Laminate and method for producing laminate

Abstract

The present disclosure addresses the problem of providing a laminate comprising a colloidal crystal layer having both color emissivity and adhesion. A laminate in which a substrate, a colloidal crystal layer that develops color by interference of light, and a resin layer are arranged in this order, and which satisfies the following conditions (1) to (4). (1) cracks are formed in the colloidal crystal layer; (2) the area ratio of the cracks in the colloidal crystal layer is 0.1%-30%; (3) voids exist between particles constituting the colloidal crystal layer; and (4) the colloidal crystal layer is brought into contact with the resin layer inside the cracks.

Description

Technical Field

[0001] The present disclosure relates to a laminate including a colloidal crystal layer and a method for manufacturing the laminate. Specifically, it relates to a laminate including a colloidal crystal layer having excellent chromogenic properties and adhesion, and a method for manufacturing the laminate. Background Art

[0002] A photonic crystal is a nano-periodic structure in which substances having different refractive indices are arranged at intervals on the order of the wavelength of light. In a photonic crystal, the refractive index changes periodically, and various interesting optical properties such as reflection of light of a specific wavelength known as Bragg reflection, light confinement using a photonic band gap, and high-resolution wave action are exhibited. Therefore, active research is currently being conducted. A colloidal crystal, which is a type of photonic crystal, has a structure in which submicron resin microparticles or silica particles are regularly arranged, and can be formed by coating a particle suspension on a substrate or the like and then drying.

[0003] A colloidal crystal has a structure in which particles are regularly and most densely packed, and Bragg reflection is generated using the refractive index difference between particles and the inter-particle space, thereby exhibiting structural color. The greater the refractive index difference between particles and the inter-particle space, the stronger the Bragg reflection. Therefore, except for inverse opal-type colloidal crystals, a colloidal crystal with the best color development can be obtained when the inter-particle space is air. However, such a colloidal crystal with excellent chromogenic properties has poor abrasion resistance and substrate adhesion due to voids between particles or between particles and the substrate. On the other hand, if the inter-particle space is filled with a resin or the like, the refractive index difference becomes smaller, and thus there is a problem that the color development of the colloidal crystal is easily lost.

[0004] In Patent Document 1 and Patent Document 2, a composition for a colloidal crystal containing core-shell type microparticles including a core part and a shell part is disclosed. Since the glass transition point of the core part is high and the glass transition point of the shell part is low, a colloidal crystal in which the shell part flows by heating and the core parts are regularly arranged in the shell part can be obtained. In addition, since the shell part easily flows by heating, the shell part is in close contact with the substrate, and entanglement of polymer chains occurs between the particles, so that a colloidal crystal having excellent abrasion resistance and substrate adhesion can be obtained.

[0005] In Patent Document 3, a colloidal crystal laminate having cracks is disclosed.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Laid-Open No. 2014-047231

[0009] Patent Document 2: Japanese Patent Laid-Open No. 2009-249527

[0010] Patent Document 3: Japanese Patent Laid-Open No. 2006-208453

[0011] However, the colloidal crystals of Patent Document 1 and Patent Document 2 have the following problems: Since the design is such that the shell part fills the particle gaps in the core part, the refractive index difference between the particles and the particle gaps becomes small, and the color-developing property of the formed colloidal crystal is not excellent.

[0012] In addition, the colloidal crystal of Patent Document 3 has the following problem: Substantially, only particles are arranged on the substrate, and the adhesion is not excellent.

[0013] As described above, it is difficult for the conventional laminate including the colloidal crystal to balance the color-developing property and the adhesion. Summary of the Invention

[0014] Problems to be Solved by the Invention

[0015] Therefore, the problem to be solved by the present disclosure is to provide a laminate including a colloidal crystal layer that balances the color-developing property and the adhesion.

[0016] Technical Means for Solving the Problem

[0017] That is, the present disclosure relates to a laminate in which a substrate, a colloidal crystal layer that develops color by light interference, and a resin layer are sequentially arranged, and the following conditions (1) to (4) are satisfied.

[0018] (1) Cracks are formed in the colloidal crystal layer

[0019] (2) The area ratio of the cracks in the colloidal crystal layer is 0.1% to 30%

[0020] (3) There are voids between the particles constituting the colloidal crystal layer

[0021] (4) The colloidal crystal layer and the resin layer are in contact inside the cracks

[0022] In addition, the present disclosure relates to the laminate, which includes a primer layer between the substrate and the colloidal crystal layer.

[0023] In addition, the present disclosure relates to the laminate, in which the particles constituting the colloidal crystal layer are core-shell type resin fine particles.

[0024] In addition, the present disclosure relates to a method for manufacturing a laminate, for manufacturing the laminate, the manufacturing method includes the following steps 1 to 3, and includes step 3 during or after step 1.

[0025] (Step 1) A step of forming a colloidal crystal layer on a substrate

[0026] (Step 2) A step of forming a resin layer on the colloidal crystal layer formed in Step 1

[0027] (Step 3) A heating step at 70 °C or higher

[0028] Effects of the Invention

[0029] Through the present disclosure, a laminate including a colloidal crystal layer that takes into account both color development property and adhesion property can be provided. Description of the Drawings

[0030] Figure 1 is a schematic cross-sectional view of the laminate according to an embodiment of the present disclosure.

[0031] Figure 2 is an SEM photograph obtained by photographing a crack in the colloidal crystal layer. Detailed Description of the Embodiments

[0032] Hereinafter, the laminate and the method for manufacturing the laminate will be described.

[0033] For clarity of explanation, the following descriptions and drawings are appropriately simplified. The scales of the respective components in the drawings for explanation may vary greatly. In addition, in each drawing, the thickness direction (lamination direction) is set as the Z axis.

[0034] In the present disclosure, unless otherwise specified, "~" indicating a numerical range includes the values described before and after it as the lower limit value and the upper limit value.

[0035] In addition, in the present disclosure, "(meth)acrylate" is a general term for acrylate and methacrylate, and "(meth)acrylic acid" and the like are based on this.

[0036] <Laminate>

[0037] Refer to Figure 1 , and an overview of the laminate of the present disclosure will be given. The laminate 100 of the present disclosure is a laminate in which a substrate 10, a colloidal crystal layer 20 that develops color by light interference, and a resin layer 30 are sequentially arranged. The colloidal crystal layer 20 has a plurality of fine particles 21, and the fine particles 21 are arranged substantially regularly, and voids 23 containing air are formed between the fine particles. In addition, a crack 24 is formed in the colloidal crystal layer 20, and the resin 31 penetrates into the crack.

[0038] The laminate 100 of the present disclosure is characterized by satisfying all of the following conditions (1) to (4).

[0039] (1) Cracks are formed in the colloidal crystal layer

[0040] (2) The area ratio of the cracks in the colloidal crystal layer is 0.1% to 30%​​

[0041] (3) There are voids between the particles constituting the colloidal crystal layer.

[0042] (4) Bring the colloidal crystal layer into contact with the resin layer inside the crack.

[0043] In the laminate of the present disclosure, cracks are formed in the colloidal crystal layer, and the resin layer is locally formed in a direction perpendicular to the film surface of the laminate. Therefore, excellent adhesion is exhibited. In addition, since the area ratio of the cracks is a specified ratio, both the adhesion and color development property of the laminate are good. In addition, by maintaining the air-containing voids between the particles constituting the colloidal crystal, the color development property of the laminate is excellent. In addition, by bringing the colloidal crystal layer into contact with the resin layer inside the crack, the adhesion between the colloidal crystal layer and the resin layer is improved, and the adhesion of the laminate is improved.

[0044] Hereinafter, each structure of the laminate of the present disclosure will be described in detail.

