Decorative sheets and resin molded products

Abstract

Provided is a decorative sheet that includes at least a base layer containing polyolefin, and that can suppress deterioration of a resin molded product incorporating the decorative sheet due to ultraviolet rays. A decorative sheet having at least a base layer, an ultraviolet absorbing layer, and a surface protective layer laminated in this order, the substrate layer comprises a polyolefin; A decorative sheet, wherein the light transmittance at a wavelength of 330 nm measured for the entire layer located closer to the surface protective layer than the base layer of the decorative sheet is 20% or less.

Description

[Technical Field]

[0001] The present disclosure relates to a decorative sheet and a resin molded product. [Background technology]

[0002] Resin molded products in which a decorative sheet is laminated onto the surface of a resin molded product are used for vehicle interior parts, building materials, home appliance housings, etc. A known molding method for such resin molded products is the insert molding method (see, for example, Patent Document 1), in which the decorative sheet is molded into a three-dimensional shape in advance using a vacuum forming mold, the molded decorative sheet is inserted into an injection molding mold, and a resin in a fluid state is injected into the mold to integrate the resin and the decorative sheet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-322501 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, molded articles using polyolefins such as polypropylene have been widely used, for example, in automobile components, from the viewpoints of recyclability, weight reduction, etc. It is desirable to use polyolefins in decorative sheets for decorating molded articles (molded resin layers) formed from such polyolefins.

[0005] The inventors of the present disclosure considered using polyolefin for the base layer of a decorative sheet and discovered a new finding that deterioration due to ultraviolet rays is likely to progress in a resin molded product that has the decorative sheet incorporated therein. Further investigation by the inventors of the present disclosure revealed that with a laminate-type decorative sheet that uses polyolefin and in which the base layer of the decorative sheet is incorporated into the resin molded product, deterioration of the base layer in the resin molded product is likely to be a problem.

[0006] Furthermore, the inventors of the present disclosure have investigated ways to improve the weather resistance of decorative sheets by incorporating a large amount of ultraviolet absorbent into the decorative sheet, but when a large amount of ultraviolet absorbent is incorporated into the decorative sheet, concerns have arisen that the design of the decorative sheet may change depending on the color of the ultraviolet absorbent, affecting the decoration of the resin molded product.

[0007] Under these circumstances, a primary object of the present disclosure is to provide a decorative sheet that includes at least a substrate layer containing polyolefin, and that can suppress ultraviolet degradation of a resin molded product incorporating the decorative sheet. Another object of the present disclosure is to provide a resin molded product that utilizes the decorative sheet. [Means for solving the problem]

[0008] The inventors of the present disclosure conducted extensive research to solve the above-mentioned problems. As a result, they found that in a decorative sheet having at least a base layer, an ultraviolet absorbing layer, and a surface protective layer laminated in this order, the base layer contains polyolefin, and by setting the light transmittance (%) at a specific wavelength, measured for all layers of the decorative sheet located closer to the surface protective layer than the base layer, to a predetermined value or less, it is possible to suppress deterioration of a resin molded product incorporating the decorative sheet due to ultraviolet light. The present disclosure was completed based on this finding and through further research.

[0009] That is, the present disclosure provides the inventions of the following aspects. Item 1. A decorative sheet having at least a base layer, an ultraviolet absorbing layer, and a surface protective layer laminated in this order, the substrate layer comprises a polyolefin; A decorative sheet, wherein the light transmittance at a wavelength of 330 nm measured for the entire layer located closer to the surface protective layer than the base layer of the decorative sheet is 20% or less. Item 2. The decorative sheet according to Item 1, which is used in applications where it is laminated with a molding resin containing polyolefin. Item 3. The decorative sheet according to Item 1 or 2, wherein the ultraviolet absorbing layer contains at least one of an ultraviolet absorber and a coloring material. Item 4. The decorative sheet according to any one of Items 1 to 3, wherein the ultraviolet absorbing layer has a first ultraviolet absorbing layer containing an ultraviolet absorber and a second ultraviolet absorbing layer containing a coloring material. Item 5. The decorative sheet according to Item 4, wherein the first ultraviolet absorbing layer is located closer to the surface protective layer than the second ultraviolet absorbing layer. Item 6. The decorative sheet according to any one of Items 1 to 5, further comprising a primer layer between the base layer and the ultraviolet absorbing layer. Item 7. The decorative sheet according to any one of Items 1 to 6, wherein the substrate layer includes a first substrate layer and a second substrate layer. Item 8. The decorative sheet according to Item 7, further comprising an adhesive layer between the first base material layer and the second base material layer. Item 9. A resin molded product having at least a molded resin layer, a base layer, an ultraviolet absorbing layer, and a surface protective layer laminated in this order, the substrate layer comprises a polyolefin; A resin molded article, wherein the light transmittance at a wavelength of 330 nm measured for the entire layer located closer to the surface protective layer than the base layer of the resin molded article is 20% or less. Item 10. The resin molded product according to Item 9, wherein the molded resin layer contains polyolefin. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a decorative sheet that includes at least a base layer containing polyolefin, and that can suppress deterioration due to ultraviolet rays of a resin molded product that the decorative sheet is incorporated into. Furthermore, according to the present disclosure, it is also possible to provide a resin molded product that uses the decorative sheet. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram of a cross-sectional structure of one embodiment of a decorative sheet according to the present disclosure. [Figure 2]1 is a schematic diagram of a cross-sectional structure of one embodiment of a decorative sheet according to the present disclosure. [Figure 3] 1 is a schematic diagram of a cross-sectional structure of one embodiment of a decorative sheet according to the present disclosure. [Figure 4] 1 is a schematic diagram of a cross-sectional structure of one embodiment of a decorative sheet according to the present disclosure. [Figure 5] 1 is a schematic diagram of a cross-sectional structure of one embodiment of a resin molded product according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] 1.Decorative sheet The decorative sheet of the present disclosure is a decorative sheet having at least a base layer, an ultraviolet absorbing layer, and a surface protective layer laminated in this order, the base layer containing polyolefin, and having a light transmittance of 20% or less at a wavelength of 330 nm measured across the entire layer of the decorative sheet located closer to the surface protective layer than the base layer. By virtue of this configuration, the decorative sheet of the present disclosure can suppress ultraviolet degradation of a resin molded product incorporating the decorative sheet, despite the use of polyolefin in the base layer of the decorative sheet. The decorative sheet and resin molded product of the present disclosure will be described in detail below with reference to FIGS. 1 to 5.

[0013] In this specification, unless explicitly stated as "greater than or equal to" or "less than or equal to," a numerical range indicated with "to" means "greater than or equal to" or "less than or equal to." For example, the notation "2 to 15 mm" means 2 mm or more and 15 mm or less. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, separately described upper and lower limits, upper and lower limits, or lower and lower limits may each be combined to form a numerical range. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the examples.

[0014] In addition, in this specification, "(meth)acrylate" means "acrylate or methacrylate," and other similar terms have the same meaning.

[0015] The decorative sheet of the present disclosure may not have a design layer or the like, and may be transparent, for example. The surface of the decorative sheet facing the surface protection layer 2 may be flat or may have an uneven shape. The surface of the decorative sheet facing the base layer 1 is preferably flat.

[0016] Laminated structure and physical properties of decorative sheets The decorative sheet 10 of the present disclosure includes at least a base layer 1, an ultraviolet absorbing layer 3, and a surface protective layer 2 in this order.

[0017] The ultraviolet absorbing layer 3 may be a single layer or a multi-layer structure consisting of two or more layers. FIGS. 2 to 5 illustrate examples of the laminated structure of a decorative sheet in which the ultraviolet absorbing layer 3 includes a first ultraviolet absorbing layer 31 and a second ultraviolet absorbing layer 32. As described below, the ultraviolet absorbing layer 3 preferably includes a first ultraviolet absorbing layer containing an ultraviolet absorber and a second ultraviolet absorbing layer containing a colorant. The second ultraviolet absorbing layer containing a colorant can also function as a design layer that enhances the decorativeness of the decorative sheet. In the decorative sheet of the present disclosure, the first ultraviolet absorbing layer 31 and the second ultraviolet absorbing layer 32 are preferably laminated in this order from the surface protective layer 2 side.

[0018] In the present disclosure, the base material layer 1 may be a single layer or multiple layers. When the base material layer 1 is multiple layers, the two or more base material layers are referred to as a first base material layer 11, a second base material layer 12, etc. (see FIG. 4). When the base material layer 1 is multiple layers, the respective base material layers 1 (for example, the first base material layer 11, the second base material layer 12) may or may not be adjacent to each other (i.e., other layers may be laminated between the respective base material layers).

[0019] The decorative sheet 10 may further include at least one layer selected from the group consisting of a primer layer 4, an adhesive layer 5, and the like, in addition to the substrate layer 1, the surface protective layer 2, and the ultraviolet absorbing layer 3. The primer layer 4 may be laminated, for example, between the ultraviolet absorbing layer 3 and the substrate layer 1, or between the layers constituting the substrate layer if the substrate layer 1 is composed of multiple layers. The adhesive layer 5 may be laminated on the side of the substrate layer 1 opposite to the surface protective layer 2, or between the layers constituting the substrate layer 1 if the substrate layer 1 is composed of multiple layers.

