Decorative sheet

Abstract

Provided is a decorative sheet that imparts a smooth texture. A decorative sheet (1) is provided with a raw material layer (2) and a surface protection layer (5) provided on one surface of the raw material layer (2), the surface of the surface protection layer (5) is provided with a concavo-convex structure including a plurality of ridge-shaped portions each protruding in a ridge shape, and the height Rpk of the protruding mountain portion of the concavo-convex structure of the surface protection layer (5) is less than 3.5 [mu] m.

Description

Technical Field

[0001] The present invention relates to a decorative sheet. Background Art

[0002] In order to give design and durability to interior and exterior materials such as doors and windows, furniture, building materials, and floor materials, decorative sheets are used for surface decoration. Decorative sheets are generally attached to the surface of substrates such as wood, wooden boards, metal plates, non-combustible boards, paper substrates, and resin substrates with adhesives to form decorative panels, and are widely used.

[0003] Design is imparted by, for example, using various printing methods to form patterns such as wood grain or stone grain. A plain color without a pattern is also preferred for the decorative sheet in some cases. Whether or not there is a pattern and the type of pattern vary depending on the application and preference.

[0004] The glossiness of the surface is also important for the design of the decorative sheet. As decorative sheets, various choices can be made, ranging from high gloss like a mirror surface to low gloss without any reflection, depending on the application and preference.

[0005] In addition, as mentioned above, as a function of the decorative sheet that is equally important as imparting design, imparting durability can be cited. Durability refers to a comprehensive evaluation of scratch resistance and stain resistance, and whether these properties can be ensured continuously for a long time. The requirements vary depending on the environment and conditions in which the decorative sheet is used, but a decorative sheet with high performance is always required.

[0006] In order to impart durability, a surface protection layer is generally formed on the outermost surface of the decorative sheet. In addition, in order to adjust the glossiness, especially to achieve low glossiness, a gloss adjuster (matt additive) is generally added to the surface protection layer.

[0007] Furthermore, since the decorative sheet is generally subjected to processing such as cutting and bending in order to form a decorative material such as a decorative plate, it is preferable that the decorative sheet has processability that can withstand such processing.

[0008] As described above, as a decorative sheet that takes design properties (low gloss), scratch resistance, and stain resistance into consideration, there is a decorative sheet described in Patent Document 1, for example.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent Application Publication No. 2019-119138 Summary of the invention

[0012] An object of the present invention is to provide a decorative sheet that imparts a smooth touch.

[0013] According to one aspect of the present invention, a decorative sheet is provided, comprising a raw material layer and a surface protection layer arranged on a surface of the raw material layer, wherein a concave-convex structure comprising a plurality of ridge-like portions, each of which protrudes in a ridge-like manner, is arranged on the surface of the surface protection layer, and a height Rpk of the protruding mountain portions of the concave-convex structure of the surface protection layer is less than 3.5 μm.

[0014] According to another aspect of the present invention, there is provided the decorative sheet according to the above aspect, wherein the protruding peak height Rpk is greater than or equal to 0.5 μm.

[0015] According to still another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein an average length RSm of roughness curve elements of the concavo-convex structure of the surface protection layer is 800 μm or less.

[0016] According to still another aspect of the present invention, there is provided the decorative sheet according to the above aspect, wherein the average length RSm is greater than or equal to 10 μm.

[0017] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the thickness of the surface protection layer is greater than or equal to 2 μm and less than 10 μm.

[0018] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the glossiness of the surface protection layer is 10.0 or less.

[0019] According to yet another aspect of the present invention, a decorative sheet involved in any one of the above aspects is provided, wherein at least a portion of the plurality of ridge-shaped portions are adjacent in a width direction, and at a position where the at least a portion of the plurality of ridge-shaped portions are adjacent in the width direction, in a cross-section parallel to the width direction and a thickness direction of the surface protective layer, a portion where the concave-convex structure is provided has a sinusoidal wave shape.

[0020] According to still another aspect of the present invention, there is provided the decorative sheet according to any one of the above aspects, wherein the surface protective layer contains a cured product of an ionizing radiation curable resin.

[0021] According to yet another aspect of the present invention, a decorative sheet according to the above aspect is provided, wherein the main component of the ionizing radiation curable resin is an acrylate containing a repeating structure, the repeating structure is any one of ethylene oxide, propylene oxide, and ε-caprolactone, and the number of repetitions of the repeating structure is greater than 3.

[0022] According to still another aspect of the present invention, there is provided a decorative material comprising: the decorative sheet according to any one of the above aspects, and a base material to which the decorative sheet is attached.

[0023] According to the present invention, a decorative sheet imparting a smooth touch can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] [ Figure 1 ] Figure 1 This is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention.

[0025] [ Figure 2 ] Figure 2 yes Figure 1 A cross-sectional view of a surface protective layer included in a decorative sheet.

[0026] [ Figure 3 ] Figure 3 This is a microscope image of a surface protection layer included in a decorative sheet according to an example of the present invention. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are embodiments that further specify any of the above aspects. The matters described below may be incorporated into the above aspects individually or in combination.

[0028] In addition, the embodiments shown below illustrate the configuration for embodying the technical concept of the present invention, and the technical concept of the present invention is not limited by the material, shape, and structure of the following components. The technical concept of the present invention can be variously modified within the technical scope specified by the claims described in the claims.

[0029] It should be noted that, for elements having the same or similar functions, the same reference symbols are marked in the drawings referred to below, and repeated descriptions are omitted. In addition, the drawings are schematic, and the relationship between the dimensions in a certain direction and the dimensions in other directions, and the relationship between the dimensions of a certain component and the dimensions of other components, etc. may be different from the actual situation.

[0030] <1> Decorative materials and decorative sheets

[0031] Figure 1 This is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention. Figure 2 yes Figure 1 A cross-sectional view of a surface protective layer included in a decorative sheet. Figure 3 This is a microscopic photograph of a surface protection layer included in a decorative sheet according to an example of the present invention.

[0032] It should be noted that Figure 2 The cross section shown is a cross section along the thickness direction of the surface protection layer. Figure 3The microscopic photographs are plane photographs obtained using a laser microscope (OLS-4000 manufactured by Olympus Corporation).

[0033] Figure 1 The decorative material 11 shown includes a substrate B and a decorative sheet 1 attached thereto. Here, the decorative material 11 is a decorative board. The decorative board can be flat, curved or folded. The decorative material 11 can also have a shape other than a board.

