JP5454057B2 - Decorative sheet - Google Patents

Description

  The present invention relates to a decorative sheet and a decorative plate obtained using the decorative sheet.

As a decorative board used for furniture, kitchen product cabinets, floor tiles and wall panels, or around the kitchen sink, a decorative sheet printed with a wood grain pattern, etc., is bonded to the building material substrate with an adhesive. Is commonly used. And the decorative sheet used for such a decorative plate has processability such as flexibility, machinability, break resistance, stain resistance, scratch resistance, water resistance, chemical resistance, weather resistance, etc. Various characteristics such as suitability for use are required.
In order to satisfy these requirements, a technique for applying a surface protective layer to the surface of a substrate that sufficiently satisfies processability is used, and an ionizing radiation curable resin composition is preferably used for the surface protective layer. . The ionizing radiation curable resin composition is a composition that is cured by ionizing radiation such as ultraviolet rays and electron beams, and the surface protective layer using this is good for the environment because it can be applied and formed without a solvent without using an organic solvent. In addition, since the crosslink density is high, various advantages such as easy surface strength such as wear resistance can be obtained.

By the way, due to the recent trend toward high-end products by consumers, it is desired that the decorative sheet and decorative plate used in the above-mentioned applications have an appearance that gives a high-class feeling. In addition to the above-described processability and suitability for use that have been generally required, high glossiness and specularity (surface smoothness) are also important as high-quality elements.
As a decorative sheet having a high gloss, a mainstream sheet is formed by applying a urethane paint to form a topcoat layer (for example, Patent Document 1). However, such urethane-coated paper can be obtained with relatively good surface properties of the coating film, but it may take several days to cure the coating film in the manufacturing process, which is disadvantageous in terms of productivity, In addition, there is a problem that it is not always satisfactory in terms of specularity (surface smoothness) and magic erasability.

  On the other hand, a method of forming a coating film using an ionizing radiation curable resin is also known. For example, after a pattern is printed on a base paper, an electron beam curable resin composition such as an acrylate resin is applied or impregnated. A decorative paper can be rapidly manufactured by irradiating the sheet with an electron beam and curing it (for example, Patent Document 2). However, a coating film made of such a conventionally known ionizing radiation curable resin composition is not always satisfactory, especially in terms of the above-mentioned use characteristics, and has a high glossiness and specularity (surface smoothness). (Sex) was not enough.

  For the purpose of obtaining a high gloss feeling, it contains a high-brightness pigment such as a base material, an adhesive layer, an aluminum filler or a pearl pigment, and is colored using a vinyl chloride / vinyl acetate copolymer and an acrylic resin as a binder resin. A decorative sheet having a layer and a transparent resin layer has been proposed (for example, Patent Document 3).

JP-A-5-92484 Japanese Patent Publication No. 1-55991 JP 2007-261143 A

However, although the decorative sheet described in Patent Document 3 has sufficient performance in terms of high glossiness, it has high performance in terms of specularity (surface smoothness) and suitability for use, particularly in terms of scratch resistance. Improvements are required to meet the needs of the company. Further, it has been found that when a metal pigment such as an aluminum filler is used as the high luster pigment for the purpose of imparting high designability, the peel strength may be significantly reduced.
Under such circumstances, the present invention has an excellent peel strength, and is excellent in suitability for use such as stain resistance, scratch resistance, water resistance, chemical resistance, weather resistance, and surface specularity. It is an object of the present invention to provide a decorative sheet excellent in high gloss feeling and a decorative plate obtained by bonding the sheet and a substrate.

  As a result of intensive studies to achieve the above object, the present inventors have formed a metallic layer having a predetermined content ratio of glitter pigment, and applied the ionizing radiation curable resin composition at a specific coating amount. By forming a surface protective layer by working, it has excellent peel strength, excellent useability such as stain resistance, scratch resistance, water resistance, chemical resistance, weather resistance, and surface specularity. A decorative sheet excellent in high glossiness could be obtained.

