Decorative sheet and method for manufacturing same

Abstract

The present invention provides: a decorative sheet which has low gloss and is excellent in terms of all of fingerprint resistance, scratch resistance, stain resistance and bending workability; and a method for manufacturing the same. A decorative sheet 1 includes a base material layer 2 and a surface protection layer 5 that is provided on one surface of the base material layer 2. The surface of the surface protection layer 5 is provided with a relief structure that includes a plurality of ridge parts that each protrude in the form of a ridge. The surface protection layer 5 contains an ionizing radiation curable resin that is composed of a cured product of an ionizing radiation curable compound. The ionizing radiation curable compound includes one or more acrylate oligomers which each have a mass average molecular weight in the range of 700 to 20,000, and are each selected from among acrylic acrylate oligomers and urethane acrylate oligomers having 2 to 15 functional groups. The proportion of the acrylate oligomers in the ionizing radiation curable compound is in the range of more than 60 mass% but not more than 100 mass%.

Description

Decorative sheet and manufacturing method thereof

[0001] TECHNICAL FIELD The present invention relates to a decorative sheet and a method for producing the same. Decorative sheets can be used, for example, for the interior and exterior decoration of buildings, and for surface decoration of fixtures, furniture, fixtures, flooring materials, and the like.

[0002] In recent years, as shown in Patent Document 1, many decorative sheets using olefin resins (e.g., polypropylene sheets) have been proposed as alternatives to decorative sheets made of polyvinyl chloride, which are of concern in terms of environmental protection. The widespread use of decorative sheets that do not contain vinyl chloride resins will reduce the generation of toxic gases and the like when incinerated.

[0003] Decorative sheets are used to impart design and durability to the surfaces of, for example, buildings, fixtures, furniture, fixtures, flooring materials, etc., and are generally widely used by laminating them to the surfaces of wood, wood boards, metal plates, non-flammable boards, paper substrates, resin substrates, etc. to form decorative sheets. Here, durability refers to, for example, scratch resistance, stain resistance, weather resistance, processability, etc. Regarding the imparting of design, decorative sheets can be selected depending on the requirements and applications, from decorative sheets with patterns such as wood grain or stone grain formed using various printing methods to decorative sheets with plain surfaces without any patterns. Similarly, fingerprint resistance and glossiness of the surface are also important factors in terms of design, and decorative sheets can be selected depending on the requirements and applications, from decorative sheets with excellent fingerprint resistance, decorative sheets with a high gloss like a mirror finish, to decorative sheets with no reflections at all.

[0004] Decorative sheets have strict durability requirements. To provide durability, a surface protective layer is typically formed on the outermost surface of the decorative sheet. Furthermore, to adjust the aforementioned gloss, particularly to achieve low gloss, a gloss adjuster (matt additive) is typically added to the surface protective layer. A decorative sheet with improved design (low gloss) and durability (scratch resistance and stain resistance) is described, for example, in Patent Document 2.

[0005] On the other hand, Patent Documents 3 to 8 propose methods for producing low-gloss decorative sheets by forming wrinkles using excimer light with a wavelength of less than 200 nm.

[0006] Japanese Patent No. 3271022 Japanese Patent No. 7003667 Japanese Patent Publication No. 2022-132678 Japanese Patent No. 7060155 Japanese Patent No. 7088431 Japanese Patent No. 7196968 Japanese Patent No. 7215514 Japanese Patent No. 7294482

[0007] In recent years, the applications of decorative sheets for decorative boards have expanded, and consumer awareness of quality has been increasing. As a result, the requirements for the design and durability of decorative sheets have become more diverse and sophisticated, and advanced performance is being sought in various properties such as low gloss, fingerprint resistance, scratch resistance, stain resistance, and bending processability.

[0008] In the technique of adding a gloss adjuster (matting agent) to the surface protective layer as described above to achieve low gloss, there is a problem that the oil repellency of the surface protective layer is reduced, making it more susceptible to fingerprints. In contrast, the technique of forming wrinkles on the surface of the surface protective layer instead of adding a gloss adjuster (matting agent) leaves room for improvement in order to achieve high levels of durability such as scratch resistance, contamination resistance, and bending processability while simultaneously achieving low gloss and fingerprint resistance.

[0009] An object of the present invention is to provide a decorative sheet that has low gloss and is excellent in all of fingerprint resistance, scratch resistance, stain resistance, and bending processability, and a method for producing the same.

[0010] According to one aspect of the present invention, there is provided a decorative sheet comprising an original fabric layer and a surface protective layer provided on one side of the original fabric layer, wherein the surface of the surface protective layer is provided with an uneven structure including a plurality of ridge-like portions each protruding in a ridge-like shape, the surface protective layer comprises an ionizing radiation curable resin formed from a cured product of an ionizing radiation curable compound, the ionizing radiation curable compound is an acrylate oligomer having a mass average molecular weight in the range of 700 to 20,000, and comprising one or more acrylate oligomers selected from an acrylic acrylate oligomer and a urethane acrylate oligomer having 2 to 15 functional groups, and the proportion of the acrylate oligomer in the ionizing radiation curable compound is in the range of more than 60% by mass and not more than 100% by mass.

[0011] According to another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the acrylate oligomer has a weight average molecular weight in the range of 700 to 7,000.

[0012] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the ionizing radiation curable compound further comprises an acrylate monomer, and the proportion of the acrylate monomer in the ionizing radiation curable compound is less than 40 mass%.

[0013] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the acrylate monomer has a cyclic structure.

[0014] In accordance with yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the acrylate monomer has a molecular weight in the range of 100 to 2,000.

[0015] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the acrylate monomer has 1 or more and 4 or less functional groups.

[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 surface protective layer contains the ionizing radiation curable resin and particles, and the ratio of the particles to the ionizing radiation curable resin is within the range of 2 to 13 parts by mass per 100 parts by mass of the ionizing radiation curable resin.

[0017] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the gloss of the surface protective layer is 10.0 or less.

[0018] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, which comprises a pattern layer between the base layer and the surface protective layer.

[0019] According to yet another aspect of the present invention, there is provided a decorative material comprising a decorative sheet according to any one of the above aspects and a substrate to which the decorative sheet is attached.

[0020] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet, comprising: forming a coating film containing a composition containing an ionizing radiation curable compound on one surface of an original sheet layer; irradiating the coating film with light having a wavelength of 200 nm or less; and, after the irradiation, irradiating with ionizing radiation or ultraviolet light having a longer wavelength than the light; wherein the composition contains, as the ionizing radiation curable compound, an acrylate oligomer having a mass average molecular weight in the range of 700 to 20,000, and one or more acrylate oligomers selected from acrylic acrylate oligomers and urethane acrylate oligomers having 2 to 15 functional groups; and the proportion of the acrylate oligomer in the ionizing radiation curable compound is in the range of more than 60% by mass but not more than 100% by mass.

[0021] According to yet another aspect of the present invention, there is provided the production method according to the above aspect, wherein the ionizing radiation-curable compound further contains an acrylate monomer, and the proportion of the acrylate monomer in the ionizing radiation-curable compound is less than 40 mass %.

[0022] According to yet another aspect of the present invention, there is provided the manufacturing method according to any one of the above aspects, wherein the light has a wavelength of 172 nm.

[0023] According to the present invention, it is possible to provide a decorative sheet that has low gloss and is excellent in all of fingerprint resistance, scratch resistance, stain resistance, and bending processability, and a method for producing the same.

[0024] Fig. 3 is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention. Fig. 4 is a cross-sectional view of a decorative material including a decorative sheet according to another embodiment of the present invention. Fig. 5 is a cross-sectional view of the surface protective layer of the decorative sheet of Figs. 1 and 2. Fig. 6 is a microscope image of the surface protective layer of a decorative sheet according to an example of the present invention.

[0025] The configuration of a decorative sheet according to an embodiment of the present invention will be described below with reference to the drawings. The embodiments described below are more specific embodiments of any of the above aspects. The following features can be incorporated into each of the above aspects, either singly or in combination.

[0026] In the drawings referred to below, 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 thickness and planar dimensions, the thickness ratio of each layer, etc. may differ from the actual ones.

[0027] Furthermore, the embodiments shown below are merely examples of configurations for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention does not limit the materials, shapes, structures, etc. of the components to those described below. The technical idea of ​​the present invention can be modified in various ways within the technical scope defined by the claims.

[0028] <1> Decorative material and decorative sheet Fig. 1 is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention. Fig. 2 is a cross-sectional view of a decorative material including a decorative sheet according to another embodiment of the present invention. Fig. 3 is a cross-sectional view of the surface protective layer of the decorative sheet of Figs. 1 and 2. Fig. 4 is a micrograph of the surface protective layer of a decorative sheet according to one example of the present invention.

[0029] The cross section shown in Fig. 3 is a cross section along the thickness direction of the surface protection layer, and the micrograph in Fig. 4 is a plan view taken with a laser microscope (OLS-4000 manufactured by Olympus Corporation).

[0030] The decorative material 11 shown in Figures 1 and 2 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 board, or may be curved or folded. The decorative board 11 may have a shape other than a board.

[0031] 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.

