Decorative sheet and decorative material using the same

Abstract

To suppress deterioration over time due to ultraviolet rays in a decorative sheet formed by laminating a layer containing a polypropylene-based resin.SOLUTION: A decorative sheet 100 includes a surface protective layer 10, a transparent resin layer 20, and a substrate layer 40 in this order. The substrate layer 40 contains a polypropylene-based resin. At least one of the surface protective layer 10 and the transparent resin layer 20 contains an ultraviolet absorber. The absorbance A1 at a wavelength of 270 nm or more and 300 nm or less of the surface protective layer 10 and the transparent resin layer 20 is 2.7 or more as measured according to JIS K0115:2004. The absorbance A2 at a wavelength of 360 nm or more and 380 nm or less of the surface protective layer 10 and the transparent resin layer 20 is 0.3 or more as measured according to JIS K0115:2004.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a decorative sheet and a decorative material using the same. [Background technology]

[0002] Decorative sheets have been used to decorate or protect the surfaces of interior and exterior building components, furniture, fixtures, home appliances, etc. Decorative sheets have a configuration that includes, for example, a surface protective layer on a substrate.

[0003] Decorative sheets are sometimes used in places exposed to sunlight, such as outdoors or indoors near windows. When decorative sheets are used in places exposed to sunlight, the color tone of the decorative sheet changes and the resin deteriorates due to the effects of ultraviolet rays. For this reason, ultraviolet absorbers are added to the surface protective layer of decorative sheets in order to improve the weather resistance of the decorative sheets.

[0004] However, there is a problem in that the ultraviolet absorber tends to bleed out from the surface protective layer over time. When the ultraviolet absorber bleeds out from the surface protective layer, the aesthetic appearance of the decorative sheet surface is impaired, and the concentration of the ultraviolet absorber in the surface protective layer decreases over time, resulting in insufficient weather resistance. To solve the problem of ultraviolet absorber bleed-out, for example, Patent Document 1 has been proposed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-117905 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0006] The decorative sheet of Patent Document 1 contains an electron beam reactive ultraviolet absorber selected from specific benzotriazole compounds, etc., in a cured layer of a resin whose main component is an electron beam curable resin. The decorative sheet of Patent Document 1 can solve the problem of ultraviolet absorber bleeding out.

[0007] On the other hand, decorative sheets are often required to be suitable for processing such as embossing, folding, and molding, and in recent years, decorative sheets have been proposed in which a layer containing a polypropylene-based resin, which has excellent processability, is laminated and then a surface protective layer is laminated thereon. When the surface protective layer of Patent Document 1 is applied to a decorative sheet formed by laminating such a layer containing a polypropylene-based resin, there have been many cases in which deterioration of the decorative sheet over time due to ultraviolet rays cannot be suppressed, even if the bleed-out of the ultraviolet absorber in the surface protective layer is suppressed.

[0008] The present invention was made under these circumstances, and aims to suppress deterioration over time due to ultraviolet rays in a decorative sheet formed by laminating layers containing polypropylene-based resins, and in a decorative material using the same. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides the following [1] and [2]. [1] A decorative sheet having a surface protective layer, a transparent resin layer, and a substrate layer in this order, the base layer contains a polypropylene-based resin, at least one of the surface protective layer and the transparent resin layer contains an ultraviolet absorber; the absorbance A1 of the surface protective layer and the transparent resin layer at a wavelength of 270 nm or more and 300 nm or less, measured in accordance with JIS K0115:2004, is 2.7 or more; the absorbance A2 of the surface protective layer and the transparent resin layer at a wavelength of 360 nm or more and 380 nm or less, measured in accordance with JIS K0115:2004, is 0.3 or more; Decorative sheet. [2] A decorative material having an adherend and the decorative sheet described in [1] above. [Effects of the Invention]

[0010] According to the present invention, deterioration over time due to ultraviolet rays can be suppressed in a decorative sheet formed by laminating layers containing a polypropylene-based resin. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view showing one embodiment of the decorative sheet of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Decorative sheet] The decorative sheet of the present invention comprises a surface protective layer, a transparent resin layer, and a substrate layer in this order, the base layer contains a polypropylene-based resin, at least one of the surface protective layer and the transparent resin layer contains an ultraviolet absorber; the absorbance A1 of the surface protective layer and the transparent resin layer at a wavelength of 270 nm or more and 300 nm or less, measured in accordance with JIS K0115:2004, is 2.7 or more; The absorbance A2 of the surface protective layer and the transparent resin layer at a wavelength of 360 nm or more and 380 nm or less, measured in accordance with JIS K0115:2004, is 0.3 or more.

[0013] In this specification, "the absorbance A1 of the surface protective layer and the transparent resin layer at a wavelength of 270 nm or more and 300 nm or less, measured in accordance with JIS K0115:2004" may be referred to as "absorbance A1," "the absorbance A2 of the surface protective layer and the transparent resin layer at a wavelength of 360 nm or more and 380 nm or less, measured in accordance with JIS K0115:2004" may be referred to as "absorbance A2," and "the absorbance A3 of the surface protective layer and the transparent resin layer at a wavelength of 310 nm, measured in accordance with JIS K0115:2004" may be referred to as "absorbance A3."

[0014] FIG. 1 is a cross-sectional view showing an embodiment of a decorative sheet 100 of the present invention. The decorative sheet 100 in Fig. 1 has, in this order, a surface protective layer 10, a transparent resin layer 20 containing a polypropylene-based resin, and a base layer 40 also containing a polypropylene-based resin. The surface protective layer 10 of the decorative sheet 100 in Fig. 1 is composed of a top coat layer 11 and a primer layer 12. The decorative sheet 100 in Fig. 1 also has a decorative layer 30 between the base layer 40 and the transparent resin layer 20.

[0015] <Absorbance> The decorative sheet of the present invention has an absorbance A1 of 2.7 or more at a wavelength of 270 nm or more and 300 nm or less, and an absorbance A2 of 0.3 or more at a wavelength of 360 nm or more and 380 nm or less. Polypropylene-based resins absorb ultraviolet light with wavelengths of 270 nm to 300 nm, causing significant degradation. Therefore, increasing the UV cutoff rate for wavelengths of 270 nm to 300 nm is thought to suppress degradation of the polypropylene-based resin in the base layer and improve the weather resistance of the decorative sheet. However, research by the present inventors has revealed frequent cases where the weather resistance of decorative sheets is not satisfactory, even when the UV cutoff rate for wavelengths of 270 nm to 300 nm is increased. The present inventors have discovered that this is due to changes in the UV absorption wavelength range caused by degraded polypropylene-based resins, etc. They have also discovered that the weather resistance of decorative sheets containing polypropylene-based resin base layers can be improved by considering the absorbance for wavelengths of 360 nm to 380 nm in addition to the absorbance for wavelengths of 270 nm to 300 nm.