[0020] The laminate structure of the decorative sheet of the present disclosure is: A laminated structure consisting of a base layer, an ultraviolet absorbing layer, and a surface protection layer stacked in this order; A laminated structure consisting of a base layer, a primer layer, an ultraviolet absorbing layer, and a surface protection layer stacked in this order; A laminated structure in which a base layer / a second ultraviolet absorbing layer / a first ultraviolet absorbing layer / a surface protective layer are laminated in this order; A laminated structure in which a base layer / primer layer / second ultraviolet absorbing layer / first ultraviolet absorbing layer / surface protective layer are laminated in this order; A laminated structure in which a second substrate layer / an adhesive layer / a first substrate layer / a primer layer / a second ultraviolet absorbing layer / a first ultraviolet absorbing layer / a surface protective layer are laminated in this order; A laminated structure in which an adhesive layer / a substrate layer / a primer layer / a second ultraviolet absorbing layer / a first ultraviolet absorbing layer / a surface protective layer are laminated in this order; A laminated structure in which an adhesive layer / a second substrate layer / an adhesive layer / a first substrate layer / a primer layer / a second ultraviolet absorbing layer / a first ultraviolet absorbing layer / a surface protective layer are laminated in this order; Examples include:

[0021] FIG. 1 shows a schematic diagram of the cross-sectional structure of one embodiment of a decorative sheet in which a base layer / ultraviolet absorbing layer / surface protective layer are laminated in this order, as one embodiment of the laminate structure of the decorative sheet of the present disclosure. FIG. 2 shows a schematic diagram of the cross-sectional structure of one embodiment of the decorative sheet of the present disclosure, in which a base layer / second ultraviolet absorbing layer / first ultraviolet absorbing layer / surface protective layer are laminated in this order. FIG. 3 shows a schematic diagram of the cross-sectional structure of one embodiment of the laminate structure of the decorative sheet of the present disclosure, in which a base layer / primer layer / second ultraviolet absorbing layer / first ultraviolet absorbing layer / surface protective layer are laminated in this order. FIG. 4 shows a schematic diagram of the cross-sectional structure of one embodiment of the laminated structure of the decorative sheet of the present disclosure, in which a second base material layer / adhesive layer / first base material layer / primer layer / second ultraviolet absorbing layer / first ultraviolet absorbing layer / surface protective layer are laminated in this order. The " / " indicates a separation between layers.

[0022] In the decorative sheet 10, the ratio of the total thickness of the substrate layer 1 (single layer or multiple layers), surface protective layer 2, ultraviolet absorbing layer 3 (single layer or multiple layers), primer layer 4 which is provided as needed, and adhesive layer 5 which is provided as needed to the thickness (total thickness) of the laminate constituting the decorative sheet 10 is, for example, 80% or more, preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.

[0023] As a specific example, when the decorative sheet 10 of the present disclosure is a laminate including a base layer 1 (single layer or multiple layers), a surface protective layer 2, an ultraviolet absorbing layer 3 (single layer or multiple layers), a primer layer 4, and an adhesive layer 5, 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, more preferably 95% or more, and even more preferably 98% or more.

[0024] In the decorative sheet of the present disclosure, the light transmittance at a wavelength of 330 nm measured for all layers located closer to the surface protective layer 2 than the base layer (for example, the entire laminate including the surface protective layer 2, the ultraviolet absorbing layer 3, and the primer layer 4, which is provided as needed) is 20% or less. In the decorative sheet of the present disclosure, the light transmittance at a specific wavelength of 330 nm is controlled to 20% or less for all layers located closer to the surface protective layer 2 than the polyolefin-containing base layer 1, so that deterioration of the polyolefin-containing base layer 1 due to ultraviolet rays can be suitably suppressed. Furthermore, when the decorative sheet is laminated with a polyolefin-containing molded resin layer and incorporated into a resin molded product, deterioration of not only the base layer but also the molded resin layer due to ultraviolet rays can be suppressed, and deterioration of the resin molded product due to ultraviolet rays can be suitably suppressed.

[0025] In the decorative sheet 10 of the present disclosure, the light transmittance at a wavelength of 330 nm measured for the entire layer located closer to the surface protective layer 2 than the base layer 1 needs to be 20% or less, but from the viewpoint of more suitably exerting the effects of the present disclosure, the light transmittance is preferably 15% or less, more preferably 10% or less, and even more preferably 5% or less, with a lower limit of, for example, 0% or 1%, and preferred ranges include 0 to 20%, 0 to 10%, 0 to 5%, 1 to 20%, 1 to 10%, and 1 to 5%. The light transmittance at a wavelength of 330 nm is a value measured by the following method.

[0026] <Light transmittance at a wavelength of 330 nm> The light transmittance is determined by measuring the spectral transmittance in the wavelength range of 300 nm to 800 nm using an ultraviolet-visible spectrophotometer, and the value at a wavelength of 330 nm in the spectrum of the spectral transmittance is used. For specific measurement methods, see the methods described in the Examples.

[0027] In the decorative sheet 10 of the present disclosure, from the viewpoint of effectively suppressing ultraviolet degradation of the resin molded article 20 incorporating the decorative sheet 10, it is important to control the light transmittance at a specific wavelength of 330 nm, measured for the entire layer located closer to the surface protective layer 2 than the base layer 1, to 20% or less. Therefore, it is not necessary to control the light transmittance at other wavelengths, such as 380 nm and 340 nm, to be below a specific value. For example, in the decorative sheet of the present disclosure, the light transmittance at a wavelength of 380 nm, measured for the entire layer located closer to the surface protective layer 2 than the base layer 1, may be greater than 30%, or may be 31% or more, 32% or more, 35% or more, 40% or more, etc. The upper limit of the light transmittance at a wavelength of 380 nm is, for example, 60%. Furthermore, for example, in the decorative sheet of the present disclosure, the light transmittance at a wavelength of 340 nm measured for the entire layer located closer to the surface protective layer 2 than the base layer 1 may be more than 10%, or may be 11% or more, 12% or more, 15% or more, 20% or more, etc. The upper limit of the light transmittance at a wavelength of 340 nm is, for example, 50%. The light transmittance at a wavelength of 380 nm or 340 nm is a value measured by changing the measurement wavelength from 330 nm to 380 nm or 340 nm in the measurement method described above in <Light transmittance at a wavelength of 330 nm>.

[0028] Each layer that forms the decorative sheet [Base material layer 1] The base layer 1 is a layer (resin sheet, resin film) that serves as a support in the decorative sheet 10 of the present disclosure and is provided for the purpose of improving the formability of the decorative sheet.

[0029] The base material layer 1 may be a single layer or multiple layers. When the base material layer 1 is multiple layers, the two or more base material layers are referred to as a first base material layer 11, a second base material layer 12, etc. (see FIG. 4). When the base material layer 1 is multiple layers, the respective base material layers (for example, the first base material layer 11, the second base material layer 12) may or may not be adjacent to each other (i.e., another layer may be laminated between the respective base material layers). The base material layer 1 is preferably composed of one or two layers.

[0030] Figure 4 illustrates a laminated structure of the decorative sheet 10 of the present disclosure, which has a first substrate layer 11 and a second substrate layer 12 as the substrate layer 1, and an adhesive layer 5 is laminated between the first substrate layer 11 and the second substrate layer 12.

[0031] The base layer 1 contains polyolefin. The base layer 1 is preferably formed from polyolefin. When the base layer 1 is a multi-layer structure, each of the layers constituting the base layer 1 (for example, the first base layer 11 and the second base layer 12) preferably contains polyolefin and is formed from polyolefin.

[0032] Specific examples of polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylenes such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); propylene-α-olefin copolymers; and ethylene-butene-propylene terpolymers. Among these, polypropylene is preferred. When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. These polyolefins may be used alone or in combination of two or more.

[0033] The polyolefin may also be a cyclic polyolefin. Cyclic polyolefins are copolymers of olefins and cyclic monomers, and examples of olefins constituting the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. Examples of cyclic monomers constituting the cyclic polyolefin include cyclic alkenes such as norbornene; and cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these, preferred are cyclic alkenes, and more preferred are norbornene.

[0034] In order to improve adhesion to a layer disposed thereon, one or both surfaces of the substrate layer 1 may be subjected to a physical or chemical surface treatment, such as an oxidation method or a roughening method, as necessary. Examples of oxidation methods used to treat the substrate layer 1 include corona discharge treatment, chromium oxidation treatment, flame treatment, hot air treatment, and ozone ultraviolet treatment. Examples of roughening methods used to treat the substrate layer 1 include sandblasting and solvent treatment. These surface treatments are appropriately selected depending on, for example, the resin components constituting the substrate layer 1, but from the viewpoints of effectiveness and operability, corona discharge treatment is preferred.

[0035] The base material layer 1 may be subjected to a known treatment such as forming an adhesive layer.

[0036] Furthermore, the base layer 1 may be colored using a colorant, or may not be colored. The base layer 1 may be colorless and transparent, colored and transparent, or translucent. The colorant used in the base layer 1 is not particularly limited, but preferably includes a colorant that does not discolor even at temperatures of 150°C or higher, and specific examples include existing dry colors, paste colors, and masterbatch resin compositions. The base layer 1 may also have an uneven shape to impart design and texture.

[0037] The total thickness of the base layer 1 is appropriately set depending on the application of the decorative sheet, the molding method for integrating it with the molding resin, etc., and is preferably 200 μm or more, more preferably 400 μm or more, and preferably 1000 μm or less, more preferably 800 μm or less. Preferred ranges include about 200 to 1000 μm, about 200 to 800 μm, about 400 to 1000 μm, and about 400 to 800 μm.

[0038] When the base layer 1 is a multi-layer structure, the thickness of the base layer located opposite the surface protective layer 2 (for example, the second base layer 12 in FIG. 4) is preferably greater than the thickness of the base layer located on the surface protective layer 2 side (for example, the first base layer 11 in FIG. 4). The thickness of the base layer located opposite the surface protective layer 2 side (for example, the second base layer 12 in FIG. 4) is preferably 100 μm or more, more preferably 200 μm or more, and preferably 800 μm or less, more preferably 600 μm or less. Preferred ranges include about 100 to 800 μm, about 100 to 600 μm, about 200 to 800 μm, and about 200 to 600 μm. The thickness of the base layer located on the surface protective layer 2 side (for example, the first base layer 11 in FIG. 4) is preferably 50 μm or more, more preferably 100 μm or more, and preferably 400 μm or less, more preferably 300 μm or less. Preferred ranges include about 50 to 400 μm, about 50 to 300 μm, about 100 to 400 μm, and about 100 to 300 μm.