[0032] The decorative sheet 1 shown in Figure 1 has a pattern layer 3 and a surface protective layer 5 provided in this order from the raw fabric layer 2 side on one surface, i.e., the front side, of the raw fabric layer 2, and a primer layer 6 provided on the other surface (i.e., the surface facing the substrate B) of the raw fabric layer 2. In Figure 1, one or more of the pattern layer 3 and the primer layer 6 may be omitted.

[0033] 2 has a design layer 3, an adhesive resin layer 4b, a transparent resin layer 4, and a surface protective layer 5 provided in this order from the original fabric layer 2 side on one surface (the front side) of the original fabric layer 2, and a primer layer 6 provided on the other surface of the original fabric layer 2 (i.e., the surface facing the substrate B). The transparent resin layer 4 has an embossed uneven pattern (embossed pattern 4a). In FIG. 2, one or more of the design layer 3, adhesive resin layer 4b, transparent resin layer 4, and primer layer 6 may be omitted. The embossed pattern 4a may not be provided.

[0034] Furthermore, if scratch resistance or other requirements are required, at least one of the transparent resin layer 4 and the surface protective layer 5 may be laminated in multiple layers. Also, in consideration of the adhesion between the layers, other known layers may be arranged. Furthermore, a concealing layer (not shown) or the like may be provided between the base layer 2 and the primer layer 6 as appropriate.

[0035] Next, each layer constituting the decorative sheet 1 will be described. <1.1> Raw Fabric Layer The raw fabric layer 2 can be made of any material selected from the group consisting of paper, synthetic resin, synthetic resin foam, rubber, nonwoven fabric, synthetic paper, and metal foil. Examples of paper include tissue paper, titanium paper, and resin-impregnated paper. Examples of synthetic resins include polyethylene, polypropylene, polybutylene, polystyrene, polycarbonate, polyester, polyamide, ethylene-vinyl acetate copolymer, polyvinyl alcohol, and acrylic. Examples of rubber include ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, styrene-butadiene copolymer rubber, styrene-isoprene-styrene block copolymer rubber, styrene-butadiene-styrene block copolymer rubber, and polyurethane. Examples of nonwoven fabric include organic and inorganic nonwoven fabrics. Examples of metals for the metal foil include aluminum, iron, gold, and silver. The raw fabric layer 2 may also be made of the same resin composition as the transparent resin layer 4. In this case, the raw fabric layer 2 is obtained by molding a resin material or a resin composition into a film shape. Examples of the molding method include calendar molding and extrusion molding.

[0036] The raw fabric layer 2 preferably has a colored layer formed by mixing an inorganic pigment with a synthetic resin, and a skin layer formed of a synthetic resin. The thickness of the skin layer is preferably 3 μm or more and 20 μm or less, and the thickness ratio of the skin layer to the colored layer (skin layer:colored layer) is preferably within the range of 1:6 to 1:50. When the raw fabric layer 2 is formed by co-extrusion, if the colored layer is the outermost layer, the pigment components contained in the colored layer will bleed and contaminate the T-die of the extruder and the rolls during transport, so it is desirable that the outermost layer be a skin layer that does not contain pigment. It is desirable to provide skin layers on both sides of the colored layer. Increasing the thickness of the skin layer and increasing its ratio to the colored layer is undesirable because it reduces the ratio of the colored layer and reduces hiding power.

[0037] It is also important that the thickness of the raw fabric layer 2 is 50 μm or more and 150 μm or less. If the thickness of the raw fabric layer 2 is less than 50 μm, the performance of covering the unevenness of the base (unevenness) will be reduced. On the other hand, if the thickness of the raw fabric layer 2 exceeds 150 μm, problems such as whitening and cracking may occur during bending.

[0038] (Inorganic Pigment) As the inorganic pigment, known inorganic pigments, such as titanium oxide, can be used to impart hiding properties. The base layer 2 serves to conceal the pattern of the substrate B. In order to obtain the hiding properties required from the standpoint of the design of the decorative sheet 1, a light transmittance of 40% or less is preferable. Low hiding properties result in the pattern of the design layer 3 and the pattern of the substrate B being mixed together, which is undesirable. By containing an inorganic pigment, a decorative sheet 1 with good hiding properties can be obtained. The mixing ratio of the inorganic pigment is preferably 5 to 50 parts by mass, based on 100 parts by mass of the resin material. A low mixing ratio of the inorganic pigment results in poor hiding properties, while a mixing ratio of 50 parts by mass or more results in embrittlement of the base layer 2, which is undesirable.

[0039] The inorganic pigment contained is not particularly limited, but examples thereof include natural inorganic pigments and synthetic inorganic pigments. Examples of natural inorganic pigments include earth pigments, calcined earth, and mineral pigments. Examples of synthetic inorganic pigments include oxide pigments, hydroxide pigments, sulfide pigments, silicate pigments, phosphate pigments, carbonate pigments, metal powder pigments, and carbon pigments. Furthermore, as the synthetic inorganic pigment, a mixed pigment containing one or more natural and synthetic inorganic pigments may be used. Furthermore, as the synthetic inorganic pigment, an organic pigment such as carbon black may be used in combination.

[0040] Furthermore, additives such as fatty acid metal salts may be added to the inorganic pigment to improve dispersibility and extrusion suitability.

[0041] When a substrate with an inactive surface such as an olefin-based substrate is used as the raw fabric layer 2, it is desirable to subject the front and back surfaces of the raw fabric layer 2 to corona treatment, plasma treatment, ozone treatment, electron beam treatment, ultraviolet treatment, dichromate treatment, etc.

[0042] <1.2> Pattern Layer A pattern layer 3 for adding a pattern to the decorative sheet 1 can be provided on the surface of the base fabric layer 2. Patterns that can be used include wood grain, pebble grain, sand grain, tiled, brickwork, fabric grain, leather-grained patterns, and geometric shapes.

[0043] Furthermore, a base solid ink layer (not shown) may be provided between the base layer 2 and the design layer 3 depending on the level of the desired design. The base solid ink layer is provided so as to cover the entire surface of the base layer 2. The base solid ink layer may also be multi-layered, consisting of two or more layers, as needed for hiding properties, etc. Furthermore, the design layer 3 may be formed by laminating as many plates as necessary to express the desired design. In this way, the design layer 3 and the base solid ink layer can be combined in various ways depending on the desired design, i.e., the design to be expressed, but there are no particular limitations.

[0044] The constituent materials of the base solid ink layer and the design layer 3 are not particularly limited. Examples of materials that can be used for the base solid ink layer and the design layer 3 include printing inks and coating agents prepared by dissolving or dispersing a matrix and a colorant such as a dye or pigment in a solvent. Examples of the matrix include various synthetic resins, such as oil-based nitrocellulose resins, two-component urethane resins, acrylic resins, styrene resins, polyester resins, urethane resins, polyvinyl resins, alkyd resins, epoxy resins, melamine resins, fluorine-containing resins, silicone resins, and rubber resins, as well as mixtures and copolymers thereof. Examples of colorants that can be used include inorganic pigments, such as carbon black, titanium white, zinc white, 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; and mixtures thereof. As the solvent, toluene, xylene, ethyl acetate, butyl acetate, methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, water, or a mixture thereof can be used.

[0045] In addition, functional additives such as extender pigments, plasticizers, dispersants, surfactants, tackifiers, adhesion aids, drying agents, hardeners, hardening accelerators, and hardening retarders may be added to the base solid ink layer and the pattern layer 3 to impart various functions.

[0046] Here, the base solid ink layer and the design layer 3 can be formed by various printing methods such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing. Furthermore, since the base solid ink layer covers the entire surface of the base layer 2, it can also be formed by various coating methods such as roll coating, knife coating, microgravure coating, and die coating. These printing and coating methods may be selected separately depending on the layer to be formed, but it is more efficient to select the same method and process them all at once.

[0047] The thickness of the design layer 3 is preferably 3 μm or more and 20 μm or less. When the thickness of the design layer 3 is within this range, the printing can be made clear, the printing workability when producing the decorative sheet 1 is improved, and production costs can be reduced.

[0048] <1.3> Transparent Resin Layer The resin material used as the main component of the transparent resin layer 4 is preferably made of an olefin-based resin, and in addition to polypropylene, polyethylene, polybutene, etc., α-olefins (for example, 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-pent ... Examples of the copolymer include a homopolymer or copolymer of two or more of α-olefins (e.g., 4-ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, etc.) and a copolymer of ethylene or an α-olefin with another monomer, such as an ethylene-vinyl acetate copolymer, an ethylene-vinyl alcohol copolymer, an ethylene-methyl methacrylate copolymer, an ethylene-ethyl methacrylate copolymer, an ethylene-butyl methacrylate copolymer, an ethylene-methyl acrylate copolymer, an ethylene-ethyl acrylate copolymer, or an ethylene-butyl acrylate copolymer.

[0049] Furthermore, it is preferable to use a highly crystalline polypropylene as the olefin resin when improving the surface strength of the decorative sheet 1. For example, the highly crystalline polypropylene preferably has a pentad fraction (mmmm fraction) of 96% or more, a melt flow rate (MFR) of 5 g / 10 min (230°C) to 40 g / 10 min (230°C), and a molecular weight distribution (MWD; Mw / Mn) of 4 or less. In this case, the surface strength is good, and the bending processability of the decorative sheet 1 is also good.

[0050] The olefin resin contained as the main component in the transparent resin layer 4 preferably accounts for 90% by mass or more of the materials contained in the transparent resin layer 4 .

