A set of laminates, active energy ray curable compositions, and a method for manufacturing laminates.

Abstract

To provide a laminate excellent in interlayer adhesion and weatherability of a coloring layer and a top coat layer.SOLUTION: Provided is a laminate including: a base material; a coloring layer made of an active energy ray-curable coating composition cured by an electron beam or cured by an ultraviolet ray in an inert gas atmosphere; and a top coat layer made of an active energy ray-curable top coat composition cured by an electron beam or cured by an ultraviolet ray in an inert gas atmosphere. The active energy ray-curable coating composition contains a nitrogen atom-containing polymerizable compound (excluding urethane (meth)acrylate) and / or a sulfur atom-containing polymerizable compound.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a laminate, a set of an active energy ray-curable composition, and a method for producing a laminate.

Background Art

[0002] The method of applying a paint to obtain a cured coating film can be roughly classified into a solvent-based paint or an aqueous paint that is dried and cured by heat, and an active energy ray-curable paint that is polymerized and cured by irradiating ultraviolet rays or electron beams. In recent years, due to the perspective of SDGs and the increase in energy costs, active energy ray-curable paints that do not require heat drying have attracted attention. Among them, the building materials field uses a large amount of paint and is particularly noteworthy.

[0003] As a means for curing an active energy ray-curable paint, it can be divided into a method of curing with ultraviolet rays and a method of curing with electron beams. When curing with ultraviolet rays, in order to cure the inside of the coating film, it is necessary for the ultraviolet rays to reach the inside of the coating film. In order to improve the curability inside the coating film, there are many restrictions in use, such as the content ratio of the pigment in the composition cannot be increased, and the coating film thickness cannot be increased. On the other hand, when curing with electron beams, since the electron beams penetrate to the inside of the film regardless of the thickness of the coating film or the content ratio of the pigment, it can be sufficiently cured to the inside, which is suitable as a method for curing the paint.

[0004] When applying a paint to a building material, overcoating may be performed by applying a top coat (clear paint) on top of a paint coating film containing a colorant. At this time, when a top coat (clear paint) is overcoated on an electron beam-cured coating film or a coating film cured with ultraviolet rays in an inert gas atmosphere, there is a problem that the coating films do not adhere to each other and delaminate. In addition, there is a problem that it is difficult to achieve both the weather resistance of the laminate.

[0005] Patent Document 1 describes a method for improving the adhesion of a second coating film by leaving the first coating film insufficiently cured when applying multiple coats of electron beam-curable paint. However, it describes a method for applying multiple coats of paint compositions containing colorants, and does not provide examples of the case where a topcoat (clear paint) is applied as a topcoat.

[0006] Patent Document 2 provides an example of a composition that exhibits good adhesion even when multiple electron beam-curable coatings are applied. However, this example involves multiple coatings of a coating composition containing a coloring agent, and does not provide an example of the case when a topcoat (clear coating) is applied. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2002-361173 [Patent Document 2] Japanese Patent Publication No. Hei 8-34868 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The object of the present invention is to provide a laminate with excellent adhesion between the colored layer and the topcoat layer, as well as excellent weather resistance.

[0009] The inventors of the present invention have conducted extensive research to solve the above problems and have found that the above problems can be solved by the laminate shown below, thereby completing the present invention.

[0010] That is, the present invention relates to a laminate comprising a substrate, a colored layer obtained by electron beam curing or ultraviolet curing of an active energy ray curable coating composition under an inert gas atmosphere, and a topcoat layer obtained by electron beam curing or ultraviolet curing of an active energy ray curable topcoat composition under an inert gas atmosphere, The present invention relates to a laminate comprising an active energy ray curable coating composition containing a nitrogen atom-containing polymerizable compound (excluding urethane (meth)acrylate) and / or a sulfur atom-containing polymerizable compound.

[0011] The present invention relates to a laminate characterized in that the nitrogen atom-containing polymerizable compound is a polymerizable compound containing an N-vinyl group and / or acrylamide.

[0012] The present invention relates to a laminate containing a sulfur atom-containing polymerizable compound that includes a mercapto group.

[0013] The present invention relates to a laminate in which the sulfur atom-containing polymerizable compound is a secondary thiol.

[0014] The present invention relates to a laminate in which the total content of nitrogen atom-containing polymerizable compounds and / or sulfur atom-containing polymerizable compounds is 3 to 60% by mass relative to 100% by mass of the active energy ray-curable coating composition.

[0015] The present invention relates to a laminate comprising an active energy ray curable coating composition and / or an active energy ray curable topcoat composition, the latter comprising an ultraviolet absorber.

[0016] The present invention relates to a laminate comprising an active energy ray curable topcoat composition containing urethane (meth)acrylate.

[0017] The present invention relates to a laminate comprising aliphatic urethane (meth)acrylate.

[0018] The present invention relates to a set of active energy ray curable compositions for electron beam curing or ultraviolet curing under an inert gas atmosphere, comprising an active energy ray curable coating composition containing a nitrogen atom-containing polymerizable compound and / or a sulfur atom-containing polymerizable compound, and an active energy ray curable topcoat composition.

