Decorative sheet, decorated resin molded product, and method for manufacturing decorated resin molded product

Abstract

To provide a decorative sheet capable of imparting excellent apparent design feeling to a decorative resin molding.SOLUTION: A decorative sheet includes at least a base material layer, and a surface protective layer, wherein a surface on the side of the surface protective layer of the base material layer has an uneven shape composed of repeated projection parts and flat parts, the surface protective layer has an uneven shape corresponding to the uneven shape of the base material layer, and when the decorative sheet is heated from 25°C to 160°C, a difference between a surface roughness Sdr value (interface development area ratio) obtained by measuring a position of the projection part of the base material layer and a surface roughness Sdr value (interface development area ratio) obtained by measuring a position of the flat part of the base material layer of the surface protective layer is 0.1 or more.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a decorative sheet, a decorated resin molded product, and a method for manufacturing a decorated resin molded product. [Background technology]

[0002] Decorative resin molded products in which a decorative sheet is laminated on the surface of a resin molded product are used for vehicle interior parts, building material interior materials, home appliance housings, etc. Known molding methods for such decorative resin molded products include an insert molding method (see, for example, Patent Document 1) in which a decorative sheet is molded into a three-dimensional shape in advance using a vacuum molding die, the molded sheet is inserted into an injection molding die, and a resin in a fluid state is injected into the die to integrate the resin and the molded sheet, an injection molding simultaneous decoration method (see, for example, Patent Documents 2 and 3) in which a decorative sheet inserted into a die during injection molding is integrated with molten resin injected into the cavity to decorate the surface of a resin molded product, and an overlay method (see, for example, Patent Document 4) in which a decorative sheet is attached to a previously molded resin molded product while heating and pressurizing it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-322501 A [Patent Document 2] Special Publication No. 50-19132 [Patent Document 3] Special Publication No. 61-17255 [Patent Document 4] JP 2012-101549 A [Patent Document 5] Japanese Patent Application Publication No. 63-249617 [Patent Document 6] Japanese Patent Application Publication No. 10-235734 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to improve the design of the decorative sheet, many decorative sheets have been proposed and manufactured by imparting a concave-convex shape to the surface by embossing. Such decorative sheets are manufactured by passing the decorative sheet between an embossing roll with a concave-convex pattern and a pressure roll while applying a predetermined temperature and pressure, forming a concave-convex shape on the surface of the decorative sheet, and then cooling to fix the concave-convex shape. For example, Patent Document 5 discloses a method for manufacturing an embossed sheet in which a preheated synthetic resin sheet is passed under pressure between an embossing roll (with powder particles filled in the recesses) and a rubber roll, and the powder particles are embedded in the preheated synthetic resin sheet to form convex portions. Patent Document 6 discloses a method for manufacturing an embossed sheet in which deep and shallow grooves coexist by passing a molten resin sheet under pressure through a deep-groove embossing roll, heating and maturing the deep-groove embossed sheet with almost no tension, and then pressing and shaping it again with a shallow-groove embossing roll.

[0005] However, when manufacturing a decorated resin molded product using a decorative sheet with a concave-convex shape formed on its surface, the decorative sheet is exposed to a high temperature and pressure environment during the molding process, such as injection molding, after vacuum heat molding. This causes the concave-convex shape on the surface of the decorative sheet to flatten (the height difference between the convex and flat parts decreases) during the molding process, resulting in a problem that the design properties of the decorative sheet before molding are lost after molding.

[0006] In this situation, the main object of the present disclosure is to provide a decorative sheet that can impart a visually excellent design feeling to a decorated resin molded product by utilizing the phenomenon in which the surface state of only the convex parts of the decorative sheet surface changes to fine concaves and convexes by molding. Another object of the present disclosure is to provide a decorated resin molded product using the decorative sheet and a manufacturing method thereof. [Means for solving the problem]

[0007] The inventors of the present disclosure conducted intensive research to solve the above problems. As a result, they found that a decorative sheet including at least a base layer and a surface protective layer, the surface of the base layer facing the surface protective layer has an uneven shape formed by repeating convex portions and flat portions, the surface protective layer has an uneven shape corresponding to the uneven shape of the base layer, and when the decorative sheet is heated from a temperature of 25° C. to a temperature of 160° C., the difference between the surface roughness Sdr value (interface developed area ratio) measured at the positions of the convex portions of the base layer and the surface roughness Sdr value (interface developed area ratio) measured at the positions of the flat portions of the base layer is 0.1 or more, and the decorative sheet can impart an excellent design feeling to a decorated resin molded product in appearance.

[0008] The inventors of the present disclosure have also found that a decorative sheet comprising at least a base layer and a surface protective layer, the surface of the base layer facing the surface protective layer has an uneven shape composed of repeated convex portions and flat portions, the surface protective layer has an uneven shape corresponding to the uneven shape of the base layer, and when the decorative sheet is heated from a temperature of 25°C to a temperature of 160°C, the surface protective layer has a difference in luminance (luminance at the position of the flat portion-luminance at the position of the convex portion) of 30 or more measured under specular reflection conditions, with an incidence angle of 15° (specifically, when the decorative sheet is placed horizontally, the incidence angle is inclined from the vertical by 15° and the reflection angle is also inclined by 15°), a resolution of 50 μm / pixel, a distance from the illumination surface to the object of 100 mm, and an illuminance of 32,000 Lx., can impart a visually excellent design feeling to a decorated resin molded product.

[0009] Furthermore, the inventors of the present disclosure have also discovered that a decorative sheet comprising at least a base material layer and a surface protective layer, wherein the surface of the base material layer facing the surface protective layer has an uneven shape composed of a repetition of convex portions and flat portions, and wherein, when a cross section in the thickness direction is observed for the convex portions constituting the uneven shape of the surface protective layer, the thickness of the surface protective layer at the center position of the convex portions is 7 μm or less, and when a cross section in the thickness direction is observed for the flat portions of the surface protective layer, the thickness of the surface protective layer at the center position of the flat portions is 10 μm or more, can impart a visually excellent design feel to a decorated resin molded product.

[0010] The present disclosure has been completed based on the above findings and through further investigation.

[0011] That is, the present disclosure provides the inventions of the following aspects. Item 1. A decorative sheet comprising at least a base layer and a surface protective layer, the surface of the base layer on the side of the surface protective layer has an uneven shape formed by repeating convex portions and flat portions, the surface protective layer has an uneven shape corresponding to the uneven shape of the base layer, A decorative sheet, in which, when the decorative sheet is heated from a temperature of 25°C to a temperature of 160°C, the difference between the surface roughness Sdr value (interface developed area ratio) measured at the position of the convex portion of the base material layer and the surface roughness Sdr value (interface developed area ratio) measured at the position of the flat portion of the base material layer is 0.1 or more. Item 2. A decorative sheet comprising at least a base layer and a surface protective layer, the surface of the base layer on the side of the surface protective layer has an uneven shape formed by repeating convex portions and flat portions, the surface protective layer has an uneven shape corresponding to the uneven shape of the base layer, When the decorative sheet is heated from a temperature of 25°C to a temperature of 160°C, the surface protective layer has a difference in luminance (luminance at the position of the flat portion - luminance at the position of the convex portion) of 30 or more, measured under specular reflection conditions of an incident angle of 15°, a resolution of 50 μm / pixel, a distance from the illumination surface to the object of 100 mm, and an illuminance of 32,000 Lx, for the positions of the convex portions and the flat portions of the base material layer. Item 3. When a cross section of a convex portion constituting the uneven shape of the surface protective layer is observed in the thickness direction, the thickness of the surface protective layer at the center position of the convex portion is 7 μm or less, 3. The decorative sheet according to item 1 or 2, wherein, when a cross section of the flat portion of the surface protective layer is observed in a thickness direction, the thickness of the surface protective layer at a center position of the flat portion is 10 μm or more. Item 4. The decorative sheet according to any one of Items 1 to 3, wherein the width of the convex portions of the base layer is 100 μm or more and 350 μm or less. Item 5. The decorative sheet according to any one of Items 1 to 4, wherein the width of the flat portion of the base layer is 50 μm or more and 600 μm or less. Item 6. The decorative sheet according to any one of Items 1 to 5, wherein the height of the protrusions on the surface of the decorative sheet facing the surface protective layer is 10 μm or more and 50 μm or less. Item 7. The decorative sheet according to any one of Items 1 to 6, wherein, when a cross section of a protrusion constituting the uneven shape of the surface protective layer is observed in a thickness direction, the thickness of the surface protective layer at a center position of the protrusion is 2 μm or more and 7 μm or less. Item 8. The decorative sheet according to any one of Items 1 to 7, further comprising a decorative layer between the surface protective layer and the base layer. Item 9. A decorated resin molded product having at least a molded resin layer, a base layer, and a surface protective layer in this order, the surface of the base layer on the side of the surface protective layer has an uneven shape formed by repeating convex portions and flat portions, The surface protective layer has a difference between the surface roughness Sdr value (interface developed area ratio) measured at the position of the convex portion of the base material layer and the surface roughness Sdr value (interface developed area ratio) measured at the position of the flat portion of the base material layer of 0.1 or more. Item 10. A decorated resin molded product having at least a molded resin layer, a base layer, and a surface protective layer in this order, the surface of the base layer on the side of the surface protective layer has an uneven shape formed by repeating convex portions and flat portions, The surface protection layer is a decorated resin molded product in which the difference in luminance (luminance at the position of the flat portion - luminance at the position of the convex portion) measured under specular reflection conditions of an incident angle of 15°, a resolution of 50 μm / pixel, a distance from the illumination surface to the object of 100 mm, and an illuminance of 32,000 Lx, for the positions of the convex portion and the flat portion of the base material layer, is 30 or more. Item 11. A method for producing a decorated resin molded product, comprising a step of laminating a molded resin layer by injecting a resin onto the base layer side of the decorative sheet according to any one of Items 1 to 8. Effect of the Invention

