JP2013226791A - Decorative sheet and decorative board using the decorative sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative sheet having a superior mirror face property, processing suitability and usability, and a decorative board using the decorative sheet.SOLUTION: A decorative sheet has, on a base material whose thickness is not smaller than 40 μm, an adhesive layer whose thickness is at least 1 to 25 μm, a surface protective layer and a film for transfer whose thickness is 15 to 200 μm in this order, the mathematic average surface roughness (Ra) of a face at a side opposite to the adhesive layer out of faces of the base material is not larger than 15 μm, the mathematic average surface roughness (Ra) of a face contacting with the surface protective layer out of faces of the film for transfer is not larger than 20 μm, and the surface protective layer is a cured material of an ionization radiation thermosetting resin composition.

Description

  The present invention relates to a decorative sheet excellent in specularity, processability and useability, and a decorative board using 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. In addition to basic performance such as processability such as flexibility and suitability for use such as stain resistance, a sheet used for such a decorative board is required to have a design property such as specularity that gives a high-class feeling. ing.
In this way, the decorative sheet that has processability and suitability for use on the upper surface of the substrate and can impart designability to the molded body includes, for example, a substrate, a pattern layer, an adhesive layer, a polyester resin layer, and a surface protective layer. Can be manufactured in this order (for example, Patent Document 1).

JP 2012-51217 A

The decorative sheet manufactured by the above-described manufacturing method uses a certain amount of adhesive in order to enhance the adhesion between the resin layer and the pattern layer. When the sheet is rolled up, irregularities on the back surface of the base material are formed in the adhesive of the adhesive layer, and the mirror surface property of the decorative sheet may be lowered.
The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide a decorative sheet having excellent specularity, processability and suitability for use, and a decorative board using the decorative sheet. .

As a result of intensive studies to achieve the above object, the present inventors have found that in a decorative sheet provided with a transfer film, the base material, the thickness of the transfer film, the arithmetic average surface roughness, and the thickness of the adhesive layer It is found that a decorative sheet having an unprecedented specularity can be obtained while maintaining processability and suitability for use, while relieving the formation of irregularities on the surface of the decorative sheet. Completed the invention.
The gist of the present invention is as follows.

[1] On a substrate having a thickness of 40 μm or more, at least an adhesive layer having a thickness of 1 to 25 μm, a surface protective layer, and a transfer film having a thickness of 15 to 200 μm in this order, The arithmetic average surface roughness (Ra) of the surface of the substrate opposite to the adhesive layer is 15 μm or less, and the arithmetic average surface roughness (Ra of the surface of the transfer film that contacts the surface protective layer) ) Is 20 μm or less, and the surface protective layer is a cured product of an ionizing radiation curable resin composition.
[2] A decorative board having the decorative sheet.

  ADVANTAGE OF THE INVENTION According to this invention, the decorative sheet which has the outstanding specularity, workability, and useability, and the decorative board using this decorative sheet 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 comprises at least an adhesive layer having a thickness of 1 to 25 μm, a surface protective layer, and a transfer film having a thickness of 15 to 200 μm on a substrate having a thickness of 40 μm or more. The arithmetic average surface roughness (Ra) of the surface of the substrate opposite to the adhesive layer is 15 μm or less, and the arithmetic average surface of the surface of the transfer film in contact with the surface protective layer Since the roughness (Ra) is 20 μm or less and the surface protective layer is a cured product of the ionizing radiation curable resin composition, it has not only processing suitability and use suitability but also extremely excellent specularity.

  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 includes a colored hiding layer 3, a colored layer 4, an adhesive layer 5, a surface protective layer 6 obtained by crosslinking and curing an ionizing radiation curable resin composition, and a transfer film 7 on a substrate 2. They are laminated in this order, and a back surface primer layer 8 is provided on the back surface of the substrate 2. In the present invention, the colored hiding layer 3 and the colored layer 4 are not necessarily provided, and other layers may exist between the layers.

