Decorative sheet

Abstract

To provide a decorative sheet that is low gloss and gives coarse texture.SOLUTION: A decorative sheet 1 comprises an original fabric layer 2 and a surface protective layer 5 provided on one surface of the original fabric layer 2, where an uneven structure including a plurality of ridge-shaped parts, each of which is protruded in a ridge-shape on the surface of the surface protective layer 5, is provided, the uneven structure of the surface protective layer 5 has a protruding crest part height Rpk of 3.5 μm or more, and an absorption spectrum of the surface protective layer 5 obtained in Fourier type infrared spectroscopy has a ratio I1095 / I1725 between the maximum value I1095 in a wave number range of 1085 to 1105 cm-1 and the maximum value I1725 in a wave number range of 1715 to 1735 cm-1 of 0.65 or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Decorative sheets are used for the surface decoration of interior and exterior materials such as fittings, furniture, construction materials, 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 surfaces 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, pattern-free decorative sheets are sometimes preferred. The choice of whether to have a pattern or not and the type of pattern vary according to the application and preferences.

[0004] The gloss of the surface is also important for the design of the decorative sheet. There are various types of decorative sheets to choose from, ranging from mirror-like high gloss to low gloss with no reflections, depending on the application and preference.

[0005] As mentioned above, durability is an important function of decorative sheets in addition to providing design. Durability is a comprehensive evaluation of scratch resistance, stain resistance, and whether these can be guaranteed for a long period of time. Although requirements vary depending on the environment and situation in which the decorative sheet is used, there is always a demand for decorative sheets with high performance.

[0006] To provide durability, a surface protective layer is generally formed on the outermost surface of the decorative sheet. Also, to adjust the aforementioned glossiness, particularly to achieve low gloss, a gloss regulator (matte additive) is generally added to the surface protective layer.

[0007] Furthermore, since decorative sheets are generally subjected to processes such as cutting and bending in order to form decorative materials such as decorative plates, it is preferable that the sheets have processability capable of withstanding 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. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 2019-119138 Summary of the Invention

[0010] An object of the present invention is to provide a decorative sheet that has a low gloss and a rough feel to the touch.

[0011] According to one aspect of the present invention, a substrate fabric layer and a surface protective layer provided on one surface of the substrate fabric layer are provided, and a concave-convex structure including a plurality of ridge-like portions each protruding in a ridge shape is provided on the surface of the surface protective layer. The concave-convex structure of the surface protective layer has a protruding peak height Rpk of 3.5 μm or more. The absorption spectrum obtained by Fourier infrared spectroscopy of the surface protective layer has a peak height Rpk of 1085 to 1105 cm. -1 Maximum value in the wavenumber range of I 1095 and 1715 to 1735 cm -1 Maximum value in the wavenumber range of I 1725 Comparison with I 1095 / I 1725 is 0.65 or more.

[0012] According to another aspect of the present invention, the above ratio I 1095 / I 1725 The decorative sheet according to the above aspect is provided in which the refractive index is 3.5 or less.

[0013] 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 protruding peak height Rpk is 25 μm or less.

[0014] 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 uneven structure of the surface protective layer has a mean length RSm of roughness curve elements of 150 μm or more.

[0015] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the average length RSm is 600 μm or less.

[0016] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the thickness of the surface protective layer is 8 μm or more.

[0017] According to yet another aspect of the present invention, there is provided a decorative sheet according to any one of the above aspects, wherein the surface protective layer has a gloss value of less than 10.0.

[0018] According to yet another aspect of the present invention, there is provided a decorative sheet relating to any of the above aspects, wherein at least a portion of the plurality of ridge portions are adjacent in the width direction, and at a position where at least a portion of the plurality of ridge portions are adjacent in the width direction, a cross section parallel to the width direction and the thickness direction of the surface protection layer has a sinusoidal shape in which the portion where the uneven structure is provided has a sinusoidal shape.

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

[0020] According to yet another aspect of the present invention, there is provided a decorative sheet according to the above aspect, wherein the ionizing radiation curable resin is an acrylate containing a repeating structure as a main component, the repeating structure is any one of ethylene oxide, propylene oxide, and ε-caprolactone, and the number of repetitions of the repeating structure is 3 or more.

[0021] According to yet another aspect of the present invention, there is provided a decorative material comprising a decorative sheet according to any of the above aspects and a substrate to which the decorative sheet is attached.

[0022] According to the present invention, it is possible to provide a decorative sheet that has low gloss and a rough feel to the touch. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of a surface protective layer included in the decorative sheet of FIG. [Diagram 3] FIG. 3 is a microscope image of a surface protective layer contained in a decorative sheet according to one example of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] 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 alone or in combination.

[0025] The embodiments described 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.

[0026] In addition, elements having the same or similar functions are given the same reference numerals in the drawings referred to below, and duplicated explanations are omitted. In addition, the drawings are schematic, and the relationship between dimensions in one direction and dimensions in another direction, the relationship between the dimensions of one member and the dimensions of another member, etc. may differ from the actual ones.

[0027] <1> Decorative materials and decorative sheets Fig. 1 is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention. Fig. 2 is a cross-sectional view of a surface protective layer included in the decorative sheet of Fig. 1. Fig. 3 is a micrograph of a surface protective layer included in a decorative sheet according to one example of the present invention.

[0028] The cross section shown in Fig. 2 is a cross section taken along the thickness direction of the surface protective layer, and the micrograph in Fig. 3 is a plan view taken with a laser microscope (OLS-4000 manufactured by Olympus Corporation).

[0029] The decorative material 11 shown in Fig. 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.

[0030] 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 a plurality of materials. The substrate B may have a shape other than a plate.

[0031] The decorative sheet 1 includes an original fabric layer 2, a pattern layer 3, a transparent resin layer 4, a surface protective layer 5, an adhesive layer 7, a primer layer 6, and a concealing layer 8. The pattern layer 3, the adhesive layer 7, the transparent resin layer 4, and the surface protective layer 5 are provided in this order from the original fabric layer 2 side on the surface of the original fabric layer 2 opposite to the surface facing the substrate B. The concealing layer 8 and the primer layer 6 are provided in this order from the original fabric layer 2 side on the surface of the original fabric layer 2 facing the substrate B. One or more of the pattern layer 3, the transparent resin layer 4, the primer layer 6, the adhesive layer 7, and the concealing layer 8 may be omitted. The elements included in the decorative sheet 1 will be described below in order.

[0032] <1.1> Original layer The raw fabric layer 2 or its material can be, for example, any material selected from paper, synthetic resin, synthetic resin foam, rubber, nonwoven fabric, synthetic paper, metal foil, etc. Examples of paper include tissue paper, titanium paper, resin-impregnated paper, etc. Examples of synthetic resin include polyethylene, polypropylene, polybutylene, polystyrene, polycarbonate, polyester, polyamide, ethylene-vinyl acetate copolymer, polyvinyl alcohol, acrylic, etc. 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, polyurethane, etc. Examples of nonwoven fabric include organic and inorganic nonwoven fabrics. Examples of metal foil include aluminum, iron, gold, silver, etc.