[0051] When a transparent resin layer 4 is provided, the thickness of the transparent resin layer 4 is preferably 50 μm or more and 100 μm or less. If it is less than 50 μm, the effect of improving the scratch resistance of the surface of the transparent resin layer 4 is low, and the purpose of providing the transparent resin layer 4 is diminished. If the thickness of the transparent resin layer 4 exceeds 100 μm, the rigidity of the decorative sheet 1 may be too high, which may cause problems such as whitening and cracking during bending. However, when a surface protective layer 5 is provided on the transparent resin layer 4, the thickness of the transparent resin layer 4 may be less than 50 μm.

[0052] The resin composition constituting the transparent resin layer 4 may contain various functional additives, such as a heat stabilizer, a light stabilizer, an ultraviolet absorber, an antiblocking agent, a catalyst scavenger, a colorant, a light scattering agent, and a gloss adjuster, as needed. These various functional additives can be appropriately selected from well-known additives.

[0053] Furthermore, the adhesive used to bond the design layer 3 and the transparent resin layer 4 can be any material selected depending on the bonding method. Examples of bonding methods include lamination methods such as thermal lamination, extrusion lamination, and dry lamination, and the adhesive can be selected from acrylic, polyester, polyurethane, and other materials. Due to their cohesive strength, a two-component curing urethane material that utilizes the reaction between isocyanate and polyol is usually desirable. There are no particular restrictions on the lamination method for the transparent resin layer 4, but methods that apply heat and pressure, extrusion lamination, dry lamination, and the like are commonly used.

[0054] The transparent resin layer 4 may also be provided with an embossed pattern (embossed pattern 4a). Ink can be embedded in the embossed pattern 4a to further improve the design. The embossed pattern 4a can be formed by embossing a sheet that has been laminated by various methods using heat and pressure, or by forming a pattern on a cooling roll and embossing the sheet simultaneously with extrusion lamination.

[0055] Alternatively, a method may be used in which the embossed pattern layer 3 and the transparent resin layer 4 are bonded together by heat or dry lamination simultaneously with extrusion.

[0056] Furthermore, to improve adhesion between the design layer 3 and the transparent resin layer 4, an adhesive resin layer 4b may be provided between the design layer 3 and the transparent resin layer 4. Specifically, when further lamination strength is required in the extrusion lamination method, an adhesive resin layer 4b may be provided between the transparent resin layer 4 and the adhesive. When the adhesive resin layer 4b is provided, lamination can be performed by co-extrusion of the transparent resin layer 4 and the adhesive resin layer 4b. The adhesive resin layer 4b can be an acid-modified resin such as polypropylene, polyethylene, or acrylic resin. The thickness of the adhesive resin layer 4b is preferably 2 μm or more to improve adhesive strength.

[0057] <1.4> Surface Protective Layer As shown in FIG. 3 , the surface protective layer 5 has a core portion 5A and a ridge portion 5B that protrudes in a ridge-like manner from one surface of the core portion 5A. This forms an uneven shape in the surface protective layer 5. Here, in the decorative sheet 1 according to one embodiment of the present invention, the term "ridge-like" refers to a long, raised, linear shape in a planar view. The ridge portion 5B may be curved or linear in a planar view, but is preferably curved from the viewpoint of the fingerprint resistance of the decorative sheet 1. Furthermore, in this embodiment, the ridge portion 5B refers to, for example, the portion from the lowest to the highest point of the uneven shape of the surface protective layer 5, and the core portion 5A refers to the portion of the surface protective layer 5 excluding the ridge portion 5B. The cross-sectional shape of the ridge portion 5B in the thickness direction of the surface protective layer 5 may be sinusoidal. The sine wave shape here refers to a shape in which the line from the lowest point to the highest point of the ridge portion 5B can be expressed as a sine wave.

[0058] Fig. 3 is a cross-sectional view schematically showing a cross section of the ridge portion 5B of the surface protective layer 5 (a cross section in the thickness direction of the surface protective layer 5), and Fig. 4 is a planar photograph showing the surface configuration of the surface protective layer 5. Here, Fig. 4 is a planar photograph obtained with a laser microscope (OLS-4000 manufactured by Olympus Corporation).

[0059] As shown in the plan view photograph of Fig. 4, the ridge portions 5B have a long, raised, linear shape in plan view. As will be described later, the ridge portions 5B are formed by irradiating the surface of a coating film of a composition containing an ionizing radiation-curable compound (coating liquid for surface protective layer) with light of a specific wavelength, causing buckling of a cured film containing an ionizing radiation-curable resin made of a cured product of the ionizing radiation-curable compound.

[0060] The shape of the ridge portions 5B can be expressed by the ratio RSm / Ra of the surface roughness index RSm (μm) in the horizontal direction (the planar direction of the surface protective layer 5, the left-right direction in FIG. 3 ) to the surface roughness index Ra (μm) in the vertical direction (the depth direction of the ridge portions 5B, the thickness direction of the surface protective layer 5, the up-down direction in FIG. 3 ). The ratio RSm / Ra is preferably in the range of 10 to 300, more preferably in the range of 10 to 250. As the ratio RSm / Ra decreases, the shape of the ridge portions 5B becomes finer, making it difficult to wipe off dirt and reducing contamination resistance. As the ratio RSm / Ra increases, the spacing between the ridges becomes wider, resulting in higher gloss. Here, the surface roughness indexes Ra and RSm are measured using a line roughness meter in accordance with JIS B0601.

[0061] The thickness t of the surface protective layer 5 is preferably in the range of 2 μm to 20 μm, more preferably in the range of 3 μm to 10 μm. If the surface protective layer 5 is too thin, it becomes difficult to achieve a low glossiness, and if it is too thick, processability decreases and whitening occurs when the layer is bent.

[0062] Here, the thickness of the surface protective layer 5 refers to the thickness of a layer having an apparent area and volume equal to those of the surface protective layer 5 and a flat surface. The thickness of the surface protective layer 5 can be determined, for example, by the following method. First, a cross section parallel to the thickness direction of the surface protective layer 5 and perpendicular to the length direction of the ridge portions 5B is imaged. Next, from this cross-sectional image, the dimension of the surface protective layer 5 in the width direction of the ridge portions 5B and the area of ​​the cross section of the surface protective layer 5 are determined. The thickness of the surface protective layer 5 is a value obtained by dividing this area by the above dimension. The thickness of the surface protective layer 5 is determined by observing the cross section with a scanning electron microscope and averaging the values ​​at 25 points. Specifically, the thickness of the surface protective layer 5 can be determined as described in the Examples below. When the ionizing radiation-curable composition serving as the coating liquid for the surface protective layer, described below, does not contain a solvent, the thickness of the coating film made of the ionizing radiation-curable composition is equal to the thickness of the surface protective layer 5.

[0063] Here, the surface protective layer 5 can be formed by various printing methods such as gravure printing, offset printing, screen printing, electrostatic printing, inkjet printing, etc. Furthermore, since the surface protective layer 5 covers the entire surface of the front side of the raw fabric layer 2, it can also be formed by various coating methods such as roll coating, knife coating, microgravure coating, and die coating. These printing or coating methods may be selected separately for each layer to be formed, or the same method may be selected and used for batch processing.

[0064] The design layer 3 and the surface protective layer 5 may be synchronized from the viewpoint of design. In this case, the surface protective layer 5 must be formed after the design layer 3 is formed, and therefore, gravure printing is preferably used. Furthermore, gravure printing allows for relatively high speed printing, which is advantageous in terms of cost and is therefore preferred. Here, synchronization means that 50% or more, preferably 70% or more, and most preferably 90% or more of the area where the surface protective layer 5 is formed overlaps with the design portion of the design layer 3 in a planar view.

[0065] The thickness of the surface protective layer 5 can be adjusted by adjusting the amount of coating in the printing method and coating method described above. The amount of coating can be calculated from the mass difference between a base sheet (including a raw fabric layer) with the surface protective layer 5 formed thereon and a base sheet without the surface protective layer 5 formed thereon, using various printing and coating methods.

[0066] The surface protective layer 5 contains, as a main component, an ionizing radiation curable resin, which is a cured product of an ionizing radiation curable compound. Specifically, the ionizing radiation curable resin is contained in an amount of preferably 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 surface protective layer 5. In the present disclosure, "ionizing radiation" refers to a charged particle beam such as an electron beam (EB). The ionizing radiation curable compound is cured by irradiation with ionizing radiation. The ionizing radiation curable compound can also be cured by ultraviolet irradiation. The ionizing radiation curable compound 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.

[0067] In the present disclosure, the term "functional group number" refers to the number of acryloyl groups or methacryloyl groups contained in one molecule of an ionizing radiation-curable compound. Furthermore, in the present disclosure, the term "acrylic" generally refers to acrylic and / or methacrylic. Similarly, the term "acryloyl" generally refers to acryloyl and / or methacryloyl, and the term "acrylate" generally refers to acrylate and / or methacrylate.

