JP5786414B2 - Decorative sheet and method for producing the same - Google Patents

Description

  The present invention relates to a decorative sheet and a method for producing the decorative sheet.

As a decorative board used for furniture, kitchen product cabinets, floor tiles, wall panels, kitchen sinks, etc., a sheet of wood grain pattern printed on a building material board is generally bonded with an adhesive. It is used for. And for sheets used for such decorative boards, use of processing suitability such as flexibility, machinability, fracture resistance, stain resistance, scratch resistance, water resistance, chemical resistance, weather resistance, etc. Various characteristics such as suitability are required.
In addition, due to the recent trend toward high-end products by consumers, there is a demand for high-grade seats and decorative boards used for the above-mentioned applications. Therefore, for such a sheet, design properties such as high glossiness and specularity that give a high-class feeling are important in addition to the processing suitability and use suitability generally required conventionally.
As a method for producing a sheet having such processability and suitability for use and capable of imparting designability to a molded article, Patent Document 1 listed below discloses protection comprising a release sheet and an ionizing radiation curable resin. A method for producing a transfer sheet in which a layer is formed and cured in a specific oxygen concentration atmosphere and then irradiated with ionizing radiation is described (Patent Document 1).

Japanese Patent No. 2649051

Since the transfer sheet manufactured by the method described in Patent Document 1 does not have a substrate, there is room for improvement in suitability for use. As a method for improving the suitability for use, for example, in a single-layer structure sheet using only one substrate, the suitability is improved by increasing the amount of material provided on the substrate and increasing the thickness of the entire sheet. Examples thereof include a method and a method of improving the suitability for use by forming a multilayer structure sheet using two substrates. However, in any of the methods, the thickness of the sheet is often increased, which causes a problem that the workability is lowered. Therefore, development of a sheet that solves such problems and has all of the above characteristics at a high level is desired.
This invention is made | formed in view of the said conventional subject, Comprising: It aims at providing the decorative sheet which has all processability, useability, and designability on a high level, and its manufacturing method.

As a result of intensive research to achieve the above object, the present inventors have found that when the surface protective layer of the decorative sheet has a certain thickness or more, curling or cracking occurs in the transfer film, resulting in reduced processability. On the contrary, it was found that if the thickness and hardness of the transfer film are increased in order to suppress the curling of the transfer film, the followability during processing of the decorative sheet is lowered and the float tends to occur. . Furthermore, it has been found that even when a base material is provided in order to improve the suitability for use and the base material has a certain thickness or more, the followability at the time of processing is lowered and floating occurs.
Based on these findings, the present inventors have conducted further research to improve the suitability for use, the suitability for processing, and the designability. In addition to defining the thickness of the surface protective layer, transfer film, and substrate, The inventors have found that an unprecedented decorative sheet exhibiting excellent properties can be obtained at the same time by setting the elastic modulus of the material and the wetting index of the transfer film to specific values, thereby completing the present invention.
The gist of the present invention is as follows.

[1] A makeup comprising, in this order, at least an adhesive layer, a colored concealing layer, a pattern layer, a primer layer, a surface protective layer obtained by crosslinking and curing an ionizing radiation curable resin composition, and a transfer film. A sheet having a thickness of 100 to 350 μm, an elastic modulus of the substrate of 800 to 8000 MPa, a thickness of the surface protective layer of 2 to 20 μm, and A decorative sheet having a thickness of 20 to 200 μm and a wetting index of the transfer film of 30 to 55 mN / m.
[2] On the substrate, at least an adhesive layer, a colored hiding layer, a pattern layer, a primer layer, a surface protective layer formed by crosslinking and curing an ionizing radiation curable resin composition, and a transfer film are provided in this order, The base material has a thickness of 100 to 350 μm, the base material has an elastic modulus of 800 to 8000 MPa, the surface protective layer has a thickness of 2 to 20 μm, and the transfer film has a thickness of 20 to 200 μm. And a transfer sheet having a wetting index of 30 to 55 mN / m, wherein a heat-sensitive adhesive constituting the adhesive layer is applied to the colored concealing layer and the heat-sensitive adhesive is heated. Then, after superposing the heat-sensitive adhesive application surface of the colored concealing layer and the base material, they are bonded by cooling, a method for producing a decorative sheet.
[3] On the substrate, at least an adhesive layer, a colored hiding layer, a pattern layer, a primer layer, a surface protective layer obtained by crosslinking and curing an ionizing radiation curable resin composition, and a transfer film are provided in this order, The base material has a thickness of 100 to 350 μm, the base material has an elastic modulus of 800 to 8000 MPa, the surface protective layer has a thickness of 2 to 20 μm, and the transfer film has a thickness of 20 to 200 μm. And a transfer sheet having a wetting index of 30 to 55 mN / m, the thermosetting adhesive constituting the adhesive layer being applied to the colored concealing layer, A method for producing a decorative sheet, comprising: superposing a thermosetting adhesive application surface and a base material;

  ADVANTAGE OF THE INVENTION According to this invention, the decorative sheet which has all processability, useability, and designability at a high level, and its manufacturing method can be provided.

It is a schematic diagram which shows the cross section of the decorative sheet of this invention. It is a schematic diagram which shows the cross section of the decorative board using the decorative sheet of this invention.

[Decorative sheet]
The decorative sheet of the present invention has a thickness of 100 to 350 μm and a modulus of elasticity of 800 to 8000 MPa, and at least an adhesive layer, a colored hiding layer, a pattern layer, a primer layer, and a thickness of 2 to 20 μm. A decorative sheet comprising a surface protective layer and a transfer film having a thickness of 20 to 200 μm and a wetting index of 30 to 55 mN / m in this order, and as described above, only the thickness of each layer In addition, since the elastic modulus of the substrate and the wetting index of the transfer film are also defined, the present invention exhibits extremely excellent characteristics in all of processing suitability, use suitability, and designability.

  In the decorative sheet having a single-layer structure as in the present invention, if the thickness and physical properties of each material constituting the layer are changed, the characteristics of the entire decorative sheet are greatly changed. It was extremely difficult to produce a decorative sheet having excellent design properties. However, the present inventors have come to obtain the decorative sheet of the present invention by defining the thickness, elastic modulus, wetting index, etc. of various materials for such problems.

