Decorative sheet

Abstract

Provided is technology that makes it possible to design the texture and appearance of a decorative sheet with a high degree of freedom. A decorative sheet (1) comprises a raw fabric layer (2) and a surface protection layer (6). A plurality of bubbles (5) are provided between the raw fabric layer (2) and a surface of the surface protection layer (6). The surface protection layer (6) includes a first glossiness adjustment layer (6A) that is provided on the raw fabric layer (2) and that contains a cured product of a first ionizing-radiation-curable resin, and a second glossiness adjustment layer (6B) that partially covers the upper surface of the first glossiness adjustment layer (6A) and that contains a cured product of a second ionizing-radiation-curable resin. The upper surface of the first glossiness adjustment layer (6A) has region in which a plurality of first protrusions (P1) that each correspond to one or more bubbles (5) and a plurality of second protrusions (P2) that are ridge-shaped coexist. The upper surface of the second glossiness adjustment layer (6B) has a plurality of protrusions (P3, P4).

Description

decorative sheet

[0001] This disclosure relates to decorative sheets.

[0002] Decorative sheets are used to enhance the aesthetic appeal and durability of interior and exterior materials such as doors, furniture, joinery, and flooring, and are used for surface decoration. Decorative sheets are generally widely used as decorative panels that are attached to the surface of substrates such as wood, wood fiberboard, metal sheets, non-combustible boards, paper substrates, and resin substrates using adhesives.

[0003] Design appeal is achieved, for example, by creating patterns such as wood grain or stone patterns using various printing methods. Plain, unpatterned decorative sheets are sometimes preferred. The presence or absence of patterns, and the type of pattern chosen, varies depending on the application and personal preference.

[0004] The glossiness of the surface is also an important aspect of the design of decorative sheets. Depending on the application and preference, a variety of decorative sheets can be selected, from highly glossy, mirror-like finishes to low-gloss finishes that show no reflections at all.

[0005] Furthermore, as mentioned above, alongside the provision of aesthetic appeal, durability is another important function of decorative sheets. Durability is a comprehensive evaluation of scratch resistance, stain resistance, and whether these properties are maintained over a long period of time. While the requirements vary depending on the environment and circumstances in which the decorative sheet is used, there is always a demand for decorative sheets with high performance.

[0006] To enhance durability, it is common practice to form a surface protective layer on the outermost surface of the decorative sheet. Furthermore, to adjust the gloss level, particularly to achieve a low gloss, it is common practice to add a gloss adjuster (matte additive) to the surface protective layer.

[0007] Furthermore, since decorative sheets are generally subjected to processes such as cutting and bending to form decorative materials such as decorative panels, it is preferable that they have the processability to withstand these processes.

[0008] As such, an example of a decorative sheet that takes into account aesthetic appeal (low gloss), scratch resistance, and stain resistance is the decorative sheet described in Patent Document 1.

[0009] Japanese Patent Publication No. 2019-119138

[0010] This disclosure aims to provide a technology that enables a high degree of freedom in designing the tactile feel or appearance of decorative sheets.

[0011] According to one aspect of the present invention, a decorative sheet is provided comprising a base layer and a surface protection layer, wherein there are a plurality of air bubbles between the surface of the surface protection layer and the base layer, the surface protection layer is provided on the base layer and includes 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 upper surface of the first gloss adjustment 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, and the upper surface of the second gloss adjustment layer has a plurality of protrusions.

[0012] According to another aspect of the present invention, a decorative sheet is provided in which the first ionizing radiation-curable resin is a first mixture of acrylate and methacrylate.

[0013] According to yet another aspect of the present invention, a decorative sheet is provided relating to any of the above aspects, wherein the plurality of protrusions on the upper surface of the second gloss-adjusting layer include a plurality of third protrusions, each corresponding to any of the plurality of first protrusions.

[0014] According to yet another aspect of the present invention, a decorative sheet is provided relating to any of the above aspects, wherein the plurality of protrusions on the upper surface of the second gloss-adjusting layer include a plurality of fourth protrusions, each of which is ridged.

[0015] According to yet another aspect of the present invention, a decorative sheet is provided in which the portion provided with the second gloss adjustment layer has a different gloss level from the portion provided with the first gloss adjustment layer but not with the second gloss adjustment layer, according to any of the above aspects.

[0016] According to still another aspect of the present invention, the specular glossiness GS(60°) of the first gloss adjustment layer is smaller than the specular glossiness GS(60°) of the second gloss adjustment layer, the specular glossiness GS(60°) of the first gloss adjustment layer is 25 or less, preferably 10 or less, and the specular glossiness GS(60°) of the second gloss adjustment layer is 0.5 or more, preferably 4 or more, and there is provided a decorative sheet according to any of the above aspects.

[0017] Alternatively, according to still another aspect of the present invention, the specular glossiness GS(60°) of the first gloss adjustment layer is larger than the specular glossiness GS(60°) of the second gloss adjustment layer, the specular glossiness GS(60°) of the first gloss adjustment layer is 0.5 or more, and the specular glossiness GS(60°) of the second gloss adjustment layer is 25 or less, and there is provided a decorative sheet according to any of the above aspects.

[0018] According to still another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects in which the absolute value of the difference between the specular glossiness GS(60°) of the second gloss adjustment layer and the specular glossiness GS(60°) of the first gloss adjustment layer is 1 or more.

[0019] According to still another aspect of the present invention, the specular glossiness GS(60°) of the first gloss adjustment layer is smaller than the specular glossiness GS(60°) of the second gloss adjustment layer, and the difference between the specular glossiness GS(60°) of the second gloss adjustment layer and the specular glossiness GS(60°) of the first gloss adjustment layer is 1 or more, and there is provided a decorative sheet according to any of the above aspects.

[0020] According to still another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects further including a primer layer interposed between the base fabric layer and the surface protection layer.

[0021] According to still another aspect of the present invention, there is provided a decorative sheet according to the above aspect in which the surface of the primer layer on the surface protection layer side has a plurality of convex portions at the positions of the plurality of first convex portions.

[0022] According to still another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects in which the plurality of air bubbles are at least partially located within the primer layer.

[0023] According to still another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the primer layer includes a cured product of a resin containing a polymer.

[0024] According to still another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, further including a pigment-containing layer interposed between the base material layer and the primer layer and containing a pigment and a binder resin.

[0025] According to still another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the pigment-containing layer partially covers the upper surface of the base material layer at the position of the second gloss adjustment layer.

[0026] According to still another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the second gloss adjustment layer and the pigment-containing layer have the same shape and position when observed from the thickness direction.

[0027] Alternatively, according to still another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein at least one of the shape and position of the second gloss adjustment layer and the pigment-containing layer is different when observed from the thickness direction.

[0028] According to still 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.

[0029] According to still another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein one or more of the plurality of bubbles have a dimension in the thickness direction of 5 μm or more.

[0030] According to still 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.

[0031] According to still another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein in the first ionizing radiation curable resin, the ratio of the number of moles of methacryloyl groups to the total number of moles of acryloyl groups and methacryloyl groups is in the range of 3% or more and 50% or less.

[0032] According to yet another aspect of the present invention, a decorative sheet is provided relating to any of the above aspects, wherein the methacrylate is monofunctional, difunctional, or trifunctional methacrylate.

[0033] According to yet another aspect of the present invention, the second ionizing radiation-curable resin is acrylate or a second mixture of acrylate and methacrylate, and the second mixture has a smaller ratio of moles of methacryloyl groups to the total number of moles of acryloyl groups and methacryloyl groups compared to the first mixture, thereby providing a decorative sheet according to any of the above aspects.

[0034] According to yet another aspect of the present invention, a decorative sheet is provided relating to any of the above aspects, wherein the acrylate contained in the first ionizing radiation-curable resin is a bifunctional or more functional acrylate having a repeating structure.

[0035] According to yet another aspect of the present invention, a decorative sheet is provided wherein the number of repetitions of the repeating structure is three or more.

[0036] According to yet another aspect of the present invention, a decorative sheet is provided relating to any of the above-mentioned sides, wherein each of the plurality of second protrusions does not overlap with any of the plurality of first protrusions.

[0037] According to yet another aspect of the present invention, a decorative sheet is provided relating to any of the above aspects, wherein one or more of the plurality of second protrusions include one or more portions that overlap with one of the plurality of first protrusions.

[0038] According to yet another aspect of the present invention, a decorative material is provided comprising a decorative sheet relating to any of the above aspects and a substrate to which the decorative sheet is attached.

[0039] According to yet another aspect of the present invention, a base layer containing a foaming agent is formed on a raw material layer; foaming is caused by the foaming agent to generate a plurality of bubbles in the base layer, thereby creating a plurality of protrusions on the surface of the base layer, each corresponding to one or more of the bubbles; then a first coating film containing a first ionizing radiation-curable resin is formed on the base layer; the first coating film is irradiated with first light having a wavelength of 200 nm or less, and then irradiated with ionizing radiation or ultraviolet light with a wavelength longer than the first light to create a plurality of first protrusions, each corresponding to the plurality of protrusions. A method for manufacturing a decorative sheet is provided, which includes obtaining a semi-cured film having a region on its surface in which multiple ridge-like second protrusions are mixed; forming a second coating film containing a second ionizing radiation-curable resin on the semi-cured film so as to partially cover the upper surface of the semi-cured film; irradiating the second coating film with a second light having a wavelength of 200 nm or less, and then irradiating the semi-cured film and the second coating film with ionizing radiation or ultraviolet light with a wavelength longer than the second light to generate multiple protrusions on the surface of the second coating film and to fully cure the semi-cured film and the second coating film.

[0040] According to yet another aspect of the present invention, a base layer containing a foaming agent is formed on a raw material layer; a first coating film containing a first ionizing radiation-curable resin is formed on the base layer; the first coating film is irradiated with first light having a wavelength of 200 nm or less, and then irradiated with ionizing radiation or ultraviolet light with a wavelength longer than the first light to obtain a semi-cured film having a plurality of ridge-like second protrusions on its surface; foaming is caused by the foaming agent to generate a plurality of bubbles in the base layer, thereby creating a plurality of protrusions on the surface of the base layer, each corresponding to one or more of the bubbles, and the A method for manufacturing a decorative sheet is provided, comprising: creating a plurality of first protrusions on the surface of a semi-cured film, each corresponding to a plurality of protrusions; then forming a second coating film containing a second ionizing radiation-curable resin on the semi-cured film so as to partially cover the upper surface of the semi-cured film; irradiating the second coating film with a second light having a wavelength of 200 nm or less; and then irradiating the semi-cured film and the second coating film with ionizing radiation or ultraviolet light with a wavelength longer than the second light to create a plurality of protrusions on the surface of the second coating film and to fully cure the semi-cured film and the second coating film.

[0041] According to yet another aspect of the present invention, a method for manufacturing a decorative sheet according to any of the above aspects is provided, wherein the first ionizing radiation-curable resin contains acrylate and methacrylate.

[0042] According to yet another aspect of the present invention, a method for manufacturing a decorative sheet according to any of the above aspects is provided, which forms a multilayer structure as the base layer, comprising a foaming agent-containing layer containing the foaming agent and a coating layer provided on the foaming agent-containing layer.

[0043] According to yet another aspect of the present invention, a method for manufacturing a decorative sheet is provided, wherein the coating layer comprises a polymer-containing resin, the multilayer structure is heated to generate foam by the foaming agent, and the polymer-containing resin is cured to obtain a primer layer comprising a cured product of the polymer-containing resin, wherein the plurality of bubbles are at least partially located.

[0044] According to yet another aspect of the present invention, a method for manufacturing a decorative sheet according to any of the above aspects is provided, wherein the foaming agent-containing layer further comprises a pigment and a binder resin.

[0045] According to this disclosure, a technology is provided that enables a high degree of freedom in designing the tactile feel or appearance of decorative sheets.

[0046] Figure 1 is a cross-sectional view of a decorative material including a decorative sheet according to the first embodiment of the present invention. Figure 2 is a microscopic image of the surface of a decorative sheet according to an example of the present invention. Figure 3 is a cross-sectional view showing one step in the manufacturing method of 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 of 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 of 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 of a decorative sheet according to the first embodiment of the present invention. Figure 7 is a cross-sectional view showing yet another step in the manufacturing method of a decorative sheet according to the first embodiment of the present invention. Figure 8 is a cross-sectional view showing yet another step in the manufacturing method of a decorative sheet according to the first embodiment of the present invention. Figure 9 is a microscopic image of the surface of a decorative sheet according to a comparative example. Figure 10 is a cross-sectional view of a decorative material including a decorative sheet according to the second embodiment of the present invention.

[0047] Embodiments of the present invention will be described below with reference to the drawings. The embodiments described below are more specific to any of the above aspects. The matters described below can be incorporated into each of the above aspects, individually or in combination.

[0048] Furthermore, the embodiments shown below illustrate configurations for realizing the technical concept of the present invention, and the technical concept of the present invention is not limited by the material, shape, and structure of the components described below. Various modifications can be made to the technical concept of the present invention within the technical scope defined by the claims described in the claims.

[0049] Elements with similar or identical functions are given the same reference numerals in the drawings referenced below, and redundant explanations are omitted. Furthermore, the drawings are schematic, and the relationships between dimensions in one direction and those in another, and the relationships between the dimensions of one component and those of other components, may differ from reality.

[0050] <1> First Embodiment <1.1> Decorative Material and Decorative Sheet Figure 1 is a cross-sectional view of a decorative material including a decorative sheet according to the first embodiment of the present invention. Figure 2 is a micrograph of the surface of a decorative sheet according to an example of the present invention. The micrograph in Figure 2 is a planar photograph obtained by imaging using a laser microscope (OLS-4000 manufactured by Olympus Corporation) of the area of ​​the surface of the first gloss adjustment layer, which will be described later, that is not covered by the second gloss adjustment layer, which will be described later.

[0051] The decorative material 11 shown in Figure 1 includes a base material B and a decorative sheet 1 attached thereto. Here, the decorative material 11 is a decorative board. The decorative board may be flat, bent, or folded. The decorative material 11 may have a shape other than a board.

[0052] In this case, base material B is a board. The board material is, for example, a wood-based board, an inorganic board, a metal plate, or a composite board made of multiple materials. Base material B may have a shape other than a board.

