Decorative sheet

Abstract

The present invention provides: a decorative sheet having excellent scratch resistance; and a technology that makes it possible to design a decorative sheet with a high degree of flexibility in texture and external appearance. A decorative sheet 1 is provided with a raw fabric layer 2, a primer layer 4, and a surface protective layer 6 in this order, and has a plurality of air bubbles 5 between a surface of the surface protective layer 6 and the raw fabric layer 2. The surface protective layer 6 includes: a first gloss adjustment layer 61 that is provided on the primer layer 4 and that contains a cured product of a first ionizing radiation curable resin; and a second gloss adjustment layer 62 that partially coats the upper surface of the first gloss adjustment layer 61 and that contains a cured product of a second ionizing radiation curable resin. The surface of the second gloss adjustment layer 62 includes a plurality of protrusions, each of which has a ridge shape. A ratio B / A is greater than 1, where B represents the height of the upper surface of the first gloss adjustment layer 61 relative to the lower surface of the primer layer 4 at a position of the plurality of bubbles 5, and A represents the height of the upper surface of the first gloss adjustment layer 61 relative to the lower surface of the primer layer 4 at a position away from the plurality of bubbles 5.

Description

Decorative sheet

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

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

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

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

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

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

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

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

[0009] Japanese Patent Application Laid-Open No. 2019-119138

[0010] An object of the present invention is to provide a technology that allows for a high degree of freedom in the design of the feel or appearance of a decorative sheet, and to provide a decorative sheet that has excellent scratch resistance.

[0011] According to one aspect of the present invention, there is provided a decorative sheet comprising an original fabric layer, a primer layer, and a surface protective layer in this order, with a plurality of air bubbles between the surface of the surface protective layer and the original fabric layer, the surface protective layer comprising a first gloss adjustment layer provided on the primer 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 surface of the second gloss adjustment layer comprising a plurality of convex portions, each of which is ridge-shaped, and the ratio B / A of the height B of the upper surface of the first gloss adjustment layer relative to the lower surface of the primer layer at the positions of the plurality of air bubbles to the height A of the upper surface of the first gloss adjustment layer relative to the lower surface of the primer layer at a position away from the plurality of air bubbles is greater than 1.

[0012] According to another aspect of the present invention, there is provided a decorative sheet relating to the above aspect, in which the surface on the second gloss adjustment layer side includes an area in which a plurality of first convex portions, each corresponding to one or more of the plurality of bubbles, and a plurality of ridge-shaped convex portions as a plurality of second convex portions are mixed.

[0013] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the surface of the first gloss adjustment layer has a plurality of third convex portions at the positions of the plurality of first convex portions, respectively.

[0014] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the surface of the primer layer facing the surface protection layer has a plurality of convex portions at the positions of the plurality of first convex portions.

[0015] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein each of the plurality of second protrusions does not overlap any of the plurality of first protrusions.

[0016] Alternatively, according to yet another aspect of the present invention, a decorative sheet according to any of the above aspects is provided, wherein one or more of the plurality of second convex portions includes one or more portions that each overlap with one of the plurality of first convex portions.

[0017] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the plurality of bubbles are at least partially located within the primer layer.

[0018] According to yet another aspect of the present invention, there is provided a decorative sheet relating to any of the above aspects, further comprising a pigment-containing layer interposed between the base fabric layer and the primer layer, the pigment-containing layer containing a pigment and a binder resin, the pigment-containing layer being positioned between the second gloss adjustment layer and the base fabric layer and partially covering the upper surface of the base fabric layer.

[0019] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the first ionizing radiation curable resin includes a first mixture of an acrylate and a methacrylate.

[0020] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein in the first ionizing radiation curable resin, the proportion of the number of moles of methacryloyl groups to the total number of moles of acryloyl groups and the number of moles of methacryloyl groups is in the range of 3% or more and 50% or less.

[0021] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the methacrylate is a monofunctional, difunctional, or trifunctional methacrylate.

[0022] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the second ionizing radiation curable resin is an acrylate.

[0023] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the second ionizing radiation curable resin contains a di- or higher functional acrylate containing a repeating structure.

[0024] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the repeating structure is repeated three or more times.

[0025] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the thickness of each of the first gloss adjustment layer and the second gloss adjustment layer is in the range of 2 μm or more and 20 μm or less.

[0026] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the second gloss control layer further contains particles having an average particle size of 10 μm or less.

[0027] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the mass of the particles is in the range of 0.5 parts by mass or more and 20 parts by mass or less when the mass of the second ionizing radiation curable resin is 100 parts by mass.

[0028] According to yet another aspect of the present invention, there is provided a decorative sheet according to any of the above aspects, wherein the specular gloss GS(60°) of the second gloss adjustment layer is smaller than the specular gloss GS(60°) of the first gloss adjustment layer, the specular gloss GS(60°) of the first gloss adjustment layer is 3 or more, and the specular gloss GS(60°) of the second gloss adjustment layer is 10 or less.

[0029] According to yet another aspect of the present invention, there is provided a decorative sheet relating to any of the above aspects, wherein the specular gloss GS(60°) of the second gloss adjustment layer is smaller than the specular gloss GS(60°) of the first gloss adjustment layer, and the difference between the specular gloss GS(60°) of the first gloss adjustment layer and the specular gloss GS(60°) of the second gloss adjustment layer is 1 or more.

[0030] According to yet another aspect of the present invention, there is provided a decorative material comprising a decorative sheet according to any one of the above aspects and a substrate to which the decorative sheet is attached.

[0031] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet, comprising: forming a base layer containing a foaming agent on an original layer; foaming with the foaming agent to generate a plurality of bubbles in the base layer, thereby generating a plurality of convex portions on the surface of the base layer, each convex portion corresponding to one or more of the plurality of bubbles; then forming a first coating film containing a first ionizing radiation curable resin on the base layer; performing a first irradiation step of irradiating the first coating film with ionizing radiation or ultraviolet light to semi-cure the first coating film, thereby obtaining a semi-cured film having a plurality of third convex portions on its surface, each convex portion corresponding to one of the plurality of convex portions; forming a second coating film containing a second ionizing radiation curable resin on the semi-cured film so as to partially cover an upper surface of the semi-cured film; and irradiating the semi-cured film and the second coating film with ionizing radiation or ultraviolet light to completely cure the semi-cured film and the second coating film.

[0032] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet, comprising: forming a base layer containing a foaming agent on an original layer; forming a first coating film containing a first ionizing radiation curable resin on the base layer; carrying out a first irradiation step of irradiating the first coating film with ionizing radiation or ultraviolet light to semi-cure the first coating film to obtain a semi-cured film; causing foaming by the foaming agent to generate a plurality of bubbles in the base layer or in a laminate consisting of the base layer and the semi-cured film, thereby generating a plurality of third convex portions on the surface of the semi-cured film, each of which corresponds to one or more of the plurality of bubbles; forming a second coating film containing a second ionizing radiation curable resin on the semi-cured film so as to partially cover an upper surface of the semi-cured film; and irradiating the semi-cured film and the second coating film with ionizing radiation or ultraviolet light to completely cure the semi-cured film and the second coating film.

[0033] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet according to any of the above aspects, wherein the complete curing of the semi-cured film and the second coating film includes a second irradiation step in which the second coating film is irradiated with light having a wavelength of 200 nm or less to produce, on the surface of the second coating film, a plurality of first convex portions that respectively correspond to the plurality of third convex portions and a plurality of second convex portions that are each ridge-shaped, and then a third irradiation step in which the semi-cured film and the second coating film are irradiated with ionizing radiation or ultraviolet light having a longer wavelength than the light irradiated in the second irradiation step.

[0034] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet according to any of the above aspects, in which a multilayer structure is formed as the base layer, the multilayer structure including a foaming agent-containing layer containing the foaming agent and a coating layer provided on the foaming agent-containing layer.

[0035] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet according to any of the above aspects, wherein the coating layer comprises a resin containing a polymer, and the multilayer structure is heated to cause foaming by the foaming agent and to harden the resin containing the polymer, thereby obtaining a primer layer containing a hardened product of the resin containing the polymer and in which the plurality of bubbles are at least partially positioned.

[0036] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet according to any one of the above aspects, wherein the foaming agent-containing layer further contains a pigment and a binder resin.

[0037] According to yet another aspect of the present invention, there is provided a method for producing a decorative sheet according to any of the above aspects, wherein the first ionizing radiation curable resin contains an acrylate and a methacrylate.

[0038] The present invention provides a decorative sheet with excellent scratch resistance and a technology that allows for a high degree of freedom in the design of the feel or appearance of the decorative sheet.

[0039]

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

[0040] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are more specific embodiments of any of the above aspects. The following items can be incorporated into each of the above aspects, either singly or in combination.

[0041] Furthermore, the embodiments shown below are merely examples of configurations for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not limited by the materials, shapes, structures, etc. of the components described below. Various modifications can be made to the technical idea of ​​the present invention within the technical scope defined by the claims.

[0042] In the drawings, elements having the same or similar functions are denoted by the same reference numerals, and redundant explanations will be omitted. Furthermore, the drawings are schematic, and the relationship between dimensions in one direction and dimensions in another direction, and the relationship between the dimensions of one member and the dimensions of another member, etc. may differ from the actual relationship.

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

[0044] The decorative material 11 shown in Figure 1 includes a substrate B and a decorative sheet 1 attached thereto. Here, the decorative material 11 is a decorative board. The decorative board may be a flat plate, or may be curved or folded. The decorative material 11 may have a shape other than a plate.

[0045] Here, the substrate B is a plate material. The plate material is, for example, a wood board, an inorganic board, a metal plate, or a composite board made of multiple materials. The substrate B may have a shape other than a plate.

[0046] The decorative sheet 1 includes a base fabric layer 2, a pigment-containing layer 3, a primer layer 4, and a surface protective layer 6. The pigment-containing layer 3, the primer layer 4, and the surface protective layer 6 are provided in this order from the base fabric layer 2 side on the surface of the base fabric layer 2 opposite the surface facing the substrate B. The decorative sheet 1 may further include one or more other layers.

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

[0048] The surface protection layer 6 includes a first gloss adjustment layer 61 provided on the primer layer 4 and a second gloss adjustment layer 62 partially covering the upper surface of the first gloss adjustment layer 61. The surface of the second gloss adjustment layer 62 includes a plurality of protrusions, each of which is ridge-shaped.

[0049] In the decorative sheet 1, the ratio B / A of the height B of the upper surface of the first gloss adjustment layer 61 relative to the lower surface of the primer layer 4 at the position of the multiple bubbles 5 to the height A of the upper surface of the first gloss adjustment layer 61 relative to the lower surface of the primer layer 4 at a position distant from the multiple bubbles 5 is greater than 1. Hereinafter, the height B at the position of the multiple bubbles 5 will also be referred to as the "foamed portion height," and the height A at a position distant from the multiple bubbles 5 will also be referred to as the "non-foamed portion height."

[0050] As described above, the decorative sheet 1 has multiple bubbles 5 between the surface of the surface protective layer 6 and the base fabric layer 2, and multiple ridge-like protrusions on the surface of the second gloss-controlling layer 62, thereby providing a unique tactile sensation not previously available. The ratio B / A, which indicates the ratio of the foamed portion height B to the non-foamed portion height A, is a parameter related to the tactile sensation of the unevenness. By increasing the ratio B / A to greater than 1, the unique tactile sensation of the decorative sheet 1 can be enhanced. The magnitude of this unique tactile sensation is hereinafter also referred to as "tactile intensity." From the perspective of tactile intensity, the ratio B / A is preferably 1.5 or more, more preferably 2.0 or more. On the other hand, from the perspective of scratch resistance, the ratio B / A is preferably 10.0 or less, more preferably 7.0 or less. The foamed portion height B and the non-foamed portion height A are specifically measured using the method described below.

[0051] In one embodiment, the decorative sheet 1 includes an area on the surface facing the second gloss adjustment layer 62 where a plurality of first protrusions P1, each corresponding to one or more of the bubbles 5, and a plurality of second protrusions P2 are mixed. Here, the surface of the second gloss adjustment layer 62 includes an area where a plurality of first protrusions P1, each corresponding to one or more of the bubbles 5, and a plurality of ridge-like protrusions as the plurality of second protrusions P2 are mixed. Furthermore, the surface of the first gloss adjustment layer 61 facing the second gloss adjustment layer 62 has a plurality of third protrusions P3 at the positions of the plurality of first protrusions P1, respectively. Furthermore, the surface of the primer layer 4 facing the surface protection layer 6 has a plurality of protrusions P0 at the positions of the plurality of first protrusions P1, respectively.

[0052] The elements contained in the decorative sheet 1 will be explained below one by one.

[0053] <1.1.1> Raw Fabric Layer The raw fabric layer 2 may have various forms such as a film, a sheet, a plate, an irregularly shaped molded body, etc. Here, as an example, the raw fabric layer 2 is in the form of a film.

[0054] The raw fabric layer 2 or its material can be any material selected from, for example, paper, synthetic resin, synthetic resin foam, rubber, nonwoven fabric, synthetic paper, and metal foil. Examples of paper include tissue paper, titanium paper, and resin-impregnated paper. Examples of synthetic resins include polyethylene, polypropylene, polybutylene, polystyrene, polycarbonate, polyester, polyamide, ethylene-vinyl acetate copolymer, polyvinyl alcohol, and acrylic. Examples of rubber include ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, styrene-butadiene copolymer rubber, styrene-isoprene-styrene block copolymer rubber, styrene-butadiene-styrene block copolymer rubber, and polyurethane. Examples of nonwoven fabrics include organic and inorganic nonwoven fabrics. Examples of metals for the metal foil include aluminum, iron, gold, and silver.

