Decorative sheet, decorative molded article, and method for manufacturing decorative molded article

Abstract

To provide a decorative sheet having a small change in designability before and after stretching.SOLUTION: A decorative sheet comprising a resin substrate layer, a colored layer, and a transparent resin layer in this order in a thickness direction, wherein in an L * a * b * color system, an absolute value of a difference between L * by an SCE method measured from a transparent resin layer side after subjecting the decorative sheet to a tensile test (room temperature, elongation percentage of 40%) and L * by the SCE method measured from the transparent resin layer side before subjecting the decorative sheet to the tensile test is 1.5 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a decorative sheet, a decorated molded article, and a method for manufacturing a decorated molded article. [Background technology]

[0002] Conventionally, a technique for imparting design to a desired molded body by attaching a decorative sheet to the surface of the molded body has been known. For example, by attaching a decorative sheet to the roof panel or bonnet panel of a vehicle such as an automobile, it is possible to change the appearance of the vehicle or impart a desired design to the vehicle without painting or the like. Various decorative sheets for attachment to the surface of vehicle exterior materials have been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-192609 Summary of the Invention [Problem to be solved by the invention]

[0004] Decorative sheets are applied not only to flat molded bodies such as vehicles, but also to molded bodies with three-dimensional curved surfaces. That is, the decorative sheet is applied to the surface of the molded body while conforming to the three-dimensional shape of the molded body. In this case, the decorative sheet is usually stretched while being applied to the surface of the molded body. However, this stretching can cause color or decorative unevenness in the decorative sheet. That is, this stretching can impair the design of the decorative sheet.

[0005] An object of the present disclosure is to provide a decorative sheet in which the change in design before and after stretching is minimal, a decorated molded product including the decorative sheet, and a method for manufacturing the decorated molded product. [Means for solving the problem]

[0006] The decorative sheet of the present disclosure includes a resin substrate layer, a colored layer, and a transparent resin layer in this order in the thickness direction. * a * b * In the color system, the L measured by the SCE method from the transparent resin layer side after subjecting the decorative sheet to a tensile test (room temperature, elongation rate 40%) * and the L measured by the SCE method from the transparent resin layer side before subjecting the decorative sheet to the tensile test. * The absolute value of the difference between is 1.5 or less. The decorated molded product of the present disclosure includes a molded body and the decorative sheet, and the resin substrate layer of the decorative sheet is located closer to the molded body than the transparent resin layer. In one embodiment, the method for producing a decorated molded article of the present disclosure includes the steps of preparing a molded article and the decorative sheet, and attaching the decorative sheet to the surface of the molded article. In one aspect, the method for manufacturing a decorated molded product of the present disclosure includes the steps of preparing a molded body and the decorative sheet, preforming the decorative sheet into a shape that matches the shape of the molded body to which the decorative sheet will be attached, and attaching the preformed decorative sheet to the surface of the molded body. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a decorative sheet in which the change in design is small before and after stretching, a decorated molded product including the decorative sheet, and a method for manufacturing the decorated molded product. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional schematic view of one embodiment of the decorative sheet of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional schematic view of one embodiment of the decorative sheet of the present disclosure. [Figure 3] FIG. 3 is a schematic cross-sectional view of one embodiment of the decorated molded product of the present disclosure. [Figure 4] FIG. 4 shows an example of an image of a cross section of a decorative sheet observed with a laser microscope. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure can be implemented in many different forms, and should not be construed as being limited to the description of the embodiments exemplified below. For clarity of explanation, the drawings may show the width, thickness, shape, etc. of each component schematically compared to the embodiments, but these are merely examples and do not limit the interpretation of the present disclosure. In this specification and each drawing, elements similar to those already described with reference to the previous drawings will be designated by the same reference numerals, and detailed description may be omitted as appropriate. In the present disclosure, "sheet" also encompasses articles called "films."

[0010] In the following description, each component (for example, resin material, colorant, additive, and organic solvent) that appears, such as a component contained in each layer or film, may be used alone or in combination of two or more types.

[0011] In the present disclosure, the term "molded body" refers to a molded body before being decorated with the decorative sheet of the present disclosure, and the term "decorated molded article" refers to a molded body that has been decorated with the decorative film of the present disclosure.

[0012] [Decorative sheet] The decorative sheet of the present disclosure includes a resin substrate layer, a colored layer, and a transparent resin layer in this order in the thickness direction. The decorative sheet is attached to the surface of a desired molded body and is used to impart, for example, a design to the molded body.

[0013] 1 is a cross-sectional view schematically illustrating an example of a decorative sheet according to the present disclosure. The decorative sheet 1 in FIG. 1 includes a resin substrate layer 10, a colored layer 12, and a transparent resin layer 14, arranged in this order in the thickness direction of the decorative sheet 1.

[0014] Fig. 2 is a cross-sectional view schematically illustrating another example of the decorative sheet of the present disclosure. The decorative sheet 1 in Fig. 2 includes a cover film 18, an adhesive layer 16, a resin substrate layer 10, a colored layer 12, and a transparent resin layer 14, arranged in this order in the thickness direction of the decorative sheet 1.

[0015] <Brightness, etc.> The decorative sheet of the present disclosure has a ΔL * (40%) is 1.5 or less. * (40%), L * a * b * In the color system, the L measured from the transparent resin layer side after subjecting the decorative sheet to a tensile test (room temperature, elongation rate 40%) * and L measured from the transparent resin layer side before the decorative sheet was subjected to the tensile test. * It means the absolute value of the difference between

[0016] In one embodiment, the decorative sheet of the present disclosure has a ΔL * (100%) is 3.5 or less. * (100%) is L * a * b * In the color system, the L measured from the transparent resin layer side after subjecting the decorative sheet to a tensile test (room temperature, elongation rate 100%) * and L measured from the transparent resin layer side before the decorative sheet was subjected to the tensile test. * It means the absolute value of the difference between

[0017] L * a * b * The color system is standardized by the International Commission on Illumination (CIE) and is adopted in JIS Z8781-4:2013. * a * b * In the color system, lightness is L * The chromaticity, which indicates the hue and saturation, is a * and b * In this disclosure, L * a * b * Color space L * , a * and b *is a value measured using the SCE method. The SCE method is a method that uses a spectrophotometer to measure color by eliminating specular reflection light using a light trap, in accordance with JIS Z8722:2009.

