Decorative sheet

Abstract

The present invention provides technology enabling design with a high degree of freedom with regard to the tactile feel or appearance of a decorative sheet. A decorative sheet (1) comprises a base layer (2) and a surface protective layer (6) provided thereon. The decorative sheet (1) has a plurality of bubbles (5) between the surface of the surface protective layer (6) and the base layer (2). The surface of the surface protective layer (6) includes a region containing a mix of a plurality of first protrusions (P1) each corresponding to one or more of the plurality of bubbles (5) and a plurality of second protrusions (P2) each having a ridge shape.

Description

Decorative sheet

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

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

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

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

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

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

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

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

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

[0010] An object of the present invention is to provide a technique that allows for a high degree of freedom in the design of the feel or appearance of a decorative sheet.

[0011] According to one aspect of the present invention, there is provided a decorative sheet comprising an original fabric layer and a surface protective layer disposed thereon, with a plurality of air bubbles between the surface of the surface protective layer and the original fabric layer, and the surface of the surface protective layer including an area where a plurality of first convex portions, each corresponding to one or more of the plurality of air bubbles, and a plurality of second convex portions, each of which is ridge-shaped, are mixed.

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

[0013] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the surface of the primer layer facing the surface protection layer has a plurality of convex portions at the positions of the plurality of first convex portions.

[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 plurality of bubbles are at least partially located within the primer layer.

[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 primer layer contains a cured product of a resin containing a polymer.

[0016] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, further comprising a pigment-containing layer interposed between the base layer and the primer layer, the pigment and binder resin being contained therein.

[0017] According to yet another aspect of the present invention, there is provided a decorative sheet relating to the above aspect, in which the surface of the surface protection layer includes one or more first regions and one or more second regions, the pigment-containing layer is located only between the one or more first regions and the original fabric layer, and the multiple first convex portions are located in the first regions.

[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 thickness of the primer layer excluding the portion corresponding to the first convex portion is 20 μm or less.

[0019] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein at least one of the plurality of bubbles has a dimension of 5 μm or more in the thickness direction of the surface protective layer.

[0020] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the thickness of the surface protective layer is in the range of 2 μm or more and 15 μm or less.

[0021] 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 surface protective layer contains a cured product of an ionizing radiation curable resin.

[0022] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the ionizing radiation curable resin contains a di- or higher functional acrylate containing a repeating structure.

[0023] 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 surface protective layer further contains particles having an average particle size of 10 μm or less.

[0024] According to yet another aspect of the present invention, there is provided a decorative sheet comprising a raw fabric layer and a surface protective layer disposed thereon, wherein the surface of the surface protective layer includes an area in which a plurality of first convex portions, each of which has an approximately circular shape in a planar view, and a plurality of second convex portions, each of which is ridge-shaped, are mixed.

[0025] According to yet another aspect of the present invention, there is provided a decorative sheet comprising a raw fabric layer and a surface protective layer provided thereon, wherein the surface of the surface protective layer includes an area in which a plurality of first recesses, each of which has an approximately circular shape in a planar view, and a plurality of second recesses, each of which is groove-shaped, are mixed.

[0026] 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 20 or less.

[0027] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein each of the plurality of second protrusions does not overlap any of the plurality of first protrusions.

[0028] Alternatively, according to yet another aspect of the present invention, a decorative sheet according to any of the above aspects is provided, wherein one or more of the plurality of second protrusions includes one or more portions that overlap with one of the plurality of first protrusions.

[0029] 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.

[0030] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet, comprising: forming a base layer containing a foaming agent on a raw fabric layer; causing foaming with the foaming agent to generate a plurality of bubbles in the base layer, thereby generating a plurality of convex portions on the surface of the base layer, each corresponding to one or more of the bubbles; then forming a coating film containing an ionizing radiation curable resin on the base layer; irradiating the coating film with light having a wavelength of 200 nm or less to generate an area on the surface of the coating film where a plurality of first convex portions corresponding respectively to the plurality of convex portions and a plurality of second convex portions, each of which is ridge-shaped, are mixed; and then completely curing the coating film to obtain a surface protective layer.

[0031] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet according to the above aspect, in which a multilayer structure is formed as the base layer, the multilayer structure including a foaming agent-containing layer containing the foaming agent and a coating layer provided on the foaming agent-containing layer.

[0032] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet according to any of the above aspects, wherein the coating layer comprises a resin containing a polymer, and the multilayer structure is heated to cause foaming by the foaming agent and harden the resin containing the polymer, thereby obtaining a primer layer containing a cured product of the resin containing the polymer and in which the plurality of bubbles are at least partially positioned.

[0033] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet according to any one of the above aspects, wherein the foaming agent-containing layer further contains a pigment and a binder resin.

[0034] According to yet another aspect of the present invention, there is provided a plate used in the manufacture of decorative sheets, the plate having a transfer surface including an area in which a plurality of first recesses, each of which has an approximately circular shape in a planar view, and a plurality of second recesses, each of which is groove-shaped, are mixed.

[0035] According to yet another aspect of the present invention, there is provided a plate used in the manufacture of a decorative sheet, the plate having a transfer surface including an area in which a plurality of first convex portions, each of which has an approximately circular shape in a planar view, and a plurality of second convex portions, each of which is ridge-shaped, are mixed.

[0036] According to yet another aspect of the present invention, there is provided a method for manufacturing a decorative sheet, which includes forming a resin layer on a raw material layer and transferring a structure provided on the transfer surface of a plate relating to any of the above aspects to the surface of the resin layer.

[0037] According to yet another aspect of the present invention, there is provided a method for manufacturing a plate used in the manufacture of a decorative sheet, the method including: forming a base layer containing a foaming agent on a substrate; causing foaming with the foaming agent to generate a plurality of bubbles in the base layer, thereby generating a plurality of convex portions on the surface of the base layer, each corresponding to one or more of the plurality of bubbles; then forming a coating film containing an ionizing radiation curable resin on the base layer; irradiating the coating film with light having a wavelength of 200 nm or less to generate regions on the surface of the coating film where a plurality of first convex portions corresponding respectively to the plurality of convex portions and a plurality of second convex portions, each of which is ridge-shaped, are mixed; and then completely curing the coating film to obtain a cured film.

[0038] The present invention provides a technique that allows for a high degree of freedom in the design of the feel or appearance of a decorative sheet.

[0039]

[0033] Figure 1 is a cross-sectional view of a decorative material including a decorative sheet according to a first embodiment of the present invention. Figure 2 is a microscope image of the surface of a decorative sheet according to one example of the present invention. Figure 3 is a cross-sectional view showing one step in the manufacturing method for a decorative sheet according to the first embodiment of the present invention. Figure 4 is a cross-sectional view showing another step in the manufacturing method for a decorative sheet according to the first embodiment of the present invention. Figure 5 is a cross-sectional view showing yet another step in the manufacturing method for a decorative sheet according to the first embodiment of the present invention. Figure 6 is a cross-sectional view showing yet another step in the manufacturing method for a decorative sheet according to the first embodiment of the present invention. Figure 7 is a microscope image of the surface of a decorative sheet according to a comparative example. Figure 8 is a cross-sectional view of a decorative material including a decorative sheet according to a second embodiment of the present invention. Figure 9 is a microscope image of a cross-section of a decorative sheet according to Example 11 of the present invention. Figure 10 is a microscope image of another cross-section of a decorative sheet according to Example 11 of the present invention. Figure 11 is a microscope image of a cross-section of a decorative sheet according to Reference Example 1. Figure 12 is a microscope image of a cross-section of a decorative sheet according to Reference Example 2.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] <1> First embodiment <1.1> Decorative material and decorative sheet Fig. 1 is a cross-sectional view of a decorative material including a decorative sheet according to a first embodiment of the present invention. Fig. 2 is a microscope image of the surface of a decorative sheet according to an example of the present invention. The microscope image in Fig. 2 is a planar image obtained using a laser microscope (OLS-4000 manufactured by Olympus Corporation).