[0068] The surface protective layer 5 is a cured film of a coating film formed using a composition containing an ionizing radiation-curable compound (hereinafter referred to as the "ionizing radiation-curable composition"), and as described above, contains, as a main component, an ionizing radiation-curable resin, which is a cured product of the ionizing radiation-curable compound. The ionizing radiation-curable compound is an acrylate oligomer having a mass-average molecular weight in the range of 700 to 20,000, and includes one or more acrylate oligomers selected from acrylic acrylate oligomers and urethane acrylate oligomers having 2 to 15 functional groups. The ionizing radiation-curable compound may further contain an acrylate monomer, which will be described later. The proportion of the acrylate oligomer in the ionizing radiation-curable compound is in the range of more than 60% by mass to 100% by mass, and preferably in the range of more than 60% by mass to 80% by mass.

[0069] By including the acrylate oligomer having a mass-average molecular weight in the range of 700 to 20,000 in the ionizing radiation-curable composition, the shaping properties are improved, improving the formability of the uneven structure including ridges in the surface protective layer 5, thereby contributing to low gloss and improved fingerprint resistance. Furthermore, a high mass-average molecular weight of the acrylate oligomer results in a high viscosity. High viscosity tends to cause a problem in which gloss does not decrease when the line speed is increased in the first irradiation step described below. In contrast, when the mass-average molecular weight of the acrylate oligomer is 20,000 or less, such a problem can be suppressed even when the line speed is increased, thereby achieving low gloss while improving production efficiency. The mass-average molecular weight of the acrylate oligomer is preferably in the range of 700 to 7,000. Here, the mass-average molecular weight is a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

[0070] Furthermore, in the acrylate oligomer contained in the ionizing radiation-sensitive composition, the number of functional groups possessed by the urethane acrylate oligomer is in the range of 2 or more and 15 or less, which contributes to further improving shapability. In the acrylate oligomer contained in the ionizing radiation-sensitive composition, the number of functional groups possessed by the acrylic acrylate oligomer may be, for example, the same as that of the urethane acrylate oligomer, in the range of 2 or more and 15 or less. When the ionizing radiation-sensitive composition contains the acrylate oligomer, the crosslink density of the ionizing radiation-curable resin, which is the cured product, is increased, and scratch resistance and contamination resistance are improved.

[0071] As the acrylate oligomer, commercially available products may be used, for example, EBECRYL (registered trademark) 9270, KRM9465, EBECRYL270, EBECRYL4858, EBECRYL8402, EBECRYL8409, EBECRYL9270, KRM2000 (all bifunctional urethane acrylates, manufactured by Daicel Allnex Corporation), UN-2601, UN-6200, UN-6304, UN-63 06 (all bifunctional urethane acrylates, manufactured by Negami Chemical Industrial Co., Ltd.), UA-4200, UA-4400, UA-1100H (all bifunctional urethane acrylates, manufactured by Shin-Nakamura Chemical Co., Ltd.), EBECRYL4513, EBECRYL4738, EBECRYL4740, EBECRYL4820, EBECRYL9260, EBECRYL8701, EBECRYL4265 (all trifunctional urethane acrylates, manufactured by Daicel Chemical Industries, Ltd.) Allnex Co., Ltd.), SMT-001 (trifunctional urethane acrylate, Negami Chemical Industrial Co., Ltd.), EBECRYL4666, EBECRYL4680, EBECRYL8210, KRM8528 (tetrafunctional urethane acrylate, Daicel Allnex Co., Ltd.), EBECRYL1290, EBECRYL5129, EBECRYL8254, KRM8200, KRM8452 (hexafunctional urethane acrylate, Daicel Allnex Co., Ltd.) Examples of such acrylates include UN-3320HA (15-functional urethane acrylate, manufactured by Negami Chemical Industrial Co., Ltd.), UN-3320HC (6-functional urethane acrylate, manufactured by Negami Chemical Industrial Co., Ltd.), UN-904 (10-functional urethane acrylate, manufactured by Negami Chemical Industrial Co., Ltd.), UN-3320HS (15-functional urethane acrylate, manufactured by Negami Chemical Industrial Co., Ltd.), OAP-5000, OAP-2531 (all acrylic acrylates, manufactured by Negami Chemical Industrial Co., Ltd.). All of these have a mass average molecular weight in the range of 700 to 20,000.

[0072] Among the above, for example, UA-4400 (bifunctional urethane acrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.) has a mass average molecular weight of 1,400 and a viscosity of 3,000 Pa·s / 25°C, EBECRYL8701 (trifunctional urethane acrylate, manufactured by Daicel-Allnex Corporation) has a mass average molecular weight of 2,000 and a viscosity of 4,500 Pa·s / 60°C, SMT-001 (trifunctional urethane acrylate, manufactured by Negami Chemical Industrial Co., Ltd.) has a mass average molecular weight of 1,700 and a viscosity of 1,000 Pa·s / 25°C, and EBECRYL4666 (tetrafunctional urethane acrylate, manufactured by Daicel-Allnex Corporation) has a mass average molecular weight of 1,700 and a viscosity of 1,000 Pa·s / 25°C. EBECRYL5129 (hexafunctional urethane acrylate, manufactured by Daicel Allnex Corporation) has a mass average molecular weight of 800 and a viscosity of 700 Pa s / 60°C, UN-904 (10-functional urethane acrylate, manufactured by Negami Chemical Industrial Co., Ltd.) has a mass average molecular weight of 4900 and a viscosity of 500,000 Pa s / 25°C, and UN-3320HS (15-functional urethane acrylate, manufactured by Negami Chemical Industrial Co., Ltd.) has a mass average molecular weight of 5,000 and a viscosity of 185,000 Pa s / 25°C. The acrylate oligomers may be used alone or in combination of two or more.

[0073] It is preferable that the ionizing radiation-curable compound further contains an acrylate monomer. When the ionizing radiation-curable composition further contains an acrylate monomer in addition to the acrylate oligomer described above as the ionizing radiation-curable compound, the viscosity of the composition is reduced, thereby achieving the effect of, for example, shortening the time it takes for the coating film to buckle due to light irradiation. This effect is particularly significant when the acrylate oligomer has a large number of functional groups. When the ionizing radiation-curable compound contains an acrylate monomer, the proportion of the acrylate monomer in the ionizing radiation-curable compound is less than 40% by mass, for example, preferably in the range of 10% by mass or more but less than 40% by mass, and more preferably in the range of 20% by mass or more but less than 40% by mass.

[0074] The number of functional groups possessed by the acrylate monomer is preferably 1 or more and 4 or less. The number of functional groups possessed by the acrylate monomer is particularly preferred from the viewpoints of low gloss and production efficiency. That is, when the number of functional groups possessed by the acrylate monomer is large, the crosslinking density of the composition increases, resulting in reduced fluidity, and the effect of adding the acrylate monomer, i.e., shortening the time required for buckling due to light irradiation of the coating film, tends to be difficult to achieve. Furthermore, when the fluidity of the composition is low, a problem of gloss not decreasing tends to occur when the line speed in the light irradiation step is increased. In contrast, when the number of functional groups possessed by the acrylate monomer is 4 or less, such a problem can be suppressed even when the line speed is increased, contributing to achieving low gloss while improving production efficiency.

[0075] The molecular weight of the acrylate monomer is preferably in the range of 100 to 2,000, and more preferably in the range of 200 to 1,500.

[0076] Specific examples of acrylate monomers (excluding acrylate monomers having a cyclic structure, which will be described later) include tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, PO-modified neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane ethoxy triacrylate, glycerin propoxy triacrylate, pentaerythritol, pentaerythritol ethoxy tetraacrylate, pentaerythritol (tri / tetra)acrylate, etc. The acrylate monomers may be used alone or in combination of two or more.

[0077] The acrylate monomer may have a cyclic structure. When the acrylate monomer is a compound having a cyclic structure (hereinafter also referred to as a cyclic acrylate monomer), stain resistance is particularly improved. This effect is believed to be due to the following reasons.

[0078] As described later in this specification, the surface protective layer 5 is formed by a first irradiation step and a second irradiation step. In the first irradiation step, a crosslinking reaction of the ionizing radiation curable resin occurs only on the surface of the coating film, and in the second irradiation step, curing of the entire coating film occurs. The first irradiation step is generally performed in a nitrogen gas atmosphere with a low oxygen concentration. A nitrogen gas atmosphere with a low oxygen concentration is a hydrophobic atmosphere. Meanwhile, the cyclic structure portion of the cyclic acrylate monomer contained in the coating film is hydrophobic. Therefore, the cyclic structure portion of the cyclic acrylate monomer is easily exposed to the surface of the coating film. As a result, the cyclic structure portion of the cyclic acrylate monomer is more abundant on the surface of the surface protective layer 5 than in regions other than the surface. Because the cyclic structure portion of the cyclic acrylate monomer is bulky, when a colored contaminant, such as a hair dye, adheres to the surface protective layer 5, the dye molecules of the contaminant are prevented from coming into contact with the ionizing radiation curable resin, which does not have a cyclic structure. It is believed that this is why ionizing radiation curable resins having a cyclic structure exhibit excellent resistance to coloring and contamination.

[0079] The term "cyclic structure" refers to a ring structure based on a carbon skeleton. The cyclic structure may be one in which the ring constituent atoms are only carbon (i.e., a carbocyclic ring), or one in which the ring constituent atoms are carbon and an element other than carbon (i.e., a heterocyclic ring). The cyclic structure may be a monocyclic ring or a polycyclic ring. The polycyclic ring may be a fused ring, a spiro ring, or a bridged ring. The cyclic structure may be composed of, for example, a monocyclic to tetracyclic hydrocarbon. That is, the cyclic structure may be composed of, for example, a monocyclic or a dicyclic to tetracyclic hydrocarbon. The cyclic structure has, for example, 5 or more ring constituent atoms, preferably 5 to 18, more preferably 6 to 18, and even more preferably 6 to 10 ring constituent atoms.