That is, the present invention
(1) A decorative sheet obtained by laminating at least a concealing layer, a metallic layer, and a surface protective layer in this order on a substrate, wherein the content ratio of the glitter pigment contained in the metallic layer is the resin solid content of the metallic layer 15 to 45 parts by mass with respect to 100 parts by mass, the surface protective layer is obtained by crosslinking and curing the ionizing radiation curable resin composition, and the coating amount of the ionizing radiation curable resin composition is 3 to 3. A decorative sheet characterized by being 8 g / m ² ;
(2) The decorative sheet according to the above (1), which has a penetration preventing layer between the metallic layer and the surface protective layer,
(3) The decorative sheet according to (1) or (2), wherein the glitter pigment is a metal pigment,
(4) The decorative sheet according to any one of (1) to (3), wherein the base material is made of a paper base material or polyethylene terephthalate resin, and (5) the substrate and the above (1) to (4). A decorative sheet formed by bonding the decorative sheet according to any one of the above through an adhesive layer,
Is to provide.

  According to the present invention, it has excellent peel strength, excellent useability such as stain resistance, scratch resistance, water resistance, chemical resistance, and weather resistance, and excellent surface specularity and high glossiness. It is possible to provide a decorative sheet in which the decorative sheet and the sheet and the substrate are bonded via an adhesive layer.

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 of this invention.

[Decorative sheet]
The decorative sheet of the present invention is a decorative sheet in which a concealing layer, a metallic layer, and a surface protective layer are sequentially laminated on a base material, and the content ratio of the glitter pigment contained in the metallic layer is that of the metallic layer. It is in the range of 15 to 45 parts by mass with respect to 100 parts by mass of the resin solid content, and the surface protection layer is formed by crosslinking and curing the ionizing radiation curable resin composition, and the coating amount of the ionizing radiation curable resin composition Is 3 to 8 g / m ² .
A typical structure of the decorative sheet of the present invention will be described with reference to FIG. FIG. 1 is a schematic view showing one cross section of a preferred embodiment of the decorative sheet 1 of the present invention. In the example shown in FIG. 1, an ionizing radiation curable material coated on the base material 2 with a concealing layer 3, a pattern layer 6, a metallic layer 4, a penetration preventing layer 7, and a coating amount of ^{3 to} 8 g / m ² . The surface protective layer 5 formed by crosslinking and curing the resin composition is laminated in this order.
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 is obtained by joining the decorative sheet 1 and the substrate 10 via an adhesive layer 9.
Hereinafter, the present invention will be described in detail with reference to FIG. 1 showing one preferred embodiment of the present invention.

<< Substrate 2 >>
The base material 2 used in the present invention is not particularly limited as long as it is usually used as a decorative sheet, such as various papers, plastic films, plastic sheets, metal foils, metal sheets, metal plates, and wood. A wooden board, a ceramic material, etc. can be suitably selected according to a use. Each of these materials may be used alone, but may be a laminate of any combination such as a composite of paper or a composite of paper and a plastic film.
When using these substrates, particularly plastic films or plastic sheets, as a substrate, an oxidation method or a concavo-convex method may be applied to one or both sides as desired in order to improve the adhesion to the layer provided thereon. Physical or chemical surface treatment can be applied.
Examples of the oxidation method include corona discharge treatment, chromium oxidation treatment, flame treatment, hot air treatment, ozone / ultraviolet treatment method, and 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 generally, a corona discharge treatment method is preferably used 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, coating for adjusting the color, or a pattern from a design standpoint. May be formed in advance.