[0045] <Colloidal crystal layer>

[0046] Regarding the colloidal crystal layer, as Figure 1 and Figure 2 shown, fine particles are regularly arranged to form a close-packed structure, and voids exist between the particles. In addition, cracks exist between the crystal regions. The laminate of the present disclosure utilizes the refractive index difference between the close-packed particles and the air present in the particle gaps to generate Bragg reflection, thereby exhibiting vivid structural colors. The colloidal crystal layer can be formed by coating a colloidal crystal composition containing the following fine particles (A) and water on a substrate.

[0047] <Crack>

[0048] The colloidal crystal layer has cracks. In the present disclosure, a crack means a minute gap existing in the colloidal crystal layer, and includes both a gap that does not penetrate in the thickness direction (Z-axis direction) of the colloidal crystal layer and a penetrating gap. The crack has a short-axis direction as the width, preferably 500 nm or more, more preferably 1 μm or more. On the other hand, the width of the crack is preferably 50 μm or less, more preferably 30 μm or less.

[0049] Here, the width of the crack is defined as the width measured in the horizontal direction (XY plane direction) on the surface where the colloidal crystal layer is in contact with the resin layer. In addition, the depth of the crack is preferably 25% or more, more preferably 50% or more of the film thickness of the colloidal crystal layer. In addition, the upper limit is 100%. Here, the depth of the crack is defined as the depth measured in the horizontal direction with respect to the cross-section in a cross-section perpendicular to the surface of the laminate, that is, the depth in the Z-axis direction.

[0050] It is important that the area ratio of the cracks is 0.1% to 30%. The area ratio is preferably 1% to 20%. When the area ratio of the cracks is 0.1% or more, the contact between the resin layer inside the cracks and the colloidal crystal layer increases, and the adhesion of the laminate becomes good. In addition, when the area ratio of the cracks is 30% or less, a laminate with excellent color development properties is obtained.

[0051] Here, the area ratio of the cracks means the ratio of the total area of the cracks contained in an arbitrary XY-plane region of 200 μm × 300 μm when observing the laminate in the direction of the resin layer 30, expressed as a percentage. In the present disclosure, the surface of the laminate is observed with an optical microscope, and the ratio of the total area of the cracks contained in the 200 μm × 300 μm region is expressed as a percentage using image analysis software WinROOF manufactured by Mitani Corporation.

[0052] In addition, the colloidal crystal is formed together with the drying of the solvent, and the width of its cracks can be controlled by drying conditions, the type of solvent, the particle diameter of the particles forming the colloidal crystal, etc.

[0053] <Void>

[0054] It is important that the colloidal crystal layer has voids between the particles constituting the colloidal crystal layer. In the present disclosure, the void means a particle gap having air. When air exists in the particle gap, the refractive index difference between the particles and the particle gap becomes large, and the color development properties of the laminate become good.

[0055] In addition, in the present disclosure, the voids between the particles are different in size from the cracks. When voids with a most frequent pore diameter of 10 nm to 200 nm are detected in the colloidal crystal layer by the nitrogen adsorption method, it can be judged that the particle gap of the colloidal crystal layer is air. The most frequent pore diameter can use the peak in the nitrogen adsorption isotherm on the adsorption side obtained by analysis based on the Barrett-Joyner-Halenda method (BJH method) as the most frequent pore diameter. In the BJH method, a Harkins-Jura type formula is used to calculate the reference t curve, and analysis is performed based on the volume frequency distribution. In the present disclosure, measurement is performed using an apparatus named BELSORP-maxII manufactured by Microtrac BEL Corporation.

[0056] <Fine Particle (A)>

[0057] Examples of the fine particles (A) constituting the colloidal crystal layer include resin fine particles of a polymer containing an ethylenically unsaturated monomer, inorganic fine particles such as silica or titanium dioxide, etc. In terms of the aspect that a reactive group capable of crosslinking with adjacent particles in the colloidal crystal layer, or with a resin layer or a substrate adjacent to the colloidal crystal layer can be easily introduced, resin fine particles are preferred, and resin fine particles containing an acrylic resin or a styrene-acrylic resin are more preferred.

[0058] Further, the resin fine particles are preferably a polymer in which the core and the shell are insoluble in water, and have a core-shell structure including a core (inner layer) and a shell (outer layer) that are mutually incompatible. The core functions as a site for maintaining the spherical shape, and the shell has fluidity and functions as an adhering site. By coating a substrate with a composition containing core-shell resin fine particles (hereinafter, also referred to as a composition for colloidal crystal), the core-shell resin fine particles flow and aggregate and are regularly arranged to form a colloidal crystal layer, and the shells of adjacent core-shell resin fine particles, and the shell of the core-shell resin fine particle and the substrate layer are easily adhered, and the laminate exhibits excellent adhesion.

[0059] When the resin fine particles constituting the colloidal crystal layer contain a polymer of an ethylenically unsaturated monomer, the target resin can be obtained by subjecting the ethylenically unsaturated monomer to emulsion polymerization.

[0060] <Ethylenically Unsaturated Monomer>

[0061] Examples of the ethylenically unsaturated monomer include aromatic ethylenically unsaturated monomers such as styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, vinylnaphthalene, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxytetraethylene glycol (meth)acrylate, phenoxyhexaethylene glycol (meth)acrylate, phenyl (meth)acrylate; ethylenically unsaturated monomers containing a linear or branched alkyl group such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, heptyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, docosyl (meth)acrylate; ethylenically unsaturated monomers containing an alicyclic alkyl group such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentyl (meth)acrylate, adamantyl (meth)acrylate; ethylenically unsaturated monomers containing a fluorinated alkyl group such as trifluoroethyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate; ethylenically unsaturated monomers containing a carboxyl group such as (anhydride) maleic acid, fumaric acid, itaconic acid, citraconic acid, or an alkyl monoester or alkenyl monoester thereof, β-(meth)acryloyloxyethyl succinate monoester, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid; ethylenically unsaturated monomers containing a sulfo group such as 2-acrylamido-2-methylpropanesulfonic acid sodium salt, allyl sulfonic acid methyl ester, sodium allyl methyl sulfonate, allyl sulfonic acid ester, sodium allyl sulfonate, ammonium allyl sulfonate, vinyl sulfonic acid.(Meth)acrylamide, N-methoxymethyl-(meth)acrylamide, N-ethoxymethyl-(meth)acrylamide, N-propoxymethyl-(meth)acrylamide, N-butoxymethyl-(meth)acrylamide, N-pentoxymethyl-(meth)acrylamide, N,N-bis(methoxymethyl)acrylamide, N-ethoxymethyl-N-methoxymethylmethacrylamide, N,N-bis(ethoxymethyl)acrylamide, N-ethoxymethyl-N-propoxymethylmethacrylamide, N,N-bis(propoxymethyl)acrylamide, N-butoxymethyl-N-(propoxymethyl)methacrylamide, N,N-bis(butoxymethyl)acrylamide, N-butoxymethyl-N-(methoxymethyl)methacrylamide, N,N-bis(pentoxymethyl)acrylamide, N-methoxymethyl-N-(pentoxymethyl)methacrylamide, N,N-dimethylaminopropylacrylamide, N,N-diethylaminopropylacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, diacetoneacrylamide and other ethylenically unsaturated monomers containing amide groups; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycerol mono(meth)acrylate, 4-hydroxyvinylbenzene, 1-ethynyl-1-cyclohexanol, allyl alcohol and other ethylenically unsaturated monomers containing hydroxyl groups; methoxypolyethylene glycol (meth)acrylate, polyethylene glycol (meth)acrylate and other ethylenically unsaturated monomers containing polyoxyethylene groups; dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, methylethylaminoethyl (meth)acrylate, dimethylaminostyrene, diethylaminostyrene and other ethylenically unsaturated monomers containing amino groups; glycidyl (meth)acrylate, 3,4-epoxycyclohexyl (meth)acrylate and other ethylenically unsaturated monomers containing epoxy groups; diacetone (meth)acrylamide, acetoacetoxy (meth)acrylate, 2-acetoacetoxyethyl (meth)acrylate and other ethylenically unsaturated monomers containing keto groups;Allyl (meth)acrylate, 1-methylallyl (meth)acrylate, 2-methylallyl (meth)acrylate, 1-butenyl (meth)acrylate, 2-butenyl (meth)acrylate, 3-butenyl (meth)acrylate, 1,3-dimethyl-3-butenyl (meth)acrylate, 2-chloroallyl (meth)acrylate, 3-chloroallyl (meth)acrylate, o-allylphenyl (meth)acrylate, 2-(allyloxy)ethyl (meth)acrylate, allyl lactoyl (meth)acrylate, citronellyl (meth)acrylate, geranyl (meth)acrylate, rhodinol (meth)acrylate, cinnamyl (meth)acrylate, diallyl maleate, diallyl itaconate, vinyl (meth)acrylate, vinyl crotonate, vinyl oleate, vinyl linoleate, 2-(2'-vinyloxyethoxy)ethyl (meth)acrylate, ethylene glycol di(meth)acrylate, triethylene glycol (meth)acrylate, tetraethylene glycol (meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, 1,1,1-trimethylol ethane diacrylate, 1,1,1-trimethylol ethane triacrylate, 1,1,1-trimethylol propane triacrylate, divinylbenzene, divinyl adipate, diallyl isophthalate, diallyl phthalate, diallyl maleate and other ethylenically unsaturated monomers having two or more ethylenically unsaturated groups; ethylenically unsaturated monomers containing an alkoxysilyl group such as γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltributoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-methacryloxymethyltrimethoxysilane, γ-acryloxymethyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinylmethyldimethoxysilane; ethylenically unsaturated monomers containing a hydroxymethyl group such as N-hydroxymethyl(meth)acrylamide, N,N-dihydroxymethyl(meth)acrylamide, alkyl etherified N-hydroxymethyl(meth)acrylamide.;

