Decorative sheet

Abstract

Provided is a decorative sheet having excellent heat resistance, scratch resistance, and stain resistance. A decorative sheet (1) comprises a raw material layer (2) and a surface protection layer, wherein the surface protection layer is provided on the raw material layer (2), the decorative sheet (1) comprising: a first gloss adjustment layer (5) which includes a cured object of a first ionizing-radiation-curable resin; and a second gloss adjustment layer (6) which partly covers the upper surface of the first gloss adjustment layer (5), includes a cured object of a second ionizing-radiation-curable resin, and has, on the upper surface thereof, a rugged structure in which the ratio RSm / Ra of an average length RSm to an arithmetic average roughness Ra of roughness curve elements is in the range of 10-600, the rugged structure including a plurality of ridge portions each having a protruding ridge shape.

Description

Decorative sheet

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

[0002] Decorative materials used for the surface decoration of the interior and exterior of buildings, fittings, furniture, etc. are generally in the form of decorative boards, which are formed by attaching a decorative sheet to the surface of a substrate via an adhesive or the like. The decorative sheet is typically provided with a desired pattern, such as a wood grain or stone pattern. Furthermore, decorative sheets that not only simply express a wood grain or stone pattern in a two-dimensional manner, but also express a three-dimensional texture similar to the surface of natural wood or stone, are also widely used, primarily in applications where a luxurious feel is desired.

[0003] Various methods have been devised for expressing a three-dimensional textured effect in combination with a flat pattern on the surface of a decorative sheet, and are used according to the purpose. For example, rather than actually forming a three-dimensional effect on the surface of a decorative material, there is a method in which the glossiness of the surface of the decorative material is made different between the areas that should be expressed as concaves or convexities and other areas, thereby visually expressing a three-dimensional textured effect by utilizing the illusion of the human eye. With this method, even if there are no actual concaves or convexities that the viewer can perceive, the areas with a relatively high glossiness are perceived as convexities and the areas with a relatively low glossiness are perceived as concaves.

[0004] To manufacture such a decorative sheet, for example, first, a printed layer containing a pattern corresponding to the area where the depressions are to be expressed is formed on one surface of the substrate. Next, a transparent or translucent first gloss adjustment layer with low gloss is formed on the entire surface of the substrate on which the printed layer is formed. Next, a transparent or translucent second gloss adjustment layer with high gloss is formed on the entire surface of the first gloss adjustment layer except for the area corresponding to the pattern. Note that by reversing the relationship between high and low gloss levels between the first gloss adjustment layer and the second gloss adjustment layer, a decorative sheet with a reversed relationship between the depressions and protrusions can be obtained.

[0005] According to this method, by simply preparing two types of paint that impart different gloss levels, it is possible to create a three-dimensional texture-like effect on any substrate without the need for special chemicals. Furthermore, the formation of gloss-adjusting layers with different gloss levels can be carried out using conventional printing methods such as gravure printing, following the formation of the pattern (pattern ink layer). Therefore, no special equipment is required, production efficiency is high, and alignment of the second synthetic paint layer with the pattern is easy. Furthermore, the second gloss-adjusting layer can be much thinner than the height difference of the unevenness that should be perceived by the viewer, thereby reducing the amount of resin used and providing advantages in terms of flexibility, making it easy to realize a decorative sheet with excellent folding processability.

[0006] International Publication No. 2022 / 182259 Japanese Patent Application Laid-Open No. 2014-188842

[0007] An object of the present invention is to provide a decorative sheet that is excellent in design, heat resistance, scratch resistance, and stain resistance.

[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, wherein the surface protective layer is provided on the original fabric layer and comprises a first gloss adjustment layer containing a cured product of a first ionizing radiation curable resin; and a second gloss adjustment layer partially covering the upper surface of the first gloss adjustment layer and containing a cured product of a second ionizing radiation curable resin, the second gloss adjustment layer having an uneven structure on its upper surface, the ratio RSm / Ra of the average length RSm of the roughness curve elements to the arithmetic mean roughness Ra being in the range of 10 or more and 600 or less, the uneven structure comprising a plurality of ridge portions each protruding in a ridge-like shape.

[0009] According to another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the cured product of the first ionizing radiation curable resin contains one or more bonds selected from the group consisting of a urethane bond, a carbonate bond, and an amide bond.

[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 first gloss adjustment layer further contains a cured product of a thermosetting resin.

[0011] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the proportion of the solid content of the thermosetting resin in the total of the solid content of the first ionizing radiation curable resin and the solid content of the thermosetting resin is 90 mass% or less.

[0012] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the cured product of the thermosetting resin contains one or more bonds selected from the group consisting of urethane bonds, carbonate bonds, and amide bonds.

[0013] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the thermosetting resin includes one or more of an aqueous urethane dispersion, an aqueous epoxy dispersion, and an aqueous polyamine dispersion.

[0014] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the first ionizing radiation curable resin is an aqueous dispersion or emulsion containing at least one of a urethane acrylate and a polyurethane resin, the thermosetting resin is an aqueous dispersion containing a polyurethane resin, and the polyurethane resin contained in the thermosetting resin contains a reaction product of a polyisocyanate and a polyol including at least one of a polyester polyol and a polycarbonate polyol.

[0015] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the thickness of each of the first gloss adjustment layer and the second gloss adjustment layer is in the range of 2 μm or more and 20 μm or less.

[0016] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the second ionizing radiation curable resin contains a di- or higher functional acrylate containing a repeating structure.

[0017] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the repeating structure is repeated three or more times.

[0018] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the second gloss control layer further contains particles having an average particle size of 10 μm or less.

[0019] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, in which the mass of the particles is in the range of 0.5 parts by mass or more and 20 parts by mass when the mass of the second ionizing radiation curable resin is 100 parts by mass.

[0020] According to yet another aspect of the present invention, there is provided a decorative material comprising a decorative sheet according to any one of the above aspects and a substrate to which the decorative sheet is attached.

[0021] According to yet another aspect of the present invention, there is provided a method for manufacturing a decorative sheet, comprising: forming a first gloss adjustment layer containing a cured product of a first ionizing radiation curable resin on an original layer; and forming a second gloss adjustment layer partially covering the upper surface of the first gloss adjustment layer, containing a cured product of a second ionizing radiation curable resin, and having on its upper surface an uneven structure having a ratio RSm / Ra of the average length RSm of the roughness curve elements to the arithmetic mean roughness Ra in the range of 10 or more and 600 or less, wherein the uneven structure includes a plurality of ridge portions each protruding in a ridge-like shape.

[0022] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet according to the above aspect, wherein the first gloss adjustment layer further contains a cured product of a thermosetting resin.

[0023] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet according to the above aspect, wherein the first ionizing radiation curable resin is an aqueous dispersion or emulsion containing at least one of a urethane acrylate and a polyurethane resin, the thermosetting resin is an aqueous dispersion containing a polyurethane resin, and the polyurethane resin contained in the thermosetting resin contains a reaction product of a polyisocyanate and a polyol containing at least one of a polyester polyol and a polycarbonate polyol.

[0024] According to the present invention, a decorative sheet having excellent design, heat resistance, scratch resistance and stain resistance is provided.

[0025] 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 second gloss adjustment layer included in the decorative sheet of Fig. 1. Fig. 3 is a microscope image of a second gloss adjustment layer included in a decorative sheet according to one example of the present invention. Fig. 4 is a cross-sectional view showing an enlarged portion of the second gloss adjustment layer shown in Fig. 2.

[0026] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are more specific embodiments of any of the above aspects. The following items can be incorporated into each of the above aspects, either singly or in combination.

[0027] Furthermore, the embodiments shown below are merely examples of configurations for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not limited by the materials, shapes, structures, etc. of the components described below. Various modifications can be made to the technical idea of ​​the present invention within the technical scope defined by the claims.

[0028] 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.

[0029] <1> Decorative material and decorative sheet Figure 1 is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention. Figure 2 is a cross-sectional view of a second gloss adjustment layer included in the decorative sheet of Figure 1. Figure 3 is a micrograph of a second gloss adjustment layer included in a decorative sheet according to one example of the present invention. Figure 4 is a cross-sectional view showing an enlarged portion of the second gloss adjustment layer shown in Figure 2.

[0030] 2 and 4 are cross sections taken along the thickness direction of the second gloss adjustment layer. The micrograph in Fig. 3 is a plan view taken with a laser microscope (OLS-4000 manufactured by Olympus Corporation).

[0031] The decorative material 11 shown in Figure 1 includes a substrate B and a decorative sheet 1 attached thereto. Here, the decorative material 11 is a decorative board. The decorative board may be a flat plate, or may be curved or folded. The decorative material 11 may have a shape other than a plate.

[0032] 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.

