Decorative sheet

Abstract

A decorative sheet (1) is provided with a raw fabric layer (2) and a surface protective layer (5) provided on one surface of the raw fabric layer (2). An uneven structure is provided on a surface of the surface protective layer (5). The uneven structure of the surface protective layer (5) exhibits a load length ratio Rmr (10%) of 0.4-0.7 at a cutting level of 10%, a root-mean-square gradient Rdq of 0.15-0.4, and a root-mean-square height Rq of 2.3-5.6 μm.

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] 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.

[0008] Japanese Patent Application Publication No. 2019-119138

[0009] The present invention aims to provide a decorative sheet that gives the feel of cool wood.

[0010] 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 0.4 or more and 0.7 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 2.3 μm or more and 5.6 μm or less.

[0011] 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.

[0012] 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.

[0013] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the particles have an average particle size of 3 μm or more.

[0014] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the particles have an average particle size of 3 μm or more and 11 μm or less.

[0015] 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.

[0016] 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.

[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 acrylate.

[0018] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the resin is a trifunctional acrylate containing a repeating structure, and the number of repetitions of the repeating structure is 9 or more and 15 or less.

[0019] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, 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 25 or less.

[0020] 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 t of the surface protective layer is 9 μm or more and 14 μm or less.

[0021] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, further comprising a design layer between the base layer and the surface protective layer.

[0022] 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.

[0023] 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.

[0024] According to the present invention, a decorative sheet is provided that provides a cool wood feel.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] <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.

[0030] 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).

[0031] 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.

[0032] 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.

[0033] 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.

[0034] <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.

[0035] 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.

[0036] <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.

[0037] 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.

[0038] <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.

[0039] <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.

[0040] 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.

[0041] 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.

[0042] <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.

[0043] The resin material for the adhesive layer 7 is not particularly limited, and may be appropriately selected from acrylic, polyester, polyurethane, epoxy, and other resin materials. Alternatively, an ethylene-vinyl acetate copolymer resin adhesive may be used as the resin material for the adhesive layer 7. The coating method may 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 may be omitted if sufficient adhesive strength is obtained between the transparent resin layer 4 and the design layer 3.

[0044] <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.

[0045] 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.

[0046] <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.

[0047] 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.

[0048] 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.

[0049] The surface protective layer 5 preferably covers the entire upper surface of the underlying layer (the 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., the transparent resin layer 4) is not exposed on the surface.

[0050] The uneven structure of the surface protective layer 5 has a load length ratio Rmr(10%) of 0.4 or more and 0.7 or less at a cutting level of 10%, preferably 0.45 or more and 0.65 or less, and more preferably 0.5 or more and 0.6 or less.

[0051] 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 distance in the depth direction from the highest point on the roughness curve is 10% of the maximum cross-sectional height Rt, based on the highest point on the roughness curve. When a user lightly touches the uneven structure with their finger, the finger touches a portion from the highest point of the convex portion to approximately 10% of the height 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.

[0052] The load length ratio Rmr (10%) is expressed by the following formula 1.

[0053] where ln is the evaluation length and Ml(10%) is the load length of the roughness curve at the cutting level of 10%.

[0054] 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.

[0055] 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.

[0056] The root mean square slope Rdq is expressed by the following equation 2.

[0057] where l is the sampling length and dZ(x) / dx is the local slope of the roughness curve.

[0058] The concave-convex structure has a root mean square height Rq of 2.3 μm or more and 5.6 μm or less, preferably 3 μm or more and 5 μm or less, and more preferably 3.5 μm or more and 4.5 μm or less.

[0059] 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.

[0060] The root mean square height Rq is expressed by the following equation 3.

[0061] where l is the reference length and Z(x) is the ordinate value of the roughness curve.

[0062] The thickness t of the surface protective layer 5 is preferably 9 μm or more and 14 μm or less. The thickness t of the surface protective layer 5 is more preferably 10 μm or more and 13 μm or less. If the thickness of the surface protective layer 5 is too small or too large, it becomes difficult to achieve the "cold wood feel." Furthermore, if the thickness of the surface protective layer 5 is too large, it becomes difficult to achieve high fingerprint resistance, high stain resistance, and high scratch resistance. Fingerprint resistance, stain resistance, and scratch resistance 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] The acrylate is preferably a trifunctional or higher acrylate, more preferably a tetrafunctional 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 tetrafunctional or lower.