[0062] These monomers may be used alone or in combination of two or more kinds.

[0063] <Average particle diameter>

[0064] The average particle diameter of the fine particles (A) is preferably in the range of 100 nm to 500 nm. In addition, the average particle diameter in the present disclosure can be measured by dynamic light scattering method, and the peak of the obtained volume particle diameter distribution data (histogram) is set as the average particle diameter.

[0065] In addition, the coefficient of variation (Cv value) of the average particle diameter of the fine particles (A) is preferably 30% or less, more preferably 20% or less. When the coefficient of variation is 30% or less, the regularity of the particle arrangement is improved, and the color development property of the laminate becomes better. The coefficient of variation is a value representing the uniformity of the particle diameter and can be calculated by the following formula.

[0066] Formula: Coefficient of variation Cv value (%) = standard deviation of particle diameter / average particle diameter × 100

[0067] [In the formula, the unit of the standard deviation is the same as that of the average particle diameter]

[0068] <Glass transition point>

[0069] When the fine particles (A) are resin fine particles, it is preferably that the glass transition point (Tg) satisfies the following conditions.

[0070] When the fine particles (A) are core-shell type resin fine particles, the Tg of the resin constituting the core is not particularly limited. For example, it can be appropriately adjusted as long as it is in the range of 50°C to 200°C, preferably 60°C to 190°C, and more preferably 80°C to 180°C.

[0071] In addition, when the fine particles (A) are not core-shell type but single-structure resin fine particles, the Tg of the resin is preferably 50°C or higher, more preferably 60°C to 500°C, further preferably 80°C to 300°C, still further preferably 90°C to 150°C, and particularly preferably 95°C to 120°C. In addition, the glass transition point can be obtained using a differential scanning calorimeter (DSC).

[0072] <Reactive group>

[0073] The fine particles (A) are preferably those having a reactive group that forms a crosslink with the resin layer or the undercoat layer described later. By having a reactive group in the fine particles (A), crosslinking can be carried out between the colloidal crystal layer and the resin layer, or between the colloidal crystal layer and the undercoat layer, further improving the adhesion of the laminate.

[0074] Examples of the reactive group that can be introduced into the microparticles (A) include an epoxy group, a carboxyl group, a hydroxyl group, a keto group, a hydrazide group, etc., and a keto group is more preferable. Particularly, in the case where the reactive group is a keto group and the crosslinking agent is a hydrazide crosslinking agent, a keto-hydrazide crosslink can be formed. The keto-hydrazide crosslink does not have an adverse effect on the various physical properties of the colloidal crystal, can form a crosslink at a low temperature and in a short time by the volatilization of water, and thus can be suitably used in this respect and is effective in the case of using a film substrate that is easily damaged by heating. In addition, since the keto group has high hydrophilicity, it is considered that if an ethylenically unsaturated monomer having a keto group is used in the copolymer composition, the keto group is introduced to the outside of the resin microparticles, that is, near the interface with the water medium, and can efficiently form a crosslink with the hydrazide crosslinking agent.

[0075] When the microparticles (A) have a reactive group, regarding the content of the reactive group, in the case of a single particle, based on the mass of the resin microparticles, it is preferably in the range of 0.1 mmol / g to 3.0 mmol / g, more preferably in the range of 0.5 mmol / g to 3.0 mmol / g. In addition, in the case of core-shell particles, based on the mass of the shell, it is preferably in the range of 0.1 mmol / g to 3.0 mmol / g, more preferably in the range of 0.5 mmol / g to 3.0 mmol / g. By being 0.1 mmol / g or more, excellent adhesion is exhibited by crosslink formation even in a laminate in which the contact area between particles or between a particle and a substrate is small. In addition, by being 3.0 mmol / g or less, the affinity between the colloidal crystal layer and the resin layer is improved, and the adhesion of the laminate is excellent.

[0076] The colloidal crystal layer may also contain a black colorant. The black colorant serves to absorb scattered light in the laminate and make the color development clearer. As the black colorant, microparticles colored black or carbon black, graphite, etc. can be used. From the viewpoint of having little influence on the shape of the reflection spectrum in the visible region and excellent durability such as weather resistance, carbon black is preferred.

[0077] <Resin layer>

[0078] The resin layer is a layer provided on the colloidal crystal layer for the purpose of improving the adhesion of the colloidal crystal layer, and it is important to contact the colloidal crystal layer inside the crack of the colloidal crystal layer. By contacting the colloidal crystal layer and the resin layer inside the crack, the resin layer locally forms a coating film in the direction perpendicular to the film surface of the laminate, and the laminate exhibits excellent adhesion. In addition, if the undercoat layer described later contacts the resin layer inside the crack of the colloidal crystal layer, the adhesion of the laminate is further improved, and thus it is preferred.

[0079] The resin layer can be formed into a film, for example, by coating a resin layer-forming composition containing water and resin fine particles (B) on the colloidal crystal layer and drying as needed. Alternatively, it can be formed by coating a resin layer-forming composition capable of dry lamination on a substrate, drying, and then press-bonding and laminating it onto a laminate including the colloidal crystal layer.

[0080] Furthermore, the resin layer may contain additives within the scope of achieving the effects of the present disclosure. Examples of such additives include ultraviolet absorbers, surfactants, and color materials, whether colorless or colored.

[0081] <Resin fine particles (B)>

[0082] The resin fine particles (B) are preferably present in the form of an aqueous dispersion in the resin layer-forming composition for forming the resin layer. The resin fine particles (B) are preferably polymers of ethylenically unsaturated monomers, more preferably acrylic resins or styrene-acrylic resins.

[0083] <Ethylenically unsaturated monomers>

[0084] Regarding the ethylenically unsaturated monomers that can be used in the resin fine particles (B), the description of the vinyl unsaturated monomers exemplified in the fine particles (A) can be cited.