[0019] The present invention relates to a method for manufacturing a laminate, which comprises applying an active energy ray-curable coating composition containing a nitrogen atom-containing polymerizable compound and / or a sulfur atom-containing polymerizable compound onto a substrate, forming a colored layer by electron beam curing or ultraviolet curing in an inert gas atmosphere, applying an active energy ray-curable topcoat composition onto the colored layer, and forming a topcoat layer by electron beam curing or ultraviolet curing in an inert gas atmosphere.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments for carrying out the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist thereof.

[0021] In the following description, (meth)acrylate means methacrylate and / or acrylate.

[0022] Hereinafter, components included in the active energy ray-curable coating composition (hereinafter, also simply referred to as "coating" or "coating composition") and the active energy ray-curable topcoat composition (hereinafter, also simply referred to as "topcoat" or "topcoat composition") of the present embodiment will be described. The coating and the topcoat are also collectively referred to as an active energy ray-curable composition.

[0023] <Polymerizable Compound> The coating composition and the topcoat composition of the present invention contain a polymerizable compound. There is no particular limitation on the polymerizable compound that can be used in the present invention, and known compounds capable of radical polymerization can be used.

[0024] The radical polymerizable compound is preferably a compound having a radically polymerizable ethylenically unsaturated bond, and any compound having at least one ethylenically unsaturated bond in the molecule may be used, including those having chemical forms such as monomers, oligomers, and polymers. Also, the radical polymerizable compound is preferably a compound having a radically polymerizable thiol group.

[0025] Examples of radical polymerizable compounds include unsaturated carboxylic acids such as (meth)acrylic acid, itaconic acid, and maleic acid, and their salts; anhydrides having ethylenically unsaturated groups; styrene; and compounds having ethylenically unsaturated properties such as various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, and unsaturated urethanes.

[0026] ((meth)acrylate monomer) As radical polymerizable compounds, (meth)acrylates are preferred, and as (meth)acrylate monomers, specifically, 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, β-carboxyethyl (meth)acrylate, 4-tert-butylcyclohexanol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, alkoxylated tetrahydrofurfuryl (meth)acrylate, caprolactone (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isoamyl (meth)acrylate, and 2-phenoxyethyl (meth)acrylate. Monofunctional (meth)acrylates such as isodecyl (meth)acrylate, 3,3,5-trimethylcyclohexanol (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, norbornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (oxyethyl) (meth)acrylate, 1,4-cyclohexanedimethanol (meth)acrylate, cyclic trimethylolpropaneformal (meth)acrylate, benzyl (meth)acrylate, EO-modified (2)nonylphenol acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, 1,3-Butylene glycol di(meth)acrylate, 1,4-Butanediol di(meth)acrylate, 3-Methyl-1,5-Pentanediol di(meth)acrylate, 1,6-Hexanediol di(meth)acrylate, 1,9-Nonanediol di(meth)acrylate, 1,10-Decanediol di(meth)acrylate, 1,2-Dodecanediol di(meth)acrylate, Neopentyl glycol di(meth)acrylate, Polyethylene glycol (200) di(meth)acrylate, Polyethylene glycol (300) di(meth)acrylate, Polyethylene glycol (400) di(meth)acrylate, Polyethylene glycol (600) di(meth)acrylate, Neopentyl glycol di(meth)acrylate, Dipropyl Difunctional (meth)acrylates such as benzoyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, EO-modified (2) 1,6-hexanediol di(meth)acrylate, PO-modified (2) neopentyl glycol di(meth)acrylate, (neopentyl glycol-modified) trimethylolpropane di(meth)acrylate, dimethylol tricyclodecane di(meth)acrylate, EO-modified (4) bisphenol A di(meth)acrylate, PO-modified (4) bisphenol A di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, dimethylol-tricyclodecane di(meth)acrylate, dicyclopentanyl di(meth)acrylate, tris(2-hydroxyethyl) isocyanurate di(meth)acrylate, Trifunctional (meth)acrylates such as trimethylolpropane tri(meth)acrylate, EO-modified (3) trimethylolpropane tri(meth)acrylate, PO-modified (3) trimethylolpropane tri(meth)acrylate, ε-caprolactone-modified tris-(2-(meth)acryloxyethyl) isocyanurate, ethoxylated isocyanurate tri(meth)acrylate, tris(2-hydroxyethyl) isocyanurate tri(meth)acrylate, pentaerythritol tri(meth)acrylate, Pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and other tetrafunctional (meth)acrylates, Dipentaerythritol penta(meth)acrylate and other penta(meth)acrylates, Examples include hexafunctional (meth)acrylates such as dipentaerythritol hexa(meth)acrylate. The numbers in parentheses indicate the number of moles of EO and PO modification, or the molecular weight of the polyethylene glycol portion.

