Resin composition and resin sheet

Abstract

Provided are a resin composition having high colorability and a resin sheet made from this resin composition. The resin composition contains particles (A) and a curable component (B). The average particle size of the particles (A) calculated from a particle size distribution measured by differential centrifugal sedimentation is from 100 nm to 250 nm. The total chlorine concentration in the curable component (B) is 1 wt% or less relative to the total amount of the curable component (B).

Description

[Technical Field]

[0001] The present disclosure relates to a resin composition and a resin sheet. [Background technology]

[0002] Conventionally, resin compositions that exhibit structural color by blending fine particles such as fillers into resin-containing compositions have been known. Structural color is a phenomenon in which color is produced by diffraction (interference) that occurs when light is incident on a collection of particles with a periodic structure.

[0003] For example, Patent Document 1 discloses that in an epoxy resin composition containing polycrystalline colloidal particles made of silicon oxide in an epoxy resin, the average distance between colloidal particles in the polycrystalline particles is 85 nm or more and 240 nm or less, and the average particle size of the colloidal particles is 70 nm or more and 238 nm or less. It also discloses that when a resin film is produced from this epoxy resin composition, it has high heat resistance and exhibits a coloring effect, primarily blue. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-228003 Summary of the Invention

[0005] An object of the present disclosure is to provide a resin composition that has high color development even when formed into a film, and a resin sheet made from this resin composition.

[0006] A resin composition according to one embodiment of the present disclosure contains particles (A) and a curable component (B). The particles (A) have an average particle size of 100 nm or more and 250 nm or less, as calculated from a particle size distribution measured by a frequency-dependent centrifugal sedimentation method. The total chlorine concentration in the curable component (B) is 1.0 wt% or less, based on the total amount of the curable component (B).

[0007] A resin sheet according to one embodiment of the present disclosure includes a cured product of the resin composition. DETAILED DESCRIPTION OF THE INVENTION

[0008] 1. Overview The resin composition and resin sheet of this embodiment will be outlined below. In the following description, the expression "A and / or B" means either "A," "B," or "A and B."

[0009] The resin composition of this embodiment (hereinafter also referred to as composition (X)) contains particles (A) and a curable component (B). The particles (A) have an average particle size calculated from the particle size distribution measured by differential centrifugal sedimentation (hereinafter also referred to as DCS method) of 100 nm to 250 nm. The total chlorine concentration in the curable component (B) is 1 wt % or less based on the total amount of the curable component (B). In the present disclosure, the average particle size of the particles (A) is obtained by measuring the particle size distribution of the particles (A) by the DCS method using a disc centrifugal particle size distribution measuring device (CPS disc centrifuge model DC24000 manufactured by CPS Instruments).

[0010] By including curable component (B), composition (X) can disperse particles (A) in composition (X), allowing particles (A) to be dispersed in a colloidal state in composition (X). Furthermore, particles (A) with an average particle diameter of 100 nm or more and 250 nm or less, as calculated from the particle size distribution measured by the DCS method, can become colloidal particles (colloidal particles) in composition (X) and be regularly arranged. This allows color development to be imparted to the resin sheet obtained by curing composition (X).

[0011] Although it is known that structural colors can be produced in conventional resin compositions by arranging fine particles in the resin composition, the color development properties of the resulting film-shaped sheet are not necessarily high. For example, the epoxy resin composition of Patent Document 1 leaves room for improvement in the intensity of color development when molded into a film.

[0012] The inventors conducted extensive research to obtain a resin sheet capable of exhibiting high color development, and as a result, discovered that the color development of the resin sheet may be affected by impurities that may be contained in the curable component (B). The inventors then discovered that the total chlorine concentration contained in the curable component (B) in the composition (X) affects the color development.

[0013] As a result, it was found that in composition (X), by setting the total chlorine concentration in the curable component (B) to 1 wt % or less relative to the total amount of the curable component (B), it is possible to impart high color development to a resin sheet produced from composition (X). In this disclosure, "color development" refers to the tendency for structural color to occur. For example, in this embodiment, a cured product produced from composition (X) is likely to develop structural color due to the arrangement of colloidal particles. Specifically, color development can be evaluated based on the "shape of the transmittance spectrum," "peak wavelength of the transmission spectrum," and "total light transmittance," by measuring transmittance using the method described in "(3-1) Color Development" in the Examples below.