[0085] <Reactive groups>

[0086] The resin fine particles (B) preferably have reactive groups that form crosslinks with the colloidal crystal layer or the bottom coating described later. By having reactive groups in the resin fine particles (B), crosslink formation can be carried out between the colloidal crystal layer and the resin layer, or between the resin layer and the bottom coating, further improving the adhesion of the laminate.

[0087] Examples of the reactive groups that can be introduced into the resin fine particles (B) include epoxy groups, carboxyl groups, hydroxyl groups, keto groups, hydrazide groups, etc., and keto groups are more preferred. Especially when the reactive group is a keto group and the crosslinking agent is a hydrazide crosslinking agent, keto-hydrazide crosslinking can be formed. Keto-hydrazide crosslinking does not have an adverse effect on the physical properties of the colloidal crystal, can form crosslinks at low temperature and in a short time by the volatilization of water, and can be suitably used in this regard, and is effective when using a film substrate that is easily damaged by heating. In addition, since the keto group has high hydrophilicity, it is considered that if an ethylenically unsaturated monomer having a keto group is used in the copolymer composition, the keto group is introduced to the outside of the resin fine particles, that is, near the interface with the water medium, and can form crosslinks with the hydrazide crosslinking agent efficiently.

[0088] When the resin fine particles (B) have reactive groups, the content of the reactive groups is preferably in the range of 0.1 mmol / g to 3.0 mmol / g, more preferably in the range of 0.5 mmol / g to 3.0 mmol / g, based on the mass of the resin fine particles. By being 0.1 mmol / g or more, excellent adhesion is exhibited through crosslinking formation even in a laminate with a small contact area between particles or between particles and the substrate. In addition, by being 3.0 mmol / g or less, the affinity between the colloidal crystal layer and the resin layer is improved, and the adhesion of the laminate is improved.

[0089] <Average particle diameter>

[0090] The average particle diameter of the resin fine particles (B) is preferably in the range of 80 nm to 1000 nm. If the average particle diameter is 80 nm or more, the components of the resin layer do not penetrate into the particle gaps of the colloidal crystal layer, but only penetrate into the cracks inside the colloidal crystal layer. Therefore, both the color development and adhesion of the laminate become good. In addition, if the average particle diameter is 1000 nm or less, the resin layer penetrates into the cracks inside, so the adhesion of the laminate becomes good.

[0091] <Glass transition point>

[0092] The glass transition point (Tg) of the resin fine particles (B) is preferably in the range of -25°C to 45°C, more preferably in the range of -10°C to 30°C. If Tg is -25°C or more, it is possible to prevent the resin component of the resin layer from flowing excessively and penetrating into the particle gaps of the colloidal crystal layer, and the color development of the laminate becomes excellent. On the other hand, if Tg is 45°C or less, the film-forming property of the resin fine particles (B) is sufficiently ensured. Therefore, after drying the resin layer composition, the color development property of the laminate is good. In addition, since the adhesion of the resin layer to the colloidal crystal layer is improved, the adhesion of the laminate is improved. The glass transition point can be determined using a DSC (differential scanning calorimeter).

[0093] <Substrate layer>

[0094] The substrate is not particularly limited and can be appropriately selected according to the use. For example, thermoplastic resin substrates such as polyvinyl chloride sheets, polyethylene terephthalate (PET) films, polypropylene films, polyethylene films, nylon films, polystyrene films, and polyvinyl alcohol films can be mentioned; metal substrates such as aluminum foils; glass substrates, paper substrates such as coated paper; and cloth substrates.

[0095] Regarding the substrate, the coated surface may be smooth or may have irregularities. In addition, the substrate may be any one of transparent, translucent, and opaque. In order to make the color development of the colloidal crystal layer more obvious, a substrate pre-colored black or the like may be used. In addition, these substrates may be used alone or may be a laminate including two or more layers.

[0096] The thickness of the substrate is not particularly limited, and it can generally be appropriately selected within the range of 5 μm to 500 μm.

[0097] <Bottom coating>

[0098] In order to further improve the adhesion of the colloidal crystal layer to the substrate, it is preferable to have a bottom coating on the substrate. The bottom coating can be formed by coating a resin composition for the bottom coating on the substrate before forming the colloidal crystal layer. The resin composition for the bottom coating contains a resin component, and the resin forming the bottom coating is not particularly limited. For example, acrylic resin, styrene acrylic resin, urethane resin, olefin resin, polyester resin, and composite resins obtained by compounding these resins can be cited. These resins can be used alone or two or more of them can be used in combination.

[0099] From the viewpoints of adhesion to the substrate or the colloidal crystal layer, resistance of the bottom coating, etc., the bottom coating preferably contains acrylic resin, styrene acrylic resin, or urethane resin. In addition, within the range where the effects of the present disclosure are exhibited, the bottom coating may also contain additives. As such additives, for example, ultraviolet absorbers, surfactants, or achromatic black particles or colored pigments can be cited.

[0100] The thickness of the bottom coating is preferably 0.5 μm to 30 μm.

[0101] <Reactive group>

[0102] The resin forming the bottom coating preferably has a reactive group that forms a crosslink with the colloidal crystal layer or the resin layer. By having a reactive group in the resin forming the bottom coating, crosslink formation can be carried out between the bottom coating and the colloidal crystal layer or between the bottom coating and the resin layer, further improving the adhesion of the laminate.

[0103] Examples of the reactive group that can be introduced into the resin forming the undercoat layer include an epoxy group, a carboxyl group, a hydroxyl group, a ketone group, a hydrazide group, etc., and a ketone group is more preferable. Particularly, in the case where the reactive group is a ketone group and the crosslinking agent is a hydrazide crosslinking agent, a ketone-hydrazide crosslink can be formed. The ketone-hydrazide crosslink does not have an adverse effect on the physical properties of the colloidal crystal, and can form a crosslink at a low temperature and in a short time by the evaporation of water. In this regard, it can be suitably used and is effective in the case of using a film substrate that is easily damaged by heating. In addition, since the ketone group has high hydrophilicity, it is considered that if an ethylenically unsaturated monomer having a ketone group is used in the copolymer composition, the ketone group is introduced to the outside of the resin fine particles, that is, near the interface with the water medium, and can efficiently form a crosslink with the hydrazide crosslinking agent.

[0104] When the undercoat layer has a reactive group, the content of the reactive group is preferably in the range of 0.1 mmol / g to 3.0 mmol / g, more preferably 0.5 mmol / g to 3.0 mmol / g, based on the mass of the undercoat layer. By being 0.1 mmol / g or more, excellent adhesion is exhibited by crosslink formation even in a laminate in which the contact area between particles or between particles and the substrate is small. In addition, by being 3.0 mmol / g or less, the affinity between the undercoat layer and the colloidal crystal layer is improved, and the adhesion of the laminate is improved.

[0105] <Manufacturing method of laminate>

[0106] The manufacturing method of the laminate of the present disclosure preferably has the following steps 1 and 2.

[0107] Step 1) A step of applying a composition for colloidal crystal on a substrate to form a coating film, and drying as needed to form a colloidal crystal layer.

[0108] Step 2) A step of applying a composition for resin layer on the colloidal crystal layer formed in Step 1, and drying as needed to form a resin layer.

[0109] When the particles constituting the colloidal crystal layer are core-shell type resin fine particles, it is preferable to perform the following step 3 during or after step 1 and before step 2.

[0110] Step 3) A heat treatment at 70 °C or higher is performed within a range that does not impair the color development of the colloidal crystal.