[0033] Taking into consideration the printing workability, costs, and the like, the thickness of the base fabric layer 2 is preferably within the range of 20 μm to 250 μm.

[0034] <1.2> Primer layer When an olefin-based resin is used as the material of the raw fabric layer 2, the surface of the raw fabric layer 2 is often in an inactive state. Therefore, in this case, it is preferable to provide a primer layer 6 between the raw fabric layer 2 and the substrate B. When the raw fabric layer 2 is made of an olefin-based material, the primer layer 6 may be omitted, and the raw fabric layer 2 may be subjected to a surface modification treatment such as corona treatment, plasma treatment, ozone treatment, electron beam treatment, ultraviolet treatment, and dichromate treatment in order to improve the adhesion between the raw fabric layer 2 and the substrate B.

[0035] Materials for the primer layer 6 can be, for example, the materials described below for the pattern layer 3. Since the primer layer 6 is applied to the back surface of the decorative sheet 1, and considering that the decorative sheet 1 is wound up in a web form, an inorganic filler may be added to the primer layer 6 to avoid blocking and to increase adhesion to the adhesive. Examples of inorganic fillers include silica, alumina, magnesia, titanium oxide, barium sulfate, etc.

[0036] <1.3> Hiding layer In order to impart the decorative sheet 1 with the ability to conceal the substrate B, for example, a colored sheet is used as the base layer 2, or an opaque concealing layer 8 is provided. The concealing layer 8 can be made of the same material as that described below for the design layer 3. However, since the purpose of the concealing layer 8 is to provide concealment, it is preferable to use, for example, an opaque pigment, titanium oxide, iron oxide, or the like as the pigment. In addition, in order to enhance the concealment, it is also possible to add metals such as gold, silver, copper, and aluminum to the material of the concealing layer 8. In general, flake-shaped aluminum pieces are often added.

[0037] <1.4> Picture layer The pattern layer 3 is a layer formed by printing a pattern on the base layer 2 using ink. As the binder for the ink, for example, nitrocellulose, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acrylic, polyesters, or modified products thereof can be used alone or in combination. The binder may be water-based, solvent-based, or emulsion type, and may be a one-liquid type or a two-liquid type using a hardener. The pattern layer 3 may be formed by a method in which a layer formed with a hardening ink is hardened by irradiation with ultraviolet rays or electron beams. The most common method among them is a method in which a urethane-based ink is used and hardened by isocyanate. The ink used to form the pattern layer 3 may further contain, in addition to the binder, for example, pigments contained in ordinary inks, colorants such as dyes, extender pigments, solvents, various additives, etc. Examples of pigments having high versatility include condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, and pearl pigments such as mica.

[0038] In addition to applying ink, it is also possible to apply a design to the pattern layer 3 by vapor deposition or sputtering of various metals. In particular, it is preferable that a light stabilizer is added to the ink. This can suppress deterioration of the decorative sheet 1 itself caused by light deterioration of the ink, and extend the life of the decorative sheet 1.

[0039] <1.5>Adhesive layer The adhesive layer 7 is also called a heat-sensitive adhesive layer, an anchor coat layer, or a dry lamination adhesive layer.

[0040] The resin material of the adhesive layer 7 is not particularly limited, and may be appropriately selected from, for example, acrylic, polyester, polyurethane, and epoxy resin materials. In addition, for example, an ethylene-vinyl acetate copolymer resin adhesive may be used as the resin material of the adhesive layer 7. The coating method may be appropriately selected depending on the viscosity of the adhesive. In general, gravure coating is used, and after the adhesive layer 7 is formed on the upper surface of the pattern layer 3 by gravure coating, the transparent resin layer 4 is laminated. Note that the adhesive layer 7 may be omitted if sufficient adhesive strength is obtained between the transparent resin layer 4 and the pattern layer 3.

[0041] <1.6>Transparent resin layer An olefin-based resin is preferably used as the resin material of the transparent resin layer 4. Examples of the olefin-based resin include polypropylene, polyethylene, polybutene, and the like, as well as α-olefins (e.g., propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3 Examples of the copolymerizable monomer include a homopolymer of an α-olefin such as 1-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, etc., or a copolymerization of two or more of these monomers, and a copolymerization of ethylene or an α-olefin with another monomer such as an ethylene-vinyl acetate copolymer, an ethylene-vinyl alcohol copolymer, an ethylene-methyl methacrylate copolymer, an ethylene-ethyl methacrylate copolymer, an ethylene-butyl methacrylate copolymer, an ethylene-methyl acrylate copolymer, an ethylene-ethyl acrylate copolymer, and an ethylene-butyl acrylate copolymer.

[0042] In order to improve the surface strength of the decorative sheet 1, it is preferable to use highly crystalline polypropylene as the resin for the transparent resin layer 4. Note that various additives such as heat stabilizers, light stabilizers, antiblocking agents, catalyst scavengers, colorants, light scattering agents, and gloss adjusters can also be added to the transparent resin layer 4 as necessary. Generally, phenol-based, sulfur-based, phosphorus-based, and hydrazine-based heat stabilizers and hindered amine-based light stabilizers are added in any combination.

[0043] <1.7>Surface protective layer The surface protection layer 5 includes a core portion 5A and a plurality of ridge portions 5B each protruding in a ridge shape from one surface of the core portion 5A. These ridge portions 5B form an uneven structure.

[0044] Here, in the decorative sheet 1 according to this embodiment, "ridge-like" refers to a convex shape that is linear in plan view. The ridge portions 5B may be curved or linear in plan view, but are preferably curved in view of the fingerprint resistance of the decorative sheet 1. Each of the ridge portions 5B may be branched or unbranched in plan view. In addition, in the present disclosure, the ridge portions 5B are, for example, the portions from the lowest portion to the tip of the uneven shape provided on the surface of the surface protective layer 5, and the core portion 5A refers to the portion of the surface protective layer 5 excluding the ridge portions 5B.

[0045] The ridge portions 5B are curved and at least some of them are adjacent to each other in the width direction, as shown in Fig. 3. At a position where at least some of the ridge portions 5B are adjacent to each other in the width direction, the cross section of the surface protective layer 5 parallel to the width direction and the thickness direction of the surface protective layer 5 has a wave shape such as a sine wave shape in the portion where the uneven structure is provided, as shown in Fig. 2.

[0046] The uneven structure of the surface protective layer 5 has a protruding peak height Rpk of 3.5 μm or more. Here, the "protruding peak height Rpk" is a surface property parameter defined in JIS B0671-2:2002. This protruding peak height Rpk is more preferably 4.5 μm or more, and even more preferably 7.0 μm or more. A decorative sheet with a reduced protruding peak height Rpk does not give a rough tactile sensation to a user when the user slides the skin over the surface of the surface protective layer, for example, when the user slides a finger over the surface of the surface protective layer.

