Decorative sheet

Abstract

To provide a decorative sheet having excellent durability.SOLUTION: The surface-protecting layer (5) includes an uneven portion (5A) having the uneven structure and a core portion (5A) interposed between the primary film layer (2) and the uneven portion (5B), a ratio (5A / ) of a thickness T1 of the uneven portion 5B to a thickness T2 of the core portion T1 is in a range of 0.2 or more and 15 or less, a thickness T2 of the core portion is in a range of 1 μm or more and 10 μm or less, and the surface-protecting layer (5) contains a cured product of an ionizing radiation-curable resin having an average number of functional groups of 1.5 or more and 9 or less. 5B T2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a decorative sheet. The decorative sheet can be used, for example, for the interior and exterior decoration of buildings, and for the surface decoration of fixtures, furniture, fixtures, flooring materials, and the like. [Background technology]

[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. By not using vinyl chloride resin, these decorative sheets suppress the generation of toxic gases and the like when incinerated.

[0003] Decorative sheets are widely used in architecture to impart design and durability to the surface of wood, wood boards, metal sheets, non-flammable boards, paper substrates, or resin substrates. These sheets are laminated with adhesives or other adhesives to create decorative panels. Design options range from wood grain or stone grain patterns printed using various printing methods to plain surfaces, depending on the requirements and application. Similarly, surface gloss is also an important design feature, ranging from a high mirror-like gloss to a low gloss with no reflections at all. Another important function of decorative sheets, alongside design, is durability. Durability is a comprehensive assessment of, for example, scratch resistance, stain resistance, and whether these properties are maintained over a long period of time. Decorative sheets are used for architectural interior materials in homes and public facilities, architectural exterior components such as entrance doors, surface materials for building fixtures, and surface materials for home appliances. Because of this, they are exposed to direct sunlight, wind, and rain every day, requiring extremely high weather resistance.

[0004] To impart 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 that takes into consideration design (low gloss), scratch resistance, and stain resistance is, for example, the decorative sheet described in Patent Document 2.

[0005] On the other hand, Patent Documents 3 to 7 propose a method for producing a low-gloss decorative sheet by forming wrinkles using excimer light with a wavelength of less than 200 nm. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 3271022 [Patent Document 2] Japanese Patent Application Publication No. 2019-119138 [Patent Document 3] International Publication No. 2021 / 201105 [Patent Document 4] Japanese Patent Publication No. 2022-008024 [Patent Document 5] International Publication No. 2022 / 054644 [Patent Document 6] International Publication No. 2022 / 054645 [Patent Document 7] International Publication No. 2022 / 054646 Summary of the Invention [Problem to be solved by the invention]

[0007] In recent years, due to the expansion of applications for decorative panels using decorative sheets and the increasing sophistication of consumer awareness of quality, decorative sheets are being required to have durability such as weather resistance and stain resistance. An object of the present invention is to provide a decorative sheet having excellent durability. [Means for solving the problem]

[0008] According to one aspect of the present invention, there is provided a decorative sheet comprising an original fabric layer and a surface protective layer provided on one surface of the original fabric layer, wherein an uneven structure is provided on the surface of the surface protective layer, the surface protective layer including an uneven portion having the uneven structure and a core portion interposed between the original fabric layer and the uneven portion, wherein the ratio T1 / T2 of the thickness T1 of the uneven portion to the thickness T2 of the core portion is within the range of 0.2 to 15, and the thickness T2 of the core portion is within the range of 1 μm to 10 μm, and the surface protective layer includes a cured product of an ionizing radiation curable resin having an average number of functional groups of 1.5 to 9.

[0009] According to another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the uneven structure includes a plurality of protrusions, each of which is ridge-shaped.

[0010] 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 ionizing radiation curable resin is an acrylate.

[0011] 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 average number of functional groups is in the range of 2 or more and 6 or less. 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.

[0012] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, further comprising a design layer between the base layer and the surface protective layer.

[0013] 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. [Effects of the Invention]

[0014] According to the present invention, a decorative sheet having excellent durability is provided. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of a decorative material including a decorative sheet according to another embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view of the surface protective layer of the decorative sheet of FIGS. 1 and 2. [Figure 4] 1 is a photomicrograph of a surface protective layer of a decorative sheet according to an example of the present invention. [Figure 5] 1 is a cross-sectional view of a decorative sheet according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] 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.

[0017] 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.

[0018] In the drawings, elements having the same or similar functions are denoted by the same reference numerals, and redundant explanations will be omitted. Furthermore, the drawings are schematic, and the relationship between dimensions in one direction and dimensions in another direction, and the relationship between the dimensions of one member and the dimensions of another member, etc. may differ from the actual relationship.

[0019] <1> Decorative materials and decorative sheets 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.

[0020] The cross section shown in Fig. 3 is a cross section along the thickness direction of the surface protection layer. The micrograph in Fig. 4 is a plan view photograph obtained by a laser microscope (OLS-4000 manufactured by Olympus Corporation).

[0021] 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 material 11 may have a shape other than a board.

[0022] 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.

[0023] The decorative sheet 1 shown in Fig. 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 Fig. 1, one or more of the pattern layer 3 and the primer layer 6 may be omitted.

[0024] In addition, the decorative sheet 1 shown in FIG. 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). Here, an embossed uneven pattern (embossed pattern 4a) is provided on the transparent resin layer 4. 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. Also, the embossed pattern 4a does not have to be provided.

[0025] 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 fabric layer 2 and the primer layer 6 as appropriate.

[0026] Next, each layer that constitutes the decorative sheet 1 will be described.

[0027] <1.1> Raw fabric layer The raw fabric layer 2 can be made of any material selected from paper, synthetic resin, synthetic resin foam, rubber, nonwoven fabric, synthetic paper, metal foil, etc. Examples of paper include tissue paper, titanium paper, and resin-impregnated paper. Examples of synthetic resins include polyethylene, polypropylene, polybutylene, polystyrene, polycarbonate, polyester, polyamide, ethylene-vinyl acetate copolymer, polyvinyl alcohol, and acrylic. Examples of rubber include ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, styrene-butadiene copolymer rubber, styrene-isoprene-styrene block copolymer rubber, styrene-butadiene-styrene block copolymer rubber, and polyurethane. Examples of nonwoven fabrics include organic and inorganic nonwoven fabrics. Examples of metals for the metal foil include aluminum, iron, gold, and silver. The raw fabric layer 2 may also be a sheet 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 resin composition into a film. Examples of the molding method include calendar molding and extrusion molding.

[0028] The raw fabric layer 2 preferably has a colored layer made by mixing an inorganic pigment with a synthetic resin, and a skin layer made of 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 is preferably 1:6 to 1:50. When the raw fabric layer 2 is formed by co-extrusion, if the colored layer is formed as 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. For this reason, it is desirable that the outermost layer be a skin layer that does not contain pigment. It is more desirable to have skin layers on both sides of the colored layer. If the skin layer is made too thick and its ratio to the colored layer is too large, the ratio of the colored layer will decrease, and the hiding power will likely decrease.

[0029] The thickness of the raw fabric layer 2 is preferably 50 μm or more and 150 μm or less. If the raw fabric layer 2 is too thin, the performance of covering the unevenness of the base (unevenness) will decrease. On the other hand, if the raw fabric layer 2 is too thick, problems such as whitening and cracking may occur during bending.

[0030] (inorganic pigments) 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. To achieve the required hiding power from the standpoint of the design of the decorative sheet 1, the light transmittance of the base layer 2 is preferably 40% or less. If the hiding power is low, the pattern of the design layer 3 and the pattern of the substrate B tend to intermingle. By incorporating an inorganic pigment into the base layer 2, a decorative sheet 1 with good hiding power can be obtained. The amount of inorganic pigment is preferably 5 to 50 parts by mass per 100 parts by mass of the resin material. If the amount of inorganic pigment is small, the hiding power tends to decrease. Furthermore, if the amount of inorganic pigment is too large, the base layer 2 tends to become embrittled. The inorganic pigment is not particularly limited, but examples include natural inorganic pigments and synthetic inorganic pigments. Examples of natural inorganic pigments include earth-based 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, a mixed pigment containing one or more natural and synthetic inorganic pigments may be used as the inorganic pigment. Furthermore, a pigment such as carbon black may also be used in combination as the synthetic inorganic pigment.

