acrylate compounds such as trifluoromethyl (meth)acrylate and pentafluoroethyl (meth)acrylate; α-olefin compounds such as diisobutylene, isobutylene, linearene, ethylene, and propylene; and conjugated diene compounds such as isoprene and butadiene.

[0130] Examples of the crosslinkable monomer include vinyl compounds such as vinyl monomers like divinylbenzene, 1,4-divinyloxybutane, and divinylsulfone; and (meth)acrylic compounds such as tetramethylolmethane tetra(meth)acrylate, polytetramethylene glycol diacrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. Dipentaerythritol penta(meth)acrylate, glycerol tri(meth)acrylate, glycerol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol Polyfunctional (meth)acrylate compounds such as di(meth)acrylate; allyl compounds such as triallyl (iso)cyanurate, triallyl trimellitate, diallyl phthalate, diallyl acrylamide, and diallyl ether; silane compounds such as tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, isopropyltrimethoxysilane, isobutyltrimethoxysilane, cyclohexyltrimethoxysilane, n-hexyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, trimethoxysilylstyrene, γ-(meth)acryloxypropyltrimethoxysilane, 1,3-divinyltetramethyldisiloxane, methylphenyldimethoxysilane, and diphenyldimethoxysilane are examples of silane alkoxide compounds;Examples of suitable silane alkoxides include polymerizable double bonds such as vinyltrimethoxysilane, vinyltriethoxysilane, dimethoxymethylvinylsilane, dimethoxyethylvinylsilane, diethoxymethylvinylsilane, diethoxyethylvinylsilane, ethylmethyldivinylsilane, methylvinyldimethoxysilane, ethylvinyldimethoxysilane, methylvinyldiethoxysilane, ethylvinyldiethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane; cyclic siloxanes such as decamethylcyclopentasiloxane; modified (reactive) silicone oils such as single-end-modified silicone oil, double-end-modified silicone oil, and side-chain silicone oil; and carboxyl group-containing monomers such as (meth)acrylic acid, maleic acid, and maleic anhydride.

[0131] Examples of the photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-(4-(2-hydroxyethoxy)phenyl)-2-hydroxy-2-methyl-1-propan-1-one, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and (1-hydroxycyclohexyl)phenyl ketone.

[0132] The resin material may contain an organic solvent-soluble resin, a thermoplastic resin, poly(meth)acrylic acid, etc. The resin material may also contain various additives such as a coloring inhibitor, an antioxidant, and an adhesion promoter, and may also contain a solvent.

[0133] (First substrate and second substrate) The first substrate and the second substrate are preferably substrates having optical transparency (light-transmitting substrates). The first substrate and the second substrate are preferably transparent substrates. For example, light is transmitted from one side of the transparent substrate to the other side through the transparent substrate. For example, when a substance on the other side of the transparent substrate is viewed from one side through the transparent substrate, the substance can be seen. "Transparent" also includes "semi-transparent." The transparent substrate may be colorless and transparent, or colored and transparent.

[0134] The materials of the first substrate and the second substrate are not particularly limited. The materials of the first substrate and the second substrate may be the same or different. Examples of materials for the substrate include glass and resin films. Examples of glass include soda-lime glass, lead glass, borosilicate glass, and glass of various compositions for general construction, as well as functional glass such as heat-reflecting glass, heat-absorbing glass, and tempered glass. Examples of resin films include polyester films such as polyethylene terephthalate, polyolefin films such as polypropylene, and acrylic resin films. Because of their excellent transparency, formability, adhesiveness, and processability, the transparent substrate is preferably a resin substrate, more preferably a resin film, and even more preferably a polyethylene terephthalate film.

[0135] The first and second substrates preferably comprise a substrate body and a transparent conductive film formed on the surface of the substrate body so that an electric field for light control can be applied. Examples of the transparent conductive film include indium tin oxide (ITO), SnO2, and In2O3.

[0136] From the viewpoint of improving the visibility of the light-control laminate, the visible light transmittance of the first substrate and the second substrate is preferably 75% or more, and more preferably 80% or more.

[0137] The visible light transmittance of the substrate can be measured by spectroscopic measurement or the like in accordance with ISO13837:2008. Alternatively, it can also be measured by a method in accordance with JIS K6714 standard or the like.

