Decorative sheet

Abstract

Provided is a decorative sheet excellent in water resistance, low glossiness, and scratch resistance. A decorative sheet (1) comprises: a raw fabric layer (2) containing paper; a pigment-containing layer (3) provided on the raw fabric layer (2) and containing a pigment and a cured product of a first ionizing radiation-curable resin; and a surface protective layer (4) provided on the pigment-containing layer (3). The surface protective layer (4) includes a cured product of a second ionizing radiation-curable resin as a resin cured product, and an irregular structure including a plurality of ridge-shaped parts each protruding in a ridge shape is provided on a surface of the surface protective layer (4). The ratio RSm / Ra of an average length RSm and arithmetic average roughness Ra of a roughness curvilinear element of the irregular structure is within the range of 10-800.

Description

Decorative sheet

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

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

[0003] Designs can be added by forming patterns such as wood grain or stone grain using various printing methods. Plain decorative sheets without patterns are sometimes preferred. The choice of whether to have a pattern or not and the type of pattern vary depending on the application and preference.

[0004] The glossiness of the surface is also important for the design of decorative sheets. There are a variety of decorative sheets to choose from depending on the application and preference, ranging from high gloss like a mirror to low gloss that does not reflect light at all.

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

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

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

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

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

[0010] An object of the present invention is to provide a decorative sheet that is excellent in water resistance, low gloss, and scratch resistance.

[0011] According to one aspect of the present invention, there is provided a decorative sheet comprising: a raw fabric layer containing paper; a pigment-containing layer provided on the raw fabric layer and containing a pigment and a cured product of a first ionizing radiation curable resin; and a surface protective layer provided on the pigment-containing layer, wherein the surface protective layer contains a cured product of a second ionizing radiation curable resin as the cured resin product, and has an uneven structure on its surface including a plurality of ridge-like portions each protruding in a ridge-like shape, and the uneven structure has a ratio RSm / Ra of the average length RSm of the roughness curve elements to the arithmetic mean roughness Ra in the range of 10 or more and 800 or less.

[0012] According to another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the first ionizing radiation curable resin contains an acrylate.

[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 thickness of the pigment-containing layer is in the range of 0.5 μm or more and 20 μm or less.

[0014] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the thickness of the surface protective layer is in the range of 2 μm or more and 20 μm or less.

[0015] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the sum of the thickness of the pigment-containing layer and the thickness of the surface protective layer is in the range of 3 μm or more and 40 μm or less.

[0016] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the mass of the pigment is 3 parts by mass or more and 50 parts by mass or less when the mass of the first ionizing radiation curable resin is 100 parts by mass.

[0017] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the pigment is titanium oxide.

[0018] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the second ionizing radiation curable resin contains an acrylate.

[0019] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the second ionizing radiation curable resin contains a di- or higher functional acrylate containing a repeating structure.

[0020] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the repeating structure is repeated three or more times.

[0021] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the number of repetitions of the repeating structure is 30 or less.

[0022] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the surface protective layer further contains particles having an average particle size of 10 μm or less.

[0023] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, in which the mass of the particles is in the range of 0.5 parts by mass or more and 20 parts by mass or less when the mass of the second ionizing radiation curable resin is 100 parts by mass.

[0024] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the glossiness of the surface protective layer is 20.0 or less.

[0025] According to yet another aspect of the present invention, there is provided a decorative material comprising the decorative sheet according to any one of the above aspects and a substrate to which the decorative sheet is attached.

[0026] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet, comprising: forming a first coating film containing a pigment and a first ionizing radiation curable resin on a raw material layer containing paper; forming a second coating film containing a second ionizing radiation curable resin as a resin on the first coating film; and irradiating the second coating film with ionizing radiation or ultraviolet light to completely cure the second coating film.

[0027] According to yet another aspect of the present invention, there is provided a method for manufacturing a decorative sheet according to the above aspect, wherein the complete curing of the second coating film includes an irradiation step of irradiating the second coating film with light having a wavelength of 200 nm or less, and then an irradiation step of irradiating the second coating film with ionizing radiation or ultraviolet light having a longer wavelength than the light irradiated in the irradiation step.

[0028] According to the present invention, a decorative sheet having excellent water resistance, low gloss and scratch resistance is provided.

[0029] 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. Fig. 4 is a cross-sectional view showing an enlarged portion of the surface protective layer shown in Fig. 2.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] <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 layer included in a decorative sheet according to one example of the present invention. Figure 4 is a cross-sectional view showing an enlarged portion of the surface protective layer shown in Figure 2.

[0034] 2 and 4 are cross sections taken along the thickness direction of the surface protection layer, and the micrograph in Fig. 3 is a plan view taken with a laser microscope (OLS-4000 manufactured by Olympus Corporation).

[0035] 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.

[0036] 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.

[0037] The decorative sheet 1 includes a raw fabric layer 2, a pigment-containing layer 3, and a surface protective layer 4. The pigment-containing layer 3 and the surface protective layer 4 are provided in this order from the raw fabric layer 2 side on the side of the raw fabric layer 2 opposite the side facing the substrate B. The decorative sheet 1 may further include one or more other layers, such as a transparent resin layer. Below, the elements included in the decorative sheet 1 will be explained one by one.

[0038] <1.1> Raw Fabric Layer The raw fabric layer 2 contains paper. The raw fabric layer 2 may have a single-layer structure or a multi-layer structure. In one example, the raw fabric layer 2 is entirely made of paper. In another example, the raw fabric layer 2 has a multi-layer structure, and at least the outermost layer facing the surface protective layer 4 is made of paper. When the raw fabric layer 2 has a multi-layer structure, it may include one or more layers made of a material other than paper in addition to one or more layers made of paper.

[0039] The paper may be, for example, tissue paper, resin-mixed paper, titanium paper, resin-impregnated paper, flame-retardant paper, or inorganic paper. The paper contained in the raw paper layer 2 may be, for example, paper containing cellulose fibers. The raw paper layer 2 may have various forms, such as a film, a sheet, a plate, or a molded body.

