Decorative sheet

Abstract

Provided is a decorative sheet which has excellent damage resistance and affords a unique tactile sensation. A decorative sheet (1) comprises a raw fabric layer (2) and a surface protective layer (5) disposed on one surface of the raw fabric layer (2), wherein: the surface protective layer (5) includes a cured product of a resin and has, on the surface thereof, a relief structure including a plurality of ridge portions each protruding in ridge shape; and the relief structure has a texture aspect ratio Str of 0.8 or more and an areal material ratio Smr1 of 13% or less by which protruding peak portions and core portions are distinguished.

Description

Decorative sheet

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

[0002] Decorative sheets are used for the purpose of decorating the surfaces of interior and exterior materials such as building fixtures, furniture, fixtures, and flooring, i.e., for the purpose of imparting design and durability to these components. 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 disclosure is to provide a decorative sheet that is highly scratch-resistant and provides a unique feel to the touch.

[0011] According to one aspect of the present invention, there is provided a decorative sheet comprising an original fabric layer and a surface protective layer provided on one surface of the original fabric layer, wherein the surface protective layer contains a cured resin and has an uneven structure on its surface including a plurality of ridge-like portions each protruding in a ridge-like shape, wherein the uneven structure has an aspect ratio Str of the surface texture of 0.8 or more and a load area ratio Smr1 separating the protruding ridge portions from the core portion of 13% or less.

[0012] According to another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the specular gloss GS(60°) of the portion corresponding to the uneven structure is 5% or less.

[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 has a thickness of 7 μm or less.

[0014] 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 an ionizing radiation curable resin.

[0015] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the resin is an acrylate.

[0016] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the acrylate includes a polyfunctional acrylate containing a repeating structure.

[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 surface protective layer further contains particles dispersed in the cured product.

[0018] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the amount of the particles is in the range of 3 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the cured product.

[0019] 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.

[0020] 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.

[0021] According to the present disclosure, it is possible to provide a decorative sheet that is highly scratch-resistant and provides a unique feel to the touch.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] <1> Decorative material and decorative sheet Figure 1 is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention. Figure 2 is a cross-sectional view of a surface protective layer included in the decorative sheet of Figure 1. Figure 3 is a micrograph of a surface protective layer included in a decorative sheet according to one example of the present invention.

[0027] 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).

[0028] 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.

[0029] 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.

[0030] 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.

[0031] <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.

[0032] 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.

[0033] <1.2> Primer Layer When an olefin-based resin is used as the material for 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.

[0034] 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.

[0035] <1.3> Concealing Layer To impart concealing properties to the substrate B to the decorative sheet 1, 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 enhance 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.

[0036] <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 either 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 or electron beams. 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.

[0037] 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.

[0038] <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.

[0039] 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.

[0040] <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.

[0041] 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.

[0042] <1.7> Surface Protection Layer The surface of the surface protection layer 5 has an uneven structure including a plurality of ridge-like portions 5B, each of which protrudes in a ridge-like manner. Here, the surface protection layer 5 includes a base 5A and a plurality of ridge-like portions 5B, each of which protrudes in a ridge-like manner from one surface of the base 5A. These ridge-like portions 5B form the uneven structure.

[0043] 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 structure provided on the surface of the surface protective layer 5, and the base portion 5A refers to the portion of the surface protective layer 5 excluding the ridge portions 5B.

[0044] 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.

[0045] The uneven structure formed by the ridge portions 5B has a surface texture aspect ratio Str of 0.8 or more. Here, the surface texture aspect ratio Str is a surface texture parameter defined in ISO 25178. The surface texture aspect ratio Str is preferably 0.8 or more, and more preferably 0.85 or more. The surface texture aspect ratio Str is at most 1, but in one example it is 0.94 or less, and in another example it is 0.93 or less.

[0046] When the aspect ratio Str of the surface texture is 0.8 or more, the deviation in the length direction of the ridge portions 5B is sufficiently small. Therefore, when a finger is slid across the surface of the surface protection layer 5, the influence of the direction of the finger sliding on the tactile sensation is sufficiently small. Furthermore, when the aspect ratio Str of the surface texture is 0.85 or more, the isotropy of the tactile sensation is further enhanced, and the fine graininess described below can be perceived more clearly.

[0047] However, if the aspect ratio Str of the surface texture is greater than 0.94, the tactile sensation may become excessively isotropic, resulting in a monotonous sensation. Furthermore, if the tactile sensation becomes excessively isotropic, a discrepancy may arise between a specific design (such as wood grain or stone grain) and the tactile sensation, potentially damaging the realism desired by users. Therefore, the aspect ratio Str of the surface texture is preferably 0.94 or less, and more preferably 0.93 or less.