[0055] The thickness of the raw fabric layer 2 is preferably in the range of 20 μm to 250 μm. If the raw fabric layer 2 is thin, the ability to cover unevenness of the base (unevenness) will decrease. If the raw fabric layer 2 is thick, problems such as whitening and cracking may occur during bending.

[0056] When a substrate with an inactive surface, such as an olefin-based substrate, is used as the raw fabric layer 2, it is desirable to subject the front and back surfaces of the raw fabric layer 2 to treatment such as corona treatment, plasma treatment, ozone treatment, electron beam treatment, ultraviolet treatment, and dichromate treatment.

[0057] <1.1.2> Pigment-containing layer The pigment-containing layer 3 is provided on the base fabric layer 2 and is a layer containing a pigment and a binder resin. The pigment-containing layer 3 is, for example, a continuous film formed by coating one entire surface of the base fabric layer 2 with ink. In this case, the pigment-containing layer 3 can serve as a concealing layer that conceals the substrate B or the base fabric layer 2. In this case, the pigment-containing layer 3 can also serve as a planarizing layer.

[0058] The pigment-containing layer 3 may have a single-layer structure or a multi-layer structure. When the pigment-containing layer 3 has a multi-layer structure, all of the layers may be continuous films, all of the layers may be discontinuous films, or one or more layers may be continuous films and the remaining layers may be discontinuous films.

[0059] The pigment-containing layer 3 can be formed using, for example, a printing ink (or a coating agent) in which a binder resin serving as a matrix and a pigment are dissolved or dispersed in a solvent.

[0060] Examples of binder resins that can be used include various synthetic resins such as oil-based nitrocellulose resin, two-component urethane resin, acrylic resin, styrene resin, polyester resin, urethane resin, polyvinyl resin, alkyd resin, epoxy resin, melamine resin, fluorine resin, silicone resin, and daimi rubber resin, as well as mixtures or copolymers of these.

[0061] The pigment is at least one of a white pigment and a colored pigment. Examples of the pigment include inorganic pigments such as carbon black, titanium oxide (titanium white), zinc white, red iron oxide, yellow lead, Prussian blue, and cadmium red; organic pigments such as azo pigments, lake pigments, anthraquinone pigments, phthalocyanine pigments, isoindolinone pigments, and dioxazine pigments; and mixtures thereof.

[0062] The average particle size of the pigment is preferably in the range of 50 nm to 5 μm, and more preferably in the range of 100 nm to 1 μm. This average particle size is the median diameter (D50) of the particles in the surface protective layer 6, which will be described later.

[0063] The amount of pigment is preferably in the range of 2 parts by mass to 50 parts by mass, and more preferably in the range of 5 parts by mass to 30 parts by mass, per 100 parts by mass of binder resin.

[0064] Examples of the solvent that can be used include toluene, xylene, ethyl acetate, butyl acetate, methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, water, and mixtures thereof.

[0065] The ink used to form the pigment-containing layer 3 may contain the binder resin in various forms. For example, the ink may be solvent-free. Alternatively, the ink may contain the binder resin in the form of a solution, emulsion, or dispersion. According to one example, the ink contains the binder resin in the form of a water-based emulsion or dispersion. Furthermore, the ink may be cured by volatilization of the solvent, by irradiation with ionizing radiation, or by heat curing.

[0066] The ink may further contain a foaming agent, which can be used to generate bubbles 5. Here, as an example, it is assumed that the ink further contains a foaming agent.

[0067] Examples of foaming agents that can be used include inorganic foaming agents such as sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, ammonium nitrite, sodium borohydride, light metals, and azotides; organic foaming agents such as azo-based, nitroso-based, and hydrazide-based foaming agents; and combinations of two or more thereof. Examples of azo-based organic foaming agents that can be used include azodicarbonamide. Examples of nitroso-based organic foaming agents that can be used include N,N'-dinitrosopentamethylenetetramine. Examples of hydrazide-based organic foaming agents that can be used include 4,4'-oxybisbenzenesulfonylhydrazide.

[0068] The amount of the foaming agent is preferably in the range of 1 to 20 parts by mass, more preferably in the range of 5 to 15 parts by mass, per 100 parts by mass of the binder resin.

[0069] When the ink contains a blowing agent, it may further contain a blowing aid to lower the decomposition temperature of the blowing agent. For example, when the ink contains an azo-based organic blowing agent such as azodicarbonamide, it may further contain a metal catalyst. Furthermore, when the ink contains a nitroso-based organic blowing agent such as N,N'-dinitrosopentamethylenetetramine, it may further contain a urea-based blowing aid.

[0070] In addition, functional additives such as plasticizers, dispersants, surfactants, tackifiers, adhesion aids, drying agents, curing agents, curing accelerators, and curing retarders may be added to the ink to impart various functions.

[0071] <1.1.3> Primer layer The primer layer 4 is provided on the pigment-containing layer 3. Here, the primer layer 4 covers the entire surface of one side of the raw fabric layer 2, with the pigment-containing layer 3 sandwiched therebetween.

[0072] The primer layer 4 is made of, for example, a cured resin. The primer layer 4 may further contain particles. For example, the particles described later for the second gloss adjustment layer 62 may be used as the particles.

[0073] When the mass of the primer layer 4 is 100 parts by mass, the mass of the cured resin contained in the primer layer 4 is preferably 60 parts by mass or more, more preferably 70 parts by mass or more, and even more preferably 80 parts by mass or more.

[0074] The cured resin contained in the primer layer 4 is, for example, a cured resin described above for the binder resin of the pigment-containing layer 3. The cured resin contained in the primer layer 4 may be another cured resin, for example, a cured resin described below for the surface protective layer 6.

[0075] The resin used to form the primer layer 4 may be a solvent-free resin, a water-based resin, or a non-aqueous (organic solvent-based) resin.

[0076] The cured resin may be a cured product of a thermosetting resin, a cured product of an ionizing radiation curable resin, or a cured product of a resin containing a thermosetting resin and an ionizing radiation curable resin. Here, "ionizing radiation" refers to a charged particle beam such as an electron beam. The ionizing radiation curable resin is cured by irradiation with ionizing radiation. The ionizing radiation curable resin can also be cured by irradiation with ultraviolet light.

[0077] The cured resin preferably includes a cured product of a resin containing a polymer, for example, a cured product of an aqueous emulsion containing a polymer or a cured product of a solvent-based resin containing a polymer, for the reasons described below.

[0078] As described below, in the production of the decorative sheet 1, for example, a foaming agent-containing layer made of the above-mentioned ink containing a foaming agent and a coating layer containing uncured resin are first formed in this order on the base layer 2, and then the multilayer structure containing these is heated. During this heating process, at least a portion of the gas generated by thermal decomposition of the foaming agent is absorbed into the coating layer, generating bubbles within the coating layer. If the crosslink density of the resin constituting the coating layer is sufficiently low, the coating layer can absorb a large amount of gas. In addition, in this case, coalescence of bubbles is likely to occur within the coating layer. Therefore, if the crosslink density of the resin constituting the coating layer is sufficiently low, large bubbles may be generated within the coating layer. However, if the crosslink density of the resin constituting the coating layer is low, the structure containing the bubbles is likely to be destroyed.

[0079] The coating layer formed from the above-mentioned aqueous or solvent-based resin is mainly composed of a polymer with a low crosslinking density, and therefore has appropriate flexibility and strength. Therefore, when the coating layer is formed from the above-mentioned aqueous or solvent-based resin, large bubbles are generated in the coating layer, and the structure containing such large bubbles is less likely to be destroyed.

[0080] As described above, here, the bubbles 5 are at least partially located within the primer layer 4. The surface of the primer layer 4 facing the surface protection layer 6, i.e., the upper surface, includes a plurality of protrusions P0 each corresponding to one or more of the bubbles 5. In this embodiment, the bubbles 5 generate the protrusions P0 on the upper surface of the primer layer 4, and the protrusions P0 generate the third protrusions P3 on the surface of the first gloss adjustment layer 61. The third protrusions P3 then generate the first protrusions P1 on the surface of the second gloss adjustment layer 62.

[0081] 1, one bubble 5 may form one convex portion P0, or two or more bubbles 5 may form one convex portion P0. The number of bubbles 5 forming one convex portion P0 is preferably 15 or less, more preferably 10 or less, and even more preferably 5 or less.

[0082] Here, most of the protrusions P0 are each formed by a single bubble 5. Therefore, most of the protrusions P0 have a substantially dome shape, and have a substantially circular shape in plan view.

[0083] One or more of the bubbles 5 preferably have a dimension DZ of 5 μm or more, and more preferably 8 μm or more, in the thickness direction of the surface protective layer 6. Bubbles 5 with a large dimension DZ can cause convex portions P0 with a large height H0 to form on the upper surface of the primer layer 4. Here, the height H0 of the convex portions P0 is measured based on a region of the upper surface of the primer layer 4 where no convex portions P0 form.

[0084] The dimension DZ of the bubbles 5 in the thickness direction of the surface protective layer 6 is preferably 100 μm or less, and more preferably 80 μm or less. A decorative sheet 1 having bubbles 5 with a large dimension DZ tends to have a large variation in the dimension DZ.

[0085] Most of the bubbles 5 are spherical or have a similar shape. Therefore, most of the bubbles 5 have the dimension DZ and the dimensions in each direction perpendicular to the thickness direction that are substantially equal to each other.

[0086] The thickness TP of the primer layer 4, excluding the portion corresponding to the first convex portion P1, i.e., the portion other than the convex portion P0, is preferably 20 μm or less, more preferably 15 μm or less. Ｍａｘ Ratio of TP / DZ Ｍａｘ is preferably 2 or less, more preferably 1 or less, and even more preferably 0.9 or less. Ｍａｘ When the value of the height H0 of the projection P0 is increased, the height H0 of the projection P0 is decreased.

[0087] The thickness TP is preferably 2 μm or more, and more preferably 5 μm or more. Ｍａｘ is preferably 0.05 or more, more preferably 0.1 or more, and even more preferably 0.2 or more. Ｍａｘ is preferably large.

[0088] The height H0 of the convex portion P0 is preferably 1 μm or more, and more preferably 2 μm or more. A large height H0 is preferable to form the first convex portion P1 with a large height H1 on the surface of the surface protective layer 6. Here, the height H1 of the first convex portion P1 is the height of the top of the first convex portion P1 based on the lowest position of its periphery. The height H0 of the convex portion P0 is, for example, 20 μm or less, and, for another example, 15 μm or less.

[0089] <1.1.4> Surface Protective Layer The surface protective layer 6 is provided on the primer layer 4. As described above, the surface protective layer 6 includes a first gloss adjustment layer 61 provided on the primer layer 4 and a second gloss adjustment layer 62 that partially covers the upper surface of the first gloss adjustment layer 61. According to one example, the surface protective layer 6 consists of the first gloss adjustment layer 61 and the second gloss adjustment layer 62. Here, the first gloss adjustment layer 61 covers the entire upper surface of the primer layer 4.

[0090] <1.1.4.1> First Gloss Adjustment Layer The surface of the first gloss adjustment layer 61 has a plurality of third convex portions P3 at the positions of the plurality of convex portions P0, that is, at the positions of the plurality of first convex portions P1 described below.

[0091] The first gloss adjustment layer 61 contains a cured resin product of a first ionizing radiation curable resin. The first gloss adjustment layer 61 may further contain particles. When the mass of the first gloss adjustment layer 61 is taken as 100 parts by mass, the mass of the cured resin product contained in the first gloss adjustment layer 61 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. The first gloss adjustment layer 61 may be made of a cured resin product of the first ionizing radiation curable resin.

[0092] Here, "ionizing radiation" refers to a charged particle beam such as an electron beam. The first ionizing radiation curable resin is cured by irradiation with ionizing radiation. The first ionizing radiation curable resin can also be cured by irradiation with ultraviolet light.

[0093] The first ionizing radiation curable resin may be any known resin, such as various monomers or commercially available oligomers, including (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, or epoxy resins. The first ionizing radiation curable resin may be either an aqueous resin or a non-aqueous (organic solvent-based) resin. The first ionizing radiation curable resin may be solvent-free.

[0094] The first ionizing radiation curable resin preferably contains an acrylate or a first mixture of an acrylate and a methacrylate as a main component, and more preferably a first mixture of an acrylate and a methacrylate as a main component. Here, the term "main component" refers to a content of preferably 60 parts by mass or more, more preferably 70 parts by mass or more, and most preferably 80 parts by mass or more, per 100 parts by mass of the resin components constituting the first ionizing radiation curable resin. This proportion may be 100 parts by mass.

