Decorative sheet, production method for same, and decorative article

Abstract

Provided is a decorative sheet comprising a laminate that has a first main surface and a second main surface positioned on the opposite side from the first main surface side and that has at least a first design layer and a transparent base material layer in this order from the first main surface side to the second main surface side, wherein the first design layer has at least a colored first print layer, a reflective second print layer, and a colored third print layer in this order from the first main surface side to the second main surface side, and the value of chroma * in an L*a*b* color space, as measured when the first print layer and the third print layer are overlapped on a white board having a whiteness of 75%, is not more than 10.

Description

Decorative sheet, method for producing the same, and decorated article

[0001] The present disclosure relates to a decorative sheet, a method for producing the same, and a decorated article.

[0002] Conventionally, for vehicle interior and exterior parts, building interior materials, home appliance housings, etc., a decorated resin molded product in which a decorative sheet is laminated on the surface of a resin molded product has been used. In the production of such a decorated resin molded product, a molding method such as integrating a decorative sheet with a design previously applied by injection molding is used. As a typical example of such a molding method, there is an insert molding method in which a decorative sheet is previously formed into a three-dimensional shape by a vacuum molding die, the decorative 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 decorative sheet.

[0003] The decorated resin molded product obtained by such a molding method is used for various applications such as vehicle interior and exterior parts as described above. Therefore, in addition to three-dimensional moldability that can follow three-dimensional molding and surface characteristics such as scratch resistance on the surface, with the diversification of recent consumers' preferences, various design senses are required. For example, developments such as imparting texture to a resin molded product by applying dulling or unevenness in accordance with specific portions of a pattern have been promoted (for example, Patent Document 1). In addition, as having various design senses, synthetic resin molded parts having a changing design surface have been proposed (for example, Patent Document 2).

[0004] Furthermore, a decorative sheet in which a light source is arranged on the side opposite to the observer side of the decorative sheet and different designs are exhibited when the light source is lit and extinguished has also been proposed (for example, Patent Document 3).

[0005] JP-A-2009-132145 JP-A-2010-125817 JP-A-2013-14051

[0006] As described above, a decorative sheet that exhibits different designs when the light source is lit and extinguished is known. In such a decorative sheet, the design layer is configured by a combination of a portion that transmits light from the light source and a portion that blocks light from the light source, and is designed to exhibit different designs when the light source is lit and extinguished.

[0007] The inventors of the present disclosure have noted that in such a decorative sheet, the transmitted light from the light source is strongly affected by the color of the design layer in the portion where the light has transmitted, and there may be a problem that the intended design by the transmitted light is not manifested when the light source is lit.

[0008] Under such circumstances, the main object of the present disclosure is to provide a decorative sheet that exhibits different designs when the light source is lit and when it is turned off, and includes a design layer that has little influence on the design manifested by the transmitted light when the light source is lit. Further, the present disclosure also aims to provide a method for manufacturing the decorative sheet and a decorated article using the decorative sheet.

[0009] The inventors of the present disclosure have conducted intensive studies to solve the above problems. As a result, a decorative sheet composed of a laminate including a first main surface and a second main surface located on the side opposite to the first main surface side, and at least a first design layer and a transparent base material layer in this order from the first main surface side toward the second main surface side, wherein the first design layer includes, at least in this order from the first main surface side toward the second main surface side, a colored first printing layer, a reflective second printing layer, and a colored third printing layer, and the chroma C in the Lab color space * a * b * of the value is set to be not more than a predetermined value, whereby the first design layer has less influence on the design manifested by the transmitted light when the light source is lit, and it has been found that the intended design by the transmitted light is manifested when the light source is lit. The present disclosure has been completed by further studies based on such findings.

[0010] ​​That is, the present disclosure provides inventions in the following embodiments. Item 1. A decorative sheet comprising a laminate having a first main surface and a second main surface located on the opposite side of the first main surface, wherein, from the first main surface side toward the second main surface side, at least a first design layer and a transparent substrate layer are provided in this order, the first design layer comprises, from the first main surface side toward the second main surface side, at least a colored first printing layer, a reflective second printing layer and a colored third printing layer in this order, the first printing layer and the third printing layer are measured on a white plate with a whiteness of 75% with these layers stacked. * a * b * Saturation C in the color space *A decorative sheet in which the value is 10 or less. Item 2. The decorative sheet according to Item 1, wherein the second printing layer contains a pigment that specularly reflects or diffusely reflects visible light. Item 3. The decorative sheet according to Item 1 or 2, in which the second printing layer is partially formed. Item 4. The decorative sheet according to any one of Items 1 to 3, wherein the change rate of the light transmittance due to the presence or absence of the second printing layer in the first design layer is within 25%. Item 5. The decorative sheet according to any one of Items 1 to 4, further comprising a second design layer partially provided between the first design layer and the transparent base material layer and / or on the second main surface side of the transparent base material layer. Item 6. The decorative sheet according to Item 5, in which the second design layer is embedded in the transparent base material layer. Item 7. The decorative sheet according to Item 5 or 6, wherein the optical density of the second design layer is greater than the optical density of the first design layer. Item 8. The decorative sheet according to any one of Items 5 to 7, further comprising an adhesive layer between the first design layer and the second design layer. Item 9. The decorative sheet according to any one of Items 1 to 8, further comprising a protective layer on the first main surface side of the first design layer. Item 10. The decorative sheet according to Item 9, wherein the protective layer contains an acrylic resin or a radiation-curable resin. Item 11. The decorative sheet according to Item 9 or 10, further comprising an adhesive layer between the protective layer and the first design layer. Item 12. A method for manufacturing a decorative sheet composed of a laminate comprising at least a first design layer, a transparent base material layer, and a second main surface located on the side opposite to the first main surface, in this order, from the first main surface side to the second main surface side. The first design layer includes at least a colored first printing layer, a reflective second printing layer, and a colored third printing layer, in this order, from the first main surface side to the second main surface side. The L measured by overlapping the first printing layer and the third printing layer on a white plate having a whiteness of 75% * a * b * Chroma C in the color space *A method for manufacturing a decorative sheet, wherein the coefficient is 10 or less. Clause 13. A decorative resin molded article comprising a second main surface of a decorative sheet according to any one of Clauses 1 to 11 and a transparent molded resin layer laminated together. Clause 14. A decorative article comprising a decorative resin molded article according to Clause 13, wherein a light source is arranged on the side of the molded resin layer opposite to the decorative sheet side.

[0011] The primary objective of this disclosure is to provide a decorative sheet that exhibits different designs when the light source is on and when it is off, and which has a design layer that has little influence on the design exhibited by transmitted light when the light source is on. Furthermore, this disclosure also aims to provide a method for manufacturing the decorative sheet and a decorative article using the decorative sheet.

[0012] This is a schematic diagram of the cross-sectional structure of one form of the decorative sheet of this disclosure. This is a schematic diagram of the cross-sectional structure of one form of the decorative sheet of this disclosure. This is a schematic diagram of the cross-sectional structure of one form of the decorative sheet of this disclosure. This is a schematic diagram of the cross-sectional structure of one form of the decorative resin molded product of this disclosure. This is a schematic diagram for explaining the design that appears when the light source is turned off in the decorative sheet of this disclosure from the cross-sectional structure. This is a schematic diagram for explaining the design that appears when the light source is turned on in the decorative sheet of this disclosure from the cross-sectional structure.

[0013] [Decorative Sheet] The decorative sheet of this disclosure comprises a first main surface and a second main surface located on the opposite side of the first main surface, and is composed of a laminate comprising, in order from the first main surface side to the second main surface side, at least a first design layer and a transparent substrate layer, and the first design layer comprises, in order from the first main surface side to the second main surface side, at least a colored first printed layer, a reflective second printed layer and a colored third printed layer, and the first and third printed layers are measured in L when these layers are stacked on a white plate with a whiteness of 75%. * a * b * Saturation C in the color space * The value of is characterized by being 10 or less. The decorative sheet of this disclosure has such a configuration, making it possible to display different designs when the light source is on and when it is off.

[0014] The decorative sheets of this disclosure will be described in detail below with reference to Figures 1 to 5. In this specification, numerical ranges indicated by "~" mean "greater than or equal to" and "less than or equal to". For example, the notation 2 to 15 mm means 2 mm or more and 15 mm or less. In numerical ranges described in stages in this disclosure, the upper or lower limit stated in one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Alternatively, upper and lower limits, upper and lower limits, or lower and lower limits described separately may be combined to form numerical ranges. Furthermore, in numerical ranges described in this disclosure, the upper or lower limit stated in one numerical range may be replaced with the values ​​shown in the examples. In this specification, "(meth)acrylate" means "acrylate or methacrylate," and other similar terms have the same meaning.

[0015] Furthermore, in this disclosure, transparent may be colorless transparent (for example, with a total light transmittance of 80% or more and a haze of 20% or less), colored transparent (for example, with a total light transmittance of 25% or more and a haze of 20% or less), or semi-transparent when a light source described later is transmitted through it (for example, with a total light transmittance of 50% or more and less than 80%, and a haze of 20% or more).

[0016] (Laminated structure and physical properties of the decorative sheet) The decorative sheet 10 of this disclosure comprises, for example, a first main surface 10a and a second main surface 10b located on the opposite side from the first main surface 10a, as shown in Figures 1 to 4. The decorative sheet 10 of this disclosure is composed of a laminate comprising, at least, a first design layer 1 and a transparent substrate layer 3 in this order, from the first main surface 10a side toward the second main surface 10b side.

