JP2017019274A - Decorative sheet, decorative laminate and production method of decorative laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative sheet in which generation of a whitening scratch or shaving of a symbol pattern layer due to wear (shaving of a symbol) can be suppressed even when foreign matters such as sands rub a surface of a decorative laminate due to walking, and a decorative laminate using the decorative sheet and a production method of the decorative laminate.SOLUTION: There is provided a decorative sheet 1 suitable for being laminated on a cork sheet, the decorative sheet is formed of a laminate comprising a base material sheet 2, a transparent resin layer 4, and a surface protective layer 5 in an order in a thickness direction, (1) the transparent resin layer has thickness of 90 μm or more and 300 μm or less, and (2) the surface protective layer has thickness of 20 μm or more and 40 μm or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a decorative sheet, a decorative plate, and a method for manufacturing the decorative plate.

  Conventionally, an interior material used for the interior of a building is required to have a design property, and a decorative board is used as such an interior material. In particular, the surface of the decorative board used for the floor surface is required to have scratch resistance as well as design properties.

  Further, in Western cultures, it is normal to walk on the ground even indoors such as houses, so low pressure melamine floors are mainly used for Western floors in consideration of scratch resistance. However, the low-pressure melamine floor has a problem that sound easily resonates during walking, the touch is hard, and it is cold.

  In recent years, instead of a low-pressure melamine floor, a floor (so-called hybrid floor) in which a decorative sheet made of a vinyl chloride resin is bonded to a chip board typically represented by cork as a decorative board base material has been used. Chipboards are mechanically pulverized wood chips, bark, small-diameter logs and construction waste materials discarded at the site of demolition work, which are discarded at a lumber mill, and then compression-molded with a synthetic resin adhesive. It is a base material obtained by molding into a plate material.

  The above-mentioned hybrid floor is excellent in that it uses a chip board as a decorative board base material, is environmentally friendly, has sound insulation and heat insulation effects, and has a soft touch feeling. Productivity is improved and color variation during construction is suppressed. However, in Europe, a decorative board that does not use a vinyl chloride resin is required in consideration of environmental problems.

  As a decorative board not using a vinyl chloride resin, for example, a decorative board in which a decorative sheet using an olefin resin is bonded to a decorative board substrate is used. As a decorative sheet using an olefin-based resin, for example, it has a pattern layer, a transparent adhesive layer, a transparent resin layer, and a transparent surface protective layer in this order on the base sheet, and is synthesized on the back of the base sheet. A decorative sheet for flooring having a resin backer layer has been proposed (see, for example, Patent Document 1).

  In the decorative sheet for flooring of Patent Document 1, the thickness of the transparent resin layer and the decorative sheet for flooring is within a specific range, and on the base sheet, a pattern layer, a transparent adhesive layer, a transparent resin layer, and It is obtained by forming a synthetic resin backer layer by extruding a molten resin in a specific range of thickness to the back surface of the base material sheet of the intermediate sheet on which the transparent surface protective layer is formed. At least one of the functional resin layer and the synthetic resin backer layer is characterized by containing a thermoplastic resin as a resin component.

  Although a decorative board using such a decorative sheet is also an excellent decorative board, it is not assumed to walk on a dirt foot, and further scratch resistance is required. In recent years, in particular, the design of the indoor floor and the outdoor wooden deck has been unified, and the construction has been carried out so that the entire room can be seen wide by eliminating the step. Is brought in, and sand and other foreign matters rub against the surface of the decorative board when walking, causing whitening scratches (scratches), and the pattern layer of the decorative sheet is scraped off due to wear over a long period of time. This problem is particularly noticeable when a deep embossed concave pattern is formed from the surface protective layer side of the decorative sheet.

  Therefore, even when foreign matter such as sand is rubbed against the surface of the decorative board by walking, a decorative sheet in which the occurrence of whitening scratches and abrasion due to wear of the pattern pattern layer (pattern removal) is suppressed, and the decorative sheet are provided. Development of the decorative board used is desired.

Japanese Patent No. 5045180

  The present invention is a decorative sheet suitable for use as a decorative board by laminating at least on a cork sheet, and even when foreign matters such as sand rub against the decorative board surface by walking, An object of the present invention is to provide a decorative sheet in which shaving (pattern removal) due to wear of the pattern layer is suppressed, a decorative board using the decorative sheet, and a method for manufacturing the decorative board.

  As a result of intensive studies, the inventor has found that the above object is obtained by laminating at least a transparent resin layer having a specific thickness and a surface protective layer having a specific thickness in this order on a base sheet. The present invention has been completed.

That is, this invention relates to the manufacturing method of the following decorative sheet, a decorative board, and a decorative board.
1. A decorative sheet suitable for laminating at least on a cork sheet,
The decorative sheet is composed of a laminate including a base sheet, a transparent resin layer, and a surface protective layer in order in the thickness direction,
(1) The transparent resin layer has a thickness of 90 μm or more and 300 μm or less,
(2) The surface protective layer has a thickness of 20 μm or more and 40 μm or less.
A decorative sheet characterized by that.
2. Item 2. The decorative sheet according to Item 1, wherein the decorative sheet has an embossed concave pattern from the surface protective layer side.
3. The decorative sheet has an embossed concave pattern from the surface protective layer side,
Item 1. The embossed concave pattern partly or entirely has a concave depth from the reference surface of 0 μm or more with respect to the surface of the transparent resin layer at a portion not having the embossed concave pattern as a reference surface. The decorative sheet described in 1.
4). When the surface protective layer is composed of a single layer, the surface protective layer contains fine particles having a particle diameter larger than the thickness of the single layer, and 2) when the surface protective layer is composed of multiple layers. Item 4. The decorative sheet according to any one of Items 1 to 3, which contains fine particles having a particle diameter larger than the thickness of the outermost layer constituting the multilayer.
5. Item 5. The decorative sheet according to Item 4, wherein the content of the fine particles is 5 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the resin component of the layer containing the fine particles.
6). Item 6. The decorative sheet according to Item 4 or 5, wherein the fine particles are silica fine particles.
7). Item 7. The decorative sheet according to any one of Items 1 to 6, wherein the base sheet and the transparent resin layer contain a non-halogen thermoplastic resin.
8). The decorative sheet according to Item 7, wherein the non-halogen thermoplastic resin is an olefin-based thermoplastic resin.
9. Item 9. The decorative sheet according to any one of Items 1 to 8, wherein the surface protective layer contains an ionizing radiation curable resin.
10. A decorative board in which at least a cork sheet and the decorative sheet according to any one of Items 1 to 9 are laminated in this order on a decorative board substrate.
11. The decorative board base material is at least one selected from the group consisting of medium density wood fiber board, high density wood fiber board, particle board, softwood plywood, hardwood plywood, early-wood plywood, polyvinyl chloride, polypropylene and polyethylene. The decorative board according to Item 10 above.
12 A method for producing a decorative board, comprising a step of laminating at least a cork sheet and the decorative sheet according to any one of Items 1 to 9 on the decorative board substrate so that the layer configuration is in this order.

