decorative sheet

Abstract

The present invention provides a decorative sheet that is highly scratch-resistant and has a unique texture. The decorative sheet (1) comprises a base layer (2) and a surface protection layer (5) provided on one surface of the base layer (2). The surface protection layer (5) contains a cured resin and has an uneven surface structure including a plurality of ridge-like portions, each of which protrudes in a ridge-like manner. The uneven surface structure has an aspect ratio Str of 0.8 or more, and a load area ratio Smr1 separating the protruding ridges from the core portion is 13% or less.

Description

[Technical Field]

[0001] This invention relates to a decorative sheet. [Background technology]

[0002] Decorative sheets are used, for example, for the purpose of surface decoration of interior and exterior materials such as doors, furniture, joinery, and flooring, that is, to provide aesthetic appeal and durability to these materials. Decorative sheets are generally widely used as decorative panels that are attached to the surface of substrates such as wood, wood fiberboard, metal plates, non-combustible boards, paper substrates, and resin substrates using adhesives.

[0003] Design appeal is achieved, for example, by creating patterns such as wood grain or stone patterns using various printing methods. Plain, unpatterned decorative sheets are sometimes preferred. The presence or absence of patterns, and the type of pattern chosen, varies depending on the application and personal preference.

[0004] The glossiness of the surface is also an important aspect of the design of decorative sheets. Depending on the application and preference, a variety of decorative sheets can be selected, from highly glossy, mirror-like finishes to low-gloss finishes that show no reflections at all.

[0005] Furthermore, as mentioned above, alongside the provision of aesthetic appeal, durability is another important function of decorative sheets. Durability is a comprehensive evaluation of scratch resistance, stain resistance, and whether these properties are maintained over a long period of time. While the requirements vary depending on the environment and circumstances in which the decorative sheet is used, there is always a demand for decorative sheets with high performance.

[0006] To enhance durability, it is common practice to form a surface protective layer on the outermost surface of the decorative sheet. Furthermore, to adjust the gloss level, particularly to achieve a low gloss, it is common practice to add a gloss adjuster (matte additive) to the surface protective layer.

[0007] Furthermore, since decorative sheets are generally subjected to processes such as cutting and bending to form decorative materials such as decorative panels, it is preferable that they have the processability to withstand these processes.

[0008] As such, an example of a decorative sheet that takes into account aesthetic appeal (low gloss), scratch resistance, and stain resistance is the decorative sheet described in Patent Document 1. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2019-119138 [Overview of the Initiative]

[0010] The purpose of this disclosure is to provide a decorative sheet that has excellent scratch resistance and a unique tactile feel. [Means for solving the problem]

[0011] According to one aspect of the present invention, a decorative sheet is provided comprising a base layer and a surface protection layer provided on one surface of the base layer, wherein the surface protection layer contains a cured resin and has an uneven structure on its surface including a plurality of ridge-like portions, each of which protrudes in a ridge-like manner, the aspect ratio Str of the surface properties of the uneven structure is 0.8 or more, and the load area ratio Smr1 separating the protruding peaks and the core portion is 13% or less.

[0012] According to another aspect of the present invention, a decorative sheet is provided 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, a decorative sheet according to any of the above aspects is provided, wherein the surface protective layer has a thickness of 7 μm or less.

[0014] According to yet another aspect of the present invention, a decorative sheet is provided relating to any of the above aspects, wherein the resin is an ionizing radiation-curable resin.

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

[0016] According to still 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 still another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the surface protective layer further includes particles dispersed in the cured product.

[0018] According to still 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 with respect to 100 parts by mass of the cured product.

[0019] According to still another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, further including a pattern layer between the base fabric layer and the surface protective layer.

[0020] According to still another aspect of the present invention, there is provided a decorative material including a decorative sheet according to any of the above aspects and a base material to which the decorative sheet is attached.

[0021] According to the present disclosure, it is possible to provide a decorative sheet having excellent scratch resistance and giving a unique tactile sensation.

Brief Description of the Drawings

[0022] [Figure 1] FIG. 1 is a cross-sectional view of a decorative material including a decorative sheet according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the surface protective layer included in the decorative sheet of FIG. 1. [Figure 3] FIG. 3 is a microscopic image of the surface protective layer included in a decorative sheet according to an example of the present invention.

Embodiments for Carrying Out the Invention

[0023] Embodiments of the present invention will be described below with reference to the drawings. The embodiments described below are more specific to any of the above aspects. The matters described below can be incorporated into each of the above aspects, individually or in combination.

[0024] Furthermore, the embodiments shown below illustrate configurations for realizing the technical concept of the present invention, and the technical concept of the present invention is not limited by the material, shape, and structure of the components described below. Various modifications can be made to the technical concept of the present invention within the technical scope defined by the claims described in the claims.

[0025] Elements with similar or identical functions are given the same reference numerals in the drawings referenced below, and redundant explanations are omitted. Furthermore, the drawings are schematic, and the relationships between dimensions in one direction and those in another, and the relationships between the dimensions of one component and those of other components, may differ from reality.

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

[0027] Note that the cross-section shown in Figure 2 is a cross-section along the thickness direction of the surface protective layer. Also, the microscope image in Figure 3 is a planar image obtained with a laser microscope (Olympus OLS-4000).

[0028] The decorative material 11 shown in Figure 1 includes a base material B and a decorative sheet 1 attached thereto. Here, the decorative material 11 is a decorative board. The decorative board may be flat, bent, or folded. The decorative material 11 may have a shape other than a board.

[0029] In this case, base material B is a board. The board material is, for example, a wood-based board, an inorganic board, a metal plate, or a composite board made of multiple materials. Base material B may have a shape other than a board.

[0030] The decorative sheet 1 includes a base layer 2, a pattern layer 3, a transparent resin layer 4, a surface protection layer 5, an adhesive layer 7, a primer layer 6, and a concealing layer 8. The pattern layer 3, adhesive layer 7, transparent resin layer 4, and surface protection layer 5 are provided in this order from the base layer 2 side on the side of the base layer 2 opposite to the side facing the substrate B. The concealing layer 8 and primer layer 6 are provided in this order from the base layer 2 side on the side of the base layer 2 facing the substrate B. One or more of the pattern layer 3, transparent resin layer 4, primer layer 6, adhesive layer 7, and concealing layer 8 may be omitted. The elements included in the decorative sheet 1 will be described in order below.