[0044] 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.

[0045] 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.

[0046] The decorative sheet 1 includes a base fabric layer 2, a pigment-containing layer 3, a primer layer 4, and a surface protective layer 6. The pigment-containing layer 3, the primer layer 4, and the surface protective 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. The decorative sheet 1 may further include one or more other layers.

[0047] The decorative sheet 1 has a plurality of bubbles 5 between the surface of the surface protective layer 6 and the base fabric layer 2. Here, the bubbles 5 are at least partially located within the primer layer 4.

[0048] The surface of the surface protective layer 6 includes an area where a plurality of first protrusions P1, each corresponding to one or more of the bubbles 5, and a plurality of second protrusions P2, each having a ridge shape, are mixed together. Here, the surface of the primer layer 4 facing the surface protective layer 6 has protrusions P0 at the positions of the first protrusions P1.

[0049] The elements contained in the decorative sheet 1 will be explained below one by one.

[0050] <1.1.1> Raw Fabric Layer The raw fabric layer 2 may have various forms such as a film, a sheet, a plate, an irregularly shaped molded body, etc. Here, as an example, the raw fabric layer 2 is in the form of a film.

[0051] The raw fabric layer 2 or its material can be any material selected from, for example, paper, synthetic resin, synthetic resin foam, rubber, nonwoven fabric, synthetic paper, and metal foil. Examples of paper include tissue paper, titanium paper, and resin-impregnated paper. Examples of synthetic resins include polyethylene, polypropylene, polybutylene, polystyrene, polycarbonate, polyester, polyamide, ethylene-vinyl acetate copolymer, polyvinyl alcohol, and acrylic. Examples of rubber include ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, styrene-butadiene copolymer rubber, styrene-isoprene-styrene block copolymer rubber, styrene-butadiene-styrene block copolymer rubber, and polyurethane. Examples of nonwoven fabrics include organic and inorganic nonwoven fabrics. Examples of metals for the metal foil include aluminum, iron, gold, and silver.

[0052] The thickness of the raw fabric layer 2 is preferably in the range of 20 μm to 250 μm. If the raw fabric layer 2 is thin, the ability to cover unevenness of the base (unevenness) will decrease. If the raw fabric layer 2 is thick, problems such as whitening and cracking may occur during bending.

[0053] When a substrate with an inactive surface, such as an olefin-based substrate, is used as the raw fabric layer 2, it is desirable to subject the front and back surfaces of the raw fabric layer 2 to treatment such as corona treatment, plasma treatment, ozone treatment, electron beam treatment, ultraviolet treatment, and dichromate treatment.

[0054] <1.1.2> Pigment-Containing Layer The pigment-containing layer 3 is provided on the raw fabric layer 2 and is a layer containing a pigment and a binder resin. The pigment-containing layer 3 is, for example, a continuous film formed by coating one entire surface of the raw fabric layer 2 with ink. In this case, the pigment-containing layer 3 can serve as a concealing layer that conceals the substrate B or the raw fabric layer 2. In this case, the pigment-containing layer 3 can also serve as a planarizing layer.

[0055] The pigment-containing layer 3 may have a single-layer structure or a multi-layer structure. When the pigment-containing layer 3 has a multi-layer structure, all of the layers may be continuous films, all of the layers may be discontinuous films, or one or more layers may be continuous films and the remaining layers may be discontinuous films.

[0056] The pigment-containing layer 3 can be formed using, for example, a printing ink (or a coating agent) in which a binder resin serving as a matrix and a pigment are dissolved or dispersed in a solvent.

[0057] Examples of binder resins that can be used include 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 daimi rubber resin, as well as mixtures or copolymers of these.

[0058] The pigment is at least one of a white pigment and a colored pigment. Examples of the pigment include inorganic pigments such as carbon black, titanium oxide (titanium white), zinc white, red iron oxide, yellow lead, Prussian blue, and cadmium red; organic pigments such as azo pigments, lake pigments, anthraquinone pigments, phthalocyanine pigments, isoindolinone pigments, and dioxazine pigments; and mixtures thereof.

[0059] The average particle size of the pigment is preferably in the range of 50 nm to 5 μm, and more preferably in the range of 100 nm to 1 μm. This average particle size is the median diameter (D50) of the particles in the surface protective layer 6, which will be described later.

[0060] The amount of pigment is preferably in the range of 2 parts by mass to 50 parts by mass, and more preferably in the range of 5 parts by mass to 30 parts by mass, per 100 parts by mass of binder resin.

[0061] 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.

[0062] The ink used to form the pigment-containing layer 3 may contain the binder resin in various forms. For example, the ink may be solvent-free. Alternatively, the ink may contain the binder resin in the form of a solution, emulsion, or dispersion. According to one example, the ink contains the binder resin in the form of a water-based emulsion or dispersion. Furthermore, the ink may be cured by volatilization of the solvent, by irradiation with ionizing radiation, or by heat curing.

[0063] The ink may further contain a foaming agent, which can be used to generate bubbles 5. Here, as an example, it is assumed that the ink further contains a foaming agent.

[0064] Examples of foaming agents that can be used include inorganic foaming agents such as sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, ammonium nitrite, sodium borohydride, light metals, and azides; organic foaming agents such as azo, nitroso, and hydrazide; or combinations of two or more thereof. Examples of azo organic foaming agents that can be used include azodicarbonamide. Examples of nitroso organic foaming agents that can be used include N,N'-dinitrosopentamethylenetetramine. Examples of hydrazide organic foaming agents that can be used include 4,4'-oxybisbenzenesulfonylhydrazide.

[0065] The amount of the foaming agent is preferably in the range of 1 to 20 parts by mass, more preferably in the range of 5 to 15 parts by mass, per 100 parts by mass of the binder resin.

[0066] When the ink contains a blowing agent, it may further contain a blowing aid to lower the decomposition temperature of the blowing agent. For example, when the ink contains an azo-based organic blowing agent such as azodicarbonamide, it may further contain a metal catalyst. Furthermore, when the ink contains a nitroso-based organic blowing agent such as N,N'-dinitrosopentamethylenetetramine, it may further contain a urea-based blowing aid.

[0067] In addition, functional additives such as plasticizers, dispersants, surfactants, tackifiers, adhesion aids, drying agents, curing agents, curing accelerators, and curing retarders may be added to the ink to impart various functions.

[0068] <1.1.3> Primer layer The primer layer 4 is provided on the pigment-containing layer 3. Here, the primer layer 4 covers the entire surface of one side of the raw fabric layer 2, with the pigment-containing layer 3 sandwiched therebetween.

[0069] The primer layer 4 is made of, for example, a cured resin. The primer layer 4 may further contain particles. For example, the particles described later for the surface protection layer 6 may be used as the particles.

[0070] When the mass of the primer layer 4 is 100 parts by mass, the mass of the cured resin contained in the primer layer 4 is preferably 60 parts by mass or more, more preferably 70 parts by mass or more, and even more preferably 80 parts by mass or more.

[0071] The cured resin contained in the primer layer 4 is, for example, a cured resin described above for the binder resin of the pigment-containing layer 3. The cured resin contained in the primer layer 4 may be another cured resin, for example, a cured resin described below for the surface protective layer 6.

[0072] The resin used to form the primer layer 4 may be a solvent-free resin, a water-based resin, or a non-aqueous (organic solvent-based) resin.

[0073] The cured resin may be a cured product of a thermosetting resin, a cured product of an ionizing radiation curable resin, or a cured product of a resin containing a thermosetting resin and an ionizing radiation curable resin. 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 irradiation with ultraviolet light.