[0017] The first design layer 1 comprises, in order from the first main surface 10a to the second main surface 10b, at least a colored first printed layer 11, a reflective second printed layer 12, and a colored third printed layer 13. Furthermore, in this disclosure, the first printed layer 11 and the third printed layer 13 are measured in a state where these layers are stacked on a white plate with a whiteness of 75%. * a * b * Saturation C in the color space* The value is less than or equal to 10.

[0018] The decorative sheet 10 of this disclosure can be suitably used for decorating the surface of resin molded products such as vehicle interior and exterior parts, building interior materials, and home appliance casings. Therefore, the decorative sheet 10 of this disclosure can be suitably used as a decorative sheet for three-dimensional molding. For example, the decorative sheet 10 of this disclosure can be molded as a decorative sheet for three-dimensional molding and laminated with a molded resin layer described later to suitably obtain a decorated resin molded product. When the decorative sheet 10 of this disclosure is incorporated into a decorated resin molded product 20 and used for various applications such as vehicle interior and exterior parts, building interior materials, and home appliance casings, as shown in Figure 4, the first main surface 10a is positioned on the observer side and the second main surface 10b is positioned on the light source 30 side.

[0019] As shown in Figures 2 to 4, the decorative sheet 10 of the present disclosure may further comprise a second design layer 2. When the decorative sheet 10 of the present disclosure is provided with a second design layer 2, it is preferable that the second design layer 2 be provided between the first design layer 1 and the transparent substrate layer 3 and / or on the second main surface 10b side of the transparent substrate layer 3. From the viewpoint of more favorably exhibiting the effects of the present invention, it is preferable that the second design layer 2 in the decorative sheet 10 of the present disclosure is a partially provided layer, and more specifically, when the decorative sheet 10 is observed from the first main surface 10a side, it is preferable that there are parts where the second design layer 2 is provided and parts where it is not provided.

[0020] In addition to the first design layer 1, the transparent substrate layer 3, and the second design layer 2 provided as needed, the decorative sheet 10 of this disclosure may further include one or more other layers at arbitrary positions, depending on the function to be imparted to the decorative sheet, such as a protective layer 4, an adhesive layer (not shown), and a primer layer (not shown).

[0021] The laminated structure of the decorative sheet of this disclosure includes, in order from the second main surface 10b side, a laminated structure in which a transparent substrate layer / first design layer (third printing layer / second printing layer / first printing layer) is laminated in this order; a laminated structure in which a transparent substrate layer / second design layer / first design layer (third printing layer / second printing layer / first printing layer) is laminated in this order; a laminated structure in which a second design layer / transparent substrate layer / first design layer (third printing layer / second printing layer / first printing layer) is laminated in this order; a laminated structure in which a transparent substrate layer / second design layer / first design layer (third printing layer / second printing layer / first printing layer) / protective layer is laminated in this order; and a laminated structure in which a second design layer / transparent substrate layer / first design layer (third printing layer / second printing layer / first printing layer) / protective layer is laminated in this order. A laminated structure in which a transparent substrate layer / second design layer / first design layer (third printing layer / second printing layer / first printing layer) / primer layer / protective layer is laminated in this order; A laminated structure in which a second design layer / transparent substrate layer / first design layer (third printing layer / second printing layer / first printing layer) / primer layer / protective layer is laminated in this order; A laminated structure in which a transparent substrate layer / second design layer / adhesive layer / first design layer (third printing layer / second printing layer / first printing layer) / primer layer / protective layer is laminated in this order; A laminated structure in which a second design layer / transparent substrate layer / adhesive layer / first design layer (third printing layer / second printing layer / first printing layer) / primer layer / protective layer is laminated in this order; An adhesive layer / transparent substrate layer / second design layer / first design layer (third printing layer / second printing layer / first printing layer) / primer layer / protective layer is laminated in this order; Examples include a laminated structure in which the second design layer, adhesive layer, transparent substrate layer, first design layer (third printing layer, second printing layer, first printing layer), primer layer, and protective layer are laminated in this order.

[0022] Figure 1 shows a schematic cross-sectional view of an example of a decorative sheet in which a transparent substrate layer / first design layer (third printing layer / second printing layer / first printing layer) is laminated in the order shown from the second main surface 10b side, as one aspect of the laminated structure of the decorative sheet of this disclosure. Figure 2 shows a schematic cross-sectional view of an example of a decorative sheet in which a transparent substrate layer / second design layer / first design layer (third printing layer / second printing layer / first printing layer) is laminated in the order shown from the second main surface 10b side, as one aspect of the laminated structure of the decorative sheet of this disclosure. Figure 3 shows a schematic cross-sectional view of an example of a decorative sheet in which a transparent substrate layer / second design layer / first design layer (third printing layer / second printing layer / first printing layer) / protective layer is laminated in the order shown from the second main surface 10b side, as one aspect of the laminated structure of the decorative sheet of this disclosure.

[0023] In the decorative sheet 10, the ratio of the total thickness of the first design layer 1, the transparent base material layer 3, the second design layer 2 (optionally provided), the protective layer 4 (optionally provided), the adhesive layer (optionally provided), and the primer layer (optionally provided) to the thickness (total thickness) of the laminate constituting the decorative sheet 10 is, for example, 80% or more, preferably 90% or more, and more preferably 95% or more.

[0024] As a specific example, if the decorative sheet 10 of this disclosure includes a first design layer 1, a transparent substrate layer 3, a second design layer 2, and a protective layer 4, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the decorative sheet 10 is, for example, 80% or more, preferably 90% or more, and more preferably 95% or more. Also, if the decorative sheet 10 of this disclosure includes a first design layer 1, a transparent substrate layer 3, a second design layer 2, a protective layer 4, and an adhesive layer, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the decorative sheet 10 is, for example, 80% or more, preferably 90% or more, and more preferably 95% or more. Furthermore, if the decorative sheet 10 of this disclosure includes a first design layer 1, a transparent substrate layer 3, a second design layer 2, a protective layer 4, an adhesive layer, and a primer layer, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the decorative sheet 10 is, for example, 80% or more, preferably 90% or more, and more preferably 95% or more.

[0025] In the first design layer 1 of the decorative sheet 10 of this disclosure, the first printing layer 11 and the third printing layer 13 are measured on a white board with a whiteness of 75% with these layers stacked on top of each other. * a * b * Saturation C in the color space * The value of is 10 or less. The saturation C * The value of chrominance C may be 10 or less, but from the viewpoint of more favorably exhibiting the effects of the present invention, it is preferably 5 or less, and preferred ranges include 0 to 10, 0 to 5, etc. * The value is measured by the method described in [Color Measurement of Decorative Sheet 1] below.

[0026] Furthermore, from the viewpoint of more favorably exhibiting the effects of the present invention, the first printing layer 11 and the third printing layer 13 are measured in a state where these layers are stacked on a white board with a whiteness of 75%. * a * b * L in color space * From the viewpoint of pattern reproduction (two-tone color) due to the difference in brightness caused by the presence or absence of the second printing layer, the value is preferably 0 to 50. From the viewpoint of color combinations that result in low saturation, the L * a * b * a in the color space * The value is preferably -10 or more and 10 or less, more preferably -5 or more and 5 or less. From a similar viewpoint, the L * a * b * b in color space * The values ​​are preferably -10 or more and 10 or less, more preferably -5 or more and 5 or less. * Value, a * Value and b * The values ​​are those measured by the method described in [Color Measurement of Decorative Sheets 1] below.

[0027] Furthermore, from the viewpoint of more favorably exhibiting the effects of the present invention, in the decorative sheet 10 of the present disclosure, the first printing layer 11 of the first design layer 1 is measured on a white board with a whiteness of 75% L * a * b *L in color space * The value is preferably 50 or more, and a preferred range is 50 to 100. * The value is measured by the method described in [Color Measurement of Decorative Sheet 1] below.

[0028] Furthermore, from the viewpoint of more favorably exhibiting the effects of the present invention, in the decorative sheet 10 of the present disclosure, the third printing layer 13 of the first design layer 1 is measured on a white board with a whiteness of 75% L * a * b * L in color space * The value is preferably 50 or less, and a preferred range is 0 to 50. * The value is measured by the method described in [Color Measurement of Decorative Sheet 1] below.

[0029] [Color Measurement of Decorative Sheet 1] Color measurement is performed from the first main surface side in accordance with the provisions of JIS Z 8722. The measurement conditions are a D65 light source and a field of view of 10°. Color measurement is performed in the lamination direction of the decorative sheet at locations where the second design layer and the second printing layer are not present, specifically at portion A where only the first printing layer of the first design layer is present, portion B where only the third printing layer of the first design layer is present, and portion AB where only the first and third printing layers of the first design layer overlap. If, for example, a transparent protective layer and a transparent substrate layer are formed over the entire surface of the decorative sheet, the measurement is performed at locations where the protective layer and transparent substrate layer are present for all color measurements. The measuring diameter of the colorimeter is φ10, and the decorative sheet is placed on a white plate (whiteness 75%) for measurement.

[0030] Furthermore, from the viewpoint of more favorably exhibiting the effects of the present invention, in the decorative sheet 10 of the present disclosure, the color temperature change [K] of transmitted light measured by the following (measurement of color temperature change [K] of transmitted light) is preferably 500 or less, more preferably 250 or less, and preferred ranges include 0 to 500 and 0 to 250.

[0031] (Measurement of Color Temperature Change of Transmitted Light [K]) The color temperature change of transmitted light [K] of the decorative sheet is measured by measuring the color temperature at a position in the lamination direction of the decorative sheet where the first and second design layers are not present, using this as a reference, and calculating the difference between this and the color temperature at the overlapping portion AB of the first design layer where only the first and third printing layers are present. A spectroradiometer is used to measure the color temperature, and the transmitted light is measured on a light panel with a white light source, and the difference from the light source is calculated. The color temperature of the light source is 3900K, and the illuminometer is selected in accordance with the general type AA class illuminometer of JIS C 1609-1:2006.