[0034] Here, the substrate B is a plate. The plate is, for example, a wooden plate, an inorganic plate, a metal plate, or a composite plate composed of a plurality of materials. The substrate B may have a shape other than a plate.

[0035] The decorative sheet 1 includes a raw material layer 2, a pattern layer 3, a transparent resin layer 4, a surface protection layer 5, an adhesive layer 7, a primer layer 6, and a concealing layer 8. The pattern layer 3, the adhesive layer 7, the transparent resin layer 4, and the surface protection layer 5 are sequentially arranged on the surface of the raw material layer 2 opposite to the surface facing the substrate B from the raw material layer 2 side. The concealing layer 8 and the primer layer 6 are sequentially arranged on the surface of the raw material layer 2 facing the substrate B from the raw material layer 2 side. One or more of the pattern layer 3, the transparent resin layer 4, the primer layer 6, the adhesive layer 7, and the concealing layer 8 may be omitted. The elements included in the decorative sheet 1 are described in sequence below.

[0036] <1.1> Raw material layer

[0037] As the raw material layer 2 or its material, for example, a material selected arbitrarily from paper, synthetic resin, synthetic resin foam, rubber, non-woven fabric, synthetic paper, metal foil, etc. can be used. As paper, thin leaf paper, titanium paper, resin-impregnated paper, etc. can be exemplified. As synthetic resin, polyethylene, polypropylene, polybutene, polystyrene, polycarbonate, polyester, polyamide, ethylene-vinyl acetate copolymer, polyvinyl alcohol, acrylic acid, etc. can be exemplified. As rubber, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, styrene-butadiene copolymer rubber, styrene-isoprene-styrene block copolymer rubber, styrene-butadiene-styrene block copolymer rubber, polyurethane, etc. can be exemplified. As non-woven fabric, organic or inorganic non-woven fabric can be used. As the metal of the metal foil, aluminum, iron, gold, silver, etc. can be exemplified.

[0038] Taking printing workability, cost, and the like into consideration, the thickness of the original material layer 2 is preferably within a range of 20 μm to 250 μm.

[0039] <1.2> Primer layer

[0040] When an olefin resin is used as the material of the raw material layer 2, the surface of the raw material layer 2 is often in an inert state. Therefore, in this case, it is preferred to provide a primer layer 6 between the raw material layer 2 and the substrate B. When the raw material layer 2 is composed of an olefin material, in order to omit the primer layer 6 and improve the adhesion between the raw material layer 2 and the substrate B, the raw material layer 2 may be subjected to a surface modification treatment such as a corona treatment, a plasma treatment, an ozone treatment, an electron beam treatment, an ultraviolet treatment, a dichromic acid treatment, etc.

[0041] As the material of the primer layer 6, for example, the material of the pattern layer 3 described later can be used. Since the primer layer 6 is applied to the back side of the decorative sheet 1, when the decorative sheet 1 is wound in a web shape, in order to avoid sticking and improve the adhesion with the adhesive, an inorganic filler can be added to the primer layer 6. Examples of the inorganic filler include silicon dioxide, aluminum oxide, magnesium oxide, titanium oxide, barium sulfate, and the like.

[0042] <1.3> Hidden layer

[0043] In order to provide concealment to the base material B in the decorative sheet 1, for example, a colored sheet can be used as the raw material layer 2 or an opaque concealing layer 8 can be provided. The concealing layer 8 can be made of the same material as the pattern layer 3 described later. However, since the concealing layer 8 is intended for concealment, it is preferred to use an opaque pigment, titanium oxide, iron oxide, etc. as the pigment. In addition, in order to improve concealment, for example, metals such as gold, silver, copper, and aluminum can be added to the material of the concealing layer 8. Usually, thin aluminum sheets are added.

[0044] <1.4> Pattern layer

[0045] The pattern layer 3 is a layer formed by printing a pattern on the raw material layer 2 using ink. As a binder for the ink, for example, nitrocellulose, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acrylic, polyester, or their modified products can be used alone or in combination. The binder can be any of aqueous, solvent-based, and emulsion-based, and can be a one-component type or a two-component type using a curing agent. The pattern layer 3 can be formed by a method of curing a layer formed by curable ink by irradiation with ultraviolet rays or electron beams. Among them, the most common method is a method of using a carbamate-based ink and curing it with an isocyanate. In addition to the binder, the ink used to form the pattern layer 3 can also contain colorants such as pigments and dyes contained in ordinary inks, body pigments, solvents, various additives, etc. As pigments with high versatility, for example, pearl pigments such as condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolones, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, and mica can be listed.

[0046] In addition to the application of ink, the pattern layer 3 can also be designed by evaporation or sputtering of various metals. In particular, it is preferred to add a light stabilizer to the ink. This can suppress the deterioration of the decorative sheet 1 itself caused by light deterioration of the ink and extend the life of the decorative sheet 1.

[0047] <1.5> Adhesive layer

[0048] The adhesive layer 7 is also called a heat-sensitive adhesive layer, an anchor coating layer, or a dry lamination adhesive layer.

[0049] The resin material of the adhesive layer 7 is not particularly limited, for example, it can be appropriately selected and used from resin materials such as acrylic acid, polyester, polyurethane, epoxy, etc. In addition, as the resin material of the adhesive layer 7, for example, ethylene-vinyl acetate copolymer resin adhesive can also be used. The coating method can be appropriately selected according to the viscosity of the adhesive, etc. Usually a gravure coater is used, and after the gravure coater is used to form the adhesive layer 7 on the pattern layer 3, the transparent resin layer 4 is laminated. It should be noted that, when the bonding strength between the transparent resin layer 4 and the pattern layer 3 is fully obtained, the adhesive layer 7 can be omitted.

[0050] <1.6> Transparent resin layer

[0051] As the resin material of the transparent resin layer 4, an olefin resin is preferably used. As the olefin resin, for example, in addition to polypropylene, polyethylene, polybutene, etc., alpha olefins (for example, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1 1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, etc.) or copolymers of two or more thereof; copolymers obtained by copolymerizing ethylene or α-olefins with monomers other than these, such as ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, ethylene-methyl methacrylate copolymers, ethylene-ethyl methacrylate copolymers, ethylene-butyl methacrylate copolymers, ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, ethylene-butyl acrylate copolymers, etc.

