Decorative sheet

Abstract

A decorative sheet (1) is provided with a base material layer (2) and a surface protective layer (5) provided on one surface of the base material layer (2). A dip / bump structure is provided on the surface of the surface protective layer (5). The dip / bump structure of the surface protective layer (5) has a load length ratio Rmr (10%) at a cutting level of 10% of 0.05-0.35 inclusive, a root-mean-square gradient Rdq of 0.15-0.4 inclusive, and a root-mean-square height Rq of 0.4 μm-4.0 μm inclusive.

Description

Decorative sheet

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

[0002] Decorative sheets are used for the purpose of imparting design and durability to the surface decoration of interior and exterior materials such as building fixtures, furniture, fixtures, and flooring materials. Decorative sheets are generally widely used as decorative panels that are attached via an adhesive or the like to the surface of substrates such as wood, wood boards, metal plates, non-combustible boards, paper substrates, and resin substrates.

[0003] Designs can be added by forming patterns such as wood grain or stone grain using various printing methods. Plain decorative sheets without patterns are sometimes preferred. The choice of whether to have a pattern or not 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 decorative sheets. There are a variety of decorative sheets to choose from depending on the application and preference, ranging from high gloss like a mirror to low gloss that does not reflect light at all.

[0005] As mentioned above, durability is an important function of decorative sheets, along with providing design. Durability is a comprehensive assessment of scratch resistance, stain resistance, and whether these can be maintained over a long period of time. Requirements vary depending on the environment and situation in which the decorative sheet is used, but decorative sheets with high performance are always in demand.

[0006] To impart durability, a surface protective layer is generally formed on the outermost surface of the decorative sheet, and to adjust the aforementioned gloss, particularly to achieve low gloss, a gloss adjuster (matt additive) is generally added to the surface protective layer.

[0007] Furthermore, decorative sheets are generally subjected to processes such as cutting and bending in order to form decorative materials such as decorative plates, and therefore it is preferable that the decorative sheets have processability that can withstand these processes.

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

[0009] Japanese Patent Application Publication No. 2019-119138

[0010] An object of the present invention is to provide a decorative sheet that gives the feeling of warmth of wood to the touch.

[0011] According to one aspect of the present invention, there is provided a decorative sheet comprising a raw fabric layer and a surface protective layer provided on one surface of the raw fabric layer, wherein an uneven structure is provided on the surface of the surface protective layer, and the uneven structure of the surface protective layer has a load length ratio Rmr(10%) at a cutting level of 10% of 0.05 or more and 0.35 or less, a root mean square slope Rdq of 0.15 or more and 0.4 or less, and a root mean square height Rq of 0.4 μm or more and 4.0 μm or less.

[0012] According to another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the gloss of the surface protective layer is less than 10.

[0013] 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 surface protective layer contains a cured resin and particles.

[0014] 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 particles have an average particle size of 3 μm or more.

[0015] 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 particles have an average particle size of 3 μm or more and 10 μm or less.

[0016] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the particles are contained in the surface protective layer in an amount of 3 to 11 parts by mass per 100 parts by mass of the resin.

[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 resin is an ionizing radiation curable resin.

[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 resin is an acrylate.

[0019] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the resin is a trifunctional acrylate containing a repeating structure, and the number of repetitions of the repeating structure is 15 or more and 20 or less.

[0020] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the resin is a tetrafunctional acrylate containing a repeating structure, and the number of repetitions of the repeating structure is 20 or more and 35 or less.

[0021] 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 protective layer is 2 μm or more and 10 μm or less.

[0022] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, further comprising a design layer between the base layer and the surface protective layer.

[0023] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the design layer has a wood grain pattern.

[0024] According to yet another aspect of the present invention, there is provided a decorative material comprising a decorative sheet according to any one of the above aspects and a substrate to which the decorative sheet is attached.

[0025] According to the present invention, a decorative sheet is provided that gives the feel of the warmth of wood.

[0026] Fig. 1 is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention. Fig. 2 is a cross-sectional view of a surface protective layer included in the decorative sheet of Fig. 1. Fig. 3 is a microscope image of a surface protective layer included in a decorative sheet according to one example of the present invention.

[0027] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are more specific embodiments of any of the above aspects. The following items can be incorporated into each of the above aspects, either singly or in combination.

[0028] Furthermore, the embodiments shown below are merely examples of configurations for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not limited by the materials, shapes, structures, etc. of the components described below. Various modifications can be made to the technical idea of ​​the present invention within the technical scope defined by the claims.

[0029] In the drawings, elements having the same or similar functions are denoted by the same reference numerals, and redundant explanations will be omitted. Furthermore, the drawings are schematic, and the relationship between dimensions in one direction and dimensions in another direction, and the relationship between the dimensions of one member and the dimensions of another member, etc. may differ from the actual relationship.

[0030] <1> Decorative material and decorative sheet Fig. 1 is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention. Fig. 2 is a cross-sectional view of a surface protective layer included in the decorative sheet of Fig. 1. Fig. 3 is a micrograph of a surface protective layer included in a decorative sheet according to one example of the present invention.

[0031] The cross section shown in Fig. 2 is a cross section along the thickness direction of the surface protection layer, and the micrograph in Fig. 3 is a plan view photograph obtained by a laser microscope (OLS-4000 manufactured by Olympus Corporation).

[0032] The decorative material 11 shown in Figure 1 includes a substrate B and a decorative sheet 1 attached thereto. Here, the decorative material 11 is a decorative board. The decorative board may be a flat plate, or may be curved or folded. The decorative material 11 may have a shape other than a plate.

[0033] Here, the substrate B is a plate material. The plate material is, for example, a wood board, an inorganic board, a metal plate, or a composite board made of multiple materials. The substrate B may have a shape other than a plate.

[0034] The decorative sheet 1 includes a base fabric layer 2, a design layer 3, a transparent resin layer 4, a surface protective layer 5, an adhesive layer 7, a primer layer 6, and a concealing layer 8. The design layer 3, adhesive layer 7, transparent resin layer 4, and surface protective layer 5 are provided in this order from the base fabric layer 2 side on the surface of the base fabric layer 2 opposite the surface facing the substrate B. The concealing layer 8 and primer layer 6 are provided in this order from the base fabric layer 2 side on the surface of the base fabric layer 2 facing the substrate B. One or more of the design layer 3, transparent resin layer 4, primer layer 6, adhesive layer 7, and concealing layer 8 may be omitted. Below, the elements included in the decorative sheet 1 will be explained in order.

[0035] <1.1> Raw Fabric Layer The raw fabric layer 2 or its material can be any material selected from, for example, paper, synthetic resin, synthetic resin foam, rubber, nonwoven fabric, synthetic paper, metal foil, etc. Examples of paper include tissue paper, titanium paper, and resin-impregnated paper. Examples of synthetic resins include polyethylene, polypropylene, polybutylene, polystyrene, polycarbonate, polyester, polyamide, ethylene-vinyl acetate copolymer, polyvinyl alcohol, and acrylic. Examples of rubber include 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, and polyurethane. Examples of nonwoven fabric include organic and inorganic nonwoven fabrics. Examples of metals for the metal foil include aluminum, iron, gold, and silver.

[0036] The thickness of the raw fabric layer 2 is preferably within the range of 20 μm to 250 μm, taking into consideration the ease of printing and costs.

[0037] <1.2> Primer Layer When an olefin-based resin is used as the material of the raw fabric layer 2, the surface of the raw fabric layer 2 is often in an inactive state. Therefore, in this case, it is preferable to provide a primer layer 6 between the raw fabric layer 2 and the substrate B. When the raw fabric layer 2 is made of an olefin-based material, the primer layer 6 may be omitted, and the raw fabric layer 2 may be subjected to a surface modification treatment such as corona treatment, plasma treatment, ozone treatment, electron beam treatment, ultraviolet treatment, or dichromate treatment in order to improve the adhesion between the raw fabric layer 2 and the substrate B.

[0038] Materials that can be used for the primer layer 6 include, for example, the materials described below for the design layer 3. Since the primer layer 6 is applied to the back surface of the decorative sheet 1, and considering that the decorative sheet 1 will be wound up in web form, an inorganic filler may be added to the primer layer 6 to avoid blocking and increase adhesion to the adhesive. Examples of inorganic fillers include silica, alumina, magnesia, titanium oxide, and barium sulfate.

