Decorative sheet and decorative panel

Abstract

The present invention provides a decorative sheet that has excellent anti-slip properties, anti-slip durability, impact resistance, and stain resistance, as well as excellent designability.　The present invention provides a decorative sheet having a surface protective layer on the outermost surface thereof, the decorative sheet being characterized in that: (1) the Martens hardness of the surface protective layer is 30-170 N / mm2, said Martens hardness being the value of the Martens hardness of a cross section measured by pressing a diamond indenter into the surface protective layer at a position away from fine particles when fine particles are included in the surface protective layer; (2) the surface protective layer has recesses and projections, the recesses and projections having a sandy tone, woodgrain tone, bark tone, stone-grain tone, or leather-tone embossed shape, and the average interval Sm of the recesses and projections being 180-950 µm; (3) the maximum height Rz of the surface protective layer is 10-45 µm; and (4) the ratio of the area of a portion from the surface to a depth of 30 µm in the surface protective layer is 40% or greater.

Description

Decorative sheets and decorative panels

[0001] The present invention relates to a decorative sheet and a decorative board.

[0002] Decorative sheets are used by being attached to the surfaces of wooden boards, plastic boards, etc. for the purpose of surface protection, decoration, etc. The decorative panels obtained in this way are used in various building materials, furniture, etc.

[0003] Conventional decorative sheets generally have a smooth surface, which means that when used as flooring for flooring, stairs, etc., people tend to slip when walking on them, which can cause them to fall.

[0004] Therefore, in order to impart anti-slip properties to the surface of the decorative sheet, a decorative floor sheet has been proposed in which multiple convex portions are formed on the surface, the cross-sectional shape of the convex portions in the height direction is trapezoidal or conical, and the shape of the convex portions in a planar view is polygonal and has convex portions within a specific range of sizes (Patent Document 1).

[0005] However, the flooring material of Patent Document 1 has a problem of insufficient slip resistance. Furthermore, decorative sheets with fillers added to the surface protective layer or embossed decorative sheets have a problem in that the filler surface is scraped off during use, causing the specific surface irregularities to disappear and the slip resistance to gradually decrease.

[0006] Furthermore, decorative sheets are used by being attached to the surface of wood boards, plastic boards, etc., and are therefore subject to collisions with objects. For this reason, decorative sheets are required to have impact resistance. Furthermore, when dirt adheres to the surface, it is required that it be easy to wipe off, and therefore contamination resistance is also required.

[0007] Furthermore, decorative sheets are required to have excellent design properties because they are attached to the surface of an article for decorative purposes. The decorative floor sheet described in Patent Document 1 has polygonal convex portions, which make it clearly identifiable as a plastic industrial product, resulting in poor design properties.

[0008] Therefore, there is a demand for the development of a decorative sheet that is excellent in anti-slip properties, anti-slip durability, impact resistance, and stain resistance, as well as having excellent design properties.

[0009] Patent No. 6606901

[0010] A primary object of the present invention is to provide a decorative sheet that is excellent in anti-slip properties, anti-slip durability, impact resistance, and stain resistance, and also has excellent design properties.

[0011] As a result of extensive research, the inventors discovered that the above-mentioned objectives can be achieved in a decorative sheet having a surface protective layer on the outermost surface, when the surface of the surface protective layer satisfies certain conditions, and thus completed the present invention.

[0012] That is, the present invention relates to the following decorative sheet and decorative board: 1. A decorative sheet having a surface protective layer on the outermost surface, wherein: (1) the Martens hardness of the surface protective layer is 30 to 170 N / mm ２ and the Martens hardness is a value measured by pressing a diamond indenter into a position that avoids fine particles when the surface protective layer contains fine particles, and measuring the Martens hardness of a cross section, (2) the surface protective layer has irregularities, and the irregularities have an embossed shape with a sand-grain, wood-grain, wood-bark, stone-grain or leather-grain look, and the average spacing Sm of the irregularities is 180 μm to 950 μm, (3) the maximum height Rz of the surface protective layer is 10 to 45 μm, and (4) the surface protective layer has an area ratio of 40% or more from the surface to a depth of 30 μm. ２Item 1. The decorative sheet according to item 1, wherein Rz is 10 to 19 μm. 3. The decorative sheet according to item 1 or 2, wherein Rz is 10 to 19 μm. 4. The decorative sheet according to any one of items 1 to 3, wherein Sm is 450 to 750 μm. 5. The decorative sheet according to any one of items 1 to 4, wherein the surface protective layer has an area ratio of 50 to 90% at a depth greater than 30 μm from the surface. 6. The decorative sheet according to any one of items 1 to 5, wherein the surface protective layer has an area ratio of 60 to 85% at a depth greater than 30 μm from the surface. 7. The decorative sheet according to any one of items 1 to 6, wherein the surface protective layer contains an ionizing radiation curable resin. 8. The decorative sheet according to any one of items 1 to 7, wherein the thickness of the surface protective layer is 10 to 40 μm. 9. The decorative sheet according to any one of items 1 to 8, wherein the surface protective layer contains at least one agent selected from the group consisting of an antibacterial agent, an antiviral agent, and an antiallergen. 10. Item 10. The decorative sheet according to any one of items 1 to 9, having a picture pattern layer, a transparent resin layer, and the surface protective layer, in that order, on a base sheet. 11. The decorative sheet according to any one of items 1 to 9, having a picture pattern layer, a transparent resin layer, and the surface protective layer, in that order, on a base sheet, and at least a backer layer is laminated on the back surface of the base sheet. 12. A decorative board having the decorative sheet according to any one of items 1 to 11, on a base material. 13. The decorative board according to item 12, wherein the base material is a wood veneer, a wood plywood, a wood fiberboard, or a particle board.

[0013] The decorative sheet of the present invention has excellent anti-slip properties, anti-slip durability, impact resistance, and stain resistance, and also has excellent design properties. Therefore, decorative boards laminated with the decorative sheet of the present invention can be used for various building materials, furniture, etc.

[0014] 1 is a schematic diagram (cross-sectional view) of a decorative sheet of the present invention. FIG. 1 shows a diamond indenter (a) used in measuring Martens hardness in this specification, a schematic diagram of the indentation operation (b), and an example of indentation load and displacement (c). FIG. 2 is a diagram showing a measured cross-sectional curve of a decorative sheet produced in Example 4. FIG. 3 is a diagram showing the location where the measured cross-sectional curve was measured in Example 4. FIG. 4 is a diagram showing the measurement results of volume area 1 of a decorative sheet produced in Example 4. FIG. 5 is a diagram showing the measurement results of volume area 2 of a decorative sheet produced in Example 4. FIG. 6 is a diagram showing a measured cross-sectional curve of a decorative sheet produced in Example 7. FIG. 7 is a diagram showing the location where the measured cross-sectional curve was measured in Example 7. FIG. 8 is a diagram showing the measurement results of volume area 1 of a decorative sheet produced in Example 7. FIG. 9 is a diagram showing the measurement results of volume area 2 of a decorative sheet produced in Example 7. FIG. 10 is a diagram showing a measured cross-sectional curve of a decorative sheet produced in Comparative Example 7. FIG. 11 is a diagram showing the location where the measured cross-sectional curve was measured in Comparative Example 7. FIG. 12 is a diagram showing the measurement results of volume area 1 of a decorative sheet produced in Comparative Example 7. FIG. 13 is a diagram showing the measurement results of volume area 2 of a decorative sheet produced in Comparative Example 7.

[0015] 1. Decorative Sheet The decorative sheet of the present invention is a decorative sheet having a surface protective layer on the outermost surface, wherein: (1) the Martens hardness of the surface protective layer is 30 to 170 N / mm ２ (1) The Martens hardness is a value measured by pressing a diamond indenter into a position avoiding fine particles when the surface protective layer contains fine particles, and measuring the Martens hardness of the cross section; (2) The surface protective layer has irregularities, and the irregularities have an embossed shape with a sand-grain, wood-grain, wood-bark, stone-grain, or leather-grain texture, and the average spacing Sm of the irregularities is 180 μm to 950 μm; (3) The maximum height Rz of the surface protective layer is 10 to 45 μm; and (4) The surface protective layer has an area ratio of 40% or more from the surface to a depth of 30 μm. The decorative sheet of the present invention has the above characteristics, resulting in excellent anti-slip properties, anti-slip durability, impact resistance, and stain resistance, as well as excellent design. Therefore, the decorative floor sheet of the present invention can be suitably used for floors.