[0018] A typical SCE measurement device uses D65 as the light source of an integrating sphere spectrophotometer, the receiver is positioned at +8 degrees relative to the normal to the sample, the receiver opening angle is 10 degrees, the light trap is positioned at -8 degrees relative to the normal to the sample, and the viewing angle is 10 degrees.

[0019] That is, in this disclosure, L * , a * and b * is the value calculated from the diffuse light reflection SCE spectrum measured from the transparent resin layer side of the decorative sheet. * a * b * Color space L * , a * and b * and mean respectively.

[0020] The specific conditions for the tensile test are as follows. Chuck distance: 50mm Pulling speed: 50mm / min ·Temperature: Room temperature (25℃) Stretching rate: 40% or 100%

[0021] In the decorative sheet of the present disclosure, ΔL * (40%) is 1.5 or less, preferably 1.2 or less, more preferably 1.0 or less, and particularly preferably 0.7 or less. * A decorative sheet exhibiting a brightness of 40% or more can impart the desired design to an adherend, even if it is stretched when attached to the adherend, because the difference in brightness before and after stretching is small. In other words, the decorative sheet of the present disclosure can be attached to a variety of surface shapes while maintaining the desired design.

[0022] In the decorative sheet of the present disclosure, ΔL *In one embodiment, ΔL (100%) is 3.5 or less, preferably 3.0 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. * A decorative sheet exhibiting a brightness of 100% (100%) can impart the desired design to an adherend, even if it is significantly stretched when attached to the adherend, because the difference in brightness before and after stretching is small. In other words, the decorative sheet of the present disclosure can be attached to a variety of surface shapes while maintaining the desired design.

[0023] In the decorative sheet of the present disclosure, L * is preferably 3.0 or less, more preferably 2.0 or less, and even more preferably 1.5 or less. As such, the decorative sheet of the present disclosure preferably exhibits a black or dark color. By using such a decorative sheet, a good black or dark color can be imparted to the adherend.

[0024] In the decorative sheet of the present disclosure, a * The absolute value of is preferably 2.0 or less, more preferably 1.5 or less, even more preferably 1.0 or less, and even more preferably 0.5 or less.

[0025] In the decorative sheet of the present disclosure, b before being subjected to the tensile test (stretching rate 0%) * The absolute value of is preferably 3.0 or less, more preferably 2.0 or less, even more preferably 1.5 or less, and even more preferably 1.0 or less.

[0026] In the present disclosure, L measured on the decorative sheet before the tensile test * , a * and b * L1 * , a1 * and b1 * The L measured on the decorative sheet after the tensile test is * , a * and b * respectively L2 * , a2* and b2 * Also written as: In the present disclosure, the color difference ΔE before and after the tensile test is defined as: ΔE=((L2 * -L1 * ) 2 +(a2 * -a1 * ) 2 +(b2 * -b1 * ) 2 ) 1 / 2 It is defined as:

[0027] In the present disclosure, the ΔE(40%) of the decorative sheet before and after a tensile test at a stretch ratio of 40% is preferably 1.5 or less, more preferably 1.2 or less, even more preferably 1.0 or less, and even more preferably 0.7 or less. A decorative sheet exhibiting such a ΔE(40%) can impart the desired design to an adherend, even if it is stretched when attached to the adherend, because the color difference before and after stretching is small.

[0028] In the present disclosure, the ΔE(100%) of the decorative sheet before and after a tensile test at a stretch rate of 100% is preferably 3.5 or less, more preferably 3.0 or less, even more preferably 2.5 or less, and even more preferably 2.0 or less. A decorative sheet exhibiting such a ΔE(100%) can impart a desired design to an adherend, even if it is stretched significantly when attached to the adherend, because the color difference before and after stretching is small.

[0029] L * , a * and b * is the average value of the measurements taken at three locations.

[0030] The decorative sheet of the present disclosure may have a glossy or matte appearance.

[0031] The overall thickness of the decorative sheet of the present disclosure is preferably 100 μm or more and 600 μm or less, more preferably 150 μm or more and 400 μm or less. Here, if the decorative sheet includes a cover film, the thickness of the cover film is not included in the overall thickness of the decorative sheet. This is because the cover film is removed when the decorative sheet is attached. If the thickness is within the above range, for example, the decorative sheet can be well stretched while maintaining its design, so that it conforms to the three-dimensional shape of the adherend. If the thickness is equal to or less than the upper limit, for example, a decrease in the conformability of the decorative sheet to the adherend can be suppressed. If the thickness is equal to or greater than the lower limit, for example, extreme elongation when the decorative sheet is reattached to the adherend can be suppressed, and the decorative sheet is less likely to leave a mark when foreign matter is present on the adherend.

[0032] <Resin base layer> The decorative sheet of the present disclosure includes a resin substrate layer.

[0033] The resin substrate layer contains a resin material. As the resin material, since the colored layer may be formed by applying a resin composition for a colored layer onto the resin substrate layer, a resin having solvent resistance to the extent that swelling or deformation does not occur in the organic solvent used in the resin composition for a colored layer is preferred. In other words, the resin substrate layer is preferably a solvent-resistant resin layer.

[0034] Examples of resins having solvent resistance (hereinafter also referred to as "solvent-resistant resins") include polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyamide (nylon-6, nylon-66, polymetaxylene adipamide, etc.), polyimide, polyetherimide, polyamideimide, polycarbonate, modified polyphenylene ether, polyacetal, polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polybenzimidazole, polybenzoxazole, and fluorine-based resins.

[0035] Among these, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, ABS resin, and fluorine-based resin are preferred from the viewpoint of excellent room-temperature stretchability, and polyvinyl chloride is more preferred from the viewpoint of an excellent balance of solvent resistance, stretchability, and shape retention after preforming. Polyvinyl chloride is more preferred from the viewpoint of excellent stretchability and good conformability to a three-dimensional shape when the decorative sheet is attached to an adherend.

[0036] Polyvinyl chloride may be a homopolymer of vinyl chloride or a copolymer of vinyl chloride and a comonomer copolymerizable with vinyl chloride. Examples of the comonomer include vinyl esters such as vinyl acetate and vinyl propionate; α-olefins such as ethylene and propylene; (meth)acrylic acid esters such as methyl (meth)acrylate and ethyl (meth)acrylate; dicarboxylic acid diesters such as maleic acid diester and fumaric acid diester; vinyl cyanides such as (meth)acrylonitrile; vinyl halides such as vinylidene chloride and vinyl bromide; and vinyl ethers such as methyl vinyl ether and ethyl vinyl ether. "(Meth)acrylic" encompasses both "acrylic" and "methacrylic," and "(meth)acrylate" encompasses both "acrylate" and "methacrylate."