[0053] The decorative sheet 1 comprises a base layer 2, a pigment-containing layer 3, a primer layer 4, and a surface protection layer 6. The pigment-containing layer 3, the primer layer 4, and the surface protection layer 6 are provided in this order from the base layer 2 side, on the side of the base layer 2 opposite to the side facing the substrate B. The decorative sheet 1 may further include one or more other layers.

[0054] The decorative sheet 1 has a plurality of air bubbles 5 between the surface of the surface protective layer 6 and the base layer 2. Here, the air bubbles 5 are at least partially located within the primer layer 4.

[0055] The surface protection layer 6 includes a first gloss adjustment layer 6A and a second gloss adjustment layer 6B that partially covers it.

[0056] The surface of the first gloss adjustment layer 6A includes a region where multiple first protrusions P1, each corresponding to one or more of the air bubbles 5, and multiple second protrusions P2, each ridge-like, are mixed together. Here, the surface of the primer layer 4 facing the surface protection layer 6 has protrusions P0 at the positions of the first protrusions P1.

[0057] The surface of the second gloss adjustment layer 6B has a plurality of protrusions. These protrusions include a plurality of third protrusions P3, each corresponding to one of the first protrusions, and a plurality of fourth protrusions P4, each having a ridge-like shape.

[0058] The elements included in decorative sheet 1 will be explained in order below.

[0059] <1.1.1> Raw Material Layer The raw material layer 2 can have various forms such as film, sheet, plate, and irregularly shaped molded body. Here, as an example, the raw material layer 2 is in the form of a film.

[0060] The base layer 2 or its materials can be arbitrarily 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. Organic and inorganic nonwoven fabrics can be used as nonwoven fabrics. Examples of metals for metal foil include aluminum, iron, gold, and silver.

[0061] The thickness of the base layer 2 is preferably within the range of 20 μm to 250 μm. If the base layer 2 is made thinner, its ability to cover unevenness in the substrate (unevenness) will decrease. If the base layer 2 is thick, defects such as whitening and cracking may occur during bending.

[0062] When using a substrate with an inert surface, such as an olefin-based substrate, as the base layer 2, it is desirable to perform treatments such as corona treatment, plasma treatment, ozone treatment, electron beam treatment, ultraviolet treatment, and dichromate treatment on both sides of the base layer 2.

[0063] <1.1.2> Pigment-containing layer The pigment-containing layer 3 is provided on the base material layer 2 and is a layer containing pigment and binder resin. The pigment-containing layer 3 is a continuous film formed by covering one entire surface of the base material layer 2 with ink, for example. In this case, the pigment-containing layer 3 can serve as an opacity layer that conceals the substrate B or the base material layer 2. In this case, the pigment-containing layer 3 can also serve as a planarization layer.

[0064] The pigment-containing layer 3 may have a single-layer structure or a multilayer structure. If the pigment-containing layer 3 has a multilayer structure, all of its layers may be continuous films, all of its layers may be discontinuous films, or one or more layers may be continuous films and the remaining layers may be discontinuous films.

[0065] The pigment-containing layer 3 can be formed, for example, using a printing ink (or coating agent) which is obtained by dissolving or dispersing a binder resin that serves as a matrix, along with a pigment and a coloring agent such as a dye, in a solvent.

[0066] As the binder resin, various synthetic resins such as oily nitrate resin, two-component urethane resin, acrylic resin, styrene resin, polyester resin, urethane resin, polyvinyl resin, alkyd resin, epoxy resin, melamine resin, fluororesin, silicone resin, and Omi rubber resin, or mixtures or copolymers thereof, can be used.

[0067] The pigment is at least one of a white pigment and a colored pigment. Examples of pigments include inorganic pigments such as carbon black, titanium dioxide (titanium white), zinc oxide, iron oxide, lead yellow, Prussian blue, and cadmium red; organic pigments such as azo pigments, lake pigments, anthraquinone pigments, phthalocyanine pigments, isoindolinone pigments, and dioxazine pigments; or mixtures thereof.

[0068] 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 of the surface protective layer 6, which will be described later.

[0069] The amount of pigment is preferably in the range of 2 parts by mass or more and 50 parts by mass or less, and more preferably in the range of 5 parts by mass or more and 30 parts by mass or less, per 100 parts by mass of binder resin.

[0070] As solvents, for example, toluene, xylene, ethyl acetate, butyl acetate, methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, water, or mixtures thereof can be used.

[0071] The ink used to form the pigment-containing layer 3 may contain a 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. For example, the ink may contain the binder resin in the form of an aqueous emulsion or dispersion. Furthermore, the ink may harden by the evaporation of a solvent, by irradiation with ionizing radiation, or by heat curing.

[0072] The above ink may further contain a foaming agent. The foaming agent can be used to generate bubbles 5. Here, as an example, we assume that the above ink further contains a foaming agent.

[0073] As blowing agents, for example, inorganic blowing agents such as sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, ammonium nitrite, sodium borode, light metals, and azides; organic blowing agents such as azo, nitroso, and hydrazide types; or combinations of two or more thereof can be used. As an azo organic blowing agent, for example, azodicarbonamide can be used. As a nitroso organic blowing agent, for example, N,N'-dinitrosopentamethylenetetramine can be used. As a hydrazide organic blowing agent, for example, 4,4'-oxybisbenzenesulfonyl hydrazide can be used.

[0074] The amount of foaming agent is preferably in the range of 1 part by mass to 20 parts by mass, and more preferably in the range of 5 parts by mass to 15 parts by mass, per 100 parts by mass of binder resin.

[0075] If the above ink contains a foaming agent, it may further contain a foaming aid to lower the decomposition temperature of the foaming agent. For example, if the above ink contains an azo-based organic foaming agent such as azodicarbonamide, it may further contain a metal catalyst. Also, if the above ink contains a nitroso-based organic foaming agent such as N,N'-dinitrosopentamethylenetetramine, it may further contain a urea-based foaming aid.

[0076] Furthermore, functional additives such as plasticizers, dispersants, surfactants, tackifiers, adhesion aids, drying agents, curing agents, curing accelerators, and curing retarders may be added to the above inks to impart various functions.

[0077] <1.1.3> Primer Layer The primer layer 4 is provided on top of the pigment-containing layer 3. Here, the primer layer 4 covers the entire surface of one side of the raw material layer 2 with the pigment-containing layer 3 in between.

[0078] The primer layer 4 is made of, for example, a cured resin. The primer layer 4 may further contain particles. As particles, for example, the particles described later for the surface protective layer 6 can be used.

[0079] When the mass of the primer layer 4 is 100 parts by mass, the mass of the resin cured product 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.

[0080] The cured resin contained in the primer layer 4 is, for example, the cured resin of the binder resin of the pigment-containing layer 3 as described above. The cured resin contained in the primer layer 4 may also be other cured resins, for example, the cured resin of the surface protective layer 6 as described later.

[0081] The resin used to form the primer layer 4 may be solvent-free, water-based, or non-water-based (organic solvent-based).

[0082] The above-mentioned cured resin product 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 both a thermosetting resin and an ionizing radiation-curable resin. Here, "ionizing radiation" refers to charged particle beams such as electron beams. Ionizing radiation-curable resins harden upon irradiation with ionizing radiation. Ionizing radiation-curable resins can also be hardened by irradiation with ultraviolet light.

[0083] The cured resin product preferably contains a cured resin containing a polymer, for example, a cured aqueous emulsion containing a polymer or a cured solvent-based resin containing a polymer. The reasons for this are explained below.

[0084] As described later, in the manufacture of decorative sheet 1, for example, first, a foaming agent-containing layer made of the above-mentioned ink containing a foaming agent and a coating layer containing uncured resin are formed on the base layer 2 in this order, and then the multilayer structure containing these is heated. During this heating process, at least a portion of the gas produced by the thermal decomposition of the foaming agent is incorporated into the coating layer, generating bubbles within the coating layer. If the crosslinking density of the resin constituting the coating layer is sufficiently low, the coating layer can incorporate a large amount of gas. In this case, bubble coalescence is likely to occur within the coating layer. Therefore, if the crosslinking density of the resin constituting the coating layer is sufficiently low, large bubbles can be generated within the coating layer. However, if the crosslinking density of the resin constituting the coating layer is low, the structure containing bubbles is prone to destruction.

[0085] The coating layer formed from the above-mentioned water-based or solvent-based resin is mainly composed of polymers with low crosslinking density, and therefore can possess moderate flexibility and moderate strength. For this reason, when a coating layer is formed from the above-mentioned water-based or solvent-based resin, it is possible to create large air bubbles within the coating layer, while making it difficult for the structure containing such large air bubbles to break down.

[0086] As described above, in this configuration, the bubble 5 is 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, contains one or more protrusions P0, each corresponding to one or more of the bubbles 5. In this configuration, the bubble 5 creates protrusions P0 on the upper surface of the primer layer 4, and the protrusions P0 create a first protrusion P1 on the surface of the surface protective layer 6.

[0087] As shown in Figure 1, one bubble 5 may form one protrusion P0, or two or more bubbles 5 may form one protrusion P0. The number of bubbles 5 forming one protrusion P0 is preferably 15 or less, more preferably 10 or less, and even more preferably 5 or less.

[0088] In this case, most of the protrusions P0 are formed by a single air bubble 5. Therefore, most of the protrusions P0 have a roughly dome shape and a roughly circular shape when viewed from above.

[0089] Preferably, one or more of the bubbles 5 have a dimension DZ in the thickness direction of the surface protective layer 6 of 5 μm or more, and more preferably 8 μm or more. Bubbles 5 with a large dimension DZ can create a protrusion P0 with a large height H0 on the upper surface of the primer layer 4. Here, the height H0 of the protrusion P0 is the height relative to the area on the upper surface of the primer layer 4 where the protrusion P0 does not occur.

[0090] The air bubbles 5 preferably have a dimension DZ in the thickness direction of the surface protective layer 6 of 100 μm or less, and more preferably 80 μm or less. Decorative sheets 1 having air bubbles 5 with a large dimension DZ tend to have a large variation in the dimension DZ.

[0091] Furthermore, most of the bubbles 5 are spherical or have a similar shape. Therefore, for most of the bubbles 5, the dimension DZ is approximately equal to the dimensions in each direction perpendicular to the thickness direction.

[0092] The primer layer 4, excluding the portion corresponding to the first protrusion P1, in this case the portion other than the protrusion P0, preferably has a thickness TP of 20 μm or less, and more preferably 15 μm or less. Also, the thickness TP and the maximum value of dimension DZ DZ Ｍａｘ Ratio TP / DZ Ｍａｘ It is preferably 2 or less, more preferably 1 or less, and even more preferably 0.9 or less. Thickness TP or ratio TP / DZ Ｍａｘ Increasing the value of the protrusion P0 reduces the height H0 of the protrusion P0.

[0093] The thickness TP is preferably 2 μm or more, and more preferably 5 μm or more. Also, the ratio TP / DZ Ｍａｘ The ratio is preferably 0.05 or higher, more preferably 0.1 or higher, and even more preferably 0.2 or higher. For stable manufacturing, the thickness TP or ratio TP / DZ Ｍａｘ It is preferable that it be large.

[0094] The height H0 of the protrusion P0 is preferably 1 μm or more, and more preferably 2 μm or more. A large height H0 is preferable for generating a first protrusion P1 with a large height H1 on the surface of the surface protective layer 6. Here, the height H1 of the first protrusion P1 is the height of the top of the protrusion, with respect to the lowest point on its periphery. In one example, the height H0 of the protrusion P0 is 20 μm or less, and in another example, it is 15 μm or less.

[0095] <1.1.4> Surface protective layer The surface protective layer 6 is provided on top of the primer layer 4. Here, the surface protective layer 6 covers the entire upper surface of the primer layer 4.

[0096] As described above, the surface protection layer 6 includes a first gloss adjustment layer 6A and a second gloss adjustment layer 6B that partially covers it. Each of the first gloss adjustment layer 6A and the second gloss adjustment layer 6B has an uneven surface. That is, the surface protection layer 6 has an uneven surface.

[0097] The surface of the surface protective layer 6 preferably has a root mean square slope Sdq within the range of 1.0 to 2.5, more preferably within the range of 1.1 to 2.5, and even more preferably within the range of 1.2 to 2.5.

[0098] Here, the "root mean square slope Sdq of the surface of the surface protection layer" is the root mean square slope Sdq measured for a region that includes a first partial region, which is a part of the upper surface of the first gloss adjustment layer that is not covered by the second gloss adjustment layer, and a second partial region, which is a part of the upper surface of the second gloss adjustment layer. This region is selected such that the ratio of the area of ​​the first partial region to the area of ​​the second partial region matches the ratio of the total area of ​​the upper surface of the first gloss adjustment layer that is not covered by the second gloss adjustment layer to the total area of ​​the upper surface of the second gloss adjustment layer.

[0099] The root mean square slope Sdq mentioned above is obtained by measurement using a laser microscope (ISO 25178). Specifically, the surface of the decorative sheet is imaged at 10x magnification using a laser microscope. For example, a VK-X3000 (manufactured by KEYENCE) is used as the laser microscope. Next, image processing is performed on the image obtained. After that, the root mean square slope Sdq is obtained from the data of this image. Specifically, the root mean square slope Sdq is calculated for the five regions selected as described above, and these are arithmetic mean. For image processing and surface roughness measurement software, for example, the VK-X3000 Multi-File Analysis Application is used. For image processing, height reduction (medium) and noise reduction (medium) are performed.

[0100] The "root mean square slope Sdq of the surface protective layer" is a numerical representation of the steepness of the convex or concave parts of the surface protective layer, and represents the average value of the local gradient of this uneven structure. When the value of the root mean square slope Sdq is large, the gradient of the convex or concave parts becomes larger, and the effect of the uneven structure on reducing the specular gloss GS (60°) becomes greater. However, if the value of the root mean square slope Sdq is too small, it becomes difficult to wipe off dirt adhering to the surface of the decorative sheet 1, making it difficult to achieve high stain resistance. Note that the upper limit of the root mean square slope Sdq is not set in relation to the surface properties of the surface protective layer, but is set as a value that can be measured by the above measurement method (upper measurement limit).

[0101] The ratio P1 / P2 between "the ratio P1 (%) of the surface area of ​​the first gloss adjustment layer to the total surface area of ​​the decorative sheet" and "the ratio P2 (%) of the surface area of ​​the second gloss adjustment layer to the total surface area of ​​the decorative sheet" can be, for example, within the range of 1 / 9 or more and 9 / 1 or less. Note that the ratio P1 / P2 corresponds to the ratio SS1 / SS2 of the area SS1 of the surface of the first gloss adjustment layer that is not covered by the second gloss adjustment layer and the surface area SS2 of the second gloss adjustment layer.