[0016] The decorative sheet of the present invention will be described in detail below. In the decorative sheet of the present invention, the surface is the so-called "front side," which is the side opposite to the side that comes into contact with the substrate when the decorative sheet of the present invention is laminated to a substrate or the like, and is the side that is visible after lamination. In this specification, the direction of the surface of the decorative sheet of the present invention will sometimes be referred to as the "front" or "top," and the opposite side as the "back" or "bottom." In the following description, the lower and upper limits of numerical ranges expressed by "to" mean "greater than or equal to" (for example, if α to β, it means greater than or equal to α and less than or equal to β).

[0017] The layer thickness in this specification is a value measured at a location on the decorative sheet where there are no irregularities such as embossments or protruding fine particle heads.

[0018] (Layer Structure of the Decorative Sheet of the Present Invention) The decorative sheet of the present invention may have the above-mentioned surface protective layer on the outermost surface, and the specific structure may be appropriately set depending on the application of the decorative sheet, etc. For example, a decorative sheet may have, on a base sheet, any one of a picture pattern layer, a transparent adhesive layer, a transparent resin layer, and a primer layer, and have a surface protective layer on the outermost surface.

[0019] The decorative sheet of the present invention will be specifically described below using as a representative example a decorative sheet having, on a base sheet, a picture pattern layer, a transparent adhesive layer, a transparent resin layer, a primer layer and the surface protective layer in that order.

[0020] (Base Sheet) A picture pattern layer and the like are sequentially laminated on the surface (front surface) of the base sheet.

[0021] The substrate sheet is preferably, for example, a sheet (film) formed from a thermoplastic resin. Specific examples include olefin resins such as polyethylene, ethylene-α-olefin copolymer, polypropylene, polymethylpentene, polybutene, ethylene-propylene copolymer, propylene-butene copolymer, ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, and ethylene-(meth)acrylic acid ester copolymer; polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, polycarbonate, polyethylene naphthalate, ionomer, acrylic acid ester polymer, and methacrylic acid ester polymer. The substrate sheet is formed by using these resins alone or in combination of two or more.

[0022] In this specification, "(meth)acrylic acid" means acrylic acid and / or methacrylic acid, and the same applies to other moieties written as (meth).

[0023] The substrate sheet may be colored. In this case, the color can be achieved by adding a coloring agent (pigment or dye) to the thermoplastic resin. Examples of coloring agents that can be used include inorganic pigments such as titanium dioxide, carbon black, and iron oxide, and organic pigments such as phthalocyanine blue, as well as various dyes. One or more of these can be selected from known or commercially available coloring agents. The amount of coloring agent added can also be appropriately determined depending on the desired color tone, etc.

[0024] The substrate sheet may contain various additives such as fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, antioxidants, ultraviolet absorbers, and light stabilizers, as required.

[0025] The thickness of the substrate sheet can be appropriately set depending on the application and method of use of the final product, but is generally preferably 20 to 300 μm.

[0026] If necessary, the surface (front surface) of the substrate sheet may be subjected to a corona discharge treatment in order to improve the adhesion of the ink that forms the picture pattern layer. The corona discharge treatment may be carried out by a known method and under known conditions. If necessary, the back surface of the substrate sheet may be subjected to a corona discharge treatment or a back surface primer layer may be formed.

[0027] (Picture / Design Layer) The decorative sheet of the present invention may have a picture / design layer.

[0028] The picture pattern layer imparts a desired pattern (design) to the decorative sheet, and the type of pattern is not limited, and examples include wood grain patterns, leather patterns, stone grain patterns, sand grain patterns, tile patterns, brickwork patterns, fabric patterns, geometric shapes, letters, symbols, and abstract patterns.

[0029] The method for forming the picture pattern layer is not particularly limited, and for example, the picture pattern layer may be formed on the surface of the substrate sheet by a printing method using an ink obtained by dissolving (or dispersing) a known colorant (dye or pigment) together with a binder resin in a solvent (or dispersion medium). From the viewpoint of reducing VOCs in the decorative sheet, an aqueous composition can also be used as the ink.

[0030] Examples of colorants include inorganic pigments such as carbon black, titanium white, zinc white, red iron oxide, iron blue, and cadmium red; organic pigments such as azo pigments, lake pigments, anthraquinone pigments, quinacridone pigments, phthalocyanine pigments, isoindolinone pigments, and dioxazine pigments; metal powder pigments such as aluminum powder and bronze powder; pearlescent pigments such as titanium oxide-coated mica and bismuth oxide chloride; fluorescent pigments; and luminous pigments. These colorants can be used alone or in combination. These colorants may be used together with fillers such as silica, extender pigments such as organic beads, neutralizers, surfactants, and the like.

[0031] As binder resins, in addition to hydrophilically treated polyester-based urethane resins, polyesters, polyacrylates, polyvinyl acetates, polybutadiene, polyvinyl chloride, chlorinated polypropylenes, polyethylene, polystyrene, polystyrene-acrylate copolymers, rosin derivatives, alcohol adducts of styrene-maleic anhydride copolymers, cellulose-based resins, etc. can also be used. More specifically, for example, polyacrylamide-based resins, poly(meth)acrylic acid-based resins, polyethylene oxide-based resins, poly(N-vinylpyrrolidone)-based resins, water-soluble polyester-based resins, water-soluble polyamide-based resins, water-soluble amino-based resins, water-soluble phenol-based resins, other water-soluble synthetic resins, water-soluble natural polymers such as polynucleotides, polypeptides, and polysaccharides, etc., can also be used. Furthermore, for example, modified natural rubber, synthetic rubber, polyvinyl acetate-based resins, (meth)acrylic resins, polyvinyl chloride-based resins, polyurethane-polyacrylic resins, etc., mixtures of the above natural rubbers, and other resins can also be used. The above binder resins can be used alone or in combination of two or more.

[0032] Examples of the solvent (or dispersion medium) include petroleum-based organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ester-based organic solvents such as ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and 2-ethoxyethyl acetate; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, and propylene glycol; ketone-based organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether-based organic solvents such as diethyl ether, dioxane, and tetrahydrofuran; chlorine-based organic solvents such as dichloromethane, carbon tetrachloride, trichloroethylene, and tetrachloroethylene; and inorganic solvents such as water. These solvents (or dispersion media) can be used alone or in combination of two or more.

[0033] Examples of printing methods used to form the picture pattern layer include gravure printing, offset printing, screen printing, flexographic printing, electrostatic printing, and inkjet printing. When forming a solid picture pattern layer over the entire surface, examples of coating methods include roll coating, knife coating, air knife coating, die coating, lip coating, comma coating, kiss coating, flow coating, and dip coating. Other methods that may be used include hand-drawing, ink-flowing, photography, transfer printing, laser beam writing, electron beam writing, partial vapor deposition of metals or the like, and etching, or may be used in combination with other forming methods.

[0034] The thickness of the picture pattern layer is not particularly limited and can be set appropriately depending on the product characteristics, but the layer thickness is about 0.1 to 10 μm.

[0035] (Colored Concealing Layer) In the decorative sheet of the present invention, a colored concealing layer may be further formed between the substrate sheet and the picture pattern layer.

[0036] The colored concealing layer is only required to be able to conceal the base color of the adherend when the decorative sheet and the adherend are joined together, and is usually formed so as to cover the base sheet.

[0037] The colored concealing layer can be formed by the above-mentioned known printing methods, and the ink used to form the picture pattern layer can be used as it is.

[0038] The coating amount is 2 to 30 g / m 2 The thickness of the colored concealing layer is usually about 0.1 to 20 μm, preferably about 1 to 10 μm.

[0039] (Adhesive Layer) In order to improve adhesion between the transparent resin layer and the picture pattern layer described below, an adhesive layer may be formed on the picture pattern layer. The adhesive layer is preferably a transparent adhesive layer, and examples of the transparent adhesive layer include colorless transparent, colored transparent, and translucent adhesive layers.

[0040] The adhesive is not particularly limited, and any adhesive known in the field of decorative sheets can be used.

[0041] Examples of adhesives known 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 colorants can be used alone or in combination of two or more. Two-component curing polyurethane resins or polyester resins using isocyanate as a curing agent can also be used.

[0042] The transparent adhesive layer can be formed by the above-mentioned known printing method.

[0043] The thickness of the transparent adhesive layer is not particularly limited, but the thickness after drying is about 0.1 to 30 μm, preferably about 1 to 20 μm.

