JP6915489B2 - A decorative sheet, a decorative board provided with the decorative sheet, and a method for manufacturing the same. - Google Patents

Description

The present invention relates to a decorative sheet, a decorative board provided with the decorative sheet, and a method for producing the same.

Conventionally, the surfaces of tables, counters, walls, floors, etc. are impregnated with an uncured resin solution of melamine resin on a paper base material such as titanium paper, and if necessary, laminated on a core paper such as phenol resin impregnated paper. , A melamine decorative board manufactured by curing an uncured melamine resin by a hot press is used.

On the other hand, in order to express a high-class design, the surface of the decorative board is provided with an uneven shape. As such an uneven shape, a gloss matte uneven shape is known (for example, Patent Documents 1 and 2). The gloss matte uneven shape means an uneven shape in which a high gloss region and a low gloss region are mixed in a pattern on the surface of an article. On the surface of an article having a gloss matte uneven shape, the low gloss region visually looks recessed as compared with the high gloss region, regardless of the physical unevenness, thereby expressing a three-dimensional design feeling. ..

Patent Document 3 discloses a decorative board capable of expressing a gloss matte-like design feeling and a method for manufacturing the decorative board. The decorative board described in Patent Document 3 includes a paper base material, a release layer provided on a part of the surface of the paper material base material and containing a cured product of an ionizing thermosetting resin, and the rest of the surface of the paper material base material. It is provided with a surface layer containing a cured product of a melamine resin provided on (a portion of the surface of a paper substrate on which a release layer is not provided). The decorative board described in Patent Document 3 is a step of providing a release layer on a part of the surface of a paper-based base material, impregnating the paper-based base material with an uncured melamine resin, and using the uncured melamine resin to form a release layer. It is produced by a method including a step of thermally curing the uncured melamine resin by heating after coating the melamine resin and a step of peeling off the cured resin film covering the release layer.

Special Publication No. 49-39166 Special Fair 1-20065 Gazette International Publication No. 2016/148091

When the permeability of the ionizing radiation curable resin to the paper substrate is large, the thickness of the release layer is reduced, and as a result, the thickness of the cured resin film covering the release layer is increased, and the cured resin film covering the release layer is increased. May remain without being peeled off from the release layer. On the other hand, if the permeability of the uncured melamine resin to the paper substrate is small, the impregnation of the uncured melamine resin to the paper substrate is insufficient, and as a result, the surface layer may peel off from the paper substrate. .. Therefore, it is preferable that the permeability of the ionizing radiation curable resin to the paper substrate is small and the permeability of the uncured product of the melamine resin to the paper substrate is large.

The permeability of the uncured material of the ionizing radiation curable resin and the melamine resin to the paper base material should be adjusted by selecting the type of the paper base material (for example, the type and amount of the inorganic component contained in the paper base material). Can be done. However, if the permeability of the ionizing radiation curable resin to the paper substrate is reduced, the permeability of the uncured melamine resin to the paper substrate is also reduced, while the permeability of the uncured melamine resin to the paper substrate is reduced. Increasing the value also increases the permeability of the ionizing thermosetting resin to the paper substrate. Therefore, it is difficult to reduce the permeability of the ionizing radiation curable resin to the paper substrate and increase the permeability of the uncured melamine resin to the paper substrate only by selecting the type of the paper substrate.

Therefore, the present invention comprises a decorative sheet provided with a coating layer capable of suppressing the permeation of the ionizing radiation curable resin into the paper substrate without inhibiting the permeation of the uncured melamine resin into the paper substrate. A main object is to provide a decorative board provided with the decorative sheet and a method for producing the same.

In order to solve the above problems, the present invention includes the following inventions.
[1] A decorative sheet comprising a first surface and a support layer having a second surface located on the opposite side of the first surface, and a release layer provided on a part of the first surface of the support layer.
The support layer comprises a paper substrate and a coating layer forming the first surface of the support layer.
The release layer contains a cured product of an ionizing radiation curable resin.
A decorative sheet in which the coating layer contains casein in an amount of 35% by mass or more and 85% by mass or less based on the total mass of the coating layer.
[2] The decorative sheet according to [1], wherein the coating layer contains a dried product of an acrylic resin emulsion in an amount of 15% by mass or more and 65% by mass or less based on the total mass of the coating layer.
[3] The decorative sheet according to [1] or [2], wherein the paper base material contains an inorganic component.
[4] The decorative sheet according to [3], wherein the inorganic component contains titanium oxide.
[5] The decorative sheet according to [4], wherein the amount of titanium oxide contained in the paper-based base material is 5% by mass or more and 40% by mass or less based on the total mass of the paper-based base material.
[6] The decorative sheet according to any one of [1] to [5], wherein the release layer contains a silicone-based release agent.
[7] The decorative sheet according to any one of [1] to [6], wherein the support layer further includes a decorative layer located between the paper base material and the coating layer.
[8] The core layer, the decorative sheet according to any one of [1] to [7] provided on the core layer, and the surface layer provided on the rest of the first surface of the support layer of the decorative sheet. A decorative board provided with a cured product of melamine resin filled in the voids of the paper-based base material of the decorative sheet.
The surface layer contains a cured product of melamine resin and contains
The surface layer has an opening that exposes the surface of the release layer of the decorative sheet.
The opening of the surface layer forms a recess on the surface of the decorative board.
A decorative board in which a cured product of melamine resin contained in the surface layer is integrated with a cured product of melamine resin filled in the voids of a paper substrate.
[9] The method for manufacturing a decorative board according to [8].
(1) Step of preparing the decorative sheet according to any one of [1] to [7] (2) The melamine resin filled in the voids of the paper-based substrate by impregnating the decorative sheet with the uncured melamine resin composition. A step of forming an impregnated decorative sheet including an uncured product and an uncured melamine resin layer that covers the rest of the first surface of the support layer and the release layer.
(3) A step of laminating the impregnated decorative sheet on the precursor layer of the core layer,
(4) A step of curing the uncured melamine resin and the uncured melamine resin layer filled in the voids of the paper substrate, and
(5) Of the precursor layer of the surface layer formed by curing the uncured melamine resin layer, the step of peeling off the portion covering the release layer and forming the surface layer on the rest of the first surface of the support layer is included. ,Method.

According to the present invention, a decorative board provided with a coating layer capable of suppressing the penetration of an ionizing radiation curable resin into a paper substrate without inhibiting the penetration of the uncured melamine resin into the paper substrate, and the production thereof. A method is provided.

FIG. 1 is a plan view of a decorative board according to an embodiment of the present invention. FIG. 2 is an enlarged view of a region represented by reference numeral R in FIG. FIG. 3 is a cross-sectional view taken along the line AA of FIG. FIG. 4 is a cross-sectional view taken along the line BB of FIG. FIG. 5 is an explanatory diagram for explaining an embodiment of the method for manufacturing a decorative board shown in FIG. FIG. 6 is an explanatory diagram (continuation of FIG. 5) for explaining one embodiment of the method for manufacturing a decorative board shown in FIG. FIG. 7 is an explanatory diagram (continuation of FIG. 6) for explaining one embodiment of the method for manufacturing a decorative board shown in FIG. FIG. 8 is an explanatory diagram for explaining a method of measuring the peeling weight.

Decorative board The decorative board 10 according to the embodiment of the present invention will be described below with reference to the drawings. 1 is a plan view of the decorative board 10, FIG. 2 is an enlarged view of a region indicated by reference numeral R in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line AA of FIG. 4 is a cross-sectional view taken along the line BB of FIG.

As shown in FIGS. 1 to 4, the decorative board 10 has a first direction X, a second direction Y, and a thickness direction Z that are orthogonal to each other. In the present embodiment, the first direction X corresponds to the longitudinal direction of the decorative plate 10, the second direction Y corresponds to the lateral direction of the decorative plate 10, but the first direction X corresponds to the lateral direction of the decorative plate 10. The second direction Y may correspond to the longitudinal direction of the decorative plate 10.

As shown in FIGS. 1 to 4, the decorative plate 10 has a first surface S10 and a second surface T10 located on the opposite side of the first surface S10.

As shown in FIGS. 3 and 4, the decorative board 10 includes a core layer 1, a decorative sheet 2 provided on the core layer 1, and a surface layer 3 provided on the decorative sheet 2.

Core layer The core layer 1 can be configured in the same manner as the core layer generally used in the field of decorative boards. The core layer 1 has, for example, a porous base material and a cured product of a thermosetting resin filled in the voids of the porous base material.

Examples of the porous substrate include a fiber sheet and the like. Examples of the fiber sheet include paper, non-woven fabric, and woven fabric. Examples of paper include titanium paper, thin leaf paper, kraft paper, linter paper, paperboard, gypsum board paper, so-called vinyl wallpaper raw fabric, which is sol-coated or dry-laminated with polyvinyl chloride resin, high-quality paper, coated paper, and parchment paper. Japanese paper and the like can be mentioned. Other fiber sheets include, for example, sheets composed of inorganic fibers such as glass fiber, asbestos, potassium titanate fiber, alumina fiber, silica fiber and carbon fiber; synthetic resin fibers such as polyester, vinylon, polyethylene and polypropylene. Examples include sheets to be constructed.

Examples of the thermosetting resin include phenol resin, unsaturated polyester resin, polyurethane resin (including two-component curable polyurethane), epoxy resin, aminoalkyd resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, and melamine. -Urea cocondensation resin, silicon resin, polysiloxane resin and the like can be mentioned.

As the precursor layer of the core layer 1, for example, a thermosetting resin impregnated sheet can be used. The core layer 1 can be formed, for example, by heating a thermosetting resin impregnated sheet to cure the thermosetting resin. Examples of the thermosetting resin-impregnated sheet include phenol resin-impregnated paper, which is widely used as the core paper for melamine decorative boards. The thermosetting resin can be cured, for example, in a step of thermosetting a thermosetting resin impregnated sheet together with other layers (for example, a decorative sheet 2 or the like).

The phenol resin impregnated paper is, for example, ^{kraft paper having a basis weight of 150 g / m 2} or more and 250 g / m ² or less as a core paper impregnated with phenol resin so as to have an impregnation rate of 45% or more and 60% or less, and 100 ° C. or more and 140 ° C. It can be produced by drying below. Commercially available phenol resin impregnated paper may be used.

The thermosetting resin impregnated sheet may be a prepreg based on a glass cloth or a glass non-woven fabric. The prepreg can be produced, for example, by impregnating a glass cloth or a glass non-woven fabric with a thermosetting resin.

The thickness of the core layer 1 can be adjusted as appropriate, but is preferably 300 μm or more and 1750 μm or less, and more preferably 300 μm or more and 1400 μm or less.

The decorative board 10 may have a reinforcing layer laminated on one surface or both surfaces of the core layer 1, if necessary. For example, in order to hide the blackish brown color tone of the core paper from being seen through from the surface of the decorative plate 10, a barrier paper made of titanium paper mixed with titanium white pigment is placed between the core layer 1 and the support layer 21. Can be laminated. Further, in order to offset the warp of the decorative plate 10 generated during thermal pressure molding, a balance paper or the like made of titanium paper is laminated on the back surface of the core layer 1 (the surface on the second surface T10 side of the core layer 1). be able to. These reinforcing layers are impregnated with an uncured resin composition containing a thermosetting resin such as a melamine resin, and then hot-press molded together with other layers (for example, core layer 1, decorative sheet 2, etc.). Allows it to be integrated with other layers.