  The decorative sheet of the present invention is a decorative sheet suitable for use as a decorative plate by being laminated on at least a cork sheet, and has a transparent resin layer having a specific thickness and a specific thickness on the base sheet. The surface protective layers are laminated in this order, and even when sand or other foreign matter rubs against the surface of the decorative board by walking, whitening scratches and scraping (pattern removal) due to abrasion of the pattern layer are suppressed. Has been. The decorative sheet and decorative plate of the present invention are useful as a decorative sheet and decorative plate used for flooring.

It is sectional drawing which showed typically an example of the decorative sheet of this invention. It is sectional drawing which showed typically an example of the decorative sheet of this invention. It is sectional drawing which showed typically an example of the decorative sheet of this invention. It is an example of the top view of the decorative sheet of this invention. It is an example of the top view (enlarged view) of the decorative sheet of the present invention. When the decorative sheet of the present invention has an embossed concave pattern, the depth X of the embossed concave pattern from the reference surface with the surface of the transparent resin layer 4 (the surface of the portion not having the embossed concave pattern) as a reference surface It is sectional drawing which showed typically (distance to the deepest part). In the figure, T1 indicates the thickness of the transparent resin layer 4, and T2 indicates the thickness of the surface protective layer 5. It is sectional drawing which expanded the cross section of the embossed concave pattern in the case where the decorative sheet of this invention has an embossed concave pattern, and was typically illustrated to (a)-(f). It is sectional drawing which showed typically an example of the decorative board of this invention.

1. The decorative sheet of the present invention is a decorative sheet suitable for use as a decorative plate by laminating at least on a cork sheet, and in that order in the thickness direction, a base sheet, a transparent resin layer, and a surface protection A layered product comprising a layer,
(1) The transparent resin layer has a thickness of 90 μm or more and 300 μm or less,
(2) The surface protective layer has a thickness of 20 μm or more and 40 μm or less.
It is characterized by that.

  The decorative sheet of the present invention having the above characteristics is a decorative sheet suitable for use as a decorative board by being laminated on at least a cork sheet, and has a transparent resin layer having at least a specific thickness and a base sheet. The surface protective layers with a specific thickness are laminated in this order, so that even when foreign objects such as sand rub against the surface of the decorative board by walking, whitening scratches or abrasion due to the pattern layer wear (pattern removal) ) Is suppressed. The decorative sheet and decorative plate of the present invention are useful as a decorative sheet and decorative plate used for flooring.

  Hereinafter, the decorative sheet will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an example of the decorative sheet of the present invention. A decorative sheet 1 shown in FIG. 1 has a pattern layer 3, a transparent resin layer 4, and a surface protective layer 5 laminated on a base sheet 2, and has an embossed concave pattern from the surface protective layer 5 side. .

  FIG. 2 shows an embodiment in which the surface protective layer 5 is composed of a single layer and contains fine particles A7 having a particle diameter larger than the thickness of the surface protective layer 5 in the decorative sheet illustrated in FIG.

  FIG. 3 shows an aspect in which the decorative sheet illustrated in FIG. 2 has a gloss adjusting layer 8 on the transparent resin layer 4 so as to be adjacent to the surface protective layer 5 (single surface protective layer).

  Hereinafter, each layer which comprises the decorative sheet of this invention is demonstrated concretely. In the following description, the lower and upper limit of the numerical range represented by “to” means “more than or less” (for example, α to β is α to β).

The base material sheet has a pattern layer or the like sequentially laminated on the surface (front surface) thereof. Although the material of a base material sheet is not limited, It is preferable to contain a non-halogen-type thermoplastic resin.

  Examples of the non-halogen thermoplastic resin include low density polyethylene (including linear low density polyethylene), medium density polyethylene, high density polyethylene, ethylene-α olefin copolymer, homopolypropylene, polymethylpentene, polybutene, ethylene- Olefin-based thermoplastic resins such as propylene copolymer, propylene-butene copolymer, ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, or mixtures thereof, polyethylene terephthalate, polybutylene terephthalate, Thermoplastic ester resins such as polyethylene naphthalate, polyethylene naphthalate-isophthalate copolymer, polycarbonate, polyarylate, polymethyl methacrylate, polyethyl methacrylate, ethyl polyacrylate, polyacrylate Thermoplastic acrylic resins such as butyl, nylon-6, polyamide-based thermoplastic resin such as nylon-66, or, polyimide, polyurethane, polystyrene, acrylonitrile - butadiene - styrene resin. Further, these non-halogen thermoplastic resins may be used alone or in combination of two or more. Of these, olefin-based thermoplastic resins are preferred because they are excellent in printability and embossing suitability for the pattern layer and are inexpensive.

  The base material sheet may be colored. In this case, a coloring material (pigment or dye) can be added to the non-halogen thermoplastic resin as described above for coloring. As the colorant, for example, inorganic pigments such as titanium dioxide, carbon black and iron oxide, organic pigments such as phthalocyanine blue, and various dyes can be used. These can be selected from one or more known or commercially available ones. Further, the addition amount of the colorant may be appropriately set according to the desired color tone.

  The base sheet contains various additives such as fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, antioxidants, UV absorbers, and light stabilizers as necessary. It may be.

  As for the thickness of a base material sheet, 40-100 micrometers is preferable. When the thickness of the base sheet is less than 40 μm, when the decorative board base has a concavo-convex shape, there is a possibility that the unevenness on the decorative board surface cannot be sufficiently suppressed. Moreover, when the thickness of a base material sheet exceeds 100 micrometers, when a decorative sheet is preserve | saved in a roll state, there exists a possibility that roll lamination may become difficult by being wound. As for the thickness of a base material sheet, 60-80 micrometers is more preferable. The base sheet may be composed of a single layer or multiple layers.

  The substrate sheet may be subjected to corona discharge treatment on the surface (front surface) in order to enhance the adhesion of the ink forming the pattern layer. What is necessary is just to implement the method and conditions of a corona discharge process according to a well-known method. Moreover, you may give a corona discharge process to the back surface of a base material sheet, and may form the back surface primer layer mentioned later as needed.

Pattern pattern layer The pattern pattern layer is an arbitrary layer that imparts a desired pattern (design) to the decorative sheet, and the type of the pattern is not limited. For example, a wood grain pattern, a leather pattern, a stone pattern, a grain pattern, a tiled pattern, a brickwork pattern, a cloth pattern, a geometric figure, a character, a symbol, an abstract pattern, and the like can be given.

  The method for forming the pattern layer is not particularly limited. For example, an ink obtained by dissolving (or dispersing) a known colorant (dye or pigment) in a solvent (or dispersion medium) together with a binder resin is used. What is necessary is just to form on the base-material sheet | seat surface by the printing method. As the ink, an aqueous composition can be used from the viewpoint of reducing the VOC of the decorative sheet.

  Examples of the colorant include inorganic pigments such as carbon black, titanium white, zinc white, dial, bitumen, and cadmium red; azo pigments, lake pigments, anthraquinone pigments, quinacridone pigments, phthalocyanine pigments, isoindolinone pigments, dioxazine pigments. Organic pigments such as aluminum powder, metal powder pigments such as bronze powder, pearlescent pigments such as titanium oxide-coated mica and bismuth oxide chloride; fluorescent pigments; These colorants can be used alone or in admixture of two or more. These colorants may be used together with fillers such as silica, extender pigments such as organic beads, neutralizing agents, surfactants and the like.