[0111] By undergoing Step 3, the shell of the core-shell resin fine particles flows, and the surface state of the coating film changes. When forming the resin layer, it is easy for the colloidal crystal layer to come into contact with the resin layer inside the cracks, so the adhesion of the laminate becomes good. The heating temperature in Step 3 is more preferably 80°C or higher. On the other hand, the upper limit value of the heating temperature only needs to be in the range that maintains the shape of the fine particles (A). When the fine particles (A) are resin fine particles, it only needs to be lower than the glass transition point (Tg) of the resin (in the case of core-shell resin fine particles, it is the resin constituting the core), and it is preferably 5°C or more lower than the Tg. Specifically, the heating temperature only needs to be adjusted below 200°C, and preferably below 180°C.

[0112] Among them, in Step 1, the case of undergoing a process of dip coating and forming an oil-based film based on silicone oil as disclosed in Japanese Patent Laid-Open No. 2015-27930 is not preferred in terms of the fact that cracks are not easily formed in the colloidal crystal layer.

[0113] In addition, it is important that the colloidal crystal layer has cracks and the area ratio of the cracks is 0.1% to 30%. The cracks in the colloidal crystal layer can be controlled by the drying conditions in Step 1, the solvent type of the colloidal crystal composition, the particle diameter of the fine particles (A), etc.

[0114] For example, by lowering the drying temperature, the area ratio of the cracks in the colloidal crystal layer decreases, and by raising the drying temperature, the area ratio of the cracks increases. In addition, the smaller the particle diameter of the fine particles (A), the lower the area ratio of the cracks, and the larger the particle diameter, the higher the area ratio of the cracks.

[0115] The colloidal crystal composition only needs to contain at least the fine particles (A) and water, and may also contain additives such as a crosslinking agent, a surfactant, and a black colorant as needed.

[0116] The fine particles (A) and the crosslinking agent are as described above. Among them, a combination of the fine particles (A) having a ketone group as a reactive group and a hydrazide crosslinking agent is preferred.

[0117] The resin layer composition only needs to contain at least the resin fine particles (B) and water, and may also contain additives such as a crosslinking agent, a surfactant, an ultraviolet absorber, and a colorant as needed.

[0118] The resin fine particles (B) and the crosslinking agent are as described above. Among them, a combination of the resin fine particles (B) having a ketone group as a reactive group and a hydrazide crosslinking agent is preferred.

[0119] The coating method of each composition is not particularly limited, and it can be appropriately selected from known coating methods for use. In addition, the drying method is not particularly limited, and it can be air-dried using a drying gas or the like, heated, or a combination of these can be used. The step 3 may also include the heating and drying of the colloidal crystal layer.

[0120] In addition, this manufacturing method may also include steps such as forming a bottom coating. As described above, for the resin composition for the bottom coating, a composition having the same composition as the resin layer composition may also be used.

[0121] [Examples]

[0122] Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to these. In the examples and comparative examples, "parts" and "%" mean "parts by mass" and "mass%" unless otherwise specified.

[0123] <Average particle diameter, Cv value>

[0124] Regarding the average particle diameter, the microparticle dispersion is diluted 500 times with water, and about 5 ml of the diluted solution is measured by dynamic light scattering measurement method (the measurement device is Nanotrac UPA manufactured by Microtrac BEL Co., Ltd.), and the peak of the volume particle diameter distribution data (histogram) obtained is set as the average particle diameter. In addition, the coefficient of variation Cv value representing the uniformity of the particle diameter is calculated by the following formula.

[0125] Formula: Cv value (%) = standard deviation of particle diameter / average particle diameter × 100

[0126] [In the formula, the standard deviation has the same unit as the average particle diameter]

[0127] <Glass transition point>

[0128] The glass transition point is measured using a DSC (differential scanning calorimeter manufactured by TA Instruments). Specifically, about 2 mg of a sample obtained by drying the resin microparticle dispersion is weighed on an aluminum pan, the aluminum pan is placed on a DSC measurement holder, and the endothermic peak of the DSC curve obtained under the heating condition of 5 °C / minute is read from the endothermic side baseline shift (inflection point) chart to obtain the glass transition point.

[0129] <Manufacture of microparticles (A)>

[0130] [Production Example 1] Production of core-shell type resin microparticles

[0131] 99.0 parts of styrene, 1.0 part of acrylic acid, 4.0 parts of a 25% aqueous solution of Aqualon AR-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., an anionic reactive surfactant (polyoxyethylene styrenated phenyl ether sulfates)) (1.0 part of solid content), and 39.0 parts of ion-exchanged water were mixed and stirred to prepare an emulsion of ethylenically unsaturated monomers in the first stage. In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser, 95.0 parts of ion-exchanged water and 1.5% of the emulsion in the first stage were added. The internal temperature of the reaction vessel was raised to 70 °C, and nitrogen replacement was carried out thoroughly. Then, 6.0 parts of a 2.5% aqueous solution of potassium persulfate (0.15 part of solid content) as an initiator was added to start the polymerization. While raising the internal temperature to 80 °C and maintaining the temperature, the remaining part of the emulsion and 4.2 parts of a 2.5% aqueous solution of potassium persulfate (0.11 part of solid content) were added dropwise over 2 hours, and the reaction was carried out simultaneously to synthesize core particles.

[0132] Next, 27.6 parts of styrene, 13.2 parts of n-butyl acrylate, 2.2 parts of methacrylic acid, 1.7 parts of a 25% aqueous solution of Aqualon AR-10 (0.4 part of solid content), and 16.7 parts of ion-exchanged water were mixed and stirred to prepare an emulsion of ethylenically unsaturated monomers in the second stage. Twenty minutes after the completion of the dropwise addition in the first stage, the dropwise addition of the emulsion in the second stage was started. While maintaining the internal temperature at 80 °C, the emulsion in the second stage and 1.6 parts of a 2.5% aqueous solution of potassium persulfate (0.04 part of solid content) were added dropwise over 2 hours, and the reaction was carried out simultaneously to obtain an aqueous dispersion of core-shell resin microparticles.

[0133] After the reaction, water was added to adjust the solid content to 45.0%. In addition, 1.7 parts of 25% aqueous ammonia (NH3(aqua, aq)) was added to neutralize the core-shell resin microparticles. The amount of the aqueous ammonia prepared is equivalent to the amount for neutralizing all the carboxyl groups contained in the shell (1 equivalent hereinafter). The average particle diameter of the obtained microparticles was 248 nm, the Cv value was 12.9%, the Tg of the core was 100.1 °C, and the Tg of the shell was 51.8 °C.

[0134] [Production Example 2 to Production Example 7] Production of Core-Shell Resin Microparticles

[0135] Aqueous dispersions of core-shell resin fine particles were obtained in the same manner as in Production Example 1, except that the formulation was changed to that shown in Table 1. Water in the reaction vessel was charged such that it was 67% relative to the total amount of ethylenically unsaturated monomers. An emulsion of ethylenically unsaturated monomers was prepared by adding water such that the concentration of ethylenically unsaturated monomers in the emulsion was 69% and the concentration of surfactant was 0.69%. In the 2.5% aqueous solution of potassium persulfate, the distribution at the start of the reaction / when adding the first-stage emulsion / when adding the second-stage emulsion was set to the same ratio as in Production Example 1. In addition, ammonia water equivalent to 1 equivalent relative to the carboxyl groups contained in the shell was added to neutralize the core-shell resin fine particles.

[0136] In addition, in Production Examples 6 and 7, the amount of the first-stage emulsion charged into the reaction vessel was changed from 1.5% to 2.0% and 1.0% respectively.

[0137]

[0138] [Production Example 8] Production of single-structure resin fine particles

[0139] 99.0 parts of styrene, 1.0 part of methacrylic acid, 4.0 parts (1.0 part of solid content) of a 25% aqueous solution of Aqualon AR-10, and 40.4 parts of ion-exchanged water were premixed and stirred to prepare an emulsion of ethylenically unsaturated monomers.