[0016] If the absorbance A1 is less than 2.7 or the absorbance A2 is less than 0.3, the weather resistance of the decorative sheet cannot be improved. The absorbance A1 is preferably 3.0 or more, more preferably 3.4 or more, and even more preferably 3.8 or more. If the absorbance A1 is too high, the ultraviolet absorber may bleed out. Therefore, the absorbance A1 is preferably 6.0 or less, more preferably 5.7 or less, and even more preferably 5.5 or less. The absorbance A2 is preferably 0.4 or more, more preferably 0.5 or more, and even more preferably 0.6 or more. If the absorbance A2 is too high, the ultraviolet absorber may bleed out. Therefore, the absorbance A2 is preferably 1.5 or less, more preferably 1.0 or less, and even more preferably 0.8 or less.

[0017] The absorbances A1 and A2 are both the absorbances of the surface protective layer and the transparent resin layer. In other words, the absorbances A1 and A2 are not the absorbances of the surface protective layer alone, nor the absorbances of the transparent resin layer alone, but the combined absorbances of the surface protective layer and the transparent resin layer. In the present invention, the absorbances A1 and A2 refer to the combined absorbances of the surface protective layer and the transparent resin layer, so that it is possible to prevent an excessive amount of ultraviolet absorber from being contained in either the surface protective layer or the transparent resin layer. Therefore, in the present invention, it is possible to easily prevent the bleed-out of the ultraviolet absorber.

[0018] The absorbance A1 and the absorbance A2 can be adjusted, for example, by the content ratio of the ultraviolet absorber and the thickness of the layer containing the ultraviolet absorber. In order to easily achieve an absorbance A1 of 2.7 or more and an absorbance A2 of 0.3 or more, it is preferable that the ultraviolet absorber contains two or more ultraviolet absorbers having different maximum absorption wavelengths.

[0019] The absorbance A1 can be measured, for example, as follows. First, a laminate is prepared by forming a surface protective layer on a transparent resin layer. Then, in accordance with JIS K0115:2004, the average absorbance of the laminate measured at wavelengths of 270 nm to 300 nm can be defined as absorbance A1. The average absorbance at wavelengths of 270 to 300 nm is defined as the average absorbance measured at 1 nm intervals (31 absorbance values ​​in total) at wavelengths of 270 nm to 300 nm. The absorbance A2 can be calculated as the average value of the absorbance measured at a wavelength of 360 nm or more and 380 nm or less for the laminate in accordance with JIS K0115: 2004. The average value of the absorbance at a wavelength of 360 nm or more and 380 nm or less is the average value of the absorbance measured at 1 nm intervals for a wavelength of 360 nm or more and 380 nm or less (a total of 21 absorbance values).

[0020] As described above, the absorbance A1 and the absorbance A2 refer to the combined absorbance of the surface protective layer and the transparent resin layer. When the absorbance of the surface protective layer is defined as absorbance A1I and the absorbance of the transparent resin layer is defined as absorbance A1II, it is preferable that the absorbance A1I and the absorbance A1II are in the following ranges. To prevent deterioration of the transparent resin layer, the absorbance A1I is preferably 0.5 or more, more preferably 1.0 or more, and even more preferably 1.5 or more. If the absorbance A1I is too high, the ultraviolet absorber may bleed out from the surface protective layer or the hardness of the surface protective layer may decrease. Therefore, the absorbance A1I is preferably 5.0 or less, more preferably 4.5 or less, and even more preferably 4.0 or less. The absorbance A1II is preferably 0.5 or more, more preferably 1.0 or more, and even more preferably 1.5 or more. If the absorbance A1II is too high, the ultraviolet absorber may bleed out from the transparent resin layer. Therefore, the absorbance A1II is preferably 5.5 or less, more preferably 5.0 or less, and even more preferably 4.5 or less. The absorbance A1I is obtained by measuring the absorbance A1II of the transparent resin layer at a wavelength of 270 nm or more and 300 nm or less in accordance with JIS K0115:2004, and subtracting the absorbance A1II from the absorbance A1 (absorbance A1I = absorbance A1 - absorbance A1II). The absorbance A1II is the average value of the absorbances measured at a wavelength of 270 nm or more and 300 nm or less on the transparent resin layer.

[0021] When the absorbance of the surface protective layer and the absorbance of the transparent resin layer are defined as absorbance A2I and A2II, respectively, it is preferable that the absorbances A2I and A2II are within the following ranges. To prevent deterioration of the transparent resin layer, the absorbance A2I is preferably 0.15 or more, more preferably 0.2 or more, and even more preferably 0.25 or more. If the absorbance A2I is too high, the ultraviolet absorber may bleed out of the surface protective layer or the hardness of the surface protective layer may decrease. Therefore, the absorbance A2I is preferably 1.2 or less, more preferably 0.9 or less, and even more preferably 0.7 or less. The absorbance A2II is preferably 0.05 or more, more preferably 0.07 or more, and even more preferably 0.09 or more. If the absorbance A2II is too high, the ultraviolet absorber may bleed out from the transparent resin layer. Therefore, the absorbance A2II is preferably 1.3 or less, more preferably 1.0 or less, and even more preferably 0.8 or less. The absorbance A2I is determined by measuring the absorbance A2II of the transparent resin layer at a wavelength of 360 nm or more and 380 nm or less in accordance with JIS K0115:2004, and subtracting the absorbance A2II from the absorbance A2 (absorbance A2I = absorbance A2 - absorbance A2II). Note that the absorbance A2II is the average value of the absorbances measured at a wavelength of 360 nm or more and 380 nm or less on the transparent resin layer.

[0022] To improve weather resistance, the decorative sheet of the present invention preferably has an absorbance A3 at a wavelength of 310 nm of 1.1 or more, more preferably 1.6 or more, and even more preferably 2.0 or more. If the absorbance A3 is too high, the ultraviolet absorber may bleed out. For this reason, the absorbance A3 is preferably 3.0 or less, more preferably 2.8 or less, and even more preferably 2.6 or less.

[0023] When the absorbance of the surface protective layer is defined as absorbance A3I and the absorbance of the transparent resin layer is defined as absorbance A3II, it is preferable that the absorbance A3I and the absorbance A3II are in the following ranges. To prevent deterioration of the transparent resin layer, the absorbance A3I is preferably 0.3 or more, more preferably 0.5 or more, and even more preferably 0.7 or more. If the absorbance A3I is too high, the ultraviolet absorber may bleed out of the surface protective layer or the hardness of the surface protective layer may decrease. Therefore, the absorbance A3I is preferably 2.8 or less, more preferably 2.5 or less, and even more preferably 2.2 or less. The absorbance A3II is preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.3 or more. If the absorbance A3II is too high, the ultraviolet absorber may bleed out from the transparent resin layer. Therefore, the absorbance A3II is preferably 2.7 or less, more preferably 2.5 or less, and even more preferably 2.3 or less. The absorbance A3I is obtained by measuring the absorbance A3II of the transparent resin layer at a wavelength of 310 nm in accordance with JIS K0115:2004 and subtracting the absorbance A3II from the absorbance A3 (absorbance A3I = absorbance A3 - absorbance A3II).