[0032] Furthermore, from the viewpoint of more favorably exhibiting the effects of the present invention, in the first design layer 1 of the decorative sheet 10 of the present disclosure, the overlapping portion of the first printed layer, second printed layer, and third printed layer of the first design layer, as measured on a black board, has a brightness difference (ΔL) compared to the area where the second printed layer is absent. * The brightness difference (ΔL) is preferably 0.2 or more, more preferably 1.2 or more, with an upper limit of 100 or less. * These values ​​are measured by the method described later in [Color Measurement of Decorative Sheets 2].

[0033] [Color Measurement of Decorative Sheets 2] For each of the obtained decorative sheets, color measurement is performed from the first main surface side in accordance with the provisions of JIS Z 8722. Color measurement is performed in the lamination direction of the decorative sheet at locations where the second design layer does not exist, specifically at portion C where only the second printing layer of the first design layer exists, and at overlapping portions A, B, and C of the first design layer where the first printing layer, second printing layer, and third printing layer exist. Furthermore, if, for example, a transparent protective layer and a transparent substrate layer are formed over the entire surface of the decorative sheet, the measurement is performed at locations where the protective layer and transparent substrate layer are present for all color measurements. The measuring diameter of the colorimeter is set to φ10, and the decorative sheet is placed on a black plate (lightness of the black plate: L * Value 2.6) Place it on top and perform the measurement.

[0034] Furthermore, from the viewpoint of more favorably exhibiting the effects of the present invention, the percentage change in light transmittance (%) in the first design layer 1 of the decorative sheet 10 of this disclosure due to the presence or absence of the second printing layer 12 is preferably 25% or less, more preferably 15% or less, and a preferred range is approximately 0 to 25%, more preferably 0 to 15%. The percentage change in light transmittance (%) in the first design layer 1 due to the presence or absence of the second printing layer 12 means the percentage change in light transmittance of the first design layer 1 due to the presence of the second printing layer 12, based on the light transmittance of the portion of the first design layer 1 where the second printing layer 12 is not present (the position where the first printing layer 11 and the third printing layer 13 are present). If the light transmittance of the first design layer 1 decreases due to the presence of the second printing layer 12, the percentage change in light transmittance will be negative. A densitometer (341C; X-Rite measuring diameter φ2) is used to measure the print density and light transmittance. The densitometer should be selected to comply with ISO 5-2:2009.

[0035] [Each layer constituting the decorative sheet] [First design layer 1] The first design layer 1 is a layer provided for purposes such as adding decorative properties to the decorative sheet 10. The first design layer 1 is provided on the first main surface 10a side of the transparent base material layer 3. Furthermore, the design of the first design layer 1 is visible from the first main surface 10a side when the light source on the second main surface 10b side is turned off.

[0036] The first design layer 1 can be, for example, a layer formed with a desired pattern using an ink composition. For example, when the light source is turned off, the first design layer 1 is visible and the design of the second design layer 2 is not visible, and when the light source is turned on, the patterned design of the second design layer 2 (for example, a pattern such as symbols or textual information) can be made visible.

[0037] The patterns formed by the first design layer 1 are not particularly limited, but examples include symbols, textual information, stone patterns that mimic the surface of rocks such as wood grain patterns and marble patterns (e.g., travertine marble patterns), fabric patterns that mimic the texture of cloth or cloth-like patterns, tile patterns, brick patterns, etc., and may also be patterns that combine these, such as marquetry or patchwork, or they may be solid colors (so-called solid colors). These patterns are formed by multicolor printing using ordinary yellow, red, blue, and black process colors, but they can also be formed by multicolor printing using spot colors, etc., by preparing plates for each color that makes up the pattern. Among these, wood grain patterns are preferred for the patterns formed by the first design layer 1.

[0038] In this disclosure, the first design layer 1 comprises, in order from the first main surface 10a to the second main surface 10b, at least a colored first printed layer 11, a reflective second printed layer 12, and a colored third printed layer 13. That is, the first design layer 1 is composed of a laminate in which, in order from the first main surface 10a, at least a colored first printed layer 11, a reflective second printed layer 12, and a colored third printed layer 13 are laminated.

[0039] (First Printed Layer 11) The first printed layer 11 is colored and constitutes a part of the first design layer 1. The first printed layer 11 may be formed over the entire surface of the first main surface 10a of the decorative sheet 10, or it may be formed only in part.

[0040] The first printing layer 11 may be a single-color printing layer, either partially or entirely, or it may have a pattern, either partially or entirely.

[0041] In the decorative sheet of this disclosure, the first printed layer 11 and the third printed layer 13 are measured on a white board with a whiteness of 75% with these layers stacked on top of each other. * a * b * Saturation C in the color space * The value of is 10 or less. That is, the decorative sheet of this disclosure has a saturation C when the first printing layer 11 and the third printing layer 13 overlap. *In the case of color combinations where the value of is 10 or less, the transmitted light from the light source is less strongly influenced by the color of the design layer in the area through which the light is transmitted, and the design can be expressed with the intended luminescence color based on the color of the light source when the light source is turned on. Therefore, in the decorative sheet of this disclosure, by using the area where the second printing layer 12 does not exist to represent symbols, character information, etc., the symbols, character information, etc. will glow with low saturation when the light source is turned on, and the intended design can be expressed by the transmitted light.

[0042] The first printed layer 11 can be formed, for example, by printing an ink for forming the first printed layer using a conventionally known printing method such as gravure printing, screen printing, or offset printing. The ink composition used to form the first printed layer 11 is a binder mixed with colorants such as pigments and dyes, extender pigments, solvents, stabilizers, plasticizers, catalysts, curing agents, etc., as appropriate.

[0043] As a binder used in the ink composition, the saturation C in relation to the third printing layer 13 * While there are no particular limitations as long as the value of is 10 or less, examples 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 individually or in combination of two or more types.

[0044] As a colorant used in the ink composition, the saturation C in relation to the third printing layer 13 is * If the value is 10 or less, there are no particular restrictions, but examples include inorganic pigments such as carbon black (ink), iron black, titanium white, antimony white, lead yellow, titanium yellow, iron oxide, cadmium red, ultramarine, and cobalt blue; organic pigments or dyes such as quinacridone red, isoindolinone yellow, and phthalocyanine blue; metallic pigments consisting of flaky foil pieces of aluminum, brass, etc.; and pearlescent pigments consisting of flaky foil pieces of titanium dioxide-coated mica, basic lead carbonate, etc.

[0045] The thickness of the first printed layer 11 is not particularly limited, but from the viewpoint of more favorably exhibiting the effects of the present invention, it is preferably 1 μm or more, and preferably 15 μm or less, with a preferred range being approximately 1 to 15 μm.

[0046] (Second Printed Layer 12) The second printed layer 12 is reflective and constitutes a part of the first design layer 1. The second printed layer 12 may be formed over the entire surface on the first main surface 10a side of the decorative sheet 10, or it may be formed partially, but it is preferable that it is formed partially.

[0047] The second printing layer 12 can be formed, for example, by printing an ink for forming the second printing layer using a conventionally known printing method such as gravure printing, screen printing, or offset printing. The ink composition used for forming the second printing layer 12 is a binder mixed with a coloring agent such as a pigment or dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, a curing agent, etc., as appropriate. However, the ink composition is selected so that the second printing layer 12 has light reflectivity.

[0048] The binder used in the ink composition is not particularly limited as long as it can impart reflectivity to the second printing layer 12. Examples 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, and the like. These binders may be used individually or in combination of two or more.

[0049] The colorants used in the ink composition are not particularly limited as long as they can impart reflectivity to the second printing layer 12. Examples include inorganic pigments such as titanium white, antimony white, and barium sulfate; metallic pigments consisting of flaky foil pieces such as aluminum and brass; and pearlescent pigments consisting of flaky foil pieces such as titanium dioxide-coated mica and basic lead carbonate, which exhibit specular or diffuse reflection of visible light.

[0050] The thickness of the second printed layer 12 is not particularly limited, but from the viewpoint of more favorably exhibiting the effects of the present invention, it is preferably 1 μm or more, and preferably 15 μm or less, with a preferred range being approximately 1 to 15 μm.

[0051] (Third Printing Layer 13) The third printing layer 13 is colored and constitutes a part of the first design layer 1. The third printing layer 13 may be formed over the entire surface on the first main surface 10a side of the decorative sheet 10, or it may be formed only in part.

[0052] The third printing layer 13 may be a single-color printing layer partially or entirely, or it may have a pattern partially or entirely. For example, if the first printing layer 11 is formed with a pattern, in any region of the portion where the third printing layer 13 overlaps with the first printing layer 11, the pattern of the third printing layer 13 is measured on a white plate with a whiteness of 75% with the first printing layer 11 and the third printing layer 13 stacked on top of each other. * a * b * Saturation C in the color space * The relationship may be formed such that the value of is 10 or less.

[0053] As described above, in the decorative sheet of this disclosure, the first printed layer 11 and the third printed layer 13 are measured on a white board with a whiteness of 75% with these layers stacked on top of each other. * a * b * Saturation C in the color space * The value of is 10 or less, which means that the transmitted light from the light source is less strongly influenced by the color of the design layer in the area through which the light is transmitted, and the intended design can be expressed by the transmitted light when the light source is turned on. Specifically, when the light source is turned off, in the area where the second printed layer 12 is not formed, a mixture of the color of the first printed layer 11 and the color of the third printed layer 13 can be observed from the surface. The first printed layer 11 and the third printed layer 13 may be in direct contact, and a colorless transparent layer may exist between the first printed layer 11 and the third printed layer 13, but it is preferable that the first printed layer 11 and the third printed layer 13 are in direct contact.