[0140] In a reaction vessel equipped with a stirrer, thermometer, dropping funnel, and reflux condenser, 68.9 parts of ion-exchanged water and 3% of the emulsion were added, the internal temperature was raised to 80°C, and nitrogen replacement was thoroughly performed. Then, 6.0 parts (0.15 part of solid content) of a 2.5% aqueous solution of potassium persulfate as an initiator was added to start emulsion polymerization. While maintaining the internal temperature at 80°C, the remaining portion of the emulsion and 6.0 parts (0.15 part of solid content) of a 2.5% aqueous solution of potassium persulfate were added dropwise over 3 hours, and the reaction was further continued for 4 hours to obtain an aqueous dispersion of styrene-acrylic resin. After completion of the reaction, ammonia water equivalent to 1 equivalent relative to the carboxyl groups contained in the resin fine particles was added for neutralization, and the solid content of the aqueous dispersion was adjusted to 45.0% with ion-exchanged water. The average particle diameter of the obtained fine particles was 224 nm, the Cv value was 13.4%, and the Tg was 116.1°C.

[0141] [Production Example 9] Production of single-structure resin fine particles

[0142] 85.6 parts of styrene, 12.1 parts of 2-acetoacetoxyethyl methacrylate, 2.3 parts of methacrylic acid, 4.0 parts of a 25% aqueous solution of Aqualon AR-10 (1.0 part of solid content), and 40.4 parts of ion-exchanged water were premixed and stirred to prepare an emulsion of ethylenically unsaturated monomers.

[0143] In a reaction vessel equipped with a stirrer, thermometer, dropping funnel, and reflux condenser, 68.9 parts of ion-exchanged water and 3% of the emulsion were added, the internal temperature was raised to 80 °C, and nitrogen replacement was carried out thoroughly. Then, 6.0 parts of a 2.5% aqueous solution of potassium persulfate (0.15 part of solid content) as an initiator was added to start emulsion polymerization. While maintaining the internal temperature at 80 °C, the remaining part of the emulsion and 6.0 parts of a 2.5% aqueous solution of potassium persulfate (0.15 part of solid content) were added dropwise over 3 hours, and then the reaction was carried out for 4 hours to obtain an aqueous dispersion of styrene-acrylic resin. After the reaction was completed, ammonia water equivalent to 1 equivalent of the carboxyl groups contained in the resin fine particles was added for neutralization, and the solid content of the aqueous dispersion was adjusted to 45.0% with ion-exchanged water. The average particle diameter of the obtained fine particles was 230 nm, the Cv value was 12.1%, and the Tg was 102.1 °C.

[0144] [Production Example 10] Preparation of silica particles

[0145] As the silica particles, Seahostar KE-W20 (average particle diameter 210 nm) manufactured by Nippon Shokubai Co., Ltd. was used.

[0146] [Production Example 11] Production of core-shell resin fine particles

[0147] In a reaction vessel equipped with a stirrer, thermometer, dropping funnel, and reflux condenser, 400 parts by weight of ion-exchanged water and 0.02 part by weight of sodium dodecylbenzenesulfonate were charged and heated to 80 °C while stirring. Then, 0.3 part by weight of potassium persulfate as an initiator was used, and a mixed solution of 35 parts by weight of styrene, 10 parts by weight of methyl methacrylate, and 5 parts by weight of divinylbenzene as a polymerizable monomer composition for forming the core was added dropwise over 100 minutes. After the addition was completed, stirring was continued for 30 minutes to obtain core particles.

[0148] After the above stirring, a mixed solution prepared by further adding 0.2 part by weight of octyl thioglycolate as a chain transfer agent to a polymerizable monomer composition for forming the shell containing 20 parts by weight of methyl methacrylate, 15 parts by weight of n-butyl acrylate, 6 parts by weight of methacrylic acid, 6 parts by weight of 2-hydroxyethyl acrylate, and 3 parts by weight of glycidyl methacrylate was added dropwise over 100 minutes. After the addition, stirring was continued for 2 hours, and then cooling was carried out to obtain an aqueous dispersion of core-shell resin fine particles.

[0149] After the reaction was completed, the solid content of the aqueous dispersion was adjusted to 20.0% using ion-exchanged water. The average particle diameter of the obtained microparticles was 220 nm, the Cv value was 12.6%, the Tg of the core was 100.1 °C, and the Tg of the shell was 51.8 °C.

[0150] <Manufacture of Microparticles (B)>

[0151] [Production Example 12] Production of Resin Microparticles

[0152] 40.2 parts of styrene, 57.8 parts of n-butyl acrylate, 2.0 parts of methacrylic acid, 4.0 parts (1.0 part of solid content) of a 25% aqueous solution of Aqualon AR-10, and 40.4 parts of ion-exchanged water were premixed and stirred to prepare an emulsion of ethylenically unsaturated monomers.

[0153] In a reaction vessel equipped with a stirrer, thermometer, dropping funnel, and reflux condenser, 68.9 parts of ion-exchanged water and 3% of the emulsion were added, the internal temperature was raised to 80 °C, and nitrogen replacement was carried out thoroughly. Then, 6.0 parts (0.15 part of solid content) of a 2.5% aqueous solution of potassium persulfate as an initiator was added to start emulsion polymerization. While maintaining the internal temperature at 80 °C, the remaining part of the emulsion and 6.0 parts (0.15 part of solid content) of a 2.5% aqueous solution of potassium persulfate were added dropwise over 3 hours, and the reaction was further continued for 4 hours to obtain an aqueous dispersion of styrene-acrylic resin. After the reaction was completed, neutralization was carried out by adding ammonia water in an amount equivalent to the carboxyl groups contained in the resin microparticles, and the solid content of the aqueous dispersion was adjusted to 45.0% using ion-exchanged water. The average particle diameter of the obtained microparticles was 225 nm, the Cv value was 13.9%, and the Tg was 7.4 °C.

[0154] [Production Examples 13 to 20] Production of Resin Microparticles

[0155] Except for changing to the formulation shown in Table 2, the procedure was carried out in the same manner as in Production Example 12 to obtain an aqueous dispersion of resin microparticles. The water in the reaction vessel was charged so as to be 67% based on the total amount of ethylenically unsaturated monomers. The emulsion of ethylenically unsaturated monomers was prepared by adding water so that the concentration of ethylenically unsaturated monomers in the emulsion became 69% and the concentration of the surfactant became 0.69%. In addition, ammonia water in an amount equivalent to the carboxyl groups contained in the resin microparticles was added to neutralize the resin microparticles.

[0156] [Production Example 21] Production of Resin Microparticles

[0157] Pre-mix 35.7 parts of styrene, 52.3 parts of n-butyl acrylate, 10.0 parts of 2-acetoacetoxyethyl methacrylate, 2.0 parts of methacrylic acid, 4.0 parts of a 25% aqueous solution of Aqualon AR-10 (1.0 part of solid content), and 40.4 parts of ion-exchanged water and stir to prepare an emulsion of ethylenically unsaturated monomers.

[0158] In a reaction vessel equipped with a stirrer, thermometer, dropping funnel, and reflux condenser, add 68.9 parts of ion-exchanged water, 3% of the emulsion, and 2.0 parts of a 25% aqueous solution of Aqualon AR-10. Raise the internal temperature to 80 °C, thoroughly displace with nitrogen, and then add 6.0 parts of a 2.5% aqueous solution of potassium persulfate (0.15 part of solid content) as an initiator to start emulsion polymerization. While maintaining the internal temperature at 80 °C, dropwise add the remaining part of the emulsion and 6.0 parts of a 2.5% aqueous solution of potassium persulfate (0.15 part of solid content) over 3 hours, and then react for another 4 hours to obtain an aqueous dispersion of styrene-acrylic resin. After completion of the reaction, add ammonia water equivalent to 1 equivalent of the carboxyl groups contained in the resin microparticles for neutralization, and adjust the solid content of the aqueous dispersion to 45.0% with ion-exchanged water. The average particle diameter of the obtained microparticles is 105 nm, the Cv value is 14.9%, and the Tg is 8.2 °C.