[0048] The uneven structure formed by the ridge portions 5B has an areal surface area ratio Smr1 (hereinafter sometimes abbreviated as "areal surface area ratio Smr1") separating the protruding peaks and the core portion of the substrate of 13% or less. Here, the areal surface area ratio Smr1 separating the protruding peaks and the core portion of the substrate of 13% or less is a surface texture parameter defined in ISO 25178. Specifically, the areal surface area ratio Smr1 indicates the areal surface area ratio at a level that separates the region from the apex of the highest peak on the surface to the top of the core portion of the substrate of 13% or less and the region below that (core portion) in the height distribution. The areal surface area ratio Smr1 is preferably 13% or less, and more preferably 11% or less. In one example, the areal surface area ratio Smr1 is 9% or more, and in another example, 9.3% or more.

[0049] When a concave-convex structure having a load area ratio Smr1 of 13% or less is pressed with a finger, the finger comes into contact with the convex portions over a small area. Therefore, such a convex-convex structure allows the user to perceive a tactile sensation similar to that given to a user when touching a convex-convex structure consisting of fine convex portions. Furthermore, if an isotropic tactile sensation is given when a finger is slid over the convex-convex structure, and this tactile sensation is similar to that given to a user when a convex-convex structure consisting of fine convex portions (a fine convex sensation) is given to a user, the user will perceive a tactile sensation similar to that given to a user by a layer in which fine spherical particles are uniformly dispersed and these spherical particles are partially exposed on the surface (a fine granular sensation). Therefore, a load area ratio Smr1 of 13% or less is important for obtaining a fine granular sensation.

[0050] On the other hand, if the area load ratio Smr1 is less than 9%, the convex portions become too fine, which may make it difficult to feel the tactile sensation resulting from the uneven structure, or the tactile sensation may become too monotonous. In order for the uneven structure to be fine yet easily recognizable, the area load ratio Smr1 is preferably 9% or more. If the area load ratio Smr1 is 9.3% or more, the tactile sensation resulting from the uneven structure can be felt even more clearly. For example, the tactile sensation obtained from an uneven structure having an area load ratio Smr1 of less than 9.3% is classified into the third group (feeling the presence of an uneven structure consisting of fine convex portions) described below in terms of the fine convex sensation, but the tactile stimulation is weak, and the fine convex sensation tends to be difficult to fully perceive.

[0051] The aspect ratio Str and area load ratio Smr1 of the surface texture are each one of the characteristics of the surface protective layer 5 that affect the feel of the decorative sheet 1 .

[0052] The surface protection layer 5 having a concave-convex structure with a large aspect ratio Str on its surface provides the user with substantially the same tactile sensation when the user presses the concave-convex structure with their skin and slides their skin over the concave-convex structure, for example, when the user presses the concave-convex structure with their finger and slides their finger over the concave-convex structure, regardless of the direction in which the finger is slid. In other words, the concave-convex structure with a large aspect ratio Str of the surface texture provides the user with an isotropic tactile sensation.

[0053] When a user presses a concave-convex structure with a small surface area load ratio Smr1 with their skin, for example, when they press the concave-convex structure with their finger, the finger comes into contact with the convex portions over a small area. In this situation, the tactile sensation that the concave-convex structure gives to the user is similar to the tactile sensation that a concave-convex structure made up of fine convex portions gives to the user (hereinafter referred to as a fine convex sensation).

[0054] Furthermore, when the uneven structure provides an isotropic tactile sensation to the user, and this tactile sensation is similar to the tactile sensation provided to the user by an uneven structure consisting of fine protrusions, the user perceives a tactile sensation similar to the tactile sensation provided to the user by a layer in which fine spherical particles are uniformly dispersed and these spherical particles are partially exposed on the surface (hereinafter referred to as a fine granular sensation).

[0055] The thickness of the surface protective layer 5 is preferably 11 μm or less, more preferably 7 μm or less, and even more preferably 5 μm or less. The thickness of the surface protective layer 5 is preferably 3 μm or more, and more preferably 4 μm or more.

[0056] Here, the thickness of the surface protective layer 5 is the thickness of a layer having the same apparent area and volume as the surface protective layer 5 and a flat surface. The thickness of the surface protective layer 5 is determined, for example, by the following method. First, a cross section parallel to the thickness direction of the surface protective layer 5 and perpendicular to the length direction of the ridge portions 5B is imaged. Next, from this cross-sectional image, the dimension of the surface protective layer 5 in the width direction of the ridge portions 5B and the area of ​​the cross section of the surface protective layer 5 are determined. The thickness of the surface protective layer 5 is a value obtained by dividing this area by the above dimension. Note that 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.

[0057] If the coating film is made thicker, the cured film is more likely to expand in the in-plane direction during the first irradiation step described below, and therefore wrinkles corresponding to the ridge portions 5B are more likely to appear on the coating film surface. However, if the coating film is made excessively thick, for example, there is a possibility that the number of wrinkles per unit area will remain small and individual wrinkles will grow. For these reasons, if the thickness of the surface protection layer 5 is increased, the aspect ratio Str of the surface texture may decrease or the area load ratio Smr1 may increase.