Decorative sheet As shown in FIGS. 3 and 4, the decorative sheet 2 has a support layer 21 having a second surface T21 located on the opposite side of the first surface S21 and the first surface S21, and the first surface of the support layer 21. A mold release layer 22 provided in a part of S21 is provided.

Support layer As shown in FIGS. 3 and 4, the support layer 21 is formed between the paper base material 211, the coating layer 212 forming the first surface S21 of the support layer 21, and the paper base material 211 and the coating layer 212. It is provided with a decorative layer 213 located at.

Paper-based base material The paper-based base material 211 can be appropriately selected from base papers generally used in the field of decorative boards or decorative papers. Examples of the paper base material 211 include titanium paper, thin leaf paper, kraft paper, coated paper, art paper, sulfate paper, glassin paper, parchment paper, paraffin paper, Japanese paper and the like.

The basis weight of the paper base material 211 can be adjusted as appropriate, but is preferably 30 g / m ² or more and 200 g / m ² or less, and more preferably 40 g / m ² or more and 150 g / m ² or less.

The thickness of the paper base material 211 can be adjusted as appropriate, but is preferably 30 μm or more and 200 μm or less, and more preferably 50 μm or more and 170 μm or less.

The paper base material 211 preferably contains an inorganic component. The inorganic component contained in the paper base material 211 may be one kind or two or more kinds. The paper-based base material 211 containing an inorganic component can be produced, for example, by blending an inorganic component with a raw material of paper and making the inorganic component into paper in a papermaking process.

The inorganic component can be appropriately selected from the inorganic components generally used in the field of decorative boards or decorative papers. Examples of the inorganic component include an inorganic filler (inorganic filler), an inorganic pigment, and the like.

Examples of the inorganic filler include titanium oxide, calcium oxide, magnesium oxide, zinc oxide, calcium carbonate, magnesium carbonate, silica, kaolin, clay, barium sulfate, calcium hydroxide, aluminum hydroxide, alumina, magnesium hydroxide, and talc. , Mica, hydrotalcite, aluminum silicate, magnesium silicate, calcium silicate, calcined talc, wollastonite, potassium titanate, magnesium sulfate, calcium sulfate, magnesium phosphate and the like.

Examples of inorganic pigments include titanium oxide, zinc oxide, carbon black, black iron oxide, yellow iron oxide, chrome yellow, molybdate orange, cadmium yellow, nickel titanium yellow, iron oxide (valve handle), cadmium red, and ultramarine. Navy blue, cobalt blue, chromium oxide, cobalt green, aluminum powder, bronze powder, mica titanium, zinc sulfide and the like can be mentioned.

The inorganic component is, for example, inorganic particles. The average particle size of the inorganic particles is not particularly limited, but is preferably 0.1 μm or more and 50 μm or less, and more preferably 0.1 μm or more and 10 μm or less. The average particle size means the median diameter of the volume-based particle size distribution measured by the laser diffraction / scattering method.

The inorganic component is preferably titanium oxide. Paper containing titanium oxide is called titanium paper. As the amount of titanium oxide contained in the paper-based base material 211 is increased, the permeability of the uncured product of the ionizing radiation curable resin and the melamine resin to the paper-based base material 211 can be improved.

The amount of the inorganic component contained in the paper base material 211 can be appropriately adjusted according to the type of the inorganic component and the like. The amount of titanium oxide contained in the paper-based base material 211 is preferably 5% by mass or more and 50% by mass or less, and more preferably 5% by mass or more and 40% by mass or less, based on the total mass of the paper-based base material 211. The total mass of the paper-based base material 211 means the total mass of the paper-based base material 211 when dried (that is, the total mass of the solid content in the paper-based base material 211).

Coating layer The coating layer 212 is provided on the decorative layer 213 and forms the first surface S21 of the support layer 21. The coating layer 212 may form a part of the first surface S21 of the support layer 21, but it is preferable that the coating layer 212 forms the entire first surface S21 of the support layer 21.

The coating layer 212 contains casein in an amount of 35% by mass or more and 85% by mass or less based on the total mass of the coating layer 212. As a result, the permeation of the ionizing radiation curable resin into the paper base material 211 can be suppressed without inhibiting the permeation of the uncured product of the melamine resin into the paper base material 211. The amount of casein contained in the coating layer 212 is preferably 40% by mass or more and 80% by mass or less, and more preferably 40% by mass or more and 60% by mass or less, based on the total mass of the coating layer 212. The total mass of the coating layer 212 means the total mass of the coating layer 212 when dried (that is, the total mass of the solid content in the coating layer 212).

As casein, α-casein, β-casein, γ-casein or a mixture thereof can be used.

The coating layer 212 preferably contains a dried product of an acrylic resin emulsion (water-based acrylic resin). The amount of the dried product of the acrylic resin emulsion contained in the coating layer 212 is preferably 15% by mass or more and 65% by mass or less, more preferably 20% by mass or more and 60% by mass or less, based on the total mass of the coating layer 212. More preferably, it is 40% by mass or more and 60% by mass or less. The total mass of the coating layer 212 means the total mass of the coating layer 212 when dried (that is, the total mass of the solid content in the coating layer 212).

Examples of the acrylic resin contained in the acrylic resin emulsion include carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and fumaric acid, methyl (meth) acrylic acid, ethyl (meth) acrylic acid, and (meth) acrylic. Alkyl (meth) acrylate monomers such as acid (iso) propyl and (meth) acrylate (iso) butyl, aromatic monomers such as styrene, vinyltoluene, and chlorostyrene, dimethyl maleate, dimethyl fumarate, and itacon. Dibasic acid diester monomers such as dimethyl acid, diethyl maleate, diethyl fumarate, diethyl itacone, acrylonitrile, n-butoxymethyl (meth) acrylamide, vinyl acetate, monomers such as acetoacetoxyethyl (meth) acrylate, or Examples thereof include a resin obtained by copolymerizing these mixtures.

Copolymerization of a mixture of monomers can be carried out, for example, by emulsion polymerization. An acrylic resin emulsion can be obtained by emulsion polymerization of a mixture of monomers. Emulsion polymerization can be carried out in water, for example, in the presence of an emulsifier. Examples of the emulsifier include anionic emulsifiers such as potassium oleate, sodium laurate, sodium dodecylbenzene sulfonate, sodium alkylnaphthalene sulfonate, sodium polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl ether, and polyoxyethylene oxypropylene. Nonionic emulsifiers such as block polymers and reactive emulsifiers such as polyethylene glycol mono (meth) acrylate, 2- (meth) acryloyloxyethyl sulfonate ammonium, (meth) acryloyl polyoxyalkylene alkyl ether phosphate and the like can be mentioned. .. Examples of the polymerization initiator in emulsion polymerization include water-soluble polymerization initiators such as peroxides such as ammonium persulfate, potassium persulfate, sodium persulfate, hydrogen peroxide, and peroxyesters. The polymerization initiator may be used in combination with a reducing agent such as ferrous chloride, ferrous sulfate, or L-ascorbic acid. Chain transfer agents such as n-dodecyl mercaptan may be used for molecular weight adjustment.

The weight average molecular weight of the acrylic resin contained in the acrylic resin emulsion is preferably 50,000 or more and 300,000 or less, and more preferably 50,000 or more and 200,000 or less. The "weight average molecular weight" is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

The amount of the acrylic resin contained in the acrylic resin emulsion is preferably 15% by mass or more and 65% by mass or less, more preferably 20% by mass or more and 60% by mass or less, still more preferably 40, based on the total mass of the acrylic resin emulsion. It is mass% or more and 60 mass% or less.

Examples of the aqueous solvent contained in the acrylic resin emulsion include water, an alcohol solvent and the like. Examples of the alcohol solvent include methanol, ethanol, isopropanol, n-butanol, ethyl cellosolve, butyl cellosolve, 1-methoxy-2-propanol, diacetone alcohol and the like. As the aqueous solvent, one type may be used alone, or two or more types may be used in combination.

The glass transition temperature (Tg) of the acrylic resin emulsion is preferably −30 ° C. or higher and 70 ° C. or lower, and more preferably −30 ° C. or higher and 50 ° C. or lower. As the acrylic resin emulsion, it is preferable to use a mixture of an acrylic resin emulsion (A) having a Tg of −30 ° C. or higher and 10 ° C. or lower and an acrylic resin emulsion (B) having a Tg of 10 ° C. or higher and 50 ° C. or lower. The acrylic resin emulsion (A) is mainly involved in viscosity adjustment, and the acrylic resin emulsion (B) is mainly involved in film formation. The acrylic resin emulsions (A) and (B) may be used alone. The mixing ratio of the acrylic resin emulsion (A) and the acrylic resin emulsion (B) (mass of the acrylic resin emulsion (A): mass of the acrylic resin emulsion (B)) is preferably 2: 1 to 1:15, more preferably. Is 2: 1 to 1:10. The Tg can be obtained by calculation from the Tg and the composition ratio of the homopolymer of each monomer in the monomer mixture.

The thickness of the coating layer 212 can be adjusted as appropriate, but is preferably 1 μm or more and 20 μm or less, and more preferably 1 μm or more and 5 μm or less.

Decorative layer The decorative layer 213 is provided on the paper-based base material 211 and is located between the paper-based base material 211 and the coating layer 212. The decorative layer 213 is a layer provided as needed, and the present invention also includes an embodiment in which the decorative layer 213 is omitted. In the embodiment in which the decorative layer 213 is omitted, the coating layer 212 is provided on the paper-based base material 211.

The decorative layer 213 imparts decorativeness (design) to the decorative board 10. The decorative layer 213 is, for example, a colored layer, a pattern layer, or a combination thereof.

The colored layer imparts a desired color to the decorative board 10. The colored layer is, for example, a solid layer formed on the entire surface of the paper substrate 211 on the first surface S21 side. The color of the colored layer is usually an opaque color, but it may be a transparent color when the color or pattern of the base such as the paper-based base material 211 is utilized. Further, when the color or pattern of the base material such as the paper-based base material 211 is utilized, it is not necessary to form the colored layer.

The pattern layer imparts a desired pattern to the decorative board 10. The pattern layer is, for example, a printing layer formed on a part or the whole of the surface of the paper substrate 211 on the first side S21 side or a part or the whole of the surface of the colored layer on the first side S21 side. The patterns constituting the pattern layer include, for example, wood grain patterns composed of spring and autumn wood regions of annual ring cross sections, conduits, leather (skin grain) patterns, and stones on the surface of stone materials such as marble, granite, and sand rock. Examples include eye patterns, grain patterns, tiled patterns, brickwork patterns, cloth patterns, geometric figures, characters, symbols, and abstract patterns.

As shown in FIG. 1, the decorative layer 213 in the present embodiment imparts a wood grain pattern to the decorative board 10.

The thickness of the decorative layer 213 can be adjusted as appropriate, but is preferably 0.1 μm or more and 50 μm or less, and more preferably 0.1 μm or more and 20 μm or less.

Release layer The release layer 22 is provided on a part of the first surface S21 of the support layer 21. Of the first surface S21 of the support layer 21, the region where the release layer 22 is provided may be one continuous region or a plurality of discontinuous regions. The release layer 22 may be composed of one continuous layer or may be composed of a plurality of discontinuous layers. When the release layer 22 is composed of one continuous layer, the thickness of the release layer 22 may be constant or may be partially different. When the release layer 22 is composed of a plurality of discontinuous layers, the thickness of each layer may be constant or may be partially different. When the release layer 22 is composed of a plurality of discontinuous layers, the thickness of one layer and the thickness of another layer may be the same or different. The thickness of the release layer 22 can be adjusted as appropriate, but is preferably 0.1 μm or more and 50 μm or less, and more preferably 0.1 μm or more and 20 μm or less.