[0027] In paint compositions, (meth)acrylates having a cyclic structure are preferred. Examples of cyclic structures include alicyclic and heterocyclic types. In topcoat compositions, (meth)acrylates having a cyclic structure or an isocyanurate structure are preferred. These offer advantages such as good adhesion, weather resistance, and other physical properties such as printability.

[0028] The content of these (meth)acrylates is not particularly limited, but the total content of (meth)acrylates, nitrogen atom-containing polymerizable compounds, and sulfur atom-containing polymerizable compounds is preferably 20 to 100%, and more preferably 40 to 95% by mass, relative to the total amount of components of the paint composition excluding the colorants. Furthermore, the total content of these (meth)acrylates, nitrogen atom-containing polymerizable compounds, and sulfur atom-containing polymerizable compounds is preferably 20 to 95% by mass, and more preferably 40 to 95% by mass, relative to the total amount of the topcoat composition. If nitrogen atom-containing polymerizable compounds and / or sulfur atom-containing polymerizable compounds are not included, the above numerical ranges represent the preferred content of (meth)acrylates.

[0029] (polymerizable compounds containing nitrogen atoms and / or polymerizable compounds containing sulfur atoms) The paint composition of the present invention contains a polymerizable compound containing a nitrogen atom and / or a polymerizable compound containing a sulfur atom. The polymerizable compound containing a nitrogen atom is not particularly limited as long as it contains a nitrogen atom, but examples include acrylamides such as acryloylmorpholine, diacetone acrylamide, N-hydroxyethyl acrylamide, N-isopropyl acrylamide, and N,N-diethyl acrylamide, and compounds having an N-vinyl group such as N-vinylcarbazole, 1-vinylimidazole, N-vinyl-2-pyrrolidone, N-vinylcaprolactam, and N-vinylformamide. From the viewpoint of adhesion and other factors, polymerizable compounds containing an N-vinyl group and / or acrylamides are preferred as the polymerizable compound containing a nitrogen atom.

[0030] The sulfur atom-containing polymerizable compound is not particularly limited as long as it contains a sulfur atom, but examples include compounds having a mercapto group. Examples of radical polymerizable compounds having a mercapto group include secondary thiols such as pentaerythritol tetrakis(3-mercaptobutyrate), 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(2-(3-sulfanylbutanoyloxy)ethyl)-1,3,5-triazinan-2,4,6-trione, and trimethylolpropane tris(3-mercaptobutyrate), and primary thiols such as trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptopropionate), tris-[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, tetraethylene glycol bis(3-mercaptopropionate), 2-ethylhexyl-3-mercaptopropionate, and methoxybutyl-β-mercaptopropionate. Among these, secondary thiols such as pentaerythritol tetrakis(3-mercaptobutyrate) and 1,4-bis(3-mercaptobutyryloxy)butane are preferred because they have a high adhesion-enhancing effect.

[0031] The paint composition of the present invention preferably contains 20 to 80% by mass of a nitrogen atom-containing polymerizable compound based on the total amount of the paint composition, more preferably 20 to 60% by mass, and even more preferably 20 to 40% by mass. If a sulfur atom-containing polymerizable compound is also included, it may be 0% by mass. When the composition is within the above range, adhesion and weather resistance of the coating film are improved.

[0032] The paint composition of the present invention preferably contains 1 to 20% by mass of a sulfur atom-containing polymerizable compound, and more preferably 3 to 10% by mass. If a nitrogen atom-containing polymerizable compound is included, it may be 0% by mass. Within these ranges, adhesion and hardness of the coating film are improved.

[0033] The paint composition of the present invention preferably contains a total amount of nitrogen atom-containing polymerizable compounds and / or sulfur atom-containing polymerizable compounds of 3 to 60% by mass, and more preferably 5 to 40% by mass, based on 100% by mass of the active energy ray-curable paint composition. When the content is within the above range, adhesion and hardness of the coating film are improved.

[0034] (Other (meth)acrylates) Furthermore, the paint composition and topcoat composition of the present invention can utilize urethane (meth)acrylates such as aliphatic urethane (meth)acrylate and aromatic urethane (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, epoxy (meth)acrylate, etc. Among these, urethane (meth)acrylate is preferred because it easily achieves both hardness and adhesion of the coating film. Moreover, aliphatic urethane (meth)acrylate is even more preferred because it has high weather resistance.

[0035] The number of functional groups in urethane (meth)acrylate is not particularly limited, but it is preferably 1 to 4 functional groups, and more preferably 2 to 3 functional groups. Within this range, adhesion is excellent.

[0036] Aliphatic urethane (meth)acrylates are urethane (meth)acrylates in which both the polyol component and the isocyanate component are aliphatic, and which do not have aromatic rings in the molecule. Examples of urethane (meth)acrylates include oligomers formed by reacting polyvalent isocyanate compounds, polyol compounds, and hydroxyl group-containing (meth)acrylates; and oligomers formed by reacting polyvalent isocyanate compounds and hydroxyl group-containing (meth)acrylates. Commercially available products include, for example, EBECRYL4858, EBECRYL8311, EBECRYL8402, EBECRYL8701, EBECRYL9260, EBECRYL8606, and EBECRYL8301R from Daicel Ornex, and CN8888NS, CN8898NS, CN8881NS, CN964NS, and CN9013NS from Sartomer.