[0014] In the present disclosure, the "total chlorine concentration" refers to the concentration of compounds having chlorine atoms that can be contained in the curable component (B). The total chlorine concentration can be measured in accordance with JIS K7243-3:2005 and calculated using the following formula:

[0015] Total chlorine concentration [ppm] = (c × V × F × A) × 1000 / W In the above formula, c is the concentration (0.01) [mol / L] of the silver nitrate aqueous solution that is the titration solution, V is the titration volume (mL) of the silver nitrate aqueous solution, F is the factor of the silver nitrate aqueous solution, A is the gram equivalent of chlorine (35.3) [g / mol], and W is the amount (g) of the curable component (B) to be measured. In this case, "compounds having chlorine atoms" include saponifiable chlorine such as 1,2-chlorohydrin, 1,3-chlorohydrin, and 1-chloro-2-glycidyl ether, as well as inorganic chlorine.

[0016] The reason why a resin sheet made from composition (X) can exhibit structural color and achieve high color development is not clearly understood, but is presumed to be due to the following reasons.

[0017] As described above, particles (A) can be dispersed in a colloidal state in composition (X) using curable component (B) as a dispersion medium and arranged with regularity. Having an average particle diameter of 100 nm or more and 250 nm or less, as determined from the particle size distribution measured by the DCS method, contributes to the development of structural color. On the other hand, particles (A) with a relatively small average particle diameter, such as 100 nm or more and 250 nm or less, are easily affected by the charges of components other than particles (A) in composition (X). In particular, components containing chlorine atoms, due to their high electronegativity, easily affect the arrangement of particles (A), making it difficult for particles (A) to arrange regularly. Furthermore, if the arrangement of particles (A) is hindered, curing composition (X) becomes difficult. In contrast, in this embodiment, the total chlorine concentration in the curable component (B) is 1.0 wt % or less relative to the total amount of the curable component (B), which makes it difficult for the charge from components containing highly polar chlorine atoms to affect the alignment of the particles (A) when dispersed in a colloidal state. This makes it easier to maintain the alignment of the particles (A) in the composition (X) to the extent that the composition (X) exhibits a highly color-developing structural color. Furthermore, the composition (X) can be cured well. This is thought to facilitate the generation of structural color when a sheet is produced using the composition (X), thereby achieving high color development.

[0018] The resin sheet of this embodiment is made of a cured product of the composition (X), and therefore the resin sheet can produce a structural color derived from the particles (A) in the composition (X), thereby achieving high color development.

[0019] 2.Details The resin composition and resin sheet of the present embodiment will be described in detail below. However, the embodiment described below is merely one of various embodiments of the present disclosure. The following embodiment can be modified in various ways depending on the design as long as the object of the present disclosure can be achieved.

[0020] [Resin composition] As described above, the resin composition (composition (X)) of this embodiment contains particles (A) and a curable component (B). Because composition (X) is prone to producing structural color, even when composition (X) is formed into a film by coating or the like, the cured product of composition (X) can exhibit high color development.

[0021] In the composition (X), the particles (A) are dispersed using the liquid component in the composition (X) as a dispersion medium. The composition (X) can be cured to produce a resin sheet.

[0022] The viscosity of composition (X) at 25° C. is preferably 0.5 Pa·s or more and 20 Pa·s or less. In this case, when a resin sheet is produced from composition (X), the resin sheet can maintain high color development and ensure moldability of the resin sheet.

[0023] In this embodiment, high color development can be imparted to a cured product prepared from composition (X). However, composition (X) itself may be color development, or a coating film of composition (X) prepared from composition (X) before curing may be color development. That is, a dried or semi-cured product of composition (X) may be color development. If composition (X) is color development, the cured product may have even higher color development when composition (X) is cured. In this case, the concentration (density) changes before and after curing, and the concentration increases upon curing, making it easier to reflect incident light.

[0024] Components that can be contained in composition (X) will be described.

[0025] (particle) Composition (X) contains particles (A). The particles (A) have an average particle diameter of 50 nm or more and 500 nm or less, calculated from the particle size distribution measured by the DCS method. This can impart color development to a cured product of composition (X). In this embodiment, particles (A) behave as colloidal particles in composition (X). In this disclosure, "colloidal particles" refer to particles that, when blended with other components, can be dispersed in composition (X) using appropriate components other than colloidal particles as a dispersant and exist in a colloidal state. It is more preferable that the average particle diameter of particles (A) calculated from the particle size distribution measured by the DCS method be 70 nm or more and 350 nm or less, and even more preferable that it be 100 nm or more and 250 nm or less.

[0026] The maximum particle size of the particles (A) is preferably 250 nm or less. The maximum particle size of the particles (A) is measured and calculated by a frequency-dependent centrifugal sedimentation method (i.e., DCS method) using a CPS.

[0027] The shape of the particles (A) is not particularly limited, and may be at least one selected from the group consisting of spherical, rod-like, plate-like, needle-like, fibrous, and film-like shapes. Among these, the shape of the particles (A) is preferably substantially spherical. In the present disclosure, "substantially spherical" does not necessarily mean a strict spherical shape such as a perfect sphere, but includes shapes that are generally considered to be spherical. For example, the substantially spherical shape also includes ellipsoidal shapes, shapes with irregularities on the surface, and the like.