[0031] Furthermore, additives such as fatty acid metal salts may be added to the inorganic pigment to improve dispersibility and extrusion suitability.

[0032] When an inactive material such as an olefin-based resin is used on the surface of the raw fabric layer 2, it is desirable to subject both sides of the raw fabric layer 2 to corona treatment, plasma treatment, ozone treatment, electron beam treatment, ultraviolet treatment, dichromate treatment, etc.

[0033] <1.2> Picture layer A pattern layer 3 for adding a pattern to the decorative sheet 1 can be provided on the surface of the raw fabric layer 2. Examples of patterns that can be used include wood grain, stone grain, sand grain, tiled, brickwork, fabric grain, leather-grained patterns, and geometric shapes.

[0034] Furthermore, a base solid ink layer (not shown) may be provided between the base layer 2 and the picture 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 have a multi-layer structure of two or more layers depending on the need for hiding power, etc. Furthermore, the picture layer 3 may be formed by laminating the number of plates required to express the desired design. In this way, the picture 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.

[0035] The materials constituting 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 matrices that can be used 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.

[0036] 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.

[0037] 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.

[0038] 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 particularly clear, the printing workability when producing the decorative sheet 1 is improved, and production costs can be easily reduced.

[0039] <1.3>Transparent resin layer The resin material used as the main component of the transparent resin layer 4 is preferably 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-pentene) may be used. Examples of suitable olefins include homopolymers or copolymers of two or more of the above olefins (e.g., 4-ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, etc.), as well as copolymers of ethylene or α-olefins with other monomers, such as ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-butyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, etc. Furthermore, when it is desired to improve the surface strength of the decorative sheet 1, it is preferable to use highly crystalline polypropylene.

[0040] Here, in this specification, the term "main component" refers to 90% by mass or more of the material in question, unless otherwise specified.

[0041] 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 the transparent resin layer 4 is too thin, 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 transparent resin layer 4 is too thick, the decorative sheet 1 may have too high rigidity, 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.

[0042] 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.

[0043] 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, two-component curing urethane materials that utilize the reaction between isocyanate and polyol are typically preferred. There are no particular restrictions on the lamination method for the transparent resin layer 4, but methods that apply heat and pressure, extrusion lamination, and dry lamination are commonly used.

[0044] 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 provided by a method in which a sheet that has been laminated by various methods is embossed later by heat and pressure, or by a method in which a pattern is provided on a cooling roll and embossed simultaneously with extrusion lamination.

[0045] Alternatively, a method may be used in which the transparent resin layer 4, which has been embossed simultaneously with extrusion, and the pattern layer 3 are bonded together by heat or dry lamination.

[0046] 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 design layer 3. When the adhesive resin layer 4b is provided, the transparent resin layer 4 and the adhesive resin layer 4b can be laminated by a co-extrusion method. 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.

[0047] When an embossed pattern 4a is applied to the transparent resin layer 4, the uneven structure caused by the embossing can be expressed by the cut level difference Rdc. The "cut level difference Rdc" is a surface texture parameter defined in JIS B0601:2013. The cut level difference Rdc indicates the cut level difference of the roughness curve and expresses the steepness of the uneven shape. Here, the position of the highest peak of the roughness curve is used as the reference for the cut level c. Also, here, c(Rmr1) is defined as the cut level when the load length ratio Rmr of the roughness curve is 10%, and c(Rmr2) is defined as the cut level when the load length ratio Rmr of the roughness curve is 25%. The cut level difference Rdc (μm) of the roughness curve is the difference between the cut level c(Rmr1) and the cut level c(Rmr2).

[0048] The Rdc of the transparent resin layer 4 is preferably 0.2 μm or more and 2.9 μm or less. If the Rdc is too small, the effect of embedding ink, etc. tends to be weak. Furthermore, if the Rdc is too large, when the surface protection layer 5 is formed on the transparent resin layer 4, the surface tends to have a rough, gritty feel rather than a moist feel. The Rdc of the transparent resin layer 4 is preferably 0.2 μm or more and 1.0 μm or less.

[0049] <1.4>Surface protective layer As shown in Fig. 3, the surface protective layer 5 includes a concave-convex portion 5A having a concave-convex structure and a core portion 5B interposed between the raw fabric layer 2 and the concave-convex portion 5A. Here, the concave-convex structure includes a plurality of convex portions, each of which is ridge-shaped. In one example, the surface protective layer 5 includes the concave-convex portion 5A and the core portion 5B.

[0050] Here, in the decorative sheet 1 according to this embodiment, the term "ridge-like" refers to a convex shape that is linear in plan view. The uneven portion 5A may be curved or linear in plan view, but is preferably curved in view of the fingerprint resistance of the decorative sheet 1. Each of the uneven portions 5A may or may not be branched in plan view. Furthermore, in the present disclosure, the uneven portion 5A refers to, for example, the portion from the lowest point to the tip of the uneven shape provided on the surface of the surface protective layer 5, and the core portion 5B refers to the portion of the surface protective layer 5 excluding the uneven portion 5A.

[0051] The concave-convex portions 5A are curved, and at least some of them are adjacent to each other in the width direction, as shown in Fig. 4. At a position where at least some of the concave-convex portions 5A are adjacent to each other in the width direction, the cross section of the surface protective layer 5 parallel to the width direction and the thickness direction of the surface protective layer 5 has a wave shape, such as a sine wave shape, in the portion where the concave-convex structure is provided, as shown in Fig. 3.

[0052] The surface protective layer 5 preferably covers the entire upper surface of the underlying layer (for example, the transparent resin layer 4 in the embodiment shown in FIG. 2) that contacts the surface protective layer 5. That is, in the decorative sheet 1 according to this embodiment, it is preferable that the underlying layer that contacts the surface protective layer 5 is not exposed on the surface.

[0053] The uneven structure preferably has a roughness curve element average length RSm (μm) of 50 μm or more and 600 μm or less, and more preferably 100 μm or more and 500 μm or less. Here, the "roughness curve element average length RSm" is a surface texture parameter defined in JIS B0601:2013. If this average length Rsm is too large, it is difficult to obtain a low-gloss decorative sheet. If this average length Rsm is too small, the stain resistance is likely to be reduced.

[0054] The ratio RSm / Ra of the average length Rsm of the roughness curve elements to the arithmetic mean roughness Ra is preferably in the range of 10 to 300. More preferably, RSm / Ra is in the range of 10 to 250. As the ratio RSm / Ra value decreases, the shape of the uneven portion 5A becomes finer, making it difficult to wipe off dirt and tending to reduce contamination resistance. As the ratio RSm / Ra value increases, the spacing between the ridge shapes becomes wider, tending to increase gloss. Here, the arithmetic mean roughness Ra is a measured value when measured using a line roughness meter (in accordance with JIS B0601:2013).

[0055] The thickness of the surface protective layer 5 is preferably in the range of 2 μm or more and 20 μm or less. More preferably, the thickness of the surface protective layer 5 is in the range of 5 μm or more and 20 μm or less. If the thickness of the surface protective layer 5 is too small, it tends to be difficult to achieve a low gloss. On the other hand, if the thickness of the surface protective layer 5 is too large, the processability decreases, and the decorative sheet is likely to whiten when folded.