[0054] The third printing layer 13 can be formed, for example, by printing an ink for forming the third printing layer using a conventionally known printing method such as gravure printing, screen printing, or offset printing. The ink composition used to form the third printing layer 13 is a binder mixed with colorants such as pigments and dyes, extender pigments, solvents, stabilizers, plasticizers, catalysts, curing agents, etc., as appropriate.

[0055] As a binder used in the ink composition, the saturation C in relation to the first printing layer 11 * While there are no particular limitations as long as the value of is 10 or less, examples 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 individually or in combination of two or more types.

[0056] As a colorant used in the ink composition, the saturation C in relation to the first printing layer 11 is * If the value is 10 or less, there are no particular restrictions, but examples include inorganic pigments such as carbon black (ink), iron black, titanium white, antimony white, lead yellow, titanium yellow, iron oxide, cadmium red, ultramarine, and cobalt blue; organic pigments or dyes such as quinacridone red, isoindolinone yellow, and phthalocyanine blue; metallic pigments consisting of flaky foil pieces of aluminum, brass, etc.; and pearlescent pigments consisting of flaky foil pieces of titanium dioxide-coated mica, basic lead carbonate, etc.

[0057] The thickness of the third printed layer 13 is not particularly limited, but from the viewpoint of more favorably exhibiting the effects of the present invention, it is preferably 1 μm or more, and preferably 15 μm or less, with a preferred range being approximately 1 to 15 μm.

[0058] In this disclosure, the overall thickness of the first design layer 1 is not particularly limited, but from the viewpoint of more favorably exhibiting the effects of the invention of this disclosure, it is preferably 2 μm or more, and preferably 45 μm or less, and a preferred range is approximately 2 to 45 μm.

[0059] From the viewpoint of more favorably exhibiting the effects of the present invention, it is preferable that the surface of the first design layer 1 on the first main surface 10a side is flat. If the surface of the first design layer 1 on the first main surface 10a side is flat, light incident from the first main surface 10a side is reflected at the surface of the first design layer 1 without being scattered by the influence of the design based on other layers (for example, the second design layer 2 which may be provided as needed). For example, regardless of the pattern of the second design layer 2, the light is reflected uniformly at the surface of the first design layer 1 on the first main surface 10a side, so that the design based on the second design layer 2 is difficult to see even when the lights are off.

[0060] Figure 5 shows a schematic diagram illustrating the design of the decorative sheet of this disclosure when the light source is turned off, based on its cross-sectional structure. Figure 6 also shows a schematic diagram illustrating the design of the decorative sheet of this disclosure when the light source is turned on, based on its cross-sectional structure.

[0061] For example, in Figure 5 (when the light source is off), if we take the case where the wood grain pattern is represented by the first design layer 1 of the decorative sheet of this disclosure, the reflected light A observed from the first main surface 10a side is reflected light from the overlapping portion of the first printing layer 11 and the third printing layer 13, and has low saturation. Because the light passes through the transparent substrate layer 3 to the second main surface 10b side of the decorative sheet, it appears dark (the wood grain vascular tissue is represented). Reflected light B appears brown due to light reflection by the reflective second printing layer 12. Reflected light C has low saturation because the first printing layer and the third printing layer 13 overlap, and the light is absorbed by the second design layer 2, making it appear dark (the wood grain vascular tissue is represented). Furthermore, reflected light D is reflected light from the overlapping portion of the first printing layer 11 and the second printing layer 12, and appears brown due to light reflection by the reflective second printing layer 12. For example, if the first printing layer 11 is brown, the L of the third printing layer 13 is measured with the first printing layer 11 and the third printing layer 13 stacked on a white plate with a whiteness of 75%. *a * b * Saturation C in the color space * The blue or purple color was selected so that the value of the parameter is 10 or less.

[0062] Next, in Figure 6 (when the light source is lit), taking the case where the wood grain pattern is represented by the first design layer 1 of the decorative sheet of this disclosure as an example, the transmitted light E and transmitted light F when observed from the first main surface 10a side are the transmitted light in the overlapping portion of the first printing layer 11 and the third printing layer 13, and are not strongly affected by the color of the first design layer, and can produce the intended emission color. Also, because there is little change in the amount of transmitted light due to the presence or absence of the second printing layer, the transmitted light E and transmitted light F can be seen as almost identical. The first design layer 1 can be said to be a design layer that has little influence on the design expressed by the transmitted light when the light source is lit. On the other hand, the positions of transmitted light G and transmitted light H appear dark because the light is blocked by the second design layer 2, which is present.

[0063] As described above, the decorative sheet of this disclosure is a decorative sheet that exhibits different designs when the light source is on and when it is off, and comprises a design layer (first design layer 1) that has little influence on the design exhibited by transmitted light when the light source is on.

[0064] [Second Design Layer 2] The second design layer 2 is a layer provided as needed for purposes such as adding decorative properties to the laminate together with the first design layer 1. The second design layer 2 is a layer provided partially on the second main surface 10b side of the first design layer 1. Preferably, the second design layer 2 is provided partially between the first design layer 1 and the transparent substrate layer 3, and / or on the second main surface 10b side of the transparent substrate layer 3.

[0065] The second design layer 2 can be formed in the same way as the first design layer 1, for example, by printing an ink for forming the second design layer using a conventionally known printing method such as gravure printing, screen printing, or offset printing. Examples of ink compositions used to form the second design layer 2 include the same ones as those exemplified for the first design layer 1, including binders, colorants, etc.

[0066] The patterns formed by the second design layer 2 are the same as those exemplified in the first design layer 1, but as mentioned above, it is preferable that the second design layer 2 has a pattern-like design.

[0067] Furthermore, the second design layer 2 may include a portion composed of a thin metal film. The metal and formation method for forming the thin metal film are the same as those exemplified in the first design layer 1.

[0068] The thickness of the second design layer 2 is not particularly limited, but the lower limit is preferably 1 μm or more, more preferably 2 μm or more, and the upper limit is preferably 30 μm or less, more preferably 20 μm or less, with a preferred range of approximately 1 μm to 30 μm, and more preferably 2 μm to 20 μm.

[0069] Furthermore, the range of the OD (Optical Density) value of the second design layer 2 in the visible light region is approximately 2.5 to 6.0, and preferably 4.0 to 6.0.

[0070] In the decorative sheet 10 of this disclosure, it is also preferable that the second design layer 2 is embedded in the transparent substrate layer 3. This prevents the second design layer 2 from protruding above the surface of the transparent substrate layer 3. Therefore, the surface of the first design layer 1 on the first main surface 10a side can be made flatter. In other words, in the decorative sheet 10, it becomes possible to make the surface of the first design layer 1 on the first main surface 10a side flatter, regardless of the partial presence of the second design layer 2.

[0071] Therefore, when the decorative sheet 10 is viewed from the observer's side (i.e., the first main surface 10a side), light incident from the first main surface 10a side is reflected off the surface of the first design layer 1 without being scattered by the design based on the second design layer 2 (in other words, it is uniformly reflected off the surface of the first design layer 1 on the first main surface 10a side, regardless of the pattern of the second design layer 2), so that the design based on the second design layer 2 is difficult to see even when the lights are off.

[0072] To produce a laminate in which the second design layer 2 is embedded in the transparent substrate layer 3, as shown in the decorative sheet 10 in Figures 2 and 3, one possible method is to melt the surface of the transparent substrate layer 3 by heating or the like, and then embed the second design layer 2 into the molten surface of the transparent substrate layer 3 by pressing or the like.

[0073] For the above processing, a hot press machine can be used, and processing conditions such as a temperature of 110°C to 130°C and a pressure of approximately 0.3 MPa to 0.8 MPa for 8 to 60 minutes can be cited.

[0074] In the decorative sheet 10 shown in Figures 2 and 3, the second design layer 2 is embedded in the transparent base material layer 3, and this second design layer 2 has thickness. Therefore, the combined thickness of the second design layer 2 and the first design layer 1 is greater than the thickness of the first design layer 1 alone.

[0075] More specifically, in the decorative sheet 10 shown in Figures 2 and 3, the combined thickness of the second design layer 2 in the portion where the second design layer 2 is provided, and the thickness of the first design layer 1 provided on the first main surface 10a side of the second design layer 2, is greater than the thickness of the first design layer 1 in the portion where the second design layer 2 is not provided.

[0076] Due to this difference in thickness, in the decorative sheet 10 shown in Figures 2 and 3, the design based on the second design layer 2 can be seen when a light source is turned on from the second main surface 10b side and observed from the first main surface 10a side.

[0077] In this case, it is preferable that the optical density of the second design layer 2 is greater than the optical density of the first design layer 1.

[0078] When the optical density of the second design layer 2 is greater than that of the first design layer 1, light from a light source positioned on the second main surface 10b side will pass through with higher transmittance in the area where only the first design layer 1 is provided, but the transmittance will decrease significantly in the area where the second design layer 2 is present. This will allow the design based on the second design layer 2 to be more clearly visible when observed from the first main surface 10a side.

[0079] Conversely, if the optical density of the second design layer 2 is lower than that of the first design layer 1, the optical density of the first design layer 1 becomes dominant, and the difference in transmittance between the areas where the second design layer 2 is present and the areas where it is not becomes smaller with respect to light from a light source placed on the second main surface 10b side. As a result, it becomes difficult to visually perceive the design based on the second design layer 2 when observed from the first main surface 10a side.