As various papers used as the substrate, thin paper, kraft paper, titanium paper and the like can be used. These paper base materials are made of acrylic resin, styrene butadiene rubber, melamine resin for further strengthening the interlaminar strength between the fibers of the paper base material or to prevent the occurrence of scuffing. Further, a resin such as urethane resin may be added (resin impregnation after paper making, or embedded during paper making). For example, inter-paper reinforced paper, resin-impregnated paper, and the like.
In addition to these, various papers often used in the field of building materials, such as linter paper, paperboard, base paper for gypsum board, or a vinyl wallpaper raw material provided with a vinyl chloride resin layer on the surface of the paper, can be mentioned. Furthermore, coated paper, art paper, sulfuric acid paper, glassine paper, parchment paper, paraffin paper, Japanese paper, or the like used in the office field or normal printing and packaging can also be used. Moreover, although distinguished from these papers, woven fabrics and non-woven fabrics of various fibers having an appearance and properties similar to paper can be used as the base material. Examples of the various fibers include inorganic fibers such as glass fibers, asbestos fibers, potassium titanate fibers, alumina fibers, silica fibers, and carbon fibers, or synthetic resin fibers such as polyester fibers, acrylic fibers, and vinylon fibers.

  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. Examples of the various wood-based boards include wood fiber boards such as wood veneer, plywood, laminated lumber, particle board, or MDF (medium density fiber board). Examples of the ceramic material include ceramic building materials such as gypsum board, calcium silicate board, and wood cement board, ceramics, glass, firewood, and fired tile. In addition to these, composites of various materials such as fiber reinforced plastic (FRP) plates, paper honeycombs with iron plates pasted on both sides, polyethylene plates sandwiched between two aluminum plates, etc. can also be used as a substrate. .

Among the above, the base material is preferably a paper base material, a plastic film made of a polyterephthalate resin, or the like from the viewpoint of cost, heat resistance, adhesion to a substrate, suitability for electron beam irradiation, durability, etc. Considering the properties, a plastic film made of polyterephthalate resin is more preferable. In addition, even when a paper substrate is used as the substrate, surface irregularities due to the irregularities peculiar to the paper substrate are manifested, resulting in a unique specularity that is different from when a plastic film is used as the substrate. The design feeling to express is obtained. Therefore, in this invention, a base material can be selected according to the design feeling desired.
Although there is no restriction | limiting in particular about the thickness of the base material 2, When using a paper base material, a basic weight is about 20-150 g / m < ² > normally, Preferably it is the range of 30-100 g / m < ² >. Moreover, when using the film and sheet | seat which use a plastic as a raw material, thickness is about 20-150 micrometers normally, Preferably it is the range of 30-100 micrometers. If the thickness is within the above range, sufficient strength as a decorative sheet can be ensured, and even if the decorative sheet is used for kitchen products, etc., even if nonflammability or flame retardancy is required, sufficient It is possible to cope with this, which is preferable.

<< Hiding layer 3 >>
The covering layer 3 covered over the entire surface shown in FIG. 1 is provided for the purpose of improving the design of the decorative sheet of the present invention and improving the adhesion between the substrate and the pattern layer or metallic layer. The concealing layer 3 is formed when the surface of the substrate 2 is colored so that the substrate 2 itself is colored or uneven in color, and gives the intended color to the surface of the substrate 2. Can do. The concealing layer 3 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 of the base material or the base.

As the ink used for forming the concealing layer, an ink in which 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 appropriately mixed is used. The binder is not particularly limited, and examples thereof include polyurethane resins, vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-acrylic copolymer resins, chlorinated polypropylene resins, acrylic resins, polyesters. Arbitrary resins, polyamide resins, butyral resins, polystyrene resins, nitrocellulose resins, cellulose acetate resins 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 concealing layer 3 is about 1 to 20 μm.

<< Metallic layer 4 >>
The metallic layer 4 shown in FIG. 1 imparts a glossy decorative property to the decorative sheet, and is a layer that imparts a particularly high gloss feeling. The metallic layer 4 may be provided on the entire surface, may be provided on a part thereof, or may form a pattern. Patterns include stone patterns that simulate the surface of rocks such as wood grain patterns, marble patterns (for example, travertine marble patterns), fabric patterns that simulate cloth and cloth-like patterns, tiled patterns, brickwork patterns, There are also patterns such as marquetry and patchwork that combine these.