[0040] <1.2> Pigment-Containing Layer The pigment-containing layer 3 is, for example, a continuous film that covers the entire surface of one side of the raw fabric layer 2. The pigment-containing layer 3 can serve as a concealing layer that conceals the substrate B or the raw fabric layer 2. The pigment-containing layer 3 can also serve as a planarizing layer.

[0041] The pigment-containing layer 3 contains a pigment and a cured product of a first ionizing radiation curable resin. In one example, the pigment-containing layer 3 contains only the first ionizing radiation curable resin as the cured resin product. In another example, the pigment-containing layer 3 contains the first ionizing radiation curable resin and a thermosetting resin as the cured resin products. Here, "ionizing radiation" refers to a charged particle beam such as an electron beam. The first ionizing radiation curable resin is cured by irradiation with ionizing radiation. The first ionizing radiation curable resin can also be cured by irradiation with ultraviolet light. Thermosetting resins will be described later.

[0042] When the mass of the pigment-containing layer 3 is taken as 100 parts by mass, the mass of the cured product of the first ionizing radiation curable resin contained in the pigment-containing layer 3 is preferably 50 parts by mass or more and 97 parts by mass or less, and more preferably 60 parts by mass or more and 95 parts by mass or less.

[0043] The first ionizing radiation curable resin may be any known resin, such as various monomers or commercially available oligomers, including, for example, a (meth)acrylic resin, a silicone resin, a polyester resin, a urethane resin, an amide resin, or an epoxy resin. The first ionizing radiation curable resin may be either an aqueous resin or a non-aqueous (organic solvent-based) resin. The first ionizing radiation curable resin may be solvent-free. The first ionizing radiation curable resin preferably contains an acrylate.

[0044] The first ionizing radiation curable resin is, for example, a water-based dispersion or emulsion containing at least one of a urethane acrylate and a polyurethane resin, and may be, for example, a dispersion or emulsion containing a resin having an acryloyl group.

[0045] In another example, the first ionizing radiation curable resin is a mixture of acrylate and methacrylate. When such a mixture is used as the first ionizing radiation curable resin, high adhesion can be achieved between the pigment-containing layer 3 and the surface protective layer 4.

[0046] The cured product of the first ionizing radiation curable resin preferably contains one or more bonds selected from the group consisting of a urethane bond, a carbonate bond, and an amide bond.

[0047] As described above, the pigment-containing layer 3 may contain a first ionizing radiation curable resin and a thermosetting resin as the cured resin. For example, the thermosetting resin may contain one or more of an aqueous urethane dispersion, an aqueous epoxy dispersion, and an aqueous polyamine dispersion. For example, the aqueous dispersion may contain a carboxylic acid derivative having a polycarbonate skeleton.

[0048] When an aqueous dispersion or emulsion is used as at least one of the first ionizing radiation curable resin and the thermosetting resin, a surfactant may remain in the pigment-containing layer 3 as a trace thereof.

[0049] The additives added to the first ionizing radiation curable resin are intended to improve the functionality of the final product, as will be described later, and are, for example, one or more of an antibacterial agent, an antifungal agent, an ultraviolet absorber, and a light stabilizer. The total amount of the additives is preferably 15 parts by mass or less, and more preferably 10 parts by mass or less, per 100 parts by mass of the first ionizing radiation curable resin.

[0050] The pigment includes at least one of a white pigment and a colored pigment. Examples of the pigment include inorganic pigments such as carbon black, titanium oxide (titanium white), zinc oxide, red iron oxide, yellow lead, iron blue, and cadmium red; organic pigments such as azo pigments, lake pigments, anthraquinone pigments, phthalocyanine pigments, isoindolinone pigments, and dioxazine pigments; or mixtures thereof. The pigment is preferably titanium oxide.

[0051] The average particle size of the pigment is preferably in the range of 50 nm to 5 μm, and more preferably in the range of 100 nm to 1 μm. This average particle size is the median diameter (D50) of the particles in the surface protective layer 4, which will be described later.

[0052] The amount of pigment is preferably in the range of 3 to 50 parts by mass, more preferably 5 to 30 parts by mass, per 100 parts by mass of the first ionizing radiation curable resin. If the amount of pigment is small, the effect of concealing the substrate B or the raw fabric layer 2, i.e., the concealing ability, tends to decrease. For example, if the amount is less than 3 parts by mass, it becomes difficult to achieve high concealing ability. Furthermore, if the amount is more than 50 parts by mass, the uniformity of the coating film may decrease.

[0053] The thickness of the pigment-containing layer 3 is preferably in the range of 0.5 μm to 20 μm, more preferably in the range of 2 μm to 15 μm, and even more preferably in the range of 3 μm to 10 μm. If the thickness of the pigment-containing layer 3 is small, it becomes difficult to achieve high hiding power. If the thickness of the pigment-containing layer 3 is large, the processability of the decorative sheet 1 decreases, and it becomes prone to whitening when folded.

[0054] <1.4> Surface Protective Layer The surface protective layer 4 is provided on the pigment-containing layer 3. Here, the surface protective layer 4 covers the entire upper surface of the pigment-containing layer 3.

[0055] The specular gloss GS(60°) of the surface protective layer 4 is preferably 20.0 or less, more preferably 18 or less, and even more preferably 15 or less. For example, the specular gloss GS(60°) of the surface protective layer 4 is 0.5 or more. Here, the "specular gloss GS(60°)" is the specular gloss measured at an incident angle of 60 degrees using a glossmeter conforming to ISO 2813. The specular gloss GS(60°) is sometimes expressed with "%" following the numerical value, but the "%" will be omitted here.

[0056] An uneven structure is provided on the surface of the surface protective layer 4. The uneven structure provided on the upper surface of the surface protective layer 4 serves to reduce the specular gloss GS (60°) of the surface protective layer 4.

