Decorative sheet

Abstract

To provide a decorative sheet which has excellent three-dimensional feeling by an internal uneven shape even after molding.SOLUTION: A decorative sheet has a transparent resin film layer having an uneven shape on one surface, and a decorative layer formed along the uneven shape of the transparent resin film layer, wherein the uneven shape has a plurality of projections projecting to the side of the decorative layer from the side of the transparent resin film layer, and each of the plurality of projections is formed in a multistage.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] Conventionally, decorative resin molded products in which a decorative sheet is laminated on the surface of a resin molded product have been used for vehicle interior and exterior parts, building material interior materials, home appliance housings, etc. In the manufacture of such decorative resin molded products, a molding method is used in which a decorative sheet to which a design has been previously applied is integrated with a resin by injection molding. Representative examples of such molding methods include an insert molding method in which a decorative sheet is previously molded into a three-dimensional shape using a vacuum molding die, the decorative sheet is inserted into an injection molding die, and a resin in a fluid state is injected into the die to integrate the resin and the decorative sheet, and an injection molding simultaneous decoration method in which a decorative sheet inserted into a die during injection molding is integrated with the molten resin injected into the cavity.

[0003] For example, there are decorative sheets that have a printed layer on the back side of the acrylic film that is located on the front side of the decorative sheet, and a three-dimensional shape is expressed inside the decorative sheet by forming a concave-convex shape on the printed layer side. In such decorative sheets, the precise lines and shadows of the concave-convex shape create a sense of realism and luxury compared to patterns expressed by simple printing.

[0004] In recent years, the designs required for decorative sheets have become more diverse, and there is a demand for a greater variety of three-dimensional effects.

[0005] In addition, there is a problem in that the uneven shape formed inside the decorative sheet becomes smoother or smaller due to the heat and pressure during injection molding in methods such as insert molding of the decorative sheet, or during the preforming (vacuum molding) that precedes this, resulting in a deterioration of the high quality texture provided by the uneven shape. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2010-82912 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present disclosure has as its main object the provision of a decorative sheet that has an excellent three-dimensional effect due to the internal uneven shape even after molding, and also has as its object the provision of a decorated resin molded product using the decorative sheet. [Means for solving the problem]

[0008] The inventors of the present disclosure have conducted intensive research to solve the above problems. As a result, they have found that in a decorative sheet including a transparent resin film layer having an uneven shape on one side and a decorative layer formed along the uneven shape of the transparent resin film layer, the uneven shape has a plurality of convex parts of different heights protruding from the transparent resin film layer side to the decorative layer side, and further, by forming each of the plurality of convex parts in a multi-step shape, an excellent three-dimensional effect due to the uneven shape inside the decorative sheet can be achieved even after molding. The present disclosure has been completed based on such findings and through further research.

[0009] That is, the present disclosure provides the inventions of the following aspects. Item 1. A transparent resin film layer having an uneven shape on one surface, a decorative layer formed along the uneven shape of the transparent resin film layer; A decorative sheet comprising: the uneven shape includes a plurality of protrusions protruding from the transparent resin film layer side to the decorative layer side, The decorative sheet, wherein each of the plurality of protrusions is formed in a multi-stage shape. Item 2. The decorative sheet according to item 1, further comprising a support film layer on the decorative layer side. Item 3. The decorative sheet according to item 2, wherein the support film layer is formed so as to fill in recesses on the decorative layer side. Item 4. The decorative sheet according to item 2 or 3, further comprising an adhesive layer between the decorative layer and the support film layer. Item 5. The decorative sheet according to any one of Items 1 to 4, wherein the surface of the transparent resin film layer opposite to the decorative layer side is smooth. Item 6. A transparent resin film layer having an uneven shape on one surface, a decorative layer formed along the uneven shape of the transparent resin film layer; A molded resin layer; A decorated resin molded product comprising: the uneven shape includes a plurality of protrusions protruding from the transparent resin film layer side to the decorative layer side, The plurality of protrusions are each formed in a multi-stage shape. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide a decorative sheet that has an excellent three-dimensional effect due to the internal uneven shape even after molding. In addition, according to the present disclosure, it is also possible to provide a decorated resin molded product using the decorative sheet. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic diagram of a cross-sectional structure of one embodiment of a decorative sheet according to the present disclosure. [Diagram 2] FIG. 2 is a schematic cross-sectional view for illustrating a multi-step shape of convex portions of a transparent resin film layer. [Diagram 3] 1 is a schematic diagram of a cross-sectional structure of one embodiment of a decorative sheet according to the present disclosure. [Figure 4] 1 is a schematic diagram of a cross-sectional structure of one embodiment of a decorated resin molded product according to the present disclosure. [Diagram 5] FIG. 2 is a schematic plan view for explaining a method for measuring the width of each step and the width of the uppermost step of a convex portion of a transparent resin film layer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] 1.Decorative sheet The decorative sheet of the present disclosure is a decorative sheet including a transparent resin film layer having an uneven shape on one side and a decorative layer formed along the uneven shape of the transparent resin film layer, and the uneven shape has a plurality of convex portions protruding from the transparent resin film layer side to the decorative layer side, and each of the plurality of convex portions is formed in a multi-step shape. By having such a configuration, the decorative sheet of the present disclosure exhibits an excellent three-dimensional effect due to the internal uneven shape even after molding. The decorative sheet of the present disclosure will be described in detail below.