[0031] <1.1>Primitive layer For the base layer 2 or its materials, any material can be arbitrarily 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 fabrics include organic and inorganic nonwoven fabrics. Examples of metals for metal foil include aluminum, iron, gold, and silver.

[0032] The thickness of the base material layer 2 is preferably within the range of 20 μm to 250 μm, taking into consideration factors such as printability and cost.

[0033] <1.2>Primary layer When an olefin-based resin is used as the material for the base layer 2, the surface of the base layer 2 is often inert. Therefore, in this case, it is preferable to provide a primer layer 6 between the base layer 2 and the substrate B. When the base layer 2 is made of an olefin-based material, the primer layer 6 may be omitted, and in order to improve the adhesion between the base layer 2 and the substrate B, the base layer 2 may be subjected to surface modification treatments such as corona treatment, plasma treatment, ozone treatment, electron beam treatment, ultraviolet treatment, or dichromate treatment.

[0034] As for the material of the primer layer 6, for example, the materials described later for the pattern layer 3 can be used. Since the primer layer 6 is applied to the back surface of the decorative sheet 1, and considering that the decorative sheet 1 is wound in a web-like shape, an inorganic filler may be added to the primer layer 6 to avoid blocking and to improve adhesion with the adhesive. Examples of inorganic fillers include silica, alumina, magnesia, titanium oxide, and barium sulfate.

[0035] <1.3> Concealing layer To impart opacity to the decorative sheet 1 relative to the base material B, for example, a colored sheet can be used as the base layer 2, or an opaque opacity layer 8 can be provided. The opacity layer 8 can be made of the same material as that used for the pattern layer 3, as described later. However, since the purpose of the opacity layer 8 is opacity, it is preferable to use opaque pigments, such as titanium dioxide or iron oxide, as the pigment. Furthermore, to enhance opacity, metals such as gold, silver, copper, or aluminum can be added to the material of the opacity layer 8. Generally, flake-shaped aluminum pieces are often added.

[0036] <1.4>Pattern Layer The pattern layer 3 is a layer formed by printing a pattern onto the base material layer 2 using ink. As the ink binder, for example, nitrated cotton, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acrylic, polyesters, or modified versions thereof can be used individually or in combination. The binder may be water-based, solvent-based, or emulsion type, and may be a one-component type or a two-component type using a curing agent. The pattern layer 3 may also be formed by curing a layer formed with a curable ink by irradiation with ultraviolet light or electron beams. Among these, the most common method is to use a urethane-based ink and cure it with isocyanate. In addition to the binder, the ink used to form the pattern layer 3 may further contain, for example, pigments, dyes, and other colorants, extender pigments, solvents, and various additives found in ordinary inks. Examples of highly versatile pigments include condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolon, cobalt, phthalocyanine, carbon, titanium dioxide, iron oxide, mica, and other pearl pigments.

[0037] In addition to ink application, it is also possible to apply designs to the pattern layer 3 by vapor deposition or sputtering of various metals. In particular, it is preferable that a light stabilizer is added to the ink. This suppresses the deterioration of the decorative sheet 1 itself caused by light degradation of the ink, and extends the lifespan of the decorative sheet 1.

[0038] <1.5>Adhesive layer The adhesive layer 7 is also called the heat-sensitive adhesive layer, anchor coat layer, or dry lamination adhesive layer.

[0039] The resin material of the adhesive layer 7 is not particularly limited, but can be appropriately selected from resin materials such as acrylic, polyester, polyurethane, and epoxy. 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 after forming the adhesive layer 7 on the upper surface of the pattern layer 3 by gravure coating, the transparent resin layer 4 is laminated. Note that the adhesive layer 7 can be omitted if sufficient adhesive strength is obtained between the transparent resin layer 4 and the pattern layer 3.

[0040] <1.6>Transparent resin layer As the resin material for the transparent resin layer 4, olefin-based resins are preferably used. Examples of olefin-based resins include polypropylene, polyethylene, polybutene, and 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 include homopolymers of (such as -ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, etc.) 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. Various additives such as heat stabilizers, light stabilizers, blocking inhibitors, catalyst scavengers, colorants, light scattering agents, and gloss adjusters may be added to the transparent resin layer 4 as needed. Generally, phenol-based, sulfur-based, phosphorus-based, and hydrazine-based heat stabilizers are used, and hindered amine-based light stabilizers are used, in any combination.

[0042] <1.7>Surface protective layer The surface of the surface protection layer 5 is provided with an uneven surface structure that includes 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 portion 5A and a plurality of ridge-like portions 5B, each of which protrudes in a ridge-like manner from one side of the base portion 5A. These ridge-like portions 5B form the above-described uneven surface structure.

[0043] Here, in the decorative sheet 1 according to this embodiment, "ridged" refers to a convex shape that is linear in plan view. The ridged portion 5B may be curved or straight in plan view, but it is preferable that it be curved from the viewpoint of fingerprint resistance of the decorative sheet 1. Each of the ridged portions 5B may or may not be branched in plan view. In this disclosure, the ridged portion 5B is, for example, the portion from the lowest part 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 ridged portion 5B.

[0044] As shown in Figure 3, for example, each of the ridge-like portions 5B is curved, and at least a portion of them are adjacent in the width direction. At the positions where at least a portion of the ridge-like portions 5B are adjacent in the width direction, the cross-section of the surface protective layer 5 parallel to this width direction and the thickness direction of the surface protective layer 5, as shown in Figure 2, has a wave shape such as a sinusoidal shape in the portion where the uneven structure is provided.

[0045] The uneven structure formed by the ridged portion 5B has a surface texture aspect ratio Str of 0.8 or greater. 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 greater, and more preferably 0.85 or greater. 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] If the aspect ratio Str of the surface texture is set to 0.8 or higher, the bias in the length direction of the ridged portion 5B becomes sufficiently small. Therefore, when a finger is slid across the surface of the protective layer 5, the influence of the direction in which the finger is slid on the tactile sensation becomes sufficiently small. Furthermore, if the aspect ratio Str of the surface texture is set to 0.85 or higher, the isotropy of the tactile sensation is further enhanced, and the fine granular texture described later becomes more clearly perceptible.