[0056] Here, the thickness of the surface protective layer 5 refers to the thickness of a layer having the same apparent area and volume as the surface protective layer 5 and a flat surface. The thickness of the surface protective layer 5 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 concave-convex portion 5A is imaged. Next, the dimension of the surface protective layer 5 in the width direction of the concave-convex portion 5A and the area of ​​the cross section of the surface protective layer 5 are determined from this cross-sectional image. The thickness of the surface protective layer 5 is obtained by dividing this area by the above dimension. The thickness of the surface protective layer 5 is also 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. Note that when the coating liquid for the surface protective layer described below does not contain a solvent, the thickness of the coating film made of the coating liquid for the surface protective layer is equal to the thickness of the surface protective layer 5.

[0057] The thickness T1 of the uneven portion 5A is preferably in the range of 2 μm or more and 15 μm or less, and more preferably in the range of 4 μm or more and 12 μm or less. If the thickness T1 is too small, it is likely to be difficult to obtain a low-gloss decorative sheet. Furthermore, if the thickness T1 is too small, the uneven portion 5A is likely to be etched when the decorative sheet 1 is subjected to a weather resistance test. In this case, the gloss value of the decorative sheet 1 is likely to change. If the thickness T1 is too large, it is likely to be difficult to achieve high durability. Furthermore, if the thickness T1 is too large, it may be difficult to remove dirt that has entered the uneven portion 5A.

[0058] The thickness T2 of the core portion 5B is in the range of 1 μm or more and 10 μm or less. The thickness T2 is preferably in the range of 2 μm or more and 6 μm or less, and more preferably in the range of 3 μm or more and 5 μm or less. When the thickness T2 is in the above range, high durability can be achieved. If the thickness T2 is too large, the processability decreases, and the decorative sheet is prone to whitening when folded.

[0059] The ratio T1 / T2 of the thickness T1 of the concave-convex portion 5A to the thickness T2 of the core portion 5B is in the range of 0.2 or more and 15 or less. The ratio T1 / T2 is preferably in the range of 0.5 or more and 10 or less, and more preferably in the range of 0.8 or more and 8 or less. If the ratio T1 / T2 is too small, it tends to be difficult to achieve high weather resistance. If the ratio T1 / T2 is too large, it tends to be difficult to achieve high processability.

[0060] A method for measuring the thickness T2 of the core portion 5B will be described below with reference to Fig. 5. Fig. 5 is a cross-sectional view of a decorative sheet according to one embodiment of the present invention. First, a cross section parallel to the thickness direction of the surface protective layer 5 and perpendicular to the length direction of the concave-convex portion 5A is imaged. Next, an arbitrary region having a length L of 5 mm, which is the dimension perpendicular to the thickness direction of the surface protective layer, is selected from the obtained image. This region is shown in Figure 5. The surface protective layer has multiple recesses A to N within this region. Next, for each of these recesses, the distance from the bottom of the recess to the surface of the surface protective layer 5 facing the raw layer 2 is measured. Next, recesses with the smallest distance are selected, and selection continues until the total number of recesses reaches 80% of the total number of recesses in this region. The arithmetic mean of the distances for the selected recesses is then determined as the thickness T2 of the core portion 5B. Note that for simplicity, only 14 recesses are shown in Figure 5, but the region may contain more than 14 recesses.

[0061] The pattern layer 3 and the surface protective layer 5 may be synchronized from the standpoint of design. In this case, the pattern layer 3 is formed first, followed by the surface protective layer 5, so gravure printing is preferably used. Gravure printing is also advantageous in terms of cost because it allows for relatively high-speed printing. Here, synchronization means that 50% or more, preferably 70% or more, and more preferably 90% or more of the area where the surface protective layer 5 is formed overlaps with the pattern portion of the pattern layer 3 in a planar view.

[0062] 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 difference in mass between a base sheet (including a raw fabric layer) with the surface protective layer 5 formed and one without the surface protective layer formed, using various printing and coating methods.

[0063] The surface protective layer 5 contains a cured product of an ionizing radiation curable resin. The surface protective layer 5 preferably contains an ionizing radiation curable resin as a main material. The main material refers to a content of 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. Here, "ionizing radiation" refers to a charged particle beam such as an electron beam. The ionizing radiation curable resin is cured by irradiation with ionizing radiation. The ionizing radiation curable resin can also be cured by ultraviolet irradiation. The ionizing radiation curable resin used here is cured by irradiation with light having a wavelength of 200 nm or less, and has a high absorption coefficient for this light. In one example, the surface protective layer 5 is made of a cured product of an ionizing radiation curable resin.

[0064] The ionizing radiation curable resin has an average number of functional groups of 1.5 or more and 9 or less. The average number of functional groups of the ionizing radiation curable resin is preferably in the range of 2 or more and 6 or less. If the average number of functional groups of the ionizing radiation curable resin is less than 1.5, excellent durability cannot be achieved. If the average number of functional groups of the ionizing radiation curable resin is more than 9, unreacted functional groups are likely to be present in the cured product of the ionizing radiation curable resin. In this case, moisture is likely to penetrate into the positions containing the unreacted functional groups, making it impossible to achieve excellent durability.

[0065] The ionizing radiation curable resin may be any known resin, such as various monomers or commercially available oligomers, including (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins. The additional ionizing radiation curable resin may be either an aqueous resin or a non-aqueous (organic solvent-based) resin, and may be used alone or in combination of two or more types. When one type of resin is used as the ionizing radiation curable resin, the number of functional groups of this resin may be the average number of functional groups of the ionizing radiation curable resin.

[0066] The main component of the ionizing radiation curable resin is preferably an acrylate. Here, the main component of the ionizing radiation curable resin means that the main component is 60 parts by mass or more, assuming that the total solid content of the ionizing radiation curable resin is 100 parts by mass. The ionizing radiation curable resin preferably contains 70 parts by mass or more of acrylate, more preferably 80 parts by mass or more. The ionizing radiation curable resin is more preferably an acrylate.

[0067] The acrylate preferably contains a difunctional or higher acrylate, and more preferably a trifunctional or higher acrylate. When the number of functional groups in the acrylate is large, a surface protective layer 5 with excellent scratch resistance is likely to be obtained. There is no upper limit to the number of functional groups in the acrylate, but according to one example, it is 15 or less.

[0068] When an acrylate contains a repeating unit, it is easy to achieve low gloss. This repeating unit is, for example, any one of an ethylene oxide (EO) unit, a propylene oxide (PO) unit, and an ε-caprolactone (CL) unit. The repeating unit is preferably ethylene oxide or propylene oxide. In a tri- or higher functional acrylate containing a repeating unit, the repeating unit may be present between an acryloyl group and a methylol group in an open ring state.

[0069] The number of repetitions of the repeating structure is preferably 3 or more. If an acrylate with a high number of repetitions is used, when the surface protective layer 5 is formed by the first and second irradiation steps described below, the cured film is more likely to expand in the in-plane direction, and therefore wrinkles corresponding to the uneven portions 5A are more likely to occur on the coating film surface. In addition, it becomes possible to generate wrinkles uniformly over a wide area, contributing to improving the uniformity of the tactile feel. However, if the number of repetitions is too high, the crosslinking density decreases, and the scratch resistance of the surface protective layer is likely to decrease.

[0070] Examples of trifunctional acrylates containing repeating units include EO-modified, PO-modified, or CL-modified trimethylolpropane triacrylate, glycerin triacrylate, isocyanurate triacrylate, or pentaerythritol triacrylate. In trifunctional acrylates containing repeating units, the number of repeating units is preferably 3 or more and 30 or less, and more preferably 3 or more and 20 or less.

[0071] The tetrafunctional acrylate containing a repeating unit is, for example, EO-modified, PO-modified, or CL-modified pentaerythritol tetraacrylate. In the tetrafunctional acrylate containing a repeating unit, the number of repeating units is preferably 12 or more, more preferably 12 to 50, and even more preferably 20 to 50.

[0072] The repeat number of the repeating structure can be analyzed using MALDI-TOF-MS. Ionizing radiation curable resins may have a molecular weight distribution. If there is a molecular weight distribution, the repeat number is determined to be the repeat number corresponding to the molecular weight with the strongest peak in the MALDI-TOF-MS mass spectrum.