[0037] The content of the solvent-resistant resin in the resin substrate layer is preferably 40% by mass or more, more preferably 45% by mass or more, and even more preferably 50% by mass or more.

[0038] As the resin substrate layer, it is preferable to use a resin film, more preferably to use a resin film containing a solvent-resistant resin, even more preferably to use a resin film containing at least one selected from polyvinyl chloride and ABS resin, and even more preferably to use a resin film containing polyvinyl chloride.

[0039] Specific examples of the resin film include polyvinyl chloride films and ABS resin films, with polyvinyl chloride films being preferred. As the polyvinyl chloride film, any film made from a known hard, semi-hard, or soft resin composition containing polyvinyl chloride as the main component can be used.

[0040] The content of polyvinyl chloride in the polyvinyl chloride film is preferably 40% by mass or more, more preferably 45% by mass or more, and even more preferably 50% by mass or more.

[0041] The resin substrate layer may be transparent, translucent, or opaque. In one embodiment, the resin substrate layer may contain a colorant and preferably exhibits a black color. By using a black resin substrate layer, a decorative sheet with even better jet blackness can be obtained. As a colorant for imparting black color, for example, a black pigment and a black dye, which will be described later, can be used, and a description thereof will be omitted in this section. The total light transmittance of the black resin substrate layer is preferably 10% or less, more preferably 5% or less, even more preferably 3% or less, and particularly preferably 1% or less. The total light transmittance is measured in accordance with JIS K7361-1:1997.

[0042] In one embodiment, the content of the colorant in the resin substrate layer is preferably 0.1% by mass to 10% by mass, more preferably 2.0% by mass to 8.0% by mass, which allows the resin substrate layer to be given a desired color, particularly black, for example.

[0043] The resin substrate layer may contain additives such as antioxidants, ultraviolet absorbers, light stabilizers, heat stabilizers, dispersants, surfactants, leveling agents, silane coupling agents, plasticizers, softeners, fillers, and tackifiers.

[0044] In one embodiment, the polyvinyl chloride film contains a plasticizer. The content of the plasticizer in the polyvinyl chloride film may be 100 parts by mass or less, 10 parts by mass or more to 90 parts by mass or less, or 20 parts by mass or more to 80 parts by mass or less, relative to 100 parts by mass of polyvinyl chloride.

[0045] Examples of the plasticizer include phthalic acid plasticizers, fatty acid plasticizers, phosphoric acid plasticizers, polyester plasticizers, polyethylene plasticizers, and epoxy plasticizers. Examples of the phthalic acid plasticizer include phthalate diesters such as dioctyl phthalate, di-2-ethylhexyl phthalate, dihexyl phthalate, dibutyl phthalate, diheptyl phthalate, diisodecyl phthalate, and diisononyl phthalate. Examples of the fatty acid plasticizer include aliphatic polybasic acid diesters such as dioctyl adipate, dioctyl azelate, and dioctyl cebarate; and citric acid triesters such as tributyl acetyl citrate, trioctyl acetyl citrate, and tributyl citrate.

[0046] The thickness of the resin substrate layer is preferably 50 μm or more and 300 μm or less, more preferably 70 μm or more and 250 μm or less, and even more preferably 90 μm or more and 200 μm or less. When the thickness is in the above range, for example, the shape retention of the decorative sheet after preforming is improved.

[0047] <Colored layer> The decorative sheet of the present disclosure includes a colored layer between a resin substrate layer and a transparent resin layer. The colored layer is a layer that imparts design properties or base hiding properties, particularly black color, to the decorative sheet. The colored layer is preferably a black layer, and preferably contains a black colorant. Examples of black colorants include black pigments and black dyes.

[0048] The black pigment may be either an organic pigment or an inorganic pigment, and examples thereof include carbon black, graphite, fullerene, carbon nanofiber, carbon nanotube, lamp black, bone black, acetylene black, titanium black, cobalt black, copper (II) oxide, black iron oxide, copper manganese black, copper chromium black, manganese dioxide, and activated carbon.

[0049] Examples of black dyes include nigrosine dyes, pyrazole azo dyes, anilino azo dyes, triphenylmethane dyes, anthraquinone dyes, anthrapyridone dyes, benzylidene dyes, oxol dyes, pyrazolotriazole azo dyes, pyridone azo dyes, cyanine dyes, phenothiazine dyes, pyrrolopyrazole azomethine dyes, xathene dyes, phthalocyanine dyes, benzopyran dyes, indigo dyes, pyrromethene dyes, triarylmethane dyes, azomethine dyes, perylene dyes, perinone dyes, quatarylene dyes, and quinophthalone dyes.

[0050] The content of the colorant in the colored layer is preferably 10% by mass to 45% by mass, more preferably 15% by mass to 40% by mass, which allows the colored layer to have a desired color, particularly black, for example.

[0051] The colored layer preferably contains a resin material. The resin material may be a thermoplastic resin or a cured product of a thermosetting resin. Examples of thermoplastic resins include (meth)acrylic resins such as polymethyl (meth)acrylate and polyethyl (meth)acrylate, vinyl resins such as polyvinyl chloride and polyvinyl acetate, polyolefins, polystyrene, ABS resins, polycarbonates, polyesters, polyamides, and polyurethanes. Examples of thermosetting resins include unsaturated polyester resins, (meth)acrylic urethanes, epoxy-modified (meth)acrylic resins, epoxy-modified unsaturated polyesters, alkyd resins, and phenolic resins.

[0052] Among these, thermoplastic resins are preferred as the resin material, and from the viewpoint of stretchability and adhesion, at least one selected from (meth)acrylic resins and polyvinyl chloride is more preferred, and at least one selected from (meth)acrylic resins and vinyl chloride-vinyl acetate copolymers is even more preferred.

[0053] The content of the resin material in the colored layer is preferably 55% by mass or more and 90% by mass or less, and more preferably 60% by mass or more and 85% by mass or less, which can impart durability to the colored layer, for example.

[0054] The colored layer may contain additives, such as antioxidants, ultraviolet absorbers, light stabilizers, heat stabilizers, dispersants, surfactants, leveling agents, silane coupling agents, plasticizers, softeners, fillers, and tackifiers.