[0138] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0139] The following materials were prepared:

[0140] Base material particles: Base particle A (black particles, Sekisui Chemical Co., Ltd. "Micropearl KBN-512", average particle diameter 12.0 μm, CV value 4.0%) Base particle B (black particles, average particle diameter 13.1 μm, CV value 3.0%, prepared according to Synthesis Example 1 below) Base particle C (black particles, Sekisui Chemical Co., Ltd. "Micropearl KBN-507", average particle diameter 7.0 μm, CV value 4.0%) Base particle D (epoxy resin particles, average particle diameter 9.8 μm, CV value 7.3%, prepared according to Synthesis Example 2 below) Base particle E (white particles, Sekisui Chemical Co., Ltd. "Micropearl SP-210", average particle size 10.0 μm, CV value 5.0%)

[0141] (Synthesis Example 1) 170 g of methyltrimethoxysilane (MTMS) and 35 g of water were stirred at 25°C for 1 hour, and then a mixture of 1200 g of water and 12 g of 1N aqueous ammonia solution was added and stirred for another 1 hour to obtain a dispersion of MTMS seed particles.

[0142] 13 g of a 1% aqueous solution of ammonium dodecyl sulfate was mixed into a solution prepared by stirring 96 g of methyltrimethoxysilane and 467 g of water at 25° C. 220 g of the above dispersion was added to the resulting mixture, and the mixture was stirred for 20 minutes to prepare an organopolysiloxane dispersion.

[0143] Next, 5 g of azobisisobutyronitrile (polymerization initiator, AIBN) was dissolved in 50 g of acrylonitrile to prepare a mixed solution. This mixed solution and a solution of 3 g of sulfate ester salt (emulsifier, "Newcol 707SF" manufactured by Nippon Nyukazai Co., Ltd.) dissolved in 100 g of ion-exchanged water were stirred at 20,000 rpm for 1 minute using a homogenizer to prepare a monomer emulsion. The monomer emulsion was added to the organopolysiloxane dispersion and stirred for 1 hour. After stirring, the mixture was then held at 70°C for 6 hours to allow radical polymerization of the monomer, thereby preparing a composite particle dispersion. The resulting dispersion was cooled, washed with methanol, the supernatant methanol was removed, and the mixture was dried in an oven at 80°C for 1 hour to obtain composite particles. The resulting composite particles were then calcined at 580°C for 180 minutes under a nitrogen atmosphere to obtain base particle B.

[0144] (Synthesis Example 2) A reaction vessel equipped with a thermometer, stirrer, and condenser was charged with 10 parts by weight of bisphenol A epoxy resin (DIC Corporation's "EXA-850-CRP"), 7.5 parts by weight of polyvinylpyrrolidone (dispersion stabilizer), and 250 parts by weight of ethanol, and the mixture was stirred at 65°C for 1 hour to achieve a uniform solution. Next, 2.1 parts by weight of 4,4'-diaminodiphenylmethane (amine curing agent) and 35 parts by weight of ethanol were mixed and uniformly dissolved, and then added to the reaction vessel and reacted at 65°C for 20 hours to obtain a reaction product. The resulting reaction product was washed with methanol and then classified to obtain base particle D.

[0145] Thermosetting resin: Thermosetting resin F (bisphenol A epoxy resin, DIC "EXA-850-CRP") Thermosetting resin G (bisphenol A epoxy resin, DIC "EXA-4850-150")

[0146] Hardener: 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane (amine curing agent, "NBDA" manufactured by Mitsui Chemicals, Inc.)

[0147] Thermoplastic resin raw material: styrene monomer

[0148] Example 1 (1) Preparation of adhesive particles In a separable flask, 10 parts by weight of base particle A, 2 parts by weight of thermosetting resin F, 2 parts by weight of thermosetting resin G, 25 parts by weight of polyvinylpyrrolidone ("K-30" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 5 parts by weight of hexadecyltrimethylammonium bromide, 500 parts by weight of methanol, and 500 parts by weight of ethanol were mixed and dissolved. Next, 2 parts by weight of an amine curing agent was added, and the mixture was reacted at 45°C for 20 hours. Thereafter, the mother liquor was separated, washed with methanol, and then dried under vacuum at 25°C for 24 hours to obtain adhesive particles.

[0149] (2) Fabrication of PDLC-type light-control laminate A 50 μm thick PET film was prepared as the material for the first and second substrates. An acrylic hard coat resin (Lioduras TYZ, manufactured by Toyo Ink Co., Ltd.) with dispersed zirconia particles was applied to one side of the PET film and then cured by UV irradiation to form a first hard coat layer with a thickness of 0.8 μm. An acrylic hard coat resin (Lioduras TYAB, manufactured by Toyo Ink Co., Ltd.) was applied to the other side of the PET film and then cured by UV irradiation to form a second hard coat layer with a thickness of 2.0 μm. In this way, a base film was obtained.