[0037] The urethane (meth)acrylate content is preferably 10 to 80% by mass, and more preferably 10 to 50% by mass, relative to the total amount of the paint composition. Within this range, adhesion to the substrate and / or topcoat is good, and the viscosity of the paint does not become too high, resulting in excellent coatability. Furthermore, the urethane (meth)acrylate content is preferably 10 to 80% by mass, and more preferably 10 to 50% by mass, relative to the total amount of the topcoat composition. Within this range, adhesion to the colored layer is good, and the viscosity of the topcoat does not become too high, resulting in excellent coatability.

[0038] <UV absorber> The coating composition and topcoat composition of the present invention may contain an ultraviolet absorber. Examples of ultraviolet absorbers include organic ultraviolet absorbers such as salicylic acid-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, and cyanoacrylate-based ultraviolet absorbers, or inorganic ultraviolet absorbers consisting of fine particles of zinc oxide, titanium dioxide, and cerium oxide. Among these, triazine-based ultraviolet absorbers are more preferred because they have high ultraviolet absorption capacity and are less likely to degrade even when exposed to high energy such as ultraviolet rays.

[0039] Examples of benzotriazole-based UV absorbers include 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, and polyethylene glycol 3-[3-(benzotriazole-2-yl)-5-tert-butyl-4-hydroxyphenyl]propionic acid. Examples of triazine-based UV absorbers include 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-[(hexyl)oxy]phenol, 1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and 1,3,5-tri[[3,5-bis-(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]. Other commercially available products include ADEKA's ADEKA Stub LA-F70 and ADEKA Stub LA-40, and BASF Japan's Tinuvin 405 and Tinuvin 479.

[0040] <Light stabilizer> Furthermore, the coating composition and topcoat composition of the present invention may contain a light stabilizer. Examples of light stabilizers include hindered amine light stabilizers (HALS), phenolic antioxidants, phosphorus antioxidants, and sulfur antioxidants. Among these, HALS are more preferred because they have high thermal stability and excellent radical scavenging ability. Specifically, examples of HALS include 2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2'-n-butylmalonate bis(1,2,2,6,6-pentamethyl-4-piperidyl), bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, and methyl(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate. Examples include cate, 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)amino]-6-(2-hydroxyethylamine)-1,3,5-triazine), tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, and 1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate. Commercially available products include ADEKA's ADEKA Stab LA-72 and ADEKA Stab LA-82, and BASF Japan's Tinuvin 123 and Tinuvin 249.

[0041] UV absorbers and light stabilizers may be added to the composition in any amount, but from the standpoint of compatibility, their total amount is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, based on the total amount of the paint composition. Furthermore, the UV absorber content is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 8% by mass or less, based on the total amount of the paint composition. The light stabilizer content is preferably 7% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, based on the total amount of the paint composition. The content in the topcoat composition is the same as the preferred content in the paint.

[0042] <Coloring agent> The paint composition of the present invention may contain a colorant. At least one of pigments and dyes can be used as the colorant. Pigments are preferred from the viewpoint of weather resistance. There are no particular restrictions on the colorant that can be used in the present invention, and known pigments and dyes can be used. Both inorganic pigments and organic pigments can be used as pigments.

[0043] Examples of inorganic pigments include carbon blacks such as furnace black, lamp black, acetylene black, and channel black, as well as iron oxide, titanium oxide, and complex oxides.

[0044] Organic pigments include soluble azo pigments such as β-naphthol-based, β-oxynaphthoic acid-based, β-oxynaphthoic acid-based anilide-based, acetoacetate anilide-based, and pyrazolone-based pigments; Examples include insoluble azo pigments such as β-naphthol-based, β-oxynaphthoic acid-based anilide-based, acetoacetate anilide-based monoazo, acetoacetate anilide-based disazo, and pyrazolone-based pigments; phthalocyanine-based pigments such as copper phthalocyanine blue, halogenated (e.g., chlorinated, brominated, etc.) copper phthalocyanine blue, sulfonated copper phthalocyanine blue, and metal-free phthalocyanines; polycyclic and heterocyclic pigments such as quinacridone-based, dioxazine-based, slene-based (pyrantrone, anthantrone, indanthrone, anthrapyrimidine, flavanthrone, thioindigo-based, anthraquinone-based, perinone-based, perylene-based, etc.), isoindolinone-based, metal complex-based, quinophthalone-based, and diketopyrrolopyrrole-based pigments; and others.

[0045] More specifically, using the CI color index, examples of black pigments include CIPigment Black 1, 6, 7, 9, 10, 11, 12, 26, 27, 28, and 31.

[0046] Examples of white pigments include CIPigment White 5, 6, 7, 12, and 28.