[0024] <Surface protective layer> The surface protective layer is a layer located on the surface of the transparent resin layer opposite to the substrate layer, and may be formed as a single layer or as two or more layers as shown in FIG. In this specification, the layer of the surface protective layer that is farthest from the transparent resin layer is referred to as the "top coat layer." That is, when the surface protective layer is formed from a single layer, the surface protective layer has a single-layer structure of the top coat layer. When the surface protective layer is formed from two or more layers, the layer located between the top coat layer and the transparent resin layer means a layer other than the top coat layer among the layers that make up the surface protective layer. The top coat layer preferably contains a cured product of a curable resin composition.

[0025] The surface protective layer preferably includes a top coat layer and a primer layer located closer to the transparent resin layer than the top coat layer. By forming the surface protective layer from the top coat layer and the primer layer and incorporating an ultraviolet absorber in both the top coat layer and the primer layer, it is possible to suppress deterioration over time due to ultraviolet light while also making it easier to suppress bleeding out of the ultraviolet absorber.

[0026] The surface protective layer is mainly made of resin. It is preferable that the resin constituting the surface protective layer does not substantially contain a polypropylene-based resin. By substantially not containing a polypropylene-based resin as the resin constituting the surface protective layer, it is preferable in that the weather resistance of the surface protective layer can be easily improved. "Substantially free of polypropylene-based resin" means that the proportion of polypropylene-based resin relative to the total resin components constituting the surface protective layer is 1% by mass or less, preferably 0.1% by mass or less, more preferably 0.01% by mass or less, and even more preferably 0% by mass.

[0027] <Ultraviolet absorber> The decorative sheet must contain an ultraviolet absorber in at least one of the surface protective layer and the transparent resin layer, and preferably contains an ultraviolet absorber in both the surface protective layer and the transparent resin layer. When the surface protective layer is formed from two or more layers, it is preferable that the ultraviolet absorber is contained in at least the top coat layer, and it is more preferable that the ultraviolet absorber is contained in all layers constituting the surface protective layer. The following embodiments regarding the ultraviolet absorber are common to the ultraviolet absorber in the surface protective layer and the ultraviolet absorber in the transparent resin layer unless otherwise specified.

[0028] In order to make it easier to set the absorbance A1 and absorbance A2 within a predetermined range, the decorative sheet preferably contains two or more types of ultraviolet absorbents with different maximum absorption wavelengths. When the ultraviolet absorber having a smaller maximum absorption wavelength of the two types of ultraviolet absorbents is defined as ultraviolet absorber 1 and the ultraviolet absorber having a larger maximum absorption wavelength is defined as ultraviolet absorber 2, the maximum absorption wavelengths of ultraviolet absorber 1 and ultraviolet absorber 2 are preferably in the following ranges. The maximum absorption wavelength of UV absorber 1 is preferably 270 nm or more and 310 nm or less, more preferably 280 nm or more and 300 nm or less, and the maximum absorption wavelength of UV absorber 2 is preferably 330 nm or more and 370 nm or less, more preferably 340 nm or more and 360 nm or less.

[0029] Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, and triazine-based ultraviolet absorbers, with triazine-based ultraviolet absorbers being preferred. Among the triazine-based ultraviolet absorbers, hydroxyphenyltriazine-based ultraviolet absorbers are preferred from the viewpoint of weather resistance. That is, the decorative sheet of the present invention preferably contains a triazine-based ultraviolet absorber in at least one of the surface protective layer and the transparent resin layer, and more preferably contains a hydroxyphenyltriazine-based ultraviolet absorber in at least one of the surface protective layer and the transparent resin layer. Moreover, ultraviolet absorbers having a reactive functional group such as a (meth)acryloyl group, a vinyl group, or an allyl group are preferred because they are more likely to suppress bleeding out.

[0030] Examples of the hydroxyphenyltriazine-based ultraviolet absorber include those represented by the following general formula (1).

[0031] [ka]

[0032] In general formula (1), R 11 is a divalent organic group, and R 12 is -OC(=O)R 15 and R 13 , R 14 and R 15 are each independently a hydrogen atom or a monovalent organic group, and n 11 and n 12 are each independently an integer of 0 to 5. 13 and R 14 When there are multiple, they may be the same or different. R 11 Examples of the divalent organic group include aliphatic hydrocarbon groups such as alkylene groups and alkenylene groups, and from the viewpoint of weather resistance, alkylene groups are preferred, and the number of carbon atoms therein is preferably 1 or more, more preferably 2 or more, and the upper limit is preferably 16 or less, more preferably 12 or less, even more preferably 8 or less, and particularly preferably 4 or less. These aliphatic hydrocarbon groups may be linear, branched, or cyclic, and from the viewpoint of weather resistance, linear or branched groups are preferred, and linear groups are more preferred.

[0033] R 13 and R 14 From the viewpoint of weather resistance, R is preferably a hydrogen atom. 13 and R 14 When is a monovalent organic group, preferred examples include an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, and an arylalkyl group. From the viewpoint of weather resistance, aromatic hydrocarbon groups such as an aryl group and an arylalkyl group are preferred, and an aryl group, particularly a phenyl group, is preferred. R 15 From the viewpoint of weather resistance, R is preferably a monovalent organic group, and preferred examples thereof include an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, and an arylalkyl group. From the viewpoint of weather resistance, R is more preferably an aliphatic hydrocarbon group such as an alkyl group or an alkenyl group, and even more preferably an alkyl group. 15When the monovalent organic group is an aliphatic hydrocarbon group such as an alkyl group or an alkenyl group, it may be linear, branched, or cyclic, and is preferably linear or branched from the viewpoint of weather resistance. From the viewpoint of weather resistance, the number of carbon atoms is preferably 2 or more, more preferably 4 or more, and the upper limit is preferably 16 or less, more preferably 12 or less, and even more preferably 10 or less.

[0034] Further, examples of the hydroxyphenyltriazine-based ultraviolet absorbers include those represented by the following general formula (2). The hydroxyphenyltriazine compound represented by general formula (2) does not contain an ester bond in the molecule, and therefore the molecular structure is less likely to be distorted. Therefore, the hydroxyphenyltriazine compound represented by general formula (2) is preferable to the hydroxyphenyltriazine compound represented by general formula (1) in that it is superior in suppressing bleed-out and maintaining long-term weather resistance. The change in molecular structure originating from the ester bond is believed to be caused by acidic conditions, and therefore the hydroxyphenyltriazine compound represented by general formula (2) can exhibit excellent effects when used outdoors where it is exposed to acid rain.

[0035] [ka]

[0036] In general formula (2), R 21 is a monovalent organic group, and R 21 is a hydrogen atom or a monovalent organic group, and R 22 and R 23 are each independently a hydroxyl group or a monovalent organic group, and n 21 , n 22 and n 23 are each independently an integer of 1 to 5. 21 , R 22 and R 23 When there are multiple, they may be the same or different.