[0074] The cured resin preferably includes a cured product of a resin containing a polymer, for example, a cured product of an aqueous emulsion containing a polymer or a cured product of a solvent-based resin containing a polymer, for the reasons described below.

[0075] As described below, in the production of the decorative sheet 1, for example, a foaming agent-containing layer made of the above-mentioned ink containing a foaming agent and a coating layer containing uncured resin are first formed in this order on the base layer 2, and then the multilayer structure containing these is heated. During this heating process, at least a portion of the gas generated by thermal decomposition of the foaming agent is absorbed into the coating layer, generating bubbles within the coating layer. If the crosslink density of the resin constituting the coating layer is sufficiently low, the coating layer can absorb a large amount of gas. In addition, in this case, coalescence of bubbles is likely to occur within the coating layer. Therefore, if the crosslink density of the resin constituting the coating layer is sufficiently low, large bubbles may be generated within the coating layer. However, if the crosslink density of the resin constituting the coating layer is low, the structure containing the bubbles is likely to be destroyed.

[0076] The coating layer formed from the above-mentioned aqueous or solvent-based resin is mainly composed of a polymer with a low crosslinking density, and therefore has appropriate flexibility and strength. Therefore, when the coating layer is formed from the above-mentioned aqueous or solvent-based resin, large bubbles are generated in the coating layer, and the structure containing such large bubbles is less likely to be destroyed.

[0077] As described above, here, the bubbles 5 are at least partially located within the primer layer 4. The surface of the primer layer 4 facing the surface protective layer 6, i.e., the upper surface, includes a plurality of protrusions P0 each corresponding to one or more of the bubbles 5. In this embodiment, the bubbles 5 generate the protrusions P0 on the upper surface of the primer layer 4, and the protrusions P0 generate first protrusions P1 on the surface of the surface protective layer 6.

[0078] 1, one bubble 5 may form one convex portion P0, or two or more bubbles 5 may form one convex portion P0. The number of bubbles 5 forming one convex portion P0 is preferably 15 or less, more preferably 10 or less, and even more preferably 5 or less.

[0079] Here, most of the protrusions P0 are each formed by a single bubble 5. Therefore, most of the protrusions P0 have a substantially dome shape, and have a substantially circular shape in plan view.

[0080] One or more of the bubbles 5 preferably have a dimension DZ of 5 μm or more, and more preferably 8 μm or more, in the thickness direction of the surface protective layer 6. Bubbles 5 with a large dimension DZ can cause convex portions P0 with a large height H0 to form on the upper surface of the primer layer 4. Here, the height H0 of the convex portions P0 is measured based on a region of the upper surface of the primer layer 4 where no convex portions P0 form.

[0081] The dimension DZ of the bubbles 5 in the thickness direction of the surface protective layer 6 is preferably 100 μm or less, and more preferably 80 μm or less. A decorative sheet 1 having bubbles 5 with a large dimension DZ tends to have a large variation in the dimension DZ.

[0082] Most of the bubbles 5 are spherical or have a similar shape. Therefore, most of the bubbles 5 have the dimension DZ and the dimensions in each direction perpendicular to the thickness direction that are substantially equal to each other.

[0083] The thickness TP of the primer layer 4, excluding the portion corresponding to the first convex portion P1, i.e., the portion other than the convex portion P0, is preferably 20 μm or less, more preferably 15 μm or less. ＭａｘRatio of TP / DZ Ｍａｘ is preferably 2 or less, more preferably 1 or less, and even more preferably 0.9 or less. Ｍａｘ When the value of the height H0 of the projection P0 is increased, the height H0 of the projection P0 is decreased.

[0084] The thickness TP is preferably 2 μm or more, and more preferably 5 μm or more. Ｍａｘ is preferably 0.05 or more, more preferably 0.1 or more, and even more preferably 0.2 or more. Ｍａｘ is preferably large.

[0085] The height H0 of the convex portion P0 is preferably 1 μm or more, and more preferably 2 μm or more. A large height H0 is preferable to form the first convex portion P1 with a large height H1 on the surface of the surface protective layer 6. Here, the height H1 of the first convex portion P1 is the height of the top of the first convex portion P1 based on the lowest position of its periphery. The height H0 of the convex portion P0 is, for example, 20 μm or less, and, for another example, 15 μm or less.

[0086] <1.1.4> Surface Protective Layer The surface protective layer 6 is provided on the primer layer 4. Here, the surface protective layer 6 covers the entire upper surface of the primer layer 4.

[0087] As described above, the surface of the surface protection layer 6 includes an area where a plurality of first convex portions P1, each corresponding to one or more of the bubbles 5, and a plurality of second convex portions P2, each of which is ridge-shaped, are mixed.

[0088] The first convex portions P1 are formed by the convex portions P0 on the surface of the surface protective layer 6. Therefore, the first convex portions P1 are located above the convex portions P0 provided on the upper surface of the primer layer 4, and each has a shape corresponding to the convex portions P0. As described above, most of the convex portions P0 have a substantially dome shape and a substantially circular shape in plan view, and therefore, most of the first convex portions P1 also have a substantially dome shape and a substantially circular shape in plan view, as shown in FIG.

[0089] The second convex portions P2 are wrinkles that occur on the surface of the surface protective layer 6. The second convex portions P2 may be curved or linear in plan view, but from the viewpoint of fingerprint resistance of the surface of the decorative sheet 1, it is preferable that they be curved as exemplified in Figure 2.

[0090] The first convex portions P1 and the second convex portions P2 affect the tactile feel of the surface protective layer 6. The first convex portions P1 and the second convex portions P2 also affect the glossiness of the surface protective layer 6.

[0091] The height H1 of the first protrusion P1 is preferably 1 μm or more, and more preferably 2 μm or more. According to one example, the height H1 of the first protrusion P1 is 20 μm or less, and according to another example, 15 μm or less. According to one example, the diameter R of the first protrusion P1 is in the range of 20 μm or more and 300 μm or less, and according to another example, the diameter R is in the range of 50 μm or more and 200 μm or less. The ratio H1 / R of the height H1 to the diameter R is preferably in the range of 0.01 or more and 0.1 or less, and more preferably in the range of 0.02 or more and 0.08 or less.

[0092] The height H2 of the second protrusion P2 is preferably 1 μm or more, and more preferably 2 μm or more. According to one example, the height H2 of the second protrusion P2 is 20 μm or less, and according to another example, 15 μm or less. Here, the height H2 of the second protrusion P2 is the height of the top of the second protrusion P2 based on its edge. According to one example, the width W of the second protrusion P2 is in the range of 2 μm or more and 200 μm or less, and according to another example, the width W is in the range of 5 μm or more and 100 μm or less. The ratio H2 / W of the height H2 to the width W is preferably in the range of 0.01 or more and 0.5 or less, and more preferably in the range of 0.02 or more and 0.1 or less.

[0093] The ratio R / W of the diameter R of the first convex portion P1 to the width W of the second convex portion P2 is preferably in the range of 1 to 100, and more preferably in the range of 2 to 50. The ratio H1 / H2 of the height H1 of the first convex portion P1 to the height H2 of the second convex portion P2 is preferably in the range of 0.1 to 10, and more preferably in the range of 0.2 to 5. The ratio S1 / S2 of the total area S1 of the first convex portion P1 to the total area S2 of the second convex portion P2, obtained by planar observation, is preferably in the range of 0.1 to 10, and more preferably in the range of 0.2 to 5.

[0094] The specular gloss GS(60°) of the surface protective layer 6 is preferably 20 or less, more preferably 18 or less, and even more preferably 15 or less. For example, the specular gloss GS(60°) of the surface protective layer 6 is 0.5 or more. Here, the "specular gloss GS(60°)" is the specular gloss measured at an incident angle of 60 degrees using a gloss meter conforming to ISO 2813. The specular gloss GS(60°) is sometimes expressed with "%" added after the numerical value, but the "%" will be omitted here.