[0159]

[0160] [Production Example 22] Production of resin microparticles

[0161] In a reaction vessel equipped with a stirrer, thermometer, two dropping funnels, and reflux condenser, charge 185.0 parts of water, 42.9 parts of JONCRYL 67 (styrene-acrylic resin Mw 12500, acid value 213 mgKOH / g, manufactured by BASF) as a polymer emulsifier, and 11.1 parts of 25% ammonia water. Heat while stirring to dissolve the polymer emulsifier. Then, while under nitrogen reflux, raise the temperature to 80 °C. In the two dropping funnels, dropwise add a mixture of 21.0 parts of styrene, 69.0 parts of n-butyl acrylate, and 10.0 parts of 2-acetoacetoxyethyl acrylate from one of them over 2 hours. Dropwise add 3.6 parts of a 20% aqueous solution of ammonium persulfate from the other over 2 hours. After completion of the dropwise addition, react for another 5 hours to obtain an aqueous dispersion of resin microparticles. After completion of the reaction, adjust the solid content of the aqueous dispersion to 40.0% with ion-exchanged water. The average particle diameter of the obtained resin microparticles is 74 nm, the CV value is 23.1%, and the Tg is -1.3 °C.

[0162] [Production Example 23] Production of resin microparticles

[0163] In a reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser, 40.0 parts of water, 50.0 parts of methanol, 3.7 parts of methyl methacrylate, 5.3 parts of n-butyl acrylate, and 1.0 part of 2-acetoacetoxyethyl methacrylate were charged. Further, after heating to a temperature of 80 °C under nitrogen reflux, 4.2 parts of a 5% aqueous solution of ammonium persulfate were added. Then, the reaction was carried out for 5 hours to obtain an aqueous dispersion of resin microparticles. After the reaction was completed, the solid content of the aqueous dispersion was adjusted to 10.0% using ion-exchanged water. The average particle diameter of the obtained resin microparticles was 766 nm, the CV value was 8.2%, and the Tg was -0.5 °C.

[0164] [Production Example 24] Production of Resin Microparticles

[0165] In a reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser, 20.0 parts of water, 60.0 parts of methanol, 3.7 parts of methyl methacrylate, 5.3 parts of n-butyl acrylate, and 1.0 part of 2-acetoacetoxyethyl methacrylate were charged. Further, after heating to a temperature of 80 °C under nitrogen reflux, 4.2 parts of a 5% aqueous solution of ammonium persulfate were added. Then, the reaction was carried out for 5 hours to obtain an aqueous dispersion of resin microparticles. After the reaction was completed, the solid content of the aqueous dispersion was adjusted to 10.0% using ion-exchanged water. The average particle diameter of the obtained resin microparticles was 1132 nm, the CV value was 9.9%, and the Tg was -0.5 °C.

[0166] <Preparation of Composition for Colloidal Crystal>

[0167] [Production Example 25]

[0168] To 100.0 parts of the aqueous dispersion of the core-shell type resin microparticles of Production Example 1, 1.0 part of Surfynol 420 (manufactured by Nissin Chemical Industry Co., Ltd., an acetylene-based nonionic surfactant) as a surfactant and 2.3 parts of a carbon black aqueous dispersion CW-1 (manufactured by Orient Chemical Industries Co., Ltd.) were added and stirred to prepare a composition for colloidal crystal.

[0169] [Production Examples 26 to 35]

[0170] A composition for colloidal crystal was prepared in the same manner as in Production Example 25 except that the formulation composition was changed to that shown in Table 3.

[0171] [Table 3]

[0172] Table 3.

[0173]

[0174] <Preparation of Composition for Resin Layer>

[0175] [Production Example 36]

[0176] To 100.0 parts of the aqueous dispersion of resin microparticles of Production Example 12, 0.5 part of Emulgen 1108 (a nonionic surfactant manufactured by Kao Corporation) as a surfactant and 1.0 part of Surfynol 420 were added and stirred to prepare a resin layer composition.

[0177] [Production Examples 37 to 48]

[0178] A resin layer composition was prepared in the same manner as in Production Example 36, except that the formulation composition shown in Table 4 was changed.

[0179] [Table 4]

[0180] Table 4.

[0181]

[0182] <Preparation of Undercoat Composition>

[0183] The compositions of Production Examples 36 to 40 in the <Preparation of Resin Layer Composition> were also used as the undercoat composition.

[0184] [Production Example 49]

[0185] To 100.0 parts of Super Flex 210 (a polyurethane resin) manufactured by Daiichi Kogyo Seiyaku Co., Ltd., 0.5 part of Emulgen 1108 as a surfactant and 1.0 part of Surfynol 420 were added and stirred to prepare an undercoat composition.

[0186] [Production Example 50]

[0187] To 100.0 parts of Plas Coat Z-221 (a polyester resin) manufactured by Gohsei Chemical Industry Co., Ltd., 0.5 part of Emulgen 1108 as a surfactant and 1.0 part of Surfynol 420 were added and stirred to prepare an undercoat composition.

[0188] <Manufacture of Laminate>

[0189] [Example 1]

[0190] A bar coater was selected to coat the colloidal crystal composition shown in Table 5 on the corona-treated surface of Toyobo ester film E5100 so that the dried thickness became 10.0 μm, and it was dried at 50°C for 1 minute to form a colloidal crystal layer. Further, the obtained laminate was heated at 80°C for 3 minutes. Subsequently, a bar coater was selected to coat the resin layer composition shown in Table 5 on the colloidal crystal layer so that the dried thickness became 10.0 μm, and it was dried at 80°C for 1 minute to obtain a laminate having a PET / colloidal crystal layer / resin layer structure.

[0191] [Example 2]

[0192] A bar coater was used to coat the resin composition for the undercoat shown in Table 5 on the corona-treated surface of Toyobo ester film E5100 so that the dried thickness became 3.0 μm, and then it was dried in an oven at 50°C for 3 minutes to form an undercoat. Subsequently, a bar coater was selected to coat the colloidal crystal composition shown in Table 5 on the undercoat so that the dried thickness became 10.0 μm, and it was dried at 50°C for 1 minute to form a colloidal crystal layer. Further, the obtained laminate was heated at 80°C for 3 minutes. Subsequently, a bar coater was selected to coat the resin layer composition shown in Table 5 on the colloidal crystal layer so that the dried thickness became 10.0 μm, and it was dried at 80°C for 1 minute to obtain a laminate having a PET / undercoat / colloidal crystal layer / resin layer structure.

[0193] [Examples 3 to 31]

[0194] A laminate was produced by the same method as in Example 2, except that the combination shown in Table 5 was changed.

[0195] [Comparative Example 1]

[0196] A bar coater was used to coat the resin composition for the undercoat shown in Table 6 on the corona-treated surface of Toyobo ester film E5100 so that the dried thickness became 3.0 μm, and then it was dried in an oven at 50°C for 3 minutes to form an undercoat. Subsequently, on the undercoat, the colloidal crystal composition shown in Table 6 was formed into a colloidal crystal layer by the method described in paragraph

[0105] of Japanese Patent Laid-Open No. 2015-27930. Further, the obtained laminate was heated at 80°C for 3 minutes. Subsequently, a bar coater was selected to coat the resin layer composition shown in Table 6 on the colloidal crystal layer so that the dried thickness became 10.0 μm, and it was dried at 80°C for 1 minute to obtain a laminate having a PET / undercoat / colloidal crystal layer / resin layer structure.