[0039] <1.3> Concealing Layer To provide the decorative sheet 1 with concealing properties for the substrate B, for example, a colored sheet is used as the base layer 2, or an opaque concealing layer 8 is provided. The concealing layer 8 can be made of, for example, the same material as that used for the design layer 3, which will be described later. However, since the purpose of the concealing layer 8 is to provide concealing properties, it is preferable to use, for example, an opaque pigment, titanium oxide, iron oxide, or the like, as the pigment. Furthermore, to improve concealing properties, metals such as gold, silver, copper, and aluminum can also be added to the material of the concealing layer 8. Generally, flake-shaped aluminum pieces are often added.

[0040] <1.4> Design Layer The design layer 3 is a layer formed by printing a design onto the base layer 2 using ink. Examples of ink binders include soluble nitrocellulose, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acrylic, polyesters, and modified versions thereof, either alone or in combination. The binder may be aqueous, solvent-based, or emulsion-based, and may be a one-component type or a two-component type incorporating a curing agent. The design layer 3 may be formed by curing a layer formed with a curable ink by exposure to ultraviolet light, electron beams, or the like. The most common method is to use a urethane-based ink that is cured with an isocyanate. The ink used to form the design layer 3 may further contain, in addition to the binder, pigments and colorants such as dyes, extender pigments, solvents, and various additives typically found in inks. Examples of versatile pigments include condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, and pearl pigments such as mica.

[0041] In addition to applying ink, it is also possible to apply a design to the pattern layer 3 by vapor deposition or sputtering of various metals. In particular, it is preferable that a light stabilizer be added to the ink. This can suppress deterioration of the decorative sheet 1 itself caused by light degradation of the ink, and extend the life of the decorative sheet 1.

[0042] In the decorative sheet 1 shown in Figure 1, the pattern layer 3 is provided between the base fabric layer 2 and the adhesive layer 7, but it can be provided at any position between the base fabric layer 2 and the surface protective layer 5. The pattern layer 3 preferably has a wood grain pattern. If the pattern layer 3 has a wood grain pattern, the user can easily sense the texture of wood from the visual information. The pattern layer 3 may be omitted.

[0043] <1.5> Adhesive Layer The adhesive layer 7 is also called a heat-sensitive adhesive layer, an anchor coat layer, or a dry lamination adhesive layer.

[0044] The resin material for the adhesive layer 7 is not particularly limited, and can be appropriately selected from acrylic, polyester, polyurethane, epoxy, and other resin materials. Furthermore, an ethylene-vinyl acetate copolymer resin adhesive can also be used as the resin material for the adhesive layer 7. The coating method can be appropriately selected depending on the viscosity of the adhesive. Generally, gravure coating is used, and the adhesive layer 7 is formed on the upper surface of the design layer 3 by gravure coating, and then the transparent resin layer 4 is laminated. The adhesive layer 7 can be omitted if sufficient adhesive strength can be obtained between the transparent resin layer 4 and the design layer 3.

[0045] <1.6> Transparent Resin Layer An olefin-based resin is preferably used as the resin material for the transparent resin layer 4. Examples of the olefin-based resin include polypropylene, polyethylene, polybutene, and the like, as well as α-olefins (e.g., 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-pentene, 4-ethyl-1-hexene, 3 Examples of the copolymer include homopolymers of α-olefins such as 9-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, and 12-ethyl-1-tetradecene, or copolymers of two or more of these, as well as copolymers of ethylene or α-olefins with other monomers, such as ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-butyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-butyl acrylate copolymer.

[0046] Furthermore, in order to improve the surface strength of the decorative sheet 1, it is preferable to use highly crystalline polypropylene as the resin for the transparent resin layer 4. Note that, if necessary, various additives such as heat stabilizers, light stabilizers, antiblocking agents, catalyst scavengers, colorants, light scattering agents, and gloss adjusters can also be added to the transparent resin layer 4. Generally, phenol-based, sulfur-based, phosphorus-based, hydrazine-based, and other heat stabilizers are added, and hindered amine-based, and other light stabilizers are added, in any combination.

[0047] <1.7> Surface Protection Layer 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 an uneven structure.

[0048] Here, in the decorative sheet 1 according to this embodiment, the term "ridge-like" refers to a convex shape that is linear in plan view. The ridge portions 5B may be curved or linear in plan view, but are preferably curved in view of the fingerprint resistance of the decorative sheet 1. Each ridge portion 5B may be branched or unbranched in plan view. In addition, in the present disclosure, the ridge portions 5B refer to, for example, the portion from the lowest point to the tip of the uneven shape provided on the surface of the surface protective layer 5, and the core portion 5A refers to the portion of the surface protective layer 5 excluding the ridge portions 5B.

[0049] The ridge portions 5B are curved, and at least some of them are adjacent to each other in the width direction, as shown in Fig. 3. At a position where at least some of the ridge portions 5B are adjacent to each other in the width direction, the cross section of the surface protective layer 5 parallel to the width direction and the thickness direction of the surface protective layer 5 has a wave shape, such as a sine wave shape, in the portion where the uneven structure is provided, as shown in Fig. 2.

[0050] The surface protective layer 5 preferably covers the entire upper surface of the underlying layer (transparent resin layer 4 in this embodiment) that contacts the surface protective layer 5. That is, in the decorative sheet 1 according to this embodiment, it is preferable that the underlying layer that contacts the surface protective layer 5 (i.e., transparent resin layer 4) is not exposed on the surface.

[0051] The uneven structure of the surface protective layer 5 has a load length ratio Rmr(10%) of 0.05 or more and 0.35 or less at a cutting level of 10%. The load length ratio Rmr(10%) is preferably 0.1 or more and 0.3 or less, and more preferably 0.15 or more and 0.25 or less. The smaller the load length ratio Rmr(10%), the steeper the slope near the top of the convex portion, so that when a user touches the uneven structure with their finger, the amount of contact between the finger and the convex portion is reduced, making it difficult for the user's heat to be transferred to the decorative sheet, and increasing the sense of warmth felt by the user.

[0052] The load length ratio Rmr (10%) is the ratio of the load length of the roughness curve at a cut level of 10% to the evaluation length. The cut level of 10% is a level where the depth distance from the highest point on the roughness curve is 10% of the maximum cross-sectional height Rt. When a user lightly touches the uneven structure with their finger, the finger touches a portion of the uneven structure that is approximately 10% of the height of the convex portion from the highest point of the convex portion. Therefore, the load length ratio Rmr (10%) correlates with the amount of contact between the finger and the convex portion when the user lightly touches the uneven structure with their finger. The load length ratio Rmr (10%) and the maximum cross-sectional height Rt are surface texture parameters specified in JIS B0601:2013. A contact-type surface roughness meter can be used to measure the roughness curve.

[0053] The load length ratio Rmr (10%) is expressed by the following formula 1.

[0054] where ln is the evaluation length and Ml(10%) is the load length of the roughness curve at the cutting level of 10%.

[0055] The uneven structure of the surface protective layer 5 has a root mean square slope Rdq of 0.15 or more and 0.4 or less, preferably 0.2 or more and 0.35 or less, and more preferably 0.25 or more and 0.3 or less.

[0056] The root-mean-square slope Rdq is the root-mean-square of the local slope of the roughness curve over a reference length. The root-mean-square slope Rdq is a parameter that can be used to evaluate the magnitude of the local slope angle. Specifically, the root-mean-square slope Rdq is a numerical representation of the steepness of the convex or concave portions included in the uneven structure. The root-mean-square slope Rdq is a surface texture parameter defined in JIS B0601:2013.

[0057] The root mean square slope Rdq is expressed by the following equation 2.

[0058] where l is the sampling length and dZ(x) / dx is the local slope of the roughness curve.

[0059] The uneven structure of the surface protection layer 5 has a root mean square height Rq of 0.4 μm or more and 4.0 μm or less, preferably 1.0 μm or more and 3.5 μm or less, and more preferably 1.5 μm or more and 3.0 μm or less.

[0060] The root mean square height Rq is the root mean square of the ordinate value Z(x) of the roughness curve over the reference length l. The root mean square height Rq is a parameter that can be used to evaluate the size of the convex or concave portions in the height direction of the uneven structure. The root mean square height Rq is a surface texture parameter defined in JIS B0601:2013.

[0061] The root mean square height Rq is expressed by the following equation 3.

[0062] where l is the reference length and Z(x) is the ordinate value of the roughness curve.