[0058] The surface protective layer 5 contains a cured resin. Preferably, the surface protective layer 5 further contains particles dispersed in the cured resin.

[0059] The cured resin contained in the surface protective layer 5 is preferably a cured product of 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.

[0060] 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.

[0061] 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% by mass or more of the ionizing radiation curable resin. The ionizing radiation curable resin preferably contains 70% by mass or more of acrylate, more preferably 80% by mass or more. The ionizing radiation curable resin is more preferably an acrylate.

[0062] The acrylate is preferably a difunctional or higher acrylate, and more preferably contains 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 lower.

[0063] To obtain a surface protective layer 5 having excellent scratch resistance, the acrylate preferably contains a tri- or higher functional acrylate. The acrylate preferably contains a tri- or lower functional acrylate. For example, such an acrylate is a trifunctional acrylate, and for another example, it is a combination of a trifunctional acrylate and a difunctional acrylate.

[0064] The total proportion of the trifunctional acrylate and the difunctional acrylate in the ionizing radiation curable resin is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, and may be 100% by mass.

[0065] The proportion of the trifunctional acrylate in the ionizing radiation curable resin is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 60% by mass or more. This proportion may be 100% by mass.

[0066] 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.

[0067] The number of repetitions of the repeating structure is preferably 3 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 in the first irradiation step described below, and therefore wrinkles corresponding to the ridge portions 5B are more likely to appear on the coating film surface. In other words, the number of repetitions can affect the surface properties of the surface protective layer 5. However, if the number of repetitions is increased, the crosslinking density decreases, and the scratch resistance of the surface protective layer 5 decreases.

[0068] The proportion of the total acrylate containing a repeating unit in the ionizing radiation curable resin is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. This proportion may be 100% by mass. If this proportion is increased, expansion of the cured film in the in-plane direction becomes more likely to occur in the first irradiation step. In other words, this proportion may affect the surface properties of the surface protective layer 5.

[0069] In a preferred embodiment, the ionizing radiation curable resin is a trifunctional acrylate containing a repeating unit. In another preferred embodiment, the ionizing radiation curable resin is a combination of a trifunctional acrylate containing a repeating unit and a difunctional acrylate containing a repeating unit. In yet another preferred embodiment, the ionizing radiation curable resin is a combination of a trifunctional acrylate containing a repeating unit and a difunctional acrylate not containing a repeating unit, such as tricyclodecane dimethanol diacrylate.

[0070] Examples of trifunctional acrylates containing repeating units include EO-modified, PO-modified, or CL-modified trimethylolpropane triacrylate, glycerin triacrylate, isocyanurate triacrylate, or pentaerythritol triacrylate. In trifunctional acrylates containing repeating units, the number of repeating units is preferably in the range of 4 to 15, and more preferably in the range of 9 to 15. The molecular weight of the trifunctional acrylates containing repeating units is, for example, in the range of 296 to 1174.

[0071] The bifunctional acrylate containing a repeating unit is, for example, polyethylene glycol diacrylate or polypropylene glycol diacrylate, and may contain a caprolactone structure. In the bifunctional acrylate containing a repeating unit, the number of repeats of the repeating unit is preferably in the range of 4 to 14, and more preferably in the range of 4 to 9. The molecular weight of the bifunctional acrylate containing a repeating unit is, for example, in the range of 170 to 1139, and in another example, in the range of 184 to 1391.

[0072] When a trifunctional acrylate containing a repeating structure and a bifunctional acrylate containing a repeating structure are used in combination, the number of repeating units in the bifunctional acrylate is preferably smaller than the number of repeating units in the trifunctional acrylate. For example, when the number of repeating units in the trifunctional acrylate is within the range of 9 to 15, the number of repeating units in the bifunctional acrylate is preferably within the range of 3 to 9. Reducing the number of repeating units in the bifunctional acrylate reduces the ease of molecular movement in the surface protective layer 5, thereby increasing the hardness of the surface protective layer and tending to improve its scratch resistance.

[0073] 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.

[0074] The particles contained in the surface protection layer 5 may 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.

[0075] The particles preferably have an average particle size (D50) in the range of 3 μm to 8 μm, more preferably in the range of 4 μm to 8 μm, and even more preferably in the range of 5 μm to 8 μm.

[0076] When the surface protective layer 5 contains particles, wrinkles can be more uniformly formed on the coating surface in the first irradiation step described below. If the average particle size (D50) of the particles is large, the particles tend to fall off from the surface protective layer 5, which may make it difficult to achieve high scratch resistance. If the particles are small, the effect of forming wrinkles uniformly is small.

[0077] Here, "average particle size" or "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.

[0078] The amount of particles in the surface protective layer 5 is preferably in the range of 3 parts by mass to 10 parts by mass, more preferably in the range of 5 parts by mass to 10 parts by mass, per 100 parts by mass of the cured resin.

