Decorative sheet and resin molded article

Abstract

To provide a decorative sheet which has a metal thin-film layer and is excellent in damp heat resistance, heat resistance and weather resistance.SOLUTION: A decorative sheet comprises at least a primer layer and a metal thin-film layer adjacent to the primer layer. The primer layer is formed of a cured product of a resin composition containing a resin and an alkoxysilane having an alkyl or aryl group. The alkoxysilane having an alkyl or aryl group has no substituent group reactive with the resin contained in the resin composition.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Conventionally, resin molded products in which a decorative sheet is laminated onto the surface of a resin molded product have been used for vehicle interior and exterior parts, building materials, housings for home appliances, etc. In manufacturing such resin molded products, molding methods have been used in which a decorative sheet, which has been previously given a design, is integrated with the resin by injection molding. Representative examples of molding methods for resin molded products include an insert molding method (see, for example, Patent Document 1) in which a decorative sheet is previously molded into a three-dimensional shape using a vacuum forming mold, and the molded sheet is inserted into an injection mold and a fluid resin is injected into the mold to integrate the resin and the molded sheet, and an injection-molding simultaneous decoration method (see, for example, Patent Documents 2 and 3) in which a decorative sheet inserted into a mold during injection molding is integrated with the molten resin injected into the cavity to decorate the surface of a resin molded product.

[0003] The decorative sheets used in these techniques can be broadly divided into laminate-type decorative sheets and transfer-type decorative sheets.

[0004] Laminate-type decorative sheets are laminated on a supporting substrate with a protective layer positioned on the outermost surface, and are used so that the supporting substrate is incorporated into the resin molded product by laminating a molding resin on the supporting substrate side. On the other hand, transfer-type decorative sheets are laminated on a supporting substrate with a protective layer either directly or via an optional release layer, and after laminating a molding resin on the side opposite the supporting substrate, the supporting substrate is peeled off so that no supporting substrate remains in the resin molded product. These two types of decorative sheets are used depending on the shape and desired function of the resin molded product. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-322501 [Patent Document 2] Special Publication No. 50-19132 [Patent Document 3] Special Publication No. 61-17255 Summary of the Invention [Problem to be solved by the invention]

[0006] A technique for imparting a metallic design to a resin molded product is known in which a decorative sheet having a thin metal layer is disposed on the surface of the product.

[0007] Decorative sheets having a metal thin film layer are prone to discoloration of the metal thin film layer in a humid and hot environment, resulting in a loss of design quality, and therefore, decorative sheets having a metal thin film layer are required to have excellent resistance to humidity and heat.

[0008] Furthermore, when a decorative sheet having a metal thin film layer is intended for use in the interior of an automobile or the like, not only is it required to have resistance to moist heat, but it also needs to have resistance to heat in higher temperature environments and weather resistance in high light energy irradiation environments.

[0009] A primary object of the present disclosure is to provide a decorative sheet having a metal thin film layer, which has excellent moist heat resistance, heat resistance, and weather resistance. A further object of the present disclosure is to provide a resin molded product using the decorative sheet. [Means for solving the problem]

[0010] The inventors of the present disclosure conducted extensive research to solve the above-mentioned problems. As a result, they found that a decorative sheet comprising at least a primer layer and a metal thin film layer adjacent to the primer layer, the primer layer being formed from a cured product of a resin composition containing a resin and an alkoxysilane having an alkyl group or an aryl group, and the alkoxysilane having an alkyl group or an aryl group does not have a substituent that is reactive with the resin in the resin composition, has excellent moist heat resistance, heat resistance, and weather resistance. The present disclosure was completed based on this finding and through further research.

[0011] That is, the present disclosure provides the inventions of the following aspects. Item 1. A substrate comprising at least a primer layer and a metal thin film layer adjacent to the primer layer, the primer layer is formed from a cured product of a resin composition containing a resin and an alkoxysilane having an alkyl group or an aryl group, The decorative sheet, wherein the alkoxysilane having an alkyl group or an aryl group does not have a substituent reactive with the resin in the resin composition. Item 2. The decorative sheet according to Item 1, wherein the metal thin film layer contains tin. Item 3. The decorative sheet according to Item 1 or 2, wherein the content of the alkoxysilane having an alkyl group or an aryl group in the resin composition of the primer layer is 0.4% by mass or more and 17% by mass or less. Item 4. The decorative sheet according to any one of Items 1 to 3, wherein the alkyl group of the alkoxysilane having an alkyl group or an aryl group has 1 or more and 8 or less carbon atoms. Item 5. The decorative sheet according to any one of Items 1 to 4, wherein the alkoxysilane having an alkyl group or an aryl group has 5 or more and 10 or less carbon atoms in the aryl group. Item 6. The decorative sheet according to any one of Items 1 to 5, wherein the resin in the resin composition of the primer layer contains a polyol. Item 7. The decorative sheet according to any one of Items 1 to 6, wherein the resin composition of the primer layer further contains a curing agent. Item 8. The decorative sheet according to any one of Items 1 to 7, comprising at least a protective layer, the primer layer, the metal thin film layer adjacent to the primer layer, and a substrate, in this order. Item 9. The decorative sheet according to any one of Items 1 to 8, comprising at least a substrate, a protective layer, the primer layer, and a metal thin film layer adjacent to the primer layer, in this order. Item 10. A laminated ... the primer layer is formed from a cured product of a resin composition containing a resin and an alkoxysilane having an alkyl group or an aryl group, A resin molded article, wherein the alkoxysilane having an alkyl group or an aryl group does not have a substituent reactive with the resin in the resin composition. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to provide a decorative sheet having a metal thin film layer and having excellent moist heat resistance, heat resistance, and weather resistance. Also, according to the present disclosure, it is possible to provide a method for manufacturing a resin molded product using the decorative sheet. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram of a cross-sectional structure of an example of a decorative sheet according to the present disclosure. [Figure 2] 1 is a schematic cross-sectional view of an example (first embodiment) of a decorative sheet of the present disclosure. [Figure 3] 1 is a schematic cross-sectional view of an example (first embodiment) of a decorative sheet of the present disclosure. [Figure 4] FIG. 4 is a schematic cross-sectional view of a resin molded product obtained by using the decorative sheet shown in FIG. [Figure 5] FIG. 2 is a schematic cross-sectional view of an example (second embodiment) of the decorative sheet of the present disclosure. [Figure 6] FIG. 2 is a schematic cross-sectional view of an example (second embodiment) of the decorative sheet of the present disclosure. [Figure 7]FIG. 7 is a schematic cross-sectional view of a resin molded product with a transfer substrate obtained by using the decorative sheet shown in FIG. [Figure 8] FIG. 8 is a schematic cross-sectional view of a resin molded article obtained by peeling off the transfer substrate from the resin molded article with transfer substrate shown in FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0014] 1.Decorative sheet The decorative sheet of the present disclosure includes at least a primer layer and a metal thin film layer adjacent to the primer layer, the primer layer being formed from a cured product of a resin composition containing a resin and an alkoxysilane having an alkyl or aryl group, and the alkoxysilane having an alkyl or aryl group does not have a substituent that is reactive with the resin in the resin composition. Due to this configuration, the decorative sheet of the present disclosure exhibits excellent moist heat resistance, heat resistance, and weather resistance despite having a metal thin film layer. The decorative sheet of the present disclosure will be described in detail below.

[0015] 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.

[0016] In addition, in this specification, "(meth)acrylate" means "acrylate or methacrylate," and other similar terms have the same meaning.

[0017] Decorative sheet laminate structure As shown in FIGS. 1 to 3 and 5 and 6, the decorative sheet of the present disclosure includes at least a primer layer and a metal thin film layer adjacent to the primer layer. The decorative sheet of the present disclosure may include a substrate 5, if necessary, for purposes such as improving the shape retention of the decorative sheet. As will be described later, when a resin molded product is produced using the decorative sheet of the present disclosure, a first embodiment of the decorative sheet (laminate-type decorative sheet) can be used in which the substrate 5 (hereinafter sometimes referred to as lamination substrate 5a) of the decorative sheet is included in the resin molded product, as shown in FIGS. 2 and 3; or a second embodiment of the decorative sheet (transfer-type decorative sheet) can be used in which the substrate 5 of the decorative sheet is used for transfer, and after transfer, the substrate 5 (hereinafter sometimes referred to as transfer substrate 5b) is peeled off and is not included in the resin molded product, as shown in FIGS. 5 and 6.

[0018] Furthermore, as shown in Figures 1 to 3 and Figures 5 and 6, the decorative sheet of the present disclosure may be provided with a protective layer 3, a second primer layer 22, a third primer layer 23, a decorative layer 4, an adhesive layer 6, a transparent substrate layer (not shown), etc., as needed.

[0019] The protective layer 3 is a layer that is provided as needed for the purpose of improving the scratch resistance, stain resistance, and weather resistance of the decorative sheet.

[0020] The second primer layer 22 is a layer that is provided as needed on the metal thin film layer 1 on the side opposite to the primer layer 2, and is provided adjacent to the metal thin film layer 1. The second primer layer 22 is provided to improve adhesion to a layer located on the metal thin film layer 1 on the side opposite to the primer layer 2.

[0021] The third primer layer 23 is a layer that is provided, if necessary, between the protective layer 3 and the metal thin film layer 1 in order to improve adhesion between the protective layer 3 and the layer located thereunder. It is preferable that the protective layer 3 and the third primer layer 23 are adjacent to each other.

[0022] The decorative layer 4 is a layer that is provided on the side of the primer layer 2 opposite the metal thin film layer 1 as needed to impart decorativeness to the resin molded product. The decorative layer 4 is composed of at least one layer selected from the group consisting of a pattern layer, a color clear layer, and a clear layer. Here, the pattern layer is a layer that has the function of expressing a patterned design such as a design or letter. The pattern expressed by the pattern layer is not particularly limited, but examples include patterns consisting of wood grain, stone grain, cloth grain, sand grain, geometric patterns, and letters. The color clear layer is a layer that has the function of adding additional gloss to the metallic tone of the metal thin film layer 1 and adjusting the color of the metal. The clear layer has the function of diffusing reflected light from the metal thin film layer 1 and enhancing the sense of depth of the design of the decorative sheet, for example.

