Laminate, set of active energy ray-curable compositions, and method for manufacturing laminate

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, an active energy ray-curable composition set, and a method for producing the laminate. [Background technology]

[0002] Methods for applying paint to obtain a cured coating can be broadly divided into solvent-based paints and water-based paints that dry and cure using heat, and active energy ray-curable paints that polymerize and cure by irradiating with ultraviolet light or electron beams. In recent years, active energy ray-curable paints, which do not require heat drying, have been attracting attention due to the SDGs and rising energy costs. In particular, paints are used in large quantities in the building materials field, and are attracting particular attention.

[0003] Methods for curing active energy ray-curable paints are divided into ultraviolet curing and electron beam curing. When curing with ultraviolet light, the ultraviolet light must reach the interior of the paint film to achieve curing. To improve the curability of the interior of the paint film, there are many restrictions on use, such as the inability to increase the pigment content in the composition or the inability to increase the coating film thickness. On the other hand, when curing with electron beams, the electron beams penetrate into the film regardless of the coating film thickness or the pigment content, allowing for sufficient curing to the interior, making this a suitable method for curing paints.

[0004] When applying paint to building materials, a top coat (clear paint) may be applied over a paint film containing a colorant. When this top coat (clear paint) is applied over a paint film that has been cured with electron beams or UV rays under an inert gas atmosphere, the two coatings may not adhere well together, resulting in delamination. Another issue is that it is difficult to achieve weather resistance for the laminate.

[0005] Patent Document 1 describes a method for improving the adhesion of a second coating film by insufficiently curing the first coating film when recoating an electron beam curable coating. However, the method involves recoating a coating composition containing a colorant, and does not provide any examples of recoating a top coat (clear coating).

[0006] Patent Document 2 exemplifies a composition that exhibits good adhesion even when recoated with an electron beam curable coating material. However, the coating composition contains a colorant, and there is no example of a case where a top coat (clear coating) is recoated. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2002-361173 [Patent Document 2] JP 8-34868 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a laminate having excellent adhesion between a colored layer and a top coat layer and excellent weather resistance.

[0009] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by the laminate described below, and have thus completed the present invention.

[0010] That is, the present invention provides a laminate having a substrate, a colored layer obtained by curing an active energy ray-curable coating composition with electron beams or with ultraviolet rays in an inert gas atmosphere, and a top coat layer obtained by curing an active energy ray-curable top coat composition with electron beams or with ultraviolet rays in an inert gas atmosphere, The present invention relates to a laminate in which 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.

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

[0012] The present invention relates to the laminate, wherein the sulfur atom-containing polymerizable compound contains a mercapto group.

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

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

[0015] The present invention relates to the laminate, wherein the active energy ray-curable coating composition and / or the active energy ray-curable top coat composition contains an ultraviolet absorber.

[0016] The present invention relates to the laminate, wherein the active energy ray-curable top coat composition contains a urethane (meth)acrylate.

[0017] The present invention relates to the laminate, wherein the urethane (meth)acrylate comprises an 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, which set includes 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 top coat composition.

[0019] The present invention relates to a method for producing 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, curing the composition with electron beams or with ultraviolet light in an inert gas atmosphere to form a colored layer, and applying an active energy ray-curable top coat composition onto the colored layer, curing the composition with electron beams or with ultraviolet light in an inert gas atmosphere to form a top coat layer. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described in detail. Note that the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the present invention.

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

[0022] The components contained in the active energy ray-curable coating composition (hereinafter also simply referred to as a "coating" or "coating composition") and the active energy ray-curable top coat composition (hereinafter also simply referred to as a "top coat" or "top coat composition") of this embodiment will be described below. The coating material and the top coat are also collectively referred to as the active energy ray-curable composition.

[0023] <Polymerizable compound> The coating composition and top coat composition of the present invention contain a polymerizable compound. The polymerizable compound that can be used in the present invention is not particularly limited, and any known compound capable of radical polymerization can be used.