[0037] R 21 , R 22 and R 23The monovalent organic group is R 13 , R 14 In terms of weather resistance, aliphatic hydrocarbon groups such as alkyl groups and alkenyl groups are more preferred, and alkyl groups are even more preferred. 21 , R 22 and R 23 The monovalent organic group may be linear, branched, or cyclic, and is preferably linear or branched from the viewpoint of weather resistance, and more preferably linear. The number of carbon atoms is preferably 2 or more, more preferably 3 or more, and the upper limit is preferably 16 or less, more preferably 12 or less, and even more preferably 8 or less, from the viewpoint of weather resistance. Also, n 21 , n 22 and n 23 is preferably 2 or more, and multiple R 21 , R 22 and R 23 may be the same or different, and from the viewpoint of weather resistance, multiple R 21 are preferably the same, and R 22 and R 23 It is preferable that R 22 and R 23 Preferably, one of R is a hydrogen atom. 21 , R 22 and R 23 When is a monovalent organic group, it is preferable that they are the same organic group.

[0038] The content of the ultraviolet absorber in the surface protective layer is not particularly limited as long as the absorbances A1 and A2 are within the above ranges. By setting the content of the ultraviolet absorber in the surface protective layer to a predetermined amount or more, it is possible to easily set the absorbances A1 and A2 within the above ranges. Furthermore, by setting the content of the ultraviolet absorber in the surface protective layer to a predetermined amount or more, it is possible to easily suppress deterioration of the transparent resin layer. Furthermore, by setting the content of the ultraviolet absorber in the surface protective layer to a predetermined amount or less, it is possible to easily suppress bleed-out. The content of the ultraviolet absorber in the top coat layer constituting the surface protection layer is preferably more than 0.5 parts by mass and not more than 10.0 parts by mass, more preferably 1.0 parts by mass or more and not more than 8.0 parts by mass, even more preferably 2.0 parts by mass or more and not more than 7.0 parts by mass, and even more preferably 3.0 parts by mass or more and not more than 6.5 parts by mass, relative to 100 parts by mass of the resin constituting the top coat layer. When the other layer constituting the surface protective layer contains an ultraviolet absorber, the content of the ultraviolet absorber in the other layer is preferably 1 part by mass to 40 parts by mass, more preferably 5 parts by mass to 30 parts by mass, and even more preferably 7 parts by mass to 25 parts by mass, relative to 100 parts by mass of the resin constituting the other layer. An example of the other layer is a primer layer.

[0039] <Radical Scavenger> At least one of the surface protective layer and the transparent resin layer preferably contains a radical scavenger. The surface protective layer is the layer that UV rays first enter among the layers constituting the decorative sheet, so it preferably contains a radical scavenger. When the surface protective layer has a multilayer structure, it is preferable that the top coat layer contains a radical scavenger. The following embodiments regarding the radical scavenger are common to the radical scavenger in the surface protective layer and the radical scavenger in the transparent resin layer unless otherwise specified.

[0040] Examples of the radical scavenger include aromatic radical scavengers, amine radical scavengers, organic acid radical scavengers, catechin radical scavengers, and hindered amine radical scavengers, and among these, hindered amine radical scavengers are preferred. A hindered amine radical scavenger has a structure containing a 2,2,6,6-tetramethylpiperidine skeleton in its molecule.

[0041] When the surface protective layer contains a radical scavenger, the radical scavenger preferably contains at least one of a radical scavenger i having an ethylenic double bond polymerizable with the resin constituting the surface protective layer and a radical scavenger ii not having an ethylenic double bond polymerizable with the resin constituting the surface protective layer.More preferably, the top coat layer contains at least one of a radical scavenger i having an ethylenic double bond polymerizable with the resin constituting the top coat and a radical scavenger ii not having an ethylenic double bond polymerizable with the resin constituting the top coat layer. The ethylenic double bond is contained in functional groups such as a (meth)acryloyl group, a vinyl group, and an allyl group.

[0042] When only radical scavenger i is used, almost all of the radical scavengers in the surface protective layer are immobilized, and almost no radical scavengers are able to move freely within the surface protective layer, making it difficult to exhibit radical scavenging performance. On the other hand, since radical scavenger i polymerizes with the resin that constitutes the surface protective layer, when the resin that constitutes the surface protective layer contains a cured product (particularly a cured product of an ionizing radiation-curable resin composition), the radical scavenger i reduces the crosslink density of the cured product (particularly a cured product of an ionizing radiation-curable resin composition), making it likely that the scratch resistance will decrease. Therefore, it is preferable that the surface protective layer contains radical scavengers I and II in an appropriate blending ratio, since this easily improves "radical scavenging properties," "scratch resistance," and "bleed-out suppression." When the surface protective layer has a multilayer structure, it is preferable that the top coat layer contains both radical scavengers I and II as radical scavengers, or that the top coat layer contains only radical scavenger II as a radical scavenger.

[0043] The blending ratio of the radical scavenger i to the radical scavenger ii on a mass basis is preferably 8:2 to 0:10. By adjusting the ratio of radical scavenger i to radical scavenger ii to be 2 or more relative to 8, weather resistance can be improved and a decrease in the crosslink density of the cured product of the surface protective layer can be easily suppressed.

[0044] The content of the radical scavenger in the top coat layer constituting the surface protection layer is preferably 0.5 parts by mass or more and 10 parts by mass or less, more preferably 1 part by mass or more and 8 parts by mass or less, and even more preferably 1.5 parts by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the resin constituting the top coat layer. Furthermore, when the other layer constituting the surface protective layer contains a radical scavenger, the content of the radical scavenger in the other layer is preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably 0.5 parts by mass or more and 8 parts by mass or less, and even more preferably 1 part by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the resin constituting the other layer.

[0045] The radical scavenger i has an ethylenic double bond polymerizable with the resin constituting the surface protective layer. Examples of groups having an ethylenic double bond include a (meth)acryloyl group, a crotonoyl group, a vinyl group, and an allyl group, and among these, a (meth)acryloyl group is preferred. That is, the radical scavenger i is preferably one having a (meth)acryloyl group. The number of ethylenic double bonds in the radical scavenger i is not particularly limited, and may be 1 or 2 or more. In addition, only one type of radical scavenger i may be used, or two or more types may be used.

[0046] Examples of the radical scavenger i having one ethylenic double bond include 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4-(meth)acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-cyano-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,6-tetramethylpiperidine, pentamethylpiperidinyl (meth)acrylate, the compound having CAS number 1010692-24-6, and the compound having CAS number 1010692-21-3. Examples of the radical scavenger i having two or more ethylenic double bonds include 1-(meth)acryloyl-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 1-(meth)acryloyl-4-cyano-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotoyloxy-2,2,6,6-tetramethylpiperidine, the compound with CAS number 1954659-42-7, and the compound with CAS number 1010692-23-5.

[0047] The radical scavenger ii does not have an ethylenic double bond polymerizable with the resin constituting the surface protective layer. Only one type of radical scavenger ii may be used, or two or more types may be used.