  Hereinafter, the specific layer structure and the material of each layer of the decorative sheet of the present invention will be described with reference to FIG. A decorative sheet 1 shown in FIG. 1 has a surface protection formed by crosslinking and curing an adhesive layer 3 covering a whole surface 2, a colored hiding layer 4, a pattern layer 5, a primer layer 6, and an ionizing radiation curable resin composition. The layer 7 and the transfer film 8 are laminated in this order, and a back primer layer 9 is provided on the back surface of the substrate 2. In the present invention, other layers may exist between the layers.

"Base material"
The material of the base material used in the present invention may be any material as long as it satisfies the thickness and elastic modulus described below, and various plastic films, plastic sheets, metal foils, metal sheets, metal plates Etc. can be appropriately selected depending on the application. Each of these materials may be used alone, but a laminate of any combination of the plates may be used. Among these materials, plastic films and plastic sheets made of olefin resins, acrylic resins, PVC resins, polyester resins and the like are preferable. From the viewpoint of production cost and environmental impact during production, olefin resins Is preferred.
When such a plastic film or plastic sheet is used as a base material, a physical method such as an oxidation method or a concavo-convex method on one or both sides may be used if desired in order to improve the adhesion with the layer provided on the plastic film or plastic sheet. Or it is preferable to perform a chemical surface treatment.
Examples of the oxidation method include corona discharge treatment, chromium oxidation treatment, flame treatment, hot air treatment, and ozone-ultraviolet treatment method. Examples of the unevenness method include a sand blast method and a solvent treatment method. These surface treatments are appropriately selected depending on the type of substrate, but in general, the corona discharge treatment method is preferable from the viewpoints of effects and operability.
In addition, the base material may be subjected to a treatment such as forming a primer layer for strengthening the interlayer adhesion between the base material and each layer, painting for adjusting the color, or a pattern from a design standpoint. May be formed in advance.
As the substrate, a substrate having a thickness of 100 to 350 μm and an elastic modulus of 800 to 8000 MPa is used. When the thickness of the base material is less than 100 μm, the concealing property is lowered, and it becomes easy to pick up the unevenness of the substrate when processed as a decorative plate, so that the surface smoothness is lowered and the pencil hardness is also lowered. On the other hand, when the thickness of the base material exceeds 350 μm, the decorative sheet becomes thick and it becomes difficult to form a roll. As thickness of this base material, 150-300 micrometers is more preferable, and 150-250 micrometers is still more preferable. On the other hand, when the elastic modulus is less than 800 MPa, the pencil hardness is lowered, and when the elastic modulus exceeds 8000 MPa, the stiffness of the base material becomes too large to make it difficult to roll, and the processability at the time of manufacture is significantly lowered. The elastic modulus of this base material is more preferably 1000 to 4000 MPa, and still more preferably 1000 to 2000 MPa. In the present invention, the elastic modulus is a value measured according to JIS K 7161-5-4.

  As a plastic film or a plastic sheet, what consists of various synthetic resins is mentioned. Synthetic resins include polyethylene resin, polypropylene resin, polymethylpentene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, vinyl chloride-vinyl acetate copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene-vinyl. Representative examples include alcohol copolymer resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate-isophthalate copolymer resin, polymethyl methacrylate resin, polyethyl methacrylate resin, polybutyl acrylate resin, nylon 6 or nylon 66 And polyamide resin, cellulose triacetate resin, cellophane, polystyrene resin, polycarbonate resin, polyarylate resin, polyimide resin, and the like.

  As metal foil, a metal sheet, or a metal plate, what consists of aluminum, iron, stainless steel, or copper, for example can be used, and what gave these metals by plating etc. can also be used. In addition to these, composites of various materials, such as fiber reinforced plastic (FRP) plates, paper honeycombs with iron plates pasted on both sides, and two aluminum plates sandwiched with polyethylene resin can also be used as the base material. .

<Adhesive layer>
In the present invention, the adhesive layer 3 is provided between the substrate 2 and the colored hiding layer 4. A layer other than the adhesive layer 3 may exist between the base material 2 and the colored hiding layer 4.
Although there is no restriction | limiting in particular as an adhesive agent used for a contact bonding layer, A thermosetting adhesive or a heat sensitive adhesive is preferable from the manufacturing process of this invention.

  The thermosetting adhesive preferably includes a composition having a property of causing a chemical reaction by heat to cause crosslinking, such as a two-component curable urethane adhesive, a polyester urethane adhesive, or a polyether urethane. -Based adhesives, acrylic adhesives, polyester-based adhesives, polyamide-based adhesives, polyvinyl acetate-based adhesives, epoxy-based adhesives, rubber-based adhesives, etc. A urethane-based adhesive is preferred. By using a two-component curable urethane adhesive, a stronger adhesive strength can be obtained, and a decorative sheet excellent in flexibility can be provided. Here, the urethane-based resin constituting the two-component curable urethane-based adhesive is a polyurethane having a polyol (polyhydric alcohol) as a main component and an isocyanate as a crosslinking agent (curing agent).

The polyol has two or more hydroxyl groups in the molecule. Examples of the polyol include polyethylene glycol, polypropylene glycol, butylene glycol, neopentyl glycol, 1,6-hexanediol, acrylic polyol, polyester polyol, polyether polyol, and the like.
As the isocyanate, those usually used in the production of polyurethane can be used in the present invention. Examples of the isocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, lysine ester triisocyanate, 1,4,8-triisocyanate octane, 1,3,6-triisocyanate hexane, 2,5 Aliphatic polyisocyanates such as 1,7-trimethyl-1,8-diisocyanate-5-isocyanate methyloctane, 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanate methyl-3 , 5,5-trimethylcyclohexyl isocyanate (common name: isophorone diisocyanate), 1,3,5-triisocyanate cyclohexane, , 3,5-trimethylisocyanatocyclohexane, 2- (3-isocyanatopropyl) -2,5-di (isocyanatomethyl) -bicyclo (2,2,1) heptane, etc., 1,3- or Aroaliphatic polyisocyanates such as 1,4-xylylene diisocyanate or mixtures thereof, 1,3- or 1,4-bis (1-isocyanate-1-methylethyl) benzene, 1,3,5-triisocyanate methylbenzene , M-phenylene diisocyanate, p-phenylene diisocyanate, triphenylmethane-4,4 ′, 4 ″ -triisocyanate, 4,4′-diphenylmethane-2,2 ′, 5,5′-tetraisocyanate, etc. Isocyanates and derivatives of these polyisocyanates are used. These polyisocyanates may be used alone or in combination of two or more of these polyisocyanates, including aliphatic polyisocyanates, alicyclic polyisocyanates and araliphatic polyisocyanates, And these polyisocyanate derivatives, etc. These polyisocyanates are excellent in safety, hygiene and weather resistance.