[0057] Here, an uneven structure including a plurality of ridge-like portions each protruding in a ridge-like shape is provided on the surface of the surface protection layer 4. That is, as shown in Figures 2 and 4, the surface protection layer 4 includes a core portion 4A which is a thin layer having a flat upper surface, and a plurality of ridge-like portions 4B each protruding in a ridge-like shape from the upper surface of the core portion 4A.

[0058] In the present disclosure, the ridge portion 4B refers to, for example, the portion from the lowest part to the tip of a protrusion provided on the surface of the surface protection layer 4, and the core portion 4A refers to the portion of the surface protection layer 4 excluding the ridge portion 4B. Furthermore, the term "ridge-like" refers to a convex shape that extends linearly in a plan view.

[0059] The ridge portions 4B may be curved or linear in plan view, but are preferably curved as shown in Fig. 3 from the viewpoint of fingerprint resistance of the surface of the decorative sheet 1. The surface protection layer 4 having ridge portions 4B can be formed, for example, as described below, by irradiating the surface of a coating film containing a second ionizing radiation curable resin with light of a specific wavelength, and causing the cured film formed on the surface of the coating film to expand in the in-plane direction.

[0060] The uneven structure on the upper surface of the surface protective layer 4 has a ratio RSm / Ra of the average length RSm of the roughness curve elements to the arithmetic mean roughness Ra in the range of 10 to 800. The ratio RSm / Ra is preferably in the range of 10 to 600, more preferably in the range of 10 to 500, even more preferably in the range of 10 to 400, even more preferably in the range of 50 to 400, and even more preferably in the range of 50 to 350. When the ratio RSm / Ra is reduced, the pitch of the convex portions becomes smaller. As a result, it becomes difficult to wipe off dirt adhering to the surface of the decorative sheet 1, and the contamination resistance decreases. When the ratio RSm / Ra is increased, the pitch of the convex portions becomes larger, and the effect of the uneven structure on reducing the specular gloss GS(60°) of the surface protective layer 4 is reduced.

[0061] The ratio RSm / Ra is preferably equal to or greater than 80. Increasing the ratio RSm / Ra increases the pitch of the convex portions, improving the affinity of water or detergents (water containing surfactants or alcohol) to the upper surface of the surface protective layer 4. If the surface protective layer 4 of the decorative sheet 1 has such surface properties, even if the surface becomes dirty, the dirt can be easily wiped off with water or detergent.

[0062] It is most preferable that the ratio RSm / Ra is equal to or greater than 100. If the ratio RSm / Ra is within this range, a commonly available cleaning sponge can be brought into contact with the boundaries of the convex portions and the areas in their vicinity on the upper surface of the surface protective layer 4. Therefore, even if the surface of the decorative sheet 1 becomes soiled, the dirt can be easily wiped off using a commonly available cleaning sponge.

[0063] Here, the arithmetic mean roughness Ra and the mean length RSm of the roughness curve elements are measured using a line roughness meter (in accordance with JIS B0601:2013).

[0064] The arithmetic mean roughness Ra is preferably in the range of 0.2 μm to 10.0 μm, more preferably in the range of 0.5 μm to 5.0 μm, and even more preferably in the range of 0.8 μm to 4.0 μm.

[0065] The average length RSm of the roughness curve elements is preferably in the range of 50 μm or more and 800 μm or less, more preferably in the range of 80 μm or more and 600 μm or less, and even more preferably in the range of 100 μm or more and 500 μm or less.

[0066] The upper surface of the surface protection layer 4 may have a sinusoidal shape in a cross section parallel to the thickness direction and the arrangement direction of the ridge portions 4B. Here, the "sinusoidal shape" refers to a shape in which a line extending from the lowest point C of the ridge portions 4B to the highest point D (vertex) can be expressed as a sine wave, as shown in FIG.

[0067] The thickness of the surface protective layer 4 is preferably in the range of 2 μm to 20 μm, more preferably in the range of 2.5 μm to 15 μm, and most preferably in the range of 3 μm to 12 μm. If the thickness of the surface protective layer 4 is small, it is difficult to achieve the above-mentioned surface properties by the method described below while referring to the ratio RSm / Ra, etc. If the thickness of the surface protective layer 4 is large, the processability of the decorative sheet 1 decreases and it becomes more likely to whiten when folded.

[0068] Here, the thickness of the surface protective layer 4 is the thickness of a layer that has the same apparent area and volume as the surface protective layer 4 and a flat surface. The thickness of the surface protective layer 4 is determined, for example, by the following method. First, a cross section parallel to the thickness direction of the surface protective layer 4 and perpendicular to the length direction of the ridge portions 4B is imaged. Next, from this cross-sectional image, the dimension of the surface protective layer 4 in the width direction of the ridge portions 4B and the area of ​​the cross section of the surface protective layer 4 are determined. The thickness of the surface protective layer 4 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 this coating liquid is equal to the thickness of the surface protective layer 4.

[0069] Furthermore, the thickness of the surface protection layer 4 is preferably set so that the ratio of the thickness (or height) of the ridge portion 4B to the thickness of the core portion 4A (thickness of the ridge portion 4B / thickness of the core portion 4A) is within the range of 0.01 to 2.0, and more preferably within the range of 0.1 to 1.0.

[0070] The surface protective layer 4 contains a cured resin. As described below, the surface protective layer 4 may further contain particles. When the mass of the surface protective layer 4 is taken as 100 parts by mass, the mass of the cured resin contained in the surface protective layer 4 is preferably 60 parts by mass or more, more preferably 70 parts by mass or more, and even more preferably 80 parts by mass or more.

[0071] The surface protective layer 4 contains a cured product of the second ionizing radiation curable resin as the cured resin product. According to one example, the surface protective layer 4 contains only the cured product of the second ionizing radiation curable resin as the cured resin product other than the particles. According to another example, the surface protective layer 4 contains only the cured product of the second ionizing radiation curable resin as the cured resin product. As described above, the ionizing radiation is a charged particle beam such as an electron beam. The second ionizing radiation curable resin is cured by irradiation with ionizing radiation. The second ionizing radiation curable resin can also be cured by irradiation with ultraviolet light. The second ionizing radiation curable resin used here is cured by irradiation with light having a wavelength of 200 nm or less, and has a high absorption coefficient for this light.