[0047] However, if the aspect ratio Str of the surface texture is greater than 0.94, the isotropy of the tactile sensation may increase excessively, potentially resulting in a monotonous texture. Furthermore, if the tactile sensation becomes excessively isotropic, a discrepancy may arise between the tactile sensation and, for example, a specific design (such as wood grain or stone pattern), potentially compromising the realism desired by the user. 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 ridged portion 5B has a load area ratio Smr1 (hereinafter sometimes abbreviated as load area ratio Smr1) of 13% or less that separates the protruding peak portion from the core portion. Here, the load area ratio Smr1 that separates the protruding peak portion from the core portion is a surface texture parameter defined in ISO 25178. Specifically, the load area ratio Smr1 represents the load area ratio at the level that separates the region from the top of the highest peak on the surface to the upper end of the core portion (protruding peak portion) from the region below it (core portion) in the height distribution. The load area ratio Smr1 is preferably 13% or less, and more preferably 11% or less. In one example, the load area ratio Smr1 is 9% or more, and in another example, it is 9.3% or more.

[0049] In a textured surface with a load area ratio Smr1 of 13% or less, when pressed with a finger, the finger makes contact with the protrusions over a small area. Therefore, such a textured surface allows the user to perceive a tactile sensation similar to that of a textured surface composed of fine protrusions when touched with a finger. Furthermore, if the textured surface provides an isotropic tactile sensation when slid with a finger, and this sensation is similar to that of a textured surface composed of fine protrusions (fine protrusion sensation), the user perceives a tactile sensation similar to that of a layer where fine spherical particles are uniformly dispersed and partially exposed on the surface (fine granular sensation). Thus, a load area ratio Smr1 of 13% or less is important for obtaining a fine granular sensation.

[0050] On the other hand, if the load area ratio Smr1 is less than 9%, the protrusions may become too fine, making it difficult to perceive the tactile sensation derived from the uneven structure, or the tactile sensation may become too monotonous. For the uneven structure to be fine yet for the tactile sensation derived from it to be easily recognizable, it is preferable that the load area ratio Smr1 be 9% or higher. If the load area ratio Smr1 is 9.3% or higher, the tactile sensation derived from the uneven structure becomes even more clearly perceptible. For example, the tactile sensation obtained from an uneven structure with a load area ratio Smr1 of less than 9.3% is classified as Group 3 (the presence of an uneven structure consisting of fine protrusions is felt) as described later for fine protrusion sensation, but the tactile stimulation is weak, and the fine protrusion sensation tends not to be sufficiently perceived.

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

[0052] The surface protection layer 5, which has a surface texture with a large aspect ratio Str, provides the user with a nearly identical tactile sensation when the user presses the surface texture with their skin and slides their skin over it, or when the user presses the surface texture with their finger and slides their finger over it, regardless of the direction in which the finger is slid. In other words, a surface texture with a large aspect ratio Str provides the user with an isotropic tactile sensation.

[0053] When a user presses a small uneven surface with a load area ratio Smr1 against their skin, for example, when pressing the uneven surface with their finger, the finger or other object comes into contact with the protrusions over a small area. In this situation, the tactile sensation that the uneven surface provides to the user is similar to the tactile sensation that an uneven surface consisting of fine protrusions provides to the user (hereinafter referred to as "fine protrusion sensation").

[0054] Furthermore, if the uneven structure provides the user with an isotropic tactile sensation, and this tactile sensation is similar to that provided to the user by an uneven structure consisting of fine protrusions, the user perceives a tactile sensation similar to that 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 "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 protection layer 5 is the thickness of a layer that has the same apparent area and volume as the surface protection layer 5 and has a flat surface. The thickness of the surface protection layer 5 can be determined, for example, by the following method. First, a cross-section is imaged that is parallel to the thickness direction of the surface protection layer 5 and perpendicular to the length direction of the ridged portion 5B. Next, from this cross-sectional image, the dimensions of the surface protection layer 5 in the width direction of the ridged portion 5B and the area of ​​the cross-section of the surface protection layer 5 are determined. The thickness of the surface protection layer 5 is the value obtained by dividing this area by the above dimensions. Note that if the coating liquid for the surface protection layer, which will be described later, does not contain a solvent, the thickness of the coating film made from the coating liquid for the surface protection layer is equal to the thickness of the surface protection layer 5.

[0057] If the above coating is made thicker, expansion of the cured film in the in-plane direction becomes more likely during the first irradiation process described later, and therefore, wrinkles corresponding to the ridged portions 5B are more likely to form on the surface of the coating. However, if the above coating is made excessively thick, for example, individual wrinkles may grow while the number of wrinkles per unit area remains small. For this reason, increasing the thickness of the surface protective layer 5 may result in a decrease in the aspect ratio Str of the surface properties or an increase in the load area ratio Smr1.

[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 resin of ionizing radiation. Here, "ionizing radiation" refers to charged particle beams such as electron beams. Ionizing radiation-curable resins harden when irradiated with ionizing radiation. Ionizing radiation-curable resins can also be hardened by ultraviolet irradiation. The ionizing radiation-curable resin used here hardens when irradiated with light with a wavelength of 200 nm or less, while having a large absorption coefficient for this light.

[0060] The amount of 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 materials such as various monomers and commercially available oligomers can be used, for example, (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins can be used. The ionizing radiation-curable resin may be either an aqueous resin or a non-aqueous (organic solvent) resin.

[0061] The main component of the ionizing radiation-curable resin is preferably 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 acrylate in an amount of 70% by mass or more, and more preferably 80% by mass or more. The ionizing radiation-curable resin is more preferably acrylate.

[0062] The acrylate is preferably a two- or more functional acrylate, and more preferably contains three or more functional acrylates. There is no upper limit to the number of functional groups in the acrylate, but one example suggests it is six or fewer.