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

[0025] Examples of radically polymerizable compounds include unsaturated carboxylic acids such as (meth)acrylic acid, itaconic acid, and maleic acid, and salts thereof, anhydrides having an ethylenically unsaturated group, styrene, and various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, and unsaturated urethanes, and other compounds having ethylenic unsaturation.

[0026] ((Meth)acrylate Monomer) The radical polymerizable compound is preferably a (meth)acrylate, and specific examples of the (meth)acrylate monomer include 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, β-carboxylethyl (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 methyl acrylate, 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 trimethylolpropane formal (meth)acrylate, benzyl (meth)acrylate, EO-modified (2) nonylphenol acrylate, and (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, hydroxypivalic acid neopentyl glycol di(meth)acrylate, dipropylene glycol Bifunctional (meth)acrylates such as ethylene 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, dimethyloltricyclodecane di(meth)acrylate, EO-modified (4) bisphenol A di(meth)acrylate, PO-modified (4) bisphenol A di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, dicyclopentanyl di(meth)acrylate, and 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 isocyanuric acid tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, and pentaerythritol tri(meth)acrylate; tetrafunctional (meth)acrylates such as pentaerythritol tetra(meth)acrylate and ditrimethylolpropane tetra(meth)acrylate; Pentafunctional (meth)acrylates such as dipentaerythritol penta(meth)acrylate, and hexafunctional (meth)acrylates such as dipentaerythritol hexa(meth)acrylate. The numbers in parentheses indicate the number of moles of EO and PO modifications, or the molecular weight of the polyethylene glycol portion.

[0027] The (meth)acrylate used in the coating composition is preferably a (meth)acrylate having a cyclic structure. Examples of the cyclic structure include alicyclic and heterocyclic structures. The (meth)acrylate used in the top coat composition is preferably a (meth)acrylate having a cyclic structure or a (meth)acrylate having an isocyanurate structure. These have the advantage of not only good adhesion and weather resistance but also good physical properties such as printability.

[0028] The content of these (meth)acrylates is not particularly limited, but the total content of the (meth)acrylate, nitrogen-containing polymerizable compound, and sulfur-containing polymerizable compound is preferably 20 to 100% by mass, and more preferably 40 to 95% by mass, based on the total amount of components of the coating composition excluding the colorant. Furthermore, the total content of these (meth)acrylate, nitrogen-containing polymerizable compound, and sulfur-containing polymerizable compound is preferably 20 to 95% by mass, and more preferably 40 to 95% by mass, based on the total amount of the top coat composition. When the nitrogen-containing polymerizable compound and / or sulfur-containing polymerizable compound is not included, the above numerical ranges refer to the preferred content of (meth)acrylate.

[0029] (Nitrogen atom-containing polymerizable compound and / or sulfur atom-containing polymerizable compound) The coating composition of the present invention contains a nitrogen-atom-containing polymerizable compound and / or a sulfur-atom-containing polymerizable compound. The nitrogen-atom-containing polymerizable compound 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 the like, the nitrogen-atom-containing polymerizable compound is preferably a polymerizable compound containing an N-vinyl group and / or acrylamide.

[0030] The sulfur atom-containing polymerizable compound is not particularly limited as long as it contains a sulfur atom, and examples thereof include compounds having a mercapto group. Examples of radically 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-triazinane-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 adhesiveness-imparting effect.

[0031] The coating composition of the present invention preferably contains 20 to 80% by mass, more preferably 20 to 60% by mass, and even more preferably 20 to 40% by mass of a nitrogen-containing polymerizable compound relative to the total amount of the coating composition. Furthermore, when a sulfur-containing polymerizable compound is contained, the content may be 0% by mass. When the content is within the above range, adhesion and weather resistance of the coating film are improved.