[0028] Specific examples of the components of particles (A) include at least one selected from the group consisting of silica, acrylic microparticles, and silica-PMMA core-shell particles. Among these, particles (A) are preferably silica. Particles (A) more preferably contain substantially spherical silica. Particles (A) preferably contain at least one of spherical silica and fused silica. Particles (A) may contain components other than those listed above, provided that the effects of the present disclosure are not impaired.

[0029] The coefficient of variation (CV) of the particles (A) calculated from the particle size distribution is preferably 20% or less. In this case, it is difficult to cause differences in the interparticle distances between the particles (A) in the composition (X). Therefore, the degree of color development of the resin sheet produced from the composition (X) can be further improved. It is more preferable that the coefficient of variation of the particles (A) calculated from the particle size distribution is 10% or less.

[0030] Furthermore, when the particles (A) described below contain a plurality of particle groups having different average particle diameters, the average particle diameter obtained by weighting the average particle diameters of the plurality of particle groups having different average particle diameters preferably has a coefficient of variation calculated from the particle size distribution of the particles (A) of 10%.

[0031] It is more preferable that the particles (A) contain substantially spherical silica and that the coefficient of variation (CV) of the particles (A) calculated from the particle size distribution is 20% or less. In this case, the color development of the composition (X) is particularly likely to be improved. It is particularly preferable that the particles (A) contain substantially spherical silica and that the coefficient of variation (CV) of the particles (A) calculated from the particle size distribution is 10% or less.

[0032] The volume ratio of particles (A) relative to the total solid content of composition (X) preferably satisfies any one of the ratios shown below. That is, when the average particle diameter of particles (A) is 115 nm or more and 160 nm or less, the volume ratio of particles (A) in the resin composition is preferably 23 vol% or more and 29 vol% or less, relative to the total solid content of composition (X). When the average particle diameter of particles (A) is more than 160 nm and 185 nm or less, the volume ratio of particles (A) in the resin composition is preferably 23 vol% or more and 34 vol% or less, relative to the total solid content of composition (X). When the average particle diameter of particles (A) is 190 nm or more and 230 nm or less, the volume ratio of particles (A) in the resin composition is preferably 29 vol% or more and 34 vol% or less, relative to the total solid content of composition (X). When any one of these ratios is satisfied, even when composition (X) is molded into a film to produce a resin sheet, the resin sheet can be imparted with even higher color development properties. In the present disclosure, the term "total amount of solids in composition (X)" refers to the total amount of components in composition (X) excluding volatile components such as solvents. When particles (A) contain multiple particle groups with different average particle sizes, the term "average particle size" refers to the average particle size calculated as a weighted average of the average particle sizes of each particle group.

[0033] The particles (A) may contain at least two particle groups having different average particle sizes. In this case, it is preferable that the average particle size d1 of the particle group (A1) having the smallest average particle size and the average particle size d2 of the particle group (A2) having the largest average particle size satisfy the relationship of the following formula (1):

[0034] d1×1.01≦d2≦d1×1.20 (1) In this case, even when the particles (A) contain a plurality of particle groups having different average particle diameters, the particles (A) can be more favorably dispersed in the composition (X), and the interparticle distance between the particles (A) can also be appropriately maintained. For this reason, it is easy to control the color tone of the color development of the cured product produced from the composition (X). As shown in the above formula (1), the average particle diameter d2 is larger than the average particle diameter d1. When the average particle diameter d1 of the particle group (A1) having the smallest average particle diameter is, for example, 100 nm or more and 170 nm or less, the average particle diameter d2 of the particle group (A2) having the largest average particle diameter is preferably, for example, 101 nm or more and 204 nm or less. As shown in the above formula (1), the average particle diameter d1 and the average particle diameter d2 satisfy the relationship d1 < d2, that is, the average particle diameter d2 is larger than the average particle diameter d1. Therefore, for example, when the average particle diameter d1 is 100 nm, the average particle diameter d2 is 101 nm or more and 120 nm or less, and when the average particle diameter d1 is 170 nm, the average particle diameter d2 is 187 nm or more and 204 nm or less. When the average particle diameter d1 of the particle group (A1) having the smallest average particle diameter is, for example, 70 nm or more and 150 nm or less, it is more preferable that the average particle diameter d2 of the particle group (A2) having the largest average particle diameter is, for example, 71 nm or more and 180 nm or less.

[0035] When the particles (A) contain a plurality of particle groups having different average particle diameters, the maximum particle diameter of the particles (A) is preferably 70 nm or more and 350 nm or less.