[0079] When the amount of particles added is within the above range, the effect of generating wrinkles uniformly is particularly large. If the amount of particles added is too large, the particles are likely to fall off from the surface protective layer 5, making it difficult to achieve high scratch resistance. If the amount of particles added is too small, it may be difficult to generate an uneven structure on the surface of the surface protective layer 5 that gives the user an isotropic feel and a fine convex feel.

[0080] The decorative sheet 1 preferably has a specular gloss GS(60°) of 10% or less, more preferably 7% or less, and even more preferably 5% or less, in the portion corresponding to the uneven structure. Here, "specular gloss GS(60°)" is a measured value measured at an incident angle of 60 degrees using a glossmeter conforming to JIS Z8741:1997. The specular gloss GS(60°) of the portion corresponding to the uneven structure is a minimum of 0%, and in one example, is 0.1% or more.

[0081] <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 will be omitted here.

[0082] First, 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.

[0083] The coating liquid for the surface protective layer contains the above-mentioned resin and the above-mentioned particles. 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 the ultraviolet absorber that can be used include benzotriazoles, benzoates, benzophenones, and triazines. Examples of the light stabilizer 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).

[0084] In the second 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.

[0085] After forming a coating film made from the coating liquid for a 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 200 nm or less (hereinafter referred to as first radiation). The ionizing radiation curable resin contained in the coating liquid for a surface protective layer has a large absorption coefficient for the first radiation. Therefore, the first radiation incident on the coating film can only reach a position several tens to several hundreds of nanometers away from the outermost surface. Therefore, in the first irradiation step, a 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 other regions uncured.

[0086] The coating film after the first 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 first irradiation step is as follows.

[0087] As described above, the first radiation can only reach a position tens to hundreds of nanometers away from the outermost surface of the coating film. In other words, the crosslinking reaction of the ionizing radiation-curable resin occurs only on the surface of the coating film, and highly fluid uncured resin is present in regions more than tens to hundreds of nanometers away from the outermost surface. The molecules contained in the highly fluid resin swell the cured film, increasing its volume. This increase in volume in the in-plane direction generates in-plane compressive stress in the cured film, which in turn buckles the cured film and causes wrinkles on the surface of the coating film.

[0088] The first 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 the excimer.

[0089] 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).

[0090] 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.

[0091] The first irradiation step is performed in an atmosphere with a low oxygen concentration. Oxygen has a high absorption coefficient for light of 200 nm or less. Therefore, the first irradiation step is preferably performed in, for example, a nitrogen gas atmosphere. 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 film surface. Therefore, changing the residual oxygen concentration in the reaction atmosphere can also change the surface properties of the surface protective layer 5. The oxygen concentration in the gas phase in the first irradiation step, i.e., the residual oxygen concentration in the reaction atmosphere, is preferably 200 ppm or less, more preferably 30 ppm or less.

[0092] In the first irradiation step, the distance from the light source to the coating film (hereinafter referred to as the irradiation distance) is preferably 30 mm or less, more preferably 10 mm or less. The irradiation distance is, for example, 5 mm or more. As the irradiation distance increases, the absorption of light of 200 nm or less by oxygen increases.

[0093] The integrated light amount of the first 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 It is more preferable that the integrated light amount is set to the following: If the integrated light amount is small, the expansion of the cured film in the in-plane direction is small, whereas if the integrated light amount is large, the surface condition of the coating film is deteriorated.

[0094] In the first irradiation step, the temperature of the coating film made of the coating liquid for the surface protective layer is preferably controlled within a range of 20°C or higher and 65°C or lower. Increasing the temperature of the coating film reduces the viscosity of the coating liquid for the surface protective layer and increases its fluidity. In addition, increasing the temperature of the coating film increases the flexibility of the cured film. Therefore, the temperature of the coating film affects the formation of wrinkles on the coating film surface. Therefore, by changing the temperature, the surface properties of the surface protective layer 5 can be changed.

[0095] 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 a second radiation to cure the entire coating film. In this way, the surface protective layer 5 is obtained.

[0096] The second radiation is ionizing radiation such as an electron beam, or ultraviolet radiation having a longer wavelength than the first radiation. When ultraviolet radiation is used as the second radiation, the ultraviolet radiation has a wavelength at which the ionizing radiation curable resin exhibits a smaller absorption coefficient.

[0097] When ionizing radiation is used as the second radiation, the dose of the second radiation is preferably 3 kGy to 50 kGy, more preferably 5 kGy to 40 kGy, and even more preferably 5 kGy to 10 kGy. If the dose is too low, curing will be insufficient, and if the dose is too high, the ionizing radiation is more likely to induce embrittlement of the decorative sheet.