  As the ink used for forming the metallic layer, an ink obtained by appropriately mixing a glossy pigment having a high glossiness, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, a curing agent and the like into a binder is used. As a binder, the thing similar to the binder of the ink used for formation of a concealing layer can be used. Among these, from the viewpoint of obtaining good specularity, acrylic resins such as acrylic polyol, polyurethane resins, nitrocellulose resins such as nitrified cotton alkyd, vinyl chloride-vinyl acetate-acrylic copolymer resins, etc. are preferable. Can be used alone or in combination.

As bright pigments having high gloss, metallic pigments (metallic pigments) made of scale-like foil pieces of metals, alloys, or metal compounds such as aluminum, chromium, nickel, tin, titanium, copper, gold, silver, brass, etc. Or, for example, a film in which two or more kinds of resin layers having different refractive indexes such as a polyester resin layer and an acrylic resin layer are laminated in a thickness of about several μm or less to generate an iris color due to light interference (for example, A pigment made of a scaly foil piece obtained by cutting “Marl Film” (registered trademark) manufactured by Marl, Inc. can be used. Of these, metal pigments (metallic pigments) made of scale-like foil pieces of metals, alloys, or metal compounds are preferable. Moreover, you may use what gave surface treatments, such as an alkylphosphate ester compound process, to this metal pigment, especially an aluminum pigment. By applying this treatment, the surface of the metal pigment is modified to form an oxide film (passive layer) such as aluminum oxide (Al ₂ O ₃ ), and at the same time, a thick hydrophobic film with alkyl chains on the surface. Therefore, metallic shine is uniformly developed over the entire surface of the decorative sheet, and the design can be improved.
The particle size of these glittering pigments may be appropriately selected according to the required high glossiness, transparency, etc., but usually about 1 to 100 μm is used, and 5 to 50 μm is preferable.
In the ink used for forming the metallic layer, the content ratio of the glitter pigment is preferably 15 to 45 parts by mass and more preferably 20 to 40 parts by mass with respect to 100 parts by mass of the binder resin solid content. When the pigment ratio of the glitter pigment is within the above range, a high gloss feeling can be obtained while maintaining good ink coatability.

  The thickness of the metallic layer is preferably 1 to 50 μm and more preferably 5 to 30 μm from the viewpoint of obtaining a high gloss feeling.

"Picture layer 6"
The pattern layer 6 shown in FIG. 1 gives decorativeness to the decorative sheet, and is formed by printing various patterns using ink and a printing machine. Examples of the pattern include the same patterns as those for forming the metallic layer described above. These patterns are formed by multicolor printing with normal yellow, red, blue, and black process colors, and also constitute the pattern. It is also formed by multicolor printing using special colors prepared by preparing individual color plates.
As the pattern ink used for the pattern layer 6, the same ink as that used for the masking layer 3 can be used.

<< Penetration prevention layer 7 >>
The permeation prevention layer 7 shown in FIG. 1 is a layer provided as desired, and has a function of preventing the ionizing radiation curable resin constituting the surface protective layer 5 from penetrating into the base material 2. In particular, this is particularly effective when the substrate 2 is a permeable substrate such as paper or nonwoven fabric. Therefore, the penetration preventing layer 7 may be positioned between the base material 2 and the surface protective layer 5, but a layer made of a curable resin having adhesiveness with the ionizing radiation curable resin constituting the surface protective layer 5, As shown in FIG. 1, it is preferably provided between the metallic layer 4 and the surface protective layer 5. Accordingly, the surface of the layer such as the concealing layer 3 and the pattern layer 6 existing on the base material 2 is smoothed, and the function of improving the adhesion between these and the surface protective layer 5 is also achieved.

<< surface protective layer 5 >>
The surface protective layer 5 is obtained by crosslinking and curing the ionizing radiation curable resin composition as described above, and the coating amount of the ionizing radiation curable resin composition is 3 to 8 g / m ^2. It is. Here, the ionizing radiation curable resin composition is one having an energy quantum capable of crosslinking and polymerizing molecules in an electromagnetic wave or a charged particle beam, that is, crosslinking or curing by irradiating ultraviolet rays or electron beams. Refers to a resin composition.