  In the case of using the thermosetting adhesive, the solvent used as a coating agent is not particularly limited. For example, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl Examples thereof include water-insoluble organic solvents such as ether, water-soluble organic solvents such as methanol, ethanol, isopropyl alcohol, and normal propyl alcohol, water, and mixed solvents thereof. In addition, as a coating agent, it is also possible to use the solventless type coating agent which does not use a solvent. Solventless type coating agents are those that are environmentally friendly and are preferably used.

  In the case of using a solvent, the coating agent (adhesive) in the case of forming an adhesive layer with a thermosetting adhesive contains a resin composition and, if necessary, other additives in the solvent. It is prepared by dissolving, dispersing and mixing by a method.

  In the case of forming an adhesive layer with a thermosetting adhesive, for example, the above-described coating agent (adhesive) is applied on the colored concealing layer, and after forming the adhesive layer, the base material to be bonded is laminated to 30 to 120 By aging at a temperature of several hours to several days, it can be formed by curing the adhesive.

  The heat-sensitive adhesive is generally an adhesive mainly composed of a thermoplastic resin that is solid at normal temperature, melts or softens by heating, develops adhesiveness, and solidifies and solidifies when cooled. Say. This is dissolved in an appropriate solvent or melted by heating, applied to one or both adhesive surfaces of the adherend, heated and superposed, and then cooled to adhere. is there.

  Examples of the heat-sensitive adhesive include (meth) acrylic resin-based, polyurethane resin-based, polyester-based, polyamide resin-based, (meth) acrylic acid ester-olefin copolymer resin, vinyl acetate resin, ethylene-vinyl acetate copolymer Easy-adhesion resin alone such as coalescence resin, ionomer resin, olefin-α-olefin copolymer resin, and thermoplastic resin that is the main component of olefin resin and foamed resin composition, and thermoplastic resin that is the main component of the film layer A blend product is mentioned.

In any adhesive, various known methods such as roll coating, gravure coating, air knife coating, comma coating and the like are used as the coating method, and gravure coating and comma coating are preferable from the viewpoint of productivity. Used.
The adhesive layer is preferably applied so that the coating amount is 0.1 to 20 g / m ² , preferably about 1 to 10 g / m ² .

<Coloring hiding layer>
In the present invention, the colored hiding layer 4 is provided for the purpose of improving the design of the decorative sheet and improving the adhesion between the base material and the picture layer. The colored masking layer 4 can adjust the color of the surface by giving an intended color when the base material 2 is colored or has color unevenness. The colored concealing layer is usually formed with an opaque color for the purpose of concealing the base material or the base, but it can also be formed with a colored transparent color to make use of the pattern possessed by the base or the base.

As the ink used for forming the colored hiding layer, an ink obtained by appropriately mixing a binder, a colorant such as a pigment or a dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, or a curing agent is used. The binder is not limited. For example, polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-acrylic copolymer resin, chlorinated polypropylene resin, acrylic resin, polyester-based resin. Any of resin, polyamide-based resin, butyral-based resin, polystyrene-based resin, nitrocellulose-based resin, cellulose acetate-based resin and the like may be used alone or in combination of two or more.
The colorant may be appropriately selected from the use of the decorative sheet and the color compatibility with the pattern layer. For example, carbon black (black), iron black, titanium white, antimony white, yellow lead, titanium yellow, and petal , Inorganic pigments such as cadmium red, ultramarine, and cobalt blue, organic pigments or dyes such as quinacridone red, isoindolinone yellow, and phthalocyanine blue, metal pigments made of scaly foil pieces such as aluminum and brass, titanium dioxide-coated mica, base And nacreous (pearl) pigments composed of scaly foil pieces such as conductive lead carbonate.
The thickness of the colored hiding layer 4 is preferably 0.5 to 20 μm, more preferably 1 to 10 μm, and still more preferably 1 to 6 μm.

《Picture layer》
The pattern layer 5 shown in FIG. 1 gives decorativeness to the decorative sheet, and is formed by printing various patterns using ink and a printing machine. The pattern can be formed by multicolor printing with normal yellow, red, blue, and black process colors, or by multicolor printing with special colors prepared by preparing individual color plates constituting the pattern. Is done. As the pattern ink used for the pattern layer, the same ink as that used for the colored hiding layer 4 can be used.

<< Primer layer >>
The primer layer is used for the purpose of improving the adhesion between the respective layers, but preferably also fulfills a function of imparting sufficient weather resistance to the decorative sheet.
As the ink used for forming the primer layer, an ink in which an extender, a solvent, a stabilizer, a plasticizer, a catalyst, a curing agent and the like are appropriately mixed with the binder is used as necessary. The binder is not limited, and examples thereof include ester resins, urethane resins, acrylic resins, urethane-acrylic copolymer resins, polycarbonate resins, vinyl chloride-vinyl acetate copolymers, polyvinyl butyral resins, and nitrocellulose resins. These resins may be used alone or in combination of two or more. There is no limitation on the method for applying the primer layer. For example, one or two or more resins are used as a coating composition or ink composition using a solvent or the like, and an appropriate application means such as a roll coating method or a gravure printing method is used. Can be formed.