[0072] The second ionizing radiation curable resin may be any known resin, such as various monomers or commercially available oligomers, including (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, or epoxy resins. The second ionizing radiation curable resin may be either an aqueous resin or a non-aqueous (organic solvent-based) resin. The second ionizing radiation curable resin may be solvent-free.

[0073] The main component of the second ionizing radiation curable resin is preferably an acrylate, and the main component here means that the content is 60 parts by mass or more, more preferably 70 parts by mass or more, and most preferably 80 parts by mass or more per 100 parts by mass of the resin components constituting the second ionizing radiation curable resin.

[0074] The acrylate is preferably a difunctional or higher acrylate, and more preferably a trifunctional or higher acrylate. In order to obtain a surface protective layer 4 having excellent scratch resistance, the acrylate is preferably a trifunctional or higher acrylate. There is no upper limit to the number of functional groups of the acrylate, but according to one example, it is hexafunctional or lower.

[0075] 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.

[0076] 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 during the second irradiation step described below, and therefore wrinkles corresponding to the ridge portions 4B are more likely to appear on the coating film surface. However, increasing the number of repetitions reduces the crosslinking density and the scratch resistance of the surface protective layer 4. Furthermore, if the repeating unit is hydrophilic, if the number of repetitions is too high, water will easily seep into the surface protective layer 4 when it adheres to the surface protective layer 4. Therefore, the number of repetitions is preferably 30 or less, and more preferably 20 or less.

[0077] 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.

[0078] The second ionizing radiation curable resin may be a single type of acrylate or a mixture of two or more types of acrylates. For example, the second ionizing radiation curable resin may be a mixture of an acrylate containing a repeating unit and an acrylate not containing a repeating unit. In this case, the above-mentioned ratio RSm / Ra can be easily adjusted. The ratio M2 / M1 of the mass M1 of the acrylate containing a repeating unit to the mass M2 of the acrylate not containing a repeating unit is preferably, for example, within a range of 2.0 or less.

[0079] When the second ionizing radiation curable resin contains an acrylate, it may further contain a methacrylate.

[0080] In addition to the cured resin, the surface protective layer 4 may further contain particles. Examples of the particles contained in the surface protective layer 4 include particles made of an organic material such as polyethylene (PE) wax, polypropylene (PP) wax, and resin beads, and particles made of an inorganic material such as silica, glass, alumina, titania, zirconia, calcium carbonate, and barium sulfate.

[0081] The average particle size (D50) of the particles is preferably 10 μm or less, more preferably 1 μm or more and 8 μm or less, even more preferably 2 μm or more and 7 μm or less, and most preferably 3 μm or more and 6 μm or less. If the average particle size (D50) of the particles is large, the particles are more likely to fall off from the surface protective layer 4, which may make it difficult to achieve high scratch resistance. If the particles are small, the effect of generating wrinkles uniformly is reduced.

[0082] 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 4 obtained from this coating liquid will also contain particles. The average particle size of the particles contained in the surface protective layer 4 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 4.

[0083] The amount of particles in the surface protective layer 4 is preferably in the range of 0.5 parts by mass or more and 20 parts by mass or less, more preferably in the range of 0.5 parts by mass or more and 10 parts by mass or less, even more preferably in the range of 2 parts by mass or more and 8 parts by mass or less, and even more preferably in the range of 2 parts by mass or more and 6 parts by mass or less, relative to 100 parts by mass of the cured resin.

[0084] 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 4, which may make it difficult to achieve high scratch resistance.

[0085] The total thickness of the pigment-containing layer 3 and the surface protective layer 4 is preferably in the range of 3 μm to 40 μm, more preferably in the range of 4.5 μm to 30 μm. When the total thickness of these layers is in the above range, high water resistance can be achieved.

[0086] The thickness of the decorative sheet 1 is preferably in the range of 30 μm to 160 μm, and more preferably in the range of 50 μm to 130 μm. When the thickness of the decorative sheet 1 is in the above range, it is easy to bend, and therefore high processability can be achieved.

[0087] <2> Manufacturing Method of Decorative Sheet The decorative sheet 1 is manufactured, for example, by the following method. First, a first coating film containing a pigment and a first ionizing radiation curable resin is formed on one surface of a paper-containing raw fabric layer 2. Here, the first coating film is formed so as to cover the entire upper surface of the raw fabric layer 2.

[0088] In one example, the first coating film consists solely of a mixture of a pigment and a first ionizing radiation curable resin. In another example, the first coating film consists solely of a mixture of a pigment, a first ionizing radiation curable resin, and an additive dissolved therein.

[0089] The first coating film is formed by applying a coating liquid for the pigment-containing layer to the base layer 2. The first 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.

[0090] The coating liquid for the pigment-containing layer contains the above-mentioned pigment and a first ionizing radiation-curable resin. The coating liquid for the pigment-containing layer may further contain other components, such as a thermosetting resin, a solvent, and additives for improving the functionality of the final product, such as one or more antibacterial agents and antifungal agents. The coating liquid for the pigment-containing layer may further contain other additives such as an ultraviolet absorber and a light stabilizer. Examples of ultraviolet absorbers that can be used include benzotriazoles, benzoates, benzophenones, and triazines. Examples of light stabilizers that can be used include hindered amines. When the coating liquid for the pigment-containing layer contains a solvent, the first coating film described above is obtained by applying the coating liquid and drying the resulting coating film.

[0091] Next, a first irradiation step is carried out. In the first irradiation step, the first coating film is irradiated with a first radiation to cure the first coating film. The first irradiation step may be carried out so that the first coating film is completely cured, or so that the first coating film is incompletely cured.

