Laminate and decorative article

Abstract

To provide a laminate exhibiting different designs in lighting-on and lighting-off of a light source which makes a design exhibited in lighting-off of the light source less likely to be visible in lighting-off of the light source, and makes the design visible in lighting-off of the light source.SOLUTION: A laminate has a first main surface arranged on an observer side and a second main surface arranged on a light source side, wherein the first main surface has an uneven shape, and has at least a first design layer, a transparent resin layer and a second design layer in this order from the first main surface side, the laminate further has a third design layer on the first main surface side or the second main surface side of the second design layer, the surface on the first main surface side of the second design layer is relatively flatter than the uneven shape of the first main surface, and the third design layer is partially provided.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a laminate and a decorated article. [Background technology]

[0002] Decorative resin molded products, in which a decorative sheet is laminated onto the surface of a resin molded product, have traditionally been used for vehicle interior and exterior components, building materials, and home appliance housings. To manufacture such decorative resin molded products, a molding method is used in which a decorative sheet, to which a design has been previously applied, is integrated with the resin by injection molding. A typical example of such a molding method is an insert molding method in which the decorative sheet is first molded into a three-dimensional shape using a vacuum molding mold, and then the decorative sheet is inserted into an injection molding mold and a fluid resin is injected into the mold to integrate the resin and the decorative sheet.

[0003] Decorative resin molded articles obtained by such molding methods are used in a variety of applications, such as interior and exterior vehicle parts, as described above. Therefore, in addition to three-dimensional formability that can follow three-dimensional molding and surface properties such as scratch resistance, diverse design sensations are also required in response to the recent diversification of consumer preferences. For example, developments have been made to impart texture to resin molded articles by imparting matte finishes or unevenness to specific portions of a pattern (e.g., Patent Document 1). Furthermore, synthetic resin molded parts with variable design surfaces have been proposed as products with diverse design sensations (e.g., Patent Document 2).

[0004] Furthermore, a decorative sheet has also been proposed in which a light source is arranged on the opposite side of the decorative sheet from the viewer side, and which exhibits different designs when the light source is on and when it is off (for example, Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-132145 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-125817 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-14051 [Patent Document 4] Japanese Patent Application Publication No. 2020-49844 Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, laminates that exhibit different designs when a light source is on and when it is off are known.

[0007] For example, Patent Document 4 discloses a laminate having a first main surface disposed on the viewer side and a second main surface disposed on the light source side, and including, in order from the second main surface side, at least a first design layer, a second design layer, and a transparent substrate layer, wherein an uneven shape is provided on the surface of the transparent substrate layer facing the second design layer. This laminate is excellent in that the design that appears when the light source is on is not visible when the light source is off, and the design is visible only when the light source is on.

[0008] On the other hand, there is a demand for a laminate that displays a different design when the light source is on and when it is off, such that the design that appears when the light source is off is difficult to see when the light source is on, but the design is visible when the light source is off.

[0009] The main object of the present invention is to provide a laminate that displays a different design when a light source is on and when it is off, where the design that appears when the light source is off is difficult to see when the light source is on, but the design is visible when the light source is off. Another object of the present invention is to provide a decorated article using the laminate. [Means for solving the problem]

[0010] The present inventors have conducted extensive research to solve the above-mentioned problems. As a result, they have found that a laminate having a first main surface disposed on the viewer side and a second main surface disposed on the light source side, the first main surface having an uneven shape, further comprising, in order from the first main surface side, at least a first design layer, a transparent resin layer, a second design layer, and a third design layer on the first main surface side or the second main surface side of the second design layer, the surface on the first main surface side of the second design layer being relatively flatter than the uneven shape of the first main surface, and the laminate having the third design layer partially provided thereon, exhibits different designs when the light source is on and when it is off, and that when the light source is on, the designs that are exhibited when the light source is off (specifically, the designs based on the uneven shape of the first main surface side surface of the laminate and the designs based on the first design layer) are difficult to see, but the designs are visible when the light source is off. The present invention was completed based on these findings and through further investigation.

[0011] That is, the present invention provides the following aspects. Item 1. A first main surface disposed on the viewer side and a second main surface disposed on the light source side, The first main surface has an uneven shape, A laminate including, in order from the first main surface side, at least a first design layer, a transparent resin layer, and a second design layer, A third design layer is further provided on the first main surface side or the second main surface side of the second design layer, The surface of the second design layer on the first main surface side is relatively flatter than the uneven shape of the first main surface, A laminate, wherein the third design layer is provided partially. Item 2. The laminate according to Item 1, wherein the surface of the transparent resin layer on the first main surface side has an uneven shape corresponding to the uneven shape of the first main surface. Item 3. The laminate according to Item 1 or 2, further comprising a surface protection layer on the outermost surface on the first main surface side. Item 4. The laminate according to any one of Items 1 to 3, further comprising a transparent substrate layer on the second main surface side of the second design layer and the third design layer. Item 5. The laminate according to any one of Items 1 to 4, wherein the laminate is in the form of a sheet. Item 6. The laminate according to any one of Items 1 to 5, comprising, in order from the second main surface side, at least a transparent molded resin layer, the second design layer, the transparent resin layer, and the first design layer. Item 7. The laminate according to any one of Items 1 to 6, a light source disposed on the second main surface side of the laminate; A decorative article comprising: [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a laminate that exhibits a different design when a light source is on and when it is off, wherein the design that appears when the light source is off is difficult to see when the light source is on, but the design is visible when the light source is off. Furthermore, according to the present invention, it is also possible to provide a decorated article using the laminate. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic cross-sectional view of an example of a laminate of the present invention. [Figure 2] 1 is a schematic cross-sectional view of an example of a laminate of the present invention. [Figure 3] 1 is a schematic cross-sectional view of an example of a laminate of the present invention. [Figure 4] 1 is a schematic cross-sectional view of an example of a laminate of the present invention. [Figure 5] 1 is a schematic cross-sectional view of an example of a decorated article using the laminate of the present invention. [Figure 6] 1 is an example of an image diagram of the laminate of the present invention when viewed from the first main surface side (observer side) when the light source 30 is turned on. [Figure 7] 1 is an example of an image diagram of the laminate of the present invention when viewed from the first main surface side (observer side) when the light source 30 is turned on. DETAILED DESCRIPTION OF THE INVENTION

[0014] 1.Laminate The laminate of the present invention has a first main surface positioned on the viewer side and a second main surface positioned on the light source side, the first main surface having an uneven shape, and is a laminate comprising, in order from the first main surface side, at least a first design layer, a transparent resin layer, and a second design layer, and further comprises a third design layer on the first main surface side or the second main surface side of the second design layer, the surface on the first main surface side of the second design layer being relatively flatter than the uneven shape of the first main surface, and the third design layer being partially provided.By having such a configuration, the laminate of the present invention manifests a different design when the light source is on and when it is off, and when the light source is on, the design that is manifested when the light source is off (specifically, the design based on the uneven shape of the first main surface side surface of the laminate and the design by the first design layer) is difficult to see, but when the light source is off, the design is visible.

[0015] The laminate of the present invention can be suitably used for decorating the surfaces of resin molded products such as vehicle interior / exterior parts, building materials, and home appliance housings. Therefore, the laminate of the present invention can be suitably used as a decorative sheet for three-dimensional molding. In particular, when the laminate of the present invention is in the form of a sheet, it can be molded as a decorative sheet for three-dimensional molding and laminated with a molded resin layer 5 described below to suitably form a decorated resin molded product.

[0016] The laminate of the present invention will be described in detail below with reference to FIGS. 1 to 5. In this specification, unless otherwise specified, numerical ranges indicated with "to" mean "not less than" or "not more than." For example, the expression 2 to 15 mm means 2 mm or more and 15 mm or less. In this specification, "(meth)acrylate" means "acrylate or methacrylate," and other similar terms have similar meanings.

[0017] Layer structure and uneven shape of laminate 1 to 5, the laminate 10 of the present invention has a first main surface 11 arranged on the viewer side and a second main surface 12 arranged on the light source side. Specifically, when the laminate 10 of the present invention is used for various applications such as vehicle interior / exterior parts, building materials, and home appliance housings, the first main surface 11 is arranged on the viewer side and the second main surface 12 is arranged on the light source side.

[0018] The laminate 10 of the present invention comprises, in order from the first main surface side 11, at least a first design layer 21, a transparent resin layer 1, and a second design layer 22, and further comprises a third design layer 23 on the first main surface 11 side or the second main surface 12 side of the second design layer 22. Furthermore, in the laminate 10 of the present invention, the first main surface 11 has an uneven shape.

