Decorative sheets and decorative materials

Abstract

To provide a decorative sheet and a decorative material capable of suppressing a cold sensation imparted to a user.SOLUTION: A decorative sheet 10 includes a substrate 12 and a protective layer 30. The protective layer includes an uneven surface 32 composing a surface of the decorative sheet. The uneven surface includes a wrinkle structure. A maximum height Rz stipulated by JIS B0601:2013 on the uneven surface is 2 μm or more. A heat-conductivity λ1 of the substrate is 30 W / cm K or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to decorative sheets and decorative materials. [Background technology]

[0002] Conventionally, decorative sheets have been used for the interior and exterior of buildings, fixtures, furniture and home appliances, and the interiors of vehicles. Decorative sheets may have a design layer. The design layer includes a pattern layer corresponding to a predetermined pattern, color, etc. A protective layer may be provided on the surface of the decorative sheet. The protective layer may have an uneven surface (a so-called matte surface). A protective layer with an uneven surface functions, for example, as a matte layer to suppress the gloss of the decorative sheet's surface. In this case, light incident on the protective layer (matte layer) is diffused by scattering on this uneven surface, thereby reducing the gloss on the surface of the protective layer (matte layer).

[0003] In recent years, a method has been proposed for manufacturing uneven surfaces by using excimer light to form wrinkle-like uneven surfaces on the surface of a resin. An example of such a method for manufacturing uneven surfaces is disclosed in Patent Document 1. In Patent Document 1, first, excimer light is irradiated onto the surface of a coating made of a photocurable resin. Then, ultraviolet light is irradiated onto the coating to cure the entire coating. As a result, wrinkles are formed on the surface of the coating. In Patent Document 1, a coating with low gloss is obtained due to the wrinkles formed in this way. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-24102 [Overview of the project] [Problems that the invention aims to solve]

[0005] Customer demand for decorative sheets is diverse and wide-ranging, and effects other than the visual matting effect mentioned above are now being sought. In particular, decorative sheets are sometimes required to suppress the cooling sensation, or a chilling feeling, that the user receives when they come into contact with the sheet.

[0006] The embodiments of this disclosure aim to provide decorative sheets and decorative materials that suppress the sensation of coldness given to the user. [Means for solving the problem]

[0007] A decorative sheet according to one embodiment of the present disclosure is A decorative sheet comprising a base material and a protective layer, The protective layer has an uneven surface that constitutes the surface of the decorative sheet, The aforementioned uneven surface has a wrinkled structure, The maximum height Rz of the aforementioned uneven surface, as defined in JIS B0601:2013, is 2 μm or more. The thermal conductivity λ1 of the aforementioned substrate is 30 W / cm·K or less.

[0008] In a decorative sheet according to one embodiment of the present disclosure, The maximum height Rz of the aforementioned uneven surface, as defined in JIS B0601:2013, may be 12.5 μm or less.

[0009] In a decorative sheet according to one embodiment of the present disclosure, The protective layer may include a resin layer and a plurality of particles.

[0010] In a decorative sheet according to one embodiment of the present disclosure, The content of the particles in the protective layer may be 5 parts by mass or less per 100 parts by mass of the resin forming the resin layer.

[0011] A decorative sheet according to one embodiment of the present disclosure is It may also include a design layer.

[0012] According to one embodiment of the present disclosure, a cosmetic material includes an adherent body and the cosmetic sheet described above provided on the adherent body.

Advantages of the Invention

[0013] According to one embodiment of the present disclosure, it is possible to provide a cosmetic sheet and a cosmetic material that are suppressed from giving a cold feeling to a user.

Brief Description of the Drawings

[0014] [Figure 1] FIG. 1 is a diagram for explaining one embodiment of the present disclosure, and is a cross-sectional view of an example of a cosmetic sheet. <s [Figure 2] FIG. 2 is a photograph showing an example of the wrinkle structure of a cosmetic sheet.

Modes for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings attached to this specification, for ease of understanding the drawings, the scale, the aspect ratio of the vertical and horizontal dimensions, etc. are changed and exaggerated from those of the actual object. Note that the embodiments shown below are examples of the embodiments of the present disclosure. Therefore, the present disclosure should not be construed as being limited to these embodiments.

[0016] In this specification, the terms "plate", "sheet", and "film" are not distinguished from each other based only on the difference in name. For example, the "sheet" includes a member called a "plate" or a "film".

[0017] In this specification, "planar view" refers to a state in which a target plate-like (sheet-like, film-like) member is viewed from the normal direction of the member. For example, when a certain plate-like member "has a rectangular shape in planer view", it means that the member has a rectangular shape when viewed from the normal direction with respect to the plate surface of the member.

[0018] In this specification, terms used to specify shape, geometric conditions, and physical properties, and their degrees, such as "parallel," "orthogonal," and "identical," as well as the ranges referred to by values ​​of length, angle, and physical properties, are not strictly limited to those ranges, but include ranges to which similar functions can be expected, unless otherwise stated.

[0019] The decorative sheet 10 of the embodiments of this disclosure can be used, for example, as a component constituting the outermost layer of the interior and exterior of buildings, fixtures, furniture and home appliances, and the interior of vehicles. More specifically, the decorative sheet 10 may be used, for example, as interior components of buildings such as walls, ceilings, and floors; exterior components such as exterior walls, eaves, roofs, fences, and railings; fixtures or joinery components such as window frames, doors, door frames, handrails, baseboards, moldings, and trim; general furniture such as chests of drawers, shelves, and desks; kitchen furniture such as dining tables and sinks; surface decorative panels for cabinets of home appliances, office automation equipment, etc.; and interior and exterior components of vehicles. The decorative sheet 10 may also be used as packaging material, anti-glare film for displays, whiteboards or blackboards, various cards such as credit cards, cash cards, telephone cards, and various certificates, keyboard keys, transparent panels (window glass, etc.) such as windows, doors, and partitions, and artificial leather. For example, decorative sheet 10 is a decorative sheet for floors used on the floors of buildings.

[0020] The decorative sheet 10 in the embodiment of this disclosure may be laminated on other members (adherents). In this case, the adherent and the decorative sheet 10 provided on the adherent constitute a decorative material. The adherent may be, for example, a member that constitutes the lower layer of the interior and exterior of a building, fixtures, furniture and home appliances, or the interior of a vehicle. If the decorative sheet 10 is a decorative sheet for floors, the adherent is a member that constitutes the lower layer of the floor of a building. The adherent and the decorative sheet for floors provided on the adherent constitute a floor as a decorative material.

[0021] The decorative sheet 10 of the embodiment of this disclosure has a surface 10a and a back surface 10b located on the opposite side of the surface 10a. The decorative sheet 10 of the embodiment of this disclosure comprises a base material 12 and a protective layer 30. The base material 12 has the function of supporting the protective layer 30. The base material 12 of the embodiment of this disclosure has a surface 12a and a back surface 12b located on the opposite side of the surface 12a. The back surface 12b of the base material 12 constitutes the back surface 10b of the decorative sheet 10. The protective layer 30 has an uneven surface 32. The protective layer 30 further has a back surface 34 located on the opposite side of the uneven surface 32. The back surface 34 of the protective layer 30 faces the surface 12a of the base material 12. The uneven surface 32 constitutes the surface 10a of the decorative sheet 10. The uneven surface 32 is a so-called matte surface. The protective layer 30 of the embodiment of this disclosure is a matte layer. In the decorative sheet 10 of the embodiment of this disclosure, light incident on the protective layer 30 is diffusely reflected by the uneven surface 32. As a result, the gloss on the surface 10a of the decorative sheet 10 is reduced. In other words, the protective layer 30 functions as a matte layer, and a matte effect is exhibited on the protective layer 30.