[0012] According to the present disclosure, it is possible to provide a decorative sheet capable of imparting a visually excellent design to a decorated resin molded product. In addition, according to the present disclosure, it is also possible to provide a decorated resin molded product using the decorative sheet and a manufacturing method thereof. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a schematic diagram of a cross-sectional structure of one embodiment of a decorative sheet according to the present disclosure before heating. [Diagram 2] FIG. 2 is a schematic diagram of a cross-sectional structure of one embodiment of a decorative sheet according to the present disclosure after heating. [Diagram 3] FIG. 2 is a schematic diagram of a cross-sectional structure of one embodiment of a decorative sheet according to the present disclosure before heating. [Figure 4] FIG. 2 is a schematic diagram of a cross-sectional structure of one embodiment of a decorative sheet according to the present disclosure after heating. [Diagram 5] 1 is a schematic diagram of a cross-sectional structure of one embodiment of a decorated resin molded product according to the present disclosure. [Figure 6] 3 is a schematic diagram of an embossed pattern formed on a surface protective layer of a decorative sheet after heating according to the present disclosure. FIG. [Figure 7] 3 is a schematic diagram of an embossed pattern formed on a surface protective layer of a decorative sheet after heating according to the present disclosure. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] 1.Decorative sheet The decorative sheet according to the first embodiment of the present disclosure is a decorative sheet including at least a base layer and a surface protective layer, the surface of the base layer facing the surface protective layer has an uneven shape formed by repeating convex portions and flat portions, the surface protective layer has an uneven shape corresponding to the uneven shape of the base layer, and when the decorative sheet is heated from a temperature of 25° C. to a temperature of 160° C., the surface protective layer has a difference of 0.1 or more between the surface roughness Sdr value (interface developed area ratio) measured at the positions of the convex portions of the base layer and the surface roughness Sdr value (interface developed area ratio) measured at the positions of the flat portions of the base layer. The decorative sheet according to the first embodiment of the present disclosure has such a specific configuration and can impart an excellent design feeling to a decorated resin molded product in appearance.

[0015] The decorative sheet according to the second embodiment of the present disclosure is a decorative sheet including at least a base layer and a surface protective layer, the surface of the base layer on the side of the surface protective layer has an uneven shape formed by repeating convex and flat portions, the surface protective layer has an uneven shape corresponding to the uneven shape of the base layer, and when the decorative sheet is heated from a temperature of 25° C. to a temperature of 160° C., the surface protective layer has an incident angle of 15° (specifically, when the decorative sheet is placed horizontally, the incident angle is inclined from the vertical direction by 15°, and the reflection angle is also inclined by 15°), a resolution of 50 μm / pixel, a distance from the illumination light-emitting surface to the object of 100 mm, an illuminance of 32000 Lx, and a difference in brightness (brightness at the position of the flat portion-brightness at the position of the convex portion) of 30 or more at the positions of the convex and flat portions of the base layer. The decorative sheet according to the second embodiment of the present disclosure has such a specific configuration, and thus can impart an excellent design feeling to the decorated resin molded product.

[0016] The decorative sheet of the present disclosure will be described in detail below. In this specification, the numerical range indicated by "to" means "greater than or equal to" or "less than or equal to." 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 the same meaning.

[0017] Laminated structure of decorative sheet As shown in Fig. 1 and Fig. 3, the decorative sheet 10 of the present disclosure has a laminated structure in which at least a base layer 1 and a surface protective layer 2 located on the surface are laminated. As described later, the surface of the base layer 1 on the surface protective layer 2 side has an uneven shape formed by repeating convex portions 11 and flat portions 12. Furthermore, the surface protective layer 2 has an uneven shape corresponding to the uneven shape of the base layer 1. Note that in the uneven shapes of the base layer 1 and the surface protective layer 2 of the present disclosure, the convex portions are formed so as to protrude in the direction of the surface protective layer 2 side of the decorative sheet 10, and the flat portions are located between two convex portions.

[0018] As described later, Fig. 1 and Fig. 3 show the decorative sheet 10 of the present disclosure before being heated, and Fig. 2 and Fig. 4 show the decorative sheet 10a of the present disclosure after being heated. When the decorative sheets 10 shown in Fig. 1 and Fig. 3 are heated to a temperature of 25°C to 160°C (for example, when a decorated resin molded product is manufactured by molding), the convex parts 11 of the base layer 1 and the convex parts 21 of the surface protective layer 2 are crushed in the heated decorative sheet 10a, and a fine uneven shape is formed at the positions S of the convex parts 11 of the base layer 1 (the regions where the convex parts of the decorative sheet 10 before being heated were present) (see Fig. 2 and Fig. 4). As described later, in the decorative sheet 10 of the present disclosure, in order to form a fine uneven shape at the position S of the protruding portion 11 of the base material layer 1 by heating from a temperature of 25° C. to a temperature of 160° C., for example, when forming the uneven shape of the base material layer 1 of the decorative sheet 10 of the present disclosure by embossing, it is desirable to perform the embossing under low temperature conditions to leave a large internal stress in the base material layer 1. Conventionally, in the embossing process, in order to prevent the protruding portions of the uneven shape given to the decorative sheet from being crushed and flattened in the subsequent molding process, a method of performing the embossing under high temperature conditions to prevent a large stress from remaining in the protruding portions of the base material layer has been adopted, but in the present disclosure, a fine uneven shape is formed at the position S of the protruding portion 11 of the base material layer 1 by utilizing the phenomenon that the surface state of only the protruding portions changes to a fine unevenness due to the large stress remaining in the protruding portions of the base material layer, and it is possible to give a decorative resin molded product an excellent design feeling by appearance.

[0019] As shown in Fig. 3, in the decorative sheet of the present disclosure, a decorative layer 3 may be provided between the base layer 1 and the surface protective layer 2 as needed, for the purpose of enhancing the appearance of the design. The decorative layer 3 may be provided with a concealing layer as needed, in addition to a pattern layer having a pattern, for the purpose of suppressing color change or variation in the base layer 1. The concealing layer may be provided on the base layer 1 side of the decorative layer. In addition, a primer layer (not shown) may be provided in contact with the surface of the surface protective layer 2 on the base layer 1 side as needed, for the purpose of increasing the adhesion between the surface protective layer 2 and the layer located thereunder.

[0020] Furthermore, in the decorative sheet of the present disclosure, a back surface adhesive layer (not shown) may be provided, if necessary, on the back surface of the base material layer 1 (the surface opposite to the surface protective layer 2) for the purpose of increasing adhesion with the molded resin when molding the decorated resin molded product.

[0021] Examples of the laminate structure of the decorative sheet of the present disclosure include a laminate structure in which base layer 1 / surface protective layer 2 are laminated; a laminate structure in which base layer 1 / decorative layer 3 / surface protective layer 2 are laminated in this order; a laminate structure in which back adhesive layer / base layer 1 / decorative layer 3 / surface protective layer 2 are laminated in this order; a laminate structure in which base layer 1 / primer layer / surface protective layer 2 are laminated in this order; a laminate structure in which base layer 1 / decorative layer 3 / primer layer / surface protective layer 2 are laminated in this order; a laminate structure in which back adhesive layer / base layer 1 / decorative layer 3 / primer layer / surface protective layer 2 are laminated in this order; and the like.

[0022] Fig. 1 shows a cross-sectional view of a decorative sheet having a laminated structure of a base layer 1 / a surface protective layer 2 as an embodiment of the laminated structure of the decorative sheet 10 of the present disclosure. Fig. 3 shows a cross-sectional view of a decorative sheet having a laminated structure of a base layer 1 / a decorative layer 3 / a surface protective layer 2 as an embodiment of the laminated structure of the decorative sheet 10 of the present disclosure.

[0023] Decorative sheet uneven shape 1 and 3, in the decorative sheet 10 of the present disclosure before heating, the surface of the base layer 1 on the side of the surface protection layer 2 has an uneven shape composed of repeated convex portions and flat portions. Furthermore, the surface protection layer 2 has an uneven shape corresponding to the uneven shape of the base layer 1.

[0024] As shown in the schematic diagrams of FIG. 2 and FIG. 4, the decorative sheet 10 of the present disclosure is heated from a temperature of 25° C. to a temperature of 160° C., whereby a fine uneven shape is formed at the positions S of the protrusions 11 of the base layer 1.

[0025] More specifically, for example, in the first embodiment of the decorative sheet 10 of the present disclosure, when the decorative sheet 10 of the present disclosure is heated from a temperature of 25° C. to a temperature of 160° C., the difference (absolute value) between the surface roughness Sdr value (interface developed area ratio) measured at the position S of the convex portion 11 of the base layer 1 and the surface roughness Sdr value (interface developed area ratio) measured at the position T of the flat portion 12 of the base layer 1 is 0.1 or more. A specific method for measuring these surface roughness Sdr values ​​is as described in the Examples. The surface roughness Sdr value is a composite parameter (a parameter focusing on both the height direction and the planar direction) for evaluating three-dimensional surface properties (surface roughness) defined by the International Organization for Standardization (ISO) in the international standard ISO25178, and is a parameter that indicates how much the developed area (surface area) of a defined area has increased relative to the area of ​​the defined area. For example, the Sdr value of a completely flat surface is 0.

[0026] From the viewpoint of particularly suitably exerting the effects of the present disclosure, in the first embodiment of the present disclosure, the difference (absolute value) of the surface roughness Sdr value is preferably about 0.12 or more, more preferably about 0.15 or more, and even more preferably about 0.2 or more. The upper limit of the difference (absolute value) of the surface roughness Sdr value can be, for example, 2.0 or less, 2.5 or less, etc. Preferred ranges of the difference (absolute value) of the surface roughness Sdr value can be about 0.1 to 2.5, about 0.1 to 2.0, about 0.12 to 2.5, about 0.12 to 2.0, about 0.15 to 2.5, about 0.15 to 2.0, about 0.2 to 2.5, about 0.2 to 2.0, etc.