[0080] To make the optical density of the second design layer 2 greater than that of the first design layer 1, for example, the thickness of the second design layer 2 in the decorative sheet 10 can be made greater than the thickness of the first design layer 1.

[0081] [Transparent Substrate Layer 3] The transparent substrate layer 3 is a layer provided to give rigidity to the decorative sheet 10 and maintain its shape. The transparent substrate layer 3 is transparent enough to transmit light from a light source when the light source is placed on the second main surface 10b side (in the embodiments of this disclosure, transparency also includes translucency). That is, the transparent substrate layer 3 is usually transparent (colorless transparent, colored transparent, or translucent), and may be colored to the extent that the design based on the second design layer 2 is visible when the decorative sheet 10 of this disclosure is observed from the first main surface 10a side when the light source is lit. For example, the transparent substrate layer 3 may contain a matting agent such as silica or a coloring agent. As a coloring agent, the coloring agents exemplified in the first design layer 1 described above can be used. In addition, the transparent substrate layer 3 may be painted to adjust the color, or have patterns formed to give it a design.

[0082] The transparent substrate layer 3 can be made of a transparent resin, a paper-like substrate, etc., from the viewpoint of making the decorative sheet 10 suitable for three-dimensional molding and suitably displaying different designs when the light source is on and off. The transparent resin is preferably made of a transparent thermoplastic resin. The transparent thermoplastic resin is not particularly limited, but examples include transparent acrylonitrile-butadiene-styrene resin (hereinafter sometimes referred to as "ABS resin"), acrylic resin; polyolefin resins such as polypropylene and polyethylene; polycarbonate resin; vinyl chloride resin; polyethylene terephthalate (PET) resin; acrylonitrile-styrene-acrylic acid ester resin, etc. Among these, the transparent substrate layer 3 is preferably made of transparent ABS resin. The resin forming the transparent substrate layer 3 may be one type or two or more types.

[0083] The thickness of the transparent substrate layer 3 is not particularly limited, but from the viewpoint of making the decorative sheet 10 suitable for three-dimensional molding and suitably displaying different designs when the light source is on and off, the lower limit is preferably 50 μm or more, more preferably 100 μm or more, the upper limit is preferably 1000 μm or less, more preferably 500 μm or less, and the preferred range is about 50 μm to 1000 μm, more preferably about 100 μm to 500 μm, and even more preferably about 200 μm to 400 μm.

[0084] To improve adhesion with adjacent layers, the transparent substrate layer 3 may be subjected to physical or chemical surface treatments, such as oxidation or embossing, on one or both sides as needed. Examples of oxidation methods used for surface treatment of the transparent substrate layer 3 include corona discharge treatment, plasma treatment, chromium oxidation treatment, flame treatment, hot air treatment, and ozone ultraviolet treatment. Examples of embossing methods used for surface treatment of the transparent substrate layer 3 include sandblasting and solvent treatment. These surface treatments are appropriately selected depending on the type of resin constituting the transparent substrate layer 3, but corona discharge treatment is preferred from the viewpoint of effectiveness and ease of operation.

[0085] [Protective Layer 4] The protective layer 4 is a layer provided as needed, located on the outermost surface of the decorative sheet 10, in order to enhance the chemical resistance, scratch resistance, etc., of the decorative sheet 10. In the embodiments of this disclosure, the resin forming the protective layer 4 is not particularly limited, and examples include thermosetting resins, thermoplastic resins, and ionizing radiation curable resins.

[0086] Among these, ionizing radiation-curable resin is preferred from the viewpoint of more effectively improving the smoothness of the surface of the decorative sheet 10, further enhancing scratch resistance, and providing excellent surface properties. However, the resin forming the protective layer 4 can be appropriately selected depending on the application of the decorative sheet 10.

[0087] (Ionizing radiation-curable resin) The ionizing radiation-curable resin used to form the protective layer 4 is a resin that crosslinks and hardens when irradiated with ionizing radiation. Specifically, it is a mixture of at least one of the following: prepolymers, oligomers, and monomers having polymerizable unsaturated bonds or epoxy groups in their molecules.

[0088] Here, ionizing radiation refers to electromagnetic waves or charged particle beams that have energy quanta capable of polymerizing or crosslinking molecules. Typically, ultraviolet (UV) or electron beams (EB) are used, but it also includes other electromagnetic waves such as X-rays and gamma rays, and charged particle beams such as alpha rays and ion beams. Among ionizing radiation-curable resins, electron beam-curable resins can be made solvent-free, do not require photopolymerization initiators, and provide stable curing characteristics, making them suitable for use in forming the protective layer 4.

[0089] As the monomer used as an ionizing radiation-curable resin, (meth)acrylate monomers having radically polymerizable unsaturated groups in the molecule are preferred, and among these, polyfunctional (meth)acrylate monomers are preferred. As a polyfunctional (meth)acrylate monomer, any (meth)acrylate monomer having two or more polymerizable unsaturated bonds (bifunctional or more), preferably three or more (trifunctional or more), in the molecule is acceptable. Specifically, polyfunctional (meth)acrylates 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, hydroxypivalate neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphate di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, isocyanurate di(meth)acrylate, and trimethylol di(meth)acrylate. Examples include ropane 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, and the like. These monomers may be used individually or in combination of two or more.

[0090] Furthermore, as the oligomer used as an ionizing radiation-curable resin, (meth)acrylate oligomers having radically polymerizable unsaturated groups in the molecule are preferred, and among these, polyfunctional (meth)acrylate oligomers having two or more polymerizable unsaturated bonds (bifunctional or more) in the molecule are preferred. Examples of polyfunctional (meth)acrylate oligomers include polycarbonate (meth)acrylate, acrylic silicone (meth)acrylate, urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, polybutadiene (meth)acrylate, silicone (meth)acrylate, and oligomers having cationic polymerizable functional groups 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 in the terminal or side chain, and can be obtained, for example, by esterifying a polycarbonate polyol with (meth)acrylic acid. The polycarbonate (meth)acrylate may also be, for example, a urethane (meth)acrylate having a polycarbonate skeleton. A 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. Acrylic silicone (meth)acrylate can be obtained by radical copolymerizing a silicone macromonomer with a (meth)acrylate monomer. A urethane (meth)acrylate can be obtained, for example, by esterifying a polyurethane oligomer obtained by reacting a polyether polyol or polyester polyol with a polyisocyanate compound with (meth)acrylic acid. Epoxy (meth)acrylates can be obtained, for example, by reacting (meth)acrylic acid with the oxirane ring of a relatively low molecular weight bisphenol-type epoxy resin or novolac-type epoxy resin to esterify it.Furthermore, carboxyl-modified epoxy (meth)acrylates, obtained by partially modifying this epoxy (meth)acrylate with a dibasic carboxylic acid anhydride, can also be used. Polyester (meth)acrylates can be obtained, for example, by esterifying the hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends, obtained by condensation of a polycarboxylic acid and a polyhydric alcohol, with (meth)acrylic acid, or by esterifying the terminal hydroxyl groups of an oligomer obtained by adding an alkylene oxide to a polycarboxylic acid with (meth)acrylic acid. Polyether (meth)acrylates can be obtained by esterifying the hydroxyl groups of a polyether polyol with (meth)acrylic acid. Polybutadiene (meth)acrylates can be obtained by adding (meth)acrylic acid to the side chains of a polybutadiene oligomer. Silicone (meth)acrylates can be obtained by adding (meth)acrylic acid to the ends or side chains of a silicone having polysiloxane bonds in its main chain. Among these, polycarbonate (meth)acrylate and urethane (meth)acrylate are particularly preferred as polyfunctional (meth)acrylate oligomers. These oligomers may be used individually or in combination of two or more.

[0091] Among the ionizing radiation-curable resins described above, polycarbonate (meth)acrylate is preferable from the viewpoint of obtaining excellent three-dimensional moldability. Furthermore, from the viewpoint of achieving both three-dimensional moldability and scratch resistance, it is even more preferable to use a combination of polycarbonate (meth)acrylate and urethane (meth)acrylate.

[0092] (Other Additive Components) In addition to the inorganic and organic particles mentioned above, various additives may be added to the ionizing radiation-curable resin composition that forms the protective layer 4, depending on the desired physical properties to be provided to the protective layer 4. Examples of such additives include weather-resistant agents such as ultraviolet absorbers and light stabilizers, abrasion-resistant agents, polymerization inhibitors, crosslinking agents, infrared absorbers, antistatic agents, adhesion enhancers, leveling agents, thixotropic agents, coupling agents, plasticizers, defoamers, fillers, solvents, colorants, and matting agents. These additives can be appropriately selected from commonly used ones, and examples of matting agents include silica particles and aluminum hydroxide particles. Furthermore, reactive ultraviolet absorbers and light stabilizers having polymerizable groups such as (meth)acryloyl groups in their molecules can also be used as ultraviolet absorbers and light stabilizers.

[0093] (Thickness of ionizing radiation-curable resin) The thickness of the ionizing radiation-curable resin forming the protective layer 4 is not particularly limited, but is preferably 30 μm or less, more preferably 5 μm to 20 μm, and more preferably 7 μm to 15 μm. When the protective layer 4 is formed using a curable resin such as an ionizing radiation-curable resin, the above thickness refers to the thickness after curing.

[0094] (Formation of protective layer 4 when using ionizing radiation-curable resin) The protective layer 4 is formed, for example, by preparing an ionizing radiation-curable resin composition containing an ionizing radiation-curable resin, applying it, and crosslinking and curing it. In embodiments of this disclosure, the prepared coating solution is applied to a layer located below the protective layer 4 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.