[0023] The adhesive layer 6 is a layer that is provided, as necessary, on the side of the metal thin film layer 1 opposite the primer layer 2 side, or on the side of the lamination substrate 5a opposite the primer layer 2. When the decorative sheet of the present disclosure has a transfer substrate 5b, the adhesive layer 6 may be, for example, a layer that forms the surface of the transfer layer 7 opposite the transfer substrate 5b side. This can improve the adhesion between the transfer layer 7 and the molded resin layer 8. Furthermore, when the adhesive layer 6 is provided on the side of the metal thin film layer 1 opposite the primer layer 2, the metal thin film layer 1 and the adhesive layer 6 may be adjacent to each other, or a second primer layer 22 may be laminated between the metal thin film layer 1 and the adhesive layer 6.

[0024] Furthermore, although not shown, the decorative sheet of the present disclosure may have a transparent substrate layer, if necessary. The transparent substrate layer also functions to enhance the scratch resistance, contamination resistance, and weather resistance of the decorative sheet. The transparent substrate layer also functions to enhance the formability of the decorative sheet of the present disclosure. For example, when the decorative sheet of the present disclosure has a protective layer 3, the transparent substrate layer is preferably disposed between the primer layer 2 and the protective layer 3.

[0025] Furthermore, although not shown in the figures, in the transfer-type decorative sheet of the second embodiment, a release layer may be provided between the substrate 5 and the protective layer 3 if necessary in order to improve the peelability of the substrate 5 from the protective layer 3.

[0026] As described above, when a resin molded product is produced using the decorative sheet of the present disclosure, the decorative sheet of the first embodiment, in which the substrate 5 (lamination substrate 5a) of the decorative sheet is included in the resin molded product, or the transfer-type decorative sheet of the second embodiment, in which the substrate 5 (transfer substrate 5b) of the decorative sheet is not included in the resin molded product, can be used. That is, in the decorative sheet of the first embodiment, the molded resin layer 8 is formed on the substrate 5 side, so that the substrate 5 is included in the resin molded product, as shown in FIG. 4. On the other hand, in the transfer-type decorative sheet of the second embodiment, as shown in FIGS. 7 and 8, the molded resin layer 8 is formed on the opposite side of the substrate 5, so that after obtaining a resin molded product with a transfer substrate as shown in FIG. 7, for example, the substrate 5 is peeled off, so that the substrate 5 is not included in the resin molded product, as shown in FIG. 8. The layers transferred using the transfer substrate 5b (i.e., the protective layer 3, the second primer layer 22, the primer layer 2, the metal thin film layer 1, the third primer layer 23, the decorative layer 4, the adhesive layer 6, the transparent substrate layer, etc.) are collectively referred to as the transfer layer 7 (see Figures 5 to 8).

[0027] As a laminate structure of the decorative sheet of the first aspect of the present disclosure, A laminated structure consisting of a substrate, a thin metal film layer, and a primer layer stacked in this order; A laminated structure consisting of a substrate, a thin metal film layer, a primer layer, and a protective layer in this order; A laminated structure in which a substrate / second primer layer / metal thin film layer / primer layer / protective layer are laminated in this order; A laminated structure in which a substrate / second primer layer / metal thin film layer / primer layer / third primer layer / protective layer are laminated in this order; A laminated structure in which a substrate / second primer layer / metal thin film layer / primer layer / decorative layer / third primer layer / protective layer are laminated in this order; A laminated structure in which adhesive layer / substrate / second primer layer / metal thin film layer / primer layer / decorative layer / third primer layer / protective layer are laminated in this order; A laminated structure consisting of a substrate, adhesive layer, metal thin film layer, primer layer, decorative layer, third primer layer, and protective layer in this order; A laminated structure in which the substrate / adhesive layer / second primer layer / metal thin film layer / primer layer / decorative layer / third primer layer / protective layer are laminated in this order; A laminated structure in which adhesive layer / substrate / adhesive layer / second primer layer / metal thin film layer / primer layer / decorative layer / transparent substrate layer / third primer layer / protective layer are laminated in this order; Examples include:

[0028] Fig. 1 shows a schematic cross-sectional view of an example of a decorative sheet in which a metal thin film layer 1 and a primer layer 2 are laminated, as one embodiment of the laminate structure of the decorative sheet of the present disclosure. Fig. 2 shows a schematic cross-sectional view of an example of a decorative sheet in which a substrate 5, a metal thin film layer 1, and a primer layer 2 are laminated in this order, as one embodiment of the laminate structure of the decorative sheet of the present disclosure. Fig. 3 shows a schematic cross-sectional view of an example of a decorative sheet in which a substrate 5, a second primer layer 22, a metal thin film layer 1, a primer layer 2, a decorative layer 4, a third primer layer 23, and a protective layer 3 are laminated in this order, as one embodiment of the laminate structure of the decorative sheet of the first embodiment.

[0029] In addition, as a laminate structure of the decorative sheet according to the second aspect of the present disclosure, A laminated structure consisting of a substrate, a primer layer, and a thin metal film layer stacked in this order; A laminated structure consisting of a substrate, a protective layer, a primer layer, and a thin metal film layer stacked in this order; A laminated structure in which a substrate / protective layer / primer layer / metal thin film layer / second primer layer are laminated in this order; A laminated structure in which the substrate / protective layer / third primer layer / decorative layer / primer layer / metal thin film layer / second primer layer are laminated in this order; A laminated structure consisting of a substrate / protective layer / third primer layer / clear layer / decorative layer / primer layer / metal thin film layer / second primer layer in this order; A laminated structure consisting of a substrate / protective layer / third primer layer / clear layer / primer layer / metal thin film layer / second primer layer / adhesive layer in this order; A laminated structure in which the substrate / release layer / protective layer / third primer layer / decorative layer / primer layer / metal thin film layer / second primer layer / adhesive layer are laminated in this order; A laminated structure in which the substrate / release layer / protective layer / third primer layer / decorative layer / primer layer / metal thin film layer / second primer layer / adhesive layer are laminated in this order; Examples include:

[0030] Fig. 5 shows a schematic cross-sectional view of an example of a decorative sheet having a laminated structure of the second embodiment in which a substrate 5, a primer layer 2, and a metal thin film layer 1 are laminated in this order. Fig. 6 shows a schematic cross-sectional view of an example of a decorative sheet having a laminated structure of the second embodiment in which a substrate 5, a protective layer 3, a third primer layer 23, a decorative layer 4, a primer layer 2, a metal thin film layer 1, a second primer layer 22, and an adhesive layer 6 are laminated in this order.

[0031] Composition of each layer that forms the decorative sheet [Base material 5] The base material 5 is formed from a resin sheet (resin film) that serves as a support in the decorative sheet of the present disclosure.

[0032] In the decorative sheet of the first embodiment, the resin component used for the substrate 5 (lamination substrate 5a) is not particularly limited and may be appropriately selected depending on the three-dimensional formability and compatibility with the molded resin layer, but a thermoplastic resin is preferred. Specific examples of thermoplastic resins include acrylonitrile-butadiene-styrene resin (hereinafter sometimes referred to as "ABS resin"); acrylonitrile-styrene-acrylic acid ester resin; acrylic resin; polyolefin resins such as polypropylene and polyethylene; polycarbonate resin; vinyl chloride resin; and polyethylene terephthalate (PET) resin. Among these, ABS resin is preferred from the viewpoint of three-dimensional formability. The resin component forming the lamination substrate 5a may be one type alone or a mixture of two or more types. The lamination substrate 5a may be formed from a single-layer sheet of these resins, or may be formed from a multi-layer sheet of the same or different resins.

[0033] The lamination substrate 5a may be subjected to a physical or chemical surface treatment such as an oxidation method or a roughening method on one or both sides as needed to improve adhesion with adjacent layers. Examples of oxidation methods used to treat the surface of the substrate 5 include corona discharge treatment, plasma treatment, chromium oxidation treatment, flame treatment, hot air treatment, and ozone ultraviolet treatment. Examples of roughening methods used to treat the surface of the lamination substrate 5a include sandblasting and solvent treatment. These surface treatments are appropriately selected depending on the type of resin component constituting the lamination substrate 5a, but from the standpoints of effectiveness, operability, and the like, corona discharge treatment is preferred.

[0034] The lamination substrate 5a may be colored by blending a coloring agent or the like, painted to adjust the color, or patterned to impart design features.

[0035] The thickness of the lamination base material 5a is not particularly limited and is set appropriately depending on the application of the decorative sheet, but may be, for example, about 50 to 800 μm, preferably about 100 to 600 μm, and more preferably about 200 to 500 μm. When the thickness of the lamination base material 5a is within the above range, the decorative sheet can be provided with even better three-dimensional formability, etc.

[0036] In addition, in the decorative sheet of the second embodiment, the substrate 5 (transfer substrate 5b) is a layer provided for transferring the transfer layer 7 to the molded resin layer 8, and is formed from a resin sheet (resin film) that also serves as a support.

[0037] The resin component used for the transfer substrate 5b is not particularly limited and may be appropriately selected depending on factors such as the releasability from the protective layer 3, but a thermoplastic resin is preferred. Specific examples of the thermoplastic resin include those exemplified for the lamination substrate 1a of the first embodiment. Among these, polyethylene terephthalate (PET) resin is preferred for the transfer substrate 5b. The resin component forming the transfer substrate 5b may be a single type or a mixture of two or more types. The transfer substrate 5b may be formed from a single-layer sheet of these resins, or may be formed from a multi-layer sheet of the same or different resins.

[0038] The thickness of the transfer substrate 5b is not particularly limited and is appropriately set depending on the application of the decorative sheet, but is usually about 10 to 150 μm, preferably about 10 to 125 μm, and more preferably about 10 to 80 μm.

[0039] [Release layer] In the decorative sheet of the second embodiment, the release layer is provided, if necessary, between the transfer substrate 5b and the protective layer 3. The release layer serves to improve the releasability of the transfer substrate 5b from the protective layer 3.

[0040] The release layer may be a solid release layer that covers the entire surface of the transfer substrate 5b (solid on the entire surface), or may be provided on a part of the surface. In general, a solid release layer is preferred in consideration of releasability.