[0027] From the viewpoint of particularly suitably exerting the effects of the present disclosure, in the first embodiment of the present disclosure, the surface roughness Sdr value (interface developed area ratio) of the surface protective layer 2 measured at the position S of the convex portion 11 of the base layer 1 is preferably about 0.05 or more, more preferably about 0.10 or more, and even more preferably about 0.15 or more. The upper limit of the surface roughness Sdr value is, for example, 3.5 or less, 3.0 or less, etc. Preferred ranges of the surface roughness Sdr value include about 0.05 to 3.5, about 0.05 to 3.0, about 0.10 to 3.5, about 0.10 to 3.0, about 0.15 to 3.5, about 0.15 to 3.0, etc.

[0028] Moreover, from the viewpoint of particularly suitably exerting the effects of the present disclosure, in the first embodiment of the present disclosure, the surface roughness Sdr value (interface developed area ratio) of the surface protective layer 2 measured at the position T of the flat portion 12 of the base layer 1 is preferably about 0.2 or less, more preferably about 0.1 or less, and further preferably about 0.05 or less. The lower limit of the surface roughness Sdr value can be, for example, 0. Preferred ranges of the surface roughness Sdr value include about 0 to 0.2, about 0 to 0.1, and about 0 to 0.05.

[0029] For example, in the second embodiment of the decorative sheet 10 of the present disclosure, when the decorative sheet 10 of the present disclosure is heated from a temperature of 25° C. to a temperature of 160° C., the surface protective layer 2 has a luminance difference (luminance at position T of the flat portion 12−luminance at position S of the convex portion 11) of 30 or more measured under regular reflection conditions for the positions S and T of the convex portion 11 and the flat portion 12 of the base layer 1 at an incidence angle of 15° (specifically, when the decorative sheet is placed horizontally, the incidence angle is inclined from the vertical direction by 15° and the reflection angle is also inclined by 15°), a resolution of 50 μm / pixel, a distance from the illumination light-emitting surface to the object of 100 mm, and an illuminance of 32,000 Lx. The specific method for measuring these luminances is as described in the Examples.

[0030] From the viewpoint of particularly suitably exerting the effects of the present disclosure, in the second embodiment of the present disclosure, the difference in luminance is preferably about 50 or more, more preferably about 60 or more, and further preferably about 80 or more. The upper limit of the difference in luminance is, for example, 200 or less, 150 or less, etc. Preferred ranges of the difference in luminance include about 30 to 200, about 30 to 200, about 50 to 200, about 50 to 200, about 60 to 200, about 60 to 200, about 80 to 200, about 80 to 200, etc.

[0031] From the viewpoint of particularly suitably exerting the effects of the present disclosure, in the second embodiment of the present disclosure, the surface protective layer 2 has a luminance measured at a position T of the flat portion 12 of the base layer 1 of preferably about 70 or more, more preferably about 100 or more, even more preferably about 130 or more, and even more preferably 150 or more. The upper limit of the luminance is, for example, 230 or less, 200 or less, etc. Preferred ranges of the luminance include about 70 to 230, about 70 to 200, about 100 to 230, about 100 to 200, about 130 to 230, about 130 to 200, about 160 to 230, about 160 to 200, etc.

[0032] In the second embodiment of the present disclosure, the surface protective layer 2 has a luminance measured at the position S of the convex portion 11 of the base layer 1 of preferably about 140 or less, more preferably about 130 or less, even more preferably about 120 or less, even more preferably 100 or less, and even more preferably 70 or less. The lower limit of the luminance can be, for example, 0. Preferred ranges of the luminance include about 0 to 140, about 0 to 120, about 0 to 100, and about 0 to 70.

[0033] In the first embodiment of the present disclosure, it is preferable to satisfy the above-mentioned luminance as in the second embodiment of the decorative sheet 10 of the present disclosure. Also, in the second embodiment of the present disclosure, it is preferable to satisfy the above-mentioned surface roughness Sdr value as in the first embodiment of the decorative sheet 10 of the present disclosure.

[0034] From the viewpoint of particularly suitably exerting the effects of the present disclosure, the width H1 of the convex portion 11 of the base layer 1 is preferably about 50 μm or more, more preferably about 100 μm or more, and even more preferably about 150 μm or more, and is preferably about 350 μm or less, more preferably about 300 μm or less, and examples of preferred ranges include about 50 to 350 μm, about 50 to 300 μm, about 100 to 350 μm, about 100 to 300 μm, about 150 to 350 μm, and about 150 to 300 μm. In addition, in the decorative sheet 10 of the present disclosure, the surface protective layer 2 has an uneven shape corresponding to the uneven shape of the base layer 1, and the width of the convex portion 21 of the surface protective layer 2 is slightly larger than the width H1 of the convex portion 11 of the base layer 1. These are also exemplified as preferred values ​​for the width of the convex portion 21 of the surface protective layer 2.

[0035] Furthermore, from the viewpoint of particularly suitably exerting the effects of the present disclosure, the width H2 of the flat portion 12 of the base layer 1 is preferably about 50 μm or more, more preferably about 100 μm or more, even more preferably about 150 μm or more, and is preferably about 600 μm or less, more preferably about 500 μm or less, even more preferably about 350 μm or less, and preferred ranges include about 50 to 600 μm, about 50 to 500 μm, about 50 to 350 μm, about 100 to 600 μm, about 100 to 500 μm, about 100 to 350 μm, about 150 to 600 μm, about 150 to 500 μm, and about 150 to 350 μm. In the decorative sheet 10 of the present disclosure, the surface protective layer 2 has an uneven shape corresponding to the uneven shape of the base layer 1, and the width of the flat portion 22 of the surface protective layer 2 is slightly smaller than the width H2 of the flat portion 12 of the base layer 1. These are also exemplified as preferred values ​​for the width of the flat portion 22 of the surface protective layer 2.

[0036] Furthermore, from the viewpoint of particularly suitably exerting the effects of the present disclosure, the height of the convex portions on the surface of the decorative sheet 10 of the present disclosure facing the surface protection layer 2 is preferably about 10 μm or more, more preferably about 15 μm or more, even more preferably about 20 μm or more, and is preferably about 50 μm or less, more preferably about 40 μm or less, even more preferably about 30 μm or less, and preferred ranges include about 10 to 50 μm, about 10 to 40 μm, about 10 to 30 μm, about 15 to 50 μm, about 15 to 40 μm, about 15 to 30 μm, about 20 to 50 μm, about 20 to 40 μm, and about 20 to 30 μm.

[0037] Furthermore, from the viewpoint of particularly suitably exerting the effects of the present disclosure, when a cross section in the thickness direction of the convex portions 21 constituting the uneven shape of the surface protective layer 2 of the decorative sheet 10 of the present disclosure is observed, the thickness D1 of the surface protective layer 2 at the center position of the convex portions 21 is preferably about 2 μm or more, more preferably about 3 μm or more, even more preferably about 5 μm or more, and is preferably about 15 μm or less, more preferably about 13 μm or less, even more preferably about 10 μm or less, and even more preferably about 7 μm or less, and preferred ranges include about 2 to 15 μm, about 2 to 13 μm, about 2 to 10 μm, about 2 to 7 μm, about 3 to 15 μm, about 3 to 13 μm, about 3 to 10 μm, about 3 to 7 μm, about 5 to 15 μm, about 5 to 13 μm, about 5 to 10 μm, and about 5 to 7 μm.

[0038] From the viewpoint of particularly favorably exerting the effects of the present disclosure, it is preferable that, when a cross section in the thickness direction is observed for the convex portions 21 of the surface protective layer 2 constituting the uneven shape of the decorative sheet 10 of the present disclosure, the thickness D1 of the surface protective layer 2 at the center position of the convex portions 21 is about 15 μm or less, and, when a cross section in the thickness direction is observed for the flat portions 22 of the surface protective layer 2, the thickness of the surface protective layer 2 at the center position of the flat portions 22 is about 10 μm or more. In addition, the thickness of the flat portions 22 of the protective layer 2 is thicker than the thickness of the convex portions 21. As described above, the thickness D1 of the surface protective layer 2 at the center position of the convex portion 21 is preferably about 2 μm or more, more preferably about 3 μm or more, and even more preferably about 5 μm or more, and is preferably about 13 μm or less, more preferably about 10 μm or less, and even more preferably 7 μm or less. Preferred ranges include about 2 to 15 μm, about 2 to 13 μm, about 2 to 10 μm, about 2 to 7 μm, about 3 to 15 μm, about 3 to 13 μm, about 3 to 10 μm, about 3 to 7 μm, about 5 to 15 μm, about 5 to 13 μm, about 5 to 10 μm, and about 5 to 7 μm. Furthermore, the thickness D2 of the surface protective layer 2 at the center position of the flat portion 22 is preferably about 10 μm or more, more preferably about 15 μm or more, and the upper limit is, for example, about 30 μm or less, about 25 μm or less, and the preferred ranges of the thickness are about 10 to 30 μm, about 10 to 25 μm, about 15 to 30 μm, and about 15 to 25 μm. When the surface protective layer 2 contains particles (such as inorganic particles and organic particles described below), the thicknesses of the convex portions 21 and the flat portions 22 of the surface protective layer 2 refer to the thicknesses of the portions where the particles are not located on the surface of the surface protective layer 2.

[0039] In the decorative sheet 10, the heated decorative sheet 10a, and the decorated resin molded product 20 of the present disclosure, the uneven pattern (pattern) expressed by the uneven shape is not particularly limited. For example, the uneven pattern expressed by the uneven shape is a line pattern. More specifically, in the schematic diagram of FIG. 6, a design is formed on the surface of the heated decorative sheet 10a by repeating a plurality of convex linear stripes (position S of the convex portion 11 of the base layer 1 of the decorative sheet 10) extending linearly in one direction (y direction) and the area between them (position T of the flat portion 12 of the base layer 1 of the decorative sheet 10). In addition, the schematic diagram of FIG. 7 shows a carbon pattern composed of a shape in which a plurality of lines are arranged in one direction and a shape in which a plurality of lines are arranged in a direction perpendicular to the shape. Specific examples of the uneven pattern include a hairline pattern, a wood grain pattern, a geometric pattern (dots, stripes, woven fabric, carbon, etc.), and the like.