[0032] The coating composition of the present invention preferably contains 1 to 20 mass % of a sulfur atom-containing polymerizable compound, more preferably 3 to 10 mass %. Furthermore, when a nitrogen atom-containing polymerizable compound is contained, the amount may be 0 mass %. When the amount is within the above range, adhesion and hardness of the coating film are improved.

[0033] In the coating composition of the present invention, the total content of the nitrogen-atom-containing polymerizable compound and / or the sulfur-atom-containing polymerizable compound is preferably 3 to 60 mass %, more preferably 5 to 40 mass %, relative to 100 mass % of the active energy ray-curable coating composition. When it is in this range, adhesion and hardness of the coating film are improved.

[0034] (Other (meth)acrylates) Furthermore, the coating composition and top coat composition of the present invention can use urethane (meth)acrylates such as aliphatic urethane (meth)acrylates and aromatic urethane (meth)acrylates, polyester (meth)acrylates, polyether (meth)acrylates, and epoxy (meth)acrylates. Among these, urethane (meth)acrylates are preferred because they can easily achieve both hardness and adhesion of the coating film. Furthermore, aliphatic urethane (meth)acrylates are more preferred because of their high weather resistance.

[0035] The number of functional groups of the urethane (meth)acrylate is not particularly limited, but is preferably 1 to 4, and more preferably 2 to 3. When within the above range, excellent adhesion is achieved.

[0036] Aliphatic urethane (meth)acrylate refers to a urethane (meth)acrylate in which the polyol and isocyanate components constituting it are both aliphatic and do not have an aromatic ring in the molecule. Examples of urethane (meth)acrylates include oligomers obtained by reacting a polyisocyanate compound, a polyol compound, and a hydroxyl group-containing (meth)acrylate; and oligomers obtained by reacting a polyisocyanate compound and a hydroxyl group-containing (meth)acrylate. Commercially available products include EBECRYL4858, EBECRYL8311, EBECRYL8402, EBECRYL8701, EBECRYL9260, EBECRYL8606, and EBECRYL8301R manufactured by Daicel Allnex Corporation, and CN8888NS, CN8898NS, CN8881NS, CN964NS, and CN9013NS manufactured by Sartomer Corporation.

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

[0038] <UV absorber> The coating composition and top coat 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, as well as inorganic ultraviolet absorbers made of fine particles of zinc oxide, titanium oxide, or cerium oxide. Among these, triazine-based ultraviolet absorbers are more preferred because they have high ultraviolet absorption ability and are resistant to degradation even when exposed to high energy such as ultraviolet light.

[0039] Specific examples of benzotriazole-based ultraviolet absorbers include 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, and 3-[3-(benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl]propionic acid ester of polyethylene glycol. Specific examples of triazine-based ultraviolet absorbers include 2-(4,6-diphenyl-1,3,5-triazin-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]. Commercially available products include ADK STAB LA-F70 and ADK STAB LA-40 manufactured by ADEKA Corporation, and Tinuvin 405 and Tinuvin 479 manufactured by BASF Japan Ltd.

[0040] <Light stabilizer> Furthermore, the coating composition and top coat composition of the present invention may contain a light stabilizer. Examples of light stabilizers include hindered amine light stabilizers (HALS), phenolic antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. Among these, HALS is more preferred due to its high thermal stability and excellent radical scavenging ability. Specific examples of HALS include 2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2'-n-butylmalonic acid 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. tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)amino]-6-(2-hydroxyethylamine)-1,3,5-triazine), tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, 1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate, etc. Commercially available products include Adeka STAB LA-72 and Adeka STAB LA-82 manufactured by ADEKA Corporation, and Tinuvin 123 and Tinuvin 249 manufactured by BASF Japan Ltd.

[0041] The UV absorber and light stabilizer may be added to the composition in any amount, but from the viewpoint of compatibility, their total content is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, relative to the total amount of the coating composition. Furthermore, the content of the UV absorber is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 8% by mass or less, relative to the total amount of the coating composition. The content of the light stabilizer is preferably 7% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, relative to the total amount of the coating composition. The content in the top coat composition is the same as the preferred content in the coating.