[0095] To achieve relative adhesion between the first gloss adjustment layer 61 and the second gloss adjustment layer 62, the first coating film containing the first ionizing radiation-curable resin must be semi-cured by irradiation with ionizing radiation or ultraviolet light. To achieve semi-curing, the ionizing radiation or ultraviolet light irradiation must be adjusted to leave sufficient C═C bonds derived from acryloyl groups or methacryloyl groups in the first coating film. This can be achieved even when an acrylate is used as the main component, but the optimal range for ionizing radiation or ultraviolet light irradiation becomes narrower. On the other hand, by using a first mixture of acrylate and methacrylate as the main component, semi-curing of the first coating film containing the first ionizing radiation-curable resin by irradiation with ionizing radiation or ultraviolet light can be achieved within a wider optimal range for ionizing radiation or ultraviolet light irradiation.

[0096] The methacrylate is preferably a monofunctional, difunctional, or trifunctional methacrylate. The methacrylate may be any one of a monofunctional methacrylate, a difunctional methacrylate, and a trifunctional methacrylate, or may be two or more of them.

[0097] When a methacrylate with a large number of functional groups is used, the degree of crosslinking is increased and scratch resistance is improved compared to when a methacrylate with a small number of functional groups is used. However, when a methacrylate with an excessively large number of functional groups is used, the rate of the crosslinking reaction due to irradiation with ionizing radiation or ultraviolet light increases, narrowing the process window in which high adhesion can be achieved between the first gloss adjustment layer 61 and the second gloss adjustment layer 62.

[0098] The acrylate may be a difunctional or higher functional acrylate, or a trifunctional or higher functional acrylate. From the viewpoint of scratch resistance, the acrylate is preferably trifunctional or higher. There is no upper limit to the number of functional groups of the acrylate, but according to one example, it is hexafunctional or lower.

[0099] The acrylate may or may not contain a repeating structure. In one embodiment, the acrylate preferably contains a repeating structure. Specific examples of the repeating structure include the same specific examples as those described in the second ionizing radiation curable resin described below. In one example, the number of repetitions of the repeating structure may be 2 or more. In another example, the number of repetitions of the repeating structure may be 40 or less, and in another example, 20 or less.

[0100] When the first ionizing radiation curable resin contains a first mixture of acrylate and methacrylate, the ratio of the number of moles of methacryloyl groups to the total number of moles of acryloyl groups and methacryloyl groups is preferably in the range of 3% to 50%, more preferably 5% to 40%. Increasing the ratio of methacrylate in the first mixture widens the process window that enables high adhesion to be achieved between the first gloss adjustment layer 61 and the second gloss adjustment layer 62. However, if the ratio is too high, the scratch resistance of the decorative sheet 1 decreases.

[0101] The thickness of the first gloss adjustment layer 61 is preferably in the range of 2 μm to 20 μm, more preferably in the range of 3 μm to 20 μm, and even more preferably in the range of 5 μm to 15 μm. If the thickness of the first gloss adjustment layer 61 is reduced, scratch resistance decreases. If the thickness of the first gloss adjustment layer 61 is increased, the processability of the decorative sheet 1 decreases, and it becomes more likely to whiten when folded.

[0102] Here, the thickness of the first gloss adjustment layer 61 is the thickness of a layer that has the same apparent area and volume as the first gloss adjustment layer 61 and a flat surface. The thickness of the first gloss adjustment layer 61 is determined, for example, by the following method. First, a cross section parallel to the thickness direction of the first gloss adjustment layer 61 is imaged. Next, from this cross-sectional image, the dimension of the first gloss adjustment layer 61 in a direction perpendicular to the thickness direction and the area of ​​the cross section of the first gloss adjustment layer 61 are determined. The thickness of the first gloss adjustment layer 61 is a value obtained by dividing this area by the above dimension. Note that if the coating liquid for the first gloss adjustment layer described below does not contain a solvent, the thickness of the coating film made of this coating liquid is equal to the thickness of the first gloss adjustment layer 61. The thickness of the second gloss adjustment layer 62 can also be determined by the same method as above.

[0103] The first gloss adjustment layer 61 preferably has a higher specular gloss GS(60°) than the second gloss adjustment layer 62. The specular gloss GS(60°) of the first gloss adjustment layer 61 is preferably 3 or more, more preferably 5 or more, and even more preferably 7 or more. In one example, the specular gloss GS(60°) of the first gloss adjustment layer 61 is 30 or less. Here, the "specular gloss GS(60°)" is the specular gloss measured at an incident angle of 60 degrees using a gloss meter conforming to ISO 2813. Note that the specular gloss GS(60°) is sometimes expressed by adding "%" after the numerical value, but the "%" will be omitted here.

[0104] <1.1.4.2> Second gloss adjustment layer The second gloss adjustment layer 62 partially covers the upper surface of the first gloss adjustment layer 61. The second gloss adjustment layer 62 and the first gloss adjustment layer 61 constitute the surface protection layer 6.

[0105] The second gloss adjustment layer 62 faces the pigment-containing layer 3 with the first gloss adjustment layer 61 sandwiched therebetween.

[0106] As described above, here, the surface of the second gloss adjustment layer 62 includes an area where a plurality of first convex portions P1, each corresponding to one or more of the bubbles 5, and a plurality of second convex portions P2, each of which is ridge-shaped, are mixed.

[0107] The first convex portions P1 are formed on the surface of the second gloss adjustment layer 62 by the third convex portions P3. The third convex portions P3 are formed on the surface of the first gloss adjustment layer 61 by the convex portions P0. Therefore, the first convex portions P1 are located above the convex portions P0 provided on the upper surface of the primer layer 4, and each has a shape corresponding to the convex portions P0. As described above, most of the convex portions P0 have a substantially dome shape and are substantially circular in plan view, and therefore, most of the first convex portions P1 also have a substantially dome shape and are substantially circular in plan view, as shown in FIG. 2 .

[0108] Here, the second convex portions P2 are wrinkles that occur on the surface of the second gloss adjustment layer 62. The second convex portions P2 may be curved or linear in plan view, but from the viewpoint of fingerprint resistance of the surface of the decorative sheet 1, it is preferable that they be curved as exemplified in Fig. 2. A decorative sheet having a plurality of second convex portions P2, each of which is ridge-shaped, has excellent scratch resistance.

[0109] The first convex portions P1 and the second convex portions P2 affect the tactile feel of the surface protective layer 6. The first convex portions P1 and the second convex portions P2 also affect the glossiness of the surface protective layer 6.

[0110] The height H1 of the first protrusion P1 is preferably 1 μm or more, and more preferably 2 μm or more. According to one example, the height H1 of the first protrusion P1 is 20 μm or less, and according to another example, 15 μm or less. According to one example, the diameter R of the first protrusion P1 is in the range of 20 μm or more and 300 μm or less, and according to another example, the diameter R is in the range of 50 μm or more and 200 μm or less. The ratio H1 / R of the height H1 to the diameter R is preferably in the range of 0.01 or more and 0.1 or less, and more preferably in the range of 0.02 or more and 0.08 or less.

[0111] The height H2 of the second protrusion P2 is preferably 1 μm or more, and more preferably 2 μm or more. According to one example, the height H2 of the second protrusion P2 is 20 μm or less, and according to another example, 15 μm or less. Here, the height H2 of the second protrusion P2 is the height of the top of the second protrusion P2 based on its edge. According to one example, the width W of the second protrusion P2 is in the range of 2 μm or more and 200 μm or less, and according to another example, the width W is in the range of 5 μm or more and 100 μm or less. The ratio H2 / W of the height H2 to the width W is preferably in the range of 0.01 or more and 0.5 or less, and more preferably in the range of 0.02 or more and 0.1 or less.

[0112] The ratio R / W of the diameter R of the first convex portion P1 to the width W of the second convex portion P2 is preferably in the range of 1 to 100, and more preferably in the range of 2 to 50. The ratio H1 / H2 of the height H1 of the first convex portion P1 to the height H2 of the second convex portion P2 is preferably in the range of 0.1 to 10, and more preferably in the range of 0.2 to 5. The ratio S1 / S2 of the total area S1 of the first convex portion P1 to the total area S2 of the second convex portion P2, obtained by planar observation, is preferably in the range of 0.1 to 10, and more preferably in the range of 0.2 to 5.

[0113] The second gloss adjustment layer 62 preferably has a lower specular gloss GS(60°) than the first gloss adjustment layer 61. The second convex portions P2 can, for example, serve to make the specular gloss GS(60°) of the second gloss adjustment layer 62 lower than the specular gloss GS(60°) of the first gloss adjustment layer 61. The specular gloss GS(60°) of the second gloss adjustment layer 62 is preferably 10 or less, more preferably 7 or less, and even more preferably 5 or less. According to one example, the specular gloss GS(60°) of the second gloss adjustment layer 62 is 0.5 or more.

[0114] The difference between the specular gloss GS(60°) of the first gloss adjustment layer 61 and the specular gloss GS(60°) of the second gloss adjustment layer 62 is preferably at least 1, more preferably at least 3, and even more preferably at least 5. In one example, this difference is 20 or less.

[0115] The thickness of the second gloss adjustment layer 62 is preferably in the range of 2 μm to 20 μm, more preferably in the range of 3 μm to 20 μm, even more preferably in the range of 5 μm to 15 μm, and most preferably in the range of 5 μm to 12 μm. If the thickness of the second gloss adjustment layer 62 is reduced, it becomes difficult to form second convex portions P2 with a large height H2 on its surface. If the thickness of the second gloss adjustment layer 62 is increased, it becomes difficult to form first convex portions P1 with a large height H1 on its surface. Furthermore, if the thickness of the second gloss adjustment layer 62 is increased, the processability of the decorative sheet 1 decreases, and it becomes more susceptible to whitening when folded.

[0116] The second gloss adjustment layer 62 contains a cured product of a second ionizing radiation curable resin. As described below, the second gloss adjustment layer 62 may further contain particles. When the mass of the second gloss adjustment layer 62 is taken as 100 parts by mass, the mass of the cured product contained in the second gloss adjustment layer 62 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.

[0117] As described above, the ionizing radiation is a charged particle beam such as an electron beam. The second ionizing radiation curable resin is cured by irradiation with ionizing radiation. The second ionizing radiation curable resin can also be cured by irradiation with ultraviolet light. The second ionizing radiation curable resin used here is cured by irradiation with light having a wavelength of 200 nm or less, and has a large absorption coefficient for this light.

[0118] The second ionizing radiation curable resin may be any known resin, such as various monomers or commercially available oligomers, including (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, or epoxy resins. The second ionizing radiation curable resin may be either an aqueous resin or a non-aqueous (organic solvent-based) resin. The second ionizing radiation curable resin may be solvent-free.

[0119] The main component of the second ionizing radiation curable resin is preferably an acrylate. Here, the main component refers to a content of 60 parts by mass or more, more preferably 70 parts by mass or more, and most preferably 80 parts by mass or more, per 100 parts by mass of the resin components constituting the second ionizing radiation curable resin. This proportion may be 100 parts by mass.

[0120] The acrylate is preferably a difunctional or higher acrylate, and more preferably a trifunctional or higher acrylate. In order to obtain a surface protective layer 6 having excellent scratch resistance, the acrylate is preferably a trifunctional or higher acrylate. There is no upper limit to the number of functional groups of the acrylate, but according to one example, it is hexafunctional or lower.

[0121] The acrylate may or may not contain a repeating unit. In one embodiment, the acrylate preferably contains a repeating unit. This repeating unit is, for example, an ethylene oxide (EO) unit, a propylene oxide (PO) unit, or an ε-caprolactone (CL) unit. In the acrylate, the repeating unit may be present between the acryloyl group and the methylol group in an open ring state.

[0122] The number of repetitions of the repeating structure is preferably 3 or more. If an acrylate with a large number of repetitions is used, the cured film is more likely to expand in the in-plane direction in the second irradiation step described below, and therefore wrinkles corresponding to the second convex portions P2 are more likely to appear on the coating film surface. However, if the number of repetitions is increased, the crosslinking density decreases, and the scratch resistance of the surface protective layer 6 decreases. Therefore, the number of repetitions is preferably 30 or less, and more preferably 20 or less.

[0123] The number of repetitions of the repeating structure can be analyzed using MALDI-TOF-MS. The second ionizing radiation curable resin may have a molecular weight distribution. When the second ionizing radiation curing resin has a molecular weight distribution, the number of repetitions is determined to be the number of repetitions corresponding to the molecular weight having the strongest peak in the mass spectrum of MALDI-TOF-MS.

[0124] When the second ionizing radiation curable resin contains an acrylate, it may further contain a methacrylate. For example, the second ionizing radiation curable resin may be a second mixture of an acrylate and a methacrylate, in which the proportion of the number of moles of methacryloyl groups in the total number of moles of acryloyl groups and the number of moles of methacryloyl groups is smaller than that in the first mixture. The proportion in the second mixture is preferably 90% or less, and more preferably 80% or less, of the proportion in the first mixture.

[0125] The second gloss adjustment layer 62 may further contain particles. Examples of the particles contained in the second gloss adjustment layer 62 include particles made of an organic material such as polyethylene (PE) wax, polypropylene (PP) wax, and resin beads, and particles made of an inorganic material such as silica, glass, alumina, titania, zirconia, calcium carbonate, and barium sulfate.

[0126] The average particle size (D50) of the particles is preferably 10 μm or less, more preferably 1 μm or more and 8 μm or less, even more preferably 2 μm or more and 7 μm or less, and most preferably 3 μm or more and 6 μm or less. If the average particle size (D50) of the particles is large, the particles are more likely to fall off from the second gloss adjustment layer 62, which may make it difficult to achieve high scratch resistance. If the particles are small, the effect of generating wrinkles uniformly is reduced.