[0040] Composition of each layer of the decorative sheet [Base material layer 1] The substrate layer 1 is a resin sheet (resin film) that serves as a support in the decorative sheet of the present disclosure. The resin component used in the substrate layer 1 is not particularly limited and may be appropriately selected depending on the three-dimensional formability and compatibility with the molded resin, but preferably includes a resin film made of a thermoplastic resin. Specific examples of the thermoplastic resin include acrylonitrile-butadiene-styrene resin (hereinafter sometimes referred to as "ABS resin"), acrylonitrile-styrene-acrylic acid ester resin (hereinafter sometimes referred to as "ASA resin"), acrylic resin, polyolefin resin such as polypropylene and polyethylene, polycarbonate resin, vinyl chloride resin, polyethylene terephthalate (PET), etc. Among these, ABS resin and acrylic resin are preferred from the viewpoint of three-dimensional formability. In addition, the substrate layer 1 may be formed of a single-layer sheet of these resins, or may be formed of a multi-layer sheet of the same or different resins.

[0041] The softening point of the thermoplastic resin is preferably about 80 to 155°C, more preferably about 90 to 140°C, and further preferably about 105 to 125°C.

[0042] The flexural modulus of the base layer 1 is not particularly limited. For example, when the decorative sheet of the present disclosure is integrated with a molding resin by insert molding, the flexural modulus of the base layer 1 in the decorative sheet of the present disclosure at 25°C is 500 to 4,000 MPa, preferably 750 to 3,000 MPa. Here, the flexural modulus at 25°C is a value measured in accordance with JIS K7171. When the flexural modulus at 25°C is 500 MPa or more, the decorative sheet has sufficient rigidity, and even when subjected to insert molding, the surface characteristics and moldability become even better. In addition, when the flexural modulus at 25°C is 3,000 MPa or less, sufficient tension can be applied when produced by roll-to-roll, and sagging is unlikely to occur, so that the pattern can be printed over without shifting, and so-called pattern registration becomes good.

[0043] In order to improve adhesion with a layer provided thereon, the substrate layer 1 may be subjected to physical or chemical surface treatment such as oxidation or roughening on one or both sides as necessary. Examples of the oxidation method used as the surface treatment of the substrate layer 1 include corona discharge treatment, chromium oxidation treatment, flame treatment, hot air treatment, and ozone ultraviolet treatment. Examples of the roughening method used as the surface treatment of the substrate layer 1 include sandblasting and solvent treatment. These surface treatments are appropriately selected depending on the type of resin component constituting the substrate layer 1, but from the viewpoints of effect and operability, a corona discharge treatment is preferably used.

[0044] The base layer 1 may be subjected to a known treatment such as forming an adhesive layer.

[0045] Furthermore, the base layer 1 may be colored with a colorant or may not be colored. The base layer 1 may be colorless and transparent, colored and transparent, or translucent. The colorant used in the base layer 1 is not particularly limited, but is preferably a colorant that does not discolor even at temperatures of 150° C. or higher, and specifically includes existing dry colors, paste colors, masterbatch resin compositions, and the like.

[0046] The thickness of the substrate layer 1 is appropriately set depending on the application of the decorative sheet, the molding method for integrating it with the molding resin, etc., but is usually about 25 to 1000 μm, and is preferably about 50 to 700 μm. More specifically, when the decorative sheet of the present disclosure is subjected to an insert molding method, the thickness of the substrate layer 1 is usually about 50 to 1000 μm, preferably about 100 to 700 μm, and more preferably about 100 to 500 μm. When the decorative sheet of the present disclosure is subjected to an injection molding simultaneous decoration method, the thickness of the substrate layer 1 is usually about 25 to 200 μm, preferably about 50 to 200 μm, and more preferably about 70 to 200 μm. When the decorative sheet of the present disclosure is subjected to an overlay method, the thickness of the substrate layer 1 is usually about 50 to 350 μm, and is preferably about 100 to 300 μm. The thickness of the base layer 1 is the thickness at the portion where the flat portion 22 of the surface protection layer 2 is located.

[0047] 1 and 2, it is preferable that the surface of the base layer 1 facing the surface protective layer 2 has an uneven shape formed thereon corresponding to the uneven shape formed in the surface protective layer 2 described below. This can more effectively enhance the appearance of the design.

[0048] [Surface protection layer 2] The surface protective layer 2 is a layer provided to protect the surface of the decorated resin molded product while imparting an excellent design to the decorated resin molded product by its uneven shape. An uneven shape is formed on the surface of the surface protective layer 2. More specifically, an uneven shape is formed on both sides of the surface protective layer 2. Therefore, an uneven shape corresponding to the uneven shape is also formed on the surface of the layer (e.g., the base material layer 1, a primer layer provided as needed, and the decorative layer 3) that is in contact with the base material layer 1 side of the surface protective layer 2. Details of the uneven shape provided on the surface protective layer 2 are as described above.

[0049] As described above, there is no particular limitation on the design expressed on the surface of the decorative sheet by the uneven shape of the surface protective layer 2. Examples of the design expressed by the uneven shape include a hairline pattern, a wood grain pattern, and a geometric pattern (dots, stripes, woven fabric, carbon, etc.).

[0050] The material constituting the surface protective layer 2 is not particularly limited, and examples thereof include thermoplastic resins, thermosetting resins, ionizing radiation curable resins, etc. Among these, from the viewpoint of suitably imparting an excellent design feeling in appearance to the decorated resin molded product, it is preferable that the surface protective layer 2 is composed of a cured product of an ionizing radiation curable resin composition. The ionizing radiation curable resin used to form the surface protective layer 2 will be described in detail below.

[0051] (ionizing radiation curable resin) The ionizing radiation curable resin used in the formation of the surface protective layer 2 is a resin that is crosslinked and cured by irradiation with ionizing radiation, and specifically includes a suitable mixture of at least one of prepolymers, oligomers, and monomers having polymerizable unsaturated bonds or epoxy groups in the molecule. Here, the ionizing radiation means electromagnetic waves or charged particle beams that have an energy quantum capable of polymerizing or crosslinking molecules, and usually ultraviolet rays (UV) or electron beams (EB) are used, but also includes electromagnetic waves such as X-rays and γ-rays, α-rays, ion beams, and other charged particle beams. Among the ionizing radiation curable resins, electron beam curable resins are preferably used in the formation of the surface protective layer 2 because they can be made solvent-free, do not require a photopolymerization initiator, and have stable curing properties.

[0052] 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 them, a polyfunctional (meth)acrylate monomer is preferable. The polyfunctional (meth)acrylate monomer may be a (meth)acrylate monomer having two or more (bifunctional 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 phosphoric acid di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, isocyanurate di(meth)acrylate, trimethylol propionate, and the like. Examples of the monomer 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, caprolactone modified dipentaerythritol hexa(meth)acrylate, etc. These monomers may be used alone or in combination of two or more.

[0053] As the oligomer used as the ionizing radiation curable resin, a (meth)acrylate oligomer having a radical polymerizable unsaturated group in the molecule is preferable, and among them, a polyfunctional (meth)acrylate oligomer having two or more (two or more functional) polymerizable unsaturated bonds in the molecule is preferable. Examples of the polyfunctional (meth)acrylate oligomer 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 cationic polymerizable functional group in the molecule (e.g., novolac type epoxy resin, bisphenol type 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, and can be obtained, for example, 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 the reaction of a polyether polyol or a polyester polyol with a polyisocyanate compound with (meth)acrylic acid. Epoxy (meth)acrylates can be obtained, for example, by reacting an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolac type epoxy resin with (meth)acrylic acid to effect esterification.In addition, a carboxyl-modified epoxy (meth)acrylate obtained by partially modifying this epoxy (meth)acrylate with a dibasic carboxylic anhydride can also be used. The polyester (meth)acrylate can be obtained, for example, by esterifying the hydroxyl group of a polyester oligomer having hydroxyl groups at both ends obtained by condensation of a polyvalent carboxylic acid and a polyhydric alcohol with (meth)acrylic acid, or by esterifying the terminal hydroxyl group of an oligomer obtained by adding an alkylene oxide to a polyvalent carboxylic acid with (meth)acrylic acid. The polyether (meth)acrylate can be obtained by esterifying the hydroxyl group of a polyether polyol with (meth)acrylic acid. The polybutadiene (meth)acrylate can be obtained by adding (meth)acrylic acid to the side chain of a polybutadiene oligomer. The silicone (meth)acrylate can be obtained by adding (meth)acrylic acid to the end or side chain of a silicone having a polysiloxane bond in the main chain. These oligomers may be used alone or in combination of two or more.

[0054] Among the above-mentioned ionizing radiation curable resins, it is preferable to use polycarbonate (meth)acrylate from the viewpoint of obtaining excellent three-dimensional moldability while further improving the appearance design, wear resistance and moldability. It is also preferable to use a combination of polycarbonate (meth)acrylate and urethane (meth)acrylate.

[0055] The surface protective layer 2 may contain at least one of inorganic particles and resin particles. In the surface protective layer 2, the inorganic particles and resin particles mainly have the function of reducing the gloss of the surface protective layer 2. When the surface protective layer 2 contains inorganic particles or resin particles, these particles are dispersed in the surface protective layer 2.

[0056] The inorganic particles are not particularly limited as long as they are particles formed by an inorganic compound, and examples thereof include silica particles, calcium carbonate particles, barium sulfate particles, alumina particles, and glass balloon particles. The inorganic particles may be used alone or in combination of two or more types. The particle diameter of the inorganic particles is, for example, about 0.5 to 20 μm, preferably about 1 to 10 μm. In the present invention, the particle diameter of the inorganic particles is a value measured by a spray-type dry measurement method using a Shimadzu laser diffraction particle size distribution analyzer SALD-2100, in which the powder to be measured is sprayed from a nozzle using compressed air, dispersed in the air, and measured.

