Decorative sheet

Abstract

To provide a decorative sheet having low glossiness due to matte effect and having excellent appearance.SOLUTION: There is provided a decorative sheet 1 which has a base material 2 and a surface layer 3 provided on the base material 2. The surface layer 3 is composed of an ultraviolet cured material layer 6 formed on a surface 2a of the base material 2 and an excimer light-cured material layer 7 formed on a surface 6a of the ultraviolet cured material layer 6. The surface layer 3 contains a urethane acrylate and a vinyl chloride-vinyl acetate copolymer, wherein the mass ratio between the urethane acrylate and the vinyl chloride-vinyl acetate copolymer in the surface layer, urethane acrylate:vinyl chloride-vinyl acetate copolymer is 100:2 to 100:60.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Decorative sheets are used to enhance the aesthetic appeal of various applications, such as wall coverings, joinery, fixtures and fittings, surface decoration of furniture, and exterior finishes for automobiles and low-voltage electrical equipment. Examples of such decorative sheets include those with a low-gloss (matte) layer on a base material.

[0003] For example, a decorative sheet has been proposed having a decorative layer containing a coloring agent on a substrate, and a clear layer on the decorative layer containing wet gel silica particles with an average particle size of 5 μm or less as measured by the Coulter counter method (AP50 μm). It has been stated that with such a configuration, even when there is a clear layer containing inorganic particles, it is possible to provide a decorative sheet that suitably retains the color of the colored layer and has a good matte surface (see, for example, Patent Document 1).

[0004] Furthermore, a decorative sheet has been proposed in which the gloss of the area of ​​the coating structure irradiated with electromagnetic waves on the surface of the coating structure provided on the substrate is reduced compared to before electromagnetic wave irradiation by irradiating the surface of the coating structure with excimer light irradiated from an excimer lamp. It is stated that this configuration makes it possible to provide a decorative sheet having areas with different levels of matte finish (see, for example, Patent Document 2). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2015-77691 [Patent Document 2] Japanese Patent Publication No. 2018-164901 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, the decorative sheet described in Patent Document 1 above has the problem that, because it merely incorporates silica particles into the clear layer, it does not provide a sufficient matte effect and does not easily exhibit low gloss.

[0007] Furthermore, in the decorative sheet described in Patent Document 2, silica particles or the like are not incorporated into the clear layer, and it is merely irradiated with excimer light, so a sufficient matte effect cannot be obtained, and an uneven surface is formed in the clear layer, which has the problem of reduced aesthetic appeal (design).

[0008] Therefore, the present invention has been made in view of the above problems, and aims to provide a decorative sheet that has low gloss due to a matte effect and is aesthetically pleasing. [Means for solving the problem]

[0009] To achieve the above objective, the decorative sheet of the present invention comprises a base material and a surface layer provided on the base material, wherein the surface layer is composed of an ultraviolet-cured material layer formed on the surface of the base material and an excimer photocured material layer formed on the surface of the ultraviolet-cured material layer, the surface layer contains urethane acrylate and vinyl chloride-vinyl acetate copolymer, and the mass ratio of urethane acrylate to vinyl chloride-vinyl acetate copolymer in the surface layer is urethane acrylate:vinyl chloride-vinyl acetate copolymer = 100:2 to 100:60. [Effects of the Invention]

[0010] The present invention makes it possible to provide a decorative sheet with excellent aesthetics, having low gloss and uniformly formed irregularities across the entire surface of the surface layer. [Brief explanation of the drawing]

[0011] [Figure 1] This is a cross-sectional view showing a decorative sheet according to an embodiment of the present invention. [Figure 2] This is a laser microscope image showing the surface condition of the surface layer of the decorative sheet in Example 1. [Figure 3] This is a laser microscope image showing the surface condition of the surface layer of the decorative sheet in Comparative Example 1. [Modes for carrying out the invention]

[0012] The decorative sheet of the present invention will be described in detail below. However, the present invention is not limited to the following embodiments, and can be modified and applied as appropriate without altering the essence of the invention.