[0073] The ionizing radiation curable resin preferably contains at least one of an acrylate oligomer and an acrylate monomer, and more preferably contains both an acrylate oligomer and an acrylate monomer.

[0074] The acrylate oligomer is preferably an acrylate oligomer selected from the group consisting of acrylic acrylate oligomers and 2- to 15-functional urethane acrylate oligomers. "Acrylic acrylate oligomer" refers to an oligomer in which an acrylic group is added to the side chain of an acrylic oligomer. "Urethane acrylate oligomer" refers to an oligomer having a urethane bond and an acrylic group. Acrylate oligomers can improve the overall physical properties of decorative sheets. Specifically, acrylate oligomers can improve the formability of the surface protective layer 5. Furthermore, acrylate oligomers can improve the processability and chemical resistance of decorative sheets. It is believed that the flexibility of urethane acrylate oligomers, derived from the urethane bond, contributes to the above-mentioned effects.

[0075] When the acrylate oligomer has low functionality (for example, 2 to 6 functionalities), it is easy to achieve a lower gloss level. When the acrylate oligomer has high functionality (for example, 6 to 15 functionalities), it can particularly improve the scratch resistance of the surface protective layer 5.

[0076] Examples of acrylate oligomers include EBECRYL9270 (difunctional urethane acrylate) (manufactured by Daicel-Allnex Corporation), EBECRYL4666 (tetrafunctional urethane acrylate) (manufactured by Daicel-Allnex Corporation), EBECRYL5129 (hexafunctional urethane acrylate) (manufactured by Daicel-Allnex Corporation), 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.), and OAP-5000 (acrylic acrylate) (manufactured by Negami Chemical Industrial Co., Ltd.). The acrylate oligomers may be used alone or in combination of two or more.

[0077] The ionizing radiation curable resin contains the acrylate oligomer in a proportion ranging, for example, from 10 to 70% by mass. The ionizing radiation curable resin contains the acrylate oligomer in a proportion ranging, for example, from 25 to 60% by mass, and more preferably from 30 to 50% by mass. If the mass of the acrylate oligomer relative to the mass of the ionizing radiation curable resin is small, it may be difficult for the decorative sheet to fully exhibit its processability and chemical resistance. On the other hand, if the mass of the acrylate oligomer relative to the mass of the ionizing radiation curable resin is large, the coating liquid for the surface protective layer may become highly viscous, which may reduce the formability of the surface protective layer 5 and increase the gloss.

[0078] When emphasis is placed on weather resistance, the acrylate monomer preferably contains a di- to hexa-functional acrylate monomer that does not have an ether bond. This acrylate monomer may have an ester bond (R1-COO-R2). The di- to hexa-functional acrylate monomer that does not have an ether bond can prevent oxidative degradation originating from the ether bond.

[0079] Examples of di- to hexa-functional acrylate monomers that do not have an ether bond include 1,3-propanediol diacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, 1,12-dodecanediol diacrylate, neopentyl glycol diacrylate, 3-methyl-1,5-pentanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and hexamethylolethane hexaacrylate (i.e., 2,2,3,3-tetra[(acryloyloxy)methyl]-1,4-butanediol diacrylate). The acrylate monomers may be used alone or in combination of two or more. The di- to hexa-functional acrylate monomer is preferably a di- to tetra-functional acrylate monomer.

[0080] The acrylate monomer may further contain a monofunctional acrylate monomer having a cyclic structure. The monofunctional acrylate monomer can improve the scratch resistance of the surface protective layer 5. The monofunctional acrylate monomer also has the effect of reducing the viscosity of the coating liquid for the surface protective layer and reducing the gloss of the surface protective layer 5. The monofunctional acrylate monomer preferably has a viscosity of about 100 mPa·s or less at 25°C.

[0081] The reason why the monofunctional acrylate monomer can improve the scratch resistance of the surface protective layer 5 is believed to be as follows.

[0082] According to one example, the surface protective layer 5 is formed by a first irradiation step and a second irradiation step, as described later in this specification. 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, the entire coating film is cured. Here, 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. On the other hand, the cyclic structure portion of the monofunctional acrylate monomer contained in the coating film is hydrophobic. Therefore, the cyclic structure portion is easily exposed on the surface of the coating film. As a result, the surface of the surface protective layer 5 contains more cyclic structure portions than regions other than the surface. It is believed that the cyclic structure portion contributes to the hardness of the surface of the surface protective layer 5, thereby improving the strength and scratch resistance of the surface protective layer 5.

[0083] 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 or bicyclic 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.

[0084] Examples of cyclic structures include isobornyl, adamantyl, dicyclopentanyl, cyclohexyl, cyclopentyl, cyclopentadienyl, 3,4-epoxycyclohexyl, 6,7-epoxydecahydro-1,4:5,8-dimethanonaphthalene, decahydronaphthalene, tricyclodecane, benzyl, and phenyl. The isobornyl, adamantyl, dicyclopentanyl, 6,7-epoxydecahydro-1,4:5,8-dimethanonaphthalene, and tricyclodecane groups correspond to bridged rings and have particularly bulky structures.

[0085] The monofunctional acrylate monomer having a cyclic structure may or may not have a substituent on the cyclic structure. When the monofunctional acrylate monomer having a cyclic structure has a substituent on the cyclic structure, the term "cyclic structure" refers to the ring portion without the substituent. When the monofunctional acrylate monomer having a cyclic structure has a bulky substituent such as a tert-butyl group on the cyclic structure, it is believed that the bulky substituent portion, in addition to the cyclic structure, also functions to improve the strength and scratch resistance of the surface protective layer 5.

[0086] Examples of the monofunctional acrylate monomer having a cyclic structure include cyclopropyl acrylate, cyclobutyl acrylate, cyclooctyl acrylate, dicyclopentadienyl acrylate, cyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, cyclopentyl (meth)acrylate, dicyclopentanyl (meth)acrylate, 3,4-epoxycyclohexylmethyl acrylate, 6,7-epoxydecahydro-1,4:5,8 Examples of suitable acrylates include 1-dimethanonaphthalen-2-yl acrylate, isobornyl (meth)acrylate, 2-adamantylprop-2-enoate (i.e., 2-adamantyl acrylate), 1-adamantyl (meth)acrylate, 3-hydroxy-1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, 2-isopropyl-2-adamantyl (meth)acrylate, benzyl (meth)acrylate, and phenoxyethyl (meth)acrylate. The term "(meth)acrylate" is used herein to encompass acrylates, methacrylates, and combinations thereof. Monofunctional acrylate monomers having a cyclic structure may be used alone or in combination of two or more.

[0087] In the method of forming a surface protection layer 5 by the first and second irradiation steps described below, if a monofunctional acrylate monomer having a cyclic structure is used, the monofunctionality makes it possible to obtain a surface protection layer with a better surface condition, i.e., a surface protection layer with more uniformly formed wrinkles on the surface.

[0088] When the ionizing radiation curable resin contains an acrylate oligomer, a di- to hexa-functional acrylate monomer having no ether bond, and a monofunctional acrylate monomer, the monofunctional acrylate monomer is contained in the surface protective layer 5 in an amount of, for example, 10 to 70 parts by mass, preferably 15 to 60 parts by mass, and more preferably 20 to 50 parts by mass, where the total amount of the acrylate oligomer, di- to hexa-functional acrylate monomer, and monofunctional acrylate monomer is 100 parts by mass. The ionizing radiation curable resin may be a combination of a di- or higher functional acrylate oligomer and a monofunctional acrylate monomer.

[0089] The surface protection layer 5 may contain particles. Adding particles of an optimal particle size and content allows for the formation of a uniform surface. 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. The average particle size (D50) of the particles is preferably 10 μm or less. The average particle size (D50) of the particles is preferably 3 μm or more. The average particle size (D50) of the particles is preferably 3 μm or more and 10 μm or less, and more preferably 4 μm or more and 10 μm or less.