[0057] When the surface protective layer 2 contains inorganic particles, the content of the inorganic particles is not particularly limited, but is preferably about 1 to 60 parts by mass, and more preferably about 10 to 40 parts by mass, relative to 100 parts by mass of the above-mentioned ionizing radiation curable resin. The inorganic particles may be used alone or in combination of two or more types.

[0058] The resin particles are not particularly limited as long as they are particles formed from a resin, and examples thereof include urethane beads, nylon beads, acrylic beads, silicone beads, styrene beads, melamine beads, urethane acrylic beads, polyester beads, and polyethylene beads. The resin particles may be used alone or in combination of two or more types. The particle diameter of the resin particles is, for example, about 0.5 to 30 μm, and preferably about 1 to 20 μm. The particle diameter of the resin particles is a value measured by the same method as that of the inorganic particles.

[0059] When the surface protective layer 2 contains resin particles, the content of the resin particles is not particularly limited, but is preferably about 1 to 200 parts by mass, and more preferably about 10 to 150 parts by mass, relative to 100 parts by mass of the ionizing radiation curable resin contained in the above-mentioned ionizing radiation curable resin composition.

[0060] In addition, when the surface protective layer 2 contains at least one of inorganic particles and resin particles, some of these particles may protrude from the surface of the surface protective layer 2, or the particles may be buried inside the surface protective layer 2.

[0061] (Other added ingredients) Various additives can be blended into the surface protective layer 2 depending on the desired physical properties to be provided to the surface protective layer 2. Examples of the 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, defoamers, fillers, solvents, colorants, and the like. These additives can be appropriately selected from those commonly used. In addition, 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 absorbers and light stabilizers.

[0062] (Formation of surface protective layer 2) The surface protection layer 2 is formed, for example, by preparing an ionizing radiation curable resin composition containing an ionizing radiation curable resin, applying the composition, and crosslinking and curing the composition. The viscosity of the ionizing radiation curable resin composition may be any viscosity that allows an uncured resin layer to be formed by a coating method described below. As described below, in the present disclosure, the surface protection layer 2 can be suitably manufactured by applying a resin that constitutes the surface protection layer 2 to the surface on the side of the base layer 1 on which the uneven shape is formed, and curing the resin.

[0063] In the present disclosure, the prepared resin is applied by a known method such as gravure coating, bar coating, roll coating, reverse roll coating, or comma coating, preferably by gravure coating, to form an uncured resin layer.

[0064] 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, thereby forming the surface protective layer 2. 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 typically, the acceleration voltage is about 70 to 300 kV.

[0065] In addition, since the higher the acceleration voltage is in the irradiation of the electron beam, the greater the penetration ability, when a resin that is easily deteriorated by electron beam irradiation is used under the surface protective layer 2, 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 2. This makes it possible to suppress excess irradiation of the electron beam to the layer located under the surface protective layer 2, and to minimize the deterioration of each layer due to excess electron beams.

[0066] The radiation dose is preferably an amount at which the crosslink density of the surface protective layer 2 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).

[0067] Furthermore, the electron beam source is not particularly limited, and various electron beam accelerators such as Cockcroft-Walton type, Van de Graft type, resonant transformer type, insulating core transformer type, linear type, dynamitron type, and high frequency type can be used.

[0068] When ultraviolet light is used as the ionizing radiation, light rays containing ultraviolet light having a wavelength of 190 to 380 nm may be emitted. The source of ultraviolet light is not particularly limited, but examples thereof include high pressure mercury lamps, low pressure mercury lamps, metal halide lamps, and carbon arc lamps.

[0069] The surface protective layer 2 thus formed may be treated by adding various additives to impart functions such as a hard coat function, an anti-fogging coat function, an anti-fouling coat function, an anti-glare coat function, an anti-reflection coat function, an ultraviolet shielding coat function, and an infrared shielding coat function.

[0070] [Decorative layer 3] The decorative layer 3 is a layer that is provided as necessary between the base material layer 1 and the surface protective layer 2, or between the base material layer 1 and the primer layer when a primer layer is provided, for the purpose of imparting decorativeness to the decorative sheet. From the viewpoint of enhancing the visual design, it is preferable that the decorative layer 3 is provided along the uneven shape of the surface protective layer 2.

[0071] Examples of the decorative layer 3 include a pattern layer having a pattern, and a concealing layer having no pattern and intended to suppress color change or variation in the base layer 1 .

[0072] The decorative layer 3 may be a layer on which a desired pattern is formed using, for example, an ink composition. The ink composition used to form the decorative layer 3 is a 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, and the like, as appropriate.

[0073] 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.

[0074] The colorant used in the ink composition is not particularly limited, but examples thereof include inorganic pigments such as carbon black, 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 foil flakes of aluminum, brass, and the like; and pearlescent pigments consisting of scaly foil flakes of titanium dioxide-coated mica, basic lead carbonate, and the like.

[0075] The pattern formed by the decorative layer 3 is not particularly limited, and examples thereof include a wood grain pattern, a marble pattern (e.g., a travertine marble pattern) or other stone pattern that imitates the surface of rock, a fabric pattern that imitates a cloth or fabric-like pattern, a tiled pattern, a brickwork pattern, etc., and may also be a combination of these patterns such as marquetry or patchwork, or may be a single plain color (so-called solid color on the entire surface). These patterns are formed by multi-color printing using the usual process colors of yellow, red, blue, and black, but can also be formed by multi-color printing using special colors that are performed by preparing plates of the individual colors that make up the pattern.

[0076] The thickness of the decorative layer 3 is not particularly limited, but may be, for example, 1 to 30 μm, and preferably 1 to 20 μm. The thickness of the decorative layer 3 is the thickness at the portion where the flat portion 22 of the surface protective layer 2 is located.

[0077] The decorative layer 3 may also be a metal thin film layer. Examples of metals that form the metal thin film layer include tin, indium, chromium, aluminum, nickel, copper, silver, gold, platinum, zinc, and alloys containing at least one of these metals. The method for forming the metal thin film layer is not particularly limited, and examples include deposition methods such as vacuum deposition, sputtering, and ion plating using the above metals. The metal thin film layer may be provided over the entire surface or may be provided partially.

[0078] When the decorative layer 3 is a metal thin film layer, its thickness is not particularly limited, but from the viewpoint of enhancing the design of the decorative sheet, the optical density (OD value) is preferably about 0.6 to 1.8, and more preferably about 0.8 to 1.4. The thickness (OD value) of the metal thin film layer is the thickness at the portion where the flat portion 22 of the surface protective layer 2 is located.

[0079] (Hidden layer) In the decorative layer 3, the concealing layer is a layer that is provided as necessary between the substrate layer 1 and the surface protective layer 2, between the substrate layer 1 and the primer layer if a primer layer is provided, or between the substrate layer 1 and the pattern layer if a pattern layer is provided in the decorative layer 3, for the purpose of suppressing color changes or variations in the substrate layer 1.

[0080] The concealing layer is provided to prevent the base layer from adversely affecting the color tone and pattern of the decorative sheet, and is therefore generally formed as a layer of an opaque color.

[0081] The concealing layer is formed using an ink composition in which a binder is appropriately mixed with a colorant such as a pigment or a dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, a hardener, etc. The ink composition for forming the concealing layer is appropriately selected from those used for the decorative layer described above.

[0082] The concealing layer is usually set to a thickness of about 1 to 20 μm, and is desirably formed as a so-called solid printed layer. Note that the thickness of the concealing layer is the thickness at the portion where the flat portion 22 of the surface protection layer 2 is located.

[0083] The concealing layer is formed by a conventional printing method such as gravure printing, offset printing, silk screen printing, printing by transfer from a transfer sheet, inkjet printing, etc.; or a conventional coating method such as gravure coating, gravure reverse coating, gravure offset coating, spinner coating, roll coating, reverse roll coating, etc.

[0084] [Primer layer] The primer layer is a layer that is provided, as necessary, in contact with the surface of the surface protective layer 2 on the side of the base layer 1 for the purpose of increasing the adhesion between the surface protective layer 2 and the layer located thereunder. The primer layer is provided along the uneven shape of the surface protective layer 2.

[0085] As the primer composition constituting the primer layer, those containing urethane resin, (meth)acrylic resin, (meth)acrylic-urethane copolymer resin, vinyl chloride-vinyl acetate copolymer, polyester resin, butyral resin, chlorinated polypropylene, chlorinated polyethylene, etc. as a binder resin are preferably used, and these resins can be used alone or in combination of two or more. Among these, urethane resin, (meth)acrylic resin, and (meth)acrylic-urethane copolymer resin are preferred.

[0086] As the urethane resin, polyurethane containing polyol (polyhydric alcohol) as a main component and isocyanate as a crosslinking agent (curing agent) can be used. As the polyol, one having two or more hydroxyl groups in the molecule, such as polyester polyol, polyethylene glycol, polypropylene glycol, acrylic polyol, polyether polyol, etc. can be used. As the isocyanate, a polyvalent isocyanate having two or more isocyanate groups in the 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, hydrogenated diphenylmethane diisocyanate, etc. can also be used to form the resin by mixing the urethane resin and the butyral resin.

[0087] In terms of adhesion to the surface protective layer 2 after crosslinking, the likelihood of interactions occurring after lamination of the surface protective layer 2, physical properties, and moldability, it is preferable to combine an acrylic polyol or a polyester polyol as the polyol with 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.

[0088] 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 consisting 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.

[0089] As the (meth)acrylic-urethane copolymer resin, for example, an acrylic-urethane (polyester urethane) block copolymer resin is preferable. As the curing agent, the above-mentioned various isocyanates are used. As for the acrylic-urethane (polyester urethane) block copolymer resin, it is preferable to adjust the acrylic / urethane ratio (mass ratio) to a range of preferably 9 / 1 to 1 / 9, more preferably 8 / 2 to 2 / 8, as desired.

[0090] The thickness of the primer layer is not particularly limited, but is, for example, about 0.5 to 20 μm, and preferably 1 to 5 μm. The thickness of the primer layer is the thickness at the portion where the flat portion 22 of the surface protection layer 2 is located.