[0063] To obtain a surface protective layer 5 with excellent scratch resistance, it is preferable that the acrylate contains a trifunctional or higher acrylate. Furthermore, it is preferable that the acrylate contains a trifunctional or lower acrylate. Such an acrylate may, in one example, be a trifunctional acrylate, or in another example, a combination of a trifunctional acrylate and a difunctional acrylate.

[0064] The total proportion of trifunctional acrylates and bifunctional acrylates 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.

[0065] The proportion of 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 also be 100% by mass.

[0066] The acrylate preferably contains a repeating structure. This repeating structure is, for example, one of the following: an ethylene oxide (EO) structure, a propylene oxide (PO) structure, or an ε-caprolactone (CL) structure. The repeating structure is preferably ethylene oxide or propylene oxide. In the acrylate, the above repeating structure may be interposed 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 high number of repetitions is used, expansion in the in-plane direction of the cured film is more likely to occur in the first irradiation step described later, and therefore, wrinkles corresponding to the ridged portions 5B are more likely to occur on the surface of the coating film. In other words, this number of repetitions can affect the surface properties of the surface protective layer 5. However, if this 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 repeating structures 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. Increasing this proportion makes it easier for the cured film to expand in the in-plane direction during the first irradiation step. That is, this proportion can 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 structure. In another preferred embodiment, the ionizing radiation-curable resin is a combination of a trifunctional acrylate containing a repeating structure and a bifunctional acrylate containing a repeating structure. In yet another preferred embodiment, the ionizing radiation-curable resin is a combination of a trifunctional acrylate containing a repeating structure and a bifunctional acrylate that does not contain a repeating structure, such as tricyclodecanedimethanol diacrylate.

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

[0071] The bifunctional acrylate containing a repeating structure is, for example, polyethylene glycol diacrylate or polypropylene glycol diacrylate, and may also contain a caprolactone structure. In the bifunctional acrylate containing a repeating structure, the number of repetitions of the repeating structure 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 structure is, in one example, in the range of 170 to 1139, and in another example, in the range of 184 to 1391.

[0072] When using a trifunctional acrylate containing a repeating structure and a bifunctional acrylate containing a repeating structure in combination, it is preferable that the number of repetitions of the repeating structure in the bifunctional acrylate is less than the number of repetitions of the repeating structure in the trifunctional acrylate. For example, if the number of repetitions of the repeating structure in the trifunctional acrylate is in the range of 9 to 15, it is preferable that the number of repetitions of the repeating structure in the bifunctional acrylate is in the range of 3 to 9. Reducing the number of repetitions of the repeating structure in the bifunctional acrylate tends to increase the hardness of the surface protective layer 5 and improve its scratch resistance because the ease of molecular movement in the surface protective layer 5 decreases.

[0073] The number of repetitions in the above repeating structure can be analyzed using MALDI-TOF-MS. Ionizing radiation-curable resins may have a molecular weight distribution. If a molecular weight distribution exists, the number of repetitions should be the number of repetitions corresponding to the molecular weight with the strongest peak in the MALDI-TOF-MS mass spectrum.

[0074] The particles included in the surface protective layer 5 may be, for example, particles made of organic materials such as polyethylene (PE) wax, polypropylene (PP) wax, or resin beads, or particles made of inorganic materials such as silica, glass, alumina, titania, zirconia, calcium carbonate, or barium sulfate.

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

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

[0077] Here, "average particle size" or "average particle size (D50)" refers to the median diameter (D50) measured by a laser diffraction / scattering particle size distribution analyzer. Note that if the coating liquid for the surface protection layer contains particles, the surface protection layer 5 obtained from this coating liquid will also contain particles. The average particle size of the particles contained in the surface protection layer 5 can be determined by observing its cross-section, measuring the particle sizes of multiple particles, and averaging the result. The value obtained in this way is substantially the same as the median diameter (D50) measured by a laser diffraction / scattering particle size distribution analyzer. Therefore, the range of average particle size described above can also be interpreted as the range of average particle size of the particles contained in the surface protection layer 5.

[0078] The amount of particles in the surface protective layer 5 is preferably within the range of 3 parts by mass to 10 parts by mass, and more preferably within 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 added particles is within the above range, the effect of uniformly creating wrinkles is particularly great. If the amount of added particles is too high, the particles are more likely to fall off the surface protective layer 5, making it difficult to achieve high scratch resistance. If the amount of added particles is too low, it may be difficult to create an uneven surface on the surface protective layer 5 that gives the user an isotropic tactile feel and a fine texture.

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

[0081] <2> Manufacturing method of decorative sheets The decorative sheet 1 is manufactured, for example, by the following method. For simplicity, the descriptions of the pattern layer 3, transparent resin layer 4, primer layer 6, adhesive layer 7, and concealing layer 8 are omitted here.

[0082] First, a coating film consisting of a surface protective coating liquid is formed on one side of the raw material 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 by various coating methods such as roll coating, knife coating, microgravure coating, and die coating.

[0083] The coating solution for the surface protective layer contains the resin and the particles described above. The coating solution for the surface protective layer may further contain a solvent and additives for improving the functionality of the final product, such as antimicrobial agents and antifungal agents. The coating solution for the surface protective layer may further contain other additives such as ultraviolet absorbers and light stabilizers. Examples of ultraviolet absorbers that can be used include benzotriazole-based, benzoate-based, benzophenone-based, and triazine-based types. Examples of light stabilizers that can be used include hindered amine-based types. Furthermore, according to the method described herein, a surface protective layer 5 having low gloss can be formed without gloss modifiers (matte additives).

[0084] In the second irradiation step described later, when the entire coating film consisting of the surface protective layer coating liquid is cured by ultraviolet irradiation, it is preferable that the surface protective layer coating liquid further contains a photoinitiator. The photoinitiator is not particularly limited, but examples include benzophenone-based, acetophenone-based, benzoin ether-based, and thioxanthone-based photoinitiators.

[0085] After forming a coating film consisting of a surface protection coating liquid, a first irradiation step is performed. In the first irradiation step, light with a wavelength of 200 nm or less (hereinafter referred to as first radiation) is irradiated onto the coating film. The ionizing radiation-curable resin contained in the surface protection coating liquid has a large absorption coefficient for first radiation. Therefore, first radiation incident on the coating film can only reach a distance of tens to hundreds of nanometers from its outermost surface. Consequently, in the first irradiation step, a crosslinking reaction proceeds in the surface region of the coating film, forming an extremely thin cured film, while other regions remain uncured as the crosslinking reaction does not proceed.