[0127] Here, "average particle size" or "average particle size (D50)" refers to the median size (D50) measured using a laser diffraction / scattering particle size distribution analyzer. If the coating liquid for the second gloss adjustment layer contains particles, the second gloss adjustment layer 62 obtained from this coating liquid will also contain particles. The average particle size of the particles contained in the second gloss adjustment layer 62 can be determined by observing the cross section of the layer and averaging the particle sizes of multiple particles. The value obtained in this manner is essentially the same as the median size (D50) measured using a laser diffraction / scattering particle size distribution analyzer. Therefore, the above-mentioned average particle size range can also be interpreted as the average particle size range of the particles contained in the second gloss adjustment layer 62.

[0128] The amount of particles in the second gloss adjustment layer 62 is preferably in the range of 0.5 parts by mass or more and 20 parts by mass or less, more preferably in the range of 0.5 parts by mass or more and 10 parts by mass or less, even more preferably in the range of 2 parts by mass or more and 8 parts by mass or less, and even more preferably in the range of 2 parts by mass or more and 6 parts by mass or less, relative to 100 parts by mass of the cured product of the second ionizing radiation curable resin.

[0129] When the amount of particles added is within the above range, the effect of generating wrinkles uniformly is particularly large. If the amount of particles added is too large, the particles are likely to fall off from the second gloss adjustment layer 62, which may make it difficult to achieve high scratch resistance.

[0130] While the decorative sheet 1 described above includes multiple first convex portions P1 on the surface of the second gloss adjustment layer 62, the decorative sheet 1 may also include third convex portions P3 as the first convex portions P1 in portions of the surface of the first gloss adjustment layer 61 that are not covered by the second gloss adjustment layer 62. Furthermore, in the decorative sheet 1 described above, the second convex portions P2 are ridge-shaped, but the second convex portions P2 do not have to be ridge-shaped. For example, the second convex portions P2 may have an uneven structure formed by particles. In this case, the second convex portions P2 may be provided on the upper surface of the first convex portions P1.

[0131] 3 to 7 are cross-sectional views showing a method for 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.

[0132] First, a base layer containing a foaming agent is formed on one surface of the base layer 2. Here, the base layer has a multi-layer structure including an ink layer 3A and a coating layer 4A as shown in FIG.

[0133] In this example, the ink layer 3A is a foaming agent-containing layer that contains a foaming agent and becomes the pigment-containing layer 3 through foaming treatment. The ink layer 3A can be obtained by forming a coating film made of the ink described above for the pigment-containing layer 3 on one side of the base layer 2 and, if necessary, drying this coating film. The coating film can be formed by various printing methods, such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing, or various coating methods, such as roll coating, knife coating, microgravure coating, and die coating. The coating film is dried at a temperature lower than the thermal decomposition temperature of the foaming agent.

[0134] The coating layer 4A is a layer formed on the ink layer 3A. Here, the coating layer 4A is a layer that becomes the primer layer 4 by undergoing a foaming treatment and a curing treatment. The coating layer 4A can be obtained by forming a coating film made of a primer layer coating liquid on the ink layer 3A and drying this coating film as necessary.

[0135] The primer layer coating liquid contains a resin that produces the cured resin described above for the primer layer 4. Here, as an example, the primer layer coating liquid is an aqueous emulsion containing a polymer or a solvent-based resin containing a polymer.

[0136] The primer layer coating liquid may further contain the particles described above for the primer layer 4. The primer layer coating liquid may further contain other components, such as a solvent, and additives for improving the functionality of the final product, such as one or more antibacterial agents and antifungal agents. The primer layer coating liquid may further contain other additives such as an ultraviolet absorber and a light stabilizer. Examples of ultraviolet absorbers that can be used include benzotriazoles, benzoates, benzophenones, and triazines. Examples of light stabilizers that can be used include hindered amines.

[0137] The coating layer 4A can be formed by various printing methods such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing, or various coating methods such as roll coating, knife coating, microgravure coating, and die coating. The coating film is dried at a temperature lower than the thermal decomposition temperature of the foaming agent.

[0138] This coating film may be subjected to a pre-curing treatment. The pre-curing treatment is a treatment carried out to increase the viscosity of the coating film or to reduce the flexibility of the coating film and to increase its strength. The pre-curing treatment is, for example, a heat treatment at a temperature lower than the thermal decomposition temperature of the foaming agent, or irradiation with ionizing radiation. The pre-curing treatment is carried out so that, when the foaming agent is thermally decomposed, the gas generated by the thermal decomposition can be captured in the coating layer 4A and bubbles can coalesce within the coating layer 4A.

[0139] Next, foaming and curing processes are performed. In the foaming process, foaming is caused by a foaming agent to generate a plurality of bubbles 5 in the base layer, thereby generating a plurality of protrusions P0 on the surface of the base layer, each of which corresponds to one or more of the bubbles 5. In the curing process, the resin contained in the base layer is cured.

[0140] Here, the multilayer structure is heated. As the temperature of the multilayer structure increases, the foaming agent contained in the ink layer 3A thermally decomposes. At least a portion of the gas generated by this thermal decomposition is captured in the coating layer 4A, generating bubbles within the coating layer 4A. The bubbles coalesce within the coating layer 4A, generating larger bubbles. The size of the generated bubbles can be adjusted to some extent by adjusting the heating temperature. Foaming is typically achieved within the recommended temperature range for each foaming agent product. Depending on the situation, the amount of gas generated can be adjusted, for example, by treating at a lower temperature within the recommended temperature range. These bubbles form convex portions on the upper surface of the coating layer 4A. Subsequently, if necessary, a curing treatment is performed to stabilize the bubble-containing structure. For example, the foam-generated coating layer 4A can be further heat-treated or irradiated with ionizing radiation. In this manner, the pigment-containing layer 3 and primer layer 4 shown in FIG. 4 are obtained.

[0141] Next, a first coating film 61A made of the coating liquid for the first gloss adjustment layer is formed on the undercoat layer, as shown in Fig. 5. In this example, a first coating film 61A made of the coating liquid for the first gloss adjustment layer is formed on the primer layer 4.

[0142] The first coating film 61A can be formed by various printing methods such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing, or various coating methods such as roll coating, knife coating, microgravure coating, and die coating.

[0143] The coating liquid for the first gloss adjustment layer contains the first ionizing radiation curable resin described above for the first gloss adjustment layer 61. As described above, the first ionizing radiation curable resin preferably contains, as a main component, an acrylate or a first mixture of an acrylate and a methacrylate.

[0144] The coating liquid for the first gloss adjustment layer may further contain other components, such as the above-mentioned particles, solvents, and additives for improving the functionality of the final product, such as one or more antibacterial agents and antifungal agents. The coating liquid for the first gloss adjustment layer may further contain other additives such as an ultraviolet absorber and a light stabilizer. Examples of the ultraviolet absorber that can be used include benzotriazole-based, benzoate-based, benzophenone-based, and triazine-based stabilizers. Examples of the light stabilizer that can be used include hindered amine-based stabilizers.

[0145] The first coating film 61A having the third convex portion P3 can be formed, for example, by the following method. First, the first coating film 61A is formed so that the thickness at positions other than the convex portion P0 is greater than the thickness at the position of the convex portion P0. For example, the first coating film 61A is formed so that the first coating film 61A has a substantially flat upper surface. Then, the first coating film 61A is dried to form the third convex portion P3 on the surface of the first coating film 61A.

[0146] When the first coating film 61A is formed to have a substantially flat upper surface, the portions of the first coating film 61A corresponding to the convex portions P0 are thinner than the portions not corresponding to the convex portions P0. Therefore, during the drying process, the former portions lose less solvent than the latter portions. Therefore, during the drying process, the former portions lose less volume than the latter portions, and the latter portions lose more volume than the former portions. Therefore, after the drying process, third convex portions P3 corresponding to the convex portions P0 are formed on the surface of the first coating film 61A.

[0147] Alternatively, the first coating film 61A having the third convex portions P3 can also be formed by applying the first coating film 61A so that the third convex portions P3 are generated on the upper surface immediately after application.

[0148] When the first coating film 61A is completely cured by ultraviolet light irradiation in the third irradiation step described below, the coating liquid for the first gloss control layer preferably further contains a photoinitiator. The photoinitiator is not particularly limited, but examples thereof include benzophenone-based, acetophenone-based, benzoin ether-based, and thioxanthone-based photoinitiators.

[0149] Next, a first irradiation step is carried out. In the first irradiation step, the first coating film 61A is irradiated with a first radiation to semi-cure the first coating film 61A to obtain a semi-cured film. Here, "semi-cured" refers to a state in which the coating film is solid but still contains sufficient C=C bonds derived from acryloyl groups and methacryloyl groups. The semi-cured film has the third convex portions P3 described above on its surface.

[0150] The first radiation is, for example, ionizing radiation. As described above, the ionizing radiation is a charged particle beam such as an electron beam. The first radiation may be ultraviolet light, for which the first ionizing radiation curable resin exhibits a small absorption coefficient. The wavelength of the ultraviolet light irradiated onto the first coating film is preferably greater than 200 nm, more preferably in the range of 230 nm to 450 nm, and even more preferably in the range of 250 nm to 400 nm.

[0151] Irradiating the first coating film 61A with ionizing radiation or ultraviolet light as described above allows the curing to proceed substantially uniformly throughout the entire thickness of the first coating film 61A. Therefore, unlike the second coating film 62A described below, the first coating film 61A after semi-curing does not have any irregularities on its surface.

[0152] The first coating film 61A is preferably irradiated with the first radiation so that the unreacted rate of the first coating film 61A, i.e., the ratio of the number of C=C bonds after irradiation with the first radiation to the number of C=C bonds before irradiation with the first radiation, is within the range of 5% or more and 80% or less, more preferably within the range of 10% or more and 60% or less, and even more preferably within the range of 15% or more and 50% or less.

[0153] The first coating film 61A is preferably irradiated with the first radiation so that the cumulative light amount is within the range of 3% to 30% of the minimum cumulative light amount required to completely cure the first coating film 61A, more preferably within the range of 5% to 25%, and even more preferably within the range of 8% to 20%.

[0154] The minimum integrated amount of light required to completely cure the first coating film 61A is, for example, 10 mJ / cm ２ More than 1000mJ / cm ２ It is within the following range:

[0155] The first coating film 61A is preferably irradiated with the first radiation so that the absorbed dose is within the range of 0.2% or more and 50% or less of the minimum absorbed dose required to completely cure the first coating film, more preferably within the range of 0.5% or more and 40% or less, and even more preferably within the range of 1% or more and 30% or less.

[0156] The minimum absorbed dose required to completely cure the first coating film 61A is, for example, in the range of 5 kGy to 200 kGy.

[0157] As described above, the first ionizing radiation curable resin preferably contains an acrylate, and more preferably contains a methacrylate in addition to the acrylate. The methacrylate can slow down the rate of the crosslinking reaction caused by the first radiation exposure and widen the process window in which the desired cured state can be achieved.

[0158] Next, a second coating film 62A made of a coating liquid for a second gloss adjustment layer is formed on the semi-cured first coating film 61A. The second coating film 62A is formed so as to partially cover the upper surface of the semi-cured film. The second coating film 62A 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.

[0159] The coating liquid for the second gloss adjustment layer contains the second ionizing radiation curable resin described above. As described above, the second ionizing radiation curable resin is, in one example, an acrylate. In another example, the second ionizing radiation curable resin is a second mixture of an acrylate and a methacrylate, in which the proportion of the number of moles of methacryloyl groups in the total number of moles of acryloyl groups and the number of moles of methacryloyl groups is smaller than that of the first mixture.

[0160] The coating liquid for the second gloss adjustment layer may further contain other components, such as the above-mentioned particles, solvents, and additives for improving the functionality of the final product, such as one or more antibacterial agents and antifungal agents. The coating liquid for the second gloss adjustment layer may further contain other additives such as an ultraviolet absorber and a light stabilizer. Examples of the ultraviolet absorber that can be used include benzotriazole-based, benzoate-based, benzophenone-based, and triazine-based stabilizers. Examples of the light stabilizer that can be used include hindered amine-based stabilizers.

[0161] Next, the semi-cured film and the second coating film 62A are irradiated with ionizing radiation or ultraviolet light to completely cure the semi-cured film and the second coating film 62A. For example, the second irradiation step and the third irradiation step described below are performed sequentially.

[0162] In the second irradiation step, the second coating film 62A is irradiated with second radiation. The second radiation is light having a wavelength of 200 nm or less.

[0163] The second ionizing radiation-curable resin contained in the second gloss-adjusting layer coating liquid has a large absorption coefficient for the second radiation. Therefore, the second radiation incident on the second coating film 62A can only reach a position several tens to several hundreds of nanometers from the outermost surface. Therefore, in the second irradiation step, the crosslinking reaction proceeds in the surface region of the second coating film 62A, forming an extremely thin cured film, while the crosslinking reaction does not proceed in other regions, leaving the second coating film 62A uncured.

[0164] The second coating film 62A after the second irradiation step has, on its surface, convex portions corresponding to the first convex portions P1 and wrinkles corresponding to the second convex portions P2. The inventors believe that the reason why the above structure is formed on the coating film surface by the second irradiation step is as follows.