[0033] The decorative sheet 1 includes a base fabric layer 2, a solid ink layer 3, a pattern ink layer 4, a first gloss adjustment layer 5, and a second gloss adjustment layer 6. The solid ink layer 3, the pattern ink layer 4, the first gloss adjustment layer 5, and the second gloss adjustment layer 6 are provided in this order from the base fabric layer 2 side on the surface of the base fabric layer 2 opposite the surface facing the substrate B. One or both of the solid ink layer 3 and the pattern ink layer 4 may be omitted. One or more other layers, such as a transparent resin layer, may be provided between the pattern ink layer 4 and the first gloss adjustment layer 5. The elements included in the decorative sheet 1 will be explained below in order.

[0034] <1.1> Raw Fabric Layer The raw fabric layer 2 or its materials include papers such as tissue paper, resin-mixed paper, titanium paper, resin-impregnated paper, flame-retardant paper, and inorganic paper; woven or nonwoven fabrics made of natural or synthetic fibers; synthetic resin substrates including synthetic resins such as homo- or random polyolefin resins such as polypropylene resin and polyethylene resin, copolymer polyester resin, amorphous crystalline polyester resin, polyethylene naphthalate resin, polybutylene resin, acrylic resin, polyamide resin, polycarbonate resin, polyvinyl chloride resin, polyvinylidene chloride resin, and fluorine-based resin; wood-based substrates such as wood veneer, veneer, plywood, laminated lumber, particle board, and medium-density fiberboard; inorganic substrates such as gypsum board, cement board, calcium silicate board, and ceramic board; metal-based substrates made of metals such as iron, copper, aluminum, and stainless steel; or composites or laminates thereof. The raw fabric layer 2 can have various forms such as film, sheet, plate, and irregularly shaped molded body.

[0035] <1.2> Solid Ink Layer The solid ink layer 3 is a continuous film formed by coating one entire surface of the base fabric layer 2 with ink. The solid ink layer 3 can serve as a concealing layer that conceals the substrate B or the base fabric layer 2. The solid ink layer 3 can also serve as a flattening layer. The solid ink layer 3 may have a single-layer structure or a multi-layer structure.

[0036] The solid ink layer 3 can be formed using, for example, a printing ink (or coating agent) prepared by dissolving or dispersing a matrix and a colorant such as a dye or pigment in a solvent.

[0037] As the matrix, for example, various synthetic resins such as oil-based nitrocellulose resin, two-component urethane resin, acrylic resin, styrene resin, polyester resin, urethane resin, polyvinyl resin, alkyd resin, epoxy resin, melamine resin, fluorine resin, silicone resin, and Daibirubber resin, or mixtures or copolymers of these can be used.

[0038] 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.

[0039] Examples of the solvent that can be used include toluene, xylene, ethyl acetate, butyl acetate, methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, water, and mixtures thereof.

[0040] To the ink described above, functional additives such as extender pigments, plasticizers, dispersants, surfactants, tackifiers, adhesion aids, drying agents, curing agents, curing accelerators, and curing retarders may be added in order to impart various functions.

[0041] <1.3> Pattern Ink Layer The pattern ink layer 4 is provided to add a pattern to the decorative sheet 1. The pattern pattern may be, for example, a wood grain pattern, a pebble pattern, a sand grain pattern, a tiled pattern, a brickwork pattern, a fabric pattern, a leather-grained pattern, or a geometric figure. In the example of FIG. 1 , the pattern ink layer 4 is a printed pattern that partially covers the upper surface of the solid ink layer 3. This printed pattern is provided directly below the second gloss adjustment layer. In other words, the second gloss adjustment layer 6 is provided so as to overlap the pattern ink layer 4. In other words, the printed pattern contained in the pattern ink layer 4 and the pattern of the second gloss adjustment layer 6 are orthogonally projected onto a plane perpendicular to the thickness direction and have the same shape and position. Hereinafter, the state in which the orthogonal projections onto a plane perpendicular to the thickness direction are orthogonally projected onto a plane perpendicular to the thickness direction will sometimes be abbreviated as "the shapes and positions are consistent."

[0042] The pattern ink layer 4 can be formed using, for example, the ink described above for the solid ink layer 3. The pattern ink layer 4 is formed using the number of plates necessary to express the desired design. That is, the pattern ink layer 4 may be a layer consisting of one printed pattern made of a single ink, or may be a layer consisting of multiple printed patterns made of different inks. In the latter case, one printed pattern may match the shape and position of the pattern of the second gloss adjustment layer 6, or a combination of two or more printed patterns may match the shape and position of the pattern of the second gloss adjustment layer 6. For example, one printed pattern or a combination of two or more printed patterns may match the shape and position of the pattern of the second gloss adjustment layer 6, with the remaining printed patterns located in areas corresponding to the openings of the second gloss adjustment layer 6.

[0043] When the pattern ink layer 4 contains only one printing pattern, this printing pattern has a different color from the solid ink layer 3. When the pattern ink layer 4 contains multiple printing patterns, and a combination of these printing patterns matches the shape and position of the pattern of the second gloss adjustment layer 6, one or more of these printing patterns, for example, all of these printing patterns, have a different color from the solid ink layer 3. When the pattern ink layer 4 contains multiple printing patterns, and one printing pattern or a combination of two or more printing patterns matches the shape and position of the pattern of the second gloss adjustment layer 6, and the remaining printing patterns are located in areas corresponding to the openings of the second gloss adjustment layer 6, one or more of the former printing patterns have a different color from the solid ink layer 3 and one or more of the latter printing patterns. For example, all of the former printing patterns have a different color from the solid ink layer 3 and all of the latter printing patterns.

[0044] Here, as an example, the pattern ink layer 4 is a layer consisting of one printing pattern made of a single ink, and is a different color from the solid ink layer 3.

[0045] <1.4> Transparent Resin Layer As described above, the decorative sheet 1 can further include a transparent resin layer between the pattern ink layer 4 and the first gloss adjustment layer 5. The transparent resin layer can contribute to improving the abrasion resistance of the decorative sheet 1.

[0046] The transparent resin layer is preferably made of a resin composition containing an olefin-based resin as a main material, such as polypropylene, polyethylene, or polybutene. The olefin resin may be a homopolymer or copolymer of two or more α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, and 12-ethyl-1-tetradecene. The olefin-based resin may be a copolymer of ethylene or an α-olefin with another monomer, such as an ethylene-vinyl acetate copolymer, an ethylene-vinyl alcohol copolymer, an ethylene-methyl methacrylate copolymer, an ethylene-ethyl methacrylate copolymer, an ethylene-butyl methacrylate copolymer, an ethylene-methyl acrylate copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-butyl acrylate copolymer, etc. In particular, when further improving the surface strength, it is preferable to use a highly crystalline polypropylene.

[0047] The transparent resin layer may contain additives such as a heat stabilizer, an ultraviolet absorber, a light stabilizer, an antiblocking agent, a catalyst scavenger, and a colorant. These additives can be appropriately selected from known additives. The transparent resin layer can be formed by various lamination methods such as a method using heat and pressure, an extrusion lamination method, and a dry lamination method.

[0048] <1.5> First Gloss Adjustment Layer The first gloss adjustment layer 5 is provided on the base layer 2. Here, the first gloss adjustment layer 5 covers the solid ink layer 3 and the pattern ink layer 4.

[0049] The first gloss adjustment layer 5 is made of a cured resin. The first gloss adjustment layer 5 may further contain particles. For example, the particles described below for the second gloss adjustment layer 6 may be used as the particles. When the mass of the first gloss adjustment layer 5 is taken as 100 parts by mass, the mass of the cured resin contained in the first gloss adjustment layer 5 is preferably 60 parts by mass or more, more preferably 70 parts by mass or more, and even more preferably 80 parts by mass or more.

[0050] The first gloss adjustment layer 5 contains a cured resin of a first ionizing radiation curable resin as a cured resin. Here, "ionizing radiation" refers to a charged particle beam such as an electron beam. The first ionizing radiation curable resin is cured by irradiation with ionizing radiation. The first ionizing radiation curable resin can also be cured by irradiation with ultraviolet light.

[0051] The first ionizing radiation curable resin may be any known resin, such as various monomers or commercially available oligomers, including (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, or epoxy resins. The first ionizing radiation curable resin may be either an aqueous resin or a non-aqueous (organic solvent-based) resin. The first ionizing radiation curable resin may be solvent-free.

[0052] The first ionizing radiation curable resin is, for example, a water-based dispersion or emulsion containing at least one of a urethane acrylate and a polyurethane resin, and may be, for example, a dispersion or emulsion containing a resin having an acryloyl group.

[0053] The cured product of the first ionizing radiation curable resin preferably contains one or more bonds selected from the group consisting of a urethane bond, a carbonate bond, and an amide bond.

[0054] The first gloss adjustment layer 5 can further contain a cured product of a thermosetting resin as the cured resin.

[0055] The thermosetting resin may, for example, include one or more of an aqueous urethane dispersion, an aqueous epoxy dispersion, and an aqueous polyamine dispersion, such as a dispersion containing a carboxylic acid derivative having a polycarbonate backbone.