[0047] Examples of yellow pigments include CIPigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 18, 24, 53, 73, 74, 75, 83, 93, 95, 97, 98, 100, 108, 109, 110, 114, 119, 120, 128, 129, 138, 139, 164, 174, 150, 151, 154, 155, 167, 180, 184, 185, 213, 216, and 227.

[0048] Examples of blue or cyan pigments include CIPigment Blue 1, 2, 14, 15, 15:1, 15:2, 15:3, 15:4, 28, 36, 60, and 62.

[0049] As red or crimson pigments, CIPigment RED 1, 3, 5, 19, 21, 22, 31, 38, 42, 43, 48:1, 48:2, 48:3, 48:4, 48:5, 49:1, 50, 52, 53:1, 57:1, 57:2, 58:4, 63:1, 81, 81:1, 81:2, 81:3, 81:4, 83, 90, 101, 104, 108, Examples include 112, 114, 122, 144, 146, 148, 149, 150, 166, 168, 169, 170, 172, 173, 176, 177, 178, 184, 185, 187, 193, 202, 209, 214, 242, 254, 255, 264, 266, 269, and CIPigment Violet 19.

[0050] Examples of green pigments include CIPigment Green 1, 2, 3, 4, 7, 8, 10, 15, 17, 26, 36, 45, and 50.

[0051] Examples of purple pigments include CIPigment Violet 1, 2, 3, 4, 5:1, 12, 13, 14, 15, 16, 17, 19, 23, 25, 29, 31, 32, 36, 37, 39, and 42.

[0052] Examples of orange pigments include CIPigment Orange 13, 16, 20, 34, 36, 38, 39, 43, 51, 61, 63, 64, and 74.

[0053] The colorants used in the paint composition of the present invention may be used individually or in combination of two or more. The amount of colorant added is preferably 3 to 60% by mass of the paint composition. A colorant addition of 3 to 60% by mass results in good coloring properties.

[0054] The topcoat composition of the present invention is a clear coating that is substantially free of coloring pigments. "Substantially free" means intentionally omitted for coloring purposes, and it is preferable that the colored layer is clearly visible from above the topcoat layer when a topcoat layer with a thickness of 12 μm is formed on top of the colored layer. Therefore, a coloring agent may be included in an amount that does not impair visibility. Specifically, the amount of coloring agent in the coating composition is preferably 3% by mass or less, and more preferably 1% by mass or less. However, this does not apply to coloring agents with low coloring power.

[0055] <Resin> The paint composition and topcoat composition of the present invention may contain a resin. Examples of resins contained in the present invention include polyvinyl chloride, acrylic resin, epoxy resin, polyester resin, polyurethane resin, cellulose derivatives (e.g., ethylcellulose, cellulose acetate, nitrocellulose), vinyl chloride-vinyl acetate copolymer, polyamide resin, polyvinyl acetal resin, diallyl phthalate resin, alkyd resin, rosin-modified alkyd resin, petroleum resin, urea resin, and synthetic rubber such as butadiene-acrylonitrile copolymer. Furthermore, these resins can also be used after modification. Specifically, examples include chlorination, bromination, amine modification, and carboxylic acid modification. The resin may be used alone or in combination of two or more types.

[0056] <Additives> The paint composition and topcoat composition of the present invention may appropriately contain known additives. Examples include sensitizers, polymerization initiators, polymerization inhibitors, fluorescent whitening agents, curing agents, coupling agents, plasticizers, leveling agents, surface modifiers, defoaming agents, substrate wetting agents, antistatic agents, extender pigments, pigment dispersants, rust inhibitors, antibacterial agents, antiviral agents, and the like.

[0057] <Solvent> The paint composition and topcoat composition of the present invention preferably contain substantially no organic solvents or water. "Substantially no" means that they contain 3% or less, more preferably 1% or less, of the total mass of the paint.

[0058] <Viscosity> The viscosity of the coating composition and topcoat composition of the present invention is not particularly limited and can be set appropriately depending on the coating method. For example, in the case of coating by a roll coater, the viscosity at 25°C is preferably 100 to 2000 mPa·s, more preferably 200 to 1000 mPa·s, and most preferably 200 to 500 mPa·s. When the viscosity at 25°C is within the above range, the coating and printability is excellent. Viscosity is measured using a viscoelasticity measuring device (DiscoveryHR-2, manufactured by T.A. Instruments Japan Co., Ltd.) with a cone diameter of 20 mm, a cone angle of 1 degree, a temperature of 25°C, and a shear rate of 0.1 sec. -1 The temperature is increased at a constant rate, and after 60 seconds the shear rate is set to 100 sec. -1 When it reaches this point, the shear rate is 100 sec. -1 This refers to the measured value at that time.