[0019] When observed from the first main surface 11 side, the laminate 10 exhibits different designs when the light source 30 is on and when it is off. When it is off, the design based on the uneven shape of the surface on the first main surface 11 side and the design based on the first design layer 21 are visible. When it is on, the designs based on the second design layer 22 and the third design layer 23 are visible. In the laminate 10 of the present invention, when the light source 30 is on, the design that appears when the light source 30 is off is difficult to see, but when the light source is off, the design is visible. In order to exhibit such properties, in the laminate 10 of the present invention, a transparent resin layer 1 is disposed between the first design layer 21 and the second design layer 22, and further, it is important that the surface 22a on the first main surface 11 side of the second design layer 22 has a shape that is relatively flatter than the uneven shape of the first main surface 11.

[0020] The surface 22a of the second design layer 22 on the first main surface 11 side only needs to be flatter than the uneven shape of the first main surface 11. Specifically, the depth of the recesses on the surface 22a of the second design layer 22 on the first main surface 11 side is made smaller than the depth of the recesses of the uneven shape of the first main surface 11. From the viewpoint of more suitably exerting the effects of the present invention, it is preferable that the surface 22a of the second design layer 22 on the first main surface 11 side is substantially flat. For example, it is preferable that the uneven shape of the first main surface 11 is not reflected in the shape of the surface 22a of the second design layer 22 on the first main surface 11 side, and even in this case, it is acceptable for the surface 22a to have some uneven shape.

[0021] The surface of the second design layer 22 on the second main surface 12 side also preferably has a relatively flat shape compared to the uneven shape of the first main surface 11, and more preferably is substantially flat.

[0022] For example, as shown in FIGS. 4 and 5 , in the laminate 10 of the present invention, a surface protective layer 3 may be further provided on the first design layer 21 (on the first main surface 11 side) to provide surface protection properties such as scratch resistance and chemical resistance. Furthermore, a primer layer (not shown) may be provided as needed to improve adhesion between the surface protective layer 3 and the layer located below it (such as the first design layer 21). For example, an adhesive layer (not shown) may be provided on at least one surface of the second design layer 22. Furthermore, as shown in FIG. 5 , when a molded resin layer 5 is laminated on the second main surface 12 side, a back adhesive layer (not shown) may be provided on the second main surface 12 side of the transparent substrate layer 4 (on the back side of the transparent substrate layer 4) as needed to improve adhesion between the laminate 10 of the present invention and the molded resin layer 5.

[0023] The laminate of the present invention may further include one or more other layers depending on the function to be imparted to the laminate or the decorative article.

[0024] The laminate structure of the laminate of the present invention may be, in order from the first main surface side, a laminate structure in which a first design layer / transparent resin layer 1 / second design layer / third design layer are laminated; a laminate structure in which a first design layer / transparent resin layer 1 / third design layer / second design layer are laminated; a laminate structure in which a first design layer / transparent resin layer 1 / second design layer / third design layer / transparent substrate layer are laminated; a laminate structure in which a first design layer / transparent resin layer 1 / third design layer / second design layer / transparent substrate layer are laminated; a surface Laminated structure of surface protective layer / first design layer / transparent resin layer 1 / second design layer / third design layer / transparent substrate layer;Laminated structure of surface protective layer / first design layer / transparent resin layer 1 / third design layer / second design layer / transparent substrate layer;Laminated structure of surface protective layer / first design layer / transparent resin layer 1 / second design layer / adhesive layer / third design layer / transparent substrate layer;Laminated structure of surface protective layer / first design layer / transparent resin layer 1 / third design layer / second design layer / adhesive layer / Laminated structure with a transparent substrate layer laminated; Laminated structure with a surface protective layer / first design layer / transparent resin layer 1 / adhesive layer / second design layer / third design layer / transparent substrate layer laminated; Laminated structure with a surface protective layer / first design layer / transparent resin layer 1 / third design layer / adhesive layer / second design layer / transparent substrate layer laminated; Laminated structure with a surface protective layer / first design layer / transparent resin layer 1 / third design layer / second design layer / transparent substrate layer / molded resin layer laminated; Surface protective layer / 1 Examples include a laminated structure in which a design layer / transparent resin layer 1 / second design layer / adhesive layer / third design layer / transparent substrate layer / molded resin layer are stacked; a laminated structure in which a surface protective layer / first design layer / transparent resin layer 1 / third design layer / second design layer / transparent substrate layer / back adhesive layer / molded resin layer are stacked; and a laminated structure in which a surface protective layer / first design layer / transparent resin layer 1 / second design layer / adhesive layer / third design layer / transparent substrate layer / back adhesive layer / molded resin layer are stacked.

[0025] Figure 1 shows a schematic cross-sectional view of an example of a laminate having a first design layer, a transparent resin layer 1, a second design layer, and a third design layer stacked in order from the first main surface side, as one embodiment of the laminate structure of the laminate of the present invention. Figure 2 shows a schematic cross-sectional view of an example of a laminate having a first design layer, a transparent resin layer 1, a third design layer, and a second design layer stacked in order from the first main surface side, as one embodiment of the laminate structure of the laminate of the present invention. Figure 3 shows a schematic cross-sectional view of an example of a laminate having a first design layer, a transparent resin layer, a second design layer, a third design layer, and a transparent substrate layer stacked in order from the first main surface side, as one embodiment of the laminate structure of the laminate of the present invention. Figure 4 shows a schematic cross-sectional view of an example of a laminate having a surface protective layer, a first design layer, a transparent resin layer, a second design layer, a third design layer, and a transparent substrate layer stacked in order from the first main surface side, as one embodiment of the laminate structure of the laminate of the present invention. Figure 5 shows a schematic cross-sectional view of an example of a laminate in which, from the first main surface side, a surface protection layer / first design layer / transparent resin layer 1 / second design layer / third design layer / transparent substrate layer / molded resin layer are laminated, as one embodiment of the laminate structure of the laminate of the present invention.

[0026] Furthermore, in the laminate 10 of the present invention, it is preferable that the surface of the first design layer 21 on the first main surface 11 side has an uneven shape 21a. It is preferable that the uneven shape of the first main surface 11 of the laminate 10 and the uneven shape 21a of the surface on the first main surface 11 side of the first design layer 21 correspond to each other. As shown in Figures 1 and 2, when the first design layer 21 constitutes the first main surface 11 of the laminate 10, the uneven shape 21a of the surface on the first main surface 11 side of the first design layer 21 matches the uneven shape of the first main surface 11.

[0027] In the laminate 10 of the present invention, it is also preferable that the surface of the first design layer 21 on the second main surface 12 side has an uneven shape. As shown in Figures 1 and 2, it is preferable that the uneven shape 21a on the surface of the first design layer 21 on the first main surface 11 side and the uneven shape on the second main surface 12 side have corresponding shapes.

[0028] Furthermore, in the laminate 10 of the present invention, the transparent resin layer 1 may have an uneven shape. When the transparent resin layer 1 has an uneven shape, the uneven shape is preferably provided on the first main surface 11 side (i.e., the transparent resin layer 1 has an uneven shape 1a on the first main surface 11 side), as shown in FIGS. 1 to 5. The uneven shape 1a on the first main surface side of the transparent resin layer 1 corresponds, for example, to the uneven shape 21a on the surface of the first design layer 21 on the first main surface 11 side. That is, in the laminate 10 of the present invention, an uneven shape corresponding to the uneven shape of the first main surface 11 can be provided, for example, from the first main surface 11 to the transparent resin layer 1 (particularly, to the surface of the transparent resin layer 1 on the first main surface 11 side).

[0029] From the viewpoint of more suitably exerting the effects of the present invention, in the laminate 10 of the present invention, the ratio of the depth D of the recesses of the uneven shape on the first main surface 11 to the thickness of the transparent resin layer 1 is preferably 60% or less, and preferably 10% or more, with a preferred range being 10 to 60%.

[0030] Furthermore, in order to more suitably exert the effects of the present invention, in the laminate 10 of the present invention, the depth D of the recesses of the uneven shape on the first main surface 11 is preferably 10 μm or more and 100 μm or less.

[0031] The depth of the recesses can be measured, for example, by observing the cross section with a microscope. The depth D of the recesses is the height from the recesses to the protrusions of the uneven shape of the first main surface 11, as shown in Figures 1 to 3.