[0067] 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.

[0068] The number of repetitions of the repeating structure is preferably 9 or more. If an acrylate with a large 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 large 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 small number of repetitions is used, it may be difficult to achieve high processability.

[0069] 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 9 or more and 15 or less.

[0070] 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 25 or less.

[0071] 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.

[0072] 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, the feel of cool wood is more likely to be obtained when a finger is pressed against the surface of the decorative sheet 1 and then slid across the surface.

[0073] The particles preferably have an average particle size (D50) of 3 μm or more, more preferably 3 μm or more and 11 μm or less, and even more preferably 3 μm or more and 8 μm or less.

[0074] 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) is too large, it becomes difficult to achieve the "cold 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, when the particles are small, the effect of generating wrinkles uniformly tends to be reduced. Furthermore, when the particles are small, it becomes difficult to achieve the cold wood feel.

[0075] 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.

[0076] 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 resin. The amount of particles added is more preferably 4 to 8 parts by mass per 100 parts by mass of resin. Note that "100 parts by mass of resin" refers to the parts by mass of the solid content of the resin.

[0077] When the amount of particles added is within the above range, wrinkles can be more uniformly formed on the coating surface in the second irradiation step described below, resulting in a reduction in gloss and an improvement in design properties.

[0078] If the amount of particles added is large, the particles are likely to fall off from the surface protective layer 5, making it difficult to achieve high scratch resistance. Also, if the amount of particles added is large, it may be difficult to achieve high stain resistance. Also, if the amount of particles added is small, the effect of creating uniform wrinkles is likely to be reduced. Therefore, if the amount of particles added is small, it may be difficult to achieve the "cool wood feel."

[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 and stirred. The coating liquid for the surface protective layer contains, for example, the resin and the particles described above. Here, the main component of the resin is assumed to be acrylate. While a typical stirring method may result in particles appearing to be uniformly mixed at first glance, particle aggregation and other factors can cause uneven particle dispersion in microscopic regions. In this case, wrinkles are less likely to form uniformly on the surface of the surface protective layer 5. In this case, the load length ratio Rmr (10%) of the uneven structure is likely to be small. The above-mentioned unevenness can be eliminated by stirring the coating liquid for the surface protective layer more strongly or for a longer period of time than with a typical stirring method. In this case, the load length ratio Rmr (10%) can be increased.

[0082] 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).

[0083] 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.

[0084] Next, a coating film made of a coating liquid for the surface protective layer is formed on one surface of the raw fabric 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 More than 60mJ / cm 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] Next, a 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 irradiation light. Therefore, the second irradiation light 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 present inventors also believe that the reason why the above method can provide a surface protection layer 5 having surface properties characterized by the above parameters is as follows.

[0092] As described above, when a coating film made of a coating liquid for a surface protective layer is irradiated with the second radiation, a cured film is formed on the surface, and the cured film increases in volume in the in-plane direction, causing wrinkles on the surface of the coating film. Since the second radiation is usually applied from a vertical direction, the increase in the volume of the cured film in the in-plane direction is greater in regions having a nearly horizontal surface than in regions having an inclined surface. That is, the rate of increase in the volume of the cured film in the in-plane direction is greater at the tops of the convex portions and the bottoms of the concave portions than in other parts.

[0093] Furthermore, in the process of forming these wrinkles, mass transfer occurs within the coating film from regions corresponding to the concave portions of the wrinkles to regions corresponding to the convex portions of the wrinkles, resulting in a decrease in the thickness of the coating film in the regions that will become the concave portions and an increase in the thickness of the coating film in the regions that will become the convex portions. If the coating film is irradiated with the first radiation prior to irradiation with the second radiation, mass transfer within the coating film that accompanies an increase in the in-plane volume of the cured film is moderated. In other words, if the coating film has been irradiated with the first radiation, deformation of the coating film surface due to irradiation with the second radiation is less likely to occur compared to when irradiation of the coating film with the first radiation is omitted. However, thicker portions are more likely to deform because there is a greater amount of material that can contribute to deformation than thinner portions.

[0094] In this way, the convex portions experience a high rate of increase in volume in the in-plane direction of the cured film and are prone to deformation. Therefore, as irradiation with the second radiation continues, the ridge-like convex portions formed on the surface of the coating film expand so that the portion of the cross section perpendicular to the length direction that corresponds to the surface of the coating film takes on a convex curved shape, for example, and their width increases.