[0090] When the surface protective layer 5 contains particles, wrinkles can be more uniformly formed on the coating surface in the method for forming the surface protective layer by the first and second irradiation steps described below. If 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. If the particles are small, the effect of forming wrinkles uniformly in the above method is small.

[0091] Here, the "average particle size (D50)" refers to the median size (D50) measured using a laser diffraction / scattering particle size distribution analyzer. If the coating liquid for the surface protective layer contains particles, the surface protective layer 5 obtained from this coating liquid will also contain particles. The average particle size of the particles contained in the surface protective layer 5 can be determined by observing the cross section of the layer and averaging the particle sizes of multiple particles. The value obtained in this manner is essentially 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.

[0092] The particles are preferably contained in the surface protective layer 5 in an amount ranging from 0.5 to 10 parts by mass, based on 100 parts by mass of the ionizing radiation curable resin. The amount of particles added is more preferably from 3 to 10 parts by mass, and even more preferably from 4 to 10 parts by mass, based on 100 parts by mass of the ionizing radiation curable resin. Note that the "mass of the ionizing radiation curable resin" refers to the mass of the solid content of the ionizing radiation curable resin.

[0093] When the amount of particles added is within the above range, the effect of uniformly forming wrinkles is particularly large in the method of forming a surface protective layer by the first and second irradiation steps described below. When the amount of particles added is large, the particles are likely to fall off from the surface protective layer 5, making it difficult to achieve high scratch resistance. When the amount of particles added is small, the effect of uniformly forming wrinkles is small.

[0094] When the entire surface protective layer 5 is cured by UV light, a photopolymerization initiator needs to be added to the coating liquid for the surface protective layer. The photopolymerization initiator is not particularly limited, but examples thereof include benzophenone-based, acetophenone-based, benzoin ether-based, and thioxanthone-based initiators.

[0095] The surface protective layer 5 may further contain additives such as antibacterial agents and antifungal agents to impart required functions. 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.

[0096] 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 (a representative example is BASF's product name "Tinuvin 144"), BASF's product 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.

[0097] 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 too small, the resin's stability against ultraviolet light may be reduced. On the other hand, if the amount added is too large, 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 irregularity. In this case, if the amount of hindered amine light stabilizer is too large, curing near the surface may be inhibited. 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.

[0098] The glossiness of the surface protective layer 5 is desirably 20.0 or less. The glossiness of the surface protective layer 5 is more preferably 10.0 or less, and even more preferably 5.0 or less. Here, the "glossiness" is a value measured at an incident angle of 60 degrees using a glossmeter conforming to JIS Z8741:1997.

[0099] The Martens hardness of the surface protective layer 5 is 25 N / mm 2 More than 250N / mm 2 The Martens hardness of the surface protective layer 5 is preferably within the following range: 2 More than 230N / mm 2 It is more preferably within the range of 45 N / mm 2 More than 210N / mm 2 The Martens hardness of the surface protective layer 5 is within the range described above. When the Martens hardness of the surface protective layer 5 is within the above range, the surface protective layer 5 itself has a certain hardness, making it possible to achieve particularly excellent scratch resistance. In addition, curling of the decorative sheet 1 caused by cure shrinkage of the surface protective layer 5 is reduced, making it easier to laminate to a substrate. In addition, the surface protective layer 5 itself can be given appropriate flexibility, making the decorative sheet 1 less likely to tear.

[0100] The Martens hardness may be the Martens hardness of the cured product of the ionizing radiation curable resin that constitutes the surface protective layer 5. In other words, the Martens hardness of the cured product of the ionizing radiation curable resin that constitutes the surface protective layer 5 is 25 N / mm 2 More than 250N / mm 2 It is preferable to use a cured product having a strength within the following range: 35N / mm 2 More than 230N / mm 2 It is more preferable to use a cured product having a viscosity within the following range: 45N / mm 2 More than 210N / mm 2 It is more preferable to use a cured product within the following ranges.

[0101] The Martens hardness value can be adjusted by selecting the type and molecular weight of the ionizing radiation curable resin that constitutes the surface protective layer 5. In addition, the Martens hardness value can be adjusted by adjusting the content ratio of the multiple types of ionizing radiation curable resin that constitute the surface protective layer 5.

[0102] The Martens hardness defined in this embodiment is a value measured by a method conforming to ISO 14577. The Martens hardness defined in this embodiment is the average value of values ​​measured at 10 randomly selected points within the same sample.

[0103] <1.5> Primer layer The primer layer 6 can basically be made of the same material as the design layer 3. Considering that the primer layer 6 is applied to the back surface of the decorative sheet 1 and will be wound up in web form, inorganic fillers such as silica, alumina, magnesia, titanium oxide, or barium sulfate may be added to the primer layer 6 to avoid blocking and improve adhesion with the adhesive. The coating thickness of the primer layer 6 is preferably in the range of 0.1 μm to 3.0 μm, as its purpose is to ensure adhesion with the substrate B. Note that the primer layer 6 is preferably provided when the surface of the base fabric layer 2 is inactive. For example, when the surface of the base fabric layer 2 is active, the primer layer 6 may be omitted.

[0104] <2> Manufacturing method of decorative sheet The decorative sheet 1 shown in Fig. 1 can be manufactured, for example, by using a plate. Specifically, the shape of the uneven structure on the surface of the plate is transferred to a coating film of a coating liquid for a surface protective layer to manufacture the decorative sheet 1 shown in Fig. 1. An example of this manufacturing method will be described below. For the sake of simplicity, explanations of the design layer 3 and primer layer 6 will be omitted.

[0105] First, a plate for primary transfer is prepared, which is a laminate including a first underlayer and a concave-convex layer. Specifically, this plate is prepared by the following method. First, a first underlayer is prepared, and a coating film made of a coating liquid for the uneven layer is formed on one side of this layer. The first underlayer can be the same as the base layer described above. The coating liquid for the uneven layer contains, for example, an ionizing radiation curable resin and a photopolymerization initiator. The coating film made of the coating liquid for the uneven layer can be formed, for example, by printing.

[0106] Next, after forming a coating film made from the coating liquid for the uneven layer, a first irradiation step is carried out. In the first irradiation step, the coating film is irradiated with light having a wavelength of 200 nm or less (hereinafter referred to as the first radiation). The ionizing radiation curable resin contained in the coating liquid for the uneven layer has a large absorption coefficient for the first radiation. Therefore, the first radiation incident on the coating film can only reach a position several tens to several hundreds of nm 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 coating film uncured.

[0107] The coating film after the first irradiation step has wrinkles on its surface corresponding to the uneven portions 5A, similar to the above-described surface protective layer 5. The present inventors believe that the reason why wrinkles are formed on the coating film surface by the first irradiation step is as follows.

[0108] As described above, the first radiation can only reach a position tens to hundreds of nanometers from the outermost surface of the coating film. In other words, the crosslinking reaction of the ionizing radiation-curable resin occurs only on the surface of the coating film, and regions more than tens to hundreds of nanometers from the outermost surface are uncured and contain highly fluid molecules. These highly fluid molecules swell the cured film, 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 coating film surface.

[0109] The first radiation can be extracted from excimer VUV light. Excimer VUV light can be produced from a lamp that uses a rare gas or a rare gas halide compound. When high-energy electrons are externally applied to a lamp that contains a rare gas or a rare gas halide compound, a large number of discharge plasmas (dielectric barrier discharges) are generated. This plasma discharge excites the atoms of the discharge gas (rare gas), which momentarily enters an excimer state. When returning from this excimer state to the ground state, light is emitted in a wavelength range specific to that excimer.

[0110] The gas used in the excimer lamp may be any conventional gas that emits light of 200 nm or less. Examples of gases that can be used 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 ranging from approximately 172 nm (Xe), approximately 126 nm (Ar), approximately 146 nm (Kr), approximately 165 nm (ArBr), and approximately 193 nm (ArF).