[0052] In addition, in order to improve the surface strength of the decorative sheet 1, highly crystalline polypropylene is preferably used as the resin of the transparent resin layer 4. It should be noted that various additives such as (for example) heat stabilizers, light stabilizers, anti-blocking agents, catalyst scavengers, colorants, light scattering agents, and gloss regulators may be added to the transparent resin layer 4 as needed. As heat stabilizers, phenolic, sulfur, phosphorus, hydrazine, etc. are generally added in any combination, and as light stabilizers, hindered amines, etc. are generally added in any combination.

[0053] <1.7> Surface protection layer

[0054] The surface protection layer 5 includes a core portion 5A and a plurality of ridge portions 5B each protruding in a ridge shape from one surface of the core portion 5A. These ridge portions 5B form a concavo-convex structure.

[0055] Here, in the decorative sheet 1 involved in the present embodiment, "ridge-shaped" refers to a convex shape that is linear in a plan view. The shape of the ridge portion 5B in a plan view may be curved or linear, but from the perspective of the anti-fingerprint property of the decorative sheet 1, a curved shape is preferred. Each of the ridge portions 5B may be branched or unbranched in a plan view. In addition, in the present disclosure, the ridge portion 5B is, for example, a portion from the lowest portion to the top of the concave-convex shape provided on the surface of the surface protection layer 5, and the core portion 5A refers to the portion of the surface protection layer 5 other than the ridge portion 5B.

[0056] For example, Figure 3 As shown, the ridge portions 5B are each curved, and at least a portion thereof is adjacent to each other in the width direction. At a position where at least a portion of the ridge portions 5B is adjacent to each other in the width direction, a cross section of the surface protection layer 5 parallel to the width direction and the thickness direction of the surface protection layer 5 is as shown in FIG. Figure 2 As shown, the portion provided with the concavo-convex structure has a wave shape such as a sine wave shape.

[0057] The height Rpk of the protruding peaks of the concavo-convex structure of the surface protection layer 5 is less than 3.5 μm. Here, the "height Rpk of the protruding peaks" is a surface property parameter specified in JIS B0671-2:2002. The height Rpk of the protruding peaks is more preferably less than 3.0 μm, and further preferably less than 2.8 μm. When the user slides the skin on the surface of the surface protection layer, for example, when the user slides the finger on the surface of the surface protection layer, the decorative sheet with an increased height Rpk of the protruding peaks can give the user a rough touch.

[0058] The height Rpk of the protruding peak is preferably 0.5 μm or more, more preferably 0.8 μm or more, and further preferably 1.0 μm or more. When the user slides the skin on the surface of the surface protection layer, for example, slides the finger on the surface of the surface protection layer, the decorative sheet with a reduced height Rpk of the protruding peak can generate a large friction force.

[0059] According to one example, the average length RSm of the roughness curve element of the concavo-convex structure of the surface protection layer 5 is preferably 800 μm or less, more preferably 600 μm or less, and further preferably 500 μm or less. According to other examples, the average length RSm of the roughness curve element of the concavo-convex structure of the surface protection layer 5 is preferably 350 μm or less, more preferably 320 μm or less, and further preferably 300 μm or less. Here, "the average length RSm of the roughness curve element" is a surface property parameter specified in JIS B0601:2013. When the user slides the skin on the surface of the surface protection layer, for example, when sliding the finger on the surface of the surface protection layer, the average length RSm of the roughness curve element is preferably within the above range to give the user a smooth touch.

[0060] The average length RSm is preferably 10 μm or more, more preferably 50 μm or more, and further preferably 80 μm or more. It is difficult to produce a structure in which the average length RSm is small and the protruding peak height Rpk is somewhat large.

[0061] The thickness of the surface protection layer 5 is preferably 2 μm or more and less than 10 μm, more preferably 2 μm or more and less than 8 μm. When the thickness of the surface protection layer 5 is reduced, it is difficult to increase the height Rpk of the protruding peak or the average length RSm. When the thickness of the surface protection layer 5 is increased, the height Rpk of the protruding peak or the average length RSm tends to increase.

[0062] Here, the thickness of the surface protection layer 5 is the thickness of a layer having a flat surface and an apparent area and volume equal to the surface protection layer 5. The thickness of the surface protection layer 5 is calculated, for example, by the following method. First, a section parallel to the thickness direction of the surface protection layer 5 and perpendicular to the length direction of the ridge 5B is photographed. Next, the size of the surface protection layer 5 in the width direction of the ridge 5B and the area of ​​the section of the surface protection layer 5 are calculated based on the cross-sectional image. The thickness of the surface protection layer 5 is a value obtained by dividing the area by the above-mentioned size. It should be noted that, in the case where the surface protection layer coating liquid described later does not contain a solvent, the thickness of the coating film formed by the surface protection layer coating liquid is equal to the thickness of the surface protection layer 5.

[0063] The glossiness of the surface protection layer 5 is preferably 10.0 or less, and more preferably 8.0 or less. Here, the "glossiness" is a value measured at an incident angle of 60 degrees using a gloss meter in accordance with JIS Z8741:1997.

[0064] <2> Method for manufacturing decorative sheet

[0065] The decorative sheet 1 is produced, for example, by the following method. Here, for simplicity, the description of the pattern layer 3, the transparent resin layer 4, the primer layer 6, the adhesive layer 7, and the concealing layer 8 is omitted.

[0066] First, a coating film composed of a coating liquid for a surface protective layer is formed on one surface of the raw material layer 2. The coating film can be formed by various printing methods such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing; or various coating methods such as roll coating, blade coating, micro gravure coating, and die coating.

[0067] The coating liquid for the surface protection layer contains an ionizing radiation curable resin. Here, "ionizing radiation" is a charged particle beam such as an electron beam. The ionizing radiation curable resin is cured by irradiation with ionizing radiation. In addition, the ionizing radiation curable resin can also be cured by ultraviolet irradiation. The ionizing radiation curable resin used here is cured by irradiation with light having a wavelength of less than 200nm, and on the other hand, has a large absorption coefficient for the light.

[0068] In the coating liquid for the surface protection layer, when the total solid content is set to 100 parts by mass, the amount of the ionizing radiation curable resin is preferably 60 parts by mass or more, more preferably 70 parts by mass or more, and further preferably 80 parts by mass or more. As the ionizing radiation curable resin, various monomers or commercially available oligomers and other known resins can be used, for example, (meth) acrylic resins, silicone resins, polyester resins, carbamate resins, amide resins, epoxy resins can be used. The ionizing radiation curable resin can be any one of an aqueous resin or a non-aqueous (organic solvent) resin.