[0013] <Decorative sheet> As shown in Figure 1, the decorative sheet 1 of the present invention comprises a base material 2 and a surface layer 3 provided on the surface 2a of the base material 2.

[0014] <Base material> The base material 2 consists of, for example, a thermoplastic resin sheet, and this thermoplastic resin sheet can be one that is normally used as the base material in decorative sheet 1. Specific examples include polyvinyl chloride sheets, glycol-modified polyethylene terephthalate (PETG) sheets, amorphous crystalline polyester resin (APET) sheets, polyolefin sheets (polyethylene sheets, polypropylene sheets, etc.), acrylonitrile butadiene styrene resin (ABS) sheets, polycarbonate sheets, etc. Furthermore, as an amorphous crystalline polyester resin (APET) sheet used in base material 2, recycled polyethylene terephthalate (RPET) sheets made from PET bottles and the like can be used.

[0015] As the thermoplastic resin sheet, from the viewpoint of being easy to perform secondary surface processing and having excellent three-dimensional formability, a glycol-modified polyethylene terephthalate sheet is preferred. The glycol-modified polyethylene terephthalate sheet is a kind of polyethylene terephthalate. While the glycol component of polyethylene terephthalate is ethylene glycol, it is an amorphous polyester containing, as the glycol component, in addition to ethylene glycol, a diol other than ethylene glycol (1,4-cyclohexanedimethanol).

[0016] Further, the thermoplastic resin sheet may be a stretched sheet or an unstretched sheet. Further, the thermoplastic resin sheet may contain additives such as a colorant, an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a storage stabilizer, a lubricant, and a filler, as necessary. Incidentally, from the viewpoint of design properties, the thermoplastic resin sheet is preferably colored.

[0017] The thickness of the base material 2 is not particularly limited, but is preferably 50 to 800 μm, and more preferably 250 to 500 μm. If the thickness of the base material 2 is 50 μm or more, the mechanical strength and the concealing property can be sufficiently improved. Further, if the thickness of the base material 2 is 800 μm or less, the three-dimensional formability is more excellent, and it becomes easier to ensure flexibility and printing suitability.

[0018] <Surface layer> The surface layer 3 is a coating film of a paint containing urethane acrylate and monofunctional acrylate as main components and containing a vinyl chloride-vinyl acetate copolymer.

[0019] This surface layer 3 can be formed by applying a paint containing a vinyl chloride-vinyl acetate copolymer onto the surface 2a of the base material 2 and curing it. The surface layer 3 is composed of an ultraviolet curable layer 6 formed on the surface 2a of the base material 2 and an excimer light curable layer 7 formed on the surface 6a of the ultraviolet curable layer 6.

[0020] Furthermore, as shown in Figure 1, wrinkles are formed on the surface 3a of the surface layer 3 (i.e., the surface opposite to the substrate 2 side).

[0021] As the urethane acrylate that forms the surface layer 3, 2 to 10 functional acrylates are used, such as phenylglycamicyl ether acrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, and dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer. Also, EBECRYL8402, KRM8452, EBECRYL210, EBECRYL220, EBECRYL4500, EBECRYL230, EBECRYL270, EBECRYL4858, EBECRYL8804, EBECRYL8807, EBECRYL9270, EBECRYL4100, EBECRYL4513, EBECRYL8311, EBECRYL8465, EBECRYL9260, EBECRYL8701, KRM8667, E Commercially available products such as BECRYL4265, EBECRYL4587, EBECRYL4200, EBECRYL8210, EBECRYL1290, EBECRYL5129, EBECRYL8254, EBECRYL8301R, KRM8200, KRM8904, RUA-062NS (containing a bifunctional acrylate monomer), U-6LPA, UA-1100H, U-200PA, UA-160TM, and UV-7600B (all product names) can be used. These urethane acrylates may be used individually or in combination of two or more types.