[0044] (Transparent Resin Layer) The decorative floor sheet of the present invention may have a transparent resin layer.

[0045] The transparent resin layer is not particularly limited as long as it is transparent, and includes colorless and transparent, colored and transparent, translucent, etc. Examples of resins constituting the transparent resin layer include polyethylene, ethylene-α-olefin copolymer, polypropylene such as homopolypropylene and random polypropylene, polymethylpentene, polybutene, ethylene-propylene copolymer, propylene-butene copolymer, ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, olefin-based resins such as olefin-based elastomers, polyethylene terephthalate, polybutylene terephthalate, polyamide, ionomer, acrylic acid ester-based polymer, methacrylic acid ester-based polymer, polycarbonate, cellulose triacetate, etc. These resins can be used alone or in combination of two or more.

[0046] The transparent resin layer is preferably a transparent thermoplastic resin layer, more preferably contains an olefin-based resin such as a polypropylene resin or a polyethylene resin, and it is even more preferable that the resin constituting the transparent resin layer is the above-mentioned olefin-based resin or ionomer-based resin.

[0047] The transparent resin layer may be colored as long as it has transparency, but it is preferable not to blend any colorant therein.

[0048] The thickness of the transparent resin layer is usually about 20 to 200 μm, but may exceed this range depending on the intended use of the decorative floor sheet.

[0049] (Primer Layer) A primer layer may be provided on the 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 primer agents include urethane resin-based primer agents made from acrylic-modified urethane resin (acrylic urethane-based resin), primer agents made from urethane-cellulose-based resin (e.g., a resin obtained by adding hexamethylene diisocyanate to a mixture of urethane and soluble nitrocellulose), and resin-based primer agents made from a block copolymer of acrylic and urethane. Additives may be blended into the primer agent as needed. Examples of additives include fillers such as calcium carbonate and clay, flame retardants such as magnesium hydroxide, antioxidants, lubricants, foaming agents, ultraviolet absorbers, and light stabilizers. The amount of additives blended can be appropriately determined depending on the product characteristics.

[0050] The amount of primer applied is not particularly limited, but is usually 0.1 to 100 g / m ２ , preferably 0.1 to 50 g / m ２ That's about it.

[0051] The thickness of the primer layer is not particularly limited, but is usually about 0.01 to 10 μm, preferably about 0.1 to 1 μm.

[0052] (Surface Protective Layer) The decorative sheet of the present invention has a surface protective layer having a Martens hardness (hardness) of 30 to 170 N / mm ２ The surface protective layer preferably has a Martens hardness of 70 to 150 N / mm ２ is.

[0053] The Martens hardness in this specification was measured using a Martens hardness measuring device PICODENTOR HM-500 (manufactured by Fischer Instruments) in accordance with ISO 14577. The indentation conditions were as follows: at room temperature (laboratory ambient temperature), a load of 0 to 5 mN was first applied for 10 seconds, followed by holding the load at 5 mN for 5 seconds, and finally, the load was removed from 5 to 0 mN for 10 seconds, as shown in Figure 2(c). In this specification, the Martens hardness of the cross section of the surface protective layer was measured to avoid the influence of the hardness of layers other than the surface protective layer. In this case, the decorative sheet was embedded in resin (such as a cold-setting type epoxy two-component curing resin or a UV-curable resin) and left to harden at room temperature for 24 hours or more. The hardened embedded sample was then cut and mechanically polished to expose the cross section of the surface protection layer, and the Martens hardness of the cross section was measured by pressing a diamond indenter into the cross section (in the case where fine particles such as filler are contained in the layer, at a position avoiding the fine particles).

[0054] The Martens hardness of the surface protective layer can be appropriately set by 1) mixing multiple resin components, 2) adding an elastomer to the resin, or the like. For example, when using a urethane acrylate, as described below, as the resin component constituting the surface protective layer, the desired Martens hardness can be obtained by appropriately blending a bifunctional urethane acrylate and a hexafunctional urethane acrylate, or by using only a trifunctional urethane acrylate with a molecular weight of approximately 1500. Here, bifunctional urethane acrylate refers to a urethane acrylate having two radically polymerizable acryloyl groups per molecule. Similarly, trifunctional urethane acrylate and hexafunctional urethane acrylate refer to urethane acrylates having three and six radically polymerizable acryloyl groups per molecule, respectively.

[0055] The decorative sheet of the present invention also has a specific uneven shape on its surface. In the decorative sheet of the present invention, the unevenness forming the uneven shape is an embossed shape with a sand-grain, wood-grain, wood-bark, pebble, or bark texture. By having the unevenness in the above-mentioned embossed shape, the decorative sheet of the present invention can be made to have excellent anti-slip properties, anti-slip durability, impact resistance, and stain resistance, as well as excellent design properties.

[0056] The average spacing (Sm) of the irregularities is 180 μm to 950 μm. If Sm is less than 180 μm, the design is inferior, and if it exceeds 950 μm, the anti-slip properties are inferior. Sm is preferably 450 to 750 μm.

[0057] The Sm is an index showing the spacing between the irregularities of the surface protective layer, and is calculated by extracting a reference length L from the roughness curve of the surface protective layer in the direction of the average line, calculating the sum of the lengths of the average lines corresponding to one peak and one adjacent valley, and then expressing the average value of the sum. A small Sm indicates a fine surface texture (a dense state of irregularities).

[0058] The maximum height (Rz) of the surface protective layer is 10 to 45 μm. If Rz is less than 10 μm, the design is inferior, and if it exceeds 45 μm, the stain resistance is inferior. Rz is preferably 10 to 30 μm, and more preferably 10 to 19 μm.

[0059] The Rz is an index showing the maximum height of the surface protective layer, and is calculated by extracting a reference length L from the roughness curve of the surface protective layer in the direction of the mean line, and expressing the sum of the height Ha from the mean line of this extracted portion to the highest peak and the depth Hb to the lowest valley (Rz = Ha + Hb).

[0060] The above Sm and Rz are in accordance with the surface roughness standards of JIS B0601 (1994) and JIS B0601 (2001), respectively.

[0061] The above Sm and Rz can both be obtained by measuring the surface roughness, which can be measured using a surface roughness profiler such as a Surfcom 120A (manufactured by Tokyo Seimitsu Co., Ltd.).

[0062] In the decorative sheet of the present invention, the surface protective layer has an area ratio of 40% or more from the surface to a depth of 30 μm. If this ratio is less than 40%, the anti-slip properties of the decorative sheet will be poor. This ratio is preferably 50 to 90%, more preferably 60 to 85%. If the upper limit of this ratio is within the above range, the design of the decorative sheet will be further improved. The area from the surface to a depth of 30 μm is the area that comes into contact with the foot when walking on the surface of the decorative sheet, and is also referred to as the "contact area." The above ratio is measured by the following method.

[0063] [Proportion of the area (contact area) of the portion from the surface to a depth of 30 μm] The proportion of the area (contact area) of the portion from the surface of the decorative sheet to a depth of 30 μm is measured using a laser microscope VK-X1000 (manufactured by Keyence Corporation). Specifically, the proportion of the area (contact area) of the portion from the surface of the decorative sheet to a depth of 30 μm is measured using a laser microscope VK-X1000 (manufactured by Keyence Corporation) under the condition of a lens magnification of 50 times. ２ In this area, the entire volume area 1 is measured from the surface of the decorative sheet. Next, the volume area 2 is measured from the surface to a depth of 30 μm, and the contact area ratio is calculated based on the following formula: (Contact area ratio (%)) = (Volume area 2 / Volume area 1) × 100

[0064] The volume area 1 is the area of ​​all surfaces that form the surface of the decorative sheet, such as the area of ​​the smooth parts of the surface of the decorative sheet, the wall surfaces and bottom surfaces of the irregularities, etc. The volume area 2 is the area obtained by measuring the surface area from the surface to a depth of 30 μm using the laser microscope VK-X1000, and is the contact area mentioned above.

