Decorative sheet

Abstract

To provide a decorative sheet which has excellent three-dimensional feeling by an internal uneven shape.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 different in height projecting to the side of the decorative layer from the side of the transparent resin film layer, and each of the plurality of projections has a ratio (h / w) of a height (μm) to a width w (μm) of 100% or less.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] However, in recent years, the designs required for decorative sheets have increased from the traditional realistic look that mimics natural objects such as real carbon and hairlines to a more advanced three-dimensional look that expresses artificial geometric patterns and layered textures. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-82912 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure has as its main object the provision of a decorative sheet having an excellent three-dimensional effect due to an internal uneven shape, and further has as its object the provision of a decorated resin molded product using the decorative sheet. [Means for solving the problem]

[0007] The inventors of the present disclosure conducted intensive research to solve the above problems. As a result, they found that 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 setting the ratio (h / w) of the height h (μm) to the width w (μm) of each of the plurality of convex parts to 100% or less, an excellent three-dimensional effect is achieved by the uneven shape inside the decorative sheet. The present disclosure was completed based on such findings and through further research.

[0008] 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 having different heights protruding from the transparent resin film layer side to the decorative layer side, The decorative sheet, wherein the ratio (h / w) of the height h (μm) to the width w (μm) of each of the plurality of protrusions is 100% or less. 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 having different heights protruding from the transparent resin film layer side to the decorative layer side, The plurality of protrusions each have a ratio (h / w) of height h (μm) to width w (μm) of 100% or less. Effect of the Invention

[0009] According to the present disclosure, it is possible to provide a decorative sheet having an excellent three-dimensional effect due to an internal uneven shape. Also, according to the present disclosure, it is possible to provide a decorated resin molded product using the decorative sheet. [Brief description of the drawings]

[0010] [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] 1 is a schematic diagram of a cross-sectional structure of one embodiment of a decorative sheet according to the present disclosure. [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 decorative sheet according to the present disclosure. [Diagram 5] 1 is a schematic diagram of a cross-sectional structure of one embodiment of a decorative sheet according to the present disclosure. [Figure 6] 1 is a schematic diagram of a cross-sectional structure of one embodiment of a decorated resin molded product according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] 1.Decorative sheet The decorative sheet of the present disclosure is a decorative sheet comprising 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 having a plurality of convex portions of different heights protruding from the transparent resin film layer side to the decorative layer side, and each of the plurality of convex portions has a ratio (h / w) of height h (μm) to width w (μm) of 100% or less. The decorative sheet of the present disclosure has such a configuration, and thus an excellent three-dimensional effect is achieved by the internal uneven shape. The decorative sheet of the present disclosure will be described in detail below.

[0012] 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.

[0013] 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.

[0014] 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. Although not shown, an adhesive layer may be provided, if necessary, on the surface of the support film layer 3 opposite the decorative layer 2 side.

[0015] 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. FIGS. 1 and 2 show schematic diagrams of a cross-sectional structure of one embodiment of a decorative sheet in which a transparent resin film layer / decorative layer is laminated as one embodiment of the laminated structure of the decorative sheet of the present disclosure. FIGS. 3 and 4 show schematic diagrams 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 in this order as one embodiment of the laminated structure of the decorative sheet of the present disclosure. FIG. 5 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.

[0016] 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.

[0017] In the present disclosure, the uneven shape of the transparent resin film layer 1 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. Here, the plurality of convex parts 1a of different heights specifically means that the plurality of convex parts have a height difference of 5 μm or more. In the uneven shape, the ratio (h / w) of the height h (μm) to the width w (μm) of each of the plurality of convex parts 1a is 100% or less. 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 convex parts 1a of different heights, and further, by reducing the ratio (h / w) of the height h of the convex parts to the width w of the convex parts, the uneven shape can be visually recognized from various angles, and an excellent three-dimensional effect can be felt.

[0018] From the viewpoint of more suitably exerting the effects of the present disclosure, the ratio (h / w) is preferably about 10 to 100%, and more preferably about 20 to 60%.

[0019] The height h of each protrusion 1a is obtained by measuring the difference (distance) between the position of the recess 1b (line B) and the highest position of the protrusion 1a in the cross section in the thickness direction of the transparent resin film layer 1 of the decorative sheet 10, for example, as shown in the schematic diagrams of Figures 1 to 6. For example, as shown in Figure 2, when the heights of both ends of the protrusion 1a of the transparent resin film layer are different (lines B1 and B2) in the cross section in the thickness direction of the decorative sheet, the height h with the largest value is adopted. Also, as shown in Figure 2, when multiple protrusions 1a with different heights are combined to form one protrusion 1a with different heights, the height h with the largest value is adopted. Also, for multiple protrusions, three or more points on the cross section are measured and evaluated.

[0020] In order to more suitably exert the effects of the present disclosure, the height h of the protrusions 1a is preferably about 3 to 100 μm, and more preferably about 8 to 60 μm.

[0021] In order to more suitably exert the effects of the present disclosure, the width w of the protrusion 1a is preferably about 30 to 500 μm, and more preferably about 100 to 300 μm.

[0022] In order to more suitably exert the effects of the present disclosure, the width x between the protrusions 1a is preferably about 3 to 200 μm, and more preferably about 10 to 150 μm. The width x between the protrusions is the distance between the protrusions located on both sides of the protrusion 1a whose height h and width w are measured, and the smaller value is adopted.

[0023] In the decorative sheet of the present disclosure, the design expressed by the uneven shape of the transparent resin film layer 1 formed inside is not particularly limited, but for example, a striped pattern, a carbon pattern, and the like are particularly suitable.