It is preferable to add a weather resistance improver to the resin composition constituting the primer layer from the viewpoint of improving the weather resistance of the decorative sheet 1. Examples of the weather resistance improver include an ultraviolet absorber (hereinafter sometimes referred to as “UVA”) and a light stabilizer. The ultraviolet absorber (UVA) absorbs harmful ultraviolet rays and improves the long-term weather resistance and stability of the decorative sheet 1 of the present invention. In addition, the light stabilizer itself absorbs little ultraviolet light, but stabilizes by efficiently capturing harmful free radicals generated by ultraviolet energy.
These ultraviolet absorbers may be either inorganic or organic, and as the inorganic ultraviolet absorber, titanium dioxide, cerium oxide, zinc oxide or the like having an average particle diameter of about 5 to 120 nm can be preferably used. . Examples of the organic ultraviolet absorber include benzotriazole-based compounds, specifically 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-tert-). Amylphenyl) benzotriazole, 3- [3- (benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl] propionic acid ester of polyethylene glycol, and triazines, specifically 2- ( 4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] phenol, 1,3,5-triazine-2,4,6 (1H, 3H, 5H)- And trione, 1,3,5-tri [[3,5-bis- (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] and the like.

  The ultraviolet absorber can be blended easily by kneading into a resin or the like constituting the primer layer, or by dissolving or dispersing the ultraviolet absorber in a solvent or the like and applying it to the primer layer. It is preferable to contain this ultraviolet absorber in the range of 6-15 mass% in the solid content of a primer layer. When the amount is 6% by mass or more, a sufficient ultraviolet absorption effect can be obtained, and a decrease in adhesion between the primer layer and the substrate 2 does not occur even in a weathering accelerated test or the like. Further, when the content is 15% by mass or less, the ultraviolet absorber does not bleed out. From the above points, the content of the ultraviolet absorber is preferably in the range of 8 to 13% by mass.

Next, as the light stabilizer, for example, hindered amine (HALS), specifically, 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, tetrakis (2,2,6,6-tetramethyl-4) -Piperidyl) -1,2,3,4-butanetetracarboxylate and the like. Moreover, as a commercial item, the product name "Tinubin 123" by Ciba Specialty Chemicals, etc. are mentioned.
In addition, as the ultraviolet absorber or light stabilizer, a reactive ultraviolet absorber or light stabilizer having a polymerizable group such as a (meth) acryloyl group in the molecule can be used.

  The thickness of the primer layer is preferably 0.5 to 20 μm. When the thickness of the primer layer is within the above range, sufficient adhesion and weather resistance can be obtained, and further, cracking hardly occurs during processing. From the above points, the thickness of the primer layer is more preferably 1 to 20 μm, more preferably 1 to 10 μm, and still more preferably 1 to 6 μm.

≪Back primer layer≫
The base material 2 may be provided with a primer layer 9 on the back surface for the purpose of improving adhesiveness with various adherends. It does not specifically limit as a material used for formation of the back surface primer layer 9, An acrylic resin, a vinyl chloride-vinyl acetate copolymer, polyester, polyurethane, chlorinated polypropylene, chlorinated polyethylene etc. are mentioned. The material used for the back primer layer 9 is appropriately selected depending on the adherend.

<Surface protective layer>
As described above, the surface protective layer 7 has a specific thickness, and is obtained by crosslinking and curing the ionizing radiation curable resin composition. The ionizing radiation curable resin composition has an energy quantum capable of crosslinking and polymerizing molecules in electromagnetic waves or charged particle beams, that is, crosslinked and cured by irradiation with ultraviolet rays or electron beams. It refers to a resin composition.

  This surface protective layer imparts suitability for use to the decorative sheet, such as stain resistance, scratch resistance, water resistance, chemical resistance, and weather resistance, depending on the application. And by making a surface protective layer into the said layer thickness, the especially outstanding peeling strength can be provided to a decorative sheet.

(Ionizing radiation curable resin composition)
As the ionizing radiation curable resin used for the surface protective layer, a conventionally known compound may be appropriately used. Specifically, it can be appropriately selected from polymerizable monomers, polymerizable oligomers or prepolymers conventionally used as ionizing radiation curable resin compositions.
Typically, a (meth) acrylate monomer having a radically polymerizable unsaturated group in the molecule is suitable as the polymerizable monomer, and polyfunctional (meth) acrylate is particularly preferable. The polyfunctional (meth) acrylate is not particularly limited as long as it is a (meth) acrylate having two or more ethylenically unsaturated bonds in the molecule.
Specifically, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) ) Acrylate, polyethylene glycol di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified diphosphate ( (Meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene oxide modified trimethylo Propane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris ( (Acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ethylene oxide modified dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate, Examples include ethylene oxide-modified bisphenol A diacrylate. These polyfunctional (meth) acrylates may be used alone or in combination of two or more.

In the present invention, together with the polyfunctional (meth) acrylate, a monofunctional (meth) acrylate can be appropriately used in combination as long as the object of the present invention is not impaired for the purpose of reducing the viscosity.
Examples of the monofunctional (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, and cyclohexyl (meth) ) Acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, and the like. These monofunctional (meth) acrylates may be used alone or in combination of two or more.

Next, as the polymerizable oligomer, an oligomer having a radical polymerizable unsaturated group in the molecule, for example, epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, polyether (meth) acrylate And the like.
The epoxy (meth) acrylate oligomer can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin and esterifying it. Further, a carboxyl-modified epoxy (meth) acrylate oligomer obtained by partially modifying this epoxy (meth) acrylate oligomer with a dibasic carboxylic acid anhydride can also be used.
The urethane (meth) acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by a reaction between a polyether polyol or a polyester polyol and a polyisocyanate with (meth) acrylic acid.
Polyester (meth) acrylate oligomers include, for example, esterifying hydroxyl groups of polyester oligomers having hydroxyl groups at both ends obtained by condensation of polyvalent carboxylic acid and polyhydric alcohol with (meth) acrylic acid, It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding an alkylene oxide to a carboxylic acid with (meth) acrylic acid.
The polyether (meth) acrylate oligomer can be obtained by esterifying the hydroxyl group of the polyether polyol with (meth) acrylic acid.