[0013] Laminated structure of decorative sheet As shown in Fig. 1, the decorative sheet 10 of the present disclosure includes at least a transparent resin film layer 1 and a decorative layer 2. The transparent resin film layer 1 has an uneven shape on one surface. The decorative layer 2 is formed along the uneven shape of the transparent resin film layer 1. That is, the surface of the decorative layer 2 opposite the transparent resin film layer 1 has an uneven shape. It is preferable that the surface of the transparent resin film layer 1 opposite the surface having the uneven shape is smooth.

[0014] The decorative sheet 10 of the present disclosure may include a support film layer 3 on the decorative layer 2 side, if necessary, for the purpose of improving shape retention. The support film layer 3 may be formed so as to fill in the recesses of the uneven shape on the decorative layer 2 side. Note that the entire recesses may be filled with the support film layer 3, or a part of the recesses may be filled with the support film layer 3, and a gap may exist between the support film layer 3 and the uneven shape on the decorative layer 2 side.

[0015] In addition, in the decorative sheet 10 of the present disclosure, an adhesive layer 4 may be provided, if necessary, between the decorative layer 2 and the support film layer 3. In addition, although not shown, an adhesive layer may be provided, if necessary, on the surface of the support film layer 3 opposite to the decorative layer 2 side.

[0016] Examples of the laminated structure of the decorative sheet of the present disclosure include a laminated structure in which a transparent resin film layer / decorative layer is laminated in this order; a laminated structure in which a transparent resin film layer / decorative layer / support film layer is laminated in this order; a laminated structure in which a transparent resin film layer / decorative layer / adhesive layer / support film layer is laminated in this order; and a laminated structure in which a transparent resin film layer / decorative layer / adhesive layer / support film layer / adhesive layer is laminated in this order. FIG. 1 shows a schematic diagram of a cross-sectional structure of one embodiment of a decorative sheet in which a transparent resin film layer / decorative layer / support film layer is laminated, as one embodiment of the laminated structure of the decorative sheet of the present disclosure. FIG. 3 shows a schematic diagram of a cross-sectional structure of one embodiment of a decorative sheet in which a transparent resin film layer / decorative layer / adhesive layer / support film layer is laminated in this order, as one embodiment of the laminated structure of the decorative sheet of the present disclosure.

[0017] Decorative sheet uneven shape The decorative sheet 10 of the present disclosure includes a transparent resin film layer 1 having an uneven shape on one surface, and a decorative layer 2 formed along the uneven shape of the transparent resin film layer 1. That is, the uneven shape formed at the interface between the transparent resin film layer 1 and the decorative layer 2 constitutes the uneven shape inside the decorative sheet. When the decorative sheet of the present disclosure is observed from the transparent resin film layer 1 side (that is, the side that is visible when the decorative sheet 10 is laminated with the molded resin layer 5 to form the decorated resin molded product 20), the uneven shape is visible through the transparent resin film layer 1, and a high three-dimensional effect can be felt.

[0018] In the present disclosure, the uneven shape of the transparent resin film layer 1 includes a plurality of protruding portions 1a protruding from the transparent resin film layer 1 side to the decorative layer 2 side. In the uneven shape, the plurality of protruding portions 1a are each formed in a multi-step shape. That is, in the decorative sheet of the present disclosure, the uneven shape of the transparent resin film layer 1 formed inside the decorative sheet is formed with a plurality of protruding portions 1a in a multi-step shape, thereby expressing a three-dimensional design like a pyramid viewed from above, and further, the stepped edges are formed on the protruding portions, so that the three-dimensional shape is suitably prevented from being damaged by heat and pressure during molding of the decorative sheet, and even after molding, an excellent three-dimensional effect due to the internal uneven shape can be expressed.

[0019] Furthermore, in the decorative sheet 10 of the present disclosure, by adjusting the height H of each multi-step convex portion 1a, the number of steps, the height h of each step, the width wn of each step, the width w of the top step, and even the shape of the convex portion 1a when viewed in a plane, and by making the shape of the convex portion 1a when viewed in a plane polygonal or circular, the individual convex portions can be made multi-stepped in various shapes, and it is possible to impart a variety of designs to the surface of the decorated resin molded product.

[0020] For example, the schematic diagram of Fig. 2 illustrates a case where the number of steps of the protrusion 1a is three, the total height of the protrusion 1a is H, the height of the first step is h1, the height of the second step is h2, the height of the third step is h3, the width of the first step is w1, the width of the second step is w2, and the width of the third step (i.e., the width of the top step) is w. Also, Fig. 5 illustrates a schematic diagram where the shape of the protrusion 1a when viewed from above is a rhombus.

[0021] The number of steps of the convex portion 1a is not particularly limited, but if the shape of each convex portion is to be multi-stepped even after the decorative sheet is formed, it is preferable to have, for example, about 2 to 9 steps, depending on the width w and height h of each step.

[0022] From the viewpoint of suitably exerting the effects of the present invention, the height H (total height) of the protrusion 1a is preferably about 3 to 100 μm, and more preferably about 8 to 60 μm.