[0102] <1.1.4.1> First gloss adjustment layer The first gloss adjustment layer 6A covers the entire upper surface of the primer layer 4. The surface of the first gloss adjustment layer 6A includes a region in which multiple first protrusions P1, each corresponding to one or more of the air bubbles 5, and multiple second protrusions P2, each ridge-like, are mixed together.

[0103] The first protrusions P1 are formed on the surface of the first gloss adjustment layer 6A by the protrusions P0. Therefore, the first protrusions P1 are located above the protrusions P0 provided on the upper surface of the primer layer 4, and each has a shape corresponding to the protrusions P0. As described above, most of the protrusions P0 have a roughly dome shape and a roughly circular shape in plan view, so most of the first protrusions P1 also have a roughly dome shape and a roughly circular shape in plan view, as shown in Figure 2.

[0104] The second protrusion P2 is a wrinkle formed on the surface of the first gloss adjustment layer 6A. The second protrusion P2 may be curved or straight in plan view, but from the viewpoint of fingerprint resistance of the surface of the decorative sheet 1, it is preferable that it be curved, as illustrated in Figure 2.

[0105] The first protrusion P1 and the second protrusion P2 affect the tactile feel of the surface protective layer 6. Furthermore, the first protrusion P1 and the second protrusion P2 also affect the gloss level of the first gloss adjustment layer 6A.

[0106] The height H1 of the first protrusion P1 is preferably 1 μm or more, and more preferably 2 μm or more. In one example, the height H1 of the first protrusion P1 is 20 μm or less, and in another example, 15 μm or less. In one example, the diameter R of the first protrusion P1 is in the range of 20 μm to 300 μm, and in another example, the diameter R is in the range of 50 μm to 200 μm. The ratio H1 / R of height H1 to diameter R is preferably in the range of 0.01 to 0.1, and more preferably in the range of 0.02 to 0.08.

[0107] The height H2 of the second protrusion P2 is preferably 1 μm or more, and more preferably 2 μm or more. In one example, the height H2 of the second protrusion P2 is 20 μm or less, and in another example, 15 μm or less. Here, the height H2 of the second protrusion P2 is the height of the top with respect to its edge. In 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 in another example, the width W is in the range of 5 μm or more and 100 μm or less. The ratio H2 / W of height H2 to width W is preferably in the range of 0.01 or more and more preferably in the range of 0.02 or more and 0.1 or less.

[0108] The ratio R / W of the diameter R of the first protrusion P1 to the width W of the second protrusion P2 is preferably within the range of 1 to 100, and more preferably within the range of 2 to 50. The ratio H1 / H2 of the height H1 of the first protrusion P1 to the height H2 of the second protrusion P2 is preferably within the range of 0.1 to 10, and more preferably within the range of 0.2 to 5. The ratio S1 / S2 of the total area S1 of the first protrusion P1 to the total area S2 of the second protrusion P2, obtained by observation in a plan view, is preferably within the range of 0.1 to 10, and more preferably within the range of 0.2 to 5.

[0109] The surface of the first gloss adjustment layer 6A preferably has a root mean square slope Sdq of 0.5 or more and 2.5 or less, more preferably 0.8 or more and 2.5 or less, and even more preferably 1.0 or more and 2.5 or less. Here, this root mean square slope Sdq is a value obtained by the same method as described above for the root mean square slope Sdq of the surface of the surface protection layer 6, except that five regions on the surface of the first gloss adjustment layer 6A that are not covered by the second gloss adjustment layer 6B are selected as the five regions for which the root mean square slope Sdq should be determined. Here again, the upper limit of the root mean square slope Sdq is not set in relation to the surface properties of the first gloss adjustment layer 6A, but is set as a value that can be measured by the measurement method described later (measurement upper limit).

[0110] It is even more desirable that the root mean square slope Sdq of the surface of the first gloss adjustment layer 6A be between 1.3 and 2.5. Most desirable that the root mean square slope Sdq of the surface of the first gloss adjustment layer 6A be between 1.5 and 2.5. The larger the value of the root mean square slope Sdq of the surface of the first gloss adjustment layer 6A, the lower the gloss of the first gloss adjustment layer 6A, which can contribute more significantly to the decrease in gloss of the decorative sheet 1.

[0111] The specular gloss GS(60°) of the first gloss adjustment layer 6A is preferably 25 or less, more preferably 20 or less, even more preferably 18 or less, even more preferably 15 or less, and even more preferably 10 or less. In one example, the specular gloss GS(60°) of the first gloss adjustment layer 6A is 0.5 or more. Here, "specular gloss GS(60°)" is the specular gloss measured at an incident angle of 60 degrees using a gloss meter compliant with ISO 2813. Note that the specular gloss GS(60°) may be expressed with a "%" sign following the numerical value, but the "%" sign is omitted here.

[0112] The thickness of the first gloss adjustment layer 6A 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 2 μm to 10 μm. If the thickness of the first gloss adjustment layer 6A is reduced, it becomes difficult to create a second protrusion P2 with a large height H2 on its surface. If the thickness of the first gloss adjustment layer 6A is increased, it becomes difficult to create a first protrusion P1 with a large height H1 on its surface. In addition, if the thickness of the first gloss adjustment layer 6A is increased, the processability of the decorative sheet 1 decreases, and it becomes more prone to whitening when bent.

[0113] Here, the thickness of the first gloss adjustment layer 6A is the thickness of a layer that has the same apparent area and volume as the first gloss adjustment layer 6A and has a flat surface. The thickness of the first gloss adjustment layer 6A can be determined, for example, by the following method. First, a cross-sectional image parallel to the thickness direction of the first gloss adjustment layer 6A is taken. Next, from this cross-sectional image, the dimensions in the direction perpendicular to the thickness direction of the first gloss adjustment layer 6A and the area of ​​the cross-section of the first gloss adjustment layer 6A are determined. The thickness of the first gloss adjustment layer 6A is the value obtained by dividing this area by the above dimensions. Note that if the coating liquid for the first gloss adjustment layer, which will be described later, does not contain a solvent, the thickness of the coating film made from this coating liquid is equal to the thickness of the first gloss adjustment layer 6A.

[0114] The first gloss-adjusting layer 6A contains a cured resin. As will be described later, the first gloss-adjusting layer 6A may further contain particles. When the mass of the first gloss-adjusting layer 6A is 100 parts by mass, the mass of the cured resin contained in the first gloss-adjusting layer 6A 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.

[0115] The first gloss adjustment layer 6A contains a cured resin product of the first ionizing radiation-curable resin. As described above, ionizing radiation is a charged particle beam such as an electron beam. The first ionizing radiation-curable resin hardens upon irradiation with ionizing radiation. The first ionizing radiation-curable resin can also be hardened by irradiation with ultraviolet light. The first ionizing radiation-curable resin used here hardens upon irradiation with light having a wavelength of 200 nm or less, while having a large absorption coefficient for this light.

[0116] The first ionizing radiation-curable resin is, in one example, a first mixture of acrylate and methacrylate. The first ionizing radiation-curable resin does not necessarily contain methacrylate. However, it is preferable that the first ionizing radiation-curable resin further contains methacrylate in addition to acrylate, as described below.

[0117] The methacrylate enables the partial curing of the first coating film containing the first ionizing radiation-curable resin by irradiation with ionizing radiation or ultraviolet light, thereby achieving high adhesion between the first gloss adjustment layer 6A and the second gloss adjustment layer 6B. If the main component of the first ionizing radiation-curable resin does not contain methacrylate resin, not only will the desired adhesion not be obtained, but the scratch resistance and stain resistance may also be insufficient as a result.

[0118] In the first ionizing radiation-curable resin, the ratio of moles of methacryloyl groups to the total number of moles of acryloyl groups is preferably in the range of 3% to 50%, and more preferably in the range of 5% to 40%. Increasing the above ratio widens the process window in which high adhesion between the first gloss adjustment layer 6A and the second gloss adjustment layer 6B can be achieved. However, if the above ratio is increased excessively, the scratch resistance of the decorative sheet 1 decreases.

[0119] The methacrylate is preferably monofunctional, difunctional, or trifunctional. The methacrylate may be any of monofunctional, difunctional, or trifunctional methacrylates, or two or more of these.

[0120] When a methacrylate with a high number of functional groups is used, the degree of crosslinking is increased and scratch resistance is improved compared to when a methacrylate with a low number of functional groups is used. However, when a methacrylate with an excessively high number of functional groups is used, the rate of the crosslinking reaction due to ionizing radiation or ultraviolet light irradiation increases, which narrows the process window in which high adhesion can be achieved between the first gloss adjustment layer 6A and the second gloss adjustment layer 6B.

[0121] The acrylate is preferably a bifunctional or more functional acrylate, and more preferably a trifunctional or more functional acrylate. In order to obtain a first gloss-adjusting layer 6A with excellent scratch resistance, it is preferable that the acrylate be trifunctional or more. There is no upper limit to the number of functional groups of the acrylate, but according to one example, it is 6 functional or less.

[0122] The acrylate preferably contains a repeating structure. This repeating structure is, for example, one of the following: an ethylene oxide (EO) structure, a propylene oxide (PO) structure, or an ε-caprolactone (CL) structure. The repeating structure is preferably ethylene oxide or propylene oxide. In the acrylate, the above repeating structure may be interposed between the acryloyl group and the methylol group in a ring-opened state.

[0123] The number of repetitions of the repeating structure is preferably three or more. If an acrylate with a high number of repetitions is used, expansion in the in-plane direction of the cured film is more likely to occur in the first irradiation step described later, and therefore, wrinkles are more likely to form on the surface of the coating film. However, if the number of repetitions is increased, the crosslinking density decreases, and the scratch resistance of the decorative sheet 1 decreases. Therefore, the number of repetitions is preferably 30 or less, and more preferably 20 or less.

[0124] The number of repetitions in the above repeating structure can be analyzed using MALDI-TOF-MS. Ionizing radiation-curable resins may have a molecular weight distribution. If a molecular weight distribution exists, the number of repetitions should be the number of repetitions corresponding to the molecular weight with the strongest peak in the mass spectrum obtained by MALDI-TOF-MS.

[0125] The first gloss-adjusting layer 6A may further contain particles in addition to the cured resin. Examples of particles that can be included in the first gloss-adjusting layer 6A include particles made of organic materials such as polyethylene (PE) wax, polypropylene (PP) wax, and resin beads, or particles made of inorganic materials such as silica, glass, alumina, titania, zirconia, calcium carbonate, and barium sulfate.

[0126] The average particle size (D50) is preferably 20 μm or less, more preferably 10 μm or less, even 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) is increased, it becomes easier for particles to fall off from the first gloss adjustment layer 6A, and it may become difficult to achieve high scratch resistance. If the particles are small, the effect of uniformly generating wrinkles is reduced. Here, "average particle size" or "average particle size (D50)" is the median diameter (D50) measured by a laser diffraction / scattering particle size distribution analyzer. Note that if the coating liquid for the first gloss adjustment layer contains particles, the first gloss adjustment layer 6A obtained from this coating liquid will also contain particles. The average particle size of the particles contained in the first gloss adjustment layer 6A can be obtained by observing its cross-section, measuring the particle sizes of multiple particles, and averaging the result. The value obtained in this way is substantially the same as the median diameter (D50) measured by a laser diffraction / scattering particle size distribution analyzer. Therefore, the range of average particle size described above can also be interpreted as the range of average particle size of the particles contained in the first gloss adjustment layer.

[0127] The amount of particles in the first gloss adjustment layer 6A is preferably in the range of 0.5% to 20% by mass, more preferably in the range of 0.5% to 10% by mass, even more preferably in the range of 2% to 8% by mass, and most preferably in the range of 2% to 6% by mass, based on 100% by mass of the cured resin.

[0128] When the amount of added particles is within the above range, the effect of creating wrinkles uniformly is particularly great. If the amount of added particles is too high, it is easy for the particles to fall off from the first gloss adjustment layer 6A, and it may become difficult to achieve high scratch resistance.

[0129] <1.1.4.2> Second gloss adjustment layer The second gloss adjustment layer 6B partially covers the upper surface of the first gloss adjustment layer 6A. In this case, the second gloss adjustment layer 6B partially covers the area on the upper surface of the first gloss adjustment layer 6A where the first protrusion P1 is provided, and also partially covers the area where the second protrusion P2 is provided.

[0130] The surface of the second gloss adjustment layer 6B includes a region where multiple third protrusions P3, each corresponding to one of the multiple first protrusions P1, and multiple fourth protrusions P4, each having a ridge-like shape, are mixed together.

[0131] The third protrusion P3 is formed on the surface of the second gloss adjustment layer 6B by the first protrusion P1. Therefore, the third protrusion P3 is located above the first protrusion P1 which is provided on the upper surface of the first gloss adjustment layer 6A, and each has a shape corresponding to the first protrusion P1. As described above, most of the first protrusion P1 has a roughly dome shape and a roughly circular shape in plan view, so most of the third protrusion P3 also have a roughly dome shape and a roughly circular shape in plan view.

[0132] The fourth protrusion P4 is a wrinkle formed on the surface of the second gloss adjustment layer 6B. The fourth protrusion P4 may be curved or straight in plan view, but from the viewpoint of fingerprint resistance of the surface of the decorative sheet 1, it is preferable that it be curved, similar to the second protrusion P2.

[0133] The third protrusion P3 and the fourth protrusion P4 affect the tactile feel of the surface protective layer 6. Furthermore, the third protrusion P3 and the fourth protrusion P4 also affect the glossiness of the second gloss adjustment layer 6B.

[0134] Here, a structure is illustrated in which the multiple protrusions on the upper surface of the second gloss adjustment layer 6B are the third protrusion P3 and the fourth protrusion P4. However, the multiple protrusions on the upper surface of the second gloss adjustment layer 6B may consist only of the fourth protrusion P4. The third protrusion P3 has a lower degree of shape agreement with the first protrusion P0 compared to the first protrusion P1. Therefore, for example, the bulge that occurs on the upper surface of the second gloss adjustment layer 6B due to the first protrusion P1 may be low in height, and in this case, the fourth protrusion P4 may also occur at the location of this bulge, making it impossible to confirm the existence of the third protrusion P3. Consequently, the third protrusion P3 may have the dimensions and shape described above for the first protrusion P1, but it may have smaller dimensions than the first protrusion P1, or its existence may not be confirmed at all.