[0039] When the substrate layer 1 is a multi-layer structure, the substrate layers can be bonded together by providing a primer layer 4, an adhesive layer 5, etc. between the substrate layers.

[0040] (ultraviolet absorbing layer 3) The decorative sheet of the present disclosure includes an ultraviolet absorbing layer 3, and the light transmittance at a wavelength of 330 nm measured for the entire layer located closer to the surface protective layer 2 than the base layer 1 is controlled to 20% or less, thereby making it possible to suitably suppress ultraviolet degradation of the polyolefin-containing base layer 1. Furthermore, when the decorative sheet is laminated with a polyolefin-containing molded resin layer and incorporated into a resin molded product, ultraviolet degradation of not only the base layer but also the molded resin layer can be suppressed, making it possible to suitably suppress ultraviolet degradation of the resin molded product.

[0041] The ultraviolet absorbing layer 3 may be a single layer or a multi-layer structure of two or more layers. 2 to 4 show examples of the laminated structure of a decorative sheet in which the ultraviolet absorbing layer 3 includes a first ultraviolet absorbing layer 31 and a second ultraviolet absorbing layer 32.

[0042] The ultraviolet absorbing layer 3 preferably contains at least one of an ultraviolet absorber and a coloring material. In the present disclosure, the coloring material in the ultraviolet absorbing layer 3 preferably contains a material that exhibits ultraviolet absorbing function. As described below, the ultraviolet absorbing layer 3 preferably has a first ultraviolet absorbing layer containing an ultraviolet absorber and a second ultraviolet absorbing layer containing a coloring material. The second ultraviolet absorbing layer containing a coloring material can also function as a design layer that enhances the decorativeness of the decorative sheet and the resin molded product. In the decorative sheet of the present disclosure, the first ultraviolet absorbing layer 31 and the second ultraviolet absorbing layer 32 are preferably laminated in this order from the surface protective layer 2 side.

[0043] Examples of the ultraviolet absorber include organic ultraviolet absorbers and inorganic ultraviolet absorbers. From the viewpoint of more suitably exhibiting the effects of the present invention, examples of the organic ultraviolet absorber include benzophenone-based ultraviolet absorbers, triazine-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, benzoxazine-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, and salicylic acid-based ultraviolet absorbers. Examples of the inorganic ultraviolet absorber include titanium dioxide, cerium oxide, and zinc oxide. The ultraviolet absorbing layer 3 may contain only one type of ultraviolet absorber, or two or more types.

[0044] From the viewpoint of more suitably exerting the effects of the invention of the present disclosure, the content of the ultraviolet absorber contained in the ultraviolet absorbing layer 3 is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more, and is preferably 15% by mass or less, more preferably 12% by mass or less, and even more preferably 10% by mass or less. Preferred ranges include about 0.5 to 15% by mass, about 0.5 to 12% by mass, about 0.5 to 10% by mass, about 1 to 15% by mass, about 1 to 12% by mass, about 1 to 10% by mass, about 3 to 15% by mass, about 3 to 12% by mass, and about 3 to 10% by mass.

[0045] Furthermore, from the viewpoint of more effectively achieving the effects of the present invention, the coloring material contained in the ultraviolet absorbing layer 3 is preferably a pigment or dye that exhibits the function of absorbing ultraviolet light. Specific examples of pigments include azo pigments such as condensed azo, phthalocyanine pigments such as phthalocyanine blue, threne pigments such as anthraquinone and perylene, condensed polycyclic pigments such as quinacridone, titanium pigments such as titanium oxide, iron oxide pigments such as red iron oxide, chromate pigments such as yellow lead, aluminate pigments such as cobalt blue, and metal oxides such as carbon black and aluminum oxide. Specific examples of dyes include perylene dyes, coumarin dyes, thioindigo dyes, anthraquinone dyes, thioxanthone dyes, ferrocyanides, quinoline dyes, and isoindolinone dyes. The ultraviolet absorbing layer 3 may contain only one type of dye, or two or more types of dyes.

[0046] From the viewpoint of more suitably exerting the effects of the invention of the present disclosure, the content of the colorant contained in the ultraviolet absorbing layer 3 is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. Preferred ranges include about 1 to 50% by mass, about 1 to 40% by mass, about 1 to 30% by mass, about 5 to 50% by mass, about 5 to 40% by mass, about 5 to 30% by mass, about 10 to 50% by mass, about 10 to 40% by mass, and about 10 to 30% by mass.

[0047] The ultraviolet absorbing layer 3 can be formed, for example, from a resin composition containing at least one of an ultraviolet absorber and a colorant, and a resin. The resin contained in the resin composition is not particularly limited, but examples thereof include polyol and / or its cured product, acrylic resin, (meth)acrylic-urethane copolymer resin, polyester, butyral resin, styrene resin, polyester, urethane resin, chlorinated polyolefin, vinyl chloride-vinyl acetate copolymer resin, polyvinyl butyral resin, alkyd resin, petroleum resin, ketone resin, epoxy resin, melamine resin, fluororesin, silicone resin, cellulose derivative, rubber resin, etc. These resins may be used alone or in combination of two or more.

[0048] For example, when the ultraviolet absorbing layer 3 contains an ultraviolet absorber (for example, in the case of the first ultraviolet absorbing layer 31 containing an ultraviolet absorber), the resin is preferably a polyol and / or a cured product thereof, a urethane resin, an acrylic resin, a (meth)acrylic-urethane copolymer resin, a polyester, a butyral resin, etc. Among these resins, polyol and / or a cured product thereof, a urethane resin, an acrylic resin, and an acrylic urethane resin are preferred.

[0049] When the ultraviolet absorbing layer 3 contains an ultraviolet absorber (for example, when the first ultraviolet absorbing layer 31 contains an ultraviolet absorber), the layer is preferably formed from a resin composition containing a polyol and polyurethane. The polyol may be any compound having two or more hydroxyl groups in the molecule, and specific examples thereof include polyester polyol, polyethylene glycol, polypropylene glycol, acrylic polyol, polyether polyol, etc., with acrylic polyol being preferred.

[0050] When a polyol and a polyurethane are used, the mass ratio thereof (polyol / polyurethane) is preferably 5 / 5 or more, preferably 7 / 3 or more, or preferably 9.5 / 0.5 or less, more preferably 9 / 1 or less. A preferred range for the mass ratio (polyol / polyurethane) is 5 / 5 or more and 9.5 / 0.5 or less, more preferably 7 / 3 or more and 9 / 1 or less.

[0051] An example of a cured product of polyol is polyurethane, which uses polyol (polyhydric alcohol) as a base component and isocyanate as a crosslinking agent (curing agent).

[0052] Specific examples of isocyanates include polyisocyanates having two or more isocyanate groups in the 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. When an isocyanate is used as a curing agent, the content of the isocyanate in the resin composition for forming an ultraviolet-absorbing layer is not particularly limited, but from the viewpoints of adhesion and printability, it is preferably 3 parts by mass or more, and preferably 45 parts by mass or less, and more preferably 25 parts by mass or less, per 100 parts by mass of the polyol. The content of the isocyanate in the resin composition for forming an ultraviolet-absorbing layer is preferably 3 parts by mass or more and 45 parts by mass or less, and more preferably 3 parts by mass or more and 25 parts by mass or less, per 100 parts by mass of the polyol.

[0053] Among the above polyurethanes, from the viewpoint of improving adhesion after crosslinking, a preferred combination is one in which an acrylic polyol or a polyester polyol is used as the polyol and hexamethylene diisocyanate or 4,4-diphenylmethane diisocyanate is used as the crosslinking agent; a more preferred combination is one in which an acrylic polyol is used with hexamethylene diisocyanate.

[0054] The acrylic resin is not particularly limited, and examples thereof include a homopolymer of a (meth)acrylic acid ester, a copolymer of two or more different (meth)acrylic acid ester monomers, or a copolymer of a (meth)acrylic acid ester and another monomer. More specific examples of the (meth)acrylic resin include (meth)acrylic acid esters such as polymethyl(meth)acrylate, polyethyl(meth)acrylate, polypropyl(meth)acrylate, polybutyl(meth)acrylate, methyl(meth)acrylate-butyl(meth)acrylate copolymer, ethyl(meth)acrylate-butyl(meth)acrylate copolymer, ethylene-methyl(meth)acrylate copolymer, and styrene-methyl(meth)acrylate copolymer.

[0055] The acrylic urethane resin is not particularly limited, but examples thereof include acrylic-urethane block copolymers, specifically acrylic-polyester urethane block copolymers. The ratio of acrylic to urethane in the acrylic-urethane block copolymer is not particularly limited, but for example, the acrylic / urethane ratio (mass ratio) is preferably 9 / 1 or less, more preferably 8 / 2 or less, and also preferably 1 / 9 or more, more preferably 2 / 8 or more. The preferred range of the acrylic / urethane ratio (mass ratio) is 1 / 9 or more and 9 / 1 or less, more preferably 2 / 8 or more and 8 / 2 or less.

[0056] Furthermore, for example, when the ultraviolet absorbing layer 3 contains a colorant (for example, in the case of the second ultraviolet absorbing layer 32 containing a colorant), the resin contained in the resin composition forming the layer is preferably an acrylic resin, a styrene resin, a polyester, a urethane resin, a chlorinated polyolefin, a vinyl chloride-vinyl acetate copolymer resin, a polyvinyl butyral resin, an alkyd resin, a petroleum resin, a ketone resin, an epoxy resin, a melamine resin, a fluororesin, a silicone resin, a cellulose derivative, a rubber resin, or the like.