[0022] An example of a decorative sheet 10 having such a base material 12 and protective layer 30 will be described below with reference to Figure 1. Figure 1 shows a cross-section of an example of a decorative sheet 10. In the illustrated example, the decorative sheet 10 further comprises a design layer 20. In the illustrated example, the decorative sheet 10 has the base material 12, the design layer 20, the adhesive layer 14, the transparent resin layer 16, the primer layer 18, and the protective layer 30 in this order. Note that the design layer 20, the adhesive layer 14, the transparent resin layer 16, and the primer layer 18 are not essential components of the decorative sheet 10. The decorative sheet 10 does not need to have one or more of the design layer 20, the adhesive layer 14, the transparent resin layer 16, and the primer layer 18. Also, the decorative sheet 10 may have other members (layers) intended to perform a specific function.

[0023] The base material 12 has the function of supporting the protective layer 30. In particular, in the embodiments of this disclosure, the base material 12 supports the design layer 20, the adhesive layer 14, the transparent resin layer 16, the primer layer 18, and the protective layer 30. The base material 12 is positioned facing the back surface 34 of the protective layer 30. The base material 12 may be a film-like member.

[0024] The thickness t1 of the base material 12 is not particularly limited. For example, the thickness t1 may be 10 × 10 -4 It is more than cm. The thickness t1 is 20 × 10 -4 It is more preferable that it be 50 x 10 cm or more. -4 It is even more preferable that the thickness be 10 cm or more. From the viewpoint of keeping the overall thickness of the decorative sheet 10 small and making it easy to handle the decorative sheet 10, it is preferable that the thickness t1 (cm) be small. The thickness t1 is, for example, 0.1 cm or less. The thickness t1 is 300 × 10 -4 It is more preferable that it be less than or equal to 100 x 10 -4 It is even more preferable that it be less than or equal to cm.

[0025] The thermal conductivity λ1 of the base material 12 is 30 W / cm·K or less. This suppresses the absorption of heat by the base material 12 itself. The thermal conductivity λ1 is more preferably 25 W / cm·K or less, more preferably 20 W / cm·K or less, and even more preferably 10 W / cm·K or less.

[0026] The thermal conductivity λ1 of the substrate 12 is measured by the hot-wire (probe) method. The thermal conductivity λ1 of the substrate 12 can be measured in accordance with JIS R 2616:2001 using a thermal conductivity meter (Kyoto Electronics Manufacturing Co., Ltd., rapid thermal conductivity meter QTM500) from the amount of heat generated by the hot wire (heater wire) and the temperature rise. The thermal conductivity λ1 of the substrate 12 can also be measured in accordance with ASTM D5930 using the above-mentioned thermal conductivity meter.

[0027] The material of the base material 12 is not particularly limited as long as its thermal conductivity λ1 is 30 W / cm·K or less. For example, resin materials and fibrous materials can be used as the material of the base material 12. Resin materials include, for example, polyester resins such as polyethylene terephthalate, olefin resins such as polyethylene and polypropylene, vinyl chloride resins such as polyvinyl chloride, and acrylic resins. Fibrous materials include, for example, paper, woven fabric, nonwoven fabric, or these impregnated with resin. The base material 12 may consist of only one layer made of these materials. Alternatively, the base material 12 may consist of multiple layers made of these materials. If the base material 12 consists of multiple layers, the layers may consist of different materials. From the viewpoint of suppressing heat transfer through the base material 12 and suppressing heat absorption by the base material 12 itself, it is preferable that the material of the base material 12 includes polyethylene terephthalate or paper.

[0028] The base material 12 may have voids. A base material 12 having voids may be, for example, a resin material or fibrous material having multiple voids. A base material 12 having voids may also be polyethylene terephthalate having multiple voids. The presence of voids in the base material 12 can reduce the thermal conductivity λ1 of the base material 12.

[0029] The design layer 20 has the function of displaying a design that should be visible to an observer viewing the decorative sheet 10. This design is, for example, a picture, photograph, figure, pattern, mark, letter, color, or other pictorial representation. The design layer 20 may display a single-color pictorial representation as the design. The design layer 20 is positioned facing the back surface 34 of the protective layer 30. In the embodiments of this disclosure, the design layer 20 is positioned between the substrate 12 and the protective layer 30. The thickness of the design layer 20 may be 0.5 μm or more and 20 μm or less. Preferably, the thickness of the design layer 20 may be 1 μm or more and 10 μm or less. More preferably, the thickness of the design layer 20 may be 2 μm or more and 5 μm or less.

[0030] The design layer 20 may include a colored layer 22 and a pattern layer 24. The colored layer 22 is a layer that imparts a desired color to the entire surface of the substrate 12. The colored layer 22 may be a so-called solid layer. The colored layer 22 may have a single color. The colored layer 22 may also have a pattern composed of multiple colors. The pattern layer 24 is a layer that constitutes the design to be displayed by the design layer 20. The colored layer 22 and the pattern layer 24 can each be formed by coating, printing, etc., using ink. As the ink, for example, one containing a binder resin and a coloring agent such as a pigment or dye may be used. The design layer 20 may have only the colored layer 22 and only the pattern layer 24. That is, the design layer 20 may have only the colored layer 22, or only the pattern layer 24.

[0031] The transparent resin layer 16 has the function of protecting the design layer 20. The transparent resin layer 16 also has the function of increasing the strength of the decorative sheet 10. The transparent resin layer 16 is positioned facing the back surface 34 of the protective layer 30. In the embodiments of this disclosure, the transparent resin layer 16 is positioned between the design layer 20 and the protective layer 30. The transparent resin layer 16 is formed of a transparent resin material. The resin material may be, for example, a polyolefin resin, polyester resin, polycarbonate resin, acrylonitrile-butadiene-styrene resin (ABS resin), acrylic resin, vinyl chloride resin, etc. The transparent resin layer 16 may contain weather-resistant agents such as ultraviolet absorbers and light stabilizers, as well as additives such as colorants. The thickness of the transparent resin layer 16 may be 20 μm or more and 150 μm or less. Preferably, the thickness of the transparent resin layer 16 may be 40 μm or more and 120 μm or less. More preferably, the thickness of the transparent resin layer 16 may be 60 μm or more and 100 μm or less.

[0032] In this specification, "transparent" means that the visible light transmittance is 50% or more, preferably 80% or more. Visible light transmittance is determined as the average value of the total light transmittance at each wavelength when measured at 1 nm intervals within the measurement wavelength range of 380 nm to 780 nm using a spectrophotometer (Shimadzu Corporation "UV-3100PC", compliant with JIS K0115). Furthermore, "transparent" includes colorless transparent and colored transparent.

[0033] The adhesive layer 14 has the function of bonding the design layer 20 and the transparent resin layer 16 to each other. If the decorative sheet 10 does not have a design layer 20, the adhesive layer 14 may bond the base material 12 and the transparent resin layer 16 to each other. As the material of the adhesive layer 14, for example, an adhesive such as a urethane adhesive, an acrylic adhesive, an epoxy adhesive, or a rubber adhesive may be used. The thickness of the adhesive layer 14 may be 0.1 μm or more and 30 μm or less. Preferably, the thickness of the adhesive layer 14 may be 1 μm or more and 15 μm or less. More preferably, the thickness of the adhesive layer 14 may be 2 μm or more and 10 μm or less.