  As binder resin, in addition to polyester urethane resin treated with hydrophilicity, polyester, polyacrylate, polyvinyl acetate, polybutadiene, polyvinyl chloride, chlorinated polypropylene, polyethylene, polystyrene, polystyrene-acrylate copolymer, rosin derivative Alcohol adducts of styrene-maleic anhydride copolymers, cellulose resins, and the like can also be used in combination. More specifically, for example, polyacrylamide resins, poly (meth) acrylic resins, polyethylene oxide resins, poly N-vinyl pyrrolidone resins, water-soluble polyester resins, water-soluble polyamide resins, water-soluble amino acids. Also usable are water-based resins, water-soluble phenolic resins, other water-soluble synthetic resins; water-soluble natural polymers such as polynucleotides, polypeptides, polysaccharides, and the like. Also, for example, natural rubber, synthetic rubber, polyvinyl acetate resin, (meth) acrylic resin, polyvinyl chloride resin, polyurethane-polyacrylic resin, etc. modified or a mixture of the above natural rubber, etc. Resin can also be used. The said binder resin can be used individually or in combination of 2 or more types.

  Examples of the solvent (or dispersion medium) include petroleum organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and acetic acid-2 -Ester-based organic solvents such as ethoxyethyl; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone Organic solvents; ether organic solvents such as diethyl ether, dioxane, tetrahydrofuran; dichloromethane, carbon tetrachloride, trichloroethylene, tetrachloroethylene, etc. Chlorinated organic solvents; inorganic solvents such as water. These solvents (or dispersion media) can be used alone or in admixture of two or more.

  Examples of the printing method used for forming the pattern layer 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. When forming a solid pattern pattern layer, for example, roll coating method, knife coating method, air knife coating method, die coating method, lip coating method, comma coating method, kiss coating method, flow coating method, dip coating Various coating methods such as a coating method may be mentioned. In addition, the hand-drawn method, the ink-sink method, the photographic method, the transfer method, the laser beam drawing method, the electron beam drawing method, the metal partial evaporation method, the etching method, etc. may be used or combined with other forming methods. Good.

  The thickness of the pattern layer is not particularly limited and can be appropriately set according to product characteristics, but the layer thickness is about 0.1 to 15 μm.

Transparent resin layer The transparent resin layer is not particularly limited as long as it is transparent and has a thickness of 90 μm or more and 300 μm or less, and includes any of colorless and transparent, colored and transparent. The material of the transparent resin layer is not limited, but preferably contains a non-halogen thermoplastic resin. In this invention, the thickness of a transparent resin layer is the thickness shown by T1 of FIG.2 and FIG.6, and is the average value which measured the thickness of 10 transparent resin layers from the cross-sectional photograph of a decorative sheet.

  Examples of the non-halogen thermoplastic resin include low density polyethylene (including linear low density polyethylene), medium density polyethylene, high density polyethylene, ethylene-α olefin copolymer, homopolypropylene, polymethylpentene, polybutene, ethylene- Olefin-based thermoplastic resins such as propylene copolymer, propylene-butene copolymer, ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, or mixtures thereof, polyethylene terephthalate, polybutylene terephthalate, Thermoplastic ester resins such as polyethylene naphthalate, polyethylene naphthalate-isophthalate copolymer, polycarbonate, polyarylate, polymethyl methacrylate, polyethyl methacrylate, ethyl polyacrylate, polyacrylate Thermoplastic acrylic resins such as butyl, nylon-6, polyamide-based thermoplastic resin such as nylon-66, or, polyimide, polyurethane, polystyrene, acrylonitrile - butadiene - styrene resin. Further, these non-halogen thermoplastic resins may be used alone or in combination of two or more. Of these, olefin-based thermoplastic resins are preferred because they are excellent in printability and embossing suitability for the pattern layer and are inexpensive.

  The transparent resin layer may be colored as long as it has transparency.

  The thickness of the transparent resin layer may be 90 μm or more and 300 μm or less, among which 150 μm or more and 300 μm or less is preferable, and 200 μm or more and 250 μm or less is more preferable. By setting the thickness of the transparent resin layer to 90 μm or more and 300 μm or less, even when foreign matter such as sand rubs against the surface of the decorative board of the present invention by walking, it is scraped by generation of whitening scratches or wear of the pattern layer (Picture taken) can be suppressed. This effect is also obtained when a deep embossed concave pattern is formed from the surface protective layer side of the decorative sheet. These effects of the present invention can be obtained by a combination of a transparent resin layer having a specific thickness and a surface protective layer having a specific thickness.

Surface protective layer The decorative sheet of the present invention has a surface protective layer formed on the surface. The thickness of the surface protective layer of the decorative sheet of the present invention may be 20 μm or more and 40 μm or less, among which 25 μm or more and 40 μm or less is preferable, and 30 μm or more and 35 μm or less is more preferable. In the present invention, the thickness of the surface protective layer is the thickness indicated by T2 in FIG. 2 and FIG. Value. The thickness of the surface protective layer can be specified from a cross-sectional photograph of the decorative sheet, like the transparent resin layer.

  By setting the thickness of the surface protective layer to 20 μm or more and 40 μm or less, even if foreign matter such as sand rubs against the surface of the decorative board of the present invention by walking, it is scraped by generation of whitening scratches or wear of the pattern layer ( Can be suppressed). This effect is also obtained when a deep embossed concave pattern is formed from the surface protective layer side of the decorative sheet. These effects of the present invention are obtained by a combination of a transparent resin layer having a specific thickness and a surface protective layer.

  When the decorative sheet of the present invention has a gloss adjusting layer described later, the surface protective layer is formed adjacent to the gloss adjusting layer. Specifically, the back surface of the surface protective layer is adjacent to the gloss adjusting layer. When the decorative sheet of the present invention has a gloss adjusting layer, the surface protective layer is preferably transparent.

  The surface protective layer preferably contains fine particles (fine particles A) having a particle diameter larger than the thickness of the surface protective layer. The fine particles A act as an additive for improving the scratch resistance of the surface protective layer. In the present specification, it can be confirmed by SEM (scanning electron microscope) that the particle diameter of the fine particles A is larger than the thickness of the surface protective layer. For example, the decorative sheet is cut in a direction perpendicular to the surface. And the location of the surface protective layer of the obtained cross section can be confirmed by observing using SEM (scanning electron microscope). The fine particles A preferably have one or more fine particles A in the observation of a length of 200 μm in the confirmation by the SEM.

  The particle diameter of the fine particles A is not particularly limited as long as it is larger than the thickness of the surface protective layer. When the particle diameter of the fine particles A is equal to or less than the thickness of the surface protective layer, the surface protective layer has insufficient scratch resistance.