[0092] The first radiation is, for example, ionizing radiation. As described above, the ionizing radiation is a charged particle beam such as an electron beam. The first radiation may be ultraviolet light, for which the first ionizing radiation curable resin exhibits a small absorption coefficient. The wavelength of the ultraviolet light irradiated onto the first coating film is preferably greater than 200 nm, more preferably in the range of 230 nm to 450 nm, and even more preferably in the range of 250 nm to 400 nm.

[0093] When the first coating film is irradiated with ionizing radiation or ultraviolet light, the first coating film can be cured substantially uniformly throughout its entire thickness. Therefore, unlike the second coating film described below, the first coating film after curing does not have any irregularities on its surface.

[0094] The minimum integrated amount of light required to completely cure the first coating film is, for example, 10 mJ / cm ２ More than 1000mJ / cm ２ The minimum absorbed dose required to completely cure the first coating is, for example, in the range of 3 kGy to 200 kGy.

[0095] When the first coating film contains a thermosetting resin, the first coating film may be heated following the first irradiation step to cause a crosslinking reaction of the thermosetting resin. This heating is preferably carried out at a temperature in the range of 80° C. to 200° C., more preferably at a temperature in the range of 100° C. to 160° C. Even when the first coating film contains a thermosetting resin, it is not necessary to heat the first coating film immediately after the first irradiation step.

[0096] The first irradiation step may be omitted. For example, if the first coating film loses its fluidity upon drying or heating, the first irradiation step can be omitted.

[0097] Next, a second coating film made of a coating liquid for forming a surface protective layer is formed on the cured first coating film. Here, the second coating film is formed so as to cover the entire upper surface of the first coating film.

[0098] The second 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.

[0099] The coating liquid for forming the surface protective layer contains the second ionizing radiation curable resin described above. As described above, the second ionizing radiation curable resin is, for example, an acrylate. In another example, the second ionizing radiation curable resin is a mixture of an acrylate and a methacrylate.

[0100] The coating liquid for the surface protective layer may further contain other components, such as the above-mentioned particles, solvent, and additives for improving the functionality of the final product, such as one or more antibacterial agents and antifungal agents. 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 benzotriazole-based, benzoate-based, benzophenone-based, and triazine-based stabilizers. Examples of the light stabilizer that can be used include hindered amine-based stabilizers.

[0101] Next, the second coating film is irradiated with ionizing radiation or ultraviolet light to completely cure the second coating film. For example, the second and third irradiation steps described below are carried out in sequence.

[0102] In the second irradiation step, the second coating film is irradiated with second radiation, which is light having a wavelength of 200 nm or less.

[0103] The second ionizing radiation-curable resin contained in the coating liquid for the surface protective layer has a large absorption coefficient for the second radiation. Therefore, the second radiation incident on the second coating film can only reach a position several tens to several hundreds of nanometers away from the outermost surface. Therefore, in the second irradiation step, the crosslinking reaction proceeds in the surface region of the second coating film, forming an extremely thin cured film, while the crosslinking reaction does not proceed in other regions, leaving the other regions uncured.

[0104] The second coating film after the second irradiation step has wrinkles on its surface corresponding to the ridge portions 4 B. The inventors believe that the reason why wrinkles are formed on the coating film surface by the second irradiation step is as follows.

[0105] As described above, the second radiation can only reach a position tens to hundreds of nanometers away from the outermost surface of the second coating film. That is, the crosslinking reaction of the second ionizing radiation-curable resin occurs only on the surface of the second coating film, and regions more than tens to hundreds of nanometers away from the outermost surface are uncured and contain highly fluid molecules. These highly fluid molecules swell the cured film, thereby increasing its volume. The increase in volume in the in-plane direction causes the cured film to buckle, resulting in wrinkles on the surface of the second coating film.

[0106] The second radiation can be extracted from excimer VUV (Vacuum Ultra Violet) light. Excimer VUV light can be generated from a lamp using a rare gas or a rare gas halide compound. When high-energy electrons are externally applied to a lamp filled with a rare gas or a rare gas halide compound, a large number of discharge plasmas (dielectric barrier discharges) are generated. This plasma discharge excites atoms of the discharge gas (rare gas), which momentarily transition to an excimer state. When returning from this excimer state to the ground state, light is emitted in a wavelength range specific to that excimer.

[0107] 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).

[0108] 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.

[0109] The second irradiation step is carried out in an atmosphere with a low oxygen concentration. Oxygen has a high absorption coefficient for light of 200 nm or less. Therefore, the second irradiation step is preferably carried out in, for example, a nitrogen gas atmosphere. The oxygen concentration in the gas phase in the second irradiation step, i.e., the residual oxygen concentration in the reaction atmosphere, is preferably 2000 ppm or less, and more preferably 1000 ppm or less.

[0110] 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 second coating film. Therefore, changing the residual oxygen concentration in the reaction atmosphere can also change the surface properties of the surface protective layer 4.

[0111] The cumulative amount of the second radiation is 0.5 mJ / cm ２ More than 200mJ / cm ２ It is preferable to set the concentration within the range of 1 mJ / cm ２ More than 100mJ / cm ２ It is more preferable to set it within the range of 3 mJ / cm ２ More than 50mJ / cm ２ It is more preferable to set it within the range of 5 mJ / cm ２ 30mJ / cm or more ２It is most preferable to set the integrated light dose within the following range: If the integrated light dose is small, the expansion of the cured film in the in-plane direction will be small, whereas if the integrated light dose is large, the surface condition of the second coating film will deteriorate.

[0112] In the third irradiation step, the second coating film is irradiated with third radiation. The third radiation is ionizing radiation or ultraviolet light having a longer wavelength than the light irradiated in the second irradiation step. The third radiation can be any of the radiations described above for the first radiation.

[0113] In the third irradiation step, the crosslinking reaction proceeds throughout the entire thickness of the second coating film.

[0114] The cumulative light amount of the third radiation is 10 mJ / cm ２ More than 500mJ / cm ２ It is preferable to set the dose within the range of 50 mJ / cm ２ More than 400mJ / cm ２ It is more preferable to set it within the range of 100 mJ / cm ２ More than 300mJ / cm ２ It is more preferable to set it within the following range.