[0048] Radical scavengers II include 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, bis(1-octyloxyloxy-2,2,6,6-tetramethyl-4-piperidinyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate, and methyl(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate. , 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethyl-4-piperidinyl)amino]-6-(2-hydroxyethylamine)-1,3,5-triazine), tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, bis-(1,2,2,6,6-pentamethyl-4-piperidyl)-2-(3,5-di-t-butyl-4-hydroxy-benzyl)-2-n-butylmalonate, and the like.

[0049] <<Top coat layer>> The top coat layer preferably contains a cured product of a curable resin composition in order to enhance the scratch resistance of the decorative sheet. Furthermore, the proportion of the cured product of the curable resin composition relative to all resin components constituting the top coat layer is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.

[0050] Examples of the cured product of the curable resin include a cured product of a thermosetting resin, a cured product of an ionizing radiation curable resin, or a mixture thereof. Among these, a cured product of an ionizing radiation curable resin composition is preferred from the viewpoint of increasing the crosslink density of the top coat layer and improving the scratch resistance and weather resistance. Furthermore, among ionizing radiation curable resin compositions, a cured product of an electron beam curable resin composition is more preferred from the viewpoint of being able to be applied without a solvent and being easy to handle.

[0051] A thermosetting resin composition is a composition containing at least a thermosetting resin, and is a resin composition that cures when heated. Examples of thermosetting resins include acrylic resins, urethane resins, phenolic resins, urea-melamine resins, epoxy resins, unsaturated polyester resins, and silicone resins. In a thermosetting resin composition, a curing agent is added to the curable resin as needed.

[0052] -Ionizing radiation curable resin- The ionizing radiation-curable resin composition is a composition containing a compound having an ionizing radiation-curable functional group (hereinafter also referred to as "ionizing radiation-curable compound"). The ionizing radiation-curable functional group is a group that crosslinks and cures upon irradiation with ionizing radiation, and preferred examples of the ionizing radiation-curable functional group include functional groups having an ethylenic double bond, such as a (meth)acryloyl group, a vinyl group, and an allyl group. Furthermore, ionizing radiation refers to electromagnetic waves or charged particle beams that have an energy quantum capable of polymerizing or crosslinking molecules. Typically, ultraviolet (UV) rays or electron beams (EB) are used, but it also includes other electromagnetic waves such as X-rays and gamma rays, and charged particle beams such as alpha rays and ion beams. Specifically, the ionizing radiation curable compound can be appropriately selected from polymerizable monomers and polymerizable oligomers that have been conventionally used as ionizing radiation curable resins.

[0053] As the polymerizable monomer, a (meth)acrylate monomer having a radically polymerizable unsaturated group in the molecule is preferred, and among them, a polyfunctional (meth)acrylate monomer is preferred. Here, "(meth)acrylate" means "acrylate or methacrylate." Examples of polyfunctional (meth)acrylate monomers include (meth)acrylate monomers having two or more ionizing radiation-curable functional groups in the molecule, and having at least a (meth)acryloyl group as the functional group. From the viewpoint of improving processability, scratch resistance, and weather resistance, the number of functional groups in the polyfunctional (meth)acrylate monomer is preferably from 2 to 8, more preferably from 2 to 6, even more preferably from 2 to 4, and even more preferably from 2 to 3. These polyfunctional (meth)acrylates may be used alone or in combination of two or more.

[0054] Examples of polymerizable oligomers include (meth)acrylate oligomers having two or more ionizing radiation-curable functional groups in the molecule, and having at least a (meth)acryloyl group as the functional group, such as urethane (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, polyester (meth)acrylate oligomers, polyether (meth)acrylate oligomers, polycarbonate (meth)acrylate oligomers, and acrylic (meth)acrylate oligomers. Other polymerizable oligomers include highly hydrophobic polybutadiene (meth)acrylate oligomers having (meth)acrylate groups in the side chains of polybutadiene oligomers, silicone (meth)acrylate oligomers having polysiloxane bonds in the main chain, aminoplast resin (meth)acrylate oligomers obtained by modifying aminoplast resins having many reactive groups in their small molecules, and oligomers having cationically polymerizable functional groups in the molecules of novolac epoxy resins, bisphenol epoxy resins, aliphatic vinyl ethers, aromatic vinyl ethers, etc.

[0055] These polymerizable oligomers may be used alone or in combination of two or more. From the viewpoint of improving processability, scratch resistance, and weather resistance, urethane (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, polyester (meth)acrylate oligomers, polyether (meth)acrylate oligomers, polycarbonate (meth)acrylate oligomers, and acrylic (meth)acrylate oligomers are preferred, urethane (meth)acrylate oligomers and polycarbonate (meth)acrylate oligomers are more preferred, and urethane (meth)acrylate oligomers are even more preferred.

[0056] From the viewpoint of improving processing characteristics, scratch resistance, and weather resistance, the number of functional groups of these polymerizable oligomers is preferably 2 or more and 8 or less, with the upper limit being more preferably 6 or less, even more preferably 4 or less, and even more preferably 3 or less. From the viewpoint of improving processability, scratch resistance, and weather resistance, the weight-average molecular weight of these polymerizable oligomers is preferably from 2,500 to 7,500, more preferably from 3,000 to 7,000, and even more preferably from 3,500 to 6,000. Here, the weight-average molecular weight is an average molecular weight measured by GPC analysis and converted into standard polystyrene.

[0057] In the ionizing radiation-curable resin composition, a monofunctional (meth)acrylate may be used in combination for the purpose of reducing the viscosity of the ionizing radiation-curable resin composition, etc. These monofunctional (meth)acrylates may be used alone or in combination of two or more kinds.

[0058] From the viewpoint of a balance between processing characteristics, scratch resistance, and weather resistance, the thickness of the top coat layer is preferably 1.5 μm or more and 20 μm or less, more preferably 2 μm or more and 15 μm or less, and even more preferably 3 μm or more and 10 μm or less.

[0059] <Primer layer> The decorative sheet of this embodiment preferably has, as a surface protective layer, a primer layer formed on the transparent resin layer side of the top coat layer in addition to the top coat layer, which can improve adhesion between the top coat layer and the transparent resin layer.

[0060] The primer layer is mainly composed of a binder resin, and may contain additives such as an ultraviolet absorber and a radical scavenger, if necessary. Preferred examples of binder resins include urethane resins, acrylic polyol resins, acrylic resins, ester resins, amide resins, butyral resins, styrene resins, urethane-acrylic copolymers, polycarbonate-based urethane-acrylic copolymers (urethane-acrylic copolymers derived from polymers (polycarbonate polyols) having carbonate bonds in the polymer main chain and two or more hydroxyl groups at the terminals and side chains), vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-acrylic copolymer resins, chlorinated propylene resins, nitrocellulose resins (nitrocellulose), and cellulose acetate resins. These can be used alone or in combination. For example, a mixture of a polycarbonate-based urethane-acrylic copolymer and an acrylic polyol resin can be used as the binder resin.