[0023] In order to favorably exert the effects of the present invention, the height h of each step of the protrusion 1a is preferably about 3 to 50 μm, and more preferably about 8 to 30 μm.

[0024] In order to favorably exert the effects of the present invention, the width wn of each step of the protrusion 1a is preferably about 10 to 200 μm, and more preferably about 20 to 100 μm.

[0025] In order to favorably exert the effects of the present invention, the width w of the uppermost step of the protrusion 1a is preferably about 10 to 300 μm, and more preferably about 20 to 200 μm.

[0026] The width of each step and the width of the top step are values ​​measured in a direction perpendicular to the sides forming the periphery (outer edge) of the protrusion when the protrusion is viewed in a plane (for example, as shown in the schematic diagram of Figure 5, in the case of a diamond, the direction is perpendicular to the opposing sides, and in the case of a circle, the direction is perpendicular to the tangent).

[0027] 1, 3 and 4 show an example in which each protrusion 1a is disposed independently of the other, but each protrusion 1a may be connected to each other at least in a part. An example in which each protrusion 1a is connected to each other is an example in which a plurality of protrusions (multi-step protrusions) constituting each protrusion 1a are connected to each other to form one layer having a concave-convex shape.

[0028] The pattern in which the protrusions 1a are arranged is not particularly limited. For example, by arranging a large number of protrusions 1a in a matrix, a decorative sheet 10 having protrusions 1a formed in a matrix on the surface thereof can be obtained.

[0029] The shape of each convex portion 1a when viewed in plan (shape of the outer edge) is not particularly limited, and may be, for example, a polygonal shape (e.g., a triangle, a quadrilateral (square, rectangle, diamond, etc.), a pentagon, a hexagon, etc.), a circle (perfect circle, ellipse, etc.), or other geometric pattern.

[0030] In the decorative sheet of the present disclosure, the above-mentioned uneven shape may be formed in at least a part of the region that imparts a high three-dimensional effect due to the uneven shape when the decorative sheet is observed from the transparent resin film layer 1. That is, in the decorative sheet of the present disclosure, the above-mentioned uneven shape may be formed in a part of the region, or may be formed in the entire region.

[0031] Composition of each layer that forms the decorative sheet [Transparent resin film layer 1] In the decorative sheet 10 of the present disclosure, the transparent resin film layer 1 is usually a layer provided so as to be located on the outermost surface of the decorative sheet 10 and the decorated resin molded product 20. From the viewpoint of improving the formability of the decorative sheet 10 of the present disclosure, the material of the transparent resin film layer 1 is preferably a thermoplastic resin. In addition, since the decorated resin molded product using the decorative sheet of the present disclosure is observed from the transparent resin film layer 1 side, in order to express a high three-dimensional effect due to the above-mentioned uneven shape, the transparent resin film layer 1 needs to have transparency. Note that the transparency referred to here includes translucency to the extent that the uneven shape can be seen through the transparent resin film layer 1, and colored transparency.

[0032] The transparent resin film layer 1 has an uneven shape on one surface. As described later, the uneven shape is formed by embossing. For example, the transparent resin film layer 1 and the decorative layer 2 are laminated together, and embossing is performed from the decorative layer 2 side, so that the uneven shape extending from the decorative layer 2 to the transparent resin film layer 1 can be formed.

[0033] The thermoplastic resin used in the transparent resin film layer 1 is preferably an acrylic resin, a vinyl chloride resin, an ABS resin (acrylonitrile-styrene-butadiene copolymer), a styrene resin, a polycarbonate resin, a polyester resin such as polyethylene terephthalate or a moldable polyester resin, or a polyolefin resin such as polyethylene, polypropylene, polymethylpentene, polybutene, an ethylene-propylene copolymer, a propylene-butene copolymer, or an olefin thermoplastic elastomer. Among these, an acrylic resin or a polyester resin is more preferable, and an acrylic resin is particularly preferable. The thermoplastic resin may be used alone or in combination of two or more kinds.

[0034] Examples of the acrylic resin include polymethyl(meth)acrylate, polybutyl(meth)acrylate, methyl(meth)acrylate-butyl(meth)acrylate copolymer, methyl(meth)acrylate-styrene copolymer, and the like, which may be used alone or in combination of two or more. In the present disclosure, (meth)acrylate means acrylate or methacrylate.

[0035] As the polyester resin, polyester thermoplastic elastomers, amorphous polyesters, etc. can be used. The polyester thermoplastic elastomers include block polymers using aromatic polyesters with high crystallinity and high melting points as hard segments and amorphous polyethers with glass transition temperatures of -70°C or lower as soft segments, and the aromatic polyesters with high crystallinity and high melting points are, for example, polybutylene terephthalate, and the amorphous polyethers are, for example, polytetramethylene glycol. As the amorphous polyesters, a representative example is ethylene glycol-1,4-cyclohexanedimethanol-terephthalic acid copolymer.