[0063] The thickness t of the surface protective layer 5 is preferably 2 μm or more and 10 μm or less. The thickness t of the surface protective layer 5 is more preferably 3 μm or more and 10 μm or less. If the thickness of the surface protective layer 5 is too small or too large, it becomes difficult to achieve a "warm wooden feel." Furthermore, if the thickness of the surface protective layer 5 is too small, it becomes difficult to achieve a low gloss level. Furthermore, if the thickness of the surface protective layer 5 is too large, it becomes difficult to achieve high processability. Processability will be described later. Here, the thickness of the surface protective layer 5 is determined by observing the cross section with a scanning electron microscope and averaging the values ​​at 25 points. Specifically, the thickness of the surface protective layer 5 can be determined as described in the examples below. When the coating liquid for the surface protective layer described below does not contain a solvent, the thickness of the coating film made of the coating liquid for the surface protective layer is equal to the thickness of the surface protective layer 5.

[0064] The surface protective layer 5 preferably contains a cured resin and particles. The resin contained in the surface protective layer 5 is preferably an ionizing radiation curable resin. Here, "ionizing radiation" refers to a charged particle beam such as an electron beam. The ionizing radiation curable resin is cured by irradiation with ionizing radiation. The ionizing radiation curable resin can also be cured by irradiation with ultraviolet light. The ionizing radiation curable resin used here is cured by irradiation with light having a wavelength of 200 nm or less, and has a large absorption coefficient for this light.

[0065] The amount of the cured ionizing radiation curable resin in the surface protective layer 5 is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. As the ionizing radiation curable resin, known resins such as various monomers and commercially available oligomers can be used, including (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins. The ionizing radiation curable resin may be either an aqueous resin or a non-aqueous (organic solvent-based) resin.

[0066] The main component of the ionizing radiation curable resin is preferably an acrylate. Here, the main component of the ionizing radiation curable resin means a component that accounts for 60 mass% or more of the ionizing radiation curable resin. The ionizing radiation curable resin preferably contains 70 mass parts or more of acrylate, more preferably 80 mass parts or more. The ionizing radiation curable resin is more preferably an acrylate.

[0067] The acrylate is preferably a difunctional or higher acrylate, more preferably a trifunctional or higher acrylate. In order to obtain a surface protective layer 5 having excellent scratch resistance, the acrylate is preferably a trifunctional or higher acrylate. There is no upper limit to the number of functional groups of the acrylate, but according to one example, it is hexafunctional or less, preferably tetrafunctional or less.

[0068] The acrylate preferably contains a repeating unit. This repeating unit is, for example, any one of an ethylene oxide (EO) unit, a propylene oxide (PO) unit, and an ε-caprolactone (CL) unit. The repeating unit is preferably ethylene oxide or propylene oxide. In the acrylate, the repeating unit may be present between the acryloyl group and the methylol group in an open ring state.

[0069] The number of repetitions of the repeating structure is preferably 3 or more, more preferably 15 or more. The number of repetitions of the repeating structure is, for example, 50 or less. If an acrylate with a high number of repetitions is used, the cured film is more likely to expand in the in-plane direction during the second irradiation step described below, and therefore wrinkles corresponding to the ridge portions 5B are more likely to appear on the coating film surface. Furthermore, if an acrylate with a high number of repetitions is used, the gloss value tends to decrease and the design tends to improve. However, if the number of repetitions is increased, the crosslinking density decreases and the scratch resistance of the surface protective layer decreases. Furthermore, if an acrylate with a low number of repetitions is used, it may be difficult to achieve high processability.

[0070] In a preferred embodiment, the ionizing radiation curable resin is a trifunctional acrylate containing a repeating unit. The trifunctional acrylate containing a repeating unit is, for example, EO-modified, PO-modified, or CL-modified trimethylolpropane triacrylate, glycerin triacrylate, isocyanurate triacrylate, or pentaerythritol triacrylate. In the trifunctional acrylate containing a repeating unit, the number of repeating units is preferably 15 or more and 20 or less.

[0071] In another preferred embodiment, the ionizing radiation curable resin is a tetrafunctional acrylate containing a repeating unit. The tetrafunctional acrylate containing a repeating unit is, for example, EO-modified, PO-modified, or CL-modified pentaerythritol tetraacrylate. In the tetrafunctional acrylate containing a repeating unit, the number of repeating units is preferably 20 or more and 35 or less.

[0072] The number of repetitions of the repeating structure can be analyzed using MALDI-TOF-MS. Ionizing radiation curable resins may have a molecular weight distribution. When a molecular weight distribution exists, the number of repetitions is determined to be the number of repetitions corresponding to the molecular weight having the strongest peak in the MALDI-TOF-MS mass spectrum.

[0073] The particles contained in the surface protective layer 5 can be, 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, titania, zirconia, calcium carbonate, and barium sulfate. When the surface protective layer 5 contains particles, a "warm wooden feel" is easily obtained when a finger is pressed against the surface of the decorative sheet 1 and then slid across the surface.

[0074] The particles preferably have an average particle size (D50) of 3 μm or more, more preferably 3 μm or more and 10 μm or less, and even more preferably 4 μm or more and 10 μm or less.

[0075] When the surface protective layer 5 contains particles, wrinkles can be more uniformly generated on the coating surface in the second irradiation step described below. As the average particle size (D50) of the particles increases, the user tends to feel a stronger sense of particle unevenness. Therefore, if the average particle size (D50) of the particles is too large, it becomes difficult to achieve a "warm wood feel." Furthermore, as the average particle size (D50) of the particles increases, particles tend to fall off easily from the surface protective layer 5, making it difficult to achieve high scratch resistance. Furthermore, the use of large particles may make it difficult to achieve high processability. Furthermore, when particles are small, the effect of generating wrinkles uniformly tends to be reduced. Therefore, when particles are small, it becomes difficult to achieve a "warm wood feel."

[0076] Here, the "average particle size (D50)" refers to the median size (D50) measured using a laser diffraction / scattering particle size distribution analyzer. When the coating liquid for the surface protective layer contains particles, the surface protective layer 5 obtained from this coating liquid will also contain particles. The average particle size of the particles contained in the surface protective layer 5 can be determined by observing the cross section of the layer and averaging the particle sizes of multiple particles. The value obtained in this manner is substantially the same as the median size (D50) measured using a laser diffraction / scattering particle size distribution analyzer. Therefore, the above-mentioned range of average particle size can also be interpreted as the range of average particle sizes of the particles contained in the surface protective layer 5.

[0077] The particles are preferably contained in the surface protective layer 5 in an amount of 3 to 11 parts by mass per 100 parts by mass of the resin. The amount of particles added is more preferably 4 to 10 parts by mass per 100 parts by mass of the resin. Note that "100 parts by mass of the resin" refers to the parts by mass of the solid content of the resin.

[0078] When the amount of particles added is within the above range, wrinkles can be more uniformly generated on the coating surface in the second irradiation step described below. Furthermore, when the amount of particles added is large, particles are likely to fall off from the surface protective layer 5, which may make it difficult to achieve high scratch resistance and high processability. Furthermore, when the amount of particles added is large, it may make it difficult to achieve high contamination resistance. Furthermore, when the amount of particles added is small, the effect of generating wrinkles uniformly is likely to be reduced.

[0079] The glossiness of the surface protective layer 5 is preferably less than 10.0. The glossiness of the surface protective layer 5 is preferably 5 or less. Here, the "glossiness" is a measured value measured at an incident angle of 60 degrees using a glossmeter in accordance with JIS Z8741:1997.

[0080] <2> Manufacturing Method of Decorative Sheet The decorative sheet 1 is manufactured, for example, by the following method. For the sake of brevity, explanations of the design layer 3, transparent resin layer 4, primer layer 6, adhesive layer 7, and hiding layer 8 are omitted here.

[0081] First, a coating liquid for the surface protective layer is prepared. The coating liquid for the surface protective layer contains, for example, the resin and the particles described above. The coating liquid for the surface protective layer may further contain a solvent and additives for improving the functionality of the final product, such as an antibacterial agent and an antifungal agent. The coating liquid for the surface protective layer may further contain other additives such as an ultraviolet absorber and a light stabilizer. Examples of ultraviolet absorbers that can be used include benzotriazoles, benzoates, benzophenones, and triazines. Examples of light stabilizers that can be used include hindered amines. Note that, according to the method described herein, a surface protective layer 5 having a low gloss can be formed without a gloss adjuster (matt additive).

[0082] In the third irradiation step described below, when the entire coating film made of the coating liquid for surface protective layer is cured by ultraviolet irradiation, it is preferable that the coating liquid for surface protective layer further contains a photoinitiator. The photoinitiator is not particularly limited, but examples thereof include benzophenone-based, acetophenone-based, benzoin ether-based, and thioxanthone-based photoinitiators.