[0061] The thickness of the primer layer is preferably 1 μm or more and 10 μm or less, more preferably 2 μm or more and 8 μm or less, and even more preferably 3 μm or more and 6 μm or less.

[0062] <Transparent resin layer> The transparent resin layer is located between the surface protective layer and the substrate layer. Examples of resins constituting the transparent resin layer include polypropylene resins, polyolefin resins other than polypropylene resins (polyethylene, polymethylpentene, polybutene, etc.), polyester resins, polycarbonate resins, acrylonitrile-butadiene-styrene resins (hereinafter also referred to as "ABS resins"), acrylic resins, vinyl chloride resins, etc. Among these, polypropylene resins are preferred from the viewpoint of processability.

[0063] From the viewpoint of processability, the content of polypropylene-based resin in the transparent resin layer is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, of the total resin components of the transparent resin layer.

[0064] Examples of the polypropylene resin for the transparent resin layer include a propylene homopolymer, an ethylene-propylene copolymer, a propylene-butene copolymer, an ethylene-propylene-butene copolymer, etc. Among these, a propylene homopolymer, an ethylene-propylene copolymer, and a propylene-butene copolymer are preferred, and a propylene homopolymer is more preferred.

[0065] The transparent resin layer preferably contains an ultraviolet absorber and a radical scavenger. The content of the ultraviolet absorber in the transparent resin layer is not particularly limited as long as the absorbances A1 and A2 fall within the above ranges. The content of the ultraviolet absorber in the transparent resin layer is preferably 0.05 to 10 parts by mass, more preferably 0.07 to 5 parts by mass, even more preferably 0.09 to 3 parts by mass, and even more preferably 0.10 to 1 part by mass, relative to 100 parts by mass of the resin constituting the transparent resin layer. In particular, when the thickness of the transparent resin layer is within the range described below, the content of the ultraviolet absorber is preferably within the above range. The content of the radical scavenger in the transparent resin layer is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, even more preferably 1 to 5 parts by mass, and even more preferably 1.5 to 3 parts by mass, relative to 100 parts by mass of the resin constituting the transparent resin layer. In particular, when the thickness of the transparent resin layer is within the range described below, the content of the radical scavenger is preferably within the above range.

[0066] The transparent resin layer may be transparent to such an extent that the substrate layer side can be seen through the transparent resin layer, and may be colorless and transparent, colored and transparent, or translucent.

[0067] The thickness of the transparent resin layer is preferably from 20 μm to 150 μm, more preferably from 40 μm to 120 μm, and even more preferably from 60 μm to 100 μm, from the viewpoint of a balance between scratch resistance, processability, and weather resistance. The thickness of the transparent resin layer is preferably thicker than that of the substrate layer, from the viewpoint of protecting the decorative layer and obtaining excellent scratch resistance.

[0068] <Base material layer> The base layer is a layer containing a polypropylene-based resin, and is located on the opposite side of the transparent resin layer from the surface protective layer. From the viewpoint of processability, the content of polypropylene resin in the base layer is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and even more preferably 80% by mass or more, based on the total resin components of the base layer.

[0069] Examples of the polypropylene resin for the base layer include a propylene homopolymer, an ethylene-propylene copolymer, a propylene-butene copolymer, an ethylene-propylene-butene copolymer, etc. Among these, a propylene homopolymer, an ethylene-propylene copolymer, and a propylene-butene copolymer are preferred, and a propylene homopolymer is more preferred.

[0070] When the base layer contains a resin other than a polypropylene-based resin, for example, a thermoplastic resin such as a polyolefin-based resin other than a polypropylene-based resin (polyethylene, polymethylpentene, polybutene, etc.), a polyester resin, a polycarbonate resin, an acrylonitrile-butadiene-styrene resin (hereinafter also referred to as "ABS resin"), an acrylic resin, or a vinyl chloride resin can be used.

[0071] The substrate layer may be colorless and transparent, but is preferably colored from the viewpoint of design. When the substrate layer is colored, a coloring agent such as a dye or a pigment can be added to the substrate layer. Among these coloring agents, a pigment is preferred because it is easy to prevent fading. Pigments include white pigments such as zinc oxide, white lead, lithopone, titanium dioxide, precipitated barium sulfate, and barite; black pigments such as carbon black; red pigments such as red lead and iron oxide red; Examples include yellow pigments such as yellow lead and zinc yellow (zinc yellow type 1, zinc yellow type 2); and blue pigments such as ultramarine blue and Prussian blue (potassium iron ferrocyanide).

[0072] The content of the colorant is, for example, preferably 1 part by mass or more and 50 parts by mass or less, more preferably 3 parts by mass or more and 40 parts by mass or less, even more preferably 5 parts by mass or more and 30 parts by mass or less, and even more preferably 5 parts by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the resin constituting the base layer.

[0073] The base layer may contain additives as needed. Examples of additives include inorganic fillers such as calcium carbonate and clay, flame retardants such as magnesium hydroxide, antioxidants, lubricants, foaming agents, ultraviolet absorbers, and radical scavengers. The amount of additives added can be adjusted as appropriate within a range that does not impair the effects of the present invention. In the present invention, since the absorbances A1 and A2 are set within predetermined ranges, the weather resistance of the substrate layer can be improved without containing an ultraviolet absorber and a radical scavenger in the substrate layer.

[0074] From the viewpoint of a balance between design and processability, the thickness of the base layer is preferably 20 μm or more and 150 μm or less, more preferably 25 μm or more and 120 μm or less, even more preferably 30 μm or more and 100 μm or less, and even more preferably 40 μm or more and 80 μm or less.

[0075] In order to enhance adhesion between the base layer and other layers of the decorative sheet or the adherend, one or both sides of the base layer may be subjected to a surface treatment such as a physical surface treatment such as an oxidation method or a roughening method, or a chemical surface treatment, or a primer layer may be formed.

[0076] <Decorative layer> From the viewpoint of improving the design, the decorative sheet of the present invention preferably has a decorative layer at any position on the decorative sheet. From the viewpoint of improving the weather resistance of the decorative layer, the position where the decorative layer is formed is preferably between the substrate layer and the transparent resin layer.

[0077] The decorative layer may be, for example, a colored layer that covers the entire surface (a so-called solid colored layer), or a patterned layer formed by printing various patterns using ink and a printing machine, or a combination of these.

[0078] The ink used for the decorative layer is a mixture of a binder resin with an appropriate amount of pigment, colorant such as dye, extender pigment, solvent, stabilizer, plasticizer, catalyst, hardener, ultraviolet absorber, radical scavenger, etc. The binder resin for the decorative layer is not particularly limited, and examples thereof include urethane resin, acrylic polyol resin, acrylic resin, ester resin, amide resin, butyral resin, styrene resin, urethane-acrylic copolymer, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-acrylic copolymer resin, chlorinated propylene resin, nitrocellulose resin, cellulose acetate resin, etc. In addition, various types of resins can be used, such as one-component curing resins and two-component curing resins containing a curing agent such as an isocyanate compound.