[0095] As the protrusions expand to have the above-described cross-sectional shape and the distance between the protrusions decreases, the amount of the second radiation reaching the recesses decreases, and therefore, in the recesses, the rate at which the volume of the cured film increases in the in-plane direction decreases.

[0096] As a result, an uneven structure is formed that has features such as a gentle slope near the top of the projections, etc. In other words, a surface protection layer 5 having surface properties characterized by the above-mentioned parameters is obtained.

[0097] The uniformity of particle distribution in the coating film affects the uniformity of the distribution of convex and concave portions, and therefore affects the surface properties of the surface protective layer 5. Therefore, in the above-mentioned method, the coating liquid for the surface protective layer is stirred more strongly or for a longer period of time than in a normal stirring method, thereby eliminating non-uniform particle dispersion.

[0098] 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.

[0099] 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).

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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 ２ It 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.

[0104] 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.

[0105] The third radiation is ionizing radiation such as an electron beam, or ultraviolet radiation having a longer wavelength than the first radiation.

[0106] 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:

[0107] 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.

[0108] <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 of such a decorative sheet 1, for example, 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 "cool feel of wood." This decorative sheet 1 not only has a low gloss and excellent design, but also has an excellent feel. This feel will be explained below.

[0109] 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 large. 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 easily conducted to the decorative sheet 1, and the decorative sheet 1 gives the user a cool feeling to the touch.

[0110] Furthermore, the decorative sheet 1 described above has a root-mean-square slope Rdq of the uneven structure that falls within the aforementioned range. The decorative sheet 1 described above also has a root-mean-square height Rq of the uneven structure that falls within the aforementioned range. The convex portions that form this uneven structure are moderately steep and have an appropriate 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.

[0111] 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 cool feel, 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 feel. Therefore, the decorative sheet 1 gives the user a feel that combines these two tactile sensations, i.e., a "cool wood feel."

[0112] 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%). Therefore, 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 "cold wood feel."

[0113] 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.

[0114] Furthermore, as described above, the surface protective layer 5 can achieve a low gloss. In this case, the reflection of external light on the surface of the surface protective layer 5 can be reduced. Therefore, for example, if the pattern layer 3 has a wood grain pattern, the wood grain pattern can be visually recognized as a clear pattern. In this case, it is particularly likely to give the user the "feeling of cool wood." Note that although the above parameters are related to low gloss, other parameters are also involved in achieving low gloss. For this reason, a low-gloss decorative sheet does not necessarily meet the requirements of the above parameters.

[0115] 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.

[0116] 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.

[0117] 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 in-plane expansion of the cured film according to the progress of the crosslinking reaction will change. The thickness of the cured film and the degree of in-plane expansion of the cured film will also be affected by the integrated light amount in the first and second irradiation steps. The thickness of the cured film and the degree of in-plane expansion of the cured film will also affect 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.

[0118] Therefore, for example, by appropriately setting the stirring method of the coating liquid for the surface protective layer, 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 protective layer having the desired surface properties.

[0119] The following describes examples of the present invention.

[0120] 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.

[0121] 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.

[0122] Next, a coating liquid for the surface protective layer was prepared. The coating liquid for the surface protective layer was prepared by blending the following ionizing radiation curable resin with the following particles. Ionizing radiation curable resin Type: Trimethylolpropane EO-modified triacrylate (15 moles of EO added) Product name: SR9035 (manufactured by Sartomer) Blend: 100 parts by mass Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend: 2 parts by mass 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. A ZT-20 stirring vessel (manufactured by Satake Multinics Co., Ltd.) was used. A Satake Multi A Mixer AT14-VPR-0.09BI (manufactured by Satake Multinics Co., Ltd.) was used for stirring. Central stirring was used as the stirring method. The power for stirring the coating liquid for the surface protective layer was 0.75 kW, and the stirring time was 5 minutes.

[0123] 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 11.58 μm.

[0124] 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 50 mJ / cm. ２ This caused the coating film to be semi-cured.

[0125] Thereafter, a second irradiation step was carried out. Specifically, under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 500 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 50 mJ / cm. ２ This caused wrinkles to form on the surface of the coating film.