[0036] As the transparent resin film layer 1, for example, a single-layer or multi-layer resin film made of the above-mentioned resin can be used. In addition, various additives such as stabilizers, plasticizers, colorants, ultraviolet absorbers, hindered amine-based light stabilizers, and extender pigments may be added to the transparent resin film layer 1 as necessary to adjust the physical properties. These additives may be used alone or in combination of two or more. The transparent resin film layer 1 may be colored to the extent that transparency is not impaired. For coloring the transparent resin film layer 1, for example, known colorants exemplified for the decorative layer 2 described later can be used.

[0037] The thickness of the transparent resin film layer 1 (total thickness in the case of a multi-layered film) is not particularly limited, but is preferably about 30 to 300 μm, more preferably about 100 to 200 μm, from the viewpoints of cost, performance required for a decorated resin molded product, formability of the decorative sheet, etc. The thickness of the transparent resin film layer 1 refers to the thickness of a portion where no concave portion of the uneven shape is formed.

[0038] The front surface, back surface, or both front and back surfaces of the transparent resin film layer 1 may be subjected to a known adhesion enhancing treatment such as corona discharge treatment, plasma treatment, formation of a primer layer using a urethane resin, etc., as necessary, in order to improve adhesion with other layers in contact with the transparent resin film layer 1.

[0039] In addition, a surface protective layer (not shown) may be further provided on at least a portion of the surface of the transparent resin film layer 1 opposite the decorative layer 2, if necessary, for the purposes of improving the surface properties of the decorative sheet or achieving a matte design.

[0040] The resin forming the surface protective layer is not particularly limited, and examples thereof include thermosetting resins, ionizing radiation curing resins, and thermoplastic resins. Specific examples of the resin forming the surface protective layer include a two-component curing resin and a matte coating agent containing a matte agent. Here, the two-component curing resin is preferably a two-component curing resin of polyol and isocyanate.

[0041] As the polyol, there are various types such as acrylic polyol, polyester polyol, epoxy polyol, etc., but acrylic polyol is preferred. As the acrylic polyol, there are vinyl chloride modified acrylic polyol, vinyl chloride-vinyl acetate modified acrylic polyol, chlorinated polyolefin modified acrylic polyol, methyl (meth)acrylate-2 hydroxyethyl (meth)acrylate copolymer, octyl (meth)acrylate-ethylhexyl (meth)acrylate-2 hydroxyethyl (meth)acrylate copolymer, methyl (meth)acrylate-butyl (meth)acrylate-2 hydroxyethyl (meth)acrylate-styrene copolymer, etc., but vinyl chloride modified acrylic polyol is particularly preferred.

[0042] Also, as the isocyanate, a conventionally known compound may be appropriately used. For example, aromatic isocyanates such as 2,4-tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), naphthalene diisocyanate, and 4,4'-diphenylmethane diisocyanate, or polyisocyanates such as aliphatic (or alicyclic) isocyanates such as 1,6-hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), methylene diisocyanate (MDI), hydrogenated tolylene diisocyanate, and hydrogenated diphenylmethane diisocyanate, may be used. Alternatively, adducts or oligomers of these various isocyanates, such as adducts of tolylene diisocyanate and tolylene diisocyanate trimer, may also be used.

[0043] The matte agent used in the matte coating agent is not particularly limited, but may be, for example, particles made of inorganic substances such as silica, alumina, calcium carbonate, aluminosilicate, barium sulfate, etc., or organic polymers such as acrylic beads, polyethylene, urethane resin, polycarbonate, polyamide (nylon), etc. The average particle size of the particles is preferably 0.5 to 20 μm, more preferably 0.5 to 10 μm, and the amount added is preferably 2 to 40 mass %, more preferably 5 to 30 mass %, based on the matte coating agent (excluding the solvent). The shape of the particles is polyhedral, spherical, scaly, etc. Among the above inorganic or organic particles, silica is preferred.

[0044] Moreover, the matte agent is preferably transparent. As such a matte agent, for example, inorganic matte agents consisting of particles such as silica, spherical silica, alumina, kaolinite, calcium carbonate, barium sulfate, glass, etc., and organic matte agents such as polycarbonate resin, acrylic resin, polyamide (nylon) resin, urea resin, silicon-based resin, etc. can be used. The particle shape of the matte agent is spherical, polyhedral, scale-like, etc. Furthermore, the particle size of the matte agent is about 1 to 10 μm. The amount of the matte agent to be added may be an amount according to the required low gloss level. Furthermore, as the surface protection layer is the outermost surface, it is also preferable to select a matte agent having excellent abrasion resistance. Examples of such matte agents include spherical silica and alumina. The average particle size of the matte agent is usually 1 to 10 μm.

[0045] [Decorative layer 2] In the decorative sheet of the present disclosure, the decorative layer 2 is a layer provided along the uneven shape of the transparent resin film layer in order to impart a high three-dimensional effect to the decorative sheet by the uneven shape. For example, as shown in Figures 1, 3 and 4, the decorative layer 2 is laminated along the uneven shape of the transparent resin film layer 1, and the decorative layer 2 fills the recesses 1b of the uneven shape of the transparent resin film layer 1. In addition, the surface of the decorative layer 2 opposite to the transparent resin film layer 1 has a recess.