[0032] From the same viewpoint, the width W of the recesses in the uneven shape of first main surface 11 is preferably about 30 to 500 μm, and more preferably about 100 to 300 μm. The width W of the recesses can be measured, for example, by observing the cross section with a microscope. The width W of the recesses is the distance between adjacent protrusions in the uneven shape of first main surface 11, as shown in FIGS. 1 to 3.

[0033] The uneven shape on the first main surface 11 can be suitably formed, for example, by embossing. For example, a laminate in which at least the first design layer 21 and the transparent resin layer 1 are laminated is prepared, and the uneven shape can be formed on the first main surface 11 side of the first design layer 21 by embossing from the first main surface 11 side. In this case, by adjusting the depth of the recesses formed by embossing, the uneven shape can also be formed on the first design layer 21 and the transparent resin layer 1 by a single embossing process.

[0034] Embossing is a known method, for example, by pressing a heat-softened layer with an embossing plate to form a concave-convex pattern on the surface of the laminate, followed by cooling and fixing. A known sheet-fed or rotary embossing machine can be used for embossing.

[0035] Even when other layers such as a surface protective layer 3 and a primer layer are present, the unevenness can be formed in these layers as well by, for example, embossing a laminate in which these layers and the first design layer 21 are laminated on the transparent resin layer 1. In this case, the unevenness formed in each layer can be matched. For example, as shown in FIG. 4, the unevenness of the surface protective layer 3 corresponds to the unevenness of the first design layer 21.

[0036] Each layer that forms the laminate [First design layer 21] The first design layer 21 is a layer provided on the first main surface 11 side of the transparent resin layer 1 for the purpose of imparting decorativeness to the laminate. When the laminate 10 of the present invention is observed from the first main surface 11 side, the design of the first design layer 21 is a design that is visible when the light source 30 on the second main surface 12 side is turned off. When the light source 30 is turned on, the design of the first design layer 21 is difficult to see from the first main surface 11 side, and the designs of the second design layer 22 and the third design layer 23 are visible. On the other hand, when the light source 30 is turned off, the designs of the second design layer 22 and the third design layer 23 are difficult to see when the laminate 10 of the present invention is observed from the first main surface 11 side.

[0037] 6 and 7 each show an image of the laminate 10 of the present invention when viewed from the first main surface 11 side (observer side) with the light source 30 turned on. In FIGS. 6 and 7, the black portion is the design of the third design layer 23, and the three rectangular portions therein (a geometric pattern in FIG. 6 and a gray gradation pattern in FIG. 7) are the design of the second design layer 22. The third design layer 23 functions as a light-blocking layer that blocks light transmission, while the second design layer functions as a pattern layer that transmits light. The design of the first design layer 21 is difficult to see from the first main surface 11 side. That is, for example, in FIG. 6, the observer can see three shining rectangles accompanied by a geometric pattern. Also, for example, in FIG. 7, the observer can see three shining rectangles accompanied by a gradation.

[0038] From the viewpoint of more suitably exerting the effects of the present invention, it is preferable that the surface of the first design layer 21 on the first main surface 11 side has an uneven shape 21a. Furthermore, it is preferable that the uneven shape of the first main surface 11 and the uneven shape 21a on the surface of the first design layer 21 on the first main surface 11 side correspond to each other. As shown in Figures 1 and 2, when the first design layer 21 constitutes the first main surface 11 of the laminate 10, the uneven shape 21a on the surface of the first design layer 21 on the first main surface 11 side matches the uneven shape of the first main surface 11.

[0039] In the laminate 10 of the present invention, it is also preferable that the surface of the first design layer 21 on the second main surface 12 side has an uneven shape. As shown in Figures 1 and 2, it is preferable that the uneven shape 21a on the surface of the first design layer 21 on the first main surface 11 side and the uneven shape on the second main surface 12 side have corresponding shapes.

[0040] Since the first design layer 21 having an uneven shape scatters light, it is easy to achieve the effect of making the designs based on the second design layer 22 and the third design layer 23 less visible when the light is off.

[0041] When the first design layer 21 has an uneven shape, the uneven shape may be provided only on the first main surface 11 side, or may also be provided on the second main surface 12 side, as shown in Figures 1 to 5.

[0042] The first design layer 21 can be, for example, a layer on which a desired pattern is formed using an ink composition. For example, if the first design layer 21 has a monochrome design over the entire surface and the second design layer 22 and the third design layer 23 have patterned designs, the monochrome design over the entire surface of the first design layer 21 can be seen when the light source is turned off, and the designs of the second design layer 22 and the third design layer 23 cannot be seen, but when the light source is turned on, the patterned designs of the second design layer 22 and the third design layer 23 (for example, the aforementioned patterns such as symbols and text information) can be seen.

[0043] The first design layer 21 may be provided partially on the transparent resin layer 1 or may be provided over the entire surface, and is preferably provided over the entire surface.

[0044] The first design layer 21 can be formed, for example, by printing an ink for forming the first design layer onto the transparent resin layer 1 using a conventionally known printing method such as gravure printing, silk screen printing, offset printing, etc. Examples of the ink composition used to form the first design layer 21 include the same inks as those exemplified for the second design layer 22 described below, including binders, colorants, etc.

[0045] The patterns formed by the first design layer 21 are exemplified as the same as those exemplified for the second design layer 22 described below, but as mentioned above, it is preferable that the first design layer 21 have a monochrome design all over.

[0046] The first design layer 21 may also include a portion made of a metal thin film. The metals and forming methods for forming the metal thin film may be the same as those exemplified for the second design layer 22.

[0047] The thickness of the first design layer 21 is not particularly limited, but the lower limit is preferably 1 μm or more, and the upper limit is preferably 20 μm or less, more preferably 10 μm or less, with preferred ranges being about 1 to 20 μm, and about 1 to 10 μm. Note that if the first design layer 21 has an uneven shape, the thickness of the first design layer 21 is the thickness at the positions of the convex portions of the uneven shape.

[0048] To more effectively achieve the effects of the present invention, the optical density (OD value) of the first design layer 22 is preferably 2.5 or less and preferably 0.3 or more, with a preferred range of 0.3 to 2.5. It is preferable that the sum of the OD value of the first design layer and the OD value of the second design layer (described below) is less than 3.5.

[0049] [Transparent resin layer 1] The transparent resin layer 1 is provided between the first design layer 21 and the second and third design layers 22 and 23, and when the light source 30 is turned on, it functions to make the design that appears when the light source 30 is turned off (for example, the design of the first design layer 21) less visible while making the designs of the second design layer 22 and the third design layer 23 more visible, and when the light source 30 is turned off, it functions to make the design that appears when the light source 30 is turned off (for example, the design of the first design layer 21) more visible while making the designs of the second design layer 22 and the third design layer 23 less visible. If the transparent resin layer 1 were not present, for example, even when the light source 30 is turned on, the design that appears when the light source 30 is turned off (for example, the design of the first design layer 21) would be visible together with the designs of the second design layer 22 and the third design layer 23, making it difficult to achieve the object of the present invention.

[0050] As shown in FIG. 5 , the transparent resin layer 1 is transparent enough to transmit light from the light source 30 when the light source 30 is disposed on the second main surface 12 side (in the present invention, "transparent" includes "semi-transparent"). That is, the transparent resin layer 1 is usually transparent (colorless transparent, colored transparent, or semi-transparent), and may be colored as long as the designs based on the second design layer 22 and the third design layer 23 are visible when the laminate 10 of the present invention is lit when observed from the first main surface 11 side. For example, the transparent resin layer 1 may contain a matting agent such as silica, a colorant, or the like. The colorants exemplified for the second design layer 22 described below can be used as the colorant. The transparent resin layer 1 may also be painted to adjust the color, or a pattern may be formed to impart design features.

[0051] As described above, the transparent resin layer 1 may have an uneven shape. When the transparent resin layer 1 has an uneven shape, the uneven shape is preferably provided on the first main surface 11 side (the transparent resin layer 1 has an uneven shape 1a on the first main surface 11 side) as shown in FIGS. 1 to 5 . The uneven shape 1a on the first main surface 11 side of the transparent resin layer 1 corresponds to, for example, the uneven shape of the first main surface 11 described above and the uneven shape of the first design layer 21. That is, in the laminate 10 of the present invention, the uneven shape can be provided so as to extend from the first main surface 11 to the transparent resin layer 1. Note that the surface on the second main surface 12 side of the transparent resin layer 1 preferably has a shape that is relatively flatter than the uneven shape of the first main surface 11 of the laminate 10, and more preferably is substantially flat. When the surface of the transparent resin layer 1 on the second main surface 12 side is flat, the layer in contact with the surface of the transparent resin layer 1 on the second main surface 12 side (for example, the surface of the second design layer 22 in contact with the surface of the transparent resin layer 1 on the second main surface 12 side, or the surface of the third design layer 23 in contact with the surface of the transparent resin layer 1 on the second main surface 12 side) preferably has a shape that is relatively flatter than the uneven shape of the first main surface 11 of the laminate 10, and more preferably is substantially flat. Note that, although there are no particular restrictions on "relatively flat," the maximum height roughness Rz of the surface of the transparent resin layer 1 on the second main surface 12 side is preferably 50% or less of the Rz of the uneven shape of the first main surface 11. Rz is measured in accordance with JIS B0601 (1996).