[0135] The fourth protrusion P4 may have the dimensions and shape described above for the second protrusion P2. The dimensions of the fourth protrusion P4 may be the same as those of the second protrusion P2, or they may be different. The shape of the pattern formed by the fourth protrusion P4 is different from the shape of the pattern formed by the second protrusion P2. For example, the shape of the pattern formed by the fourth protrusion P4 is completely independent of the shape of the pattern formed by the second protrusion P2. However, if the thickness of the second gloss adjustment layer 6B is small, the pattern formed by the second protrusion P2 may affect the shape of the pattern formed by the fourth protrusion P4.

[0136] The surface of the second gloss adjustment layer 6B preferably has a root mean square slope Sdq of 0.5 or more and 2.5 or less, more preferably 0.8 or more and 2.5 or less, and even more preferably 1.0 or more and 2.5 or less. Here, this root mean square slope Sdq is a value obtained by the same method as described above for the root mean square slope Sdq of the surface of the surface protection layer 6, except that five regions on the surface of the second gloss adjustment layer 6B are selected as the five regions for which the root mean square slope Sdq should be determined. Here again, the upper limit of the root mean square slope Sdq is not set in relation to the surface properties of the second gloss adjustment layer 6B, but is set as a value that can be measured by the measurement method described later (measurement upper limit).

[0137] It is even more desirable that the value of the root mean square slope Sdq of the surface of the second gloss adjustment layer 6B be between 1.3 and 2.5. Most desirable that the value of the root mean square slope Sdq of the surface of the second gloss adjustment layer 6B be between 1.5 and 2.5. The larger the value of the root mean square slope Sdq of the surface of the second gloss adjustment layer 6B, the lower the gloss of the second gloss adjustment layer 6B becomes, which can contribute more significantly to the decrease in gloss of the decorative sheet 1.

[0138] The specular gloss GS (60°) of the second gloss adjustment layer 6B is preferably 25 or less, more preferably 20 or less, more preferably 18 or less, and even more preferably 15 or less. The specular gloss GS (60°) of the second gloss adjustment layer 6A is 0.5 or more in one example, and 4 or more in another example.

[0139] In one example, the specular gloss GS(60°) of the first gloss adjustment layer 6A is smaller than that of the second gloss adjustment layer 6B. In another example, the specular gloss GS(60°) of the first gloss adjustment layer 6A is larger than that of the second gloss adjustment layer 6B. The difference between the specular gloss GS(60°) of the second gloss adjustment layer 6B and the specular gloss GS(60°) of the first gloss adjustment layer 6A is preferably 1 or more, more preferably 3 or more, and even more preferably 5 or more. When utilizing these differences in specular gloss GS(60°) for designing the appearance, it is preferable that the absolute value of the difference between the specular gloss GS(60°) of the second gloss adjustment layer 6B and the specular gloss GS(60°) of the first gloss adjustment layer 6A is large.

[0140] The thickness of the second gloss adjustment layer 6B 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 2 μm to 10 μm. If the thickness of the second gloss adjustment layer 6B is reduced, it becomes difficult to create a fourth protrusion P4 with a large height on its surface. If the thickness of the second gloss adjustment layer 6B is increased, it becomes difficult to create a third protrusion P3 with a large height on its surface, or it becomes difficult to create the third protrusion P3 at all. In addition, if the thickness of the second gloss adjustment layer 6B is increased, the processability of the decorative sheet 1 decreases, and it becomes more prone to whitening when folded. The thickness of the second gloss adjustment layer 6B can be measured by the same method as described above for the thickness of the first gloss adjustment layer 6A. Furthermore, if the coating liquid for the second gloss adjustment layer, which will be described later, does not contain a solvent, the thickness of the coating film made from this coating liquid is equal to the thickness of the second gloss adjustment layer 6B.

[0141] The second gloss-adjusting layer 6B contains a cured resin. As will be described later, the second gloss-adjusting layer 6B may further contain particles. When the mass of the second gloss-adjusting layer 6B is 100 parts by mass, the mass of the cured resin contained in the second gloss-adjusting layer 6B 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.

[0142] The second gloss adjustment layer 6B contains a cured resin product of a second ionizing radiation-curable resin. As described above, ionizing radiation is a charged particle beam such as an electron beam. The second ionizing radiation-curable resin hardens upon irradiation with ionizing radiation. The second ionizing radiation-curable resin can also be hardened by irradiation with ultraviolet light. The second ionizing radiation-curable resin used here hardens upon irradiation with light with a wavelength of 200 nm or less, while having a large absorption coefficient for this light.

[0143] As the second 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 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 also be solvent-free.

[0144] The main component of the second ionizing radiation-curable resin is preferably acrylate. Here, the main component refers to a quantity 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 constituent resin components.

[0145] The acrylate is preferably a two-functional or more-functional acrylate, and more preferably a three-functional or more-functional acrylate. For obtaining a surface protective layer 6 with excellent scratch resistance, it is preferable that the acrylate be three-functional or more. There is no upper limit to the number of functional groups in the acrylate, but one example suggests it is six-functional or less.

[0146] The acrylate preferably contains a repeating structure. This repeating structure is, for example, an ethylene oxide (EO) structure, a propylene oxide (PO) structure, or an ε-caprolactone (CL) structure. In the acrylate, the above repeating structure can be interposed between the acryloyl group and the methylol group in an open ring state.

[0147] The number of repetitions of the repeating structure is preferably three or more. If an acrylate with a high number of repetitions is used, expansion in the in-plane direction of the cured film is more likely to occur in the first irradiation step described later, and therefore, wrinkles corresponding to the second protrusions P2 are more likely to occur on the surface of the coating film. However, if the number of repetitions is increased, the crosslinking density decreases, and the scratch resistance of the decorative sheet 1 decreases. Therefore, the number of repetitions is preferably 30 or less, and more preferably 20 or less.

[0148] The number of repetitions of the above repeating structure can be analyzed using MALDI-TOF-MS. The second ionizing radiation-curable resin may have a molecular weight distribution. If a molecular weight distribution exists, the above number of repetitions should correspond to the molecular weight with the strongest peak in the MALDI-TOF-MS mass spectrum.

[0149] If the second ionizing radiation-curable resin contains acrylate, it may further contain methacrylate. For example, the second ionizing radiation-curable resin may be a second mixture of acrylate and methacrylate. In this case, it is preferable that the second mixture has a smaller ratio of methacryloyl groups to the total number of moles of acryloyl groups and methacryloyl groups compared to the first mixture. The above ratio in the second mixture is preferably 90% or less, and more preferably 80% or less, of the above ratio in the first mixture.

[0150] The second gloss-adjusting layer 6B may further contain particles in addition to the cured resin. Examples of particles included in the second gloss-adjusting layer 6B include particles made from organic materials such as polyethylene (PE) wax, polypropylene (PP) wax, and resin beads, or particles made from inorganic materials such as silica, glass, alumina, titania, zirconia, calcium carbonate, and barium sulfate.

[0151] The average particle size (D50) is preferably 20 μm or less, more preferably 10 μm or less, even 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) is increased, particle shedding from the second gloss adjustment layer 6B becomes more likely, and it may become difficult to achieve high scratch resistance. If the particles are small, the effect of uniformly creating wrinkles is reduced.

[0152] Here, "average particle size" or "average particle size (D50)" is the median diameter (D50) measured by a laser diffraction / scattering particle size distribution analyzer, as described above. If the coating liquid for the second gloss adjustment layer contains particles, the second gloss adjustment layer 6B obtained from this coating liquid will also contain particles. The average particle size of the particles contained in the second gloss adjustment layer 6B can be determined by observing its cross-section, measuring the particle sizes of multiple particles, and averaging the result. The value obtained in this way is substantially the same as the median diameter (D50) measured by a laser diffraction / scattering particle size distribution analyzer. Therefore, the range of average particle size described above can also be interpreted as the range of average particle size of the particles contained in the second gloss adjustment layer 6B.

[0153] The amount of particles in the second gloss adjustment layer 6B is preferably in the range of 0.5 parts by mass to 20 parts by mass, more preferably in the range of 0.5 parts by mass to 10 parts by mass, even more preferably in the range of 2 parts by mass to 8 parts by mass, and most preferably in the range of 2 parts by mass to 6 parts by mass, based on 100 parts by mass of the cured resin.

[0154] When the amount of added particles is within the above range, the effect of creating wrinkles uniformly is particularly great. If the amount of added particles is too high, it is easy for the particles to fall off from the second gloss adjustment layer 6B, and it may become difficult to achieve high scratch resistance.

[0155] <1.2> Method of manufacturing decorative sheet Figures 3 to 8 are cross-sectional views showing a method of manufacturing 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.

[0156] First, a base layer containing a foaming agent is formed on one side of the raw material layer 2. Here, the base layer has a multilayer structure including the ink layer 3A and the coating layer 4A shown in Figure 3.

[0157] In this case, the ink layer 3A is a foaming agent-containing layer that contains a foaming agent and becomes the pigment-containing layer 3 through a foaming process. The ink layer 3A can be obtained by forming a coating film consisting of the ink described above on one side of the base material layer 2 for the pigment-containing layer 3, and drying this coating film as needed. For forming the coating film, 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 can be used. The drying of the coating film is carried out under conditions lower than the thermal decomposition temperature of the foaming agent.

[0158] The coating layer 4A is a layer formed on top of the ink layer 3A. Here, the coating layer 4A is a layer that becomes the primer layer 4 by undergoing foaming and curing treatments. The coating layer 4A can be obtained by forming a coating film made of a primer coating liquid on top of the ink layer 3A and drying this coating film as needed.

[0159] The primer coating liquid contains a resin that produces the resin curing product described above for the primer layer 4. Here, as an example, the primer coating liquid is assumed to be a polymer-containing aqueous emulsion or a polymer-containing solvent-based resin.

[0160] The primer coating solution may further contain the particles described above for the primer layer 4. The primer coating solution may further contain other components, such as a solvent, and one or more additives for improving the function of the final product, such as antimicrobial agents and antifungal agents. The primer coating solution may further contain other additives such as ultraviolet absorbers and light stabilizers. Examples of ultraviolet absorbers include benzotriazole-based, benzoate-based, benzophenone-based, and triazine-based types. Examples of light stabilizers include hindered amine-based types.

[0161] The coating layer 4A can be applied using 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 under conditions lower than the thermal decomposition temperature of the foaming agent.

[0162] The coating film may be subjected to a pre-curing treatment. Pre-curing treatment is performed to increase the viscosity of the coating film or decrease its flexibility, while also increasing its strength. Pre-curing treatment may be, for example, heat treatment under conditions lower than the thermal decomposition temperature of the foaming agent, or irradiation with ionizing radiation. Pre-curing treatment is performed in such a way that when the foaming agent is thermally decomposed, the resulting gas can be incorporated into the coating layer 4A, and the bubbles within the coating layer 4A can coalesce.

[0163] Next, foaming and curing treatments are performed. In the foaming treatment, foaming is induced by a foaming agent, generating multiple bubbles 5 in the substrate layer, which in turn creates multiple protrusions P0 on the surface of the substrate layer, each corresponding to one or more of the bubbles 5. In the curing treatment, the resin contained in the substrate layer is cured.

[0164] Here, the multilayer structure described above is heated. As the temperature of the multilayer structure rises, the foaming agent contained in the ink layer 3A undergoes thermal decomposition. At least a portion of the gas produced by this thermal decomposition is incorporated into the coating layer 4A, generating bubbles within the coating layer 4A. Within the coating layer 4A, the bubbles coalesce to form larger bubbles. These bubbles form protrusions on the upper surface of the coating layer 4A. Subsequently, if necessary, a curing treatment is performed to stabilize the structure containing the bubbles. For example, the coating layer 4A that has generated bubbles is subjected to further heat treatment or ionizing radiation irradiation. In this way, the pigment-containing layer 3 and primer layer 4 shown in Figure 4 are obtained.

[0165] Next, a coating film consisting of the first gloss adjustment layer coating liquid is formed on the substrate layer. Here, as shown in Figure 5, a first coating film 6A0 consisting of the first gloss adjustment layer coating liquid is formed on the primer layer 4. The first coating film 6A0 is formed such that the thickness at locations other than the protrusions P0 is greater than the thickness at the locations of the protrusions P0. For example, the first coating film 6A0 is formed to have a substantially flat upper surface, as shown in Figure 5.

[0166] The first coating film 6A0 can be formed by various printing methods such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing, or by various coating methods such as roll coating, knife coating, microgravure coating, and die coating.

[0167] The coating solution for the first gloss adjustment layer contains the first ionizing radiation-curable resin described above for the first gloss adjustment layer 6A. As described above, the first ionizing radiation-curable resin is a first mixture of acrylate and methacrylate.

[0168] The coating solution for the first gloss-adjusting layer may further contain other components, such as the aforementioned particles, solvent, and one or more additives for improving the functionality of the final product, such as antibacterial agents and antifungal agents. The coating solution for the first gloss-adjusting layer may further contain other additives such as ultraviolet absorbers and light stabilizers. Examples of ultraviolet absorbers include benzotriazole-based, benzoate-based, benzophenone-based, and triazine-based types. Examples of light stabilizers include hindered amine-based types.

[0169] Next, the first coating 6A0 is irradiated with ionizing radiation or with ionizing radiation and ultraviolet light to partially cure the first coating 6A0. For example, the first irradiation step and the second irradiation step described below are carried out in sequence.

[0170] In the first irradiation step, the first coating film 6A0 is irradiated with first radiation as first light. First radiation is light with a wavelength of 200 nm or less.

[0171] The first ionizing radiation-curable resin contained in the coating liquid for the first gloss adjustment layer has a large absorption coefficient for the first radiation. Therefore, the first radiation incident on the first coating film 6A0 can only reach a distance of several tens to several hundreds of nanometers from its outermost surface. Consequently, in the first irradiation process, the crosslinking reaction proceeds in the surface region of the first coating film 6A0, forming an extremely thin cured film, while the crosslinking reaction does not proceed in other regions, leaving them uncured.