[0047] This protruding peak height Rpk is preferably 25 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less. A decorative sheet with a large protruding peak height Rpk is difficult to manufacture with high reproducibility.

[0048] The uneven structure of the surface protective layer 5 preferably has an average length RSm of roughness curve elements of 150 μm or more, more preferably 200 μm or more, and even more preferably 250 μm or more. Here, the "average length RSm of roughness curve elements" is a surface property parameter defined in JIS B0601:2013. When a user slides their skin over the surface of the surface protective layer, for example, when they slide their finger over the surface of the surface protective layer, the average length RSm of the roughness curve elements is preferably within the above range in order to provide the user with a rough tactile sensation.

[0049] This average length RSm is preferably 600 μm or less, more preferably 550 μm or less, and even more preferably 500 μm or less. If this average length RSm is increased, the frequency with which a user senses the presence of the ridge portion 5B when sliding a finger over the surface of the surface protection layer may decrease.

[0050] The absorption spectrum obtained by Fourier infrared spectroscopy of the surface protective layer 5 is 1085 to 1105 cm -1 Maximum value in the wavenumber range of I 1095 and 1715 to 1735 cm -1 Maximum value in the wavenumber range of I 1725 Comparison with I 1095 / I 1725 A preferable surface protective layer 5 has a ratio I 1095 / I 1725 The low-gloss surface protective layer 5 has a ratio I 1095 / I 1725 is within the above range.

[0051] Ratio I 1095 / I 1725 is preferably 3.5 or less, and more preferably 2.7 or less. 1095 / I 1725 A surface protective layer 5 having a large surface roughness tends to have low scratch resistance.

[0052] Here, the above-mentioned Fourier type infrared spectrometry will be described. Infrared light with wavelengths in the range of 2.5 to 25 μm can change the vibrational and rotational states of molecules. The energy required to change these vibrational and rotational states varies depending on the structure of the molecule. Infrared spectroscopy is a measurement method that utilizes this to obtain information about the chemical structure and state of a substance.

[0053] In Fourier infrared spectrometry, for example, measurement is performed as follows. First, light from a light source is obliquely incident on a semi-transparent mirror and split into two beams of transmitted light and reflected light. The beam that has passed through the semi-transparent mirror is reflected by a fixed mirror and is obliquely re-incident on the semi-transparent mirror. The beam reflected by the semi-transparent mirror is reflected by a movable mirror and is obliquely re-incident on the semi-transparent mirror. The beam reflected by the semi-transparent mirror out of the light reflected from the fixed mirror and the beam reflected by the movable mirror that has passed through the semi-transparent mirror are combined to generate an interference wave. While changing the distance from the semi-transparent mirror to the movable mirror, this interference wave is irradiated onto a sample, and the intensity of the light that has passed through the sample is measured. The intensity data obtained in this way is separated into the intensities of each wave number component by calculation (Fourier transform) to obtain a transmittance spectrum.

[0054] In the Fourier infrared spectrometry used here, instead of measuring the transmitted light intensity in the above-mentioned Fourier infrared spectrometry, the reflected light intensity is measured by the following attenuated total reflection method (ATR method).

[0055] In Fourier transform infrared spectroscopy using the ATR method, instead of directly incident on the sample, the interference wave is incident on a measurement prism that is in contact with the surface of the sample. The interference wave is incident on the measurement prism so that it is totally reflected at the interface between the prism and the sample. In this way, evanescent waves seep into the area of ​​the sample near the interface, and light of a specific wave number component is absorbed by molecules in this area. Then, in Fourier transform infrared spectroscopy using the ATR method, instead of measuring the intensity of transmitted light, the intensity of reflected light is measured. The intensity data obtained in this way is then separated by calculation into the intensities of each wave number component (Fourier transform) to obtain the ATR spectrum.

[0056] The penetration depth (depth of penetration) of the evanescent wave increases as the wavelength becomes longer. Therefore, the baseline of the ATR spectrum, in which the horizontal axis is the wavelength and the vertical axis is the reflected light intensity (or reflectance), slopes downward to the right. The penetration depth of the evanescent wave is also affected by the angle of incidence of the interference wave on the interface and the refractive index of the prism and the sample. Therefore, the ATR spectrum is corrected by the reciprocal of the wavelength, etc. By performing such correction, a spectrum having the same peak intensity ratio as the transmittance spectrum can be obtained. Then, by converting this spectrum, an absorption spectrum can be obtained, in which the horizontal axis is the wave number and the vertical axis is the absorbance.

[0057] The penetration depth of the evanescent wave is small, and can be adjusted by the angle of incidence of the interference wave and the refractive index of the prism. Therefore, Fourier transform infrared spectroscopy using the ATR method can prevent the underlying layer from becoming noise, even if the object to be measured is a thin layer. In addition, Fourier transform infrared spectroscopy using the ATR method allows non-destructive measurement as long as the object to be measured is exposed on the surface of the sample.

[0058] As described above, the absorption spectrum obtained by Fourier infrared spectroscopy of the surface protective layer 5 has a ratio I 1095 / I 1725 is within the specified range. 1085 to 1105 cm -1 Maximum value in the wavenumber range of I 1095 is a value related to the number of ether bonds contained in the surface protective layer 5. -1 Maximum value in the wavenumber range of I 1725 is a value related to the number of ester bonds. Therefore, the ratio I 1095 / I 1725 corresponds to the ratio of the number of ether bonds to the number of functional groups of the acrylate contained in the ionizing radioactive resin of the coating liquid for the surface protective layer described below.

[0059] The thickness of the surface protective layer 5 is preferably 8 μm or more, more preferably 10 μm or more, and even more preferably 15 μm or more. If the thickness of the surface protective layer 5 is reduced, it becomes difficult to increase the protruding peak height Rpk and the average length RSm. If the thickness of the surface protective layer 5 is increased, the protruding peak height Rpk and the average length RSm tend to increase. There is no upper limit to the thickness of the surface protective layer 5, but from the viewpoint of costs, etc., it is preferably 30 μm or less, and more preferably 25 μm or less.

[0060] Here, the thickness of the surface protective layer 5 is the thickness of a layer having the same apparent area and volume as the surface protective layer 5 and a flat surface. The thickness of the surface protective layer 5 is determined, for example, by the following method. First, a cross section parallel to the thickness direction of the surface protective layer 5 and perpendicular to the length direction of the ridge portion 5B is imaged. Next, from this cross-sectional image, the dimension of the surface protective layer 5 in the width direction of the ridge portion 5B and the area of ​​the cross section of the surface protective layer 5 are determined. The thickness of the surface protective layer 5 is a value obtained by dividing this area by the above dimension. Note that, when the coating liquid for the surface protective layer described later does not contain a solvent, the thickness of the coating film made of the coating liquid for the surface protective layer is equal to the thickness of the surface protective layer 5.

[0061] The gloss of the surface protective layer 5 is preferably less than 10.0, and more preferably equal to or less than 8.0. Here, the "gloss" is a value measured at an incidence angle of 60 degrees using a gloss meter conforming to JIS Z8741:1997.