[0095] The thickness of the surface protective layer 6 is preferably in the range of 2 μm to 15 μm, and more preferably in the range of 2 μm to 10 μm. If the thickness of the surface protective layer 6 is reduced, it becomes difficult to form second convex portions P2 with a large height H2 on the surface. If the thickness of the surface protective layer 6 is increased, it becomes difficult to form first convex portions P1 with a large height H1 on the surface. Furthermore, if the thickness of the surface protective layer 6 is increased, the processability of the decorative sheet 1 decreases, and it becomes more susceptible to whitening when folded.

[0096] Here, the thickness of the surface protective layer 6 is the thickness of a layer that has the same apparent area and volume as the surface protective layer 6 and a flat surface. The thickness of the surface protective layer 6 is determined, for example, by the following method. First, a cross section parallel to the thickness direction of the surface protective layer 6 is imaged. Next, from this cross-sectional image, the dimension in the direction perpendicular to the thickness direction of the surface protective layer 6 and the area of ​​the cross section of the surface protective layer 6 are determined. The thickness of the surface protective layer 6 is a value obtained by dividing this area by the above dimension. Note that when the coating liquid for the surface protective layer described below does not contain a solvent, the thickness of the coating film made of this coating liquid is equal to the thickness of the surface protective layer 6.

[0097] The surface protective layer 6 contains a cured resin. As described below, the surface protective layer 6 may further contain particles. When the mass of the surface protective layer 6 is taken as 100 parts by mass, the mass of the cured resin contained in the surface protective 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.

[0098] The surface protection layer 6 contains a cured product of an ionizing radiation curable resin as the cured resin. As described above, ionizing radiation is 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 irradiation with ultraviolet light. The 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.

[0099] As the ionizing radiation curable resin, known materials such as various monomers and commercially available oligomers can be used, for example, (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, or epoxy resins can be used. The ionizing radiation curable resin may be either an aqueous resin or a non-aqueous (organic solvent-based) resin. The ionizing radiation curable resin may be solvent-free.

[0100] The main component of the ionizing radiation curable resin is preferably an acrylate. Here, the term "main component" 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 resin component constituting the resin.

[0101] The acrylate is preferably a difunctional or higher acrylate, and more preferably a trifunctional or higher acrylate. In order to obtain a surface protective layer 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.

[0102] The acrylate preferably contains a repeating unit, such as an ethylene oxide (EO) unit, a propylene oxide (PO) unit, or an ε-caprolactone (CL) unit. In the acrylate, the repeating unit may be in a ring-opened state and interposed between the acryloyl group and the methylol group.

[0103] 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 in the first irradiation step described below, and therefore wrinkles corresponding to the second convex portions P2 are more likely to occur 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.

[0104] 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.

[0105] In addition to the cured resin, the surface protective layer 6 may further contain particles. Examples of the particles contained in the surface protective layer 6 include particles made of an organic material such as polyethylene (PE) wax, polypropylene (PP) wax, and resin beads, and particles made of an inorganic material such as silica, glass, alumina, titania, zirconia, calcium carbonate, and barium sulfate.

[0106] The average particle size (D50) of the particles is preferably 10 μm or less, more preferably in the range of 1 μm to 8 μm, even more preferably in the range of 2 μm to 7 μm, and most preferably in the range of 3 μm to 6 μm. If the average particle size (D50) of the particles is large, the particles may easily fall off from the surface protective layer 6, making it difficult to achieve high scratch resistance. If the particles are small, the effect of generating wrinkles uniformly is reduced.

[0107] Here, "average particle size" or "average particle size (D50)" refers to the median size (D50) measured using a laser diffraction / scattering particle size distribution analyzer. When the coating liquid for the surface protective layer contains particles, the surface protective layer 6 obtained from this coating liquid will also contain particles. The average particle size of the particles contained in the surface protective layer 6 can be determined by observing the cross section of the layer and averaging the particle sizes of multiple particles. The value obtained in this manner is substantially the same as the median size (D50) measured using a laser diffraction / scattering particle size distribution analyzer. Therefore, the above-mentioned range of average particle size can also be interpreted as the range of average particle sizes of the particles contained in the surface protective layer 6.

[0108] The amount of particles in the surface protective 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 even more preferably in the range of 2 parts by mass or more and 6 parts by mass or less, relative to 100 parts by mass of the cured resin.

[0109] When the amount of particles added is within the above range, the effect of generating wrinkles uniformly is particularly large. If the amount of particles added is too large, the particles are likely to fall off from the surface protective layer 6, which may make it difficult to achieve high scratch resistance.

[0110] <1.2> Manufacturing Method of Decorative Sheet Figures 3 to 6 are cross-sectional views showing a manufacturing method of a decorative sheet according to the first embodiment of the present invention. The decorative sheet 1 described above is manufactured, for example, by the following method.

[0111] First, a base layer containing a foaming agent is formed on one surface of the base layer 2. Here, the base layer has a multi-layer structure including an ink layer 3A and a coating layer 4A as shown in FIG.

[0112] In this example, the ink layer 3A is a foaming agent-containing layer that contains a foaming agent and becomes the pigment-containing layer 3 through foaming treatment. The ink layer 3A can be obtained by forming a coating film made of the ink described above for the pigment-containing layer 3 on one side of the base layer 2 and, if necessary, drying this coating film. The 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. The coating film is dried at a temperature lower than the thermal decomposition temperature of the foaming agent.

[0113] The coating layer 4A is a layer formed on the ink layer 3A. Here, the coating layer 4A is a layer that becomes the primer layer 4 by undergoing a foaming treatment and a curing treatment. The coating layer 4A can be obtained by forming a coating film made of a primer layer coating liquid on the ink layer 3A and drying this coating film as necessary.

[0114] The primer layer coating liquid contains a resin that produces the cured resin described above for the primer layer 4. Here, as an example, the primer layer coating liquid is an aqueous emulsion containing a polymer or a solvent-based resin containing a polymer.

[0115] The primer layer coating liquid may further contain the particles described above for the primer layer 4. The primer layer coating liquid may further contain other components, such as a solvent, and additives for improving the functionality of the final product, such as one or more antibacterial agents and antifungal agents. The primer layer coating liquid may further contain other additives such as an ultraviolet absorber and a light stabilizer. Examples of ultraviolet absorbers that can be used include benzotriazoles, benzoates, benzophenones, and triazines. Examples of light stabilizers that can be used include hindered amines.

[0116] The coating layer 4A 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. The coating film is dried at a temperature lower than the thermal decomposition temperature of the foaming agent.

[0117] This coating film may be subjected to a pre-curing treatment. The pre-curing treatment is a treatment carried out to increase the viscosity of the coating film or to reduce the flexibility of the coating film and to increase its strength. The pre-curing treatment is, for example, a heat treatment at a temperature lower than the thermal decomposition temperature of the foaming agent, or irradiation with ionizing radiation. The pre-curing treatment is carried out so that, when the foaming agent is thermally decomposed, the gas generated by the thermal decomposition can be captured in the coating layer 4A and bubbles can coalesce within the coating layer 4A.

[0118] Next, foaming and curing processes are performed. In the foaming process, foaming is caused by a foaming agent to generate a plurality of bubbles 5 in the base layer, thereby generating a plurality of protrusions P0 on the surface of the base layer, each of which corresponds to one or more of the bubbles 5. In the curing process, the resin contained in the base layer is cured.