[0083] The coating liquid for the surface protective layer is preferably stirred sufficiently to uniformly disperse the particles in the dispersion medium before being applied to one surface of the base layer 2. When the particles are uniformly dispersed in the dispersion medium, wrinkles are more likely to be uniformly formed on the surface of the surface protective layer 5.

[0084] Next, a coating film made of the surface protective layer coating liquid is formed by applying the surface protective layer coating liquid to one surface of the raw sheet layer 2. This 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, knife coating, microgravure coating, and die coating.

[0085] After forming a coating film made from the coating liquid for the surface protective layer, a first irradiation step is carried out. In the first irradiation step, the coating film is irradiated with light having a wavelength of approximately 200 nm or more and 400 nm or less (hereinafter referred to as first radiation). This semi-cures the coating film. By semi-curing the coating film through the first irradiation step, it is possible to uniformly generate a wrinkled uneven structure (texture) that will be generated in the second irradiation step described below. Alternatively, by appropriately setting the irradiation conditions for the first irradiation step, it is possible to adjust the uneven structure, particularly the depth of the uneven structure.

[0086] The light source used in the first irradiation step can be selected from, for example, a high-pressure mercury lamp, a metal halide lamp, and a single-wavelength LED lamp emitting light with a wavelength of 200 nm or more and 400 nm or less.

[0087] The integrated light amount in the first irradiation step is 2 mJ / cm ２ More than 100mJ / cm ２ It is preferable that the dose is 10 mJ / cm or less. ２ More than 80mJ / cm ２ More preferably, it is 20 mJ / cm or less. ２ 60mJ / cm or more ２ It is more preferable that the cumulative light amount is set to the following: If the cumulative light amount is small, the effect of the first irradiation step described above will not be achieved; if the cumulative light amount is large, the coating film will be completely cured, and wrinkles will not be formed in the subsequent second irradiation step.

[0088] After the first irradiation step is completed, the second irradiation step is carried out. In the second irradiation step, the coating film is irradiated with light having a wavelength of 200 nm or less (hereinafter referred to as second radiation). The ionizing radiation curable resin contained in the coating liquid for the surface protective layer has a large absorption coefficient for the second radiation. Therefore, the second radiation incident on the coating film can only reach a position several tens to several hundreds of nm away from the outermost surface. Therefore, in the second irradiation step, the crosslinking reaction proceeds in the surface region of the coating film, forming an extremely thin cured film, while the crosslinking reaction does not proceed in other regions, leaving the coating film semi-cured.

[0089] The coating film after the second irradiation step has wrinkles on its surface corresponding to the ridge portions 5 B. The present inventors believe that the reason why wrinkles are formed on the coating film surface by the second irradiation step is as follows.

[0090] As described above, the second radiation can only reach a position tens to hundreds of nanometers away from the outermost surface of the coating film. That is, the crosslinking reaction of the ionizing radiation-curable resin caused by irradiation with the second radiation occurs only on the surface of the coating film, and regions at a distance of more than tens to hundreds of nanometers from the outermost surface are partially uncured, resulting in the presence of highly fluid molecules. These highly fluid molecules swell the cured film, thereby increasing its volume. The increase in volume in the in-plane direction generates in-plane compressive stress, causing the cured film to buckle, resulting in wrinkles on the surface of the coating film.

[0091] The second radiation can be extracted from excimer VUV (Vacuum Ultra Violet) light. Excimer VUV light can be generated from a lamp using a rare gas or a rare gas halide compound. When high-energy electrons are externally applied to a lamp filled with a rare gas or a rare gas halide compound, a large number of discharge plasmas (dielectric barrier discharges) are generated. This plasma discharge excites atoms of the discharge gas (rare gas), which momentarily transition to an excimer state. When returning from this excimer state to the ground state, light is emitted in a wavelength range specific to that excimer.

[0092] The gas used in the excimer lamp may be any conventional gas that emits light of 200 nm or less. Examples of the gas include rare gases such as Xe, Ar, and Kr, and mixtures of rare gases such as ArBr and ArF with halogen gases. The wavelength (center wavelength) of excimer lamps varies depending on the gas, and examples include wavelengths of approximately 172 nm (Xe), approximately 126 nm (Ar), approximately 146 nm (Kr), approximately 165 nm (ArBr), and approximately 193 nm (ArF).

[0093] Considering the magnitude of photon energy and the difference between wavelength and bond energy of organic matter, it is preferable to use a xenon lamp that emits excimer light with a central wavelength of 172 nm as the light source. Also, considering the cost of maintaining the equipment and the availability of materials, it is preferable to use a xenon lamp as the light source.

[0094] The second irradiation step is carried out in an atmosphere with a low oxygen concentration. Oxygen has a high absorption coefficient for light of 200 nm or less. Therefore, the second irradiation step is preferably carried out in, for example, a nitrogen gas atmosphere. The oxygen concentration in the gas phase in the second irradiation step, i.e., the residual oxygen concentration in the reaction atmosphere, is preferably 2000 ppm or less, and more preferably 1000 ppm or less.

[0095] Furthermore, oxygen in the atmosphere inhibits radical polymerization. Therefore, the residual oxygen concentration in the reaction atmosphere affects the formation of wrinkles on the coating surface. Therefore, changing the residual oxygen concentration in the reaction atmosphere can also change the surface properties of the surface protective layer 5.

[0096] The cumulative amount of the second radiation is 0.5 mJ / cm ２ More than 200mJ / cm ２ It is preferable that the dose is 1 mJ / cm or less. ２ More than 100mJ / cm ２ More preferably, it is 3 mJ / cm or less. ２ More than 50mJ / cm ２ More preferably, it is 5 mJ / cm or less. ２ 30mJ / cm or more ２It is most preferable to set the integrated light dose as follows: If the integrated light dose is small, the expansion of the cured film in the in-plane direction will be small; if the integrated light dose is large, the surface condition of the coating film will deteriorate.

[0097] After the second irradiation step, the third irradiation step is carried out. In the third irradiation step, the coating film is irradiated with a third radiation to cure the entire coating film. In this way, the surface protective layer 5 is obtained.

[0098] The third radiation is ionizing radiation such as an electron beam, or ultraviolet radiation having a longer wavelength than the first radiation.

[0099] The cumulative light amount of the third radiation is 10 mJ / cm ２ More than 500mJ / cm ２ It is preferable that the dose is 50 mJ / cm or less. ２ More than 400mJ / cm ２ More preferably, it is 100 mJ / cm or less. ２ More than 300mJ / cm ２ It is more preferable that:

[0100] The decorative sheet 1 can be produced by, for example, the method described above. The decorative sheet 1 may also be produced by other methods. For example, a plate may be formed using the method described above for the surface protective layer 5, and the surface protective layer 5 having a relief structure on its surface may be formed by transfer using this plate.

[0101] The inventors believe that the main reason why the above method can produce a surface protection layer 5 having surface properties characterized by the above-mentioned parameters is as follows. As described above, by appropriately setting the irradiation conditions of the first radiation, the periodicity of the concave-convex structure and the depth of the concave-convex structure (i.e., the height-wise size of the convex and concave portions) can be adjusted. For example, increasing the integrated light dose of the first radiation increases the degree of semi-curing of the semi-cured coating film obtained by irradiation with the first radiation. Subsequently, irradiation with the second radiation cures only the surface layer of the coating film, causing the cured film to buckle and form the concave-convex structure. The higher the degree of semi-curing of the coating film obtained by irradiation with the first radiation, the higher the bending rigidity of the surface layer (cured layer) of the coating film and the higher the viscosity of the lower layer (semi-cured layer) located below the surface layer (cured layer) during irradiation with the second radiation. The higher the bending rigidity of the surface layer, the larger the periodicity of the concave-convex structure formed. The higher the viscosity of the lower layer, the more difficult it is to increase the volume of the surface layer, resulting in a shallower depth of the concave-convex structure. Thus, it is believed that the integrated light dose of the first radiation affects the periodicity of the unevenness of the uneven structure and the depth of the uneven structure. Furthermore, it is believed that the thickness of the coating film formed from the coating liquid for surface protective layer also affects the depth of the uneven structure. A thicker coating film formed from the coating liquid for surface protective layer is more likely to have a deeper uneven structure. Furthermore, it is believed that the integrated light dose of the second radiation also affects the degree of expansion of the cured film in the thickness direction and in-plane direction, thereby affecting the periodicity of the unevenness of the uneven structure and the depth of the uneven structure. Increasing the integrated light dose of the second radiation tends to reduce the periodicity of the unevenness and deepen the depth of the uneven structure. Furthermore, it is believed that the oxygen concentration in the gas phase in the second irradiation step affects the shape of the convex portions of the uneven structure. The effect of a low oxygen concentration in the gas phase in the second irradiation step on the crosslinking reaction is greater closer to the surface of the coating film, so the crosslinking reaction is more likely to be promoted at the apex of the convex portions in the second irradiation step. Therefore, curing proceeds more easily at the apex of the convex portions than in other parts of the convex portions. Furthermore, by combining the irradiation with the first radiation with the irradiation with the second radiation, the coating film is already semi-cured at the start of the second irradiation step, and therefore, the curing progresses particularly quickly at the tops of the convex portions, and after the curing has progressed, the cured film is less likely to expand in the in-plane direction.As a result, the slope near the top of the convex portion tends to be steeper than the other portions of the convex portion.