[0042] <Coloring agent> The coating composition of the present invention can contain a colorant. As the colorant, at least one of a pigment and a dye can be used. From the viewpoint of weather resistance, a pigment is preferred. There are no particular limitations on the colorant that can be used in the present invention, and known pigments and dyes can be used. As the pigment, both inorganic pigments and organic pigments can be used.

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

[0044] Examples of organic pigments include soluble azo pigments such as β-naphthol, β-hydroxynaphthoic acid, β-hydroxynaphthoic acid anilide, acetoacetic acid anilide, and pyrazolone; Examples of suitable pigments include insoluble azo pigments such as β-naphthol, β-oxynaphthoic acid anilide, monoazo acetoacetate anilide, disazo acetoacetate anilide, and pyrazolone pigments; phthalocyanine pigments such as copper phthalocyanine blue, halogenated (e.g., chlorinated, brominated) copper phthalocyanine blue, sulfonated copper phthalocyanine blue, and metal-free phthalocyanine; and polycyclic and heterocyclic pigments such as quinacridone, dioxazine, threne (pyranthrone, anthanthrone, indanthrone, anthrapyrimidine, flavanthrone, thioindigo, anthraquinone, perinone, perylene, etc.), isoindolinone, metal complex, quinophthalone, and diketopyrrolopyrrole pigments.

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

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

[0047] Examples of yellow pigments include CI Pigment 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] Blue or cyan pigments include CI Pigment Blue 1, 2, 14, 15, 15:1, 15:2, 15:3, 15:4, 28, 36, 60, 62, and the like.

[0049] Red or crimson pigments include CI Pigment 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, 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, CI Pigment Violet 19, etc.

[0050] Green pigments include CI Pigment Green 1, 2, 3, 4, 7, 8, 10, 15, 17, 26, 36, 45, 50, and the like.

[0051] Purple pigments include CI Pigment 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] Orange pigments include CI Pigment Orange 13, 16, 20, 34, 36, 38, 39, 43, 51, 61, 63, 64, and 74.

[0053] The colorant used in the coating composition of the present invention may be used alone or in combination of two or more. The amount of the colorant added is preferably 3 to 60 mass% in the coating composition. When the amount of the colorant added is 3 to 60 mass%, good colorability is achieved.

[0054] The top coat composition of the present invention is a clear coating that is substantially free of coloring pigments. "Substantially free" means that the coloring pigment is not intentionally added for coloring purposes. It is preferable that the coloring layer is clearly visible from above the top coat layer when a top coat layer is formed on the coloring layer to a thickness of 12 μm. Therefore, a coloring agent may be included to the extent that visibility is not impaired. Specifically, the amount of the coloring agent in the coating composition is preferably 3% by mass or less, more preferably 1% by mass or less. However, this does not apply if the coloring agent has low coloring power.

[0055] <Resin> The coating composition and top coat composition of the present invention can contain a resin. Examples of resins that can be contained in the present invention include polyvinyl chloride, acrylic resins, epoxy resins, polyester resins, polyurethane resins, cellulose derivatives (e.g., ethyl cellulose, cellulose acetate, nitrocellulose), vinyl chloride-vinyl acetate copolymers, polyamide resins, polyvinyl acetal resins, diallyl phthalate resins, alkyd resins, rosin-modified alkyd resins, petroleum resins, urea resins, and synthetic rubbers such as butadiene-acrylonitrile copolymers. Furthermore, these resins can also be modified before use. Specific examples include chlorinated, brominated, amine-modified, and carboxylic acid-modified resins. The resins can be used alone or in combination of two or more.