[0172] The first coating film 6A0 after the first irradiation process has a protrusion corresponding to the first protrusion P1 and a wrinkle corresponding to the second protrusion P2 on its surface. The inventors believe that the reason why the above structure is produced on the coating film surface by the first irradiation process is as follows.

[0173] As described above, the first radiation can only reach a distance of tens to hundreds of nanometers from the outermost surface of the first coating film 6A0. That is, the crosslinking reaction of the first ionizing radiation-curable resin occurs only on the surface of the first coating film 6A0, and regions further than tens to hundreds of nanometers from the outermost surface remain uncured, containing highly fluid molecules. These highly fluid molecules increase the volume of the cured film by causing it to swell. The in-plane compressive stress caused by the increase in volume in the in-plane direction causes the cured film to buckle, resulting in wrinkles on the surface of the first coating film 6A0.

[0174] Furthermore, swelling and buckling of the cured film are more likely to occur in areas with a large amount of uncured resin, while they are less likely to occur in areas with a small amount of uncured resin. As shown in Figure 5, immediately before the first irradiation process, the amount of uncured resin is small in the area of ​​the first coating film 6A0 corresponding to the protrusion P0, and large in other parts of the first coating film 6A0. Therefore, wrinkles are less likely to form in the area of ​​the surface of the first coating film 6A0 corresponding to the former, and more likely to form in the area of ​​the latter. During the process of wrinkle growth in the latter area, migration of uncured resin from the former area to the latter area may occur. As a result, a protrusion corresponding to the protrusion P0 appears in the area of ​​the surface of the first coating film 6A0 corresponding to the former.

[0175] The first type of radiation can be extracted from excimer VUV (Vacuum Ultra Violet) light. Excimer VUV light can be generated from lamps using noble gases or noble gas halide compounds. When high-energy electrons are supplied from an external source to a lamp containing a noble gas or noble gas halide compound, numerous discharge plasmas (dielectric barrier discharges) are generated. This plasma discharge excites the atoms of the discharge gas (noble gas), causing them to instantaneously enter an excimer state. When returning from this excimer state to the ground state, light in a wavelength range specific to the excimer state is emitted.

[0176] The gas used in an excimer lamp can be any conventionally used gas, as long as it emits light of 200 nm or less. As gases, noble gases such as Xe, Ar, and Kr, or mixed gases of noble gases and halogen gases such as ArBr and ArF can be used. The wavelength (center wavelength) of an excimer lamp varies depending on the gas used, and for example, it has wavelengths of approximately 172 nm (Xe), approximately 126 nm (Ar), approximately 146 nm (Kr), approximately 165 nm (ArBr), and approximately 193 nm (ArF).

[0177] Considering the magnitude of the photon energy and the difference between the wavelength and the bonding energy of the organic material, it is preferable to use a xenon lamp that emits excimer light with a central wavelength of 172 nm as the light source. Furthermore, considering the costs of equipment maintenance and material availability, it is also preferable to use a xenon lamp as the light source.

[0178] The first irradiation step is carried out in an atmosphere with a low oxygen concentration. Oxygen has a large absorption coefficient for light below 200 nm. Therefore, it is preferable to carry out the first irradiation step in a nitrogen gas atmosphere, for example. The oxygen concentration in the gas phase during 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.

[0179] 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 first coating film 6A0. Consequently, changing the residual oxygen concentration in the reaction atmosphere may also change the surface properties of the first gloss adjustment layer 6A.

[0180] The integrated light quantity of the first radiation is 0.5 mJ / cm ２ or more and 200 mJ / cm ２ or less, preferably, and 1 mJ / cm ２ or more and 100 mJ / cm ２ or less, more preferably, and 3 mJ / cm ２ or more and 50 mJ / cm ２ or less, still more preferably, and 5 mJ / cm ２ or more and 30 mJ / cm ２ or less, most preferably. When the integrated light quantity is reduced, the curing of the surface becomes insufficient and wrinkles do not occur. Also, when the integrated light quantity is reduced, the expansion of the cured film in the in-plane direction becomes small. When the integrated light quantity is increased, the surface state of the first coating film 6A0 deteriorates.

[0181] In the second irradiation step, the first coating film 6A0 is irradiated with the second radiation. The second radiation is either ionizing radiation or ultraviolet light having a wavelength longer than that of the first 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 more than 200 nm, more preferably in the range of 230 nm or more and 450 nm or less, and still more preferably in the range of 250 nm or more and 400 nm or less.

[0182] In the second irradiation step, a crosslinking reaction is allowed to proceed throughout the entire thickness of the first coating film 6A0. Thereby, the first coating film 6A0 is semi-cured to obtain a semi-cured film 6A1 shown in FIG. 6.

[0183] The irradiation of the second radiation to the first coating film 6A0 is preferably performed so that the unreacted rate of the first coating film 6A0, that is, the ratio of the number of C═C bonds after the irradiation of the second radiation to the number of C═C bonds before the irradiation of the first radiation, is in the range of 5% or more and 80% or less, more preferably in the range of 10% or more and 60% or less, and still more preferably in the range of 15% or more and 50% or less.

[0184] The irradiation of the first coating film 6A0 with the second radiation is preferably carried out so that the integrated light amount is within the range of 3% to 30% of the minimum integrated light amount required to completely cure the first coating film 6A0, more preferably within the range of 5% to 25%, and even more preferably within the range of 8% to 20%.

[0185] The minimum integrated light intensity required to completely cure the first coating film 6A0 is, for example, 10 mJ / cm². ２ More than 1000mJ / cm ２ It is within the following range.

[0186] The irradiation of the first coating film 6A0 with the second radiation is preferably carried out so that the absorbed dose is within the range of 0.2% to 50% of the minimum absorbed dose required to completely cure the first coating film 6A0, more preferably within the range of 0.5% to 40%, and even more preferably within the range of 1% to 30%.

[0187] Furthermore, the minimum absorbed dose required to completely cure the first coating film 6A0 is, for example, within the range of 5 kGy to 200 kGy.

[0188] As described above, the first ionizing radiation-curable resin further contains methacrylate in addition to acrylate. The methacrylate reduces the rate of the crosslinking reaction caused by the first radiation, widening the process window that allows for the achievement of the desired curing state.

[0189] Next, as shown in Figure 7, a second coating film 6B0, consisting of a second gloss adjustment layer coating liquid, is formed on the semi-cured film 6A1. The second coating film 6B0 is formed so as to partially cover the upper surface of the semi-cured film 6A1. The second coating film 6B0 can be formed by various printing methods, such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing. Among these, gravure printing is preferred.

[0190] The coating solution for the second gloss adjustment layer contains the above-mentioned second ionizing radiation-curable resin. As described above, the second ionizing radiation-curable resin is, in one example, acrylate. In another example, the second ionizing radiation-curable resin is a second mixture of acrylate and methacrylate, in which the ratio of moles of methacryloyl groups to the total number of moles of acryloyl groups is smaller compared to the first mixture.

[0191] The coating solution for the second gloss-adjusting layer may further contain other components, such as the aforementioned particles, solvent, and one or more additives for improving the functionality of the final product, such as antibacterial agents and antifungal agents. The coating solution for the second gloss-adjusting layer may further contain other additives such as ultraviolet absorbers and light stabilizers. Examples of ultraviolet absorbers that can be used include benzotriazole-based, benzoate-based, benzophenone-based, and triazine-based types. Examples of light stabilizers that can be used include hindered amine-based types.

[0192] Next, the semi-cured film 6A1 and the second coating film 6B0 are irradiated with ionizing radiation or with ionizing radiation and ultraviolet light to create a plurality of protrusions on the surface of the second coating film 6B0 and to fully cure the semi-cured film 6A1 and the second coating film 6B0. For example, the third and fourth irradiation steps described below are carried out sequentially.

[0193] In the third irradiation step, the second coating film 6B0 is irradiated with a third radiation as the second light to create multiple protrusions on the surface of the second coating film 6B0. The third radiation is light with a wavelength of 200 nm or less.

[0194] The second ionizing radiation-curable resin contained in the coating liquid for the second gloss adjustment layer has a large absorption coefficient for the third radiation. Therefore, the third radiation incident on the second coating film 6B0 can only reach a distance of tens to hundreds of nanometers from its outermost surface. Consequently, in the third irradiation step, the crosslinking reaction proceeds in the surface region of the second coating film 6B0, forming an extremely thin cured film, while the crosslinking reaction does not proceed in other regions, leaving them uncured.

[0195] The second coating film 6B0 after the third irradiation step may have protrusions on its surface corresponding to the third protrusion P3. Furthermore, the second coating film 6B0 after the third irradiation step has wrinkles on its surface corresponding to the fourth protrusion P4. The inventors believe that the reason for the formation of wrinkles on the coating film surface by the third irradiation step is the same as the reason for the formation of wrinkles on the coating film surface by the first irradiation step.

[0196] In the third irradiation step, the third radiation may also be applied to the surface of the portion of the semi-cured film 6A1 that is not covered by the second coating film 6B0. However, since the semi-cured film 6A1 is semi-cured, molecular flow within the film is unlikely to occur. Therefore, the surface properties of the semi-cured film 6A1 will not change significantly due to irradiation with the third radiation.

[0197] Furthermore, the third radiation does not reach the portion of the semi-cured film 6A1 that is covered by the second coating film 6B0. Therefore, no cross-linking reaction occurs in this portion due to irradiation by the third radiation.

[0198] The third type of radiation can be extracted from excimer VUV (Vacuum Ultra Violet) light. Excimer VUV light can be generated from lamps using noble gases or noble gas halide compounds. When high-energy electrons are supplied from an external source to a lamp containing a noble gas or noble gas halide compound, numerous discharge plasmas (dielectric barrier discharges) are generated. This plasma discharge excites the atoms of the discharge gas (noble gas), causing them to instantaneously enter an excimer state. When returning from this excimer state to the ground state, it emits light in a wavelength range specific to the excimer state.

[0199] The gas used in an excimer lamp can be any conventionally used gas, as long as it emits light of 200 nm or less. As gases, noble gases such as Xe, Ar, and Kr, or mixed gases of noble gases and halogen gases such as ArBr and ArF can be used. The wavelength (center wavelength) of an excimer lamp varies depending on the gas used, and for example, it has wavelengths of approximately 172 nm (Xe), approximately 126 nm (Ar), approximately 146 nm (Kr), approximately 165 nm (ArBr), and approximately 193 nm (ArF).

[0200] Considering the magnitude of the photon energy and the difference between the wavelength and the bonding energy of the organic material, it is preferable to use a xenon lamp that emits excimer light with a central wavelength of 172 nm as the light source. Furthermore, considering the costs of equipment maintenance and material availability, it is also preferable to use a xenon lamp as the light source.

[0201] The third irradiation step is carried out in an atmosphere with a low oxygen concentration. Oxygen has a large absorption coefficient for light below 200 nm. Therefore, it is preferable to carry out the third irradiation step in a nitrogen gas atmosphere, for example. The oxygen concentration in the gas phase during the third 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.

[0202] 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. Consequently, changing the residual oxygen concentration in the reaction atmosphere may also change the surface properties of the second gloss adjustment layer 6B.

[0203] The cumulative light intensity of the third type of radiation is 0.5 mJ / cm². ２ More than 200mJ / cm ２ It is preferable to keep it within the following range: 1 mJ / cm² ２ More than 100mJ / cm ２ It is more preferable to keep it within the following range: 3 mJ / cm² ２ More than 50mJ / cm ２ It is even more preferable to keep it within the following range: 5 mJ / cm ２ 30mJ / cm or more ２ It is most preferable to keep the light intensity within the following ranges. Reducing the integrated light intensity reduces the in-plane expansion of the cured film. Increasing the integrated light intensity deteriorates the surface condition of the second coating film 6B0.

[0204] In the fourth irradiation step, the semi-cured film 6A1 and the second coating film 6B0 are irradiated with a fourth radiation. The fourth radiation is either ionizing radiation or ultraviolet light with a longer wavelength than the second light irradiated in the third irradiation step. The fourth radiation can be the same as that used for the second radiation as described above.

[0205] In the fourth irradiation step, the semi-cured film 6A1 and the second coating film 6B0 are fully cured to obtain the first gloss adjustment layer 6A and the second gloss adjustment layer 6B shown in Figure 8.

[0206] In this fourth irradiation step, a crosslinking reaction proceeds throughout the entire thickness of both the semi-cured film 6A1 and the second coating film 6B0. Furthermore, at the start of the fourth irradiation step, the semi-cured film 6A1 is in a semi-cured state. Therefore, in the areas where the semi-cured film 6A1 and the second coating film 6B0 are in contact, a crosslinking reaction may also occur between the molecules contained in the semi-cured film 6A1 and the molecules contained in the second coating film 6B0. Consequently, high adhesion can be achieved between the first gloss adjustment layer 6A and the second gloss adjustment layer 6B.

[0207] The cumulative light intensity of the fourth radiation is 10 mJ / cm². ２ More than 500mJ / cm ２ It is preferable to keep it within the following range: 50 mJ / cm² ２ More than 400mJ / cm ２ It is more preferable to keep it within the following range: 100 mJ / cm² ２ More than 300mJ / cm ２ It is even more preferable to keep it within the following range.

[0208] The fourth radiation irradiation is preferably carried out so that the absorbed dose is within the range of 5 kGy to 200 kGy, more preferably within the range of 10 kGy to 150 kGy, and even more preferably within the range of 15 kGy to 100 kGy.

[0209] In the fourth irradiation step, if a layer with sufficient intensity cannot be obtained with irradiation of only one type of radiation, the type of radiation used in the fourth irradiation step may be changed. For example, ionizing radiation may be irradiated first, followed by ultraviolet light with a longer wavelength than the light irradiated in the third irradiation step. Alternatively, ultraviolet light with a longer wavelength than the light irradiated in the third irradiation step may be irradiated first, followed by ionizing radiation. Alternatively, ultraviolet light with a longer wavelength than the light irradiated in the third irradiation step may be irradiated first, followed by ultraviolet light with an even longer wavelength.

[0210] In this way, the decorative sheet 1 shown in Figure 8 is obtained. Here, foaming by the foaming agent is caused prior to the formation of the first coating film 6A0, but it may also be caused after the formation of the semi-cured film 6A1 and before the formation of the second coating film 6B0. In this case as well, the decorative sheet 1 shown in Figure 8 can be obtained.