[0095] The uncured resin layer formed in this manner is irradiated with ionizing radiation such as electron beams or ultraviolet rays to cure the uncured resin layer and form a protective layer 4. When using electron beams as the ionizing radiation, the acceleration voltage can be appropriately selected depending on the resin used and the thickness of the layer, but typically an acceleration voltage of about 70 kV to 300 kV is used.

[0096] Furthermore, in electron beam irradiation, the higher the acceleration voltage, the greater the penetration capability. Therefore, when using a resin that is easily degraded by electron beam irradiation beneath the protective layer 4, the acceleration voltage should be selected so that the electron beam penetration depth and the thickness of the protective layer 4 are substantially equal. This suppresses the irradiation of the layers located beneath the protective layer 4 with excess electron beams, thereby minimizing the degradation of each layer due to excess electron beams.

[0097] Furthermore, the irradiation dose is preferably the amount at which the crosslinking density of the protective layer 4 saturates, and is typically selected within the range of 5 kGy to 300 kGy (0.5 Mrad to 30 Mrad), preferably 10 kGy to 50 kGy (1 Mrad to 5 Mrad).

[0098] Furthermore, there are no particular restrictions on the electron source; for example, various electron beam accelerators such as Cockcroft-Walton type, Van de Graft type, resonant transformer type, insulated core transformer type, linear type, dynamitron type, and high-frequency type can be used.

[0099] When using ultraviolet light as ionizing radiation, it is sufficient to emit light containing ultraviolet light with wavelengths of 190 nm to 380 nm. There are no particular restrictions on the ultraviolet light source, but examples include high-pressure mercury lamps, low-pressure mercury lamps, metal halide lamps, carbon arc lamps, and ultraviolet light-emitting diodes (LEDUV).

[0100] The protective layer 4 thus formed may be subjected to treatment by adding various additives to impart functions such as hard coating, anti-fogging, anti-staining, anti-glare, anti-reflective coating, ultraviolet shielding, and infrared shielding.

[0101] (Resin Film) The protective layer 4 may also be formed from a resin film. Examples of resin films include those made from thermoplastic resins or thermosetting resins, as described later. The protective layer 4 may be formed from, for example, one layer of resin film, or from two or more layers thereof. Here, as described above, from the viewpoint of more effectively improving the smoothness of the surface of the decorative sheet 10, further improving scratch resistance, and providing excellent surface properties, it is preferable to form the protective layer 4 from an ionizing radiation-curable resin. However, from the viewpoint of more strongly exhibiting the effect that the design based on the second design layer 2 becomes difficult to see when the lights are off, even after injection molding, it is preferable to form the protective layer 4 from a resin film, as in the example described later.

[0102] The thermosetting resin is not particularly limited and includes, for example, epoxy resins, phenolic resins, urea resins, unsaturated polyester resins, melamine resins, alkyd resins, polyimide resins, silicone resins, hydroxyl-functional acrylic resins, carboxyl-functional acrylic resins, amide-functional copolymers, and urethane resins.

[0103] Furthermore, the thermoplastic resin is not particularly limited and includes acrylic resins such as polymethyl (meth)acrylate and polyethyl (meth)acrylate; polyolefin resins such as polypropylene and polyethylene; polycarbonate resins; vinyl chloride resins; polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN); acrylonitrile-butadiene-styrene resin (ABS resin); acrylonitrile-styrene-acrylic acid ester resin; and others. Among these, the protective layer 4 is preferably formed of a transparent acrylic resin. The resin forming the protective layer 4 may be one type or two or more types.

[0104] (Thickness of resin film) The thickness of the protective layer 4 formed from the resin film is not particularly limited, but from the viewpoint of making the decorative sheet 10 suitable for three-dimensional molding and suitably displaying different designs when the light source is on and off, the lower limit is preferably 30 μm or more, more preferably 50 μm or more, the upper limit is preferably 300 μm or less, more preferably 150 μm or less, and the preferred range is about 30 μm to 300 μm, more preferably about 50 μm to 150 μm.

[0105] The protective layer 4, formed from a resin film, may be subjected to physical or chemical surface treatments, such as oxidation or embossing, on one or both sides as needed to improve adhesion with adjacent layers. Examples of oxidation methods used for surface treatment include corona discharge treatment, plasma treatment, chromium oxidation treatment, flame treatment, hot air treatment, and ozone ultraviolet treatment. Examples of embossing methods used for surface treatment of the protective layer 4 include sandblasting and solvent treatment. These surface treatments are appropriately selected depending on the type of resin constituting the protective layer 4, but corona discharge treatment is preferred from the viewpoint of effectiveness and ease of operation.

[0106] [Adhesive Layer] The adhesive layer is a layer provided as needed between the protective layer 4 and the first design layer 1, between the first design layer 1 and the second design layer 2, and on the surface of the second main surface 10b of the decorative sheet, for the purpose of improving adhesion. The adhesive layer that constitutes the surface of the second main surface 10b of the decorative sheet functions as a back adhesive layer. Depending on the type of upper and lower layers to be bonded via the adhesive layer, a thermoplastic resin or a thermosetting resin may be used for the adhesive layer.

[0107] Examples of thermoplastic resins used in the adhesive layer include acrylic resins, acrylic-modified polyolefin resins, chlorinated polyolefin resins, vinyl chloride / vinyl acetate copolymers, thermoplastic urethane resins, thermoplastic polyester resins, polyamide resins, and rubber-based resins. These thermoplastic resins may be used individually or in combination of two or more types.

[0108] Examples of thermosetting resins used in the adhesive layer include urethane resins and epoxy resins. These thermosetting resins may be used individually or in combination of two or more types.

[0109] The thickness of the adhesive layer is not particularly limited as long as it can bond the upper and lower layers that are bonded together via the adhesive layer; for example, it can be about 10 μm to 50 μm.

[0110] [Primer layer] The decorative sheet 10 of this disclosure may be provided with a primer layer between each layer as needed, for purposes such as improving the adhesion between each layer.

[0111] For example, when an ionizing radiation-curable resin such as an electron beam-curable resin is used for the protective layer 4, it is preferable to provide a primer layer between the protective layer 4 and the first design layer 1 in order to improve the adhesion between the protective layer 4 and the first design layer 1.

[0112] The resin used to form the primer layer is not particularly limited, but examples include urethane resin, acrylic resin, (meth)acrylic-urethane copolymer resin, polyester resin, and butyral resin. Among these resins, urethane resin, acrylic resin, and (meth)acrylic-urethane copolymer resin are preferred. These resins may be used individually or in combination of two or more.

[0113] As the urethane resin mentioned above, polyurethane can be used, with a polyol (polyhydric alcohol) as the main component and an isocyanate as the crosslinking agent (curing agent). The polyol can be any compound having two or more hydroxyl groups in its molecule, and specific examples include polyester polyol, polyethylene glycol, polypropylene glycol, acrylic polyol, and polyether polyol. The isocyanate mentioned above specifically includes polyhydric isocyanates having two or more isocyanate groups in their molecule; aromatic isocyanates such as 4,4-diphenylmethane diisocyanate; and aliphatic (or alicyclic) isocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated diphenylmethane diisocyanate.

[0114] Among the urethane resins mentioned above, from the viewpoint of improving adhesion after crosslinking, a combination of acrylic polyol or polyester polyol as the polyol and hexamethylene diisocyanate or 4,4-diphenylmethane diisocyanate as the crosslinking agent is preferred; more preferably, a combination of acrylic polyol and hexamethylene diisocyanate is preferred.

[0115] The above-mentioned acrylic resin is not particularly limited, but examples include homopolymers of (meth)acrylic acid esters, copolymers of two or more different (meth)acrylic acid ester monomers, or copolymers of (meth)acrylic acid esters and other monomers. More specifically, examples of (meth)acrylic resins include (meth)acrylic acid esters such as polymethyl (meth)acrylate, polyethyl (meth)acrylate, polypropyl (meth)acrylate, polybutyl (meth)acrylate, (meth)acrylate-butyl (meth)acrylate copolymer, (meth)acrylate-butyl (meth)acrylate copolymer, ethylene-methyl (meth)acrylate copolymer, and styrene-methyl (meth)acrylate copolymer. These acrylic resins may be used individually or in combination of two or more.

[0116] The (meth)acrylic-urethane copolymer resin is not particularly limited, but examples include acrylic-urethane (polyester urethane) block copolymer resins. As a curing agent, the various isocyanates mentioned above can be used. The ratio of acrylic to urethane in the acrylic-urethane (polyester urethane) block copolymer resin is not particularly limited, but for example, the acrylic / urethane ratio (mass ratio) can be 9 / 1 to 1 / 9, preferably 8 / 2 to 2 / 8.

[0117] The thickness of the primer layer is not particularly limited, but for example, it can be about 0.1 μm to 10 μm, preferably about 1 μm to 10 μm.

[0118] The primer layer is formed using a resin that forms the primer layer, by conventional application methods such as gravure coating, gravure reverse coating, gravure offset coating, spinner coating, roll coating, reverse roll coating, kiss coating, wheel coating, dip coating, solid coating by silkscreen, wire bar coating, flow coating, comma coating, pour coating, brush application, and spray coating, as well as transfer coating methods.

[0119] In this context, the transfer coating method is a method of forming a primer layer and an adhesive layer coating on a thin sheet (film substrate), and then coating the target layer surface in the decorative sheet with it.