[0056] <Additives> The coating composition and top coat composition of the present invention may contain known additives as appropriate, such as sensitizers, polymerization initiators, polymerization inhibitors, fluorescent brighteners, curing agents, coupling agents, plasticizers, leveling agents, surface conditioners, antifoaming agents, substrate wetting agents, antistatic agents, extender pigments, pigment dispersants, rust inhibitors, antibacterial agents, and antiviral agents.

[0057] <Solvent> The coating composition and top coat composition of the present invention preferably contain substantially no organic solvents or water, which means that the amount of organic solvents or water contained is 3% or less, more preferably 1% or less, based on the total mass of the coating.

[0058] <Viscosity> The viscosity of the coating composition and top coat composition of the present invention is not particularly limited and can be appropriately set depending on the coating method. For example, in the case of coating with 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. A viscosity at 25°C within the above range provides excellent coating and printing suitability. The viscosity was measured using a viscoelasticity measuring device (Discovery HR-2, manufactured by TA Instruments Japan) 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 After 60 seconds, the shear rate was increased to 100 sec -1 When the shear rate reaches 100 sec -1 This refers to the measurement value at the time.

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

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

[0061] <Top coat layer> The top coat layer of the present invention is formed by curing an active energy ray top coat composition under an inert gas atmosphere, and can be formed by applying the top coat composition onto a colored layer and curing it under an inert gas atmosphere. The top coat layer of the present invention is formed by curing an electron beam curable top coat composition, and can be formed by applying the top coat composition onto the colored layer and curing it with electron beams. The thickness of the top coat layer can be selected appropriately depending on the application, but is preferably 1 to 50 μm, more preferably 5 to 20 μm. The top coat layer is located as the outermost layer of the laminate and provides functions such as resistance and design depending on the application of the coating film. The performance required of the top coat includes transparency that allows the underlying paint layer to be visible, as well as the ability to protect the paint layer, such as scratch resistance, weather resistance, moist heat resistance, stain resistance, and chemical resistance.

[0062] <Coating method> The coating composition and top coat composition of the present invention can be applied by 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, silk screen coating, wire bar coating, flow coating, comma coating, and spray coating. Among these, roll coating and reverse roll coating are more preferred in terms of high productivity. Furthermore, when used after dilution with a solvent, the solvent on the coating surface must be thoroughly dried and volatilized before curing by irradiation with active energy rays.

[0063] <Curing method> The method for curing the coating composition and top coat 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 any known method can be used. Electron beam curing is more preferred. When curing by ultraviolet irradiation, the incorporation of a photopolymerization initiator is essential. The photopolymerization initiator is not particularly limited, and known photopolymerization initiators can be used as appropriate.

[0064] Curing properties are improved by performing UV curing under an inert gas atmosphere. Known inert gases such as nitrogen, helium, neon, and argon can be used as the inert gas. Nitrogen gas is preferred for its economical and readily available properties. The inert gas concentration is preferably 99% by volume or more, more preferably 99.9% by volume or more. Electron beam curing is typically performed under an inert gas atmosphere. Curing by electron beam irradiation is preferred because it is not subject to curing inhibition caused by blocking of UV rays, etc., which occurs with high pigment concentrations or the incorporation of UV absorbers. Furthermore, since no initiator is required, the effects of the present invention can be maximized without shortening the paint's pot life or causing deterioration of coating film performance due to initiator decomposition products after curing. As with UV curing, nitrogen gas is preferred as the inert gas. The inert gas concentration is preferably 99% by volume or more, more preferably 99.9% by volume or more.

[0065] Curing with electron beams is preferably carried out by irradiating with electron beams at 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 remains unchanged but the energy cost increases, making it economically unreasonable. If the acceleration voltage is too low, the adhesion of the coating material improves 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 top coat layer in this order, but it is also preferable that the laminate further includes a pattern layer and an anchor layer. The design layer can be provided between the colored layer and the top coat layer and can be formed by a printing method such as gravure printing or offset printing. The anchor layer can be provided between the substrate and the colored layer and can be formed by various coating methods. The anchor layer is preferably formed from an active energy ray-curable composition. [Example]

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

[0068] [Preparation of active energy ray-curable coating composition] Active energy ray-curable coating compositions B1 to B15 were prepared by mixing the raw materials at room temperature with a disperser stirring (3000 rpm) according to the formulations shown in Table 1. The numbers in Table 1 indicate the blend amounts (parts by mass).