[0057] By including a coloring material in the ultraviolet absorbing layer 3, decorative properties can be imparted to the decorative sheet and the resin molded product. For example, the ultraviolet absorbing layer 3 containing a coloring material can express patterned images such as designs and letters. Furthermore, by including a coloring material in the ultraviolet absorbing layer 3, it is possible to achieve the function of concealing the coloring of the base layer, molded resin layer, etc.

[0058] The pattern expressed by the ultraviolet absorbing layer 3 is not particularly limited, but examples thereof include patterns consisting of wood grain, stone grain, cloth grain, sand grain, geometric patterns, letters, and the like.

[0059] The ultraviolet absorbing layer 3 preferably has a first ultraviolet absorbing layer 31 containing an ultraviolet absorber and a second ultraviolet absorbing layer 32 containing a colorant. The first ultraviolet absorbing layer 31 containing an ultraviolet absorber may not contain a colorant, and the second ultraviolet absorbing layer 32 containing a colorant may not contain an ultraviolet absorber. The first ultraviolet absorbing layer 31 containing an ultraviolet absorber is preferably located closer to the surface protective layer 2 than the second ultraviolet absorbing layer 32 containing a colorant.

[0060] From the viewpoint of more suitably exerting the effects of the invention of the present disclosure, the content of the ultraviolet absorber contained in the first ultraviolet absorbing layer 31 is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, and preferred ranges include approximately 0.5 to 20% by mass, approximately 0.5 to 15% by mass, approximately 0.5 to 10% by mass, approximately 1 to 20% by mass, approximately 1 to 15% by mass, approximately 1 to 10% by mass, approximately 3 to 20% by mass, approximately 3 to 15% by mass, and approximately 3 to 10% by mass.

[0061] Furthermore, from the viewpoint of more suitably exerting the effects of the invention of the present disclosure, the content of the colorant contained in the second ultraviolet absorbing layer 32 is preferably 1% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, and preferred ranges include approximately 1 to 50% by mass, approximately 1 to 40% by mass, approximately 1 to 30% by mass, approximately 10 to 50% by mass, approximately 10 to 40% by mass, approximately 10 to 30% by mass, approximately 15 to 50% by mass, approximately 15 to 40% by mass, and approximately 15 to 30% by mass.

[0062] Various additives can be blended into the resin composition forming the ultraviolet absorbing layer 3 depending on the desired physical properties to be imparted. Examples of these additives include weather resistance improvers such as light stabilizers, abrasion resistance improvers, polymerization inhibitors, crosslinking agents, infrared absorbers, antistatic agents, adhesion improvers, leveling agents, thixotropy-imparting agents, coupling agents, plasticizers, antifoaming agents, fillers, solvents, matting agents, etc. These additives can be appropriately selected from commonly used ones, and examples of matting agents include silica particles and aluminum hydroxide particles.

[0063] The total thickness of the ultraviolet absorbing layer 3 is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 5 μm or less, and preferred ranges include about 0.1 to 10 μm, about 0.1 to 8 μm, about 0.1 to 5 μm, about 0.5 to 10 μm, about 0.5 to 8 μm, about 0.5 to 5 μm, about 1 to 10 μm, about 1 to 8 μm, and about 1 to 5 μm.

[0064] The total thickness of the first ultraviolet absorbing layer 31 is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1 μm or more, and is preferably 5 μm or less, more preferably 4 μm or less, and even more preferably 3 μm or more, and preferred ranges include about 0.1 to 5 μm, about 0.1 to 4 μm, about 0.1 to 3 μm, about 0.5 to 5 μm, about 0.5 to 4 μm, about 0.5 to 3 μm, about 1 to 5 μm, about 1 to 4 μm, and about 1 to 3 μm.

[0065] The total thickness of the second ultraviolet absorbing layer 32 is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1 μm or more, and is preferably 5 μm or less, more preferably 4 μm or less, and even more preferably 3 μm or less, and preferred ranges include about 0.1 to 5 μm, about 0.1 to 4 μm, about 0.1 to 3 μm, about 0.5 to 5 μm, about 0.5 to 4 μm, about 0.5 to 3 μm, about 1 to 5 μm, about 1 to 4 μm, and about 1 to 3 μm.

[0066] The ultraviolet absorbing layer 3 is formed using a resin composition for forming an ultraviolet absorbing layer by a common coating method such as gravure coating, gravure reverse coating, gravure offset coating, spinner coating, roll coating, reverse roll coating, kiss coating, wheel coating, dip coating, solid coating by silk screen, wire bar coating, flow coating, comma coating, flow coating, brush coating, or spray coating.

[0067] [Surface protection layer 2] The surface protection layer 2 is a layer provided to protect the surface of the resin molded product.

[0068] The material constituting the surface protective layer 2 is not particularly limited as long as it exhibits the function of protecting the surface of the resin molded article, and examples thereof include thermoplastic resins, thermosetting resins, and ionizing radiation curable resins. Among these, from the viewpoint of suitably imparting the function of a surface protective layer to the resin molded article, it is preferable that the surface protective layer 2 be composed of a cured product of an ionizing radiation curable resin composition. The ionizing radiation curable resin used to form the surface protective layer 2 will be described in detail below.

[0069] (ionizing radiation curable resin) The ionizing radiation-curable resin used to form the surface protective layer 2 is a resin that crosslinks and cures upon exposure to ionizing radiation. Specific examples include a mixture of at least one of prepolymers, oligomers, and monomers, each of which has a polymerizable unsaturated bond or epoxy group in its molecule. Here, ionizing radiation refers to electromagnetic waves or charged particle beams that have an energy quantum capable of polymerizing or crosslinking molecules. Typically, ultraviolet (UV) or electron beams (EB) are used, but ionizing radiation also includes other types of electromagnetic waves, such as X-rays and gamma rays, as well as charged particle beams, such as alpha rays and ion beams. Among ionizing radiation-curable resins, electron beam-curable resins are suitable for use in forming the surface protective layer 2 because they can be made solvent-free, do not require a photopolymerization initiator, and exhibit stable curing properties.

[0070] The monomer used as the ionizing radiation curable resin is preferably a (meth)acrylate monomer having a radical polymerizable unsaturated group in the molecule, and among these, a polyfunctional (meth)acrylate monomer is preferred. The polyfunctional (meth)acrylate monomer may be a (meth)acrylate monomer having two or more (difunctional or more), preferably three or more (trifunctional or more) polymerizable unsaturated bonds in the molecule. Specific examples of the polyfunctional (meth)acrylate include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphate di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, isocyanurate di(meth)acrylate, trimethylol propionate, and the like. Examples of suitable monomers include propane tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(acryloxyethyl)isocyanurate, propionic acid-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene oxide-modified dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate. These monomers may be used alone or in combination of two or more.

[0071] The oligomer used as the ionizing radiation-curable resin is preferably a (meth)acrylate oligomer having a radically polymerizable unsaturated group in the molecule, and particularly preferably a polyfunctional (meth)acrylate oligomer having two or more (bifunctional or more) polymerizable unsaturated bonds in the molecule. Examples of polyfunctional (meth)acrylate oligomers include polycarbonate (meth)acrylate, acrylic silicone (meth)acrylate, urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, polybutadiene (meth)acrylate, silicone (meth)acrylate, and oligomers having a cationically polymerizable functional group in the molecule (e.g., novolac epoxy resin, bisphenol epoxy resin, aliphatic vinyl ether, aromatic vinyl ether, etc.). Here, the polycarbonate (meth)acrylate is not particularly limited as long as it has a carbonate bond in the polymer main chain and a (meth)acrylate group at the end or side chain. For example, it can be obtained by esterifying a polycarbonate polyol with (meth)acrylic acid. The polycarbonate (meth)acrylate may be, for example, a urethane (meth)acrylate having a polycarbonate skeleton. The urethane (meth)acrylate having a polycarbonate skeleton can be obtained, for example, by reacting a polycarbonate polyol with a polyvalent isocyanate compound and a hydroxy (meth)acrylate. The acrylic silicone (meth)acrylate can be obtained by radical copolymerization of a silicone macromonomer with a (meth)acrylate monomer. The urethane (meth)acrylate can be obtained, for example, by esterifying a urethane resin oligomer obtained by reacting a polyether polyol or polyester polyol with a polyisocyanate compound with (meth)acrylic acid. Epoxy (meth)acrylate can be obtained, for example, by reacting (meth)acrylic acid with the oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolac type epoxy resin to esterify it.Carboxyl-modified epoxy (meth)acrylates obtained by partially modifying this epoxy (meth)acrylate with a dibasic carboxylic acid anhydride can also be used. Polyester (meth)acrylates can be obtained, for example, by esterifying the hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends, obtained by condensation of a polycarboxylic acid and a polyhydric alcohol, with (meth)acrylic acid, or by esterifying the terminal hydroxyl groups of an oligomer obtained by adding an alkylene oxide to a polycarboxylic acid with (meth)acrylic acid. Polyether (meth)acrylates can be obtained by esterifying the hydroxyl groups of a polyether polyol with (meth)acrylic acid. Polybutadiene (meth)acrylates can be obtained by adding (meth)acrylic acid to the side chain of a polybutadiene oligomer. Silicone (meth)acrylates can be obtained by adding (meth)acrylic acid to the end or side chain of a silicone having a polysiloxane bond in its main chain. These oligomers may be used alone or in combination of two or more.

[0072] Among the above-mentioned ionizing radiation curable resins, polycarbonate (meth)acrylate is preferably used from the viewpoint of obtaining superior three-dimensional moldability while further improving the appearance of the design, abrasion resistance, and moldability. It is also preferable to use a combination of polycarbonate (meth)acrylate and urethane (meth)acrylate.