[0065] FIGS. 3 to 14 show examples of measurements of the area ratio of the portion of the surface protection layer up to a depth of 30 μm from the surface in Examples 4, 7, and Comparative Example 7, which will be described later. Specifically, FIG. 3 shows the measured cross-sectional curve for Example 4, and FIG. 4 shows the location where the measured cross-sectional curve was measured in Example 4. FIG. 5 shows the measurement results for volume area 1 for Example 4, and FIG. 6 shows the measurement results for volume area 2 for Example 4. FIG. 7 shows the measured cross-sectional curve for Example 7, and FIG. 8 shows the location where the measured cross-sectional curve was measured in Example 7. FIG. 9 shows the measurement results for volume area 1 for Example 7, and FIG. 10 shows the measurement results for volume area 2 for Example 7. FIG. 11 shows the measured cross-sectional curve for Comparative Example 7, and FIG. 12 shows the location where the measured cross-sectional curve was measured in Comparative Example 7. FIG. 13 shows the measurement results for volume area 1 for Comparative Example 7, and FIG. 14 shows the measurement results for volume area 2 for Comparative Example 7. The contact area ratios were 54% for Example 4, 41% for Example 7, and 10% for Comparative Example 7. In addition, in Fig. 6 (Example 4), Fig. 10 (Example 7), and Fig. 14 (Comparative Example 7), the dark areas indicate the surface from the surface to a depth of 30 µm. In Fig. 14, there are fewer dark areas compared to Figs. 6 and 10, and it can be seen that in Comparative Example 7, the proportion of the area of ​​the portion from the surface to a depth of 30 µm is low.

[0066] The ratio of Sm, Rz and the area (contact area) of the portion from the surface to a depth of 30 μm of the surface of the surface protective layer can be appropriately set by, for example, 1) containing the fine particles described below, or 2) embossing using an embossing plate having irregularities that indicate the desired Sm, Rz and the area (contact area) of the portion from the surface to a depth of 30 μm of the surface.

[0067] The embossing method is not particularly limited, and a preferred method is, for example, a method in which the front surface of the surface protective layer is heated and softened, pressed and shaped with an embossing plate, and then cooled. Depending on the material of the decorative sheet or surface protective layer that is the final product, for example, the front surface of the transparent resin layer may be heated and softened, pressed and shaped with an embossing plate, and then the surface protective layer may be formed thereon.

[0068] For the embossing, a known sheet-fed or rotary embossing machine or the like is used.

[0069] When a picture pattern layer is formed below the surface protective layer, the surface protective layer is preferably transparent.

[0070] The resin constituting the surface protective layer is preferably a curable resin such as a thermosetting resin or an ionizing radiation curable resin (e.g., an electron beam curable resin). In particular, from the viewpoints of scratch resistance due to high surface hardness, convex shape retention, productivity, etc., the surface protective layer preferably contains an ionizing radiation curable resin, and it is more preferable that the resin constituting the surface protective layer is an ionizing radiation curable resin.

[0071] Examples of thermosetting resins include unsaturated polyester resins, polyurethane resins (including two-component curing polyurethanes), epoxy resins, aminoalkyd resins, phenolic resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, melamine-urea co-condensation resins, silicon resins, and polysiloxane resins.

[0072] The resin may contain a crosslinking agent, a curing agent such as a polymerization initiator, a polymerization accelerator, etc. For example, curing agents such as isocyanate and organic sulfonate may be added to unsaturated polyester resins and polyurethane resins, organic amines may be added to epoxy resins, and peroxides such as methyl ethyl ketone peroxide and radical initiators such as azoisobutylnitrile may be added to unsaturated polyester resins.

[0073] The surface protection layer can be formed from a thermosetting resin by, for example, applying a solution of the thermosetting resin by a coating method such as roll coating or gravure coating, followed by drying and curing.

[0074] The ionizing radiation curable resin is not limited as long as it undergoes a crosslinking polymerization reaction upon irradiation with ionizing radiation and changes into a three-dimensional polymer structure. For example, one or more prepolymers, oligomers, and monomers having a polymerizable unsaturated bond or an epoxy group in the molecule that can be crosslinked upon irradiation with ionizing radiation can be used. Examples include acrylate resins such as urethane acrylate, polyester acrylate, and epoxy acrylate; silicon resins such as siloxane; polyester resins; and epoxy resins.

[0075] Ionizing radiation includes visible light, ultraviolet light (near ultraviolet light, vacuum ultraviolet light, etc.), X-rays, electron beams, ion beams, etc., and among these, ultraviolet light and / or electron beams are preferred.

[0076] The ultraviolet light source may be an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light fluorescent lamp, or a metal halide lamp. The wavelength of the ultraviolet light is about 190 to 380 nm.

[0077] As the electron beam source, various electron beam accelerators can be used, such as Cockcroft-Waldt type, Van de Graaf type, resonant transformer type, insulating core transformer type, linear type, dynamitron type, and high frequency type. The energy of the electron beam is preferably about 100 to 1000 keV, more preferably about 100 to 300 keV. The dose of the electron beam is preferably about 2 to 15 Mrad.

[0078] Ionizing radiation curable resins are sufficiently cured by irradiation with electron beams, but when curing is performed by irradiation with ultraviolet rays, it is preferable to add a photopolymerization initiator (sensitizer).

[0079] In the case of a resin system having a radically polymerizable unsaturated group, the photopolymerization initiator may be, for example, at least one of acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether, Michler's benzoyl benzoate, Michler's ketone, diphenyl sulfide, dibenzyl disulfide, diethyl oxide, triphenylbiimidazole, isopropyl-N,N-dimethylaminobenzoate, etc. In the case of a resin system having a cationically polymerizable functional group, the photopolymerization initiator may be, for example, at least one of aromatic diazonium salts, aromatic sulfonium salts, metallocene compounds, benzoin sulfonate esters, furyloxysulfoxonium diallyliodosyl salts, etc.

[0080] The amount of the photopolymerization initiator added is not particularly limited, but is generally about 0.1 to 10 parts by mass per 100 parts by mass of the ionizing radiation curable resin.

[0081] The thickness of the surface protective layer is not particularly limited as long as it does not impede the effects of the present invention, but is preferably 1 to 200 μm, more preferably 1 to 100 μm, even more preferably 5 to 50 μm, and particularly preferably 10 to 40 μm.

[0082] The surface protective layer may contain fine particles. Examples of the fine particles include inorganic fillers such as silica, aluminum oxide, silicon carbide, silicon dioxide, calcium titanate, barium titanate, magnesium pyroborate, zinc oxide, silicon nitride, zirconium oxide, chromium oxide, iron oxide, boron nitride, diamond, emerythrite, and glass fiber; and organic material powders or beads such as acrylic, crosslinked alkyl, crosslinked styrene, inzoguanamine resin, urea-formaldehyde resin, phenolic resin, polyethylene, and nylon. One or more types of the fine particles can be used.

[0083] The average particle size of the fine particles is preferably equal to or greater than the thickness of the surface protective layer, and in order to exhibit scratch resistance, it is preferably less than "the thickness of the surface protective layer + 40 μm", and more preferably equal to or less than "the thickness of the surface protective layer + 30 μm".

[0084] The average particle size of the fine particles can be measured by known methods such as laser diffraction, Coulter counter method, sedimentation method, etc. The average particle size means the mode diameter.

[0085] The content of the fine particles in the surface protective layer is preferably 3 to 50 parts by mass, and more preferably 5 to 30 parts by mass, based on 100 parts by mass of the resin component that forms the surface protective layer.

[0086] Silicone may be added to the surface protective layer. When silicone is added to the surface protective layer, the amount of silicone added is preferably 0.1 to 1 part by mass, and more preferably 0.1 to 0.5 parts by mass, per 100 parts by mass of the resin (resin component) constituting the surface protective layer, from the viewpoint of achieving both ease of wiping and non-slip properties.

[0087] The surface protective layer may contain various additives, such as a solvent, a colorant such as a dye or a pigment, a filler such as an inorganic filler, an antifoaming agent, a leveling agent, a thixotropy-imparting agent, a flame retardant, an antibacterial agent, an antiviral agent, or an antiallergen, as needed.

[0088] The inorganic filler can be used as a means for imparting predetermined surface properties to the surface protective layer by incorporating an inorganic filler having a thickness greater than that of the surface protective layer. The inorganic filler can also be used as a matting agent, and incorporating the inorganic filler in the surface protective layer is expected to have the effect of suppressing the cure shrinkage of the surface protective layer. Therefore, in the present invention, it is preferable that the inorganic filler has been surface-treated (hydrophobized). Furthermore, among these additives, it is preferable that at least one selected from the group consisting of an antibacterial agent, an antiviral agent, and an antiallergen agent be incorporated into the surface protective layer, which is the outermost layer, in order to facilitate the attainment of its effects.

[0089] Examples of inorganic fillers include silica, aluminum oxide, silicon carbide, silicon dioxide, calcium titanate, barium titanate, magnesium pyroborate, zinc oxide, silicon nitride, zirconium oxide, chromium oxide, iron oxide, boron nitride, diamond, emery sand, and glass fiber.