  The particle diameter of the fine particles A is preferably 25 to 50 μm, and more preferably 30 to 45 μm. If the particle diameter of the fine particles A is too large, the fine particles A may be easily detached from the surface protective layer.

  The content of the fine particles A is preferably 5 to 30 parts by mass with respect to 100 parts by mass of the resin component of the surface protective layer. When the content of the fine particles A is too large, when the cueing portion of the fine particles A is rubbed and scraped off, the gloss of the rubbed portion is increased and becomes conspicuous, and the scratch resistance becomes insufficient. Moreover, when there is too little content of microparticles | fine-particles A, the scratch resistance of a surface protective layer is not enough. The content of the fine particles A is preferably 5 parts by mass or more and 30 parts by mass or less, and more preferably 10 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the resin component of the surface protective layer.

  In the present specification, the particle diameter of the fine particles A can be measured by SEM (scanning electron microscope). For example, the surface of the cross section obtained by cutting a decorative sheet in a direction perpendicular to the surface It can be measured by photographing an arbitrary portion of the protective layer using an SEM (scanning electron microscope) and averaging the particle diameter (diameter) of the reflected fine particles A.

  The surface protective layer may be composed of either a single layer or a multilayer. In the case of a multilayer, it is preferable to contain the fine particles A in the layer located on the most front side (outermost layer), and to contain fine particles A having a particle diameter 2 to 10 μm larger than the thickness of the outermost layer. preferable. In this case, the content of the fine particles A is preferably 5 parts by mass or more and 30 parts by mass or less, and more preferably 10 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the resin component of the outermost layer.

  The surface protective layer may contain fine particles (fine particles B) having a particle diameter equal to or smaller than the thickness of the surface protective layer, in addition to the fine particles A, in order to suppress glossiness due to rubbing. The method for confirming the fine particles B in the surface protective layer and the method for measuring the particle diameter are the same as those for the fine particles A. The content of the fine particles B is preferably 5 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the resin component of the surface protective layer (the layer containing the fine particles B in the case of a multilayer).

  The fine particles A and B are not particularly limited as long as they can impart scratch resistance to the surface protective layer according to the particle size and can exhibit a matting effect, and conventionally known ones can be used. Examples of the fine particles A and B include inorganic particles such as silica fine particles and silicone resin; organic particles such as crosslinked alkyl, crosslinked styrene, benzoguanamine resin, urea-formaldehyde resin, phenol resin, polyethylene, and nylon. Among these, silica fine particles are preferable.

  The resin component contained in the surface protective layer is not limited, but preferably contains an ionizing radiation curable resin or a two-component curable urethane resin. Substantially those formed from these resins are preferred. When the surface protective layer is formed from an ionizing radiation curable resin or a two-component curable urethane resin, it is easy to improve the wear resistance, impact resistance, stain resistance, scratch resistance, weather resistance, etc. of the decorative sheet. Among these, ionizing radiation curable resins are more preferable.

  The ionizing radiation curable resin is not particularly limited, and prepolymers (including oligomers) and / or monomers containing radically polymerizable double bonds capable of undergoing a crosslinking reaction upon irradiation with ionizing radiation such as ultraviolet rays and electron beams. A transparent resin containing as a main component can be used. These prepolymers or monomers can be used alone or in combination. The curing reaction is usually a cross-linking curing reaction.

  Specifically, as the prepolymer or monomer, a compound having in the molecule a radically polymerizable unsaturated group such as a (meth) acryloyl group or (meth) acryloyloxy group, or a cationically polymerizable functional group such as an epoxy group. Is mentioned. Further, a polyene / thiol prepolymer based on a combination of polyene and polythiol is also preferable. Here, the (meth) acryloyl group means an acryloyl group or a methacryloyl group.

  Examples of the prepolymer having a radically polymerizable unsaturated group include polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, melamine (meth) acrylate, triazine (meth) acrylate, and silicone (meth) acrylate. Etc. These molecular weights are usually preferably about 250 to 100,000.

  As a monomer which has a radically polymerizable unsaturated group, methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenoxyethyl (meth) acrylate etc. are mentioned as a monofunctional monomer, for example. Examples of the polyfunctional monomer include diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide tri (meth) acrylate, dipentaerythritol tetra ( And (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.

  Examples of the prepolymer having a cationic polymerizable functional group include prepolymers of epoxy resins such as bisphenol type epoxy resins and novolac type epoxy compounds, and vinyl ether type resins such as fatty acid type vinyl ethers and aromatic vinyl ethers. Examples of the thiol include polythiols such as trimethylolpropane trithioglycolate and pentaerythritol tetrathioglycolate. Examples of the polyene include those in which allyl alcohol is added to both ends of polyurethane by diol and diisocyanate.

  As the ionizing radiation used for curing the ionizing radiation curable resin, electromagnetic waves or charged particles having energy capable of causing a curing reaction of molecules in the ionizing radiation curable resin (composition) are used. Usually, ultraviolet rays or electron beams may be used, but visible light, X-rays, ion rays, or the like may be used.

  The two-component curable urethane resin is not particularly limited. Among them, a polyol component (acrylic polyol, polyester polyol, polyether polyol, epoxy polyol, etc.) having an OH group as a main component and an isocyanate component (tolylene diene) which is a curing agent component. Isocyanate, hexamethylene diisocyanate, metaxylene diisocyanate and the like) can be used.

  About the resin of the said illustration, 1 type (s) or 2 or more types can be used together.

  In order to improve the weather resistance, it is preferable to add a UV absorber such as benzotriazole, benzophenone, salicylate, or triazine to the surface protective layer. In the case of curing the resin layer by irradiating with ultraviolet rays, as photopolymerization initiators, acetophenones, benzophenones, Michler benzoylbenzoate, α-aminoxime ester, tetramethylthiuram monosulfide, thioxanthones, aromatic diazonium salts N-butylamine, triethylamine, tri-n-butylphosphine and the like can be used as photopolymerization accelerators (sensitizers) such as aromatic sulfonium salts and metallocenes.

  In addition, an antibacterial agent may be added to the surface protective layer in order to impart antibacterial properties. Antibacterial agents include inorganic antibacterial agents and organic antibacterial agents. In particular, inorganic antibacterial agents are desirable because they are generally safer than organic antibacterial agents and are excellent in durability and heat resistance. Inorganic antibacterial agents are those in which antibacterial metals such as silver, copper and zinc are supported on various inorganic carriers. As for the addition amount of an antibacterial agent, 0.1-10 mass parts is preferable with respect to 100 mass parts of resin components.

  In addition, various additives such as solvents, dyes and pigments, fillers such as extenders, antifoaming agents, leveling agents, and thixotropic agents can be added to the surface protective layer as necessary. .

  The surface protective layer is, for example, after applying an ionizing radiation curable resin or a two-component curable urethane resin on a transparent resin layer or a gloss adjusting layer described later by a known coating method such as gravure coating, roll coating, It can be formed by curing the resin.

  The gloss value of the surface protective layer can be adjusted by a method of selecting the type of each material such as a resin component and additive contained in the surface protective layer, a method of appropriately setting the content of each of the above materials, and the like.