[0056] When the thermosetting resin is an aqueous dispersion containing a polyurethane resin, the polyurethane resin may contain a reaction product of a polyisocyanate and a polyol containing at least one of a polyester polyol and a polycarbonate polyol. This polyurethane resin may or may not contain a silanol group.

[0057] The cured product of the thermosetting resin preferably contains one or more bonds selected from the group consisting of a urethane bond, an ester bond, a carbonate bond, and an amide bond.

[0058] When an aqueous dispersion or emulsion is used as at least one of the first ionizing radiation curable resin and the thermosetting resin, traces of a surfactant may remain in the first gloss adjusting layer 5 .

[0059] A cured product of the first ionizing radiation curable resin tends to have a higher melting point or softening point than a cured product of a thermosetting resin. That is, a cured product of the first ionizing radiation curable resin contributes more to heat resistance than a cured product of a thermosetting resin. Furthermore, a cured product of the first ionizing radiation curable resin has a sufficiently high crosslink density, which can contribute to achieving high scratch resistance.

[0060] However, the cured product of the thermosetting resin tends to have a higher crosslink density than the cured product of the first ionizing radiation curable resin, i.e., the cured product of the thermosetting resin contributes more to scratch resistance than the cured product of the first ionizing radiation curable resin.

[0061] Therefore, when the first gloss adjustment layer 5 contains a cured product of the first ionizing radiation curable resin and a cured product of the thermosetting resin, higher scratch resistance can be achieved compared to when the first gloss adjustment layer 5 contains only the cured product of the first ionizing radiation curable resin as the resin cured product.

[0062] The proportion of the solid content of the thermosetting resin in the total of the solid content of the first ionizing radiation curable resin and the solid content of the thermosetting resin is preferably 10% by mass or more, and more preferably 20% by mass or more. By increasing this proportion, higher scratch resistance can be achieved.

[0063] The proportion of the solid content of the thermosetting resin in the total of the solid content of the first ionizing radiation curable resin and the solid content of the thermosetting resin is preferably 90 mass % or less, and more preferably 80 mass % or less. If this proportion is excessively large, there is a possibility that the heat resistance will decrease.

[0064] The thickness of the first gloss adjustment layer 5 is preferably in the range of 2 μm to 20 μm, more preferably in the range of 2 μm to 15 μm, and even more preferably in the range of 3 μm to 10 μm. If the thickness of the first gloss adjustment layer 5 is reduced, scratch resistance decreases. If the thickness of the first gloss adjustment layer 5 is increased, the processability of the decorative sheet 1 decreases, and it becomes more likely to whiten when folded.

[0065] The first gloss adjustment layer 5 preferably has a higher specular gloss GS(60°) than the second gloss adjustment layer 6. The specular gloss GS(60°) of the first gloss adjustment layer 5 is preferably 3 or more, more preferably 5 or more, and even more preferably 7 or more. In one example, the specular gloss GS(60°) of the first gloss adjustment layer 5 is 30 or less. Here, "specular gloss GS(60°)" refers to the specular gloss measured at an incident angle of 60 degrees using a gloss meter conforming to ISO 2813. Note that the specular gloss GS(60°) is sometimes expressed by adding "%" after the numerical value, but the "%" will be omitted here.

[0066] <1.6> Second Gloss Adjustment Layer The second gloss adjustment layer 6 partially covers the upper surface of the first gloss adjustment layer 5. The second gloss adjustment layer 6 and the first gloss adjustment layer 5 form a surface protection layer.

[0067] The second gloss adjustment layer 6 faces the pattern ink layer 4 with the first gloss adjustment layer 5 sandwiched therebetween. The second gloss adjustment layer 6 is identical in shape and position to the pattern ink layer 4.

[0068] In this example, the second gloss adjustment layer 6 completely matches the shape and position of the pattern ink layer 4, but other configurations may also be employed. For example, the orthogonal projection of the pattern ink layer 4 onto a plane perpendicular to the thickness direction may be at least partially spaced from and located inside the outline of the orthogonal projection of the second gloss adjustment layer 6 onto the plane.

[0069] In addition, here, the pattern ink layer 4 consists of a single printing pattern, but if the pattern ink layer 4 consists of multiple printing patterns of different colors, the second gloss adjustment layer 6 may match the shape and position of a combination of these printing patterns. Alternatively, in this case, the second gloss adjustment layer 6 may match the shape and position of one or a combination of two or more of these printing patterns, and the remaining printing patterns may be provided in positions that do not directly face the second gloss adjustment layer 6.

[0070] It is preferable that the orthogonal projection of the second gloss adjustment layer 6 onto a plane perpendicular to the thickness direction overlaps with the orthogonal projection onto the plane of one printed pattern or a combination of two or more printed patterns whose shape and position match those of the second gloss adjustment layer 6, for preferably 50% or more of its area, more preferably 70% or more, and even more preferably 90% or more.

[0071] The surface of the second gloss adjustment layer 6 is provided with a concave-convex structure. The concave-convex structure on the upper surface of the second gloss adjustment layer 6 has a ratio RSm / Ra of the average length RSm of the roughness curve elements to the arithmetic mean roughness Ra in the range of 10 to 600. The ratio RSm / Ra is preferably in the range of 10 to 500, and more preferably in the range of 50 to 450. When the ratio RSm / Ra is reduced, the pitch of the convex portions becomes smaller. As a result, it becomes difficult to wipe off dirt adhering to the surface of the decorative sheet 1, and the contamination resistance decreases. When the ratio RSm / Ra is increased, the pitch of the convex portions becomes larger, and the effect of the concave-convex structure in reducing the specular gloss GS(60°) of the second gloss adjustment layer 6 becomes smaller.

[0072] The ratio RSm / Ra is preferably equal to or greater than 80. Increasing the ratio RSm / Ra increases the pitch of the convex portions, improving the affinity of water or detergent (water containing a surfactant or alcohol) to the upper surface of the second gloss adjustment layer 6. If the decorative sheet 1 has a second gloss adjustment layer 6 with such surface properties, even if the surface becomes dirty, the dirt can be easily wiped off with water or detergent.

[0073] It is most preferable that the ratio RSm / Ra is equal to or greater than 100. If the ratio RSm / Ra is within this range, a commonly available cleaning sponge can be brought into contact with the boundaries of the convex portions and the areas in their vicinity on the upper surface of the second gloss adjustment layer 6. Therefore, even if the surface of the decorative sheet 1 becomes soiled, the dirt can be easily wiped off using a commonly available cleaning sponge.

[0074] Here, the arithmetic mean roughness Ra and the mean length RSm of the roughness curve elements are measured using a line roughness meter (in accordance with JIS B0601:2013).

[0075] The arithmetic mean roughness Ra is preferably in the range of 0.2 μm to 10.0 μm, more preferably in the range of 0.5 μm to 5.0 μm, and even more preferably in the range of 0.8 μm to 4.0 μm.

[0076] The average length RSm of the roughness curve elements is preferably in the range of 50 μm or more and 800 μm or less, more preferably in the range of 80 μm or more and 600 μm or less, and even more preferably in the range of 100 μm or more and 500 μm or less.

[0077] The uneven structure provided on the upper surface of the second gloss adjustment layer 6 serves to lower the specular gloss GS(60°) of the second gloss adjustment layer 6 compared to the specular gloss GS(60°) of the first gloss adjustment layer 5. The specular gloss GS(60°) of the second gloss adjustment layer 6 is preferably 10 or less, more preferably 7 or less, and even more preferably 5 or less. In one example, the specular gloss GS(60°) of the second gloss adjustment layer 6 is 0.5 or more.

[0078] The difference between the specular gloss GS(60°) of the first gloss adjustment layer 5 and the specular gloss GS(60°) of the second gloss adjustment layer 6 is preferably at least 1, more preferably at least 3, and even more preferably at least 5. According to one example, this difference is 20 or less.

[0079] As described above, an uneven structure is provided on the surface of the second gloss adjustment layer 6. Here, the uneven structure includes a plurality of ridge portions each protruding in a ridge-like shape on the surface of the second gloss adjustment layer 6. That is, as shown in Figures 2 and 4, the second gloss adjustment layer 6 includes a core portion 6A which is a thin layer having a flat upper surface, and a plurality of ridge portions 6B each protruding in a ridge-like shape from the upper surface of the core portion 6A.

[0080] In the present disclosure, the ridge portion 6B refers to, for example, the portion from the lowest part to the tip of the convex portion provided on the surface of the second gloss adjustment layer 6, and the core portion 6A refers to the portion of the second gloss adjustment layer 6 excluding the ridge portion 6B. Furthermore, the term "ridge-like" refers to a convex shape that extends linearly in a planar view.