[0055] The decorative sheet of the present disclosure may have a colored layer over substantially the entire surface of the resin substrate layer, or may have a colored layer in a pattern on the resin substrate layer. From the viewpoint of imparting good black color to the adherend, it is preferable that the decorative sheet have a colored layer over substantially the entire surface of the resin substrate layer.

[0056] The thickness of the colored layer is preferably 1 μm or more and 20 μm or less, more preferably 2 μm or more and 15 μm or less, even more preferably 3 μm or more and 12 μm or less, and even more preferably 5 μm or more and 10 μm or less. Having a thickness within the above range allows, for example, the colored layer to have sufficient base concealing properties and also allows the decorative sheet to have a desired design. If the thickness of the colored layer is increased to improve base concealing properties, the design is likely to change when the decorative sheet is stretched, but this change can be suppressed in the present disclosure. In other words, the decorative sheet of the present disclosure can achieve both excellent base concealing properties and excellent design properties after stretching.

[0057] <Transparent resin layer> The decorative sheet of the present disclosure includes a transparent resin layer on a colored layer, and by providing the transparent resin layer, the colored layer can be well protected.

[0058] The transparent resin may be any resin having optical transparency, and specific examples thereof include (meth)acrylic resin, cyclic polyolefin, ABS resin, polyester, polycarbonate, cellulose resin, and fluorine-based resin. Among these, (meth)acrylic resin is preferred from the viewpoints of transparency and weather resistance.

[0059] Examples of (meth)acrylic resins include homopolymers or copolymers of (meth)acrylic acid esters and copolymers of (meth)acrylic acid esters and comonomers. Examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and glycidyl (meth)acrylate. Examples of comonomers include vinyl acetate, (meth)acrylonitrile, (meth)acrylamide, styrene, (meth)acrylic acid, itaconic acid, and maleic anhydride. The (meth)acrylic resin may be fluorine-modified.

[0060] Specific examples of the (meth)acrylic resin include polyalkyl(meth)acrylates such as polymethyl(meth)acrylate, polyethyl(meth)acrylate, polypropyl(meth)acrylate, and polybutyl(meth)acrylate.

[0061] The content of the transparent resin in the transparent resin layer is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more.

[0062] The transparent resin layer is preferably a transparent resin film containing a transparent resin, more preferably a (meth)acrylic resin film, in which the content of the (meth)acrylic resin is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.

[0063] The total light transmittance of the transparent resin layer is preferably 75% or more, more preferably 80% or more, even more preferably 85% or more, and particularly preferably 90% or more. The higher the total light transmittance, the better, but the upper limit may be, for example, 99%. The total light transmittance is measured in accordance with JIS K7361-1:1997.

[0064] The haze of the transparent resin layer is preferably 5.0% or less, more preferably 3.0% or less, and even more preferably 2.0% or less. The lower the haze, the better, but the lower limit may be, for example, 0.1%. The haze is measured in accordance with JIS K7136:2000.

[0065] The transparent resin layer may contain additives, such as antioxidants, ultraviolet absorbers, light stabilizers, heat stabilizers, dispersants, surfactants, leveling agents, silane coupling agents, plasticizers, softeners, fillers, and tackifiers.

[0066] The thickness of the transparent resin layer is preferably 10 μm or more and 200 μm or less, more preferably 20 μm or more and 150 μm or less, and even more preferably 30 μm or more and 100 μm or less. When the thickness is within the above range, for example, the transparent resin layer can provide good protection for the colored layer. When the thickness is equal to or less than the upper limit, for example, a decrease in the flexibility of the decorative sheet can be suppressed and good workability can be ensured.

[0067] <Adhesive layer> The decorative sheet of the present disclosure preferably includes an adhesive layer on the surface of the resin substrate layer opposite to the surface on which the transparent resin layer is formed, for improving adhesion to an adherend. The adhesive layer may have at least one of adhesiveness and pressure-sensitive adhesiveness.

[0068] The adhesive layer can be formed using a known adhesive composition such as an adhesive or pressure-sensitive adhesive (pressure-sensitive adhesive). Examples of the adhesive composition include adhesives such as two-component curing polyester adhesives and two-component curing urethane adhesives; and pressure-sensitive adhesives such as (meth)acrylic pressure-sensitive adhesives, urethane pressure-sensitive adhesives, epoxy pressure-sensitive adhesives, silicone pressure-sensitive adhesives, polyester pressure-sensitive adhesives, polyamide pressure-sensitive adhesives, vinyl alkyl ether pressure-sensitive adhesives, fluorine-based pressure-sensitive adhesives, and rubber pressure-sensitive adhesives.

[0069] Among these, (meth)acrylic pressure-sensitive adhesives are preferred from the viewpoint of excellent adhesiveness and processability. (Meth)acrylic pressure-sensitive adhesives are, for example, pressure-sensitive adhesives containing a (meth)acrylic polymer as a main component. (Meth)acrylic pressure-sensitive adhesives have high resistance to ultraviolet rays and the like, and are therefore preferred when used in applications where the decorative sheet is to be attached to a vehicle exterior material. In addition, (meth)acrylic pressure-sensitive adhesives are preferred because they have low initial adhesive strength and require some time for complete adhesion, which makes it easy to move the decorative sheet when positioning it after placing it on the adherend.

[0070] Examples of (meth)acrylic polymers contained in (meth)acrylic pressure-sensitive adhesives include homopolymers or copolymers of (meth)acrylic acid esters and copolymers of (meth)acrylic acid esters and comonomers. Examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and glycidyl (meth)acrylate. Examples of comonomers include vinyl acetate, (meth)acrylonitrile, (meth)acrylamide, styrene, (meth)acrylic acid, itaconic acid, and maleic anhydride.

[0071] When forming an adhesive layer on the surface of a resin substrate layer, a primer layer may be formed on the surface of the resin substrate layer to improve adhesion between the two, and then an adhesive composition may be applied to the surface of the primer layer to form the adhesive layer. The resin substrate layer may be subjected to a surface treatment. Examples of surface treatments include corona discharge treatment, plasma treatment, chromium oxidation treatment, flame treatment, hot air treatment, and ozone / ultraviolet treatment.