[0090] The method of surface treatment (hydrophobic treatment) of inorganic filler is not particularly limited, and can be carried out by known method.For example, the method of hydrophobic treatment of inorganic filler by silicone oil-based treatment agent; the method of hydrophobic treatment of inorganic filler by alkylsilazane-based treatment agent, trimethylsilylating agent and / or alkoxysilane after treating inorganic filler by above-mentioned silicone oil-based treatment agent; the method of hydrophobic treatment of inorganic filler by silicone oil-based treatment agent, and then further treatment by trimethylsilylating agent or alkylsilazane-based treatment agent; the method of hydrophobic treatment of inorganic filler by alkoxysilane; the method of treating inorganic filler by alkoxysilane, and then further treatment by silicone oil-based treatment agent, or silicone oil-based treatment agent and alkoxysilane; the method of treating inorganic filler by dimer diol siloxane and / or trimethylsilanol or cyclic siloxane. In addition to the above-mentioned hydrophobic treatment methods, other examples of hydrophobic treatment methods include treatment with various coupling agents such as silane coupling agents, titanate coupling agents, and aluminate coupling agents; surfactants such as phosphoric acid and fatty acid surfactants; oils and fats, stearic acid, etc. Hereinafter, the above-mentioned products for hydrophobizing untreated inorganic fillers (for example, all of the treatment agents such as silicone oil treatment agents, silane coupling agents, surfactants, etc.) are collectively referred to as hydrophobic treatment agents.

[0091] The method for hydrophobizing an inorganic filler with a hydrophobic treatment agent is not particularly limited and can be carried out by a known method. For example, a method (dry treatment method) in which a stock solution of the hydrophobic treatment agent or a hydrophobic treatment agent diluted in water or an organic solvent is added (e.g., sprayed) to an untreated inorganic filler; a method (wet treatment method) in which an untreated inorganic filler is treated (e.g., immersed) in a stock solution of the hydrophobic treatment agent, an aqueous solution containing the hydrophobic treatment agent, or an organic solvent containing the hydrophobic treatment agent, and then dried; etc. are mentioned. By such treatment, a part or all of the surface of the inorganic filler is (a) coated with the hydrophobic treatment agent, (b) adsorbs the hydrophobic treatment agent, or (c) is coated with and adsorbs the hydrophobic treatment agent (a combination of (a) and (b)), etc. As a result, a hydrophobized inorganic filler is obtained. The hydrophobic treatment agent may be used alone or in combination of two or more types.

[0092] The antibacterial agent includes inorganic antibacterial agents and organic antibacterial agents. In particular, inorganic antibacterial agents are desirable because they are generally safer than organic antibacterial agents and have excellent durability and heat resistance. Inorganic antibacterial agents are antibacterial metals such as silver, copper, and zinc supported on various inorganic carriers. When contained in the surface protective layer, the amount of antibacterial agent added is preferably 0.1 to 10 parts by mass per 100 parts by mass of the resin component of the surface protective layer, but the details can be adjusted appropriately depending on the type of antibacterial agent.

[0093] The antiviral agents can generally be broadly divided into organic and inorganic types. Organic antiviral agents include quaternary ammonium salts, quaternary phosphonium salts, pyridines, pyrithiones, benzimidazoles, organic iodines, isothiazolinones, anions, and ethers. Inorganic antiviral agents include those in which metal ions such as silver, copper, and zinc are supported on a carrier such as zeolite, apatite, zirconia, glass, or molybdenum oxide. When contained in the surface protective layer, the amount of the antiviral agent added is preferably 0.1 to 10 parts by mass per 100 parts by mass of the resin component of the surface protective layer, but the details can be adjusted appropriately depending on the type of antiviral agent.

[0094] Among the organic antiviral agents, benzimidazole-based antiviral agents, anionic-based antiviral agents, or ether-based antiviral agents that maintain a particle shape are particularly preferred. "Maintaining a particle shape" here means that the agent exists in a particle state without dissolving in the composition (ink before curing) that becomes the curable resin of the surface protective layer. Therefore, during the process of forming the surface protective layer, particles of imidazole-based compounds, particles of anionic compounds, or particles of ether-based compounds tend to float up, making it easier to unevenly distribute the particles of imidazole-based compounds, anionic compounds, or particles of ether-based compounds on the outermost surface side of the surface protective layer. Furthermore, unevenly distributing the particles of imidazole-based compounds, particles of anionic compounds, or particles of ether-based compounds on the outermost surface side of the surface protective layer can reduce the amount of antiviral agent added necessary to achieve a predetermined antiviral property, thereby making it easier to prevent a decrease in the scratch resistance of the surface protective layer.

[0095] The anionic antiviral agent preferably contains, for example, a styrene resin, a styrene polymer derivative compound, and an unsaturated carboxylic acid derivative compound. Furthermore, the styrene polymer derivative compound and the unsaturated carboxylic acid derivative compound preferably contain at least one structure selected from the groups consisting of styrene, sodium sulfonate, acrylic acid, maleic acid, and fumaric acid, and more preferably contain all of these structures. This is because viruses are broadly classified into two types, those with and without envelopes, and it is believed that the structures of antiviral agents that can effectively inhibit the activity of each type differ. Therefore, for example, if effectiveness against only influenza viruses, which are non-enveloped viruses, is desired, it is sufficient to contain only a styrene polymer derivative compound, and in some cases, sufficient effectiveness can be obtained by containing only a simple styrene resin.

[0096] As the inorganic antiviral agent, a silver-based antiviral agent is preferable from the viewpoint of being non-toxic to living organisms and excellent in safety, and among these, a phosphate glass-supported silver compound or a silver zeolite compound, and a molybdenum oxide-silver double salt compound are more preferable because they exhibit antiviral activity even in small amounts and therefore the amount added can be reduced.

[0097] When the silver-based antiviral agent is contained in the surface protective layer, discoloration may occur depending on the surface protective layer (the discoloration may occur due to heat or light in the paint state to which the agent is added, or may occur due to heat or light after the surface protective layer is formed), but in this case, it is possible to improve the situation by appropriately adding an ultraviolet inhibitor, a light stabilizer, etc. For example, the use of a benzotriazole-based compound for the molybdenum oxide silver double salt compound can be expected to have an effect of improving discoloration.

[0098] The antiallergen agent contains either an inorganic compound or an organic compound, and may be used alone or in combination of two or more different compounds. The inorganic compound is preferably a metal-supported material. When the antiallergen agent is contained in the first surface protective layer, the amount of the antiallergen agent added is preferably 0.1 to 10 parts by mass per 100 parts by mass of the resin component of the surface protective layer, but the details can be adjusted appropriately depending on the type of antiallergen agent.

[0099] Examples of methods for forming a surface protective layer containing an ionizing radiation curable resin include a method in which a solution (resin composition for forming a surface protective layer) containing (1) a resin such as an ionizing radiation curable resin, and (2) as necessary, other resins, fine particles, an ultraviolet absorber, an antibacterial agent, the various additives described above, etc. is applied by a coating method such as gravure coating or roll coating, and then the ionizing radiation curable resin is cured to form the surface protective layer.

[0100] (Back primer layer) If necessary, a back primer layer may be provided on the back surface of the substrate sheet (the surface opposite to the surface on which the picture pattern layer is laminated). For example, this is effective when laminating a decorative sheet and a substrate (adherend) to produce a decorative board.

[0101] The back primer layer can be formed by applying a known primer agent to the substrate sheet. Examples of primer agents include urethane resin-based primer agents made from acrylic-modified urethane resin (acrylic urethane-based resin), primer agents made from urethane-cellulose-based resin (e.g., a resin obtained by adding hexamethylene diisocyanate to a mixture of urethane and soluble nitrocellulose), and resin-based primer agents made from an acrylic-urethane block copolymer. Additives may be blended into the primer agent as needed. Examples of additives include fillers such as calcium carbonate and clay, flame retardants such as magnesium hydroxide, antioxidants, lubricants, foaming agents, ultraviolet absorbers, and light stabilizers. The amount of additives blended can be appropriately determined depending on the product characteristics.

[0102] The amount of primer applied is not particularly limited, but is usually 0.1 to 100 g / m ２ , preferably 0.1 to 50 g / m ２ That's about it.

[0103] The thickness of the back primer layer is not particularly limited, but is usually about 0.01 to 10 μm, preferably about 0.1 to 1 μm.