[0098] When ultraviolet light is used as the second radiation, the cumulative light amount of the second 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:

[0099] In this method, the surface protective layer 5 is formed so that its uneven structure has the above-mentioned surface texture. As described above, this surface texture is affected by the composition of the coating liquid for the surface protective layer, the thickness of the coating film made from this coating liquid, and various conditions in the first irradiation step. Therefore, for example, to form a surface protective layer 5 having a desired composition, thickness, and surface texture, various conditions in the first irradiation step, such as the temperature of the coating film, the oxygen concentration in the atmosphere, the irradiation distance, and the integrated light amount of the first radiation, are appropriately set so as to obtain the above-mentioned surface texture.

[0100] The decorative sheet 1 may also be manufactured by other methods. For example, a plate may be formed using the method described above for the surface protective layer 5, and this plate may be used to form the surface protective layer 5 having a concave-convex structure on its surface. For example, a plate for primary transfer may be formed using the method described above for the surface protective layer 5, a plate for secondary transfer may be formed by transfer using this primary transfer plate, and the surface protective layer 5 having a concave-convex structure on its surface may be formed by transfer using this secondary transfer plate.

[0101] <3> Effect The decorative sheet 1 described with reference to Figures 1 to 3 has the surface protective layer 5 with the above-mentioned surface properties. Such a decorative sheet 1 provides an isotropic tactile sensation to the user when the user presses the uneven structure on the surface of the surface protective layer 5 and slides their skin over the uneven structure. Furthermore, the tactile sensation provided to the user when the above uneven structure presses the skin is similar to the tactile sensation provided to the user by an uneven structure consisting of fine protrusions (fine protrusion sensation). The combination of the isotropic tactile sensation and the fine protrusion sensation allows the user to perceive a tactile sensation similar to the tactile sensation provided to the user by a layer in which fine spherical particles are uniformly dispersed and these spherical particles are partially exposed on the surface (fine granular sensation). In other words, the decorative sheet 1 provides a unique tactile sensation to the user when they touch the uneven structure on the surface of the surface protective layer 5.

[0102] Furthermore, this decorative sheet 1 has excellent scratch resistance, as described below. A surface protective layer having a textured surface structure can also be obtained by forming a layer containing particles and a binder resin so that convex portions corresponding to the shape of the particles or their aggregates are formed on the surface. However, such a surface protective layer has a large number of particles exposed on its surface, making it prone to particle shedding due to abrasion, etc. Furthermore, in a surface protective layer with such a structure, the particles or their aggregates themselves constitute the convex portions, and particle shedding significantly changes the optical properties of the surface protective layer. Therefore, when a certain portion of the surface protective layer is abraded, a large number of particles are shed from that portion, and the optical properties of that portion become significantly different from the optical properties of other portions. As a result, the abraded portion becomes easily recognized as, for example, a scratch.

[0103] In contrast, in the decorative sheet 1, the uneven structure provided on the surface of the surface protective layer 5 is obtained by creating wrinkles on the surface of the coating film. This surface protective layer 5 may contain particles, but these particles are not essential.

[0104] Furthermore, in the decorative sheet 1, even if the surface protective layer 5 contains particles, these particles are intended to cause uniform and high-density buckling of the cured film. Therefore, the number of particles per surface area of ​​the surface protective layer 5 can be small. Furthermore, particles that may fall off due to abrasion are limited to those located near the tops of the ridge portions 5B.

[0105] Furthermore, the ridge portions 5B are mostly made of a cured resin, so even if particles fall off, the effect of this falling off on the optical properties of the surface protection layer 5 is small.

[0106] Therefore, even if a portion of the surface protective layer 5 of the decorative sheet 1 is scratched, the optical properties of that portion change only slightly. Therefore, with this decorative sheet 1, it is unlikely that the scratched portion will be easily recognized as a scratch, for example. In other words, the decorative sheet 1 has excellent scratch resistance.

[0107] Examples of the present invention will be described below. Note that the "particle size" described below is the above-mentioned "average particle size (D50)".

[0108] 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.

[0109] 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. On one side of the raw fabric layer 2, a design layer 3 was formed using an oil-based nitrocellulose resin gravure printing ink (PCNT (PCRNT) various colors, manufactured by Toyo Ink Co., Ltd.).

[0110] Next, a coating liquid for a surface protective layer was applied onto the design layer 3. The following ionizing radiation curable resin A was used as the coating liquid for the surface protective layer. Ionizing radiation curable resin A Type: Trimethylolpropane EO-modified triacrylate (15 mols of EO added) Product name: SR9035 (manufactured by Sartomer) A coating film made of the coating liquid for a surface protective layer was formed to a thickness of 5 μm.

[0111] Thereafter, the first irradiation step was carried out. Specifically, under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 100 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 7 mJ / cm. ２ Here, the distance from the Xe excimer lamp to the coating film (irradiation distance) was set to 10 mm. In addition, the temperature of the raw fabric layer 2 was controlled so that the temperature of the coating film was 25°C. This caused wrinkles to form on the surface of the coating film.