[0069] The main component of the ionizing radiation curable resin is preferably an acrylate. Here, the main component of the ionizing radiation curable resin refers to a component of 60 parts by mass or more when the total solid content contained in the ionizing radiation curable resin is set to 100 parts by mass. The ionizing radiation curable resin preferably contains acrylate in an amount of 70 parts by mass or more, and more preferably contains acrylate in an amount of 80 parts by mass or more.

[0070] The acrylate is preferably a difunctional or higher acrylate, more preferably a trifunctional or higher acrylate. In order to obtain a surface protection layer 5 having excellent scratch resistance, the acrylate is preferably trifunctional or higher. There is no upper limit to the number of functional groups of the acrylate, but according to one example, it is hexafunctional or lower.

[0071] The acrylate preferably contains a repeating structure. The repeating structure is, for example, any one of an ethylene oxide (EO) structure, a propylene oxide (PO) structure, and an ε-caprolactone (CL) structure. The repeating structure is preferably ethylene oxide or propylene oxide. In a trifunctional or higher acrylate containing a repeating structure, the repeating structure may be between an acryloyl group and a hydroxymethyl group in a ring-opened state.

[0072] The number of repetitions of the repeating structure is preferably 3 or more. When an acrylic acid ester having a large number of repetitions is used, the cured film is likely to expand in the in-plane direction in the first irradiation step described later, and thus wrinkles corresponding to the ridge 5B are likely to be generated on the coating surface. However, when the number of repetitions is increased, the crosslinking density decreases, and the scratch resistance of the surface protective layer decreases.

[0073] The trifunctional acrylate containing a repeating structure is, for example, EO-modified, PO-modified or CL-modified trimethylolpropane triacrylate, glycerol triacrylate, isocyanurate triacrylate, or pentaerythritol triacrylate. In the trifunctional acrylate containing a repeating structure, the number of repetitions of the repeating structure is preferably 3 or more and 30 or less, and more preferably 3 or more and 20 or less.

[0074] The tetrafunctional acrylate containing a repeating structure is, for example, EO-modified, PO-modified or CL-modified pentaerythritol tetraacrylate. In the tetrafunctional acrylate containing a repeating structure, the number of repetitions of the repeating structure is preferably 12 or more, more preferably 12 or more and 50 or less, and further preferably 20 or more and 50 or less.

[0075] The number of repetitions of the above-mentioned repeating structure can be analyzed using MALDI-TOF-MS. The ionizing radiation curable resin may have a molecular weight distribution. In the case of having a molecular weight distribution, the number of repetitions is set to the number of repetitions corresponding to the molecular weight having the strongest peak in the MALDI-TOF-MS mass spectrum.

[0076] The surface protective layer coating liquid preferably further contains particles. When the surface protective layer coating liquid contains particles, wrinkles can be generated more uniformly on the coating film surface in the first irradiation step.

[0077] As particles, for example, particles made of organic materials such as polyethylene (PE) wax, polypropylene (PP) wax, and resin beads; or particles made of inorganic materials such as silica, glass, alumina, titanium dioxide, zirconium oxide, calcium carbonate, and barium sulfate can be used.

[0078] The average particle size (D50) of the particles is preferably 10 μm or less. The average particle size (D50) of the particles is more preferably 1 μm or more and 8 μm or less, and further preferably 2 μm or more and 6 μm or less. When large particles are used, the particles are sometimes easy to fall off from the surface protection layer 5, making it difficult to achieve high scratch resistance. When the particles are small, the effect of uniformly generating wrinkles is small.

[0079] Here, "average particle size (D50)" is the median particle size (D50) measured by a laser diffraction / scattering particle size distribution measuring device. It should be noted that, when the surface protection layer coating liquid contains particles, the surface protection layer 5 obtained from the coating liquid also contains particles. The average particle size of the particles contained in the surface protection layer 5 can be a value obtained by observing its cross section, measuring the particle size of multiple particles and averaging them. The value obtained in this way is substantially the same as the median particle size (D50) measured by a laser diffraction / scattering particle size distribution measuring device. Therefore, the range of the above-mentioned average particle size can also be read as the range of the average particle size of the particles contained in the surface protection layer 5.

[0080] The amount of particles added is preferably 0.5 to 10 parts by mass, more preferably 2 to 8 parts by mass, and further preferably 2 to 6 parts by mass, relative to 100 parts by mass of the ionizing radiation curable resin. When the amount of particles is within the above range, the effect of uniformly generating wrinkles is particularly large.

[0081] The coating liquid for the surface protection layer may also contain a solvent or an additive (such as an antibacterial agent and a mildewproof agent) for improving the function of the final product. The coating liquid for the surface protection layer may also contain other additives such as an ultraviolet absorber and a light stabilizer. As the ultraviolet absorber, for example, benzotriazole, benzoate, benzophenone, triazine, etc. can be used. As the light stabilizer, for example, hindered amines can be used. It should be noted that according to the method described here, a surface protection layer 5 with low gloss can be formed without a gloss regulator (matting additive).

[0082] In the second irradiation step described later, when the coating film composed of the surface protection layer coating liquid is cured as a whole by ultraviolet irradiation, the surface protection layer coating liquid preferably further contains a photoinitiator. The photoinitiator is not particularly limited, and examples thereof include benzophenone-based, acetophenone-based, benzoin ether-based, and thioxanthone-based photoinitiators.

[0083] After forming a coating film composed of a coating liquid for a surface protection layer, the first irradiation process is implemented. In the first irradiation process, light with a wavelength of less than 200nm (hereinafter referred to as the first irradiation light) is irradiated to the coating film. The ionizing radiation curable resin contained in the coating liquid for the surface protection layer has a large absorption coefficient for the first irradiation light. Therefore, the first irradiation light incident on the coating film can only reach a position with a distance of tens to hundreds of nm from its outermost surface. Therefore, in the first irradiation process, a cross-linking reaction is carried out in the surface area of ​​the coating film to form an extremely thin cured film, while on the other hand, no cross-linking reaction is carried out in other areas and remains uncured.

[0084] The coating film after the first irradiation step has wrinkles on the surface corresponding to the ridge-shaped portions 5B. The present inventors believe that the reason why wrinkles are generated on the coating film surface by the first irradiation step is as follows.

[0085] As mentioned above, the first irradiation light can only reach a position with a distance of tens to hundreds of nm from the outermost surface of the coating film. That is, the cross-linking reaction of the ionizing radiation curable resin occurs only on the surface of the coating film. Monomers present on the surface of the coating film, etc. are cross-linked by the irradiation of the first irradiation light via the functional groups they have to form a cured film, but these functional groups are not all used for cross-linking between monomers present on the surface of the coating film. That is, uncross-linked functional groups may remain in the cured film.