[0022] Furthermore, examples of monofunctional acrylates that form the surface layer 3 include ethyl carbitol acrylate, methoxyethylene glycol (meth)acrylate, methoxy polyethylene glycol (meth)acrylate, β-(meth)acryloyloxyethyl hydrogen phthalate, β-(meth)acryloyloxyethyl hydrogen succinate, nonylphenoxyethyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, phenoxyethyl (meth)acrylate, and phenoxypoly Ethylene glycol (meth)acrylate, butoxy polyethylene glycol (meth)acrylate, alkyl (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl Tylphthalic acid, 3-acryloyloxyglycerin mono(meth)acrylate, 2-hydroxybutyl(meth)acrylate, 2-hydroxy-1-(meth)acryloxy-3-(meth)acryloxypropane, polypropylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, poly-ε-caprolactone mono(meth)acrylate, dialkylaminoethyl(meth)acrylate, glycidyl(meth)acrylate, mono[2-(meth)acryloyloxyethyl]acidol Examples include phosphate, trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 2,2,3,4,4,4-hexafluorobutyl (meth)acrylate, perfluorooctylethyl (meth)acrylate, dicyclopentenyloxyalkyl (meth)acrylate, dicyclopentenyl (meth)acrylate, tricyclodecanyl (meth)acrylate, tricyclodecanyloxyethyl (meth)acrylate, and isobornyloxyethyl (meth)acrylate. These monofunctional acrylates may be used individually or in combination of two or more.

[0023] Furthermore, the mixing ratio of urethane acrylate and monofunctional acrylate in the surface layer 3 is not particularly limited as long as it does not impair the characteristics of the decorative sheet 1 of the present invention, but a mass ratio of urethane acrylate:monofunctional acrylate = 10:90 to 90:10 is preferred. This is because urethane acrylate has low fluidity, so if the mass ratio of urethane acrylate is large, wrinkles are less likely to occur on the surface 3a of the surface layer 3, and the low gloss due to the matte effect becomes less likely to occur. Also, monofunctional acrylate has low reactivity, so if the mass ratio of monofunctional acrylate is large, the paint hardening becomes less likely to occur.

[0024] Furthermore, the thickness T of the surface layer 3 is not particularly limited, but is preferably 1 to 45 μm, and more preferably 1 to 10 μm. If the thickness of the surface layer 3 is less than 1 μm, the movable coating area of ​​the vinyl chloride-vinyl acetate copolymer described later decreases during excimer irradiation, making it less likely for wrinkles to form and making it difficult to achieve a low gloss due to the matte effect. Also, if the thickness of the surface layer 3 is greater than 45 μm, the tactile properties decrease further and the hardness increases, which may reduce moldability. If the thickness of the surface layer 3 is greater than 10 μm, the surface roughness Sa of the surface layer 3 increases, which improves fingerprint resistance, but may reduce tactile properties.

[0025] In this invention, the decorative sheet 1 is characterized in that the mass ratio of urethane acrylate to vinyl chloride-vinyl acetate copolymer in the surface layer is urethane acrylate:vinyl chloride-vinyl acetate copolymer = 100:2 to 100:60.

[0026] With this configuration, irregularities are formed on the surface layer 3 by the vinyl chloride-vinyl acetate copolymer that does not have reactive groups, making it possible to form uniform irregularities across the entire surface 3a of the surface layer 3.

[0027] Furthermore, the mass ratio of urethane acrylate to vinyl chloride-vinyl acetate copolymer in the surface layer 3 is preferably urethane acrylate:vinyl chloride-vinyl acetate copolymer = 100:4 to 100:60.