[0041] The release layer can be formed using a resin composition containing a single or a mixture of thermoplastic resins such as silicone resins, fluororesins, acrylic resins (including, for example, acrylic-melamine resins), polyester resins, polyolefin resins, polystyrene resins, polyurethane resins, cellulose resins, vinyl chloride-vinyl acetate copolymers, and soluble nitrocellulose; copolymers of monomers that form such thermoplastic resins; or resins modified with (meth)acrylic acid or urethane. The release layer is preferably formed from a resin composition containing at least one of these resins as a main component and other resins. Here, the term "main component" refers to a resin that accounts for, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more of the resin contained in the release layer. The resin contained in the release layer may be only the main component resin (i.e., 100% by mass). The other resin may be at least one of these resins, or it may not be these resins. Among these resins, the release layer preferably contains an acrylic resin, a polyester resin, a polyolefin resin, a polystyrene resin, a copolymer of the monomers that form these resins, and a urethane-modified version of these. More specifically, the release layer is preferably formed from an acrylic-melamine resin alone, a resin composition containing an acrylic-melamine resin, a resin composition obtained by mixing a polyester resin with a urethane-modified copolymer of ethylene and acrylic acid, or a resin composition obtained by mixing an acrylic resin with an emulsion of a copolymer of styrene and acrylic. Of these, it is particularly preferable to form the release layer from an acrylic-melamine resin alone or a resin composition containing 50% by mass or more of an acrylic-melamine resin.

[0042] The material constituting the release layer may also be an ionizing radiation curable resin, which will be exemplified below for the protective layer 3. When the release layer is formed of an ionizing radiation curable resin, it is preferable to use, among the ionizing radiation curable resins, a polycarbonate (meth)acrylate (such as a polycarbonate urethane (meth)acrylate) described below.

[0043] The thickness of the release layer is, for example, about 0.01 to 5 μm, and preferably about 0.05 to 3 μm.

[0044] [Protective layer 3] This layer is provided as needed for the purpose of improving the scratch resistance, contamination resistance, and weather resistance of the decorative sheet. The resin that forms the protective layer 3 is not particularly limited, and examples thereof include thermosetting resins, thermoplastic resins, and ionizing radiation curable resins. Among these, ionizing radiation curable resins are preferred from the viewpoint of achieving both excellent scratch resistance and excellent three-dimensional formability.

[0045] The thermosetting resin forming the protective layer 3 is not particularly limited and examples thereof include resins containing a polyol resin and a curing agent, such as acrylic polyol, polyester polyol, urethane polyol such as polyester urethane polyol or acrylic urethane polyol, or polyolefin polyol such as polyethylene polyol, polypropylene polyol, polybutadiene polyol or polyisoprene polyol. The thermosetting resin may be used alone or in combination of two or more.

[0046] The thermoplastic resin forming the protective layer 3 is not particularly limited and examples thereof include acrylic resins such as polymethyl (meth)acrylate and polyethyl (meth)acrylate; polyolefin resins such as polypropylene and polyethylene; polycarbonate resin; vinyl chloride resin; polyethylene terephthalate (PET); acrylonitrile-butadiene-styrene resin (ABS resin); acrylonitrile-styrene-acrylic ester resin; etc. The thermoplastic resins may be used alone or in combination of two or more.

[0047] (ionizing radiation curable resin) The ionizing radiation-curable resin used to form the protective layer 3 is a resin that crosslinks and cures upon exposure to ionizing radiation. Specific examples include a mixture of at least one of prepolymers, oligomers, and monomers, each of which has a polymerizable unsaturated bond or an 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 protective layer 3 because they can be made solvent-free, do not require a photopolymerization initiator, and exhibit stable curing properties.

[0048] In the laminate of the present disclosure, when an ionizing radiation curable resin is used to form the protective layer 3, the protective layer 3 in the laminate may be cured, uncured, or semi-cured. If the protective layer 3 in the laminate is uncured or semi-cured, the protective layer 3 is cured after the laminate is formed.

[0049] 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 polyfunctional (meth)acrylates include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 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, trimethylolpropanediol di(meth)acrylate, and the like. Examples of the monomer include trimethylolpropane 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.

[0050] 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 polycarbonate-based urethane (meth)acrylate, which is 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 polyisocyanate 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. Urethane (meth)acrylates can be obtained, for example, by esterifying polyurethane oligomers obtained by reacting polyether polyols, polyester polyols, or caprolactone polyols with polyisocyanate compounds with (meth)acrylic acid. Epoxy (meth)acrylates can be obtained, for example, by reacting (meth)acrylic acid with the oxirane rings of relatively low-molecular-weight bisphenol epoxy resins or novolac epoxy resins for esterification.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. Among these, particularly preferred polyfunctional (meth)acrylate oligomers are polycarbonate (meth)acrylates (such as polycarbonate-based urethane (meth)acrylates), urethane (meth)acrylates, etc. These oligomers may be used alone or in combination of two or more.

[0051] Among the above-mentioned ionizing radiation curable resins, from the viewpoint of achieving both excellent scratch resistance and excellent three-dimensional formability, it is preferable to use a polycarbonate (meth)acrylate (such as a polycarbonate-based urethane (meth)acrylate), and it is particularly preferable to use a polycarbonate (meth)acrylate (such as a polycarbonate-based urethane (meth)acrylate) in combination with a polyfunctional (meth)acrylate other than the polycarbonate (meth)acrylate.

[0052] Polycarbonate (meth)acrylates can be obtained, for example, by converting some or all of the hydroxyl groups of a polycarbonate polyol to (meth)acrylates (acrylic acid esters or methacrylic acid esters). This esterification reaction can be carried out by a conventional esterification reaction. Examples include 1) a method of condensing a polycarbonate polyol with an acrylic acid halide or a methacrylic acid halide in the presence of a base, 2) a method of condensing a polycarbonate polyol with an acrylic acid anhydride or a methacrylic acid anhydride in the presence of a catalyst, and 3) a method of condensing a polycarbonate polyol with an acrylic acid or a methacrylic acid in the presence of an acid catalyst.

[0053] The polycarbonate polyol is a polymer having a carbonate bond in the polymer main chain and having two or more, preferably 2 to 50, more preferably 3 to 50 hydroxyl groups at the terminal or side chain. A typical method for producing this polycarbonate polyol is a method by polycondensation reaction of a diol compound (A), a trihydric or higher polyhydric alcohol (B), and a compound (C) that becomes a carbonyl component. The diol compound (A) used as a raw material is a diol compound represented by the general formula HO-R 1 -OH, where R 1 is a divalent hydrocarbon group having 2 to 20 carbon atoms, which may contain an ether bond within the group, such as a linear or branched alkylene group, a cyclohexylene group, or a phenylene group.

[0054] Specific examples of the diol compound (A) include ethylene glycol, 1,2-propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, polyethylene glycol, neopentyl glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,3-bis(2-hydroxyethoxy)benzene, 1,4-bis(2-hydroxyethoxy)benzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, etc. These diols may be used alone or in combination of two or more.

[0055] Examples of the trihydric or higher polyhydric alcohol (B) include alcohols such as trimethylolpropane, trimethylolethane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, glycerin, and sorbitol. Furthermore, alcohols having hydroxyl groups in which 1 to 5 equivalents of ethylene oxide, propylene oxide, or other alkylene oxides have been added to the hydroxyl groups of these polyhydric alcohols may also be used. These polyhydric alcohols may be used alone or in combination of two or more.

[0056] The compound (C) that serves as the carbonyl component is any compound selected from carbonate diesters, phosgene, or equivalents thereof. Specific examples include carbonate diesters such as dimethyl carbonate, diethyl carbonate, diisopropyl carbonate, diphenyl carbonate, ethylene carbonate, and propylene carbonate; phosgene; and halogenated formates such as methyl chloroformate, ethyl chloroformate, and phenyl chloroformate. These may be used alone or in combination of two or more.

[0057] Polycarbonate polyols are synthesized by polycondensation of the diol compound (A), a trihydric or higher polyhydric alcohol (B), and a carbonyl component compound (C) under standard conditions. For example, the molar ratio (B / A) of the diol compound (A) to the polyhydric alcohol (B) is preferably 50 / 50 or more and 99 / 1 or less, and the molar ratio of the carbonyl component compound (C) to the diol compound (A) and the polyhydric alcohol (B) is preferably 0.2 or more and 2 or less equivalents relative to the hydroxyl groups of the diol compound and the polyhydric alcohol.

[0058] The equivalent number (eq. / mol) of hydroxyl groups present in the polycarbonate polyol after polycondensation reaction at the above-mentioned charging ratio is, on average, 3 or more per molecule, preferably 50 or less, and more preferably 20 or less. Within this range, a required amount of (meth)acrylate groups is formed by the esterification reaction described below, and appropriate flexibility is imparted to the polycarbonate (meth)acrylate resin. The terminal functional groups of this polycarbonate polyol are usually OH groups, but some of them may be carbonate groups.

[0059] The method for producing the polycarbonate polyol described above is described, for example, in JP-A-64-1726. Furthermore, as described in JP-A-3-181517, this polycarbonate polyol can also be produced by transesterification of a polycarbonate diol with a trihydric or higher polyhydric alcohol.

[0060] The weight-average molecular weight of the polycarbonate (meth)acrylate used in the present disclosure is preferably 500 or more, more preferably 1,000 or more, and even more preferably 2,000 or more. There is no particular upper limit to the weight-average molecular weight of the polycarbonate (meth)acrylate, but from the viewpoint of controlling the viscosity so that it does not become too high, it is preferably 100,000 or less, more preferably 50,000 or less, and even more preferably 30,000 or less. The weight-average molecular weight of the polycarbonate (meth)acrylate is preferably in the range of 500 to 100,000, more preferably 1,000 to 50,000, and particularly preferably 2,000 to 30,000. The weight-average molecular weight of the polycarbonate (meth)acrylate in the present disclosure is the average molecular weight measured by GPC analysis and converted into standard polystyrene.