[0052] The transparent resin layer 1 can be made of a transparent resin from the viewpoint of making the laminate 10 suitable for three-dimensional molding and suitably expressing different designs when the light source is on and off. The transparent resin is preferably made of a transparent thermoplastic resin. Examples of transparent thermoplastic resins include, but are not limited to, transparent acrylonitrile-butadiene-styrene resin (hereinafter sometimes referred to as "ABS resin"), acrylic resin; polyolefin resins such as polypropylene and polyethylene; polycarbonate resin; vinyl chloride resin; polyethylene terephthalate (PET) resin; and acrylonitrile-styrene-acrylic ester resin. Among these, the transparent resin layer 1 is preferably made of a transparent acrylic resin. The transparent resin layer 1 may be made of one type of resin or two or more types of resins.

[0053] The thickness of the transparent resin layer 1 is not particularly limited, but from the viewpoint of making the laminate 10 suitable for three-dimensional molding and suitably expressing a design that differs when the light source is on and off, the lower limit is preferably 50 μm or more, more preferably 70 μm or more, and the upper limit is preferably 200 μm or less, more preferably 150 μm or less, and preferred ranges include about 50 to 200 μm, about 50 to 150 μm, about 70 to 200 μm, and about 70 to 150 μm. Note that when the transparent resin layer 1 has an uneven shape, the thickness of the transparent resin layer 1 is the thickness at the positions of the convex portions of the uneven shape.

[0054] To improve adhesion to adjacent layers, the transparent resin layer 1 may be subjected to physical or chemical surface treatments such as oxidation or roughening on one or both surfaces as needed. Examples of oxidation methods used to treat the surface of the transparent resin layer 1 include corona discharge treatment, plasma treatment, chromium oxidation treatment, flame treatment, hot air treatment, and ozone ultraviolet treatment. Examples of roughening methods used to treat the surface of the transparent resin layer 1 include sandblasting and solvent treatment. These surface treatments are appropriately selected depending on the type of resin constituting the transparent resin layer 1, but from the standpoints of effectiveness, operability, and the like, corona discharge treatment is preferred.

[0055] To more suitably exert the effects of the present invention, the total light transmittance of the transparent resin layer 1 is preferably about 70% or more, more preferably about 80% or more, and even more preferably about 90% or more. The total light transmittance is measured using a haze meter in accordance with JIS K7361-1.

[0056] [Second design layer 22] The second design layer 22 is a layer provided on the second main surface 12 side of the transparent resin layer 1 for the purpose of imparting decorativeness to the laminate 10. The design of the second design layer 22 is a design that is visible from the first main surface 11 side when the light source on the second main surface 12 side is turned on, and when the light source 30 is turned off, the design of the second design layer 22 is difficult to see from the first main surface 11 side, and the design of the first design layer 21 is visible.

[0057] When the laminate 10 of the present invention is observed from the first main surface 11 side, the second design layer 22, together with the third design layer 23 described below, is arranged to reveal a design when the light source 30 is turned on. For example, if the second design layer 22 and the third design layer 23 have patterned designs and the first design layer 21 described above has a monochrome design across the entire surface, when the light source 30 is turned off, the monochrome design across the entire surface of the first design layer 21 is visible, and the designs of the second design layer 22 and the third design layer 23 are not visible, and when the light source 30 is turned on, the patterned design of the second design layer 22 and the third design layer 23 (for example, a picture such as a symbol or text information, described below) is visible.

[0058] In addition, when the main surface of one side of the laminate is the entire surface, the second design layer 22 may be provided partially or entirely, and it is preferable that it be provided entirely.

[0059] The optical density (OD value) of the second design layer 22 is preferably 3.0 or less, and preferably 0.5 or more, with a preferred range of 0.5 to 3.0.

[0060] The second design layer 22 can be, for example, a layer on which a desired pattern is formed using an ink composition. The second design layer 22 can be formed, for example, by printing an ink for forming the second design layer using a conventionally known printing method such as gravure printing, silk screen printing, or offset printing. The ink composition used to form the second design layer 22 is an appropriate mixture of a binder, a colorant such as a pigment or dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, a hardener, etc.

[0061] The binder used in the ink composition is not particularly limited, but examples thereof include polyurethane resin, vinyl chloride / vinyl acetate copolymer resin, vinyl chloride / vinyl acetate / acrylic copolymer resin, chlorinated polypropylene resin, acrylic resin, polyester resin, polyamide resin, butyral resin, polystyrene resin, nitrocellulose resin, cellulose acetate resin, etc. These binders may be used alone or in combination of two or more.

[0062] The colorant used in the ink composition is not particularly limited, but examples thereof include inorganic pigments such as carbon black (ink), iron black, titanium white, antimony white, yellow lead, titanium yellow, red iron oxide, cadmium red, ultramarine blue, and cobalt blue; organic pigments or dyes such as quinacridone red, isoindolinone yellow, and phthalocyanine blue; metal pigments consisting of scaly flakes of aluminum, brass, or the like; and pearlescent pigments consisting of scaly flakes of titanium dioxide-coated mica, basic lead carbonate, or the like.

[0063] The pattern formed by the second design layer 22 is not particularly limited, and examples include symbols and text information, as well as geometric patterns such as dot patterns, line patterns, and carbon patterns, gradation patterns, wood grain patterns, stone patterns that imitate the surface of rock such as marble patterns (e.g., travertine marble patterns), fabric patterns that imitate fabric or cloth-like patterns, tile patterns, brickwork patterns, etc., and may also be patterns such as marquetry or patchwork that combine these, or may be a single solid color (so-called solid color). These patterns are formed by multicolor printing using the usual process colors of yellow, red, blue, and black, but can also be formed by multicolor printing using spot colors, which is performed by preparing plates for the individual colors that make up the pattern.

[0064] The second design layer 22 may also include a portion composed of a metal thin film. Examples of metals that form the metal thin film include tin, indium, chromium, aluminum, nickel, copper, silver, gold, platinum, zinc, and alloys containing at least one of these. The method for forming the metal thin film is not particularly limited, and examples include vapor deposition methods such as vacuum vapor deposition, sputtering, and ion plating using the above metals. In addition, to improve adhesion to adjacent layers, a primer layer made of a known resin may be provided on the front and back surfaces of the metal thin film.

[0065] As described above, the surface 22a of the second design layer 22 on the first main surface 11 side is relatively flatter than the uneven shape of the first main surface 11. The surface 22a of the second design layer 22 on the first main surface 11 side may have a shape that is relatively flatter than the uneven shape of the first main surface 11. Specifically, the depth of the recesses of the surface 22a of the second design layer 22 on the first main surface 11 side is relatively smaller than the depth of the recesses of the uneven shape of the first main surface 11. From the viewpoint of more suitably exerting the effects of the present invention, it is preferable that the surface 22a of the second design layer 22 on the first main surface 11 side is substantially flat. For example, it is preferable that the uneven shape of the first main surface 11 is not reflected in the shape of the surface 22a of the second design layer 22 on the first main surface 11 side, and even in this case, it is acceptable for the surface 22a to have a slight uneven shape. There are no particular restrictions on "relatively flat," but it is preferable that the maximum height roughness Rz of the surface on the first main surface 11 side, which is the second design layer 22 side, is 50% or less of the Rz of the uneven shape of the first main surface 11. Rz is measured in accordance with JIS B0601 (1996). In the region where the transparent resin layer 1 and the second design layer 22 are in contact, the shape of the surface on the second main surface side of the transparent resin layer and the shape of the surface on the first main surface side of the second design layer are complementary to each other.