[0034] The primer layer 18 has the function of improving the adhesion between the transparent resin layer 16 and the protective layer 30. The primer layer 18 is formed of a resin material, for example. The resin material may be a resin such as urethane resin, acrylic polyol resin, acrylic resin, ester resin, amide resin, butyral resin, styrene resin, urethane-acrylic copolymer, polycarbonate-based urethane-acrylic copolymer, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-acrylic copolymer resin, chlorinated propylene resin, nitrocellulose resin, or cellulose acetate resin. The primer layer 18 may contain additives such as ultraviolet absorbers and light stabilizers as needed. The thickness of the primer layer 18 may be 0.1 μm or more and 10 μm or less. Preferably, the thickness of the primer layer 18 may be 1 μm or more and 8 μm or less. More preferably, the thickness of the primer layer 18 may be 2 μm or more and 6 μm or less.

[0035] The protective layer 30 in the embodiment of this disclosure is a matte layer that exhibits a matte effect on the surface 10a of the decorative sheet 10. The protective layer 30 has an uneven surface 32 that constitutes the surface 10a of the decorative sheet 10. The uneven surface 32 is a so-called matte surface. Light incident on the protective layer 30 is diffusely reflected by this uneven surface 32. As a result, the gloss on the surface 10a of the decorative sheet 10 is reduced. That is, the protective layer 30 functions as a matte layer, and a matte effect is exhibited on the protective layer 30. The protective layer 30 may be provided over the entire surface 10a of the decorative sheet 10. Alternatively, the protective layer 30 may be provided on a part of the surface 10a of the decorative sheet 10. In the embodiment of this disclosure, the protective layer 30 includes a resin layer 36 and a plurality of particles 38. The resin layer 36 constitutes the main body portion of the protective layer 30. The uneven surface 32 is formed on the surface of the resin layer 36. That is, the resin layer 36 has the uneven surface 32. The uneven surface 32 has a wrinkled structure. The multiple particles 38 function as wrinkle-forming agents to impart a specific wrinkled structure to the uneven surface 32.

[0036] Figure 2 is a photograph showing an example of a wrinkle structure. The wrinkle structure is a structure that includes a striated uneven structure. In particular, the wrinkle structure of this embodiment includes striated protrusions and / or striated recesses. The striated protrusions and / or striated recesses have an irregular shape and are irregularly arranged in a plan view. The wrinkle structure may include a plurality of curved striated protrusions and recesses formed by being surrounded by the plurality of protrusions. The wrinkle structure may also include a plurality of curved striated recesses and protrusions formed by being surrounded by the plurality of recesses. "Curved" means that in a plan view, one striated protrusion or recess has a reversal portion in which the direction of extension reverses from one side to the other. The wrinkle structure may include meandering striated protrusions and recesses formed by being surrounded by these meandering striated protrusions. The wrinkle structure may also include meandering striated recesses and protrusions formed by being surrounded by these meandering striated recesses. "Meandering" means that, in a plan view, a single striated convex or concave portion includes two or more inverted portions, and in two adjacent inverted portions of a single convex or concave portion, the direction in which the convex or concave portion extends is reversed to the opposite direction from one another.

[0037] The convex and concave parts in the wrinkle structure may be distinguished from each other, for example, by utilizing the brightness difference of the image of the surface 10a of the decorative sheet 10. For example, the density of the density distribution image of the surface 10a of the decorative sheet 10 may be divided into gradations 0 to 255, with the darkest part of the density distribution image being assigned a gradation of 255 and the lightest part being assigned a gradation of 0. Then, gradations 0 to 127 may be treated as concave parts and gradations 128 to 255 as convex parts, and these may be distinguished by binarization. The threshold for the gradation that distinguishes the concave and convex parts can be set arbitrarily.

[0038] The thickness of the protective layer 30 may be 1 μm or more. Preferably, the thickness of the protective layer 30 may be 2 μm or more. More preferably, the thickness of the protective layer 30 may be 3 μm or more. Even more preferably, the thickness of the protective layer 30 may be 4 μm or more. Also, the thickness of the protective layer 30 may be 300 μm or less. Preferably, the thickness of the protective layer 30 may be 200 μm or less. More preferably, the thickness of the protective layer 30 may be 100 μm or less. Even more preferably, the thickness of the protective layer 30 may be 50 μm or less. In this embodiment of the disclosure, the thickness of the protective layer 30 refers to the thickness of the portion of the protective layer 30 excluding the particles 38. That is, the thickness of the protective layer 30 is the thickness of the resin layer 36. The thickness of the resin layer 36 is determined by measuring the thickness at 20 points on an image taken using a scanning electron microscope (SEM) on a cross-section parallel to the normal direction of the resin layer 36, and taking the arithmetic mean of the 20 thickness values. The SEM acceleration voltage is set to 3kV, and the magnification is set according to the thickness. The same applies to the thickness of other layers.

[0039] The 60° specular gloss of the uneven surface 32, as defined in JIS Z8741:1997, may be 5 or less. The 60° specular gloss can be measured, for example, using a gloss meter (BYK Gardner, micro-tri-gloss). By having a gloss of 5 or less on the uneven surface 32, the uneven surface 32 can exhibit a sufficient matte effect. The gloss of the uneven surface 32 may be 1 or more.

[0040] As an example, the maximum height Rz on the uneven surface 32, as defined in JIS B0601:2013, is 12.5 μm or less. The maximum height Rz on the uneven surface 32 is the arithmetic mean of the maximum height Rz values ​​at any 20 locations on the uneven surface 32. The maximum height Rz can be measured using a shape analysis laser microscope (manufactured by Keyence Corporation, VK-X150 (control unit) / VK-X160 (measurement unit)). The maximum height Rz is one of the peak and height parameters of the contour curve, and is the sum of the height of the highest peak and the depth of the deepest valley in the contour curve over a reference length. A large value for the maximum height Rz means that there are peaks that are tall when viewed from the bottom of the valley. The larger the value for the maximum height Rz, the more peaks that are tall when viewed from the bottom of the valley tend to be.

[0041] In embodiments of this disclosure, the maximum height Rz of the uneven surface 32 as defined in JIS B0601:2013 is 2 μm or more. Preferably, the maximum height Rz is 2.5 μm or more, more preferably 3 μm or more, and even more preferably 4 μm or more. The cutoff value for measuring the maximum height Rz in this specification is 0.8 mm.

[0042] As described above, the effect of limiting the numerical range of the maximum height Rz will first be explained from the perspective of making the protective layer 30 function as a matting layer and obtaining a matting effect through the uneven surface 32. As described above, by setting a lower limit on the maximum height Rz, and in particular setting the maximum height Rz to 2 μm or more, the maximum height Rz on the uneven surface 32 is ensured. This allows the uneven surface 32 to appropriately exhibit a matting effect.

[0043] Next, we will explain the effect of limiting the numerical range of the maximum height Rz, as described above, from the perspective of providing a decorative sheet 10 with excellent tactile properties. Conventionally, customer demand for decorative sheets 10 has been diverse, and there are cases where a decorative sheet 10 with excellent tactile properties is required. In some cases, a decorative sheet 10 is required to give the user a particularly "smooth" tactile sensation. Although "smooth" is a sensory expression, in this specification, "smooth" encompasses all tactile sensations that are generally perceived as "smooth." Specifically, it refers to the tactile sensation felt when touching a dry, smooth surface with the pad of a finger.