The original purpose of this surface protective layer, that is, the purpose of providing a conventional surface protective layer, is to provide the decorative sheet with suitability for use such as stain resistance, scratch resistance, water resistance, chemical resistance, and weather resistance depending on the application. It is to be. And a surface protective layer can provide especially outstanding peeling strength to a decorative sheet by making the application quantity of the ionizing radiation-curable resin composition which comprises a surface protective layer into 3-8 g / m < ² >. .
The solid content in the ionizing radiation curable resin composition is preferably in the range of 45 to 95% by mass, more preferably 55 to 85% by mass, and particularly preferably 75 to 85% by mass. If the content is within the above range, the surface specularity and high gloss can be obtained, and the suitability for use as described above can be improved.

(Ionizing radiation curable resin composition)
As the ionizing radiation curable resin used for the surface protective layer 5, 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, as the polymerizable monomer, a (meth) acrylate monomer having a radical polymerizable unsaturated group in the molecule is preferable, and among them, a polyfunctional (meth) acrylate is 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 singly or in combination of two or more.

  In the present invention, a monofunctional (meth) acrylate can be used in combination with the polyfunctional (meth) acrylate as long as the object of the present invention is not impaired, for the purpose of lowering the viscosity. Examples of monofunctional (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl ( Examples include meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and isobornyl (meth) acrylate. 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 The system etc. are mentioned. Here, 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 reaction of polyether polyol or polyester polyol and polyisocyanate with (meth) acrylic acid. Examples of polyester (meth) acrylate oligomers include esterification of hydroxyl groups of polyester oligomers having hydroxyl groups at both ends obtained by condensation of polycarboxylic 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 that have (meth) acrylate groups in the side chain of polybutadiene oligomers, and silicone (meth) acrylate oligomers that have polysiloxane bonds in the main chain. In a molecule such as an aminoplast resin (meth) acrylate oligomer modified with an aminoplast resin having many reactive groups in a small molecule, or a novolak 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, benzyldimethyl ketal, acetophenone dimethyl ketal It is done.
Examples of polymerizable oligomers 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, 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 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. Further, 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 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, 1 to 2 functional silicone methacrylate having 1 to 2 methacrylic groups is preferable, molecular weight 1000 to 6000, more preferably 3000 to 6000, functional group equivalent (molecular weight / number of functional groups) 500 to 3000, More preferably, one having a condition of 1500 to 3000 is mentioned. The silicone acrylate is preferably a polyfunctional silicone acrylate having a plurality of acrylic groups, preferably 4 or more, more preferably 4 to 6, and a molecular weight of 3000 to 100,000, more preferably 10,000 to 30000, and a functional group equivalent ( Molecular weight / number of functional groups) From 750 to 25000, more preferably from 3000 to 6000.
Content of the said 1 thru | or bifunctional silicone methacrylate is 1.5-20 mass parts with respect to 100 mass parts of ionizing radiation-curable resins, More preferably, it is 2-4 mass parts. 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, a polymerizable monomer, a polymerizable oligomer and various additives, which are the ionizing radiation curable components, are uniformly mixed at predetermined ratios to prepare a coating liquid composed of an ionizing radiation curable resin composition. To do. 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 at a coating amount of ³ to 8 g / m2. The coating liquid is applied by a known method such as gravure coating, bar coating, roll coating, reverse roll coating, or comma coating, preferably by gravure coating, to form an uncured resin layer.

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).
Further, the electron beam source is not particularly limited. For example, various electron beam accelerators such as a cockroft Walton type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type. 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.

[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 attached to the substrate 10 via the adhesive layer 9.
The substrate to be the adherend is not particularly limited, and as described above as a material used for the base material, a plastic sheet, a metal plate, a wooden board such as wood, a ceramic material, etc. are appropriately selected according to the application. can do. When these substrates, particularly plastic sheets, are used as substrates, physical or chemical surface treatment such as oxidation or unevenness is optionally applied on one or both sides to improve adhesion to the decorative sheet. Can be applied. These treatment methods are the same as those applied to the substrate.