[0059] <Base material> The substrate is not particularly limited and any known substrate can be used. Specifically, examples include coated papers such as art paper, coated paper, and cast paper; uncoated papers such as fine paper, medium-quality paper, and newsprint; synthetic papers such as Yupo paper; plastic films such as PET (polyethylene terephthalate), PP (polypropylene), and OPP (biaxially oriented polypropylene); wood; stone; and metal sheets. Among these, metal substrates used in the building materials field are preferred. Specific examples of metal substrates include galvalume steel sheets (registered trademark), aluminum sheets, tin-free steel (TFS) sheets, tinplate sheets, galvanized iron sheets, polyethylene terephthalate (PET) film laminated steel sheets, stainless steel sheets, polyethylene (PE) film laminated steel sheets, copper sheets, and brass sheets. For example, when used in exterior building materials, hardness and weather resistance are particularly required, and steel sheet substrates such as galvalume steel sheets (registered trademark) and stainless steel sheets are more preferred.

[0060] <Colored layer> The colored layer of the present invention is formed by curing an active energy ray-curable paint composition under an inert gas atmosphere, and can be formed by applying the paint composition to a substrate and curing it under an inert gas atmosphere. Furthermore, the colored layer of the present invention is formed by curing an electron beam-curable paint composition, and can be formed by applying the paint composition to a substrate and curing it with an electron beam. The thickness of the colored layer can be appropriately selected depending on the application, but 1 to 50 μm is preferred, and 5 to 20 μm is more preferred. Furthermore, the pencil hardness of the colored layer after curing is preferably 4B to 4H, and B to 2H is more preferred. Within the above range, adhesion with the topcoat layer is easily improved. In addition, within the above range, the colored layer will not be damaged in subsequent processes, making it practical. Note that pencil hardness is determined in accordance with JIS K5600-5-4, where pencils of various hardnesses are applied to the surface of the cured coating at a 45° angle, and a scratch test is performed with a load of 250g, indicating the hardest pencil that does not cause damage.

[0061] <Top coat layer> The topcoat layer of the present invention is formed by curing an active energy ray topcoat composition under an inert gas atmosphere, and can be formed by applying the topcoat composition to a colored layer and curing it under an inert gas atmosphere. Furthermore, the topcoat layer of the present invention is formed by curing an electron beam-curable topcoat composition, and can be formed by applying the topcoat composition to a colored layer and curing it with an electron beam. The thickness of the topcoat layer can be appropriately selected depending on the application, but 1 to 50 μm is preferred, and 5 to 20 μm is more preferred. The topcoat layer is located on the outermost layer of the laminate and provides functions such as resistance and aesthetics depending on the application of the coating film. In addition to the need for transparency that allows the underlying paint layer to be seen, the performance required of the topcoat includes functions that protect the paint layer, such as scratch resistance, weather resistance, heat and humidity resistance, stain resistance, and chemical resistance.

[0062] <Coating Method> Known methods such as gravure coating, gravure reverse coating, gravure offset coating, spin coating, roll coating, reverse roll coating, curtain coating, kiss coating, dip coating, silkscreen coating, wire bar coating, flow coating, comma coating, and spray coating can be applied as coating methods for the coating composition and topcoat composition of the present invention. Among these, roll coating and reverse roll coating are more preferred due to their high productivity. Furthermore, when used after solvent dilution, it is necessary to thoroughly dry and evaporate the solvent on the coated surface before curing by active energy ray irradiation.

[0063] <Curing method> The method for curing the coating composition and topcoat composition of the present invention is not particularly limited as long as it is electron beam curing or ultraviolet curing under an inert gas atmosphere, and known methods can be used. Electron beam curing is more preferred. When curing by ultraviolet irradiation, the inclusion of a photopolymerization initiator is essential. The photopolymerization initiator is not particularly limited, and known photopolymerization initiators can be used as appropriate.

[0064] UV curing is improved by performing it under an inert gas atmosphere. Known inert gases such as nitrogen, helium, neon, and argon can be used. Nitrogen gas is preferably used due to its economic rationality and availability. The concentration of the inert gas is preferably 99% by volume or higher, and more preferably 99.9% by volume or higher. Electron beam curing is usually performed under an inert gas atmosphere. Electron beam curing is preferable because it is not affected by curing inhibition due to shielding from ultraviolet light associated with high pigment concentrations or the inclusion of UV absorbers. Furthermore, since no initiator is required, the pot life of the paint is not shortened, and the coating performance does not deteriorate after curing due to initiator decomposition products, allowing the effects of the present invention to be maximized. As with UV curing, nitrogen gas is preferably used as the inert gas. The concentration of the inert gas is preferably 99% by volume or higher, and more preferably 99.9% by volume or higher.

[0065] Electron beam curing is preferably performed by irradiating with an electron beam with an acceleration voltage of 10 to 500 kV, particularly 30 to 200 kV. If the acceleration voltage is too high, the hardness of the coating film does not change, but the energy cost increases, making it economically unfeasible. If the acceleration voltage is too low, the adhesion of the paint becomes good, but the hardness of the coating film after application decreases.