[0119] Here, the multilayer structure is heated. As the temperature of the multilayer structure rises, the foaming agent contained in the ink layer 3A thermally decomposes. At least a portion of the gas generated by this thermal decomposition is captured in the coating layer 4A, generating bubbles within the coating layer 4A. Within the coating layer 4A, the bubbles coalesce to generate larger bubbles. These bubbles form convex portions on the upper surface of the coating layer 4A. Thereafter, if necessary, a curing treatment is performed to stabilize the bubble-containing structure. For example, the coating layer 4A in which bubbles have been generated is further subjected to a heat treatment or irradiated with ionizing radiation. In this manner, the pigment-containing layer 3 and primer layer 4 shown in FIG. 4 are obtained.

[0120] Next, a coating film made of a coating liquid for a surface protective layer is formed on the underlayer. Here, as shown in Fig. 5, a coating film 6A made of a coating liquid for a surface protective layer is formed on the primer layer 4. The coating film 6A is formed so that the thickness at positions other than the convex portion P0 is greater than the thickness at the position of the convex portion P0. For example, as shown in Fig. 5, the coating film 6A is formed so as to have a substantially flat upper surface.

[0121] This coating film 6A 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.

[0122] The coating liquid for the surface protective layer contains the ionizing radiation curable resin described above for the surface protective layer 6. As described above, the ionizing radiation curable resin contains, according to one example, acrylate as a main component.

[0123] The coating liquid for the surface protective layer may further contain other components, such as the above-mentioned particles, solvent, and additives for improving the functionality of the final product, such as one or more antibacterial agents and antifungal agents. The coating liquid for the surface protective layer may further contain other additives such as an ultraviolet absorber and a light stabilizer. Examples of the ultraviolet absorber that can be used include benzotriazole-based, benzoate-based, benzophenone-based, and triazine-based stabilizers. Examples of the light stabilizer that can be used include hindered amine-based stabilizers.

[0124] Next, the coating film 6A is irradiated with ionizing radiation or ultraviolet light to cure the coating film 6A. For example, the first irradiation step and the second irradiation step described below are carried out sequentially.

[0125] In the first irradiation step, the coating film 6A is irradiated with a first radiation. The first radiation is light having a wavelength of 200 nm or less.

[0126] The ionizing radiation-curable resin contained in the coating liquid for the surface protective layer has a large absorption coefficient for the first radiation. Therefore, the first radiation incident on the coating film 6A can only reach a position several tens to several hundreds of nanometers from the outermost surface. Therefore, in the first irradiation step, the crosslinking reaction proceeds in the surface region of the coating film 6A, forming an extremely thin cured film, while the crosslinking reaction does not proceed in other regions, leaving the other regions uncured.

[0127] After the first irradiation step, the coating film 6A has, on its surface, convex portions corresponding to the first convex portions P1 and wrinkles corresponding to the second convex portions P2. The inventors believe that the reason why the above structure is formed on the coating film surface by the first irradiation step is as follows.

[0128] As described above, the first radiation can only reach a position tens to hundreds of nanometers away from the outermost surface of the coating film 6A. That is, the crosslinking reaction of the first ionizing radiation curable resin occurs only on the surface of the coating film 6A, 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 coating film 6A.

[0129] Furthermore, swelling and buckling of the cured film are likely to occur in areas with a large amount of uncured resin, but are unlikely to occur in areas with a small amount of uncured resin. As shown in Figure 5, immediately before the first irradiation step, the amount of uncured resin is small in the area of ​​the coating film 6A corresponding to the protrusion P0, while the amount of uncured resin is large in other areas of the coating film 6A. Therefore, wrinkles are unlikely to form in the area of ​​the surface of the coating film 6A corresponding to the former area, but are likely to form in the area of ​​the surface of the coating film 6A corresponding to the latter area. As wrinkles grow in the latter area, uncured resin may migrate from the former area to the latter area. As a result, a protrusion corresponding to the protrusion P0 appears in the area of ​​the surface of the coating film 6A corresponding to the former area.

[0130] The first 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 the excimer.

[0131] 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).

[0132] 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.

[0133] 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.

[0134] Furthermore, oxygen in the atmosphere inhibits radical polymerization. Therefore, the residual oxygen concentration in the reaction atmosphere affects the formation of wrinkles on the surface of the coating film 6A. Therefore, changing the residual oxygen concentration in the reaction atmosphere can also change the surface properties of the surface protective layer 6.

[0135] The integrated light amount of the first 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 ２ It is most preferable to set the integrated light amount within the following range. If the integrated light amount is small, the surface will not be sufficiently cured and wrinkles will not occur. Furthermore, if the integrated light amount is small, the expansion of the cured film in the in-plane direction will be small. If the integrated light amount is large, the surface condition of the coating film 6A will deteriorate.

[0136] In the second irradiation step, the coating film 6A is irradiated with second radiation. The second radiation is ionizing radiation or ultraviolet light having a longer wavelength than the light irradiated in the first irradiation step. As described above, the ionizing radiation is a charged particle beam such as an electron beam. The wavelength of the ultraviolet light as the second radiation 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.

[0137] In the second irradiation step, the crosslinking reaction is allowed to proceed throughout the entire thickness of the coating film 6A, thereby completely curing the coating film 6A and obtaining the surface protective layer 6 shown in FIG.

[0138] The cumulative amount of the second 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.

[0139] The second radiation is preferably applied 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.

[0140] In the second irradiation step, if a layer having sufficient strength cannot be obtained by irradiation with only one type of radiation, the type of second 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 first irradiation step. Alternatively, irradiation with ultraviolet light having a longer wavelength than the light irradiated in the first 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 first irradiation step may be performed first, followed by irradiation with ultraviolet light having an even longer wavelength.

[0141] In this manner, a decorative sheet 1 is obtained in which the surface of the surface protective layer 6 has first convex portions P1 and second convex portions P2, as shown in FIG.

[0142] 1 and 2, the second protrusions P2 are adjacent to the first protrusions P1 but do not overlap with the first protrusions P1. That is, in the decorative sheet 1, the second protrusions P2 do not have portions located above the first protrusions P1.

[0143] The second convex portions P2 may include portions that overlap with the first convex portions P1. That is, the second convex portions P2 may have portions located above the first convex portions P1 in the decorative sheet 1. Such a structure can be obtained, for example, by using a coating liquid for the surface protective layer that has a high viscosity, thereby suppressing excessive movement of the uncured resin in the first irradiation step.

[0144] <1.3> Effects Figure 7 is a microscope image of the surface of a decorative sheet according to a comparative example. The decorative sheet shown in Figure 7 was obtained by the same method as that described with reference to Figures 3 to 6, except that no foaming agent was used. This decorative sheet does not contain air bubbles, and therefore its surface protective layer does not have any protrusions on its surface that result from air bubbles. In this decorative sheet, the only protrusions provided on the surface of the surface protective layer are ridge-like protrusions that form wrinkles. Therefore, the feel and gloss of this decorative sheet are mainly determined by the ridge-like protrusions.

[0145] In contrast, the decorative sheet 1 has a surface protective layer 6 that has first protrusions P1 resulting from air bubbles 5 and ridge-like second protrusions P2 that form wrinkles on its surface. A concave-convex structure including the first protrusions P1 and the second protrusions P2 can provide a different tactile feel and optical properties than a concave-convex structure including only the second protrusions P2. The mechanisms that produce the first protrusions P1 and the second protrusions P2 are different, and their dimensions can be set independently. Furthermore, the ratio between the total area of ​​the first protrusions P1 and the total area of ​​the second protrusions P2 can also be set arbitrarily. In this way, the technology described above for the decorative sheet 1 allows for a high degree of freedom in the design of the tactile feel or appearance of the decorative sheet.