[0073] The surface protective layer 2 may also contain at least one of inorganic particles and organic particles. In the surface protective layer 2, the inorganic particles and organic particles mainly have the function of reducing the gloss of the surface protective layer 2 (mattifying the surface protective layer 2). When the surface protective layer 2 contains inorganic particles or organic particles, these particles are dispersed in the surface protective layer 2. The surface protective layer 2 may be mattified by dispersing particles inside the surface protective layer 2, or by having particles present on the surface portion of the surface protective layer 2. When the surface protective layer 2 is mattified, the entire surface of the surface protective layer 2 may be mattified, or it may be mattified partially with a glossy finish in part. The surface of the surface protective layer 2 may be flat or may have an uneven shape.

[0074] The inorganic particles are not particularly limited as long as they are particles formed from an inorganic compound, and examples thereof include silica particles, calcium carbonate particles, barium sulfate particles, alumina particles, and glass balloon particles. One type of inorganic particle may be used alone, or two or more types may be used in combination. The particle diameter of the inorganic particles is, for example, about 0.5 μm or more, preferably about 1 μm or more, and preferably about 20 μm or less, more preferably about 10 μm or less. Preferred particle diameter ranges for the inorganic particles include about 0.5 to 20 μm, about 0.5 to 10 μm, about 1 to 20 μm, and about 1 to 10 μm. In the present invention, the particle diameter of the inorganic particles is defined as the average particle diameter of 30 random inorganic particles when the cross section of the surface protective layer 2 is observed with a scanning electron microscope (SEM).

[0075] When the surface protective layer 2 contains inorganic particles, the content of the inorganic particles is not particularly limited, but is preferably at least about 1 part by mass, more preferably at least about 10 parts by mass, and preferably not more than about 60 parts by mass, more preferably not more than about 40 parts by mass, per 100 parts by mass of the ionizing radiation curable resin. Preferred ranges for the content of the inorganic particles include about 1 to 60 parts by mass, about 1 to 40 parts by mass, about 10 to 60 parts by mass, and about 10 to 40 parts by mass, per 100 parts by mass of the ionizing radiation curable resin. The inorganic particles may be used alone or in combination of two or more types.

[0076] The organic particles are not particularly limited as long as they are particles formed from a resin, and examples thereof include urethane beads, nylon beads, acrylic beads, silicone beads, styrene beads, melamine beads, urethane acrylic beads, polyester beads, and polyethylene beads. One type of organic particle may be used alone, or two or more types may be used in combination. The particle diameter of the organic particles is approximately 0.5 μm or more, preferably approximately 1 μm or more, and is preferably approximately 30 μm or less, and more preferably approximately 20 μm or less. Preferred particle diameter ranges for the organic particles include approximately 0.5 to 30 μm, approximately 0.5 to 20 μm, approximately 1 to 30 μm, and approximately 1 to 20 μm. The particle diameter of the organic particles is a value measured by the same method as for the inorganic particles described above.

[0077] When the surface protective layer 2 contains organic particles, the content of the organic particles is not particularly limited, but is preferably at least about 1 part by mass, more preferably at least about 10 parts by mass, and is preferably at most about 200 parts by mass, more preferably at most 150 parts by mass, relative to 100 parts by mass of the ionizing radiation curable resin. Preferred ranges for the content of the organic particles include about 1 to 200 parts by mass, about 1 to 150 parts by mass, about 10 to 200 parts by mass, and more preferably about 10 to 150 parts by mass, relative to 100 parts by mass of the ionizing radiation curable resin.

[0078] In addition, when the surface protective layer 2 contains at least one of inorganic particles and organic particles, some of these particles may protrude from the surface of the surface protective layer 2, or the particles may be buried inside the surface protective layer 2.

[0079] (Other added ingredients) Various additives can be blended into the surface protective layer 2 depending on the desired physical properties of the surface protective layer 2. Examples of such additives include weather resistance improvers such as ultraviolet absorbers and light stabilizers, abrasion resistance improvers, polymerization inhibitors, crosslinking agents, infrared absorbers, adhesion improvers, leveling agents, thixotropy-imparting agents, coupling agents, plasticizers, antifoaming agents, fillers, solvents, and colorants. These additives can be appropriately selected from commonly used additives. Furthermore, reactive ultraviolet absorbers and light stabilizers having a polymerizable group such as a (meth)acryloyl group in the molecule can also be used as the ultraviolet absorber and light stabilizer.

[0080] (Formation of surface protective layer 2) The surface protective layer 2 is formed, for example, by preparing an ionizing radiation curable resin composition containing an ionizing radiation curable resin (containing the aforementioned inorganic particles, organic particles, various additives, etc., as necessary), applying the composition, and curing it. The viscosity of the ionizing radiation curable resin composition may be any viscosity that allows the formation of an uncured resin layer by the application method described below.

[0081] In the present disclosure, the prepared resin composition is applied by a known method such as gravure coating, bar coating, roll coating, reverse roll coating, or comma coating, preferably gravure coating, to form an uncured resin layer.

[0082] The uncured resin layer thus formed is irradiated with ionizing radiation such as electron beams or ultraviolet rays to cure the uncured resin layer and form the surface protective layer 2. When electron beams are used as the ionizing radiation, the acceleration voltage can be appropriately selected depending on the resin used and the thickness of the layer, but typically the acceleration voltage is 70 kV or more and 300 kV or less. The preferred range of the acceleration voltage is 70 to 300 kV.

[0083] In electron beam irradiation, the higher the acceleration voltage, the greater the penetration ability, so when a resin that is easily deteriorated by electron beam irradiation is used below the surface protective layer 2, the acceleration voltage is selected so that the penetration depth of the electron beam is substantially equal to the thickness of the surface protective layer 2. This makes it possible to prevent excess electron beam irradiation of layers located below the surface protective layer 2, and minimize deterioration of each layer due to excess electron beams.

[0084] The irradiation dose is preferably an amount at which the crosslinking density of the surface protective layer 2 is saturated, and is usually 5 kGy or more (0.5 Mrad or more), preferably 10 kGy or more (1 Mrad or more), and usually 300 kGy or less (30 Mrad or less), preferably 50 kGy or less (5 Mrad or less). The preferred range of the irradiation dose is selected from the ranges of 5 to 300 kGy (0.5 to 30 Mrad), 5 to 50 kGy (0.5 to 5 Mrad), 10 to 300 kGy (1 to 30 Mrad), and 10 to 50 kGy (1 to 5 Mrad).

[0085] Furthermore, the electron beam source is not particularly limited, and various electron beam accelerators such as Cockcroft-Walton type, Van de Graaf type, resonant transformer type, insulating core transformer type, linear type, dynamitron type, and high frequency type can be used.

[0086] When ultraviolet rays are used as the ionizing radiation, light rays containing ultraviolet rays with a wavelength of 190 to 380 nm may be emitted. The ultraviolet source is not particularly limited, but examples thereof include high-pressure mercury lamps, low-pressure mercury lamps, metal halide lamps, and carbon arc lamps.

[0087] The surface protective layer 2 thus formed may be treated by adding various additives to impart functions such as hard coating, anti-fogging coating, anti-fouling coating, anti-glare coating, anti-reflection coating, ultraviolet shielding coating, and infrared shielding coating.

[0088] The thickness of the surface protective layer 2 is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more, and is preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. Preferred ranges include about 1 to 50 μm, about 1 to 30 μm, about 1 to 20 μm, about 3 to 50 μm, about 3 to 30 μm, about 3 to 20 μm, about 5 to 50 μm, about 5 to 30 μm, and about 5 to 20 μm.

[0089] [Primer layer 4] The primer layer 4 is a layer that is provided as necessary for the purpose of increasing the adhesion between layers, etc. The primer layer 4 is provided, for example, between the substrate layer 1 and the ultraviolet absorbing layer 3. The primer layer 4 is also provided, for example, between the first substrate layer 11 and the second substrate layer 12. The primer layer 4 is used mainly for the purpose of increasing the adhesion between the substrate layer 1 and the ultraviolet absorbing layer 3, and is preferably provided so as to come into contact with the substrate layer 1 or the ultraviolet absorbing layer 3.

[0090] The primer composition constituting the primer layer 4 is not particularly limited, and preferred are those containing a binder resin such as a urethane resin, a (meth)acrylic resin, a (meth)acrylic-urethane copolymer resin, a vinyl chloride-vinyl acetate copolymer, a polyester resin, a butyral resin, chlorinated polypropylene, or chlorinated polyethylene, and these resins can be used alone or in combination. Among these, urethane resins, (meth)acrylic resins, and (meth)acrylic-urethane copolymer resins are preferred.

[0091] The urethane resin may be a urethane resin containing a polyol (polyhydric alcohol) as the base and an isocyanate as the crosslinking agent (curing agent). The polyol may have two or more hydroxyl groups in its molecule, such as polyester polyol, polyethylene glycol, polypropylene glycol, acrylic polyol, or polyether polyol. The isocyanate may be a polyisocyanate having two or more isocyanate groups in its molecule, an aromatic isocyanate such as 4,4-diphenylmethane diisocyanate, or an aliphatic (or alicyclic) isocyanate such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, or hydrogenated diphenylmethane diisocyanate. Alternatively, the urethane resin may be mixed with a butyral resin.

[0092] From the viewpoint of improving the formability of the decorative sheet 10, when forming the primer layer 4, it is preferable to combine an acrylic polyol or a polyester polyol as the polyol with hexamethylene diisocyanate or 4,4-diphenylmethane diisocyanate as the crosslinking agent, and it is particularly preferable to use a combination of an acrylic polyol and hexamethylene diisocyanate.