[0086] Since the first irradiation light does not reach the monomers present at a position far from the surface of the coating film, their cross-linking reaction does not occur. However, a part of the monomers present at a position far from the surface of the coating film moves toward the cured film, so a cross-linking reaction occurs. In this way, the number of molecules participating in the cross-linking reaction increases.

[0087] When the number of molecules participating in the cross-linking reaction on the coating surface increases, the volume of the cured film increases. The cross-linking reaction occurs only on the surface of the coating, so the cured film cannot increase in volume in the thickness direction and expands in the in-plane direction. As a result, wrinkles are generated on the surface of the coating.

[0088] The first irradiation light can be extracted from excimer VUV (Vacuum Ultra Violet) light. Excimer VUV light can be generated by a lamp using a rare gas or a rare gas halide. When high-energy electrons are applied from the outside to a lamp enclosing a rare gas or a rare gas halide gas, a large amount of discharge plasma (dielectric barrier discharge) is generated. Through this plasma discharge, the atoms of the discharge gas (rare gas) are excited and instantly become a quasi-molecular state. When returning to the ground state from the quasi-molecular state, light in a wavelength region unique to the quasi-molecule is emitted.

[0089] The gas used for the excimer lamp can be any gas used in the past as long as it emits light below 200nm. As the gas, rare gases such as Xe, Ar, and Kr, and mixed gases of rare gases such as ArBr and ArF and halogen gases can be used. The wavelength (center wavelength) of the excimer lamp varies depending on the gas, for example, it has a wavelength of about 172nm (Xe), about 126nm (Ar), about 146nm (Kr), about 165nm (ArBr), about 193nm (ArF), etc.

[0090] Considering the difference between the size of photon energy, wavelength and the binding energy of organic matter, it is preferred to use a xenon lamp that emits excimer light with a central wavelength of 172nm as a light source. In addition, if the cost of equipment maintenance and the acquisition of materials are also considered, it is preferred to use a xenon lamp as a light source.

[0091] The first irradiation step is performed in an atmosphere with a low oxygen concentration. Oxygen has a large absorption coefficient for light below 200 nm. Therefore, the first irradiation step is preferably performed in a nitrogen atmosphere, for example. The oxygen concentration in the gas phase of the first irradiation step, that is, the residual oxygen concentration in the reaction atmosphere is preferably set to 2000 ppm or less, and more preferably set to 1000 ppm or less.

[0092] In addition, oxygen in the atmosphere inhibits free radical polymerization. Therefore, the residual oxygen concentration in the reaction atmosphere affects the formation of wrinkles on the coating surface. Therefore, when the residual oxygen concentration in the reaction atmosphere changes, the surface properties of the surface protection layer 5 may also change.

[0093] The integrated light intensity of the first irradiation light is preferably set to 0.5 mJ / cm 2 Above 200mJ / cm 2 Below, more preferably 1 mJ / cm 2 Above 100mJ / cm 2 Below, more preferably set to 3mJ / cm 2 Above 50mJ / cm 2 When the accumulated light intensity is reduced, the expansion of the cured film in the in-plane direction becomes smaller. When the accumulated light intensity is increased, the surface state of the coating film deteriorates.

[0094] After the first irradiation step is completed, the second irradiation step is performed. In the second irradiation step, the coating film is irradiated with the second radiation or irradiation light to cure the entire coating film. Thus, the surface protection layer 5 is obtained.

[0095] The second radiation or irradiation light is ionizing radiation such as electron beams, or ultraviolet light having a longer wavelength than the first irradiation light.

[0096] When the second radiation or irradiation light is ultraviolet light, the integrated light amount of the second irradiation light is preferably set to 10 mJ / cm 2Above 500mJ / cm 2 Below, more preferably 50 mJ / cm 2 Above 400mJ / cm 2 Below, more preferably 100 mJ / cm 2 Above 300mJ / cm 2 the following.

[0097] The decorative sheet 1 can be manufactured, for example, by the above method. The decorative sheet 1 can also be manufactured by other methods. For example, the surface protection layer 5 can be formed by forming a plate using the above method and transferring using the plate to form a surface protection layer 5 having a concavo-convex structure on the surface.

[0098] <3> Effect

[0099] Reference Figures 1 to 3 The surface protection layer 5 of the decorative sheet 1 described above has the above-mentioned surface properties. Such a decorative sheet 1 provides a smooth touch feeling to the user when the user slides the skin on the surface of the surface protection layer 5, for example, when the user slides the finger on the surface of the surface protection layer 5. That is, the decorative sheet 1 does not allow the user to feel the presence of large irregularities, and the finger or the like can slide with a small friction force.

[0100] The decorative sheet 1 that gives a smooth touch to the user is suitable for applications that have many opportunities to contact the user's skin or applications that contact the user's skin for a long time, such as furniture. When an article using the decorative sheet 1 contacts the user's skin, the user will not feel uncomfortable.

[0101] Since the surface protection layer 5 of the decorative sheet 1 has the above-mentioned surface properties, low gloss can be achieved even without a gloss regulator (matting additive). The gloss regulator reduces the oleophobicity of the layer formed by the resin material, so the surface protection layer containing the gloss regulator is easy to adhere to fingerprints. The surface protection layer 5 without the gloss regulator is difficult to absorb oil, so fingerprints are difficult to adhere. In addition, the surface protection layer 5 with excellent oleophobicity is difficult to adsorb oil or pollutants. In addition, when the surface of the surface protection layer 5 without the gloss regulator is scratched, the particles of the gloss regulator will not fall off, so the decorative sheet 1 including such a surface protection layer 5 is difficult to produce gloss changes and scratches.

[0102] The reason why the surface protection layer 5 having the above-mentioned surface properties can be obtained by the above-mentioned method is as follows.

[0103] Oxygen in the gas phase not only absorbs short-wavelength ultraviolet rays, but also hinders free radical polymerization. The effect of oxygen contained in the gas phase on free radical polymerization is greatest in the portion adjacent to the gas phase in the coating film composed of ionizing radiation curable resin, and becomes smaller as the distance from the coating film surface increases. Therefore, in the first irradiation step, by changing the oxygen concentration in the gas phase, the relationship between the distance from the coating film surface and the degree of progress of the crosslinking reaction can be changed.