The release layer 22 is preferably formed on the first surface S21 of the support layer 21 in a predetermined pattern (pattern pattern), and is visually recessed or has low gloss (艷) among the pattern patterns formed by the decorative layer 213. It is more preferable that the pattern is aligned with the region to be erased). As a pattern formed by the release layer 22, for example, when the decorative layer 213 has a wood grain pattern, a conduit portion of the wood grain board, a concave or low gloss area such as a spring wood area, and when the decorative layer 213 has a stone grain pattern, a recess of a travertin marble plate. Part, stone plate surface unevenness such as recesses on the open surface of the granite board, cloth surface texture in the case of cloth pattern, wrinkle shape of leather grain in the case of leather pattern, joint recess in the case of tiled pattern or brickwork pattern, etc. In addition, patterns such as satin finish, grain, hairline, brick groove, letters, symbols, and geometric patterns can be mentioned.

The release layer 22 is a layer formed by curing a composition containing an ionizing radiation curable resin (composition for forming a release layer), and contains a cured product of the ionizing radiation curable resin. As the release layer forming composition, a liquid composition containing an ionizing radiation curable resin is usually used.

The ionizing radiation curable resin is a resin that undergoes a cross-linking polymerization reaction by irradiation with ionizing radiation and changes into a three-dimensional polymer structure. Examples of the ionizing radiation include visible light, ultraviolet rays (near ultraviolet rays, vacuum ultraviolet rays, etc.), X-rays, electron beams, ionizing rays, etc., but ultraviolet rays, electron beams, etc. are preferable.

As the ionizing radiation curable resin, for example, one or more kinds of monomers, oligomers, prepolymers and the like having a polymerizable unsaturated bond, an epoxy group or the like in the molecule which can be crosslinked by irradiation with ionizing radiation can be used. In particular, it is preferable to use one or more of the polyfunctional monomer and the oligomer. Examples of the ionizing radiation curable resin include acrylate resins such as urethane acrylate, polyester acrylate and epoxy acrylate, silicon resins such as siloxane, polyester resins and epoxy resins.

Examples of the polymerizable monomer include (meth) acrylate-based monomers having a radically polymerizable unsaturated group in the molecule. In particular, polyfunctional (meth) acrylates are preferred. In addition, "(meth) acrylate" means acrylate or methacrylate. The polyfunctional (meth) acrylate may be any (meth) acrylate having two or more ethylenically unsaturated bonds in the molecule, and is not particularly limited. One type of polyfunctional (meth) acrylate may be used alone, or two or more types may be used in combination. A monofunctional (meth) acrylate may be used in combination with the polyfunctional (meth) acrylate for the purpose of lowering the viscosity thereof.

Examples of the polymerizable oligomer include oligomers having a radically polymerizable unsaturated group in the molecule, such as epoxy (meth) acrylate-based, urethane (meth) acrylate-based, polyester (meth) acrylate-based, and polyether (meth) acrylate-based. Can be mentioned. Further, as the polymerizable oligomer, a highly hydrophobic polybutadiene (meth) acrylate-based oligomer having a (meth) acrylate group in the side chain of the polybutadiene oligomer, a silicone (meth) acrylate-based oligomer having a polysiloxane bond in the main chain, and a small one. Examples thereof include aminoplast resin (meth) acrylate-based oligomers obtained by modifying an aminoplast resin having many reactive groups in the molecule. Examples of the oligomer having a cationically polymerizable functional group in the molecule include novolak type epoxy resin, bisphenol type epoxy resin, aliphatic vinyl ether, aromatic vinyl ether and the like.

The weight average molecular weight of the ionizing radiation curable resin is preferably 500 or more, more preferably 1000 or more. When the weight average molecular weight of the ionizing radiation curable resin is within the above range, when the release layer forming composition is applied to the support layer 21, the release layer forming composition does not easily penetrate into the support layer 21. It is easy to form a coating film of the composition for forming a release layer.

The weight average molecular weight of the ionizing radiation curable resin is preferably 80,000 or less, more preferably 50,000 or less. When the weight average molecular weight of the ionizing radiation curable resin is in the above range, the viscosity of the release layer forming composition can be easily adjusted to a viscosity suitable for coating.

The "weight average molecular weight" is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

The ionizing radiation curable resin is preferably at least one selected from polyfunctional monomers and oligomers having a weight average molecular weight of 500 or more. Examples of such a polyfunctional monomer or oligomer include acrylate resins such as dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, urethane acrylate, polyester acrylate, and epoxy acrylate.

If necessary, the release layer forming composition may contain a component involved in the curing reaction of the ionizing radiation curable resin, for example, a photopolymerization initiator (sensitizer). For example, when the ionizing radiation curable resin is cured by irradiation with ultraviolet rays, the composition for forming a release layer preferably contains a photopolymerization initiator (sensitizer). Since the ionizing radiation curable resin is sufficiently cured by irradiating it with an electron beam, when the ionizing radiation curable resin is cured by irradiating it with an electron beam, the release layer forming composition is a photopolymerization initiator (sensitization). Agent) may not be included.

When the ionizing radiation curable resin has a radically polymerizable unsaturated group, the photopolymerization initiator includes, for example, acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether, Michler benzoyl benzoate, Michler ketone, diphenyl sulfide, etc. At least one of dibenzyldisulfide, diethyl oxide, triphenylbiimidazole, isopropyl-N, N-dimethylaminobenzoate and the like can be used. When the ionizing radiation curable resin has a cationically polymerizable functional group, examples of the photopolymerization initiator include aromatic diazonium salts, aromatic sulfonium salts, metallocene compounds, benzoin sulfonic acid esters, and freeleoxysulfoxonium. At least one kind such as diallyl iodosyl salt can be used.

The amount of the photopolymerization initiator contained in the release layer forming composition is not particularly limited, but is usually 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the ionizing radiation curable resin.

The release layer 22 is, if necessary, a solvent-drying resin (a resin such as a thermoplastic resin that can be formed into a film simply by drying a solvent added to adjust the solid content at the time of coating) and thermosetting. It may contain a sex resin or the like.

By adding the solvent-drying resin to the release layer forming composition, it is possible to effectively prevent film defects on the coated surface of the release layer forming composition when the release layer 22 is formed. As the solvent-drying resin, for example, a thermoplastic resin can be used, and as the thermoplastic resin, for example, a styrene resin, a (meth) acrylic resin, a vinyl acetate resin, a vinyl ether resin, or a halogen-containing resin can be used. , Alicyclic olefin resin, polycarbonate resin, polyester resin, polyamide resin, cellulose derivative, silicone resin and rubber or elastomer. Examples of the thermosetting resin include phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine-urea cocondensation resin, and silicon resin. Examples thereof include polysiloxane resin.

The release layer 22 may contain a silicone-based release agent. The silicone-based mold release agent contained in the release layer 22 is derived from the silicone-based mold release agent (silicone oil) added to the release layer forming composition. The silicone-based mold release agent added to the release layer forming composition may be a reactive silicone-based mold release agent or a non-reactive silicone-based mold release agent. When the silicone-based mold release agent added to the release layer forming composition is a reactive silicone-based mold release agent, the silicone-based mold release agent is the other component of the release layer 22 (for example, a curable resin). It can be contained in the release layer 22 in a state of being bound to a cured product or the like). One type of silicone release agent may be used alone, or two or more types may be used in combination.

The silicone release agent is a modified silicone having an organopolysiloxane structure as a basic structure and having an organic group introduced into a side chain and / or a terminal. The end into which the organic machine is introduced may be one end or both ends.

The reactive silicone-based release agent refers to a modified silicone having an organic group introduced into the side chain and / or the terminal, which is reactive depending on the nature of the organic group to be introduced. Examples of the reactive silicone-based release agent include amino-modified silicone, epoxy-modified silicone, mercapto-modified silicone, carboxyl-modified silicone, carbinol-modified silicone, phenol-modified silicone, methacryl-modified silicone, and heterogeneous functional group-modified silicone. .. More specifically, amino-modified polydimethylsiloxane, epoxy-modified polydimethylsiloxane, mercapto-modified polydimethylsiloxane, carboxyl-modified polydimethylsiloxane, carbinol-modified polydimethylsiloxane, phenol-modified polydimethylsiloxane, methacryl-modified polydimethylsiloxane, heterologous. Examples thereof include functional group-modified polydimethylsiloxane. As the reactive silicone-based release agent, one type may be used alone, or two or more types may be used in combination.

The non-reactive silicone-based release agent is not particularly limited as long as it is a silicone having no reactive functional group such as an amino group, an epoxy group, a mercapto group, a carboxy group, a hydroxy group, a (meth) acryloyl group and an allyl group. Examples of the non-reactive silicone-based release agent include silicone composed of polysiloxane, polyether-modified silicone, aralkyl-modified silicone, fluoroalkyl-modified silicone, long-chain alkyl-modified silicone, higher fatty acid ester-modified silicone, and higher fatty acid amide. Examples thereof include modified silicone and phenyl-modified silicone. More specifically, polyether-modified polydimethylsiloxane, aralkyl-modified polydimethylsiloxane, fluoroalkyl-modified polydimethylsiloxane, long-chain alkyl-modified polydimethylsiloxane, higher fatty acid ester-modified polydimethylsiloxane, higher fatty acid amide-modified polydimethylsiloxane, Examples thereof include phenyl-modified polydimethylsiloxane. One type of non-reactive silicone-based release agent may be used alone, or two or more types may be used in combination.

It is preferable to use a polyether-modified silicone as the silicone-based release agent. The polyether-modified silicone has a polysiloxane main chain and has one or more polyoxyalkylene groups as substituents. The main chain may form a ring.

The bonding position of the polyoxyalkylene group in the polyether-modified silicone can be any suitable bonding position. For example, the polyoxyalkylene group may be attached to both ends of the main chain, to one end of the main chain, or to the side chain. The polyether-modified silicone is preferably a side-chain type polyether-modified silicone in which a polyoxyalkylene group is bonded to a side chain.

The side chain type polyether-modified silicone is represented by, for example, the general formula (1).

In the general formula (1), R independently represents an alkyl group having 1 to 3 carbon atoms, R ¹ represents an alkylene group having 1 to 4 ^{carbon atoms, and R 2} represents a hydrogen atom or 1 to 15 carbon atoms. Representing an alkyl group, R ³ _{is a} polyoxyalkylene group represented by − (C ₂ H ₄ O) a − (C ₃ H ₆ O) _b −, a is 1 to 50, and b is 0 to 0. It is 30, m is 1 to 7000, and n is 1 to 50.

In the general formula (1), R is preferably a methyl group.

Examples of the polyether-modified silicone include trade names "KF-6011" (HLB: 14.5), "KF-6011P" (HLB: 14.5), and "KF-6012" manufactured by Shin-Etsu Silicone Co., Ltd. HLB: 7.0), "KF-6013" (HLB: 10.0), "KF-6015" (HLB: 4.5), "KF-6016" (HLB: 4.5), "KF-6017" (HLB: 4.5), "KF-6017P" (HLB: 4.5), "KF-6043" (HLB: 14.5), "KF-6004" (HLB: 9.0), "KF351A" (HLB: 12), "KF352A" (HLB: 7), "KF353" (HLB: 10), "KF354L" (HLB: 16), "KF355A" (HLB: 12), "KF615A" (HLB: 10) ), "KF945" (HLB: 4), "KF-640" (HLB: 14), "KF-642" (HLB: 12), "KF-643" (HLB: 14), "KF-644" ( Side-chain type (linear type) polyether modification such as HLB: 11), "KF-6020" (HLB: 4), "KF-6204" (HLB: 10), "X22-4515" (HLB: 5) Silicone oil; side chain type (branched chain type) polyether modification such as trade name "KF-6028" (HLB: 4.0), "KF-6028P" (HLB: 4.0) manufactured by Shin-Etsu Silicone Co., Ltd. Silicone oil; side chain type (branched chain type, alkyl co-modified type) polyether-modified silicone oil such as trade name "KF-6038" (HLB: 3.0) manufactured by Shin-Etsu Silicone Co., Ltd. can be mentioned.