[0062] <2> Manufacturing method of decorative sheet The decorative sheet 1 is produced, for example, by the following method. For the sake of brevity, explanations regarding the design layer 3, transparent resin layer 4, primer layer 6, adhesive layer 7, and concealing layer 8 are omitted here.

[0063] First, a coating film made of a coating liquid for a surface protective layer is formed on one surface of the raw fabric layer 2. This coating film can be formed by various printing methods such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing, and various coating methods such as roll coating, knife coating, microgravure coating, and die coating.

[0064] The coating liquid for the surface protective layer contains 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. The ionizing radiation curable resin used here is cured by irradiation with light having a wavelength of 200 nm or less, and has a large absorption coefficient for this light.

[0065] In the coating liquid for surface protection layer, when the total solid content is 100 parts by mass, the amount of the ionizing radiation curable resin 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. As the ionizing radiation curable resin, known ones such as various monomers and commercially available oligomers can be used, and for example, (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins can be used. The ionizing radiation curable resin may be either an aqueous resin or a non-aqueous (organic solvent) resin.

[0066] The main component of the ionizing radiation curable resin is preferably an acrylate. Here, the main component of the ionizing radiation curable resin means that the main component is 60 parts by mass or more when the total solid content of the ionizing radiation curable resin is 100 parts by mass. The ionizing radiation curable resin preferably contains 70 parts by mass or more of acrylate, and more preferably contains 80 parts by mass or more of acrylate.

[0067] The acrylate is preferably a bifunctional or higher acrylate, and more preferably a trifunctional or higher acrylate. In order to obtain a surface protective layer 5 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 6-functional or lower.

[0068] The acrylate preferably contains a repeating structure. The repeating structure is, for example, any one of an ethylene oxide (EO) structure, a propylene oxide (PO) structure, and an ε-caprolactone (CL) structure. The repeating structure is preferably ethylene oxide or propylene oxide. In a trifunctional or higher acrylate containing a repeating structure, the repeating structure may be present between an acryloyl group and a methylol group in a ring-opened state.

[0069] 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 likely to expand in the in-plane direction in the second irradiation step described below, and therefore wrinkles corresponding to the ridge portions 5B are likely to appear on the coating film surface. However, if the number of repetitions is increased, the crosslink density decreases, and the scratch resistance of the surface protective layer decreases.

[0070] The trifunctional acrylate containing a repeating unit is, for example, EO-modified, PO-modified or CL-modified trimethylolpropane triacrylate, glycerin triacrylate, isocyanurate triacrylate or pentaerythritol triacrylate. In the trifunctional acrylate containing a repeating unit, the number of repeats of the repeating unit is preferably 3 or more and 30 or less, more preferably 3 or more and 20 or less.

[0071] The tetrafunctional acrylate containing a repeating unit is, for example, EO-modified, PO-modified, or CL-modified pentaerythritol tetraacrylate. In the tetrafunctional acrylate containing a repeating unit, the number of repeating units is preferably 12 or more, more preferably 12 or more and 50 or less, and even more preferably 20 or more and 50 or less.

[0072] The number of repetitions of the repeating structure can be analyzed by using MALDI-TOF-MS. Ionizing radiation curable resins may have a molecular weight distribution. If there is a molecular weight distribution, the number of repetitions is the number of repetitions corresponding to the molecular weight with the strongest peak in the MALDI-TOF-MS mass spectrum.

[0073] It is preferable that the coating liquid for forming a surface protective layer further contains particles. When particles are contained in the coating liquid for forming a surface protective layer, wrinkles can be more uniformly generated on the coating surface in the second irradiation step.

[0074] Examples of the particles that can be used include particles made of organic materials such as polyethylene (PE) wax, polypropylene (PP) wax, and resin beads, and particles made of inorganic materials such as silica, glass, alumina, titania, zirconia, calcium carbonate, and barium sulfate.

[0075] The average particle size (D50) of the particles is preferably 10 μm or less. The average particle size (D50) of the particles is more preferably 1 μm or more and 8 μm or less, and further preferably 2 μm or more and 6 μm or less. When large particles are used, the particles are likely to fall off from the surface protective layer 5, and it may be difficult to achieve high scratch resistance. When the particles are small, the effect of generating wrinkles uniformly is small.

[0076] Here, the "average particle size (D50)" is the median size (D50) measured by a laser diffraction / scattering type particle size distribution measuring device. When the coating liquid for the surface protective layer contains particles, the surface protective layer 5 obtained from this coating liquid also contains particles. The average particle size of the particles contained in the surface protective layer 5 can be determined by observing the cross section of the layer, measuring the particle sizes of a plurality of particles, and averaging the measured values. The value thus obtained is substantially the same as the median size (D50) measured by a laser diffraction / scattering type particle size distribution measuring device. Therefore, the above-mentioned range of the average particle size can also be read as the range of the average particle size of the particles contained in the surface protective layer 5.

[0077] The amount of the particles added is preferably 0.5 parts by mass or more and 10 parts by mass or less, more preferably 2 parts by mass or more and 8 parts by mass or less, and even more preferably 2 parts by mass or more and 6 parts by mass or less, relative to 100 parts by mass of the ionizing radiation curable resin. When the amount of the particles is within the above range, the effect of generating wrinkles uniformly is particularly large.

[0078] The coating liquid for the surface protective layer may further contain a solvent and additives for improving the performance of the final product, such as an antibacterial agent and an antifungal agent. The coating liquid for the surface protective layer may further contain other additives such as an ultraviolet absorber and a light stabilizer. As the ultraviolet absorber, for example, a benzotriazole-based, benzoate-based, benzophenone-based, or triazine-based agent may be used. As the light stabilizer, for example, a hindered amine-based agent may be used. According to the method described herein, a surface protective layer 5 having a low gloss level can be formed without a gloss adjuster (matt additive).

[0079] The coating liquid for the surface protective 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.

[0080] The amount of initiator added is preferably 0.1 to 10 parts by mass, more preferably 0.25 to 8 parts by mass, and even more preferably 0.5 to 6 parts by mass, relative to 100 parts by mass of the ionizing radiation curable resin. If the amount of initiator is small, the effect of the first irradiation step described below is not significant. If the amount of initiator is too large, the coating film is completely cured by the first irradiation step, and wrinkles are not formed in the subsequent second irradiation step.

[0081] After forming a coating film made of the coating liquid for surface protection layer, a first irradiation step is preferably carried out. In the first irradiation step, light having a wavelength of about 200 nm or more and 400 nm or less (hereinafter referred to as first irradiation light) is irradiated to the coating film. This semi-cures the coating film. By semi-curing the coating film by carrying out the first irradiation step, it is possible to mass-produce and stabilize the wrinkled uneven structure (texture) generated by the second irradiation step described below. Alternatively, by appropriately setting the irradiation conditions of the first irradiation step, it is possible to adjust the uneven structure, in particular the depth of the uneven structure.