[0028] Furthermore, if the content of vinyl chloride-vinyl acetate copolymer per 100 parts by mass of urethane acrylate in the surface layer 3 is less than 2 parts by mass, the amount of vinyl chloride-vinyl acetate copolymer is small, and therefore the formation of wrinkles by the vinyl chloride-vinyl acetate copolymer described later is not sufficiently promoted, making it difficult to form uniform irregularities across the entire surface 3a of the surface layer 3. Also, if the content of vinyl chloride-vinyl acetate copolymer per 100 parts by mass of urethane acrylate in the surface layer 3 is greater than 60 parts by mass, the monomer components are excessively absorbed by the vinyl chloride-vinyl acetate copolymer, causing it to lose fluidity. Therefore, the formation of wrinkles by the vinyl chloride-vinyl acetate copolymer described later is not sufficiently promoted, making it difficult to form uniform irregularities across the entire surface 3a of the surface layer 3.

[0029] Furthermore, the coating for forming the surface layer 3 may contain other components besides urethane acrylate, monofunctional acrylate, and vinyl chloride-vinyl acetate copolymer, to the extent that it does not impair the effects of the invention. Examples of other components include photopolymerization initiators, weathering agents, colorants, ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, preservative stabilizers, plasticizers, lubricants, and fillers.

[0030] For example, alkylphenone-based, acylphosphine oxide-based, and cationic initiators can be used as photopolymerization initiators. In addition, UV absorbers and light stabilizers can be used as weathering agents.

[0031] <Manufacturing method> When manufacturing the decorative sheet 1 of the present invention, first, a base material 2 made of the thermoplastic resin sheet described above is prepared. This thermoplastic resin sheet may be a commercially available product, or it may be manufactured by a known manufacturing method such as the calendering method or extrusion molding method.

[0032] Next, a coating containing a solvent, urethane acrylate, monofunctional acrylate, a photopolymerization initiator, and a vinyl chloride-vinyl acetate copolymer is applied to the surface 2a of the substrate 2 to form a coating film that will become the surface layer 3 on the surface 2a of the substrate 2.

[0033] Furthermore, when using a urethane acrylate containing a bifunctional acrylate monomer such as RUA-062NS mentioned above, the use of monofunctional acrylate can be omitted.

[0034] Furthermore, the method of coating the paint is not particularly limited and includes, for example, the cast coating method, die coating method, gravure coating method, roll knife coating method, reverse roll coating method, roll coating method, and comma coating method.

[0035] Next, the coating film formed on the surface 2a of the substrate 2 is irradiated with excimer light. More specifically, the coating film is irradiated with excimer light having a short peak wavelength (within the range of 120 to 230 nm). As a result, hardening occurs only on the outermost surface of the coating film, which will become the surface layer 3, and the excimer photocured material layer 7 described above is formed.

[0036] In this process, non-uniformity occurs between the surface and interior of the coating film, and coating components migrate from the unreacted portion inside the coating film to the surface, causing wrinkles to form on the surface of the coating film. As a result, it becomes possible to achieve low gloss (low gloss) in the surface layer 3. Furthermore, the vinyl chloride-vinyl acetate copolymer inside the coating film does not have reactive groups and easily migrates to the surface of the coating film (i.e., the excimer photocured product layer 7). Therefore, the vinyl chloride-vinyl acetate copolymer promotes the formation of the aforementioned wrinkles, creating irregularities on the surface. As a result, it becomes possible to uniformly form irregularities across the entire surface 3a of the surface layer 3.

[0037] Furthermore, when irradiating with excimer light using an excimer lamp, the peak wavelength of the electromagnetic wave can be changed by changing the discharge gas filled in the excimer lamp. Examples of discharge gases used to irradiate with excimer light of the above peak wavelength include Ar2 , Kr 2 Xe 2 The following can be used.