[0093] Examples of the (meth)acrylic resin include a homopolymer of a (meth)acrylic acid ester, a copolymer of two or more different (meth)acrylic acid ester monomers, or a copolymer of a (meth)acrylic acid ester and another monomer. Specifically, (meth)acrylic resins made of a homopolymer or copolymer containing a (meth)acrylic acid ester, such as polymethyl(meth)acrylate, polyethyl(meth)acrylate, polypropyl(meth)acrylate, polybutyl(meth)acrylate, a methyl(meth)acrylate-butyl(meth)acrylate copolymer, an ethyl(meth)acrylate-butyl(meth)acrylate copolymer, an ethylene-methyl(meth)acrylate copolymer, or a styrene-methyl(meth)acrylate copolymer, are preferably used.

[0094] As the (meth)acrylic-urethane copolymer, for example, an acrylic-urethane (polyester urethane) block copolymer is preferred. As the curing agent, the various isocyanates mentioned above are used. If desired, the acrylic-urethane (polyester urethane) block copolymer preferably has an acrylic / urethane ratio (mass ratio) of 1 / 9 or more, more preferably 2 / 8 or more. Furthermore, the acrylic / urethane ratio (mass ratio) is preferably 9 / 1 or less, more preferably 8 / 2 or less.

[0095] The thickness of the primer layer 4 is not particularly limited, but is, for example, 0.5 μm or more, preferably 1 μm or more, and is preferably 20 μm or less, more preferably 5 μm or less. Preferred ranges include about 0.5 to 20 μm, and about 1 to 5 μm.

[0096] The primer layer 4 is formed using a primer composition by a common coating method such as gravure coating, gravure reverse coating, gravure offset coating, spinner coating, roll coating, reverse roll coating, kiss coating, wheel coating, dip coating, solid coating by silk screen, wire bar coating, flow coating, comma coating, flow coating, brush coating, spray coating, or transfer coating. Here, the transfer coating method is a method in which a coating film of the primer layer 4 is formed on a thin sheet (film substrate), and then the surface of the target layer in the decorative sheet is coated with the primer layer 4.

[0097] [Adhesive layer 5] The adhesive layer 5 is a layer that is provided as needed for the purpose of increasing the adhesion between layers.

[0098] The adhesive layer 5 is provided, for example, between the first base material layer 11 and the second base material layer 12. Although not shown, in the decorative sheet 10, the adhesive layer 5 can also be a layer that forms the surface of the base material layer 1 opposite to the surface protection layer 2 side. This can improve the adhesion between the decorative sheet 10 and the molded resin layer 6.

[0099] The adhesive layer 5 is formed using, for example, a resin composition.

[0100] Examples of the resin composition include rubber-based resins, acrylic resins, epoxy resins, urethane resins, polyolefins, etc. Among these, urethane resins and polyolefin resins are preferably used. By using urethane resins and polyolefin resins, stronger adhesive strength can be obtained, and a decorative sheet with excellent flexibility can be provided.

[0101] The urethane resin is a urethane resin that uses polyol (polyhydric alcohol) as the main component and isocyanate as the crosslinking agent (curing agent).

[0102] The polyol has two or more hydroxyl groups in the molecule, and examples of the polyol include polyethylene glycol, polypropylene glycol, butylene glycol, neopentyl glycol, 1,6-hexanediol, acrylic polyol, polyester polyol, and polyether polyol.

[0103] The isocyanate used in the present invention is one that is commonly used in the production of urethane resins. Examples of the isocyanate include aliphatic polyisocyanates such as trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, lysine ester triisocyanate, 1,4,8-triisocyanato octane, 1,3,6-triisocyanato hexane, and 2,5,7-trimethyl-1,8-diisocyanato-5-isocyanato methyl octane; 1,3-cyclopentene diisocyanate; Alicyclic compounds such as isocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (common name: isophorone diisocyanate), 1,3,5-triisocyanatocyclohexane, 1,3,5-trimethylisocyanatocyclohexane, and 2-(3-isocyanatopropyl)-2,5-di(isocyanatomethyl)-bicyclo(2,2,1)heptane Examples of polyisocyanates that can be used include aralkyl polyisocyanates such as polyisocyanates, 1,3- or 1,4-xylylene diisocyanate or mixtures thereof, 1,3- or 1,4-bis(1-isocyanato-1-methylethyl)benzene and 1,3,5-triisocyanatomethylbenzene, and aromatic polyisocyanates such as m-phenylene diisocyanate, p-phenylene diisocyanate, triphenylmethane-4,4',4"-triisocyanate and 4,4'-diphenylmethane-2,2',5,5'-tetraisocyanate, as well as derivatives of these polyisocyanates. Two or more of these polyisocyanates may be used in combination. Of these polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, aralkyl polyisocyanates, and polyisocyanate derivatives thereof are preferably used. These polyisocyanates are excellent in safety, hygiene, and weather resistance.

[0104] Preferred examples of polyolefin resins include polyolefins and modified polyolefins such as acid-modified polyolefins, chlorinated polyolefins, and acrylic-modified polyolefins. For example, acid-modified polyolefins are polymers modified by block polymerization or graft polymerization of polyolefins with an acid component. Chlorinated polyolefins are olefin resins in which some of the hydrogen atoms are replaced with chlorine atoms. Acrylic-modified polyolefins are polymers modified by block polymerization or graft polymerization of an acrylic resin and an olefin resin. The modified polyolefin is preferably a thermoplastic elastomer (styrene-butadiene-styrene (SBS resin) or styrene-isoprene-styrene (SIS resin)) using polystyrene in the hard segment and any polyolefin in the soft segment, or a hydrogenated thermoplastic elastomer resin such as styrene-ethylene-butylene-styrene (SEBS resin) or styrene-ethylene-propylene-styrene (SEPS resin) obtained by hydrogenating these resins. These resins may be further acid-modified or chlorinated. The polyolefin resin contained in the adhesive layer 5 may be one type or two or more types.

[0105] Specific examples of polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylenes such as homopolypropylene, polypropylene block copolymers (e.g., propylene and ethylene block copolymers), and polypropylene random copolymers (e.g., propylene and ethylene random copolymers); propylene-α-olefin copolymers; and ethylene-butene-propylene terpolymers. Among these, polypropylene is preferred. When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer.

[0106] Modified polyolefins include copolymers of these polyolefins with polar molecules such as acrylic acid and methacrylic acid. Acid-modified polyolefins include acid-modified polypropylene. Chlorinated polyolefins include chlorinated polypropylene. Acrylic-modified polyolefins include acrylic-modified polypropylene.

[0107] Examples of the acid component used for the acid modification include carboxylic acids or anhydrides such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride.

[0108] The thickness of adhesive layer 5 is not particularly limited, but is, for example, 0.5 μm or more, preferably 1 μm or more, and preferably 20 μm or less, more preferably 10 μm or less. Preferred ranges include about 0.5 to 20 μm, and about 1 to 10 μm.

[0109] 2.Resin molded products The resin molded product of the present disclosure is formed by integrating a molded resin layer 6 with the decorative sheet 10 of the present disclosure.

[0110] 5, the resin molded article 20 of the present disclosure is a resin molded article obtained by laminating the decorative sheet 10 of the present disclosure on a molded resin layer 6. That is, the resin molded article 20 of the present disclosure is a resin molded article in which at least a molded resin layer 6, a base layer 1, an ultraviolet absorbing layer 3, and a surface protective layer 2 are laminated in this order, and the base layer 1 contains polyolefin and is characterized in that the light transmittance at a wavelength of 330 nm measured for the entire layer located closer to the surface protective layer 2 than the base layer 1 is 20% or less.

[0111] Fig. 5 shows a cross-sectional structure of one embodiment of the resin molded product of the present disclosure. Fig. 5 is a schematic cross-sectional view of a resin molded product 20 in which the decorative sheet 10 having the layered structure shown in Fig. 4 and the molded resin layer 6 are integrated together.

[0112] The resin molded article of the present disclosure is produced, for example, by various injection molding methods, such as insert molding, simultaneous injection molding and decoration, blow molding, and gas injection molding, using the decorative sheet of the present disclosure. Among these injection molding methods, insert molding and simultaneous injection molding and decoration are preferred. The resin molded article of the present disclosure can also be produced by a decorating method, such as vacuum pressure bonding, in which the decorative sheet of the present disclosure is attached to a three-dimensional resin molded body (molded resin layer) prepared in advance.

[0113] In the insert molding method, first, in the vacuum forming step, the decorative sheet of the present disclosure is vacuum-formed in advance into the surface shape of the molded article (offline preforming) using a vacuum forming mold, and then excess portions are trimmed as necessary to obtain a molded sheet. This molded sheet is inserted into an injection mold, the injection mold is closed, and a fluid resin is injected into the mold and solidified. The decorative sheet is integrated with the outer surface of the resin molded article at the same time as injection molding, thereby producing a resin molded article.

[0114] More specifically, the resin molded article of the present disclosure is produced by an insert molding method including the following steps. a vacuum forming step of forming the decorative sheet of the present disclosure into a three-dimensional shape in advance using a vacuum forming mold; A trimming step of trimming excess portions of the vacuum-formed decorative sheet to obtain a molded sheet; An integration process in which the molded sheet is inserted into an injection mold, the mold is closed, and fluid resin is injected into the mold to integrate the resin and the molded sheet.

[0115] In the vacuum forming step of the insert molding method, the decorative sheet may be heated and formed. The heating temperature is not particularly limited and may be selected appropriately depending on the type of resin constituting the decorative sheet, the thickness of the decorative sheet, etc. In the present disclosure, since the base layer 1 is made of polyolefin, the heating temperature is usually about 100 to 180°C, preferably about 120 to 160°C. Furthermore, in the integration step, the temperature of the resin in a fluid state is not particularly limited, but may usually be about 160 to 240°C, preferably about 180 to 220°C.