[0104] (Backer layer) A backer layer (a synthetic resin layer for increasing scratch resistance or mitigating the effects of the substrate (adherend)) may be provided on the back surface of the substrate sheet. Note that the above-mentioned scratch resistance particularly refers to dents caused when a load is applied to a portion. The decorative sheet of the present invention has sufficient scratch resistance even without a backer layer, but providing a backer layer can further improve various performances such as scratch resistance.

[0105] The backer layer is preferably formed by extrusion molding of a molten resin, for example, by extrusion molding using a T-die.

[0106] Methods for bonding the back surface of the substrate sheet to the backing layer include a method of bonding the substrate sheet to the backing layer obtained by extrusion molding of molten resin by heat fusion, and a method of bonding by providing an adhesive layer (and optionally a primer layer) between the substrate sheet and the backing layer.

[0107] Resins constituting the backer layer include, but are not limited to, thermoplastic resins such as polyethylene, polypropylene (PP), polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polymethylene, polymethylpentene, polyethylene terephthalate, amorphous polyethylene terephthalate (A-PET), highly heat-resistant polyalkylene terephthalate (for example, polyethylene terephthalate in which part of the ethylene glycol is substituted with 1,4-cyclohexanedimethanol, diethylene glycol, or the like, known as PET-G (manufactured by Eastman Chemical Company)), polybutylene terephthalate (PBT), polycarbonate, polyarylate, polyethylene naphthalate, polyethylene naphthalate-isophthalate copolymer, polyimide, polystyrene, polyamide, ABS (acrylonitrile-butadiene-styrene copolymer), etc. These resins can be used alone or in combination of two or more.

[0108] The thickness of the backer layer can be appropriately set depending on the application and method of use of the final product, and is generally preferably 100 to 800 μm, more preferably 100 to 600 μm.

[0109] If necessary, the adhesive surface of the backing layer may be subjected to a known adhesion-facilitating treatment such as corona discharge treatment, plasma treatment, degreasing treatment, surface roughening treatment, etc. In addition, a primer layer may be further provided on the back surface in consideration of adhesion to the adherend.

[0110] (Vesiculation of Various Additives Contained in Each Layer of the Decorative Sheet) The various additives added to the above-mentioned layers of the decorative sheet of the present invention (such as inorganic fillers added to the primer layer or surface protective layer) are preferably vesiculated. The method for vesiculating the various additives is not particularly limited, and they can be vesiculated by any known method, among which supercritical reverse phase evaporation is preferred.

[0111] In addition to supercritical reverse-phase evaporation, other vesicle-forming methods include the Bangham method, extrusion, hydration, reverse-phase evaporation, and freeze-thawing. Briefly, the Bangham method involves placing chloroform or a chloroform / methanol mixed solvent in a flask or other container, followed by dissolving phospholipids. The solvent is then removed using an evaporator to form a thin lipid film, and a dispersion of additives is added. The resulting solution is then hydrated and dispersed in a vortex mixer to obtain vesicles. The extrusion method involves preparing a thin phospholipid solution and passing it through a filter, replacing the mixer used as an external perturbation in the Bangham method, to obtain vesicles. The hydration method is a preparation method similar to the Bangham method, but does not use a mixer; instead, vesicles are obtained by gently stirring and dispersing the solution. The reverse phase evaporation method involves dissolving phospholipids in diethyl ether or chloroform, adding a solution containing an additive to form a W / O emulsion, removing the organic solvent from the emulsion under reduced pressure, and then adding water to obtain vesicles.The freeze-thaw method uses cooling and heating as external perturbations, and obtains vesicles by repeating this cooling and heating process.

[0112] Supercritical reverse-phase evaporation is described in detail below. Supercritical reverse-phase evaporation is a method in which a substance forming the outer membrane of a vesicle is uniformly dissolved in carbon dioxide in a supercritical state or at a temperature or pressure above the supercritical point, and an aqueous phase containing various additives as water-soluble or hydrophilic encapsulation substances is added to the mixture to form a capsule-like vesicle encapsulating the various additives as encapsulation substances in a single layer. Carbon dioxide in a supercritical state refers to carbon dioxide in a supercritical state at or above its critical temperature (30.98°C) and critical pressure (7.3773±0.0030 MPa). Carbon dioxide under a temperature or pressure above its critical point refers to carbon dioxide under conditions in which only the critical temperature or only the critical pressure exceeds the critical conditions. This method can produce unilamellar vesicles with a diameter of 50 to 800 nm. Generally, a vesicle is a general term for a small vesicle having a spherical, closed membrane structure and containing a liquid phase inside, and in particular, a liposome is one whose outer membrane is composed of biological lipids such as phospholipids.

[0113] Examples of the phospholipids include glycerophospholipids such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidic acid, phosphatidylglycerol, phosphatidylinositol, cardiopin, egg yolk lecithin, hydrogenated egg yolk lecithin, soybean lecithin, and hydrogenated soybean lecithin; and sphingophospholipids such as sphingomyelin, ceramide phosphorylethanolamine, and ceramide phosphorylglycerol.

[0114] The substance that can be used to form the outer membrane may also be a dispersant such as a nonionic surfactant or a mixture of a nonionic surfactant with cholesterol or triacylglycerol.

[0115] As the nonionic surfactant, one or more of polyglycerin ether, dialkylglycerin, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ether, polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester, polyoxyethylene polyoxypropylene copolymer, polybutadiene-polyoxyethylene copolymer, polybutadiene-poly2-vinylpyridine, polystyrene-polyacrylic acid copolymer, polyethylene oxide-polyethylethylene copolymer, polyoxyethylene-polycaprolactam copolymer, etc. can be used.

[0116] As the cholesterols, one or more of cholesterol, α-cholestanol, β-cholestanol, cholestane, desmosterol (5,24-cholestadien-3β-ol), sodium cholate, cholecalciferol, and the like can be used.

[0117] The outer membrane of the liposome may be formed from a mixture of a phospholipid and a dispersant. In the decorative sheet of the present invention, by using a liposome whose outer membrane is formed from a phospholipid, it is possible to improve the compatibility between the resin composition, which is the main component of each layer, and various additives.

[0118] (Method for manufacturing decorative sheet) The decorative sheet of the present invention can be obtained by forming at least the above-mentioned surface protective layer on the outermost surface, for example, by laminating a picture pattern layer, a transparent adhesive layer, a transparent resin layer, and a primer layer on a base sheet, and then forming a surface protective layer on the outermost surface.

[0119] Furthermore, when the decorative sheet is embossed, it may be after the formation of the surface protective layer or before the formation of the surface protective layer. For example, as a specific embodiment, 1) a picture pattern layer, a transparent resin layer, and a primer layer may be formed in this order on the substrate sheet, and then the surface protective layer may be formed, and finally the embossing may be performed. As another specific embodiment, 2) a picture pattern layer, a transparent resin layer, and a primer layer may be formed in this order on the substrate sheet, and then the embossing may be performed, and finally the surface protective layer may be formed. As yet another specific embodiment, 3) a picture pattern layer and a transparent resin layer may be formed in this order on the substrate sheet, and then the embossing may be performed, and then a primer layer may be provided, and finally the surface protective layer may be formed. When the Sm, Rz, and area ratio of the portion up to a depth of 30 μm from the surface of the surface protective layer are adjusted by embossing, it is preferable to perform embossing after the formation of the surface protective layer.

[0120] The embossing is carried out, for example, at a sheet temperature of 120°C to 160°C and a pressure of 10 to 40 kg / cm 2 The concave-convex pattern can be transferred to the printed surface of the decorative sheet with a pressure of 1000 psi.

[0121] 2. Decorative Board The decorative board of the present invention is a decorative board having the above-mentioned decorative sheet on a substrate. The decorative sheet may be laminated on the substrate so that the surface protective layer of the decorative sheet is the outermost layer.

[0122] The substrate (adherend) is not limited, and the same materials as known decorative sheets can be used. Examples include wood, metal, ceramics, plastics, and glass. In particular, the decorative sheet of the present invention is suitable for use with wood. Specific examples of wood include veneers, wood veneers, wood plywood, wood fiberboards, particle boards, and medium-density fiberboards (MDF) made from various materials such as cedar, cypress, zelkova, pine, lauan, teak, and melapy.