[0066] <Laminate> The laminate of the present invention may have a substrate, a colored layer, and a topcoat layer in that order, but a form that further includes a pattern layer and an anchor layer is also preferable. The pattern layer can be provided between the coloring layer and the topcoat layer, and can be formed by printing methods such as gravure printing or offset printing. The anchor layer can be provided between the substrate and the coloring layer, and can be formed by various coating methods. Furthermore, it is preferable that the anchor layer be formed from an active energy ray curable composition. [Examples]

[0067] The present invention will be described in detail below with reference to examples, but the following examples do not limit the scope of the rights of the present invention in any way.

[0068] [Preparation of active energy ray-curable paint compositions] According to the formulations listed in Table 1, each raw material was mixed at room temperature by disperser stirring (3000 rpm) to prepare active energy ray curable coating compositions B1 to B15. The numbers in Table 1 indicate the amount (parts by mass) of each component.

[0069] [Preparation of Active Energy Ray Curable Topcoat Compositions] According to the formulations listed in Table 2, each raw material was mixed at room temperature by disperser stirring (3000 rpm) to prepare activated energy ray curable topcoat compositions T1 to T7. The numbers in Table 2 indicate the amount (parts by mass) of each component.

[0070] [Preparation of a comparative composition for active energy ray curing] According to the formulations listed in Table 2, each raw material was mixed at room temperature by disperser stirring (3000 rpm) to prepare the activated energy ray curable comparative compositions T8 to T9. The numbers in Table 2 indicate the amount (parts by mass) of each component.

[0071] [Fabrication of laminates] (Example 1) The obtained active energy ray-curable coating composition B1 was applied to a base material, galvalume steel sheet (registered trademark) (manufactured by Yodogawa Steel Works, Yodo GL Eco Green, thickness 0.27 mm), using a bar coater #8 (coating film thickness approximately 12 μm). Subsequently, the coating composition was cured by irradiating it with an electron beam using an electron beam irradiation device i-Compact EB (manufactured by Iwasaki Electric Co., Ltd., acceleration voltage 90 kV, irradiation dose 100 kGy) in a nitrogen atmosphere (99.95 vol%) to form a colored layer. Furthermore, the active energy ray-curable topcoat composition T1 was applied using a bar coater #8 so as to partially overlap the colored layer (coating film thickness approximately 12 μm). To shield the portion of the colored layer that was not coated with the topcoat composition from electron beams, a metal plate was used to cover the area. An electron beam irradiation device, i-Compact EB (manufactured by Iwasaki Electric Co., Ltd., acceleration voltage 90kV, irradiation dose 100kGy), was then used to irradiate the topcoat composition with electron beams in a nitrogen atmosphere (99.95 vol%) to produce the laminate of Example 1. The interlayer adhesion and weather resistance of the obtained laminate were evaluated in the areas where the colored layer and topcoat layer were laminated. Furthermore, the pencil hardness was evaluated in the areas where the topcoat layer was not laminated and the colored layer was exposed. The results are shown in Table 3.

[0072] (Examples 2-17, Comparative Examples 1-4) Laminates for Examples 2-17 and Comparative Examples 1-4 were prepared and evaluated using the same method as in Example 1, except for the changes described in Tables 3-4. The results are shown in Tables 3-4.

[0073] [Interlayer adhesion (cross-cut test)] Eleven vertical and eleven horizontal cuts were made on the laminate at 1 mm intervals using a cutter. A 12 mm wide adhesive tape (Nichiban Co., Ltd., cellophane tape) was applied to these areas, and the tape was peeled off at a 90° angle to the laminate. This process was repeated three times, and the results were evaluated according to the following evaluation criteria. A: The top coat layer did not peel off at all. B: The topcoat layer was partially peeled off, and the paint film retention rate was 70% or more. C: The topcoat layer was partially peeled off, and the remaining paint film percentage was between 30% and 70%. D: The topcoat layer was partially peeled off, and the remaining paint film percentage was less than 30%. The practical range is A to C.

[0074] [Visibility] In areas where the topcoat layers are stacked, we checked whether the boundary between the areas with and without a colored layer beneath the topcoat layer was visible, and evaluated it according to the following evaluation criteria. A: The boundary is clearly defined, and the top coat layer is highly visible. B: The boundary lines are difficult to distinguish, and the top coat layer is not easily visible.

[0075] [Weather resistance] Weather resistance was evaluated using a xenon lamp (product name "Q-SUN Xe-1", manufactured by Q-Lab) at 120W / m 2 The surface condition of the test specimens after 700 hours was evaluated according to the following evaluation criteria. This process involved irradiating the specimens with ultraviolet light for 102 minutes under irradiation conditions of 63°C on a black panel, followed by a shower process in which water was sprayed for 18 minutes while irradiating them with ultraviolet light under the same irradiation conditions. A: No abnormalities, or only very minor surface abnormalities. B: Minor surface abnormalities occur. C: Numerous surface abnormalities occurred. An abnormality refers to a decrease in gloss or the occurrence of blistering (partial swelling of the paint film), and the ranges that are usable are A and B.