"Base material"
As the substrate, one having a thickness of 40 μm or more and an arithmetic average surface roughness (Ra) of the back surface of the substrate of 15 μm or less is used. If the thickness of the substrate is less than 40 μm, the strength as a decorative sheet is lowered. In light of the above viewpoint and cost, the thickness of the base material is preferably 40 to 650 μm, more preferably 40 to 500 μm, more preferably 45 to 500 μm, and still more preferably 48 to 250 μm.
Further, when the arithmetic average surface roughness (Ra) of the back surface of the base material exceeds 15 μm, the unevenness of the base material is formed on the surface of the transfer film when the decorative sheet is rolled up, and the specularity of the decorative sheet is lowered. Resulting in. From the above viewpoint, the arithmetic average surface roughness (Ra) of the back surface of the substrate is preferably 0.5 to 13 μm, and more preferably 0.8 to 12 μm.
In addition, in this invention, arithmetic mean surface roughness (Ra) means the value measured by the method as described in the column of the below-mentioned Example, and the back surface of a base material is an adhesive layer among the surfaces of a base material. Means the opposite side.

As specific examples of the substrate, various plastic films, plastic sheets, metal foils, metal sheets, metal plates and the like 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 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. .

<Coloring hiding layer>
In the present invention, it is preferable to provide at least one of the colored concealment layer 3 and the colored layer 4 between the base material and the adhesive layer for the purpose of improving the design of the decorative sheet. The colored masking layer 3 can adjust the surface color by giving the intended color when the base material 2 is colored or uneven in color. 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. Examples include resins, polyamide resins, butyral resins, polystyrene resins, nitrocellulose resins, and cellulose acetate resins. These 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 colored 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 3 is preferably 0.5 to 20 μm, more preferably 1 to 10 μm, and still more preferably 1 to 6 μm.

<Colored layer>
The colored layer 4 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. In addition, as a colored layer in this invention, it is good also as a layer which printed the ink with respect to the whole surface of an object, without forming a pattern. As the pattern ink used for the colored layer, the same ink as that used for the colored hiding layer 3 can be used.

<Adhesive layer>
In the present invention, the adhesive layer 5 is provided between the substrate 2 and the surface protective layer 6. A layer other than the adhesive layer 5 such as the colored concealment layer 3 and the colored layer 4 may exist between the base material 2 and the adhesive layer 5.
In the present invention, the thickness of the adhesive layer 5 is 1 to 25 μm. When the thickness of the adhesive layer exceeds 25 μm, it becomes difficult to form the surface of the adhesive layer smoothly, and when the thickness of the adhesive layer is less than 1 μm, sufficient adhesive force cannot be obtained. From the above viewpoint, the thickness of the adhesive layer is preferably 2.5 to 15 μm, and more preferably 3 to 10 μm.

Although there is no restriction | limiting in particular as an adhesive agent used for a contact bonding layer, From a viewpoint of a manufacturing process, a thermosetting type adhesive or a heat sensitive adhesive is preferable, and a thermosetting type adhesive is more preferable.
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. It can be formed by aging at a temperature of several hours to several days to cure 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.

《Primer layer》
In the present invention, a primer layer may be provided between arbitrary layers for the purpose of improving the adhesion between the respective layers and 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 back surface primer layer 8 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 8, An acrylic resin, a vinyl chloride-vinyl acetate copolymer, polyester, a polyurethane, chlorinated polypropylene, chlorinated polyethylene etc. are mentioned. The material used for the back primer layer 8 is appropriately selected depending on the adherend.

<Surface protective layer>
In the present invention, the surface protective layer 6 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.

(Ionizing radiation curable resin composition)
As the ionizing radiation curable resin composition used for the surface protective layer, conventionally known compounds can be appropriately used. Specifically, it can be appropriately selected from polymerizable monomers, polymerizable oligomers, or prepolymers conventionally used as ionizing radiation curable resins.
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.
The ionizing radiation curable resin used in the present invention is preferably a polyfunctional urethane acrylate oligomer, and more preferably a bifunctional urethane acrylate oligomer.