[0104] When this relationship changes, the thickness of the cured film generated on the surface of the coating film by the first irradiation process and the expansion degree of the cured film in the in-plane direction based on the cross-linking reaction change. The accumulated light amount of the first irradiation process will also affect the thickness of the cured film and the expansion degree of the cured film in the in-plane direction. Moreover, the thickness of the cured film and the expansion degree of the cured film in the in-plane direction will affect the surface properties of the surface protective layer. In addition, the thickness of the coating film will also affect the formation of wrinkles.

[0105] Therefore, for example, by appropriately setting the composition of the ionizing radiation curable resin, the thickness of the coating film, the oxygen concentration in the gas phase in the first irradiation step, and the integrated light amount in the first irradiation step, a surface protective layer having desired surface properties can be obtained.

[0106] Example

[0107] Hereinafter, examples of the present invention will be described.

[0108] <Example 1>

[0109] The reference was created by Figures 1 to 3 The decorative sheet 1 is described. It should be noted that in this example, the transparent resin layer 4, the primer layer 6, the adhesive layer 7 and the concealing layer 8 are omitted.

[0110] First, prepare a unit area mass of 50g / m 2 As the raw material layer 2, an impregnated paper (GFR-506: manufactured by Kojin Co., Ltd.) was used. On one surface of the raw material layer 2, a pattern layer 3 was formed using an oily nitrocellulose resin-based gravure printing ink (PCNT (PCRNT) various colors: manufactured by Toyo Ink Co., Ltd.).

[0111] Next, a coating liquid for a surface protective layer is applied onto the pattern layer 3. As the coating liquid for a surface protective layer, a coating liquid prepared by blending the following particles into the following ionizing radiation curable resin is used.

[0112] ·Ionizing radiation curable resin

[0113] Type: Ethylene glycol diacrylate (EO9 molar addition)

[0114] Product name: Light Acrylate 9EG-A (manufactured by Kyoeisha Chemical Co., Ltd.)

[0115] Mixing: 100 parts by mass

[0116] ·particle

[0117] Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.)

[0118] Particle size: 5μm

[0119] Mixing: 0.5 parts by mass

[0120] A coating film composed of the surface protective layer coating liquid was formed to have a thickness of 5 μm.

[0121] Then, the first irradiation step was performed. Specifically, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 500 ppm under atmospheric pressure so that the accumulated light intensity was 50 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating liquid was irradiated with ultraviolet rays having a wavelength of 172 nm. As a result, wrinkles were generated on the surface of the coating film.

[0122] Next, the second irradiation step is performed. Specifically, the coating film is irradiated with ionizing radiation to cure the entire coating film, thereby forming the surface protection layer 5.

[0123] The decorative sheet 1 was obtained through the above-mentioned process.

[0124] <Example 2>

[0125] The decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used.

[0126] ·Ionizing radiation curable resin

[0127] Type: Trimethylolpropane EO modified triacrylate (EO6 molar addition)

[0128] Product name: Miramer M3160 (made by Miwon)

[0129] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 500 ppm under atmospheric pressure so that the accumulated light intensity was 50 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0130] <Example 3>

[0131] The decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used.

[0132] ·Ionizing radiation curable resin

[0133] Type: Trimethylolpropane EO modified triacrylate (EO15 molar addition)

[0134] Product name: SR9035 (Sartomer)

[0135] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 500 ppm under atmospheric pressure so that the accumulated light intensity was 50 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0136] <Example 4>

[0137] The decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used.

[0138] ·Ionizing radiation curable resin

[0139] Type: Trimethylolpropane EO modified triacrylate (EO3 molar addition)

[0140] Product name: Miramer M3130 (made by Miwon)

[0141] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 200 ppm under atmospheric pressure so that the accumulated light intensity was 100 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0142] <Example 5>

[0143] The decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used.

[0144] ·Ionizing radiation curable resin

[0145] Type: Trimethylolpropane PO modified triacrylate (PO6 molar addition)

[0146] Product name: NK Ester A-TMPT-6PO (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0147] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 500 ppm under atmospheric pressure so that the accumulated light intensity was 50 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0148] <Example 6>

[0149] The decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used.

[0150] ·Ionizing radiation curable resin

[0151] Type: Caprolactone-modified tris-(2-acryloyloxyethyl) isocyanurate (caprolactone (CL) 3 mol addition)

[0152] Product name: NK Ester A-9300-3CL (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0153] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 200 ppm under atmospheric pressure so that the accumulated light intensity was 100 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0154] <Example 7>

[0155] A decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used. A coating film composed of the surface protective layer coating liquid was formed to have a thickness of 1 μm.

[0156] ·Ionizing radiation curable resin

[0157] Type: Trimethylolpropane EO modified triacrylate (EO6 molar addition)

[0158] Product name: Miramer M3160 (made by Miwon)

[0159] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 500 ppm under atmospheric pressure so that the accumulated light intensity was 10 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0160] <Example 8>

[0161] The decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used. A coating film composed of the surface protective layer coating liquid was formed to have a thickness of 2 μm.

[0162] ·Ionizing radiation curable resin

[0163] Type: Trimethylolpropane EO modified triacrylate (EO6 molar addition)

[0164] Product name: Miramer M3160 (made by Miwon)

[0165] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 500 ppm under atmospheric pressure so that the accumulated light intensity was 10 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0166] <Example 9>

[0167] A decorative sheet 1 was produced in the same manner as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used. A coating film made of the surface protective layer coating liquid was formed to have a thickness of 9 μm.

[0168] ·Ionizing radiation curable resin

[0169] Type: Trimethylolpropane EO modified triacrylate (EO3 molar addition)

[0170] Product name: Miramer M3130 (made by Miwon)

[0171] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 500 ppm under atmospheric pressure so that the accumulated light intensity was 150 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0172] <Example 10>

[0173] The decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used.

[0174] ·Ionizing radiation curable resin

[0175] Type: Ethoxylated pentaerythritol tetraacrylate (EO35 molar addition)

[0176] Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0177] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 200 ppm under atmospheric pressure so that the accumulated light intensity was 50 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0178] <Example 11>

[0179] The decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used.

[0180] ·Ionizing radiation curable resin

[0181] Type: Ethoxylated pentaerythritol tetraacrylate (EO50 molar addition)

[0182] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 200 ppm under atmospheric pressure so that the accumulated light intensity was 50 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0183] <Example 12>

[0184] The decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used.