[0111] 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.

[0112] 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.

[0113] 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 uneven layer.

[0114] The cumulative light intensity of the first radiation is 0.5 mJ / cm 2 More than 200mJ / cm 2 It is preferable that the dose is 1 mJ / cm or less. 2 More than 100mJ / cm 2 More preferably, it is 3 mJ / cm or less. 2 More than 50mJ / cm 2 It is more preferable that the dose is 5 mJ / cm or less, and 2 More than 30mJ / cm 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.

[0115] The reason why a concavo-convex layer having the above-described surface properties can be obtained by such a method is as follows.

[0116] Oxygen in the gas phase not only absorbs short-wavelength ultraviolet light but also inhibits radical polymerization. The effect of oxygen in the gas phase on radical polymerization is greatest in the portion of the coating film containing the ionizing radiation-curable resin that is adjacent to the gas phase, and decreases as the distance from the coating surface increases. Therefore, by changing the oxygen concentration in the gas phase in the first irradiation step, the relationship between the distance from the coating surface and the progress of the crosslinking reaction can be changed.

[0117] If this relationship changes, the thickness of the cured film formed on the surface of the coating film by the first irradiation step and the degree of in-plane expansion of the cured film as the crosslinking reaction progresses will change. The integrated light dose in the first irradiation step also affects the thickness of the cured film and the degree of in-plane expansion of the cured film. The thickness of the cured film and the degree of in-plane expansion of the cured film also affect the surface properties of the surface protective layer. Furthermore, the particle size and amount of particles in the coating film, as well as the thickness of the coating film, also affect the formation of wrinkles.

[0118] Therefore, for example, by appropriately setting the composition of the ionizing radiation curable resin, the thickness of the coating film, the oxygen concentration in the gas phase in the first irradiation step, and the accumulated light amount in the first irradiation step, it is possible to obtain an uneven layer having the desired surface properties.

[0119] 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. This results in a concavo-convex layer including a concavo-convex structure.

[0120] 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 small absorption coefficient.

[0121] The cumulative light intensity of the second radiation is 10 mJ / cm 2 More than 500mJ / cm 2 It is preferable that the dose is 50 mJ / cm or less. 2 More than 400mJ / cm 2 It is more preferable that the dose is 100 mJ / cm or less, and 2 More than 300mJ / cm 2 It is more preferable that:

[0122] By the above method, a plate for primary transfer is formed.

[0123] Next, a coating film made of a transfer film coating liquid is formed on the relief layer of the primary transfer plate. The transfer film coating liquid contains, for example, UV-curable polydimethylsiloxane. The transfer film made of such a coating liquid can be easily peeled off from the surface protection layer.

[0124] Next, a second underlayer is provided on the coating film made of the transfer film coating liquid. The second underlayer is, for example, optically transparent. The second underlayer is, for example, a film made of polyethylene terephthalate. Next, a third irradiation step is carried out. In the third irradiation step, a third radiation is irradiated onto the coating film from the second underlayer side to harden the entire coating film. This results in a transfer film having a concavo-convex structure complementary to the concavo-convex structure of the concavo-convex layer. The third radiation is the same as the second radiation described above. The integrated light amount of the third radiation is the same as the integrated light amount of the second radiation described above.

[0125] Next, the laminate including the transfer film and the second underlayer is peeled off from the primary transfer plate. The peeled laminate is called the secondary transfer plate. In this way, the secondary transfer plate is obtained. The secondary transfer plate may be obtained by electroforming using the primary transfer plate as a matrix.

[0126] Next, the surface of the secondary transfer plate on the transfer film side is subjected to a surface treatment. The surface treatment is performed, for example, by the following method. First, the transfer film is treated with ozone, and then modified with fluoroalkylsilane by vapor phase deposition. The fluoroalkylsilane is, for example, perfluorodecyltriethoxysilane.

[0127] Next, a raw fabric layer 2 is prepared, and a coating film made of a coating liquid for a surface protective layer is formed on one surface of the raw fabric layer 2. As described in the section <1.4> Surface protective layer, the coating liquid for a surface protective layer contains an ionizing radiation curable resin and, if necessary, particles and additives. The coating film made of the coating liquid for a surface protective layer can be formed, for example, by printing.

[0128] The coating film made of the coating liquid for the surface protective layer can be formed by various printing methods, such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing. Furthermore, since the surface protective layer 5 covers the entire surface of the front side of the base 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 and coating methods can be combined as appropriate.

[0129] Next, after forming a coating film made of the coating liquid for surface protective layer, a fourth irradiation step is carried out in which the coating film is irradiated with a fourth radiation to semi-cure the coating film to obtain a semi-cured film.

[0130] The light source used in the fourth irradiation step can be selected from, for example, a high-pressure mercury lamp, a metal halide lamp, and a single-wavelength LED lamp emitting light with a wavelength of 200 nm or more and 400 nm or less.

[0131] The cumulative light intensity of the fourth irradiation step is 2 mJ / cm 2 More than 100mJ / cm 2 It is preferable that the dose is 10 mJ / cm or less. 2 More than 80mJ / cm 2 More preferably, it is 20 mJ / cm or less. 2 More than 60mJ / cm 2 It is more preferable that the integrated light amount is as follows: If the integrated light amount is too small or too large, it becomes difficult to form a coating film made of the coating liquid for surface protective layer.

[0132] Next, a plate for secondary transfer is pressed onto the laminate including the original layer 2 and the semi-cured film made of the coating liquid for the surface protective layer so that the transfer film comes into contact with the semi-cured film.

[0133] Next, a fifth irradiation step is carried out. In the fifth irradiation step, the coating film is irradiated with a fifth radiation from the side of the secondary transfer plate to harden the entire coating film. This imparts to the coating film a concave-convex structure complementary to the concave-convex structure of the transfer film, i.e., the shape of the concave-convex structure of the concave-convex layer. The fifth radiation is the same as the second radiation. The integrated light amount of the fifth radiation is the same as the integrated light amount of the second radiation.

[0134] Next, the secondary transfer plate is peeled off from the laminate including the original layer 2 and the coating film made of the coating liquid for the surface protective layer, thus obtaining the decorative sheet 1.

[0135] The above describes a method for manufacturing a decorative sheet 1 using a plate. With this method, it is possible to easily adjust the thickness T1 of the concave-convex portion 5A and the thickness T2 of the core portion 5B.

[0136] In the above-described method, the transfer is performed twice, but the number of times of transfer may be one, or three or more.

[0137] Moreover, the decorative sheet 1 can be formed without using a plate. For example, the decorative sheet 1 can be formed in the same manner as the plate formation method described above, except that a base layer is used as the first base layer and a surface protective layer coating liquid is used as the uneven layer coating liquid, provided that the average number of functional groups of the ionizing radiation curable resin contained in the surface protective layer coating liquid is in the range of 1.5 to 9.

[0138] <1.3> Effects The decorative sheet described above has a surface protective layer 5 including a concave-convex portion 5A having a concave-convex structure and a core portion 5B. The ratio T1 / T2 of the thickness T1 of the concave-convex portion 5A to the thickness T2 of the core portion 5B is in the range of 0.2 to 15, the thickness T2 of the core portion is in the range of 1 μm to 10 μm, and the surface protective layer 5 contains a cured product of an ionizing radiation-curable resin having an average number of functional groups of 1.5 to 9. Such a decorative sheet has excellent durability, such as scratch resistance and weather resistance.

[0139] Furthermore, because the decorative sheet 1 described above has a surface protective layer 5 with an uneven surface structure, the gloss (gloss level) of the surface protective layer can be adjusted even without including a gloss adjuster (matt additive) in the surface protective layer. For example, the decorative sheet 1 described above can be made low gloss. Gloss adjusters reduce the oil repellency of layers formed from resin materials, making them more susceptible to fingerprints. In one example, because the surface protective layer 5 does not include a gloss adjuster, it does not absorb oil and has relatively improved oil repellency. Therefore, in various situations, such as during on-site construction, furniture assembly, and in the daily lives of residents, fingerprints are less likely to adhere to the decorative sheet 1 having the surface protective layer 5.