Surface layer As shown in FIGS. 2 to 4, the surface layer 3 is provided on the rest of the first surface S21 of the support layer 21 and surrounds a part or the whole of the release layer 22. The rest of the first surface S21 of the support layer 21 means a region of the first surface S21 of the support layer 21 in which the release layer 22 is not formed. Of the first surface S21 of the support layer 21, the region where the surface layer 3 is formed may be the entire remaining portion of the first surface S21 or may be a part of the remaining portion of the first surface S21. .. Of the first surface S21 of the support layer 21, the region where the surface layer 3 is formed may be one continuous region or a plurality of discontinuous regions. The surface layer 3 may be composed of one continuous layer or may be composed of a plurality of discontinuous layers. When the surface layer 3 is composed of one continuous layer, the thickness of the surface layer 3 may be constant or may be partially different. When the surface layer 3 is composed of a plurality of discontinuous layers, the thickness of each layer may be constant or may be partially different. When the surface layer 3 is composed of a plurality of discontinuous layers, the thickness of one layer and the thickness of another layer may be the same or different.

The ratio (Sa: Sb) of the area (Sa) of the region where the surface layer 3 is formed to the area (Sb) where the release layer 22 is formed in the first surface S21 of the support layer 21 is preferable. It is 3: 7 to 9: 1, more preferably 5: 5 to 8: 2. When the area ratio is within the above range, the design feeling of the uneven shape expressed by the decorative board 10 becomes clearer.

As shown in FIGS. 2 to 4, the surface layer 3 has an opening 30 that exposes the surface S22 of the release layer 22. Since the first surface S21 of the support layer 21 is formed by the coating layer 212, the permeation of the ionizing radiation curable resin contained in the release layer forming composition into the paper base material 211 is suppressed. Therefore, the thickness of the coating film of the release layer forming composition and the thickness of the release layer 22 can be adjusted within desired ranges. As a result, the thickness of the portion CL1 covering the release layer 22 of the precursor layer CL of the surface layer 3 can be adjusted to a desired range, and in the step (5), the portion CL1 covering the release layer 22 can be adjusted. Can be prevented from remaining on the release layer 22 without being peeled off.

The opening 30 of the surface layer 3 is in position with the release layer 22 in a plan view. In the present invention, "positional tuning" means that at least a part of the opening 30 of the surface layer 3 overlaps with at least a part of the release layer 22 in a plan view. The opening 30 of the surface layer 3 may have a portion that does not overlap the release layer 22 in a plan view, but the entire opening 30 of the surface layer 3 overlaps at least a part of the release layer 22. Is preferable. The release layer 22 may have a portion that does not overlap with the opening 30 of the surface layer 3 in a plan view.

In addition, in this invention, "plan view" means observing a target member or part from the thickness direction Z of the decorative board 10. For example, in FIGS. 3 and 4, it means looking down from above toward the figure. Further, "planar view" is a virtual concept that treats a target member or part as being observable even when it is hidden by another member or part and cannot be actually observed. That is, "plan view" corresponds to projecting the target member or portion onto a virtual plane perpendicular to the thickness direction Z of the decorative board 10.

As shown in FIGS. 2 to 4, the opening 30 of the surface layer 3 forms a recess 4 on the first surface S10 of the decorative plate 10, and the bottom surface of the recess 4 is formed by the surface S22 of the release layer 22. It is formed.

The depth of the recess 4 is preferably 0.1 μm or more and 50 μm or less, and more preferably 0.1 μm or more and 30 μm or less. When the depth of the concave portion 4 is within the above range, the design feeling of the uneven shape expressed by the decorative plate 10 becomes clear.

The depth of the recess 4 is such that a region in which the release layer 22 is not formed (a region in which the surface layer 3 is formed) and a release layer 22 are formed in the first surface S10 of the decorative plate 10. It is measured as the height difference from the area. The measurement is carried out using a three-dimensional surface roughness measuring instrument SE-30K manufactured by Kosaka Laboratory Co., Ltd. according to the method specified in JIS B 0601: 2013. The maximum height roughness (Rz) of the surface is used as a parameter of the height difference, and the average value of 10 points is defined as the "height difference".

As shown in FIGS. 2 to 4, in the first surface S10 of the decorative board 10, the region adjacent to the recess 4 (the region formed by the surface S3 of the surface layer 3) is relatively convex. A concave-convex shape is formed on the first surface S10 of the decorative plate 10. Of the first surface S10 of the decorative plate 10, the region formed by the bottom surface of the recess 4 (the surface S22 of the release layer 22) is a relatively rough surface, and is a low-gloss region having diffuse reflection with respect to incident light. On the other hand, in the first surface S10 of the decorative plate 10, the region adjacent to the recess 4 (the region formed by the surface S3 of the surface layer 3) is relatively mirror-finished and has specular reflectivity with respect to the incident light. It becomes a high gloss area to have. As a result, the decorative board 10 can express a gloss matte-like design feeling based on the uneven shape. In particular, by aligning the uneven shape of the decorative board 10 (that is, the high gloss area and the low gloss area) with the pattern of the decorative layer 213, the decorative board 10 expresses an excellent gloss matte design feeling. be able to. For example, when the decorative layer 213 forms a wood grain pattern, the recess 4 is positioned at the conduit portion in the wood grain pattern (that is, the groove portion of the streak formed by the cut surface opening of the conduit) and the positions of both in a plan view. In the wood grain pattern, the area adjacent to the recess 4 is aligned with the area other than the conduit part in the wood grain pattern so that the positions of the two are aligned in the plan view. The conduit portion of the above has a relatively concave appearance, whereby the decorative board 10 can express the design feeling (texture) of the surface uneven shape similar to the real wood grain pattern.

A recess other than the recess 4 may be formed on the first surface S10 of the decorative plate 10. For example, a recess may be formed on the surface S3 of the surface layer 3.

The surface layer 3 is a layer formed by curing a composition containing a melamine resin (melamine resin composition), and contains a cured product of the melamine resin. As the melamine resin composition, a liquid composition containing a melamine resin is usually used.

The thickness of the surface layer 3 can be appropriately adjusted in relation to the thickness of the release layer 22, but is preferably 1 μm or more and 500 μm or less, and more preferably 1 μm or more and 300 μm or less.

In the decorative board 10, the voids of the paper base material 211 of the decorative sheet 2 are filled with the cured product of the melamine resin, and the cured product of the melamine resin contained in the surface layer 3 is filled in the voids of the paper base material 211. It is integrated with the cured product of the melamine resin. As a result, the bonding strength between the support layer 21 and the surface layer 3 can be improved, and the surface layer 3 is less likely to peel off from the support layer 21 when the decorative board 10 is used. In particular, since the first surface S21 of the support layer 21 is formed by the coating layer 212, the permeation of the melamine resin contained in the melamine resin composition into the paper base material 211 is not hindered. Therefore, as a result of being able to impregnate the voids of the paper base material 211 with a sufficient amount of melamine resin, a sufficient amount of the cured product of the melamine resin contained in the surface layer 3 is filled in the voids of the paper base material 211. It can be integrated with the cured product of melamine resin. As a result, the bonding strength between the support layer 21 and the surface layer 3 can be improved, and the surface layer 3 is less likely to peel off from the support layer 21 when the decorative board 10 is used.

The other layer decorative board 10 may be provided with other layers such as an adhesive layer and a primer layer, if necessary.

The adhesive layer decorative board 10 may have an adhesive layer, if necessary. The adhesive layer can be formed, for example, between one layer and another to enhance the adhesion of these layers. The adhesive layer is preferably a transparent adhesive layer. "Transparency" includes all of colorless transparent, colored transparent, translucent and the like.

The adhesive is not particularly limited, and an adhesive known in the field of decorative boards can be appropriately selected and used. Examples of the adhesive include thermoplastic resins such as polyamide resins, acrylic resins and vinyl acetate resins, and thermosetting resins such as urethane resins. One type of adhesive may be used alone, or two or more types may be used in combination. A two-component curable polyurethane resin or polyester resin using isocyanate as a curing agent can also be used.

The thickness of the adhesive layer is not particularly limited, but is usually 0.1 μm or more and 30 μm or less, preferably 1 μm or more and 20 μm or less.

The primer layer decorative board 10 may have a primer layer between one layer and another layer, such as a surface on the second surface T10 side of the core layer 1, if necessary. Providing a primer layer on the surface of the core layer 1 on the second surface T10 side is useful, for example, when the decorative board 10 and the adherend are laminated to manufacture a decorative member. Examples of the adherend include flat plates of various materials, plate materials such as curved plates, three-dimensional articles, sheets (or films), and the like. Specifically, wood members such as wood single board, wood plywood, particle board, MDF (medium density fiber board) and other wood fiber boards and wood members used as three-dimensional articles; , Three-dimensional shaped articles, metal members used as sheets, etc .; ceramics such as glass and ceramics, non-cement ceramic materials such as plaster, non-ceramic ceramic materials such as ALC (lightweight cellular concrete) plates and solids Ceramic members used as shape articles, etc .; polyolefin resins such as acrylic resin, polyester resin, polystyrene resin, polypropylene, ABS (acrylonitrile-butadiene-styrene copolymer) resin, phenol resin, vinyl chloride resin, cellulose resin, Examples thereof include plate materials such as rubber, three-dimensional articles, resin members used as sheets and the like. In addition, these members may be used alone or in combination of two or more.

The adherend may be appropriately selected according to the intended use, and is used for interior / exterior members of buildings such as walls, ceilings, and floors, and fittings such as window frames, doors, handrails, skirting boards, peripheral edges, and moldings. In this case, a wood member, a metal member, a resin member, and a member in which these are combined are preferable. The thickness of the adherend may be appropriately selected depending on the application and material, and is usually 0.1 mm or more and 5 mm or less, preferably 0.1 mm or more and 3 mm or less.

The primer layer can be formed by applying a known primer agent to a desired surface or the like. Examples of the primer include a urethane resin-based primer made of an acrylic-modified urethane resin (acrylic urethane-based resin) and the like, and a urethane-cellulose-based resin (for example, a resin obtained by adding hexamethylene diisocyanate to a mixture of urethane and nitrified cotton. ), A resin-based primer made of a block copolymer of acrylic and urethane, and the like. Additives may be added to the primer, if necessary. Examples of the additive include a filler such as calcium carbonate and clay, a flame retardant such as magnesium hydroxide, an antioxidant, a lubricant, a foaming agent, an ultraviolet absorber, a light stabilizer and the like. The blending amount of the additive can be appropriately adjusted according to the product characteristics.

The amount of the primer applied is not particularly limited, but is usually 0.1 g / m ² or more and 100 g / m ² or less, preferably 0.1 g / m ² or more and 50 g / m ² or less. The thickness of the primer layer is not particularly limited, but is usually 0.01 μm or more and 10 μm or less, preferably 0.1 μm or more and 1 μm or less.