[0185] ·Ionizing radiation curable resin

[0186] Type: Ethoxylated pentaerythritol tetraacrylate (EO20 molar addition)

[0187] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 100 ppm under atmospheric pressure so that the accumulated light intensity was 100 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0188] <Example 13>

[0189] The decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used.

[0190] ·Ionizing radiation curable resin

[0191] Type: Propoxylated pentaerythritol tetraacrylate (PO35 molar addition)

[0192] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 200 ppm under atmospheric pressure so that the accumulated light intensity was 50 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0193] <Example 14>

[0194] The decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used.

[0195] ·Ionizing radiation curable resin

[0196] Type: Caprolactone modified pentaerythritol tetraacrylate (CL20 molar addition)

[0197] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 100 ppm under atmospheric pressure so that the accumulated light intensity was 100 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0198] <Example 15>

[0199] A decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used. A coating film composed of the surface protective layer coating liquid was formed to have a thickness of 1 μm.

[0200] ·Ionizing radiation curable resin

[0201] Type: Ethoxylated pentaerythritol tetraacrylate (EO35 molar addition)

[0202] Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0203] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 200 ppm under atmospheric pressure so that the accumulated light intensity was 10 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0204] <Example 16>

[0205] The decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used. A coating film composed of the surface protective layer coating liquid was formed to have a thickness of 2 μm.

[0206] ·Ionizing radiation curable resin

[0207] Type: Ethoxylated pentaerythritol tetraacrylate (EO35 molar addition)

[0208] Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0209] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 200 ppm under atmospheric pressure so that the accumulated light intensity was 10 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0210] <Example 17>

[0211] A decorative sheet 1 was produced in the same manner as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used. A coating film made of the surface protective layer coating liquid was formed to have a thickness of 9 μm.

[0212] ·Ionizing radiation curable resin

[0213] Type: Ethoxylated pentaerythritol tetraacrylate (EO20 molar addition)

[0214] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 200 ppm under atmospheric pressure so that the accumulated light intensity was 150 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0215] <Example 18>

[0216] The decorative sheet 1 was produced by the same method as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used.

[0217] ·Ionizing radiation curable resin

[0218] Type: Ethoxylated dipentaerythritol hexaacrylate (EO12 molar addition)

[0219] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 100 ppm under atmospheric pressure so that the accumulated light intensity was 150 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0220] <Example 19>

[0221] A decorative sheet 1 was produced in the same manner as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used. A coating film made of the surface protective layer coating liquid was formed to have a thickness of 9 μm.

[0222] ·Ionizing radiation curable resin

[0223] Type: Ethoxylated pentaerythritol tetraacrylate (EO20 molar addition)

[0224] <Example 20>

[0225] A decorative sheet 1 was produced in the same manner as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used. A coating film made of the surface protective layer coating liquid was formed to have a thickness of 9 μm.

[0226] ·Ionizing radiation curable resin

[0227] Type: Ethoxylated pentaerythritol tetraacrylate (EO20 molar addition)

[0228] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 500 ppm under atmospheric pressure so that the accumulated light intensity was 150 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0229] <Comparative Example 1>

[0230] A decorative sheet was produced in the same manner as in Example 1 except for the following points. Specifically, in this example, a coating liquid prepared by blending the following particles in the following ionizing radiation curable resin was used as a coating liquid for a surface protective layer.

[0231] ·Ionizing radiation curable resin

[0232] Type: Trimethylolpropane EO modified triacrylate (EO6 molar addition)

[0233] Product name: Miramer M3160 (made by Miwon)

[0234] Mixing: 100 parts by mass

[0235] ·particle

[0236] Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.)

[0237] Particle size: 5μm

[0238] Mixing: 15 parts by mass

[0239] Then, the coating film composed of the surface protection layer coating liquid is cured only by the second irradiation step without performing the first irradiation step.

[0240] <Comparative Example 2>

[0241] A decorative sheet was produced in the same manner as in Example 1 except for the following points. Specifically, in this example, a coating liquid prepared by blending the following particles in the following ionizing radiation curable resin was used as a coating liquid for a surface protective layer.

[0242] ·Ionizing radiation curable resin

[0243] Type: Ethoxylated pentaerythritol tetraacrylate (EO35 molar addition)

[0244] Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0245] Mixing: 100 parts by mass

[0246] ·particle

[0247] Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.)

[0248] Particle size: 5μm

[0249] Mixing: 15 parts by mass

[0250] Then, the coating film composed of the surface protection layer coating liquid is cured only by the second irradiation step without performing the first irradiation step.

[0251] <Comparative Example 3>

[0252] A decorative sheet was produced in the same manner as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used. A coating film made of the surface protective layer coating liquid was formed to have a thickness of 10 μm.

[0253] ·Ionizing radiation curable resin

[0254] Type: Trimethylolpropane EO modified triacrylate (EO6 molar addition)

[0255] Product name: Miramer M3160 (made by Miwon)

[0256] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 500 ppm under atmospheric pressure so that the accumulated light intensity was 150 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0257] <Comparative Example 4>

[0258] A decorative sheet was produced in the same manner as in Example 1 except for the following points. That is, in this example, the following ionizing radiation curable resin was used. A coating film made of the surface protective layer coating liquid was formed to have a thickness of 10 μm.

[0259] ·Ionizing radiation curable resin

[0260] Type: Ethoxylated pentaerythritol tetraacrylate (EO35 molar addition)

[0261] Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0262] In the first irradiation step, a Xe excimer lamp was used in a nitrogen atmosphere with an oxygen concentration of 200 ppm under atmospheric pressure so that the accumulated light intensity was 150 mJ / cm 2 The surface of the coating film composed of the surface protective layer coating solution was irradiated with ultraviolet rays having a wavelength of 172 nm.

[0263] <Evaluation>

[0264] The following evaluations were performed on each of the decorative sheets.

[0265] (1) Glossiness

[0266] Glossiness The 60-degree glossiness was measured using Rhopoint IQ (manufactured by Konica Minolta, Inc.) The “60-degree glossiness value” in Tables 1 to 4 below indicates the 60-degree glossiness.

[0267] (2) Skin touch

[0268] Skin feel was evaluated by the following method.

[0269] First, in order to make the evaluation criteria consistent among the evaluators, we conducted preliminary preparations. Specifically, we prepared 10 standard test pieces with different surface properties. Then, we asked the 20 evaluators to slide their fingers on the surface of the standard test pieces while blindfolded, and then divide the touch into the following 5 groups.