[0072] The adhesive layer may contain additives, such as antioxidants, ultraviolet absorbers, light stabilizers, heat stabilizers, dispersants, surfactants, leveling agents, silane coupling agents, plasticizers, softeners, fillers, tackifiers, dyes, and pigments.

[0073] The thickness of the adhesive layer is preferably 10 μm or more and 150 μm or less, more preferably 30 μm or more and 120 μm or less, and even more preferably 40 μm or more and 100 μm or less, which allows, for example, sufficient adhesive strength to be obtained.

[0074] The adhesive layer may have a groove or uneven structure on the surface that comes into contact with the adherend. A decorative sheet in which the adhesive layer has a groove or uneven structure has improved degassing performance, and can therefore further improve air trap problems when the decorative sheet is attached to the adherend.

[0075] The grooves are continuous open passages or elongated recesses. From the viewpoint of degassing properties, the grooves preferably extend to the outer periphery of the adhesive layer. When the decorative sheet is attached to the surface of an adherend, the presence of these passages allows air (fluid) trapped at the interface between the adhesive layer and the adherend to flow out to the periphery of the adherend.

[0076] The grooves can have various shapes or patterns. Examples of the groove shape, when viewed from the transverse direction of the groove, include a substantially V-shape, a substantially U-shape, a substantially rectangular shape, a substantially trapezoidal shape, or a combination thereof. The adhesive layer may have the grooves at random locations or in a regular pattern.

[0077] For example, when the surface of the adhesive layer is viewed from above, the recesses in the uneven structure may have an irregular shape, such as an irregular shape due to a sea-island structure or a shape in which recesses of non-uniform shapes are irregularly present.

[0078] <Cover film> The decorative sheet of the present disclosure preferably further comprises a cover film disposed on the surface of the adhesive layer. The cover film protects the adhesive layer from exposure during production, transportation, or storage of the decorative sheet. The cover film is usually peeled off before use of the decorative sheet. In one embodiment, the cover film is peeled off after preforming the decorative sheet and before attaching it to a molded body.

[0079] The cover film is preferably a film that can be easily peeled off from the adhesive layer without damaging the adhesive layer, and examples thereof include resin films, paper (release paper) such as fine paper and glassine paper, and laminated films of paper and a covering layer. Examples of resin films include films made of resin materials such as polyester, polyurethane, polyvinyl chloride, polyvinylidene chloride, and polyolefin.

[0080] The surface of the resin film, paper, or laminated film that comes into contact with the adhesive layer is preferably subjected to an easy-release treatment, such as coating with a release resin such as a silicone resin or a fluororesin. The cover film may contain the additives described above.

[0081] The cover film preferably has a surface shape that allows the grooves or uneven structure to be formed in the adhesive layer. By providing the adhesive layer on a cover film having the surface shape, the grooves or uneven structure can be formed in the adhesive layer.

[0082] The thickness of the cover film is preferably 10 μm or more and 200 μm or less, and more preferably 50 μm or more and 150 μm or less.

[0083] <Surface protective layer> The decorative sheet of the present disclosure may further include a surface protective layer on one surface of the transparent resin layer, thereby obtaining a decorative sheet having, for example, a well-balanced excellent weather resistance, abrasion resistance, and chemical resistance.

[0084] The surface protective layer is preferably a layer formed from a curable composition, i.e., a hard coat layer. Examples of the curable component contained in the curable composition include a thermosetting component and an active energy ray-curable component. From the viewpoints of weather resistance, abrasion resistance, and chemical resistance, the active energy ray-curable component is preferred.

[0085] Examples of the thermosetting component include thermosetting resins such as epoxy resins, melamine resins, guanamine resins, urea resins, unsaturated polyesters, thermosetting urethane resins, thermosetting (meth)acrylic resins, and aminoalkyd resins.

[0086] The active energy ray-curable component is a component that cures when irradiated with active energy rays. Examples of active energy rays include electromagnetic waves such as ultraviolet rays (UV), X-rays, and gamma rays; and charged particle beams such as electron beams (EB), alpha rays, and ion beams.

[0087] Examples of the active energy ray curable component include compounds having at least one functional group selected from vinyl group, allyl group, and (meth)acryloyl group. Examples of the active energy ray curable component include oligomers or polymers such as urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, and polyether (meth)acrylate; polyfunctional (meth)acrylate monomers such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and tris(2-(meth)acryloxyethyl)isocyanurate; and modified products thereof. As the active energy ray-curable component, a mono(meth)acrylate having one (meth)acryloyl group in the molecule may also be used. A photopolymerization initiator may be used together with the active energy ray-curable component.

[0088] The surface protective layer may contain a weather resistance improver. This can improve, for example, the weather resistance of the surface protective layer. Examples of weather resistance improvers include ultraviolet absorbers, antioxidants, and hindered amine light stabilizers. The content of the weather resistance improver in the surface protective layer is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.1% by mass or more and 5% by mass or less. The surface protective layer may contain the above-mentioned additives.

[0089] The thickness of the surface protective layer is preferably 1 μm or more and 20 μm or less, more preferably 2 μm or more and 15 μm or less, and even more preferably 3 μm or more and 13 μm or less. This can further improve, for example, the abrasion resistance and weather resistance of the surface protective layer. If the thickness is equal to or less than the upper limit, for example, a decrease in the flexibility of the decorative sheet can be suppressed.

[0090] <Other layers> The decorative sheet of the present disclosure may further include layers other than the surface protective layer, transparent resin layer, colored layer, resin substrate layer, adhesive layer, and cover film.

[0091] The decorative sheet may have a primer layer between the resin substrate layer and the adhesive layer. This can improve adhesion between the resin substrate layer and the adhesive layer, for example. The primer layer can be formed by, for example, a coating method. That is, the primer layer can be formed by dissolving a resin material for forming the primer layer in an appropriate solvent to obtain a coating liquid, applying the coating liquid to the surface of the resin substrate layer, and drying the liquid.

[0092] Examples of resin materials contained in the primer layer include (meth)acrylic resins, butyral resins, polyolefins, chlorinated polyolefins, vinyl chloride-vinyl acetate copolymers, polyesters, and polyurethanes. The primer layer may contain the additives described above.

[0093] The thickness of the primer layer is preferably 0.1 μm or more and 5 μm or less, more preferably 0.1 μm or more and 3 μm or less, which can further improve the adhesion between the resin substrate layer and the adhesive layer, for example.