[0115] The irradiation of the third radiation is preferably carried out so that the absorbed dose is in the range of 5 kGy or more and 200 kGy or less, more preferably in the range of 10 kGy or more and 150 kGy or less, and even more preferably in the range of 15 kGy or more and 100 kGy or less.

[0116] In the third irradiation step, if a layer having sufficient strength cannot be obtained by irradiation with only one type of radiation, the type of third radiation may be changed. For example, irradiation with ionizing radiation may be performed first, followed by irradiation with ultraviolet light having a longer wavelength than the light irradiated in the second irradiation step. Alternatively, irradiation with ultraviolet light having a longer wavelength than the light irradiated in the second irradiation step may be performed first, followed by irradiation with ionizing radiation. Alternatively, irradiation with ultraviolet light having a longer wavelength than the light irradiated in the second irradiation step may be performed first, followed by irradiation with ultraviolet light having an even longer wavelength.

[0117] In this manner, a decorative sheet 1 is obtained. In the decorative sheet 1 obtained by the above method, there is no interface between the core portion 4A and the rib portion 4B, and they are integrally formed.

[0118] <3> Effects The decorative sheet 1 described above has the property of being able to prevent stains or traces thereof caused by water absorption, that is, it has water resistance, which will be explained below.

[0119] As described above, the raw web layer 2 contains paper. Therefore, if the pigment-containing layer 3 is omitted, when water adheres to the surface protective layer 4, the water is absorbed by the paper contained in the raw web layer 2. This water-absorbed area can be seen as a stain. Furthermore, in the water-absorbed area, the paper shrinks during the drying process, and traces of water absorption can be seen even after drying.

[0120] The surface protective layer 4 can impart a certain degree of water resistance to the decorative sheet 1. However, as described above, the surface protective layer 4 has an uneven structure on its surface, and therefore its thickness is non-uniform. Therefore, in order to achieve high water resistance with this surface protective layer 4 alone, its minimum thickness must be sufficiently large. However, because the thickness of the second coating film can affect the surface properties of the surface protective layer 4, the thickness of the surface protective layer 4 cannot be determined by considering only water resistance.

[0121] In contrast, the decorative sheet 1 described above has a pigment-containing layer 3 containing a cured product of a first ionizing radiation curable resin. The first ionizing radiation curable resin has a higher crosslink density than cured products of resins such as thermosetting resins. Therefore, even if water adhering to the surface protective layer 4 reaches the pigment-containing layer 3, the water does not pass through the pigment-containing layer 3. Therefore, the decorative sheet 1 described above can achieve high water resistance.

[0122] Furthermore, the decorative sheet 1 has a textured structure on the surface of its surface protection layer. This textured structure preferably has a ratio RSm / Ra of the average length RSm of the roughness curve elements to the arithmetic mean roughness Ra within the above range. Such a textured structure makes it possible to achieve a low gloss level.

[0123] Furthermore, the decorative sheet 1 has an uneven structure including a plurality of ridge-like protrusions on the surface of its surface protection layer. Such an uneven structure makes it possible to achieve high scratch resistance.

[0124] Examples of the present invention will be described below. Note that the "particle size" described below is the above-mentioned "average particle size (D50)".

[0125] <Example 1> The decorative sheet 1 described with reference to Figs. 1 to 4 was produced by the following method. ２ An impregnated paper (GFR-506, manufactured by Kohjin Co., Ltd.) was prepared as the raw paper layer 2.

[0126] Next, a coating liquid for a pigment-containing layer having the following composition was applied onto the raw film layer 2. The coating liquid for a pigment-containing layer was applied so that the thickness of the pigment-containing layer 3 would be 5 μm.

[0127] (Coating liquid for pigment-containing layer) First ionizing radiation curable resin Type: Water-based UV curable resin Product name: Shikoh (registered trademark) UV-W300 (manufactured by Mitsubishi Chemical Corporation) Pigment Type: Titanium oxide Average particle size: 230 nm Blending ratio: 15 parts by mass Thereafter, a first irradiation step was carried out. Specifically, the first coating film made of the coating liquid for pigment-containing layer was irradiated with an electron beam as ionizing radiation so that the absorbed dose of the first coating film was 3 kGy. This cured the first coating film.

[0128] Subsequently, a coating liquid for forming a surface protective layer having the following composition was printed on the first coating film: The coating liquid for forming a surface protective layer was printed so that the thickness of the surface protective layer 4 would be 5 μm.

[0129] (Coating liquid for surface protective layer) Second ionizing radiation curable resin Type: trimethylolpropane EO-modified triacrylate (EO 6 moles added) Product name: Miramer M3160 (manufactured by Miwon) Blending: 100 parts by mass Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blending: 0.5 parts by mass Next, a second irradiation step was carried out. Specifically, ultraviolet light having a wavelength of 172 nm was irradiated onto the surface of the second coating film made of the coating liquid for surface protective layer at an integrated light intensity of 50 mJ / cm using a Xe excimer lamp under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 500 ppm. ２ This caused wrinkles to form on the surface of the second coating film.

[0130] Subsequently, the third irradiation step was carried out. Specifically, the second coating film was irradiated with 100 kGy of ionizing radiation to completely cure the second coating film, thereby forming the surface protective layer 4. In this manner, the decorative sheet 1 was obtained.

[0131] <Example 2> The decorative sheet 1 described with reference to Figures 1 to 4 was produced in the same manner as in Example 1, except that the following resin was used as the second ionizing radiation curable resin and the thickness of the surface protective layer 4 was 20 µm.

[0132] Second ionizing radiation curable resin Type: Trimethylolpropane EO modified triacrylate (EO 30 moles added) Product name: NAM-AT30E (manufactured by Nagase America) Blend: 100 parts by weight

[0133] Example 3 The decorative sheet 1 described with reference to FIGS. 1 to 4 was produced in the same manner as in Example 1, except that the thickness of the surface protective layer 4 was set to 1 μm.