[0061] In the ionizing radiation-curable resin composition, the polycarbonate (meth)acrylate is preferably used together with a polyfunctional (meth)acrylate other than the polycarbonate (meth)acrylate. The mass ratio of the polycarbonate (meth)acrylate to the polyfunctional (meth)acrylate (polycarbonate (meth)acrylate / polyfunctional (meth)acrylate) is more preferably 50 / 50 or more and 98 / 2 or less. When the mass ratio of the polycarbonate (meth)acrylate to the polyfunctional (meth)acrylate is less than 98 / 2 (i.e., when the amount of polycarbonate (meth)acrylate is 98 mass% or less of the total amount of the two components), the durability and chemical resistance described above are further improved. On the other hand, when the mass ratio of polycarbonate (meth)acrylate to multifunctional (meth)acrylate is greater than 50 / 50 (i.e., when the amount of polycarbonate (meth)acrylate is 50 mass% or more of the total amount of the two components), the three-dimensional moldability is further improved. Preferably, the mass ratio of polycarbonate (meth)acrylate to multifunctional (meth)acrylate is 60 / 40 or more and 95 / 5 or less.

[0062] In the present disclosure, the polyfunctional (meth)acrylate other than the polycarbonate (meth)acrylate used in combination with the polycarbonate (meth)acrylate is not particularly limited as long as it is a (meth)acrylate with two or more functionalities. Here, "bifunctional" means having two ethylenically unsaturated bonds ((meth)acryloyl groups) in the molecule. The number of functional groups is preferably 2 or more, or preferably 6 or less.

[0063] Furthermore, the polyfunctional (meth)acrylate used in combination with the polycarbonate (meth)acrylate may be either an oligomer or a monomer, but from the viewpoint of achieving both excellent scratch resistance and excellent three-dimensional moldability, a polyfunctional (meth)acrylate oligomer is preferred.

[0064] Examples of the polyfunctional (meth)acrylate oligomer used in combination with polycarbonate (meth)acrylate include urethane (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, polyester (meth)acrylate oligomers, and polyether (meth)acrylate oligomers. Urethane (meth)acrylate oligomers can be obtained, for example, by esterifying a polyurethane oligomer obtained by reacting a polyether polyol or polyester polyol with a polyisocyanate with (meth)acrylic acid. Epoxy (meth)acrylate oligomers can be obtained, for example, by reacting the oxirane ring of a relatively low-molecular-weight bisphenol epoxy resin or novolac epoxy resin with (meth)acrylic acid for esterification. Carboxyl-modified epoxy (meth)acrylate oligomers, in which the epoxy (meth)acrylate oligomers are partially modified with a dibasic carboxylic acid anhydride, can also be used. The polyester (meth)acrylate oligomer can be obtained by esterifying the hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends, obtained by condensation of a polycarboxylic acid with 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.The polyether (meth)acrylate oligomer can be obtained by esterifying the hydroxyl groups of a polyether polyol with (meth)acrylic acid.

[0065] Furthermore, other polyfunctional (meth)acrylate oligomers that can be used in combination with polycarbonate (meth)acrylate include highly hydrophobic polybutadiene (meth)acrylate oligomers having (meth)acrylate groups on the side chains of polybutadiene oligomers, silicone (meth)acrylate oligomers having polysiloxane bonds in the main chain, and aminoplast resin (meth)acrylate oligomers obtained by modifying aminoplast resins having many reactive groups in a small molecule.

[0066] Specific examples of the polyfunctional (meth)acrylate monomers used in combination with polycarbonate (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, and isocyanurate di(meth). ) acrylate, trimethylolpropane tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(acryloxyethyl) isocyanurate, propionic acid-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene oxide-modified dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, etc. The above-mentioned polyfunctional (meth)acrylate oligomers and polyfunctional (meth)acrylate monomers may be used alone or in combination of two or more.

[0067] In the present disclosure, monofunctional (meth)acrylates can be appropriately used in combination with the polyfunctional (meth)acrylates used in combination with polycarbonate (meth)acrylates, for purposes such as reducing the viscosity, as long as the purpose of the present disclosure is not impaired. Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, and isobornyl (meth)acrylate. These monofunctional (meth)acrylates can be used alone or in combination of two or more.

[0068] The content of polycarbonate (meth)acrylate in the ionizing radiation curable resin composition forming the protective layer 3 is not particularly limited, but from the viewpoint of achieving both excellent scratch resistance and excellent three-dimensional formability, it is preferably 98% by mass or less, more preferably 90% by mass or less, and also preferably 50% by mass or more, more preferably 65% ​​by mass or more. The content of polycarbonate (meth)acrylate in the ionizing radiation curable resin composition forming the protective layer 3 preferably ranges from 50% by mass to 98% by mass, more preferably 65% ​​by mass to 90% by mass.

[0069] When the protective layer 3 is formed using an ionizing radiation curable resin, the protective layer 3 is formed, for example, by preparing an ionizing radiation curable resin composition, applying the composition, and curing it by crosslinking. 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.

[0070] In the present disclosure, the prepared coating solution is applied to a desired thickness by a known method such as gravure coating, bar coating, roll coating, reverse roll coating, or comma coating, preferably by gravure coating, to form an uncured resin layer.

[0071] 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 protective layer 3. 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.

[0072] In electron beam irradiation, the higher the acceleration voltage, the greater the penetration ability. Therefore, when a resin that is easily deteriorated by electron beam irradiation is used under the protective layer 3, the acceleration voltage is selected so that the penetration depth of the electron beam is substantially equal to the thickness of the protective layer 3. Furthermore, when a release layer formed on the transfer substrate and the protective layer 3 are cured together with the electron beam by the electron beam, the acceleration voltage is selected so that the penetration depth of the electron beam is substantially equal to the total thickness of the release layer and the protective layer 3. This makes it possible to suppress excess electron beam irradiation on the transfer substrate located under the release layer, and minimize deterioration of the transfer substrate due to excess electron beams.

[0073] The exposure dose is an amount that provides sufficient crosslink density in the protective layer 3, and is preferably 30 kGy (3 Mrad) or more, and preferably 300 kGy (30 Mrad) or less, and more preferably 100 kGy (10 Mrad) or less. The exposure dose is preferably 30 kGy (3 Mrad) or more and 300 kGy (30 Mrad) or less, and more preferably 30 kGy (3 Mrad) or more and 100 kGy (10 Mrad) or less. Setting the exposure dose within this range can suppress deterioration of layers located below the protective layer 3 due to ionizing radiation that has penetrated the protective layer 3. Note that the above example is for a case in which the number of functional groups in the polyfunctional (meth)acrylate is two, and an appropriate exposure dose is required depending on the number of functional groups.

[0074] 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.

[0075] When ultraviolet light is used as the ionizing radiation, light rays containing ultraviolet light with a wavelength of 190 nm or more and 380 nm or less may be emitted. The ultraviolet light source is not particularly limited, but examples thereof include high-pressure mercury lamps, low-pressure mercury lamps, metal halide lamps, carbon arc lamps, ultraviolet light-emitting diodes (LED-UV), etc.

[0076] The thickness of the protective layer 3 is not particularly limited, but is preferably 1 μm or more, more preferably 2 μm or more, and even more preferably 3 μm or more, and is preferably 20 μm or less, and more preferably 15 μm or less. The thickness of the protective layer 3 preferably ranges from 1 μm to 20 μm, more preferably from 2 μm to 20 μm, and even more preferably from 3 μm to 15 μm. When the thickness falls within this range, the laminate can effectively exhibit excellent scratch resistance and excellent three-dimensional formability. Furthermore, when the protective layer 3 is formed from an ionizing radiation-curable resin, the ionizing radiation-curable resin composition can be uniformly irradiated with ionizing radiation, which allows for uniform curing and is economically advantageous.

[0077] [Metal thin film layer 1] The metal thin film layer 1 in the present disclosure is a layer that is disposed on the molded resin layer 8 side (the article side) of the decorative sheet relative to the primer layer 2, and is a layer that exhibits a metallic design. The metal thin film layer 1 is a layer that is disposed adjacent to the primer layer 2.

[0078] A "metallic design" refers to a design that gives the user of a resin molded product (decorated article) using a decorative sheet the impression of a metallic surface. Examples of metallic designs include, but are not limited to, metallic color and metallic luster. The arrangement of the metal thin film layer in the decorative sheet is appropriately selected depending on the application of the decorative sheet and is not particularly limited. For example, it is preferable that the metal thin film layer is arranged over the entire surface (solid) of one side of the decorative sheet. In other words, it is preferable that the metal thin film layer is arranged continuously over the entire area of ​​one side of the decorative sheet. In other words, it is preferable that the metal thin film layer is arranged so as to impart a metallic design to the entire area of ​​one side of the decorative sheet.

[0079] The thickness of the metal thin film layer is not particularly limited as long as it can provide a desired metallic design. The thickness of the metal thin film layer is usually 5 nm to 100 nm, for example, more preferably 10 nm to 90 nm, and particularly preferably 10 nm to 80 nm. The thickness of the metal thin film layer is a value measured by cutting the decorative sheet perpendicular to the sheet plane to prepare an ultrathin section so that the cross section can be observed, and observing the cross section of the ultrathin section with a transmission electron microscope.

[0080] The optical density of the metal thin film layer can be appropriately selected depending on the desired metallic design and is not particularly limited. The optical density of the metal thin film layer is, for example, 0.6 or more, preferably 0.8 or more, more preferably 1.0 or more, and for example, 1.8 or less, preferably 1.6 or less, more preferably 1.4 or less, with preferred ranges including 0.6 to 1.8, 0.6 to 1.6, 0.6 to 1.4, 0.8 to 1.8, 0.8 to 1.6, 0.8 to 1.4, 1.0 to 1.8, 1.0 to 1.6, and 1.0 to 1.4. By achieving an optical density satisfying these values, a metallic design can be imparted to the decorative sheet, and when the decorative sheet is placed on an article, the layer placed on the article side of the metal thin film layer can be prevented from being visible through the decorative sheet. Furthermore, color unevenness (uneven metallic luster) of the metal thin film layer can be suppressed.