[0044] In the embodiments of this disclosure, the surface 10a of the decorative sheet 10 is composed of an uneven surface 32 having a wrinkled structure. The maximum height Rz of the uneven surface 32 is 2 μm or more, and in particular 2.5 μm or more. This reduces the area in which the user comes into contact with the surface 10a of the decorative sheet 10 when the user comes into contact with it. For example, the user cannot come into contact with the bottom of the recesses of the wrinkled structure. The portion of the surface 10a that the user comes into contact with is limited to the vicinity of the apex of the protrusions of the wrinkled structure. This reduces the area in which the user comes into contact with the surface 10a compared to the case where the surface 10a of the decorative sheet 10 is composed of a flat surface. By reducing the area in which the user comes into contact with the surface 10a, the friction that the user feels between themselves and the surface 10a can be reduced.

[0045] As an example, the maximum height Rz on the uneven surface 32 is 12.5 μm or less. By having a maximum height Rz of 12.5 μm or less on the uneven surface 32, the height of the protrusions included in the wrinkle structure of the uneven surface 32 becomes smaller than that of an uneven surface 32 with a maximum height Rz greater than 12.5 μm. Also, by having a smaller height of the protrusions included in the wrinkle structure, the height difference between multiple protrusions included in the wrinkle structure becomes smaller. As a result, the multiple protrusions included in the wrinkle structure of the uneven surface 32 become smaller in height and more uniform. This makes it possible to suppress the feeling of roughness that a user who comes into contact with the surface 10a of the decorative sheet 10 will feel when they come into contact with the multiple protrusions of the wrinkle structure. From the viewpoint of suppressing the feeling of roughness that the user will feel, it is more preferable that the maximum height Rz be 11.5 μm or less, and even more preferable that it be 10.5 μm or less.

[0046] The resin layer 36 comprises a resin composition. The resin composition used in the resin layer 36 may include an ionizing radiation-curable resin. An ionizing radiation-curable resin is a resin having an ionizing radiation-curable functional group. An ionizing radiation-curable functional group is a group that crosslinks upon irradiation with ionizing radiation. An ionizing radiation-curable functional group may be a functional group having an ethylenically double bond, such as a (meth)acryloyl group, a vinyl group, or an allyl group. In this specification, (meth)acryloyl group refers to an acryloyl group or a metacloyl group. In this specification, (meth)acrylate refers to an acrylate or a methacrylate. Ionizing radiation refers to electromagnetic waves or charged particle beams that have energy quanta capable of polymerizing and / or crosslinking molecules. As ionizing radiation, electromagnetic waves such as ultraviolet rays (UV), electron beams (EB), X-rays, and gamma rays, or charged particle beams such as alpha rays and ion beams may be used.

[0047] As the ionizing radiation-curable resin, electron beam-curable resins or ultraviolet-curable resins may be used. The ionizing radiation-curable resin may be appropriately selected from polymerizable monomers and polymerizable oligomers that have been conventionally used as ionizing radiation-curable resins.

[0048] As polymerizable monomers, (meth)acrylate monomers having radical polymerizable unsaturated groups in the molecule are preferred. In particular, polyfunctional (meth)acrylate monomers are preferred as polymerizable monomers. Polyfunctional (meth)acrylate monomers may have two or more ionizing radiation-curable functional groups in the molecule, and at least one (meth)acryloyl group as a functional group. The number of functional groups of polyfunctional (meth)acrylate monomers may be 2 to 8. Preferably, the number of functional groups of polyfunctional (meth)acrylate monomers may be 2 to 6. These polyfunctional (meth)acrylates may be used individually or in combination of multiple types.

[0049] The polymerizable oligomer may be, for example, a (meth)acrylate oligomer having two or more ionizing radiation-curable functional groups in its molecule, and having at least one (meth)acryloyl group as such functional group. The polymerizable oligomer may be, for example, a urethane (meth)acrylate oligomer, an epoxy (meth)acrylate oligomer, a polyester (meth)acrylate oligomer, a polyether (meth)acrylate oligomer, a polycarbonate (meth)acrylate oligomer, an acrylic (meth)acrylate oligomer, or the like. Furthermore, polymerizable oligomers may also include highly hydrophobic polybutadiene (meth)acrylate oligomers having (meth)acrylate groups in the side chains of polybutadiene oligomers, silicone (meth)acrylate oligomers having polysiloxane bonds in the main chain, aminoplast resin (meth)acrylate oligomers obtained by modifying aminoplast resins that have many reactive groups in a small molecule, and oligomers having cationic polymerizable functional groups in the molecules of novolac-type epoxy resins, bisphenol-type epoxy resins, aliphatic vinyl ethers, aromatic vinyl ethers, etc.

[0050] These polymerizable oligomers may be used individually or in combination. The polymerizable oligomers may be urethane (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, polyester (meth)acrylate oligomers, polyether (meth)acrylate oligomers, polycarbonate (meth)acrylate oligomers, or acrylic (meth)acrylate oligomers. Preferably, the polymerizable oligomers may be urethane (meth)acrylate oligomers or polycarbonate (meth)acrylate oligomers. More preferably, the polymerizable oligomers may be urethane (meth)acrylate oligomers.

[0051] The number of functional groups in these polymerizable oligomers may be between 2 and 8. Preferably, the number of functional groups in the polymerizable oligomers may be between 2 and 6. The weight-average molecular weight of the polymerizable oligomers may be between 2500 and 7500. Preferably, the weight-average molecular weight of the polymerizable oligomers may be between 3000 and 7000. More preferably, the weight-average molecular weight of the polymerizable oligomers may be between 3500 and 6000. Here, the weight-average molecular weight is the average molecular weight measured by GPC analysis and converted to standard polystyrene.

[0052] In embodiments of this disclosure, a polymerizable oligomer and a polymerizable monomer may be used as the resin forming the resin layer 36. The polymerizable oligomer may be a polyfunctional urethane (meth)acrylate oligomer. Preferably, the polymerizable oligomer may be a polyfunctional urethane acrylate oligomer. The polymerizable monomer may be a polyfunctional polymerizable monomer. Preferably, the polymerizable monomer may be a polyfunctional (meth)acrylate monomer. More preferably, the polymerizable monomer may be a polyfunctional acrylate monomer. The mixing ratio of the polymerizable oligomer and the polymerizable monomer can be appropriately adjusted according to the required properties.

[0053] The resin composition used in the resin layer 36 may contain other components in addition to the resin described above, depending on the desired performance. For example, the resin composition used in the resin layer 36 may contain monofunctional (meth)acrylate for purposes such as reducing its viscosity. These monofunctional (meth)acrylates may be used individually or in combination of multiple types.

[0054] Furthermore, if the above-mentioned resin is an ultraviolet-curable resin that hardens when exposed to ultraviolet light, it may contain additives such as photopolymerization initiators and photopolymerization accelerators. As a photopolymerization initiator, one or more selected from, for example, acetophenone, benzophenone, α-hydroxyalkylphenone, Michler ketone, benzoin, benzyldimethylketal, benzoylbenzoate, α-acyloxime esters, thioxanthones, etc., may be used. A photopolymerization accelerator can reduce polymerization inhibition by air during curing and accelerate the curing speed. As a photopolymerization accelerator, one or more selected from, for example, p-dimethylaminobenzoate isoamyl ester, p-dimethylaminobenzoate ethyl ester, etc., may be used.