[0046] The decorative layer 2 can be formed of a pattern layer and / or a solid print layer. The pattern of the pattern layer is arbitrary, but can be selected according to the design expressed by the uneven shape of the transparent resin film layer 1. As the pattern of the pattern layer, in addition to the above-mentioned stripe pattern and carbon pattern, for example, wood grain, stone grain, cloth grain, sand grain, leather pattern, tile pattern, brick pattern, geometric pattern, letters, symbols, etc., are used alone or in combination according to the purpose.

[0047] The decorative layer 2 can be formed by applying (printing) an ink composition for forming a decorative layer onto the transparent resin film layer 1. The ink composition for forming a decorative layer is composed of a binder resin, a colorant such as a pigment or dye, and various additives added thereto as appropriate. Examples of the binder resin include acrylic resin, vinyl chloride-vinyl acetate copolymer, polyester resin, cellulose resin, chlorinated polypropylene, urethane resin, and polyamide resin. A single resin selected from the above, or a mixed resin of two or more types is used. The binder resin may be used alone or in combination of two or more types.

[0048] Examples of colorants that can be used include inorganic pigments such as titanium white, zinc white, carbon black, iron black, red oxide, chrome vermilion, cadmium red, ultramarine blue, cobalt blue, yellow lead, and titanium yellow, organic pigments (including dyes) such as phthalocyanine blue, indanthrene blue, isoindolinone yellow, benzidine yellow, quinacridone red, polyazo red, and perylene red, metal pigments made of scaly foil powder such as aluminum and brass, and pearlescent (pearl) pigments made of scaly foil powder such as titanium dioxide-coated mica and basic lead carbonate. The colorants may be used alone or in combination of two or more.

[0049] A specific example of the decorative layer 2 is a solid printed layer of a metallic color.

[0050] The decorative layer 2 can be formed by applying ink for forming a decorative layer onto the transparent resin film layer 1 by a printing method such as gravure printing, silk screen printing, or offset printing, or a known coating method such as roll coating.

[0051] The thickness of the decorative layer 2 is not particularly limited, but is preferably about 0.5 to 20 μm, and more preferably about 1 to 10 μm. The thickness of the decorative layer 2 refers to the thickness of the portion where the concave portions of the uneven shape are not formed.

[0052] The decorative layer 2 may be a metal thin film layer. Examples of metals forming the metal thin film layer include tin, indium, chromium, aluminum, nickel, copper, silver, gold, platinum, zinc, and alloys containing at least one of these metals. The method for forming the metal thin film layer is not particularly limited, and examples include deposition methods such as vacuum deposition, sputtering, and ion plating using the above metals. In this case, the thickness of the decorative layer 2 (metal thin film layer) is not particularly limited, but from the viewpoint of enhancing the design and formability of the decorative sheet, the optical density (OD value) is about 0.6 to 1.8, preferably about 0.8 to 1.5. In addition, in order to improve adhesion with adjacent layers, an adhesive layer using a known resin may be provided on the front and back surfaces of the metal thin film layer.

[0053] [Support film layer 3] In the decorative sheet of the present disclosure, the support film layer 3 is a layer that is provided on the decorative layer 2 side (the side opposite to the transparent resin film layer 1) of the decorative sheet 10 as necessary to fulfill the role of a support member. When used in the production of a decorated resin molded product by the insert molding method described below, the decorative sheet of the present disclosure preferably has the support film layer 3.

[0054] The material of the support film layer 3 is not particularly limited, but examples thereof include ABS resin, polyolefin resin, styrene resin, (meth)acrylic resin, vinyl chloride resin, polycarbonate resin, etc. As the polyolefin resin, polypropylene resin is preferable. Among these resins, ABS resin and polypropylene resin are particularly preferable. Furthermore, when the molding resin constituting the molded resin layer 5 is ABS resin, ABS resin is preferable, and when it is polypropylene resin, polypropylene resin is preferable.

[0055] 3 to 5, in the decorative sheet of the present disclosure, the support film layer 3 may be laminated so as to fill in the concaves of the uneven shape on the decorative layer 2 side. As a method for filling the concaves with the support film layer 3, for example, there is a method in which the support film layer 3 is softened by heating and then laminated on the surface on which the uneven shape is formed.

[0056] In the decorative sheet 10 of the present disclosure, all of the uneven recesses on the decorative layer 2 side (the uneven recesses of the decorative layer 2, and if an adhesive layer 4 described below is further provided, the uneven recesses of the adhesive layer 4, etc.) may be filled with the support film layer 3, or only a portion of the recesses may be filled with the support film layer 3, and a gap may exist between the support film layer 3 and the uneven recesses on the decorative layer 2 side.

[0057] The thickness of the support film layer 3 is not particularly limited and may be, for example, about 0.1 to 0.5 mm, more preferably about 0.2 to 0.4 mm. The thickness of the support film layer 3 refers to the thickness of the portion that does not fill the recesses of the uneven shape on the decorative layer 2 side of the decorative sheet 10.

[0058] [Adhesive layer 4] In the decorative sheet 10 of the present disclosure, an adhesive layer 4 may be provided between the decorative layer 2 and the support film layer 3, if necessary, for the purpose of increasing adhesion between these layers. Although not shown in the drawings, an adhesive layer may be provided on the surface of the support film layer 3 opposite to the decorative layer 2, if necessary.