[0038] Then, by irradiating the coating with ultraviolet light (350-450 nm) to cure it, an ultraviolet-cured material layer 6 is formed, and a surface layer 3 is formed consisting of the ultraviolet-cured material layer 6 formed on the surface 2a of the substrate 2 and the excimer photocured material layer 7 formed on the surface 6a of the ultraviolet-cured material layer 6, and uniform irregularities are formed on the entire surface 3a of the surface layer 3. As a result, a decorative sheet 1 is manufactured that maintains low gloss due to excimer irradiation, while improving aesthetics due to the uniformly formed irregularities.

[0039] Furthermore, even if the coating is irradiated again with excimer light (within the range of 120-230 nm) instead of the ultraviolet light (350-450 nm) mentioned above, the coating will not completely harden.

[0040] Furthermore, in the decorative sheet 1 of the present invention, as described above, uniform irregularities are formed on the entire surface 3a of the surface layer 3 by the vinyl chloride-vinyl acetate copolymer, so that the standard deviation σ of the surface roughness Sa [μm] on the surface 3a of the surface layer 3 becomes 0.2 μm or less, making it possible to provide a decorative sheet 1 with excellent aesthetics.

[0041] The term "surface roughness Sa" used here refers to the "three-dimensional surface texture parameter (three-dimensional arithmetic mean roughness)" as defined in ISO 25178.

[0042] Furthermore, the "standard deviation σ of surface roughness Sa" indicates the extent of the surface roughness Sa (the variation in surface roughness Sa), and this standard deviation σ can be calculated using the method described later.

[0043] Furthermore, due to the matting effect caused by the wrinkles described above, the gloss level G on the surface 3a of the surface layer 3 of the decorative sheet 1 of the present invention becomes 5 or less, thus enabling low gloss.

[0044] The term "glossiness" used here refers to an indicator of low gloss, specifically the 60° glossiness measured according to the method compliant with JIS Z 8741:1997.

[0045] Furthermore, from the viewpoint of further improving low gloss and enhancing the aesthetic appeal, a gloss level G of 4 or less is preferable, and 3 or less is more preferable.

[0046] As described above, in the decorative sheet 1 of the present invention, the surface layer 3 contains urethane acrylate and vinyl chloride-vinyl acetate copolymer, and the mass ratio of urethane acrylate to vinyl chloride-vinyl acetate copolymer in the surface layer 3 is urethane acrylate:vinyl chloride-vinyl acetate copolymer = 100:2 to 100:60. Therefore, it is possible to provide a decorative sheet 1 with excellent aesthetics in which uniform irregularities are formed throughout the surface 3a of the surface layer 3.

[0047] Furthermore, the matting effect caused by the wrinkles mentioned above makes it possible to provide a decorative sheet 1 with low gloss. [Examples]

[0048] The present invention will be described below based on examples. However, the present invention is not limited to these examples, and these examples can be modified and altered in accordance with the spirit of the invention; such modifications do not exclude them from the scope of the invention.

[0049] The materials used to manufacture the decorative sheet are listed below. (1) Urethane acrylate: 9-functional urethane acrylate (manufactured by Mitsubishi Chemical Corporation, product name: UV-7620EA) (2) Monofunctional acrylate: Tetrahydrofurfuryl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., product name: Light Acrylate THF-A) (3) Vinyl chloride-vinyl acetate copolymer 1: (Manufactured by Kaneka Corporation, product name: HM515) (4) Vinyl chloride-vinyl acetate copolymer 2: (Manufactured by Kaneka Corporation, product name: T5HX) (5) Vinyl chloride-vinyl acetate copolymer 3: (Manufactured by Nisshin Chemical Industry Co., Ltd., product name: Solvine AL) (6) Vinyl chloride-vinyl acetate copolymer 4: (Manufactured by Nisshin Chemical Industry Co., Ltd., product name: Solvine CL) (7) Initiator 1: Alkylphenone-based photopolymerization initiator (manufactured by IGM Resins BV, trade name: Omnirad1173) (8) Reactive resin 1: Lauryl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., product name: Light Acrylate LA) (9) Reactive resin 2: Stearyl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., product name: Light Acrylate SA) (10) Reactive resin 3: Trimethylolpropaneethoxytriacrylate (manufactured by Daicel Ornex, product name: EBECRYL160S)