[0086] The coating film after the first irradiation process has wrinkles on its surface corresponding to the ridged portion 5B. The inventors believe the reason why wrinkles form on the coating film surface due to the first irradiation process is as follows.

[0087] As described above, the first radiation can only reach a distance of tens to hundreds of nanometers from the outermost surface of the coating film. In other words, the crosslinking reaction of the ionizing radiation-curable resin occurs only at the surface of the coating film, and in regions further than tens to hundreds of nanometers from the outermost surface, there is uncured resin with high fluidity. 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, resulting in buckling of the cured film and the formation of wrinkles on the coating film surface.

[0088] The first type of radiation can be extracted from excimer VUV (Vacuum Ultra Violet) light. Excimer VUV light can be generated from lamps using noble gases or noble gas halide compounds. When high-energy electrons are supplied from an external source to a lamp containing a noble gas or noble gas halide compound, numerous discharge plasmas (dielectric barrier discharges) are generated. This plasma discharge excites the atoms of the discharge gas (noble gas), causing them to instantaneously enter an excimer state. When returning from this excimer state to the ground state, light in the wavelength range specific to the excimer state is emitted.

[0089] The gas used in an excimer lamp can be any conventionally used gas, as long as it emits light of 200 nm or less. As gases, noble gases such as Xe, Ar, and Kr, or mixed gases of noble gases and halogen gases such as ArBr and ArF can be used. The wavelength (center wavelength) of an excimer lamp varies depending on the gas used, and for example, it has 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 the photon energy and the difference between the wavelength and the bonding energy of the organic material, it is preferable to use a xenon lamp that emits excimer light with a central wavelength of 172 nm as the light source. Furthermore, considering the costs of equipment maintenance and material availability, it is also preferable to use a xenon lamp as the light source.

[0091] The first irradiation step is carried out in an atmosphere with a low oxygen concentration. Oxygen has a large absorption coefficient for light below 200 nm. Therefore, it is preferable to carry out the first irradiation step in a nitrogen gas atmosphere, for example. Furthermore, oxygen in the atmosphere inhibits radical polymerization. Therefore, the residual oxygen concentration in the reaction atmosphere affects the formation of wrinkles on the surface of the coating film. 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 during the first irradiation step, i.e., the residual oxygen concentration in the reaction atmosphere, is preferably 200 ppm or less, and 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, and more preferably 10 mm or less. The irradiation distance is, for example, 5 mm or more. Increasing the irradiation distance increases the absorption of light below 200 nm by oxygen.

[0093] The cumulative light intensity of the first radiation is 0.5 mJ / cm². 2 More than 200mJ / cm 2 The following is preferable: 1 mJ / cm 2 More than 100mJ / cm 2More preferably, it is set as follows: 3 mJ / cm 2 or more and 50 mJ / cm 2 or less. When the integrated light quantity is reduced, the expansion of the cured film in the in-plane direction becomes smaller. When the integrated light quantity is increased, the surface state of the coating film deteriorates.

[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 the range of 20°C or more and 65°C or less. When the temperature of the coating film is increased, the viscosity of the coating liquid for the surface protective layer decreases and its fluidity increases. Also, when the temperature of the coating film is increased, the flexibility of the cured film increases. Therefore, the temperature of the coating film affects the formation of wrinkles on the coating film surface. Accordingly, by changing the above 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 the second radiation to cure the entire coating film. Thereby, the surface protective layer 5 is obtained.

[0096] The second radiation is ionizing radiation such as an electron beam or ultraviolet light having a longer wavelength compared to the first radiation. When ultraviolet light is used as the second radiation, this ultraviolet light shall have 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 or more and 50 kGy or less, more preferably 5 kGy or more and 40 kGy or less, and even more preferably 5 kGy or more and 10 kGy or less. If the dose is too low, curing will be insufficient, and if the dose is too high, there is a high possibility that the ionizing radiation will induce embrittlement of the decorative sheet.

[0098] When ultraviolet light is used as the second radiation, the integrated light quantity of the second radiation is preferably 10 mJ / cm 2 or more and 500 mJ / cm 2 or less, and more preferably 50 mJ / cm 2 or more and 400 mJ / cm 2It is more preferable to use the following: 100 mJ / cm² 2 More than 300mJ / cm 2 The following is even more preferable.

[0099] In this method, the surface protection layer 5 is formed such that its uneven structure has the surface properties described above. As described above, the composition of the coating liquid for the surface protection layer, the thickness of the coating film made from this coating liquid, and various conditions in the first irradiation step all affect these surface properties. Therefore, for example, in order to form a surface protection layer 5 having a desired composition, thickness, and surface properties, 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 that the above surface properties can be obtained.

[0100] The decorative sheet 1 may be manufactured by other methods. For example, a plate may be formed for the surface protective layer 5 using the method described above, and this plate may be used to form the surface protective layer 5 having an uneven surface structure. For example, a plate for primary transfer may be formed for the surface protective layer 5 using the method described above, a plate for secondary transfer may be formed by transfer using this primary transfer plate, and the surface protective layer 5 having an uneven surface structure 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 a surface protective layer 5 having the surface properties described above. When a user presses their skin against the uneven structure on the surface of the surface protective layer 5 of such a decorative sheet 1 and slides their skin over this uneven structure, the user receives an isotropic tactile sensation. Furthermore, the tactile sensation that the above-described uneven structure provides to the user when pressed against by the user is similar to the tactile sensation (fine convex sensation) provided to the user by an uneven structure consisting of fine convex parts. The combination of isotropic tactile sensation and fine convex sensation makes the user perceive a tactile sensation similar to that 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 above-described decorative sheet 1 provides a unique tactile sensation to the user who touches the uneven structure on the surface of its surface protective layer 5.