(Layer structure of decorative sheet)
If the decorative sheet of the present invention is composed of a laminate including a base sheet, a transparent resin layer, and a surface protective layer in order in the thickness direction, the specific configuration (layer configuration) is not limited. . For example, a decorative sheet formed by laminating a pattern layer, a transparent adhesive layer, a transparent resin layer, a primer layer, and a surface protective layer in this order on a base material sheet. In this specification, the direction in which the surface protective layer is laminated as viewed from the base sheet is referred to as “upper” or “front surface”, and the direction in which the back primer layer is laminated as viewed from the base sheet. It is called “bottom” or “back”. The “front surface (side)” or “surface of the surface protective layer (side)” of the decorative sheet or decorative plate means a surface that is visually recognized after the decorative sheet or decorative plate is applied.

  Hereinafter, with reference to the decorative sheet having such a layer configuration as a representative example, the layers other than the base sheet, the pattern layer, the transparent resin layer, and the surface protective layer described above will be specifically described.

Transparent adhesive layer A transparent adhesive layer may be formed on the pattern layer in order to enhance the adhesion between the transparent resin layer and the pattern layer. The transparent adhesive layer is not particularly limited as long as it is transparent, and includes any of transparent and colorless, colored and translucent.

  It does not specifically limit as an adhesive agent, A well-known adhesive agent can be used in the field of a decorative sheet. Examples of known adhesives in the field of decorative sheets include thermoplastic resins such as polyamide resins, acrylic resins and vinyl acetate resins, and thermosetting resins such as urethane resins. These adhesives can be used individually by 1 type or in combination of 2 or more types. Further, a two-component curable polyurethane resin or polyester resin using isocyanate as a curing agent can also be applied.

  Although the thickness of a transparent adhesive bond layer is not specifically limited, Thickness is about 0.1-30 micrometers, Preferably it is about 1-20 micrometers.

A primer layer may be provided on the primer layer transparent resin layer. The primer layer can be formed by applying a known primer agent to the surface of the transparent resin layer. Examples of the primer agent include a urethane resin-based primer agent made of an acrylic-modified urethane resin (acrylic urethane-based resin), a urethane-cellulose resin (for example, a resin obtained by adding hexamethylene diisocyanate to a mixture of urethane and nitrified cotton) ), A resinous primer agent made of a block copolymer of acrylic and urethane, and the like. You may mix | blend an additive with a primer agent as needed. Examples of the additive include fillers such as calcium carbonate and clay, flame retardants such as magnesium hydroxide, antioxidants, lubricants, foaming agents, ultraviolet absorbers, and light stabilizers. The blending amount of the additive can be appropriately set according to the product characteristics.

  Although the thickness of a primer layer is not specifically limited, Usually, 0.01-10 micrometers, Preferably it is about 0.1-1 micrometer.

Gloss Control Layer A gloss control layer may be formed on the decorative sheet of the present invention. As a form of the decorative sheet in which the gloss adjusting layer is formed, for example, the form of FIG.

  When the gloss adjusting layer is formed on the decorative sheet of the present invention, the gloss adjusting layer is formed on the transparent resin layer so as to be adjacent to the surface protective layer. More specifically, the back surface of the gloss adjusting layer is adjacent to the front surface of the transparent resin layer (or the primer layer when the decorative sheet of the present invention has the primer layer).

  From the viewpoint of design, the gloss adjusting layer may be formed on a part of the surface on the front surface side (surface side visually recognized after the decorative sheet or decorative plate is applied), and (2 ) It may be formed on the entire front surface side (entire surface). That is, the gloss adjustment layer may be (1) partially formed with respect to the surface on the front surface side, and (2) formed over the entire surface with respect to the surface on the front surface side. May be. In the form of FIG. 3, the gloss adjusting layer is formed on a part of the front side surface, and the surface protective layer is formed on the entire front side.

Here, the gloss value of the gloss adjusting layer is G _A , and the gloss value of the surface protective layer is _GP . If the decorative sheet of the present invention have a luster control layer, the relationship between the gloss values G _A luster control layer and the luster value G _P of the aforementioned surface protective layer is a G _P ≠ G _A. Here, the _{G P} and the _{G A} in the present specification is a value measured according to Japanese Industrial Standard JIS Z8741. Specifically, in the present invention, the gloss value is measured under the condition of an incident angle = 60 ° using PG-3D manufactured by Nippon Denshoku Industries Co., Ltd. as a gross meter. In the present specification, the gloss value is also referred to as a gloss value or a gloss value.

Either (1) the gloss adjustment layer is formed on a part of the front surface side, or (2) the gloss adjustment layer is formed on the entire front surface side. Even so, both the gloss adjusting layer and the surface protective layer are visually recognized on the surface visually recognized after the decorative sheet or decorative plate is applied, and the gloss values of the gloss adjusting layer and the surface protective layer are the same. relationship is _{G P} ≠ _{G a.} Therefore, when the decorative sheet of the present invention is attached to the adherend, the influence of the uneven shape (duck) generated on the decorative sheet surface is further suppressed, and the design of the decorative sheet or decorative plate is improved. Therefore, the decorative sheet of the present invention in which the gloss adjusting layer is formed is a preferred embodiment as the present invention.

Next, the case (1) where the gloss adjusting layer is formed on a part of the surface on the front side (simply referred to as the case (1) above) will be described. In the case of (1), the area ratio of the area where the gloss adjusting layer occupies per 1 cm ² of the front surface area of the decorative sheet or decorative plate is preferably 20 to 80%. In this case, it is preferable that the gloss adjusting layer is formed so that the front surface (surface to be visually recognized) side of the gloss adjusting layer has a pattern shape. When the gloss adjustment layer is in a pattern and the ratio of the area is 20 to 80%, the gloss difference between the gloss adjustment layer and the surface protective layer becomes clearer, and as a result, the design is further improved, and The influence of the uneven shape can be further suppressed. In addition, when the gloss adjustment layer is formed so as to have the pattern shape, the type of the pattern is not particularly limited. Specific examples of the pattern include those similar to the various patterns exemplified in the pattern pattern layer described above.

In this specification, the ratio of the area of the gloss adjusting layer (area where the gloss adjusting layer is present) occupying per 1 cm ² of the front surface area of the decorative sheet or decorative plate is defined as the ratio of the gloss adjusting layer. It may be called an occupied area ratio. The occupation area ratio of the gloss adjusting layer is calculated from plate-making data at the stage of producing a plate for forming the gloss adjusting layer. The occupied area ratio of the gloss adjusting layer can be calculated from the shape of the plate.

For the (1), in order to the uneven shape of the impact to further suppress (the further inconspicuous irregularities), the relationship between G _A and the G _P is G _{A <G P} is preferred. More preferably, G _A < _GP and G _A ≦ 5.

  The method for forming the gloss adjusting layer is not particularly limited. For example, as in the case of the above-described pattern layer, it is dissolved (or dispersed) in a solvent (or dispersion medium) together with known colorants (dyes, pigments, etc.) and vehicles. It can form with the ink obtained. About a coloring agent and a solvent, the thing similar to the coloring agent and solvent which were illustrated by the coloring agent and solvent in the above-mentioned pattern pattern layer, respectively can be used.