[0059] In the present disclosure, when the adhesive layer 4 is provided between the decorative layer 2 and the support film layer 3, an uneven shape can be formed by embossing the decorative layer 2 from the side opposite the transparent resin film layer 1, and then the adhesive layer can be formed on top of the uneven shape.

[0060] Examples of the adhesive material constituting the adhesive layer 4 include a two-component curing urethane resin using an isocyanate as a curing agent, a chlorinated polyolefin such as chlorinated polypropylene, a (meth)acrylic resin, a vinyl chloride-vinyl acetate copolymer, and a mixture of a (meth)acrylic resin and a vinyl chloride-vinyl acetate copolymer. The (meth)acrylic resin and the vinyl chloride-vinyl acetate copolymer in the adhesive layer may be the same as those used for the decorative layer 2. When the support film layer 3 is an ABS resin or a polyolefin resin, it is preferable to use a two-component curing urethane resin using an isocyanate as a curing agent, a chlorinated polyolefin such as chlorinated polypropylene, or the like as the adhesive layer.

[0061] The adhesive layer 4 can be formed by applying the above-mentioned adhesive to a known printing or coating method such as gravure printing, roll coating, etc. The thickness of the adhesive layer is not particularly limited and is usually about 1 to 50 μm.

[0062] Embossing In the decorative sheet 10 of the present disclosure, the internal uneven shape described above can be formed by embossing. Specifically, a sheet having at least a transparent resin film layer 1 and a decorative layer 2 is prepared, and the sheet is embossed from the decorative layer 2 side to form an uneven shape with recesses reaching the transparent resin film layer 1. By making the shape of the protrusions formed by the embossing plate multi-stepped, it is possible to form an uneven shape having a plurality of multi-stepped protrusions 1a protruding from the transparent resin film layer 1 side to the decorative layer 2 side.

[0063] The embossing method is usually carried out by applying heat and pressure. The embossing method by applying heat and pressure is a method in which the surface of the sheet is heated and softened, pressed with an embossing plate to form the uneven pattern of the embossing plate, and then cooled and fixed. The shape of the embossing plate used for the embossing process corresponds to the uneven shape formed on the transparent resin film layer 1 and the decorative layer 2. For example, a known sheet-fed or rotary embossing machine can be used for the embossing process.

[0064] In the embossing method using heat and pressure, for example, there is a method in which embossing is performed on the decorative layer 2, and a method in which the decorative layer 2 is applied on top of the uneven shape of the transparent resin film layer 1 that has already been given an uneven shape, so as to follow the uneven shape. For example, by embossing, an embossing plate can reach from the decorative layer 2 to the transparent resin film layer 1, thereby forming recesses that reach the transparent resin film layer 1. Specifically, a sheet having a layer including at least the decorative layer 2 and the transparent resin film layer 1 is prepared, and embossing is performed from above the decorative layer 2 to form an area provided with an uneven shape having a plurality of multi-stepped protrusions 1a.

[0065] The heating temperature in the embossing process is not particularly limited, but is preferably about 180°C to 220°C.

[0066] As described above, the surface of the transparent resin film layer 1 opposite to the surface having the uneven shape is preferably smooth, and the smoothness can be enhanced by mirror finishing. The mirror finishing of the surface of the transparent resin film layer 1 can be performed using a mirror roller or the like. Specifically, the sheet after embossing can be passed between a heated mirror roller and a rubber roller to apply heat and pressure. The mirror roller is pressed against the surface of the transparent resin film layer 1, and the back side of the sheet is pressed with a rubber sheet. The mirror roller can be a metal roller with a mirror surface made by chrome plating or the like on the surface of an iron core, and the rubber roller can be a roller with an iron core surface covered with rubber such as silicone rubber.

[0067] The mirror finish can impart excellent mirror properties to the front side of the transparent resin film layer 1. The mirror properties are preferably 1 μm or less, more preferably 0.1 μm or less, in terms of arithmetic mean roughness Ra according to JIS B0601 (1996). In other words, the mirror-finished surface is a surface whose arithmetic mean roughness Ra is preferably 1 μm or less, more preferably 0.1 μm or less.

[0068] 2. Decorative resin moldings The decorated resin molded product 20 of the present disclosure is formed by integrating the decorative sheet 10 of the present disclosure with a molded resin. That is, the decorated resin molded product 20 of the present disclosure is a decorated resin molded product including at least a transparent resin film layer 1 having an uneven shape on one surface, a decorative layer 2 formed along the uneven shape of the transparent resin film layer 1, and a molded resin layer 5, and the uneven shape includes a plurality of convex parts 1a of different heights protruding from the transparent resin film layer 1 side to the decorative layer 2 side, and each of the plurality of convex parts 1a is formed in a multi-step shape. In addition, as described for the decorative sheet 10 of the present disclosure, the decorated resin molded product may be provided with a support film layer 3, an adhesive layer 4, and an adhesive layer provided on the surface of the support film layer 3 opposite to the decorative layer 2 side.