[0082] The light source used in the first irradiation step can be selected from, for example, a high-pressure mercury lamp, a metal halide lamp, and a single-wavelength LED lamp emitting light with a wavelength of 200 nm or more and 400 nm or less.

[0083] The cumulative light intensity of the first irradiation step is 2 mJ / cm 2 More than 100mJ / cm 2 It is preferable to set the dose to 10 mJ / cm or less. 2 More than 80mJ / cm 2 More preferably, it is 20 mJ / cm or less. 2 More than 60mJ / cm 2 It is more preferable to set the integrated light amount to the following value. If the integrated light amount is small, the effect of the first irradiation step described above will not be achieved. If the integrated light amount is large, the coating film will be completely cured, and wrinkles will not be formed in the subsequent second irradiation step.

[0084] Next, a second irradiation step is carried out. In the second irradiation step, the coating film is irradiated with light having a wavelength of 200 nm or less (hereinafter referred to as the second irradiation light). The ionizing radiation curable resin contained in the coating liquid for the surface protective layer has a large absorption coefficient for the second irradiation light. Therefore, the second irradiation light incident on the coating film can only reach a position several tens to several hundreds of nm away from the outermost surface. Therefore, in the second irradiation step, the crosslinking reaction proceeds in the surface region of the coating film to form an extremely thin cured film, while in other regions, the crosslinking reaction does not proceed and the coating film remains semi-cured.

[0085] The coating film after the second irradiation step has wrinkles on its surface corresponding to the ridge portions 5 B. The present inventors consider the reason why wrinkles are formed on the coating film surface by the second irradiation step to be as follows.

[0086] As described above, the second irradiation light can only reach a position several tens to several hundreds of nm away from the outermost surface of the coating film. That is, the crosslinking reaction of the ionizing radiation curable resin caused by the irradiation of the second irradiation light occurs only on the surface of the coating film. The monomers and the like present on the surface of the coating film form a cured film by crosslinking through the functional groups they possess when irradiated with the second irradiation light, but not all of these functional groups are used for crosslinking between the monomers present on the surface of the coating film. That is, uncrosslinked functional groups may remain in the cured film.

[0087] The second irradiation light does not reach the monomers present at positions away from the surface of the coating film, so the crosslinking reaction does not occur. However, some of the monomers present at positions away from the surface of the coating film migrate to the cured film, where they undergo crosslinking reaction. In this way, the number of molecules involved in the crosslinking reaction increases.

[0088] When the number of molecules involved in the crosslinking reaction on the coating surface increases, the volume of the cured film increases. Since the crosslinking reaction occurs only on the surface of the coating, the cured film cannot increase in volume in the thickness direction, but expands in the in-plane direction. As a result, wrinkles appear on the surface of the coating.

[0089] The second irradiation light can be extracted from excimer VUV (Vacuum Ultra Violet) light. Excimer VUV light can be produced from a lamp using a rare gas or a rare gas halide compound. When high-energy electrons are provided from the outside to a lamp containing a rare gas or a rare gas halide compound gas, a large number of discharge plasmas (dielectric barrier discharges) are generated. This plasma discharge excites the atoms of the discharge gas (rare gas), which momentarily enters an excimer state. When returning from this excimer state to the ground state, light in a wavelength range specific to that excimer is emitted.

[0090] The gas used in the excimer lamp may be any conventional gas that emits light of 200 nm or less. The gas may be a rare gas such as Xe, Ar, or Kr, or a mixed gas of a rare gas such as ArBr or ArF and a halogen gas. The wavelength (center wavelength) of the excimer lamp varies depending on the gas, and may be, for example, about 172 nm (Xe), about 126 nm (Ar), about 146 nm (Kr), about 165 nm (ArBr), or about 193 nm (ArF).

[0091] Considering the magnitude of photon energy and the difference between the wavelength and the 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.

[0092] The second irradiation step is carried out in an atmosphere with a low oxygen concentration. Oxygen has a large 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, more preferably 1000 ppm or less.

[0093] In addition, oxygen in the atmosphere inhibits radical polymerization. Therefore, the residual oxygen concentration in the reaction atmosphere affects the formation of wrinkles on the coating surface. Therefore, changing the residual oxygen concentration in the reaction atmosphere can also change the surface properties of the surface protective layer 5.

[0094] The cumulative light intensity of the second irradiation step is 0.5 mJ / cm 2 More than 200mJ / cm 2 It is preferable that the dose is 1 mJ / cm or less. 2 More than 100mJ / cm 2 More preferably, it is 3 mJ / cm or less. 2 More than 50mJ / cm 2 It is more preferable that the integrated light amount is less than 100 nm. If the integrated light amount is small, the expansion of the cured film in the in-plane direction is small. If the integrated light amount is large, the surface condition of the coating film is deteriorated.

[0095] After the second irradiation step is completed, the third irradiation step is carried out. In the third irradiation step, the coating film is irradiated with a third radiation or light to cure the entire coating film. As a result, the surface protective layer 5 is obtained.

[0096] The third radiation or exposure light is ionizing radiation such as an electron beam, or ultraviolet light having a longer wavelength compared to the second exposure light.

[0097] If the third radiation or irradiation light is ultraviolet light, its integrated light quantity is 10 mJ / cm 2 More than 500mJ / cm 2 It is preferable to set the dose to 50 mJ / cm or less. 2 More than 400mJ / cm 2 More preferably, it is 100 mJ / cm or less. 2 More than 300mJ / cm 2 It is even more preferable that:

[0098] <3> effect The decorative sheet 1 described with reference to Figures 1 to 3 has the above-mentioned surface properties in the surface protective layer 5. Such a decorative sheet 1 gives the user a rough tactile sensation when the user slides the skin over the surface of the surface protective layer 5, for example, when the user slides a finger over the surface of the surface protective layer 5. In other words, this decorative sheet 1 allows the user to sense the presence of large irregularities.

[0099] The decorative sheet 1, which provides a rough feel to the user, is suitable for use when the user has many opportunities to come into contact with the skin of the user and the article whose appearance is to be reproduced with the decorative sheet 1 is rough to the touch. Specifically, the decorative sheet 1 is suitable for use on furniture and the like.

[0100] Since the surface protective layer 5 of the decorative sheet 1 has the above-mentioned surface properties, it can achieve a low gloss even without containing a gloss regulator (matt additive). The gloss regulator reduces the oil repellency of the layer formed from the resin material, so that the surface protective layer containing the gloss regulator is prone to fingerprints. The surface protective layer 5 without the gloss regulator is less likely to absorb oil, so that fingerprints are less likely to be left on the surface. Furthermore, the surface protective layer 5 with excellent oil repellency is less likely to cause oil stains or adsorption of contaminants. Furthermore, the surface protective layer 5 without the gloss regulator does not lose the particles of the gloss regulator when its surface is scratched, and therefore the decorative sheet 1 containing such a surface protective layer 5 is less likely to cause gloss changes or scratches.