[0134] <Example 4> The decorative sheet 1 described with reference to Figures 1 to 4 was produced in the same manner as in Example 1, except that the following resin was used as the second ionizing radiation curable resin: Second ionizing radiation curable resin Type: Ethoxylated trimethylolpropane triacrylate Product name: A-TMPT-6PO (manufactured by Shin-Nakamura Chemical Co., Ltd.) Blend: 100 parts by mass

[0135] <Example 5> The decorative sheet 1 described with reference to Figures 1 to 4 was produced in the same manner as in Example 1, except that the following resin was used as the particles: Particles Product name: Sylysia 780 (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 11.3 μm Blending: 5 parts by mass

[0136] Example 6 The decorative sheet 1 described with reference to FIGS. 1 to 4 was produced in the same manner as in Example 1, except that the thickness of the pigment-containing layer 3 was set to 1.5 μm.

[0137] Example 7 The decorative sheet 1 described with reference to FIGS. 1 to 4 was produced in the same manner as in Example 1, except that the thickness of the pigment-containing layer 3 was set to 22 μm.

[0138] <Example 8> The decorative sheet 1 described with reference to Figures 1 to 4 was produced in the same manner as in Example 1, except that the following resin was used as the first ionizing radiation curable resin: First ionizing radiation curable resin Type: Water-based UV curable resin Product name: UVPUD-7502E (manufactured by UBE)

[0139] Example 9 The decorative sheet 1 described with reference to Figures 1 to 4 was produced in the same manner as in Example 1, except that the following resin mixture was used as the second ionizing radiation curable resin. Second ionizing radiation curable resin (First acrylate) Type: Trimethylolpropane EO-modified triacrylate (EO 6 moles added) Product name: Miramer M3160 (manufactured by Miwon Co., Ltd.) Blend: 60 parts by mass (Second acrylate) Type: Dipentaerythritol hexaacrylate (DPHA) Product name: ARONIX M-404 (manufactured by Toagosei Co., Ltd.) Blend: 40 parts by mass

[0140] Example 10 The decorative sheet 1 described with reference to Figures 1 to 4 was produced in the same manner as in Example 1, except that the following resin mixture was used as the second ionizing radiation curable resin. Second ionizing radiation curable resin (First acrylate) Type: Trimethylolpropane EO-modified triacrylate (EO 6 moles added) Product name: Miramer M3160 (manufactured by Miwon Co., Ltd.) Blend: 40 parts by mass (Second acrylate) Type: Dipentaerythritol hexaacrylate (DPHA) Product name: ARONIX M-404 (manufactured by Toagosei Co., Ltd.) Blend: 60 parts by mass

[0141] <Comparative Example 1> A decorative sheet similar to that described with reference to Figures 1 to 4 was produced in the same manner as in Example 1, except that the second irradiation step was omitted and the particle blending amount in the coating liquid for the surface protective layer was set to 20 parts by mass.

[0142] Comparative Example 2 A decorative sheet similar to that described with reference to Figures 1 to 4 was produced in the same manner as in Example 1, except that the following resin mixture was used as the second ionizing radiation curable resin and the thickness of the surface protective layer 4 was 1 µm. Second ionizing radiation curable resin (First acrylate) Type: Trimethylolpropane EO-modified triacrylate (EO 6 moles added) Product name: Miramer M3160 (manufactured by Miwon Co., Ltd.) Blend: 20 parts by mass (Second acrylate) Type: Dipentaerythritol hexaacrylate (DPHA) Product name: ARONIX M-404 (manufactured by Toagosei Co., Ltd.) Blend: 80 parts by mass

[0143] Comparative Example 3 A decorative sheet similar to that described with reference to FIGS. 1 to 4 was produced by the same method as in Example 1, except that the following resin was used instead of the first ionizing radiation curable resin. Type: Water-based acrylic dispersion Product name: SETAQUA6411 (manufactured by Daicel Allnex Corporation) Blend: 100 parts by mass Comparative Example 4 A decorative sheet similar to that described with reference to FIGS. 1 to 4 was produced by the same method as in Example 1, except that the following resin was used instead of the first ionizing radiation curable resin. Type: Thermosetting polyurethane resin Product name: WS-5661 (manufactured by Mitsui Chemicals, Inc.) Blend: 100 parts by mass Evaluation Each of the above decorative sheets was evaluated as follows. Those rated "AAA", "AA", or "A" were considered to pass, as they presented no problems in actual use.

[0144] (1) Thickness of the Surface Protective Layer The thickness of the surface protective layer was measured using the same method as described above. Specifically, the decorative sheet was embedded in a resin such as a cold-setting epoxy resin or a UV-curable resin, and the resin was allowed to fully harden. Next, the decorative sheet was cut so that the cross section of the decorative sheet was exposed, and the measurement surface was obtained by mechanically polishing it.

[0145] Subsequently, a 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 imaging mode, and at a magnification of 2000. No sputtering was performed on the measurement sample.

[0146] Next, the dimensions of the surface protective layer in the width direction of the ridge portion and the cross-sectional area of ​​the surface protective layer were determined from this cross-sectional image. The thickness of the surface protective layer was calculated by dividing this area by the above dimensions. The thickness thus obtained was equal to the thickness of the coating film made of the surface protective layer coating liquid. The thickness of the pigment-containing layer was also measured using the same method as above.

[0147] (2) Gloss The gloss was measured as specular gloss GS(60°) using a Rhopoint IQ-S (manufactured by Rhopoint Instruments). The "60° gloss value" in Tables 1 and 2 below represents this specular gloss GS(60°).

[0148] (3) Scratch Resistance Each decorative sheet was attached to wood substrate B using a urethane adhesive. A steel wool rubbing test was then conducted to evaluate scratch resistance. Specifically, the decorative sheet was rubbed back and forth 20 times with steel wool while applying a load of 100 g, and the occurrence of scratches on the surface of the decorative sheet and any changes in gloss were visually confirmed.