[0081] The ridge portions 6B may be curved or linear in plan view, but are preferably curved as shown in Fig. 3 from the viewpoint of fingerprint resistance of the surface of the decorative sheet 1. The second gloss adjustment layer 6 having the ridge portions 6B can be formed, for example, as described below, by irradiating the surface of a coating film containing a second ionizing radiation curable resin with light of a specific wavelength, and causing the cured film formed on the surface of the coating film to expand in the in-plane direction.

[0082] The upper surface of the second gloss adjustment layer 6 may have a sine wave shape in a cross section parallel to the thickness direction and the arrangement direction of the ridge portions 6 B. Here, the “sine wave shape” refers to a shape in which the line from the lowest point C to the highest point D (vertex) of the ridge portions 6 B can be expressed as a sine wave, as shown in FIG.

[0083] The uneven structure of the second gloss adjustment layer 6 preferably has a protruding peak height Rpk of 0.5 μm or more and less than 3.5 μm. Here, "protruding peak height Rpk" is a surface quality parameter defined in JIS B0671-2:2002. This protruding peak height Rpk is more preferably 3.0 μm or less, and even more preferably 2.8 μm or less. Furthermore, this protruding peak height Rpk is more preferably 0.8 μm or more, and even more preferably 1.0 μm or more. Within this range, a decorative sheet with a uniform surface condition can be easily provided.

[0084] The thickness of the second gloss adjustment layer 6 is preferably in the range of 2 μm to 20 μm, more preferably in the range of 2 μm to 15 μm, and even more preferably in the range of 3 μm to 12 μm. If the thickness of the second gloss adjustment layer 6 is small, it is difficult to achieve the above-mentioned surface properties by the method described below while referring to the ratio RSm / Ra, etc. If the thickness of the second gloss adjustment layer 6 is large, the processability of the decorative sheet 1 decreases and it becomes more likely to whiten when folded.

[0085] Here, the thickness of the second gloss adjustment layer 6 is the thickness of a layer having the same apparent area and volume as the second gloss adjustment layer 6 and a flat surface. The thickness of the second gloss adjustment layer 6 is determined, for example, by the following method. First, a cross section parallel to the thickness direction of the second gloss adjustment layer 6 and perpendicular to the length direction of the ridge portion 6B is imaged. Next, from this cross-sectional image, the dimension of the second gloss adjustment layer 6 in the width direction of the ridge portion 6B and the area of ​​the cross section of the second gloss adjustment layer 6 are determined. The thickness of the second gloss adjustment layer 6 is a value obtained by dividing this area by the above dimension. Note that when the coating liquid for the second gloss adjustment layer described below does not contain a solvent, the thickness of the coating film made of this coating liquid is equal to the thickness of the second gloss adjustment layer 6.

[0086] Furthermore, it is preferable to set the thickness of the second gloss adjustment layer 6 so that the ratio of the thickness (or height) of the ridge portion 6B to the thickness of the core portion 6A (thickness of the ridge portion 6B / thickness of the core portion 6A) is within the range of 0.01 or more and 2.0 or less, and it is more preferable to set it so that it is within the range of 0.1 or more and 1.0 or less.

[0087] The second gloss adjustment layer 6 contains a cured resin. As described below, the second gloss adjustment layer 6 may further contain particles. When the mass of the second gloss adjustment layer 6 is taken as 100 parts by mass, the mass of the cured resin contained in the second gloss adjustment layer 6 is preferably 60 parts by mass or more, more preferably 70 parts by mass or more, and even more preferably 80 parts by mass or more.

[0088] The second gloss adjustment layer 6 contains a cured product of a second ionizing radiation curable resin as the cured resin. As described above, the ionizing radiation is a charged particle beam such as an electron beam. The second ionizing radiation curable resin is cured by irradiation with ionizing radiation. The second ionizing radiation curable resin can also be cured by irradiation with ultraviolet light. The second ionizing radiation curable resin used here is cured by irradiation with light having a wavelength of 200 nm or less, and has a large absorption coefficient for this light.

[0089] The second ionizing radiation curable resin may be any known resin, such as various monomers or commercially available oligomers, including (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, or epoxy resins. The second ionizing radiation curable resin may be either an aqueous resin or a non-aqueous (organic solvent-based) resin. The second ionizing radiation curable resin may be solvent-free.

[0090] The main component of the second ionizing radiation curable resin is preferably an acrylate, and the main component here means that the content is 60 parts by mass or more, more preferably 70 parts by mass or more, and most preferably 80 parts by mass or more per 100 parts by mass of the resin components constituting the second ionizing radiation curable resin.

[0091] The acrylate is preferably a bifunctional or higher acrylate, and more preferably a trifunctional or higher acrylate. In order to obtain a second gloss adjustment layer 6 having excellent scratch resistance, the acrylate is preferably a trifunctional or higher acrylate. There is no upper limit to the number of functional groups of the acrylate, but according to one example, it is hexafunctional or lower.

[0092] The acrylate preferably contains a repeating unit. This repeating unit is, for example, any one of an ethylene oxide (EO) unit, a propylene oxide (PO) unit, and an ε-caprolactone (CL) unit. The repeating unit is preferably ethylene oxide or propylene oxide. In the acrylate, the repeating unit may be present between the acryloyl group and the methylol group in an open ring state.

[0093] The number of repetitions of the repeating structure is preferably 3 or more. If an acrylate with a large number of repetitions is used, the cured film is more likely to expand in the in-plane direction during the second irradiation step described below, and therefore wrinkles corresponding to the ridge portions 6B are more likely to appear on the coating film surface. However, if the number of repetitions is increased, the crosslinking density decreases, and the scratch resistance of the surface protective layer decreases. Therefore, the number of repetitions is preferably 30 or less, and more preferably 20 or less.

[0094] The number of repetitions of the repeating structure can be analyzed using MALDI-TOF-MS. Ionizing radiation curable resins may have a molecular weight distribution. When a molecular weight distribution exists, the number of repetitions is determined to be the number of repetitions corresponding to the molecular weight having the strongest peak in the MALDI-TOF-MS mass spectrum.

[0095] In addition to the cured resin, the second gloss adjustment layer 6 may further contain particles. Examples of the particles contained in the second gloss adjustment layer 6 include particles made of organic materials such as polyethylene (PE) wax, polypropylene (PP) wax, and resin beads, and particles made of inorganic materials such as silica, glass, alumina, titania, zirconia, calcium carbonate, and barium sulfate.

[0096] The average particle size (D50) of the particles is preferably 10 μm or less, more preferably 1 μm to 8 μm, even more preferably 2 μm to 7 μm, and most preferably 3 μm to 6 μm. Increasing the average particle size (D50) of the particles can lead to particles easily falling off the second gloss adjustment layer 6, making it difficult to achieve high scratch resistance. Small particles reduce the effect of uniformly forming wrinkles. Here, "average particle size" or "average particle size (D50)" refers to the median diameter (D50) measured using a laser diffraction / scattering particle size distribution analyzer. If the second gloss adjustment layer coating liquid contains particles, the second gloss adjustment layer 6 obtained from this coating liquid will also contain particles. The average particle size of the particles contained in the second gloss adjustment layer 6 can be determined by observing the cross section of the layer and averaging the particle sizes of multiple particles. The value thus obtained is substantially the same as the median diameter (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 size of the particles contained in the second gloss control layer.

[0097] The amount of particles in the second gloss adjustment layer 6 is preferably in the range of 0.5 parts by mass or more and 10 parts by mass or less, more preferably in the range of 2 parts by mass or more and 8 parts by mass or less, and most preferably in the range of 2 parts by mass or more and 6 parts by mass or less, per 100 parts by mass of the cured resin.

[0098] When the amount of particles added is within the above range, the effect of generating wrinkles uniformly is particularly large. If the amount of particles added is too large, the particles are likely to fall off from the second gloss adjustment layer 6, which may make it difficult to achieve high scratch resistance.

[0099] <2> Manufacturing Method of Decorative Sheet The decorative sheet 1 is manufactured, for example, by the following method: First, a solid ink layer 3 is formed on one surface of the base layer 2. The solid ink layer 3 can be formed by various printing methods, such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing, or various coating methods, such as roll coating, knife coating, microgravure coating, and die coating.

[0100] Next, a pattern ink layer 4 is formed on the solid ink layer 3. The pattern ink layer 4 can be formed by various printing methods, such as gravure printing, offset printing, screen printing, electrostatic printing, inkjet printing, etc. Among these, gravure printing is preferred because it allows for relatively high speed printing and is advantageous in terms of cost.

[0101] Next, a first coating film made of a coating liquid for the first gloss adjustment layer is formed on the above surface of the base layer 2 so as to cover the solid ink layer 3 and the pattern ink layer 4. This first coating film can be formed by various printing methods such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing, or various coating methods such as roll coating, knife coating, microgravure coating, and die coating.