  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.

  The number average molecular weight (number average molecular weight in terms of polystyrene measured by GPC method) of the ionizing radiation curable resin is preferably 1,000 to 10,000, and more preferably 2,000 to 10,000. If the number average molecular weight is within the above range, the processability is excellent, and the coating agent composition can have an appropriate thixotropy, so that the surface protective layer can be easily formed.

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 the additive include a weather resistance improver, an abrasion resistance improver, a polymerization inhibitor, a crosslinking agent, an infrared absorber, a film reinforcing agent, an antistatic agent, an adhesion improver, a leveling agent, a thixotropic agent, Examples include coupling agents, plasticizers, antifoaming agents, fillers, solvents, and coloring agents.
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.
As the film reinforcing agent, for example, a polyester resin (“film reinforcing agent” manufactured by Showa Ink Industry Co., Ltd.) 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, and molecular weight is 1,000 to 6,000, more preferably 3. 3,000 to 6,000, functional group equivalent (molecular weight / number of functional groups) 500 to 3,000, more preferably 1,500 to 3,000.
The silicone acrylate is preferably a polyfunctional silicone acrylate having a plurality of acrylic groups, preferably 4 or more, and more preferably 4-6, and a molecular weight of 3,000-100,000, more preferably 10,000- Examples include those having conditions of 30,000, functional group equivalent (molecular weight / functional group number) 750 to 25,000, more preferably 3,000 to 6,000.
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 thus prepared is applied by a known method such as gravure coating, bar coating, roll coating, reverse roll coating, comma coating, preferably gravure coating, and an uncured resin layer is formed. Let it form.
In the present invention, the thickness of the surface protective layer after curing is preferably 2 to 20 μm, more preferably 3 to 15 μm, and still more preferably 5 to 10 μm, from the viewpoint of scratch resistance and specularity.

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 has a thickness of 15 to 200 μm, and is not particularly limited as long as the arithmetic average surface roughness (Ra) of the surface in contact with the surface protective layer among the surfaces of the transfer film is 20 μm or less, A conventionally well-known thing can be used. When the thickness is less than 15 μm, the transfer film is likely to be curled or wrinkled, and the specularity after peeling is deteriorated. When the thickness exceeds 200 μm, the peelability at the time of construction, processing suitability, and cost deteriorate, and this is not preferable from the viewpoint of environmental considerations. From the above viewpoint, the thickness of the transfer film is preferably 18 to 195 μm, and more preferably 22 to 190 μm.
If the arithmetic average surface roughness (Ra) of the surface of the transfer film that contacts the surface protective layer exceeds 20 μm, the surface of the decorative sheet is not smooth. From the above viewpoint, the arithmetic average surface roughness (Ra) of the surface in contact with the surface protective layer is preferably 0.02 to 15 μm, and more preferably 0.05 to 12 μm.

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. Among these, polyester film, stretched polyester film, polyethylene film, polyethylene terephthalate film, and polypropylene film are preferable from the viewpoint of maintaining mirror properties (surface smoothness), polyethylene terephthalate film, and biaxially stretched polypropylene film. A film is more preferable, and a polyethylene terephthalate film and a biaxially stretched polypropylene film are still more preferable.
The transfer film can be appropriately selected depending on the application. A polyethylene terephthalate film is preferable for the cutting property and specularity of the decorative plate, and a biaxially stretched polypropylene film is preferable for lapping suitability.
For the transfer film, in order to improve the adhesion with the layer provided on it, one surface is subjected to physical or chemical surface treatment such as oxidation method or unevenness method as necessary. Can do.
Examples of the oxidation method include corona discharge treatment, chromium oxidation treatment, flame treatment, hot air treatment, ozone-ultraviolet treatment method, and the like.
Examples of the unevenness method include a sand blast method and a solvent treatment method. These surface treatments are appropriately selected according to the type of transfer film, but in general, a corona discharge treatment method is preferable from the viewpoints of effects and operability.
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.