[0066] The surface of the second design layer 22 on the second main surface 12 side also preferably has a relatively flat shape compared to the uneven shape of the first main surface 11, and is more preferably approximately flat. While there are no particular restrictions on "relatively flat," it is preferable that the maximum height roughness Rz of the surface on the second main surface 12 side of the second design layer 22 be 50% or less of the Rz of the uneven shape of the first main surface 11. Rz is measured in accordance with JIS B0601 (1996).

[0067] The thickness of the second design layer 22 is not particularly limited, but the lower limit is preferably 1 μm or more, and the upper limit is preferably 30 μm or less, more preferably 20 μm or less, with preferred ranges being about 1 to 30 μm and about 1 to 20 μm. Note that if the second design layer 22 has an uneven shape, the thickness of the second design layer 22 is the thickness at the positions of the convex portions of the uneven shape.

[0068] [Third design layer 23] The third design layer 23 is a layer provided on the first main surface 11 or second main surface 12 of the second design layer 22 for the purpose of imparting decorativeness to the laminate 10. Specifically, as shown in FIG. 2, when the third design layer 23 is provided on the first main surface 11 of the second design layer 22, the third design layer 23 is present between the transparent resin layer 1 and the second design layer 22. Also, as shown in FIG. 3, when the laminate 10 includes the transparent substrate layer 4 described below and the third design layer 23 is provided on the second main surface 12 of the second design layer 22, the third design layer 23 is present between the second design layer 22 and the transparent substrate layer 4. 2, when the third design layer 23 is provided on the first main surface 11 side of the second design layer 22, in the area where the second design layer and the transparent resin layer are in direct contact, the surface on the first main surface side of the second design layer should be relatively flatter than the uneven shape of the first main surface. In other words, in the area where the third design layer 23 is not provided, the surface on the first main surface side of the second design layer should be relatively flatter than the uneven shape of the first main surface.

[0069] The third design layer 23 is provided partially when the main surface of the laminate 10 is the entire surface. When the laminate 10 of the present invention is observed from the first main surface 11 side, the third design layer 23, together with the second design layer 22 described above, is provided so as to reveal a design when the light source 30 is turned on. As described above, for example, if the second design layer 22 and the third design layer 23 have patterned designs and the first design layer 21 has a monochromatic design over the entire surface, when the light source 30 is turned off, the monochromatic design over the entire surface of the first design layer 21 is visible, and the designs of the second design layer 22 and the third design layer 23 are not visible, and when the light source 30 is turned on, the patterned design (for example, a picture such as a symbol or text information, as described below) of the second design layer 22 and the third design layer 23 can be visible.

[0070] The optical density (OD value) of the third design layer 23 is preferably 3.5 or more and preferably 7.0 or less, with a preferred range being 3.5 to 7.0.

[0071] The third design layer 23 can be formed, for example, by printing an ink for forming the third design layer using a conventionally known printing method such as gravure printing, silk screen printing, offset printing, etc. Examples of the ink composition used to form the third design layer 23 include the same ones as those exemplified for the second design layer 22 described above, including binders, colorants, etc.

[0072] The patterns formed by the third design layer 23 are exemplified as the same as those exemplified for the second design layer 22 described above, but as mentioned above, it is preferable that the third design layer 23 be formed partially and, together with the second design layer 22, express the desired design.

[0073] The third design layer 23 may also include a portion made of a metal thin film. The metals and forming methods for forming the metal thin film may be the same as those exemplified for the second design layer 22.

[0074] The thickness of the third design layer 23 is not particularly limited, but the lower limit is preferably 1 μm or more, and the upper limit is preferably 20 μm or less, more preferably 10 μm or less, with preferred ranges being approximately 1 to 20 μm and approximately 1 to 10 μm.

[0075] [Transparent base layer 4] The transparent substrate layer 4 is a layer that is provided as needed on the second main surface 12 side of the second design layer 22 and the third design layer 23 in order to provide rigidity and maintain the shape of the laminate 10. When the laminate 10 is in a sheet form, the transparent substrate layer 4 is provided to make the laminate suitable for vacuum forming (three-dimensional forming) by insert molding or the like.

[0076] As shown in Figures 3 to 5, the transparent substrate layer 4 is transparent enough to transmit light from the light source 30 when the light source 30 is disposed on the second main surface 12 side (as mentioned above, in the present invention, "transparent" also includes "semi-transparent"). That is, the transparent substrate layer 4 is usually transparent (colorless transparent, colored transparent, semi-transparent), and may be colored as long as the designs based on the second design layer 22 and the third design layer 23 are visible when the laminate 10 of the present invention is lit when observed from the first main surface 11 side. For example, the transparent substrate layer 4 may contain a matting agent such as silica, a colorant, etc. As the colorant, the colorants exemplified for the second design layer 22 described above can be used.

[0077] The transparent substrate layer 4 can be made of a transparent resin, a paper substrate, or the like, from the viewpoint of making the laminate 10 suitable for three-dimensional molding and suitably expressing different designs when the light source is on and off. The transparent resin is preferably made of a transparent thermoplastic resin. Examples of transparent thermoplastic resins include, but are not limited to, transparent acrylonitrile-butadiene-styrene resin (hereinafter sometimes referred to as "ABS resin"), acrylic resin; polyolefin resins such as polypropylene and polyethylene; polycarbonate resin; vinyl chloride resin; polyethylene terephthalate (PET) resin; and acrylonitrile-styrene-acrylic ester resin. Among these, the transparent substrate layer 4 is preferably made of a transparent ABS resin. The transparent substrate layer 4 may be made of one type of resin or two or more types of resins.

[0078] The thickness of the transparent substrate layer 4 is not particularly limited, but from the viewpoint of making the laminate 10 suitable for three-dimensional molding and suitably expressing a design that differs depending on whether the light source is on or off, the lower limit is preferably 50 μm or more, more preferably 100 μm or more, and the upper limit is preferably 1000 μm or less, more preferably 500 μm or less, with preferred ranges being about 50 to 1000 μm and about 100 to 500 μm. More specifically, when a transparent ABS resin is used as the transparent substrate layer 4, the thickness is preferably about 100 to 500 μm, and even more preferably 200 to 400 μm.

[0079] The transparent substrate layer 4 may be subjected to a physical or chemical surface treatment such as an oxidation method or a roughening method on one or both surfaces as needed to improve adhesion to adjacent layers. Examples of oxidation methods used for surface treatment of the transparent substrate layer 4 include corona discharge treatment, plasma treatment, chromium oxidation treatment, flame treatment, hot air treatment, and ozone ultraviolet treatment. Examples of roughening methods used for surface treatment of the transparent substrate layer 4 include sandblasting and solvent treatment. These surface treatments are appropriately selected depending on the type of resin constituting the transparent substrate layer 4, but from the viewpoints of effectiveness, operability, etc., corona discharge treatment is preferred.

[0080] [Surface protection layer 3] The surface protective layer 3 is a layer that is provided as needed to protect the surface of the laminate 10. In the laminate 10, the surface protective layer 3 is provided on the outermost surface on the first main surface 11 side.

[0081] As described above, even when the laminate 10 has the surface protective layer 3, the surface protective layer 3 can be formed with a concave-convex shape by embossing the laminate 10 together with the first design layer 21, the transparent resin layer 1, etc. Thus, as shown in the schematic diagrams of Figures 4 and 5, the surface protective layer 3 may have a concave-convex shape 3a. The concave-convex shape 3a may be provided on the first main surface 11 side, or may be provided on the second main surface 12 side.

[0082] From the viewpoint of more suitably exerting the effects of the present invention, it is preferable that the surface of the surface protective layer 3 on the first main surface 11 side has an uneven shape 3a. Furthermore, it is preferable that the uneven shape of the first main surface 11 and the uneven shape 3a of the surface of the surface protective layer 3 on the first main surface 11 side correspond to each other. As shown in Figures 4 and 5, when the surface protective layer 3 forms the first main surface 11 of the laminate 10, the uneven shape 3a of the surface of the surface protective layer 3 on the first main surface 11 side matches the uneven shape of the first main surface 11.

[0083] In the laminate 10 of the present invention, the surface protective layer 3 may be provided over the entire surface of the first main surface 11, or may be provided partially. However, from the viewpoint of suitably protecting the surface of the laminate 10, it is preferable that the surface protective layer 3 be provided over the entire surface of the first main surface 11.

[0084] Furthermore, the surface protection layer 3 is usually transparent (colorless transparent, colored transparent, translucent), but may be colored or may contain a matting agent such as silica, as long as the designs of the second design layer 22 and the third design layer 23 are visible when the light source 30 is turned on when the laminate 10 of the present invention is observed from the first main surface 11 side. As the colorant, the colorants exemplified for the first design layer 21 described above can be used.