[0081] Optical density refers to the Optical Density (OD) value. The OD value expressed in optical density is determined by "log10(Iin / Iout)" where Iin is the intensity of incident light incident at a normal angle and Iout is the intensity of transmitted light transmitted at a normal angle, and can be measured using a microspectrophotometer.

[0082] The metal forming the metal thin film layer is not particularly limited as long as it can impart a metallic design to the decorative sheet. The metal thin film layer may be formed of only one type of metal, or may be formed of two or more types of metals. Examples of metals include simple metals such as tin, indium, chromium, aluminum, and copper, or alloys containing at least one of these metals. Among these, it is preferable that the metal forming the metal thin film layer contains tin.

[0083] More specifically, the tin forming the metal thin film layer can be tin alone or an alloy containing tin. In the case of an alloy, the proportion of tin in the metal thin film layer is preferably, for example, the largest proportion among all the metals contained in the metal thin film layer. The proportion of tin relative to all the metals contained in the metal thin film layer may be, for example, 50 mol% or more, 70 mol% or more, or 90 mol% or more. In the present disclosure, the metal thin film layer is preferably formed of tin alone.

[0084] Tin has good extensibility, allowing the decorative sheet to easily conform to the shape of an article. Metal thin film layers formed from tin are prone to fading in humid and hot environments, high temperature environments, and even high light energy irradiation environments. Therefore, by providing the decorative sheet of the present disclosure with a predetermined primer layer 2 described below, the effects of improving moist and heat resistance, heat resistance, and weather resistance are significant.

[0085] The method for forming the metal thin film layer is not particularly limited as long as it can impart a metallic design to the decorative sheet, and examples thereof include vapor deposition methods such as vacuum vapor deposition, sputtering, and ion plating. Furthermore, the method for forming the metal thin film layer may be a method of applying a paste containing the above-mentioned metal, or a plating method using the above-mentioned metal. In the present disclosure, the vacuum vapor deposition method is preferred because it is low cost and causes little damage to the substrate. The vapor deposition conditions may be appropriately set depending on the melting temperature or evaporation temperature of the metal used. The metal thin film layer may be, for example, a metal vapor deposition layer.

[0086] [Primer layer 2] In the decorative sheet of the present disclosure, the primer layer 2 is a layer provided adjacent to the metal thin film layer 1. More specifically, the primer layer 2 is a layer disposed in contact with the surface of the metal thin film layer 1 opposite the side on which the molded resin layer 8 is disposed (i.e., the surface on the observer side of the decorative sheet and the resin molded product). The primer layer 2 functions to enhance adhesion with the laminate on the side opposite to the metal thin film layer side it contacts. Furthermore, the addition of alkoxysilane inhibits fading of the metal thin film layer 1 in a humid heat environment, a high temperature environment, and a high light energy irradiation environment.

[0087] The primer layer 2 is formed from a cured product of a resin composition containing a resin and an alkoxysilane having an alkyl or aryl group. The cured product of the resin composition refers to a cured product (solidified product) of the resin obtained by solidifying the resin composition by drying, or a cured product of the resin obtained by curing the resin composition through a chemical reaction. The alkoxysilane having an alkyl or aryl group does not have a substituent that is reactive with the resin in the resin composition that forms the primer layer. Due to these characteristics, the primer layer 2, when in contact with the metal thin film layer 1, exhibits the function of suppressing fading of the metal thin film layer 1 in humid and hot environments, high-temperature environments, and high-energy light irradiation environments.

[0088] Examples of substituents reactive with the resin in the resin composition forming the primer layer 2 include thiol groups, epoxy groups, vinyl groups, amino groups, (meth)acrylic groups, and isocyanate groups. In the present disclosure, the alkoxysilane in the primer layer 2 does not have these substituents. The alkoxysilane in the primer layer 2 may have a substituent (non-reactive substituent) as long as the substituent is not reactive with the resin in the resin composition forming the primer layer 2. Examples of such non-reactive substituents include alkyl groups and aryl groups. When the alkoxysilane in the primer layer 2 has a substituent, the non-reactive substituent may be one type or two or more types. The alkoxysilane in the primer layer 2 may not have a functional group (substituent) other than an alkyl group, an aryl group, or an alkoxy group. That is, the alkoxysilane in the primer layer 2 may be an unsubstituted alkylalkoxysilane, an unsubstituted arylalkoxysilane, or an unsubstituted alkylarylalkoxysilane. The alkoxysilane in the primer layer 2 may be one type or two or more types.

[0089] The number of carbon atoms in the alkyl group of the alkoxysilane having an alkyl group or an aryl group is preferably 1 or more and preferably 8 or less, with a preferred range being 1 to 8. The number of carbon atoms in the aryl group of the alkoxysilane having an alkyl group or an aryl group is preferably 5 or more and preferably 8 or less, with a preferred range being 5 to 8.

[0090] Specific examples of the alkoxysilane of the primer layer 2 include trimethoxysilanes having an alkyl group having 1 to 8 carbon atoms, such as methyltrimethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, hexyltrimethoxysilane, and octyltrimethoxysilane; triethoxysilanes having an alkyl group having 1 to 8 carbon atoms, such as methyltriethoxysilane, ethyltriethoxysilane, n-propyltriethoxysilane, hexyltriethoxysilane, and octyltriethoxysilane; trimethoxysilanes having an aryl group having 5 to 10 carbon atoms, such as phenyltrimethoxysilane and naphthyltrimethoxysilane; triethoxysilanes having an aryl group having 5 to 10 carbon atoms, such as phenyltriethoxysilane and naphthyltriethoxysilane; dimethoxysilanes having two alkyl groups having 1 to 8 carbon atoms, such as dimethyldimethoxysilane; and diethoxysilanes having two alkyl groups having 1 to 8 carbon atoms, such as dimethyldiethoxysilane.

[0091] The content of alkoxysilane having an alkyl group or an aryl group in the resin composition that forms primer layer 2 is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 3 parts by mass or more, relative to 100 parts by mass of the resin, and is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less; preferred ranges include 0.5 to 20 parts by mass, 0.5 to 15 parts by mass, 0.5 to 10 parts by mass, 1 to 20 parts by mass, 1 to 15 parts by mass, 1 to 10 parts by mass, 3 to 20 parts by mass, 3 to 15 parts by mass, and 3 to 10 parts by mass.

[0092] Furthermore, the content of alkoxysilane having an alkyl group or an aryl group in the resin composition forming the primer layer 2 is preferably 0.4 mass% or more, more preferably 0.8 mass% or more, and even more preferably 2.4 mass% or more, and is preferably 17.0 mass% or less, more preferably 13.0 mass% or less, and even more preferably 9.0 mass% or less. Preferred ranges include 0.4 to 17.0 mass%, 0.4 to 13.0 mass%, 0.4 to 9.0 mass%, 0.8 to 17.0 mass%, 0.8 to 13.0 mass%, 0.8 to 9.0 mass%, 2.4 to 17.0 mass%, 2.4 to 13.0 mass%, and 2.4 to 9.0 mass%.

[0093] Examples of resins contained in the resin composition forming the primer layer 2 include thermosetting resins and thermoplastic resins. Specific examples of resins include polyester resins, polyurethane resins, polyacrylic resins, and polyolefin resins. Examples of polyester resins include polyester polyols. Examples of polyurethane resins include urethane polyols such as polyester urethane polyols and acrylic urethane polyols. Examples of polyacrylic resins include acrylic polyols. Examples of polyolefin resins include polyolefin polyols such as polyethylene polyols, polypropylene polyols, polybutadiene polyols, and polyisoprene polyols.

[0094] The resin used to form the primer layer 2 may be, for example, a polymer of polycarbonate diol urethane acrylate or a polymer of polyfunctional urethane acrylate. These resins are generally made from urethane acrylate as a raw material and polymerized (resinized) by polymerizing the acrylic groups, and therefore can be considered as polyacrylic resins.

[0095] The resin used to form the primer layer 2 may be one of the above-mentioned resins, or two or more of them may be used in combination.

[0096] In the present disclosure, the resin preferably contains at least one of polyester polyol and acrylic polyol, because, for example, this can improve the three-dimensional formability of the decorative sheet of the present disclosure while improving the adhesion between the primer layer 2 and the metal thin film layer 1, and enable it to be placed on the surfaces of various articles.

[0097] Examples of polyester polyols include condensed polyester diols obtained by reacting low-molecular-weight diols with dicarboxylic acids, polylactone diols obtained by ring-opening polymerization of lactones, and polycarbonate diols. Examples of dicarboxylic acids include aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, maleic acid, and fumaric acid, and aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid. Examples of lactones that can be used include ε-caprolactone. Specific examples of polyester polyols include polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polyneopentyl adipate, polyethylene butylene adipate, polybutylene hexabtylene adipate, polydiethylene adipate, poly(polytetramethylene ether) adipate, polyethylene azate, polyethylene sebacate, polybutylene azate, polybutylene sebacate, and polyhexamethylene carbonate diol.

[0098] The acrylic polyol is not particularly limited as long as it is an acrylic resin having a plurality of hydroxyl groups, and examples thereof include copolymers having a plurality of hydroxyl groups obtained by copolymerizing one or more of (meth)acrylic acid alkyl ester monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, octyl (meth)acrylate, and ethylhexyl (meth)acrylate with one or more of (meth)acrylic acid ester monomers having a hydroxyl group in the molecule such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate, and further, if necessary, with a styrene monomer or the like.

[0099] In the present disclosure, it is preferable that the resin contains at least an acrylic polyol, and it is particularly preferable that the resin contains an acrylic polyol as a main component. "The resin is mainly composed of an acrylic polyol" means that the proportion of the acrylic polyol in the entire resin is the highest. The proportion of the acrylic polyol in the entire resin may be, for example, 70% by mass or more, 90% by mass or more, or even 100% by mass.