  Furthermore, other polymerizable oligomers include polybutadiene (meth) acrylate oligomers with high hydrophobicity having (meth) acrylate groups in the side chain of polybutadiene oligomers, and silicone (meth) acrylate oligomers having polysiloxane bonds in the main chain. In an aminoplast resin (meth) acrylate oligomer modified with an aminoplast resin having many reactive groups in a small molecule, or in a molecule such as a novolac type epoxy resin, bisphenol type epoxy resin, aliphatic vinyl ether, aromatic vinyl ether, etc. There are oligomers having a cationic polymerizable functional group.

When an ultraviolet curable resin composition is used as the ionizing radiation curable resin composition, it is desirable to add about 0.1 to 5 parts by mass of the photopolymerization initiator with respect to 100 parts by mass of the resin composition. The initiator for photopolymerization can be appropriately selected from those conventionally used and is not particularly limited. For example, for a polymerizable monomer or polymerizable oligomer having a radically polymerizable unsaturated group in the molecule. Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2 -Phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propane-1 - 4- (2-hydroxyethoxy) phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4′-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2 -Tertiary butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, etc. It is done.
Examples of the polymerizable oligomer having a cationic polymerizable functional group in the molecule include aromatic sulfonium salts, aromatic diazonium salts, aromatic iodonium salts, metallocene compounds, and benzoin sulfonic acid esters.
Moreover, as a photosensitizer, p-dimethylbenzoic acid ester, tertiary amines, a thiol type sensitizer, etc. can be used, for example.
In the present invention, it is preferable to use an electron beam curable resin composition as the ionizing radiation curable resin composition. The electron beam curable resin composition can reduce the amount of solvent used, is more preferable from the viewpoint of environment and health, and does not require a photopolymerization initiator, and can provide stable curing characteristics. It is.

Moreover, various additives can be mix | blended with the ionizing radiation-curable resin composition in this invention according to the desired physical property of the cured resin layer obtained. Examples of this additive include a weather resistance improver, an abrasion resistance improver, a polymerization inhibitor, a crosslinking agent, an infrared absorber, an antistatic agent, an adhesion improver, a leveling agent, a thixotropic agent, a coupling agent, A plasticizer, an antifoamer, a filler, a solvent, a coloring agent, etc. are mentioned.
Here, as the weather resistance improving agent, an ultraviolet absorber or a light stabilizer can be used. The ultraviolet absorber may be either inorganic or organic. As the inorganic ultraviolet absorber, titanium dioxide, cerium oxide, zinc oxide or the like having an average particle size of about 5 to 120 nm can be preferably used. Examples of the organic ultraviolet absorber include benzotriazole-based compounds, specifically 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-tert-). Amylphenyl) benzotriazole, 3- [3- (benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl] propionic acid ester of polyethylene glycol, and the like. On the other hand, examples of the light stabilizer include hindered amines, specifically 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, tetrakis (2,2,6,6-tetramethyl-4-piperidyl)- 1,2,3,4-butanetetracarboxylate and the like. In addition, as the ultraviolet absorber or light stabilizer, a reactive ultraviolet absorber or light stabilizer having a polymerizable group such as a (meth) acryloyl group in the molecule can be used.

Examples of the wear resistance improver include, for inorganic substances, spherical particles such as α-alumina, silica, kaolinite, iron oxide, diamond, and silicon carbide. Examples of the particle shape include a sphere, an ellipsoid, a polyhedron, a scale shape, and the like. Although there is no particular limitation, a spherical shape is preferable. Organic materials include synthetic resin beads such as cross-linked acrylic resin and polycarbonate resin. The particle size is usually about 30 to 200% of the film thickness. Among these, spherical α-alumina is particularly preferable because it has high hardness and a large effect on improving wear resistance, and it is relatively easy to obtain spherical particles.
Examples of the polymerization inhibitor include hydroquinone, p-benzoquinone, hydroquinone monomethyl ether, pyrogallol, and t-butylcatechol. Examples of the crosslinking agent include a polyisocyanate compound, an epoxy compound, a metal chelate compound, an aziridine compound, and an oxazoline compound. Used.
As the filler, for example, barium sulfate, talc, clay, calcium carbonate, aluminum hydroxide and the like are used.
Examples of the colorant include known coloring pigments such as quinacridone red, isoindolinone yellow, phthalocyanine blue, phthalocyanine green, titanium oxide, and carbon black.
As the infrared absorber, for example, a dithiol metal complex, a phthalocyanine compound, a diimmonium compound, or the like is used.

The ionizing radiation curable resin composition may contain silicone (meth) acrylate for the purpose of improving specularity and glossiness.
Silicone (meth) acrylate is one of modified silicone oils in which (meth) acrylic groups are introduced among silicone oils made of polysiloxane. The structure of the modified silicone oil is roughly divided into a side chain type, a double-end type, a single-end type, and a double-end side chain type depending on the bonding position of the (meth) acryl group to be substituted. There is no restriction | limiting in particular in a coupling | bonding position. Moreover, there is no restriction | limiting in particular also in the number of substitution of a (meth) acryl group, However, It is preferable to use combining silicone methacrylate and silicone acrylate.
As such silicone methacrylate, from the viewpoint of improving specularity and glossiness, mono- or bifunctional silicone methacrylate having one or two methacryl groups is preferable, molecular weight 1000 to 6000, more preferably 3000 to 6000, functional group. The equivalent (molecular weight / functional group number) is 500 to 3000, more preferably 1500 to 3000. The silicone acrylate is preferably a polyfunctional silicone acrylate having a plurality of acrylic groups, preferably 4 or more, and more preferably 4-6, having a molecular weight of 3000-100000, more preferably 10,000-30000, and a functional group equivalent ( Molecular weight / number of functional groups) From 750 to 25000, more preferably from 3000 to 6000.
The content of the monofunctional or bifunctional silicone methacrylate is 1.5 to 20 parts by mass, more preferably 2 to 4 parts by mass with respect to 100 parts by mass of the ionizing radiation curable resin, from the viewpoint of improving specularity and glossiness. It is. Moreover, content of the said polyfunctional silicone acrylate is 1-20 mass parts with respect to 100 mass parts of ionizing radiation curable resin, More preferably, it is 1-10 mass parts.
The ratio of the content of silicone methacrylate and silicone acrylate is from 1: 1 to 1: 5, more preferably from 1: 2 to 1: 3 (both mass ratios).