[0102] <3> Effects The decorative sheet 1 described with reference to Figures 1 to 3 has the surface properties of the surface protective layer 5 described above. When a user presses their skin against the surface of the surface protective layer 5 and slides their skin over the surface, such as when they press their finger against the surface of the surface protective layer 5 and slide their finger over the surface, the decorative sheet 1 gives the user the "warm feel of wood." This decorative sheet 1 not only has low gloss and excellent design, but also has an excellent feel. This feel will be explained below.

[0103] In the decorative sheet 1 described above, the load length ratio Rmr (10%) of the uneven structure of the surface protective layer 5 is within the above-mentioned range. Therefore, when a user lightly touches the uneven structure with their finger, the contact area between the finger and the protrusions is relatively small. Furthermore, when the decorative sheet 1 is placed at room temperature, the surface temperature of the decorative sheet 1 is usually lower than the user's body temperature. Therefore, when a user touches the decorative sheet 1 with their finger, the user's heat is not easily transferred to the decorative sheet 1, and the user can feel a warmth to the touch.

[0104] Furthermore, the decorative sheet 1 described above has a root-mean-square slope Rdq of the uneven structure of the surface protective layer 5 that falls within the above-mentioned range. The decorative sheet 1 described above also has a root-mean-square height Rq of the uneven structure of the surface protective layer 5 that falls within the above-mentioned range. The convex portions that form this uneven structure are moderately steep and have a moderate size in the height direction. Therefore, when a user runs their finger over the surface of the surface protective layer 5, the decorative sheet 1 stimulates the user's finger, giving the user a feeling of moderate roughness, i.e., a wood-like feel.

[0105] In this way, when the load length ratio Rmr (10%) of the uneven structure is within the above-mentioned range, the decorative sheet 1 gives the user a warm tactile sensation, and when the root-mean-square slope Rdq and root-mean-square height Rq of the uneven structure are within the above-mentioned range, the decorative sheet 1 gives the user a wood-like tactile sensation. Therefore, the decorative sheet 1 gives the user a tactile sensation that combines these two tactile sensations, i.e., a "warm wood tactile sensation."

[0106] In addition, when the frequency of unevenness in the uneven structure is approximately the same, an uneven structure in which the shape of the apexes of the convex portions is steep will have a smaller load length ratio Rmr (10%) than an uneven structure in which the shape of the apexes of the convex portions is gentle. In this case, it is possible to distinguish between the two using only the parameter of the load length ratio Rmr (10%). On the other hand, an uneven structure in which the shape of the apexes of the convex portions is steep and the frequency of unevenness is high may have the same load length ratio Rmr (10%) as an uneven structure in which the shape of the apexes of the convex portions is gentle and the frequency of unevenness is low. In this case, it is not possible to distinguish between the two using only the parameter of the load length ratio Rmr (10%). In other words, it is not possible to express that the convex portions of the uneven structure are moderately steep and have a moderate size in the height direction (i.e., provide a wood-like feel to the user) using only the parameter of the load length ratio Rmr (10%). For this reason, it is appropriate to use the load length ratio Rmr (10%) in combination with the root mean square slope Rdq and root mean square height Rq as parameters that express the "warm feel of wood."

[0107] Because the surface protective layer 5 of the decorative sheet 1 has the above-described surface properties, it can achieve a low gloss even without containing a gloss adjuster (matt additive). Because gloss adjusters reduce the oil repellency of layers formed from resin materials, surface protective layers 5 containing gloss adjusters are prone to fingerprints. Surface protective layers 5 that do not contain gloss adjusters are less likely to absorb oil and therefore less likely to be marked with fingerprints. Furthermore, surface protective layers 5 with excellent oil repellency are less likely to develop oil stains or adsorb contaminants. Furthermore, surface protective layers 5 that do not contain gloss adjusters do not lose gloss adjuster particles when their surface is scratched, and therefore decorative sheets 1 containing such surface protective layers 5 are less likely to develop gloss changes or scratches.

[0108] Furthermore, as described above, the surface protective layer 5 can achieve a low gloss. In this case, it is possible to reduce the reflection of external light on the surface of the surface protective layer 5. Therefore, for example, if the design layer 3 has a wood grain pattern, the wood grain pattern can be visually recognized as a clear pattern. Note that although the above parameters are related to low gloss, parameters other than the above parameters are also involved in achieving low gloss. For this reason, a low-gloss decorative sheet does not necessarily satisfy the requirements of the above parameters.

[0109] Furthermore, the reason why the surface protection layer 5 having the above-described surface properties can be obtained by the above-described method is believed to be due to the following reasons in addition to those explained above.

[0110] The oxygen in the gas phase in the second irradiation step not only absorbs short-wavelength ultraviolet light but also inhibits radical polymerization. The effect of oxygen contained in the gas phase on radical polymerization is greatest in the portion of the coating film made of an ionizing radiation-curable resin adjacent to the gas phase, and decreases as the distance from the coating film surface increases. Therefore, by changing the oxygen concentration in the gas phase in the second irradiation step, it is possible to change the relationship between the distance from the coating film surface and the progress of the crosslinking reaction.

[0111] If this relationship changes, the thickness of the cured film formed on the surface of the coating film by the second irradiation step and the degree of expansion of the cured film in the in-plane direction according to the progress of the crosslinking reaction will change. As described above, the degree of expansion of the cured film in the thickness direction and in the in-plane direction is also affected by the integrated light amount in the first and second irradiation steps. Furthermore, the degree of expansion of the cured film in the thickness direction and in the in-plane direction affects the surface properties of the surface protective layer. Furthermore, the particle size and amount of particles in the coating film, as well as the thickness of the coating film, also affect the formation of wrinkles.

[0112] Therefore, for example, by appropriately setting the composition of the ionizing radiation curable resin, the particle size and amount of added particles, the thickness of the coating film, the oxygen concentration in the gas phase in the second irradiation step, and the integrated light amount in the first and second irradiation steps, it is possible to obtain a surface protection layer having the desired surface properties.

[0113] The following describes examples of the present invention.

[0114] 1 to 3 was produced by the following method. In this example, the transparent resin layer 4, primer layer 6, adhesive layer 7, and hiding layer 8 were omitted.

[0115] First, the basis weight is 50 g / m ２ An impregnated paper (GFR-506, manufactured by Kojin Co., Ltd.) was prepared as the raw fabric layer 2. A design layer 3 was formed on one surface of the raw fabric layer 2 using an oil-based nitrocellulose resin gravure printing ink (PCNT (PCRNT) various colors, manufactured by Toyo Ink Co., Ltd.). The design pattern of the design layer was a wood grain pattern.

[0116] Next, a coating liquid for a surface protective layer was prepared. The following ionizing radiation curable resin was used as the coating liquid for the surface protective layer. Ionizing radiation curable resin Type: Trimethylolpropane EO-modified triacrylate (EO 15 moles added) Product name: SR9035 (manufactured by Sartomer) Blend: 100 parts by mass

[0117] Next, the coating liquid for the surface protective layer was stirred. Stirring was performed as follows. First, the coating liquid for the surface protective layer was placed in a stirring vessel. The stirring vessel used was a ZT-20 (manufactured by Satake Multinics Co., Ltd.). A Satake Multi A Mixer AT14-VPR-0.09BI (manufactured by Satake Multinics Co., Ltd.) was used for stirring. The stirring method was central stirring. The power for stirring was 0.75 kW, and the stirring time was 5 minutes.