[0197] [Comparative Example 2]

[0198] Using a bar coater, the resin composition for the undercoat layer shown in Table 6 was applied to the corona-treated surface of Toyobo ester film E5100 such that the thickness after drying became 3.0 μm, and it was dried in an oven at 50°C for 3 minutes to form an undercoat layer. Subsequently, a bar coater was selected to apply the composition for colloidal crystal shown in Table 6 onto the undercoat layer such that the thickness after drying became 10.0 μm, and it was dried at 100°C for 30 seconds to form a colloidal crystal layer. Further, the obtained laminate was heated at 80°C for 3 minutes. Subsequently, a bar coater was selected to apply the composition for the resin layer shown in Table 6 onto the colloidal crystal layer such that the thickness after drying became 10.0 μm, and it was dried at 80°C for 1 minute to obtain a laminate having a PET / undercoat layer / colloidal crystal layer / resin layer structure.

[0199] [Comparative Example 3]

[0200] Using a bar coater, the resin composition for the undercoat layer shown in Table 6 was applied to the corona-treated surface of Toyobo ester film E5100 such that the thickness after drying became 3.0 μm, and it was dried in an oven at 50°C for 3 minutes to form an undercoat layer. Subsequently, a bar coater was selected to apply the composition for colloidal crystal shown in Table 6 such that the thickness after drying became 10.0 μm, and it was dried at 120°C for 30 minutes to form a colloidal crystal layer. Further, the obtained laminate was heated at 80°C for 3 minutes. Subsequently, a bar coater was selected to apply the composition for the resin layer shown in Table 6 onto the colloidal crystal layer such that the thickness after drying became 10.0 μm, and it was dried at 80°C for 1 minute to obtain a laminate having a PET / undercoat layer / colloidal crystal layer / resin layer structure.

[0201] [Comparative Example 4]

[0202] Using a bar coater, the resin composition for the undercoat layer shown in Table 6 was applied to the corona-treated surface of Toyobo ester film E5100 such that the thickness after drying became 3.0 μm, and then it was dried in an oven at 50°C for 3 minutes to form an undercoat layer. Subsequently, a bar coater was selected to apply the composition for colloidal crystal shown in Table 6 onto the undercoat layer such that the thickness after drying became 10.0 μm, and it was dried at 50°C for 3 minutes to form a colloidal crystal layer. Subsequently, a bar coater was selected to apply the composition for the resin layer shown in Table 6 onto the colloidal crystal layer such that the thickness after drying became 10.0 μm, and it was dried at 80°C for 1 minute to obtain a laminate having a PET / undercoat layer / colloidal crystal layer / resin layer structure.

[0203] [Comparative Example 5]

[0204] Using a bar coater, the resin composition for the undercoat shown in Table 6 was applied to the corona-treated surface of Toyobo E5100 polyester film so that the dried thickness became 3.0 μm. Then, it was dried in an oven at 50 °C for 3 minutes to form an undercoat. Subsequently, a bar coater was selected to apply the colloidal crystal composition shown in Table 6 onto the undercoat so that the dried thickness became 10.0 μm, and it was dried at 50 °C for 1 minute to form a colloidal crystal layer. Further, the obtained laminate was heated at 80 °C for 3 minutes to obtain a laminate having a structure of PET / undercoat / colloidal crystal layer.

[0205] <Evaluation of laminate>

[0206] The obtained laminate was evaluated as follows. The results are shown in Tables 5 and 6.

[0207] <Crack area ratio>

[0208] The surface of the laminate was observed with an optical microscope, and the proportion of the total area of cracks contained in a 200 μm × 300 μm region was expressed as a percentage using the image analysis software WinROOF manufactured by Mitani Corporation.

[0209] <Contact between the colloidal crystal layer and the resin layer inside the crack>

[0210] The cross-section of the laminate was observed with a scanning electron microscope (SEM) to confirm whether there was contact between the colloidal crystal layer and the resin layer inside the crack.

[0211] <Presence or absence of voids>

[0212] The presence or absence of voids in the colloidal crystal layer was judged as follows.

[0213] First, for the obtained laminate, after cutting out a cross-section, analysis was performed based on the Barrett-Joyner-Halenda method (BJH method) to obtain the peak in the nitrogen adsorption isotherm on the adsorption side as the most frequent pore diameter. In the BJH method, a Harkins-Jura type formula was used to calculate the reference t curve, and analysis was performed based on the volume frequency distribution. The device used for measurement was BELSORP-maxII manufactured by Microtrac BEL Corporation.

[0214] When voids with a most frequent pore diameter of 10 nm to 200 nm were detected by the nitrogen adsorption method, it was judged that the gaps between the particles forming the colloidal crystal were air, and it was evaluated as having voids.

[0215] [Chromogenic property]

[0216] For the laminate, a reflection spectrum was measured in the wavelength range of 350 nm to 850 nm using a UV-visible-near-infrared spectrophotometer (V-770D manufactured by JASCO Corporation, integrating sphere unit ISN-923). The reflectance at each wavelength was the relative reflectance measured with reference to a standard white plate with a known reflectance (SRS-99-010 manufactured by Labsphere, Inc.). For all laminates, the reflection spectrum was measured from the side of the colloidal crystal layer. For the obtained reflection spectrum, the maximum value of the reflectance derived from structural color and the difference (ΔR) in reflectance from the baseline independent of structural color were calculated. The larger ΔR is, the more excellent the chromogenic property is. Based on the obtained ΔR, evaluation was carried out according to the following criteria.

[0217] S: ΔR is 20% or more (very good)

[0218] A: ΔR is 10% or more and less than 20% (good)

[0219] B: ΔR is 5% or more and less than 10% (usable)

[0220] C: ΔR is less than 5%, or the peak of the reflectance derived from structural color cannot be discriminated (not usable)

[0221] [Adhesion]

[0222] For the laminate, a tape adhesion test based on Japanese Industrial Standards (JIS) K5600 was carried out, and the peeling of the coating film was observed. The evaluation criteria are as follows.

[0223] S: The area of scratches or peeling is less than 5% (very good)

[0224] A: The area of scratches or peeling is 5% or more and less than 15% (good)

[0225] B: The area of scratches or peeling is 15% or more and less than 35% (usable)

[0226] C: The area of scratches or peeling is 35% or more (not usable)

[0227]

[0228] [Table 6]

[0229]

[0230] This application claims priority based on Japanese Patent Application No. 2022-200986 filed on December 16, 2022, and incorporates the entire contents disclosed therein into this application.

[0231] Explanation of Reference Numerals in the Drawings

[0232] 10: Substrate

[0233] 20: Colloidal Crystal Layer

[0234] 21: Fine Particles

[0235] 23: Void

[0236] 24: Crack

[0237] 30: Resin Layer

[0238] 31: Resin

[0239] 100: Laminate

Claims

1. A laminate having a substrate, a colloidal crystal layer that colors by light interference, and a resin layer disposed in this order, and satisfying the following conditions (1) to (4). (1) Cracks are formed in the colloidal crystal layer. (2) The area ratio of the cracks in the colloidal crystal layer is 0.1% to 30%. (3) There are voids between the particles constituting the colloidal crystal layer. (4) The colloidal crystal layer is in contact with the resin layer inside the cracks.

2. The laminate according to claim 1, wherein an undercoat layer is included between the substrate and the colloidal crystal layer.

3. The laminate according to claim 1 or 2, wherein the particles constituting the colloidal crystal layer are core-shell type resin fine particles.

4. A method for manufacturing a laminate, which manufactures the laminate according to claim 3, the manufacturing method including the following steps 1 to 3, and including step 3 in the middle of step 1 or between step 1 and step 2. (Step 1) A step of forming a colloidal crystal layer on a substrate (Step 2) A step of forming a resin layer on the colloidal crystal layer formed in step 1 (Step 3) A step of heating at 70°C or higher.

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