  When the decorative board of the present invention is used for a kitchen peripheral product, a ceramic material, especially a board made mainly of volcanic ash can be preferably used as the substrate. Specific examples of such a plate include a volcanic glassy foam, a substrate in which a volcanic glassy foam and a metal foil such as an aluminum foil as a radiation sheet are combined, or a paper further on the substrate. Examples include a substrate on which a base material is laminated. Such a substrate can be produced and used, or a commercially available product such as “Dielite FTL (trade name)” manufactured by Daiken Kogyo Co., Ltd. can be used.

  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 such as flat plates and curved plates of various materials, 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 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 the adhesive from exuding on 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, hot press, roll press, laminator, wrapping, edge applicator, vacuum press, etc. The decorative sheet is bonded to the substrate surface by pressing with an apparatus to obtain a decorative plate.

The adhesive is applied using an application device such as a spray, a spreader, or a bar coater. As the adhesive, vinyl acetate resin-based, urea resin-based, melamine resin-based, phenol resin-based, isocyanate-based adhesives are used alone or as a mixed adhesive obtained by arbitrarily mixing them. As needed, inorganic powders such as talc, calcium carbonate, clay and titanium white, 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 80% by mass and an application amount of 50 to 300 g / m ² .
Adhesion of the decorative sheet on the substrate is usually performed by forming an adhesive layer 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 is also optionally cut by cutting the decorative board and applying optional decorations such as grooving and chamfering to the surface and the mouth using a cutting machine such as a router or a cutter. Can be applied. And various uses, for example, interior or exterior materials of buildings such as walls, ceilings, floors, window frames, doors, handrails, skirting boards, surrounding edges, surface decorative panels for furniture such as malls, peripheral products for kitchens, furniture or It can be used for decorative panels on cabinets such as light electric and OA equipment, interiors and exteriors of vehicles.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by this example.
(Evaluation method)
The decorative sheet obtained in each example was evaluated by the following methods.
(1) Cellophane tape resistance (evaluation of peel strength)
A cellophane tape (cellophane adhesive tape manufactured by Nichiban Co., Ltd., “cello tape (registered trademark)” 25 mm width) is strongly adhered to the surface of the decorative board obtained in Examples and Comparative Examples at room temperature. The cellophane tape was forcibly peeled in the direction of 90 degrees with the surface. The condition of the surface of the decorative board was evaluated according to the following criteria. The cellophane tape was peeled off in two cases: a case where the surface of the decorative board was scratched with a cutter (with a crosscut) and a case where the surface was not scratched (without a crosscut).
A: The test was carried out 10 times or more in the same place, but no peeling was observed.
B: The test was carried out five times or more at the same place, but no peeling was observed.
C: No peeling was observed at the first time, but peeling was observed at a part of the cellophane tape contact portion after the second time. There is no problem in practical use.
D: Peeling was observed at part of the cellophane tape contact part.
E: Peeling was observed over the entire surface of the cellophane tape contact portion.
(2) Evaluation of metallic design properties The metallic design properties of the decorative boards obtained in the examples and comparative examples were visually observed and evaluated according to the following criteria.
A: Metallic radiance can be confirmed evenly over the entire surface of the silver ink application region, and the color of the concealing layer is sufficiently concealed.
B: Although the metallic luster can be confirmed evenly over the entire area where the silver ink is applied, the color of the concealing layer can be seen through slightly. There is no problem in practical use.
C: Although the metallic shine can be confirmed, the color of the masking layer can be seen through. There is no problem in practical use.
D: A metallic luster is hardly confirmed, and a concealing layer is seen.
(3) Evaluation of specularity The state of the surface of the obtained decorative sheet was visually evaluated according to the following criteria.
A: Unevenness on the surface cannot be confirmed at all.
B: Unevenness on the surface can hardly be confirmed.
C: Some irregularities on the surface are confirmed, but there is no problem.
D: Surface irregularities are remarkable.
(4) Evaluation of contamination resistance According to JIS K-6902, the contaminant was applied to the surface of the cosmetic material, and the residual state of the contaminant after wiping off was visually observed. Judgment criteria were evaluated as follows.
A: No contaminants remain.
B: Contaminant remains, but it is minor and has no practical problem.
C: Contaminant remains remarkably.
(5) Evaluation of scratch resistance Steel wool (# 0000) is attached to a weight adjusted to a load of 29.4 kPa (300 g / cm ² ), and the surface of the cosmetic material is rubbed 50 times. The change in gloss was visually observed. Judgment criteria were evaluated as follows.
A: No change at all.
B: Although there is a change, it is minor and has no practical problem.
C: Change is remarkable.
(6) Evaluation of chemical resistance Hydrochloric acid (5% by mass), sodium hydroxide aqueous solution (5% by mass), residential detergent ("Sunpaul (trade name)" manufactured by Dainippon Insect Chrysanthemum), household mold remover ("Kabikiller (trade name)" manufactured by Johnson Co., Ltd.), kitchen bleach ("Kitchen Hiter (trade name)" manufactured by Kao Corporation) is applied to the surface of the cosmetic material, and the surface of the decorative sheet surface after wiping is removed. It was observed visually. Judgment criteria were evaluated as follows.
A: The state of the surface does not change at all.
B: A part of the surface was rough, but it was slight and had no problem in practical use.
C: The surface was extremely rough.
(7) Evaluation of water resistance The cosmetic material was immersed in a water bath containing 60 ° C. warm water for 168 hours, then immersed in a water layer containing 100 ° C. boiling water for 2 hours, and then allowed to stand at room temperature for 24 hours. It was visually observed whether changes such as blistering occurred. Judgment criteria were evaluated as follows.
A: No change at all.
B: Although there is a change, it is minor and has no practical problem.
C: Changes such as swelling are clear.
(8) Evaluation of weather resistance (appearance)
The decorative boards obtained in Examples and Comparative Examples were left under the conditions of the SWOM test specified in JIS A-6909, and then the appearance was visually evaluated and evaluated according to the following criteria.
A: No change at all.
B: A part of the surface can be lifted, but it is slight and has no practical problem.
C: The float of the surface is remarkable.