[0069] [Preparation of active energy ray-curable top coat composition] Active energy ray-curable top coat compositions T1 to T7 were prepared by mixing the raw materials at room temperature with a disperser at 3000 rpm according to the formulations shown in Table 2. The numbers in Table 2 indicate the blend amounts (parts by mass).

[0070] [Preparation of active energy ray-curable comparative composition] Actinic ray-curable comparative compositions T8 to T9 were prepared by mixing the raw materials at room temperature with a disper stirrer (3000 rpm) according to the formulations shown in Table 2. The numbers in Table 2 indicate the blend amounts (parts by mass).

[0071] [Laminate fabrication] Example 1 The obtained active energy ray-curable coating composition B1 was applied to a substrate, Galvalume steel sheet (registered trademark, Yodogawa Steel Works, Yodo GL Eco Green, thickness 0.27 mm) using a bar coater #8 (coating thickness approximately 12 μm). Subsequently, using an electron beam irradiation device i-Compact EB (Iwasaki Electric Co., Ltd., acceleration voltage 90 kV, exposure dose 100 kGy), electron beams were irradiated in a nitrogen atmosphere (99.95% by volume) to cure the coating composition and form a colored layer. Furthermore, active energy ray-curable top coat composition T1 was applied to the colored layer using a bar coater #8 so as to overlap it partially (coating thickness approximately 12 μm). The colored layer was covered with a metal plate to shield the portion not coated with the top coat composition from the electron beam. Using an electron beam irradiation device i-Compact EB (manufactured by Iwasaki Electric Co., Ltd., acceleration voltage 90 kV, exposure dose 100 kGy), electron beams were irradiated in a nitrogen atmosphere (99.95% by volume) to cure the top coat composition, producing the laminate of Example 1. The interlayer adhesion and weather resistance of the resulting laminate were evaluated in the portions where the colored layer and top coat layer were laminated. In addition, the pencil hardness was evaluated in the portion where the top coat layer was not laminated and the colored layer was exposed. The results are shown in Table 3.

[0072] (Examples 2 to 17, Comparative Examples 1 to 4) Except for the changes shown in Tables 3 and 4, laminates of Examples 2 to 17 and Comparative Examples 1 to 4 were produced and evaluated in the same manner as in Example 1. The results are shown in Tables 3 and 4.

[0073] [Interlayer adhesion (cross-cut test)] The laminate was scratched with a cutter in 11 lines vertically and horizontally at 1 mm intervals. A 12 mm wide adhesive tape (Nichiban Co., Ltd., cellophane tape) was attached to these areas and peeled off at a 90° angle to the laminate three times. The results were evaluated according to the following criteria. A: The top coat layer did not peel off at all. B: The topcoat layer was partially peeled off, and the coating film remaining rate was 70% or more. C: The topcoat layer was partially peeled off, and the remaining coating rate was 30% or more and less than 70%. D: The topcoat layer was partially peeled off, and the coating film remaining rate was less than 30%. The practical range is A to C.