[0118] Next, a coating liquid for a surface protective layer was applied onto the design layer 3. A coating film made of the coating liquid for a surface protective layer was formed to a thickness of 4.3 μm.

[0119] Thereafter, a first irradiation step was carried out. Specifically, a high-pressure mercury lamp was used to irradiate ultraviolet light having a dominant wavelength of 365 nm onto the surface of the coating film made of the coating liquid for surface protective layer in the atmosphere, with the ultraviolet light being irradiated at an integrated light intensity of 60 mJ / cm. ２ This caused the coating film to be semi-cured.

[0120] Thereafter, a second irradiation step was carried out. Specifically, under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 200 ppm, ultraviolet light having a wavelength of 172 nm was irradiated onto the surface of the coating film made of the coating liquid for surface protective layer using a Xe excimer lamp at an integrated light intensity of 60 mJ / cm. ２ This caused wrinkles to form on the surface of the coating film.

[0121] Subsequently, the third irradiation step was carried out. Specifically, the coating film was irradiated with ionizing radiation to cure the entire film, thereby forming a surface protective layer 5. In this manner, a decorative sheet 1 was obtained.

[0122] <Example 2> Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions: In this example, the following particles were added to the coating liquid for surface protective layer, and the particle blend amount was 2 parts by mass per 100 parts by mass of ionizing radiation curable resin: Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend amount: 2 parts by mass Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 5.8 μm.

[0123] <Example 3> Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions: In this example, the same particles as those used in Example 2 were added to the coating liquid for surface protective layer, with the particle blend amount being 3 parts by mass per 100 parts by mass of ionizing radiation curable resin; and a coating film made of the coating liquid for surface protective layer was formed to a thickness of 4.1 μm.

[0124] <Example 4> Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions: In this example, the same particles as those used in Example 2 were added to the coating liquid for surface protective layer, and the amount of particles was 4 parts by mass per 100 parts by mass of ionizing radiation curable resin. Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 5.9 μm.

[0125] <Example 5> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the same particles as those used in Example 2 were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin. Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 4.1 μm.

[0126] Example 6 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. In this example, the same particles as those used in Example 2 were added to the surface protective layer coating liquid, with the particle amount being 5 parts by mass per 100 parts by mass of the ionizing radiation curable resin. The stirring power for the surface protective layer coating liquid was 0.3 kW, and the stirring time was 5 minutes. A coating film made of the surface protective layer coating liquid was then formed to a thickness of 4.1 μm.

[0127] <Example 7> Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions: In this example, the same particles as those used in Example 2 were added to the coating liquid for surface protective layer, with the particle amount being 9.7 parts by mass per 100 parts by mass of ionizing radiation curable resin. A coating film made of the coating liquid for surface protective layer was then formed to a thickness of 5.3 μm.

[0128] <Example 8> Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions: In this example, the same particles as those used in Example 2 were added to the coating liquid for surface protective layer, and the amount of particles was 10.3 parts by mass per 100 parts by mass of ionizing radiation curable resin. Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 5 μm.

[0129] Example 9 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions: In this example, the same particles as used in Example 2 were added to the coating liquid for surface protective layer, and the amount of particles was 11.7 parts by mass per 100 parts by mass of ionizing radiation curable resin. A coating film made of the coating liquid for surface protective layer was then formed to a thickness of 5.3 μm.

[0130] <Comparative Example 1> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the same particles as those used in Example 2 were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin. Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 1.4 μm.

[0131] <Comparative Example 2> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the same particles as used in Example 2 were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin. Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 1.8 μm.

[0132] <Example 10> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the same particles as used in Example 2 were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin. Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 2.3 μm.

[0133] <Example 11> Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions: In this example, the same particles as used in Example 2 were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin. Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 2.5 μm.

[0134] <Example 12> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the same particles as used in Example 2 were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin. Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 9.2 μm.

[0135] Comparative Example 3 Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the same particles as those used in Example 2 were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin. Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 12.3 μm.

[0136] Comparative Example 4 Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the same particles as those used in Example 2 were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin. Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 15.2 μm.

[0137] <Example 13> Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions: In this example, the following particles were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin: Particles Product name: Sylysia 310P (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 2 μm Blend: 5 parts by mass Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 4.8 μm.

[0138] Example 14 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions: In this example, the following particles were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin. Particles Product name: Sylysia 420 (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 3 μm Blend: 5 parts by mass Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 4.6 μm.

[0139] Example 15 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions: In this example, the following particles were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin: Particles Product name: Sylysia 430 (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 4 μm Blend: 5 parts by mass Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 5.1 μm.

[0140] Example 16 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions: In this example, the following particles were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin. Particles Product name: Sylysia 450 (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 8 μm Blend: 5 parts by mass Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 4.9 μm.

[0141] Example 17 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions: In this example, the following particles were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin: Particles Product name: Sylysia 882 (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 10 μm Blend: 5 parts by mass Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 5.5 μm.

[0142] Comparative Example 5 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions: In this example, the following particles were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin. Particles Product name: Sylysia 780 (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 11 μm Blend: 5 parts by mass Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 4.8 μm.

[0143] Comparative Example 6 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following particles were added to the coating liquid for surface protective layer, and the amount of particles was 5 parts by mass per 100 parts by mass of ionizing radiation curable resin. Particles Product name: Sicastar 43-00-154 (manufactured by Corefront Co., Ltd.) Particle size: 14 μm Blend: 5 parts by mass Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 5.3 μm.

[0144] Comparative Example 7 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following ionizing radiation curable resin was used. Ionizing radiation curable resin Type: Trimethylolpropane triacrylate Product name: NK Ester A-TMPT (manufactured by Shin-Nakamura Chemical Co., Ltd.) Furthermore, the same particles as those used in Example 2 were added to the coating liquid for the surface protective layer, with the amount of particles being 5 parts by mass per 100 parts by mass of the ionizing radiation curable resin. Then, a coating film made of the coating liquid for the surface protective layer was formed to a thickness of 5 μm.

[0145] Comparative Example 8 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following ionizing radiation curable resin was used. Ionizing radiation curable resin Type: Trimethylolpropane EO-modified triacrylate (3 EO moles added) Product name: Miramer M3130 (manufactured by Miwon Co., Ltd.) Furthermore, the same particles as used in Example 2 were added to the coating liquid for the surface protective layer, with the particle blend amount being 5 parts by mass per 100 parts by mass of the ionizing radiation curable resin. Then, a coating film made of the coating liquid for the surface protective layer was formed to a thickness of 4.9 μm.

[0146] Comparative Example 9 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following ionizing radiation curable resin was used. Ionizing radiation curable resin Type: Trimethylolpropane EO-modified triacrylate (6 moles of EO added) Product name: Miramer M3160 (manufactured by Miwon Co., Ltd.) Furthermore, the same particles as used in Example 2 were added to the coating liquid for the surface protective layer, with the particle blend amount being 5 parts by mass per 100 parts by mass of the ionizing radiation curable resin. Then, a coating film made of the coating liquid for the surface protective layer was formed to a thickness of 4.9 μm.

[0147] Comparative Example 10 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following ionizing radiation curable resin was used. Ionizing radiation curable resin Type: Trimethylolpropane EO-modified triacrylate (9 moles of EO added) Product name: SR502 (manufactured by Sartomer) Furthermore, the same particles as used in Example 2 were added to the coating liquid for the surface protective layer, with the particle blend amount being 5 parts by mass per 100 parts by mass of the ionizing radiation curable resin. Then, a coating film made of the coating liquid for the surface protective layer was formed to a thickness of 5.3 μm.

[0148] <Example 18> Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following ionizing radiation curable resin was used. Ionizing radiation curable resin Type: Trimethylolpropane EO-modified triacrylate (20 moles of EO added) Product name: NK Ester AT-20E (manufactured by Shin-Nakamura Chemical Co., Ltd.) Furthermore, the same particles as used in Example 2 were added to the coating liquid for the surface protective layer, with the amount of particles being 5 parts by mass per 100 parts by mass of the ionizing radiation curable resin. Then, a coating film made from the coating liquid for the surface protective layer was formed to a thickness of 6.1 μm.

[0149] <Example 19> Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following ionizing radiation curable resin was used. Ionizing radiation curable resin Type: Ethoxylated pentaerythritol tetraacrylate (20 moles of EO added) Furthermore, the same particles as used in Example 2 were added to the coating liquid for surface protective layer, with the particle amount being 5 parts by mass per 100 parts by mass of the ionizing radiation curable resin. Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 4.1 μm.