The veneer 10 is a veneer with a high degree of design because it is shaped with a clear concavo-convex shape and can express the design feeling of the concavo-convex shape including the gloss matte-like concavo-convex shape. The decorative board 10 can be used for various purposes by subjecting it to a predetermined molding process or the like. For example, the decorative board 10 is laminated on a base material such as a wood base material, a gold base material, a non-gold base material, a resin base material, and the interior of a building such as a wall, a ceiling, and a floor, and a vehicle such as a vehicle or a ship. It can be used for interiors, furniture, light electric appliances, cabinets of OA equipment, etc. Specific examples of wood base materials include veneer, veneer, wood plywood, particle board, and medium density fiberboard made from various materials such as cedar, cypress, pine, pine, oak, lauan, teak, and melamy. MDF), laminated lumber, chipboard, composite base material on which chipboard is laminated, and the like can be mentioned. Examples of the metal base material include a single metal material such as iron, copper, aluminum, and titanium, or a base material made of an alloy containing one or more of these metal materials. Examples of the non-gold inorganic material base material include ceramic materials such as calcium silicate, gypsum, cement and earthenware, and base materials made of stone materials such as granite and limestone. Examples of the resin base material include a base material made of polyvinyl chloride, polystyrene, polyester resin, acrylic resin, polyolefin resin, phenol resin, urea resin and the like.

Method for manufacturing decorative board Hereinafter, an embodiment of the method for manufacturing the decorative board 10 will be described with reference to the drawings. 5 to 7 are explanatory views for explaining one embodiment of the method for manufacturing the decorative board 10. Note that FIG. 6 is a continuation of FIG. 5, and FIG. 7 is a continuation of FIG.

The method for manufacturing the decorative board 10 according to the present embodiment is as follows.
(1) Step of preparing the decorative sheet 2 (2) The decorative sheet 2 is impregnated with the uncured melamine resin composition, and the uncured melamine resin filled in the voids of the paper base material 211 and the support layer 21 are the first. A step of forming an impregnated decorative sheet M1 including the rest of one surface S21 and an uncured melamine resin layer L1 that covers the release layer 22.
(3) A step of laminating the impregnated decorative sheet M1 on the precursor layer L2 of the core layer 1.
(4) A step of curing the uncured melamine resin and the uncured melamine resin layer L1 filled in the voids of the paper base material 211, and
(5) Of the precursor layer CL of the surface layer 3 formed by curing the uncured melamine resin layer L1, the portion CL1 covering the release layer 22 is peeled off, and the surface is surfaced on the rest of the first surface S21 of the support layer 21. The step of forming the layer 3 is included.
Hereinafter, each step will be described.

Process (1)
The step (1) is a step of preparing the decorative sheet 2. The decorative sheet 2 can be produced by a method including the following steps (1-1) to (1-3).

Process (1-1)
The step (1-1) is a step of forming the decorative layer 213 on the paper-based base material 211 as shown in FIG. 5 (a). In the embodiment in which the decorative layer 213 is omitted, the step (1-1) is omitted. Before forming the decorative layer 213 on the paper-based base material 211, the surface of the paper-based base material 211 may be subjected to treatments such as corona discharge treatment, plasma treatment, and ozone treatment. Thereby, the adhesion of the decorative layer 213 can be improved.

Examples of the method for forming the decorative layer 213 include a coating method and a printing method. Examples of the coating method include a roll coating method, a knife coating method, an air knife coating method, a die coating method, a lip coating method, a comma coating method, a kiss coating method, a flow coating method, and a dip coating method. Examples of the printing method include a gravure printing method, an offset printing method, a screen printing method, a flexographic printing method, an electrostatic printing method, an inkjet printing method, and the like.

The ink used to form the decorative layer 213 is, for example, a mixture of a solvent or a dispersion medium and components such as a colorant and a binder resin. The ink may contain a colorant, an extender pigment, a stabilizer, a plasticizer, a catalyst, a curing agent and the like as other components. The ink may be an aqueous composition from the viewpoint of reducing VOC (volatile organic compound) of the sheet.

Colorants contained in the ink include, for example, inorganic pigments such as carbon black, iron black, titanium white, antimony white, yellow lead, titanium yellow, petal handle, cadmium red, ultramarine blue, cobalt blue; quinacridone red, isoindolinone. Organic pigments or dyes such as yellow and phthalocyanine blue; metal pigments made of scaly foil pieces such as aluminum and brass; pearl gloss pigments made of scaly foil pieces such as titanium dioxide-coated mica and basic lead carbonate. Can be mentioned. One type of colorant may be used alone, or two or more types may be used in combination.

Examples of the binder resin contained in the ink include urethane resin, acrylic urethane resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-acrylic copolymer resin, chlorinated polypropylene resin, acrylic resin, and polyester resin. , Polylamin resin, butyral resin, polystyrene resin, nitrocellulose resin (nitrated cotton), cellulose acetate resin and the like. As the binder resin, one type may be used alone, or two or more types may be used in combination.

Examples of the solvent or dispersion medium contained in the ink include petroleum-based organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ethyl acetate, butyl acetate, -2-methoxyethyl acetate, and acetate. Ester-based organic solvents such as -2-ethoxyethyl; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, propylene glycol; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc. Ketone-based organic solvent; ether-based organic solvent such as diethyl ether, dioxane, tetrahydrofuran; chlorine-based organic solvent such as dichloromethane, carbon tetrachloride, trichloroethylene, tetrachloroethylene; inorganic solvent such as water and the like. As the solvent or dispersion medium, one type may be used alone, or two or more types may be used in combination.

The decorative layer 213 may be formed by a method such as a hand-drawing method, a suminagashi method, a photographic method, a transfer method, a laser beam drawing method, or an electron beam drawing method. When the decorative layer 213 is a metal layer (metal thin film) such as aluminum, chromium, gold, silver, or copper, the decorative layer 213 can be formed by a method such as a vapor deposition method, a sputtering method, or an etching method.

The thickness of the decorative layer 213 at the time of coating (thickness before drying) is preferably 1 μm or more and 300 μm or less, more preferably 1 μm or more and 200 μm or less, and the thickness of the decorative layer 213 after drying is preferably 0.1 μm or more. It is 30 μm or less, more preferably 0.1 μm or more and 20 μm or less.

Process (1-2)
The step (1-2) is a step of forming the coating layer 212 on the decorative layer 213 as shown in FIG. 5 (b). In step (1-2), the support layer 21 having the second surface T21 located on the opposite side of the first surface S21 and the first surface S21, the paper-based base material 211 and the first surface S21 of the support layer 21. A support layer 21 having a coating layer 212 forming the above and a decorative layer 213 located between the paper base material 211 and the coating layer 212 is formed.

Examples of the coating method for forming the coating layer 212 include a roll coating method, a knife coating method, an air knife coating method, a die coating method, a lip coating method, a comma coating method, a kiss coating method, a flow coating method, and a dip coating method. Can be mentioned.

The composition used for forming the coating layer 212 (composition for forming the coating layer) is, for example, a mixture of components such as casein and an acrylic resin emulsion (aqueous acrylic resin).

The thickness of the coating layer 212 at the time of coating (thickness before drying) is preferably 1 μm or more and 300 μm or less, more preferably 1 μm or more and 200 μm or less, and the thickness of the coating layer 212 after drying is preferably 0.1 μm or more. It is 30 μm or less, more preferably 0.1 μm or more and 20 μm or less.

Process (1-3)
As shown in FIG. 5C, the step (1-3) is a step of forming the release layer 22 on a part of the first surface S21 of the support layer 21. In the step (1-3), the decorative sheet 2 including the support layer 21 and the release layer 22 formed on a part of the first surface S21 of the support layer 21 is formed.

The composition for forming the release layer 22 (composition for forming the release layer) contains an ionizing radiation curable resin. Since the first surface S21 of the support layer 21 is formed by the coating layer 212, the permeation of the ionizing radiation curable resin contained in the release layer forming composition into the paper base material 211 is suppressed. Therefore, the thickness of the coating film of the release layer forming composition and the thickness of the release layer 22 can be adjusted within desired ranges. As a result, the thickness of the portion CL1 covering the release layer 22 of the precursor layer CL of the surface layer 3 can be adjusted to a desired range, and in the step (5), the portion CL1 covering the release layer 22 can be adjusted. Can be prevented from remaining on the release layer 22 without being peeled off.

The release layer forming composition may contain a silicone-based release agent (silicone oil). Since the silicone-based release agent is oriented on the surface of the release layer 22 when the release layer forming composition is cured, the release layer 22 is imparted with releasability. Thereby, in the step (5), when the portion CL1 covering the release layer 22 of the precursor layer CL of the surface layer 3 is peeled off, the peelability of the portion CL1 can be improved.

The release layer 22 is formed, for example, by printing a release layer forming composition on a part of the first surface S21 of the support layer 21 in a predetermined pattern and irradiating it with ionizing radiation to cure it. Can be done. Examples of the printing method used for forming the release layer 22 include a gravure printing method, an offset printing method, a screen printing method, a flexographic printing method, an electrostatic printing method, and an inkjet printing method. The release layer forming composition may be applied to a part of the first surface S21 of the support layer 21 by using a method other than the printing method, and examples of the application method include a roll coating method and a gravure coating method. Law etc. can be mentioned.

When ultraviolet rays are used as the ionizing radiation for curing the ionizing radiation curable resin, the ultraviolet sources include, for example, ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arc lamps, black light fluorescent lamps, metal halide lamps, etc. Light source can be used. The wavelength of ultraviolet rays is, for example, 190 nm or more and 380 nm or less. When an electron beam is used as the ionizing radiation for curing the release layer forming composition, the electron beam source may be, for example, Cockcroftwald type, Van de Graaff type, Resonant transformer type, Insulated core transformer type, etc. A linear type, a dynamitron type, a high frequency type or the like electron beam accelerator can be used. The energy of the electron beam is usually 100 keV or more and 1000 keV or less, preferably 100 keV or more and 300 keV or less. The irradiation amount of the electron beam is preferably 2 Mrad or more and 15 Mrad or less.

The release layer forming composition preferably contains an extender pigment. Thereby, thixotropy can be imparted to the release layer forming composition, and the pattern shape of the release layer forming composition is maintained when the release layer forming composition is printed using the plate. Can be made to. Examples of the extender pigment include silica, talc, clay, barium sulfate, barium carbonate, calcium sulfate, calcium carbonate, magnesium carbonate and the like. Of these, silica, which has a high degree of freedom in material design and is excellent in designability, whiteness, and coating stability as an ink, is preferable, and fine powder silica is particularly preferable.

The amount of the extender pigment contained in the release layer forming composition is usually 0.1 part by mass or more and 20 parts by mass or less, preferably 0 part by mass, based on 100 parts by mass of the resin contained in the release layer forming composition. It is 5 parts by mass or less, 15 parts by mass or less, more preferably 2 parts by mass or more and 15 parts by mass or less, and even more preferably 5 parts by mass or more and 15 parts by mass or less. By setting the content of the extender pigment in the above range, it is possible to impart sufficient thixotropy to the composition for forming a release layer, and it is possible to obtain the effect of imparting a raised shape and the appearance of fine uneven surfaces.

The release layer forming composition may be colorless or colored. In the case of coloring, the same colorant as that used in the decorative layer can be used.