[0150] This substrate film was placed in a vacuum device and evacuated. The vacuum level was 9.0×10 -4 After the pressure reached 100 Pa, argon gas was introduced, and an SiOx layer, an SiO2 layer, and an SiOx layer were deposited in this order on the surface of the first hard coat layer by DC magnetron sputtering in an argon gas atmosphere, and an indium tin oxide (ITO) layer was then laminated on top of them. Specifically, an ITO sintered body target containing 7 wt% SnO2 was used, and a cathode with a maximum horizontal magnetic flux density of 1000 gauss on the target surface was used, and the chamber pressure was 3.5 × 10 -1A 18 nm thick conductive layer (indium tin oxide layer) was formed while introducing Pa, Ar gas, and O2 gas at a ratio of 100:1 into a vacuum chamber. The substrate was then annealed at 160°C for 9 minutes in an IR heating oven (Mino Group Co., Ltd.) to obtain a first substrate and a second substrate (transparent conductive film substrate). Adhesive particles were deposited on the surface of the first substrate at a density of 15 particles / cm. 2 Next, a light-adjusting material (prepared in accordance with the method described in "Macromolecules", Vol. 26, pp. 6132-6134 (1993)) was laminated, and then a second substrate was laminated. At this time, the pressure was 5 kgf / cm 2 The adhesive particles were adhered to the first and second substrates by heating at 100° C. for 60 minutes under a pressure of 1000 kJ / cm 2 to prepare a light-control laminate.

[0151] Example 2 ,4, 5 , Reference example 3 and Comparative Examples 2 and 3). Adhesive particles and light-control laminates were produced in the same manner as in Example 1, except that the materials for the adhesive particles were changed as shown in Tables 1 and 2. ,4, 5 , Reference example 3 In Comparative Example 3, similarly to Example 1, thermosetting resins F and G were used.

[0152] (Comparative Example 1) 10 parts by weight of base particles A, 100 parts by weight of methanol, and 900 parts by weight of ion-exchanged water containing 1.5% by weight of sodium p-styrenesulfonate were added to a separable flask and thoroughly dispersed. Then, a solution of 7 parts by weight of styrene monomer and 0.1 parts by weight of ammonium peroxodisulfate dissolved in 30 parts by weight of ion-exchanged water was added and reacted at 70°C for 10 hours. The mother liquor was then separated, washed with ion-exchanged water, and dried under reduced pressure at 55°C for 24 hours to produce particles in which the surface of the base particles was coated with a thermoplastic resin and did not contain a thermosetting resin portion. A light-control laminate was produced in the same manner as in Example 1, except that the obtained particles were used.

[0153] Comparative Example 4 A light-controlling laminate was prepared in the same manner as in Example 1, except that the adhesive particles used were particles in which the surface of base particle A was grafted with a thermoplastic resin ("Micropearl KBS-507-KA4" manufactured by Sekisui Chemical Co., Ltd., average particle diameter 7.16 μm, CV value 5.0%).

[0154] (evaluation) (1) Particle diameter of the base particle, thickness of the coating portion, and particle diameter of the adhesive particle The particle diameter of the base particle, the thickness of the coating portion, and the particle diameter of the adhesive particle were determined by the above-mentioned methods. In addition, the ratio of the thickness of the coating portion to the particle diameter of the adhesive particle (thickness of the coating portion / particle diameter of the adhesive particle) was calculated.

[0155] (2) Dripping prevention The above-described transparent conductive film substrates were prepared as the first and second substrates. The obtained adhesive particles were applied to the surface of the first substrate at a density of 15 particles / cm. 2 The adhesive particles were sprayed onto the surface of the adhesive layer so that the thickness of the adhesive layer was 1 / 4 of the original thickness. Next, a second substrate was laminated on the surface. After that, the adhesive layer was heated at 200°C for 60 minutes, and the particle surface was observed using a digital microscope (Keyence Corporation, "VHX-2000") to see if any liquid was dripping. The image magnification was set to 200x, and 50 random adhesive particles were observed. The dripping suppression property was evaluated according to the following criteria.