[0024] 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 uneven shape that satisfies the above relationship may be formed in a part of the region, or may be formed in the entire region.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] [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 Fig. 1 to Fig. 6, 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] A specific example of the decorative layer 2 is a solid printed layer of a metallic color.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] [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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] [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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] Embossing In the decorative sheet 10 of the present disclosure, the above-mentioned internal uneven shape 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 adjusting the depth of an embossing plate used for embossing, it is possible to form an uneven shape in which a plurality of convex parts 1a of different heights protrude from the transparent resin film layer 1 side to the decorative layer 2 side, and the ratio (h / w) of the height h (μm) of the plurality of convex parts 1a to the width w (μm) is 100% or less.

[0057] 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.

[0058] 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 a region in which the multiple protruding portions 1a of the uneven shape satisfy the ratio (h / w).

[0059] The heating temperature in the embossing process is not particularly limited, but is preferably about 180°C to 220°C.

[0060] Furthermore, after embossing, the ratio (h / w) of the plurality of convex portions 1a of the uneven shape may be adjusted. For example, after the embossing step, the surface of the transparent resin film layer 1 may be mirror-finished to deform the uneven shape and adjust the ratio (h / w). The adjustment by mirror-finishing may be performed when the ratio (h / w) of the convex portions 1a of the uneven shape is not 100% or less in the embossing, or may be performed when it is 100% or less.

[0061] 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 improved by mirror processing. The mirror processing 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 having 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 having an iron core covered with rubber such as silicone rubber. By pressing the mirror roller, the uneven shape immediately after being formed by embossing can be deformed, and the ratio (h / w) can be adjusted to 100% or less. If the ratio (h / w) is satisfied by embossing, the mirror processing may be performed without substantially changing the ratio (h / w).

[0062] 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.

[0063] In the present disclosure, after the embossing step, the support film 3 can be laminated so as to fill the recesses of the uneven shape of the sheet, thereby adjusting the ratio (h / w) to 55% or less. The method of laminating the support film layer 3 so as to fill the recesses is as described above. The adjustment of the ratio (h / w) by laminating the support film layer 3 may be performed when the ratio (h / w) of the protruding parts 1a of the uneven shape is not 100% or less in the embossing process, or may be performed when it is 100% or less. In addition, when the ratio (h / w) is satisfied by the embossing process, the support film 3 may be laminated without substantially changing the ratio (h / w).

[0064] Furthermore, in the present disclosure, after embossing, both the mirror finish and lamination of the support film 3 can be performed, so that the ratio (h / w) is adjusted to 100% or less. Specifically, after the embossing step, a step of laminating the support film so as to fill in the recesses of the uneven shape of the sheet, and a step of performing mirror finish on the surface of the transparent resin film layer 1 opposite to the side on which the uneven shape is formed, are performed, so that the ratio (h / w) is adjusted to 100% or less. When both mirror finish and lamination of the support film 3 are performed, the order is not particularly limited, but from the viewpoint of protecting the mirror surface formed by the mirror finish, it is preferable to perform mirror finish after lamination of the support film 3.

[0065] 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 has a ratio (h / w) of height h (μm) to width w (μm) of 100% or less. 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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

[0079] 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.

[0080] [Examples 1 to 7 and Comparative Examples 1 to 3] <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, an embossing process was performed on the decorative layer using an embossing plate (forming a stripe pattern) to form a concave-convex shape. For Example 6, an adhesive (polyester resin composition polyester polyol:isocyanate=100:10) was further applied to the decorative layer by gravure printing to form an adhesive layer (thickness 30 μm).

[0081] The plate depth of the embossing plate used in each Example and Comparative Example is different. In Examples 1 to 7 and Comparative Example 3, the plate depth of the embossing plate is not uniform (plate depth is 30 to 60 μm in Examples 1 and 4 to 9, 10 to 45 μm in Example 2, and 5 to 30 μm in Example 3), whereas the plate depth of the embossing plate is uniform in Comparative Examples 1 and 2 (plate depth is 26 μm in Comparative Example 1 and 45 μm in Comparative Example 2). The cross section of the obtained decorative sheet was observed under a microscope, and three convex portions were randomly selected (having a height difference of 5 μm or more) from the uneven shape formed on the transparent resin film layer, and the width w (μm) of the convex portions, the height h (μm) of the convex portions, the ratio (h / w) of the height h to the width w of the convex portions, and the width x (μm) between the convex portions were measured. As shown in Figure 2, when the heights h of both ends of the convex portion of the transparent resin film layer are different in the cross section in the thickness direction of the decorative sheet, the larger value of height h was adopted. Also, as shown in Figure 2, when multiple convex portions of different heights are combined to form one convex portion of different heights, the larger value of height h was adopted. The width x between the convex portions is the distance between the convex portions located on both sides of the convex portion whose height h and width w were measured, and the smaller value was adopted. The results are shown in Table 1.

[0082] (3D effect rating: 1) The decorative sheet obtained above was 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.

[0083] (3D effect rating 2) The decorative sheet obtained above was 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 test sample at a 45° angle to the horizontal surface, 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.

[0084] [Table 1] [Explanation of symbols]

[0085] 1 Transparent resin film layer 1a Convex part 1b Recess 2. Decorative layer 3 Support film layer 4 Adhesive layer 5 Molded 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 having different heights protruding from the transparent resin film layer side to the decorative layer side, The decorative sheet, wherein the ratio (h / w) of the height h (μm) to the width w (μm) of each of the plurality of protrusions is 100% or less.

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 having different heights protruding from the transparent resin film layer side to the decorative layer side, The plurality of protrusions each have a ratio (h / w) of height h (μm) to width w (μm) of 100% or less.

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