[0101] The reason why the surface protective layer 5 having the above-mentioned surface properties can be obtained by the above-mentioned method is as follows.

[0102] Oxygen in the gas phase not only absorbs short-wavelength ultraviolet rays, but also inhibits radical polymerization. The effect of oxygen in the gas phase on radical polymerization is greatest in the portion of the coating film made of ionizing radiation curable resin adjacent to the gas phase, and decreases as the distance from the coating film surface increases. Therefore, by changing the oxygen concentration in the gas phase in the second irradiation step, the relationship between the distance from the coating film surface and the progress of the crosslinking reaction can be changed.

[0103] If this relationship changes, the thickness of the cured film formed on the surface of the coating film by the second irradiation step and the degree of expansion of the cured film in the in-plane direction according to the progress of the crosslinking reaction will change. The thickness of the cured film and the degree of expansion of the cured film in the in-plane direction are also affected by the integrated light amount in the second irradiation step. The thickness of the cured film and the degree of expansion of the cured film in the in-plane direction also affect the surface properties of the surface protective layer. Furthermore, the thickness of the coating film also affects the formation of wrinkles.

[0104] Therefore, for example, by appropriately setting the composition of the ionizing radiation curable resin, the thickness of the coating film, the oxygen concentration in the gas phase in the second irradiation step, and the integrated light amount in the second irradiation step, a surface protection layer having desired surface properties can be obtained. EXAMPLES

[0105] In the following, examples of the present invention are described.

[0106] <Example 1> The decorative sheet 1 described with reference to Figures 1 to 3 was produced by the following method. In this example, the transparent resin layer 4, primer layer 6, adhesive layer 7 and concealing layer 8 were omitted.

[0107] First, the basis weight is 50g / m 2 The impregnated paper (GFR-506: manufactured by Kohjin Co., Ltd.) was prepared as the original fabric layer 2. On one side of the original fabric layer 2, a picture layer 3 was formed using an oil-based nitrocellulose resin-based gravure printing ink (PCNT (PCRNT) various colors: manufactured by Toyo Ink Co., Ltd.).

[0108] Next, a coating liquid for a surface protective layer was applied onto the design layer 3. The coating liquid for the surface protective layer was a mixture of the following ionizing radiation curable resin with the following particles and initiator: Ionizing radiation curable resin Type: Ethylene glycol diacrylate (9 moles of EO) Product name: Light Acrylate 9EG-A (Kyoeisha Chemical Co., Ltd.) Blend: 100 parts by mass ·particle Product name: Silica 250N (manufactured by Fuji Silysia Chemical) Particle size: 5μm Blend: 2 parts by mass Initiator Product name: Omnirad (registered trademark) 184 (manufactured by IGM Resins BV) Composition: 1 part by mass The coating film made of the coating liquid for surface protective layer was formed so as to have a thickness of 10 μm.

[0109] Thereafter, the first irradiation step was carried out. Specifically, the ultraviolet light was irradiated to the surface of the coating film made of the coating liquid for surface protection layer in the atmosphere using a high-pressure mercury lamp emitting ultraviolet light having a main wavelength of 365 nm at an integrated light amount of 100 mJ / cm. 2 Thus, the coating film was semi-cured.

[0110] Subsequently, the second irradiation step was carried out. Specifically, under atmospheric pressure and in a nitrogen gas atmosphere with an oxygen concentration of 500 ppm, ultraviolet rays having a wavelength of 172 nm were irradiated to the surface of the coating film made of the coating liquid for surface protective layer with an integrated light amount of 150 mJ / cm using a Xe excimer lamp. 2 This caused wrinkles to form on the surface of the coating film.

[0111] Subsequently, a third irradiation step was carried out. Specifically, the coating film was irradiated with ionizing radiation to cure the entire coating film, thereby forming a surface protective layer 5. In this manner, a decorative sheet 1 was obtained.

[0112] <Example 2> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: That is, in this example, the following ionizing radiation curable resin was used. ·Ionizing radiation curable resin Type: Trimethylolpropane EO modified triacrylate (EO 6 moles added) Product name: Miramer M3160 (Miwon) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protective layer at atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 500 ppm using a Xe excimer lamp at an integrated light intensity of 150 mJ / cm 2 The irradiation was performed so that

[0113] <Example 3> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: That is, in this example, the following ionizing radiation curable resin was used. ·Ionizing radiation curable resin Type: Trimethylolpropane EO modified triacrylate (EO 15 moles added) Product name: SR9035 (Sartomer) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protective layer at atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 500 ppm using a Xe excimer lamp at an integrated light intensity of 150 mJ / cm 2 The irradiation was performed so that

[0114] <Example 4> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: That is, in this example, the following ionizing radiation curable resin was used. ·Ionizing radiation curable resin Type: Trimethylolpropane EO modified triacrylate (EO 3 moles added) Product name: Miramer M3130 (Miwon) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protection 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 amount of 200 mJ / cm 2 The irradiation was performed so that

[0115] <Example 5> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: That is, in this example, the following ionizing radiation curable resin was used. ·Ionizing radiation curable resin Type: Trimethylolpropane PO modified triacrylate (6 moles of PO added) Product name: NK Ester A-TMPT-6PO (manufactured by Shin-Nakamura Chemical Co., Ltd.) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protective layer at atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 500 ppm using a Xe excimer lamp at an integrated light intensity of 150 mJ / cm 2 The irradiation was performed so that

[0116] <Example 6> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: That is, in this example, the following ionizing radiation curable resin was used. ·Ionizing radiation curable resin Type: Caprolactone-modified tris-(2-acryloxyethyl) isocyanurate (3 moles of caprolactone (CL) added) Product name: NK Ester A-9300-3CL (manufactured by Shin-Nakamura Chemical Co., Ltd.) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protection 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 amount of 200 mJ / cm 2 The irradiation was performed so that

[0117] <Example 7> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following ionizing radiation curable resin was used. The coating film made of the coating liquid for surface protective layer was formed to a thickness of 8 μm. ·Ionizing radiation curable resin Type: Trimethylolpropane EO modified triacrylate (EO 6 moles added) Product name: Miramer M3160 (Miwon) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protective layer at atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 500 ppm using a Xe excimer lamp at an integrated light intensity of 150 mJ / cm 2 The irradiation was performed so that

[0118] <Example 8> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following ionizing radiation curable resin was used. The coating film made of the coating liquid for surface protective layer was formed to a thickness of 15 μm. ·Ionizing radiation curable resin Type: Trimethylolpropane EO modified triacrylate (EO 6 moles added) Product name: Miramer M3160 (Miwon) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protection 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 amount of 200 mJ / cm 2 The irradiation was performed so that

[0119] <Example 9> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: That is, in this example, the following ionizing radiation curable resin was used. ·Ionizing radiation curable resin Type: Ethoxylated pentaerythritol tetraacrylate (35 moles of EO added) Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Co., Ltd.) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protection layer at atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 200 ppm using a Xe excimer lamp at an integrated light amount of 150 mJ / cm 2 The irradiation was performed so that