[0120] [Decorated Resin Molded Products and Decorated Articles] The decorated resin molded products 20 and decorated articles 40 of this disclosure each utilize the decorative sheet 10 of this disclosure. The decorated resin molded product 20 of this disclosure is a laminate of the second main surface 10b side of the decorative sheet 10 of this disclosure and a molded resin layer 5. The decorated resin molded product 20 of this disclosure is used together with a light source 30 to constitute a decorated article 40. For example, in the decorated resin molded product 20 shown in Figure 4, the light source 30 is arranged on the second main surface 10b side of the decorative sheet 10 to constitute a decorated article 40.

[0121] The decorated resin molded articles of this disclosure can be manufactured, for example, using the decorative sheet of this disclosure by various injection molding methods such as insert molding, injection molding with simultaneous decoration, blow molding, and gas injection molding. Among these injection molding methods, insert molding and injection molding with simultaneous decoration are preferred. Furthermore, the decorated resin molded articles of this disclosure can also be manufactured by a decoration method in which the decorative sheet of this disclosure is attached to a pre-prepared three-dimensional resin molded body (molded resin layer), such as by vacuum bonding.

[0122] In the insert molding method, first, in the vacuum forming process, the decorative sheet of this disclosure is vacuum-formed to the surface shape of the molded product using a vacuum forming die (offline pre-forming), and then excess portions are trimmed as needed to obtain a molded sheet. This molded sheet is inserted into an injection molding die, the injection molding die is clamped, and a fluid resin is injected into the die and solidified, thereby integrating the decorative sheet with the outer surface of the resin molded product at the same time as injection molding, and thus a decorated resin molded product is manufactured.

[0123] More specifically, the decorative resin molded product of this disclosure is manufactured by an insert molding method including the following steps: a vacuum molding step of pre-forming the decorative sheet of this disclosure into a three-dimensional shape using a vacuum molding die; a trimming step of trimming the excess portion of the vacuum-formed decorative sheet to obtain a molded sheet; and an integration step of inserting the molded sheet into an injection molding die, closing the injection molding die, and injecting a fluid resin into the injection molding die to integrate the resin and the molded sheet.

[0124] In the vacuum forming step of the insert molding method, the decorative sheet may be heated during the molding process. The heating temperature at this time is not particularly limited and can be appropriately selected depending on the type of resin constituting the decorative sheet and the thickness of the decorative sheet, for example, it can be about 100 to 180°C, preferably about 120 to 160°C. In addition, the temperature of the resin in the fluid state during the integration step is not particularly limited, but can usually be about 160 to 240°C, preferably about 180 to 220°C.

[0125] Furthermore, in the injection molding simultaneous decoration method, the decorative sheet of the present disclosure is placed in a female mold that is also used as a vacuum molding die and has suction holes for injection molding. After pre-molding (in-line pre-molding) in this female mold, the injection molding die is clamped, and the fluid resin is injected and filled into the mold and solidified. The decorative sheet of the present disclosure is then integrated onto the outer surface of the resin molded product simultaneously with the injection molding, thereby manufacturing a decorated resin molded product.

[0126] More specifically, the decorated resin molded product of this disclosure is manufactured by an injection molding simultaneous decoration method including the following steps: A pre-forming step in which the decorated sheet of this disclosure is pre-formed by placing the decorated sheet so that the surface opposite to the first main surface 10a of the decorated sheet faces the molding surface of a movable mold having a molding surface of a predetermined shape, heating and softening the decorated sheet, and then vacuum suction from the movable mold side to make the softened decorated sheet adhere to the molding surface of the movable mold; an integration step in which, after clamping the movable mold having the decorated sheet adhered to the molding surface and the fixed mold, a molded resin layer is formed by injecting and filling a fluid resin into the cavity formed by both molds and solidifying it, thereby laminating and integrating the molded resin layer and the decorated sheet; and a removal step in which the movable mold is separated from the fixed mold and the decorated resin molded product having all layers of the decorated sheet laminated is removed.

[0127] In the pre-molding step of the injection molding simultaneous decoration method, the heating temperature of the decorative sheet is not particularly limited and can be appropriately selected depending on the type of resin constituting the decorative sheet and the thickness of the decorative sheet, but it can usually be set to around 70 to 160°C. In the injection molding step, the temperature of the resin in the flow state is not particularly limited, but it can usually be set to around 160 to 240°C, preferably around 180 to 220°C.

[0128] In the vacuum crimping method, first, the decorative sheet and the resin molded body (molded resin layer) of the present disclosure are placed in a vacuum crimping machine consisting of a first vacuum chamber located on the upper side and a second vacuum chamber located on the lower side, such that the decorative sheet faces the first vacuum chamber side, the resin molded body faces the second vacuum chamber side, and the side of the decorative sheet opposite to the first main surface 10a faces the resin molded body side, and the two vacuum chambers are set into a vacuum state. The resin molded body is placed on a lifting platform provided on the second vacuum chamber side, which can be raised and lowered vertically. Next, the first vacuum chamber is pressurized, and the molded body is pressed against the decorative sheet using the lifting platform, and the decorative sheet is stretched and attached to the surface of the resin molded body by utilizing the pressure difference between the two vacuum chambers. Finally, the two vacuum chambers are opened to atmospheric pressure, and the excess portion of the decorative sheet is trimmed as needed to obtain the decorative resin molded product of the present disclosure.

[0129] In the vacuum bonding method, it is preferable to include a step of heating the decorative sheet to soften it and improve its moldability before pressing the resin molded body against the decorative sheet. A vacuum bonding method that includes this step is sometimes specifically called a vacuum heating bonding method. The heating temperature in this step can be appropriately selected depending on the type of resin constituting the decorative sheet and the thickness of the decorative sheet, but it can usually be set to around 60 to 180°C.

[0130] In the decorative resin molded articles of this disclosure, the molded resin layer may be formed by selecting a resin according to the application. The resin forming the molded resin layer may be a thermoplastic resin or a thermosetting resin.

[0131] Examples of thermoplastic resins include polyethylene, polyolefins such as polypropylene, ABS resin, styrene resin, polycarbonate, acrylic resin, and polyvinyl chloride. These thermoplastic resins may be used individually or in combination of two or more. In this disclosure, since the base layer of the decorative sheet 10 contains polyolefin, polyolefins such as polyethylene and polypropylene are particularly preferred.

[0132] Examples of thermosetting resins include urethane resins and epoxy resins. These thermosetting resins may be used individually or in combination of two or more types.

[0133] There are no particular restrictions on the type of light source; examples include light-emitting diode (LED) bulbs, incandescent bulbs, fluorescent lamps, and natural light.

[0134] The decorative articles 40 of this disclosure (including decorative sheets and decorative resin molded products) exhibit different designs when the light source is on and when it is off, and can therefore be used, for example, as interior or exterior materials for vehicles such as automobiles; building components such as window frames and door frames; interior materials for buildings such as walls, floors, and ceilings; housings for home appliances such as television receivers and air conditioners; and containers.

[0135] 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.

[0136] [Manufacturing of Decorative Sheets] <Examples 1-4 and Comparative Examples 1-14> Decorative sheets for each example and comparative example were manufactured according to the following procedure. A second design layer (2 μm thick) was partially formed on one main surface (first main surface) of a 400 μm thick transparent substrate layer made of ABS resin by gravure printing. The second design layer is a striped printed layer made of polybutyl methacrylate / vinyl chloride-vinyl acetate copolymer containing carbon black (ink) as a coloring agent.

[0137] Next, a third printed layer (1 μm thick) of the first design layer was partially (patterned) formed on the second design layer and on the transparent substrate layer exposed from the second design layer by gravure printing. The third printed layer is a striped printed layer made of polybutyl methacrylate / vinyl chloride-vinyl acetate copolymer containing an organic pigment as a coloring agent. The color schemes of the third printed layer are as shown in Table 1. Furthermore, a second printed layer (1 μm thick) of the first design layer was partially (patterned) formed on the third printed layer of the first design layer by gravure printing. The second printed layer is a striped printed layer made of polybutyl methacrylate / vinyl chloride-vinyl acetate copolymer containing titanium dioxide, aluminum flakes, and pearl pigment. Next, a first printed layer (1 μm thick) of the first design layer was partially (patterned) formed on the second printed layer of the first design layer by gravure printing. The first printing layer is a striped printing layer made of polybutyl methacrylate / vinyl chloride-vinyl acetate copolymer containing organic pigments. The color schemes of the first printing layer are as shown in Table 1.

[0138] Next, a hot press machine using a stainless steel mirror plate was used to perform a hot press process on the first design layer at 120°C and under pressure of 0.5 MPa for 10 minutes. This hot press process melted the surface of the transparent substrate layer beneath the second design layer, embedding the second design layer (the striped design layer) into the transparent substrate layer and flattening the surface of the first design layer.

[0139] Next, an electron beam-curable resin containing 80 parts by mass of a bifunctional polycarbonate acrylate (weight-average molecular weight 10,000) and 20 parts by mass of a hexafunctional urethane acrylate (weight-average molecular weight 6,000) was applied to the surface of the first design layer by bar coating to a thickness of 10 μm after curing, thereby forming a protective layer (uncured) made of uncured electron beam-curable resin.

[0140] Next, the uncured protective layer was irradiated with an electron beam at an acceleration voltage of 195 kV and an irradiation dose of 50 kGy (5 Mrad) to cure the electron beam-curable resin and form a protective layer. A decorative sheet was then manufactured, consisting of a decorative sheet 10 in which a transparent substrate layer, a partially provided second design layer, a first design layer (a laminated structure consisting of a partially provided third printing layer, a partially provided second printing layer, and a partially provided first printing layer), and a protective layer covering the entire surface were laminated in this order. In the obtained decorative sheet, the second design layer was embedded in the transparent substrate layer. The thickness of the first design layer in the obtained decorative sheet was 3 μm, and the thickness of the second design layer was 2 μm.