[0102] The coating liquid for the first gloss adjustment layer contains the first ionizing radiation curable resin described above. The coating liquid for the first gloss adjustment layer may further contain other components, such as the particles, thermosetting resin, solvent, and additives for improving the functionality of the final product, such as one or more of an antibacterial agent and an antifungal agent. The coating liquid for the first gloss adjustment layer may further contain other additives such as an ultraviolet absorber and a light stabilizer. Examples of the ultraviolet absorber that can be used include benzotriazole-based, benzoate-based, benzophenone-based, and triazine-based stabilizers. Examples of the light stabilizer that can be used include hindered amine-based stabilizers.

[0103] When the coating liquid for the first gloss adjustment layer contains a dispersion or emulsion, the first coating film is dried. The first coating film can be dried, for example, by heating. This heating is preferably performed at a temperature in the range of 100°C or higher and 140°C or lower, and more preferably at a temperature in the range of 100°C or higher and 120°C or lower. Note that when the coating liquid for the first gloss adjustment layer contains a thermosetting resin, at least a portion of the thermosetting resin can be cured by this heating.

[0104] Next, a first irradiation step is carried out. In the first irradiation step, the first coating film is irradiated with a first radiation to cure the first coating film. The first irradiation step may be carried out so that the first coating film is completely cured, or so that the first coating film is incompletely cured.

[0105] The first radiation is, for example, ionizing radiation. As described above, the ionizing radiation is a charged particle beam such as an electron beam. The first radiation may be ultraviolet light, for which the first ionizing radiation curable resin exhibits a small absorption coefficient. The wavelength of the ultraviolet light irradiated onto the first coating film is preferably greater than 200 nm, more preferably in the range of 230 nm to 450 nm, and even more preferably in the range of 250 nm to 400 nm.

[0106] Irradiating the first coating film with ionizing radiation or ultraviolet light allows the first coating film to be cured substantially uniformly throughout its entire thickness. Therefore, unlike the second coating film described below, the first coating film after the first irradiation step does not have any irregularities on its surface.

[0107] The minimum integrated amount of light required to completely cure the first coating film is, for example, 10 mJ / cm ２ More than 1000mJ / cm ２ The minimum absorbed dose required to completely cure the first coating is, for example, in the range of 5 kGy to 200 kGy.

[0108] When the coating liquid for the first gloss adjustment layer contains a thermosetting resin, the first coating film may be heated following the first irradiation step to cause a crosslinking reaction of the thermosetting resin. This heating is preferably performed at a temperature in the range of 80° C. to 140° C., more preferably at a temperature in the range of 100° C. to 120° C. Even when the coating liquid for the first gloss adjustment layer contains a thermosetting resin, the first coating film does not need to be heated immediately after the first irradiation step.

[0109] The first irradiation step may be omitted. For example, if the coating liquid for the first gloss adjustment layer loses its fluidity when dried or heated, the first irradiation step can be omitted.

[0110] Next, a second coating film made of the coating liquid for the second gloss control layer is formed on the first coating film. The second coating film is formed so as to partially cover the upper surface of the first coating film. Specifically, the second coating film is formed so as to face the pattern ink layer 4 with the first coating film sandwiched therebetween. The second coating film can be formed by various printing methods, such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing. Of these, gravure printing is preferred.

[0111] The coating liquid for the second gloss adjusting layer contains the second ionizing radiation curable resin described above. As described above, the second ionizing radiation curable resin is, for example, an acrylate.

[0112] The coating liquid for the second gloss adjustment layer may further contain other components, such as the above-mentioned particles, solvents, and additives for improving the functionality of the final product, such as one or more antibacterial agents and antifungal agents. The coating liquid for the second gloss adjustment layer may further contain other additives such as an ultraviolet absorber and a light stabilizer. Examples of the ultraviolet absorber that can be used include benzotriazole-based, benzoate-based, benzophenone-based, and triazine-based stabilizers. Examples of the light stabilizer that can be used include hindered amine-based stabilizers.

[0113] Next, the second and third irradiation steps described below are carried out in sequence.

[0114] In the second irradiation step, the second coating film is irradiated with second radiation, which is light having a wavelength of 200 nm or less.

[0115] The second ionizing radiation-curable resin contained in the coating liquid for the second gloss-controlling layer has a large absorption coefficient for the second radiation. Therefore, the second radiation incident on the second coating film can only reach a position several tens to several hundreds of nanometers from the outermost surface. Therefore, in the second irradiation step, the crosslinking reaction proceeds in the surface region of the second coating film, forming an extremely thin cured film, while the crosslinking reaction does not proceed in other regions, leaving the other regions uncured.

[0116] The second coating film after the second irradiation step has wrinkles on its surface corresponding to the ridge portions 6 B. The inventors believe that the reason why wrinkles are formed on the coating film surface by the second irradiation step is as follows.

[0117] As described above, the second radiation can only reach a position tens to hundreds of nanometers away from the outermost surface of the second coating film. That is, the crosslinking reaction of the second ionizing radiation-curable resin occurs only on the surface of the second coating film, and regions more than tens to hundreds of nanometers away from the outermost surface are uncured and contain highly fluid molecules. These highly fluid molecules swell the cured film, thereby increasing its volume. The increase in volume in the in-plane direction causes the cured film to buckle, resulting in wrinkles on the surface of the second coating film.

[0118] The second radiation can be extracted from excimer VUV (Vacuum Ultra Violet) light. Excimer VUV light can be generated from a lamp using a rare gas or a rare gas halide compound. When high-energy electrons are externally applied to a lamp filled with a rare gas or a rare gas halide compound, a large number of discharge plasmas (dielectric barrier discharges) are generated. This plasma discharge excites atoms of the discharge gas (rare gas), which momentarily transition to an excimer state. When returning from this excimer state to the ground state, light is emitted in a wavelength range specific to that excimer.

[0119] The gas used in the excimer lamp may be any conventional gas that emits light of 200 nm or less. Examples of the gas include rare gases such as Xe, Ar, and Kr, and mixtures of rare gases such as ArBr and ArF with halogen gases. The wavelength (center wavelength) of excimer lamps varies depending on the gas, and examples include wavelengths of approximately 172 nm (Xe), approximately 126 nm (Ar), approximately 146 nm (Kr), approximately 165 nm (ArBr), and approximately 193 nm (ArF).

[0120] 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.

[0121] The second irradiation step is carried out in an atmosphere with a low oxygen concentration. Oxygen has a high absorption coefficient for light of 200 nm or less. Therefore, the second irradiation step is preferably carried out in, for example, a nitrogen gas atmosphere. The oxygen concentration in the gas phase in the second irradiation step, i.e., the residual oxygen concentration in the reaction atmosphere, is preferably 2000 ppm or less, and more preferably 1000 ppm or less.

[0122] Furthermore, oxygen in the atmosphere inhibits radical polymerization. Therefore, the residual oxygen concentration in the reaction atmosphere affects the formation of wrinkles on the surface of the second coating film. Therefore, changing the residual oxygen concentration in the reaction atmosphere can also change the surface properties of the second gloss control layer 6.

[0123] The cumulative amount of the second radiation is 0.5 mJ / cm ２ More than 200mJ / cm ２ It is preferable to set the concentration within the range of 1 mJ / cm ２ More than 100mJ / cm ２ It is more preferable to set it within the range of 3 mJ / cm ２ More than 50mJ / cm ２ It is more preferable to set it within the range of 5 mJ / cm ２ 30mJ / cm or more ２It is most preferable to set the integrated light dose within the following range: If the integrated light dose is small, the expansion of the cured film in the in-plane direction will be small, whereas if the integrated light dose is large, the surface condition of the second coating film will deteriorate.

[0124] In the third irradiation step, the second coating film is irradiated with third radiation. The third radiation is ionizing radiation or ultraviolet light having a longer wavelength than the light irradiated in the second irradiation step. The third radiation can be any of the radiations described above for the first radiation.

[0125] In the third irradiation step, the crosslinking reaction proceeds throughout the entire thickness of the second coating film. If the first coating film is not completely cured at the time the third irradiation step is started, the crosslinking reaction may also proceed throughout the entire thickness of the first coating film.

[0126] The cumulative light amount of the third radiation is 10 mJ / cm ２ More than 500mJ / cm ２ It is preferable to set the dose within the range of 50 mJ / cm ２ More than 400mJ / cm ２ It is more preferable to set it within the range of 100 mJ / cm ２ More than 300mJ / cm ２ It is more preferable to set it within the following range.

[0127] The irradiation of the third radiation is preferably carried out so that the absorbed dose is in the range of 5 kGy or more and 200 kGy or less, more preferably in the range of 10 kGy or more and 150 kGy or less, and even more preferably in the range of 15 kGy or more and 100 kGy or less.