[0211] In the decorative sheet 1 described with reference to Figures 1 and 2, the second protrusion P2 is adjacent to the first protrusion P1, but does not overlap with the first protrusion P1. That is, in the decorative sheet 1, the second protrusion P2 does not have a portion located above the first protrusion P1.

[0212] The second protrusion P2 may include a portion that overlaps with the first protrusion P1. That is, in the decorative sheet 1, the second protrusion P2 may have a portion located on top of the first protrusion P1. Such a structure can be obtained, for example, by using a coating liquid with high viscosity for the first gloss adjustment layer to suppress excessive movement of the uncured resin in the first irradiation step.

[0213] <1.3> Effect Figure 9 is a micrograph of the surface of the decorative sheet according to the comparative example. The decorative sheet shown in Figure 9 was obtained by the same method as described with reference to Figures 3 to 8, except that a foaming agent was not used and the second gloss adjustment layer 6B was omitted. This decorative sheet does not contain air bubbles, and therefore its surface protective layer does not have protrusions on its surface that originate from air bubbles. In this decorative sheet, the only protrusions on the surface of the surface protective layer are the ridge-like protrusions that form wrinkles. Therefore, the feel and gloss of this decorative sheet are mainly determined by the ridge-like protrusions.

[0214] In contrast, the decorative sheet 1 described above has a surface protective layer 6 on its upper surface where the first gloss adjustment layer 6A is exposed, which includes a first protrusion P1 originating from air bubbles 5 and a ridge-like second protrusion P2 forming wrinkles. The uneven structure including the first protrusion P1 and the second protrusion P2 can provide a different tactile feel and optical properties than an uneven structure including only the second protrusion P2. Furthermore, the mechanism for generating the first protrusion P1 and the mechanism for generating the second protrusion P2 are different, and their dimensions can be set independently of each other. In addition, the ratio of the total area of ​​the first protrusion P1 to the total area of ​​the second protrusion P2 can also be set arbitrarily. Thus, the technology described above for the decorative sheet 1 enables a high degree of freedom in designing the tactile feel and appearance of the decorative sheet.

[0215] Furthermore, the decorative sheet 1 described above further includes a second gloss adjustment layer 6B. The upper surface of the second gloss adjustment layer 6B may have a different uneven structure than the uneven structure provided on the upper surface of the first gloss adjustment layer 6A. For example, the third protrusion P3 may be omitted from the upper surface of the second gloss adjustment layer 6B, the dimensions of the first protrusion P1 and the third protrusion P3 may be made different, or the dimensions of the second protrusion P2 and the fourth protrusion P4 may be made different. The pattern shape of the second gloss adjustment layer 6B and the coverage rate of the first gloss adjustment layer 6A by the second gloss adjustment layer 6B can be set arbitrarily. In other words, the second gloss adjustment layer 6B allows for a greater degree of freedom in designing the tactile feel or appearance of the decorative sheet.

[0216] Furthermore, in the decorative sheet 1, the difference in refractive index between the gas constituting the bubbles 5 and the material constituting the primer layer 4 can cause scattering, refraction, or reflection of light at their interface. 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 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 bubbles 5.

[0217] Furthermore, decorative sheets having protrusions similar to the first protrusion P1 and the third protrusion P3 can be obtained, for example, by dispersing large-particle-sized particles in the topcoat layer. However, large-particle-sized particles are prone to falling off, so decorative sheets with such a structure have poor scratch resistance. The decorative sheet 1 described above generates the first protrusion P1 and the third protrusion P3 without using large-particle-sized particles. Therefore, the decorative sheet 1 can achieve high scratch resistance.

[0218] Furthermore, in the decorative sheet 1, the air bubbles 5 can also contribute to sound insulation and heat insulation.

[0219] <2> Second Embodiment Figure 10 is a cross-sectional view of a decorative material including a decorative sheet according to the second embodiment of the present invention. The decorative material 11A shown in Figure 10 is the same as the decorative material 11, except that it includes a decorative sheet 1A instead of decorative sheet 1. Furthermore, the decorative sheet 1A is the same as the decorative sheet 1, except that it employs the following configuration.

[0220] That is, the upper surface of the surface protection 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 material layer 2. Therefore, the bubbles 5 are located only between the first region 61 and the pigment-containing layer 3. Furthermore, the second gloss-adjusting layer 6B covers the region of the upper surface of the first gloss-adjusting layer 6A that is located above the pigment-containing layer 3, but does not cover the region located above the opening of the pigment-containing layer 3. That is, the second gloss-adjusting layer 6B and the pigment-containing layer 3 are identical in shape and position when viewed from the thickness direction. The first protrusion P1 and the third protrusion P3 are located above the pigment-containing layer 3. Furthermore, part of the second protrusion P2 and the fourth protrusion P4 are located above the pigment-containing layer 3, and the remainder are located above the opening of the pigment-containing layer 3. Each of the bubbles 5 may be entirely located directly above the pigment-containing layer 3, or only a portion of it may be located directly above the pigment-containing layer 3.

[0221] In other words, the pigment-containing layer 3 partially covers one main surface of the base layer 2. The bubbles 5 are located only in the portion of the primer layer 4 that is on the pigment-containing layer 3 and in its vicinity, and are not present in the other portions of the primer layer 4. The first region 61, which consists of the area directly above the pigment-containing layer 3 and the area in its vicinity on the upper surface of the surface protection layer 6, has a third protrusion P3 and a fourth protrusion P4. The second region 62, which is the remaining area on the upper surface of the surface protection layer 6, has a second protrusion P2, but does not have any of the first protrusion P1, third protrusion P3, and fourth protrusion P4.

[0222] The decorative sheet 1A can be manufactured by the same method as described with reference to Figures 3 to 8, except that the ink layer 3A is formed to partially cover one main surface of the base material layer 2, corresponding to the pigment-containing layer 3 in Figure 10, and the second coating film 6B0 is formed only on top of the pigment-containing layer.

[0223] The pigment-containing layer 3 of the decorative sheet 1A can be formed by using the ink described above for the pigment-containing layer 3 of the decorative sheet 1, and printing a specific pattern using this ink. The pigment-containing layer 3 of the decorative sheet 1A may be formed using one type of ink, or it may be formed using multiple types of inks with different compositions. When multiple types of inks are used to form the pigment-containing layer 3, the colors of these inks may differ. Also, the thickness of the pigment-containing layer 3 of the decorative sheet 1A may differ between certain parts. When multiple types of inks are used, the pigment-containing layer 3 may be formed, for example, using the number of plates necessary to express the desired design.

[0224] The technique described above for decorative sheet 1A can achieve the same effects as the technique described above for decorative sheet 1.

[0225] Furthermore, in decorative sheet 1A, the pattern of the first region 61 corresponds to the pattern of the pigment-containing layer 3, and the pattern of the second region 62 corresponds to the inverted pattern of the pigment-containing layer 3. The first region 61 and the second region 62 can have different effects on the tactile feel or appearance of the decorative sheet. Therefore, the technology described above for decorative sheet 1A allows for a greater degree of freedom in designing the tactile feel or appearance of the decorative sheet compared to the technology described above for decorative sheet 1.

[0226] For example, if the pigment-containing layer 3 has a wood grain pattern, the third protrusion P3 or the first region 61 may provide a tactile sensation similar to that of the conduit, and the second protrusion P2 or the second region 62 may provide a tactile sensation similar to that of the parts other than the conduit.

[0227] <3> Modifications The above-mentioned techniques can be modified in various ways.

[0228] For example, in the manufacture of decorative sheet 1, the foaming agent may be included in the coating layer 4A instead of the ink layer 3A.

[0229] In decorative sheet 1A, as described above, the second gloss adjustment layer 6B and the pigment-containing layer 3 have the same shape and position when viewed from the thickness direction. In decorative sheet 1A, the second gloss adjustment layer 6B and the pigment-containing layer 3 may differ in at least one of their shapes and positions when viewed from the thickness direction. Alternatively, the pigment-containing layer 3 of decorative sheet 1A may include a pattern or group of patterns that have the same shape and position as the second gloss adjustment layer 6B when viewed from the thickness direction, and one or more patterns that differ in at least one of their shapes and positions from the second gloss adjustment layer 6B when viewed from the thickness direction.

[0230] Furthermore, decorative sheets 1 and 1A may further include one or more other layers. For example, decorative sheet 1A may further include a second pigment-containing layer as a solid ink layer or opacity layer between the base layer 2 and the pigment-containing layer 3. In this case, it is preferable that one or more colors of the pattern included in the pigment-containing layer 3 are different from the colors of the second pigment-containing layer. And in this case, it is even more preferable that all the colors of the pattern included in the pigment-containing layer 3 are different from the colors of the second pigment-containing layer.

[0231] Decorative sheets 1 and 1A can be used as master plates in the manufacture of other decorative sheets. Alternatively, decorative sheets 1 and 1A can be used in the manufacture of plates used in the manufacture of other decorative sheets.

[0232] For example, by transferring the uneven structure provided on the surface protective layer 6 of decorative sheet 1 or 1A an odd number of times, a plate can be obtained in which the transfer surface includes a region in which a plurality of first recesses, each having a substantially circular shape in plan view, and a plurality of second recesses, each having a groove-like shape, are mixed. Then, a resin layer is formed on the base material layer, and the structure provided on the transfer surface of the plate is transferred to the surface of the resin layer. This makes it possible to obtain a decorative sheet having an uneven structure on the surface of the resin layer similar to the uneven structure provided on the surface protective layer 6 of decorative sheet 1 or 1A.

[0233] 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 in which the transfer surface 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. 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. As a result, a decorative sheet can be obtained in which the surface of the resin layer has an uneven structure that is the reverse of the uneven structure provided on the surface protective layer 6 of the decorative sheet 1 or 1A.

[0234] These decorative sheets do not contain air bubbles because they utilize transfer technology to create a textured surface protective layer. Furthermore, these decorative sheets offer a high degree of freedom in selecting the material for the surface protective layer and in designing the layer configuration.

[0235] Examples of the present invention are described below. Note that the "particle size" described below refers to the "average particle size (D50)" mentioned above.

[0236] <Example 1> The decorative sheet 1A described with reference to Figure 10 was manufactured by the following method.

[0237] First, the basis weight is 50 g / m². ２ Impregnated paper (GFR-506: manufactured by Kojin Co., Ltd.) was prepared as the base layer 2.

[0238] Next, a pigment-containing layer 3 was formed on one side of the base layer 2 as a pattern layer. For the formation of the pigment-containing layer 3, an ink composition was used, which was made by adding a foaming agent to a commercially available ink. As the commercially available ink, oil-based nitrated cotton resin-based gravure printing ink (PCNT (PCRNT) various colors (manufactured by Toyo Ink Co., Ltd.) was used. As the foaming agent, Matsumoto Microspheres® HF-48 (manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd.) was used. The amount of foaming agent in the ink composition was 10 parts by mass per 100 parts by mass of ink.

[0239] Gravure printing was used to print the ink composition. The ink layer 3A formed a wood-grain pattern with a pattern area ratio of 50%, and the mass per unit area after drying was 3 g / m². ２ The process was carried out in this manner. Ink layer 3A was dried at 60°C for 1 minute.

[0240] Next, the following primer coating liquid was applied to the raw material layer 2 and the ink layer 3A to form a coating layer 4A. The primer coating liquid was applied so that the primer layer 4 had a thickness of 5 μm in the portion excluding the portion corresponding to the first protrusion P1.

[0241] (Primer layer coating liquid) ・Water-based resin R1 Type: Acrylic emulsion Product name: SETAQUA 6302 (manufactured by Ornex Co., Ltd.)

[0242] Subsequently, drying and foaming treatments were performed. Specifically, the ink layer 3A and coating layer 4A formed on the base material 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 obtaining a pigment-containing layer 3 and a primer layer 4 having bubbles 5.

[0243] Next, a first gloss-adjusting layer coating liquid having the following composition was printed onto the primer layer 4 to form the first coating film 6A0. The first gloss-adjusting layer coating liquid was printed so that the thickness of the first gloss-adjusting layer 6A was 10 μm.

[0244] (Coating liquid for the first gloss adjustment layer) ・Ionizing radiation-curable resin R1 Type: Trimethylolpropane EO-modified triacrylate (EO 3 molar addition) Product name: Miramer M3130 (manufactured by Miwon) Amount: 50 parts by mass ・Ionizing radiation-curable resin R2 Type: Methoxypolyethylene glycol (400) methacrylate Product name: NK ester M-90G (manufactured by Shin Nakamura Chemical Co., Ltd.) Amount: 50 parts by mass ・Particle product name: Silysia 250N (manufactured by Fuji Silysia Chemical Co., Ltd.) Particle size: 5 μm Amount: 0.5 parts by mass

[0245] Next, the first irradiation process was carried out. Specifically, under atmospheric pressure and in a nitrogen gas atmosphere with an oxygen concentration of 500 ppm, ultraviolet light with a wavelength of 172 nm was emitted from a Xe excimer lamp onto the surface of the first coating film 6A0, with an integrated light intensity of 50 mJ / cm². ２ The irradiation was performed in such a manner. As a result, a protrusion corresponding to the first protrusion P1 and a wrinkle corresponding to the second protrusion P2 were created on the surface of the first coating film 6A0.

[0246] Next, the second irradiation process was carried out. Specifically, the first coating film 6A0 was irradiated with an electron beam as ionizing radiation, such that the absorbed dose of the first coating film 6A0 was 5 kGy. As a result, a semi-cured film 6A1 was obtained by partially curing the first coating film 6A0.

[0247] Next, a second gloss-adjusting layer coating liquid having the following composition was printed onto the semi-cured film 6A1 to form a second coating film 6B0. Gravure printing was used to print the second gloss-adjusting layer coating liquid. The second gloss-adjusting layer coating liquid was printed so that the second coating film 6B0 formed a wood grain pattern with a pattern area ratio of 50%, the position of this wood grain pattern coincided with the position of the wood grain pattern formed by the ink layer 3A, and the thickness of the second gloss-adjusting layer 6B was 5 μm.