[0036] (Curable component) The composition (X) contains a curable component (B). The curable component (B) can impart curability to the composition (X).

[0037] In this embodiment, the total chlorine concentration in the curable component (B) is 1% by weight or less, based on the total amount of the curable component (B). Therefore, in the composition (X), the alignment of the particles (A) during dispersion is less likely to be hindered, and the particles (A) are more likely to maintain their colloidal state and be aligned with regularity. This makes it easier for the cured product of the composition (X) to exhibit structural color, even when the composition (X) is formed into a film, resulting in high color development. The total chlorine concentration in the curable component (B) is more preferably 0.5% by weight or less, and even more preferably 1% by weight or less, based on the total amount of the curable component (B). It is particularly preferable for the total chlorine concentration to be substantially 0%. The total chlorine concentration in the curable component (B) can be reduced by, for example, purifying the epoxy resin by molecular distillation of the epoxy resin that can be contained in the curable component (B), and / or synthesizing an epoxy resin having a glycidyl group by epoxidizing the raw materials for synthesizing the curable component (B) by, for example, an oxidation method using a peroxide, thereby synthesizing the epoxy resin without producing compounds containing chlorine atoms, chlorine molecules, etc.

[0038] In this embodiment, the curable component (B) contains an epoxy resin containing an organic compound having a chlorine atom in its molecule. Specifically, the curable component (B) contains an organic compound having a chlorine atom in its molecule as an impurity. As described above, the composition (X) may contain impurities. Impurities include, for example, organic compounds having a chlorine atom in their molecule, which are by-produced during the production of an epoxy resin, which is an example of the curable resin (B1). Therefore, the total chlorine concentration in the curable component (B) may vary depending on the presence or absence of organic compounds having a chlorine atom in their molecule. The mass ratio of the organic compounds having a chlorine atom in their molecule contained in the curable component (B) in the composition (X) to the total amount of the curable component (B) is preferably 1.0 mass% or less. In the present disclosure, the "organic compound having a chlorine atom in its molecule" refers to a compound having at least a chlorine atom at the end of the hydrocarbon skeleton. Examples of organic compounds having a chlorine atom in their molecule include, for example, compounds derived from epichlorohydrin residues, which are by-produced during the production of glycidyl ethers by reacting an appropriate epoxy resin with epichlorohydrin. The organic compound having a chlorine atom in the molecule has, for example, a chlorine atom, a hydroxyl group, and an ether bond. Note that the "epoxy resin" referred to here may be thermosetting or photocurable.

[0039] The curable component (B) preferably contains a curable resin (B1) and a curing agent (B2), which allows the composition (X) to be cured well.

[0040] The curable resin (B1) may be, for example, a component that is cured by heat, a component that is cured by light, or a component that is cured by both heat and light. That is, the curable resin (B1) includes at least one of a photocurable resin (B11) and a thermosetting resin (B12).

[0041] Specific examples of the curable resin (B1) include the following components. In the present disclosure, acryloyl and / or methacryloyl may be referred to as (meth)acryloyl. Furthermore, acrylate and / or methacrylate may be referred to as (meth)acrylate. Furthermore, acrylic acid and / or methacrylic acid may be referred to as (meth)acrylic acid.

[0042] The photocurable resin (B11) includes, for example, a compound having an ethylenically unsaturated double bond. Specifically, the photocurable resin (B11) can include at least one compound selected from the group consisting of monofunctional (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, and polyfunctional (meth)acrylates such as diethylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and ε-caprolactone-modified pentaerythritol hexaacrylate.

[0043] The photocurable resin (B11) may contain a polyfunctional compound, i.e., a compound having two or more unsaturated bonds in one molecule. Examples of the polyfunctional compound include, for example, a trifunctional compound, such as at least one compound selected from the group consisting of trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, ε-caprolactone-modified tris-(2-acryloxyethyl)isocyanurate, and ethoxylated glycerin tri(meth)acrylate.

[0044] The thermosetting resin (B12) may include at least one selected from the group consisting of epoxy resins, polyimide resins, phenolic resins, bismaleimide triazine resins, and thermosetting polyphenylene ether resins. Examples of epoxy resins include at least one component selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, cresol novolac epoxy resins, bisphenol A novolac epoxy resins, bisphenol F novolac epoxy resins, naphthalene epoxy resins, biphenyl epoxy resins, dicyclopentadiene epoxy resins, and polyfunctional epoxy resins. However, the components that the thermosetting resin (B1) may include are not limited to those listed above.

[0045] The curing agent (B2) is a component in the curable component (B) that is reactive with the curable resin (B1). That is, the curing agent (B2) reacts with the curable resin (B1) to cure the composition (X).