[0165] As described above, the second radiation can only reach a position tens to hundreds of nanometers away from the outermost surface of the second coating film 62A. That is, the crosslinking reaction of the second ionizing radiation curable resin occurs only on the surface of the second coating film 62A, and regions more than tens to hundreds of nanometers away from the outermost surface are uncured and contain highly fluid molecules. These highly fluid molecules swell the cured film, thereby increasing its volume. The increase in volume in the in-plane direction causes the cured film to buckle, resulting in wrinkles on the surface of the second coating film 62A.

[0166] Furthermore, swelling and buckling of the cured film are likely to occur in areas with a large amount of uncured resin, but are unlikely to occur in areas with a small amount of uncured resin. As shown in FIG. 6 , immediately before the second irradiation step, the amount of uncured resin is small in the area of ​​the second coating film 62A corresponding to the third convex portion P3, while the amount of uncured resin is large in other areas of the second coating film 62A. Therefore, wrinkles are unlikely to form in the area of ​​the surface of the second coating film 62A corresponding to the former portion, but are likely to form in the area of ​​the surface of the second coating film 62A corresponding to the latter portion. As wrinkles grow in the latter portion, uncured resin may migrate from the former portion to the latter portion. As a result, convex portions corresponding to the third convex portion P3 appear in the area of ​​the surface of the second coating film 62A corresponding to the former portion.

[0167] In the second irradiation step, the second radiation may also be applied to the surface of the first coating film 61A that is not covered by the second coating film 62A. However, because the first coating film 61A is semi-cured, molecular flow within the film is unlikely to occur. Therefore, wrinkles do not form on the exposed surface of the first coating film 61A.

[0168] Furthermore, the second radiation does not reach the portion of the first coating 61A that is covered with the second coating 62A, and therefore, no crosslinking reaction occurs in this portion due to irradiation with the second radiation.

[0169] The second radiation can be extracted from excimer VUV (Vacuum Ultra Violet) light. Excimer VUV light can be generated from a lamp using a rare gas or a rare gas halide compound. When high-energy electrons are externally applied to a lamp filled with a rare gas or a rare gas halide compound, a large number of discharge plasmas (dielectric barrier discharges) are generated. This plasma discharge excites atoms of the discharge gas (rare gas), which momentarily transition to an excimer state. When returning from this excimer state to the ground state, light is emitted in a wavelength range specific to that excimer.

[0170] The gas used in the excimer lamp may be any conventional gas that emits light of 200 nm or less. Examples of the gas include rare gases such as Xe, Ar, and Kr, and mixtures of rare gases such as ArBr and ArF with halogen gases. The wavelength (center wavelength) of excimer lamps varies depending on the gas, and examples include wavelengths of approximately 172 nm (Xe), approximately 126 nm (Ar), approximately 146 nm (Kr), approximately 165 nm (ArBr), and approximately 193 nm (ArF).

[0171] Considering the magnitude of photon energy and the difference between wavelength and bond energy of organic matter, it is preferable to use a xenon lamp that emits excimer light with a central wavelength of 172 nm as the light source. Also, considering the cost of maintaining the equipment and the availability of materials, it is preferable to use a xenon lamp as the light source.

[0172] The second irradiation step is carried out in an atmosphere with a low oxygen concentration. Oxygen has a high absorption coefficient for light of 200 nm or less. Therefore, the second irradiation step is preferably carried out in, for example, a nitrogen gas atmosphere. The oxygen concentration in the gas phase in the second irradiation step, i.e., the residual oxygen concentration in the reaction atmosphere, is preferably 2000 ppm or less, and more preferably 1000 ppm or less.

[0173] 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 62A. Therefore, changing the residual oxygen concentration in the reaction atmosphere can also change the surface properties of the second gloss control layer 62.

[0174] The cumulative amount of the second radiation is 0.5 mJ / cm ２ More than 200mJ / cm ２ It is preferable to set the concentration within the range of 1 mJ / cm ２ More than 100mJ / cm ２ It is more preferable to set it within the range of 3 mJ / cm ２ More than 50mJ / cm ２ It is more preferable to set it within the range of 5 mJ / cm ２ 30mJ / cm or more ２ It is most preferable to set the integrated light amount within the following range. If the integrated light amount is small, the surface will not be sufficiently cured and wrinkles will not occur. Furthermore, if the integrated light amount is small, the expansion of the cured film in the in-plane direction will be small. If the integrated light amount is large, the surface condition of the coating film 6A will deteriorate.

[0175] In the third irradiation step, the semi-cured film and the second coating film 62A are irradiated with third radiation. The third radiation is ionizing radiation or ultraviolet light having a longer wavelength than the light irradiated in the second irradiation step. The third radiation can be any of the radiations described above for the first radiation.

[0176] In the third irradiation step, the crosslinking reaction is allowed to proceed throughout the entire thickness of each of the semi-cured film and the second coating film 62A, thereby completely curing the semi-cured film and the second coating film 62A to obtain the surface protection layer 6 shown in FIG.

[0177] At the start of the third irradiation step, the first coating film 61A is in a semi-cured state, and therefore a cross-linking reaction may occur between molecules contained in the first coating film 61A and molecules contained in the second coating film 62A at the contact portion between the first coating film 61A and the second coating film 62A, thereby achieving high adhesion between the first gloss adjustment layer 61 and the second gloss adjustment layer 62.

[0178] The cumulative light amount of the third radiation is 10 mJ / cm ２ More than 500mJ / cm ２ It is preferable to set the dose within the range of 50 mJ / cm ２ More than 400mJ / cm ２ It is more preferable to set it within the range of 100 mJ / cm ２ More than 300mJ / cm ２ It is more preferable to set it within the following range.

[0179] The irradiation of the third radiation is preferably carried out so that the absorbed dose is in the range of 5 kGy or more and 200 kGy or less, more preferably in the range of 10 kGy or more and 150 kGy or less, and even more preferably in the range of 15 kGy or more and 100 kGy or less.

[0180] In the third irradiation step, if a layer having sufficient strength cannot be obtained by irradiation with only one type of radiation, the type of third radiation may be changed. For example, irradiation with ionizing radiation may be performed first, followed by irradiation with ultraviolet light having a longer wavelength than the light irradiated in the second irradiation step. Alternatively, irradiation with ultraviolet light having a longer wavelength than the light irradiated in the second irradiation step may be performed first, followed by irradiation with ionizing radiation. Alternatively, irradiation with ultraviolet light having a longer wavelength than the light irradiated in the second irradiation step may be performed first, followed by irradiation with ultraviolet light having an even longer wavelength.

[0181] In this manner, a decorative sheet 1 having first convex portions P1 and second convex portions P2 on the surface of the second gloss adjusting layer 62 is obtained, as shown in FIG.

[0182] As mentioned above, the second convex portions P2 may have an uneven structure formed by particles. When manufacturing a decorative sheet 1 having such an uneven structure as the second convex portions P2, the second irradiation step may be omitted. In this case, first convex portions P1 corresponding to the third convex portions P2 may be formed on the surface of the second coating film using a method similar to the method for forming the third convex portions P3 on the first coating film.

[0183] 1 and 2, the second protrusions P2 are adjacent to the first protrusions P1 but do not overlap the first protrusions P1. That is, in the decorative sheet 1, the second protrusions P2 do not have portions located above the first protrusions P1.

[0184] The second convex portions P2 may include portions that overlap with the first convex portions P1. That is, the second convex portions P2 may have portions located above the first convex portions P1 in the decorative sheet 1. Such a structure can be obtained, for example, by using a coating liquid for the second gloss adjustment layer that has a high viscosity, thereby suppressing excessive movement of the uncured resin in the second irradiation step.

[0185] The decorative sheet 1 described above may be produced by the following method.

[0186] First, the multilayer structure shown in Fig. 3 is prepared. Next, the first coating film 61A described above is formed on the coating layer 4A.

[0187] Next, the first irradiation step described above is carried out, whereby the first coating film 61A is semi-cured to obtain a semi-cured film.

[0188] Next, the foaming and curing processes described above are performed. These processes form a plurality of convex portions P0 on the surface of the base layer, each corresponding to one or more of the bubbles 5, and form third convex portions P3 on the surface of the semi-cured film, each corresponding to the convex portions P0. The curing process hardens the resin contained in the base layer. These processes may also result in the bubbles 5 being partially positioned within the semi-cured film.

[0189] Next, the first gloss adjustment layer 61 and the second gloss adjustment layer 62 are formed by the method described above. The decorative sheet 1 may be manufactured in the manner described above.

[0190] <1.3> Effect Figure 8 is a micrograph of the surface of a decorative sheet according to a comparative example. The decorative sheet shown in Figure 8 was obtained by the same method as described with reference to Figures 3 to 7, except that no foaming agent was used and the first gloss adjustment layer 61 was not formed. This decorative sheet does not contain air bubbles, and therefore its surface protective layer does not have any protrusions on its surface that result from air bubbles. In this decorative sheet, the only protrusions on the surface of the surface protective layer are ridge-like protrusions that form wrinkles. Therefore, the feel and gloss of this decorative sheet are mainly determined by the ridge-like protrusions.

[0191] In contrast, the decorative sheet 1 has a second gloss-adjusting layer 62 on its surface that has first protrusions P1 resulting from air bubbles 5 and ridge-like second protrusions P2 that form wrinkles. The uneven structure including the first protrusions P1 and the second protrusions P2 can provide a different tactile sensation and optical properties than an uneven structure including only the second protrusions P2. According to one example, the first protrusions P1 provide a rough tactile sensation to the user, while the second protrusions P2 provide a smooth tactile sensation to the user. The mechanisms that generate the first protrusions P1 and the second protrusions P2 are different, and their dimensions can be set independently. Furthermore, the ratio between the total area of ​​the first protrusions P1 and the total area of ​​the second protrusions P2 can also be set arbitrarily. In this way, the technology described above for the decorative sheet 1 allows for a high degree of freedom in the design of the tactile sensation or appearance of the decorative sheet.

[0192] Furthermore, in the decorative sheet 1, scattering, refraction, or reflection of light can occur at the interface between the gas that makes up the bubbles 5 and the material that makes up the primer layer 4 due to the difference in refractive index between them. This scattering, refraction, or reflection of light can vary depending on the refractive index of the primer layer 4 and the size and number of the bubbles 5. Therefore, in the decorative sheet 1, the optical characteristics such as appearance can be adjusted by appropriately selecting the material used in the primer layer 4 and the size and number of the bubbles 5.

[0193] Furthermore, decorative sheets having dome-shaped convex portions can be obtained, for example, by dispersing particles having a relatively large particle size in the top coat layer. However, such particles tend to fall off, and such decorative sheets have poor scratch resistance. According to the method described above, it is possible to form first convex portions P1 without using such particles. Therefore, the decorative sheet 1 described above can achieve high scratch resistance.

[0194] Furthermore, according to one example, the decorative sheet 1 described above has ridge-like second convex portions P2 formed by the second and third irradiation steps. Such convex portions are obtained by adding no particles or a relatively small amount of particles to the coating liquid for the second gloss control layer. Therefore, particles are less likely to fall off in decorative sheets having second convex portions P2 obtained by the above method. Therefore, such decorative sheets 1 have excellent scratch resistance.

[0195] The decorative sheet 1 also includes a first gloss adjustment layer 61 and a second gloss adjustment layer 62 that partially covers the first gloss adjustment layer 61. According to one example, the second gloss adjustment layer 62 has a lower specular gloss GS(60°) than the first gloss adjustment layer 61. In particular, when the second gloss adjustment layer 62 has the surface properties described above, the difference between the specular gloss GS(60°) of the first gloss adjustment layer 61 and the specular gloss GS(60°) of the second gloss adjustment layer 62 can be increased. This difference in gloss can contribute to the expression of a three-dimensional texture.

[0196] Furthermore, in the decorative sheet 1, the first gloss adjustment layer 61 preferably contains an acrylate or a first mixture of an acrylate and a methacrylate. The acrylate contributes to improving scratch resistance, and the methacrylate contributes to improving adhesion between the first gloss adjustment layer 61 and the second gloss adjustment layer 62. Therefore, the decorative sheet 1 has excellent scratch resistance and adhesion.

[0197] Furthermore, the plurality of second protrusions P2 formed on the upper surface of the second gloss adjustment layer 62 by the above-described method are finer than the uneven structure formed by mechanical processing such as embossing. Because the decorative sheet 1 has such a fine uneven structure on the upper surface of the second gloss adjustment layer 62, it has a matte finish and excellent fingerprint resistance.

[0198] Furthermore, in the decorative sheet 1, the bubbles 5 can also contribute to sound insulation and heat insulation.

[0199] <2> Second embodiment Fig. 9 is a cross-sectional view of a decorative material including a decorative sheet according to a second embodiment of the present invention. The decorative material 11A shown in Fig. 9 is similar to the decorative material 11, except that it includes a decorative sheet 1A instead of the decorative sheet 1. Furthermore, the decorative sheet 1A is similar to the decorative sheet 1, except that it employs the following configuration.