[0055] The particles 38 function as a wrinkle-forming agent to impart a specific wrinkle structure to the uneven surface 32. In conventional techniques that use excimer light or the like to form a wrinkled uneven surface on the surface of a resin, it was difficult to precisely control the shape of the wrinkle structure on the uneven surface. The inventors of this invention conducted diligent research on this matter and found that by further adding particles 38 to the resin composition for forming the protective layer 30, it is possible to control the shape of the wrinkle structure on the uneven surface 32.

[0056] Conventionally, a technique is known in which particles such as silica are added to a resin layer that does not have a wrinkle structure to form a matte layer. In this technique, irregularities are formed on the surface of the resin layer by particles protruding from the surface, and these irregularities exert a matte effect. In contrast, in the embodiment of the present disclosure, the irregularities on the uneven surface 32 are realized by a wrinkle structure. The particles 38 in the embodiment of the present disclosure are not intended to form irregularities on the uneven surface 32 by themselves. In this respect, particles added to a resin layer that does not have a wrinkle structure and particles 38 in the embodiment of the present disclosure are fundamentally different. The inventors of this invention speculate that when the resin composition is irradiated with excimer light or the like, as in the manufacturing method described later, the particles 38 act as a starting point for forming protrusions and / or recesses that constitute the wrinkle structure. This makes it possible to impart shapes to the wrinkle structure that were difficult to form with conventional techniques. In the embodiment of the present disclosure, by including the particles 38 in the protective layer 30, which is a matte layer, it was possible to form an uneven surface 32 having the maximum height Rz in the above-mentioned numerical range. The following describes such particles 38.

[0057] As the particles 38, for example, organic particles or inorganic particles may be used. As the organic material constituting the organic particles, polymethyl methacrylate, acrylic-styrene copolymer resin, melamine resin, polycarbonate, polystyrene, polyvinyl chloride resin, benzoguanamine-melamine-formaldehyde condensate, silicone, fluororesin, and polyester resin may be used. As the inorganic material constituting the inorganic particles, silica, alumina, calcium carbonate, aluminosilicate, and barium sulfate may be used. Among these, silica may preferably be used as the inorganic material constituting the inorganic particles. The shape of the particles 38 may be, for example, spherical, polyhedron, flaky, amorphous, etc.

[0058] The average particle diameter of the particles 38 may be 1 μm or more. Preferably, the average particle diameter of the particles 38 may be 1.3 μm or more. More preferably, the average particle diameter of the particles 38 may be 1.5 μm or more. Even more preferably, the average particle diameter of the particles 38 may be 1.8 μm or more. The average particle diameter of the particles 38 may be 20 μm or less. Preferably, the average particle diameter of the particles 38 may be 15 μm or less. Even more preferably, the average particle diameter of the particles 38 may be 10 μm or less. In this specification, the average particle diameter of the particles 38 is the average value (arithmetic mean diameter) of the particle diameter measured for 100 randomly selected non-aggregated particles of the protective layer 30, observed in the thickness direction using a scanning electron microscope (SEM) under conditions of an acceleration voltage of 3.0 kV and a magnification of 50,000 times. The particle diameter is the value measured by the distance between two parallel lines that maximize the distance between the lines when the cross-section of particle 38 is sandwiched between two arbitrary parallel lines.

[0059] The plurality of particles 38 may include particles 38 having a maximum dimension of 1 / 2 or more the thickness of the resin layer 36. Through the inventors' studies, it was found that when the plurality of particles 38 include particles 38 having a maximum dimension of 1 / 2 or more the thickness of the resin layer 36, the shape of the wrinkle structure of the uneven surface 32 can be controlled more appropriately. Preferably, the plurality of particles 38 may include particles 38 having a maximum dimension of 1 / 2 or more the thickness of the resin layer 36. More preferably, the plurality of particles 38 may include particles 38 having a maximum dimension of 1.5 times or more the thickness of the resin layer 36. Even more preferably, the plurality of particles 38 may include particles 38 having a maximum dimension of 2 times or more the thickness of the resin layer 36. Also, the maximum dimension of the particles 38 may be 10 times or less the thickness of the resin layer 36. In this case, the thickness of the resin layer 36 is sufficiently secured for the maximum dimension of the particles 38. As a result, the resin layer 36 fully performs its function as a binder. Therefore, the particles 38 are appropriately held by the resin layer 36. Preferably, the maximum size of the particles 38 may be 8 times or less the thickness of the resin layer 36.

[0060] The maximum dimension of particle 38 is the dimension of particle 38 measured by observing the cross-section in the thickness direction of the protective layer 30 using a scanning electron microscope (SEM) under the conditions of an acceleration voltage of 3.0 kV and a magnification of 50,000 times. The maximum dimension of particle 38 is the value measured by the distance between two parallel lines that maximize the distance between the two lines when the cross-section of particle 38 is sandwiched between them. Depending on the position of the cross-section of particle 38, the maximum dimension of particle 38 measured as described above may differ from the true maximum dimension of particle 38. However, the maximum dimension of particle 38 measured as described above will never be greater than the true maximum dimension of particle 38. Therefore, it can be inferred that the true maximum dimension of particle 38 is equal to or greater than the maximum dimension of particle 38 measured as described above.

[0061] The content of particles 38 in the resin forming the resin layer 36 may be 0.5 parts by mass or more per 100 parts by mass of resin. Preferably, the content of particles 38 may be 0.75 parts by mass or more. More preferably, the content of particles 38 may be 1 part by mass or more. Even more preferably, the content of particles 38 may be 1.2 parts by mass or more. The content of particles 38 in the resin forming the resin layer 36 may be 25 parts by mass or less per 100 parts by mass of resin. Preferably, the content of particles 38 may be 15 parts by mass or less. Even more preferably, the content of particles 38 may be 10 parts by mass or less. Even more preferably, the content of particles 38 may be 7.5 parts by mass or less. Even more preferably, the content of particles 38 may be 6 parts by mass or less. Even more preferably, the content of particles 38 in the protective layer 30 is 5 parts by mass or less per 100 parts by mass of resin forming the resin layer 36. As an example, the protective layer 30 contains inorganic silica particles as particles 38 in an amount of 5 parts by mass or less per 100 parts by mass of resin forming the resin layer 36.

[0062] In the embodiments of this disclosure, as described above, the surface 10a of the decorative sheet 10 is composed of an uneven surface 32 having a wrinkled structure, and the maximum height Rz on the uneven surface 32 is 2 μm or more, and in particular 2.5 μm or more, thereby reducing the area in which the user comes into contact with the surface 10a of the decorative sheet 10. Furthermore, by having a maximum height Rz on the uneven surface 32 of 12.5 μm or less, the roughness felt by the user when coming into contact with the multiple protrusions of the wrinkled structure can be reduced. In addition, the protective layer 30 in the embodiments of this disclosure includes a resin layer 36 and a plurality of particles 38. As described above, the particles 38 in the embodiments of this disclosure are not intended to form the irregularities on the uneven surface 32 themselves. For this reason, they are essentially different from particles added to a resin layer that does not have a wrinkled structure. As an example, the content of particles 38 in the protective layer 30 is 5 parts by mass or less per 100 parts by mass of resin forming the resin layer 36. According to the decorative sheet 10 of this embodiment of the disclosure, the user who comes into contact with the surface 10a of the decorative sheet 10 will be given a smooth and dry feel with low friction.