[0094] [Manufacturing method of decorative sheet] A preferred method for producing the decorative sheet of the present disclosure will be described below. The decorative sheet of the present disclosure may be, for example: A step (hereinafter also referred to as "step (1)") of preparing a resin substrate film containing a solvent-resistant resin, a transparent resin film containing a transparent resin, and a resin composition for a colored layer containing a resin material, a colorant, and an organic solvent; A step (hereinafter also referred to as "step (2)") of applying the resin composition for a colored layer onto a resin substrate film to obtain a laminate including the resin substrate film and a colored layer provided on the film; a step of laminating the laminate and the transparent resin film so that the colored layer of the laminate and the transparent resin film are in contact with each other (hereinafter also referred to as "step (3)"); It can be produced by a method comprising:

[0095] By the above manufacturing method, a decorative sheet can be obtained which has, in the thickness direction, a resin substrate film containing a solvent-resistant resin as the resin substrate layer, a colored layer, and a transparent resin film containing a transparent resin as the transparent resin layer, in this order.

[0096] <Process (1)> The resin substrate film containing the solvent-resistant resin may be a commercially available product, or may be a film obtained by forming a resin composition containing the solvent-resistant resin by a known molding method, such as an extrusion molding method using a T-die or the like, a calendar method, or a casting method.

[0097] Details of the solvent-resistant resin are as described above. The resin substrate film may contain the above-mentioned colorants and / or additives.

[0098] As the resin substrate film, it is preferable to use a resin film containing at least one selected from polyvinyl chloride and ABS resin, more preferably a polyvinyl chloride film or an ABS resin film, and even more preferably a polyvinyl chloride film.

[0099] The thickness of the resin substrate film is preferably 50 μm or more and 300 μm or less, more preferably 70 μm or more and 250 μm or less, and even more preferably 90 μm or more and 200 μm or less.

[0100] The transparent resin film containing a transparent resin may be a commercially available product, or may be a film obtained by forming a resin composition containing a transparent resin by a known molding method, such as an extrusion molding method using a T-die or the like, a calendar method, or a casting method.

[0101] Details of the transparent resin are as described above. The transparent resin film may contain the above-mentioned additives. The transparent resin film is preferably a (meth)acrylic resin film.

[0102] The total light transmittance and haze of the transparent resin film are the same as those of the transparent resin layer described above, and therefore will not be described here.

[0103] The thickness of the transparent resin film is preferably 10 μm or more and 200 μm or less, more preferably 20 μm or more and 150 μm or less, and even more preferably 30 μm or more and 100 μm or less.

[0104] The resin composition for the colored layer contains a resin material, a colorant, and an organic solvent. Examples of the resin material include the thermoplastic resins and thermosetting resins described above in the section on the colored layer, with a thermoplastic resin being preferred, at least one selected from a (meth)acrylic resin and polyvinyl chloride being more preferred, and at least one selected from a (meth)acrylic resin and a vinyl chloride-vinyl acetate copolymer being even more preferred.

[0105] The content of the resin material in the resin composition for colored layer is preferably 55% by mass or more and 90% by mass or less, more preferably 60% by mass or more and 85% by mass or less, based on the solid content. The solid content refers to all components other than the solvent.

[0106] The colorant content in the resin composition for colored layer is preferably 10% by mass or more and 45% by mass or less, and more preferably 15% by mass or more and 40% by mass or less, based on the solid content. The resin composition for a colored layer may contain the additives described above.

[0107] Examples of organic solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, and cyclohexanone; ester solvents such as ethyl acetate, butyl acetate, amyl acetate, ethyl butyrate, butyl butyrate, butyl stearate, methyl benzoate, methyl lactate, ethyl lactate, and butyl lactate; alcohol solvents such as ethanol, propanol, butanol, pentanol, hexanol, octanol, and decanol; and hydrocarbon solvents such as toluene, xylene, hexane, and octane.

[0108] The content of the organic solvent in the resin composition for colored layer is preferably 30% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and even more preferably 60% by mass or more and 85% by mass or less.

[0109] <Process (2)> In step (2), the resin composition for the colored layer is applied to a resin substrate film to obtain a laminate comprising a resin substrate film and a colored layer. By applying the resin composition for the colored layer to a resin substrate film rather than a transparent resin film in step (2), even if the colored layer is thick, it is possible to prevent cracks, voids, etc. from occurring in the colored layer when the decorative sheet is stretched. Therefore, a decorative sheet is obtained that exhibits minimal change in design before and after stretching and maintains its ability to conceal the base. This is presumably because the above method can prevent deterioration of the transparent resin film due to the organic solvent contained in the resin composition for the colored layer, thereby preventing cracks, voids, etc. from occurring in the colored layer when stretched.

[0110] Examples of methods for applying the resin composition for the colored layer include coating methods such as bar coating, roll coating, knife coating, air knife coating, die coating, lip coating, flow coating, dip coating, spraying, and spin coating; and printing methods such as offset printing, gravure printing, flexographic printing, screen printing, and inkjet printing.

[0111] After the resin composition for colored layer is applied to the resin substrate film, it is dried to remove the organic solvent. The drying temperature is preferably from 40° C. to 200° C., more preferably from 45° C. to 150° C., and even more preferably from 50° C. to 100° C. The drying time is preferably from 30 seconds to 1 hour, more preferably from 1 minute to 30 minutes, and even more preferably from 1 minute to 10 minutes.

[0112] <Process (3)> In step (3), the laminate obtained in step (2) is laminated on a transparent resin film so that the colored layer of the laminate is in contact with the transparent resin film. Although a conventionally known lamination method can be used, it is preferable to directly bond the laminate and the transparent resin film by thermal lamination.

[0113] In the thermal lamination process, the lamination temperature is preferably 80° C. or higher and 250° C. or lower, more preferably 100° C. or higher and 230° C. or lower, and even more preferably 150° C. or higher and 200° C. or lower. This can improve the peel strength between the laminate and the transparent resin film and suppress heat-induced deterioration of the film, for example.

[0114] <Other processes> In one embodiment, the above-mentioned manufacturing method further includes a step of providing an adhesive layer and a cover film on the surface of the resin substrate film opposite the surface on which the transparent resin film is formed. Any known method, such as a transfer method or a coating method, can be used to form the adhesive layer on the resin substrate film. The adhesive layer may be formed using a conventionally known method, such as a method of applying an adhesive composition to a cover film and drying or curing it as necessary. In this case, a decorative sheet is obtained by bonding the adhesive layer formed on the cover film to a laminate including a resin substrate film, a colored layer, and a transparent resin film.