[0123] The lamination method is not limited, and can be, for example, a method of attaching the decorative sheet to the substrate using an adhesive. The adhesive can be appropriately selected from known adhesives depending on the type of substrate, etc. Examples include polyvinyl acetate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ionomer, butadiene-acrylonitrile rubber, neoprene rubber, natural rubber, etc. These adhesives can be used alone or in combination of two or more types.

[0124] The decorative board produced in this manner can be used, for example, as interior materials for buildings such as walls, ceilings, and floors, as surface decorative boards for fittings such as window frames, doors, and handrails, and as surface decorative boards for furniture or cabinets for low-voltage electrical appliances and office automation equipment, etc. In particular, the decorative board of the present invention can be suitably used as a decorative material for floors.

[0125] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0126] The following components were prepared as components of the resin composition that constitutes the surface protective layer. Bifunctional urethane acrylate oligomer A (polyol component is polyester diol, Tg: 25°C, molecular weight 1200) Bifunctional urethane acrylate oligomer B (polyol component is polyether diol, Tg: -55°C, molecular weight 5000) Bifunctional urethane acrylate oligomer C (polyol component is polyester diol, Tg: 25°C, molecular weight 1500) Bifunctional urethane acrylate oligomer D (polyol component is polyether diol modified with dicyclohexylmethane diisocyanate (hydrogenated MDI), Tg: -20°C, molecular weight 5000) Trifunctional urethane acrylate oligomer (polyol component is aliphatic urethane acrylate having an isocyanurate skeleton formed by a hexamethylene diisocyanate trimer, Tg: 100°C or higher, molecular weight 1500) Hexafunctional aliphatic urethane acrylate oligomer (Tg: 200°C or higher, molecular weight 1500, UA306H manufactured by Kyoeisha Chemical Co., Ltd.) Filler: (average particle size 10 μm, silica) Filler: (average particle size 14 μm, silica) Filler: (average particle size 20 μm, silica)

[0127] Furthermore, embossing plates for use in the embossing process were prepared in various finishes, including sand-grain, woodgrain, matte, leather grain, and stone grain. Note that these embossing plates were prepared with different Rz and Sm even though they were of the same type.

[0128] Example 1 (Preparation of Decorative Sheet) After corona discharge treatment was performed on the front and back surfaces of a substrate sheet made of a 60 μm thick colored polypropylene film, a 4 μm thick wood grain pattern layer was formed on the substrate sheet by gravure printing using a colored ink containing an acrylic resin as a binder resin. Furthermore, a 2 μm thick back primer layer was formed on the surface of the substrate sheet opposite the pattern layer by gravure printing using a resin composed of 100 parts by mass of acrylic urethane resin and nitrocellulose resin to which 5 parts by mass of hexamethylene diisocyanate had been added. A coating liquid composed of a two-component curing urethane resin was applied onto the pattern layer to form a 2 μm thick transparent adhesive layer. A polypropylene resin sheet was then extrusion laminated onto the adhesive layer to form an 80 μm thick transparent resin layer. After corona discharge treatment was performed on the surface of the transparent resin layer, a two-component curing urethane resin was applied onto the transparent resin layer to form a 1 μm thick primer layer. Next, a coating film (13 μm) of the resin composition constituting the surface protective layer shown below was formed on the primer layer by roll coating, and then the surface protective layer was formed by irradiating with an electron beam under conditions of 175 keV and 5 Mrad (50 kGy) in an environment with an oxygen concentration of 200 ppm or less. Furthermore, the surface protective layer side was heated with an infrared non-contact heater to soften the substrate sheet and transparent resin layer, and then embossed by heat and pressure to form a sand-grained uneven pattern. This produced a decorative floor sheet. The Martens hardness of the surface protective layer measured on the produced decorative floor sheet was 35 N / mm ２ [Resin composition constituting the surface protective layer] Bifunctional urethane acrylate oligomer C 100 parts by mass Fine particles (spherical silica with a mode diameter of 20 μm) 18 parts by mass

[0129] (Preparation of decorative board) A water-based emulsion adhesive (manufactured by Japan Coating Resin Co., Ltd., BA-10L (main agent):BA-11B (hardener) = 100:2.5 (mass ratio)) was applied at 80 g / m on a medium-density wood fiberboard (MDF) having a thickness of 2.5 mm. ２ The mixture was then attached to the primer layer side of the back surface of the decorative floor sheet obtained above, and left to cure at room temperature for 3 days to prepare a decorative floor board.

[0130] Examples 2 to 7, Comparative Examples 1 to 7 The decorative sheets and decorative boards shown in Tables 1 and 2 were produced in the same manner as in Example 1, except that the components and their contents of the resin composition constituting the surface protective layer, the Martens hardness, the type of embossed shape, etc. were appropriately changed.

[0131] The decorative sheets or decorative boards produced in the Examples and Comparative Examples were subjected to the following measurements.

[0132] [Martens Hardness Measurement] The Martens hardness of the surface protective layer in the cross-sectional direction was measured by the method described above. The results are shown in Tables 1 and 2. The Martens hardness values ​​in the tables are the average values ​​of 10 measurements.

[0133] [Measurement of Rz and Sm] Sm was measured according to JIS B0601 (1994), and Rz was measured according to JIS B0601 (2001). The Rz and Sm were obtained by measuring the surface roughness of the decorative board. The surface roughness was measured using a surface roughness profiler (Surfcom 120A, manufactured by Tokyo Seimitsu Co., Ltd.). The Rz and Sm in the table represent the average values ​​of the measured values ​​obtained by measuring the decorative board three times at different positions.

[0134] [Proportion of the area (contact area) of the portion from the surface to a depth of 30 μm] The proportion of the area (contact area) of the portion from the surface of each decorative sheet to a depth of 30 μm was measured using a laser microscope VK-X1000 (manufactured by Keyence Corporation). Specifically, the proportion of the area (contact area) of the portion from the surface of each decorative sheet to a depth of 30 μm was measured using a laser microscope VK-X1000 (manufactured by Keyence Corporation) under the condition of a lens magnification of 50 times. ２In this area, the entire volume area 1 was measured from the surface of the decorative sheet. Next, the volume area 2 from the surface to a depth of 30 μm was measured, and the contact area ratio was calculated based on the following formula: (Contact area ratio (%)) = (Volume area 2 / Volume area 1) × 100

[0135] FIGS. 3 to 14 show examples of measurements of the area ratio of the portion of the surface protection layer up to a depth of 30 μm from the surface in Examples 4, 7, and Comparative Example 7, which will be described later. Specifically, FIG. 3 shows the measured cross-sectional curve for Example 4, and FIG. 4 shows the location where the measured cross-sectional curve was measured in Example 4. FIG. 5 shows the measurement results for volume area 1 for Example 4, and FIG. 6 shows the measurement results for volume area 2 for Example 4. FIG. 7 shows the measured cross-sectional curve for Example 7, and FIG. 8 shows the location where the measured cross-sectional curve was measured in Example 7. FIG. 9 shows the measurement results for volume area 1 for Example 7, and FIG. 10 shows the measurement results for volume area 2 for Example 7. FIG. 11 shows the measured cross-sectional curve for Comparative Example 7, and FIG. 12 shows the location where the measured cross-sectional curve was measured in Comparative Example 7. FIG. 13 shows the measurement results for volume area 1 for Comparative Example 7, and FIG. 14 shows the measurement results for volume area 2 for Comparative Example 7. The contact area ratios were 54% for Example 4, 41% for Example 7, and 10% for Comparative Example 7. In addition, in Fig. 6 (Example 4), Fig. 10 (Example 7), and Fig. 14 (Comparative Example 7), the dark areas indicate the surface from the surface to a depth of 30 µm. In Fig. 14, there are fewer dark areas compared to Figs. 6 and 10, and it can be seen that in Comparative Example 7, the proportion of the area of ​​the portion from the surface to a depth of 30 µm is low.

[0136] The decorative sheets or decorative boards produced in the Examples and Comparative Examples were evaluated as follows.