[0200] That is, the pigment-containing layer 3 partially covers the upper surface of the base fabric layer 2. The pigment-containing layer 3 is located between the second gloss adjustment layer 62 and the base fabric layer 2. Here, the second gloss adjustment layer 62 is identical in shape and position to the pigment-containing layer 3. The bubbles 5 are located only between the second gloss adjustment layer 62 and the pigment-containing layer 3. Note that each bubble 5 may be located entirely above the pigment-containing layer 3, or only a portion thereof may be located directly above the pigment-containing layer 3. That is, the bubbles 5 are located only in the portion of the primer layer 4 located above the pigment-containing layer 3 and in the vicinity thereof, and are not present in other portions of the primer layer 4. Therefore, the region of the upper surface of the second gloss adjustment layer 62 located directly above and in the vicinity of the pigment-containing layer 3 has the first convex portion P1 and the second convex portion P2. The remaining region of the upper surface of the second gloss adjustment layer 62 has the second convex portion P2 but does not have the first convex portion P1.

[0201] In addition, although the second gloss adjustment layer 62 here completely coincides in shape and position with the pigment-containing layer 3, other configurations may also be employed. For example, the orthogonal projection of the pigment-containing layer 3 onto a plane perpendicular to the thickness direction may be at least partially spaced from and located inside the contour of the orthogonal projection of the second gloss adjustment layer 62 onto the plane. Alternatively, the orthogonal projection of the second gloss adjustment layer 62 onto the plane may be at least partially spaced from and located inside the contour of the orthogonal projection of the pigment-containing layer 3 onto the plane.

[0202] In addition, although the pigment-containing layer 3 here consists of a single printed pattern, if the pigment-containing layer 3 consists of multiple printed patterns of different colors, the second gloss adjustment layer 62 may match the shape and position of a combination of these printed patterns. Alternatively, in this case, the second gloss adjustment layer 62 may match the shape and position of one or a combination of two or more of these printed patterns, with the remaining printed patterns being provided in positions that do not directly face the second gloss adjustment layer 62.

[0203] It is preferable that the orthogonal projection of the second gloss adjustment layer 62 onto a plane perpendicular to the thickness direction overlaps with the orthogonal projection onto the same plane of one printed pattern or a combination of two or more printed patterns whose shape and position match those of the second gloss adjustment layer 62, for preferably 50% or more of its area, more preferably 70% or more, and even more preferably 90% or more.

[0204] Furthermore, it is preferable that the orthogonal projection onto the above plane of one printed pattern or a combination of two or more printed patterns whose shape and position match those of the second gloss adjustment layer 62 overlaps with the orthogonal projection of the second gloss adjustment layer 62 onto the above plane for preferably 50% or more of its area, more preferably 70% or more, and even more preferably 90% or more.

[0205] The decorative sheet 1A can be manufactured in the same manner as described with reference to Figures 3 to 7, except that the ink layer 3A is formed so as to partially cover one main surface of the base layer 2, corresponding to the pigment-containing layer 3 in Figure 9.

[0206] The techniques described above for the decorative sheet 1A can achieve the same effects as those described above for the decorative sheet 1.

[0207] Furthermore, in decorative sheet 1A, the pattern of the second gloss adjustment layer 62 corresponds to the pattern of the pigment-containing layer 3. The second gloss adjustment layer 62 and the portion of the first gloss adjustment layer 61 that is not covered by the second gloss adjustment layer 62 may have different effects on the feel or appearance of the decorative sheet. Therefore, the technique described above for decorative sheet 1A allows for greater freedom in designing the feel or appearance of the decorative sheet compared to the technique described above for decorative sheet 1.

[0208] For example, if the pigment-containing layer 3 has a wood-grain pattern, the second gloss-adjusting layer 62 can provide a texture similar to that of the vessels, and the portions of the first gloss-adjusting layer 61 that are not covered by the second gloss-adjusting layer 62 can provide a texture similar to that of the portions other than the vessels. In this case, the decorative sheet 1A can easily give the user the texture of wood through visual information alone.

[0209] <3> Modifications The above-described techniques can be modified in various ways.

[0210] For example, in the production of the decorative sheet 1, the foaming agent may be contained in the coating layer 4A instead of in the ink layer 3A. In this case, it is preferable to carry out the foaming treatment after semi-curing the first coating film 61A.

[0211] The decorative sheets 1 and 1A may further include one or more other layers. For example, the decorative sheet 1A may further include a second pigment-containing layer as a solid ink layer or a hiding layer between the base layer 2 and the pigment-containing layer 3.

[0212] Examples of the present invention are described below. Note that the "particle size" described below is the above-mentioned "average particle size (D50)."

[0213] <Example 1> The decorative sheet 1A described with reference to Fig. 9 was produced by the following method. ２ An impregnated paper (GFR-506, manufactured by Kohjin Co., Ltd.) was prepared as the raw paper layer 2. On one side of the raw paper layer 2, a pigment-containing layer 3 was formed as a design layer.

[0214] An ink composition obtained by adding a foaming agent to a commercially available ink was used to form the pigment-containing layer 3. The commercially available ink used was an oil-based nitrocellulose resin gravure printing ink (PCNT (PCRNT) various colors (manufactured by Toyo Ink Co., Ltd.)). The foaming agent used was Matsumoto Microsphere (registered trademark) HF-48 (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.). The amount of foaming agent was 10 parts by mass relative to the ink.

[0215] The ink composition was printed such that the ink layer 3A formed a wood grain pattern and the mass per area after drying was 3 g / m ２ The ink layer 3A was dried at 60° C. for 1 minute.

[0216] Next, a primer layer coating liquid having the following composition was applied onto the base layer 2 and the ink layer 3A to form a coating layer 4A. The primer layer coating liquid was applied so that the primer layer 4 had a thickness of 5 μm in the areas excluding the areas corresponding to the first convex portions P1.

[0217] (Primer layer coating liquid) Water-based resin R1 Type: Acrylic emulsion Product name: SETAQUA 6302 (manufactured by Allnex Co., Ltd.) Then, drying and foaming treatment were performed. Specifically, the ink layer 3A and the coating layer 4A formed on the base layer 2 were heated at a temperature of 130°C for 3 minutes to dry them and cause thermal decomposition of the foaming agent. This resulted in a pigment-containing layer 3 and a primer layer 4 having bubbles 5.

[0218] Next, a first coating film 61A was formed by printing a coating liquid for a first gloss adjustment layer having the following composition on the primer layer 4. The coating liquid for the first gloss adjustment layer was printed so that the thickness of the first gloss adjustment layer 61 would be 5 μm.

[0219] (Coating liquid for first gloss adjustment layer) Ionizing radiation curable resin R1 Type: Trimethylolpropane EO-modified triacrylate (3 moles of EO added) Product name: Miramer (registered trademark) M3130 (manufactured by Miwon) Blend: 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.) Blend: 50 parts by mass Particle product name: Sylysia (registered trademark) 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend: 5 parts by mass Then, a first irradiation step was carried out. Specifically, a first coating film made of the coating liquid for the first gloss adjustment layer was irradiated with an electron beam as ionizing radiation so that the absorbed dose of the first coating film was 10 kGy. This semi-cured the first coating film.

[0220] Subsequently, a coating liquid for a second gloss adjustment layer having the following composition was printed on the portion of the first coating film corresponding to the pigment-containing layer 3. The coating liquid for the second gloss adjustment layer was printed so that the thickness of the second gloss adjustment layer 62 would be 5 μm.

[0221] (Coating liquid for second gloss adjustment layer) Ionizing radiation curable resin type: trimethylolpropane EO-modified triacrylate (EO 6 moles added) Product name: Miramer (registered trademark) M3160 (manufactured by Miwon) Blend: 100 parts by mass Particle product name: Sylysia (registered trademark) 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blend: 0.5 parts by mass Next, a second irradiation step was carried out. Specifically, ultraviolet light having a wavelength of 172 nm was irradiated onto the surfaces of the first coating film 61A and the second coating film 62A using a Xe excimer lamp at an integrated light intensity of 50 mJ / cm under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 500 ppm. ２ As a result, convex portions corresponding to the first convex portions P1 and wrinkles corresponding to the second convex portions P2 were generated on the surface of the second coating film 62A.

[0222] Subsequently, the third irradiation step was carried out. Specifically, the first coating film 61A and the second coating film 62A were irradiated with 50 kGy of ionizing radiation to cure the entire film, thereby forming the surface protective layer 6. In this manner, the decorative sheet 1A was obtained.

[0223] <Example 2> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points: In this example, the blending amount of ionizing radiation curable resin R1 in the coating liquid for the first gloss adjustment layer was 80 parts by mass, and the blending amount of ionizing radiation curable resin R2 was 20 parts by mass.

[0224] <Example 3> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points: In this example, the blending amount of ionizing radiation curable resin R1 in the coating liquid for the first gloss adjustment layer was 90 parts by mass, and the blending amount of ionizing radiation curable resin R2 was 10 parts by mass.

[0225] Example 4 A decorative sheet 1A was produced by the same method as in Example 1, with the following exceptions: In this example, the following resin was used as the ionizing radiation curable resin R2, and in the coating liquid for the first gloss adjustment layer, the blending amount of ionizing radiation curable resin R1 was 90 parts by mass, and the blending 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.) Example 5 A decorative sheet 1A was produced by the same method as in Example 1, with the following exceptions: In this example, the following resin was used as the ionizing radiation curable resin R2: Ionizing radiation curable resin R2 Type: EO-modified bisphenol A dimethacrylate (10 EO moles added) Product name: NK Ester BPE-500 (manufactured by Shin-Nakamura Chemical Co., Ltd.) Example 6 A decorative sheet 1A was produced by the same method as in Example 1, with the following exceptions:

[0046] That is, in this example, the following resin was used as the ionizing radiation curable resin R2, and in the coating liquid for the first gloss adjustment layer, the blending amount of ionizing radiation curable resin R1 was 80 parts by mass, and the blending amount of ionizing radiation curable resin R2 was 20 parts by mass. - Ionizing radiation curable resin R2 Type: EO-modified bisphenol A dimethacrylate (10 EO moles added) Product name: NK Ester BPE-500 (manufactured by Shin-Nakamura Chemical Co., Ltd.) Example 7 A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following resin was used as the ionizing radiation curable resin R2, and in the coating liquid for the first gloss adjustment layer, the blending amount of ionizing radiation curable resin R1 was 90 parts by mass, and the blending amount of ionizing radiation curable resin R2 was 10 parts by mass.

[0226] Ionizing radiation curable resin R2 Type: EO-modified bisphenol A dimethacrylate (10 mols of EO added) Product name: NK Ester BPE-500 (manufactured by Shin-Nakamura Chemical Co., Ltd.) Example 8 A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points: In this example, the following resin was used as ionizing radiation curable resin R2, and in the coating liquid for the first gloss adjustment layer, the blending amount of ionizing radiation curable resin R1 was 80 parts by mass, and the blending amount of ionizing radiation curable resin R2 was 20 parts by mass.

[0227] Ionizing radiation curable resin R2 Type: polyethylene glycol (200) dimethacrylate Product name: NK Ester 4G (manufactured by Shin-Nakamura Chemical Co., Ltd.) Example 9 A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points: In this example, the following resin was used as the ionizing radiation curable resin R2.

[0228] Ionizing radiation curable resin R2 Type: Trimethylolpropane EO-modified trimethacrylate (3 mols of EO added) Product name: NK Ester TMPT-3EO (manufactured by Shin-Nakamura Chemical Co., Ltd.) Example 10 Decorative sheet 1A was produced in the same manner as in Example 1, except for the following points: In this example, the following resin was used as ionizing radiation curable resin R2.

[0229] Ionizing radiation curable resin R2 Type: trimethylolpropane PO-modified trimethacrylate (3 moles of PO added) Product name: NK Ester TMPT-3PO (manufactured by Shin-Nakamura Chemical Co., Ltd.) Example 11 Decorative sheet 1A was produced by the same method as in Example 1, except for the following points. That is, in this example, the following resin was used as the ionizing radiation curable resin in the coating liquid for the second gloss adjustment layer. Ionizing radiation curable resin type: trimethylolpropane EO-modified triacrylate (3 moles of EO added) Product name: Miramer (registered trademark) M3130 (manufactured by Miwon Co., Ltd.) Then, in the second irradiation step, ultraviolet light having a wavelength of 172 nm was irradiated to the surface of the second coating film consisting of the first coating film and the coating liquid for the second gloss adjustment layer at an integrated light intensity of 100 mJ / cm using a Xe excimer lamp under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 200 ppm. ２ The irradiation was carried out so that

[0230] Example 12 A decorative sheet 1A was produced by the same method as in Example 1, with the following exceptions. In this example, 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 (15 moles of EO added) Product name: SR9035 (manufactured by Sartomer) Example 13 A decorative sheet 1A was produced by the same method as in Example 1, with the following exceptions. In this example, 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 (9 moles of EO added) Product name: Light Acrylate 9EG-A (manufactured by Kyoeisha Chemical Co., Ltd.) Example 14 A decorative sheet 1A was produced by the same method as in Example 1, with the following exceptions. That is, in this example, 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 moles added) Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Co., Ltd.) Then, in the second irradiation step, ultraviolet light having a wavelength of 172 nm was irradiated onto the surface of the second coating film consisting of the coating liquid for the second gloss adjustment layer at atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 200 ppm using a Xe excimer lamp, with an integrated light intensity of 50 mJ / cm. ２ The irradiation was carried out so that

[0231] Example 15 A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. In this example, 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 dipentaerythritol hexaacrylate (12 moles of EO added) Product name: NK Ester A-DPH-12E (manufactured by Shin-Nakamura Chemical Co., Ltd.) The second irradiation step involved irradiating the surface of the second coating film, consisting of the first coating film and the coating liquid for the second gloss adjustment layer, with ultraviolet light at a wavelength of 172 nm using a Xe excimer lamp at an integrated light intensity of 150 mJ / cm under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 100 ppm. ２ The irradiation was carried out so that

[0232] Example 16 A decorative sheet 1A was produced in the same manner as in Example 1, except for the following: In this example, the coating liquid for the second gloss adjustment layer was printed so that the thickness of the second gloss adjustment layer 62 was 2 μm.