[0156] [Criteria for determining drip prevention] 〇〇: Less than 3 dripping adhesive particles ○: 3 or more but less than 10 dripping adhesive particles ×: 10 or more dripping adhesive particles

[0157] (3) Adhesion (tensile yield stress) Using the obtained adhesive particles, test specimens (test samples) were prepared according to the above-mentioned Adhesion Test B. The tensile yield stress of the test specimens was measured at 23°C using a Tensilon universal testing machine (RTI-1310, manufactured by A&D Co., Ltd.) (Adhesion Test B). The adhesion was evaluated according to the following criteria.

[0158] [Adhesion criteria] 〇〇: Tensile yield stress is 0.12 MPa or more ○: Tensile yield stress is 0.07 MPa or more and less than 0.12 MPa ×: Tensile yield stress is less than 0.07 MPa

[0159] (4) Light leakage prevention The adhesive particles thus obtained were used as spacers for a TN (twisted nematic) liquid crystal display element, and a TN liquid crystal display element was produced by the following method.

[0160] An SiO2 film was deposited on one side of the first and second substrates (transparent glass plates, 150 mm x 150 mm) by CVD, and then an ITO film was formed on the entire surface of the SiO2 film by sputtering. A polyimide alignment film (Nissan Chemical Industries, Ltd., "SE-7210") was then formed by spin coating, and baked at 280°C for 90 minutes to form a polyimide alignment film. After rubbing, the resulting adhesive particles were applied to the alignment film side of the first substrate in a 1 mm increments using a dry spreader (Nisshin Engineering, Inc., "DISPA-μR"). 2 The particles were dispersed so that there were 20 to 100 particles per cell. After forming a peripheral sealant (main agent: SE4500, curing agent: HAVEN CHEMICAL) around the periphery of the second substrate, the first and second substrates were placed facing each other with a rubbing direction (twist angle) of 90°. The first and second substrates were then bonded together and treated at 160°C for 90 minutes to harden the sealant and produce an empty cell. TN-type liquid crystal (Merck's "MLC-6222") was injected into the resulting empty cell, and the injection port was sealed with an adhesive (Sekisui Chemical's "Photolec A-780") to produce a TN-type liquid crystal display element, which was then heat-treated at 120°C for 30 minutes.

[0161] The obtained TN-type liquid crystal display element was sandwiched between polarizing films arranged in a crossed Nicol configuration to achieve a normally white display mode, and a voltage of 7 V was applied while observing the state of light leakage of the adhesive particles using a digital microscope (Keyence Corporation, "VHX-2000"). The image magnification was set to 200x, and the percentage of adhesive particles with light leakage was calculated in any five visual fields. The light leakage suppression ability was evaluated according to the following criteria.

[0162] [Light leakage prevention] 〇〇: Less than 3% of adhesive particles are light-passing ○: The percentage of adhesive particles with light leakage is 3% or more and less than 7% ×: 7% or more adhesive particles are light-free

[0163] The adhesive particle configurations and results are shown in Tables 1 and 2 below.

[0164] [Table 1]

[0165] [Table 2] [Explanation of symbols]

[0166] 1…adhesive particles 2...Base material particles 3...Covered part 51...PDLC type light-control laminate 52...First substrate 53...Second board 54...Photochromic layer 54A...Liquid crystal capsule 54B...Binder 61...SPD type light-control laminate 62...First substrate 63...Second board 64...Photochromic layer 64A...droplets of light-adjusting suspension 64Aa…Dispersion medium 64Ab…Light adjustment particle 64B...Resin matrix

Claims

1. A coating material having a base particle and a coating portion disposed on a surface of the base particle, the base particles are black particles, the base particle contains a polymer of a polymerizable monomer having an ethylenically unsaturated group and a colorant, the coating portion includes a thermosetting resin, The adhesive particle has a ratio of the thickness of the coating portion to the particle diameter of the adhesive particle of 0.05 or more.

2. the thermosetting resin is an epoxy resin, The adhesive particle of claim 1 , wherein the coating comprises an amine curing agent.

3. The 10% K value of the base particle is 10 N / mm ２ More than 7000N / mm ２ 3. The adhesive particle according to claim 1 or 2, wherein:

4. The adhesive particles according to any one of claims 1 to 3, and an adhesive, including a binder.

5. a first substrate, a second substrate, and a light-controlling layer disposed between the first substrate and the second substrate; A light-controlling laminate, wherein the material of the light-controlling layer comprises the adhesive particles according to any one of claims 1 to 3.

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