[0126] 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.

[0127] <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 blending amount of particles was set to 3 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 10.31 μm.

[0128] <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 blending amount of particles was 4 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed so as to have a thickness of 12.51 μm.

[0129] <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 blending amount of particles was set to 5 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed so as to have a thickness of 10.28 μm.

[0130] <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 blending amount of particles was set to 9.1 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed so as to have a thickness of 11.08 μm.

[0131] <Example 6> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. In this example, the blending amount of particles was set to 10.9 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 10.36 μm.

[0132] <Example 7> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was set to 12.1 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed so as to have a thickness of 10.23 μm.

[0133] <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, particles were not blended. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 11.18 μm.

[0134] <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 blending amount of particles was set to 5 parts by mass. Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 10.88 μm. The power for stirring the coating liquid for surface protective layer was set to 0.3 kW.

[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 blending amount of particles was set to 5 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 2.94 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 blending amount of particles was set to 5 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 6.02 μm.

[0137] <Example 8> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was set to 5 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 10.57 μm.

[0138] <Example 9> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was set to 5 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed so as to have a thickness of 13.08 μm.

[0139] <Comparative 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 blending amount of particles was set to 5 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed so as to have a thickness of 16.23 μm.

[0140] Comparative Example 6 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: Particles Product name: Sylysia 310P (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 2 μm Blending: 5 parts by mass Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 11.07 μm.

[0141] <Example 10> 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: Particles Product name: Sylysia 420 (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 3 μm Blending: 5 parts by mass Then, a coating film made from the coating liquid for surface protective layer was formed to a thickness of 10.76 μm.

[0142] <Example 11> 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: 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 10.98 μm.

[0143] Example 12 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: 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 11.80 μm.

[0144] 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: Particles Product name: Sylysia 780 (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 11 μm Blending: 5 parts by mass Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 10.00 μm.

[0145] 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: 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 from the coating liquid for surface protective layer was formed to a thickness of 12.80 μm.

[0146] 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.) The amount of particles was 5 parts by mass. In addition, a coating film made from the surface protective layer coating liquid was formed to a thickness of 10.97 μm, and then the coating film was cured only by the third irradiation step, without carrying out the first and second irradiation steps.

[0147] Comparative Example 8 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. Specifically, 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.) The amount of particles was set to 5 parts by mass. A coating film made from the surface protective layer coating liquid was formed to a thickness of 11.48 μm.

[0148] Comparative Example 9 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. Specifically, 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.) The amount of particles was set to 5 parts by mass. A coating film made from the surface protective layer coating liquid was formed to a thickness of 11.19 μm.

[0149] Example 15 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. Specifically, 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) The amount of particles was 5 parts by mass. A coating film made from the surface protective layer coating liquid was formed to a thickness of 12.07 μm.

[0150] 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 (20 moles of EO added) Product name: NK Ester AT-20E (manufactured by Shin-Nakamura Chemical Co., Ltd.) The amount of particles blended was 5 parts by mass. In addition, a coating film made of the surface protective layer coating liquid was formed to a thickness of 12.79 μm.

[0151] Example 16 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. Specifically, in this example, the following ionizing radiation curable resin was used: Ionizing radiation curable resin type: ethoxylated pentaerythritol tetraacrylate (20 moles of EO added). The amount of particles was 5 parts by mass. A coating film made from the surface protective layer coating liquid was formed to a thickness of 13.11 μm.

[0152] Example 17 First, a shaping mold was prepared. The shaping mold was prepared by the same method as the decorative sheet manufacturing method according to Example 16, 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 12.28 μm.

[0153] 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.

[0154] 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 15 μm thick PET film 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.

[0155] 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 coated onto 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 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.

[0156] On the other hand, the surface protective layer coating liquid used in Example 16 was applied to the pattern layer 3 using the same procedure as in Example 16 to prepare a coating film made of the surface protective layer coating liquid. A mold was pressed onto the prepared coating film, and then the PET film was irradiated twice with ionizing radiation similar to the ionizing radiation irradiation performed in the third irradiation step of Example 16, thereby curing the coating film. The secondary transfer film was then peeled off to form a surface protective layer. In this manner, a decorative sheet was obtained.