[0233] Example 17 A decorative sheet 1A was produced in the same manner as in Example 1, except for the following: In this example, the coating liquid for the second gloss adjustment layer was printed so that the thickness of the second gloss adjustment layer 62 was 20 μm.

[0234] <Example 18> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, particles were omitted from the coating liquid for the second gloss adjustment layer. The coating liquid for the second gloss adjustment layer was printed so that the thickness of the second gloss adjustment layer 62 was 3 μm.

[0235] Example 19 A decorative sheet 1A was produced in the same manner as in Example 1, except for the following: In this example, the blending amount of particles in the coating liquid for the second gloss control layer was set to 10 parts by mass.

[0236] Example 20 A decorative sheet 1A was produced in the same manner as in Example 1, except for the following: In this example, the coating liquid for the first gloss adjustment layer was printed so that the thickness of the first gloss adjustment layer 61 was 3 μm.

[0237] <Example 21> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points: In this example, the coating liquid for the first gloss adjustment layer was printed so that the thickness of the first gloss adjustment layer 61 was 10 μm.

[0238] <Example 22> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points: In this example, the coating liquid for the first gloss adjustment layer was printed so that the thickness of the first gloss adjustment layer 61 was 20 μm.

[0239] <Example 23> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following resin was used as the ionizing radiation curable resin R1. Ionizing radiation curable resin R1 Type: Trimethylolpropane EO-modified triacrylate (EO 6 moles added) Product name: Miramer (registered trademark) M3160 (manufactured by Miwon Co., Ltd.)

[0240] <Example 24> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following resin was used as the ionizing radiation curable resin R1. Ionizing radiation curable resin R1 Type: Trimethylolpropane EO-modified triacrylate (9 EO moles added) Product name: Miramer (registered trademark) M3190 (manufactured by Miwon Co., Ltd.)

[0241] <Example 25> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following resin was used as the ionizing radiation curable resin R1. Ionizing radiation curable resin R1 Type: Trimethylolpropane EO-modified triacrylate (15 EO moles added) Product name: Miramer (registered trademark) M3150 (manufactured by Miwon Co., Ltd.)

[0242] <Example 26> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following resin was used as the ionizing radiation curable resin R1. Ionizing radiation curable resin R1 Type: Trimethylolpropane PO-modified triacrylate (3 moles of PO added) Product name: Miramer (registered trademark) M360 (manufactured by Miwon Co., Ltd.)

[0243] Example 27 A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points: In this example, the following resin was used as the ionizing radiation curable resin for the second gloss control layer: Type of ionizing radiation curable resin: Trimethylolpropane PO-modified triacrylate (9 moles of EO added) Product name: Miramer (registered trademark) M3190 (manufactured by Miwon Co., Ltd.)

[0244] Example 28 A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points: In this example, the following resin was used as the ionizing radiation curable resin for the second gloss control layer: Type of ionizing radiation curable resin: Trimethylolpropane PO-modified triacrylate (3 EO moles added) Product name: Miramer (registered trademark) M3130 (manufactured by Miwon Co., Ltd.)

[0245] <Example 29> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following foaming agents were used: Foaming agent type: Matsumoto Microsphere (registered trademark) FN-80GS (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.)

[0246] <Example 30> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following foaming agents were used: Foaming agent type: Matsumoto Microsphere (registered trademark) F-36LV (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.)

[0247] <Example 31> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following foaming agents were used: Foaming agent type: Matsumoto Microsphere (registered trademark) FN-100M (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.)

[0248] <Example 32> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following foaming agents were used: Foaming agent type: Matsumoto Microsphere (registered trademark) FN-100 (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.)

[0249] <Example 33> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, the ionizing radiation curable resin R2 was omitted from the coating liquid for the first gloss control layer, and the following ionizing radiation curable resin R1 was used. Furthermore, in the first irradiation step, the first coating film was irradiated with electron beams so that the absorbed dose of the first coating film was 5 kGy, and the first coating film was semi-cured. - Ionizing radiation curable resin R1 Type: Trimethylolpropane EO-modified triacrylate (3 EO moles added) Product name: Miramer (registered trademark) M3130 (manufactured by Miwon Co., Ltd.) Blend: 100 parts by mass

[0250] <Example 34> A decorative sheet 1A was produced in the same manner as in Example 1, except for the following points. That is, in this example, the ionizing radiation curable resin R2 was omitted from the coating liquid for the first gloss control layer, and the following ionizing radiation curable resin R1 was used. Furthermore, in the first irradiation step, the first coating film was irradiated with electron beams so that the absorbed dose of the first coating film was 5 kGy, and the first coating film was semi-cured. - Ionizing radiation curable resin R1 Type: Trimethylolpropane EO-modified triacrylate (EO 6 moles added) Product name: Miramer (registered trademark) M3160 (manufactured by Miwon Co., Ltd.) Blend: 100 parts by mass

[0251] Example 35 A decorative sheet 1A was produced in the same manner as in Example 1, with the following exceptions: In this example, a mixture of the following resins was used as the ionizing radiation curable resin for the second gloss control layer. Ionizing radiation curable resin type: polyethylene glycol diacrylate (PEG-DA) Product name: A-400 (manufactured by Shin-Nakamura Chemical Co., Ltd.) Blend: 70 parts by mass Ionizing radiation curable resin type: isodecyl acrylate (IDA) Product name: IDAA (manufactured by Osaka Organic Chemical Industry Ltd.) Blend: 30 parts by mass

[0252] Example 36 A decorative sheet 1A was produced in the same manner as in Example 1, with the following exceptions: In this example, a mixture of the following resins was used as the ionizing radiation curable resin for the second gloss adjustment layer. Ionizing radiation curable resin type: tetrahydrofurfuryl acrylate (THFA) Product name: Viscoat #150 (manufactured by Osaka Organic Chemical Industry Ltd.) Blend: 50 parts by mass Ionizing radiation curable resin type: urethane acrylate (UA) Product name: Shikoh (registered trademark) UV-7550B (manufactured by Mitsubishi Chemical Corporation) Blend: 25 parts by mass Ionizing radiation curable resin type: pentaerythritol triacrylate (PETA) Product name: PETA (manufactured by Daicel Allnex Corporation) Blend: 25 parts by mass

[0253] Comparative Example 1 A decorative sheet similar to decorative sheet 1A was produced in the same manner as in Example 1, except that the foaming agent was omitted from the ink composition for forming the pigment-containing layer 3.

[0254] Comparative Example 2 A decorative sheet similar to decorative sheet 1A was produced in the same manner as in Example 1, except that the application of the primer layer coating liquid was omitted and the covering layer 4A and primer layer 4 were not formed.

[0255] <Comparative Example 3> A decorative sheet similar to decorative sheet 1A was produced in the same manner as in Example 1, except that the foaming agent was omitted from the ink composition for forming the pigment-containing layer 3, the second irradiation process was omitted, and the particle content in the coating liquid for the second gloss adjustment layer was set to 20 parts by mass.

[0256] <Evaluation> Each of the decorative sheets described above was evaluated as follows: Those rated "AAA", "AA" or "A" were deemed to pass, as they presented no problems in actual use.

[0257] (1) Thickness of the first and second gloss adjustment layers The thickness of the second gloss adjustment layer was measured using the same method as described above. Specifically, the decorative sheet was embedded in a resin such as a cold-setting epoxy resin or a UV-curable resin, and the resin was allowed to fully harden. Next, the decorative sheet was cut so that the cross section of the decorative sheet was exposed, and the measurement surface was obtained by mechanically polishing.

[0258] Subsequently, a cross section of the surface protective layer was imaged using a SIGMA (registered trademark) 500 scanning electron microscope manufactured by Carl Zeiss Microscopy. The imaging was performed at an acceleration voltage of 0.5 keV (low acceleration voltage), in the SE2 imaging mode, and at a magnification of 2000x. No sputtering was performed on the measurement sample.

[0259] Next, from this cross-sectional image, the dimension of the second gloss adjustment layer in the width direction of the ridge portion and the area of ​​the cross section of the second gloss adjustment layer were determined. The thickness of the second gloss adjustment layer was calculated by dividing this area by the above dimension. The thickness obtained in this way was equal to the thickness of the coating film made of the second gloss adjustment layer coating liquid. The thickness of the first gloss adjustment layer was also measured using the same method as above.

[0260] The thickness of the primer layer was also measured using the same method as above. For decorative sheet 1A in which the decorative sheet contained bubbles 5, the thickness of the primer layer 4 was measured using the same method as above for a portion of the primer layer 4 excluding the portion corresponding to the first convex portion P1.

[0261] (2) Non-foamed portion height A and foamed portion height B The foamed portion height B was obtained by the following method. First, the decorative sheet was cut in its thickness direction. This cutting was performed so that the cutting line passed through the centers of a sufficient number of bubbles. Next, the cross section of the decorative sheet was photographed using a microscope (VHX-8000) manufactured by Keyence Corporation. The magnification was 1000 times. From the bubbles contained in the image thus obtained, 10 bubbles were selected in descending order of size in the thickness direction of the decorative sheet. At the position of each selected bubble, the width W of this bubble was measured. Ｂ The area corresponding to the above was set as the measurement range. Then, in each measurement range, the maximum value of the height of the upper surface of the first gloss adjustment layer relative to the lower surface of the primer layer was measured. The above measurement was performed at 10 locations corresponding to the selected 10 bubbles, and the above maximum values ​​obtained were arithmetically averaged. This average value was defined as the foamed portion height B.

[0262] The non-foamed portion height A was obtained by the following method. First, 10 locations were arbitrarily selected from the area of ​​the image above that was sufficiently separated from the air bubbles and where the upper surface of the first gloss adjustment layer was flat. Next, the height of the upper surface of the first gloss adjustment layer relative to the lower surface of the primer layer was measured at these 10 locations. The heights thus obtained were arithmetically averaged, and this average value was defined as the non-foamed portion height A.

[0263] (3) Gloss The gloss was measured as specular gloss GS(60°) using a Rhopoint IQ-S (manufactured by Rhopoint Instruments). The "60° gloss value" in Tables 1 to 5 below represents this specular gloss GS(60°).

[0264] (4) Adhesion The adhesion of the second gloss adjustment layer to the first gloss adjustment layer was evaluated by a cross-cut test specified in JIS K5400 (discontinued). Here, slits with a depth exceeding the interface between the first gloss adjustment layer and the second gloss adjustment layer were formed in a grid pattern at 1 mm intervals on the surface of the decorative sheet. This resulted in 100 squares arranged in a grid pattern. Next, adhesive tape was attached to the surface of the decorative sheet, and the adhesive tape was then peeled off from the decorative sheet. The number of squares remaining on the decorative sheet was counted, and the adhesion was evaluated by referring to the following criteria.

[0265] AAA: The number of remaining squares was 100. AA: The number of remaining squares was within the range of 95 to 99. A: The number of remaining squares was within the range of 90 to 94. B: The number of remaining squares was 89 or less.

[0266] (5) Scratch Resistance: Each decorative sheet was attached to wood substrate B using a urethane adhesive. A steel wool rubbing test was then conducted to evaluate scratch resistance. Specifically, the decorative sheet was rubbed back and forth 20 times with steel wool while applying a load of 100 g, and the occurrence of scratches on the surface of the decorative sheet and any changes in gloss were visually confirmed.

[0267] 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.

[0268] (6) Stain Resistance To evaluate stain resistance, the Stain A test specified in the Japanese Agricultural Standards (JAS) was carried out. That is, lines of 10 mm width each were drawn on the surface protective layer of each decorative sheet using blue ink, black quick-drying ink, and red crayon, and the sheets were left for 4 hours. Thereafter, the blue ink, black quick-drying ink, and red crayon lines were wiped off with a cloth soaked in ethanol.

[0269] The evaluation criteria were as follows: AAA: Lines of each color could be easily wiped off. AA: Part of the lines of each color could be wiped off, but some stains remained. A: Part of the lines of each color could be wiped off, but some stains remained. B: Lines of each color could not be wiped off.

[0270] (7) Tactile Feel (Evaluation 1: Tactile Feel Classification) The tactile feel of the decorative sheets was evaluated using the following method. First, advance preparation was performed to ensure that the evaluation criteria were consistent among the evaluators. Specifically, decorative sheets according to Comparative Examples 1 and 3 were prepared as standard test pieces. Next, each of the five evaluators was blindfolded and asked to slide their fingers over the surface of the standard test piece while pressing it with their fingers, and then to classify the tactile feel into two groups. Two standard test pieces were given to each evaluator in random order, and the above procedure was repeated until the tactile feel of each standard test piece was classified into the same group three or more times in a row. Hereinafter, the group corresponding to the tactile feel of the decorative sheet according to Comparative Example 1 will be referred to as the "first group," and the group corresponding to the tactile feel of the decorative sheet according to Comparative Example 3 will be referred to as the "second group."