[0091] The primer layer is formed using a primer composition by a normal coating method such as gravure coating, gravure reverse coating, gravure offset coating, spinner coating, roll coating, reverse roll coating, kiss coating, wheeler 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 a primer layer or an adhesive layer is formed on a thin sheet (film substrate), and then the surface of a target layer in the decorative sheet is coated with the coating film.

[0092] [Back adhesive layer] The back surface adhesive layer (not shown) is a layer that is optionally provided on the back surface of the base material layer 1 (the surface opposite to the surface protective layer 2) for the purpose of increasing adhesion with the molding resin when molding a decorated resin molded product.

[0093] The back surface adhesive layer is made of a thermoplastic resin or a curable resin depending on the molding resin used in the decorated resin molded product.

[0094] 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.

[0095] 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.

[0096] Manufacturing method of decorative sheet The decorative sheet of the present disclosure can be produced, for example, by a method including the following steps. Step 1: forming a concave-convex shape from one side of the base layer 1 Step 2: forming a surface protective layer 2 on the surface side of the base layer 1 on which the concave-convex shape is formed

[0097] For example, the method of manufacturing the decorative sheet of the present disclosure will be described using an example in which the decorative sheet includes only a base layer 1 and a surface protective layer 2. First, in step 1, a concave-convex shape is formed on one surface of the base layer. Next, in step 2, a surface protective layer 2 is formed on the surface side of the base layer 1 on which the concave-convex shape is formed, thereby manufacturing the decorative sheet of the present disclosure.

[0098] Specifically, in step 2, the surface protective layer 2 is formed by applying a resin that constitutes the surface protective layer 2 to the surface of the base layer 1 on which the concave-convex shape is formed.

[0099] In step 1, embossing can be suitably adopted as a method for forming a concave-convex shape from one side of the base layer 1. Embossing is a known method in which the surface of an object to be embossed is heated and softened, then pressed with an embossing plate, the concave-convex shape formed on the embossing plate is imprinted on the surface of the object to be embossed, and then cooled and fixed. As described above, when forming the concave-convex shape of the base layer 1 of the decorative sheet 10 of the present disclosure by embossing, in order to impart a large internal stress to the base layer 1, it is desirable to carry out embossing under low temperature conditions, so as to leave a large internal stress in the base layer 1. Conventionally, in embossing, in order to prevent the convex parts of the uneven shape given to the decorative sheet from being crushed and flattened in the subsequent molding process, a method is adopted in which embossing is performed under high temperature conditions to prevent large internal stress from remaining in the convex parts of the base layer. However, in the present disclosure, by utilizing the phenomenon in which the surface state of only the convex parts changes to fine unevenness due to the large internal stress remaining in the convex parts of the base layer, a fine uneven shape is formed at the position S of the convex parts 11 of the base layer 1, and it becomes possible to give the decorated resin molded product an excellent design feeling in appearance. For the embossing, a known sheet-fed or rotary embossing machine can be used. The uneven shape of the surface protective layer 2 can be formed by using an embossing plate corresponding to the uneven shape to be formed in the surface protective layer 2.

[0100] In the method for producing a decorative sheet according to the present disclosure, the details of the base layer 1, the surface protective layer 2, and further the decorative layer 3 and primer layer which are provided as necessary are as described above.

[0101] In step 1, before providing the uneven shape on the surface of the base layer 1, the above-mentioned decorative layer 3, primer layer, etc. may be laminated as necessary, and then the uneven shape may be formed on the primer layer or the decorative layer 3. When the decorative layer 3, primer layer, etc. are laminated, the uneven shape can be formed on the surface of the base layer 1 by embossing from the side on which these layers are laminated, and the decorative layer 3 and primer layer can be suitably formed so as to match the uneven shape of the surface protection layer 2 to be formed thereafter.

[0102] Furthermore, in step 1, before laminating the decorative layer 3, primer layer, etc., an uneven shape may be provided on the surface of the base layer 1, and then the decorative layer 3, primer layer, etc. may be laminated. In this case as well, by laminating the decorative layer 3 and primer layer so that not all of the recesses of the uneven shape are filled, it is possible to form an uneven shape on the surface of the base layer 1, and it is possible to form the decorative layer 3 and primer layer that follow the uneven shape.

[0103] 2. Decorative resin moldings The decorated resin molded product of the present disclosure is formed by integrating a molding resin with the decorative sheet 10 of the present disclosure.

[0104] More specifically, a first embodiment of the decorated resin molded product 20 of the present disclosure is a decorated resin molded product having at least a molded resin layer, a base material layer, and a surface protection layer, in this order, in which the surface of the base material layer facing the surface protection layer has an uneven shape composed of a repetition of convex portions and flat portions, and the surface protection layer is characterized in that the difference between the surface roughness Sdr value (interface development area ratio) measured at the positions of the convex portions of the base material layer and the surface roughness Sdr value (interface development area ratio) measured at the positions of the flat portions of the base material layer is 0.1 or more.

[0105] Furthermore, a second embodiment of the decorated resin molded product 20 of the present disclosure is a decorated resin molded product comprising at least a molded resin layer, a base material layer, and a surface protection layer in this order, in which the surface of the base material layer facing the surface protection layer has an uneven shape composed of a repetition of convex portions and flat portions, and the surface protection layer is characterized in that the difference in luminance (luminance at the position of the flat portion - luminance at the position of the convex portion) measured at the positions of the convex portions and flat portions of the base material layer under specular reflection conditions of an incident angle of 15°, a resolution of 50 μm / pixel, a distance from the illumination surface to the object of 100 mm, and an illuminance of 32,000 Lx is 30 or more.

[0106] Fig. 5 shows a cross-sectional structure of one embodiment of the decorated resin molded product of the present disclosure. Fig. 5 is a schematic cross-sectional view of a decorated resin molded product 20 in which the decorative sheet 10 having the laminated structure shown in Fig. 3 is integrated with a molded resin layer 4. In the decorated resin molded product 20, the decorative sheet integrated with the molded resin layer 4 corresponds to the decorative sheet 10a after heating.

[0107] The decorated resin molded product of the present disclosure can be produced by a method including a step of forming a molded resin layer 4 by injecting a resin onto the base layer 1 side of the decorative sheet 10 of the present disclosure. Specifically, the decorated resin molded product is produced by various injection molding methods such as insert molding, simultaneous injection molding and decoration, blow molding, and gas injection molding, using the decorative sheet of the present disclosure.

[0108] In the insert molding method, first, in the vacuum forming process, the decorative sheet of the present disclosure is vacuum-formed (offline preforming) into the surface shape of the molded product in advance using a vacuum forming mold, and then excess parts are trimmed as necessary to obtain a molded sheet. This molded sheet is inserted into an injection mold, the injection mold is closed, and a resin in a fluid state is injected into the mold and solidified. At the same time as injection molding, the base layer 1 side of the decorative sheet is integrated with the outer surface of the resin molded product, thereby producing a decorated resin molded product.

[0109] More specifically, the decorated resin molded product of the present disclosure is produced by an insert molding method including the following steps.

[0110] A vacuum forming process in which the decorative sheet of the present disclosure is formed into a three-dimensional shape in advance using a vacuum forming mold; A step of trimming an excess portion of the vacuum-formed decorative sheet to obtain a formed sheet; and A process in which the molded sheet obtained in the previous process is inserted into an injection mold, the injection mold is closed, and the resin in a fluid state is injected into the mold to integrate the resin and the molded sheet.

[0111] In the vacuum forming step in the insert molding method, the decorative sheet may be heated and molded. The heating temperature is not particularly limited and may be appropriately selected depending on the type of resin constituting the decorative sheet and the thickness of the decorative sheet, but for example, when an ABS resin film is used as the base layer, the heating temperature is usually about 100 to 250°C, preferably about 130 to 200°C. In the integration step, the temperature of the resin in a fluid state is not particularly limited, but may usually be about 180 to 320°C, preferably about 220 to 280°C.

[0112] In addition, in the simultaneous injection molding decoration method, the decorative sheet of the present disclosure is placed in a female mold that also serves as a vacuum forming mold and is provided with suction holes for injection molding, and preforming (in-line preforming) is performed using this female mold.The injection molding mold is then clamped, and the resin in a fluid state is injected to fill the mold and solidify.The base layer 1 side of the decorative sheet of the present disclosure is integrated with the outer surface of the resin molded product at the same time as the injection molding to produce a decorated resin molded product.

[0113] More specifically, the decorated resin molded article of the present disclosure is produced by a simultaneous injection molding and decoration method including the following steps.

[0114] a step of preforming the decorative sheet by placing the decorative sheet of the present disclosure against a molding surface of a movable mold having a predetermined shape, with the base material of the decorative sheet facing the molding surface, heating and softening the decorative sheet and vacuum-suctioning the softened decorative sheet from the movable mold side to bring the softened decorative sheet into close contact with the molding surface of the movable mold; an injection molding process in which a movable mold and a fixed mold having a decorative sheet in close contact with each other along their molding surfaces are clamped together, and then a resin molding material in a fluid state is injected into a cavity formed by both molds, filled therein, and solidified to laminate and integrate the formed resin molded body and the decorative sheet; A process of separating the movable mold from the fixed mold to remove a resin molded body including all layers of the decorative sheet laminated thereon.

[0115] In the preforming step of the simultaneous injection molding and decoration method, the heating temperature of the decorative sheet is not particularly limited and may be appropriately selected depending on the type of resin constituting the decorative sheet, the thickness of the decorative sheet, etc., but when a polyester resin film or an acrylic resin film is used as the base layer, it can usually be about 70 to 130° C. In addition, in the injection molding step, the temperature of the resin in a fluid state is not particularly limited, but can usually be about 180 to 320° C., preferably about 220 to 280° C.

[0116] In addition, the decorated resin molded product of the present disclosure can also be produced by a decoration method (overlay method) in which a decorative sheet of the present disclosure is attached to a previously prepared three-dimensional resin molded body (molded resin layer), such as a vacuum pressure bonding method.