The wetting index of the transfer film is preferably 35 to 50 mN / m, more preferably 40 to 45 mN / m, from the viewpoint of achieving both adhesion and peelability. In the present specification, the wetting index is a value measured in accordance with JIS K 6768.
In addition, the process of peeling and transferring the transfer film is performed after (i) bonding the substrate 2 and the transfer film, that is, after laminating the transfer film with other layers to form a decorative sheet. (Ii) In order to give a role as a protective film (masking film), it may be carried out after the decorative sheet is bonded to the substrate 11 described later, or (iii) after construction and immediately before use. There is no particular limitation.

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 board of the present invention has the decorative sheet of the present invention, and can be manufactured by sticking the decorative sheet of the present invention 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>
The decorative sheet of Example 1 was produced according to the following steps (a) to (c).
(A) On a polyolefin resin sheet (polypropylene resin (PP) sheet: thickness 150 μm, arithmetic average surface roughness 10 μm on the back surface) as a base material, an ink mainly containing a urethane resin and containing titanium oxide as a coloring pigment, The colored concealment layer and the colored layer were formed by gravure printing so that the coating amount after drying was 2 g / m ³ .
(B) An ionizing radiation curable resin composition (polyethylene terephthalate film as a transfer film (PET film: manufactured by Toyobo Co., Ltd., trade name “A4100”, thickness 50 μm, arithmetic average surface roughness 0.1 μm)) A bifunctional urethane acrylate oligomer, weight average molecular weight: 3,000) was applied so that the thickness after drying was 5 μm, and cured at 165 kV, 5 Mrad to form a surface protective layer (surface protective layer after curing) Thickness: 5 μm).
(C) Corona treatment is applied to the surface of the surface protective layer obtained in (b) above, and a two-component curable adhesive (trade name “E295NT”, manufactured by Dainichi Seika Kogyo Co., Ltd.) is cured on the treated surface. After applying so that the subsequent thickness was 5 μm, a decorative sheet was prepared by laminating the adhesive layer and the colored layer (a) in contact with each other.

The arithmetic average surface roughness of the substrate and the transfer film was measured by the following method.
<Measurement method>
Arithmetic mean surface roughness (Ra)
In accordance with JIS B0601: 2001, a high precision surface roughness meter “SE-3FAT” manufactured by Kosaka Laboratory Co., Ltd. was used. A chart was drawn under the condition of 08 mm, and a portion of the measurement length L was extracted from the surface roughness curve in the direction of the center line. When the center line of the extracted portion is the X axis, the direction of the vertical magnification and the Y axis, and the roughness curve is expressed by Y = f (x), the value given by the following equation is expressed in nm. In this measurement, four pieces were measured with a reference length of 1.25 mm and expressed as an average value.

<How to make a decorative board>
On one side of the substrate (thickness: 3 mm, medium density fiberboard (MDF), according to JIS A 5905), ethylene-vinyl acetate adhesive (aqueous emulsion type, manufactured by Chuo Rika Co., Ltd., trade name) “BA-20”) was applied so that the coating amount was 60 g / m ² (wet), and a base plate and a substrate of the decorative sheet were bonded to each other to prepare a decorative board.
The following various evaluations were performed about the obtained decorative sheet and decorative board. The results are shown in Table 1.

<Examples 2 to 11 and Comparative Examples 1 to 5>
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 Table 1. The following various evaluations were performed about the obtained decorative sheet and decorative board. The results are shown in Table 1.
<Example 12>
Example 1 with the exception that the transfer film was changed to a biaxially stretched polypropylene film [OPP film: manufactured by Mitsui Chemicals, Inc., trade name: “U-1”, thickness: 20 μm, arithmetic average surface roughness: 10 μm] Similarly, a decorative sheet and a decorative board were produced. The following various evaluations were performed about the obtained decorative sheet and decorative board. The results are shown in Table 1.