[0102] Furthermore, this decorative sheet 1 has excellent scratch resistance, as explained below. A surface protection layer having an uneven surface structure can also be obtained by forming a layer containing particles and a binder resin such that protrusions corresponding to the shape of the particles or aggregates are formed on its surface. However, such a surface protection layer has a large number of exposed particles on its surface, making it prone to particle detachment due to abrasion, etc. Moreover, in a surface protection layer with such a structure, the particles or aggregates themselves constitute the protrusions, so when particles detach, the optical properties of the surface protection layer change significantly. Therefore, if a part of the surface protection layer is abraded, a large number of particles will detach from that part, and the optical properties of that part will differ significantly from those of other parts. As a result, the abraded part will be easily recognized as, for example, a scratch.

[0103] In contrast, in the decorative sheet 1 described above, the uneven structure 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, even if the surface protective layer 5 of the decorative sheet 1 described above contains particles, these particles are intended to cause uniform and high-density buckling of the cured film. Therefore, the number of particles per unit surface area of ​​the surface protective layer 5 does not need to be large. Moreover, the particles that may fall off due to abrasion are limited to those located near the top of the ridged portion 5B.

[0105] Furthermore, the ridged portion 5B is mostly composed of cured resin. Therefore, even if particle shedding occurs, this shedding has little effect on the optical properties of the surface protective layer 5.

[0106] Therefore, even if a certain part of the surface protective layer 5 of the decorative sheet 1 is rubbed, the change in the optical properties of that part is minimal. Consequently, the rubbed part of the decorative sheet 1 is unlikely to become easily recognizable as a scratch. In other words, the decorative sheet 1 has excellent scratch resistance. [Examples]

[0107] Examples of the present invention are described below. Note that the "particle size" described below refers to the "average particle size (D50)" mentioned above.

[0108] <Example 1: Comparative Example> The decorative sheet 1, as described with reference to Figures 1 to 3, was manufactured by the following method. In this example, the transparent resin layer 4, primer layer 6, adhesive layer 7, and concealing layer 8 were omitted.

[0109] First, the basis weight is 50 g / m². 2 Impregnated paper (GFR-506: manufactured by Kojin Co., Ltd.) was prepared as the base layer 2. On one side of the base layer 2, the pattern layer 3 was formed using oil-based nitrated cotton resin gravure printing ink (PCNT (PCRNT) various colors: manufactured by Toyo Ink Co., Ltd.).

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

[0111] Subsequently, the first irradiation process was carried out. Specifically, under atmospheric pressure and in a nitrogen gas atmosphere with an oxygen concentration of 100 ppm, ultraviolet light with a wavelength of 172 nm was applied to the surface of the coating film, which consists of a coating liquid for the surface protective layer, using a Xe excimer lamp, with an integrated light intensity of 7 mJ / cm². 2The irradiation was performed in such a manner. 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 base material layer 2 was controlled so that the temperature of the coating film reached 25°C. This caused wrinkles to form on the surface of the coating film.

[0112] Next, the second irradiation process was carried out. Specifically, the coating film was irradiated with ionizing radiation to harden the entire film, thereby forming a surface protective layer 5. In this way, decorative sheet 1 was obtained.

[0113] <Example 2: Comparative Example> The decorative sheet 1 was manufactured in the same manner as in Example 1, except for the following points. In other words, in this example, the coating liquid used for the surface protective layer was a mixture of the following particles with the following ionizing radiation-curable resin A. ·Ionizing radiation curable resin A Type: Trimethylolpropane EO-modified triacrylate (EO 15 molar added) Product Name: SR9035 (manufactured by Sartomer) Blend: 100 parts by mass ·particle Product Name: Silysia 250N (Manufactured by Fuji Silysia Chemical Co., Ltd.) Particle size: 5μm Blend: 5 parts by mass In this example, the coating film, which consists of a surface protective coating liquid, was formed to a thickness of 10 μm. In this way, decorative sheet 1 was obtained.

[0114] <Example 3: Implementation> The decorative sheet 1 was manufactured in the same manner as in Example 2, except for the following point. Specifically, in this example, the temperature of the raw material layer 2 was controlled so that the temperature of the coating film reached 65°C during the first irradiation process. The decorative sheet 1 was obtained in this manner.

[0115] <Example 4: Example> The decorative sheet 1 was manufactured in the same manner as in Example 2, except for the following point. Specifically, in this example, the coating film consisting of the surface protective layer coating liquid was formed to a thickness of 5 μm. The decorative sheet 1 was obtained in this manner.

[0116] <Example 5: Example> The decorative sheet 1 was manufactured in the same manner as in Example 4, except for the following point. Specifically, in this example, the temperature of the raw material layer 2 was controlled so that the temperature of the coating film reached 65°C during the first irradiation process. The decorative sheet 1 was obtained in this manner.

[0117] <Example 6: Comparative Example> The decorative sheet 1 was manufactured in the same manner as in Example 4, except for the following point. Specifically, in this example, the irradiation distance in the first irradiation step was set to 15 mm. The decorative sheet 1 was obtained in this manner.

[0118] <Example 7: Example> The decorative sheet 1 was manufactured in the same manner as in Example 1, except for the following points. In other words, in this example, a coating solution for the surface protective layer was used that was a mixture 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 (EO 15 molar added) Product Name: SR9035 (manufactured by Sartomer) Blend: 40 parts by mass ·Ionizing radiation curable resin B Type: Polyethylene glycol diacrylate (EO 4 molar addition) Product Name: Light Acrylate 14EG-A (Manufactured by Kyoeisha Chemical Co., Ltd.) Blend: 60 parts by mass ·particle Product Name: Silysia 250N (Manufactured by Fuji Silysia Chemical Co., Ltd.) Particle size: 5μm Blend: 5 parts by mass In this way, decorative sheet 1 was obtained.

[0119] <Example 8: Comparative Example> The decorative sheet 1 was manufactured in the same manner as in Example 7, except for the following point. Specifically, in this example, the temperature of the raw material layer 2 was controlled so that the temperature of the coating film reached 65°C during the first irradiation process. The decorative sheet 1 was obtained in this manner.