[0146] Furthermore, in the decorative sheet 1, scattering, refraction, or reflection of light can occur at the interface between the gas that makes up the bubbles 5 and the material that makes up the primer layer 4 due to the difference in refractive index between them. This scattering, refraction, or reflection of light can vary depending on the refractive index of the primer layer 4 and the size and number of the bubbles 5. Therefore, in the decorative sheet 1, the optical characteristics such as appearance can be adjusted by appropriately selecting the material used in the primer layer 4 and the size and number of the bubbles 5.

[0147] Furthermore, decorative sheets having protrusions similar to the first protrusions P1 can be obtained, for example, by dispersing large particles in the top coat layer. However, because large particles tend to fall off, decorative sheets having such a structure have poor scratch resistance. The decorative sheet 1 described above produces the first protrusions P1 without using large particles. Therefore, the decorative sheet 1 can achieve high scratch resistance.

[0148] Furthermore, in the decorative sheet 1, the bubbles 5 can also contribute to sound insulation and heat insulation.

[0149] <2> Second embodiment Fig. 8 is a cross-sectional view of a decorative material including a decorative sheet according to a second embodiment of the present invention. The decorative material 11A shown in Fig. 8 is similar to the decorative material 11, except that it includes a decorative sheet 1A instead of the decorative sheet 1. Furthermore, the decorative sheet 1A is similar to the decorative sheet 1, except that it employs the following configuration.

[0150] That is, the upper surface of the surface protective layer 6 includes one or more first regions 61 and one or more second regions 62. The pigment-containing layer 3 is located only between the first region 61 and the raw fabric layer 2. The first convex portion P1 is located in the first region 61. A portion of the second convex portion P2 is located in the second region 62, and the remainder is located in the first region 61. The bubbles 5 are located only between the first region 61 and the pigment-containing layer 3. Note that each of the bubbles 5 may be located entirely above the pigment-containing layer 3, or only a portion of the bubbles may be located directly above the pigment-containing layer 3.

[0151] In other words, the pigment-containing layer 3 partially covers one main surface of the base fabric layer 2. The bubbles 5 are located only in the portion of the primer layer 4 located on and near the pigment-containing layer 3, and are not present in other portions of the primer layer 4. A first region 61, consisting of a region on the upper surface of the surface protective layer 6 located directly above the pigment-containing layer 3 and a region nearby, has a first convex portion P1 and a second convex portion P2. A second region 62, which is the remaining region on the upper surface of the surface protective layer 6, has the second convex portion P2 but does not have the first convex portion P1.

[0152] The decorative sheet 1A can be manufactured in the same manner as described with reference to Figures 3 to 6, except that the ink layer 3A is formed so as to partially cover one main surface of the base fabric layer 2, corresponding to the pigment-containing layer 3 in Figure 8.

[0153] The techniques described above for the decorative sheet 1A can achieve the same effects as those described above for the decorative sheet 1.

[0154] Furthermore, in decorative sheet 1A, the pattern of first region 61 corresponds to the pattern of pigment-containing layer 3, and the pattern of second region 62 corresponds to the reverse pattern of pigment-containing layer 3. The first region 61 and the second region 62 may have different effects on the feel or appearance of the decorative sheet. Therefore, the technique described above for decorative sheet 1A allows for greater freedom in designing the feel or appearance of the decorative sheet compared to the technique described above for decorative sheet 1.

[0155] For example, if the pigment-containing layer 3 has a wood grain pattern, the first convex portion P1 or the first region 61 may provide a tactile feel similar to that of the duct portion, and the second convex portion P2 or the second region 62 may provide a tactile feel similar to that of the portion other than the duct.

[0156] <3> Modifications The above-described technique can be modified in various ways.

[0157] For example, in the production of the decorative sheet 1, the foaming agent may be contained in the coating layer 4A instead of in the ink layer 3A.

[0158] The decorative sheets 1 and 1A may further include one or more other layers. For example, the decorative sheet 1A may further include a second pigment-containing layer as a solid ink layer or a hiding layer between the base layer 2 and the pigment-containing layer 3.

[0159] Decorative sheets 1 and 1A can be used as original plates in the production of other decorative sheets, or decorative sheets 1 and 1A can be used to produce plates to be used in the production of other decorative sheets.

[0160] For example, if the uneven structure provided on the surface protective layer 6 of the decorative sheet 1 or 1A is transferred an odd number of times, a plate can be obtained whose transfer surface includes a region where a plurality of first recesses, each of which has a substantially circular shape in a plan view, and a plurality of second recesses, each of which is groove-shaped, are mixed. Then, a resin layer is formed on the base layer, and the structure provided on the transfer surface of the plate is transferred to the surface of the resin layer. This allows for a decorative sheet having a surface of the resin layer with an uneven structure similar to the uneven structure provided on the surface protective layer 6 of the decorative sheet 1 or 1A.

[0161] Furthermore, by transferring the uneven structure provided on the surface protective layer 6 of the decorative sheet 1 or 1A an even number of times, a plate can be obtained whose transfer surface includes a region where a plurality of first convex portions, each of which has a substantially circular shape in plan view, and a plurality of second convex portions, each of which has a ridge-like shape, are mixed. A resin layer is then formed on the base layer, and the structure provided on the transfer surface of the plate is transferred to the surface of the resin layer. This allows for the production of a decorative sheet having a uneven structure on the surface of the resin layer that is the inverse of the uneven structure provided on the surface protective layer 6 of the decorative sheet 1 or 1A.

[0162] These decorative sheets do not contain air bubbles because the uneven structure of the surface protective layer is created by transfer printing. Furthermore, these decorative sheets have a high degree of freedom in selecting the material for the surface protective layer and a high degree of freedom in designing the layer structure.

[0163] Examples of the present invention will be described below. Note that the "particle size" described below is the above-mentioned "average particle size (D50)".

[0164] <Example 1> The decorative sheet 1A described with reference to Fig. 8 was produced by the following method. ２ An impregnated paper (GFR-506, manufactured by Kohjin Co., Ltd.) was prepared as the raw paper layer 2. On one side of the raw paper layer 2, a pigment-containing layer 3 was formed as a design layer.

[0165] An ink composition obtained by adding a foaming agent to a commercially available ink was used to form the pigment-containing layer 3. The commercially available ink used was an oil-based nitrocellulose resin gravure printing ink (PCNT (PCRNT) various colors (manufactured by Toyo Ink Co., Ltd.)). The foaming agent used was Matsumoto Microsphere (registered trademark) HF-48 (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.). The amount of foaming agent was 10 parts by mass relative to the ink.

[0166] The ink composition was printed such that the ink layer 3A formed a wood grain pattern and the mass per area after drying was 3 g / m ２ The ink layer 3A was dried at 60° C. for 1 minute.

[0167] Next, the following primer layer coating liquid was applied onto the base layer 2 and the ink layer 3A to form a coating layer 4A. The primer layer coating liquid was applied so that the primer layer 4 had a thickness of 10 μm in the areas excluding the areas corresponding to the first convex portions P1.

[0168] (Primer layer coating liquid) Water-based resin R1 Type: Acrylic emulsion Product name: SETAQUA 6302 (manufactured by Allnex Co., Ltd.) Then, drying and foaming treatment were performed. Specifically, the ink layer 3A and the coating layer 4A formed on the base layer 2 were heated at a temperature of 130°C for 3 minutes to dry and cause thermal decomposition of the foaming agent. This resulted in a pigment-containing layer 3 and a primer layer 4 having bubbles 5.

[0169] Next, a coating liquid for a surface protective layer having the following composition was printed on the primer layer 4 to form a coating film 6A. The coating liquid for a surface protective layer was printed so that the thickness of the surface protective layer 6 would be 5 μm.