  The ink vehicle for forming the gloss adjusting layer preferably contains 50% by mass or more of urethane resin and / or polyvinyl acetal resin. The urethane resin is a polyol component such as an acrylic polyol, a polyester polyol, or a polyether polyol, and an isocyanate component such as tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, or the like, isophorone diisocyanate, hexamethylene diisocyanate, Examples include urethane resins obtained by reacting with aliphatic or cycloaliphatic isocyanates such as hydrogenated tolylene diisocyanate (linearly cross-linked or network cross-linked). be able to. Moreover, a polyvinyl acetal type resin is obtained by condensation (acetalization) of polyvinyl alcohol and aldehydes. Examples of the polyvinyl acetal resin include polyvinyl formal (formal resin), polyvinyl acetoacetal, polyvinyl propional, polyvinyl butyral (butyral resin), and polyvinyl hexyl. Among these, polyvinyl butyral is particularly preferable because it is soluble in a solvent, easily converted into an ink, and has a good appearance of visual unevenness (recognized visually as a recess).

  Moreover, in order to adjust a gloss value as needed, you may mix and use gloss adjustment resins, such as unsaturated polyester-type resin, acrylic resin, and a vinyl chloride-vinyl acetate copolymer. When the gloss adjusting resin is used, the mixing ratio is preferably in the range of 10 to 50% by mass with respect to the total amount of the vehicle. The ink for forming the gloss adjusting layer may be uncolored or may be colored by adding a colorant such as a pigment.

  Further, an extender pigment may be blended in the ink for forming the gloss adjusting layer. When the extender pigment is blended, it is possible to promote light scattering and further enhance the effect of eliminating the uneven shape (duck). The extender pigment is not particularly limited, and is suitably selected from, for example, silica, talc, clay, barium sulfate, barium carbonate, calcium sulfate, calcium carbonate, magnesium carbonate and the like. Among these, silica, which is a material having a high degree of freedom in material design such as oil absorption, particle size, pore volume, etc., and excellent in designability, whiteness, and coating stability as an ink, is preferable. Silica is preferred. In addition, as for the content, when using an extender, 5-15 mass parts is preferable with respect to 100 mass parts of inks (ink composition) other than an extender.

Gloss values G _A luster control layer, vehicle described above, luster control resin, a method for selecting a type of each substance and coloring agent (including extender pigments); and the like; how to set the contents of the above materials properly Can be adjusted.

  As the printing method used for forming the gloss adjusting layer, for example, the gravure printing method, the offset printing method, the screen printing method, the flexographic printing method, the electrostatic printing method, the inkjet method, and the like, as in the printing method used for forming the above-mentioned pattern pattern layer. The printing method etc. are mentioned. Moreover, when forming the whole surface solid-like gloss adjustment layer, the method similar to the various coating methods in formation of a pattern layer is mentioned.

  When the gloss adjusting layer is formed on a part of the surface on the front side (in the case of (1) above), the gloss adjusting layer is preferably formed so as to have a pattern shape. In particular, the gloss adjusting layer is more preferably formed in a pattern such as a dot shape, a lattice shape, or a wood grain conduit pattern (shape). Since the gloss adjustment layer is formed in the above pattern, the gloss of the area with the gloss adjustment layer is further different from the gloss of the area other than the gloss adjustment layer (area without the gloss adjustment layer). An optical illusion appears as if there is a recess, and it is visually recognized as a unique stereoscopic effect. For this reason, the uneven shape (duck) becomes less noticeable.

  When the above-mentioned pattern pattern layer is formed on the decorative sheet of the present invention, it is preferable to form the gloss adjusting layer so as to be interlocked (tuned) with the pattern of the pattern pattern layer. For example, when the pattern layer is formed in a wood grain pattern, a decorative sheet having a more excellent design can be obtained by printing the pattern in a wood conduit pattern to form a gloss adjusting layer.

  The thickness (film thickness) of the gloss adjusting layer is preferably 0.5 μm to 5 μm in consideration of printability and interaction with the resin composition for forming the surface protective layer.

If necessary, a back primer layer may be provided on the back surface of the back primer layer substrate sheet (the surface opposite to the surface on which the pattern layer is laminated). For example, it is effective when a base sheet and a decorative board base material are bonded to produce a decorative board.

  A back surface primer layer can be formed by apply | coating a well-known primer agent to a base material sheet. Examples of the primer agent include a urethane resin-based primer agent made of an acrylic-modified urethane resin (acrylic urethane-based resin), a urethane-cellulose resin (for example, a resin obtained by adding hexamethylene diisocyanate to a mixture of urethane and nitrified cotton) ), A resinous primer agent made of a block copolymer of acrylic and urethane, and the like. You may mix | blend an additive with a primer agent as needed. Examples of the additive include fillers such as calcium carbonate and clay, flame retardants such as magnesium hydroxide, antioxidants, lubricants, foaming agents, ultraviolet absorbers, and light stabilizers. The blending amount of the additive can be appropriately set according to the product characteristics.

  Although the thickness of a back surface primer layer is not specifically limited, Usually, 0.01-10 micrometers, Preferably it is about 0.1-1 micrometer.

Embossed shape The decorative sheet of the present invention may have an embossed concave pattern from the surface protective layer side. The embossing method is not limited, and for example, a method of heating and softening the front surface of the surface protective layer, pressurizing and shaping with an embossing plate, and then cooling may be mentioned as a preferable method. Depending on the material of the surface protective layer, for example, the front surface of the transparent resin layer or the gloss adjusting layer may be softened by heating, and after pressing and shaping with an embossed plate, the surface protective layer may be formed thereon. .

  For embossing, a known single-wafer or rotary embossing machine is used. Examples of the concave shape include a wood grain plate conduit groove, a stone plate surface irregularity (such as granite cleaved surface), a cloth surface texture, a satin texture, a grain, a hairline, and a striated groove.

  The decorative sheet according to the present invention has a transparent resin layer having a specific thickness and a surface protective layer having a specific thickness laminated in this order on the base sheet, so that foreign matters such as sand are exposed to the decorative plate surface by walking. Even if it rubs against the surface of the decorative sheet of the present invention, it is possible to suppress the occurrence of whitening scratches and abrasion (pattern removal) due to wear of the pattern layer. It is also obtained when a concave pattern is formed. A plan view of an example of the embossed concave pattern is shown in FIG. The concave pattern in FIG. 4 is a wood grain plate conduit groove, and FIG. 5 shows an enlarged plan view of a part of the embossed concave pattern.

  Here, the comparatively deep embossed concave pattern is based on the surface of the transparent resin layer 4 (the surface of the portion not having the embossed concave pattern: the dotted line in FIG. 6). It is defined that the depth X (distance to the deepest part) of the embossed concave pattern from the reference surface is 0 μm or more as a surface. When X is 0 μm or more, in general, whitening scratches and abrasion due to the abrasion of the pattern layer are likely to occur due to foreign matters such as sand, but the decorative sheet of the present invention has a specific condition. By providing the transparent resin layer having a thickness and the surface protective layer having a specific thickness, whitening scratches and scraping of the pattern layer (pattern removal) are suppressed. In the present specification, the relatively deep embossed concave pattern is represented by 0 μm ≦ X, and among them, 0 μm ≦ X ≦ 200 μm, particularly 40 μm ≦ X ≦ 200 μm.