[0120] <Example 9: Implementation Example> The decorative sheet 1 was manufactured in the same manner as in Example 1, except for the following points. In other words, in this example, a coating solution for the surface protective layer was used that was a mixture 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 (EO 15 molar added) Product Name: SR9035 (manufactured by Sartomer) Blend: 40 parts by mass ·Ionizing radiation curable resin C Type: Polyethylene glycol diacrylate (EO14 molar addition) Product Name: Light Acrylate 14EG-A (Manufactured by Kyoeisha Chemical Co., Ltd.) Blend: 60 parts by mass ·particle Product Name: Silysia 250N (Manufactured by Fuji Silysia Chemical Co., Ltd.) Particle size: 5μm Blend: 5 parts by mass In this way, decorative sheet 1 was obtained.

[0121] <Example 10: Comparative Example> The decorative sheet 1 was manufactured in the same manner as in Example 9, except for the following point. Specifically, in this example, the temperature of the raw material layer 2 was controlled so that the temperature of the coating film reached 65°C during the first irradiation step. The decorative sheet 1 was obtained in this manner.

[0122] <Example 11: Comparative Example> The decorative sheet 1 was manufactured in the same manner as in Example 1, except for the following points. In other words, in this example, a coating solution for the surface protective layer was used that was a mixture 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 (EO 15 molar added) Product Name: SR9035 (manufactured by Sartomer) Blend: 40 parts by mass ·Ionizing radiation curable resin D Type: Tricyclodecanedimethanol diacrylate Product Name: Light Acrylate DCP-A (Manufactured by Kyoeisha Chemical Co., Ltd.) Blend: 60 parts by mass ·particle Product Name: Silysia 250N (Manufactured by Fuji Silysia Chemical Co., Ltd.) Particle size: 5μm Blend: 5 parts by mass In this way, decorative sheet 1 was obtained.

[0123] <Example 12: Example> The decorative sheet 1 was manufactured in the same manner as in Example 11, except for the following point. Specifically, in this example, the temperature of the raw material layer 2 was controlled so that the temperature of the coating film reached 65°C during the first irradiation step. The decorative sheet 1 was obtained in this manner.

[0124] <Example 13: Comparative Example> The decorative sheet 1 was manufactured in the same manner as in Example 1, except for the following points. In other words, in this example, the coating liquid used for the surface protective layer was a mixture of the following particles with the following ionizing radiation-curable resin A. ·Ionizing radiation curable resin A Type: Trimethylolpropane EO-modified triacrylate (EO 15 molar added) Product Name: SR9035 (manufactured by Sartomer) Blend: 100 parts by mass ·particle Product Name: Silysia 250N (Manufactured by Fuji Silysia Chemical Co., Ltd.) Particle size: 5μm Blend: 5 parts by mass In this example, the first irradiation step was omitted. In this way, decorative sheet 1 was obtained.

[0125] <Example 14: Comparative Example> The decorative sheet 1 was manufactured in the same manner as in Example 13, except for the following point. Specifically, in this example, the amount of particles was 13 parts by mass per 100 parts by mass of ionizing radiation-curable resin A. The decorative sheet 1 was obtained in this manner.

[0126] <Rating> The following evaluations were performed on each of the above-mentioned decorative sheets.

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

[0128] (2) Surface texture For each of the decorative sheets mentioned above, the surface properties were measured, and the aspect ratio Str and load area ratio Smr1 of the surface properties were determined.

[0129] (3) Thickness of the surface protective layer For each of the decorative sheets described above, the thickness of the surface protective layer was measured using the same method as described above. Specifically, decorative sheet 1 was embedded in a resin such as a cold-curing epoxy resin or a UV-curing resin, and the resin was allowed to cure sufficiently. Next, it was cut so that the cross-section of decorative sheet 1 was exposed, and the measurement surface was obtained by mechanical polishing. Subsequently, the cross-section of the surface protective layer was imaged using a scanning electron microscope SIGMA500 manufactured by Carl Zeiss Microscopy. For this imaging, the acceleration voltage was set to 0.5 keV (low acceleration voltage), the imaging mode was set to SE2 mode, and the magnification was set to 2000x. No sputtering was performed on the measurement sample. Next, from this cross-sectional image, the dimensions of the surface protective layer in the width direction of the ridged portion and the area of ​​the cross-section of the surface protective layer were determined. By dividing this area by the above dimensions, the "thickness of the surface protective layer" was calculated. The "thickness of the surface protective layer" obtained in this way was equal to the thickness of the coating film made of the coating liquid for the surface protective layer.

[0130] (4) Glossiness For each of the decorative sheets mentioned above, the specular gloss (GS60°) was measured using a Rhopoint IQ (manufactured by Konica Minolta). In Tables 1 and 2 below, "gloss" refers to this specular gloss (GS60°).

[0131] (5) Isotropy of tactile sensation For each of the above decorative sheets, the isotropy of the tactile feel of the surface protective layer was evaluated using the following method.

[0132] First, preliminary preparations were made to ensure consistency in evaluation criteria among the evaluators. Specifically, standard test specimens with different surface properties were prepared. These standard test specimens included those with different aspect ratios (Str) of surface properties. Next, each of the five evaluators, blindfolded, was asked to lightly press their finger against the surface of a standard test specimen and slide their fingertip in a straight line across the surface. Then, each evaluator was asked to classify the standard test specimens into the following three groups based on the changes in tactile sensation depending on the direction in which they slid their finger. Group 1: I felt a significant change in tactile sensation depending on the direction in which I slid my finger. Group 2: They felt a slight change in tactile sensation depending on the direction in which they slid their fingers. Group 3: No change in tactile sensation was felt depending on the direction in which the finger was slid.

[0133] The above procedure was repeated until the evaluations from each evaluator matched three or more times consecutively, and the evaluation results matched three or more times consecutively among the evaluators.

[0134] Next, for each of the decorative sheets described above, each of the evaluators, while blindfolded, was asked to lightly press their fingertip against the surface of the protective layer and slide their fingertip in a straight line across the surface. Based on the magnitude of the change in tactile sensation depending on the direction of the finger slide, they were asked to classify the decorative sheets into the three groups described above. This procedure was repeated until the evaluations by each evaluator agreed three or more times in a row, and the evaluation results agreed three times in a row among the evaluators. From these results, the isotropy of tactile sensation was evaluated according to the following criteria. AA: Group 3 A: Group 2 B: Group 1 In addition, "isotropy" in Tables 1 and 2 below refers to the isotropy of this tactile sensation.