The release layer forming composition may contain a solvent for the purpose of adjusting the viscosity. As the solvent, water; hydrocarbon compounds such as toluene and xylene; alcohol compounds such as methanol, ethanol and methyl glycol; ketone compounds such as acetone and methyl ethyl ketone; ester compounds such as methyl formate and ethyl acetate; N-methylpyrrolidone and N. , Nitrogen-containing compounds such as N-dimethylformamide; ether compounds such as terrorahydrofuran and dioxane; halogenated hydrocarbon compounds such as methylene chloride and chloroform; dimethyl sulfoxide and the like. These solvents can be used alone or in admixture of two or more. The amount of the solvent in the release layer forming composition can be appropriately set according to the viscosity required for the release layer forming composition.

A known additive can be appropriately added to the release layer forming composition according to the desired physical properties. As additives, for example, ultraviolet absorbers, infrared absorbers, light stabilizers, polymerization inhibitors, cross-linking agents, antistatic agents, antioxidants, leveling agents, coupling agents, plasticizers, defoamers, fillers, Examples include thermal radical generators and aluminum chelating agents.

The release layer 22 is preferably formed on the first surface S21 of the support layer 21 in a predetermined pattern. It is preferable that the pattern of the release layer 22 corresponds to a region of the first surface S10 of the decorative plate 10 that is a concave portion or a low gloss (erasing) region. Examples of the pattern of the release layer 22 include a conduit portion of a wood grain board, a stone board surface unevenness, a cloth surface texturer, a satin finish, a sand grain, a hairline, a perforated groove, characters, symbols, and a geometric pattern.

The thickness of the release layer 22 at the time of coating (thickness before drying) is preferably 1 μm or more and 200 μm or less, more preferably 1 μm or more and 100 μm or less, and the thickness of the release layer 22 after drying is preferably 1 μm or more. It is 40 μm or less, more preferably 1 μm or more and 20 μm or less.

Process (2)
In step (2), as shown in FIG. 5 (d), the decorative sheet 2 is impregnated with the uncured melamine resin composition, and the uncured melamine resin filled in the voids of the paper substrate 211 and the support layer. Impregnated cosmetics including the rest of the first surface S21 of 21 (the region of the first surface S21 of the support layer 21 where the release layer 22 is not formed) and the uncured melamine resin layer L1 that covers the release layer 22. This is a step of forming the sheet M1.

The uncured melamine resin composition contains an uncured product of the melamine resin. The uncured melamine resin layer is a layer formed by the uncured melamine resin composition and contains an uncured product of the melamine resin. The uncured product of melamine resin is a thermosetting resin obtained by reacting melamine and formaldehyde under neutral or alkaline conditions, and the reaction product (initial condensate) of melamine and formaldehyde is methylol melamines. Includes (monomethylol melamine, dimethylol melamine, hexamethylol melamine).

Since the first surface S21 of the support layer 21 is formed by the coating layer 212, the permeation of the melamine resin contained in the uncured melamine resin composition into the paper substrate 211 is not hindered. Therefore, as a result of being able to impregnate the voids of the paper base material 211 with a sufficient amount of the uncured product of the melamine resin, the cured product of the melamine resin contained in the surface layer 3 was filled in the voids of the paper base material 211. It can be integrated with a sufficient amount of cured melamine resin. As a result, the bonding strength between the support layer 21 and the surface layer 3 can be improved, and the surface layer 3 is less likely to peel off from the support layer 21 when the decorative board 10 is used.

The uncured melamine resin composition may contain a solvent for the purpose of adjusting the viscosity. As the solvent, water; hydrocarbon compounds such as toluene and xylene; alcohol compounds such as methanol, ethanol and methyl glycol; ketone compounds such as acetone and methyl ethyl ketone; ester compounds such as methyl formate and ethyl acetate; N-methylpyrrolidone and N. , Nitrogen-containing compounds such as N-dimethylformamide; ether compounds such as terrorahydrofuran and dioxane; halogenated hydrocarbon compounds such as methylene chloride and chloroform; dimethyl sulfoxide and the like. These solvents can be used alone or in admixture of two or more. The amount of the solvent in the melamine resin composition can be appropriately set according to the viscosity of the melamine resin composition.

Known additives can be appropriately added to the uncured melamine resin composition according to the desired physical characteristics. As additives, for example, ultraviolet absorbers, infrared absorbers, light stabilizers, polymerization inhibitors, cross-linking agents, antistatic agents, antioxidants, leveling agents, coupling agents, plasticizers, defoamers, fillers, Examples include thermal radical generators and aluminum chelating agents.

When the decorative sheet 2 is impregnated with the uncured melamine resin composition, the uncured melamine resin composition is supplied, for example, from the first surface S21 side of the support layer 21. Of the supplied uncured melamine resin composition, a part of the uncured melamine resin composition is impregnated with the paper base material 211, and the rest not impregnated with the paper material base material 211 covers the rest of the first surface S21 of the support layer 21 and the release layer 22. do. The uncured melamine resin composition is not impregnated into the release layer 22, but covers the release layer 22. In order to promote the impregnation of the uncured melamine resin composition into the paper substrate 211, in addition to the supply of the uncured melamine resin composition from the first surface S21 side of the support layer 21, the second surface of the support layer 21 The uncured melamine resin composition may be supplied from the T21 side. Only the uncured melamine resin composition may be supplied from the second surface T21 side of the support layer 21. Similarly, when only the uncured melamine resin composition is supplied from the second surface T21 side of the support layer 21, a part of the supplied uncured melamine resin composition is impregnated into the paper base material 211. The remaining portion of the paper base material 211 that is not impregnated covers the remaining portion of the first surface S21 of the support layer 21 and the release layer 22. Examples of the method for supplying the uncured melamine resin composition include immersion in the uncured melamine resin composition; coating with a coater such as a kiss coater or a comma coater; and spraying with a spray device, a shower device or the like.

The thickness of the uncured melamine resin layer L1 can be appropriately adjusted in relation to the thickness of the release layer 22, but the thickness at the time of coating (thickness before drying) is preferably 1 μm or more and 800 μm or less, more preferably. Is 1 μm or more and 500 μm or less, and the thickness after drying is preferably 1 μm or more and 500 μm or less, and more preferably 1 μm or more and 300 μm or less.

When the uncured melamine resin composition is impregnated into the paper base material 211, the uncured melamine resin composition is filled in the voids of the paper base material 211. The filling rate of the uncured melamine resin composition filled in the voids of the paper base material 211 can be appropriately adjusted according to the performance required for the decorative board 10, the porosity of the paper base material 211, and the like. The filling rate of the uncured melamine resin composition is preferably 30% or more and 200% or less, and more preferably 50% or more and 150% or less. The filling rate of the resin composition is calculated by the following formula.
Filling rate (%) = [(Weight of paper base material after impregnation with resin composition-Weight of paper base material before impregnation with resin composition) / Paper base material before impregnation with resin composition Weight] x 100

Process (3)
The step (3) is a step of laminating the impregnated decorative sheet M1 on the precursor layer L2 of the core layer 1 as shown in FIG. 6 (e). In step (3), intermediate M2 is formed.

As shown in FIG. 6E, the impregnated decorative sheet M1 is laminated on the precursor layer L2 of the core layer 1 so that the second surface T21 of the support layer 21 is located on the precursor layer L2 side of the core layer 1. NS.

Process (4)
The step (4) is a step of curing the uncured melamine resin and the uncured melamine resin layer L1 filled in the voids of the paper substrate 211.

The curing of the uncured melamine resin layer L1 forms the precursor layer CL of the surface layer 3, and the curing of the precursor layer L2 of the core layer 1 forms the core layer 1.

Step (4) can be performed as follows.

First, as shown in FIG. 6 (f), the peeling film PF is laminated on the uncured melamine resin layer L1 to form the intermediate M3.

As the peeling film PF, for example, an easily adhesive resin film can be used. Examples of the easily adhesive resin film include a thermoplastic resin film, and examples of the thermoplastic resin include polyolefin resins such as polyethylene, polypropylene, and polymethylpentene; vinyl chloride-vinyl acetate copolymer, ethylene-. Vinyl resins such as vinyl acetate copolymers and ethylene-vinyl alcohol copolymers; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; methyl polymethacrylate, ethyl polymethacrylate, ethyl polyacrylate, butyl polyacrylate and the like Acrylic resin; Examples thereof include a single film such as a synthetic resin such as polystyrene, polycarbonate, polyarylate, and polyimide, or a laminate of these films.

An easy-adhesive layer may be formed on the surface of the easy-adhesive resin film by applying the easy-adhesive resin. Before forming the easy-adhesive layer, in order to improve the adhesiveness of the easy-adhesive layer, the surface of the easy-adhesive resin film may be subjected to a treatment such as a corona discharge treatment, a plasma treatment, or an ozone treatment.

Examples of the resin contained in the easy-adhesion layer (sometimes called a primer layer or an anchor layer) include acrylic resin, vinyl chloride-vinyl acetate copolymer, polyester resin, urethane resin, chlorinated polypropylene, and chlorinated polyethylene. Be done.

As the peeling film PF, a peeling film whose peeling weight is adjusted with the resin film to be peeled (the portion CL1 of the precursor layer CL of the surface layer 3 that covers the release layer 22) is used. Is preferable. For example, when the thermosetting film of the melamine resin is the object of peeling, it is preferable to adjust the peeling weight to 0.1 N / inch or more and 10 N / inch or less. If the peeling weight is less than 0.1 N / inch, it is difficult to peel off the thermosetting film of the melamine resin, and if the peeling weight exceeds 10 N / inch, the peeling film may break or other than the resin film to be peeled off. The resin film may also be peeled off. By using a peeling film whose peeling weight is adjusted to 0.1 N / inch or more and 10 N / inch or less, the resin film to be peeled can be easily removed.

The peeling weight is a value measured using the Tencilon universal material testing machine RTC-1250A manufactured by Orientec Co., Ltd., and the specific measuring method is as follows. In the intermediate M4 described later, a cut is made in the peeling film PF to a width of 1 inch, a part of the peeling film PF is peeled off with a width of 1 inch, and a part of the peeling film PF is peeled off as shown in FIG. One end (lower part) of the intermediate body M4 is fixed to the testing machine. The weight when the peeling film PF peeled off by 180 ° is peeled off at a speed of 100 mm / min in the upper direction (arrow direction) is measured, and this is referred to as "peeling weight".

As the peeling film whose peeling weight is adjusted to 0.1 N / inch or more and 10 N / inch or less, for example, a film having a base film and a cured resin layer formed on the base film is used. be able to. This film is preferably used so that the surface on the cured resin layer side is in contact with the melamine resin layer L1. The base film is not particularly limited, and examples thereof include paper, non-woven fabric, and thermoplastic resin sheet. The substrate film is preferably a thermoplastic resin sheet, and from the viewpoint of heat resistance, a polyester resin sheet such as polyethylene terephthalate is particularly preferable. The thickness of the base film is not particularly limited, and is usually 10 μm or more and 200 μm or less. Further, the cured resin layer is preferably a cured resin layer formed by curing the release layer forming composition. This makes it easy to adjust the peeling weight of the melamine resin from the thermosetting film to 0.1 N / inch or more and 10 N / inch or less. The above description applies to the composition for forming a release layer. The release layer forming composition may appropriately contain a component such as an extender pigment for the purpose of adjusting the peeling weight and the like. The thickness of the cured resin layer is usually 1 μm or more and 30 μm or less.