[0063] The effect of the decorative sheet 10 of the embodiment of this disclosure on suppressing the sensation of coldness to the user will be explained. First, the effect of limiting the numerical range of the maximum height Rz, as described above, will be explained from the perspective of suppressing the sensation of coldness to the user. When the decorative sheet 10 is used for general purposes, such as on the interior and exterior surfaces of buildings, the temperature of the surface 10a of the decorative sheet 10 is usually lower than the user's body temperature when the user is not in contact with the surface 10a of the decorative sheet 10. Here, when the user comes into contact with the surface 10a of the decorative sheet 10, if the area in contact with the surface 10a of the decorative sheet 10 is too large, the user's body temperature is rapidly taken away by the decorative sheet 10 through the large contact area, causing the user to feel cold.

[0064] In the embodiments of this disclosure, the surface 10a of the decorative sheet 10 is composed of an uneven surface 32 having a wrinkled structure. The maximum height Rz of the uneven surface 32, as defined in JIS B0601:2013, is 2 μm or more. Therefore, when a user comes into contact with the surface 10a of the decorative sheet 10, the area in contact with the surface 10a is smaller compared to when the surface 10a is composed of a flat surface. This suppresses the rapid loss of the user's body heat to the decorative sheet 10 through a large contact area, thereby suppressing the user from feeling cold. In addition, the user comes into contact with air in the areas that do not come into contact with the surface 10a of the decorative sheet 10. Generally, the thermal conductivity of air is lower than the thermal conductivity of the materials that make up a typical decorative sheet 10. By having the surface 10a of the decorative sheet 10 composed of an uneven surface 32 having a wrinkled structure, the area in contact with the surface 10a of the decorative sheet 10 is reduced, while the area in contact with air is increased. This effectively suppresses the loss of the user's body heat to the decorative sheet 10, thereby preventing the user from feeling cold. From the viewpoint of suppressing the loss of the user's body heat to the decorative sheet 10 through a large contact surface, it is more preferable that the maximum height Rz on the uneven surface 32 be 2.5 μm or more.

[0065] In the embodiments of this disclosure, as described above, the thermal conductivity λ1 of the base material 12 is 30 W / cm·K or less. By having a thermal conductivity λ1 of 30 W / cm·K or less, the absorption of heat by the base material 12 is effectively suppressed. Therefore, the absorption of heat from the surface 10a of the decorative sheet 10 into the base material 12 is effectively suppressed. This makes it possible to suppress the loss of the user's body heat to the base material 12 when the user comes into contact with the surface 10a of the decorative sheet 10. As a result, the feeling of coldness experienced by the user can be more effectively suppressed.

[0066] Next, an example of a method for manufacturing the decorative sheet 10 according to the embodiment of this disclosure will be described. First, a laminate of a base material 12, a design layer 20, an adhesive layer 14, a transparent resin layer 16, and a primer layer 18 is prepared. Next, a mixture of a resin composition and particles 38, which will later become the resin layer 36, is placed on the primer layer 18 of this laminate. The mixture may be applied to the primer layer 18 in a fluid state, for example. The mixture may be applied by, for example, gravure printing, bar coating, roll coating, reverse roll coating, comma coating, etc. Alternatively, the mixture may be attached to the primer layer 18 in a sheet-like state.

[0067] Next, the resin composition is irradiated with light having a wavelength greater than 380 nm to pre-cure the entire resin composition. Preferably, the wavelength of this light may be between 385 nm and 400 nm. Note that this pre-curing step is not essential and may be omitted.

[0068] Subsequently, the surface of the resin composition is irradiated with light having a wavelength between 100 nm and 380 nm. This causes a wrinkle structure to form on the surface of the resin composition. The mechanism by which this wrinkle structure is formed is presumed to be as follows: When light having a wavelength between 100 nm and 380 nm is irradiated onto the surface of the resin composition, because the wavelength of this light is short, the energy of the light penetrates only to the surface portion, and the energy of the light does not reach the layers below. At this time, only the surface portion of the resin composition begins to harden. As a result, hardening shrinkage occurs only on the surface, and a wrinkle structure is formed on the surface of the resin composition. This is thought to occur when only a portion of the resin composition within a certain thickness range from the surface has hardened. Furthermore, at this time, it is thought that particle 38 has a nucleus-like function that triggers the formation of the wrinkle structure. Therefore, it is presumed that the resin on the surface portion of the resin composition gathers around particle 38, forming the convex and concave parts of the wrinkle structure.

[0069] As light having a wavelength between 100 nm and 380 nm, for example, "excimer light" may be used, which includes light in the ultraviolet wavelength range from gases such as noble gases like Ar, Kr, Xe, and Ne, halides of noble gases such as F, Cl, I, and Br, or dimers of excited states formed by the discharge of mixed gases thereon, i.e., excimers. The wavelength of the excimer light and the excimer that serves as the light source may be, for example, light with a wavelength of 126 nm radiated from an Ar2 excimer (hereinafter abbreviated as "126 nm (Ar2)"), 146 nm (Kr2), 157 nm (F2), 172 nm (Xe2), 193 nm (ArF), 222 nm (KrCl), 247 nm (KrF), 308 nm (XeCl), 351 nm (XeF), etc. As excimer light, either spontaneous emission light or highly coherent laser light produced by stimulated emission may be used. Discharge lamps that emit this type of light are also called "excimer lamps." Excimer light has a single wavelength peak and a narrower half-width compared to ordinary ultraviolet light (for example, ultraviolet light emitted from metal halide lamps, mercury lamps, etc.). By using such excimer light, wrinkle formation is stabilized and the matting effect is steadily improved.

[0070] The wavelength of light irradiated onto the surface of the resin composition may be 120 nm or more. Preferably, the wavelength of light may be 140 nm or more. More preferably, the wavelength of light may be 150 nm or more. Even more preferably, the wavelength of light may be 155 nm or more. The wavelength of light irradiated onto the surface of the resin composition may be 320 nm or less. Preferably, the wavelength of light may be 300 nm or less. Even more preferably, the wavelength of light may be 250 nm or less. Even more preferably, the wavelength of light may be 200 nm or less. Even more preferably, the wavelength of light may be 172 nm (Xe2).

[0071] When light irradiated onto the surface of a resin composition has a wavelength of 172 nm, the integrated light intensity is 0.1 mJ / cm². 2 The above is also acceptable. Preferably, the integrated light intensity is 0.5 mJ / cm 2It may be as described above. More preferably, the integrated light quantity is 1 mJ / cm 2 It may be as described above. The integrated light quantity of the light irradiated on the surface of the resin composition may be 300 mJ / cm 2 It may be as described below. Preferably, the integrated light quantity may be 100 mJ / cm 2 It may be as described below. More preferably, the integrated light quantity may be 50 mJ / cm 2 It may be as described below.

[0072] When the light irradiated on the surface of the resin composition has a wavelength of 172 nm, the output density of the light may be 0.001 W / cm or more. Preferably, the output density may be 0.01 W / cm or more. More preferably, the output density may be 0.02 W / cm or more. The output density of the light irradiated on the surface of the resin composition may be 1 W / cm or less. Preferably, the output density may be 0.5 W / cm or less. More preferably, the output density may be 0.1 W / cm or less. <​​​​​​​​​The decorative sheet 10 of the embodiment of this disclosure comprises a base material 12 and a protective layer 30, the protective layer 30 having an uneven surface 32 that constitutes the surface 10a of the decorative sheet 10, the uneven surface 32 having a wrinkled structure, the maximum height Rz of the uneven surface 32 as defined in JIS B0601:2013 being 2 μm or more, and the thermal conductivity λ1 of the base material 12 being 30 W / cm·K or less.