[0112] Subsequently, the second 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.

[0113] Example 2: Comparative Example Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the coating liquid for the surface protective layer was a mixture of the following ionizing radiation curable resin A and the following particles. Ionizing radiation curable resin A Type: Trimethylolpropane EO-modified triacrylate (15 moles of EO added) Product name: SR9035 (manufactured by Sartomer) Blend: 100 parts by mass Particle product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend: 5 parts by mass In this example, the coating film made from the coating liquid for the surface protective layer was formed to a thickness of 10 μm. In this manner, decorative sheet 1 was obtained.

[0114] <Example 3: Example> Decorative sheet 1 was produced in the same manner as in Example 2, except for the following points: In this example, in the first irradiation step, the temperature of raw fabric layer 2 was controlled so that the temperature of the coating film was 65° C. In this manner, decorative sheet 1 was obtained.

[0115] <Example 4: Example> Decorative sheet 1 was produced in the same manner as in Example 2, except for the following points. That is, in this example, the coating film made of the coating liquid for the surface protective layer was formed so as to have a thickness of 5 μm. In this manner, decorative sheet 1 was obtained.

[0116] <Example 5: Example> A decorative sheet 1 was produced in the same manner as in Example 4, except for the following points: In this example, in the first irradiation step, the temperature of the raw fabric layer 2 was controlled so that the temperature of the coating film was 65° C. In this manner, a decorative sheet 1 was obtained.

[0117] <Example 6: Comparative Example> Decorative sheet 1 was produced in the same manner as in Example 4, except for the following points. That is, in this example, the irradiation distance in the first irradiation step was set to 15 mm. In this manner, decorative sheet 1 was obtained.

[0118] Example 7: Example A decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, a coating liquid for the surface protective layer was used that was a blend of the following ionizing radiation curable resin A, ionizing radiation curable resin B, and particles. Ionizing radiation curable resin A Type: Trimethylolpropane EO-modified triacrylate (15 mols of EO added) Product name: SR9035 (manufactured by Sartomer) Blend: 40 parts by mass Ionizing radiation curable resin B Type: Polyethylene glycol diacrylate (4 mols of EO added) Product name: Light Acrylate 14EG-A (manufactured by Kyoeisha Chemical Co., Ltd.) Blend: 60 parts by mass Particle product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend: 5 parts by mass In this manner, decorative sheet 1 was obtained.

[0119] Example 8: Comparative Example Decorative sheet 1 was produced in the same manner as in Example 7, except for the following points: In this example, the temperature of raw fabric layer 2 was controlled in the first irradiation step so that the temperature of the coating film was 65° C. Decorative sheet 1 was obtained in this manner.

[0120] Example 9: Example A decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, a coating liquid for the surface protective layer was used that was a blend of the following ionizing radiation curable resin A, ionizing radiation curable resin C, and particles. Ionizing radiation curable resin A Type: Trimethylolpropane EO-modified triacrylate (15 mols of EO added) Product name: SR9035 (manufactured by Sartomer) Blend: 40 parts by mass Ionizing radiation curable resin C Type: Polyethylene glycol diacrylate (14 mols of EO added) Product name: Light Acrylate 14EG-A (manufactured by Kyoeisha Chemical Co., Ltd.) Blend: 60 parts by mass Particle product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend: 5 parts by mass In this manner, decorative sheet 1 was obtained.

[0121] Example 10: Comparative Example Decorative sheet 1 was produced in the same manner as in Example 9, except for the following points: In this example, the temperature of raw fabric layer 2 was controlled in the first irradiation step so that the temperature of the coating film was 65° C. Decorative sheet 1 was obtained in this manner.

[0122] Example 11: Comparative Example Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, a coating liquid for the surface protective layer was used that was a blend of the following ionizing radiation curable resin A, ionizing radiation curable resin D, and particles. Ionizing radiation curable resin A Type: Trimethylolpropane EO-modified triacrylate (15 moles of EO added) Product name: SR9035 (manufactured by Sartomer) Blend: 40 parts by mass Ionizing radiation curable resin D Type: Tricyclodecane dimethanol diacrylate Product name: Light Acrylate DCP-A (manufactured by Kyoeisha Chemical Co., Ltd.) Blend: 60 parts by mass Particle product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend: 5 parts by mass In this manner, decorative sheet 1 was obtained.

[0123] <Example 12: Example> A decorative sheet 1 was produced in the same manner as in Example 11, except for the following points: In this example, the temperature of the raw fabric layer 2 was controlled in the first irradiation step so that the temperature of the coating film was 65° C. In this manner, a decorative sheet 1 was obtained.