<Evaluation method>
The decorative sheet obtained in each example was evaluated by the following methods.
(1) Specularity on decorative sheet, Specularity on decorative plate Each decorative sheet and decorative plate are placed under a three-wavelength region fluorescent lamp (manufactured by Panasonic Corporation: 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

(2) Processability A polyurethane hot melt adhesive (Hybon 4836 manufactured by Hitachi Chemical Co., Ltd.) melted at a temperature of 115 ° C. using a melting device (“MC-12” manufactured by Nordson Co., Ltd.) It was applied to 3R-shaped MDF (thickness 3 mm, conforming to JIS A 5905) so as to have a thickness of 80 μm to form an adhesive layer for a substrate. Next, the base material of the decorative sheet and MDF supplied with the profile laminator PL-300-PUR (PUR wrapping machine manufactured by Marunaka Co., Ltd.) are bonded via the adhesive layer for the substrate, and lapping is performed. The surface condition was evaluated according to the following criteria.
○: The base substrate, the surface protective layer are not cracked, and the transfer film is not lifted at all.
◯: There are some cracks in the base substrate, surface protective layer and transfer film, but there is no problem in actual use.
X: Base substrate, surface protective layer cracking, transfer film floating

(3) Cutting property The obtained decorative board was subjected to router cutting from the laminated surface side, and burrs were evaluated according to the following criteria.
A: There is no occurrence of burrs.
○: There are slight burrs, but there is no problem in actual use.
Δ: There are some burrs, but there is no problem in actual use.
X: Many burrs are generated.

(4) Suitability for use (adhesion)
The surface protective layer was cross-cut, and Nichiban-made cello tape (registered trademark) was applied, and the operation of abrupt peeling was performed once. The presence or absence of peeling of the coating film was confirmed by visual observation and evaluated according to the following criteria.
○: There was no peeling of the coating film.
○ △: Although peeling of the extremely light coating film is confirmed, there is no problem in actual use.
Δ: Peeling of the coating film was confirmed.

As is clear from Table 1, the decorative sheets and decorative plates of Examples 1 to 12 in which the base material, the thickness of the transfer film and the arithmetic average surface roughness, and further the thickness of the adhesive layer satisfy the provisions of the present invention, It turns out that it has all of specularity, suitability for use, and workability.
On the other hand, the decorative sheets and decorative plates of Comparative Examples 1 to 5 that do not satisfy the thickness and characteristics defined in the present invention have low specularity, suitability for use, and suitability for processing.

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

Claims (6)

  On the substrate having a thickness of 40 μm or more, the substrate has at least an adhesive layer having a thickness of 1 to 25 μm, a surface protective layer, and a transfer film having a thickness of 15 to 200 μm in this order. Among the surfaces, the arithmetic average surface roughness (Ra) of the surface opposite to the adhesive layer is 15 μm or less, and among the surfaces of the transfer film, the arithmetic average surface roughness (Ra) of the surface in contact with the surface protective layer is 20 μm. A decorative sheet, wherein the surface protective layer is a cured product of an ionizing radiation curable resin composition.   The decorative sheet according to claim 1, comprising at least one of a colored concealing layer and a colored layer between the substrate and the adhesive layer.   The decorative sheet according to claim 1 or 2, wherein the adhesive layer is formed of a thermosetting adhesive.   The decorative sheet according to any one of claims 1 to 3, wherein the transfer film is a polyethylene terephthalate film or a biaxially stretched polypropylene film.   The decorative sheet according to any one of claims 1 to 4, wherein the ionizing radiation curable resin is a bifunctional urethane acrylate oligomer.   A decorative board comprising the decorative sheet according to claim 1.