[0270] Group 1: The bumps are barely noticeable and the friction is low.

[0271] Group 2: Feel the presence of small bumps or slightly greater friction.

[0272] Group 3: The touch feeling is between the touch feeling of Group 1 and Group 2.

[0273] Group 4: Feel the presence of the big bump.

[0274] Group 5: No bumps or depressions can be felt, but strong friction can be felt.

[0275] Repeat the above steps until the evaluations of each evaluator are consistent for more than 3 consecutive times, and the evaluation results between evaluators are consistent for 3 consecutive times.

[0276] Next, for each decorative sheet, the above-mentioned evaluators were asked to slide their fingers on the surface of the surface protection layer in a blindfolded state, and then the touch was classified into the above-mentioned 5 groups. Then, this step was repeated until the evaluation of each evaluator was consistent for more than 3 consecutive times, and the evaluation results of the evaluators were consistent for 3 consecutive times. Based on the results, the skin touch was evaluated according to the following criteria.

[0277] AAA (smooth): Group 1

[0278] AA (Smoothing): Group 3

[0279] A (Smooth): Group 2

[0280] B (rough or slippery): Group 4 or 5

[0281] (3) Fingerprint resistance

[0282] As the anti-fingerprint evaluation, the fingerprint wiping property evaluation was performed.

[0283] Specifically, the 60-degree glossiness of the surface of each decorative sheet was first measured, and the 60-degree glossiness was taken as the initial glossiness. Next, an anti-fingerprint evaluation liquid was attached to the surface protective layer, and the anti-fingerprint evaluation liquid attached to the surface of the decorative sheet was wiped off. Here, a higher fatty acid was used as the anti-fingerprint evaluation liquid. Then, the 60-degree glossiness of the portion after wiping the anti-fingerprint evaluation liquid was measured, and the 60-degree glossiness was taken as the glossiness after wiping.

[0284] The fingerprint wipe rate is calculated according to the following formula.

[0285] Fingerprint wiping rate (%) = (gloss after wiping / initial gloss) × 100

[0286] The evaluation criteria are as follows.

[0287] AA: 70% or more and less than 250%

[0288] A: 50% or more and less than 70%, or 250% or more and less than 300%

[0289] B: less than 50%, or more than 300%

[0290] (4)Pollution resistance

[0291] As an evaluation of stain resistance, a stain test A specified in Japanese Agricultural Standards (JAS) was performed. That is, a line with a width of 10 mm was drawn on the surface protective layer of each decorative sheet using blue ink, black quick-drying ink, and red crayon, respectively, and left for 4 hours. Then, the lines of blue ink, black quick-drying ink, and red crayon were wiped with a cloth containing ethanol.

[0292] The evaluation criteria are as follows.

[0293] AA: Each color thread can be wiped easily.

[0294] A: You can wipe part of each color thread, but dirt will remain on some of it.

[0295] B: The colored threads cannot be wiped off.

[0296] (5) Damage resistance test

[0297] Each decorative sheet was attached to the wooden substrate B using a urethane adhesive. Then, a stainless steel wool friction test was performed as a scratch resistance evaluation. Specifically, the decorative sheet was rubbed back and forth 20 times with stainless steel wool while applying a load of 100 g, and the scratches and gloss changes on the surface of the decorative sheet were visually confirmed.

[0298] The evaluation criteria are as follows.

[0299] AA: No surface damage or gloss change

[0300] A: The surface has slight damage or gloss changes

[0301] B: The surface has obvious damage or gloss changes [Table 1]

[0302]

[0303] [Table 2]

[0304]

[0305] [Table 3]

[0306]

[0307] [Table 4]

[0308]

[0309] As shown in Tables 1 to 3, the decorative sheets involved in Examples 1 to 20 give the evaluator a smooth touch. In addition, the decorative sheets involved in Examples 1 to 20 have low gloss, excellent fingerprint resistance and stain resistance. In addition, the decorative sheets involved in Examples 2 to 20 also have excellent scratch resistance. In contrast, as shown in Table 4, the decorative sheets involved in Comparative Examples 1 and 2 do not give the evaluator a smooth touch, and the fingerprint resistance, stain resistance and scratch resistance are poor. In addition, the decorative sheets involved in Comparative Examples 3 and 4 have low gloss, excellent fingerprint resistance, stain resistance and scratch resistance, but do not give the evaluator a smooth touch.

[0310] Explanation of symbols

[0311] 1…decorative sheet, 2…raw material layer, 3…pattern layer, 4…transparent resin layer, 5…surface protection layer, 6…primer layer, 7…adhesive layer, 8…hidden layer, 11…decorative material, B…substrate.

Claims

1. A decorative sheet comprising a raw material layer and a surface protection layer provided on one surface of the raw material layer, A concavo-convex structure including a plurality of ridge-shaped portions each protruding in a ridge shape is provided on the surface of the surface protection layer. A height Rpk of protruding peaks of the concavo-convex structure of the surface protection layer is less than 3.5 μm.

2. The decorative sheet according to claim 1, wherein: The protruding peak height Rpk is greater than or equal to 0.5 μm.

3. The decorative sheet according to claim 1 or 2, wherein: The average length RSm of the roughness curve elements of the concavo-convex structure of the surface protection layer is 800 μm or less.

4. The decorative sheet according to claim 3, wherein: The average length RSm is 10 μm or more.

5. The decorative sheet according to any one of claims 1 to 4, wherein: The surface protection layer has a thickness of 2 μm or more and less than 10 μm.

6. The decorative sheet according to any one of claims 1 to 5, wherein: The glossiness of the surface protection layer is 10.0 or less.

7. The decorative sheet according to any one of claims 1 to 6, wherein: At least a portion of the multiple ridge-shaped portions are adjacent in the width direction, and at a position where at least a portion of the multiple ridge-shaped portions are adjacent in the width direction, in a cross-section parallel to the width direction and the thickness direction of the surface protective layer, a portion where the concave-convex structure is arranged has a sinusoidal wave shape.

8. The decorative sheet according to any one of claims 1 to 7, wherein: The surface protective layer contains a cured product of an ionizing radiation curable resin.

9. The decorative sheet according to claim 8, wherein: The main component of the ionizing radiation curable resin is an acrylate having a repeating structure. The repeating structure is any one of ethylene oxide, propylene oxide, and ε-caprolactone, The repeating number of the repeating structure is 3 or more.

10. A decorative material having: The decorative sheet according to any one of claims 1 to 9, and A substrate to which the decorative sheet is attached.

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