[0074] [Visibility] In the area where the top coat layer was laminated, it was confirmed whether the boundary line between the area where the colored layer was present underneath the top coat layer and the area where it was not present was visible, and the result was evaluated according to the following evaluation criteria. A: The boundary line is clearly visible and the top coat layer is highly visible. B: The boundary line is difficult to distinguish, and the top coat layer is not 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 test pieces were subjected to an irradiation process in which ultraviolet light was irradiated for 102 minutes under irradiation conditions of a black panel temperature of 63°C, and a shower process in which water was sprayed for 18 minutes while irradiating with ultraviolet light under the same irradiation conditions, and the surface condition of the test pieces after 700 hours was evaluated according to the following evaluation criteria. A: No abnormalities or very small surface abnormalities B: Minor surface abnormalities C: A large amount of surface abnormalities occurs Abnormality refers to a decrease in gloss or the occurrence of blisters (partial swelling of the coating film), and the ranges A and B are acceptable for practical use.

[0076] [Pencil hardness of colored layer] A scratch test was performed on the colored layer (cured coating film) in accordance with JIS K5600-5-4, in which pencils of various hardnesses were placed on the surface of the cured coating film at a 45° angle and a load of 250 g was applied. The hardness of the hardest pencil that did not cause a scratch was taken as the pencil hardness, and the test was evaluated according to the following criteria. A:B~2H. B: 4B~2B or 3H~4H. C: 5B or less or 5H or more. The practical ranges are A and B.

[0077] The information on each raw material in Tables 1 and 2 is as follows: (coloring agent) Mogul E: Carbon black, manufactured by Cabot Corporation Typaque CR58-2: Titanium oxide, manufactured by Ishihara Sangyo Kaisha (dispersant) Solsperse 32000: Copolymer containing acid groups, manufactured by Lubrizol DisperBYK111: Copolymer containing acid groups, manufactured by BYK (Radical polymerizable compound) EBECRYL8402: Aliphatic urethane acrylate, bifunctional, manufactured by Daicel Allnex Co., Ltd. EBECRYL210: Aromatic urethane acrylate, bifunctional, manufactured by Daicel Allnex Co., Ltd. EBECRYL1290: Aliphatic urethane acrylate, hexafunctional, manufactured by Daicel Allnex Co., Ltd. TBCHA: 4-tert-butylcyclohexyl acrylate, manufactured by KJ Chemicals FA513AS: Dicyclopentanyl acrylate, manufactured by Resonac MEDOL-10: (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd. Aronix 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 (nitrogen-containing polymerizable compound) 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 Resonac (secondary thiol) PEMP: Pentaerythritol tetrakis(3-mercaptopropionate), manufactured by CS Organic Chemicals (primary thiol) (ultraviolet absorber) Tinuvin 479: Hydroxyphenyltriazine UV absorber, manufactured by BASF (light stabilizer) ADK STAB 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 and 4, Examples 1 to 17 of the laminates of the present invention were good in interlayer adhesion, visibility, and weather resistance, whereas Comparative Examples 1 to 4 were insufficient in at least one of interlayer adhesion and visibility.

Claims

1. A laminate comprising a substrate, a colored layer obtained by curing an active energy ray-curable coating composition with an electron beam or with ultraviolet light in an inert gas atmosphere, and a top coat layer obtained by curing an active energy ray-curable top coat composition with an electron beam or with ultraviolet light in an inert gas atmosphere, A laminate in which 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.

2. 2. The laminate according to claim 1, wherein the nitrogen atom-containing polymerizable compound is a polymerizable compound containing an N-vinyl group and / or acrylamide.

3. 3. The laminate according to claim 1, wherein the sulfur atom-containing polymerizable compound contains a mercapto group.

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

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

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

7. The laminate according to claim 1 or 2, wherein the active energy ray-curable top coat composition contains a urethane (meth)acrylate.

8. The laminate according to claim 7, wherein the urethane (meth)acrylate comprises an aliphatic urethane (meth)acrylate.

9. 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 top coat composition.

10. A method for producing a laminate, comprising: 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; curing the coating composition with an electron beam or with ultraviolet light in an inert gas atmosphere to form a colored layer; applying an active energy ray-curable top coat composition onto the colored layer; and curing the coating composition with an electron beam or with ultraviolet light in an inert gas atmosphere to form a top coat layer.

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