[0150] Example 20 First, a shaping mold was prepared. The shaping mold was prepared by the same method as the manufacturing method of the decorative sheet according to Example 19, except for the following points. That is, in preparing the shaping mold, a coating film made of the surface protective layer coating liquid was formed to a thickness of 3.9 μm.

[0151] Next, using this mold, the surface shape of the mold was transferred as a template to the surface protective layer on the decorative sheet. The transfer was carried out by the following method.

[0152] A UV-curable polydimethylsiloxane liquid (agent A: X-34-4184A, agent B: X-34-4184B, manufactured by Shin-Etsu Chemical Co., Ltd.) was diluted with decamethylcyclopentasiloxane (KF-995, manufactured by Shin-Etsu Chemical Co., Ltd.) and mixed so that the weight ratios of agent A to agent B to diluent were 1:1:7 and 1:1:8, respectively, to prepare polydimethylsiloxane mixed liquids. Next, the polydimethylsiloxane liquid was applied to the above-mentioned mold for shaping at a rate of 10 g / m. ２ A coating film was formed by applying the mixture so that the thickness was 15 μm. A PET film having a thickness of 15 μm was then pressed onto the coating film. After the polydimethylsiloxane mixture was cured by UV irradiation, the mold for shaping was peeled off from the UV-cured film of the polydimethylsiloxane mixture. This UV-cured film of the polydimethylsiloxane mixture is called the primary transfer film.

[0153] Furthermore, the textured surface of the primary transfer film was subjected to UV ozone treatment, followed by surface modification with perfluorodecyltriethoxysilane by vapor deposition, and the reaction was completed in an oven at 100°C. The polydimethylsiloxane mixture was then applied to the primary transfer film in the same amount as above, and a 15 μm thick PET film was pressed against the coating. The polydimethylsiloxane mixture was cured by UV irradiation, resulting in what is called a secondary transfer film. This secondary transfer film was then peeled off from the primary transfer film to form a mold for forming the textured structure of the surface protection layer.

[0154] Meanwhile, the surface protective layer coating liquid used in Example 19 was applied to the pattern layer 3 using the same procedure as in Example 19 to prepare a coating film made of the surface protective layer coating liquid. The above-mentioned mold was pressed onto the prepared coating film, and then the ionizing radiation irradiation similar to the ionizing radiation irradiation performed in the third irradiation step of Example 19 was repeated twice from above the PET film, thereby curing the coating film. The secondary transfer film was then peeled off to form a concave-convex structure in the surface protective layer. In this manner, a decorative sheet was obtained.

[0155] <Example 21> Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following ionizing radiation curable resin was used. Ionizing radiation curable resin Type: Ethoxylated pentaerythritol tetraacrylate (35 moles of EO added) Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Co., Ltd.) Furthermore, the same particles as used in Example 2 were added to the coating liquid for the surface protective layer, with the amount of particles being 5 parts by mass per 100 parts by mass of the ionizing radiation curable resin. Then, a coating film made from the coating liquid for the surface protective layer was formed to a thickness of 5.8 μm.

[0156] Comparative Example 11 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following ionizing radiation curable resin was used. Ionizing radiation curable resin Type: Trimethylolpropane EO-modified triacrylate (6 moles of EO added) Product name: Miramer M3160 (manufactured by Miwon Co., Ltd.) Furthermore, the same particles as used in Example 2 were added to the coating liquid for surface protective layer, with the particle blend amount being 15 parts by mass per 100 parts by mass of the ionizing radiation curable resin. A coating film made of the coating liquid for surface protective layer was then formed to a thickness of 5.2 μm, and the coating film was then cured only by the third irradiation step, without performing the first and second irradiation steps.

[0157] Comparative Example 12 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following ionizing radiation curable resin was used. Ionizing radiation curable resin Type: ethylene glycol diacrylate (9 moles of EO added) Product name: Light Acrylate 9EG-A (manufactured by Kyoeisha Chemical Co., Ltd.) Furthermore, the same particles as used in Example 2 were added to the coating liquid for the surface protective layer, with the amount of particles being 5 parts by mass per 100 parts by mass of the ionizing radiation curable resin. Then, a coating film made of the coating liquid for the surface protective layer was formed to a thickness of 5.7 μm.

[0158] <Comparative Example 13> Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following ionizing radiation curable resin was used. - Ionizing radiation curable resin Type: Ethoxylated dipentaerythritol hexaacrylate (12 moles of EO added) Product name: NK Ester A-DPH-12E (manufactured by Shin-Nakamura Chemical Co., Ltd.) Furthermore, the same particles as used in Example 2 were added to the coating liquid for the surface protective layer, with the amount of particles being 5 parts by mass per 100 parts by mass of the ionizing radiation curable resin. Then, a coating film made of the coating liquid for the surface protective layer was formed to a thickness of 6.2 μm.

[0159] Comparative Example 14 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following ionizing radiation curable resin was used. Ionizing radiation curable resin Type: pentaerythritol tetraacrylate Product name: NK Ester A-TMMT (manufactured by Shin-Nakamura Chemical Co., Ltd.) Furthermore, the same particles as used in Example 2 were added to the coating liquid for the surface protective layer, with the amount of particles being 5 parts by mass per 100 parts by mass of the ionizing radiation curable resin. Then, a coating film made of the coating liquid for the surface protective layer was formed to a thickness of 6.8 μm.

[0160] <Evaluation> Each of the decorative sheets described above was subjected to the following evaluations.

[0161] (1) Thickness of the Surface Protective Layer The thickness of the surface protective layer was measured as follows. After embedding the decorative sheet 1 in a resin such as a cold-curing epoxy resin or a UV-curable resin and allowing it to fully harden, the decorative sheet 1 was cut to reveal its cross section and mechanically polished to obtain a measurement surface. The thickness of the surface protective layer was then measured using a SIGMA 500 scanning electron microscope manufactured by Carl Zeiss Microscopy. Measurements were performed at 25 random points, and the average measurement value for the 25 points was defined as the "thickness t of the surface protective layer." The measurement conditions were an acceleration voltage of 0.5 keV (low acceleration voltage), an SE2 mode, and a magnification of 2000x. No sputtering was performed on the measurement sample. The "thickness t of the surface protective layer" was equal to the thickness of the coating film made from the surface protective layer coating liquid.

[0162] (2) Glossiness The glossiness was measured at 60 degrees using a Rhopoint IQ (manufactured by Konica Minolta). The 60-degree glossiness was measured at five arbitrary points with no overlapping measurement areas, and the average value was used. The "60-degree glossiness value" in Tables 1 to 5 below represents this 60-degree glossiness.

[0163] (3) Skin Feel Skin feel was evaluated using the following method. First, preliminary preparations were made to ensure that the evaluation criteria for surface roughness were consistent among the evaluators. Specifically, three standard test pieces with different surface properties (i.e., a test piece with an Rdq of less than 0.15, a test piece with an Rdq of 0.15 to 0.4, and a test piece with an Rdq of more than 0.4) were prepared. Next, five evaluators were blindfolded and asked to slide their fingers over the surface of the standard test piece while pressing it with their fingers. They then classified the surface roughness into the following three groups. Group 1: The evaluators felt little roughness, resulting in a feel similar to that of a flat plastic plate. Group 2: The evaluators felt a moderate amount of roughness, resulting in a feel similar to that of wood. Group 3: The evaluators felt a strong roughness, resulting in a feel similar to that of a file.

[0164] The above procedure was repeated until the evaluations by each evaluator coincided three or more times in succession and the evaluation results between the evaluators coincided three times in succession.

[0165] Next, for the tactile sensation related to temperature, a preliminary preparation was conducted in a similar manner to the tactile sensation related to surface roughness to ensure that the evaluation criteria were consistent among the evaluators. Specifically, three standard test pieces with different surface properties were prepared (i.e., a test piece with an Rmr (10%) in the range of 0.05 to 0.35, a test piece with an Rmr (10%) greater than 0.35 and less than 0.4, and a test piece with an Rmr (10%) in the range of 0.4 to 0.7). Next, five evaluators were blindfolded and asked to slide their fingers over the surface of the standard test piece while pressing it with their fingers, and then to classify the tactile sensation related to temperature into the following three groups: Group a: A warm tactile sensation was obtained; Group b: A lukewarm tactile sensation was obtained; and Group c: A cold tactile sensation was obtained.

[0166] The above procedure was repeated until the evaluations by each evaluator coincided three or more times in succession and the evaluation results between the evaluators coincided three times in succession.