Next, as shown in FIG. 6 (g), the intermediate M3 was sandwiched between the two mirror-finished metal plates MP1 and MP2, pressurized and heated, and the melamine resin filled in the voids of the paper substrate 211 was formed. The uncured product and the uncured melamine resin layer L1 are cured. The curing of the uncured melamine resin layer L1 forms the precursor layer CL of the surface layer 3, and the curing of the precursor layer L2 of the core layer 1 forms the core layer 1. The peeling film PF adheres to the precursor layer CL of the surface layer 3 at this stage.

The pressure applied by the mirror-finished metal plates MP1 and MP2 is usually 0.1 kg / cm ² or more and 200 kg / cm ² or less. The heating temperature is usually 100 ° C. or higher and 200 ° C. or lower, and the heating time is usually 1 second or longer and 120 minutes or lower.

As a result, as shown in FIG. 7 (h), the core layer 1, the support layer 21 provided on the core layer 1, and the release layer 22 formed on a part of the first surface S21 of the support layer 21. An intermediate including the precursor layer CL of the surface layer 3 that covers the rest of the first surface S21 of the support layer 21 and the release layer 22, and the release film PF laminated on the precursor layer CL of the surface layer 3. M4 is formed.

As shown in FIG. 7 (h), the precursor layer CL of the surface layer 3 has a portion CL1 that covers the release layer 22 and a portion CL2 that does not cover the release layer 22. The portion CL1 that covers the release layer 22 is formed on the surface S22 of the release layer 22 so as to cover the release layer 22. The portion CL2 that does not cover the release layer 22 is formed on the first surface S21 of the support layer 21 so as to surround the release layer 22.

Process (5)
In the step (5), of the precursor layer CL of the surface layer 3 formed by curing the uncured melamine resin layer L1, the portion CL1 covering the release layer 22 is peeled off, and the first surface S21 of the support layer 21 is peeled off. This is a step of forming the surface layer 3 on the remaining portion.

In the step (5), as shown in FIG. 7 (i), the portion CL1 covering the release layer 22 of the precursor layer CL of the surface layer 3 is peeled off, and the rest of the first surface S21 of the support layer 21 is peeled off. The surface layer 3 is formed on the surface. Of the precursor layer CL of the surface layer 3, the portion CL1 that covers the release layer 22 is more easily peeled off than the remaining CL2 of the precursor layer CL of the surface layer 3. Therefore, the portion CL1 that covers the release layer 22 is peeled off together with the peeling film PF while being adhered to the peeling film PF. On the other hand, the remaining CL2 of the precursor layer CL of the surface layer 3 remains on the remaining portion of the first surface S21 of the support layer 21, and the surface layer 3 is formed. By removing the portion CL1 that covers the release layer 22, the opening 30 of the surface layer 3 is formed, and the surface S22 of the release layer 22 is exposed through the opening 30 of the surface layer 3 to make up. A recess 4 is formed on the first surface S10 of the plate 10. As a result, as shown in FIG. 7 (j), the decorative board 10 is manufactured.

Since the silicone-based release agent contained in the release layer 22 imparts releasability to the release layer 22, the partial CL1 covering the release layer 22 is easily peeled off in the step (5). When both the release layer 22 and the surface layer 3 contain a silicone-based release agent, this effect is enhanced.

The method of peeling the partial CL1 that covers the release layer 22 is not limited to the method of using a peeling film. For example, a method in which a protective film such as a masking film, an adhesive tape such as a cellophane tape or a gum tape, a shaping sheet or the like is attached to the surface of the precursor layer CL of the surface layer 3, and then the film is peeled off at the same time; Method of peeling with tape, adhesive rubber roller, adhesive rubber sheet, etc .; The precursor layer CL of the surface layer 3 is coated with a resin solution such as a chloride rubber resin, a urethane resin, or a polyester resin previously dissolved in a solvent, and dried. After that, a method of peeling off; a method of applying a hot melt adhesive to the precursor layer CL of the surface layer 3 and then peeling off at a low temperature; a resin plate or a metal plate is attached to the precursor layer CL of the surface layer 3. After that, a method of peeling off and the like can be mentioned.

The decorative board 10 manufactured by the above method has an uneven shape on the surface. Therefore, the decorative plate 10 can express the design feeling of the uneven shape based on the uneven shape. In particular, in the decorative board which is the result of the above manufacturing method, the region formed by the bottom surface of the recess 4 (the surface S22 of the release layer 22) of the first surface S10 of the decorative board 10 becomes a relatively rough surface. The region adjacent to the recess 4 (the region formed by the surface S3 of the surface layer 3) of the first surface S10 of the decorative plate 10 is relative to the first surface S10 of the decorative plate 10, while it is a low gloss region having diffuse reflection with respect to incident light. It becomes a mirror surface and becomes a high-gloss region having specular reflection with respect to incident light. As a result, the decorative board 10 can express a gloss matte-like design feeling based on the uneven shape. For example, the decorative board 10 can exhibit an appearance having a concavo-convex shape including a gloss matte-like concavo-convex shape in which the concave portion 4 gives a matte feeling and the convex portion gives a glossy feeling. In particular, by synchronizing the uneven shape with the pattern of the decorative layer 213 in a plan view, the decorative board 10 can express an excellent design feeling of the uneven shape. For example, when the decorative layer 213 forms a wood grain pattern, the decorative board 10 is made of a real wood grain by aligning the concave portion 4 with the conduit portion of the wood grain pattern so that the positions of the decorative layer 213 and the conduit portion of the wood grain pattern are aligned with each other in the plan view. It is possible to express an appearance including a gloss matte design (texture) similar to a pattern. By increasing the difference in unevenness (depth of the concave portion 4), the design feeling of the uneven shape can be made clearer.

[Example 1]
(1) Preparation of composition for mold release layer formation 60 parts by mass of ionizing radiation curable monomer (Aronix M400 manufactured by Toa Synthetic Co., Ltd.), 0.6 parts by mass of reactive silicone (X-22-164B manufactured by Shin-Etsu Chemical Co., Ltd.) , And 40 parts by mass of methyl ethyl ketone (manufactured by Maruzen Petrochemical Co., Ltd.) were mixed to prepare a composition for forming a release layer. Mixing was carried out by using a process homogenizer PH91 (manufactured by SMT Co., Ltd.) and stirring at a rotation speed of 2000 rpm for 1 hour.

(2) Manufacture of release film On the easily adhesive surface of PET film (Cosmo Shine (registered trademark) A4100 manufactured by Toyo Boseki Co., Ltd.) with a thickness of 50 μm, an ionizing radiation curable monomer (Aronix (registered trademark) M350 manufactured by Toa Synthetic Co., Ltd.) ) 100 parts by mass, 2 parts by mass of reactive silicone (X-22-164B manufactured by Shinetsu Chemical Co., Ltd.), 8 parts by mass of silica (Silicia 450 manufactured by Fuji Silysia Chemical Ltd.), and 50 parts by mass of ethyl acetate. Was applied in an amount of 5 g / m ² (when dried) and cured by irradiating with an electron beam of 5 Mrad at an acceleration voltage of 165 kV to produce a peeling film having a cured resin layer.

(3) Manufacture of decorative sheets [formation of printing paper]
Using the gravure printing method, a printing ink (Ode SPTI manufactured by DIC Graphics Corporation) was printed on a titanium base paper for building materials to produce a printing paper having a wood grain pattern pattern layer having a thickness of 3 μm. As the titanium base paper, PM-67P or KSH-801P manufactured by KJ Special Paper Co., Ltd. was used. The amount of ash (inorganic component) contained in PM-67P is 23% by mass, and the amount of ash (inorganic component) contained in KSH-801P is 35% by mass. The amount of ash is almost equal to the amount of titanium oxide.

[Formation of coating layer]
Casein (milk casein manufactured by BASF Japan Ltd.), acrylic resin emulsion at Tg = -20 ° C (ACRONAL A754 manufactured by BASF Japan Ltd., solid content: 48%, aqueous solvent: water), and Tg = 30 ° C. Acrylic resin emulsion (Ultrasol A25 manufactured by Aika Kogyo Co., Ltd., solid content: 48%, aqueous solvent: water) was mixed to prepare a composition for forming a coating layer. The composition (based on solid content) of the coating layer forming composition is 40% by mass of casein, 15% by mass of the solid content of the acrylic resin emulsion at Tg = -20 ° C, and 45% by mass of the solid content of the acrylic resin emulsion at Tg = 30 ° C. %. The composition for forming a coating layer was applied to the entire surface of the printing paper on which the pattern layer was formed, and then dried to form a coating layer having a thickness of 1 μm. The composition of the coating layer (based on solid content) is as shown in Table 1.

[Formation of release layer]
The release layer forming composition produced in (1) above is printed on a coating layer in a pattern having a width of 30 μm (constant) and a length of 50 mm, and irradiated with an electron beam of 3 Mrad at an acceleration voltage of 165 kV. As a result, a release layer having a thickness of 2 μm was formed. As a result, a decorative sheet having a printing paper having a pattern layer, a coating layer formed on the entire pattern layer forming surface of the printing paper, and a release layer provided on a part of the surface of the coating layer was manufactured. ..

(4) Manufacture of decorative board [Manufacture of impregnated decorative sheet]
60 parts by mass of uncured melamine resin (water-soluble methylol melamine resin, Nikaresin S-260 manufactured by Nippon Carbide Industries Co., Ltd.), 35 parts by mass of water, and 5 parts by mass of isopropyl alcohol with respect to the decorative sheet produced in (3) above. The liquid uncured melamine resin composition containing the above is impregnated using an impregnating device for impregnation so that the uncured melamine resin composition has ^{a ratio of 80 g / m 2} (when dried), dried, and impregnated makeup. Manufactured the sheet.

[Formation of surface layer]
The impregnated decorative sheet is laminated on three sheets of phenol resin impregnated core paper (Ota core manufactured by Ota Sangyo Co., Ltd.) manufactured by impregnating kraft paper with a phenol resin solution and having a basis weight of 245 g / m ^{2, and further impregnated makeup.} The release film produced in (2) above was laminated on the sheet so that the cured resin layer of the release film was in contact with the printed surface of the impregnated decorative sheet.

The formed laminate is sandwiched between two mirror plates and heat-molded using a heat press machine at a pressure of 100 kg / cm ² at a molding temperature of 150 ° C. for 10 minutes to heat the uncured melamine resin composition. By curing, a cured resin layer containing a cured product of melamine resin was formed.

By peeling the release film from the cured resin layer containing the cured product of the melamine resin, the portion of the cured resin layer that covers the release layer is removed, and the rest of the surface of the coating layer (of the surface of the coating layer). A surface layer was formed on the portion where the release layer was not provided).

(5) Evaluation of coating layer [Action of coating layer on impregnation of uncured material of melamine resin on titanium paper]
Whether or not the coating layer inhibits the impregnation of the uncured product of the melamine resin into the titanium base paper was evaluated from the viewpoint of the impregnation rate of the uncured product of the melamine resin and the bonding strength of the surface layer.