[0117] In the overlay method, first, the decorative sheet and the resin molded body of the present disclosure are placed in a vacuum pressure bonding machine consisting of a first vacuum chamber located on the upper side and a second vacuum chamber located on the lower side, so that the decorative sheet faces the first vacuum chamber side, the resin molded body faces the second vacuum chamber side, and the base layer 1 side of the decorative sheet faces the resin molded body side, and the two vacuum chambers are placed in a vacuum state. The resin molded body is placed on a lifting platform that is provided on the second vacuum chamber side and can be raised and lowered up and down. Next, the first vacuum chamber is pressurized, and the lifting platform is used to press the molded body against the decorative sheet, and the decorative sheet is attached to the surface of the resin molded body while being stretched by utilizing the pressure difference between the two vacuum chambers. Finally, the two vacuum chambers are opened to atmospheric pressure, and the excess part of the decorative sheet is trimmed as necessary, thereby obtaining the decorated resin molded product of the present disclosure.

[0118] In the overlay method, it is preferable to include a step of heating the decorative sheet before the step of pressing the above-mentioned molded body against the decorative sheet in order to soften the decorative sheet and improve its formability. The overlay method including this step is sometimes called a vacuum heat pressing method. The heating temperature in this step may be appropriately selected depending on the type of resin constituting the decorative sheet and the thickness of the decorative sheet, but when a polyester resin film or an acrylic resin film is used as the base layer, it can usually be about 60 to 200°C.

[0119] In the decorated resin molded product of the present disclosure, the molded resin layer may be formed by selecting a molding resin according to the application. The molding resin may be a thermoplastic resin or a thermosetting resin.

[0120] Examples of thermoplastic resins used as molding resins include polyolefin resins such as polyethylene and polypropylene, ABS resins, styrene resins, polycarbonate resins, acrylic resins, vinyl chloride resins, etc. These thermoplastic resins may be used alone or in combination of two or more.

[0121] Examples of the thermosetting resin used as the molding resin include urethane resin, epoxy resin, etc. These thermosetting resins may be used alone or in combination of two or more.

[0122] The decorated resin molded product of the present disclosure has an excellent design and can be used, for example, as interior or exterior materials for vehicles such as automobiles; construction components such as baseboards and moldings; window frames, door frames and other fittings; interior materials for buildings such as walls, floors and ceilings; housings for home appliances such as television sets and air conditioners; containers, etc. EXAMPLES

[0123] The present disclosure will be described in detail below with reference to examples and comparative examples. However, the present disclosure is not limited to the examples.

[0124] [Example 1-1] A black ABS resin film (thickness 200 μm, softening point 130° C.) was used as the substrate layer. On the substrate layer, a concealing layer having a thickness of 1 μm and a decorative layer having a thickness of 2 to 10 μm were applied by gravure printing using an ink composition containing a colorant and a resin (a mixture of an acrylic resin and a vinyl chloride-vinyl acetate copolymer) on the entire surface of the substrate layer, and then dried to form a decorative layer. Next, the obtained laminate was heated to 120 to 140° C. to soften it, and the laminate was passed between the embossing roll and the rubber roll at a heating temperature of 70 to 90° C. so that the decorative layer side was in contact with an embossing roll (plate depth 60 μm), and further rapidly cooled to 30° C. with a cooling roll to form an uneven shape on the decorative layer side of the laminate. The forming conditions of this uneven shape are low temperature conditions considering the melting point of the resin compared to the forming conditions of a general uneven shape using an embossing roll, and conditions are adopted in which the residual stress due to the imparting of the uneven shape becomes large. The concave-convex shape formed is a linear pattern in which multiple lines are arranged in one direction (see schematic diagram in Figure 6), and the width H1 (line width) of the convex portion 11 formed on the base layer is 138 μm, and the width H2 (line spacing) of the flat portion 12 is 188 μm.

[0125] Next, on the decorative layer with the uneven surface formed thereon, ionizing radiation curable resin composition A (ink containing 30% by mass of a resin consisting of 95 parts by mass of a bifunctional urethane acrylate (weight average molecular weight 20,000) having a polycarbonate skeleton and 5 parts by mass of a hexafunctional urethane acrylate (weight average molecular weight 3,000), and 70% by mass of a diluting solvent) was applied by gravure printing to form an uncured resin layer. Next, the uncured resin layer was irradiated with an electron beam at an acceleration voltage of 165 kV and a radiation dose of 50 kGy (5 Mrad) to provide a surface protective layer, thereby obtaining a decorative sheet with an uneven surface.

[0126] [Example 1-2] A decorative sheet was obtained in the same manner as in Example 1-1, except that the embossing roll was changed and the width H1 (line width) of the convex portion 11 formed on the base layer was set to 188 μm, and the width H2 (line spacing) of the flat portion of the flat portion 12 was set to 188 μm.

[0127] [Examples 1-3] A decorative sheet was obtained in the same manner as in Example 1-1, except that the embossing roll was changed and the width H1 (line width) of the convex portion 11 formed on the base layer was set to 288 μm, and the width H2 (line spacing) of the flat portion of the flat portion 12 was set to 188 μm.

[0128] [Examples 1-4] A decorative sheet was obtained in the same manner as in Example 1-1, except that the embossing roll was changed and the width H1 (line width) of the convex portion 11 formed on the base layer was set to 288 μm, and the width H2 (line spacing) of the flat portion of the flat portion 12 was set to 288 μm.

[0129] [Examples 1-5] A decorative sheet was obtained in the same manner as in Example 1-1, except that the embossing roll was changed and the width H1 (line width) of the convex portion 11 formed on the base layer was set to 288 μm, and the width H2 (line spacing) of the flat portion of the flat portion 12 was set to 588 μm.

[0130] [Comparative Example 1-1] In the production of the decorative sheet of Example 1-1, instead of "heating the obtained laminate to 120 to 140°C to soften it, passing the laminate between the embossing roll and the rubber roll at a heating temperature of 70 to 90°C so that the decorative layer side is in contact with the embossing roll (plate depth 60 μm), and further quenching to 30°C with a cooling roll," "heating the obtained laminate to 180 to 200°C to soften it, passing the laminate between the embossing roll and the rubber roll at a heating temperature of 140 to 160°C so that the decorative layer side is in contact with the embossing roll (plate depth 60 μm), and further quenching to 30°C with a cooling roll" was performed, but a decorative sheet having a concave-convex shape on the surface was obtained in the same manner as in Example 1-1. The conditions for forming this concave-convex shape are the general conditions for forming a concave-convex shape using an embossing roll. In other words, the conditions for softening the base layer at a high temperature to minimize the residual stress caused by the imparting of the concave-convex shape are adopted. During molding of the decorative sheet, the convex portions of the base layer are prevented from being flattened as much as possible due to residual stress.

[0131] [Comparative Example 1-2] A decorative sheet was obtained in the same manner as in Comparative Example 1-1, except that the embossing roll was changed and the width H1 (line width) of the convex portion 11 formed on the base layer was set to 188 μm, and the width H2 (line spacing) of the flat portion of the flat portion 12 was set to 188 μm.

[0132] [Comparative Example 1-3] A decorative sheet was obtained in the same manner as in Comparative Example 1-1, except that the embossing roll was changed and the width H1 (line width) of the convex portion 11 formed on the base layer was set to 288 μm, and the width H2 (line spacing) of the flat portion of the flat portion 12 was set to 188 μm.

[0133] [Comparative Example 1-4] A decorative sheet was obtained in the same manner as in Comparative Example 1-1, except that the embossing roll was changed and the width H1 (line width) of the convex portion 11 formed on the base layer was set to 288 μm, and the width H2 (line spacing) of the flat portion of the flat portion 12 was set to 288 μm.

[0134] [Comparative Example 1-5] A decorative sheet was obtained in the same manner as in Comparative Example 1-1, except that the embossing roll was changed and the width H1 (line width) of the convex portion 11 formed on the base layer was set to 288 μm, and the width H2 (line spacing) of the flat portion of the flat portion 12 was set to 588 μm.

[0135] <Manufacturing of decorated resin molded products> The decorative sheet was heated with an infrared heater and softened until the sheet temperature reached 25°C to 160°C. Next, vacuum molding was performed using a vacuum molding mold (maximum stretch ratio 100%) to mold it into the internal shape of the mold. The molded decorative sheet was cooled and then released from the mold. Then, injection resin (ABS resin melted at a temperature of 250°C) was injected into the cavity of the mold, and the base layer side of the decorative sheet and the injected resin were molded together. The decorative resin molded product (decorative sheet after molding) was obtained at the same time as it was removed from the mold.

[0136] <Measurement of surface roughness Sdr value (interface development area ratio) of decorative sheet before and after molding> To measure the surface roughness Sdr value of the decorative sheet, a laser microscope (Keyence VK-X1000) was used to observe the surface of the molded product magnified with a 20x objective lens, and five areas were designated on each of the convex and flat parts of the surface protection layer. The average of the measurement results was used as the surface roughness Sdr value.

[0137] For the decorative sheet before being used in the above-mentioned <Production of Decorated Resin Molding>, the surface roughness Sdr value (interface developed area ratio) of the convex part of the surface of the surface protective layer (position corresponding to the convex part of the base layer) and the flat part of the surface of the surface protective layer (position corresponding to the flat part of the base layer) were measured, and the difference was calculated. The results are shown in Table 1.

[0138] In addition, for the decorative sheet after being subjected to the above-mentioned <Production of Decorated Resin Molded Product> (the molded decorative sheet which is integrated with the molded resin layer to form a part of the decorated resin molded product), the surface roughness Sdr value (interface developed area ratio) of the convex parts of the surface of the surface protective layer (positions corresponding to the convex parts of the base layer) and the flat parts of the surface of the surface protective layer (positions corresponding to the flat parts of the base layer) were measured, and the difference was calculated. The results are shown in Table 1.