[0076] With such a decorative sheet 10, the maximum height Rz of the uneven surface 32, as defined in JIS B0601:2013, is 2 μm or more, which suppresses the rapid loss of the user's body heat to the decorative sheet 10 through a large contact surface. Furthermore, the thermal conductivity λ1 of the base material 12 is 30 W / cm·K or less, which suppresses the loss of the user's body heat to the base material 12 when the user comes into contact with the surface 10a of the decorative sheet 10. This effectively suppresses the feeling of coldness the user experiences when they come into contact with the surface 10a of the decorative sheet 10.

[0077] From the viewpoint of suppressing the feeling of coldness experienced by the user when they come into contact with the surface 10a of the decorative sheet 10, it is preferable that the maximum height Rz of the uneven surface 32 be large. On the other hand, if the maximum height Rz of the uneven surface 32 is large, the user is more likely to feel roughness when they come into contact with the surface 10a of the decorative sheet 10, making it difficult to give the user a smooth touch. For this reason, it has been difficult in the conventional technology to provide a decorative sheet 10 that suppresses the feeling of coldness experienced by the user while giving the user a smooth touch. In contrast, according to the decorative sheet 10 of the embodiment of the present disclosure, as described above, it is possible to suppress the feeling of coldness experienced by the user while giving the user a smooth touch.

[0078] The following describes an example of an experiment conducted by the inventors of this invention. However, the embodiments of this disclosure are not limited to the following experimental results.

[0079] Samples 1 to 10 were prepared under the following conditions. For each sample, the thermal conductivity λ1 and maximum height Rz of the substrate 12 were measured. In addition, a cold sensation suppression evaluation test was conducted for each sample to assess whether the cold sensation given to the user was suppressed. Furthermore, a sensory evaluation test of the smooth texture was conducted. Table 1 shows the conditions for each sample from 1 to 5 and the measurement results for the above measurement items. Table 2 shows the conditions for each sample from 6 to 10 and the measurement results for the above measurement items. In the columns for "Ultraviolet irradiation (pre-curing)", "Excimer light irradiation", and "Electron beam (EB) irradiation" in Tables 1 and 2, "○" means that the sample was subjected to ultraviolet irradiation (pre-curing), excimer light irradiation, or electron beam (EB) irradiation, as described below, during the preparation of each sample. "×" means that the sample was not subjected to ultraviolet irradiation (pre-curing), excimer light irradiation, or electron beam (EB) irradiation during the preparation of each sample.

[0080] Sample 1 A mixture was prepared by mixing 30 parts by mass of a polyfunctional oligomer with 3 functional groups, 30 parts by mass of a trifunctional monomer, and 40 parts by mass of a difunctional monomer. A photopolymerization initiator was added to this mixture to prepare a resin composition. To this resin composition, 3 parts by mass of silica particles with an average particle size of 8 μm were added as particles 38 that function as a wrinkle-forming agent to obtain an ink. As a result, the content of particles 38 in the protective layer 30 of the prepared sample was 5 parts by mass or less per 100 parts by mass of resin forming the resin layer 36. Furthermore, a laminate was prepared having a paper base material 12, a design layer 20, an adhesive layer 14, a transparent resin layer 16, and a primer layer 18 in this order. The thickness t1 of the base material 12 was 0.06 cm. The thickness of the primer layer 18 was 2 μm. Adhesive was applied to the primer layer 18 of this laminate and dried, and the above ink was applied to the adhesive and dried. The mass of the ink per unit area was 5 g / m². 2 (When dry) The ink was pre-cured by irradiating it with ultraviolet light using a UV-LED light source. The cumulative light intensity was 30 mJ / cm². 2 That was the case. Next, the surface of the resin composition was cured by irradiating the ink with excimer light (wavelength 172 nm) using an excimer lamp. The output density of the excimer light was 1 W / cm. Subsequently, the ink was irradiated with an electron beam (EB) to cure the entire resin composition, thereby obtaining a protective layer 30 from the ink. The acceleration voltage was 125 kV, and the irradiation dose was 50 kGy (5 Mrad).

[0081] Sample 2 Except for the following points, the method was the same as in Sample 1. As the base material 12, a polyethylene terephthalate (PET) sheet with multiple voids (manufactured by Toyobo Co., Ltd., product name "Kamishine") was used.

[0082] Sample 3 The procedure was the same as in Sample 1, except that the pre-curing step of irradiating the ink with ultraviolet light using a UV-LED light source and the step of curing the surface of the resin composition by irradiating it with excimer light using an excimer lamp were omitted. In other words, the procedure was the same as in Sample 1, except that the protective layer 30 was obtained from the ink only by the step of curing the entire resin composition by irradiating the ink with an electron beam.

[0083] Sample 4 Except for the following points, the method was the same as in Sample 1. As the base material 12, a void-free polyethylene terephthalate (PET) sheet (manufactured by Toyobo Co., Ltd., product name "Cosmoshine") was used.

[0084] Sample 5 Except for the following points, the method was the same as Sample 1. A polypropylene (PP) sheet was used as the base material 12.

[0085] Sample 6 The procedure was the same as in Sample 4, except that the pre-curing step of irradiating the ink with ultraviolet light using a UV-LED light source and the step of curing the surface of the resin composition by irradiating it with excimer light using an excimer lamp were omitted. In other words, the procedure was the same as in Sample 4, except that the protective layer 30 was obtained from the ink only by the step of curing the entire resin composition by irradiating the ink with an electron beam.

[0086] Sample 7 The procedure was the same as in Sample 5, except that the pre-curing step of irradiating the ink with ultraviolet light using a UV-LED light source and the step of curing the surface of the resin composition by irradiating it with excimer light using an excimer lamp were omitted. In other words, the procedure was the same as in Sample 5, except that the protective layer 30 was obtained from the ink only by the step of curing the entire resin composition by irradiating the ink with an electron beam.

[0087] Sample 8 Except for the following points, the method was the same as in Sample 1. An aluminum sheet was used as the base material 12.

[0088] Sample 9 Except for the following points, the procedure was the same as for Sample 1. A resin composition was prepared by adding a photopolymerization initiator to 100 parts by mass of a trifunctional monomer.

[0089] Sample 10 Except for the following points, the procedure was the same as for Sample 7. When adding silica particles to the resin composition to obtain the ink, the average particle size of the silica particles was set to 3 μm, and the amount of silica particles added was 15 parts by mass. As a result, the particle content 38 in the protective layer 30 of the prepared sample was greater than 5 parts by mass relative to 100 parts by mass of resin forming the resin layer 36.

[0090] The thermal conductivity λ1 of the substrate 12 was measured by the hot-wire (probe) method. Specifically, the thermal conductivity λ1 of the substrate 12 was measured in accordance with JIS R 2616:2001, using a thermal conductivity meter (Kyoto Electronics Manufacturing Co., Ltd., rapid thermal conductivity meter QTM500), based on the amount of heat generated by the hot wire (heater wire) and the temperature rise.

[0091] The maximum height Rz was measured using a shape analysis laser microscope (VK-X150 (control unit) / VK-X160 (measurement unit) manufactured by Keyence Corporation) in accordance with JIS B0601:2013. The maximum height Rz was measured at 20 locations on the uneven surface 32, and the arithmetic mean value was taken as the maximum height Rz value for each sample.