[0120] <Example 10> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: That is, in this example, the following ionizing radiation curable resin was used. ·Ionizing radiation curable resin Type: Ethoxylated pentaerythritol tetraacrylate (50 moles of EO added) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protection layer at atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 200 ppm using a Xe excimer lamp at an integrated light amount of 150 mJ / cm 2 The irradiation was performed so that

[0121] <Example 11> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: That is, in this example, the following ionizing radiation curable resin was used. ·Ionizing radiation curable resin Type: Ethoxylated pentaerythritol tetraacrylate (20 moles of EO added) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protective layer at atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 100 ppm using a Xe excimer lamp at an integrated light intensity of 200 mJ / cm 2 The irradiation was performed so that

[0122] <Example 12> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: That is, in this example, the following ionizing radiation curable resin was used. ·Ionizing radiation curable resin Type: propoxylated pentaerythritol tetraacrylate (PO35 moles added) The second irradiation step is carried out under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 200 ppm, by irradiating the surface of the coating film made of the coating liquid for the surface protective layer with ultraviolet light having a wavelength of 172 nm at an integrated light intensity of 150 mJ / cm using a Xe excimer lamp. 2 The irradiation was performed so that

[0123] <Example 13> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: That is, in this example, the following ionizing radiation curable resin was used. ·Ionizing radiation curable resin Type: Caprolactone-modified pentaerythritol tetraacrylate (CL 20 moles added) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protective layer at atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 100 ppm using a Xe excimer lamp at an integrated light intensity of 200 mJ / cm 2 The irradiation was performed so that

[0124] <Example 14> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following ionizing radiation curable resin was used. The coating film made of the coating liquid for surface protective layer was formed to a thickness of 8 μm. ·Ionizing radiation curable resin Type: Ethoxylated pentaerythritol tetraacrylate (35 moles of EO added) Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Co., Ltd.) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protection layer at atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 200 ppm using a Xe excimer lamp at an integrated light amount of 150 mJ / cm 2 The irradiation was performed so that

[0125] <Example 15> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following ionizing radiation curable resin was used. The coating film made of the coating liquid for surface protective layer was formed to a thickness of 15 μm. ·Ionizing radiation curable resin Type: Ethoxylated pentaerythritol tetraacrylate (35 moles of EO added) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protection 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 amount of 200 mJ / cm 2 The irradiation was performed so that

[0126] <Comparative Example 1> A decorative sheet was produced in the same manner as in Example 1, except for the following points: In this example, the coating liquid for the surface protective layer was a mixture of the following ionizing radiation curable resin and the following particles. ·Ionizing radiation curable resin Type: Trimethylolpropane EO modified triacrylate (EO 6 moles added) Product name: Miramer M3160 (Miwon) Blend: 100 parts by mass ·particle Product name: Silica 250N (manufactured by Fuji Silysia Chemical) Particle size: 5μm Blend: 15 parts by mass Then, the first and second irradiation steps were not carried out, and the coating film made of the coating liquid for forming a surface protective layer was cured only by the third irradiation step.

[0127] <Comparative Example 2> A decorative sheet was produced in the same manner as in Example 1, except for the following points: In this example, the coating liquid for the surface protective layer was a mixture of the following ionizing radiation curable resin and the following particles. ·Ionizing radiation curable resin Type: Ethoxylated pentaerythritol tetraacrylate (35 moles of EO added) Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Co., Ltd.) Blend: 100 parts by mass ·particle Product name: Silica 250N (manufactured by Fuji Silysia Chemical) Particle size: 5μm Blend: 15 parts by mass Then, the first and second irradiation steps were not carried out, and the coating film made of the coating liquid for forming a surface protective layer was cured only by the third irradiation step.

[0128] <Comparative Example 3> A decorative sheet was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following ionizing radiation curable resin was used. The coating film made of the coating liquid for the surface protective layer was formed to a thickness of 5 μm. ·Ionizing radiation curable resin Type: Trimethylolpropane EO modified triacrylate (EO 6 moles added) Product name: Miramer M3160 (Miwon) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protective layer at an integrated light intensity of 50 mJ / cm using a Xe excimer lamp in a nitrogen gas atmosphere with an oxygen concentration of 500 ppm under atmospheric pressure. 2 The irradiation was performed so that

[0129] <Comparative Example 4> A decorative sheet was produced in the same manner as in Example 1, except for the following points. That is, in this example, the following ionizing radiation curable resin was used. The coating film made of the coating liquid for the surface protective layer was formed to a thickness of 5 μm. ·Ionizing radiation curable resin Type: Ethoxylated pentaerythritol tetraacrylate (35 moles of EO added) Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Co., Ltd.) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protective 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 amount of 50 mJ / cm 2 The irradiation was performed so that

[0130] <Comparative Example 5> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: That is, in this example, the following ionizing radiation curable resin was used. ·Ionizing radiation curable resin Type: Epoxy ester (PO3 moles added) Product name: Epoxy Ester 200PA (Kyoeisha Chemical) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protective layer at atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 100 ppm using a Xe excimer lamp at an integrated light amount of 100 mJ / cm 2 The irradiation was performed so that

[0131] <Comparative Example 6> Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: That is, in this example, the following ionizing radiation curable resin was used. ·Ionizing radiation curable resin Type: Ethoxylated pentaerythritol tetraacrylate (4 moles of EO added) Product name: NK Ester ATM-4E (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) In the second irradiation step, ultraviolet rays having a wavelength of 172 nm are irradiated to the surface of the coating film made of the coating liquid for surface protective layer at atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 100 ppm using a Xe excimer lamp at an integrated light amount of 100 mJ / cm 2 The irradiation was performed so that

[0132] <Evaluation> Each of the above decorative sheets was subjected to the evaluations described below.

[0133] (1) Glossiness The glossiness was measured at 60 degrees using Rhopoint IQ (manufactured by Konica Minolta, Inc.) The "60 degree glossiness" in Tables 1 to 3 below indicates this 60 degree glossiness.

[0134] (2) Skin feel The skin feel was evaluated by the following method. First, we carried out advance preparations to ensure that the evaluation criteria were consistent across evaluators. Specifically, we prepared 10 standard test pieces with different surface properties. Next, we had each of the 20 evaluators blindfolded and slide their fingers over the surface of the standard test pieces, and then we had them classify the tactile sensations into the following five groups. Group 1: The presence of unevenness was clearly felt, and there was a strong roughness to the touch. Group 2: Rough texture (intermediate roughness between groups 1 and 3). Group 3: Slightly rough to the touch. Group 4: No roughness to the touch.

[0135] The above procedure was repeated until the ratings by each evaluator were consistent for three or more consecutive evaluations, and the ratings between the evaluators were consistent for three consecutive evaluations.

[0136] Next, for each of the decorative sheets, each of the evaluators was asked to slide their fingers over the surface of the surface protective layer while blindfolded, and then to classify the tactile sensation into the above-mentioned five groups. This procedure was then 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 times in a row. From these results, the skin sensation was evaluated according to the following criteria. AAA: Group 1 AA: 2nd group A: Group 3 B: Group 4.