[0128] In the third irradiation step, if a layer having sufficient strength cannot be obtained by irradiation with only one type of radiation, the type of third radiation may be changed. For example, irradiation with ionizing radiation may be performed first, followed by irradiation with ultraviolet light having a longer wavelength than the light irradiated in the second irradiation step. Alternatively, irradiation with ultraviolet light having a longer wavelength than the light irradiated in the second irradiation step may be performed first, followed by irradiation with ionizing radiation. Alternatively, irradiation with ultraviolet light having a longer wavelength than the light irradiated in the second irradiation step may be performed first, followed by irradiation with ultraviolet light having an even longer wavelength.

[0129] When the coating liquid for the first gloss adjustment layer contains a thermosetting resin and the crosslinking reaction of the thermosetting resin has not progressed sufficiently at the time of starting the second irradiation step, the first coating film may be heated between the second irradiation step and the third irradiation step, or may be heated after the third irradiation step. This heating may be performed, for example, under the same conditions as those described above for the heating performed subsequent to the first irradiation step.

[0130] In this manner, a decorative sheet 1 is obtained. In the decorative sheet 1 obtained by the above method, there is no interface between the core portion 6A and the rib portion 6B, and they are integrally formed.

[0131] <3> Effect The decorative sheet 1 includes a first gloss adjustment layer 5 and a second gloss adjustment layer 6 that partially covers the first gloss adjustment layer 5. The second gloss adjustment layer 6 has an uneven structure on its upper surface with a small ratio RSm / Ra of the average length RSm of the roughness curve elements to the arithmetic mean roughness Ra. The uneven structure with a small ratio RSm / Ra serves to lower the specular gloss GS(60°) of the second gloss adjustment layer 6 compared to the specular gloss GS(60°) of the first gloss adjustment layer 5. Therefore, such a structure can contribute to the expression of a three-dimensional effect similar to unevenness.

[0132] Furthermore, in the decorative sheet 1, the second gloss control layer 6 is identical in shape and position to the pattern ink layer 4. Therefore, the decorative sheet 1 can express a three-dimensional effect with raised portions in the areas corresponding to the pattern ink layer 4 and recessed portions in the other areas. Therefore, by appropriately selecting the color of the solid ink layer 3 and the color of the pattern ink layer 4, this decorative sheet 1 can express a luxurious design that resembles, for example, natural wood or natural stone.

[0133] Furthermore, the above-mentioned uneven structure provided on the upper surface of the second gloss adjustment layer 6 has a sufficiently large ratio RSm / Ra. Because the second gloss adjustment layer 6 of the decorative sheet 1 has such surface properties, even if the surface becomes dirty, the dirt can be easily wiped off with water or a detergent. In other words, the decorative sheet 1 has excellent contamination resistance.

[0134] Furthermore, in the decorative sheet 1, the first gloss adjustment layer 5 contains a cured product of a first ionizing radiation curable resin, and the second gloss adjustment layer 6 contains a cured product of a second ionizing radiation curable resin. Cured products of ionizing radiation curable resins contribute more to heat resistance than cured products of thermosetting resins. Furthermore, cured products of ionizing radiation curable resins have a sufficiently high crosslink density, which can contribute to achieving high scratch resistance. Therefore, the decorative sheet 1 has excellent heat resistance and scratch resistance.

[0135] Furthermore, the uneven structure including the ridge portions 6B formed on the upper surface of the second gloss adjustment layer 6 by the above-described method is finer than an uneven structure formed by mechanical processing such as embossing. Because the decorative sheet 1 has such a fine uneven structure on the upper surface of the second gloss adjustment layer 6, it has a matte finish and excellent fingerprint resistance.

[0136] Furthermore, the above-mentioned uneven structure consisting of a plurality of ridge-like protrusions, each having a shape corresponding to a portion of a particle and consisting of a plurality of randomly arranged protrusions, is superior in terms of the uniformity of the arrangement of the protrusions, i.e., the uniformity of the surface condition when observed with the naked eye. Therefore, the decorative sheet 1 is also superior in terms of design in this respect.

[0137] <4> Modifications The decorative sheet 1 can be modified in various ways.

[0138] For example, the second gloss adjustment layer 6 may be the same in shape and position as the portion of the solid ink layer 3 that is not covered by the pattern ink layer 4. The decorative sheet 1 deformed in this way can express a three-dimensional effect with the portions corresponding to the pattern ink layer 4 as recesses and the other portions as protrusions, creating a relief-like three-dimensional effect.

[0139] In the decorative sheet 1 described above, the convex portions provided on the upper surface of the second gloss adjustment layer 6 are ridge-shaped. These convex portions do not have to be ridge-shaped. For example, each of these convex portions may be part of a particle.

[0140] In the decorative sheet 1 described above, the area of ​​the upper surface of the first gloss adjustment layer 5 that is not covered by the second gloss adjustment layer 6 is flat. A concave-convex structure may be provided in this area. This concave-convex structure may be a structure similar to that described above for the ridge portion 6B, or may be a structure in which a plurality of convex portions, each consisting of a portion of a particle, are arranged. When a concave-convex structure is provided in the area of ​​the upper surface of the first gloss adjustment layer 5 that is not covered by the second gloss adjustment layer 6, it is preferable that the ratio RSm / Ra of this concave-convex structure be larger than the ratio RSm / Ra of the concave-convex structure provided on the upper surface of the second gloss adjustment layer 6.

[0141] Examples of the present invention will be described below. Note that the "particle size" described below is the above-mentioned "average particle size (D50)".

[0142] <Example 1> The decorative sheet 1 described with reference to Figs. 1 to 4 was produced by the following method. ２ Impregnated paper (GFR-506, manufactured by Kohjin Co., Ltd.) was prepared as the raw fabric layer 2. On one side of the raw fabric layer 2, a solid ink layer 3 and a pattern ink layer 4 were formed in this order using oil-based nitrocellulose resin gravure printing ink (PCNT (PCRNT) various colors, manufactured by Toyo Ink Co., Ltd.). The pattern of the pattern ink layer 4 was a wood grain pattern.

[0143] Next, a coating liquid for a first gloss adjustment layer having the following composition was applied onto the solid ink layer 3 and the pattern ink layer 4. The coating liquid for the first gloss adjustment layer was applied so that the thickness of the first gloss adjustment layer 5 would be 5 μm. The first coating film made of the coating liquid for the first gloss adjustment layer was heated to 100° C. and dried.

[0144] (Coating liquid for first gloss adjustment layer) Ionizing radiation curable resin Type: Water-based UV curable resin Product name: Shiko (registered trademark) UV-W300 (manufactured by Mitsubishi Chemical Corporation)

[0145] Subsequently, a coating liquid for a second gloss adjustment layer having the following composition was printed on the portion of the first coating film corresponding to the pattern ink layer 4. The coating liquid for the second gloss adjustment layer was printed so that the thickness of the second gloss adjustment layer 6 would be 5 μm.

[0146] (Coating liquid for second gloss adjusting layer) Ionizing radiation curable resin Type: trimethylolpropane EO modified triacrylate (EO 6 moles added) Product name: Miramer M3160 (manufactured by Miwon) Blending amount: 100 parts by mass Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blending amount: 0.5 parts by mass

[0147] Next, the second irradiation step was carried out. Specifically, under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 100 ppm, ultraviolet light having a wavelength of 172 nm was irradiated onto the surfaces of the first coating film and the second coating film made of the coating liquid for the second gloss control layer using a Xe excimer lamp at an integrated light intensity of 50 mJ / cm. ２ This caused wrinkles to form on the surface of the second coating film.

[0148] Subsequently, the third irradiation step was carried out. Specifically, the first and second coating films were irradiated with 30 kGy of ionizing radiation to completely cure them as a whole, thereby forming the first gloss adjustment layer 5 and the second gloss adjustment layer 6. In this manner, the decorative sheet 1 was obtained.

[0149] <Example 2> The decorative sheet 1 described with reference to Figures 1 to 4 was produced in the same manner as in Example 1, except that the composition of the coating liquid for the first gloss adjustment layer was changed as follows, and the first coating film was heated to 120°C after the third irradiation step to completely cure.

[0150] (Coating liquid for first gloss adjustment layer) Ionizing radiation curable resin Type: Water-based UV curable resin Product name: Shiko (registered trademark) UV-W300 (manufactured by Mitsubishi Chemical Corporation) Blend: 80 parts by mass (solid content) Thermosetting resin Type: Water-based thermosetting resin (polycarbonate type) Product name: Takelac (registered trademark) WS-5100 (manufactured by Mitsui Chemicals, Inc.) Blend: 20 parts by mass (solid content)

[0151] <Example 3> The decorative sheet 1 described with reference to Figures 1 to 4 was produced in the same manner as in Example 2, except that in the coating liquid for the first gloss adjustment layer, the blending amount of the ionizing radiation curable resin was 50 parts by mass and the blending amount of the thermosetting resin was 50 parts by mass.

[0152] <Example 4> The decorative sheet 1 described with reference to Figures 1 to 4 was produced in the same manner as in Example 2, except that in the coating liquid for the first gloss adjustment layer, the blending amount of the ionizing radiation curable resin was 20 parts by mass and the blending amount of the thermosetting resin was 80 parts by mass, based on the solid content.