[0080] Examples of the cyclic structure include an isobornyl group, an adamantyl group, a dicyclopentanyl group, a cyclohexyl group, a cyclopentyl group, a cyclopentadienyl group, a 3,4-epoxycyclohexyl group, a 6,7-epoxydecahydro-1,4:5,8-dimethanonaphthalene group, a decahydronaphthalene group, a tricyclodecane group, a benzyl group, and a phenyl group. The isobornyl group, the adamantyl group, the dicyclopentanyl group, the 6,7-epoxydecahydro-1,4:5,8-dimethanonaphthalene group, and the tricyclodecane group correspond to bridged rings and have particularly bulky structures. The cyclic acrylate monomer may or may not have a substituent on the cyclic structure. When the cyclic acrylate monomer has a bulky substituent such as a tert-butyl group on the cyclic structure, the bulky substituent portion is also thought to contribute to the staining resistance.

[0081] Examples of cyclic acrylate monomers include cyclohexyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, 4-tert-butylcyclohexyl acrylate, cyclopentyl acrylate, dicyclopentanyl acrylate, 3,4-epoxycyclohexylmethyl acrylate, 6,7-epoxydecahydro-1,4:5,8-dimethanonaphthalen-2-yl acrylate, tricyclodecane dimethanol diacrylate, isobornyl acrylate, 2-adamantylprop-2-enoate, 1-adamantyl acrylate, 3-hydroxy-1-adamantyl acrylate, 2-methyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl acrylate, 2-isopropyl-2-adamantyl acrylate, 1,3-adamantanediol diacrylate, benzyl acrylate, and phenoxyethyl acrylate. These cyclic acrylate monomers may be used alone or in combination of two or more kinds, or may be used in combination with the above-mentioned acrylate monomers not having a cyclic structure.

[0082] For example, when gravure printing is used as the coating method, the viscosity of the ionizing radiation-curable composition is preferably in the range of 10 to 500 mPa·s, and more preferably in the range of 20 to 500 mPa·s. Here, the viscosity is measured at room temperature of 25° C. To adjust the viscosity, an organic solvent can be used or an acrylate monomer with a low viscosity can be added, but from the viewpoint of environmental load, it is preferable not to use an organic solvent.

[0083] The surface protection layer 5 may contain particles. By incorporating particles of an optimal particle size and at an optimal content into the surface protection layer 5, a uniform surface can be formed. Examples of particles that can be used include organic materials such as polyethylene (PE) wax, polypropylene (PP) wax, and resin beads, as well as inorganic materials such as silica, glass, alumina, titania, zirconia, calcium carbonate, and barium sulfate. It is desirable for the average particle size (D50) of the particles to be 3 μm or more. The average particle size (D50) of the particles is preferably 3 μm or more and 11 μm or less, and more preferably 4 μm or more and 10 μm or less.

[0084] When the surface protective layer 5 contains particles having a preferred particle size, wrinkles can be more uniformly formed on the coating surface in the first irradiation step described below. Therefore, if the average particle size (D50) is too small or too large, wrinkles on the coating surface will be non-uniform. Furthermore, when large particles are used, the particles are likely to fall off from the surface protective layer 5, making it difficult to achieve high scratch resistance. When the particles are small, the effect of forming wrinkles uniformly is small.

[0085] Here, the "average particle size (D50)" refers to the median size (D50) measured using a laser diffraction / scattering particle size distribution analyzer. When the ionizing radiation-curable composition contains particles, the surface protective layer 5 obtained from this coating film will also contain particles. The average particle size of the particles contained in the surface protective layer 5 can be determined by observing the cross section of the layer and measuring the particle sizes of multiple particles, and averaging these values. The value obtained in this manner is substantially the same as the median size (D50) measured using a laser diffraction / scattering particle size distribution analyzer. Therefore, the above-mentioned range of average particle size can also be interpreted as the range of average particle sizes of the particles contained in the surface protective layer 5.

[0086] The particles are preferably contained in the surface protection layer 5 in a proportion of 2 parts by mass to 13 parts by mass with respect to 100 parts by mass of the ionizing radiation curable resin.

[0087] When the amount of particles added is within the above range, the effect of generating wrinkles uniformly is particularly large. When the amount of particles added is large, the particles tend to fall off from the surface protective layer 5, making it difficult to achieve high scratch resistance. When the amount of particles added is small, the effect of generating wrinkles uniformly is small.

[0088] When the entire surface protective layer 5 is cured by UV light, it is necessary to add a photopolymerization initiator to the surface protective layer 5. The photopolymerization initiator is not particularly limited, but examples thereof include benzaphenone-based, acetophenone-based, benzoin ether-based, and thioxanthone-based initiators.

[0089] When a photopolymerization initiator is added, it is preferably added in an amount of 0.2 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the ionizing radiation-curable compound. If the amount of photopolymerization initiator added is small, the surface curing tends to be insufficient when cured with UV light, and scratch resistance and contamination resistance tend to be poor. On the other hand, if the amount of photopolymerization initiator added is large, a problem of gloss not decreasing tends to occur when the line speed is increased in the first irradiation step described below. When considering production efficiency, the amount of photopolymerization initiator added is more preferably 3 parts by mass or less.

[0090] The surface protective layer 5 may further contain additives such as antibacterial agents and antifungal agents. Furthermore, as other additives, the surface protective layer 5 may further contain ultraviolet absorbers and light stabilizers as necessary. Generally, ultraviolet absorbers such as benzotriazoles, benzoates, benzophenones, and triazines are added as ultraviolet absorbers, and light stabilizers such as hindered amines are added as light stabilizers, in any combination.

[0091] Examples of hindered amine light stabilizers that can be used include bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butyl malonate (typical examples include those available from BASF under the trade name "Tinuvin 144"), BASF under the trade name "Tinuvin 123", and a reaction product of decanedioic acid bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) ester (1,1-dimethylethyl hydroperoxide) and octane.

[0092] When a hindered amine light stabilizer is added to the surface protective layer 5, it is preferably added in an amount ranging from 0.05 to 5 parts by mass relative to 100 parts by mass of the ionizing radiation-curable resin. The amount of hindered amine light stabilizer added is more preferably from 0.2 to 3 parts by mass. If the amount of hindered amine light stabilizer added is less than 0.05 parts by mass, the resin's stability against ultraviolet light may be reduced. On the other hand, if the amount added is more than 5 parts by mass, bleed-out may occur. Furthermore, the surface protective layer 5 can be formed by irradiating light of 200 nm or less to cure and shrink the surface vicinity, forming a fine uneven shape. In this case, if the hindered amine light stabilizer is added in an amount greater than 3 parts by mass, curing of the surface vicinity may be inhibited. In order to achieve both low gloss and weather resistance, it is desirable to add the hindered amine light stabilizer in an amount ranging from 3 parts by mass or less.

[0093] <1.5> Primer Layer The material for the primer layer 6 can basically be the same as that for the design layer 3. Considering that the primer layer 6 is applied to the back surface of the decorative sheet 1 and is wound up in web form, inorganic fillers such as silica, alumina, magnesia, titanium oxide, and barium sulfate may be added to the primer layer 6 to avoid blocking and improve adhesion with the adhesive. Since the purpose of the primer layer 6 is to ensure adhesion with the substrate B, its coating thickness is preferably within the range of 0.1 μm to 3.0 μm. The primer layer 6 is necessary when the base layer 2 has an inactive surface, such as an olefin-based material, but is not particularly necessary when the surface is active.

[0094] <2> Manufacturing Method of Decorative Sheet The decorative sheet 1 is manufactured, for example, by the following method. For the sake of brevity, explanations of the design layer 3, transparent resin layer 4, adhesive resin layer 4b, and primer layer 6 are omitted here.

[0095] First, a coating film made of an ionizing radiation curable composition, which is a coating liquid for a surface protective layer, is formed on one surface of the base layer 2. As described in the section <1.4> Surface protective layer, the ionizing radiation curable composition contains an ionizing radiation curable compound and, if necessary, particles and additives. The coating film made of the ionizing radiation curable composition can be formed, for example, by printing.

[0096] After forming a coating film made of an ionizing radiation-curable composition, a first irradiation step is carried out. In the first irradiation step, the coating film is irradiated with light having a wavelength of 200 nm or less (hereinafter referred to as first radiation). The ionizing radiation-curable compound contained in the ionizing radiation-curable composition has a large absorption coefficient for the first radiation. Therefore, the first radiation incident on the coating film can only reach a position several tens to several hundreds of nanometers away from the outermost surface. Therefore, in the first irradiation step, a crosslinking reaction proceeds in the surface region of the coating film, forming an extremely thin cured film, while the crosslinking reaction does not proceed in other regions, leaving the other regions uncured.

[0097] The coating film after the first irradiation step has wrinkles on its surface corresponding to the ridge portions 5 B. The present inventors believe that the reason why wrinkles are formed on the coating film surface by the first irradiation step is as follows.