Example 1
A PET film (thickness 50 μm, manufactured by Toyobo Co., Ltd.) is used as the base material 2, and an ink having a polycarbonate resin as a binder on one side thereof is used to gravure a (full surface) layer having a coating amount of 3 g / m ^2. The masking layer 3 was formed by printing. The pattern layer 6 is formed by gravure printing using the same resin as the polyurethane / acrylic polyol resin forming the metallic layer 4 to be described later as a binder and using an ink containing a colorant mainly composed of a dial. did.
Next, polyurethane / acryl polyol resin (mixing ratio of polyurethane resin and acrylic polyol resin (mass ratio) = 25: 75) is used as a binder, and a metal pigment (particle size: 5 to 25 μm) is 100 parts by mass of resin solid content. Using the ink contained at a content ratio of 30 parts by mass, the metallic layer 4 is formed by gravure printing at a coating amount of 5 g / m ² , and the same polyurethane as used for forming the metallic layer 4 Using a coating composition having an acrylic polyol resin as a binder, gravure printing was performed on the entire surface at a coating amount of 2 g / m ² to form a permeation prevention layer 8.
On the ink layer, 100 parts by mass of an electron beam curable resin mainly composed of an electron beam curable resin and a polyfunctional monomer, so that 1 part by mass of a modified silicone (meth) acrylate and a solid content are 50%. An electron beam curable resin composition obtained by adding methyl ethyl ketone as a solvent was coated at a coating amount of 4 g / m ² by a gravure offset coater method. After coating, an electron beam with an acceleration voltage of 125 kV and an irradiation dose of 50 kGy (5 Mrad) was irradiated to cure the electron beam curable resin composition, whereby the surface protective layer 5 was obtained. Next, curing was performed at 70 ° C. for 24 hours to obtain a decorative sheet.
In addition, the back surface of the decorative sheet and a 3 mm thick volcanic glassy multilayer board (trade name: Dailite, manufactured by Daiken Kogyo Co., Ltd.) as the substrate, ethylene, which is an aqueous emulsion manufactured by Chuo Rika Co., Ltd. -A decorative board was prepared by bonding to a wood plywood with a vinyl acetate-based adhesive "BA-820" via an adhesive layer formed by coating the wood plywood under a coating amount of 60 g / m ² (wet).
The above-described various evaluations were performed on the obtained decorative sheet and decorative plate. The results are shown in Table 1.