[0069] The decorated resin molded product of the present disclosure is produced, for example, by various injection molding methods, such as insert molding, simultaneous injection molding and decoration, blow molding, and gas injection molding, using the decorative sheet of the present disclosure. Among these injection molding methods, the insert molding and simultaneous injection molding and decoration are preferred. The decorated resin molded product 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 three-dimensional resin molded body (molded resin layer) prepared in advance.

[0070] In the insert molding method, first, in a vacuum forming step, the decorative sheet of the present disclosure is vacuum-formed in advance into the surface shape of the molded product (offline preforming) using a vacuum forming mold, and then excess parts are trimmed as necessary to obtain a molded sheet. This molded sheet is inserted into an injection mold, the injection mold is clamped, and a fluid resin is injected into the mold and solidified, and the decorative sheet is integrated with the outer surface of the resin molded product at the same time as injection molding, thereby producing a decorated resin molded product.

[0071] More specifically, the decorated resin molded product of the present disclosure is produced by an insert molding method including the following steps. A vacuum forming process in which the decorative sheet of the present disclosure is formed into a three-dimensional shape in advance using a vacuum forming mold; A trimming step of trimming an excess portion of the vacuum-formed decorative sheet to obtain a molded sheet; and An integration process in which the molded sheet is inserted into an injection mold, the mold is closed, and fluid resin is injected into the mold to integrate the resin and the molded sheet.

[0072] In the vacuum forming step in the insert molding method, the decorative sheet may be heated and molded. The heating temperature is not particularly limited and may be appropriately selected depending on the type of resin constituting the decorative sheet, the thickness of the decorative sheet, etc., but is usually about 100 to 250°C, preferably about 130 to 200°C. In the integration step, the temperature of the resin in a fluid state is not particularly limited, but is usually about 180 to 320°C, preferably about 220 to 280°C.

[0073] In addition, in the simultaneous injection molding decoration method, the decorative sheet of the present disclosure is placed in a female mold that also serves as a vacuum forming mold and is provided with suction holes for injection molding, and preforming (in-line preforming) is performed using this female mold.The injection molding mold is then clamped, and a fluid resin is injected to fill the mold and solidify.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 to produce a decorated resin molded product.

[0074] More specifically, the decorated resin molded article of the present disclosure is produced by a simultaneous injection molding and decoration method including the following steps. a preforming step of placing the decorative sheet of the present disclosure against a molding surface of a movable mold having a predetermined shape, with the surface of the decorative sheet opposite the transparent resin film layer 1 facing the molding surface, and then heating and softening the decorative sheet while vacuum-suctioning the decorative sheet from the movable mold side to bring the softened decorative sheet into close contact with the molding surface of the movable mold, thereby preforming the decorative sheet; an integration process in which a movable mold and a fixed mold are clamped together, the movable mold and the fixed mold have a decorative sheet in close contact with each other along their molding surfaces, and then a resin in a fluid state is injected into a cavity formed by the two molds, filled therein, and solidified to form a resin molded body, and the resin molded body and the decorative sheet are laminated and integrated together; A removal process in which the movable mold is separated from the fixed mold to remove a resin molded body including all layers of the decorative sheet laminated thereon.

[0075] In the preforming step of the simultaneous injection molding and decoration method, the heating temperature of the decorative sheet is not particularly limited and may be appropriately selected depending on the type of resin constituting the decorative sheet, the thickness of the decorative sheet, etc., but is usually about 70 to 130° C. In the injection molding step, the temperature of the resin in a fluid state is not particularly limited, but is usually about 180 to 320° C., preferably about 220 to 280° C.

[0076] In the vacuum bonding method, first, the decorative sheet and the resin molded body of the present disclosure are placed in a vacuum bonding machine consisting of a first vacuum chamber located on the upper side and a second vacuum chamber located on the lower side, so that the decorative sheet faces the first vacuum chamber side, the resin molded body faces the second vacuum chamber side, and the side of the decorative sheet opposite the transparent resin film layer 1 faces the resin molded body side, and the two vacuum chambers are placed in a vacuum state. The resin molded body is placed on a lifting platform provided on the second vacuum chamber side that can be raised and lowered up and down. Next, the first vacuum chamber is pressurized, and the lifting platform is used to press the molded body against the decorative sheet, and the decorative sheet is attached to the surface of the resin molded body while stretching it by utilizing the pressure difference between the two vacuum chambers. Finally, the two vacuum chambers are opened to atmospheric pressure, and the excess part of the decorative sheet is trimmed as necessary, thereby obtaining the decorated resin molded product of the present disclosure.

[0077] In the vacuum pressure bonding method, it is preferable to include a step of heating the decorative sheet before the step of pressing the above-mentioned molded body against the decorative sheet in order to soften the decorative sheet and improve its formability. The vacuum pressure bonding method including this step is sometimes called a vacuum heat and pressure bonding method. The heating temperature in this step may be appropriately selected depending on the type of resin constituting the decorative sheet, the thickness of the decorative sheet, etc., but can usually be about 60 to 200°C.

[0078] In the decorated resin molded product of the present disclosure, the molded resin layer may be formed by selecting a resin according to the application. The resin forming the molded resin layer may be a thermoplastic resin or a thermosetting resin.