[0170] (Coating liquid for surface protective layer) Ionizing radiation curable resin Type: trimethylolpropane EO-modified triacrylate (EO 6 moles added) Product name: Miramer (registered trademark) M3160 (manufactured by Miwon) Blending: 100 parts by mass Particles Product name: Sylysia (registered trademark) 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blending: 0.5 parts by mass Next, a first irradiation step was carried out. Specifically, ultraviolet light having a wavelength of 172 nm was irradiated onto the surface of the coating film 6A made of the coating liquid for surface protective layer using a Xe excimer lamp at an integrated light intensity of 50 mJ / cm under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 500 ppm. ２ As a result, convex portions corresponding to the first convex portions P1 and wrinkles corresponding to the second convex portions P2 were formed on the surface of the coating film 6A.

[0171] Subsequently, the second irradiation step was carried out. Specifically, the coating film 6A was irradiated with 50 kGy of ionizing radiation to cure the entire film, thereby forming the surface protective layer 6. In this manner, a decorative sheet 1A was obtained.

[0172] <Example 2> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following ionizing radiation curable resin was used. Ionizing radiation curable resin Type: Trimethylolpropane EO-modified triacrylate (3 EO moles added) Product name: Miramer (registered trademark) M3130 (manufactured by Miwon Co., Ltd.) The first irradiation step involved irradiating the surface of the coating film 6A made of the surface protective layer coating liquid with ultraviolet light having a wavelength of 172 nm at an integrated light intensity of 100 mJ / cm using a Xe excimer lamp under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 200 ppm. ２ The irradiation was carried out so that

[0173] <Example 3> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following ionizing radiation curable resin was used: Ionizing radiation curable resin Type: Trimethylolpropane EO-modified triacrylate (15 moles of EO added) Product name: SR9035 (manufactured by Sartomer) Then, in the first irradiation step, ultraviolet light having a wavelength of 172 nm was irradiated to the surface of the coating film 6A made of the coating liquid for the surface protective layer using a Xe excimer lamp at an integrated light intensity of 50 mJ / cm under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 500 ppm. ２ The irradiation was carried out so that

[0174] <Example 4> A decorative sheet 1A was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following ionizing radiation curable resin was used: Ionizing radiation curable resin Type: ethylene glycol diacrylate (9 moles of EO added) Product name: Light Acrylate 9EG-A (manufactured by Kyoeisha Chemical Co., Ltd.) Then, in the first irradiation step, ultraviolet light having a wavelength of 172 nm was irradiated onto the surface of the coating film 6A made of the coating liquid for the surface protective layer using a Xe excimer lamp at an integrated light intensity of 50 mJ / cm under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 500 ppm. ２ The irradiation was carried out so that

[0175] <Example 5> A decorative sheet 1A was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following ionizing radiation curable resin was used: Ionizing radiation curable resin Type: Ethoxylated pentaerythritol tetraacrylate (35 moles of EO added) Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Co., Ltd.) The first irradiation step involved irradiating the surface of the coating film 6A made of the surface protective layer coating liquid with ultraviolet light at a wavelength of 172 nm using a Xe excimer lamp at an integrated light intensity of 50 mJ / cm under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 200 ppm. ２ The irradiation was carried out so that

[0176] Example 6 A decorative sheet 1A was produced in the same manner as in Example 1, with the following exceptions. That is, in this example, the following ionizing radiation curable resin was used: Ionizing radiation curable resin Type: Ethoxylated dipentaerythritol hexaacrylate (12 moles of EO added) Product name: NK Ester A-DPH-12E (manufactured by Shin-Nakamura Chemical Co., Ltd.) The first irradiation step involved irradiating the surface of the coating film 6A made of the surface protective layer coating liquid with ultraviolet light at a wavelength of 172 nm using a Xe excimer lamp at an integrated light intensity of 150 mJ / cm under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 100 ppm. ２ The irradiation was carried out so that

[0177] Example 7 A decorative sheet 1A was produced in the same manner as in Example 1, except that the coating liquid for the surface protective layer was printed so that the thickness of the surface protective layer 6 was 2 μm.

[0178] Example 8 A decorative sheet 1A was produced in the same manner as in Example 1, except that the surface protective layer coating liquid was printed so that the thickness of the surface protective layer 6 was 20 μm.

[0179] <Example 9> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, particles were omitted from the coating liquid for the surface protective layer. The coating liquid for the surface protective layer was printed so that the thickness of the surface protective layer 6 was 3 μm.

[0180] Example 10 A decorative sheet 1A was produced in the same manner as in Example 1, except that the amount of particles in the coating liquid for the surface protective layer was changed to 10 parts by mass.

[0181] Comparative Example 1 A decorative sheet similar to Decorative Sheet 1A was produced in the same manner as in Example 1, except that the particle blending amount in the coating liquid for surface protective layer was set to 20 parts by mass and the first irradiation step was omitted.

[0182] Comparative Example 2 A decorative sheet similar to Decorative Sheet 1A was produced in the same manner as in Example 1, except that the foaming agent was omitted from the ink composition for forming the pigment-containing layer 3.

[0183] Comparative Example 3 A decorative sheet similar to decorative sheet 1A was produced in the same manner as in Example 1, except that the application of the primer layer coating liquid was omitted and the covering layer 4A and primer layer 4 were not formed.

[0184] <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.

[0185] (1) Thickness of the Surface Protective Layer The thickness of the surface protective layer was measured using the same method as described above. Specifically, the decorative sheet was embedded in a resin such as a cold-setting epoxy resin or a UV-curable resin, and the resin was allowed to fully harden. Next, the decorative sheet was cut so that the cross section of the decorative sheet was exposed, and the measurement surface was obtained by mechanically polishing it.

[0186] Subsequently, a cross section of the surface protective layer was imaged using a SIGMA (registered trademark) 500 scanning electron microscope manufactured by Carl Zeiss Microscopy. The imaging was performed at an acceleration voltage of 0.5 keV (low acceleration voltage), in the SE2 imaging mode, and at a magnification of 2000x. No sputtering was performed on the measurement sample.

[0187] Next, from this cross-sectional image, the dimensions of the surface protective layer in the width direction of the ridge portion and the cross-sectional area of ​​the surface protective layer were determined. The thickness of the surface protective layer was calculated by dividing this area by the above dimensions. The thickness obtained in this manner was equal to the thickness of the coating film made from the surface protective layer coating liquid. The thickness of the primer layer was also measured using the same method as above. For decorative sheets 1A in which bubbles 5 were contained, the thickness of the primer layer 4 was measured using the same method as above for the portion of the primer layer 4 excluding the portion corresponding to the first convex portion P1.

[0188] (2) Glossiness The glossiness was measured as specular glossiness GS(60°) using a Rhopoint IQ-S (manufactured by Rhopoint Instruments). The "60° glossiness value" in Tables 1 to 3 below represents this specular glossiness GS(60°).

[0189] (3) Tactile Feel The tactile feel of the decorative sheets was evaluated using the following method. First, advance preparation was performed to ensure that the evaluation criteria were consistent among the evaluators. Specifically, decorative sheets according to Comparative Examples 1 and 2 were prepared as standard test pieces. Next, each of the five evaluators was blindfolded and asked to slide their fingers over the surface of the standard test piece while pressing it with their fingers, and then to classify the tactile feel into two groups. Two standard test pieces were given to each evaluator in random order, and the above procedure was repeated until the tactile feel of each standard test piece was classified into the same group three or more times in a row. Hereinafter, the group corresponding to the tactile feel of the decorative sheet according to Comparative Example 1 will be referred to as the "first group," and the group corresponding to the tactile feel of the decorative sheet according to Comparative Example 2 will be referred to as the "second group."

[0190] Next, for each of the decorative sheets, each of the evaluators was blindfolded and asked to slide their fingers over the surface while pressing it, and then classify the tactile sensation into three groups. The three groups were the first and second groups, and a third group corresponding to a different tactile sensation. This procedure was repeated until the evaluations by each evaluator were consistent three or more times in a row, and the evaluation results between the evaluators were consistent three or more times in a row. From these results, the skin sensation was evaluated according to the following criteria: A: Group 3 X: Group 1 Y: Group 2

[0191] (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.