[0153] <Example 5> A decorative sheet 1 was produced in the same manner as in Example 2, with reference to Figures 1 to 4, except that in the coating liquid for the first gloss adjustment layer, the ionizing radiation curable resin was blended in an amount of 10 parts by mass and the thermosetting resin was blended in an amount of 90 parts by mass, based on the solid content.

[0154] Example 6 The decorative sheet 1 described with reference to FIGS. 1 to 4 was produced in the same manner as in Example 2, except that the composition of the coating liquid for the first gloss control layer was changed as follows.

[0155] (Coating liquid for first gloss adjustment layer) Ionizing radiation curable resin Type: Water-based UV curable resin Product name: Shiko (registered trademark) UV-W300 (manufactured by Mitsubishi Chemical Corporation) Blend: 50 parts by mass (solid content) Thermosetting resin Type: Water-based thermosetting resin (polyester-based) Product name: Takelac (registered trademark) WS-4022 (manufactured by Mitsui Chemicals, Inc.) Blend: 50 parts by mass (solid content)

[0156] Example 7 The decorative sheet 1 described with reference to FIGS. 1 to 4 was produced in the same manner as in Example 2, except that the composition of the coating liquid for the first gloss control layer was changed as follows.

[0157] (Coating liquid for first gloss adjustment layer) Ionizing radiation curable resin Type: Water-based UV curable resin Product name: UW-9102 (manufactured by UBE) Blend amount: 50 parts by mass (solid content) Thermosetting resin Type: Water-based thermosetting resin (polyester-based) Product name: Takelac (registered trademark) WS-4022 (manufactured by Mitsui Chemicals, Inc.) Blend amount: 50 parts by mass (solid content)

[0158] Example 8 The decorative sheet 1 described with reference to Figures 1 to 4 was produced in the same manner as in Example 2, except for the following points. That is, in this example, the blending amount of the ionizing radiation curable resin and the blending amount of the thermosetting resin were set to 50 parts by mass, based on solids, in the coating liquid for the first gloss adjustment layer. In addition, the composition of the coating liquid for the second gloss adjustment layer was changed as follows. The coating liquid for the second gloss adjustment layer was printed so that the thickness of the second gloss adjustment layer 6 was 20 μm.

[0159] (Coating liquid for second gloss adjustment layer) Ionizing radiation curable resin Type: Trimethylolpropane EO modified triacrylate (EO 30 moles added) Product name: NAM-AT30E (manufactured by Nagase America) Blend: 100 parts by weight Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend: 0.5 parts by weight

[0160] 1 to 4 was produced in the same manner as in Example 2, except for the following points. That is, in this example, the ionizing radiation curable resin and the thermosetting resin were blended in an amount of 50 parts by mass and 50 parts by mass, respectively, on a solids basis in the coating liquid for the first gloss adjustment layer. The coating liquid for the second gloss adjustment layer was then printed so that the thickness of the second gloss adjustment layer 6 would be 3 μm.

[0161] 1 to 4 was produced in the same manner as in Example 2, except for the following points. That is, in this example, the blending amount of the ionizing radiation curable resin and the blending amount of the thermosetting resin were set to 50 parts by mass, based on solids, in the coating liquid for the first gloss adjustment layer. The coating liquid for the first gloss adjustment layer was printed so that the thickness of the first gloss adjustment layer 5 would be 1.5 μm.

[0162] 1 to 4 was produced in the same manner as in Example 2, except for the following points. That is, in this example, the blending amount of the ionizing radiation curable resin and the blending amount of the thermosetting resin in the coating liquid for the first gloss adjustment layer were 50 parts by mass and 50 parts by mass, respectively, on a solids basis. The coating liquid for the first gloss adjustment layer was then printed so that the thickness of the first gloss adjustment layer 5 would be 22 μm.

[0163] 1 to 4 was produced in the same manner as in Example 2, except for the following points. That is, in this example, the blending amount of the ionizing radiation curable resin and the blending amount of the thermosetting resin were set to 50 parts by mass and 50 parts by mass, respectively, on a solids basis in the coating liquid for the first gloss adjustment layer. In addition, the composition of the coating liquid for the second gloss adjustment layer was changed as follows:

[0164] (Coating liquid for second gloss adjustment layer) Ionizing radiation curable resin Type: Trimethylolpropane PO modified triacrylate (PO 6 moles added) Product name: NMA-TMPT6PO (manufactured by Nagase America) Blend: 100 parts by weight Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend: 0.5 parts by weight

[0165] 1 to 4 was produced in the same manner as in Example 2, except for the following points. That is, in this example, the blending amount of the ionizing radiation curable resin and the blending amount of the thermosetting resin were set to 50 parts by mass and 50 parts by mass, respectively, on a solids basis in the coating liquid for the first gloss adjustment layer. In addition, the composition of the coating liquid for the second gloss adjustment layer was changed as follows:

[0166] (Coating liquid for second gloss adjusting layer) Ionizing radiation curable resin Type: trimethylolpropane EO modified triacrylate (EO 6 moles added) Product name: Miramer M3160 (manufactured by Miwon) Blending amount: 100 parts by mass Particles Product name: Sylysia 470 (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 14 μm Blending amount: 0.5 parts by mass

[0167] 1 to 4 was produced in the same manner as in Example 2, except for the following: In this example, the ionizing radiation curable resin and the thermosetting resin were blended in an amount of 50 parts by mass and 50 parts by mass, respectively, on a solids basis in the coating liquid for the first gloss control layer.

[0168] The composition of the coating liquid for the second gloss adjustment layer was changed as follows: The coating liquid for the second gloss adjustment layer was printed so that the thickness of the second gloss adjustment layer 6 was 2 μm.

[0169] (Coating liquid for second gloss adjusting layer) Ionizing radiation curable resin Type: trimethylolpropane EO modified triacrylate (EO 3 moles added) Product name: Miramer M3130 (manufactured by Miwon) Blending amount: 100 parts by mass Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blending amount: 0.5 parts by mass

[0170] Comparative Example 1 A decorative sheet was produced in the same manner as in Example 1, except for the following: In this example, the composition of the coating liquid for the second gloss control layer was changed as follows:

[0171] (Coating liquid for second gloss adjusting layer) Ionizing radiation curable resin Type: trimethylolpropane EO modified triacrylate (EO 6 moles added) Product name: Miramer M3160 (manufactured by Miwon) Blending amount: 100 parts by mass Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blending amount: 20 parts by mass

[0172] Comparative Example 2 A decorative sheet similar to that described with reference to Figures 1 to 4 was produced in the same manner as in Example 2, except for the following points: In this example, the composition of the coating liquid for the first gloss adjustment layer was changed as follows, and the first irradiation step was omitted.

[0173] (Coating liquid for first gloss adjustment layer) Thermosetting resin Type: Water-based thermosetting resin (polycarbonate type) Product name: Takelac (registered trademark) WS-5100 (manufactured by Mitsui Chemicals, Inc.)

[0174] 1 to 4 was produced in the same manner as in Example 2, except for the following points: In this example, the ionizing radiation curable resin and the thermosetting resin were blended in an amount of 50 parts by mass and 50 parts by mass, respectively, on a solids basis in the coating liquid for the first gloss adjusting layer.

[0175] The composition of the coating liquid for the second gloss adjustment layer was changed as follows: The coating liquid for the second gloss adjustment layer was printed so that the thickness of the second gloss adjustment layer 6 was 20 μm.

[0176] (Coating liquid for second gloss adjustment layer) Ionizing radiation curable resin Type: Trimethylolpropane EO modified triacrylate (EO 35 moles added) Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Co., Ltd.) Blending amount: 100 parts by weight Particles Product name: Silysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blending amount: 0.5 parts by weight

[0177] 1 to 4 was produced in the same manner as in Example 2, except for the following points: In this example, the ionizing radiation curable resin and the thermosetting resin were blended in an amount of 50 parts by mass and 50 parts by mass, respectively, on a solids basis in the coating liquid for the first gloss control layer.

[0178] The composition of the coating liquid for the second gloss adjustment layer was changed as follows: The coating liquid for the second gloss adjustment layer was printed so that the thickness of the second gloss adjustment layer 6 was 1 μm.

[0179] (Coating liquid for second gloss adjusting layer) Ionizing radiation curable resin Type: trimethylolpropane EO modified triacrylate (EO 3 moles added) Product name: Miramer M3130 (manufactured by Miwon) Blending amount: 100 parts by mass Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blending amount: 0.5 parts by mass

[0180] <Evaluation> Each of the decorative sheets described above was evaluated as follows: Those rated "AAA", "AA" or "A" were deemed to pass, as they presented no problems in actual use.