[0140] Furthermore, the surface protective layer 5 has an uneven surface configuration, which improves the oil repellency of the surface protective layer 5, making it possible to prevent oil stains and adsorption of contaminants onto the surface of the decorative sheet 1.

[0141] Furthermore, by configuring the surface protection layer 5 so that it does not contain a gloss adjusting agent, the particles of the gloss adjusting agent do not fall off when the surface of the decorative sheet 1 is scratched, making it possible to make the surface of the decorative sheet 1 less susceptible to changes in gloss or scratches.

[0142] Furthermore, since the surface protection layer 5 does not contain a gloss adjusting agent, whitening that can occur due to a gloss adjusting agent does not occur during bending, and therefore it is possible to prevent deterioration of bending workability. [Example]

[0143] The following describes examples of the present invention.

[0144] <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 corona treatment, and a pattern was printed on that side to form the design layer 3. The design 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 relative to the binder resin content of the ink.

[0145] Next, a primer layer 6 was formed on the back surface of the raw fabric layer 2. The primer layer 6 was formed by printing the same two-component urethane ink as that used for the design layer 3.

[0146] Next, a coating liquid for a surface protective layer was applied onto the design layer 3. The thickness of the coating film of the coating liquid for a surface protective layer was 10 μm. The coating liquid for a surface protective layer was a mixture of the following ionizing radiation curable resin and the following additive (photopolymerization initiator). ·Ionizing radiation curable resin Resin 1: Type: EBECRYL 5129 (hexafunctional urethane acrylate) (manufactured by Daicel Allnex) Blend: 30 parts by mass Resin 2: Type: 1,4-butanediol diacrylate (BDDA) (bifunctional acrylate) Blend: 40 parts by weight Resin 3: Type: Cyclohexyl acrylate Blend: 30 parts by mass Photopolymerization initiator Product name: Omnirad184 (manufactured by IGM Resins) Blend: 3 parts by mass.

[0147] Thereafter, the fourth irradiation step was carried out. Specifically, ultraviolet rays were irradiated to the surface of the coating film made of the coating liquid for the surface protective layer in the atmosphere using a high-pressure mercury lamp at an integrated light intensity of 20 mJ / cm. 2 This caused the coating film to be semi-cured.

[0148] Next, a plate for imparting a grid pattern to the coating film made of the coating liquid for the surface protective layer was pressed against the coating film.

[0149] Next, with the plate pressed against the coating film, the fifth irradiation step was carried out. Specifically, a high-pressure mercury lamp was used to irradiate the coating film with an integrated light dose of 200 mJ / cm. 2 The entire surface was cured by irradiating it with ultraviolet light so that the surface protective layer 5 was formed. In this manner, a decorative sheet was obtained.

[0150] <Example 2> A decorative sheet was obtained in the same manner as in Example 1, except that Resin 1 used in Example 1 was replaced with the following and a plate for forming the surface protective layer into ridges was used as the plate. Type: EBECRYL 9270 (bifunctional urethane acrylate) (manufactured by Daicel Allnex) Blend: 30 parts by mass.

[0151] The plates were also manufactured as follows. First, an olefin film (manufactured by RIKEN TECHNOS CORPORATION) having a thickness of 55 μm was prepared as the first underlayer. Next, a coating liquid for forming a concave-convex layer was applied onto the first undercoat layer. The coating film thickness of the coating liquid for forming a concave-convex layer was 10 μm. The coating liquid for forming a concave-convex layer was prepared by blending the following ionizing radiation curable resin with the following additives (photopolymerization initiator and particles). (ionizing radiation curable resin) Resin 1: Type: Trimethylolpropane EO-modified triacrylate (EO 3 moles added) Blend: 65 parts by mass Resin 2: Dipentaerythritol hexaacrylate Blend: 35 parts by mass (Photopolymerization initiator) Product name: Omnirad184 (manufactured by IGM Resins BV) Blend: 3 parts by mass (particle) Product name: Silysia 450 (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 8.0μm Blend: 3 parts by mass Thereafter, the first irradiation step was carried out. Specifically, an excimer lamp was used to irradiate the surface of the coating film made of the coating liquid for the concave-convex layer with an integrated light amount of 10 mJ / cm 2 . 2 This caused unevenness to form on the surface of the coating film made of the coating liquid for uneven layer.

[0152] Next, the second irradiation step was carried out. Specifically, a high-pressure mercury lamp was used to irradiate the coating film made of the coating liquid for the concave-convex layer with an accumulated light amount of 100 mJ / cm 2 . 2 The second radiation was applied so that the entire surface was cured, thereby forming a concave-convex layer. In this way, a plate for primary transfer was obtained.

[0153] Next, a coating film made of a transfer film coating liquid containing polydimethylsiloxane was formed on the concave-convex layer.

[0154] Next, a second underlayer was formed on the coating film made of the transfer film coating liquid, using a film made of polyethylene terephthalate as the second underlayer.

[0155] Next, the third irradiation step was carried out. Specifically, a high-pressure mercury lamp was used to irradiate the coating film made of the transfer film coating liquid from the second underlayer side with an accumulated light amount of 300 mJ / cm 2 . 2 The third radiation was applied so that the entire surface was cured, thereby forming a transfer film.

[0156] Next, the laminate including the transfer film and the second underlayer was peeled off from the plate for primary transfer. In this manner, a plate was produced.

[0157] <Example 3> A decorative sheet was obtained in the same manner as in Example 1, except that the same plate as used in Example 2 was used.

[0158] <Example 4> A decorative sheet was obtained in the same manner as in Example 1, except that the thickness of the coating film made of the surface protective layer coating liquid was set to 12 μm and a plate manufactured by the following method was used. Specifically, in this example, the integrated light amount in the first irradiation step was set to 3 mJ / cm 2 A plate was produced in the same manner as in Example 2, except for the above change.

[0159] <Example 5> A decorative sheet was obtained in the same manner as in Example 1, except that the thickness of the coating film made from the coating liquid for the surface protective layer was 17 μm and a plate manufactured by the following method was used as the plate. Specifically, in this example, a plate was manufactured by the same method as the plate manufacturing method in Example 2, except that pentaerythritol tetraacrylate (35 moles of EO added) was used as the ionizing radiation curable resin contained in the coating liquid for the uneven layer.

[0160] <Example 6> A decorative sheet was obtained in the same manner as in Example 1, except that Resin 1 used in Example 1 was replaced with the following and the same plate as used in Example 2 was used as the plate. Type: UN-904 (10-functional urethane acrylate) (manufactured by Negami Chemical Industrial Co., Ltd.) Blend: 30 parts by mass.

[0161] <Example 7> A decorative sheet was obtained in the same manner as in Example 1, except that Resins 1, 2 and 3 used in Example 1 were replaced with the following. Resin 1: Type: UN-3320HS (15-functional urethane acrylate) (manufactured by Negami Chemical Industrial Co., Ltd.) Blend: 50 parts by mass.

[0162] Resin 2: Type: 1,4-butanediol diacrylate (BDDA) (bifunctional acrylate) Blend: 30 parts by weight Resin 3: Type: Cyclohexyl acrylate Blend: 20 parts by mass.

[0163] <Example 8> A decorative sheet was obtained in the same manner as in Example 1, except that a plate manufactured in the same manner as in Example 2 was used, except that particles were omitted from the coating liquid for the irregular layer.

[0164] <Comparative Example 1> A decorative sheet was obtained in the same manner as in Example 1, except that the thickness of the coating film made of the surface protective layer coating liquid was 5 μm and the coating film was cured without pressing a plate against it.

[0165] <Comparative Example 2> A decorative sheet was obtained in the same manner as in Example 1, except that a resin made of cyclohexyl acrylate was used as the ionizing radiation curable resin and the same plate as used in Example 2 was used as the plate.