[0248] (Coating liquid for the second gloss adjustment layer) ・Ionizing radiation-curable resin type: Trimethylolpropane EO-modified triacrylate (EO 6 molar added) Product name: Miramer® M3160 (manufactured by Miwon Co., Ltd.) Amount: 100 parts by mass ・Particle product name: Silysia® 250N (manufactured by Fuji Silysia Chemical Co., Ltd.) Particle size: 5 μm Amount: 0.5 parts by mass

[0249] Next, the third irradiation process was carried out. Specifically, under atmospheric pressure and in a nitrogen gas atmosphere with an oxygen concentration of 500 ppm, ultraviolet light with a wavelength of 172 nm was used to illuminate the surface of the second coating film 6B0, which consists of the coating liquid for the second gloss adjustment layer, using a Xe excimer lamp, with an integrated light intensity of 50 mJ / cm². ２ The irradiation was performed in such a manner. As a result, multiple protrusions, including wrinkles corresponding to the second protrusion P2, were created on the surface of the second coating film 6B0.

[0250] Next, the fourth irradiation step was performed. Specifically, the semi-cured film 6A1 and the second coating film 6B0 were irradiated with 100 kGy of ionizing radiation to cure them completely, thereby forming a surface protection layer 6 consisting of a first gloss adjustment layer 6A and a second gloss adjustment layer 6B. In this way, a decorative sheet 1A was obtained.

[0251] <Example 2> A decorative sheet 1A was manufactured in the same manner as in Example 1, except that the amount of ionizing radiation-curable resin R1 in the coating liquid for the first gloss adjustment layer was 90 parts by mass, and the amount of ionizing radiation-curable resin R2 was 10 parts by mass.

[0252] <Example 3> A decorative sheet 1A was manufactured in the same manner as in Example 1, except that the following resin was used as the ionizing radiation-curable resin R2, and the amount of ionizing radiation-curable resin R1 in the coating solution for the first gloss adjustment layer was 90 parts by mass and the amount of ionizing radiation-curable resin R2 was 10 parts by mass. • Ionizing radiation-curable resin R2 Type: Isobornyl methacrylate Product name: Light ester IB-X (manufactured by Kyoeisha Chemical Co., Ltd.)

[0253] <Example 4> Decorative sheet 1A was manufactured in the same manner as in Example 1, except that the following resin was used as the ionizing radiation-curable resin R2: • Ionizing radiation-curable resin R2 Type: EO-modified bisphenol A dimethacrylate (EO 10 mol added) Product name: NK ester BPE-500 (manufactured by Shin Nakamura Chemical Co., Ltd.)

[0254] <Example 5> Decorative sheet 1A was manufactured in the same manner as in Example 1, except that the following resin was used as the ionizing radiation-curable resin R2, and the amount of ionizing radiation-curable resin R1 in the coating liquid for the first gloss adjustment layer was 90 parts by mass, and the amount of ionizing radiation-curable resin R2 was 10 parts by mass. • Ionizing radiation-curable resin R2 Type: EO-modified bisphenol A dimethacrylate (EO 10 molar addition) Product name: NK ester BPE-500 (manufactured by Shin Nakamura Chemical Co., Ltd.)

[0255] <Example 6> Decorative sheet 1A was manufactured in the same manner as in Example 1, except that the following resin was used as the ionizing radiation-curable resin R2, and the amount of ionizing radiation-curable resin R1 in the coating liquid for the first gloss adjustment layer was 80 parts by mass and the amount of ionizing radiation-curable resin R2 was 20 parts by mass. • Ionizing radiation-curable resin R2 Type: Polyethylene glycol (200) dimethacrylate Product name: NK ester 4G (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0256] <Example 7> Decorative sheet 1A was manufactured in the same manner as in Example 1, except that the following resin was used as the ionizing radiation-curable resin R2: • Ionizing radiation-curable resin R2 Type: Trimethylolpropane EO-modified trimhaacrylate (EO 3 molar addition) Product name: NK Ester TMPT-3EO (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0257] <Example 8> Decorative sheet 1A was manufactured in the same manner as in Example 1, except that the following resin was used as the ionizing radiation-curable resin R2: • Ionizing radiation-curable resin R2 Type: Trimethylolpropane PO-modified trimhaacrylate (PO 3 molar addition) Product name: NK ester TMPT-3PO (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0258] <Example 9> Decorative sheet 1A was manufactured in the same manner as in Example 1, except that the following resin was used as the ionizing radiation-curable resin in the coating liquid for the second gloss adjustment layer: • Type of ionizing radiation-curable resin: Trimethylolpropane EO-modified triacrylate (EO 3 molar addition) Product name: Miramer M3130 (manufactured by Miwon)

[0259] <Example 10> Decorative sheet 1A was manufactured in the same manner as in Example 1, except that the following resin was used as the ionizing radiation-curable resin in the coating liquid for the second gloss adjustment layer: • Type of ionizing radiation-curable resin: Ethylene glycol diacrylate (EO 9 molar addition) Product name: Light acrylate 9EG-A (manufactured by Kyoeisha Chemical Co., Ltd.)

[0260] <Example 11> Decorative sheet 1A was manufactured in the same manner as in Example 1, except that the following resin was used as the ionizing radiation-curable resin in the coating liquid for the second gloss adjustment layer: • Type of ionizing radiation-curable resin: Ethoxylated pentaerythritol tetraacrylate (EO 35 molar addition) Product name: NK ester ATM-35E (manufactured by Shin Nakamura Chemical Co., Ltd.)

[0261] <Example 12> A decorative sheet 1A was manufactured in the same manner as in Example 1, except that the coating liquid for the first gloss adjustment layer was applied so that the thickness of the first gloss adjustment layer 6A was 5 μm, and the coating liquid for the second gloss adjustment layer was printed so that the thickness of the second gloss adjustment layer 6B was 2 μm.

[0262] <Example 13> The decorative sheet 1 described with reference to Figures 1 to 6 was manufactured using the same method as in Example 1, except for the following points. Specifically, in this example, the coating liquid for the first gloss adjustment layer was applied so that the thickness of the first gloss adjustment layer 6A was 5 μm. Also, particles were omitted in the coating liquid for the second gloss adjustment layer. Then, the coating liquid for the second gloss adjustment layer was printed so that the thickness of the second gloss adjustment layer 6B was 3 μm.

[0263] <Example 14> A decorative sheet 1A was manufactured in the same manner as in Example 1, except for the following points. Specifically, in this example, the coating liquid for the first gloss adjustment layer was applied so that the thickness of the first gloss adjustment layer 6A was 5 μm. In addition, the following coating liquid for the second gloss adjustment layer was used.

[0264] (Coating liquid for the second gloss adjustment layer) ・Ionizing radiation-curable resin R3 Type: Trimethylolpropane EO-modified triacrylate (6 molars of EO added) Product name: Miramer M3160 (manufactured by Miwon) Amount: 60 parts by mass ・Ionizing radiation-curable resin R4 Type: Dipentaerythritol hexaacrylate Product name: Miramer M600 (manufactured by Miwon) Amount: 40 parts by mass ・Particle product name: Silysia 250N (manufactured by Fuji Silysia Chemical Co., Ltd.) Particle size: 5 μm Amount: 0.5 parts by mass

[0265] <Example 15> A decorative sheet 1A was manufactured in the same manner as in Example 1, except for the following points. Specifically, in this example, the coating liquid for the first gloss adjustment layer was applied so that the thickness of the first gloss adjustment layer 6A was 5 μm. In addition, the following coating liquid for the second gloss adjustment layer was used.

[0266] (Coating liquid for the second gloss adjustment layer) ・Ionizing radiation-curable resin R3 Type: Trimethylolpropane EO-modified triacrylate (6 molars of EO added) Product name: Miramer M3160 (manufactured by Miwon) Amount: 40 parts by mass ・Ionizing radiation-curable resin R4 Type: Dipentaerythritol hexaacrylate Product name: Miramer M600 (manufactured by Miwon) Amount: 60 parts by mass ・Particle product name: Silysia 250N (manufactured by Fuji Silysia Chemical Co., Ltd.) Particle size: 5 μm Amount: 0.5 parts by mass

[0267] <Example 16> A decorative sheet 1A was manufactured in the same manner as in Example 1, except for the following points. Specifically, in this example, the coating liquid for the first gloss adjustment layer was applied so that the thickness of the first gloss adjustment layer 6A was 5 μm. The following coating liquid for the second gloss adjustment layer was used. The coating liquid for the second gloss adjustment layer was printed so that the thickness of the second gloss adjustment layer 6B was 14 μm.

[0268] (Coating liquid for the second gloss adjustment layer) ・Ionizing radiation-curable resin R3 Type: Trimethylolpropane EO-modified triacrylate (6 molars of EO added) Product name: Miramer M3160 (manufactured by Miwon) Amount: 40 parts by mass ・Ionizing radiation-curable resin R4 Type: Dipentaerythritol hexaacrylate Product name: Miramer M600 (manufactured by Miwon) Amount: 60 parts by mass ・Particle product name: Silysia 250N (manufactured by Fuji Silysia Chemical Co., Ltd.) Particle size: 5 μm Amount: 0.5 parts by mass

[0269] <Example 17> In the coating solution for the first gloss adjustment layer, the ionizing radiation-curable resin R2 was omitted, and the amount of ionizing radiation-curable resin R1 was set to 100 parts by mass, except that the same method as in Example 1 was used to manufacture decorative sheet 1A.

[0270] <Example 18> A decorative sheet 1A was manufactured in the same manner as in Example 1, except that the ionizing radiation-curable resin R1 was omitted from the coating liquid for the first gloss adjustment layer, and the amount of ionizing radiation-curable resin R2 was set to 100 parts by mass, and the coating liquid for the first gloss adjustment layer was applied so that the thickness of the first gloss adjustment layer 6A was 5 μm.

[0271] <Example 19> A decorative sheet 1A was manufactured in the same manner as in Example 1, except for the following points. Specifically, in this example, the ionizing radiation-curable resin R1 was omitted from the coating liquid for the first gloss adjustment layer, and the amount of ionizing radiation-curable resin R2 was set to 100 parts by mass. The coating liquid for the first gloss adjustment layer was applied so that the thickness of the first gloss adjustment layer 6A was 5 μm. The coating liquid for the second gloss adjustment layer was applied so that the thickness of the second gloss adjustment layer 6B was 2 μm.

[0272] <Example 20> A decorative sheet 1A was manufactured in the same manner as in Example 1, except for the following points. Specifically, in this example, the coating liquid for the first gloss adjustment layer was applied so that the thickness of the first gloss adjustment layer 6A was 11 μm. The following coating liquid for the second gloss adjustment layer was used. The coating liquid for the second gloss adjustment layer was printed so that the thickness of the second gloss adjustment layer 6B was 5 μm.

[0273] (Coating liquid for the second gloss adjustment layer) ・Ionizing radiation-curable resin R3 Type: Trimethylolpropane EO-modified triacrylate (6 molars of EO added) Product name: Miramer M3160 (manufactured by Miwon) Amount: 60 parts by mass ・Ionizing radiation-curable resin R4 Type: Dipentaerythritol hexaacrylate Product name: Miramer M600 (manufactured by Miwon) Amount: 40 parts by mass ・Particle product name: Silysia 250N (manufactured by Fuji Silysia Chemical Co., Ltd.) Particle size: 5 μm Amount: 0.5 parts by mass

[0274] <Comparative Example 1> A decorative sheet similar to decorative sheet 1A was manufactured using the same method as in Example 1, except that the foaming agent was omitted from the ink composition for forming the pigment-containing layer 3.

[0275] <Comparative Example 2> A decorative sheet similar to decorative sheet 1A was manufactured using the same method as in Example 1, except that the application of the primer coating liquid was omitted and the coating layer 4A and primer layer 4 were not formed.

[0276] <Comparative Example 3> A decorative sheet similar to decorative sheet 1A was manufactured using the same method as in Example 1, except that the foaming agent was omitted from the ink composition for forming the pigment-containing layer 3, the amount of particles in the coating liquid for the surface protective layer was set to 20 parts by mass, and the first irradiation step was omitted.

[0277] <Evaluation> The following evaluation was performed on each of the above decorative sheets. Those rated "AAA," "AA," or "A" were deemed acceptable as they had no problems in actual use.

[0278] (1) Thickness of the layer The thickness of the first 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-curing epoxy resin or a UV-curing resin, and the resin was allowed to cure completely. Then, it was cut so that the cross-section of the decorative sheet was exposed, and the measurement surface was obtained by mechanical polishing.

[0279] Next, a cross-section of the surface protective layer was imaged using a Carl Zeiss Microscopy SIGMA® 500 scanning electron microscope. For this imaging, the acceleration voltage was set to 0.5 keV (low acceleration voltage), the imaging mode was SE2 mode, and the magnification was 2000x. Sputtering was not performed on the measurement sample.

[0280] Next, from this cross-sectional image, the dimensions of the first gloss adjustment layer in the width direction of the ridged portion and the area of ​​the cross-section of the first gloss adjustment layer were determined. By dividing this area by the above dimensions, the thickness of the first gloss adjustment layer was calculated. The thickness obtained in this way was equal to the thickness of the first coating film, which consisted of the coating liquid for the first gloss adjustment layer.

[0281] Furthermore, the thickness of the second gloss adjustment layer and the primer layer were measured using the same method as described above. For decorative sheet 1A, which contained air bubbles 5, the thickness of the primer layer 4 was measured using the same method as described above, with respect to the portion of the primer layer 4 excluding the portion corresponding to the first protrusion P1.

[0282] (2) Glossiness The glossiness was measured using the Rhopoint IQ-S (manufactured by Rhopoint Instruments) as the specular gloss GS (60°). The "60° gloss value" in Tables 1 to 6 below represents this specular gloss GS (60°).

[0283] (3) Root Mean Square Slope Sdq The root mean square slope Sdq of the surface protective layer was determined by the method described above. A VK-X3000 (manufactured by KEYENCE Corporation) was used as the laser microscope. The VK-X3000 Multi-File Analysis Application was used as the software for image processing and surface roughness measurement. For image processing, height reduction (medium level) and noise reduction (medium level) were performed.

[0284] (4) Adhesion The adhesion of the second gloss adjustment layer to the first gloss adjustment layer was evaluated by a grid test specified in JIS K5400 (now obsolete). Here, cuts with a depth exceeding the interface between the first gloss adjustment layer and the second gloss adjustment layer were formed on the surface of the decorative sheet in a grid pattern at 1 mm intervals. This created 100 squares arranged in a grid pattern. Next, adhesive tape was applied to the surface of the decorative sheet, and then the adhesive tape was peeled off the decorative sheet. The number of squares remaining on the decorative sheet was then counted, and the adhesion was evaluated by referring to this number according to the following criteria.