(Formation of surface protective layer)
In the present invention, the above-mentioned ionizing radiation curable component polymerizable monomer, polymerizable oligomer and various additives are homogeneously mixed at a predetermined ratio to prepare a coating solution comprising an ionizing radiation curable resin composition. . The viscosity of the coating solution is not particularly limited as long as it is a viscosity capable of forming an uncured resin layer on the coated surface by a coating method described later.
In the present invention, the coating solution prepared as described above is applied by adjusting the coating amount so that the thickness after curing becomes a thickness specified below. The application is performed by a known method such as gravure coating, bar coating, roll coating, reverse roll coating, comma coating, preferably gravure coating, to form an uncured resin layer.
In particular, from the viewpoint of suitability for use and design, the thickness of the surface protective layer is set to 2 to 20 μm. If the thickness of the surface protective layer is less than 2 μm, scratch resistance and specularity will not be sufficiently exhibited, and if it exceeds 20 μm, the transfer film will curl or processability (folding etc.) when plastering a decorative sheet May decrease. The thickness of the surface protective layer is more preferably from 3 to 15 μm, still more preferably from 5 to 10 μm.

In the present invention, the uncured resin layer thus formed is irradiated with ionizing radiation such as an electron beam and ultraviolet rays to cure the uncured resin layer. Here, when an electron beam is used as the ionizing radiation, the acceleration voltage can be appropriately selected according to the resin used and the thickness of the layer, but the uncured resin layer is usually cured at an acceleration voltage of about 70 to 300 kV. preferable.
In electron beam irradiation, the transmission capability increases as the acceleration voltage increases. Therefore, when using a base material that deteriorates due to the electron beam as the base material, the transmission depth of the electron beam and the thickness of the resin layer are substantially equal. By selecting the accelerating voltage so as to be equal to each other, it is possible to suppress the irradiation of the electron beam to the base material, and to minimize the deterioration of the base material due to the excessive electron beam.
The irradiation dose is preferably such that the crosslinking density of the resin layer is saturated, and is usually selected in the range of 5 to 300 kGy (0.5 to 30 Mrad), preferably 10 to 70 kGy (1 to 7 Mrad).
Furthermore, there is no restriction | limiting in particular as an electron beam source, For example, various electron beam accelerators, such as a cock loft Walton type, a bande graft type, a resonance transformer type, an insulated core transformer type, or a linear type, a dynamitron type, a high frequency type, etc. Can be used.
When ultraviolet rays are used as the ionizing radiation, those containing ultraviolet rays having a wavelength of 190 to 380 nm are emitted. There is no restriction | limiting in particular as an ultraviolet-ray source, For example, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a carbon arc lamp, etc. are used.
The cured resin layer thus formed has various functions by adding various additives, for example, a so-called hard coat function, anti-fogging coat function, and anti-fouling coat having high hardness and scratch resistance. A function, an antiglare coating function, an antireflection coating function, an ultraviolet shielding coating function, an infrared shielding coating function, and the like can also be imparted.

<Transfer film>
The transfer film is not particularly limited as long as it has a thickness and a wetting index described later, and a conventionally known transfer film can be used. Specifically, polyethylene (PE) film, polypropylene (PP) film, acrylonitrile-butadiene-styrene copolymer synthetic resin (ABS resin) film, polycarbonate (PC) film, polyethylene terephthalate (PET) film, A polybutylene terephthalate (PBT) film, a polyethylene naphthalate (PEN) film, etc. can be mentioned. In these, a polyester-type film is preferable from a viewpoint of mirror surface maintenance (surface smoothness), and a stretched polyester film is especially preferable. In the present invention, since the transfer film plays a role as a protective film (masking film), cost reduction and environmental consideration can be achieved by material reduction and process simplification. Further, by providing a transfer film having smoothness coated with a surface protective layer, a decorative sheet excellent in specularity that is not affected by the surface properties (surface irregularities) of the substrate can be produced.
As the transfer film, a film having a thickness of 20 to 200 μm and a wetting index of 30 to 55 mN / m is used. When the thickness is less than 20 μm, the transfer film tends to curl, and the mirror surface property after peeling also decreases. On the other hand, if the thickness of the transfer film exceeds 200 μm, it is not preferable from the viewpoints of peelability during construction, workability, cost, and environmental considerations. The thickness of the transfer film is more preferably 25 to 100 μm, further preferably 25 to 50 μm.
On the other hand, if the wetting index is less than 30 mN / m, the adhesion between the surface protective layer formed by crosslinking and curing the ionizing radiation curable resin composition and the transfer film becomes extremely weak and may be peeled off during the production process. There is. On the other hand, when the wetting index exceeds 55 mN / m, the adhesion between the transfer film and the surface protective layer formed by crosslinking and curing the ionizing radiation curable resin composition increases, and the transfer film cannot be peeled off. The transfer film has a wetting index of preferably 35 to 50 mN / m, and more preferably 40 to 45 mN / m.
In the present invention, the wetting index is a value measured according to JIS K 6768.
In addition, the process of peeling and transferring the transfer film may be performed after (i) the base material 2 and the transfer film are bonded together, and (ii) to serve as a protective film (masking film). It may be performed after the decorative sheet is bonded to the substrate 11 described later, or (iii) may be performed immediately after use after construction, and is not particularly limited.

The decorative sheet of the present invention has the above-described layers, but may have other layers as long as the object of the present invention is not impaired.
Moreover, as a decorative sheet of this invention, it is preferable that total thickness is 120-650 micrometers, it is more preferable that it is 180-500 micrometers, and it is still more preferable that it is 180-250 micrometers.