[0050] (Example 1) <Production of decorative sheets> First, a polyvinyl chloride sheet with a thickness of 350 μm was prepared as the base material. Next, the materials shown in Table 1 were blended to prepare the paint of Example 1 having the composition (parts by mass) shown in Table 1. This paint was applied to the surface of the base material using a bar coater and dried at 60°C for 1 minute to form a surface layer coating on the surface of the base material. Methyl ethyl ketone was used as the solvent for the paint.

[0051] Next, using an excimer irradiation device (manufactured by Ushio Inc., product name: 172nm Light Emission Unit, model: SUS1000), Xe was irradiated under a nitrogen atmosphere. 2 The coating was irradiated with excimer light (peak wavelength: 172 nm) using as the discharge gas. The integrated light intensity was 25 mJ / cm². 2 The irradiation intensity is 16 mW / cm². 2 The irradiation was applied in such a manner that it resulted in the following:

[0052] Then, using an ultraviolet irradiation device (I-Graphics Co., Ltd., 4kW high-pressure mercury lamp for ultraviolet curing (H04-L41)), ultraviolet light (main wavelength: 365nm) was irradiated onto the coating film to photo-cure the coating film, thereby forming a surface layer on the surface of the substrate and creating a decorative sheet. The ultraviolet irradiation was performed under conditions of an irradiation distance of 15cm and a lamp movement speed of 0.75m / min, with an irradiation dose of 200mJ / cm². 2 That's what I decided.

[0053] <Measuring Thickness> Next, the thickness T of the surface layer of the fabricated decorative sheet was measured using a digital microscope (Keyence Corporation, product name: VHX-5000) or a field emission scanning electron microscope (SEM) (Hitachi High-Technologies Corporation, product name: S-4800).

[0054] More specifically, the sheet was cut to expose the cross-section, and 10 locations with high and low coating heights were selected from the cross-section observed using a digital microscope (magnification: 500x) or a field emission scanning electron microscope (magnification: 1000x). The thickness was measured, and the average value was calculated. The above measurement was performed three times, and the average value of the coating heights from the three measurements was calculated and defined as the surface layer thickness T. The results are shown in Table 1.

[0055] <Measurement of glossiness> Next, the gloss level G at 60° on the surface layer of the fabricated decorative sheet was measured using a gloss meter (manufactured by Horiba, Ltd., product name: Gloss Checker IG-320) in accordance with JIS Z 8741:1997. This measurement was performed five times, and the average value of the gloss levels from these five measurements was calculated and defined as the gloss level G of the surface layer.

[0056] Furthermore, using the five gloss measurements, the standard deviation σ G The following was calculated. More specifically, the gloss levels measured five times were designated as G1, G2, G3, G4, and G5, and the result was obtained using the following formula (1). The results are shown in Table 1.

[0057]

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[0058] <Measurement of surface roughness> Next, the surface roughness Sa of the surface layer of the produced decorative sheet (the surface roughness on the surface of the surface layer opposite to the substrate side) was measured using a shape analysis laser microscope (manufactured by Keyence Corporation, product name: VK-X1000) in accordance with ISO 25178. A 404 nm semiconductor laser was used as the laser type, and a range of 277 μm × 208 μm was measured using a standard objective lens with a magnification of 50 times. In addition, the above measurement was performed 10 times, and the average value of the surface roughness Sa for 10 times was calculated and taken as the surface roughness Sa in the surface layer.

[0059] Also, the standard deviation σ was calculated using the measured surface roughness Sa for 10 times. More specifically, the measured surface roughness for 10 times was taken as Sa1, Sa2, Sa3, Sa4, Sa5, Sa 6, Sa7, Sa8, Sa9, Sa 10 and was obtained using the following formula (2). The above results are shown in Table 1. <​​​​​​​​​​​​​​​​​​​​​

[0064] Figure 3 shows a laser microscope image illustrating the surface condition of the surface layer of the decorative sheet in Comparative Example 1. As shown in Figure 3, the decorative sheet in Comparative Example 1 has uneven irregularities, indicating a decrease in aesthetic appeal (design quality).