[0139] <Measurement of brightness of decorative sheet after molding> Using a TELEDYNE Aviiva E2V camera and a CCS LNSP light, the brightness of the positions of the convex and flat parts of the base layer was measured for the surface of the surface protection layer of the decorative sheet (the decorative sheet after molding, which is integrated with the resin molded product to form a part of the decorated resin molded product) after being subjected to the above-mentioned <Production of Decorated Resin Molded Product>, and the difference (brightness at the position of the flat part - brightness at the position of the convex part) was calculated. The brightness was measured under the following conditions: incident angle 15° (specifically, when the decorative sheet is placed horizontally, the incident angle is inclined 15° from the vertical direction, and the reflection angle is also inclined 15°), resolution 50 μm / pixel, distance from the illumination surface to the object 100 mm, illuminance 32000 Lx, and regular reflection condition. The results are shown in Table 1.

[0140] <Measurement of the thickness of the surface protection layer of the decorative sheet before molding> The decorative sheet was cut in the thickness direction, and a cross-sectional image of the cross section in the thickness direction was obtained using a scanning electron microscope (SEM). The thickness D1 at the center of the convex part of the surface protective layer and the thickness D2 at the center of the flat part were measured at five points each, and the average values ​​were taken as the respective thicknesses. The results are shown in Table 1.

[0141] <Evaluation of design based on appearance> The surface of the surface protection layer side of the decorative sheet (the decorative sheet after molding, which is integrated with the resin molding to form a part of the decorated resin molding) after being subjected to the above-mentioned <Production of Decorated Resin Molded Product> was visually observed, and the three-dimensional design feeling was evaluated based on the shadows and the like observed due to the uneven shape according to the following criteria. The results are shown in Table 1. A: The shadows are sufficiently expressed on the surface of the decorative sheet, and the three-dimensional design can be clearly seen when oblique light is shone on it. C: The shading on the surface of the decorative sheet is weak overall, or when oblique light is applied, the shading is insufficient due to the light being irradiated onto the concave portions of the uneven surface, resulting in an insufficient sense of three-dimensional design.

[0142] [Table 1]

[0143] In Table 1, "-" means that the measurement was not performed.

[0144] [Example 2-1] A decorative sheet was obtained in the same manner as in Example 1-1, except that the ionizing radiation curable resin composition A was used to form the surface coating layer, and the embossing roll was changed to an embossing roll (the plate depth of the embossing roll was 45 μm) that forms a carbon pattern (see the schematic diagram of FIG. 7) consisting of a shape in which multiple lines are arranged in one direction and a shape in which multiple lines are arranged in a direction perpendicular to the shape of the multiple lines arranged in the ...

[0145] [Example 2-2] A decorative sheet was obtained in the same manner as in Example 2-1, except that the embossing roll was changed to an embossing roll that forms a geometric pattern composed of triangles (the plate depth of the embossing roll is 60 μm). The width H1 (line width) of the convex portion 11 formed on the base layer is 120 μm, and the width H2 (line spacing) of the flat portion of the flat portion 12 is 300 μm.

[0146] [Comparative Example 2-1] A decorative sheet was obtained in the same manner as in Comparative Example 1-1, except that the ionizing radiation curable resin composition A was used to form the surface coating layer, and the embossing roll was changed to an embossing roll (the plate depth of the embossing roll was 45 μm) that forms a carbon pattern composed of a shape in which multiple lines are arranged in one direction and a shape in which multiple lines are arranged in a direction perpendicular to the shape of the multiple lines arranged in the ...

[0147] [Example 3-1] A decorative sheet was obtained in the same manner as in Example 1-1, except that the surface coating layer was formed using ionizing radiation curable resin composition B (an ink containing 30% by mass of a resin composition consisting of 87 parts by mass of a bifunctional urethane acrylate (weight average molecular weight 20,000) having a polycarbonate skeleton and 5 parts by mass of a hexafunctional urethane acrylate (weight average molecular weight 3,000), 8 parts by mass of acrylic resin beads, and 70% by mass of a dilution solvent) and that the embossing roll was changed to an embossing roll (the plate depth of the embossing roll was 60 μm) that forms a line pattern consisting of lines with irregular widths and intervals. The width H1 (line width) of the convex portions 11 formed on the base layer was 100 to 200 μm, and the width H2 (line interval) of the flat portions 12 was 80 to 150 μm.

[0148] [Example 3-2] A decorative sheet was obtained in the same manner as in Example 3-1, except that the embossing roll was changed to an embossing roll that forms a geometric shape composed of diamond shapes (the plate depth of the embossing roll is 60 μm). The width H1 (line width) of the convex portion 11 formed on the base layer is 80 μm, and the width H2 (line interval) of the flat portion of the flat portion 12 is 100 μm.

[0149] For the decorative sheets obtained in Examples 2-1, 2-2, 3-1, 3-2 and Comparative Example 2-1, the following procedures were carried out in the same manner as in Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-5: production of a decorated resin molded product, measurement of the surface roughness Sdr value (interface developed area ratio) of the decorative sheet after molding, measurement of the thickness of the surface protective layer of the decorative sheet before molding, and evaluation of the design sense by appearance. The results are shown in Table 2.

[0150] [Table 2]

[0151] In Table 2, "-" means that the measurement was not performed. [Explanation of symbols]

[0152] 1 Base material layer 2 Surface protective layer 3. Decorative layer 4 Molded resin layer 10 Decorative sheet 10a Decorative sheet after molding 11 Convex portion of base layer 12 Flat portion of base layer 21 Convex portion of surface protective layer 22 Flat portion of surface protection layer D1 Thickness of the center of the protrusion of the surface protection layer D2 Thickness of the center of the flat part of the surface protection layer H1 Width of the convex part of the base layer H2 Width of the flat part of the base layer S Position of the convex part of the base layer of the decorative sheet after heating T Position of the flat part of the base layer of the decorative sheet after heating

Claims

1. A decorative sheet including at least a base layer and a surface protective layer, the surface of the base layer on the side of the surface protective layer has an uneven shape formed by repeating convex portions and flat portions, the surface protective layer has an uneven shape corresponding to the uneven shape of the base layer, the surface protective layer has a surface roughness Sdr value (interface developed area ratio) measured at a position of a flat portion of the base material layer of 0 or more and 0.2 or less, When the decorative sheet is heated from a temperature of 25°C to a temperature of 160°C, the surface protection layer has a difference between the surface roughness Sdr value (interfacial developed area ratio) measured at the position of the convex portion of the base material layer and the surface roughness Sdr value (interfacial developed area ratio) measured at the position of the flat portion of the base material layer of 0.1 or more.

2. A decorative sheet including at least a base layer and a surface protective layer, the surface of the base layer on the side of the surface protective layer has an uneven shape formed by repeating convex portions and flat portions, the surface protective layer has an uneven shape corresponding to the uneven shape of the base layer, the surface protective layer has a surface roughness Sdr value (interface developed area ratio) measured at a position of a flat portion of the base material layer of 0 or more and 0.2 or less, When the decorative sheet is heated from a temperature of 25°C to a temperature of 160°C, the surface protective layer has a difference in luminance (luminance at the position of the flat portion - luminance at the position of the convex portion) of 30 or more measured under specular reflection conditions of an incident angle of 15°, a resolution of 50 μm / pixel, a distance from an illumination surface to an object of 100 mm, and an illuminance of 32,000 Lx for the positions of the convex portions and the flat portions of the base material layer.

3. When a cross section of a convex portion constituting the uneven shape of the surface protective layer is observed in a thickness direction, the thickness of the surface protective layer at a center position of the convex portion is 7 μm or less, 3. The decorative sheet according to claim 1, wherein, when a cross section of the flat portion of the surface protective layer is observed in a thickness direction, the thickness of the surface protective layer at a center position of the flat portion is 10 μm or more.

4. The decorative sheet according to any one of claims 1 to 3, wherein the width of the convex portions of the base layer is 100 µm or more and 350 µm or less.

5. The decorative sheet according to any one of claims 1 to 4, wherein the width of the flat portion of the base layer is 50 µm or more and 600 µm or less.

6. The decorative sheet according to any one of claims 1 to 5, wherein the height of the protrusions on the surface of the decorative sheet on the side of the surface protective layer is 10 µm or more and 50 µm or less.

7. 7. The decorative sheet according to claim 1, wherein, when a cross section of a convex portion constituting the uneven shape of the surface protective layer is observed in a thickness direction, a thickness of the surface protective layer at a center position of the convex portion is 2 μm or more and 7 μm or less.

8. The decorative sheet according to any one of claims 1 to 7, further comprising a decorative layer between the surface protective layer and the base layer.

9. A decorated resin molded product including at least a molded resin layer, a base layer, and a surface protective layer in this order, the surface of the base layer on the side of the surface protective layer has an uneven shape formed by repeating convex portions and flat portions, the surface protective layer has an uneven shape corresponding to the uneven shape of the base layer, the surface protective layer has a surface roughness Sdr value (interface developed area ratio) measured at a position of a flat portion of the base material layer of 0 or more and 0.1 or less; The surface protective layer has a difference between a surface roughness Sdr value (interface developed area ratio) measured at the position of the convex portion of the base material layer and a surface roughness Sdr value (interface developed area ratio) measured at the position of the flat portion of the base material layer of 0.1 or more.

10. A decorated resin molded product including at least a molded resin layer, a base layer, and a surface protective layer in this order, the surface of the base layer on the side of the surface protective layer has an uneven shape formed by repeating convex portions and flat portions, the surface protective layer has an uneven shape corresponding to the uneven shape of the base layer, the surface protective layer has a surface roughness Sdr value (interface developed area ratio) measured at a position of a flat portion of the base material layer of 0 or more and 0.1 or less; The surface protective layer has a difference in luminance (luminance at the position of the flat portion - luminance at the position of the convex portion) of 30 or more measured under specular reflection conditions of an incident angle of 15°, a resolution of 50 μm / pixel, a distance from an illumination surface to an object of 100 mm, and an illuminance of 32,000 Lx for the positions of the convex portion and the flat portion of the base material layer.

11. A method for producing a decorated resin molded product, comprising a step of laminating a molded resin layer by injecting a resin onto the base layer side of the decorative sheet according to any one of claims 1 to 8.

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