[0098] As described above, the first radiation can only reach a position tens to hundreds of nanometers away from the outermost surface of the coating film. That is, the crosslinking reaction of the ionizing radiation-curable compound occurs only on the surface of the 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 generates in-plane compressive stress, which causes the cured film to buckle, resulting in wrinkles on the surface of the coating film.

[0099] The first radiation can be extracted from excimer VUV light. Excimer VUV light can be generated from a lamp using a rare gas or a rare gas halide compound. When high-energy electrons are externally applied to a lamp filled with a rare gas or a rare gas halide compound, a large number of discharge plasmas (dielectric barrier discharges) are generated. This plasma discharge excites atoms of the discharge gas (rare gas), which momentarily transition to an excimer state. When returning from this excimer state to the ground state, light is emitted in a wavelength range specific to the excimer.

[0100] The gas used in the excimer lamp may be any conventional gas that emits light of 200 nm or less. Examples of suitable gases include rare gases such as Xe, Ar, and Kr, and mixtures of rare gases such as ArBr and ArF with halogen gases. The center wavelength of excimer lamps varies depending on the gas used, with wavelengths of approximately 172 nm (Xe), approximately 126 nm (Ar), approximately 146 nm (Kr), approximately 165 nm (ArBr), and approximately 193 nm (ArF).

[0101] 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.

[0102] The first 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 first irradiation step is preferably carried out in, for example, a nitrogen gas atmosphere. The oxygen concentration in the gas phase in the first 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.

[0103] Furthermore, oxygen in the atmosphere inhibits radical polymerization. Therefore, the residual oxygen concentration in the reaction atmosphere affects the formation of wrinkles on the coating surface. Therefore, changing the residual oxygen concentration in the reaction atmosphere can also change the surface properties of the surface protective layer 5.

[0104] The integrated light amount of the first radiation is 0.5 mJ / cm ２ More than 200mJ / cm ２ It is preferable that the dose is 1 mJ / cm or less. ２ More than 100mJ / cm ２ More preferably, it is 3 mJ / cm or less. ２ More than 50mJ / cm ２ More preferably, it is 5 mJ / cm or less. ２ 30mJ / cm or more ２ It is most preferable to set the integrated light dose as follows: If the integrated light dose is small, the expansion of the cured film in the in-plane direction will be small; if the integrated light dose is large, the surface condition of the coating film will deteriorate.

[0105] After the first irradiation step is completed, the second irradiation step is carried out. In the second irradiation step, the coating film is irradiated with a second radiation to cure the entire coating film. In this way, the surface protective layer 5 is obtained.

[0106] The second radiation is ionizing radiation such as an electron beam, or ultraviolet radiation having a longer wavelength than the first radiation. When ultraviolet radiation is used as the second radiation, the ultraviolet radiation has a wavelength at which the ionizing radiation curable resin exhibits a smaller absorption coefficient.

[0107] The cumulative amount of the second radiation is 10 mJ / cm ２ More than 500mJ / cm ２ It is preferable that the dose is 50 mJ / cm or less. ２ More than 400mJ / cm２ More preferably, it is 100 mJ / cm or less. ２ More than 300mJ / cm ２ It is more preferable that:

[0108] <3> Functions and Others The decorative sheet 1 described with reference to Figures 1 to 4 includes a surface protective layer 5 having an uneven surface including ridges. This configuration allows the gloss (gloss level) of the surface protective layer 5 to be adjusted without the need for a gloss adjuster (matt additive). Because gloss adjusters reduce the oil repellency of layers formed from resin materials, surface protective layers 5 containing gloss adjusters are prone to fingerprints. Surface protective layers 5 that do not contain gloss adjusters are less likely to absorb oil and therefore less likely to attract fingerprints. Furthermore, surface protective layers 5 with excellent oil repellency are less likely to develop oil stains or adsorb contaminants. Furthermore, surface protective layers 5 that do not contain gloss adjusters do not lose gloss adjuster particles when scratched, and therefore decorative sheets 1 containing such surface protective layers 5 are less likely to develop gloss changes or scratches.

[0109] In this embodiment, the surface protective layer 5 is formed as a single layer, but is not limited to this configuration. For example, the surface protective layer 5 may be formed as a multilayer. That is, the surface protective layer 5 may be formed by laminating multiple layers of the same ionizing radiation curable resin or multiple layers of different ionizing radiation curable resins to form an uneven surface. When multiple layers of different ionizing radiation curable resins are laminated, for example, the outermost layer of the surface protective layer 5 may be a layer whose main component is an ionizing radiation curable resin made of a cured product of a 2- to 15-functional urethane acrylate oligomer or an acrylic acrylate oligomer having a mass average molecular weight in the range of 700 to 20,000. The layer located on the raw fabric layer 2 side of the surface protective layer 5 (i.e., the layer located below the outermost layer of the surface protective layer 5) is not particularly limited.

[0110] Tests conducted in connection with the present invention are described below. Example 1: A 55 μm-thick olefin film (manufactured by Riken Technos Corporation) was used as the base layer 2, one side of which was subjected to a corona treatment, and a pattern was printed on that side to form a pattern layer 3. The pattern layer 3 was formed using a two-component urethane ink (V180; manufactured by Toyo Ink Co., Ltd.) to which 0.5 parts by mass of a hindered amine light stabilizer (Chimasorb 944; manufactured by BASF) was added per 100 parts by mass of the binder resin of the ink.

[0111] Next, a primer layer 6 was formed on the back surface of the raw fabric layer 2 to obtain a laminate 1. The primer layer 6 was formed by printing with the same two-component urethane ink as used for the design layer 3.

[0112] A highly crystalline homopolypropylene resin having a pentad fraction of 97.8%, an MFR of 18 g / 10 min (230 ° C.), and a molecular weight distribution (MWD; Mw / Mn) of 2.3 was prepared as the polyolefin resin. 100 parts by mass of this highly crystalline homopolypropylene resin was mixed with 0.5 parts by mass of a hindered amine-based light stabilizer (BASF's "Chimassorb 944") and 0.5 parts by mass of a benzotriazole-based UV absorber (BASF's "Tinuvin 328"). The resulting mixture was co-extruded with a polyethylene-based adhesive resin using a melt extruder to produce a laminate 2 consisting of a 60 μm-thick transparent resin layer 4 and a 10 μm-thick adhesive resin layer 4b.

[0113] Next, a dry laminating adhesive (Takelac A540, manufactured by Mitsui Chemicals, Inc.) was applied to the surface of the design layer 3 of the laminate 1 obtained above in an amount of 2 g / m ２ The pattern layer 3 and the adhesive resin layer 4b of the laminate 2 obtained above were bonded together by extrusion lamination so that they faced each other via this adhesive layer (not shown), thereby obtaining a laminate 3. Subsequently, an embossed pattern 4a was formed on the surface of the laminate 3 on the transparent resin layer 4 side by pressing using an embossing mold roll.

[0114] Next, an ionizing radiation curable composition was applied as a coating liquid for a surface protective layer onto the surface of the embossed pattern 4a to form a coating film (thickness: 5 μm). The ionizing radiation curable composition used was a compound prepared by blending the following ionizing radiation curable compound 1 (acrylate oligomer) with a photopolymerization initiator.

[0115] Ionizing radiation curable compound 1 Type: bifunctional urethane acrylate oligomer Product name: UA-4400 (mass average molecular weight (Mw) 1400, manufactured by Shin-Nakamura Chemical Co., Ltd.) Blend amount: 100 parts by mass Photopolymerization initiator Product name: Omnirad 184 (manufactured by IGM Resins) Blend amount: 1 part by mass.

[0116] Thereafter, the first irradiation step was carried out. Specifically, under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 100 ppm, ultraviolet light having a wavelength of 172 nm was irradiated onto the surface of the coating film made of the ionizing radiation-curable composition using a Xe excimer lamp at an integrated light dose of 30 mJ / cm. ２ This caused wrinkles to form on the surface of the coating film.

[0117] Subsequently, a second irradiation step was carried out. Specifically, the coating film was irradiated with 200 mJ / cm using a high-pressure mercury lamp. ２ The entire surface was cured by irradiating it with ultraviolet (UV) rays so that the thickness of the surface protective layer 5 was 130 μm. In this manner, a decorative sheet 1 (total thickness 130 μm) having the same configuration as the decorative sheet 1 included in the decorative material 11 shown in FIG. 2 was obtained.

[0118] Example 2 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 1, except that ionizing radiation curable compound 1 in Example 1 was replaced with the following: Ionizing radiation curable compound 1 Type: Bifunctional urethane acrylate oligomer Product name: UN-6200 (mass average molecular weight (Mw) 6500, manufactured by Negami Chemical Industrial Co., Ltd.) Blend: 100 parts by mass.

[0119] Example 3 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 1, except that ionizing radiation curable compound 1 in Example 1 was replaced with the following: Ionizing radiation curable compound 1 Type: Bifunctional urethane acrylate oligomer Product name: UN-6304 (mass average molecular weight (Mw) 13,000, manufactured by Negami Chemical Industrial Co., Ltd.) Blend: 100 parts by mass.

[0120] Example 4 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 1, except that the following particles were added to the ionizing radiation-curable composition of Example 1. Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend amount: 5 parts by mass

[0121] Example 5 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 2, except that the following particles were added to the ionizing radiation-curable composition of Example 2. Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend amount: 5 parts by mass

[0122] Example 6 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 3, except that the following particles were added to the ionizing radiation curable composition of Example 3. Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend amount: 5 parts by mass

[0123] <Example 7> Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 2, except that no photopolymerization initiator was added to the ionizing radiation curable composition of Example 2, and that the second radiation in the second irradiation step was changed from ultraviolet light (UV) to electron beam (EB).