[0166] <Comparative Example 3> A decorative sheet was obtained in the same manner as in Example 1, except that the composition of the ionizing radiation curable resin used in Example 1 was replaced as follows and the same plate as used in Example 2 was used as the plate. Resin 1: Type: UN-3320HS (15-functional urethane acrylate) (manufactured by Negami Chemical Industrial Co., Ltd.) Blend: 60 parts by mass Resin 2: Type: 1,4-butanediol diacrylate (BDDA) (bifunctional acrylate) Blend: 20 parts by weight Resin 3: Type: Cyclohexyl acrylate Blend: 20 parts by mass.

[0167] <Comparative Example 4> A decorative sheet was obtained in the same manner as in Example 1, except that the thickness of the coating film made of the surface protective layer coating liquid was 6 μm and the same plate as used in Example 2 was used as the plate.

[0168] <Comparative Example 5> A decorative sheet was obtained in the same manner as in Example 1, except that the thickness of the coating film made of the surface protective layer coating liquid was 18 μm and the same plate as used in Example 2 was used as the plate.

[0169] <Comparative Example 6> A decorative sheet was obtained in the same manner as in Example 1, except that the thickness of the coating film made of the surface protective layer coating liquid was set to 12 μm and a plate manufactured by the following method was used. Specifically, in this example, the integrated light amount in the first irradiation step was set to 1 mJ / cm 2 A plate was produced in the same manner as in Example 2, except that the following was changed:

[0170] <Comparative Example 7> A decorative sheet was obtained in the same manner as in Example 1, except that the thickness of the coating film made from the coating liquid for the surface protective layer was 20 μm and a plate manufactured by the following method was used as the plate. Specifically, in this example, pentaerythritol tetraacrylate (35 moles of EO added) was used as the ionizing radiation curable resin contained in the coating liquid for the uneven layer, and a plate was manufactured in the same manner as the plate of Example 2, except that the thickness of the coating film made from the coating liquid for the uneven layer was 14 μm.

[0171] <Evaluation> Each of the decorative sheets described above was subjected to the following evaluations.

[0172] (1) Thickness of the surface protection layer, thickness of the uneven portion T1, and thickness of the core portion T2 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 decorative sheet was then cut to reveal its cross section, and mechanically polished to obtain a measurement surface. The cross section of the surface protective layer was then 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 SE2 mode, and at a magnification of 2000x. No sputtering was performed on the measurement sample. From this cross-sectional image, the dimensions of the surface protective layer in the width direction of the uneven portion and the area of ​​the cross section of the surface protective layer were calculated. The thickness of the surface protective layer was calculated by dividing this area by the above dimensions. 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 from the surface protective layer coating liquid.

[0173] The thickness T2 of the core portion was measured by the method described above. The thickness T1 of the concave-convex portion was obtained as the difference between the thickness t of the surface protective layer and the thickness T2 of the core portion.

[0174] (2) Measurement of the average length Rsm of the roughness profile elements The mean length of the roughness profile element, Rsm, was determined as described in the detailed description section.

[0175] (3) Glossiness The glossiness was measured at 60 degrees using Rhopoint IQ (manufactured by Konica Minolta).

[0176] (4) Weather resistance A carbon arc weather resistance test was carried out in accordance with JIS B7753:2007 using a weather resistance tester (Sunshine Weather Meter (SWOM): manufactured by Suga Test Instruments Co., Ltd.) under the following conditions. Black panel temperature: 63℃ Temperature: Approximately 46℃ Humidity: 50%RH Light source: Carbon arc Irradiance: 250±25W / m 2 Glass filter: Type A Light irradiation conditions: continuous irradiation Water spray conditions: 120 minutes of light irradiation, 18 minutes of water spray Test time: 2000 hours After the decorative sheet was left under the above conditions for 2000 hours, the change in appearance was evaluated visually by observing the entire surface of the decorative sheet.

[0177] After the visual evaluation, tape was applied to the surface protective layer and then peeled off. It was then observed whether the surface protective layer peeled off along with the tape. The decorative sheet was then evaluated according to the following evaluation criteria. The weather resistance test was conducted under accelerated conditions, so if a rating of B or higher is obtained, there is no problem in practical use.

[0178] AA: No whitening or cracks were observed over the entire surface of the decorative sheet, and no peeling of the surface protective layer occurred. A: Slight whitening was observed over an area of ​​less than 30% of the surface of the decorative sheet, and no peeling of the surface protective layer occurred. B: Slight whitening was observed over 30 to 50% of the surface area of ​​the decorative sheet, and no peeling of the surface protective layer occurred. C: Whitening or cracks were observed over 50% or more of the surface area of ​​the decorative sheet, or peeling of the surface protective layer occurred.

[0179] (7) Processability To evaluate workability, a wrapping test was conducted. A decorative sheet was attached to MDF (Medium Density Fiberboard) with adhesive, grooved, and bent at a 90-degree angle. The bent portion of the surface of each decorative sheet was observed using an optical microscope to determine whether whitening or cracks had occurred, and the state of workability was evaluated. The evaluation was performed by observing the entire bent portion from the surface side of the decorative sheet. This wrapping workability corresponds to so-called bending workability.

[0180] The evaluation criteria were as follows: The workability test involved detailed observation under an optical microscope, and if a result of B or higher was obtained, there was no problem in practical use.

[0181] AA: No whitening or cracking is observed throughout the bent portion. A: Slight whitening is observed in less than 30% of the bent area, but no cracks are observed. B: Slight whitening is observed in 30 to 50% of the bent area, but no cracks are observed. C: Whitening or cracks are observed in 50% or more of the bent area.

[0182] (5) Stain resistance To evaluate stain resistance, the Staining A Test specified in the Japanese Agricultural Standards (JAS) was conducted. Specifically, 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. The blue ink, black quick-drying ink, and red crayon lines were then wiped off with a cloth soaked in ethanol.

[0183] The evaluation criteria were as follows: AA: Lines of each color could be easily wiped off. A: I was able to wipe off some of the lines of each color, but some stains remained. B: I was unable to wipe off the lines of each color.

[0184] The evaluation results are shown in the table below. An evaluation result of B or higher is considered a pass.

[0185] [Table 1]

[0186] [Table 2] [Explanation of symbols]

[0187] 1...decorative sheet, 2...base fabric layer, 3...pattern layer, 4...transparent resin layer, 4a...embossed pattern, 4b...adhesive resin layer, 5...surface protection layer, 5A...concave and recessed portion, 5B...core portion, 6...primer layer, 11...decorative material.

Claims

1. A substrate layer and a surface protective layer provided on one surface of the substrate layer, an uneven surface structure is provided on the surface of the surface protection layer, the surface protection layer includes an uneven portion having the uneven structure and a core portion interposed between the raw fabric layer and the uneven portion, a ratio T1 / T2 of a thickness T1 of the concave-convex portion to a thickness T2 of the core portion is in the range of 0.2 or more and 15 or less; The thickness T2 of the core portion is in the range of 1 μm or more and 10 μm or less, The surface protective layer is a decorative sheet comprising a cured product of an ionizing radiation curable resin having an average functionality of 1.5 or more and 9 or less.

2. The decorative sheet according to claim 1 , wherein the uneven structure comprises a plurality of protrusions, each of which is ridge-shaped.

3. 2. The decorative sheet according to claim 1, wherein said ionizing radiation curable resin is an acrylate.

4. 2. The decorative sheet according to claim 1, wherein the average number of functional groups is in the range of 2 or more and 6 or less.

5. 2. The decorative sheet according to claim 1, wherein the gloss of said surface protective layer is 10.0 or less.

6. 2. The decorative sheet according to claim 1, further comprising a pattern layer between said base layer and said surface protective layer.

7. The decorative sheet according to any one of claims 1 to 6, a substrate to which the decorative sheet is attached; A cosmetic material comprising:

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