[0141] [Color Measurement of Decorative Sheets 1] For each of the obtained decorative sheets, color measurement was performed from the protective layer side in accordance with the provisions of JIS Z 8722. The measurement conditions were a D65 light source and a field of view of 10°. Color measurement was performed in the lamination direction of the decorative sheet at locations where the second design layer and the second printing layer were not present, specifically in area A where only the first printing layer of the first design layer was present, area B where only the third printing layer of the first design layer was present, and overlapping areas AB where only the first and third printing layers of the first design layer were present. Furthermore, since the transparent protective layer and transparent substrate layer are formed over the entire surface of the decorative sheet, all color measurements were performed at locations where the protective layer and transparent substrate layer were present. A CM-2500c (Konica Minolta, Inc.) with a measuring diameter of φ10 was used as the colorimeter, and the decorative sheet was placed on a white plate (whiteness 75%) for measurement. Visual evaluation was also performed according to the following criteria. The results are shown in Table 1. Grades A and B were considered passing grades (OK), while grade C was considered failing grades (NG).

[0142] (Visual evaluation criteria) A: Appears achromatic. B: A slight color can be perceived. C: A color can be perceived.

[0143] [Evaluation of Decorative Sheets] (Measurement of Color Temperature Change of Transmitted Light [K]) The color temperature change of transmitted light [K] was measured for each of the obtained decorative sheets. The color temperature change of transmitted light [K] was measured by measuring the color temperature at the position where only the protective layer and transparent substrate layer exist in the lamination direction of the decorative sheet, and using this as a reference, calculating the difference between this and the color temperature at the overlapping portion AB of the first design layer, where only the first printed layer and the third printed layer exist. A spectroradiometer (MK350N Premium; UPRtek Corp., measuring diameter φ7) was used to measure the color temperature, and the transmitted light was measured on a light panel with a white light source, and the difference from the light source was calculated. The color temperature of the light source was 3900K, and the illuminometer was selected in accordance with the general type AA class illuminometer of JIS C 1609-1:2006. The results are shown in Table 1.

[0144] (Color change of transmitted light (visual inspection)) For each of the obtained decorative sheets, the color change of transmitted light was visually observed and evaluated at the positions where only the protective layer and the transparent substrate layer existed, and at the overlapping portion A and B of only the first and third printing layers of the first design layer, in the lamination direction of the decorative sheet. For the visual evaluation, the decorative sheet (sample) was placed on a white board and visually judged under a D65 standard light source. Furthermore, the color change of transmitted light was visually judged on a light panel with a white light source. The evaluation criteria for the visual judgment of the color change of transmitted light are as follows.

[0145] (Evaluation Criteria) A: No discernible change in transmitted light color. B: A slight change in transmitted light color is observed. C: A clear change in transmitted light color is observed.

[0146]

[0147] <Color measurement of the overlapping portion of the first and third printing layers of the first design layer in Example 1> For the decorative sheet obtained in Example 1, the color measurement of the overlapping portion of the first and third printing layers of the first design layer (print density (OD value [a.u.]), L * Value, Saturation C *The values ​​[a.u.] and light transmittance [%] were measured. For the color measurement, instead of measuring on a white plate (whiteness 75%) as in the measurement of the decorative sheet described in [Color Measurement of Decorative Sheet 1] above, a black plate (lightness of the black plate: L) was used. * The procedure was carried out similarly, except that value 2.6 was used. The results are shown in Table 2.

[0148]

[0149] [Manufacturing of Decorative Sheets] <Example 5-21> Decorative sheets for each example were manufactured in the same manner as in Example 1, except that the second printing layer of the first design layer was changed. The second printing layer is as shown in Table 3. In Example 5-10, the second printing layer is a striped printing layer using white ink containing titanium dioxide. In Example 11-15, the second printing layer is a striped printing layer using silver ink containing aluminum flakes. In Example 16-21, the second printing layer is a striped printing layer using pearl ink containing white pearl pigment.

[0150] The difference between each of Examples 5-10 is that the titanium dioxide concentration was changed. The difference between each of Examples 11-15 is that the aluminum flake concentration was changed. The difference between each of Examples 16-21 is that the white pearl pigment concentration was changed.

[0151] [Color Measurement of Decorative Sheets 2] For each of the obtained decorative sheets, color measurements were performed from the protective layer side in accordance with the provisions of JIS Z 8722. Color measurements were performed in the lamination direction of the decorative sheet at locations where the second design layer is not present, specifically at part C where only the second printing layer of the first design layer is present, and at overlapping parts A, B, and C of the first design layer where the first, second, and third printing layers are present. Furthermore, since the transparent protective layer and transparent substrate layer are formed over the entire surface of the decorative sheet, all color measurements were performed at locations where the protective layer and transparent substrate layer are present. A CM-2500c (Konica Minolta, Inc.) with a measuring diameter of φ10 was used as the colorimeter, and the decorative sheet was placed on a black plate (lightness of the black plate: L *The measurement was performed with the value 2.6 placed on top. In addition, a densitometer (341C; X-Rite measuring diameter φ2) was used to measure the print density, light transmittance, and the rate of change in light transmittance with and without the second print layer in the first design layer. The densitometer was selected in accordance with ISO 5-2:2009. The results are shown in Table 3.

[0152] [Evaluation of Decorative Sheets (Comparison with Example 1)] (Appearance Judgment 1 (Color Difference) The color tone of the "parts A, B, and C of the first design layer where the first, second, and third printing layers exist" of each decorative sheet in Example 5-21 was visually evaluated, using the "overlapping portion A and B of the first design layer where only the first and third printing layers of the first design layer exist (on the black board)" of the decorative sheet obtained in Example 1 as the reference. The results are shown in Table 3. As shown in Table 3, the "overlapping portion A and B of the first design layer where only the first and third printing layers of the first design layer exist (on the black board)" of the decorative sheets obtained in Example 1 and Example 5-21 is the same, so Example 1 was used as the reference. (Evaluation Criteria) A: Differences in brightness and saturation are clearly visible. B: Differences in brightness and saturation are visible. C: Differences in brightness and saturation cannot be determined.

[0153] (Appearance Judgment 2 (Difference in Light Intensity) The light intensity of the "parts ABC where the first, second, and third printing layers of the first design layer exist" of each decorative sheet in Examples 5-21 was visually evaluated, using the "overlapping portion AB of only the first and third printing layers of the first design layer (on the black board)" of the decorative sheet obtained in Example 1 as a reference. The results are shown in Table 3. As shown in Table 3, the "overlapping portion AB of only the first and third printing layers of the first design layer (on the black board)" of the decorative sheets obtained in Example 1 and Example 5-21 is the same, so Example 1 was used as the reference. (Evaluation Criteria) A: No difference in light intensity can be determined. B: A slight difference in light intensity is observed. C: A clear difference in light intensity is observed.

[0154]

[0155] 1. First design layer 2. Second design layer 3. Transparent substrate layer 4. Protective layer 5. Molded resin layer 10. Decorative sheet 11. First printing layer 12. Second printing layer 13. Third printing layer 20. Decorated resin molded product 30. Light source 40. Decorated article

Claims

1. A decorative sheet comprising a first main surface and a second main surface located on the opposite side of the first main surface, wherein the laminate comprises, in order from the first main surface side to the second main surface side, at least a first design layer and a transparent substrate layer, wherein the first design layer comprises, in order from the first main surface side to the second main surface side, at least a colored first printing layer, a reflective second printing layer and a colored third printing layer, and the first and third printing layers are measured in L when these layers are stacked on a white board with a whiteness of 75%. * a * b * Saturation C in the color space * Decorative sheets whose value is 10 or less.

2. The decorative sheet according to claim 1, wherein the second printed layer contains a pigment that specularly or diffusely reflects visible light.

3. The decorative sheet according to claim 1 or 2, wherein the second printed layer is partially formed.

4. The decorative sheet according to claim 1 or 2, wherein the change in light transmittance of the first design layer with or without the second printing layer is 25% or less.

5. The decorative sheet according to claim 1 or 2, further comprising a second design layer partially provided between the first design layer and the transparent substrate layer, and / or on the second main surface side of the transparent substrate layer.

6. The decorative sheet according to claim 5, wherein the second design layer is embedded in the transparent substrate layer.

7. The decorative sheet according to claim 5, wherein the optical density of the second design layer is greater than the optical density of the first design layer.

8. The decorative sheet according to claim 5, further comprising an adhesive layer between the first design layer and the second design layer.

9. The decorative sheet according to claim 1 or 2, further comprising a protective layer on the first main surface side of the first design layer.

10. The decorative sheet according to claim 9, wherein the protective layer comprises an acrylic resin or an ionizing radiation-curable resin.

11. The decorative sheet according to claim 9, further comprising an adhesive layer between the protective layer and the first design layer.

12. A method for manufacturing a decorative sheet comprising a laminate having a first main surface and a second main surface located on the opposite side of the first main surface, wherein the laminate comprises, in order from the first main surface side toward the second main surface side, at least a first design layer and a transparent substrate layer, wherein the first design layer comprises, in order from the first main surface side toward the second main surface side, at least a colored first printing layer, a reflective second printing layer and a colored third printing layer, and the L is measured by stacking the first printing layer and the third printing layer on a white plate with a whiteness of 75%. * a * b * Saturation C in the color space * A method for manufacturing decorative sheets, wherein the result is 10 or less.

13. A decorative resin molded article comprising a decorative sheet according to claim 1 or 2, with the second main surface side laminated with a transparent molded resin layer.

14. A decorative article wherein a light source is positioned on the side of the molded resin layer of the decorative resin molded product according to claim 13 that is opposite to the decorative sheet side.

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