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

[0136] First, preliminary preparations were made to ensure consistency in evaluation criteria among the evaluators. Specifically, standard test specimens with different surface properties were prepared. These standard test specimens included those with different load area ratios (Smr1). Next, each of the five evaluators was asked to lightly press the surface of a standard test specimen with their finger while blindfolded, and to classify the standard test specimens into the following three groups based on the tactile sensations they perceived. Group 1: I sensed the presence of an uneven structure consisting of coarse protrusions. Group 2: They perceived a tactile sensation that was intermediate between that of Group 1 and that of Group 3. Group 3: I sensed the presence of an uneven structure consisting of fine protrusions.

[0137] The above procedure was repeated until the evaluations from each evaluator matched three or more times consecutively, and the evaluation results matched three or more times consecutively among the evaluators.

[0138] Next, for each of the decorative sheets described above, each of the evaluators was asked to lightly press the surface of the protective layer with their finger while blindfolded, and to classify the decorative sheet into the three groups described above based on the tactile sensation they perceived. This procedure was repeated until the evaluations by each evaluator agreed three or more times in a row, and the evaluation results agreed three times in a row among the evaluators. Based on these results, the fine texture was evaluated according to the following criteria. AA: Group 3 A: Group 2 B: Group 1 (7) Fine granular texture For each of the above decorative sheets, the fine graininess of the surface protective layer was evaluated using the following method.

[0139] First, preliminary preparations were made to ensure consistency in evaluation criteria among the evaluators. Specifically, standard test specimens with different surface properties were prepared. These standard test specimens included those with different surface property aspect ratios (Str) and load area ratios (Smr1). Next, each of the five evaluators, blindfolded, was asked to lightly press their fingers against the surface of a standard test specimen and move their fingertips in small circles. Based on the tactile sensations they perceived, they were asked to classify the standard test specimens into the following three groups. Group 1: During the circular motion of the fingertips, participants either felt a significant change in tactile sensation or perceived the presence of an uneven surface consisting of large protrusions. Group 2: During the circular motion of the fingertips, participants did not perceive any significant changes in tactile sensation or the presence of an uneven surface consisting of coarse protrusions. However, they either perceived slight changes in tactile sensation or the presence of an uneven surface consisting of protrusions intermediate between coarse and fine. Group 3: During the circular motion of the fingertips, no significant change in tactile sensation was felt, but the presence of an uneven structure consisting of minute protrusions was detected.

[0140] The above procedure was repeated until the evaluations from each evaluator matched three or more times consecutively, and the evaluation results matched three or more times consecutively among the evaluators.

[0141] Next, for each of the decorative sheets described above, each of the evaluators was asked, blindfolded, to lightly press the surface of the protective layer with their fingertips and move them in a circular motion. Based on the tactile sensation they perceived, they were asked to classify the decorative sheets into the three groups described above. This procedure was repeated until the evaluations by each evaluator agreed three or more times in a row, and the evaluation results agreed three times in a row among the evaluators. From 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. Subsequently, a steel wool rubbing test was conducted to evaluate scratch resistance. Specifically, the decorative sheet was rubbed back and forth 20 times with steel wool while applying a load of 100g, and scratches and changes in gloss on the surface of the decorative sheet were visually observed.

[0142] The evaluation criteria were as follows: AA: No scratches or changes in gloss occurred on the surface. A: Minor scratches and changes in gloss have occurred on the surface. B: Significant scratches or changes in gloss occurred on the surface.

[0143] (9) Overall evaluation Each of the above decorative sheets was evaluated based on its fine granular texture and scratch resistance. The evaluation criteria were as follows: AA: Both the graininess and scratch resistance were rated "AA". A: One of the evaluations for fine graininess and scratch resistance was "A," and the other evaluation was "AA" or "A." B: At least one of the following was rated as "B": fine graininess and scratch resistance.

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

[0145] [Table 1]

[0146] [Table 2]

[0147] As shown in Tables 1 and 2, the decorative sheets according to Examples 3 to 5, 7, 9, and 12 gave the evaluators a fine granular texture. Furthermore, the decorative sheets according to Examples 3 to 5, 7, 9, and 12 had excellent scratch resistance, and the decorative sheets according to Examples 3 to 5, 7, and 12 had particularly excellent scratch resistance. In addition, the decorative sheets according to Examples 3 to 5, 7, 9, and 12 had low gloss.

[0148] In contrast, the decorative sheets in Examples 1, 2, 6, 8, 10, and 11 had excellent scratch resistance but did not give the evaluators a fine granular texture. Furthermore, the decorative sheets in Examples 13 and 14 had poor scratch resistance. [Explanation of Symbols]

[0149] 1... Decorative sheet, 2... Raw material layer, 3... Pattern layer, 4... Transparent resin layer, 5... Surface protection layer, 5A... Base, 5B... Ridged part, 6... Primer layer, 7... Adhesive layer, 8... Concealing layer, 11... Decorative material, B... Substrate.

Claims

1. It comprises a raw material layer and a surface protection layer provided on one surface of the raw material layer, The aforementioned surface protective layer contains a cured resin and has an uneven surface structure that includes a plurality of ridge-like portions, each of which protrudes in a ridge-like manner. The amount of particles in the surface protective layer is 10 parts by mass or less per 100 parts by mass of the cured product. The aforementioned uneven structure has a surface texture aspect ratio Str of 0.8 or more, and a load area ratio Smr1 separating the protruding peaks and the core portion of 13% or less. A decorative sheet having a specular gloss GS (60°) of 10% or less in the portion corresponding to the aforementioned uneven structure.

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

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

4. The decorative sheet according to claim 1, wherein the resin is an ionizing radiation-curable resin.

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

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

7. The decorative sheet according to claim 1, wherein the surface protective layer comprises the particles dispersed in the cured product.

8. The decorative sheet according to claim 7, wherein the amount of the particles is within 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.

9. The decorative sheet according to claim 1, further comprising a pattern layer between the base material layer and the surface protective layer.

10. A decorative sheet according to any one of claims 1 to 9, The base material to which the decorative sheet is attached and A decorative material that has the following features.