[0149] The evaluation criteria were as follows: AAA: No scratches or changes in gloss occurred on the surface. AA: Minor scratches or changes in gloss occurred on a part of the surface. A: Minor scratches or changes in gloss occurred on the surface. B: Significant scratches or changes in gloss occurred on the surface.

[0150] (4) Water Resistance Each decorative sheet was attached to wood substrate B using a urethane adhesive. Water was dropped onto the surface protective layer of each decorative sheet, and the sheet was left for 24 hours with a watch glass over it. After that, the water was wiped off the surface protective layer, and the decorative sheet was observed.

[0151] The evaluation criteria were as follows: AAA: No stains or traces of water absorption were found. AA: Traces of stains or water absorption were found in some areas, but they were difficult to confirm. A: Traces of stains or water absorption were found in some areas, but they were relatively easy to confirm. B: Traces of water absorption were clearly found throughout the entire surface.

[0152] (5) Bending Processability The resulting decorative sheet was subjected to wrapping processing. The folded portions of the surface of the decorative sheet were observed using an optical microscope to determine whether whitening or cracks had occurred, and the state of processability was evaluated. This wrapping processability corresponds to the so-called bending processability.

[0153] The evaluation criteria were as follows: AAA: No whitening or cracks were observed. AA: Slight whitening was observed in some areas. A: Whitening was observed in some areas. B: Whitening was observed over the entire surface, or cracks were observed in some areas.

[0154] The evaluation results are shown in Tables 1 to 3. In the "Type of Resin" column of Tables 1 to 3, "A-1" indicates that Shikoh (registered trademark) UV-W300 (manufactured by Mitsubishi Chemical Corporation) was used as the resin, "A-2" indicates that UVPUD-7502E (manufactured by UBE) was used as the resin, "B" indicates that SETAQUA6411 (manufactured by Daicel Allnex Corporation) was used as the resin, and "C" indicates that WS-5661 (manufactured by Mitsui Chemicals, Inc.) was used as the resin.

[0155]

[0156]

[0157]

[0158] As shown in Tables 1 to 3, the decorative sheets according to Examples 1 to 10 exhibited sufficient performance in all of low gloss, scratch resistance, water resistance, and processability. In contrast, the decorative sheet according to Comparative Example 1 exhibited insufficient performance in terms of scratch resistance. The sheet according to Comparative Example 2 exhibited insufficient performance in terms of low gloss and foldability. The sheets according to Comparative Examples 3 and 4 exhibited insufficient performance in terms of water resistance.

[0159] 1...decorative sheet, 2...raw fabric layer, 3...pigment-containing layer, 4...surface protective layer, 4A...core portion, 4B...ridge portion, 11...decorative material, B...base material, C...position, D...position.

Claims

1. A base fabric layer containing paper, a pigment-containing layer provided on the base fabric layer and containing a pigment and a cured product of a first ionizing radiation curable resin, and a surface protective layer provided on the pigment-containing layer, wherein the surface protective layer contains a cured product of a second ionizing radiation curable resin as a resin cured product, and a concavo-convex structure including a plurality of ridge-shaped portions each protruding in a ridge shape is provided on the surface, and the concavo-convex structure has a ratio RSm / Ra of the average length RSm of the roughness curve element to the arithmetic mean roughness Ra within a range of 10 or more and 800 or less. A decorative sheet.

2. The decorative sheet according to claim 1, wherein the first ionizing radiation curable resin contains acrylate.

3. The decorative sheet according to claim 1 or 2, wherein the thickness of the pigment-containing layer is in the range of 0.5 µm or more and 20 µm or less.

4. The decorative sheet according to any one of claims 1 to 3, wherein the thickness of the surface protective layer is in the range of 2 µm or more and 20 µm or less.

5. The decorative sheet according to any one of claims 1 to 4, wherein the total of the thickness of the pigment-containing layer and the thickness of the surface protective layer is in the range of 3 µm or more and 40 µm or less.

6. The decorative sheet according to any one of claims 1 to 5, wherein when the mass of the first ionizing radiation curable resin is 100 parts by mass, the mass of the pigment is 3 parts by mass or more and 50 parts by mass or less.

7. The decorative sheet according to any one of claims 1 to 6, wherein the pigment is titanium oxide.

8. The decorative sheet according to any one of claims 1 to 7, wherein the second ionizing radiation curable resin contains acrylate.

9. The decorative sheet according to any one of claims 1 to 8, wherein the second ionizing radiation curable resin contains a bifunctional or higher functional acrylate containing a repeating structure.

10. The decorative sheet according to claim 9, wherein the number of repetitions of the repeating structure is 3 or more.

11. The decorative sheet according to claim 9 or 10, wherein the number of repetitions of the repeating structure is 30 or less.

12. The decorative sheet according to any one of claims 1 to 11, wherein the surface protective layer further contains particles having an average particle diameter of 10 µm or less.

13. The decorative sheet according to claim 12, wherein when the mass of the second ionizing radiation curable resin is 100 parts by mass, the mass of the particles is in the range of 0.5 parts by mass or more and 20 parts by mass or less.

14. The decorative sheet according to any one of claims 1 to 13, wherein the glossiness of the surface protective layer is 20.0 or less.

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

16. A method for manufacturing a cosmetic sheet, comprising: forming a first coating film containing a pigment and a first ionizing radiation curable resin on a raw fabric layer containing paper; forming a second coating film containing a second ionizing radiation curable resin as a resin on the first coating film; and irradiating the second coating film with ionizing radiation or ultraviolet light to completely cure the second coating film.

17. The method for manufacturing a cosmetic sheet according to claim 16, wherein the complete curing of the second coating film includes an irradiation step of irradiating the second coating film with light having a wavelength of 200 nm or less, and then an irradiation step of irradiating the second coating film with ionizing radiation or ultraviolet light having a longer wavelength than the light irradiated in the irradiation step.

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