[Decorative board]
The decorative sheet of the present invention can be used as a decorative plate by sticking to various substrates. Specifically, as shown in FIG. 2, the decorative sheet 1 is adhered to the substrate 11 via the substrate adhesive layer 10. Examples of the decorative board 11 include wood veneer, wood plywood, particle board, wood board such as MDF (medium density fiber board), plaster board such as gypsum board, gypsum slag board, calcium silicate board, asbestos slate board. , Lightweight foamed concrete board, cement board such as hollow extruded cement board, pulp cement board, asbestos cement board, fiber cement board such as wood chip cement board, ceramic board such as ceramics, porcelain, stoneware, earthenware, glass, glazing, iron plate , Galvanized steel sheets, polyvinyl chloride sol coated steel sheets, aluminum plates, copper plates and other metal plates, polyolefin resin plates, acrylic resin plates, ABS plates, polycarbonate plates and other thermoplastic resin plates, phenol resin plates, urea resin plates, unsaturated Thermosetting resin plate such as polyester resin plate, polyurethane resin plate, epoxy resin plate, melamine resin plate, phenol resin, urine So-called FRP board in which resin, unsaturated polyester resin, polyurethane resin, epoxy resin, melamine resin, diallyl phthalate resin, and other resins are impregnated and cured into glass fiber nonwoven fabric, fabric, paper, and other various fiber base materials And the like. Moreover, as a base material for decorative boards, you may use the composite base material which laminated | stacked 2 or more types of the said various base materials by well-known means, such as an adhesive agent and heat sealing | fusion.

  Further, the substrate may be subjected to a treatment such as forming a primer layer, or a coating for adjusting the color or a pattern from a design viewpoint may be formed in advance. As a substrate to be an adherend, plate materials of various materials, plate materials such as curved plates, or three-dimensional articles (molded products) in which the above materials are used alone or in combination are targeted.

  A backing material such as Japanese paper, Western paper, synthetic paper, non-woven fabric, woven fabric, cold paper, impregnated paper, synthetic resin sheet, or the like may be attached to the decorative sheet. By sticking the backing material, it acts to reinforce the decorative sheet itself, prevent cracking and tearing of the decorative sheet, prevent bleeding of the adhesive to the decorative sheet surface, and prevent the occurrence of defective products, Handling becomes easy and productivity can be improved.

  Thus, a substrate on which a decorative sheet is placed every leaf or continuously via an adhesive is attached to a cold press, a hot press, a roll press, a laminator, a wrapping, an edge applicator, a vacuum press, etc. The decorative sheet is bonded to the substrate surface by pressing with an apparatus to obtain a decorative plate.

The adhesive composing the substrate adhesive layer is applied using an application device such as a spray, spreader, bar coater or the like. As this adhesive, vinyl acetate resin-based, urea resin-based, melamine resin-based, phenol resin-based, isocyanate-based, and urethane resin-based adhesives are used alone or as a mixed adhesive obtained by arbitrarily mixing them. As needed, talc, calcium carbonate, clay, titanium white and other inorganic powders, wheat flour, wood flour, plastic powder, coloring agents, insect repellents, fungicides and the like can be added and mixed in the adhesive. . In general, the adhesive is applied to the substrate surface with a solid content of 35 to 100% by mass and a coating amount in the range of ^{20 to} 300 g / m ² .
Adhesion of the decorative sheet on the substrate is usually performed by forming an adhesive layer for the substrate on the back surface of the decorative sheet of the present invention and adhering the substrate or applying an adhesive on the substrate, and adhering the decorative sheet. It depends on the method.

  The decorative board manufactured as described above can be subjected to arbitrary decoration such as grooving and chamfering on the surface and the end of the mouth using a cutting machine such as a router or a cutter. And various uses, for example, interior or exterior materials of buildings such as walls, ceilings, floors, window frames, doors, handrails, skirting boards, peripheral edges, surface decorative panels of furniture such as malls, kitchen peripheral products, furniture or It can be used for decorative panels on cabinets such as light electric and OA equipment, interiors and exteriors of vehicles.

  The present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

<Example 1>
(A) The decorative sheet of Example 1 was produced according to the following steps (a) to (d).
(A) Polyester resin transfer film [manufactured by Toray Industries, Inc .: trade name “S50” (thickness 2
5 μm, wetting index 45 mN / m)], a surface protective layer was applied by reverse method at 5 μm, and cured by irradiation with an electron beam (conditions: 175 kV, 5 Mrad) (thickness of the surface protective layer after curing: 3 μm).
(B) A two-component curable polyester polyol resin primer [manufactured by Dainichi Seika Kogyo Co., Ltd .: trade name “E256-40”] was applied on the surface protective layer.
(C) On the primer layer, a pattern layer using a polyurethane acrylic polyol resin as a binder and a colored concealing layer were subjected to gravure printing.
(D) A two-component curable polyester polyol type adhesive [manufactured by Dainichi Seika Kogyo Co., Ltd .: trade name “E295 type”] was applied at 5 g / m ² on the colored concealing layer, and the base polypropylene ( A decorative sheet of Example 1 was obtained by laminating on PP) film [thickness 150 μm, elastic modulus 1200 MPa, manufactured by Mitsubishi Plastics, Inc .: trade name “Art Ply”] and curing at 40 ° C. for 72 hours.

(B) The decorative board of Example 1 was produced according to the following procedure.
For the substrate (medium density fiberboard (MDF) (thickness 3 mm), according to JIS A 5905), the ethylene-vinyl acetate adhesive “BA-20”, which is an aqueous emulsion manufactured by Chuo Rika Co., Ltd. A decorative plate was prepared by applying the adhesive to the substrate so as to have an application amount of 60 g / m ² (wet), and adhering to the back surface of the decorative sheet via the adhesive layer.
The following various evaluations were performed about the obtained decorative sheet and decorative board. The results are shown in Table 1.

<Examples 2 to 14 and Comparative Examples 1 to 9>
A decorative sheet and a decorative board were produced in the same manner as in Example 1 except that the thickness and characteristics of each layer were changed as shown in Tables 1 and 2. The following various evaluations were performed about the obtained decorative sheet and decorative board. The results are shown in Tables 1 and 2.