  Although the cross-sectional shape of the embossed concave pattern depends on the type of the concave pattern and the surface property of the embossed plate, typical cross-sectional shapes can be schematically illustrated in (a) to (f) of FIG. In the present invention, examples of the cross-sectional shape of the embossed concave pattern in which the effects of the present invention are easily obtained among (a) to (f) in FIG. 7 include (a), (d), and (f). Here, in (a), the bottom of the embossed concave pattern has a smooth shape. (D) is a shape in which the bottom of the embossed concave pattern is rounded, and the boundary between the embossed concave pattern and the non-embossed concave pattern is rounded. Further, (f) has a shape in which the bottom of the embossed concave pattern of the concave portion is rounded, and has a rounded spread in the middle of the concave portion.

  In addition, as a method for confirming the cross-sectional shape of the embossed concave pattern and a method for measuring the depth X, for example, in the case of the embossed concave pattern shown in FIG. This can be done by observing with an SEM (scanning electron microscope).

2. Decorative plate In the decorative plate of the present invention, at least the cork sheet and the decorative sheet of the present invention are laminated in this order on a decorative plate substrate. FIG. 8 shows an example of a decorative board in which a cork sheet 10 and a decorative sheet 1 of the present invention (a surface opposite to the surface protective layer side and the cork sheet 10 are bonded together) are laminated in this order on a decorative board substrate 9. Indicates.

  Although not limited as a decorative board substrate, for example, medium density wood fiber board, high density wood fiber board, particle board, softwood plywood, hardwood plywood, early-wood plywood, thermoplastic resin board (polyvinyl chloride, polypropylene, Polyethylene, etc.).

  Here, examples of the conifers include pine, pine, pine, cedar, cypress, pine, sequoia, and spruce. Examples of the broad-leaved tree include lawan, china, hippopotamus, sen, beech, oak, and meranti. Examples of early mature trees include poplar, falkata, acacia, chameleon, eucalyptus, terminaria and the like.

  In the case of using woody plywood such as softwood plywood, hardwood plywood, and early-wood plywood, the number of laminated wood veneers (number of plies) is not limited, but usually 3 to 7 and more preferably 5 to 7 are preferred. Moreover, the adhesive agent used at the time of wood plywood preparation is not limited, either, The well-known adhesive for woodworking can be used widely. As an adhesive, for example, polyvinyl acetate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ionomer, butadiene-acrylonitrile rubber, neoprene rubber, natural rubber and the like are effective ingredients. Adhesives to be used. Examples of the thermosetting adhesive include melamine-based, phenol-based, urea-based (such as vinyl acetate-urea) adhesives.

  Although the thickness of a decorative board base material is not limited, about 2-15 mm is preferable and about 2-12 mm is more preferable.

  The cork sheet is not particularly limited as long as it can give a good walking feeling when a decorative material is used as a flooring material (floor material), for example, and various commercially available products are used for the cork sheet itself. Can do.

  As a cork sheet used in the present invention, not only a so-called natural cork which is a material rich in elasticity obtained by peeling and processing a cork tissue of cork oak bark, but also a so-called synthetic cork made similar to cork is used. Can do.

The density of the cork sheet is preferably about 0.1 to 0.5 g / cm ^3, about 0.2-0.5 g / cm ³ is more preferable.

  The thickness of the cork sheet is preferably 1.5 mm or more and more preferably about 2.0 to 2.5 mm in terms of giving a good walking feeling to the decorative material.

  The cork sheet may be a single layer or a laminate of a plurality of cork sheets having different elastic moduli and densities.

  The lamination | stacking method which each laminates | stacks a decorative sheet, a decorative board base material, and a cork sheet is not limited, For example, the method of sticking each with an adhesive agent etc. is employable. What is necessary is just to select an adhesive agent suitably from well-known adhesive agents according to the kind etc. of to-be-adhered material. Examples include polyvinyl acetate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ionomer, butadiene-acrylonitrile rubber, neoprene rubber, natural rubber, and the like. These adhesives are used alone or in combination of two or more. This invention also includes the invention of the manufacturing method of a decorative board which has the process of laminating | stacking a cork sheet and the decorative sheet of this invention so that a layer structure may become this order on a decorative board base material.

  The decorative board manufactured in this way includes, for example, interior materials for buildings such as walls, ceilings, and floors; exterior materials such as balconies and verandas; surface decorative boards and furniture for furniture such as window frames, doors, and handrails; Alternatively, it can be used for a surface decorative plate of a cabinet such as a light electric or OA device. In particular, the decorative board can be suitably used as a floor decorative material.

  The present invention will be specifically described below with reference to examples, comparative examples, and test examples. However, the present invention is not limited to the contents shown in the examples.

Comparative Example 1
As a base sheet, a 60 μm-thick polypropylene film (manufactured by Mitsubishi Plastics Co., Ltd .: Art Ply) is prepared, and after the corona discharge treatment is performed on the back surface of the base sheet, a back primer layer (thickness 2 μm) is formed. The pattern layer was formed on the front surface of the polypropylene film by gravure printing so as to have a thickness of 2 μm. An adhesive layer was formed on the pattern layer using a urethane resin (Daiichi Seika Kogyo Co., Ltd .: Seika Bond E-263 / C-75N) to a thickness of 2 μm. A transparent polypropylene resin sheet (Nippon Polypro Co., Ltd .: Novatec PP) was laminated on the adhesive layer so as to have a thickness of 80 μm by an extrusion laminating method, thereby forming a transparent resin layer.

  Next, the surface was subjected to corona discharge treatment, and then a two-component curable urethane resin was applied to form a primer layer (primer layer for forming a surface protective layer, thickness 2 μm).

  A urethane acrylate electron beam curable resin (EB resin) is applied to the front surface of the primer layer by a gravure coating method so as to have a thickness of 15 μm after curing, and then an electron beam in an environment with an oxygen concentration of 200 ppm or less. A surface protective layer was formed by irradiating an electron beam using an irradiation apparatus under conditions of an acceleration voltage of 175 KeV and 5 Mrad to cure the electron beam curable resin.

  The electron beam curable resin contains 30 parts by mass of silica fine particles having a particle diameter equal to or smaller than the coating film thickness (particle diameter: 12 μm) with respect to 100 parts by mass of the electron beam curable resin and has a particle diameter larger than the coating film thickness. Silica fine particles (particle diameter: 18 μm) were contained in an amount of 5 parts by mass with respect to 100 parts by mass of the electron beam curable resin.