[0124] Example 13: Comparative Example Decorative sheet 1 was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, a coating liquid for the surface protective layer was used that was obtained by blending the following particles with the following ionizing radiation curable resin A. Ionizing radiation curable resin A Type: Trimethylolpropane EO-modified triacrylate (15 moles of EO added) Product name: SR9035 (manufactured by Sartomer) Blend: 100 parts by mass Particle product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend: 5 parts by mass Furthermore, in this example, the first irradiation step was omitted. Decorative sheet 1 was obtained in this manner.

[0125] Example 14: Comparative Example Decorative sheet 1 was produced in the same manner as in Example 13, except for the following points: In this example, the amount of particles was 13 parts by mass per 100 parts by mass of ionizing radiation curable resin A. In this manner, decorative sheet 1 was obtained.

[0126] <Evaluation> Each of the decorative sheets described above was subjected to the following evaluations.

[0127] (1) Shape of the protrusions For each of the decorative sheets described above, the surface protective layer was observed under a microscope to confirm the shape of the protrusions. "Protrusions" in Tables 1 and 2 below refer to the shape of these protrusions.

[0128] (2) Surface Texture The surface texture of each of the decorative sheets was measured, and the aspect ratio Str and area load ratio Smr1 of the surface texture were determined.

[0129] (3) Thickness of the Surface Protective Layer For each of the decorative sheets, the thickness of the surface protective layer was measured using the same method as described above. Specifically, the decorative sheet 1 was embedded in a resin such as a cold-curing epoxy resin or a UV-curable resin, and the resin was allowed to fully harden. The decorative sheet 1 was then cut to reveal the cross section of the decorative sheet 1, and mechanically polished to obtain a measurement surface. Subsequently, the cross section of the surface protective layer was imaged using a SIGMA 500 scanning electron microscope manufactured by Carl Zeiss Microscopy. The imaging was performed at an acceleration voltage of 0.5 keV (low acceleration voltage), in the SE2 mode, and at a magnification of 2000x. No sputtering was performed on the measurement sample. Next, from this cross-sectional image, the dimension of the surface protective layer in the width direction of the ridge portion and the area of ​​the cross section of the surface protective layer were determined. The "thickness of the surface protective layer" was calculated by dividing this area by the above dimension. The "thickness of the surface protective layer" obtained in this manner was equal to the thickness of the coating film made from the surface protective layer coating liquid.

[0130] (4) Glossiness For each of the decorative sheets, the specular glossiness (GS60°) was measured using a Rhopoint IQ (manufactured by Konica Minolta, Inc.) The "glossiness" in Tables 1 and 2 below represents this specular glossiness (GS60°).

[0131] (5) Isotropy of Touch Each of the decorative sheets above was evaluated for the isotropy of the touch of the surface protective layer by the following method.

[0132] First, advance preparations were made to ensure that the evaluation criteria were consistent across evaluators. Specifically, standard test pieces with different surface textures were prepared. These standard test pieces included those with different surface texture aspect ratios (Str). Next, five evaluators were blindfolded and asked to gently press their fingertips against the surface of the standard test piece while sliding their fingertips linearly across the surface. Each evaluator then classified the standard test pieces into the following three groups based on the change in tactile sensation depending on the direction of the finger slide. Group 1: Those who felt a significant change in tactile sensation depending on the direction of the finger slide. Group 2: Those who felt a slight change in tactile sensation depending on the direction of the finger slide. Group 3: Those who felt no change in tactile sensation depending on the direction of the finger slide.

[0133] 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.

[0134] Next, for each of the decorative sheets, each of the evaluators was blindfolded and asked to gently press the surface of the surface protective layer with a finger and slide their fingertip linearly across the surface, and to classify the decorative sheets into one of the three groups based on the magnitude of change in tactile sensation depending on the direction of the finger slide. 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 isotropy of the tactile sensation was evaluated according to the following criteria: AA: Group 3 A: Group 2 B: Group 1 Note that "isotropy" in Tables 1 and 2 below refers to this isotropy of the tactile sensation.

[0135] (6) Fine convexity For each of the decorative sheets described above, the fine convexity of the surface protective layer was evaluated by the following method.

[0136] First, advance preparations were made to ensure that the evaluation criteria were consistent among the evaluators. Specifically, standard test pieces with different surface properties were prepared. These standard test pieces included those with different areal load ratios Smr1. Next, five evaluators were blindfolded and asked to lightly press the surface of the standard test piece with their fingers, and based on the tactile sensation they perceived, they were asked to classify the standard test pieces into the following three groups. Group 1: Sensing the presence of an uneven structure consisting of coarse convex portions. Group 2: Sensing a tactile sensation intermediate between those of Group 1 and Group 3. Group 3: Sensing the presence of an uneven structure consisting of fine convex portions.

[0137] 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.

[0138] Next, for each of the above decorative sheets, each of the evaluators was asked to lightly press the surface of the surface protective layer with a finger while blindfolded, and to classify the decorative sheets into the above three groups based on the tactile sensation perceived at that time. This procedure was then 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 fine convexity was evaluated according to the following criteria: AA: Group 3 A: Group 2 B: Group 1 (7) Fine Granularity Each of the above decorative sheets was evaluated for the fine granularity of the surface protective layer using the following method.