[0079] As the colorant, a pigment having excellent hiding power and weather resistance is preferable. The same pigments as those exemplified for the base layer can be used. The content of the colorant in the base layer is preferably 5 parts by mass or more and 90 parts by mass or less, more preferably 15 parts by mass or more and 80 parts by mass or less, and even more preferably 30 parts by mass or more and 70 parts by mass or less, relative to 100 parts by mass of the resin constituting the decorative layer.

[0080] From the viewpoint of improving weather resistance, the decorative layer preferably contains a weather resistance agent such as an ultraviolet absorber or a radical scavenger.

[0081] The thickness of the decorative layer may be selected appropriately depending on the desired pattern, but from the viewpoint of concealing the base color of the adherend and improving the design, it is preferably 0.5 μm or more and 20 μm or less, more preferably 1 μm or more and 10 μm or less, and even more preferably 2 μm or more and 5 μm or less.

[0082] <Adhesive layer A> It is preferable to form an adhesive layer A between the substrate layer and the transparent resin layer in order to improve the adhesion between the two layers. When the decorative layer described above is further provided between the substrate layer and the transparent resin layer, the positional relationship between the adhesive layer A and the decorative layer is not particularly limited. Specifically, the decorative layer and the adhesive layer A may be provided in this order from the side closest to the substrate layer, or the adhesive layer A and the decorative layer may be provided in this order from the side closest to the substrate layer.

[0083] The adhesive layer A can be made of, for example, an adhesive such as a urethane adhesive, an acrylic adhesive, an epoxy adhesive, a rubber adhesive, etc. Among these adhesives, a urethane adhesive is preferred in terms of adhesive strength. Examples of urethane-based adhesives include adhesives that utilize two-component curing urethane resins containing various polyol compounds such as polyether polyols, polyester polyols, and acrylic polyols, and curing agents such as the various isocyanate compounds described above.

[0084] The thickness of the adhesive layer A is preferably 0.1 μm or more and 30 μm or less, more preferably 1 μm or more and 15 μm or less, and even more preferably 2 μm or more and 10 μm or less.

[0085] The decorative layer, adhesive layer A, primer layer and top coat layer described above can be formed by applying a coating liquid containing a composition for forming each layer using a known method such as gravure printing, bar coating, roll coating, reverse roll coating or comma coating, and then drying and curing the coating as necessary.

[0086] The decorative sheet of the present invention may be provided with unevenness by embossing or the like. When embossing, for example, the decorative sheet is heated to preferably from 80° C. to 260° C., more preferably from 100° C. to 220° C., and even more preferably from 120° C. to 200° C., and an embossing plate is pressed against the decorative sheet. The area where the embossing plate is pressed is preferably on the surface protective layer side of the decorative sheet.

[0087] [Decorative materials] The decorative material of the present invention comprises an adherend and the decorative sheet of the present invention described above, and specifically, is laminated so that the surface of the adherend that requires decoration faces the surface of the decorative sheet that faces the base layer.

[0088] <Adherent material> Examples of adherends include flat plates, curved plates, and other plates, three-dimensional articles, and sheets (or films) made of various materials. Examples include wood components used as plates or three-dimensional articles, such as wood veneers made from various types of wood, such as cedar, cypress, pine, and lauan, wood plywood, particle boards, and wood fiberboards, such as medium-density fiberboard (MDF); metal components used as plates or three-dimensional articles, such as steel plates and steel sheets made from iron or aluminum, three-dimensional articles, or sheets; ceramic components used as plates or three-dimensional articles, such as glass, ceramics, non-cement ceramic materials, such as gypsum, and non-ceramic ceramic materials, such as ALC (aerated lightweight concrete) boards; and resin components used as plates, three-dimensional articles, or sheets, such as acrylic resin, polyester resin, polystyrene resin, polypropylene resin, and other polyolefin resins, ABS (acrylonitrile-butadiene-styrene copolymer) resin, phenolic resin, vinyl chloride resin, cellulose resin, and rubber. These components can be used alone or in combination. The decorative material of the present invention is preferable in that it can improve the weather resistance of the adherend when the adherend contains a polypropylene-based resin.

[0089] The adherend may be selected from the above according to the intended use. When the adherend is used as an interior or exterior member of a building such as a wall, ceiling, or floor, or as a fitting or fixture member such as a window frame, door, handrail, baseboard, molding, or other such member, the material of the adherend is preferably at least one member selected from wood members, metal members, and resin members. When the adherend is used as an exterior member such as an entrance door, or as fittings such as a window frame or door, the material of the adherend is preferably at least one member selected from metal members and resin members.

[0090] The thickness of the adherend may be appropriately selected depending on the application and material, and is preferably 0.1 mm to 10 mm, more preferably 0.3 mm to 5 mm, and even more preferably 0.5 mm to 3 mm.

[0091] <Adhesive layer B> The adherend and decorative sheet are preferably bonded together via adhesive layer B in order to obtain excellent adhesion.

[0092] The adhesive used in the adhesive layer B is not particularly limited, and known adhesives can be used, and preferred examples include heat-sensitive adhesives and pressure-sensitive adhesives. Examples of resins used in the adhesive constituting this adhesive layer include acrylic resins, polyurethane resins, vinyl chloride resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymer resins, styrene-acrylic copolymer resins, polyester resins, and polyamide resins, and these can be used alone or in combination. Two-component curing polyurethane adhesives and polyester adhesives that use an isocyanate compound or the like as a curing agent can also be used. A pressure-sensitive adhesive may also be used for the adhesive layer B. The pressure-sensitive adhesive may be appropriately selected from acrylic, urethane, silicone, rubber, and other pressure-sensitive adhesives.

[0093] The thickness of the adhesive layer B is not particularly limited, but from the viewpoint of obtaining excellent adhesiveness, it is preferably from 1 μm to 100 μm, more preferably from 5 μm to 50 μm, and even more preferably from 10 μm to 30 μm. [Example]

[0094] Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples in any way.

[0095] 1. Evaluation and Measurement 1-1.Absorbance A laminate was produced by forming a surface protective layer on a transparent resin layer. The absorbances of the laminate, "Absorbance A1," "Absorbance A2," and "Absorbance A3," were measured using an ultraviolet-visible-near-infrared spectrophotometer (manufactured by Hitachi, Ltd., product name: U-4000) in accordance with JIS K0115:2004.