[0100] Acrylic polyol is a preferred resin from the viewpoints of improving adhesion of the primer layer 2 to the metal thin film layer 1 and the three-dimensional formability of the decorative sheet. On the other hand, a tin-containing metal thin film layer 1 is characterized by its susceptibility to discoloration due to the influence of the resin forming the primer layer 2 when placed in a humid heat environment, a high temperature environment, a high energy environment, or the like. In contrast, in the present disclosure, by using an acrylic polyol and the alkoxysilane in combination to form the primer layer 2, discoloration of the metal thin film layer 1 in a humid heat environment, a high temperature environment, or a high light energy irradiation environment can be suitably suppressed. That is, in the present disclosure, the resin composition forming the primer layer 2 contains an acrylic polyol and the alkoxysilane, thereby achieving the excellent effect of significantly suppressing discoloration of the tin-containing metal thin film layer 1 while using an acrylic polyol, which is a preferred resin from the viewpoints of adhesion and three-dimensional formability.

[0101] The resin composition forming the primer layer 2 may further contain a curing agent in addition to the resin. That is, the primer layer 2 may be a cured product of a resin composition containing a resin, a curing agent, and an alkoxysilane having an alkyl group or an aryl group. The curing agent is not particularly limited as long as it can be reacted with the above-mentioned resin to obtain a cured product, but an example is an isocyanate compound.

[0102] Examples of the isocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylene-1,4-diisocyanate, xylene-1,3-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylether diisocyanate, polymethylene polyphenylene polyisocyanate, 2-nitrodiphenyl-4, Examples of aromatic isocyanates include 4'-diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, naphthylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate, and 3,3'-dimethoxydiphenyl-4,4'-diisocyanate. Examples of the isocyanate compound include aliphatic isocyanates such as 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,6-diisocyanatohexane (1,6-hexamethylene diisocyanate, HDI), 1,6-diisocyanato-2,2,4-trimethylhexane, and methyl 2,6-diisocyanatohexanoate (lysine diisocyanate). Examples of the isocyanate compound include alicyclic diisocyanates such as isophorone diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate. Among these, aliphatic isocyanates and aromatic isocyanates are preferred from the viewpoints of improving the formability of the decorative sheet and effectively suppressing discoloration due to heat molding. The curing agent may be used alone or in combination of two or more.

[0103] When the primer layer 2 further contains a curing agent, the ratio of the curing agent in the primer layer 2 may be, for example, 1 part by weight or more, or 3 parts by weight or more, relative to 100 parts by weight of the resin. The ratio of the curing agent may be, for example, 15 parts by weight or less, or 10 parts by weight or less.

[0104] The reaction-curing urethane resin used in the primer layer 2 may be either a one-component curing type or a two-component curing type, and is preferably a two-component curing type.

[0105] When the primer layer contains a resin and a curing agent, the combination of the resin and the curing agent is preferably an acrylic polyol and a curing agent of an isocyanate compound.

[0106] The thickness of the primer layer 2 is not particularly limited and may be appropriately determined depending on the application of the decorative sheet, etc. The thickness of the primer layer 2 may be, for example, 0.5 μm or more, or 1 μm or more. The thickness of the primer layer 2 may be, for example, 3 μm or less, or 2 μm or less.

[0107] Various additives can be blended into the resin composition forming the primer layer 2 depending on the desired physical properties. Examples of such additives include weather resistance improvers such as UV absorbers and light stabilizers, abrasion resistance improvers, polymerization inhibitors, crosslinking agents, infrared absorbers, antistatic agents, adhesion improvers, leveling agents, thixotropy-imparting agents, plasticizers, antifoaming agents, fillers, solvents, colorants, and matting agents. These additives can be appropriately selected from commonly used additives. Examples of matting agents include silica particles and aluminum hydroxide particles. Furthermore, reactive UV absorbers and light stabilizers having a polymerizable group such as a (meth)acryloyl group in the molecule can also be used as the UV absorber and light stabilizer.

[0108] The primer layer 2 is formed using a resin composition for forming a primer layer, which contains a resin and an alkoxysilane having an alkyl group or an aryl group. Specifically, the primer layer 2 is formed using the primer composition by a conventional coating method such as gravure coating, gravure reverse coating, gravure offset coating, spinner coating, roll coating, reverse roll coating, kiss coating, wheel coating, dip coating, solid coating by silk screen, wire bar coating, flow coating, comma coating, flow coating, brush coating, or spray coating, or a transfer coating method. Here, the transfer coating method is a method in which a coating film of the primer layer 2 is formed on a thin sheet (film substrate), and then the primer layer is coated on the surface of the target layer in the decorative sheet.

[0109] [Second primer layer 22] The decorative sheet of the present disclosure may have a second primer layer 22. The second primer layer 22 is a layer disposed in contact with the surface of the metal thin film layer 1 opposite to the primer layer 2 (the molded resin layer 8 side). Furthermore, when the decorative sheet 10 further has a lamination substrate 5a, an adhesive layer 6, etc., the second primer layer 22 has the function of increasing the adhesion between these layers and the metal thin film layer 1.

[0110] Examples of resins that can form the second primer layer 22 include acrylic resins, polyurethane resins, acrylic-urethane copolymer resins, and polyester resins, as well as cured products of these resins. The resin used to form the second primer layer 22 is preferably a polyester resin, and more preferably a polyester polyol. The second primer layer 22 may or may not further contain a curing agent, but the former is more preferred because it can improve adhesion. The components of the second primer layer 22 can be the same as those described in the section [Primer Layer 2] above. That is, like the primer layer 2, the primer layer 22 can also be formed from a cured product of a resin composition containing the resin and the alkoxysilane having an alkyl or aryl group.

[0111] The fading of the metal thin film layer 1 is basically caused by moisture, heat, and light energy on the external side (the primer layer 2 side). However, by giving the second primer layer 22 the same effect of imparting moisture resistance, heat resistance, and weather resistance as the primer layer 2, it is possible to suppress fading on both sides of the metal thin film layer 1.

[0112] The thickness of the second primer layer 22 is not particularly limited, but is usually about 0.5 μm or more and 2.5 μm or less, and preferably about 1 μm or more and 2 μm or less.

[0113] A colorant can be mixed into the second primer layer 22 to adjust the color, improve the design, and further, to form a pattern from a design perspective. The method for forming the second primer layer 22 is not particularly limited, but examples include a method of applying a resin composition for forming the second primer layer onto the surfaces of the lamination substrate 5a, the metal thin film layer 1, etc. (the same method as for the primer layer 2).

[0114] [Third primer layer 23] The decorative sheet of the present disclosure may have a third primer layer 23. The third primer layer 23 has the function of increasing the adhesion between the protective layer 3 and the layer located on the molded resin layer 8 side of the protective layer 3. For example, as shown in Figures 3, 4, 6, 7, and 8, the third primer layer 23 is disposed in contact with the surface of the protective layer 37 on the molded resin layer 8 side (i.e., the metal thin film layer 1 side and the primer layer 2 side).

[0115] Examples of the resin that forms the third primer layer 23 include acrylic resin, polyurethane resin, acrylic-urethane copolymer resin, and polyester resin.

[0116] The thickness of the third primer layer 23 is, for example, about 0.5 μm or more and 2.5 μm or less.

[0117] [Adhesive layer 6] The adhesive layer 6 is a layer that is provided, as necessary, on the side of the metal thin film layer 1 opposite the primer layer 2 side, or on the side of the lamination substrate 5a opposite the primer layer 2. When the decorative sheet of the present disclosure has a transfer substrate 5b, the adhesive layer 6 may be, for example, a layer that forms the surface of the transfer layer 7 opposite the transfer substrate 5b side. This can improve the adhesion between the transfer layer 7 and the molded resin layer 8. Furthermore, when the adhesive layer 6 is provided on the side of the metal thin film layer 1 opposite the primer layer 2, the metal thin film layer 1 and the adhesive layer 6 may be adjacent to each other, or a second primer layer 22 may be laminated between the metal thin film layer 1 and the adhesive layer 6.

[0118] The resin forming the adhesive layer 6 is not particularly limited as long as it can improve the adhesion and bonding properties between the molded resin layer 8, the lamination substrate 5a, the metal thin film layer 1, and the second primer layer 22, and for example, a thermoplastic resin or a thermosetting resin is used. Examples of thermoplastic resins include acrylic resins, acrylic-modified polyolefin resins, chlorinated polyolefin resins, vinyl chloride-vinyl acetate copolymers, thermoplastic urethane resins, thermoplastic polyester resins, polyamide resins, and rubber-based resins. One type of thermoplastic resin may be used alone, or two or more types may be used in combination. Examples of thermosetting resins include urethane resins and epoxy resins. One type of thermosetting resin may be used alone, or two or more types may be used in combination.

[0119] When the adhesive layer 6 is used to bond the lamination substrate 5a, the metal thin film layer 1, the second primer layer 22, etc., preferred thermoplastic resins include, for example, acrylic resins, polyolefin resins such as polypropylene and polyethylene, polycarbonate resins, ABS resins, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyvinyl chloride resins such as polyvinyl chloride, chlorinated polyethylene, polyvinylidene chloride, ethylene-vinyl chloride copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-(meth)acrylic copolymer, and chlorinated resins such as polypropylene chloride and chlorinated polypropylene, and among these, acrylic resins and chlorinated resins are more preferred.

[0120] The thickness of the adhesive layer 6 is not particularly limited, but may be, for example, 0.1 μm or more, 0.5 μm or more, 0.6 μm or more, or 1.0 μm or more, and may be 30.0 μm or less, 20.0 μm or less, 8.0 μm or less, 3.5 μm or less, or 2.0 μm or less. The method for forming the adhesive layer 6 is not particularly limited. The adhesive layer 6 can be formed, for example, by applying an adhesive resin to the surface of a layer adjacent to the adhesive layer 6. Examples of application methods include dry lamination.

[0121] The adhesive layer 6 is not necessarily a necessary layer, but is preferably provided when, for example, it is assumed that the decorative sheet of the present disclosure will be applied to a decoration method in which the sheet is attached to a pre-prepared resin molded body, such as the vacuum pressure bonding method described below. When using the vacuum pressure bonding method, it is preferable to form the adhesive layer 6 using a resin that is commonly used among the various resins described above as a resin that exhibits adhesiveness when pressurized or heated.

[0122] [Decorative Layer] The decorative sheet of the present disclosure may have a decorative layer.