[0192] 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.

[0193] The evaluation results are shown in Tables 1 to 3.

[0194]

[0195]

[0196]

[0197] As shown in Table 3, the decorative sheets according to Comparative Examples 2 and 3 exhibited sufficient scratch resistance, while the decorative sheet according to Comparative Example 1 exhibited insufficient scratch resistance. In contrast, the decorative sheets according to Examples 1 to 10 exhibited sufficient scratch resistance, as shown in Tables 1 and 2. Furthermore, the decorative sheets according to Examples 1 to 10 provided a different feel to the touch than the decorative sheets according to Comparative Examples 1 to 3.

[0198] Example 11 A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points: In this example, the primer layer coating liquid was applied so that the primer layer 4 had a thickness of 20 μm in areas excluding the areas corresponding to the first convex portions P1.

[0199] Reference Example 1 A decorative sheet similar to decorative sheet 1A was produced in the same manner as in Example 11, except that the formation of the surface protective layer 6 was omitted.

[0200] Reference Example 2 A decorative sheet similar to decorative sheet 1A was produced in the same manner as in Example 11, except that the first irradiation step was omitted.

[0201] <Analysis> Cross sections of the decorative sheets according to Example 11 and Reference Examples 1 and 2 were photographed using the above-mentioned SIGMA 500 scanning electron microscope.

[0202] Fig. 9 is a microscopic image of a cross section of a decorative sheet according to Example 11 of the present invention. Fig. 10 is a microscopic image of another cross section of a decorative sheet according to Example 11 of the present invention. Fig. 11 is a microscopic image of a cross section of a decorative sheet according to Reference Example 1. Fig. 12 is a microscopic image of a cross section of a decorative sheet according to Reference Example 2.

[0203] 11 shows that bubbles generated by thermal decomposition of the foaming agent cause convex portions to form on the upper surface of the primer layer. Furthermore, FIG. 12 shows that when a coating film made of a surface protective layer coating liquid is formed on a primer layer with convex portions and the coating film is cured without performing the first irradiation step, a surface protective layer having neither first convex portions nor second convex portions on the upper surface is obtained. In other words, it can be seen that the surface protective layer formed without performing the first irradiation step serves as a planarizing layer. Furthermore, FIGS. 9 and 10 show that when a coating film made of a surface protective layer coating liquid is formed on the upper surface of a primer layer with convex portions and the first irradiation step is performed, a surface protective layer having both first convex portions and second convex portions on the upper surface is obtained, with the first convex portions located above the convex portions provided on the upper surface of the primer layer.

[0204] 1...decorative sheet, 1A...decorative sheet, 2...base layer, 3...pigment-containing layer, 3A...ink layer, 4...primer layer, 4A...coating layer, 5...air bubbles, 6...surface protective layer, 6A...coating film, 11...decorative material, 11A...decorative material, B...substrate, DZ...dimensions, H0...height, H1...height, H2...height, P0...convex portion, P1...first convex portion, P2...second convex portion, R...diameter, TP...thickness, W...width.

Claims

1. A decorative sheet comprising a base layer and a surface protective layer provided thereon, wherein there are a plurality of air bubbles between the surface of the surface protective layer and the base layer, and the surface of the surface protective layer includes a region in which a plurality of first protrusions, each corresponding to one or more of the plurality of air bubbles, and a plurality of second protrusions, each ridge-like, are mixed together.

2. The decorative sheet according to claim 1, further comprising a primer layer interposed between the raw material layer and the surface protective layer.

3. The decorative sheet according to claim 2, wherein the surface of the primer layer facing the surface protection layer has a plurality of protrusions at the positions of the plurality of first protrusions.

4. The decorative sheet according to claim 2, wherein the plurality of air bubbles are at least partially located within the primer layer.

5. The decorative sheet according to claim 2, wherein the primer layer comprises a cured resin containing a polymer.

6. The decorative sheet according to claim 2, further comprising a pigment-containing layer interposed between the raw material layer and the primer layer, the pigment-containing layer containing a pigment and a binder resin.

7. The decorative sheet according to claim 6, wherein the surface of the surface protective layer comprises one or more first regions and one or more second regions, the pigment-containing layer is located only between the one or more first regions and the base layer, and the plurality of first protrusions are located in the first regions.

8. The decorative sheet according to claim 2, wherein the primer layer has a thickness of 20 μm or less in the portion excluding the portion corresponding to the first protrusion.

9. The decorative sheet according to claim 1, wherein one or more of the plurality of bubbles have a dimension of 5 μm or more in the thickness direction of the surface protective layer.

10. The decorative sheet according to claim 1, wherein the thickness of the surface protective layer is in the range of 2 μm or more and 15 μm or less.

11. The decorative sheet according to claim 1, wherein the surface protective layer comprises a cured product of an ionizing radiation-curable resin.

12. The decorative sheet according to claim 11, wherein the ionizing radiation-curable resin comprises a bifunctional or more acrylate having a repeating structure.

13. The decorative sheet according to claim 11, wherein the surface protective layer further contains particles with an average particle size of 10 μm or less.

14. The decorative sheet according to claim 1, wherein the glossiness of the surface protective layer is 20 or less.

15. The decorative sheet according to claim 1, wherein each of the plurality of second protrusions does not overlap with any of the plurality of first protrusions.

16. The decorative sheet according to claim 1, wherein one or more of the plurality of second protrusions each include one or more portions that overlap with one of the plurality of first protrusions.

17. A decorative sheet comprising a base layer and a surface protective layer provided thereon, wherein the surface of the surface protective layer includes a region in which a plurality of first protrusions, each having a substantially circular shape in plan view, and a plurality of second protrusions, each having a ridge-like shape, are mixed, and the surface protective layer is a resin layer on which a ridged structure including the plurality of first protrusions and the plurality of second protrusions has been transferred.

18. A decorative sheet comprising a base layer and a surface protective layer provided thereon, wherein the surface of the surface protective layer includes a region in which a plurality of first recesses, each having a substantially circular shape in a plan view, and a plurality of second recesses, each having a groove-like shape, are mixed together.

19. A decorative sheet according to any one of claims 1 to 18, The base material to which the decorative sheet is attached and A decorative material that has the following features.

20. Forming a base layer containing a foaming agent on top of the raw material layer, The foaming agent causes foaming, generating multiple bubbles in the substrate layer, thereby creating multiple protrusions on the surface of the substrate layer, each corresponding to one or more of the bubbles. Subsequently, a coating film containing an ionizing radiation-curable resin is formed on the aforementioned substrate layer. The coating film is irradiated with light having a wavelength of 200 nm or less to create a region on the surface of the coating film in which multiple first protrusions, each corresponding to one of the multiple protrusions, and multiple second protrusions, each having a ridge-like shape, are mixed together. Subsequently, the coating film is completely cured to obtain a surface protective layer. A method for manufacturing decorative sheets containing [a specific material].

21. The method for manufacturing a decorative sheet according to claim 20, wherein the base layer comprises a foaming agent-containing layer containing the foaming agent and a coating layer provided on the foaming agent-containing layer, forming a multilayer structure.

22. The coating layer comprises a polymer-containing resin, A method for manufacturing a decorative sheet according to claim 21, comprising heating the multilayer structure to generate foaming by the foaming agent and curing the resin containing the polymer to obtain a primer layer containing the cured resin containing the polymer and having at least partially located plurality of bubbles.

23. The method for manufacturing a decorative sheet according to claim 21 or 22, wherein the foaming agent-containing layer further comprises a pigment and a binder resin.