[0096] 1-2. Weather resistance Using the following ultra-accelerated weathering tester, the decorative sheets obtained in the Examples and Comparative Examples were subjected to an accelerated weathering test for 1,400 hours (a test in which one cycle consisted of 20 hours of ultraviolet irradiation under the following irradiation conditions, followed by 4 hours of condensation under the following condensation conditions, and this cycle was repeated). After 1,000 hours and 1,400 hours, the appearance of the decorative sheets was visually evaluated according to the following criteria. <Ultra-accelerated weathering test equipment> An ultra-accelerated weathering test device (product name: iSuper UV Tester SUV-W161, manufactured by Iwasaki Electric Co., Ltd.) equipped with a UV lamp (product name: M04-L21WB / SUV, manufactured by Iwasaki Electric Co., Ltd.), a lamp jacket (product name: WJ50-SUV, manufactured by Iwasaki Electric Co., Ltd.), and an illuminance meter (product name: UVD-365PD, manufactured by Iwasaki Electric Co., Ltd.). <Irradiation conditions> Black panel temperature: 63°C ·Illuminance: 100mW / cm 2 ·Battle humidity: 50%RH Duration: 20 hours <Condensation conditions> ·Illuminance: 0mW / cm 2 ·Battle humidity: 98%RH Duration: 4 hours <Evaluation criteria> A: No change in appearance was observed across the entire decorative sheet. B: Slight whitening was observed on the appearance of the decorative sheet, but no change in color tone was observed in the transparent resin layer and / or the base layer. C: Slight whitening was observed on the appearance of the decorative sheet, and slight changes in color tone were observed in the transparent resin layer and / or the base layer. D: Significant whitening of the appearance of the decorative sheet and a large change in color tone of the transparent resin layer and / or substrate layer was observed.

[0097] 2. Preparation of decorative sheet [Example 1] A decorative layer was formed on one side of a substrate layer (a 60 μm-thick colored polypropylene resin sheet) that had been subjected to corona discharge treatment on both sides, using a printing ink made of a two-component curing acrylic-urethane resin. Next, an adhesive layer made of a urethane resin adhesive with a thickness of 3 μm was formed on the decorative layer. Next, a composition A containing 100 parts by mass of a polypropylene resin, ultraviolet absorber 1, ultraviolet absorber 2, and ultraviolet absorber 3 was hot-melt extruded on the adhesive layer using a T-die extruder to form a transparent resin layer having a thickness of 80 μm. The contents (parts by mass) of UV absorber 1, UV absorber 2, and UV absorber 3 were the contents (parts by mass) shown in Table 1. Further, detailed information about UV absorber 1, UV absorber 2, and UV absorber 3 is as follows:

[0098] <Detailed information on UV absorbers 1-3> UV absorber 1: Hydroxyphenyltriazine UV absorber (product name: TINUVIN 460, BASF), maximum absorption wavelength: 349 nm UV absorber 2: Hydroxyphenyltriazine UV absorber (trade name: Adekastab LA-46, ADEKA Corporation), maximum absorption wavelength: between 280 and 300 nm UV absorber 3: Hydroxyphenyltriazine UV absorber (product name: TINUVIN 477, BASF), maximum absorption wavelength: 356 nm

[0099] The surface of the transparent resin layer was subjected to a corona discharge treatment, and then the following composition B was applied onto the transparent resin layer and dried to form a primer layer having a thickness of 4 μm. <Composition B> A composition obtained by mixing 100 parts by mass of composition X (a composition consisting of a polycarbonate-based urethane-acrylic copolymer and an acrylic polyol, and hexamethylene diisocyanate in a mass ratio of 100:5) with a dilution solvent.

[0100] Next, the following composition C was applied onto the primer layer, and the ionizing radiation curable resin composition was cured by irradiating with an electron beam to form a top coat layer with a thickness of 5 μm, thereby obtaining the decorative sheet of Example 1.

[0101] <Composition C> ·Ionizing radiation curable resin composition: 100 parts by mass (Trifunctional urethane acrylate oligomer with a weight-average molecular weight of 4000) 1:1 parts by weight of the ultraviolet absorber Hindered amine radical scavenger: 3 parts by mass (Bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate)

[0102] [Examples 2 to 9], [Comparative Examples 1 to 6] The decorative sheets of Examples 2 to 9 and Comparative Examples 1 to 6 were obtained in the same manner as in Example 1, except that the type and content (parts by mass) of the UV absorber in the transparent resin layer and the type and content (parts by mass) of the UV absorber in the top coat layer were changed as shown in Table 1 or Table 2.

[0103] [Table 1]

[0104] [Table 2]

[0105] From the results in Tables 1 and 2, it can be confirmed that the decorative sheets of the examples, which have an absorbance A1 of 2.7 or more and an absorbance A2 of 0.3 or more, are able to inhibit deterioration over time due to ultraviolet rays. [Industrial Applicability]

[0106] The decorative sheet of the present invention has excellent weather resistance and is therefore suitable for use as a decorative sheet for components that are used in environments exposed to direct sunlight, such as exterior components such as entrance doors, window frames, doors, and other fixtures. [Explanation of symbols]

[0107] 100: Decorative sheet 11: Top coat layer 12: Primer layer 10: Surface protective layer 20: Transparent resin layer 30: Decorative layer 40: Base material layer

Claims

1. A decorative sheet having a surface protective layer, a transparent resin layer, and a substrate layer in this order, the base layer contains a polypropylene-based resin, at least one of the surface protective layer and the transparent resin layer contains an ultraviolet absorber; When the surface protective layer is formed of one or more layers, and the layer of the surface protective layer farthest from the transparent resin layer is defined as a top coat layer, The top coat layer contains 3.0 parts by mass or more and 8.0 parts by mass or less of the ultraviolet absorber relative to 100 parts by mass of a resin constituting the top coat, the absorbance A1 of the surface protective layer and the transparent resin layer at a wavelength of 270 nm or more and 300 nm or less, measured in accordance with JIS K0115:2004, is 3.0 or more; the absorbance A2 of the surface protective layer and the transparent resin layer at a wavelength of 360 nm or more and 380 nm or less, measured in accordance with JIS K0115:2004, is 0.6 or more and 1.0 or less; Decorative sheet.

2. 2. The decorative sheet according to claim 1, wherein the absorbance A3 of said surface protective layer and said transparent resin layer at a wavelength of 310 nm measured in accordance with JIS K0115:2004 is 1.1 or more.

3. 3. The decorative sheet according to claim 1 or 2, wherein the top coat layer contains at least one of a radical scavenger i having an ethylenic double bond polymerizable with the resin constituting the top coat, and a radical scavenger ii not having an ethylenic double bond polymerizable with the resin constituting the top coat layer.

4. 4. The decorative sheet according to claim 3, wherein said top coat layer contains only said radical scavenger ii as the radical scavenger.

5. 5. The decorative sheet according to claim 1, wherein the surface protective layer comprises the top coat layer and a primer layer located closer to the transparent resin layer than the top coat layer.

6. 6. The decorative sheet according to claim 1, wherein the resin constituting said surface protective layer is substantially free of polypropylene-based resin.

7. 7. The decorative sheet according to claim 1, wherein the transparent resin layer contains 0.05 parts by mass or more and 10.0 parts by mass or less of the ultraviolet absorber per 100 parts by mass of the resin constituting the transparent resin layer.

8. 8. The decorative sheet according to claim 1, wherein the ultraviolet absorber comprises two or more ultraviolet absorbers having different maximum absorption wavelengths.

9. 9. The decorative sheet according to claim 1, further comprising a decorative layer between said substrate layer and said transparent resin layer.

10. A decorative material comprising an adherend and the decorative sheet according to any one of claims 1 to 9.

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