[0046] The curing agent (B2) may be, for example, at least one selected from the group consisting of acid anhydrides and crosslinking agents.

[0047] When the curable resin (B1) contains a photocurable resin (B11), the curing agent (B2) preferably contains an acid anhydride. In this case, the arrangement of the particles (A) dispersed in a colloidal state in the composition (X) is less affected, and therefore the color development of the resin sheet produced from the composition (X) is less likely to be impaired. The acid anhydride includes a polybasic acid anhydride, and specifically, at least one selected from the group consisting of tetrahydromethylphthalic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, hexahydrophthalic anhydride, and 4-methylhexahydrophthalic anhydride can be mentioned.

[0048] When the curable resin (B1) contains a thermosetting resin (B12), the curing agent (B2) preferably contains at least one selected from the group consisting of diamine-based curing agents, di- or higher-functional phenol-based curing agents, acid anhydride-based curing agents, dicyandiamide, and low-molecular-weight polyphenylene ether compounds.

[0049] The curable component (B) may contain appropriate components involved in the curing of the composition (X), such as a polymerization initiator and a curing accelerator, as long as they do not impair the effects of the present disclosure. Examples of the polymerization initiator include a photopolymerization initiator and / or a thermal polymerization initiator. Examples of the photopolymerization initiator include at least one selected from the group consisting of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, α-hydroxyacetophenone, triarylsulfonium-special phosphorus anion salt, and a propylene carbonate solution of triarylsulfonium-PF6 salt. Examples of the curing accelerator include at least one selected from the group consisting of imidazole compounds, tertiary amine compounds, organic phosphine compounds, and metal soaps. Examples of the flame retardant include halogenated flame retardants and non-halogenated flame retardants.

[0050] (fumed silica) The composition (X) preferably contains fumed silica (C). In this case, the viscosity of the composition (X) can be easily adjusted to a favorable level. When a resin sheet is produced from the composition (X), the moldability of the composition (X) can be improved.

[0051] The fumed silica (C) is silica produced by a dry method and represented by the formula (-(SiO2)-). A specific example of a commercially available product of the fumed silica (C) is Aerosil (registered trademark) (product number RY200 manufactured by Nippon Aerosil Co., Ltd.).

[0052] The average primary particle diameter of the fumed silica (C) is preferably 8 nm or more and 50 nm or less. In this case, the moldability of the composition (X) can be further improved when the composition (X) is formed into a film. The average primary particle diameter of the fumed silica (C) is the average diameter measured by centrifugal sedimentation analysis. The average primary particle diameter of the fumed silica (C) is more preferably 8 nm or more and 20 nm or less, and even more preferably 10 nm or more and 15 nm or less. As mentioned above, the fumed silica (C) may be in a particulate form, but is distinguished from the particles (A) having an average particle diameter of 100 nm or more and 250 nm or less.

[0053] The mass proportion of the fumed silica (C) relative to the total solid content of the composition (X) is preferably 0.5% by mass or more and 2% by mass or less. In this case, it is possible to maintain curability while further improving moldability, and to impart high color development to the resin sheet. The mass proportion of the fumed silica (C) is more preferably 0.1% by mass or more and 5% by mass or less, and even more preferably 0.3% by mass or more and 2% by mass or less.

[0054] (colorant) The composition (X) preferably contains a coloring material (D), which makes it possible to change the color of the resin sheet produced from the composition (X).

[0055] The colorant (D) includes, for example, at least one or both of a pigment and a dye. Specific examples of the colorant (D) include at least one component selected from the group consisting of carbon black, titanium dioxide, zinc oxide (ZnO), yellow lead (PbCrO), cobalt yellow (K[Co(NO)]), red lead (PbO), red iron oxide (FeO), and chrome green (CrO). Among these, it is preferable that the colorant (D) contains at least one component selected from the group consisting of titanium dioxide (TiO) and carbon black. In this case, the color development of a resin sheet prepared from composition (X) can be made less susceptible to the color of the substrate to which composition (X) is applied. Furthermore, even if a resin sheet is prepared by applying composition (X) to a suitable substrate, it can be easily peeled from the substrate. This improves the handleability of the resin sheet. However, the colorant (D) is not limited to the above.

[0056] Composition (X) may contain components other than those described above, such as additives, as long as they do not impair the effects of the present disclosure.

[0057] The additive may be, for example, at least one selected from the group consisting of a surface modifier, an inorganic filler, and a flame retardant. Furthermore, composition (X) may contain an appropriate solvent. Examples of the surface modifier include surfactants and fluorine-containing substances. The surfactant may contain a fluorine-containing compound. Examples of the inorganic filler include aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, talc, clay, mica, and molybdenum compounds. Examples of the solvent include appropriate solvents and water.