[0115] In one embodiment, the above-mentioned manufacturing method further includes a step of providing a surface protective layer on the transparent resin film. The surface protective layer is formed, for example, as follows. A curable composition is applied to a transparent resin film to a desired thickness to form a coating film, and if an organic solvent is used, the coating film is formed by drying to remove the organic solvent. Next, if a thermosetting component is used, the coating film is heated at a temperature required for curing to be cured. If an active energy ray-curable component is used, the coating film is irradiated with active energy rays to be cured. In this manner, the surface protective layer can be formed.

[0116] Examples of methods for applying the curable composition onto a transparent resin film include bar coating, roll coating, knife coating, air knife coating, die coating, lip coating, flow coating, dip coating, spraying, and spin coating.

[0117] [Uses, decorative molded products and their manufacturing methods] Examples of materials for the adherend to which the decorative sheet of the present disclosure is attached include metal plates such as iron plates and steel plates (e.g., stainless steel plates); thermoplastic resins such as polyvinyl chloride, ABS resin, (meth)acrylic resin, polyolefin, polyester, polycarbonate, polyamide, and polyurethane; and thermosetting resins such as phenolic resin, melamine resin, and urea resin. The metal plate may be a resin-coated metal plate, such as a melamine-coated metal plate, an acrylic-coated metal plate, or a urethane-coated metal plate. The resin-coated metal plate is preferably, for example, a coated metal plate for vehicles.

[0118] Examples of the substrate (molded body) to which the decorative sheet of the present disclosure is attached include exterior panels (roof panels, side door panels, back door panels, bonnet panels, side body panels, rear end panels, etc.), bumpers, spoilers, pillars, and other exterior vehicle materials; instrument panels, door trims, and other interior vehicle materials; aircraft and ship interior or exterior materials; building materials; smartphones, tablet devices; personal computers, televisions, and other home appliances; and furniture. Among these, exterior vehicle materials are preferred.

[0119] Examples of vehicles include ordinary automobiles (buses, trucks, passenger cars, etc.), compact automobiles (small trucks, three-wheeled trucks, large motorcycles, etc.), light automobiles (light trucks, light automobiles, motorcycles, etc.), large special-purpose automobiles (road rollers, bulldozers, etc.), small special-purpose automobiles (agricultural tractors, forklifts, shovel loaders, etc.), and railroad vehicles.

[0120] The decorative sheet of the present disclosure can maintain good design, particularly black color, even after stretching, and can therefore be suitably attached to the surface of a molded article having a three-dimensional shape. In other words, by using the decorative sheet of the present disclosure, excellent design can be imparted to the three-dimensional curved surface of an adherend having a three-dimensional curved surface.

[0121] By using the decorative film of the present disclosure, for example, the appearance of a vehicle can be easily changed, specifically, the color of the vehicle body can be made two-tone. Furthermore, the decorative sheet of the present disclosure may be used to decorate the vehicle body instead of painting or plating.

[0122] The decorated molded product of the present disclosure comprises a molded body and a decorative sheet of the present disclosure disposed on the surface of the molded body. In one embodiment, the decorated molded product comprises a molded body having a three-dimensional curved surface portion and a decorative sheet of the present disclosure disposed on at least the three-dimensional curved surface portion. Here, the resin substrate layer of the decorative sheet is located closer to the molded body than the transparent resin layer. In one embodiment, the contact surface of the decorative sheet with the surface of the molded body is the adhesive layer.

[0123] Fig. 3 is a cross-sectional view schematically illustrating an example of a decorated molded product according to the present disclosure. The decorated molded product 100 in Fig. 3 includes a molded body 20 and a decorative sheet 1 disposed on the surface of the molded body 20. Fig. 3 illustrates an example in which the decorative sheet 1 includes an adhesive layer 16, a resin substrate layer 10, a colored layer 12, and a transparent resin layer 14 in this order in the thickness direction. However, the decorative sheet 1 may further include, for example, a surface protective layer (not shown) as an outermost layer on the transparent resin layer 14.

[0124] The method for manufacturing a decorated molded product of the present disclosure includes the steps of preparing a molded body and the decorative sheet of the present disclosure, and attaching the decorative sheet to the surface of the molded body. Methods for attaching the decorative sheet of the present disclosure to the surface of the molded body that is the adherend include, for example, wrapping, vacuum forming, and vacuum / pressure forming.

[0125] Since the decorative sheet has excellent stretchability at room temperature, it is preferable to attach the decorative sheet to the surface of the molded product at about room temperature. In one embodiment, the temperature for attaching the decorative sheet is preferably 5°C or higher and 40°C or lower, more preferably 10°C or higher and 30°C or lower.

[0126] A specific example of wrapping is a method in which the decorative sheet is attached to an adherend while warming and softening it with a heating device such as a hair dryer as needed. For example, a portion of the decorative sheet is attached to the adherend for temporary fixing and alignment, and then the entire decorative sheet is attached to the adherend, and then the entire decorative sheet is pressed against the adherend to adhere it tightly. At this time, the unattached portion of the decorative sheet may be stretched and attached to the three-dimensional curved surface of the adherend. Here, the decorative sheet may be pressed against the adherend by hand, or by using a tool such as a squeegee. The above-described wrapping method allows the decorative sheet of the present disclosure to be attached to the surface of a molded product having a three-dimensional curved surface using a simple dry process. This results in a decorated molded product with excellent appearance.

[0127] In the present disclosure, the planar decorative sheet may be attached to an adherend, or the decorative sheet may be preformed into a shape that matches the shape of the adherend, and the resulting formed decorative sheet may be attached to the adherend. Examples of the forming method include vacuum forming, heat forming methods such as press forming and hot press forming, and vacuum forming is preferred.

[0128] Preforming allows for the production of a molded decorative sheet having a shape that matches the shape of the adherend. The molded decorative sheet can be more easily aligned to the adherend than a flat decorative film. The decorative sheet of the present disclosure can maintain good design even after preforming.

[0129] The vacuum forming method allows for efficient production of a molded decorative sheet. Specifically, a planar decorative sheet is vacuum-pressed onto a mold having a predetermined shape. This causes the planar decorative sheet to deform along the shape of the mold. The resulting molded decorative sheet is then allowed to cool and removed from the mold. In this way, a molded decorative sheet is obtained. If necessary, unnecessary portions may be removed from the molded decorative sheet.