[0092] In the cold sensation suppression evaluation test, each sample was placed on the same polyvinyl chloride (PVC) sheet. Twenty subjects were then asked to stand barefoot on the surface 10a of each sample. The subjects were then interviewed about whether they felt a cold sensation when standing on the surface 10a of each sample.

[0093] In the sensory evaluation test of the smooth texture, 20 subjects were asked to touch the surface 10a of each sample with their hands. The subjects were then interviewed about whether they felt a smooth texture when touching the surface 10a of each sample.

[0094] [Table 1]

[0095] [Table 2]

[0096] In the "Suppression of Cold Sensation" column of Tables 1 and 2 above, "○" means that, as a result of the interviews in the cold sensation suppression evaluation test, 16 or fewer subjects reported feeling cold. "△" means that, as a result of the interviews, 10 to 15 subjects reported feeling cold. "×" means that, as a result of the interviews, 9 or more subjects reported feeling cold. In the "Smooth Texture" column of Tables 1 and 2 above, "○" means that, as a result of the interviews in the sensory evaluation test for smooth texture, 16 or fewer subjects reported feeling smooth texture. "△" means that, as a result of the interviews, 10 to 15 subjects reported feeling smooth texture. "×" means that, as a result of the interviews, 9 or more subjects reported feeling smooth texture.

[0097] As shown in Tables 1 and 2, the maximum height Rz of samples 1, 2, 4, 5, 8, and 9 was 2 μm or more. On the other hand, the maximum height Rz of samples 3, 6, and 7 was less than 2 μm. From this, it was found that an uneven surface 32 with a maximum height Rz of 2 μm or more can be formed by irradiation with ultraviolet light (pre-curing) and excimer light.

[0098] In Sample 1, where the maximum height Rz was 2 μm or more, the cold sensation suppression evaluation test result was "○". On the other hand, in Sample 3, where the resin composition curing method was different from Sample 1 and the maximum height Rz was less than 2 μm, the cold sensation suppression evaluation test result was "△". Furthermore, in Sample 4, where the maximum height Rz was 2 μm or more, the cold sensation suppression evaluation test result was "○". On the other hand, in Sample 6, where the resin composition curing method was different from Sample 4 and the maximum height Rz was less than 2 μm, the cold sensation suppression evaluation test result was "×". Furthermore, in Sample 5, where the maximum height Rz was 2 μm or more, the cold sensation suppression evaluation test result was "○". On the other hand, in Sample 7, where the resin composition curing method was different from Sample 5 and the maximum height Rz was less than 2 μm, the cold sensation suppression evaluation test result was "×". From this, it was found that a maximum height Rz of 2 μm or more is preferable for suppressing the cold sensation.

[0099] In samples 1, 2, 4, and 5, where the thermal conductivity λ1 of the base material 12 was 30 W / cm·K or less, the cold sensation suppression evaluation test result was "○". On the other hand, in sample 8, where the material of the base material 12 was different from samples 1, 2, 4, and 5, and the thermal conductivity λ1 of the base material 12 was greater than 30 W / cm·K, the cold sensation suppression evaluation test result was "×". From this, it was found that a thermal conductivity λ1 of the base material 12 of 30 W / cm·K or less is preferable for suppressing the cold sensation.

[0100] Although the thermal conductivity λ1 of the substrate 12 was 30 W / cm·K or less, samples 3, 6, and 7, where the maximum height Rz was less than 2 μm, did not result in a "○" in the cold sensation suppression evaluation test. Similarly, even when the maximum height Rz was 2 μm or more, and the thermal conductivity λ1 of the substrate 12 was greater than 30 W / cm·K, the cold sensation suppression evaluation test did not result in a "○". On the other hand, samples 1, 2, 4, and 5, where the maximum height Rz was 2 μm or more and the thermal conductivity λ1 of the substrate 12 was 30 W / cm·K or less, all resulted in a "○" in the cold sensation suppression evaluation test. From this, it was found that the cold sensation can be suppressed by having a maximum height Rz of 2 μm or more and a thermal conductivity λ1 of the substrate 12 of 30 W / cm·K or less.

[0101] In Sample 1, where the maximum height Rz was between 2 μm and 12.5 μm, the sensory evaluation test for a smooth texture resulted in a "○" (good) rating. On the other hand, in both Sample 3, where the maximum height Rz was less than 2 μm, and Sample 9, where the maximum height Rz was greater than 12.5 μm, the sensory evaluation test for a smooth texture resulted in a "×" (bad) rating. From this, it was found that a maximum height Rz of 2 μm or more and 12.5 μm or less is preferable from the perspective of making the user feel a smooth texture.

[0102] In sample 10, where the pre-curing step of irradiating the ink with ultraviolet light using a UV-LED light source and the step of curing the surface of the resin composition by irradiating it with excimer light using an excimer lamp were not performed, and the content of particles 38 in the protective layer 30 was greater than 5 parts by mass per 100 parts by mass of resin forming the resin layer 36, the result of the cold sensation suppression evaluation test was "○", but the result of the smooth touch sensory evaluation test was "×". On the other hand, in samples 1, 2, 4, and 5, where the pre-curing step of irradiating the ink with ultraviolet light using a UV-LED light source and the step of curing the surface of the resin composition by irradiating it with excimer light using an excimer lamp were performed, and the content of particles 38 in the protective layer 30 was 5 parts by mass or less per 100 parts by mass of resin forming the resin layer 36, the result of the cold sensation suppression evaluation test was "○", and the result of the smooth touch sensory evaluation test was "○". From this, it was found that, particularly from the viewpoint of providing a decorative sheet 10 that gives the user a smooth texture while suppressing the feeling of coldness, the conditions under which samples 1, 2, 4, and 5 were produced are preferable to the conditions under which sample 10 was produced.

[0103] Although one embodiment has been described with reference to specific examples, the above-mentioned example is not limited to this particular embodiment. The above-described embodiment can be implemented in various other examples, and various omissions, substitutions, modifications, and additions can be made without departing from its essence. [Explanation of Symbols]

[0104] 10 Decorative sheets 12 Base material 14 Adhesive layer 16 Transparent resin layer 18. Primer layer 20 Design Layers 22 Colored layer 24 Image Layers 30 protective layer 32 Uneven surface 34 Back side 36 resin layer 38 particles

Claims

1. A decorative sheet comprising a base material and a protective layer, The protective layer has an uneven surface that constitutes the surface of the decorative sheet, The aforementioned uneven surface has a wrinkled structure, The maximum height Rz of the aforementioned uneven surface, as defined in JIS B0601:2013, is 2 μm or more. The thermal conductivity λ1 of the substrate is 10 W / cm·K or less. The substrate is a decorative sheet having voids.

2. The decorative sheet according to claim 1, wherein the maximum height Rz of the uneven surface, as defined in JIS B0601:2013, is 12.5 μm or less.

3. The decorative sheet according to claim 1 or 2, wherein the protective layer comprises a resin layer and a plurality of particles.

4. The decorative sheet according to claim 3, wherein the content of the particles in the protective layer is 5 parts by mass or less with respect to 100 parts by mass of the resin forming the resin layer.

5. A decorative sheet according to any one of claims 1 to 4, further comprising a design layer.

6. A decorative material comprising a substrate and a decorative sheet according to any one of claims 1 to 5 provided on the substrate.

Images