[0058] The total chlorine concentration of composition (X) is preferably 5% by weight or less based on the total solid content of composition (X). In this case, even when composition (X) is formed into a film by coating or the like, the cured product of composition (X) can exhibit particularly high color development.

[0059] The composition (X) is prepared, for example, as follows.

[0060] The above-described components are mixed and stirred by an appropriate method to prepare composition (X). When preparing composition (X), an appropriate solvent may be added. Examples of the solvent include methyl ethyl ketone. However, the solvent that can be added is not limited to the above.

[0061] [Resin sheet] The resin sheet of this embodiment will be specifically described.

[0062] Since the resin sheet is made from the composition (X) described above, it can easily produce structural colors and has high color development properties. This allows the resin sheet to improve the design of the appearance of various processed products, molded products, and the like. Therefore, the resin sheet can be used, for example, as a decorative sheet. Specifically, a product can be decorated by attaching the resin sheet to the surface of the product, or a molded product can be decorated by molding with the resin sheet attached to the inner surface of the cavity of a molding die. Furthermore, a processed product can be produced by attaching a resin sheet to a substrate and then overlaying a transparent film on the resin sheet. However, the uses of the resin sheet are not limited to these.

[0063] The resin sheet can be produced by curing composition (X) under appropriate conditions. That is, the resin sheet consists of a cured product of composition (X). The resin sheet may also be produced from a dried or semi-cured product of composition (X). Specifically, composition (X) is applied to a support substrate such as a polyethylene terephthalate (PET) film to produce a coating film, and if necessary, the coating film is heated at an appropriate temperature to obtain a dried coating film. The dried coating film is a dried or semi-cured product (B-stage) of composition (X). The method for applying composition (X) is selected from the group consisting of an appropriate method, such as a bar coater, a comma direct method, a die coater method, and a gravure coater method. The obtained coating film (or dried coating film) is cured by heating the coating film (or dried coating film). This results in a resin sheet produced from composition (X). The resin sheet may also be produced by photocuring composition (X).

[0064] The curing conditions of the composition (X) can be adjusted appropriately depending on the components that can be contained in the composition (X). For example, when the curable component (B) in the composition (X) contains a photocurable resin (B11), the composition (X) can be cured by irradiating it with ultraviolet light. The ultraviolet irradiation conditions can be an exposure time of 10 seconds to 1 hour in an atmospheric environment. However, the photocuring conditions are not limited to those described above.

[0065] When the curable component (B) in the composition (X) contains a thermosetting resin (B12), the composition (X) can be cured by heating. The heating conditions can be a heating temperature of 100°C or higher and 200°C or lower, and a heating time of 0.5 hours or higher and 6 hours or lower. However, the heat curing conditions are not limited to those described above. [Example]

[0066] The present disclosure will be described in more detail below with reference to examples. However, the present disclosure is not limited to the following examples, and various modifications can be made depending on the design as long as the object of the present invention can be achieved.

[0067] (1) Preparation of resin composition First, the components shown in the composition columns of Tables 1 and 2 were prepared. These components were added and mixed to prepare a mixed solution. This mixed solution was stirred at room temperature (approximately 25°C) with an ultrasonic homogenizer for approximately 30 minutes to disperse the particles in the mixed solution, and the mixture was allowed to stand for 1 hour after stirring. This prepared a resin composition. In Examples 7 and 8, a colorant was further added to prepare a mixed solution, and the particles were dispersed in the mixed solution in the same manner.