[0285] AAA: There were 100 squares remaining. AA: There were between 95 and 99 squares remaining. A: There were between 90 and 94 squares remaining. B: There were 89 or fewer squares remaining.

[0286] (5) Each decorative sheet was attached to the wood substrate B using a scratch-resistant urethane adhesive. Subsequently, a steel wool rubbing test was conducted to evaluate scratch resistance. Specifically, the decorative sheet was rubbed back and forth 20 times with steel wool while applying a load of 100g, and scratches and changes in gloss on the surface of the decorative sheet were visually observed.

[0287] 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.

[0288] (6) Stain Resistance As a stain resistance evaluation, a stain A test as specified in the Japanese Agricultural Standards (JAS) was conducted. Specifically, lines 10 mm wide were drawn on the surface protective layer of each decorative sheet using blue ink, black quick-drying ink, and red crayon, and left for 4 hours. After that, the lines of blue ink, black quick-drying ink, and red crayon were wiped off with a cloth soaked in ethanol.

[0289] The evaluation criteria were as follows: AAA: Each colored line could be easily wiped off. AA: Some of each colored line could be wiped off, but some slight stains remained. A: Some of each colored line could be wiped off, but some stains remained. B: It was not possible to wipe off any of the colored lines.

[0290] (7) Fingerprint Resistance As part of the evaluation of fingerprint resistance, the ability to wipe away fingerprints was assessed. The 60-degree gloss of the surface of each decorative sheet was measured and defined as the "initial gloss." Next, a fingerprint resistance evaluation solution was applied to the surface protective layer of each decorative sheet, and then the fingerprint resistance evaluation solution that had adhered to the surface of the decorative sheet was wiped off. After that, the 60-degree gloss of the area from which the fingerprint resistance evaluation solution had been wiped off was measured and defined as the "gloss after wiping." A higher fatty acid was used as the fingerprint resistance evaluation solution.

[0291] The fingerprint removal rate was calculated using the following formula: Fingerprint removal rate (%) = (Glossiness after wiping / Initial glossiness) × 100 The evaluation criteria were as follows: AAA: 80% or more and less than 200% AA: 70% or more and less than 80%, or 200% or more and less than 250% A: 50% or more and less than 70%, or 250% or more and less than 300% B: Less than 50%, or 300% or more

[0292] (8) The tactile feel of the tactile decorative sheets was evaluated by the following method. First, preliminary preparations were made to ensure that the evaluation criteria were consistent among the evaluators. Specifically, the decorative sheets related to Comparative Examples 1 and 3 were prepared as standard test pieces. Next, each of the five evaluators was asked to press their fingers against the surface of the standard test piece while sliding their fingers across the surface, and then classify the tactile feel into two groups.

[0293] Each evaluator was given two standard test pieces in a random order, and the above procedure was repeated until the tactile sensation 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 sensation of the decorative sheet related to Comparative Example 1 will be referred to as "Group 1," and the group corresponding to the tactile sensation of the decorative sheet related to Comparative Example 3 will be referred to as "Group 2."

[0294] Next, for each of the above-mentioned cosmetic sheets, each of the evaluators was asked, blindfolded, to press and slide their fingers across the surface, and then classify the tactile sensation into three groups. Here, the three groups are the first and second groups described above, and a third group corresponding to a different tactile sensation from those two groups. This procedure was repeated until the evaluations by each evaluator agreed three or more times in a row, and the evaluation results agreed three times in a row among the evaluators. Based on these results, the skin feel was evaluated according to the following criteria: A: Third group X: First group Y: Second group

[0295] (9) Gloss Difference The ability to visually confirm the presence of areas with different gloss levels on the surface of the decorative sheet was evaluated using the following method. Specifically, 10 evaluators were asked to visually observe each of the above decorative sheets from an angle of 60° to the thickness direction of the decorative sheet and to judge whether or not there were areas with different gloss levels on the surface of the decorative sheet. The number of people who judged that areas with different gloss levels were present on the surface of the decorative sheet was then used to evaluate the gloss difference according to the following evaluation criteria (Evaluation 1). AAA: 10 people AA: 8 or 9 people A: 6 or 7 people B: 3 to 5 people C: 2 or fewer people

[0296] Furthermore, the following method was used to evaluate whether it could be confirmed that each of the above decorative sheets and the reference sample had the same gloss level when observed visually.

[0297] First, a reference sample was prepared. As the reference sample, a decorative sheet similar to decorative sheet 1A was manufactured using the same method as in Example 1, except for the following points. In this example, the application of the coating liquid for the first gloss adjustment layer and the first and second irradiation steps were omitted. Also, in this example, the coating liquid for the second gloss adjustment layer was applied to the entire surface of the primer layer 4.

[0298] Next, the evaluators who performed the evaluation in Evaluation 1 were asked to visually observe each of the above decorative sheets and the reference sample from an angle of 60° to the thickness direction of the decorative sheet and to judge whether the gloss level was the same or not. Here, those who judged in Evaluation 1 that there were no areas on the surface of the decorative sheet where the gloss level differed were excluded from the evaluators. Then, the gloss difference was evaluated (Evaluation 2) by referring to the following evaluation criteria based on the percentage of evaluators who judged that the gloss level was different. AAA: Less than 10% AA: 10% or more and less than 25% A: 25% or more and less than 50% B: 50% or more and less than 75% C: 75% or more

[0299] The evaluation results are shown in Tables 1 to 6.

[0300]

[0301]

[0302]

[0303]

[0304]

[0305]

[0306] In Tables 1 to 6, "Percentage of Moles of Methacryloyl Groups" represents the percentage of moles of methacryloyl groups relative to the total number of moles of acryloyl groups and methacryloyl groups. Also, in Tables 1 to 6, the "L" of the base material ＊ value, a ＊ "value" and "b ＊ The value is L, which is the color of the substrate for forming the first gloss adjustment layer 6A (i.e., the substrate with the pigment-containing layer 3 and primer layer 4 formed on top of the base layer 2). ＊ a ＊ b ＊ It is expressed in law. ＊ a ＊ b ＊ The law is L, which is standardized by the International Commission on Illumination (CIE) and adopted in JIS Z8781-4:2013. ＊ a ＊ b ＊This refers to a method of quantifying color using a color system. In Tables 1 to 6, the "first gloss adjustment layer / second gloss adjustment layer (area ratio)" is the ratio P1 / P2 described above.

[0307] As shown in Tables 1 to 6, the decorative sheets according to Examples 1 to 20 provided a different tactile feel from the decorative sheets according to Comparative Examples 1 to 3. As shown in Table 5, the decorative sheet according to Example 17 showed sufficient performance in terms of fingerprint resistance, but poor performance in terms of adhesion, scratch resistance, and stain resistance. The decorative sheets according to Examples 18 to 20 showed sufficient performance in terms of adhesion and fingerprint resistance, but poor performance in terms of scratch resistance and stain resistance. In contrast, the decorative sheets according to Examples 1 to 16 showed high performance in terms of adhesion, scratch resistance, stain resistance, and fingerprint resistance, as shown in Tables 1 to 4.

[0308] <Reference Example 1> A decorative sheet similar to decorative sheet 1A was manufactured using the same method as in Example 1, except that the second gloss adjustment layer 6B was omitted.

[0309] <Reference Example 2> A decorative sheet similar to decorative sheet 1A was manufactured using the same method as in Example 1, except that the formation of the surface protective layer 6 was omitted.

[0310] <Analysis> Cross-sections of the decorative sheets according to Reference Examples 1 and 2 were imaged using a scanning electron microscope. As a result, it was confirmed that multiple air bubbles 5 exist between the first gloss adjustment layer 6A and the base layer 2, that one or more of the air bubbles 5 correspond to multiple protrusions P0 on the upper surface of the primer layer 4, and that one or more of the air bubbles 5 correspond to multiple first protrusions P1 on the upper surface of the first gloss adjustment layer 6A.

[0311] 1...Decorative sheet, 1A...Decorative sheet, 2...Raw material layer, 3...Pigment-containing layer, 3A...Ink layer, 4...Primer layer, 4A...Coating layer, 5...Air bubbles, 6...Surface protective layer, 6A...First gloss adjustment layer, 6A0...First coating film, 6A1...Semi-cured film, 6B...Second gloss adjustment layer, 6B0...Second coating film, 11...Decorative material, 11A...Decorative material, B...Base material, DZ...Dimensions, H0...Height, H1...Height, H2...Height, P0...Protrusion, P1...First protrusion, P2...Second protrusion, P3...Third protrusion, P4...Fourth protrusion, R...Diameter, TP...Thickness, W...Width.

Claims

1. A decorative sheet comprising a base layer and a surface protection layer, wherein there are a plurality of air bubbles between the surface of the surface protection layer and the base layer, the surface protection layer comprises a first gloss adjustment layer provided on the base layer and 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 upper surface of the first gloss adjustment 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, and the upper surface of the second gloss adjustment layer has a plurality of protrusions.

2. The decorative sheet according to claim 1, wherein the first ionizing radiation-curable resin is a first mixture of acrylate and methacrylate.

3. The decorative sheet according to claim 1 or 2, wherein the plurality of protrusions on the upper surface of the second gloss-adjusting layer include a plurality of third protrusions, each corresponding to any of the plurality of first protrusions.

4. The decorative sheet according to any one of claims 1 to 3, wherein the plurality of protrusions on the upper surface of the second gloss-adjusting layer include a plurality of fourth protrusions, each of which is ridged.

5. The decorative sheet according to any one of claims 1 to 4, wherein the portion provided with the second gloss adjustment layer has a different degree of gloss than the portion provided with the first gloss adjustment layer but not with the second gloss adjustment layer.

6. The decorative sheet according to any one of claims 1 to 5, wherein the specular gloss GS(60°) of the first gloss adjustment layer is less than the specular gloss GS(60°) of the second gloss adjustment layer, the specular gloss GS(60°) of the first gloss adjustment layer is 25 or less, and the specular gloss GS(60°) of the second gloss adjustment layer is 0.5 or more.

7. The decorative sheet according to any one of claims 1 to 5, wherein the specular gloss GS(60°) of the first gloss adjustment layer is greater than the specular gloss GS(60°) of the second gloss adjustment layer, the first gloss adjustment layer has a specular gloss GS(60°) of 0.5 or more, and the second gloss adjustment layer has a specular gloss GS(60°) of 25 or less.

8. The decorative sheet according to any one of claims 1 to 7, wherein the absolute value of the difference between the specular gloss GS (60°) of the second gloss adjustment layer and the specular gloss GS (60°) of the first gloss adjustment layer is 1 or more.

9. The decorative sheet according to any one of claims 1 to 8, further comprising a primer layer interposed between the raw material layer and the surface protective layer.

10. The decorative sheet according to claim 9, 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.

11. The decorative sheet according to claim 9 or 10, wherein the plurality of air bubbles are at least partially located within the primer layer.

12. The decorative sheet according to any one of claims 9 to 11, further comprising a pigment-containing layer interposed between the raw material layer and the primer layer, the pigment-containing layer comprising a pigment and a binder resin.

13. The decorative sheet according to claim 12, wherein the pigment-containing layer partially covers the upper surface of the raw material layer at the position of the second gloss-adjusting layer.

14. The decorative sheet according to claim 13, wherein the second gloss-adjusting layer and the pigment-containing layer are identical in shape and position when viewed from the thickness direction.

15. The decorative sheet according to claim 13, wherein the second gloss-adjusting layer and the pigment-containing layer differ in at least one of their shapes and positions when observed from the thickness direction.

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

17. The decorative sheet according to any one of claims 1 to 15, 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.

18. A decorative material comprising a decorative sheet according to any one of claims 1 to 17, and a substrate to which the decorative sheet is attached.

19. Forming a base layer containing a foaming agent on a raw material layer; causing foaming by the foaming agent to generate a plurality of bubbles in the base layer, thereby creating a plurality of protrusions on the surface of the base layer, each corresponding to one or more of the bubbles; then forming a first coating film containing a first ionizing radiation-curable resin on the base layer; irradiating the first coating film with a first light having a wavelength of 200 nm or less, and then irradiating it with ionizing radiation or ultraviolet light with a wavelength longer than the first light, to obtain a semi-cured film having a region on its surface in which a plurality of first protrusions, each corresponding to the plurality of protrusions, and a plurality of ridge-like second protrusions are mixed; forming a second coating film containing a second ionizing radiation-curable resin on the semi-cured film so as to partially cover the upper surface of the semi-cured film. A method for manufacturing a decorative sheet, comprising irradiating the second coating film with a second light having a wavelength of 200 nm or less, and then irradiating the semi-cured film and the second coating film with ionizing radiation or ultraviolet light with a wavelength longer than that of the second light, thereby generating a plurality of protrusions on the surface of the second coating film and completely curing the semi-cured film and the second coating film.

20. Forming a base layer containing a foaming agent on a raw material layer; forming a first coating film containing a first ionizing radiation-curable resin on the base layer; irradiating the first coating film with first light having a wavelength of 200 nm or less, and then irradiating it with ionizing radiation or ultraviolet light with a wavelength longer than the first light to obtain a semi-cured film having a plurality of ridge-like second protrusions on its surface; causing foaming by the foaming agent to generate a plurality of bubbles in the base layer, thereby creating a plurality of protrusions on the surface of the base layer corresponding to one or more of the bubbles, and creating a plurality of first protrusions on the surface of the semi-cured film corresponding to each of the plurality of protrusions; and thereafter forming a second coating film containing a second ionizing radiation-curable resin on the semi-cured film so as to partially cover the upper surface of the semi-cured film. A method for manufacturing a decorative sheet, comprising irradiating the second coating film with a second light having a wavelength of 200 nm or less, and then irradiating the semi-cured film and the second coating film with ionizing radiation or ultraviolet light with a wavelength longer than that of the second light, thereby generating a plurality of protrusions on the surface of the second coating film and completely curing the semi-cured film and the second coating film.

21. The method for producing a decorative sheet according to claim 19 or 20, wherein the first ionizing radiation-curable resin contains acrylate and methacrylate.

22. A method for manufacturing a decorative sheet according to any one of claims 19 to 21, 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.

23. The method for manufacturing a decorative sheet according to claim 22, wherein the coating layer comprises a polymer-containing resin, the multilayer structure is heated to generate foaming by the foaming agent, and the polymer-containing resin is cured to obtain a primer layer comprising a cured product of the polymer-containing resin, wherein the plurality of bubbles are at least partially located.

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

Images