[0137] (Impact resistance (Dupont impact test)) The test was conducted in accordance with JIS K5600-5-3:1999 (General test methods for paints, Part 5: Mechanical properties of coating films, Section 3: Resistance to falling weights). Specifically, a 500 g weight was dropped from a height of 30 cm onto the surface of each floor decorative board of the Examples and Comparative Examples, and the amount of dents was measured for evaluation. Nine samples were tested, and the number of samples that developed cracks was evaluated. The evaluation criteria are as follows: A score of + / - or higher is considered to be satisfactory for practical use. ++: No cracks +: 1-2 cracks + / -: 3-8 cracks -: All cracks

[0138] (Stain Resistance) 10% of pigment carbon black (CAS1333-86-4) was added to white petrolatum (CAS8009-03-8), and the entire surface of each floor decorative sheet produced in the Examples and Comparative Examples was coated with approximately 10 g / m ２ Next, the surface was wiped dry with a dustcloth (towel material) to remove any remaining Vaseline stains, and the surface of each floor decorative sheet after wiping was visually evaluated. The evaluation criteria are as follows. A score of + / - or higher is considered to be satisfactory for practical use. ++: No remaining stains +: Inconspicuous stains + / -: Light stains -: Remaining stains

[0139] (Slip resistance (O-Y·PSM)) For each decorative panel, the slip resistance value (CSR value) was measured using a Tokyo Institute of Technology slip tester (O-Y·PSM) with socks. The evaluation criteria are as follows. The smaller the value, the more slippery it is, and the range of slip resistance values ​​that humans find comfortable is 0.30 or more and 0.50 or less. +: Measurement value is 0.35 or more and 0.50 or less (not slippery) + / -: Measurement value is 0.30 or more and less than 0.35 (slightly slippery) -: Measurement value is 0.25 or more and less than 0.30 (slippery)

[0140] (Anti-slip durability) As a treatment for promoting the disappearance of unevenness, steel wool (Japan Steel Wool Co., Ltd., material: iron, product number: #1, quality: medium) was used, and a load of 300 g / m ２ The sliding treatment was continued under the conditions until the sheet surface showed a slight change in gloss. Then, the same evaluation as in the evaluation of the anti-slip properties as described above was carried out.

[0141] (Design) The decorative sheet was visually observed from the surface protective layer side, and the design was evaluated according to the following evaluation criteria. A rating of + / - or higher was evaluated as acceptable for practical use. ++: The embossed surface irregularities match the underlying pattern design, and the design has a more textured feel than the real thing. +: The embossed surface irregularities match the underlying pattern design, and the design has a more textured feel than the real thing. + / -: The embossed surface irregularities match the underlying pattern design, but the irregularities are small, making it difficult to feel the real thing. -: The embossed surface irregularities are different from the underlying pattern design, and the design has a strange feel.

[0142] The results are shown in Tables 1 and 2.

[0143]

[0144]

[0145] Example 8 A decorative sheet was produced in the same manner as in Example 1, except that 3 parts by mass of a phosphate glass silver-supported compound (PG-711, manufactured by Koa Glass Co., Ltd.) was added as an antiviral agent to 100 parts by mass of the resin composition constituting the surface protective layer used in Example 1.

[0146] The decorative sheet produced in Example 8 was evaluated for the following properties.

[0147] (Antiviral Performance) The decorative sheet produced in Example 8 was subjected to an antiviral performance test in accordance with the antiviral testing method (ISO 21702), and the antiviral activity value against influenza virus was evaluated based on the following evaluation criteria. The evaluation criteria are as follows: +: Antiviral activity value was 2.0 or more -: Antiviral activity value was less than 2.0

[0148] The results are shown in Table 3.

[0149] Example 9 A decorative sheet was produced in the same manner as in Example 1, except that an anionic phenolic material having antiallergenic properties ("EXP20530A" manufactured by DIC Corporation) and a zinc-based material having antiallergenic properties ("EXP20530B" manufactured by DIC Corporation) were added as antiallergen agents to the resin composition constituting the surface protective layer used in Example 1. The amounts of the anionic phenolic material and the zinc-based material added were such that the solid content ratio was 23% by mass, with the resin composition constituting the surface protective layer containing the anionic phenolic material and the zinc-based material being 100% by mass.

[0150] The decorative sheet produced in Example 9 was evaluated for the following properties.

[0151] (Anti-allergen performance) The decorative sheet produced in Example 9 was evaluated for allergen performance. Specifically, the decorative sheet produced in Example 9 was cut into small pieces and immersed in an aqueous mite allergen solution for one day, after which the amount of allergens was visually confirmed using horizontal development chromatography (Mighty Checker) and evaluated according to the following evaluation criteria. The evaluation criteria are as follows: +: A reduction in the amount of allergens was confirmed (the mite allergen level was judged to be + or less (i.e., about 100 mite / m ２ -: No reduction in allergen amount was confirmed (mite allergen level judgment exceeded +)

[0152] The results are shown in Table 4.

[0153] The difference in color density of the checker confirmed that the decorative sheet of Example 9 had anti-allergen properties.

[0154] Example 10 A backer layer having a thickness of 120 μm was formed by laminating a resin layer made of polypropylene resin by melt extrusion lamination on the back surface of the decorative sheet produced in Example 1. Furthermore, after subjecting the back surface of the backer layer to a corona discharge treatment, a back surface primer layer (thickness 2 μm) was formed to produce a decorative sheet, and a decorative board was produced in the same manner as in Example 1.

[0155] The decorative boards produced in Examples 1 and 10 were evaluated for the following properties.

[0156] (Impact Resistance (Dupont Impact Test)) The test was conducted in accordance with JIS K5600-5-3:1999 (General Test Methods for Paints, Part 5: Mechanical Properties of Coating Films, Section 3: Resistance to Falling Weights). Specifically, a 500 g weight was dropped from a height of 30 cm onto the surface of the decorative panels of Examples 1 and 10 for evaluation. Nine samples were tested, and the number of cracks and dents among the nine samples were visually evaluated. The evaluation criteria are as follows: + or higher is considered to be satisfactory for practical use. ++++: No cracks +++: 1-2 cracks, no noticeable dents ++: 1-2 cracks +: 3-8 cracks -: All cracks

[0157] The results are shown in Table 5.

[0158] Compared to the decorative sheet of Example 1, the decorative sheet of Example 10 had less noticeable dents, confirming that the decorative sheet of Example 10 had improved impact resistance.

[0159] 1. Decorative floor sheet 2. Back primer layer 3. Base sheet 4. Design layer 5. Adhesive layer 6. Transparent resin layer 7. Primer layer 8. Surface protection layer 9. Embossed pattern (wood grain board conduit groove)

Claims

1. A decorative sheet having a surface protective layer on the outermost surface, (1) the Martens hardness of the surface protective layer is 30 to 170 N / mm ２ and the Martens hardness is a value measured by pressing a diamond indenter into a position avoiding fine particles when the surface protective layer contains fine particles, and measuring the Martens hardness of a cross section; (2) the surface protective layer has irregularities, and the irregularities have an embossed shape with a sand-grained, wood-grained, wood-skinned, stone-grained or leather-grained look, and the average spacing Sm of the irregularities is 180 μm to 950 μm; (3) the maximum height Rz of the surface protective layer is 10 to 45 μm; and (4) the surface protective layer has an area ratio of 40% or more for a portion of the surface protective layer that is 30 μm deep.

2. The Martens hardness is 70 to 150 N / mm ２ The decorative sheet according to claim 1 , 3. The decorative sheet according to claim 1 or 2, wherein said Rz is 10 to 19 μm.

4. The decorative sheet according to any one of claims 1 to 3, wherein said Sm is 450 to 750 μm.

5. A decorative sheet according to any one of claims 1 to 4, wherein the surface protective layer has an area ratio of 50 to 90% of the surface area that is higher than a depth of 30 μm from the surface.

6. A decorative sheet according to any one of claims 1 to 5, wherein the surface protective layer has an area ratio of 60 to 85% of the surface area that is higher than a depth of 30 μm from the surface.

7. The decorative sheet according to any one of claims 1 to 6, wherein the surface protective layer contains an ionizing radiation curable resin.

8. The decorative sheet according to any one of claims 1 to 7, wherein the thickness of said surface protective layer is 10 to 40 µm.

9. The decorative sheet according to any one of claims 1 to 8, wherein the surface protective layer contains at least one agent selected from the group consisting of antibacterial agents, antiviral agents, and antiallergen agents.

10. The decorative sheet according to any one of claims 1 to 9, which comprises a picture pattern layer, a transparent resin layer and said surface protective layer on a base sheet in that order.

11. A decorative sheet according to any one of claims 1 to 9, comprising a base sheet having a picture pattern layer, a transparent resin layer and the surface protective layer in that order, and at least a backer layer laminated on the rear surface of the base sheet.

12. A decorative board having the decorative sheet according to any one of claims 1 to 11 on a substrate.

13. The decorative board according to claim 12, wherein the substrate is a wood veneer, a wood plywood, a wood fiberboard or a particle board.