[0068] The details of the components shown in the composition column in the table are as follows: In the table, the numerical values ​​of each component are parts by mass. However, the value shown in "Volume" is the volume ratio (vol%) of the total "particles" to the total amount of "solids contained in the composition." Also, in the table, the "total chlorine concentration (chlorine content) [wt%]" is the value calculated from the formula for "total chlorine concentration" already explained, multiplied by 10,000. (curable component) Curing component 1: Bisphenol A epoxy resin (DIC Corporation product name: EPICLON 850-S. Epoxy equivalent: 183-193 g / eq., viscosity at 25°C: 11-15 Pa·s, chlorine concentration: 0.15%, refractive index: 1.55). Curing component 2: Trimethylolpropane polyglycidyl ether (Nagase ChemteX Corporation, product name: Denacol EX-321. Epoxy equivalent: 140 g / eq., viscosity at 25°C: 130 mPa. Chlorine concentration: 7.5%. Refractive index: 1.47.). Curing component 3: Trimethylolpropane polyglycidyl ether (Nagase ChemteX Corporation, product name: Denacol EX-321L, epoxy equivalent: 130 g / eq., viscosity at 25°C: 300 mPa, chlorine concentration: 0.3%, refractive index: 1.47). Curing component 4: Mixture of tetrahydromethylphthalic anhydride and tetrahydrophthalic anhydride (photoacid generator. MH-700 manufactured by New Japan Chemical Co., Ltd. Acid anhydride equivalent: 164 g / eq. Viscosity at 25°C: approximately 60 mPa·s. Chlorine concentration: 1% or less. Refractive index: 1.473.). (additives) Surface modifier: Fluorine-containing, hydrophilic, and lipophilic group-containing oligomer (DIC Corporation product name: Megafac F-556). (particle) Particle 1: Fuji Chemical Co., Ltd. Product name: Sibol-135 (average particle size 135 μm, CV value 10% or less). Particle 2: Fuji Chemical Co., Ltd. Product name: Sibol-150 (average particle size 150 μm, CV value 10% or less). Particle 3: Fuji Chemical Co., Ltd. Product name: Sibol-170 (average particle size 170 μm, CV value 10% or less). Particle 4: Fuji Chemical Co., Ltd. Product name: Sibol-200 (average particle size 200 μm, CV value 10% or less). Particle 5: Fuji Chemical Co., Ltd. Product name: Sibol-220 (average particle size 220 μm, CV value 10% or less). Particle 6: Fuji Chemical Co., Ltd. Product name: Sibol-300 (average particle size 300 μm, CV value 10% or less). The average particle size of each particle was measured by the DCS (frequency-dependent centrifugal sedimentation) method using a disc centrifugal particle size distribution measuring device (CPS disc centrifuge model DC24000 manufactured by CPS Instruments) at a rotation speed of 20,000 rpm. (fumed silica) Aerosil (registered trademark): Manufactured by Nippon Aerosil Co., Ltd. Product name: Aerosil RY200 (composition: SiO2 99.8% or more / Al2O3 0.01% or less / TiO2 0.01% or less. Average particle size 12 nm.). (colorant) Carbon black: Mitsubishi Chemical Corporation, product number #3030B (black, particle size 55 nm). Conductive titanium oxide: Ti4O7 (manufactured by Sakai Chemical Industry Co., Ltd., name ENETIA (registered trademark), navy blue, average particle size 100-140nm).

[0069] (2) Preparation of resin sheet The resin composition prepared in (1) was applied to a supporting substrate (TN-100, thickness 100 μm) to form a coating film of the resin composition on the substrate. The coating film was then placed in a heating furnace at 130°C and 160°C to dry it, forming a dry film. This resulted in a sample of a resin sheet (thickness approximately 100 μm) overlapping the substrate.

[0070] (3) Evaluation (3-1) Color development -Shape of the transmission spectrum, transmittance peak, and total light transmittance The resin sheet sample prepared in (2) was irradiated with visible light (wavelength 380 to 780 nm) using a spectrophotometer (U4100 manufactured by Hitachi High-Tech Corporation) to measure the transmittance. The shape of the obtained transmission spectrum was evaluated as follows. A: The shape of the spectrum peak is sharp and there is a clear peak top. B: The spectrum is broad overall, but a slight peak top is visible. C: The spectrum is broad overall, with no clear peak top. D: The resin composition was not cured and a resin sheet could not be produced, so measurement was not possible.

[0071] For those in which a peak top of transmittance was observed and its wavelength was obtained, the wavelength of the peak top is shown in Tables 1 and 2. In the evaluation of the shape of the spectrum, those rated C were indicated as "nd" since the peak could not be clearly detected, and those rated D were indicated as "-" since the resin composition could not be cured and measurement was not possible.

[0072] The total light transmittance was measured using a haze meter (NDH7000SP II type manufactured by Nippon Denshoku Industries Co., Ltd.), and the values ​​are shown in Tables 1 and 2.

[0073] Sheet color development The appearance of the resin sheet samples was visually inspected, and each sample was evaluated as follows based on the evaluation results of the shape of the transmission spectrum, the transmittance peak, and the total light transmittance. A: It has high transmittance and a sharp spectral shape, resulting in clear reflected light. B: The transmittance is not high, but the shape of the spectrum is sharp and good reflected light is obtained. C: The spectrum is broad, but the transmittance is high and good reflected light is obtained. D: The shape of the spectrum is broad, the transmittance is low, and no reflected light is obtained, or the resin composition is not cured, making it impossible to determine.

[0074] In Examples 1 to 13, the color development of the sheets was confirmed, and in Examples 1 to 11, particularly high color development was obtained. On the other hand, in Comparative Examples 1 and 2, the total chlorine concentration of the curable components in the resin composition was 1.0 mass% or more, so the colloidal particles could not be dispersed in the resin composition and the resin composition could not be cured, and color development was not obtained. Furthermore, in Comparative Example 3, the average particle diameter of the particles was as large as 300 nm, so although the resin composition could be cured and a sheet could be produced, the total light transmittance of the sheet was low and color development was not obtained.