[0157] 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: Ethoxylated pentaerythritol tetraacrylate (35 moles of EO added) Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Co., Ltd.) The amount of particles blended was 5 parts by mass. In addition, a coating film made from the coating liquid for the surface protective layer was formed to a thickness of 9.85 μm.

[0158] Comparative Example 12 Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. Specifically, 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.) The amount of particles was set to 15 parts by mass. A coating film made from the surface protective layer coating liquid was formed to a thickness of 11.28 μm.

[0159] 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: Ethylene glycol diacrylate (9 moles of EO added) Product name: Light Acrylate 9EG-A (manufactured by Kyoeisha Chemical Co., Ltd.) The amount of particles blended was 5 parts by mass. In addition, a coating film made from the coating liquid for the surface protective layer was formed to a thickness of 10.38 μm.

[0160] 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: Ethoxylated dipentaerythritol hexaacrylate (12 moles of EO added) Product name: NK Ester A-DPH-12E (manufactured by Shin-Nakamura Chemical Co., Ltd.) The amount of particles blended was 5 parts by mass. In addition, a coating film made from the coating liquid for the surface protective layer was formed to a thickness of 11.20 μm.

[0161] Comparative Example 15 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.) The amount of particles blended was 5 parts by mass. In addition, a coating film made from the surface protective layer coating liquid was formed to a thickness of 10.71 μm.

[0162] <Evaluation> Each of the decorative sheets described above was subjected to the following evaluations.

[0163] (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.

[0164] (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.

[0165] (3) Skin Feel Skin feel was evaluated using the following method. First, preliminary preparations were made to ensure that the evaluation criteria for the surface roughness-related feel were consistent among the evaluators. Specifically, three standard test pieces with different surface properties (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-related feel 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 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.

[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 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: a test piece with an Rmr (10%) of greater than 0.35 and less than 0.4, a test piece with an Rmr (10%) in the range of 0.4 to 0.7, and a test piece with an Rmr (10%) in the range of greater than 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 lukewarm feeling was felt; Group b: A cold feeling was felt; and Group c: A feeling that was too cold.

[0168] 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.

[0169] 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 the surface with their fingers, and then to classify the tactile sensations related to surface roughness and temperature sensation into the above 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 (cold 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 b; B (tactile sensation other than cold 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 b.

[0170] (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.

[0171] 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

[0172] (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.

[0173] 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.

[0174] (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.

[0175] 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.

[0176] (7) 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) (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%."

[0177] The evaluation results are shown in Tables 1 to 5. In Tables 1 to 5, when the same stirring method as that used for decorative sheet 1 in Example 1 was used in the manufacturing process of decorative sheet 1, this is indicated by entering the letter A in the "Stirring method" column, and when the same stirring method as that used for decorative sheet 1 in Comparative Example 2 was used, this is indicated by entering the letter B in the "Stirring method" column. "Cutting level (μm)" indicates the cutting level when the load length ratio Rmr (10%) was determined.

[0178]

[0179]

[0180]

[0181]

[0182]

[0183] As shown in Tables 1 to 5, the decorative sheets according to Examples 1 to 17 gave the evaluators the feeling of cool wood. Furthermore, the decorative sheets according to Examples 1 to 5, 8, 10 to 12, and 15 to 17 had low gloss and excellent fingerprint resistance, stain resistance, and scratch resistance. On the other hand, the decorative sheets according to Comparative Examples 1 to 15 did not give the evaluators the feeling of cool wood.

[0184] 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 fabric layer and a surface protective layer provided on one surface of the base 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 0.4 to 0.7, a root mean square slope Rdq of 0.15 to 0.4, and a root mean square height Rq of 2.3 μm to 5.6 μm.

2. The decorative sheet according to claim 1, wherein the gloss of said 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 resin and particles.

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

5. A decorative sheet according to claim 3 or 4, wherein the particles have an average particle size of 3 μm or more and 11 μm or less.

6. A 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 to 11 parts by weight per 100 parts by weight of the resin.

7. A decorative sheet according to any one of claims 3 to 6, wherein the resin is an ionizing radiation curable resin.

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

9. A 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 9 or more and 15 or less.

10. A 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 25 or less.

11. A decorative sheet according to any one of claims 1 to 10, wherein the thickness t of said surface protective layer is 9 μm or more and 14 μm or less.

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

13. The decorative sheet according to claim 12, wherein said design 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 substrate to which the decorative sheet is attached.