[0085] The material constituting the surface protective layer 3 is not particularly limited, and examples thereof include thermoplastic resins, thermosetting resins, and ionizing radiation curable resins. Among these, from the viewpoint of improving scratch resistance, the surface protective layer 3 is preferably composed of a cured product of an ionizing radiation curable resin composition. The ionizing radiation curable resin used to form the surface protective layer 3 will be described in detail below.

[0086] (ionizing radiation curable resin) The ionizing radiation-curable resin used to form the surface protective layer 3 is a resin that crosslinks and cures upon exposure to ionizing radiation. Specific examples include a mixture of at least one of prepolymers, oligomers, and monomers, each of which has a polymerizable unsaturated bond or epoxy group in its molecule. Here, ionizing radiation refers to electromagnetic waves or charged particle beams that have an energy quantum capable of polymerizing or crosslinking molecules. Typically, ultraviolet (UV) or electron beams (EB) are used, but ionizing radiation also includes other types of electromagnetic waves, such as X-rays and gamma rays, as well as charged particle beams, such as alpha rays and ion beams. Among ionizing radiation-curable resins, electron beam-curable resins are suitable for use in forming the surface protective layer 3 because they can be made solvent-free, do not require a photopolymerization initiator, and exhibit stable curing properties.

[0087] The monomer used as the ionizing radiation curable resin is preferably a (meth)acrylate monomer having a radical polymerizable unsaturated group in the molecule, and among these, a polyfunctional (meth)acrylate monomer is preferred. The polyfunctional (meth)acrylate monomer may be a (meth)acrylate monomer having two or more (difunctional or more), preferably three or more (trifunctional or more) polymerizable unsaturated bonds in the molecule. Specific examples of the polyfunctional (meth)acrylate include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphate di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, isocyanurate di(meth)acrylate, trimethylol propionate, and the like. Examples of suitable monomers include propane tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(acryloxyethyl)isocyanurate, propionic acid-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene oxide-modified dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate. These monomers may be used alone or in combination of two or more.

[0088] The oligomer used as the ionizing radiation-curable resin is preferably a (meth)acrylate oligomer having a radically polymerizable unsaturated group in the molecule, and particularly preferably a polyfunctional (meth)acrylate oligomer having two or more (bifunctional or more) polymerizable unsaturated bonds in the molecule. Examples of polyfunctional (meth)acrylate oligomers include polycarbonate (meth)acrylate, acrylic silicone (meth)acrylate, urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, polybutadiene (meth)acrylate, silicone (meth)acrylate, and oligomers having a cationically polymerizable functional group in the molecule (e.g., novolac epoxy resin, bisphenol epoxy resin, aliphatic vinyl ether, aromatic vinyl ether, etc.). Here, the polycarbonate (meth)acrylate is not particularly limited as long as it has a carbonate bond in the polymer main chain and a (meth)acrylate group at the end or side chain. For example, it can be obtained by esterifying a polycarbonate polyol with (meth)acrylic acid. The polycarbonate (meth)acrylate may be, for example, a urethane (meth)acrylate having a polycarbonate skeleton. The urethane (meth)acrylate having a polycarbonate skeleton can be obtained, for example, by reacting a polycarbonate polyol with a polyvalent isocyanate compound and a hydroxy (meth)acrylate. The acrylic silicone (meth)acrylate can be obtained by radical copolymerization of a silicone macromonomer with a (meth)acrylate monomer. The urethane (meth)acrylate can be obtained, for example, by esterifying a polyurethane oligomer obtained by reacting a polyether polyol or polyester polyol with a polyisocyanate compound with (meth)acrylic acid. Epoxy (meth)acrylate can be obtained, for example, by reacting (meth)acrylic acid with the oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolac type epoxy resin to esterify it.Carboxyl-modified epoxy (meth)acrylates obtained by partially modifying this epoxy (meth)acrylate with a dibasic carboxylic acid anhydride can also be used. Polyester (meth)acrylates can be obtained, for example, by esterifying the hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends, obtained by condensation of a polycarboxylic acid and a polyhydric alcohol, with (meth)acrylic acid, or by esterifying the terminal hydroxyl groups of an oligomer obtained by adding an alkylene oxide to a polycarboxylic acid with (meth)acrylic acid. Polyether (meth)acrylates can be obtained by esterifying the hydroxyl groups of a polyether polyol with (meth)acrylic acid. Polybutadiene (meth)acrylates can be obtained by adding (meth)acrylic acid to the side chain of a polybutadiene oligomer. Silicone (meth)acrylates can be obtained by adding (meth)acrylic acid to the end or side chain of a silicone having a polysiloxane bond in its main chain. These oligomers may be used alone or in combination of two or more.

[0089] Among the above-mentioned ionizing radiation curable resins, polycarbonate (meth)acrylate is preferably used from the viewpoint of obtaining superior three-dimensional moldability while further improving the appearance of the design, abrasion resistance, and moldability. It is also preferable to use a combination of polycarbonate (meth)acrylate and urethane (meth)acrylate.

[0090] (Other added ingredients) Various additives can be blended into the surface protective layer 3 depending on the desired physical properties of the surface protective layer 3. Examples of such additives include weather resistance improvers such as ultraviolet absorbers and light stabilizers, abrasion resistance improvers, polymerization inhibitors, crosslinking agents, infrared absorbers, antistatic agents, adhesion improvers, leveling agents, thixotropy-imparting agents, coupling agents, plasticizers, antifoaming agents, fillers, solvents, and colorants. These additives can be appropriately selected from commonly used additives. Furthermore, reactive ultraviolet absorbers and light stabilizers having a polymerizable group such as a (meth)acryloyl group in the molecule can also be used as the ultraviolet absorber and light stabilizer.

[0091] (Formation of surface protective layer 3) The surface protection layer 3 can be formed, for example, by preparing an ionizing radiation curable resin composition containing an ionizing radiation curable resin, applying this to form an uncured resin layer, and crosslinking and curing the uncured resin layer.

[0092] The viscosity of the ionizing radiation curable resin composition may be any viscosity that allows the formation of an uncured resin layer by the coating method described below.

[0093] In the present invention, the prepared resin is applied by a known method such as gravure coating, bar coating, roll coating, reverse roll coating or comma coating, preferably gravure coating, to form an uncured resin layer.

[0094] The uncured resin layer thus formed is irradiated with ionizing radiation such as an electron beam or ultraviolet light to cure the uncured resin layer and form the surface protection layer 3. When an electron beam is used as the ionizing radiation, the acceleration voltage can be appropriately selected depending on the resin used and the thickness of the layer, but a typical acceleration voltage is about 70 to 300 kV.

[0095] In electron beam irradiation, the higher the acceleration voltage, the greater the penetration ability, so when a resin that is easily deteriorated by electron beam irradiation is used below the surface protective layer 3, the acceleration voltage is selected so that the penetration depth of the electron beam is substantially equal to the thickness of the surface protective layer 3. This makes it possible to prevent excess electron beam irradiation of layers located below the surface protective layer 3, and minimize deterioration of each layer due to excess electron beams.

[0096] The irradiation dose is preferably an amount at which the crosslink density of the surface protective layer 3 becomes saturated, and is usually selected within the range of 5 to 300 kGy (0.5 to 30 Mrad), preferably 10 to 50 kGy (1 to 5 Mrad).

[0097] Furthermore, the electron beam source is not particularly limited, and various electron beam accelerators such as Cockcroft-Walton type, Van de Graaf type, resonant transformer type, insulating core transformer type, linear type, dynamitron type, and high frequency type can be used.

[0098] When ultraviolet rays are used as the ionizing radiation, light rays containing ultraviolet rays with a wavelength of 190 to 380 nm may be emitted. The ultraviolet source is not particularly limited, but examples thereof include high-pressure mercury lamps, low-pressure mercury lamps, metal halide lamps, and carbon arc lamps.

[0099] The surface protective layer 3 thus formed may be subjected to treatment to impart functions such as hard coating function, anti-fogging coating function, anti-fouling coating function, anti-glare coating function, anti-reflection coating function, ultraviolet shielding coating function, and infrared shielding coating function by adding various additives.

[0100] The thickness of the surface protection layer 3 is not particularly limited, but from the viewpoint of imparting surface protection performance such as scratch resistance and chemical resistance to the surface, the lower limit is preferably 5 μm or more, more preferably 10 μm or more, and the upper limit is preferably 30 μm or less, more preferably 20 μm or less, and preferred ranges include approximately 5 to 20 μm, approximately 5 to 10 μm, and approximately 5 to 15 μm.