[0123] The decorative layer is a layer that is provided as necessary to impart decorativeness to a resin molded product. The decorative layer is composed of, for example, a pattern layer and / or a color clear layer, a clear layer, etc. Here, the pattern layer is a layer that is provided to express a patterned design such as a design or letter. The pattern layer has a metallic luster as the metal thin film layer 1 reflects light to a certain extent through transmission.

[0124] The pattern of the pattern layer 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.

[0125] The design layer is formed using a printing ink containing a colorant, a binder resin, and a solvent or a dispersion medium.

[0126] The colorant for the printing ink used to form the design layer is not particularly limited, and examples thereof include metallic pigments consisting of scaly foil powder of metals, alloys, or metal compounds such as aluminum, chromium, nickel, tin, titanium, iron phosphide, copper, gold, silver, and brass; pearlescent pigments consisting of foil powder of mica-like iron oxide, titanium dioxide-coated mica, titanium dioxide-coated bismuth oxychloride, bismuth oxychloride, titanium dioxide-coated talc, fish scale foil, colored titanium dioxide-coated mica, and basic lead carbonate; and aluminate pigments. Examples of such colorants include fluorescent pigments such as strontium, calcium aluminate, barium aluminate, zinc sulfide, and calcium sulfide; white inorganic pigments such as titanium dioxide, zinc white, and antimony trioxide; inorganic pigments such as zinc white, red iron oxide, vermilion, ultramarine, cobalt blue, titanium yellow, yellow lead, and carbon black; and organic pigments (including dyes) such as isoindolinone yellow, Hansa Yellow A, quinacridone red, permanent red 4R, phthalocyanine blue, indanthrene blue RS, and aniline black. These colorants may be used alone or in combination of two or more.

[0127] The binder resin of the printing ink used to form the design layer is not particularly limited, and examples thereof include acrylic resin, styrene resin, polyester resin, urethane resin, chlorinated polyolefin resin, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral resin, alkyd resin, petroleum resin, ketone resin, epoxy resin, melamine resin, fluororesin, silicone resin, cellulose derivative, rubber resin, etc. These binder resins may be used alone or in combination of two or more. The solvent or dispersion medium for the printing ink used to form the design layer is not particularly limited, and examples thereof include petroleum-based organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ester-based organic solvents such as ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and 2-ethoxyethyl acetate; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, and propylene glycol; ketone-based organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether-based organic solvents such as diethyl ether, dioxane, and tetrahydrofuran; chlorine-based organic solvents such as dichloromethane, carbon tetrachloride, trichloroethylene, and tetrachloroethylene; and water. These solvents or dispersion media may be used alone or in combination of two or more.

[0128] Furthermore, the printing ink used to form the design layer may contain, as necessary, an anti-settling agent, a curing catalyst, an ultraviolet absorber, an antioxidant, a leveling agent, a thickener, an anti-foaming agent, a lubricant, etc.

[0129] The decorative layer can be formed on an adjacent layer, such as the protective layer 3 or the third primer layer 23, by a known printing method such as gravure printing, flexographic printing, silk screen printing, or offset printing.

[0130] The thickness of the decorative layer is not particularly limited, but may be, for example, about 1 to 40 μm, and preferably about 3 to 30 μm. The color clear layer has the function of adding gloss to the metallic tone of the metal thin film layer and adjusting the color of the metal. For example, the color clear layer is preferably disposed in contact with the outer surface of the primer layer 2.

[0131] The color clear layer preferably contains, for example, a colorant and a resin. The color clear layer preferably contains a resin solid. The colorant is not particularly limited, but examples thereof include color pigments and dyes. The resin used in the color clear layer is preferably a transparent resin. Examples of transparent resins include acrylic resin, polyurethane resin, acrylic-urethane copolymer resin, and polyester resin. The thickness of the color clear layer is, for example, approximately 0.5 μm or more and 4 μm or less, and preferably approximately 1.1 μm or more and 2.9 μm or less.

[0132] The color clear layer can be formed by applying a composition containing the above-mentioned colorant and resin onto the surface of a layer adjacent to the color clear layer.

[0133] The clear layer has the function of diffusing the light reflected by the metal thin film layer 1 and enhancing the sense of depth of the design of the decorative sheet, for example.

[0134] The clear layer may be, for example, a layer containing a transparent resin and a particulate material. The transparent resin may be the same as that described above for the color clear layer. The particulate material may be, for example, silica particles. The thickness and formation method of the clear layer are the same as those described above for the color clear layer.

[0135] [Transparent base layer] The decorative sheet of the present disclosure may have a transparent substrate layer. The transparent substrate layer has the function of improving the scratch resistance and weather resistance of the decorative sheet. The transparent substrate layer also has the function of improving the formability of the decorative sheet of the present disclosure. When the decorative sheet of the present disclosure has a protective layer 3, the transparent substrate layer is preferably disposed between the primer layer 2 and the protective layer 3.

[0136] Examples of materials for forming the transparent substrate layer include transparent resin substrates. Examples of resins used for the transparent resin substrate include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and acrylic resins.

[0137] The thickness of the transparent substrate layer is, for example, about 15 μm or more and 200 μm or less.

[0138] Properties and uses of decorative sheets <Moisture and heat resistance> The decorative sheet of the present disclosure has a color difference ΔE * It is preferable that ab is 3.00 or less.

[0139] The conditions for the moist heat test are that the decorative sheet is left to stand for 72 hours in an environment of 60°C and a relative humidity of 90%. The moist heat test can be carried out using a thermo-hygrostat.

[0140] In this disclosure, the color difference ΔE * ab is the L of the International Commission on Illumination (CIE) specified in JISZ8729-1994. * a * b * It is a value that conforms to the color system and is expressed by the following formula. ΔE * ab={(ΔL * ) 2 +(Δa * ) 2 +(Δb * ) 2} 1 / 2 ΔE * ab can be measured with a spectrophotometer.

[0141] In addition, the color difference ΔE * ab is an index showing the change in color after the moist heat test based on the color of the decorative sheet before the moist heat test, and ΔL * , Δa * , Δb * are the L of the decorative sheet before and after the moist heat test, respectively. * value, a * value, and b * Represents the difference in values.

[0142] <Heat resistance> The decorative sheet of the present disclosure has a color difference ΔE * It is preferable that ab is 3.00 or less. The high temperature test conditions are that the decorative sheet is left standing in a constant temperature environment (110°C for 1000 hours). The color difference ΔE of the decorative sheet before and after being placed in a constant temperature environment * The heat resistance is evaluated by measuring ab. A thermostat is used to place the decorative sheet in a constant temperature environment.

[0143] <Weather resistance> The decorative sheet of the present disclosure has a color difference ΔE of the decorative sheet after a high light energy irradiation test. * It is preferable that ab is 3.00 or less. The decorative sheet was subjected to an accelerated weathering test using a xenon lamp as a light source under conditions conforming to SAE J1885. The cumulative light intensity was 2480 kJ / m 2 The sample was exposed to the test environment until the color difference ΔE * ab is measured to evaluate weather resistance.

[0144] The decorative sheet of the present disclosure is a member used to decorate the surface of an article. The decorative sheet of the present disclosure can be used in methods for manufacturing decorated articles using various decoration methods. In other words, the decorative sheet of the present disclosure can be used as a decorative sheet suitable for the application of various decoration methods.

[0145] Examples of the decorating method using the decorative sheet of the present disclosure include various injection molding methods such as insert molding, simultaneous injection molding and decoration, blow molding, and gas injection molding, and vacuum pressure bonding.

[0146] 2. Resin molded products and their manufacturing methods The resin molded article 30 of the present disclosure is formed by integrating a molded resin with the decorative sheet of the present disclosure. Specifically, the resin molded article 30 of the present disclosure includes, in this order, at least a molded resin layer, a metal thin film layer, and a primer layer adjacent to the metal thin film layer. The primer layer is formed from a cured product of a resin composition containing a resin and an alkoxysilane having an alkyl or aryl group, and the alkoxysilane having an alkyl or aryl group does not have a substituent that is reactive with the resin in the resin composition. In the resin molded article of the present disclosure, the decorative sheet may further include at least one layer, such as the aforementioned substrate 5 (substrate for lamination 5a), second primer layer 22, third primer layer 23, protective layer 3, decorative layer 4, transparent substrate layer, or adhesive layer 6, as needed.

[0147] In the first embodiment as shown in FIGS. 2 and 3, a substrate 5 may be provided on the resin molded article 30. FIG. 4 is a cross-sectional view of the resin molded article 30 in which a molded resin layer 8 is laminated on the decorative sheet shown in FIG. 3. In the second embodiment as shown in FIG. 7, a transfer substrate 5b may be provided on the resin molded article 30 as shown in FIG. 7 (a resin molded article 30 in this state is also referred to as a resin molded article 31 with a transfer substrate). FIG. 8 shows a resin molded article 30 obtained by peeling the transfer substrate from the resin molded article with a transfer substrate 31 shown in FIG. 7, and has a configuration in which a molded resin layer 8 is laminated on the decorative sheet shown in FIG. 6.

[0148] The resin molded article 30 of the present disclosure is produced using the decorative sheet of the present disclosure by various injection molding methods, such as insert molding, simultaneous injection molding and decoration, blow molding, gas injection molding, etc. Among these injection molding methods, insert molding and simultaneous injection molding and decoration are preferred.

[0149] 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 30.

[0150] More specifically, the resin molded product 30 of the present disclosure is manufactured by an insert molding method including the following steps. The decorative sheet of the present disclosure is formed into a three-dimensional shape in advance using a vacuum forming mold in a vacuum forming process; the trimming process is performed to obtain a molded sheet by trimming off excess portions of the vacuum formed decorative sheet; and the integration process is performed to insert the molded sheet into an injection molding mold, close the injection molding mold, and inject a resin in a fluid state into the injection molding mold to integrate the resin and the molded sheet.

[0151] 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. For example, when an ABS resin film is used as the substrate, the heating temperature is usually about 120 to 200°C. In addition, in the integration step, the temperature of the resin in a fluid state is not particularly limited, but it is usually about 180 to 320°C.

[0152] 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 and allowed to solidify, 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 30.