The composition of the electron beam curable resin is as follows.
· Bifunctional urethane acrylate (Tg = 25 (° C), molecular weight 1500) 80 parts by mass · Hexafunctional urethane acrylate (Tg = 200 (° C) or higher, molecular weight 1500) 20 parts by mass Surface protective layer formed as described above Is heated with an infrared non-contact heater to soften the base sheet 1 and the transparent resin layer, and immediately embossed by hot pressure to form a grained concave pattern (wood grain 1 on the surface protective layer). ) To form a decorative sheet. The depth X of the concave pattern was 130 μm.

Finally, after the corona discharge treatment was applied to the back surface of the base material sheet, a back surface primer layer (thickness 2 μm) was formed to prepare a decorative sheet. Further, when the gloss value (incident angle 60 °) of the surface protective layer was measured using PG-3D manufactured by Nippon Denshoku Industries Co., Ltd., the gloss value ( _GP ) was 13. Incidentally, gloss value G _A luster control layer was 2.

Examples 1-20 and Comparative Examples 2-10
A decorative sheet was prepared in the same manner as in Comparative Example 1 except that the thickness of the transparent resin layer and the thickness of the surface protective layer were changed as shown in Table 1.

Production of decorative board A medium-density wood fiber board (hereinafter referred to as MDF) of 2.5 mm was prepared as a decorative board substrate. A 2.0 mm cork sheet was prepared separately. A decorative sheet was prepared by laminating a cork sheet and the decorative sheets obtained in Examples 1 to 20 and Comparative Examples 1 to 10 on the MDF.

Test Examples Each decorative board was examined for scratch resistance and pattern resistance. The scratch resistance was examined from the viewpoints of both the scratch hardness (Clemens hardness) measurement test and the Hoffman scratch test. Further, the anti-picking property was examined from the viewpoint of an abrasion resistance test (JAS standard). Each test method is shown below, and each test result is shown in Table 1.
(Clemens hardness measurement test)
A measurement test of Clemens hardness was performed in accordance with JIS K 5600-5-5 (1999). The test speed was 30 mm / s. A needle made of diamond was used as a needle for scratching the surface of the decorative material. The load when whitening damage occurred on the surface of the decorative material was examined.
(Hoffman scratch test)
The test was conducted using a Hoffman scratch hard tester manufactured by BYK-GARDNER, USA. Specifically, a scratch blade (φ7 cylindrical blade) was set so as to contact the decorative plate surface at an angle of 45 °, and the tester was moved on the decorative material. The load (weight) was gradually increased, and the test was repeated until scratches, indentations and the like were generated on the surface of the decorative board, and the load at the time of occurrence of the scratch was examined.
(Abrasion resistance test (JAS standard))
Abrasion resistance was examined in accordance with Japanese Agricultural Standards for Flooring (Abrasion Resistance, Wear A Test). Specifically, the number of rotations at which pattern removal of the pattern layer occurred was examined.

[In Table 1, shaded portions indicate comparative examples and the results. ]
As is apparent from the results in Table 1, the decorative board obtained using the decorative sheet of the example in which the thickness of the transparent resin layer and the surface protective layer is in a predetermined range has both characteristics of scratch resistance and pattern resistance. Is superior to the decorative board using the decorative sheet obtained by the comparative example in that it exhibits simultaneously. The decorative board obtained by using the decorative sheet of the present invention has a whitening damage or shaving (pattern removal) due to the occurrence of whitening scratches or wear of the pattern layer even when foreign objects such as sand rub against the decorative sheet surface by walking. It is suppressed and is particularly useful as a decorative material for floors.

  In general, it is considered that the flaw resistance and the like are improved when the thickness of the decorative sheet is increased. However, when the thickness of the decorative sheet is excessively increased, there is a drawback caused thereby. For example, 1) If large air bubbles remain between the cork sheet and the decorative sheet, they will float, so that they will not cause defects in appearance but may easily cause dents and cracks when impact is applied, and they are impact resistant. Decreases. 2) Since there is a difference in expansion and contraction due to the effect of heat between the cork sheet and the decorative sheet, the difference in expansion and contraction adds a shearing capacity between the cork sheet and the decorative sheet, and the cork sheet with low elasticity causes material destruction. Easy to wake up. 3) When the decorative sheet is warped, troubles such as peeling easily occur on the cork sheet or the decorative board substrate. 4) It becomes difficult to utilize the sound absorption performance of the cork sheet. On the other hand, the decorative sheet of the present invention exhibits the above excellent effect by setting the thicknesses of the transparent resin layer and the surface protective layer to predetermined ranges, respectively, and increases the thickness of the entire decorative sheet too much. It is possible to avoid this, and to effectively avoid the drawbacks when the thickness of the decorative sheet increases excessively.

1. Cosmetic sheet 2. 2. base material sheet Pattern layer 4. 4. Transparent resin layer 5. Surface protective layer Fine particle B
7). Fine particle A
8). Gloss adjustment layer 9. Decorative board substrate 10. Cork sheet AA ′. Example of reference line for cutting out cross section of embossed concave pattern T1. Transparent resin layer thickness T2. Surface protective layer thickness

Claims (12)

A decorative sheet suitable for laminating at least on a cork sheet,
The decorative sheet is composed of a laminate including a base sheet, a transparent resin layer, and a surface protective layer in order in the thickness direction,
(1) The transparent resin layer has a thickness of 90 μm or more and 300 μm or less,
(2) The surface protective layer has a thickness of 20 μm or more and 40 μm or less.
A decorative sheet characterized by that.   The decorative sheet according to claim 1, wherein the decorative sheet has an embossed concave pattern from the surface protective layer side. The decorative sheet has an embossed concave pattern from the surface protective layer side,
2. A part or all of the embossed concave pattern has a depth of 0 μm or more from the reference surface with respect to the surface of the transparent resin layer at a portion not having the embossed concave pattern as a reference surface. The decorative sheet described in 1.   When the surface protective layer is composed of a single layer, the surface protective layer contains fine particles having a particle diameter larger than the thickness of the single layer, and 2) when the surface protective layer is composed of multiple layers. The decorative sheet according to any one of claims 1 to 3, further comprising fine particles having a particle diameter larger than the thickness of the outermost layer constituting the multilayer.   The decorative sheet according to claim 4, wherein the content of the fine particles is 5 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the resin component of the layer containing the fine particles.   The decorative sheet according to claim 4 or 5, wherein the fine particles are silica fine particles.   The said base material sheet and the said transparent resin layer are decorative sheets in any one of Claims 1-6 containing a non-halogen-type thermoplastic resin.   The decorative sheet according to claim 7, wherein the non-halogen thermoplastic resin is an olefin-based thermoplastic resin.   The decorative sheet according to claim 1, wherein the surface protective layer contains an ionizing radiation curable resin.   A decorative board in which at least a cork sheet and the decorative sheet according to any one of claims 1 to 9 are laminated in this order on a decorative board substrate.   The decorative board base material is at least one selected from the group consisting of medium density wood fiber board, high density wood fiber board, particle board, softwood plywood, hardwood plywood, early-wood plywood, polyvinyl chloride, polypropylene and polyethylene. The decorative board according to claim 10.   The manufacturing method of a decorative board which has a process of laminating | stacking at least a cork sheet and the decorative sheet in any one of Claims 1-9 so that a layer structure may become this order on a decorative board base material.