[0167] Next, for each of the decorative sheets produced in the above examples and comparative examples, each of the evaluators was blindfolded and asked to slide their fingers over the surface of the surface protective layer while pressing it with their fingers, and then to classify the tactile sensations related to surface roughness and temperature sensation into the three groups. This procedure was repeated until the evaluations by each evaluator were consistent three or more times in a row, and the evaluation results between the evaluators were consistent three or more times in a row. From these results, the skin feel was evaluated according to the following criteria: A (warm wood feel): When the tactile sensation related to surface roughness was classified into Group 2 and the tactile sensation related to temperature sensation was classified into Group a; B (tactile sensations other than the warm wood feel): When the tactile sensation related to surface roughness was classified into a group other than Group 2, or when the tactile sensation related to temperature sensation was classified into a group other than Group a.

[0168] (4) Fingerprint Resistance To evaluate fingerprint resistance, a fingerprint wiping property evaluation was performed. Specifically, first, the 60-degree glossiness of the surface of each decorative sheet was measured, and this 60-degree glossiness was defined as the initial glossiness. Next, a fingerprint resistance evaluation liquid was applied to the surface protective layer, and the fingerprint resistance evaluation liquid applied to the decorative sheet surface was wiped off. Here, a higher fatty acid was used as the fingerprint resistance evaluation liquid. Thereafter, the 60-degree glossiness of the portion from which the fingerprint resistance evaluation liquid had been wiped off was measured, and this 60-degree glossiness was defined as the glossiness after wiping.

[0169] The fingerprint wiping rate was calculated using the following formula: Fingerprint wiping rate (%) = (glossiness after wiping / initial glossiness) x 100 The evaluation criteria were as follows: AA: 70% or more and less than 250% A: 50% or more and less than 70%, or 250% or more and less than 300% B: Less than 50%, or 300% or more.

[0170] (5) Stain Resistance To evaluate stain resistance, the Stain A test specified in the Japanese Agricultural Standards (JAS) was carried out. That is, 10 mm wide lines were drawn on the surface protective layer of each decorative sheet using blue ink, black quick-drying ink, and red crayon, and the sheets were left for 4 hours. Thereafter, the blue ink, black quick-drying ink, and red crayon lines were wiped off with a cloth soaked in ethanol.

[0171] The evaluation criteria were as follows: AA: Lines of each color could be easily wiped off. A: Part of the lines of each color could be wiped off, but some stains remained. B: Lines of each color could not be wiped off.

[0172] (6) Scratch Resistance Each decorative sheet was attached to wood substrate B using a urethane adhesive. A steel wool rubbing test was then conducted to evaluate scratch resistance. Specifically, the decorative sheet was rubbed back and forth 20 times with steel wool while applying a load of 100 g, and scratches and changes in gloss on the surface of the decorative sheet were visually confirmed.

[0173] The evaluation criteria were as follows: AA: No scratches or changes in gloss occurred on the surface. A: Minor scratches or changes in gloss occurred on the surface. B: Significant scratches or changes in gloss occurred on the surface.

[0174] (7) Processability The resulting decorative sheet was attached to wood substrate B using a urethane adhesive, with the surface of the base layer (i.e., the back surface of the decorative sheet) facing the wood substrate B. Thereafter, a V-shaped groove was made up to the boundary where the wood substrate B and the decorative sheet were attached, so as not to scratch the decorative sheet.

[0175] Next, wood substrate B was bent 90 degrees along the V-shaped groove so that the surface of the decorative sheet facing the surface protective layer (i.e., the surface of the decorative sheet) formed a mountain fold. The bent portion of the surface of the decorative sheet was observed using an optical microscope to determine whether whitening or cracks had occurred, and bending processability was evaluated.

[0176] The evaluation criteria were as follows: AA: No whitening or cracks were observed. A: Whitening was observed in some areas. B: Whitening was observed over the entire surface, or cracks were observed in some areas.

[0177] (8) Load length ratio Rmr (10%), root mean square slope Rdq, and root mean square height Rq The load length ratio Rmr (10%), root mean square slope Rdq, and root mean square height Rq were determined as described in the detailed description section. The roughness curves used to calculate Rmr (10%), Rdq, and Rq were measured using a small surface roughness measuring instrument SJ-210 (manufactured by Mitutoyo Corporation) (a contact-type surface roughness meter), and measurements were taken at five locations so as not to overlap, and the average value was used. The internal settings were as follows: roughness standard "JIS 2001," evaluation curve "R curve," filter "GAUSS," cutoff values ​​λs "8 μm," λc "2.5 mm," number of sections "5," leading / trailing "OFF," measurement speed "0.5 mm / s," and measurement range "AUTO." In addition, the cut level standard for calculating the load length ratio was set to "peak," and the cut level was set to include at least "10%."

[0178] The evaluation results are shown in Tables 1 to 5. In Tables 1 to 5, if the evaluation result for skin feel is A (the feel of warm wood), this is indicated by entering the letter A in the "skin feel" column, and if the evaluation result for skin feel is B (a feel other than the feel of warm wood), this is indicated by entering the letter B in the "skin feel" column. If, in the manufacturing process of the decorative sheet 1, the same stirring method as the stirring method for the decorative sheet 1 of Example 1 was used, this is indicated by entering the letter A in the "stirring conditions" column, and if the same stirring method as the stirring method for the decorative sheet 1 of Example 6 was used, this is indicated by entering the letter B in the "stirring conditions" column. "Cutting level (μm)" indicates the cut level when the load length ratio Rmr (10%) was determined.

[0179]

[0180]

[0181]

[0182]

[0183]

[0184] As shown in Tables 1 to 5, the decorative sheets according to Examples 1 to 21 gave the evaluators a "warm wooden feel." Furthermore, the decorative sheets according to Examples 1 to 21 had low gloss. Furthermore, the decorative sheets according to Examples 1 to 7 and 10 to 17 were excellent in all of the evaluation results for fingerprint resistance, stain resistance, scratch resistance, and processability. On the other hand, the decorative sheets according to Comparative Examples 1 to 14 did not give the evaluators a "warm wooden feel."

[0185] 1...decorative sheet, 2...base layer, 3...pattern layer, 4...transparent resin layer, 5...surface protection layer, 6...primer layer, 7...adhesive layer, 8...hiding layer, 11...decorative material, B...base material.

Claims

1. A decorative sheet comprising a base layer and a surface protective layer provided on one surface of the base layer, wherein an uneven structure is provided on the surface of the surface protective layer, and the uneven structure of the surface protective layer has a load length ratio Rmr(10%) at a cutting level of 10% of 0.05 or more and 0.35 or less, a root mean square slope Rdq of 0.15 or more and 0.4 or less, and a root mean square height Rq of 0.4 μm or more and 4.0 μm or less.

2. The decorative sheet according to claim 1, wherein the glossiness of the surface protective layer is less than 10.

3. The decorative sheet according to claim 1 or 2, wherein the surface protective layer contains a cured product of a resin and particles.

4. The decorative sheet according to claim 3, wherein the particles have an average particle diameter of 3 μm or more.

5. The decorative sheet according to claim 3 or 4, wherein the particles have an average particle diameter of 3 μm or more and 10 μm or less.

6. The decorative sheet according to any one of claims 3 to 5, wherein the particles are contained in the surface protective layer in an amount of 3 parts by mass or more and 11 parts by mass or less with respect to 100 parts by mass of the resin.

7. The decorative sheet according to any one of claims 3 to 6, wherein the resin is a radiation curable resin.

8. The decorative sheet according to any one of claims 3 to 7, wherein the resin is an acrylate.

9. The decorative sheet according to any one of claims 3 to 8, wherein the resin is a trifunctional acrylate containing a repeating structure, and the number of repetitions of the repeating structure is 15 or more and 20 or less.

10. The decorative sheet according to any one of claims 3 to 8, wherein the resin is a tetrafunctional acrylate containing a repeating structure, and the number of repetitions of the repeating structure is 20 or more and 35 or less.

11. The decorative sheet according to any one of claims 1 to 10, wherein the thickness of the surface protective layer is 2 μm or more and 10 μm or less.

12. The decorative sheet according to any one of claims 1 to 11, further comprising a pattern layer between the base layer and the surface protective layer.

13. The decorative sheet according to claim 12, wherein the pattern layer has a wood grain pattern.

14. A decorative material comprising the decorative sheet according to any one of claims 1 to 13 and a base material to which the decorative sheet is attached.

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