[0181] (1) Thickness of the Gloss Adjustment Layer The thickness of the second gloss adjustment layer was measured using the same method as described above. Specifically, the decorative sheet was embedded in a resin such as a cold-setting epoxy resin or a UV-curable resin, and the resin was allowed to fully harden. Next, the decorative sheet was cut so that the cross section of the decorative sheet was exposed, and mechanical polishing was performed to obtain a measurement surface.

[0182] Subsequently, a cross section of the second gloss adjustment layer was imaged using a scanning electron microscope SIGMA 500 manufactured by Carl Zeiss Microscopy. During this imaging, the acceleration voltage was set to 0.5 keV (low acceleration voltage), the imaging mode was set to SE2 mode, and the magnification was set to 2000x. Note that no sputtering was performed on the measurement sample.

[0183] Next, from this cross-sectional image, the dimension of the second gloss adjustment layer in the width direction of the ridge portion and the area of ​​the cross section of the second gloss adjustment layer were calculated. The thickness of the second gloss adjustment layer was calculated by dividing this area by the above dimension. The thickness of the first gloss adjustment layer was also measured by the same method as above.

[0184] (2) Glossiness Regarding glossiness, the specular glossiness GS(60°) was measured using a micro-gloss 60°xs (manufactured by BYK Corporation). The "60° glossiness value" in the following Tables 1 to 3 represents this specular glossiness GS(60°).

[0185] (3) Design Each decorative sheet was observed with the naked eye, and the design was evaluated according to the following criteria: AA: The surface condition is uniform. A: The surface condition is generally uniform. B: The surface condition is non-uniform.

[0186] (4) Scratch Resistance Each decorative sheet was attached to wood substrate B using a urethane adhesive. A steel wool rubbing test was then conducted to evaluate scratch resistance. Specifically, the decorative sheet was rubbed back and forth 20 times with steel wool while applying a load of 100 g, and the occurrence of scratches on the surface of the decorative sheet and any changes in gloss were visually confirmed.

[0187] The evaluation criteria were as follows: AAA: No scratches or changes in gloss occurred on the surface. AA: Minor scratches or changes in gloss occurred on a part of the surface. A: Minor scratches or changes in gloss occurred on the surface. B: Significant scratches or changes in gloss occurred on the surface.

[0188] (5) Stain Resistance To evaluate stain resistance, the Stain A test specified in the Japanese Agricultural Standards (JAS) was carried out. That is, 10 mm wide lines were drawn on the surface protective layer of each decorative sheet using blue ink, black quick-drying ink, and red crayon, and the sheets were left for 4 hours. Thereafter, the blue ink, black quick-drying ink, and red crayon lines were wiped off with a cloth soaked in ethanol.

[0189] The evaluation criteria were as follows: AA: Lines of each color could be easily wiped off. A: Part of the lines of each color could be wiped off, but some stains remained. B: Lines of each color could not be wiped off.

[0190] (6) Heat Resistance An iron plate, a decorative sheet, and another iron plate were stacked in this order and pressed at a temperature of 100°C and a pressure of 100 MPa for 20 seconds, after which the peelability between the iron plate and the surface of the decorative sheet was confirmed. If the heat resistance of the surface layer of the decorative sheet is low, the resin softens and adheres to the iron plate.

[0191] The evaluation criteria were as follows: AAA: The iron plate and the sheet surface were not bonded and peeled off. AA: The iron plate and the sheet surface were bonded, but peeled off with a very light force. A: The iron plate and the sheet surface were bonded, but peeled off with a light force. B: The iron plate and the sheet surface were bonded, and could not be peeled off without causing breakage of the sheet or the like.

[0192] The evaluation results are shown in Tables 1 to 3. In Tables 1 to 3, "RA" represents Shikoh (registered trademark) UV-W300 (manufactured by Mitsubishi Chemical Corporation), which is an aqueous UV-curable resin. "RB" represents Takelac (registered trademark) WS-5100 (manufactured by Mitsui Chemicals, Inc.), which is an aqueous thermosetting resin (polycarbonate-based). "RC" represents UW-9102 (manufactured by UBE), which is an aqueous UV-curable resin. "RD" represents Takelac (registered trademark) WS-4022 (manufactured by Mitsui Chemicals, Inc.), which is an aqueous thermosetting resin (polyester-based).

[0193]

[0194]

[0195]

[0196] As shown in Tables 1 and 2, the decorative sheets according to Examples 1 to 14 exhibited sufficient performance in all of design, stain resistance, scratch resistance, and heat resistance. In contrast, as shown in Table 3, the sheet according to Comparative Example 1 exhibited insufficient performance in design and scratch resistance. Furthermore, the decorative sheet according to Comparative Example 2 exhibited insufficient performance in heat resistance. The decorative sheet according to Comparative Example 3 exhibited insufficient stain resistance. The decorative sheet according to Comparative Example 4 exhibited insufficient design.

[0197] 1...decorative sheet, 2...raw fabric layer, 3...solid ink layer, 4...pattern ink layer, 5...first gloss adjustment layer, 6...second gloss adjustment layer, 6A...core portion, 6B...ridge portion, 11...decorative material, B...base material, C...position, D...position.

Claims

1. A decorative sheet comprising an original fabric layer and a surface protective layer, wherein the surface protective layer is provided on the original fabric layer, a first gloss adjustment layer comprising a cured product of a first ionizing radiation curable resin, and a second gloss adjustment layer partially covering an upper surface of the first gloss adjustment layer, comprising a cured product of a second ionizing radiation curable resin, and having an unevenness structure on its upper surface, in which the ratio RSm / Ra of the average length RSm of the roughness curve elements to the arithmetic mean roughness Ra is in the range of 10 or more and 600 or less, and the unevenness structure comprises a plurality of ridge-like portions each protruding in a ridge-like shape.

2. The decorative sheet according to claim 1, wherein the cured product of the first ionizing radiation curable resin contains one or more bonds selected from the group consisting of urethane bonds, carbonate bonds, and amide bonds.

3. The decorative sheet according to claim 1 or 2, wherein the first gloss adjustment layer further contains a cured product of a thermosetting resin.

4. A decorative sheet as described in claim 3, wherein the proportion of the solid content of the thermosetting resin in the total of the solid content of the first ionizing radiation curable resin and the solid content of the thermosetting resin is 90 mass % or less.

5. The decorative sheet according to claim 3 or 4, wherein the cured product of the thermosetting resin contains one or more bonds selected from the group consisting of urethane bonds, carbonate bonds, and amide bonds.

6. The decorative sheet according to any one of claims 3 to 5, wherein said thermosetting resin contains at least one of a water-based urethane dispersion, a water-based epoxy dispersion, and a water-based polyamine dispersion.

7. A decorative sheet as claimed in any one of claims 3 to 6, wherein the first ionizing radiation curable resin is an aqueous dispersion or emulsion containing at least one of a urethane acrylate and a polyurethane resin, the thermosetting resin is an aqueous dispersion containing a polyurethane resin, and the polyurethane resin contained in the thermosetting resin contains a reaction product of a polyisocyanate and a polyol containing at least one of a polyester polyol and a polycarbonate polyol.

8. A decorative sheet according to any one of claims 1 to 7, wherein the thickness of each of the first gloss adjustment layer and the second gloss adjustment layer is within the range of 2 µm to 20 µm.

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

10. The decorative sheet according to claim 9, wherein the repeating structure is repeated three or more times.

11. A decorative sheet according to any one of claims 1 to 10, wherein said second gloss control layer further contains particles having an average particle size of 10 μm or less.

12. The decorative sheet according to claim 11, wherein the mass of the particles is in the range of 0.5 parts by mass or more and 20 parts by mass, when the mass of the second ionizing radiation curable resin is taken as 100 parts by mass.

13. A decorative material comprising: a decorative sheet according to any one of claims 1 to 12; and a substrate to which the decorative sheet is attached.

14. A method for manufacturing a decorative sheet comprising: forming a first gloss adjustment layer containing a cured product of a first ionizing radiation curable resin on an original layer; and forming a second gloss adjustment layer partially covering the upper surface of the first gloss adjustment layer, containing a cured product of a second ionizing radiation curable resin, and having an uneven structure on its upper surface where the ratio RSm / Ra of the average length RSm of the roughness curve elements to the arithmetic mean roughness Ra is in the range of 10 or more and 600 or less, and the uneven structure includes a plurality of ridge-like portions each protruding in a ridge-like shape.

15. The method for producing a decorative sheet according to claim 14, wherein the first gloss adjustment layer further contains a cured product of a thermosetting resin.

16. A method for producing a decorative sheet as described in claim 15, wherein the first ionizing radiation curable resin is an aqueous dispersion or emulsion containing at least one of a urethane acrylate and a polyurethane resin, the thermosetting resin is an aqueous dispersion containing a polyurethane resin, and the polyurethane resin contained in the thermosetting resin contains a reaction product of a polyisocyanate and a polyol containing at least one of a polyester polyol and a polycarbonate polyol.

Images