[0139] First, advance preparations were made to ensure that the evaluation criteria were consistent among the evaluators. Specifically, standard test pieces with different surface textures were prepared. These standard test pieces included those with different surface texture aspect ratios Str and areal load ratios Smr1. Next, five evaluators were blindfolded and asked to move their fingertips in small circles while lightly pressing the surface of the standard test piece. Based on the tactile sensation they perceived, they classified the standard test pieces into the following three groups. Group 1: During the circular movement of their fingertips, they felt a significant change in the tactile sensation or sensed the presence of an uneven structure consisting of coarse convex portions. Group 2: During the circular movement of their fingertips, they did not feel a significant change in the tactile sensation or the presence of an uneven structure consisting of coarse convex portions, but they felt a slight change in the tactile sensation or sensed the presence of an uneven structure consisting of convex portions between coarse and fine. Group 3: During the circular movement of their fingertips, they did not feel a significant change in the tactile sensation and sensed the presence of an uneven structure consisting of fine convex portions.

[0140] 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.

[0141] Next, for each of the decorative sheets, each of the evaluators, while blindfolded, was asked to gently press the surface of the surface protective layer with their fingertips in a circular motion and classify the decorative sheets into one of the three groups based on the tactile sensation they perceived. This procedure was repeated until the evaluations by each evaluator were consistent for three or more consecutive evaluations, and the evaluation results were consistent between evaluators for three consecutive evaluations. Based on these results, the fine graininess was evaluated according to the following criteria: AA: Group 3 A: Group 2 B: Group 1 (8) Scratch Resistance Each decorative sheet was attached to wood substrate B using a urethane-based 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 the surface of the decorative sheet was visually inspected for scratches and changes in gloss.

[0142] 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.

[0143] (9) Overall Evaluation A comprehensive evaluation was performed on each of the above decorative sheets based on the fine granularity and scratch resistance. The evaluation criteria were as follows: AA: Both the fine granularity and scratch resistance were rated "AA". A: One of the fine granularity and scratch resistance was rated "A", and the other was rated "AA" or "A". B: At least one of the fine granularity and scratch resistance was rated "B".

[0144] The evaluation results are shown in Tables 1 and 2.

[0145]

[0146]

[0147] As shown in Tables 1 and 2, the decorative sheets of Examples 3 to 5, 7, 9, and 12 gave the evaluators a fine grained feel. Furthermore, the decorative sheets of Examples 3 to 5, 7, 9, and 12 had excellent scratch resistance, with the decorative sheets of Examples 3 to 5, 7, and 12 having particularly excellent scratch resistance. Furthermore, the decorative sheets of Examples 3 to 5, 7, 9, and 12 had low gloss.

[0148] In contrast, the decorative sheets of Examples 1, 2, 6, 8, 10, and 11 had excellent scratch resistance but did not give the evaluators a fine grainy feel. Also, the decorative sheets of Examples 13 and 14 had poor scratch resistance.

[0149] 1...decorative sheet, 2...raw fabric layer, 3...pattern layer, 4...transparent resin layer, 5...surface protection layer, 5A...base, 5B...ridged portion, 6...primer layer, 7...adhesive layer, 8...hiding layer, 11...decorative material, B...base material.

Claims

1. A decorative sheet comprising an original fabric layer and a surface protection layer provided on one surface of the original fabric layer, wherein the surface protection layer contains a cured resin and has an uneven structure on the surface including a plurality of ridge-like portions each protruding in a ridge-like shape, wherein the uneven structure has an aspect ratio Str of the surface texture of 0.8 or more, and a load area ratio Smr1 separating the protruding ridge portions from the core portion is 13% or less.

2. A decorative sheet according to claim 1, wherein the specular gloss GS (60°) of the portion corresponding to said uneven structure is 5% or less.

3. A decorative sheet according to claim 1 or 2, wherein said surface protective layer has a thickness of 7 μm or less.

4. A decorative sheet according to any one of claims 1 to 3, wherein said resin is an ionizing radiation curable resin.

5. The decorative sheet according to claim 4, wherein said resin is an acrylate.

6. The decorative sheet according to claim 5, wherein said acrylate comprises a polyfunctional acrylate containing a repeating structure.

7. The decorative sheet according to any one of claims 1 to 6, wherein said surface protective layer further contains particles dispersed in said cured product.

8. The decorative sheet according to claim 7, wherein the amount of said particles is in the range of 3 to 10 parts by mass per 100 parts by mass of said cured product.

9. The decorative sheet according to any one of claims 1 to 8, further comprising a pattern layer between said base layer and said surface protective layer.

10. A decorative material comprising the decorative sheet according to any one of claims 1 to 9 and a substrate to which the decorative sheet is attached.

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