[0153] More specifically, the resin molded article 30 of the present disclosure is manufactured by an injection molding and simultaneous decoration method including the following steps. a preforming step in which the decorative sheet of the present disclosure is placed against a molding surface of a movable mold having a predetermined shape, with the surface of the base material of the decorative sheet facing the molding surface, and then the decorative sheet is heated and softened as needed, and vacuum-suctioned 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 are clamped together, the movable mold having a decorative sheet in close contact with the molding surface, and a fluid resin is injected into the cavity formed by the two molds, filled and solidified to form a resin molded body, and the resin molded body and the decorative sheet are laminated and integrated; A removal step in which the movable mold is separated from the fixed mold to remove the resin molded body formed by laminating all layers of the decorative sheet.

[0154] 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. However, when a polyester resin film or an acrylic resin film is used as the substrate, it can usually be about 70 to 130°C. Furthermore, in the injection molding step, the temperature of the resin in a fluid state is not particularly limited, but can usually be about 180 to 320°C.

[0155] In addition, the resin molded product 30 of the present disclosure can also be produced by a decoration method such as vacuum pressure bonding, in which the decorative sheet of the present disclosure is attached to a pre-prepared three-dimensional resin molded body (molded resin layer).

[0156] In the vacuum bonding method, the decorative sheet and resin molded article of the present disclosure 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 article facing the second vacuum chamber, with the base side of the decorative sheet facing the resin molded article. The two vacuum chambers are then evacuated. The resin molded article is placed on a vertically movable platform located next to the second vacuum chamber. Next, the first vacuum chamber is pressurized, and the platform is used to press the molded article against the decorative sheet. The decorative sheet is stretched and attached to the surface of the resin molded article using the pressure difference between the two vacuum chambers. Finally, the two vacuum chambers are opened to atmospheric pressure, and excess decorative sheet is trimmed as needed to obtain the resin molded article 30 of the present disclosure.

[0157] In the vacuum pressure bonding method, it is preferable to include a step of heating the decorative sheet before the step of pressing the 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 heat-pressure bonding methods. The heating temperature in this step can be selected appropriately depending on the type of resin that makes up the decorative sheet and the thickness of the decorative sheet, but when a polyester resin film or an acrylic resin film is used as the substrate, it can usually be about 60 to 200°C.

[0158] In the resin molded product 30 of the present disclosure, the molded resin layer may be formed by selecting a resin according to the intended use. The molded resin forming the molded resin layer may be a thermoplastic resin or a thermosetting resin.

[0159] Examples of thermoplastic resins include polyolefin resins such as polyethylene and polypropylene, ABS resin, styrene resin, polycarbonate (PC) resin, acrylic resin, vinyl chloride resin, etc. These thermoplastic resins may be used alone or in combination of two or more.

[0160] 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.

[0161] In the second embodiment, the resin molded product 30 is obtained by peeling and removing the transfer substrate 5b from the resin molded product 31 with a transfer substrate, which is obtained by integrating the decorative sheet and the molding resin using the simultaneous decoration with injection molding method described above. The step of peeling and removing the transfer substrate 5b can be performed at any time. For example, the transfer substrate 5b can be peeled and removed at the same time as the obtained resin molded product 31 with a transfer substrate is removed from the molding device. Furthermore, in the resin molded product 31 with a transfer substrate, the transfer substrate 5b serves as a protective sheet for the resin molded product 30. Therefore, the resin molded product 31 with a transfer substrate may be stored without being peeled after production, and the transfer substrate may be peeled off when needed. Using the resin molded product in this manner can prevent scratches on the resin molded product due to friction during transportation, etc.

[0162] The resin molded product 30 of the present disclosure has excellent heat resistance, moist heat resistance, and weather resistance, and can therefore be used, for example, as interior or exterior materials for vehicles such as automobiles; building 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]

[0163] 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.

[0164] [Examples 1 to 7 and Comparative Examples 1 to 2] <Manufacturing decorative sheets> A biaxially oriented polyethylene terephthalate sheet (E5001, manufactured by Toyobo Co., Ltd., 25 μm thick) was prepared as a release sheet. Next, an acrylic electron beam curable resin was applied to the prepared release sheet and cured using an electron beam irradiation device to form a transparent protective layer with a thickness of 10 μm. Next, an acrylic polyol and a curing agent (hexamethylene diisocyanate-based polyisocyanate) were prepared as materials for the third primer layer. The prepared third primer material was applied to the transparent protective layer to form a third primer layer with a thickness of 1 μm. Next, a mixture of acrylic polyol with a colorant and silica particles dispersed therein was prepared as a material for the decorative layer (color clear layer). The prepared decorative layer material was applied to the third primer layer to form a decorative layer with a thickness of 2 μm. Next, resin compositions having the compositions described below were prepared as resin compositions for forming the primer layer. The resin composition for forming the primer layer was applied to the decorative layer to form a primer layer with a thickness of 1 μm. Next, a metal thin film layer (tin thin film layer) was formed on the primer layer by vacuum deposition of tin to a thickness of 60 nm. Next, a polyester polyol and a curing agent (hexamethylene diisocyanate-based polyisocyanate) were prepared as a resin composition for forming the second primer layer. The prepared resin composition was applied to the tin thin film layer to form a second primer layer with a thickness of 1 μm. Next, an ABS sheet (thickness 480 μm) was attached to the second primer layer using a heat press as a lamination substrate. The release sheet was peeled off, and a decorative sheet was produced in which the protective layer 3, third primer layer 23, decorative layer 4, primer layer 2, metal thin film layer 1, second primer layer 22, and lamination substrate 5a were laminated in this order.

[0165] <Resin composition for forming primer layer> A resin composition containing 100 parts by mass of acrylic polyol as the resin, 9 parts by mass of tolylene diisocyanate-based polyisocyanate as the curing agent, and 6 parts by mass of alkoxysilane per 100 parts by mass of the resin was used. The alkoxysilanes used in each example and comparative example are as shown in Table 1.

[0166] <Heat and humidity resistance evaluation> The decorative sheet was left in a humid and hot environment (temperature 50°C, relative humidity 95% for 1000 hours), and the color difference ΔE of the decorative sheet before and after being placed in the humid and hot environment was measured. * The values ​​ab were measured to evaluate the resistance to humidity and heat. A thermo-hygrostat PR-2J (Espec Corporation) was used to place the decorative sheet in a humid and hot environment. The results are shown in Table 1. Color difference ΔE * When ab is 3.00 or less, it can be evaluated as having high resistance to moist heat.

[0167] Color difference ΔE * ab is the L of the International Commission on Illumination (CIE) specified in JISZ8729-1994. * a * b * It is a value that conforms to the color system and is expressed by the following formula. ΔE * ab={(ΔL * ) 2 +(Δa * ) 2 +(Δb * ) 2} 1 / 2 ΔE * ab was measured using a spectrophotometer CM-3700J (Konica Minolta). Color difference ΔE * ab is an index showing the change in color after the moist heat test, with the color of the decorative sheet before the moist heat test being used as the reference color, and ΔL * , Δa * , Δb * are the L of the decorative sheet before and after the moist heat test, respectively. * value, a * value, and b * The difference between the values.

[0168] <Heat resistance evaluation> The decorative sheet is left in a constant temperature environment (110°C for 1000 hours), and the color difference ΔE of the decorative sheet before and after being placed in the constant temperature environment is measured. * The heat resistance was evaluated by measuring ab. The incubator SPHH-1 (Espec Corporation) was used to place the decorative sheet in a high-temperature environment. The results are shown in Table 1. Color difference ΔE* When ab is 3.00 or less, it can be evaluated as having high heat resistance.

[0169] <Weather resistance evaluation> Accelerated weathering tests were conducted using a xenon lamp as the light source under conditions conforming to SAE J1885. The cumulative light intensity was 2480 kJ / m 2 The sample was exposed to the test environment until the color difference ΔE * The weather resistance was evaluated by measuring ab. The results are shown in Table 1. Color difference ΔE * If ab is 3.00 or less, it can be evaluated as having high weather resistance.

[0170] [Table 1] [Explanation of symbols]

[0171] 1 Metal thin film layer 2 primer layer 22 Second primer layer 23 Third primer layer 3 protective layer 4 Decorative layer 5 Base material 5a Base material for lamination 5b Transfer substrate 6 Adhesive layer 7 Transfer layer 8 Molding resin layer 10 Decorative sheet 30 Resin molded products 31 Resin molded products with transfer substrate

Claims

1. The substrate includes at least a primer layer and a metal thin film layer adjacent to the primer layer, the primer layer is formed from a cured product of a resin composition containing a resin and an alkoxysilane having an alkyl group or an aryl group, The decorative sheet, wherein the alkoxysilane having an alkyl group or an aryl group does not have a substituent reactive with the resin in the resin composition.

2. The decorative sheet according to claim 1 , wherein the metal thin film layer contains tin.

3. The decorative sheet according to claim 1 or 2, wherein the content of the alkoxysilane having an alkyl group or an aryl group in the resin composition of the primer layer is 0.4% by mass or more and 17% by mass or less.

4. The decorative sheet according to claim 1 or 2, wherein the number of carbon atoms in the alkyl group of the alkoxysilane having an alkyl group or an aryl group is 1 or more and 8 or less.

5. The decorative sheet according to claim 1 or 2, wherein the alkoxysilane having an alkyl group or an aryl group has 5 or more and 10 or less carbon atoms in the aryl group.

6. The decorative sheet according to claim 1 , wherein the resin in the resin composition of the primer layer contains a polyol.

7. The decorative sheet according to claim 1 , wherein the resin composition of the primer layer further contains a curing agent.

8. The decorative sheet according to claim 1 or 2, comprising at least a protective layer, the primer layer, the metal thin film layer adjacent to the primer layer, and a substrate, in this order.

9. 3. The decorative sheet according to claim 1, comprising at least a substrate, a protective layer, the primer layer, and a metal thin film layer adjacent to the primer layer, in this order.

10. At least a molded resin layer, a metal thin film layer, and a primer layer adjacent to the metal thin film layer in this order; the primer layer is formed from a cured product of a resin composition containing a resin and an alkoxysilane having an alkyl group or an aryl group, A resin molded article, wherein the alkoxysilane having an alkyl group or an aryl group does not have a substituent reactive with the resin in the resin composition.

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