[0065] (Comparative Examples 5-6) Except for changing the composition of the paint components to the composition (parts by mass) shown in Table 2, an attempt was made to produce a decorative sheet in the same manner as in Example 1 described above. However, in Comparative Examples 5 and 6, the content of vinyl chloride-vinyl acetate copolymer per 100 parts by mass of urethane acrylate in the surface layer was greater than 60 parts by mass. As a result, the vinyl chloride-vinyl acetate copolymer did not dissolve in the solvent (methyl ethyl ketone), and it was not possible to produce a paint.

[0066] Therefore, in Comparative Examples 5 and 6, it was not possible to measure thickness, gloss, or surface roughness.

[0067] [Table 1]

[0068] [Table 2]

[0069] As shown in Table 1, the decorative sheets of Examples 1 to 11 have a glossiness of 5 or less on the surface layer, thus exhibiting low gloss, and the standard deviation of the surface roughness Sa is 0.2 μm or less, resulting in a uniform uneven surface across the entire surface of the surface layer, which is evident in their excellent aesthetic appearance.

[0070] On the other hand, as shown in Table 2, in the decorative sheets of Comparative Examples 1 to 3, the surface layer does not contain a vinyl chloride-vinyl acetate copolymer, but rather a reactive resin (a resin with reactive groups). As a result, the reactive resin does not migrate to the surface of the coating film, and wrinkle formation is not sufficiently promoted. Consequently, the standard deviation of the surface roughness Sa is greater than 0.2 μm, resulting in uneven surface irregularities across the entire surface of the surface layer, which is unsightly.

[0071] Furthermore, in Comparative Example 4, since the content of vinyl chloride-vinyl acetate copolymer per 100 parts by mass of urethane acrylate in the surface layer is less than 2 parts by mass, the formation of wrinkles by the vinyl chloride-vinyl acetate copolymer is not sufficiently promoted, the standard deviation of the surface roughness Sa becomes larger than 0.2 μm, and unevenness is formed throughout the surface of the surface layer, resulting in poor aesthetics. [Industrial applicability]

[0072] As described above, the present invention is suitable for decorative sheets. [Explanation of symbols]

[0073] 1 Decorative sheet 2 Base material 2a Surface of the substrate 3 Surface layer 3a Surface of the surface layer 6 UV cured layer 6a Surface of the UV-cured layer 7 Excimer photocured material layer T Surface layer thickness

Claims

1. A substrate; a surface layer provided on the substrate; Equipped with the surface layer is composed of an ultraviolet-cured material layer formed on the surface of the base material and an excimer light-cured material layer formed on the surface of the ultraviolet-cured material layer, the surface layer contains urethane acrylate and vinyl chloride-vinyl acetate copolymer, The glossiness of the surface layer is 5 or less, A decorative sheet characterized in that the standard deviation of the surface roughness of the surface layer on the surface opposite to the substrate side is 0.2 μm or less.

2. The surface roughness of the surface layer is 0.6 μm or more and 1.0 μm or less, 2. The decorative sheet according to claim 1, wherein the product of the glossiness of said surface layer and the surface roughness of said surface layer is 2.0 or more and 3.0 or less.

3. The standard deviation of the surface roughness of the surface layer is 0.01 μm or more and 0.07 μm or less, 3. The decorative sheet according to claim 1, wherein the product of the glossiness of said surface layer and the standard deviation of the surface roughness of said surface layer is 0.03 or more and 0.21 or less.

4. A decorative sheet as described in claim 1 or claim 2, characterized in that the substrate is a colored thermoplastic resin sheet.

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