[0116] In addition, in the simultaneous injection molding decoration method, the decorative sheet of the present disclosure is placed in a female mold that can also be used as a vacuum forming mold and is provided with suction holes for injection molding, and after preforming (in-line preforming) is performed using this female mold, the injection molding mold is closed, and a fluid resin is injected into the mold, filled, and solidified, and the decorative sheet of the present disclosure is integrated with the outer surface of the resin molded product at the same time as injection molding, thereby producing a resin molded product.

[0117] More specifically, the resin molded article of the present disclosure is produced by an injection molding and simultaneous decoration method including the following steps. a preforming step of placing the decorative sheet of the present disclosure on a molding surface of a movable mold having a predetermined shape, with the surface of the decorative sheet opposite to the surface protective layer 2 facing the molding surface, and then heating and softening the decorative sheet while vacuum-suctioning the decorative sheet from the movable mold side to bring the softened decorative sheet into close contact with the molding surface of the movable mold, thereby preforming the decorative sheet; an integration process in which a movable mold and a fixed mold having a decorative sheet in close contact along the molding surface are clamped together, and then a resin in a fluid state is injected into a cavity formed by both molds, filled, and solidified to form a molded resin layer, thereby laminating and integrating the molded resin layer and the decorative sheet; A removal process in which the movable mold is separated from the fixed mold to remove the resin molded product on which all layers of the decorative sheet are laminated.

[0118] In the preforming step of the simultaneous injection molding and decoration method, the heating temperature of the decorative sheet is not particularly limited and may be selected appropriately depending on the type of resin constituting the decorative sheet, the thickness of the decorative sheet, etc., but is usually about 70 to 160° C. Furthermore, in the injection molding step, the temperature of the resin in a fluid state is not particularly limited, but is usually about 160 to 240° C., preferably about 180 to 220° C.

[0119] In the vacuum bonding method, the decorative sheet of the present disclosure and the resin molded body (molded resin layer) are first placed in a vacuum bonding machine consisting of an upper first vacuum chamber and a lower second vacuum chamber, with the decorative sheet facing the first vacuum chamber and the resin molded body facing the second vacuum chamber, with the side of the decorative sheet opposite the surface protective layer 2 facing the resin molded body. The two vacuum chambers are then evacuated. The resin molded body is placed on a vertically movable platform provided on the second vacuum chamber side. Next, the first vacuum chamber is pressurized, and the platform is used to press the molded body against the decorative sheet. The decorative sheet is stretched and attached to the surface of the resin molded body using the pressure difference between the two vacuum chambers. Finally, the two vacuum chambers are opened to atmospheric pressure, and excess portions of the decorative sheet are trimmed as necessary to obtain the resin molded product of the present disclosure.

[0120] In the vacuum pressure bonding method, it is preferable to include a step of heating the decorative sheet before the step of pressing the resin molded body against the decorative sheet in order to soften the decorative sheet and improve its formability. Vacuum pressure bonding methods that include this step are sometimes called vacuum thermocompression bonding methods. The heating temperature in this step can be selected appropriately depending on the type of resin that makes up the decorative sheet, the thickness of the decorative sheet, etc., but can usually be about 60 to 180°C.

[0121] In the resin molded article of the present disclosure, the molded resin layer may be formed by selecting a resin according to the intended use. The resin forming the molded resin layer may be a thermoplastic resin or a thermosetting resin.

[0122] Examples of thermoplastic resins include polyolefins such as polyethylene and polypropylene, ABS resins, styrene resins, polycarbonates, acrylic resins, and polyvinyl chloride. These thermoplastic resins may be used alone or in combination of two or more. In the present disclosure, since the base layer of the decorative sheet 10 contains polyolefins, polyolefins such as polyethylene and polypropylene are particularly preferred.

[0123] Examples of the thermosetting resin include urethane resin, epoxy resin, etc. These thermosetting resins may be used alone or in combination of two or more.

[0124] The resin molded product of the present disclosure can be used, for example, as interior or exterior materials for vehicles such as automobiles; fittings such as window frames and door frames; interior materials for buildings such as walls, floors, and ceilings; housings for home appliances such as television sets and air conditioners; containers, etc. [Example]

[0125] The present disclosure will be described in detail below with reference to examples and comparative examples, but the present disclosure is not limited to the examples.

[0126] <Manufacturing decorative sheets> (Examples 1 to 3, 6 to 7 and Comparative Example 1) A primer layer (1.5 μm thick) was formed by gravure printing on one side of a random polypropylene film (random PP, thickness 400 μm) serving as a base layer using a resin composition for forming a primer layer. The resins contained in the resin composition for forming the primer layer were urethane resin and acrylic resin (acrylic polyol), and the ratio of urethane resin to acrylic resin (urethane resin:acrylic resin) was 40:60. In addition, 10 parts by mass of hexamethylene diisocyanate was added to the resin composition per 100 parts by mass of the resin.

[0127] Next, in Examples 1 to 3 and 7, a second ultraviolet absorbing layer (corresponding to a design layer (thickness 5 μm)) expressing the design shown in Table 1 was formed on the primer layer by gravure printing using an ink composition containing 20 parts by mass of pigment and 80 parts by mass of binder resin (50% by mass of acrylic resin, 50% by mass of vinyl chloride-vinyl acetate copolymer resin). Next, a first ultraviolet absorbing layer (thickness 2 μm) was formed on the second ultraviolet absorbing layer by gravure printing using the resin composition for forming the first ultraviolet absorbing layer shown in Table 1.

[0128] On the other hand, in Example 6 and Comparative Example 1, a second ultraviolet absorbing layer was not laminated on the primer layer, and a first ultraviolet absorbing layer (thickness 2 μm) was formed by gravure printing using the resin composition for forming the first ultraviolet absorbing layer listed in Table 1.

[0129] Resin composition A for forming the first ultraviolet-absorbing layer used in Examples 1 to 3 and 6 is a resin composition obtained by mixing 3 parts by mass of an ultraviolet absorber (triazine-based ultraviolet absorber) and 100 parts by mass of a binder resin (a mixture of an acrylic polyol resin and a vinyl chloride-vinyl acetate copolymer resin). Resin composition B for forming the first ultraviolet-absorbing layer used in Example 7 and Comparative Example 1 is a resin composition obtained by removing the ultraviolet absorber from resin composition A.

[0130] Next, a surface protective layer was formed on the first ultraviolet absorbing layer. For the surface protective layer, an electron beam curable resin composition (a mixture of 80 parts by mass of bifunctional polycarbonate acrylate (weight average molecular weight: 10,000) and 20 parts by mass of hexafunctional urethane acrylate oligomer (weight average molecular weight: 6,000)) was applied to form an uncured resin layer with a thickness of 10 μm after curing. This uncured resin layer was then irradiated with an electron beam at an acceleration voltage of 165 kV and an exposure dose of 50 kGy (5 Mrad) to cure the electron beam curable resin composition, forming the surface protective layer. Gravure printing was used to laminate the protective layer. Using the above procedure, a decorative sheet was produced in which the substrate layer, primer layer, ultraviolet absorbing layer (second ultraviolet absorbing layer, first ultraviolet absorbing layer), and surface protective layer were laminated in this order.

[0131] Example 4 A primer layer (1.5 μm thick) was formed by gravure printing on one side of a homopolypropylene film (homoPP, 100 μm thick) serving as a first base layer using a resin composition for forming a primer layer. The resins contained in the resin composition for forming the primer layer were urethane resin and acrylic resin (acrylic polyol), and the ratio of urethane resin to acrylic resin (urethane resin:acrylic resin) was 40:60. Furthermore, 10 parts by mass of hexamethylene diisocyanate was added to the resin composition per 100 parts by mass of the resin.

[0132] Next, a second UV-absorbing layer (corresponding to a design layer (thickness: 5 μm)) representing the design shown in Table 1 was formed on the primer layer by gravure printing using an ink composition containing 20 parts by mass of pigment and 80 parts by mass of binder resin (50% by mass of acrylic resin and 50% by mass of vinyl chloride-vinyl acetate copolymer resin). Next, a first UV-absorbing layer (thickness: 2 μm) was formed on the second UV-absorbing layer by gravure printing using a resin composition for forming the first UV-absorbing layer. Resin composition A for forming the first UV-absorbing layer used in Example 4 was a resin composition obtained by mixing 3 parts by mass of a UV absorber (triazine-based UV absorber) and 100 parts by mass of a binder resin (a mixture of an acrylic polyol resin and a vinyl chloride-vinyl acetate copolymer resin).

[0133] Next, a surface protective layer was formed on the first ultraviolet absorbing layer. For the surface protective layer, an electron beam curable resin composition (a mixture of 80 parts by mass of bifunctional polycarbonate acrylate (weight average molecular weight: 10,000) and 20 parts by mass of hexafunctional urethane acrylate oligomer (weight average molecular weight: 6,000)) was applied to form an uncured resin layer with a thickness of 10 μm after curing. The uncured resin layer was then irradiated with an electron beam at an acceleration voltage of 165 kV and an exposure dose of 50 kGy (5 Mrad) to cure the electron beam curable resin composition, forming a surface protective layer. Gravure printing was used to laminate the protective layer.

[0134] Next, an adhesive layer (urethane resin, thickness 10 μm) and a random polypropylene film (random PP, thickness 300 μm) as a second substrate layer were laminated on the other side of the first substrate layer. Gravure printing was used to laminate the primer layer, design layer, and adhesive layer. The second substrate layer was laminated to the adhesive layer surface of the first substrate layer. Using the above procedure, a decorative sheet was produced in which the second substrate layer, adhesive layer, first substrate layer, primer layer, ultraviolet absorbing layer (second ultraviolet absorbing layer, first ultraviolet absorbing layer), and surface protective layer were laminated in this order.