<Evaluation method>
The decorative sheet obtained in each example was evaluated by the following methods.
(Creativity)
(1) Specularity on decorative sheet, Specularity on decorative plate Each decorative sheet and decorative plate are placed under a three-wavelength light-emitting fluorescent lamp (manufactured by Twin Bird Industries Co., Ltd .: trade name “FPL27EX-N”). The reflected image on the surface was visually evaluated according to the following criteria.
◎: The image is clearly reflected ○: The image is not clearly visible, but the image is reflected ○ △: The reflected image is somewhat rough, but there is no problem in practical use ×: The reflected image Rough

(Applicability)
(2) Hard brush hardness (plastic deformation)
It measured based on JISK5600-5-4.

(Processability)
(3) Curl When each decorative sheet is cut into 10 × 10 cm, placed on a flat table, and the four sides of the decorative sheet are observed, and there is a gap between the table and the decorative sheet side Was determined to be floating.
◎: No floating at all ○: There is some floating, but there is no problem in practical use ×: There is floating

(4) Workability Lapping was performed on 3R-shaped MDF (thickness 3 mm, according to JIS A 5905), and the surface condition was evaluated according to the following criteria.
○: The base substrate, the surface protective layer are not cracked, and the transfer film layer is not lifted at all.
◯: There are some cracks in the base substrate, surface protective layer, and floating transfer film layer, but there is no problem in actual use.
X: Base substrate, surface protective layer crack, transfer film layer floating occurred (5) Productivity Productivity was evaluated according to the following criteria in the production process.
○: The transfer film does not float at all until the step (d).
○: The transfer film slightly floats up to the step (d), but there is no problem in actual production.
X: The transfer film is peeled off by the step (d).
(6) Construction suitability During construction of the decorative sheet, the peeling performance of the transfer film was evaluated according to the following criteria.
A: The transfer film can be peeled off without any problem.
○: The transfer film can be peeled off without any problem.
○: Slightly difficult to peel, but no problem in actual use.
X: The transfer film cannot be peeled off.

As is clear from Table 1, the decorative sheets of Examples 1 to 14 in which the thickness and characteristics of the base material, the surface protective layer, and the transfer film satisfy the provisions of the present invention are suitable for use, workability, and design. You can see that it has everything.
On the other hand, as apparent from Table 2, the decorative sheets of Comparative Examples 1 to 9 that do not satisfy the thickness and characteristics defined in the present invention have low use suitability, work suitability, and designability. .

DESCRIPTION OF SYMBOLS 1 Decorative sheet 2 Base material 3 Adhesive layer 4 Colored concealment layer 5 Picture layer 6 Primer layer 7 Surface protective layer 8 Transfer film 9 Back surface primer layer 10 Adhesive layer for substrate 11 Substrate

Claims (10)

  A decorative sheet comprising, in this order, at least an adhesive layer, a colored hiding layer, a pattern layer, a primer layer, a surface protective layer obtained by crosslinking and curing an ionizing radiation curable resin composition, and a transfer film on a substrate. The thickness of the substrate is 100 to 350 μm, the elastic modulus of the substrate is 800 to 8000 MPa, the thickness of the surface protective layer is 2 to 20 μm, and the thickness of the transfer film Is a decorative sheet, wherein the transfer film has a wetting index of 30 to 55 mN / m.   The decorative sheet according to claim 1, wherein the base material comprises an olefin resin.   The decorative sheet according to claim 1 or 2, wherein the transfer film is a stretched polyester film.   The decorative sheet according to any one of claims 1 to 3, wherein the base material has a thickness of 150 to 300 µm and the base material has an elastic modulus of 1000 to 4000 MPa.   The decorative sheet according to any one of claims 1 to 4, wherein the thickness of the surface protective layer is 3 to 15 µm.   The decorative sheet according to any one of claims 1 to 5, wherein the transfer film has a thickness of 25 to 100 µm and the transfer film has a wetting index of 35 to 50 mN / m. The decorative sheet according to any one of claims 1 to 6, wherein the surface protective layer is formed by applying an ionizing radiation curable resin composition onto the transfer film and crosslinking and curing the composition. The decorative sheet according to any one of claims 1 to 7, wherein the substrate is any one selected from a plastic film, a plastic sheet, a metal foil, a metal sheet, and a metal plate. On the substrate, at least an adhesive layer, a colored hiding layer, a pattern layer, a primer layer, a surface protective layer formed by crosslinking and curing an ionizing radiation curable resin composition, and a transfer film are provided in this order. The thickness is 100 to 350 μm, the elastic modulus of the substrate is 800 to 8000 MPa, the thickness of the surface protective layer is 2 to 20 μm, the thickness of the transfer film is 20 to 200 μm, and A decorative sheet in which the wetting index of the transfer film is 30 to 55 mN / m ,
The heat-sensitive adhesive constituting the adhesive layer by applying the colored concealing layer by heating the heat-sensitive adhesive, then, after superposing a heat-sensitive adhesive coated surface of the colored concealing layer and the base material was bonded by cooling Step (a) for producing the decorative sheet
A step (b) of adhering the base material side surface of the decorative sheet to the substrate via the substrate adhesive; and
A method for producing a decorative board , comprising the step (c) of peeling the transfer film after the step (a), before the step (b), or after the step (b) . On the substrate, at least an adhesive layer, a colored hiding layer, a pattern layer, a primer layer, a surface protective layer formed by crosslinking and curing an ionizing radiation curable resin composition, and a transfer film are provided in this order. The thickness is 100 to 350 μm, the elastic modulus of the substrate is 800 to 8000 MPa, the thickness of the surface protective layer is 2 to 20 μm, the thickness of the transfer film is 20 to 200 μm, and A decorative sheet in which the wetting index of the transfer film is 30 to 55 mN / m ,
A thermosetting adhesive constituting the adhesive layer is applied to the colored concealment layer, the thermosetting adhesive application surface of the colored concealment layer is superposed on the base material, and then the adhesive sheet is adhered by heating. Manufacturing step (a),
A step (b) of adhering the base material side surface of the decorative sheet to the substrate via the substrate adhesive; and
A method for producing a decorative board , comprising the step (c) of peeling the transfer film after the step (a), before the step (b), or after the step (b) .