・ Impregnation rate of uncured melamine resin The uncured melamine resin (water-soluble methylol melamine resin, Nikaresin S-260 manufactured by Nippon Carbide) is dissolved in 82.0% of the resin weight of water to dissolve the uncured melamine resin. The composition was prepared. 200 mL of the uncured melamine resin composition was supplied from the pattern layer forming surface side to a circular test piece having a diameter of 2.5 cm prepared from the printing paper produced in (3) above, and permeated. The state of the back surface of the test piece (the surface opposite to the pattern layer forming surface) was visually confirmed, and the time (seconds) from the start of supply of the uncured melamine resin composition to the wet color of the entire back surface was measured.
Using the following criteria, it was evaluated that the coating layer did not inhibit the impregnation of the uncured melamine resin into the titanium base paper in the case of S, A or B, and in the case of C or D, the coating layer , It was evaluated that it inhibits the impregnation of the uncured product of melamine resin into the titanium base paper. The evaluation results are as shown in Table 1.
S: It takes less than 20 seconds for the entire back surface to become wet.
A: It takes 20 seconds or more and less than 30 seconds for the entire back surface to become wet.
B: The time until the entire back surface becomes wet is 30 seconds or more and less than 40 seconds.
C: The time until the entire back surface becomes wet is 40 seconds or more and less than 120 seconds.
D: It takes 120 seconds or more for the entire back surface to become wet.

Further, it was evaluated whether or not the action of the coating layer on the impregnation of the uncured material of the melamine resin on the titanium paper was different depending on the amount of the inorganic content in the titanium base paper.
Regarding the time (seconds) from the start of supply of the uncured melamine resin composition to the wet color of the entire back surface, the base paper having a low inorganic content (titanium oxide content 23%) and the base paper having a high inorganic content (titanium oxide content) The difference from 35%) was calculated.
Using the following criteria, in the case of A or B, there is no difference in the action of the coating layer on the impregnation of the uncured melamine resin into the titanium paper, depending on the amount of inorganic content in the titanium base paper. In the case of C, it was evaluated that the action of the coating layer on the impregnation of the uncured material of the melamine resin on the titanium paper differs depending on the amount of the inorganic content in the titanium base paper. The evaluation results are as shown in Table 1.
A: The difference is less than 5 seconds.
B: The difference is 5 seconds or more and less than 10 seconds.
C: The difference is 10 seconds or more.

-Joint strength of surface layer 100 minute regions (2 mm x 2 mm) were formed in a 2 cm x 2 cm region by making grid-like cuts at 2 mm intervals on the surface of the surface layer of the decorative board. Scotch tape was applied to 100 minute regions, and the cells were sufficiently adhered to each other, and then rapid peeling was performed. After repeating this 10 times at the same position, the number of exfoliated microregions was measured out of 100 microregions.
In the case of A or B, it is evaluated that the bonding strength of the surface layer is sufficient (that is, the entire titanium base paper is impregnated with a sufficient amount of uncured melamine resin) using the following criteria. However, in the case of C, it was evaluated that the bonding strength of the surface layer was insufficient (that is, the entire titanium base paper was not impregnated with a sufficient amount of uncured melamine resin). The evaluation results are as shown in Table 1.
A: The number of exfoliated minute regions is zero.
B: The number of exfoliated minute regions is 10 or less.
C: The number of exfoliated minute regions is 11 or more.

[Action of coating layer on impregnation of ionizing radiation curable resin on titanium paper]
Whether or not the coating layer suppresses the impregnation of the ionizing radiation curable resin into the titanium base paper remains on the release layer and the gloss matte design feeling of the decorative board expressed based on the uneven shape. The evaluation was made based on the presence or absence of the cured resin film and its degree.
Specifically, after the release film is peeled off, the state of the surface of the decorative board is visually confirmed, and in the case of A or B, the coating layer is ionizing and radiation curable to the titanium base paper using the following criteria. It was evaluated that the impregnation of the resin was suppressed, and in the case of C, it was evaluated that the coating layer did not suppress the impregnation of the ionizing radiation curable resin into the titanium base paper. The evaluation results are as shown in Table 1.
A: Compared with Comparative Example 4 in which the coating layer was not provided, the gloss / matte effect of the conduit portion was sufficiently confirmed, and there was no surface resin residue on the conduit portion.
B: Compared with Comparative Example 4 in which the coating layer was not provided, the gloss / matte effect of the conduit portion was confirmed, and the surface resin residue of the conduit portion was small.
C: Compared with Comparative Example 4 in which the coating layer was not provided, the gloss / mat effect of the conduit portion and the resin residue of the conduit portion were equivalent.

The decorative board manufactured using the base paper having a low inorganic content (titanium oxide content 23%) is the decorative board of Comparative Example 4 manufactured using the base paper having a low inorganic content (titanium oxide content 23%). The decorative board manufactured using the base paper having a high inorganic content (titanium oxide content 35%) was compared with that of Comparative Example 4 manufactured using the base paper having a high inorganic content (titanium oxide content 35%). Compared with the veneer.

[Example 2]
In Example 2, the composition (based on solid content) of the coating layer forming composition was set to 50% by mass of casein, 12.5% by mass of solid content of an acrylic resin emulsion at Tg = -20 ° C, and acrylic at Tg = 30 ° C. This is the same as in Example 1 except that the solid content of the resin emulsion is changed to 37.5% by mass. The composition of the coating layer (based on solid content) in Example 2 is as shown in Table 1.

[Example 3]
In Example 3, the composition (based on solid content) of the coating layer forming composition was set to 60% by mass of casein, 10% by mass of the solid content of the acrylic resin emulsion at Tg = -20 ° C, and the acrylic resin emulsion at Tg = 30 ° C. The same as in Example 1 except that the solid content of the above was changed to 30% by mass. The composition of the coating layer (based on solid content) in Example 3 is as shown in Table 1.

[Example 4]
In Example 4, the composition (based on solid content) of the coating layer forming composition was set to 70% by mass of casein, 7.5% by mass of the solid content of the acrylic resin emulsion at Tg = -20 ° C, and acrylic at Tg = 30 ° C. This is the same as in Example 1 except that the solid content of the resin emulsion is changed to 22.5% by mass. The composition of the coating layer (based on solid content) in Example 4 is as shown in Table 1.

[Example 5]
In Example 5, the composition (based on solid content) of the coating layer forming composition was set to 80% by mass of casein, 5% by mass of the solid content of the acrylic resin emulsion at Tg = −20 ° C., and the acrylic resin emulsion at Tg = 30 ° C. The same as in Example 1 except that the solid content of the above was changed to 15% by mass. The composition of the coating layer (based on solid content) in Example 5 is as shown in Table 1.

[Comparative Example 1]
In Comparative Example 1, the composition (based on solid content) of the coating layer forming composition was adjusted to 0 parts by mass of casein, 25 parts by mass of solid content of an acrylic resin emulsion having Tg = -20 ° C, and an acrylic resin emulsion having Tg = 30 ° C. The same as in Example 1 except that the solid content was changed to 75 parts by mass. The composition of the coating layer (based on solid content) in Comparative Example 1 is as shown in Table 1.

[Comparative Example 2]
In Comparative Example 2, the composition (based on solid content) of the coating layer forming composition was adjusted to 20 parts by mass of casein, 20 parts by mass of solid content of an acrylic resin emulsion having Tg = -20 ° C, and an acrylic resin emulsion having Tg = 30 ° C. The same as in Example 1 except that the solid content was changed to 60 parts by mass. The composition of the coating layer (based on solid content) in Comparative Example 2 is as shown in Table 1.

[Comparative Example 3]
In Comparative Example 3, the composition (based on the solid content) of the coating layer forming composition was adjusted to 100 parts by mass of casein, 0 parts by mass of the solid content of the acrylic resin emulsion at Tg = -20 ° C, and the acrylic resin emulsion at Tg = 30 ° C. The same as in Example 1 except that the solid content was changed to 0 parts by mass. The composition of the coating layer (based on solid content) in Comparative Example 3 is as shown in Table 1.

[Comparative Example 4]
Comparative Example 4 is the same as that of Example 1 except that the coating layer was not formed.

[Comparative Example 5]
Comparative Example 5 is the same as that of Example 1 except that a composition containing 100% by mass of oily cellulose (MPF manufactured by DIC Graphic Corporation) was used as the composition for forming the coating layer based on the solid content. The composition of the coating layer (based on solid content) in Comparative Example 5 is as shown in Table 1.

[Comparative Example 6]
Comparative Example 6 was carried out except that a composition containing 50% by mass of oil-based cellulose and 50% by mass of oil-based acrylic resin (SET-OP manufactured by DIC Graphic Corporation) was used as the composition for forming the coating layer. It is the same as Example 1. The composition of the coating layer (based on solid content) in Comparative Example 6 is as shown in Table 1.

[Comparative Example 7]
Comparative Example 7 is the same as that of Example 1 except that a composition containing 100% by mass of an oil-based acrylic resin (FW manufactured by Showa Ink Kogyo Co., Ltd.) was used as the composition for forming the coating layer. The composition of the coating layer (based on solid content) in Comparative Example 7 is as shown in Table 1.

10 ... Decorative board S10 ... First side of the decorative board T10 ... Second side of the decorative board 1 ... Core layer 2 ... Decorative sheet 21 ... Support layer
S21: The first surface of the support layer
T21: The second surface of the support layer
211 ... Paper base material
212 ・ ・ ・ Coating layer
213 ... Decorative layer 22 ... Release layer
S22 ... Surface of release layer 3 ... Surface layer S3 ... Surface of surface layer 30 ... Opening of surface layer 4 ... Recessed portion formed on the first surface of the decorative plate

Claims (9)

A decorative sheet including a first surface and a support layer having a second surface located on the opposite side of the first surface, and a release layer provided on a part of the first surface of the support layer.
The support layer comprises a paper substrate and a coating layer forming the first surface of the support layer.
The release layer contains a cured product of an ionizing radiation curable resin.
A decorative sheet in which the coating layer contains casein in an amount of 35% by mass or more and 85% by mass or less based on the total mass of the coating layer. The decorative sheet according to claim 1, wherein the coating layer contains a dried product of an acrylic resin emulsion in an amount of 15% by mass or more and 65% by mass or less based on the total mass of the coating layer. The decorative sheet according to claim 1 or 2, wherein the paper base material contains an inorganic component. The decorative sheet according to claim 3, wherein the inorganic component contains titanium oxide. The decorative sheet according to claim 4, wherein the amount of titanium oxide contained in the paper-based base material is 5% by mass or more and 40% by mass or less based on the total mass of the paper-based base material. The decorative sheet according to any one of claims 1 to 5, wherein the release layer contains a silicone-based release agent. The decorative sheet according to any one of claims 1 to 6, wherein the support layer further includes a decorative layer located between the paper-based base material and the coating layer. The core layer, the decorative sheet according to any one of claims 1 to 7 provided on the core layer, the surface layer provided on the rest of the first surface of the support layer of the decorative sheet, and the decorative sheet. A decorative board provided with a cured product of melamine resin filled in the voids of a paper substrate.
The surface layer contains a cured product of melamine resin and contains
The surface layer has an opening that exposes the surface of the release layer of the decorative sheet.
The opening of the surface layer forms a recess on the surface of the decorative board.
A decorative board in which a cured product of melamine resin contained in the surface layer is integrated with a cured product of melamine resin filled in the voids of a paper substrate. The method for manufacturing a decorative board according to claim 8.
(1) Step of preparing the decorative sheet according to any one of claims 1 to 7 (2) The melamine resin filled in the voids of the paper-based substrate by impregnating the decorative sheet with the uncured melamine resin composition. A step of forming an impregnated decorative sheet including an uncured product and an uncured melamine resin layer that covers the rest of the first surface of the support layer and the release layer.
(3) A step of laminating the impregnated decorative sheet on the precursor layer of the core layer,
(4) A step of curing the uncured melamine resin and the uncured melamine resin layer filled in the voids of the paper substrate, and
(5) Of the precursor layer of the surface layer formed by curing the uncured melamine resin layer, the step of peeling off the portion covering the release layer and forming the surface layer on the rest of the first surface of the support layer is included. ,Method.

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