[0076] [Pencil hardness of the colored layer] For the colored layer (hardened coating), in accordance with JIS K5600-5-4, pencils of various hardness levels were applied to the surface of the hardened coating at a 45° angle, and a scratch test was conducted by applying a load of 250g. The hardness of the hardest pencil that did not cause damage was defined as the pencil hardness, and was evaluated according to the following criteria. A:B~2H B: 4B~2B or 3H~4H C: 5B or lower, or 5H or higher. The practical ranges are A and B.

[0077] The information for each ingredient in Tables 1 and 2 is as follows: (Coloring agent) • Mogul E: Carbon Black, manufactured by Cabot. • Typeque CR58-2: Titanium oxide, manufactured by Ishihara Sangyo Co., Ltd. (Dispersant) • Solspers 32000: A copolymer containing acid groups, manufactured by Lubrizol. • DisperBYK111: A copolymer containing acid groups, manufactured by BYK. (Radical polymerizable compounds) • EBECRYL8402: Aliphatic urethane acrylate, bifunctional, manufactured by Daicel Ornex. • EBECRYL210: Aromatic urethane acrylate, bifunctional, manufactured by Daicel Ornex. • EBECRYL1290: Aliphatic urethane acrylate, hexafunctional, manufactured by Daicel Ornex. • TBCHA: 4-tert-butylcyclohexyl acrylate, manufactured by KJ Chemicals. • FA513AS: Dicyclopentanyl acrylate, manufactured by Resonaq Corporation. MEDOL-10: (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd. • Arronix M327: ε-caprolactone modified tris-2-hydroxyethyl isocyanurate triacrylate, manufactured by Toagosei Co., Ltd. • Miramar M370: Tris-2-hydroxyethyl isocyanurate triacrylate, manufactured by MIWON. (Nitrogen atom-containing polymerizable compound) • ACMO: Acryloylmorpholine, manufactured by KJ Chemicals (a polymerizable compound containing nitrogen atoms) • V-CAP: N-vinylcaprolactam, manufactured by BASF (nitrogen atom-containing polymerizable compound) (Sulfur atom-containing polymerizable compound) • PE-1: Pentaerythritol tetrakis(3-mercaptobutyrate), manufactured by Resonaq (secondary thiol) • PEMP: Pentaerythritol tetrakis(3-mercaptopropionate), manufactured by CS Organic Chemicals (primary thiol) (UV absorber) • Tinuvin 479: Hydroxyphenyltriazine-based UV absorber, manufactured by BASF. (Light stabilizer) • ADEKA LA-72: Bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, manufactured by ADEKA Corporation.

[0078] [Table 1]

[0079] [Table 2]

[0080] [Table 3]

[0081] [Table 4]

[0082] As is clear from the results in Tables 3 to 4, Examples 1 to 17 of the laminate of the present invention exhibited good interlayer adhesion, visibility, and weather resistance. On the other hand, Comparative Examples 1 to 4 had insufficient interlayer adhesion or visibility in one or more of the following aspects.

Claims

1. A laminate comprising a metal substrate, a colored layer obtained by electron beam curing of an active energy ray curable coating composition, and a topcoat layer obtained by electron beam curing of an active energy ray curable topcoat composition, The active energy ray curable coating composition comprises a nitrogen atom-containing polymerizable compound (excluding urethane (meth)acrylate) and / or a sulfur atom-containing polymerizable compound, wherein the nitrogen atom-containing polymerizable compound is a polymerizable compound containing an N-vinyl group and / or acrylamide, and the sulfur atom-containing polymerizable compound contains a mercapto group. The active energy ray curable topcoat composition is a laminate containing (meth)acrylate.

2. The laminate according to claim 1, wherein the sulfur atom-containing polymerizable compound is a secondary thiol.

3. The laminate according to claim 1 or 2, wherein the total content of nitrogen atom-containing polymerizable compounds and / or sulfur atom-containing polymerizable compounds is 3 to 60% by mass with respect to 100% by mass of the active energy ray-curable coating composition.

4. The laminate according to claim 1 or 2, wherein the active energy ray curable coating composition and / or active energy ray curable topcoat composition contains an ultraviolet absorber.

5. The laminate according to claim 1 or 2, wherein the active energy ray curable topcoat composition comprises urethane (meth)acrylate.

6. The laminate according to claim 5, wherein the urethane (meth)acrylate comprises aliphatic urethane (meth)acrylate.

7. A laminate according to claim 1 or 2, which is for use as a building material.

8. A method for producing a laminate comprising applying an active energy ray curable coating composition to a metal substrate, the composition comprising a nitrogen atom-containing polymerizable compound and / or a sulfur atom-containing polymerizable compound and a colorant, wherein the nitrogen atom-containing polymerizable compound is a polymerizable compound containing an N-vinyl group and / or acrylamide, and the sulfur atom-containing polymerizable compound is a mercapto group, and curing by electron beam to form a colored layer, and applying an active energy ray curable topcoat composition containing (meth)acrylate on the colored layer and curing by electron beam to form a topcoat layer.

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