[0124] Example 8 A decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 2, except that the amount of the photopolymerization initiator added was changed from 1 part by mass to 3 parts by mass.

[0125] Example 9 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 2, except that the amount of the photopolymerization initiator added was changed from 1 part by mass to 5 parts by mass.

[0126] <Example 10> Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 5, except that no photopolymerization initiator was added to the ionizing radiation curable composition of Example 5, and that the second radiation in the second irradiation step was changed from ultraviolet light (UV) to electron beam (EB).

[0127] <Example 11> Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 5, except that the amount of photopolymerization initiator added to the ionizing radiation curable composition in Example 5 was changed from 1 part by mass to 3 parts by mass.

[0128] <Example 12> Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 5, except that the amount of photopolymerization initiator added to the ionizing radiation curable composition in Example 5 was changed from 1 part by mass to 5 parts by mass.

[0129] Example 13 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 1, except that ionizing radiation curable compound 1 in Example 1 was replaced with the following, and the following particles were added: Ionizing radiation curable compound 1 Type: trifunctional urethane acrylate oligomer Product name: SMT-001 (mass average molecular weight (Mw) 1700, manufactured by Negami Chemical Industrial Co., Ltd.) Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend: 5 parts by mass.

[0130] Example 14 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 5, except that the amount of particles added to the ionizing radiation curable composition in Example 5 was changed from 5 parts by mass to 2 parts by mass.

[0131] Example 15 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 5, except that the amount of particles added to the ionizing radiation curable composition in Example 5 was changed from 5 parts by mass to 3 parts by mass.

[0132] Example 16 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 5, except that the amount of particles added to the ionizing radiation curable composition in Example 5 was changed from 5 parts by mass to 11 parts by mass.

[0133] Example 17 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 5, except that the amount of particles added to the ionizing radiation curable composition in Example 5 was changed from 5 parts by mass to 12 parts by mass.

[0134] <Example 18> A decorative sheet 1 having a total thickness of 126 μm was obtained in the same manner as in Example 5, except that the thickness of the coating of the ionizing radiation curable composition of Example 5 (thickness of surface protective layer 5) was changed from 5 μm to 1 μm.

[0135] <Example 19> A decorative sheet 1 having a total thickness of 127 μm was obtained in the same manner as in Example 5, except that the thickness of the coating of the ionizing radiation curable composition of Example 5 (thickness of surface protective layer 5) was changed from 5 μm to 2 μm.

[0136] <Example 20> A decorative sheet 1 having a total thickness of 135 μm was obtained in the same manner as in Example 5, except that the thickness of the coating of the ionizing radiation curable composition of Example 5 (thickness of surface protective layer 5) was changed from 5 μm to 10 μm.

[0137] <Example 21> A decorative sheet 1 having a total thickness of 143 μm was obtained in the same manner as in Example 5, except that the thickness of the coating of the ionizing radiation curable composition of Example 5 (thickness of surface protective layer 5) was changed from 5 μm to 18 μm.

[0138] <Example 22> A decorative sheet 1 having a total thickness of 145 μm was obtained in the same manner as in Example 5, except that the thickness of the coating of the ionizing radiation curable composition of Example 5 (thickness of the surface protective layer 5) was changed from 5 μm to 20 μm.

[0139] Example 23 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 13, except that 100 parts by mass of ionizing radiation curable compound 1 (acrylate oligomer) in Example 13 was replaced with a combined system of ionizing radiation curable compound 1 (acrylate oligomer) and ionizing radiation curable compound 2 (acrylate monomer) shown below. Ionizing radiation curable compound 1 Type: Trifunctional urethane acrylate oligomer Product name: SMT-001 (mass average molecular weight (Mw) 1700, manufactured by Negami Chemical Industrial Co., Ltd.) Blend: 62 parts by mass Ionizing radiation curable compound 2 Type: Bifunctional tripropylene glycol diacrylate monomer (molecular weight M300) Blend: 38 parts by mass

[0140] Example 24 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 23, except that ionizing radiation curable compound 2 in Example 23 was replaced with the following: Ionizing radiation curable compound 2 Type: bifunctional tricyclodecane dimethanol diacrylate monomer (molecular weight M304) Blend: 38 parts by mass

[0141] Example 25 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 23, except that ionizing radiation curable compound 1 and ionizing radiation curable compound 2 in Example 23 were replaced with the following: Ionizing radiation curable compound 1 Type: hexafunctional urethane acrylate oligomer Product name: EBECRYL5129 (mass average molecular weight (Mw) 800, manufactured by Negami Chemical Industrial Co., Ltd.) Blend: 62 parts by mass Ionizing radiation curable compound 2 Type: bifunctional tricyclodecane dimethanol diacrylate monomer (molecular weight M304) Blend: 38 parts by mass

[0142] Example 26 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 23, except that ionizing radiation curable compound 1 and ionizing radiation curable compound 2 in Example 23 were replaced with the following: Ionizing radiation curable compound 1 Type: 10-functional urethane acrylate oligomer Product name: UN-904 (mass average molecular weight (Mw) 4900, manufactured by Negami Chemical Industrial Co., Ltd.) Blend: 62 parts by mass Ionizing radiation curable compound 2 Type: Bifunctional tricyclodecane dimethanol diacrylate monomer (molecular weight M304) Blend: 38 parts by mass

[0143] Example 27 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 23, except that ionizing radiation curable compound 1 and ionizing radiation curable compound 2 in Example 23 were replaced with the following: Ionizing radiation curable compound 1 Type: Acrylic acrylate oligomer Product name: OAP-5000 (mass average molecular weight (Mw) 20,000, manufactured by Negami Chemical Industrial Co., Ltd.) Blend: 62 parts by mass Ionizing radiation curable compound 2 Type: Bifunctional tricyclodecane dimethanol diacrylate monomer (molecular weight M304) Blend: 38 parts by mass

[0144] Example 28 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 13, except that 100 parts by mass of ionizing radiation curable compound 1 (acrylate oligomer) in Example 13 was replaced with a combined system of ionizing radiation curable compound 1 (acrylate oligomer) and ionizing radiation curable compound 2 (acrylate monomer) shown below. Ionizing radiation curable compound 1 Type: Trifunctional urethane acrylate oligomer Product name: SMT-001 (mass average molecular weight (Mw) 1700, manufactured by Negami Chemical Industrial Co., Ltd.) Blend: 80 parts by mass Ionizing radiation curable compound 2 Type: Bifunctional tripropylene glycol diacrylate monomer (molecular weight M300) Blend: 20 parts by mass

[0145] Example 29 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 28, except that ionizing radiation curable compound 2 in Example 28 was replaced with the following: Ionizing radiation curable compound 2 Type: Bifunctional tricyclodecane dimethanol diacrylate monomer (molecular weight M304) Blend: 20 parts by mass

[0146] Example 30 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 28, except that ionizing radiation curable compound 1 and ionizing radiation curable compound 2 in Example 28 were replaced with the following: Ionizing radiation curable compound 1 Type: hexafunctional urethane acrylate oligomer Product name: EBECRYL5129 (mass average molecular weight (Mw) 800, manufactured by Negami Chemical Industrial Co., Ltd.) Blend: 80 parts by mass Ionizing radiation curable compound 2 Type: bifunctional tricyclodecane dimethanol diacrylate monomer (molecular weight M304) Blend: 20 parts by mass

[0147] Example 31 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 28, except that ionizing radiation curable compound 1 and ionizing radiation curable compound 2 in Example 28 were replaced with the following: Ionizing radiation curable compound 1 Type: 10-functional urethane acrylate oligomer Product name: UN-904 (mass average molecular weight (Mw) 4900, manufactured by Negami Chemical Industrial Co., Ltd.) Blend: 80 parts by mass Ionizing radiation curable compound 2 Type: Bifunctional tricyclodecane dimethanol diacrylate monomer (molecular weight M304) Blend: 20 parts by mass

[0148] Example 32 Decorative sheet 1 (total thickness 130 μm) was obtained in the same manner as in Example 28, except that ionizing radiation curable compound 1 and ionizing radiation curable compound 2 in Example 28 were replaced with the following: Ionizing radiation curable compound 1 Type: Acrylic acrylate oligomer Product name: OAP-5000 (mass average molecular weight (Mw) 20,000, manufactured by Negami Chemical Industrial Co., Ltd.) Blend: 80 parts by mass Ionizing radiation curable compound 2 Type: Bifunctional tricyclodecane dimethanol diacrylate monomer (molecular weight M304) Blend: 20 parts by mass

[0149] Comparative Example 1 A decorative sheet (total thickness 130 μm) was obtained in the same manner as in Example 1, except that the ionizing radiation compound 1 in Example 1 was replaced with the following: Ionizing radiation curable compound 1 Type: Bifunctional urethane acrylate oligomer Product name: UN-6305 (mass average molecular weight (Mw) 27000, manufactured by Negami Chemical Industrial Co., Ltd.) Blend: 100 parts by mass.