[0075] Furthermore, the peak wavelengths and spectral shapes of the transmitted light spectra in each example suggest that various structural colors are exhibited, specifically, purple to blue in Examples 1, 2, 7, 8, and 11, nearly green in Examples 3 to 5, and yellow to red in Examples 6, 9, and 10.

[0076] (3-2) Tackiness (2) The tester pressed his / her bare finger against the sample prepared in (2), and visually confirmed whether or not the fingerprint remained on the surface of the resin sheet, and evaluated the tackiness according to the following criteria. A: Even if a fingerprint is pressed against the surface of the resin sheet, the fingerprint does not remain. B: When a fingerprint is pressed against the resin sheet surface, a slight fingerprint remains on the surface. C: When a fingerprint is pressed against the resin sheet surface, the fingerprint is clearly visible.

[0077] (3-3) Sheet handling (2) The sample resin sheet prepared in (2) was lightly cut around the periphery of the resin sheet with a cutter knife, and the sample was peeled off from the substrate at a slow speed to check the state of the resin sheet after peeling, and the sheet handling properties were evaluated according to the following criteria. A: The resin sheet can be easily peeled off from the substrate, and no transfer to the substrate occurs. B: The resin sheet can be peeled off from the substrate, but a small amount of the resin sheet remains on the substrate. C: When the sheet is peeled off from the substrate, most of the resin sheet remains on the substrate, or cannot be peeled off.

[0078] [Table 1]

[0079] [Table 2]

Claims

1. A resin composition containing particles (A) and a curable component (B), the particles (A) contain silica, and the curable component (B) contains an epoxy resin and an acid anhydride; The particles (A) have an average particle size calculated from a particle size distribution measured by a frequency-dependent centrifugal sedimentation method of 100 nm or more and 250 nm or less, a total chlorine concentration in the curable component (B) is 1% by weight or less based on the total amount of the curable component (B); The volume ratio of the particles (A) in the resin composition is When the average particle diameter of the particles (A) is 115 nm or more and 160 nm or less, the average particle diameter is 23 vol% or more and 29 vol% or less with respect to the total solid content of the resin composition, When the average particle size of the particles (A) is more than 160 nm and not more than 185 nm, the average particle size is 23 vol% or more and 34 vol% or less based on the total solid content of the resin composition, When the average particle diameter of the particles (A) is 190 nm or more and 230 nm or less, the average particle diameter is 29 vol% or more and 34 vol% or less with respect to the total solid content of the resin composition. Resin composition.

2. A composition comprising particles (A) and a curable component (B), the particles (A) contain silica, and the curable component (B) contains an epoxy resin and an acid anhydride; The particles (A) have an average particle size calculated from a particle size distribution measured by a frequency-dependent centrifugal sedimentation method of 100 nm or more and 250 nm or less, a total chlorine concentration in the curable component (B) is 1% by weight or less based on the total amount of the curable component (B); The particles (A) contain silica having a substantially spherical shape, the coefficient of variation of the particles (A) calculated from the particle size distribution measured by a frequency-dependent centrifugal sedimentation method is 20% or less; Resin composition.

3. A composition comprising particles (A) and a curable component (B), the particles (A) contain silica, and the curable component (B) contains an epoxy resin and an acid anhydride; The particles (A) have an average particle size calculated from a particle size distribution measured by a frequency-dependent centrifugal sedimentation method of 100 nm or more and 250 nm or less, a total chlorine concentration in the curable component (B) is 1% by weight or less based on the total amount of the curable component (B); The particles (A) contain at least two types of particle groups having different average particle sizes, the average particle diameter d1 of the particle group (A1) having the smallest average particle diameter and the average particle diameter d2 of the particle group (A2) having the largest average particle diameter satisfy the relationship of formula (1), d1 × 1.01 ≦ d2 ≦ d1 × 1.20 (1) Resin composition.

4. Further containing fumed silica (C), The resin composition according to any one of claims 1 to 3.

5. The mass ratio of the fumed silica (C) to the total solid content of the resin composition is 0.5 mass% or more and 2 mass% or less. The resin composition according to claim 4.

6. The curable component (B) contains a curable resin (B1) and a curing agent (B2), The resin composition according to any one of claims 1 to 5.

7. The curable component (B) contains an epoxy resin containing an organic compound having a chlorine atom in the molecule. The resin composition according to any one of claims 1 to 6.

8. Further containing a colorant (D), The resin composition according to any one of claims 1 to 7.

9. The colorant (D) contains at least one selected from the group consisting of Ti 4 O 7 and carbon black. The resin composition according to claim 8.

10. A cured product of the resin composition according to any one of claims 1 to 9. Resin sheet.

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