[0137] (3) Fingerprint resistance As an evaluation of fingerprint resistance, the ability to wipe off fingerprints was evaluated. Specifically, first, the 60-degree gloss of the surface of each decorative sheet was measured, and this 60-degree gloss was taken as the initial gloss. Next, a fingerprint-resistant evaluation liquid was applied onto the surface protective layer, and the fingerprint-resistant evaluation liquid applied to the surface of the decorative sheet was wiped off. Here, a higher fatty acid was used as the fingerprint-resistant evaluation liquid. Then, the 60-degree gloss of the part where the fingerprint-resistant evaluation liquid was wiped off was measured, and this 60-degree gloss was taken as the gloss after wiping.

[0138] The fingerprint removal rate was calculated using the following formula: Fingerprint removal rate (%) = (glossiness after wiping / initial glossiness) x 100 The evaluation criteria were as follows. AA: 70% or more but less than 250% A: 50% or more but less than 70%, or 250% or more but less than 300% B: Less than 50% or more than 300%

[0139] (4) Resistance to contamination To evaluate the stain resistance, the stain A test specified in the Japanese Agricultural Standards (JAS) was carried out. That is, on the surface protective layer of each decorative sheet, a line of 10 mm width was drawn with blue ink, black quick-drying ink, and red crayon, and left for 4 hours. After that, the blue ink, black quick-drying ink, and red crayon lines were wiped off with a cloth soaked in ethanol.

[0140] The evaluation criteria were as follows. AA: Lines of each color could be easily wiped off. A: I was able to wipe off some of the lines of each color, but some stains remained. B: I couldn't wipe off the lines of each color.

[0141] (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 surface of the decorative sheet was visually inspected for scratches and changes in gloss.

[0142] The evaluation criteria were as follows. AA: No scratches or changes in gloss occurred on the surface. A: Minor scratches or changes in gloss have occurred on the surface. B: Significant scratches or changes in gloss occurred on the surface.

[0143] (6) Uniformity of surface condition To evaluate mass production stability, the uniformity of the surface condition with respect to the occurrence of irregularities was visually confirmed. The evaluation criteria were as follows. AA: The surface condition is uniform. A: The surface condition is generally uniform. B: The surface condition is uneven.

[0144] (7) Fourier-type infrared spectroscopy For the Fourier infrared spectroscopy, a Fourier infrared spectrometer (FT / IR-6300) manufactured by JASCO Corporation and a single reflection type (incident angle 45°) ATR unit (ATR PRO470-H) using a diamond prism with a sample contact area of ​​2 mmφ were used.

[0145] The measurement conditions were as follows. Measurement wave number range: 4000cm -1 From 400cm -1 Resolution: 4.0cm -1 Light source: Standard light source Detector: TGS Sample chamber: Standard Sensitivity (gain): 32x Aperture diameter: 7.1mm Interferometer measurement (scan speed): 2mm / sec Filter: 10000Hz Beam splitter: Ge / KBr Apodization function: Cosine Zero Filling: The optical system was then purged with nitrogen and an absorption spectrum was obtained after 160 cumulative measurements. Prior to measuring the absorption spectrum of the sample, a background measurement was performed under the same conditions as the measurement of the sample, except that nothing was brought into contact with the diamond prism and the measurement was performed after 320 cumulative measurements.

[0146] The obtained absorption spectrum was corrected by ATR using the "deep penetration depth" method using Spectra Manager Version 2 manufactured by JASCO Corporation. 1095 / I 1725 The value was calculated.

[0147] The results are shown in Tables 1 to 3 below.

[0148] [Table 1]

[0149] [Table 2]

[0150] [Table 3]

[0151] As shown in Tables 1 and 2, the decorative sheets according to Examples 1 to 15 gave the evaluators a rough feel. The decorative sheets according to Examples 1 to 15 also had low gloss and excellent fingerprint resistance and stain resistance. The decorative sheets according to Examples 2 to 15 also had excellent scratch resistance. The decorative sheets according to Examples 1 to 15 also had excellent uniformity of surface condition, and therefore had mass production stability.

[0152] In contrast, the decorative sheets according to Comparative Examples 1 to 6, although having excellent uniformity of surface condition, did not give the evaluators a rough feel to the touch, as shown in Table 3. Furthermore, the decorative sheets according to Comparative Examples 1, 2, 5, and 6 did not achieve low gloss, and furthermore, the decorative sheets according to Comparative Examples 1 and 2 were inferior in all of fingerprint resistance, stain resistance, and scratch resistance. [Explanation of symbols]

[0153] Reference Signs List: 1...decorative sheet, 2...base material layer, 3...pattern layer, 4...transparent resin layer, 5...surface protection layer, 6...primer layer, 7...adhesive layer, 8...concealing layer, 11...decorative material, B...base material.

Claims

1. A base fabric layer and a surface protective layer provided on one surface of the base fabric layer, a concave-convex structure including a plurality of ridge-like portions each protruding in a ridge shape is provided on a surface of the surface protection layer; The uneven structure of the surface protective layer has a protruding peak height Rpk of 3.5 μm or more, The absorption spectrum obtained by Fourier infrared spectroscopy of the surface protective layer has a wavelength of 1085 to 1105 cm －１ Maximum value in the wave number range I １０９５ and 1715 to 1735 cm －１ Maximum value in the wave number range I １７２５ Comparison with I １０９５ / I １７２５ A decorative sheet having a value of 0.65 or more.

2. The ratio I １０９５ / I １７２５ 2. The decorative sheet according to claim 1, wherein the .lambda. is 3.5 or less.

3. 3. The decorative sheet according to claim 1, wherein said protruding peak height Rpk is 25 μm or less.

4. 4. The decorative sheet according to claim 1, wherein the uneven structure of the surface protective layer has a mean length RSm of roughness curve elements of 150 μm or more.

5. The decorative sheet according to claim 4, wherein said average length RSm is 600 µm or less.

6. 6. The decorative sheet according to claim 1, wherein the surface protective layer has a thickness of 8 [mu]m or more.

7. 7. The decorative sheet according to claim 1, wherein the surface protective layer has a glossiness of less than 10.

0.

8. A decorative sheet as described in any one of claims 1 to 7, wherein at least a portion of the multiple ridge portions are adjacent to each other in the width direction, and at a position where at least a portion of the multiple ridge portions are adjacent to each other in the width direction, a cross section parallel to the width direction and the thickness direction of the surface protection layer has a sinusoidal shape in the portion where the uneven structure is provided.

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

10. 10. The decorative sheet according to claim 9, wherein the ionizing radiation curable resin is an acrylate containing a repeating structure as a main component, the repeating structure is any one of ethylene oxide, propylene oxide, and ε-caprolactone, and the number of repetitions of the repeating structure is 3 or more.

11. A decorative material comprising the decorative sheet according to any one of claims 1 to 10 and a substrate to which the decorative sheet is attached.

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