[0079] Examples of the thermoplastic resin include polyolefin resins such as polyethylene and polypropylene, ABS resins, styrene resins, polycarbonate resins, acrylic resins, vinyl chloride resins, etc. These thermoplastic resins may be used alone or in combination of two or more.

[0080] 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.

[0081] The decorated resin molded product of the present disclosure has a high three-dimensional effect, such as a sense of unevenness, three-dimensionality, and a sense of depth, due to its uneven shape, and further has a high surface smoothness, so it can be used, for example, as interior or exterior materials for vehicles such as automobiles; building materials 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. EXAMPLES

[0082] The present disclosure will be described in detail below with reference to examples and comparative examples. However, the present disclosure is not limited to the examples.

[0083] [Examples 1 to 5 and Comparative Example 1] <Manufacturing of decorative sheets> As the transparent resin film layer, an acrylic film (thickness 125 μm) with smooth surfaces on both sides was prepared. An ink composition (polybutyl methacrylate / vinyl chloride-vinyl acetate copolymer) was applied to one side of the transparent resin film layer by gravure printing to form a decorative layer (thickness 5 μm). Next, from above the decorative layer, embossing was performed using an embossing plate (an embossing plate in which a plurality of concave portions having a diamond, triangle, or square shape in plan view (see Table 1) are formed by the convex portions of the embossing plate, and the shape of the convex portions corresponds to the shape of the convex portions of the transparent resin film layer) to form a concave-convex shape. For Example 5, an adhesive (polyester resin composition polyester polyol:isocyanate=100:10) was further applied from above the decorative layer by gravure printing to form an adhesive layer (thickness 30 μm).

[0084] The embossing plates used in each Example and Comparative Example are different from each other. In Examples 1 to 5, the convex parts of the embossing plate (i.e., the convex parts of the transparent resin film layer) are formed in multiple steps, and the number of steps of the convex parts, the height H, the height h of each step, the widths w1 to w6 of each step, and the width w of the top step are as shown in Table 1. For example, in Example 1, each convex part of the transparent resin film layer is formed in a diamond shape in a plan view in a multiple step (step-like) shape, and the height H of the convex parts is 76 μm, the height h of each step is 11 μm, the width wn of each step is 35 μm, and the width w of the top step is 100 μm. The widths of each step and the width of the top step are values ​​measured in a perpendicular direction to the sides forming the periphery (outer edge) of the convex parts when viewed in a plan view (for example, in the case of a diamond shape, in a perpendicular direction to the sides facing each other, as shown in the schematic diagram of FIG. 5). The results are shown in Table 1.

[0085] <Manufacturing of decorated resin molded products> The decorative sheet was placed in a vacuum forming machine (Fuse Vacuum Co., Ltd. "VPF-T1") and heated with a heater until the surface temperature reached 160°C, followed by vacuum forming. The formed decorative sheet was removed and trimmed, and then the decorative layer side was integrated with the molding resin by insert molding to obtain a decorated resin molded product. A mixture of polycarbonate and ABS resin (product name: Cycoloy IP1000BK GE Plastic) was used as the molding resin.

[0086] (Evaluation of three-dimensional effect) The decorative sheet obtained above, the decorative sheet after molding, and the decorated resin molded product were each used as a test sample, and placed on a horizontal surface under a white fluorescent lamp with the transparent resin film layer facing up. Next, the test sample was visually observed from a distance of about 50 cm from the horizontal surface at a 90° angle (directly above), and the three-dimensional effect was evaluated according to the following evaluation criteria. The evaluation criteria are as follows. A+: The uneven shape was clearly visible, and the three-dimensional effect was strongly felt by visual inspection. A: The uneven shape was visible, and a three-dimensional effect was felt by visual inspection. B: The uneven shape is somewhat difficult to see, but it is possible to confirm that the uneven shape creates a three-dimensional design. C: No irregularities were observed.

[0087] [Table 1] [Explanation of symbols]

[0088] 1 Transparent resin film layer 1a Convex part 2. Decorative layer 3 Support film layer 4 Adhesive layer 5 Molding resin layer 10 Decorative sheet 20 Decorative resin moldings

Claims

1. A transparent resin film layer having an uneven shape on one surface thereof; a decorative layer formed along the uneven shape of the transparent resin film layer; A decorative sheet comprising: the uneven shape includes a plurality of protrusions protruding from the transparent resin film layer side to the decorative layer side, The decorative sheet, wherein each of the plurality of protrusions is formed in a multi-stage shape.

2. The decorative sheet according to claim 1 , further comprising a support film layer on the decorative layer side.

3. The decorative sheet according to claim 2 , wherein the support film layer is formed so as to fill in recesses on the decorative layer side.

4. The decorative sheet according to claim 2 or 3, further comprising an adhesive layer between the decorative layer and the support film layer.

5. The decorative sheet according to any one of claims 1 to 4, wherein the surface of the transparent resin film layer opposite to the decorative layer is smooth.

6. A transparent resin film layer having an uneven shape on one surface thereof; a decorative layer formed along the uneven shape of the transparent resin film layer; A molded resin layer; A decorated resin molded product comprising: the uneven shape includes a plurality of protrusions protruding from the transparent resin film layer side to the decorative layer side, The plurality of protrusions are each formed in a multi-stage shape.

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