[0101] [Primer layer] The primer layer is a layer that is provided between the surface protection layer 3 and the first design layer 21, if necessary, so as to be in contact with the surface on the second main surface 12 side of the surface protection layer 3, for the purpose of increasing adhesion between the surface protection layer 3 and the layer located below it.

[0102] The primer composition constituting the primer layer preferably uses a binder resin such as a urethane resin, a (meth)acrylic resin, a (meth)acrylic-urethane copolymer resin, a vinyl chloride-vinyl acetate copolymer, a polyester resin, a butyral resin, chlorinated polypropylene, or chlorinated polyethylene, and these resins can be used alone or in combination. Among these, urethane resins, (meth)acrylic resins, and (meth)acrylic-urethane copolymer resins are preferred.

[0103] The urethane resin can be a polyurethane containing a polyol (polyhydric alcohol) as the base and an isocyanate as the crosslinking agent (curing agent). The polyol can have two or more hydroxyl groups in its molecule, such as polyester polyol, polyethylene glycol, polypropylene glycol, acrylic polyol, or polyether polyol. The isocyanate can be a polyisocyanate having two or more isocyanate groups in its molecule, an aromatic isocyanate such as 4,4-diphenylmethane diisocyanate, or an aliphatic (or alicyclic) isocyanate such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, or hydrogenated diphenylmethane diisocyanate. It can also be a mixture of urethane resin and butyral resin.

[0104] It is preferable to use a combination of an acrylic polyol or a polyester polyol as the polyol and hexamethylene diisocyanate or 4,4-diphenylmethane diisocyanate as the crosslinking agent, and it is particularly preferable to use a combination of an acrylic polyol and hexamethylene diisocyanate.

[0105] Examples of the (meth)acrylic resin include a homopolymer of a (meth)acrylic acid ester, a copolymer of two or more different (meth)acrylic acid ester monomers, or a copolymer of a (meth)acrylic acid ester and another monomer. Specifically, (meth)acrylic resins made of a homopolymer or copolymer containing a (meth)acrylic acid ester, such as polymethyl(meth)acrylate, polyethyl(meth)acrylate, polypropyl(meth)acrylate, polybutyl(meth)acrylate, a methyl(meth)acrylate-butyl(meth)acrylate copolymer, an ethyl(meth)acrylate-butyl(meth)acrylate copolymer, an ethylene-methyl(meth)acrylate copolymer, or a styrene-methyl(meth)acrylate copolymer, are preferably used.

[0106] As the (meth)acrylic-urethane copolymer resin, for example, an acrylic-urethane (polyester urethane) block copolymer resin is preferred. As the curing agent, the various isocyanates described above are used. If desired, the acrylic / urethane ratio (mass ratio) of the acrylic-urethane (polyester urethane) block copolymer resin is preferably adjusted within the range of 9 / 1 to 1 / 9, more preferably 8 / 2 to 2 / 8.

[0107] The thickness of the primer layer is not particularly limited, but is, for example, about 0.5 to 20 μm, and preferably about 1 to 5 μm.

[0108] The primer layer is formed using a primer composition by a conventional coating method such as gravure coating, gravure reverse coating, gravure offset coating, spinner coating, roll coating, reverse roll coating, kiss coating, wheel coating, dip coating, solid coating by silk screen, wire bar coating, flow coating, comma coating, flow coating, brush coating, spray coating, or transfer coating. Here, the transfer coating method is a method in which a coating film of the primer layer or adhesive layer is formed on a thin sheet (film substrate), and then the surface of the target layer in the laminate is coated with the resulting coating.

[0109] [Adhesive layer] The adhesive layer (not shown) is a layer provided as needed for the purpose of bonding each layer together. The adhesive layer is provided, for example, on at least one side of the second design layer 22, and can bond the second design layer 22 to the transparent resin layer 1, the third design layer 23, the transparent substrate layer 4, or the like.

[0110] The adhesive layer may be made of a thermoplastic resin, a curable resin, or the like, depending on the type of layer to be adhered.

[0111] Examples of thermoplastic resins used to form the adhesive layer include acrylic resins, acrylic-modified polyolefin resins, chlorinated polyolefin resins, vinyl chloride / vinyl acetate copolymers, thermoplastic urethane resins, thermoplastic polyester resins, polyamide resins, rubber-based resins, etc. These thermoplastic resins may be used alone or in combination of two or more.

[0112] Examples of the thermosetting resin used to form the adhesive layer include urethane resin, epoxy resin, etc. These thermosetting resins may be used alone or in combination of two or more.

[0113] The thickness of the adhesive layer is, for example, about 0.1 to 20 μm.

[0114] [Back adhesive layer] The back adhesive layer (not shown) is a layer that is provided as needed on the second main surface 12 side (the side opposite to the first design layer 21) of the transparent substrate layer 4 when a molded resin layer 5 is provided on the laminate 10, for the purpose of increasing adhesion with the molded resin layer 5 when molding the laminate 10.

[0115] For the back surface adhesive layer, a thermoplastic resin or a curable resin is used depending on the type of molded resin layer 5 used in the laminate 10.

[0116] Examples of thermoplastic resins used to form the back surface adhesive layer include acrylic resins, acrylic-modified polyolefin resins, chlorinated polyolefin resins, vinyl chloride / vinyl acetate copolymers, thermoplastic urethane resins, thermoplastic polyester resins, polyamide resins, rubber-based resins, etc. These thermoplastic resins may be used alone or in combination of two or more.

[0117] Examples of the thermosetting resin used to form the back surface adhesive layer include urethane resin, epoxy resin, etc. These thermosetting resins may be used alone or in combination of two or more.

[0118] The thickness of the back surface adhesive layer is not particularly limited as long as it can adhere the molded resin layer 5, and may be, for example, about 0.1 to 20 μm.

[0119] [Molded resin layer 5] In the laminate 10 of the present invention, a transparent molded resin layer 5 may be integrally molded on the second main surface 12 side. That is, as shown in FIG. 5 , the laminate 10 of the present invention is a laminate comprising at least the molded resin layer 5, the second design layer, the transparent resin layer 1, and the first design layer 21, in this order, and further comprising a third design layer 23 on the first main surface 11 side or the second main surface 12 side of the second design layer 22. Like the transparent substrate layer 4, the molded resin layer 5 is transparent enough to transmit light from a light source 30 when the light source 30 is disposed on the second main surface 12 side. That is, the molded resin layer 5 is typically transparent (colorless transparent, colored transparent, translucent), and may be colored as long as the designs of the second design layer 22 and the third design layer 23 are visible when the laminate 10 of the present invention is observed from the first main surface 11 side. For example, the molded resin layer 5 may contain a matting agent such as silica, a colorant, or the like. As the colorant, the colorants exemplified for the second design layer 22 described above can be used.

[0120] The molded resin layer 5 can be made of a transparent resin or the like. The transparent resin is preferably made of a transparent thermoplastic resin. Examples of transparent thermoplastic resins include, but are not limited to, transparent acrylonitrile-butadiene-styrene resin (hereinafter sometimes referred to as "ABS resin"), acrylic resin; polyolefin resins such as polypropylene and polyethylene; polycarbonate resin; vinyl chloride resin; polyethylene terephthalate (PET) resin; and acrylonitrile-styrene-acrylic ester resin. Among these, the molded resin layer 5 is preferably made of a polycarbonate resin because of its excellent transparency. The molded resin layer 5 may be made of one type of resin or two or more types of resins. The molded resin layer 5 may have a shape such as a plate or a molded body.

[0121] The laminate 10 including the molded resin layer 5 is produced by laminating the molded resin layer 5 using a known method. When the molded resin layer 5 is a resin molded body, it may be produced by an injection molding method such as an insert molding method.

[0122] In the insert molding method, first, in the vacuum forming process, the laminate before laminating the molded resin layer 5 (i.e., a laminate comprising, in order from the second main surface 12 side, at least the second design layer 22, the transparent resin layer 1, and the first design layer 21, and further comprising the third design layer 23 on either the first main surface 11 side or the second main surface 12 side of the second design layer 22) is vacuum-formed in advance into the surface shape of the molded product (offline preforming) using a vacuum forming mold, and then excess portions are trimmed as necessary to obtain a molded sheet. This molded sheet is inserted into an injection mold, the injection mold is clamped, and a fluid resin is injected into the mold from the transparent substrate layer 4 side of the laminate and solidified, and the molded sheet is integrated with the outer surface of the resin molded product at the same time as injection molding, thereby producing the laminate 10 comprising the molded resin layer 5.