[0150] Comparative Example 2 A decorative sheet (total thickness 130 μm) was obtained in the same manner as in Example 1, except that the ionizing radiation curable compound in Example 1 was changed as follows, and the following particles were used: Ionizing radiation curable compound 1 Type: bifunctional urethane acrylate oligomer Product name: UN-6305 (mass average molecular weight (Mw) 27000, manufactured by Negami Chemical Industrial Co., Ltd.) Blend amount: 100 parts by mass Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend amount: 5 parts by mass

[0151] Comparative Example 3 A decorative sheet (total thickness 130 μm) was obtained in the same manner as in Example 4, except that the first irradiation step in Example 4 was not carried out and the second irradiation step was carried out.

[0152] <Evaluation> Each of the above decorative sheets was evaluated as follows. (1) Thickness of the Surface Protective Layer The thickness of the surface protective layer was measured as follows. The decorative sheet was embedded in a resin such as a cold-curing epoxy resin or a UV-curable resin, and the resin was allowed to fully cure. The sheet was then cut so that the cross section of the decorative sheet was exposed, and mechanically polished to obtain a measurement surface. Subsequently, the cross section of the surface protective layer was imaged using a SIGMA 500 scanning electron microscope manufactured by Carl Zeiss Microscopy. The imaging was performed at an acceleration voltage of 0.5 keV (low acceleration voltage), in the SE2 mode, and at a magnification of 2000x. No sputtering was performed on the measurement sample. Next, from this cross-sectional image, the dimension of the surface protective layer in the width direction of the ridge portion and the area of ​​the cross section of the surface protective layer were determined. The thickness of the surface protective layer was calculated by dividing this area by the above dimension. Measurements were performed at 25 random points, and the average value of the 25 points was defined as the "thickness t of the surface protective layer." The "thickness t of the surface protective layer" was equal to the thickness of the coating film made of the ionizing radiation curable composition.

[0153] (2) Surface Condition The surface condition was evaluated visually for uniformity of the surface. The evaluation criteria were as follows: AA: Uniform surface condition over the entire surface. A: Surface condition with some uneven areas. B: Uneven surface condition over the entire surface.

[0154] (3) Glossiness The glossiness was measured at 60 degrees using a Rhopoint IQ (manufactured by Konica Minolta, Inc.) The "60° glossiness" in Table 1 below represents this 60° glossiness.

[0155] (4) Fingerprint Resistance To evaluate fingerprint resistance, an evaluation of fingerprint wiping ability was carried out. The 60-degree glossiness of the surface of each decorative sheet was measured and defined as "initial glossiness." Next, a fingerprint resistance evaluation liquid was applied to the surface protective layer of each decorative sheet, and then the fingerprint resistance evaluation liquid applied to the surface of the decorative sheet was wiped off. Thereafter, the 60-degree glossiness of the portion from which the fingerprint resistance evaluation liquid had been wiped off was measured and defined as "glossiness after wiping." Here, a higher fatty acid was used as the fingerprint resistance evaluation liquid.

[0156] The fingerprint wiping rate was calculated using the following formula: Fingerprint wiping rate (%) = (glossiness after wiping / initial glossiness) x 100 The evaluation criteria were as follows: An evaluation of "A" or higher indicates no practical problems. AA: 70% or more and less than 250%. A: 50% or more and less than 70%, or 250% or more and less than 300%. B: Less than 50%, or 300% or more.

[0157] (5) Stain Resistance To evaluate stain resistance, a staining A test specified in the Japanese Agricultural Standards (JAS) was performed. That is, 10 mm wide lines were drawn on the surface protective layer of each decorative sheet using blue ink, black quick-drying ink, and red crayon, and the sheets were left for 4 hours. Thereafter, the blue ink, black quick-drying ink, and red crayon lines were wiped off with a cloth soaked in ethanol, and the staining resistance by the ink was evaluated.

[0158] The evaluation criteria were as follows: AA: The lines of each color could be easily wiped off, and no stains remained. A: The lines of each color could be wiped off in some areas and not in others, and stains remained in some areas. B: The lines of each color could not be wiped off, and stains remained overall.

[0159] (6) Scratch Resistance To evaluate scratch resistance, a steel wool rubbing test was performed. That is, a urethane adhesive was applied to the primer layer side of each decorative sheet, and the sheet was then attached to wood substrate B. Next, a load of 100 g was applied to steel wool, which was rubbed back and forth 20 times across the surface of the surface protective layer, and the occurrence of scratches and changes in gloss were visually checked.

[0160] The evaluation criteria were as follows: AA: No scratches or changes in gloss occurred on the surface. A: Minor scratches or changes in gloss occurred on the surface. B: Significant scratches or changes in gloss occurred on the surface.

[0161] (7) Processability To evaluate processability, a bending processability test was conducted. Specifically, a urethane adhesive was applied to the primer layer side of each decorative sheet and the sheet was attached to a wooden substrate. Next, a V-shaped groove was made in the other side of the wooden substrate, up to the boundary where the wooden substrate and decorative sheet were attached, so as not to scratch the decorative sheet attached to the other side. Next, the wooden substrate was bent 90 degrees along the V-shaped groove so that the surface of the decorative sheet formed a mountain fold, and the bent portion of the surface of the decorative sheet was observed using an optical microscope to determine whether whitening or cracks had occurred, and the state of bending processability was evaluated.

[0162] The evaluation criteria were as follows. A rating of "A" or higher indicates no practical problems. AA: No whitening or cracking was observed. A: Whitening was observed in some areas, but no cracking was observed. B: Whitening was observed over the entire surface, or cracking was observed in some areas. The evaluation results are shown in Table 1.

[0163]

[0164]

[0165]

[0166]

[0167] As shown in Table 1, the decorative sheets of Examples 1 to 32 had low gloss and were excellent in all aspects: surface condition, fingerprint resistance, contamination resistance, scratch resistance, and bending processability. Comparative Examples 1 and 2, which used an acrylate oligomer with a high mass average molecular weight, were particularly poor in low gloss and fingerprint resistance. Furthermore, Comparative Example 3, in which the first irradiation step was omitted, did not have an uneven structure on the surface of the surface protective layer that included multiple ridge-like portions, each of which protruded in a ridge-like shape. The decorative sheet of Comparative Example 3 was poor in low gloss, fingerprint resistance, contamination resistance, and scratch resistance.

[0168] 1...decorative sheet, 2...raw material layer, 3...pattern layer, 4...transparent resin layer, 4a...embossed pattern, 4b...adhesive resin layer, 5...surface protection layer, 5A...core portion, 5B...ridge portion, 6...primer layer, 11...decorative material, B...base material.

Claims

1. A decorative sheet comprising an original fabric layer and a surface protective layer provided on one side of the original fabric layer, the surface of the surface protective layer having an uneven structure including a plurality of ridge-like portions each protruding in a ridge-like shape, the surface protective layer containing an ionizing radiation curable resin consisting of a cured product of an ionizing radiation curable compound, the ionizing radiation curable compound being an acrylate oligomer having a mass average molecular weight in the range of 700 to 20,000, and containing one or more acrylate oligomers selected from an acrylic acrylate oligomer and a urethane acrylate oligomer having 2 to 15 functional groups, the proportion of the acrylate oligomer in the ionizing radiation curable compound being in the range of more than 60% by mass and not more than 100% by mass.

2. The decorative sheet according to claim 1, wherein the mass average molecular weight of said acrylate oligomer is within the range of 700 to 7,000.

3. A decorative sheet according to claim 1 or 2, wherein the ionizing radiation curable compound further contains an acrylate monomer, and the proportion of the acrylate monomer in the ionizing radiation curable compound is less than 40 mass %.

4. The decorative sheet according to claim 3, wherein said acrylate monomer has a cyclic structure.

5. The decorative sheet according to claim 3 or 4, wherein said acrylate monomer has a molecular weight within the range of 100 to 2,000.

6. The decorative sheet according to any one of claims 3 to 5, wherein the number of functional groups possessed by said acrylate monomer is 1 or more and 4 or less.

7. A decorative sheet according to any one of claims 1 to 6, wherein the surface protective layer contains the ionizing radiation curable resin and particles, and the ratio of the particles to the ionizing radiation curable resin is within the range of 2 to 13 parts by mass per 100 parts by mass of the ionizing radiation curable resin.

8. The decorative sheet according to any one of claims 1 to 7, wherein the gloss of said surface protective layer is 10.0 or less.

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

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

11. A method for producing a decorative sheet, comprising: forming a coating film containing a composition containing an ionizing radiation curable compound on one side of an original fabric layer; irradiating the coating film with light having a wavelength of 200 nm or less; and, after the irradiation, irradiating with ionizing radiation or ultraviolet light having a longer wavelength than the light, wherein the composition contains, as the ionizing radiation curable compound, an acrylate oligomer having a mass average molecular weight in the range of 700 to 20,000, and one or more acrylate oligomers selected from an acrylic acrylate oligomer and a urethane acrylate oligomer having 2 to 15 functional groups, and the proportion of the acrylate oligomer in the ionizing radiation curable compound is in the range of more than 60 mass% and not more than 100 mass%.

12. The method according to claim 11, wherein the ionizing radiation curable compound further contains an acrylate monomer, and the proportion of the acrylate monomer in the ionizing radiation curable compound is less than 40 mass %.

13. The manufacturing method according to claim 11 or 12, wherein the light has a wavelength of 172 nm.