[0135] Example 5 A surface protective layer was formed on one side of a polyester film (polyethylene terephthalate, 50 μm thick) used as a transfer substrate. For the surface protective layer, an electron beam curable resin composition (a mixture of 80 parts by mass of bifunctional polycarbonate acrylate (weight average molecular weight: 10,000) and 20 parts by mass of hexafunctional urethane acrylate oligomer (weight average molecular weight: 6,000)) was applied to form an uncured resin layer with a thickness of 10 μm after curing. This uncured resin layer was then irradiated with an electron beam at an acceleration voltage of 165 kV and an exposure dose of 50 kGy (5 Mrad) to cure the electron beam curable resin composition, forming a surface protective layer. Gravure printing was used to laminate the protective layer.

[0136] Next, a first ultraviolet absorbing layer (thickness 2 μm) was formed on the surface protective layer by gravure printing using a resin composition for forming the first ultraviolet absorbing layer shown in Table 1. Next, a second ultraviolet absorbing layer (corresponding to a design layer (thickness 5 μm)) expressing the design shown in Table 1 was formed on the first ultraviolet absorbing layer by gravure printing using an ink composition containing 20 parts by mass of pigment and 80 parts by mass of binder resin (50% by mass of acrylic resin, 50% by mass of vinyl chloride-vinyl acetate copolymer resin).

[0137] Next, a primer layer (1.5 μm thick) was formed on the second UV-absorbing layer by gravure printing using a resin composition for forming a primer layer. The resins contained in the resin composition for forming the primer layer were urethane resin and acrylic resin (acrylic polyol), and the ratio of urethane resin to acrylic resin (urethane resin:acrylic resin) was 40:60. In addition, 10 parts by mass of hexamethylene diisocyanate was added to the resin composition per 100 parts by mass of the resin.

[0138] Next, an adhesive layer (1.5 μm thick) was formed on the primer layer by gravure printing using a resin composition for forming the adhesive layer. The resin contained in the resin composition for forming the adhesive layer was acid-modified polypropylene (hydrogenated thermoplastic elastomer (SEBS)). By the above procedure, a transfer sheet was produced in which the transfer substrate, surface protective layer, ultraviolet absorbing layer (first ultraviolet absorbing layer, second ultraviolet absorbing layer), primer layer, and adhesive layer were laminated in this order.

[0139] Next, the adhesive layer side of the transfer sheet was brought into contact with a random polypropylene film (random PP, thickness 400 μm) as a base layer, and then heat-press processing was carried out using a heat press machine to thermally transfer the image. The heat-press processing conditions were 120°C, 5 kgf / cm² pressure, and 10 minutes. After the heat press processing, the transfer substrate was peeled off to produce a decorative sheet in which the substrate layer, adhesive layer, primer layer, ultraviolet absorbing layer (second ultraviolet absorbing layer, first ultraviolet absorbing layer), and surface protective layer were laminated in this order.

[0140] <Light transmittance at a wavelength of 330 nm> The light transmittance of each of the resulting decorative sheets at a wavelength of 330 nm was measured using the following method. The results are shown in Table 1. The light transmittance was determined by measuring the spectral transmittance in the wavelength range of 300 nm to 800 nm using an ultraviolet-visible spectrophotometer (UH4150, light source D65, manufactured by Hitachi High-Tech Corporation), and the value at a wavelength of 330 nm in the spectral transmittance spectrum was recorded. The specific measurement methods in the examples and comparative examples are as follows.

[0141] (Examples 1 to 3, 6 to 7 and Comparative Example 1) Instead of random polypropylene as the base layer, a transparent polypropylene film (transparent PP, thickness 50 μm) was used to prepare a light transmittance measurement sheet (transparent polypropylene film / primer layer / ultraviolet absorbing layer (second ultraviolet absorbing layer / first ultraviolet absorbing layer) / surface protective layer). The spectral transmittance of this light transmittance measurement sheet and the spectral transmittance of the transparent PP were measured, and the light transmittance of the entire layer located closer to the surface protective layer than the base layer was calculated using the following formula: Light transmittance (%) at 330 nm of the entire layer located closer to the surface protective layer than the base layer = Light transmittance (%) at 330 nm of the light transmittance measurement sheet ÷ Light transmittance (%) of the transparent PP at 330 nm × 100

[0142] Example 4 Instead of random polypropylene as the first base layer, a transparent polypropylene film (transparent PP, thickness 50 μm) was used to prepare a light transmittance measurement sheet (transparent polypropylene film / primer layer / ultraviolet absorbing layer (second ultraviolet absorbing layer / first ultraviolet absorbing layer) / surface protective layer). Since a second base layer equivalent is not required for transmittance measurement, the measurement was performed without providing anything to replace the second base layer. As a result, in Example 4, a light transmittance measurement sheet having the same configuration as in Example 2 was measured.

[0143] Example 5 After measuring the spectral transmittance of the transfer sheet, the transfer layers (surface protective layer, ultraviolet absorbing layer (first ultraviolet absorbing layer, second ultraviolet absorbing layer), primer layer, and adhesive layer) were removed from the transfer sheet, and the spectral transmittance of only the transfer substrate was measured. The spectral transmittance of the transfer layer (i.e., the entire layer located on the surface protective layer side of the substrate layer) was calculated by the following formula: Light transmittance (%) at 330 nm of the entire layer located on the surface protective layer side of the substrate layer = Light transmittance (%) of the transfer sheet at 330 nm ÷ Light transmittance (%) of the transfer substrate at 330 nm × 100

[0144] [Manufacturing resin molded products using insert molding] Each of the resulting decorative sheets was heated with an infrared heater until the temperature of the sheet reached 140°C. After heating and softening, it was vacuum molded. The decorative sheet was released from the mold, and a die-cutting mold was hydraulically pressed against the unnecessary parts to trim them. This trimmed decorative sheet was inserted into an injection mold, which was then clamped and injection resin was injected into the cavity of the injection mold, molding the decorative sheet and the injection resin together to obtain a resin molded product in which the decorative sheet was integrated with the molded resin layer. Polypropylene resin was used as the injection resin for molding at a molding resin temperature of 200°C.

[0145] <Weather resistance evaluation> The color difference ΔE before and after the weather resistance test was measured for the resin molded article obtained above in accordance with JIS Z8722 (2009). The weather resistance test was carried out using an Atlas xenon weatherometer Ci-4000 under the following conditions: 2 The test was carried out until Furthermore, an adhesion test (adhesion test) was also conducted using the cross-cut method in accordance with JIS K5600-5-6 (1999), and the weather resistance was evaluated from the results of both tests. The results are shown in Table 1.

[0146] (Weather resistance test conditions) Step 1: 3.8 hours Irradiance: 60W / m 2 Black panel temperature: 89℃ Humidity: 50%RH Step 2: 1 hour Irradiance: 60W / m 2 Black panel temperature: 38℃ Humidity: 95%RH

[0147] (Weather resistance evaluation criteria) A+: The color difference ΔE before and after the weather resistance test was less than 2, and no peeling occurred in the adhesion test. A: The color difference ΔE before and after the weather resistance test was 2 or more and less than 3, and there was no peeling in the adhesion test. B: The color difference ΔE before and after the weather resistance test was 3 or more, and there was no peeling in the adhesion test. C: The color difference ΔE before and after the weather resistance test was 3 or more, and peeling occurred in the adhesion test.

[0148] [Table 1] [Explanation of symbols]

[0149] 1 Base material layer 2 Surface protective layer 3. UV absorption layer 31 First ultraviolet absorbing layer 32 Second ultraviolet absorbing layer 4 Primer layer 5 Adhesive layer 6 Molding resin layer 10 Decorative sheet 20 Resin molded products

Claims

1. A decorative sheet having at least a base layer, an ultraviolet absorbing layer, and a surface protective layer laminated in this order, The thickness of the base layer is 200 μm or more and 1000 μm or less, the substrate layer comprises a polyolefin; the light transmittance at a wavelength of 330 nm measured for the entire layer of the decorative sheet located closer to the surface protective layer than the base layer is 20% or less; A decorative sheet for use by forming it into a three-dimensional shape.

2. The decorative sheet according to claim 1 , which is used in an application in which it is laminated with a molding resin containing polyolefin.

3. The decorative sheet according to claim 1 , wherein the ultraviolet absorbing layer contains at least one of an ultraviolet absorbing agent and a coloring material.

4. The decorative sheet according to claim 1 or 2, wherein the ultraviolet absorbing layer comprises a first ultraviolet absorbing layer containing an ultraviolet absorber and a second ultraviolet absorbing layer containing a coloring material.

5. The decorative sheet according to claim 4 , wherein the first ultraviolet absorbing layer is located closer to the surface protective layer than the second ultraviolet absorbing layer.

6. The decorative sheet according to claim 1 or 2, further comprising a primer layer between the base layer and the ultraviolet absorbing layer.

7. The decorative sheet according to claim 1 , wherein the substrate layer includes a first substrate layer and a second substrate layer.

8. The decorative sheet according to claim 7 , further comprising an adhesive layer between the first base material layer and the second base material layer.

9. A resin molded product having at least a molded resin layer, a base layer, an ultraviolet absorbing layer, and a surface protective layer laminated in this order, The thickness of the base layer is 200 μm or more and 1000 μm or less, the substrate layer comprises a polyolefin; a light transmittance at a wavelength of 330 nm measured for the entire layer located on the surface protective layer side of the base material layer of the resin molded article is 20% or less; A resin molded product formed into a three-dimensional shape.

10. The resin molded product according to claim 9 , wherein the molded resin layer contains a polyolefin.

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