[0123] More specifically, the laminate 10 including the molded resin layer 5 is manufactured by an insert molding method including the following steps. a vacuum forming process in which the laminate before laminating the molded resin layer 5 is preformed into a three-dimensional shape using a vacuum forming mold; a trimming process in which excess parts of the vacuum formed laminate are trimmed to obtain a molded sheet; and an integration process in which the molded sheet is inserted into an injection mold, the injection mold is closed, and the resin in a fluid state is injected into the injection mold from the transparent substrate layer 4 side to integrate the resin and the molded sheet.

[0124] In the vacuum forming step of the insert molding method, the laminate may be heated and molded. The heating temperature is not particularly limited and may be selected appropriately depending on the type of resin constituting the laminate, the thickness of the laminate, etc., but is usually about 120°C to 200°C. In the integration step, the temperature of the resin in a fluid state is not particularly limited, but is usually about 180°C to 320°C.

[0125] As described above, the molded resin layer 5 may be formed by selecting a resin according to the intended use. The molded resin forming the molded resin layer 5 may be the above-mentioned thermoplastic resin or a thermosetting resin.

[0126] Examples of the thermosetting resin include urethane resin, epoxy resin, etc. These thermosetting resins may be used alone or in combination of two or more.

[0127] The laminate 10 of the present invention exhibits different designs when the light source is on and when it is off, and therefore, when used in combination with a light source, it can be used as, for example, interior or exterior materials for vehicles such as automobiles; fittings such as window frames and door frames; interior materials for buildings such as walls, floors, and ceilings; housings for home appliances such as television sets and air conditioners; containers, etc.

[0128] [Decorative items] The decorated article 20 of the present invention utilizes the laminate 10 of the present invention and includes the laminate 10 and a light source 30. As shown in Fig. 5, the light source 30 is disposed on the second main surface 12 side of the laminate 10. Details of the laminate 10 of the present invention are as described above.

[0129] The type of light source is not particularly limited, and examples include light-emitting diode (LED) bulbs, incandescent bulbs, fluorescent lamps, and natural light.

[0130] The decorative article of the present invention exhibits a different design when the light source is on and when it is off, and therefore can be used, for example, as interior or exterior materials for vehicles such as automobiles; fittings such as window frames and door frames; interior materials for buildings such as walls, floors and ceilings; housings for home appliances such as television sets and air conditioners; containers, etc. [Example]

[0131] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0132] [Laminate manufacturing] <Example> A laminate (decorative sheet) was manufactured using the following procedure. A geometric patterned design layer made of acrylic resin containing carbon black (ink) as a colorant was formed on the second main surface of a 125 μm thick transparent resin layer made of acrylic resin with a total light transmittance of 90%. The total light transmittance was measured using a Murakami Color Research Laboratory HM-150L2N haze / transmittance meter. Next, a striped design layer made of acrylic resin containing carbon black (ink) as a colorant was printed as a third design layer. Next, a solid color layer made of acrylic resin containing aluminum metallic pigment was formed as a first design layer on the first main surface of the transparent resin layer. Next, a transparent substrate layer made of ABS resin was thermally laminated to the third design layer, resulting in a laminate consisting of the first design layer / transparent resin layer / second design layer / third design layer / transparent substrate layer in that order. Next, the first design layer side of the obtained laminate was embossed using an embossing plate with a geometric pattern and an embossing plate depth of 60 μm, forming a concave-convex shape on the first design layer. The decorative sheet of the example has a first main surface positioned on the viewer side and a second main surface positioned on the light source side, the first main surface having a concave-convex shape, and is a laminate having, in order from the first main surface side, at least a first design layer, a transparent resin layer, and a second design layer, and further has a third design layer on the second main surface side of the second design layer, the surface on the first main surface side of the second design layer being relatively flatter than the concave-convex shape of the first main surface, and the third design layer is provided partially. The resulting decorative sheet had a transparent resin layer thickness of 125 μm, embossed recesses of 60 μm deep, a transparent substrate layer thickness of 400 μm, an OD value of 0.8 for the first design layer, an OD value of 1.2 for the second design layer, and an OD value of 6.0 for the third design layer. The OD values were measured using an X-rite 341C transmittance meter. The Rz of the uneven shape on the first principal surface, measured in accordance with JIS B0601 (1996), was 55 μm. The Rz of the surface on the second principal surface of the transparent resin layer was 3 μm. The cutoff value λc was 0.8 mm. In this embodiment, the transparent resin layer and the second design layer are in contact over their entire surfaces, and the shape of the surface on the second principal surface of the transparent resin layer is complementary to the shape of the surface on the first principal surface of the second design layer.

[0133] <Comparative Example> A laminate (decorative sheet) was manufactured using the following procedure. A striped design layer made of acrylic resin containing carbon black (ink) as a colorant was printed on the first main surface of a 475 μm-thick transparent substrate layer made of ABS resin. A geometric patterned picture layer made of acrylic resin containing carbon black (ink) as a colorant was then formed as the second design layer. A solid monochromatic layer made of acrylic resin containing aluminum metallic pigment was then formed as the first design layer, resulting in a laminate in which the first design layer, second design layer, third design layer, and transparent substrate layer were laminated in this order. Next, the first design layer side of the resulting laminate was embossed using a geometric pattern embossing plate with a depth of 60 μm, forming a concave-convex shape on the first design layer. Unlike the decorative sheets of the examples, the decorative sheet of the comparative example does not have a transparent resin layer between the first and second design layers. The resulting decorative sheet had embossed depressions with a depth of 60 μm, a transparent substrate layer with a thickness of 475 μm, an OD value of the second design layer of 2.2, and an OD value of the third design layer of 6.0. The OD values were measured using an X-rite 341C transmittance meter.

[0134] [Design evaluation of the second design layer when lit] The decorative sheet (laminate before molding) and the decorated resin molded product (after molding) obtained above were visually observed from the surface protection layer side (observation surface dimensions: 230.4 mm x 135.4 mm), and the correlated color temperature was 5200 (±300 K), and the average brightness was 1500 ± 300 cd / m 2 The appearance of the second design layer was visually evaluated when the light was turned on. The design of the second design layer when turned on was evaluated according to the following criteria. The results are shown in Table 1. 〇: The design based on the second design layer can be confirmed ×: The design based on the first design layer can be seen overlapping with the design based on the second design layer

[0135] [Design evaluation of the third design layer when lit] The decorative sheet (laminate before molding) and the decorated resin molded product (after molding) obtained above were visually observed from the surface protection layer side (observation surface dimensions: 230.4 mm x 135.4 mm), and the correlated color temperature was 5200 (±300 K), and the average brightness was 1500 ± 300 cd / m 2 The appearance of the third design layer was visually evaluated when the light was turned on. The design of the third design layer when turned on was evaluated according to the following criteria. The results are shown in Table 1. 〇: The design based on the third design layer can be confirmed ×: The design based on the first design layer can be seen overlapping with the design based on the third design layer

[0136] [Table 1]

[0137] The decorative sheet of the example is a laminate that displays different designs when the light source is on and off. When the light source is on, the design that appears when the light source is off (design based on the first design layer) is difficult to see, but the designs based on the second and third design layers are visible. Furthermore, when the light source is off, the design based on the first design layer is visible, but the designs based on the second and third design layers are difficult to see. [Explanation of symbols]

[0138] 1...Transparent resin layer 1a...Uneven shape of the first main surface side of the transparent resin layer 21...First design layer 21a...Concave and recessed shape on the first main surface side of the first design layer 22...Second design layer 22a...Surface on the first main surface side of the second design layer 23...Third design layer 3…Surface protective layer 3a...Concave and recessed shape of the first main surface side of the surface protection layer 4…Transparent base material layer 5...Molded resin layer 10...Laminate 11...First main surface 11a...Concave and recessed shape on the first main surface side 12...Second main surface 30…Light source

Claims

[Claim 1] a first main surface disposed on the viewer side and a second main surface disposed on the light source side; the first main surface has an uneven shape, A laminate including, in order from the first main surface side, at least a first design layer, a transparent resin layer, and a second design layer, A third design layer is further provided on the first main surface side or the second main surface side of the second design layer, The surface of the second design layer on the first main surface side is relatively flatter than the uneven shape of the first main surface, The third design layer is partially provided.

Images