[0271] Next, for each of the decorative sheets, each of the evaluators was blindfolded and asked to slide their fingers over the surface while pressing it, and then classify the tactile sensation into three groups. The three groups were the first and second groups, and a third group corresponding to a different tactile sensation. This procedure was repeated until the evaluations by each evaluator were consistent three or more times in a row, and the evaluation results between the evaluators were consistent three or more times in a row. From these results, the skin sensation was evaluated according to the following criteria: A: Group 3 X: Group 1 Y: Group 2

[0272] (Evaluation 2: Tactile Intensity) The tactile intensity of the decorative sheets classified in Group 3 in Evaluation 1, i.e., the decorative sheets of Examples 1 to 36, was evaluated using the following method. First, each of the five evaluators was blindfolded and asked to press and slide their finger across the surface of all of the decorative sheets of Examples 1 to 36, to sense the difference in tactile sensation between the decorative sheets. Next, the above-mentioned action was performed alternately on each of the decorative sheets of Examples 1 to 36 and the sample of Comparative Example 1, and the evaluators were asked to sense the magnitude of the difference in tactile sensation between them. The decorative sheets of Examples 1 to 36 were then classified into Groups 1 to 3 according to the magnitude of the difference in tactile sensation. Group 1 was the group with the greatest difference in tactile sensation, Group 3 was the group with the smallest difference in tactile sensation, and Group 2 was the group with an intermediate difference in tactile sensation.

[0273] For decorative sheets for which all evaluators agreed on the classification, the evaluation was terminated here. For the other decorative sheets, the above evaluation was repeated until all evaluators agreed on the classification. From these results, the magnitude of the difference in tactile sensation compared to the decorative sheet of Comparative Example 1 was evaluated as the intensity of the tactile sensation according to the following criteria: +++: Group 1 ++: Group 2 +: Group 3

[0274] (8) In-plane Gloss Difference The in-plane gloss difference of the decorative sheet was evaluated using two levels, Evaluation 1 and Evaluation 2, as shown below. (Evaluation 1) First, each of the 10 evaluators observed the decorative sheet from a direction 60 degrees from the perpendicular direction to its planar direction, and evaluated whether or not they felt a gloss difference in the in-plane direction. The in-plane gloss difference of the decorative sheet was evaluated based on the number of evaluators who answered that they felt a gloss difference. The evaluation criteria were as follows:

[0275] AAA: The number of evaluators who responded that they noticed a difference in gloss was 10. AA: The number was 8 or 9. A: The number was 5 to 7. B: The number was 2 to 4. C: The number was 0 or 1.

[0276] (Evaluation 2) Next, as a control decorative sheet, a decorative sheet according to Reference Example A was produced in the same manner as in Example 1, except that the first gloss adjustment layer was omitted and the second gloss adjustment layer was provided on the entire surface of the primer layer.

[0277] The evaluators who responded that they perceived a difference in gloss for the decorative sheet in Evaluation 1 were asked to observe the in-plane gloss difference for the decorative sheet of Reference Example A in the same manner as in Evaluation 1, and compare this with the gloss difference they perceived for the decorative sheet evaluated in Evaluation 1. The in-plane gloss difference for the decorative sheet was evaluated based on the ratio of the number of evaluators who responded that they perceived a greater in-plane gloss difference for the decorative sheet evaluated in Evaluation 1 compared to the decorative sheet of Reference Example A, relative to the number of evaluators mentioned above. The evaluation criteria were as follows:

[0278] AAA: The percentage of evaluators who answered that they felt a greater difference in gloss compared to Reference Example A was more than 90% and less than 100%. AA: The above percentage was more than 75% and less than 90%. A: The above percentage was more than 50% and less than 75%. B: The above percentage was more than 25% and less than 50%. C: The above percentage was less than 25%.

[0279] The evaluation results are shown in Tables 1 to 7.

[0280]

[0281]

[0282]

[0283]

[0284]

[0285]

[0286]

[0287] As shown in the above evaluation results, the decorative sheet according to Comparative Example 3 had insufficient scratch resistance and stain resistance. In contrast, the decorative sheets according to Examples 1 to 36 exhibited sufficient performance in terms of adhesion, scratch resistance, and stain resistance. Furthermore, the decorative sheets according to Examples 1 to 36 provided a different feel to the touch than the decorative sheets according to Comparative Examples 1 to 3. Furthermore, the decorative sheet according to Comparative Example 2 did not have bubbles 5 because the pigment-containing layer 3 was heated after the pigment-containing layer 3 was formed and before the coating liquid for the first gloss adjustment layer was applied.

[0288] Reference Example 1 A decorative sheet similar to decorative sheet 1A was produced by the same method as in Example 1, except for the following points: In this example, coating layer 4A was formed as follows, the first gloss adjustment layer was omitted, and the second gloss adjustment layer was formed as a continuous film covering the upper surface of primer layer 4. The primer layer coating liquid was applied so that the primer layer 4 had a thickness of 20 μm in areas excluding the areas corresponding to the third convex portions P3.

[0289] Reference Example 2 A decorative sheet similar to decorative sheet 1A was produced in the same manner as in Reference Example 1, except that the formation of the surface protective layer 6 was omitted.

[0290] <Analysis> Cross sections of the decorative sheets according to Reference Examples 1 and 2 were photographed using the above-mentioned SIGMA 500 scanning electron microscope.

[0291] Fig. 10 is a micrograph of one cross section of a decorative sheet according to Reference Example 1. Fig. 11 is a micrograph of another cross section of a decorative sheet according to Reference Example 1. Fig. 12 is a micrograph of one cross section of a decorative sheet according to Reference Example 2.

[0292] 12 shows that bubbles generated by thermal decomposition of the foaming agent cause convex portions to form on the upper surface of the primer layer. Also, from FIGS. 10 and 11, it can be seen that when a coating film made of a second gloss adjustment layer coating liquid is formed on the upper surface of a primer layer having convex portions and the second irradiation step is performed, a second gloss adjustment layer having both first convex portions and second convex portions on its upper surface, with the first convex portions positioned above the convex portions provided on the upper surface of the primer layer, can be obtained.

[0293] 1...decorative sheet, 1A...decorative sheet, 2...base layer, 3...pigment-containing layer, 3A...ink layer, 4...primer layer, 4A...coating layer, 5...air bubbles, 6...surface protective layer, 61...first gloss adjustment layer, 62...second gloss adjustment layer, 61A...first coating film, 62A...second coating film, 11...decorative material, 11A...decorative material, B...substrate, DZ...dimensions, H0...height, H1...height, H2...height, P1...first convex portion, P2...second convex portion, P3...third convex portion, R...diameter, TP...thickness, W...width.

Claims

1. A decorative sheet comprising an original fabric layer, a primer layer, and a surface protective layer in this order, with a plurality of air bubbles between the surface of the surface protective layer and the original fabric layer, wherein the surface protective layer comprises: a first gloss adjustment layer provided on the primer 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 surface of the second gloss adjustment layer comprising a plurality of ridge-like convex portions, and wherein the ratio B / A of the height B of the upper surface of the first gloss adjustment layer relative to the lower surface of the primer layer at the positions of the plurality of air bubbles to the height A of the upper surface of the first gloss adjustment layer relative to the lower surface of the primer layer at a position away from the plurality of air bubbles is greater than 1.

2. A decorative sheet as described in claim 1, wherein the surface on the second gloss adjustment layer side includes an area where a plurality of first convex portions, each corresponding to one or more of the plurality of bubbles, and a plurality of ridge-shaped convex portions as a plurality of second convex portions are mixed.

3. A decorative sheet according to claim 2, wherein the surface of said first gloss control layer has a plurality of third convex portions at the positions of said plurality of first convex portions.

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

5. A decorative sheet according to any one of claims 2 to 4, wherein each of the plurality of second protrusions does not overlap any of the plurality of first protrusions.

6. A decorative sheet as set forth in any one of claims 2 to 4, wherein one or more of said plurality of second protrusions includes one or more portions that overlap with one of said plurality of first protrusions.

7. A decorative sheet according to any one of claims 1 to 6, wherein said plurality of bubbles are at least partially located within said primer layer.

8. A decorative sheet as described in any one of claims 1 to 7, further comprising a pigment-containing layer interposed between the base fabric layer and the primer layer, the pigment-containing layer containing a pigment and a binder resin, the pigment-containing layer being positioned between the second gloss adjustment layer and the base fabric layer and partially covering the upper surface of the base fabric layer.

9. A decorative sheet according to any one of claims 1 to 8, wherein said first ionizing radiation curable resin comprises a first mixture of an acrylate and a methacrylate.

10. A decorative sheet as described in claim 9, wherein in said 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 within the range of 3% to 50%.

11. The decorative sheet according to claim 9 or 10, wherein the methacrylate is a monofunctional, difunctional or trifunctional methacrylate.

12. A decorative sheet according to any one of claims 1 to 11, wherein the second ionizing radiation curable resin is an acrylate.

13. A decorative sheet according to any one of claims 1 to 12, wherein the second ionizing radiation curable resin contains a bifunctional or higher functional acrylate containing a repeating structure.

14. The decorative sheet according to claim 13, wherein the repeating structure is repeated three or more times.

15. A decorative sheet according to any one of claims 1 to 14, wherein the thickness of each of the first gloss adjustment layer and the second gloss adjustment layer is in the range of 2 μm to 20 μm.

16. A decorative sheet according to any one of claims 1 to 15, wherein the second gloss control layer further contains particles having an average particle size of 10 μm or less.

17. A decorative sheet according to claim 16, wherein the mass of the particles is in the range of 0.5 parts by mass to 20 parts by mass, where the mass of the second ionizing radiation curable resin is 100 parts by mass.

18. A decorative sheet described in any one of claims 1 to 17, wherein the specular gloss GS(60°) of the second gloss adjustment layer is smaller than the specular gloss GS(60°) of the first gloss adjustment layer, the specular gloss GS(60°) of the first gloss adjustment layer is 3 or more, and the specular gloss GS(60°) of the second gloss adjustment layer is 10 or less.

19. A decorative sheet described in any one of claims 1 to 18, wherein the specular gloss GS(60°) of the second gloss adjustment layer is smaller than the specular gloss GS(60°) of the first gloss adjustment layer, and the difference between the specular gloss GS(60°) of the first gloss adjustment layer and the specular gloss GS(60°) of the second gloss adjustment layer is 1 or more.

20. A decorative material comprising the decorative sheet according to any one of claims 1 to 19 and a substrate to which the decorative sheet is attached.

21. A method for manufacturing a decorative sheet, comprising: forming a base layer containing a foaming agent on a raw fabric layer; causing foaming with the foaming agent to generate a plurality of bubbles in the base layer, thereby generating a plurality of convex portions on the surface of the base layer, each corresponding to one or more of the plurality of bubbles; then forming a first coating film containing a first ionizing radiation curable resin on the base layer; carrying out a first irradiation step of irradiating the first coating film with ionizing radiation or ultraviolet light to semi-cure the first coating film, thereby obtaining a semi-cured film having a plurality of third convex portions on its surface, each corresponding to the plurality of convex portions; 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; and irradiating the semi-cured film and the second coating film with ionizing radiation or ultraviolet light to completely cure the semi-cured film and the second coating film.

22. A method for producing a decorative sheet as described in claim 21, wherein the complete curing of the semi-cured film and the second coating film includes a second irradiation step in which the second coating film is irradiated with light having a wavelength of 200 nm or less to produce, on the surface of the second coating film, a plurality of first convex portions corresponding to the plurality of third convex portions and a plurality of second convex portions, each of which is ridge-shaped; and a third irradiation step in which the semi-cured film and the second coating film are irradiated with ionizing radiation or ultraviolet light having a longer wavelength than the light irradiated in the second irradiation step.

23. A method for producing a decorative sheet as described in claim 21 or 22, in which a multilayer structure is formed 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.

24. A method for producing a decorative sheet as described in claim 23, wherein the coating layer contains a resin containing a polymer, and the multilayer structure is heated to cause foaming by the foaming agent and harden the resin containing the polymer, thereby obtaining a primer layer containing a hardened product of the resin containing the polymer and in which the plurality of bubbles are at least partially positioned.

25. A method for producing a decorative sheet as set forth in claim 23 or 24, wherein said foaming agent-containing layer further contains a pigment and a binder resin.

26. A method for manufacturing a decorative sheet, comprising: forming a base layer containing a foaming agent on a raw fabric layer; forming a first coating film containing a first ionizing radiation curable resin on the base layer; carrying out a first irradiation step of irradiating the first coating film with ionizing radiation or ultraviolet light to semi-cure the first coating film to obtain a semi-cured film; causing foaming with the foaming agent to generate a plurality of bubbles in the base layer or in a laminate consisting of the base layer and the semi-cured film, thereby generating a plurality of third convex portions on the surface of the semi-cured film, each corresponding to one or more of the plurality of bubbles; 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; and irradiating the semi-cured film and the second coating film with ionizing radiation or ultraviolet light to completely cure the semi-cured film and the second coating film.

27. A method for producing a decorative sheet according to any one of claims 21 to 26, wherein the first ionizing radiation curable resin contains an acrylate and a methacrylate.

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