Examples 2, 4, and 5, Comparative Examples 1 to 8, Reference Examples 1 and 2
In Example 1, except that the content of the metal pigment contained in the ink used for forming the metallic layer and the coating amount of the ionizing radiation curable resin composition were changed to those shown in Table 1, Example 1 and Similarly, a decorative sheet and a decorative board were produced.
The above-described various evaluations were performed on the obtained decorative sheet and decorative plate. The results are shown in Table 1.

Examples 7 , 8, 10, 11, Comparative Examples 9-16 , Reference Examples 3 and 4
In Example 1, the substrate is changed from a PET film to a paper substrate (manufactured by Kojin Co., Ltd., weighing: 60 g / m ² ), the solid content of the ionizing radiation curable resin composition, and the ionizing radiation curable resin composition Examples 7 , 8 and 10 were the same as in Example 1 except that the coating amount of the product, the ink used for forming the glossy layer, and the ink used for forming the pattern layer were changed to those shown in Table 2. 11 and Comparative Examples 9 to 16 and the decorative sheets and decorative plates of Reference Examples 3 and 4 were prepared. The obtained decorative sheet and decorative plate were subjected to the various evaluations described above except for (3) mirror surface evaluation. The results are shown in Table 2. The specularity was evaluated according to the following criteria.

(9) Evaluation of specularity The state of the surface of the decorative sheet obtained in Examples 7 , 8, 10, 11, Comparative Examples 9-16 and Reference Examples 3 and 4 was visually evaluated according to the following criteria.
a: Some unevenness derived from the paper base material is seen, but unevenness (unevenness) derived from ink soaking cannot be confirmed, and a design feeling having a unique specularity is sufficiently expressed b: Paper base Although the unevenness derived from the material and the unevenness (unevenness) derived from the infiltration of the ink are slightly confirmed, a design feeling having a unique specularity is expressed. C: Unevenness derived from some paper base material Unevenness (unevenness) derived from remarkable ink penetration is confirmed

  According to the present invention, it has excellent peel strength, excellent useability such as stain resistance, scratch resistance, water resistance, chemical resistance, and weather resistance, and excellent surface specularity and high glossiness. A decorative sheet obtained by bonding the sheet and the substrate to the decorative sheet can be obtained.

1. Cosmetic sheet Base material 3. Concealment layer 4. Metallic layer 5. Surface protective layer 6. Pattern layer 7. 8. Penetration preventing layer Adhesive layer 10. substrate

Claims (6)

A decorative sheet in which at least a concealing layer, a metallic layer, and a surface protective layer are sequentially laminated on a substrate, and the content ratio of the glitter pigment contained in the metallic layer is 100 parts by mass of the resin solid content of the metallic layer against a range of 20 to 40 parts by mass, a thickness of the metallic layer is 5 to 30 [mu] m, surface protective layer is crosslinked cured ionizing radiation-curable resin composition, and the ionizing radiation-curable decorative sheet coating amount of the resin composition is characterized by a 3 to 8 g / m ^2.   The decorative sheet according to claim 1, further comprising a penetration preventing layer between the metallic layer and the surface protective layer.   The decorative sheet according to claim 1 or 2, wherein the glitter pigment is a metal pigment.   The decorative sheet according to any one of claims 1 to 3, wherein the substrate comprises a paper substrate or a polyethylene terephthalate resin. The decorative sheet according to any one of claims 1 to 4, wherein the ionizing radiation curable resin composition is an electron beam curable resin composition. A decorative board formed by bonding a substrate and the decorative sheet according to any one of claims 1 to 5 via an adhesive layer.

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