[0130] In the vacuum forming method, a mold is used. The shape of the mold is preferably such that the surface to which the decorative sheet is attached (the surface where the decorative sheet and the mold come into contact) is the same shape as the surface of the adherend to which the molded decorative sheet is attached. In other words, by using a mold with the same dimensions and shape as the part of the adherend to which the decorative sheet is attached, a molded decorative sheet with the same dimensions and shape as that part can be obtained by vacuum forming.

[0131] In one embodiment, in the case of a decorative sheet having an adhesive layer and a cover film on a resin substrate layer, the decorative sheet is preformed into a desired shape, the cover film is peeled off, and the formed decorative sheet is attached to an adherend with the exposed adhesive layer as the adhesive surface.

[0132] The present disclosure relates to, for example, the following [1] to

[14] . [1] A decorative sheet having a resin substrate layer, a colored layer, and a transparent resin layer in this order in the thickness direction, * a * b * In the color system, the L measured by the SCE method from the transparent resin layer side after subjecting the decorative sheet to a tensile test (room temperature, elongation rate 40%) * and the L measured by the SCE method from the transparent resin layer side before subjecting the decorative sheet to a tensile test. * The absolute value of the difference between the values ​​is 1.5 or less. [2]L * a * b * In the color system, the L measured by the SCE method from the transparent resin layer side after subjecting the decorative sheet to a tensile test (room temperature, elongation rate 100%) * and the L measured by the SCE method from the transparent resin layer side before subjecting the decorative sheet to a tensile test. * The decorative sheet according to [1] above, wherein the absolute value of the difference between the values ​​is 3.5 or less. [3]L * a * b * In the color system, the L measured by the SCE method from the transparent resin layer side before the tensile test * The decorative sheet according to the above [1] or [2], wherein the value of the surface roughness is 3.0 or less. [4] The decorative sheet according to any one of the above [1] to [3], wherein the colored layer is a black layer. [5] The decorative sheet according to any one of the above [1] to [4], wherein the thickness of the colored layer is 1 μm or more and 20 μm or less. [6] The decorative sheet according to any one of the above [1] to [5], wherein the resin substrate layer contains polyvinyl chloride. [7] The decorative sheet according to any one of the above [1] to [6], wherein the transparent resin layer contains a (meth)acrylic resin. [8] The decorative sheet according to any one of the above [1] to [7], further comprising an adhesive layer on the surface of the resin substrate layer opposite to the surface on the transparent resin layer side. [9] The decorative sheet according to any one of the above [1] to [8] for decorating an exterior material for a vehicle.

[10] A decorated molded product comprising a molded body and the decorative sheet according to any one of [1] to [9] above, wherein the resin substrate layer of the decorative sheet is located closer to the molded body than the transparent resin layer.

[11] The decorated molded article according to the above

[10] , wherein the molded article is an exterior material for a vehicle.

[12] A method for producing a decorated molded product, comprising the steps of preparing a molded product and the decorative sheet according to any one of [1] to [9] above, and attaching the decorative sheet to the surface of the molded product.

[13] The method for producing a decorated molded product according to the above

[12] , wherein the decorative sheet is attached to the surface of the molded product by a wrapping method.

[14] A method for producing a decorated molded product, comprising the steps of preparing a molded product and the decorative sheet described in any one of [1] to [9] above, preforming the decorative sheet into a shape that matches the shape of the molded product to which the decorative sheet will be attached, and attaching the preformed decorative sheet to the surface of the molded product. [Example]

[0133] The decorative sheet etc. of the present disclosure will be described in more detail below based on examples, but the decorative sheet etc. of the present disclosure is not limited to these descriptions.

[0134] [Materials used] A (meth)acrylic resin film (ACRYPLEN (registered trademark) HBS006H, thickness 50 μm, Mitsubishi Chemical Corporation) was used as the film constituting the transparent resin layer. Hereinafter, this film will be referred to as "acrylic film 1."

[0135] A fluorine (meth)acrylic resin film (15s0650, thickness 50 μm, Denka Co., Ltd.) was used as the film constituting the transparent resin layer. Hereinafter, this film will be referred to as "acrylic film 2." Hereinafter, the above two films will be collectively referred to as "acrylic film."

[0136] A polyvinyl chloride film (FC25382 (black) DN39 type, thickness 150 μm, containing 39 parts by mass of plasticizer per 100 parts by mass of polyvinyl chloride (PVC), Riken Technos Corporation) was used as the film constituting the resin substrate layer. Hereinafter, this film will be referred to as "PVC film 1."

[0137] A polyvinyl chloride film (BK84555, thickness 150 μm, containing 55 parts by mass of plasticizer per 100 parts by mass of PVC, Bando Chemical Industries, Ltd.) was used as the film constituting the resin substrate layer. Hereinafter, this film will be referred to as "PVC film 2."

[0138] A polyvinyl chloride film (BK84650, thickness 100 μm, containing 50 parts by mass of plasticizer per 100 parts by mass of PVC, Bando Chemical Industries, Ltd.) was used as the film constituting the resin substrate layer. Hereinafter, this film will be referred to as "PVC film 3." Hereinafter, the above three films will be collectively referred to as "PVC film."

[0139] As the adhesive constituting the adhesive layer described below, a (meth)acrylic adhesive (P-7331B, Daido Chemical Industry Co., Ltd.) was used.

[0140] A resin composition for a colored layer (a resin composition for a black layer) with a resin solid content of 26% by mass was prepared by mixing the following (1), (2), and (3) in a mass ratio of (1):(2):(3) = 8:2:2. The resin composition contained a (meth)acrylic resin and a vinyl chloride-vinyl acetate copolymer in a mass ratio of (meth)acrylic resin:vinyl chloride-vinyl acetate copolymer = 4:1. (1) Ink: EISNBK jet black (Resin solid content 31% by mass, Showa Ink Industrial Co., Ltd.) (2) Medium: EISNBK Medium (Resin solid content 31% by mass, Showa Ink Industrial Co., Ltd.) (3) Dilution solvent: methyl ethyl ketone / isobutyl acetate = 4 / 6 (mass ratio)

[0141] [Manufacturing decorative sheets] The obtained resin composition for black layer was applied to a PVC film or an acrylic film using a wire bar to the following thickness after drying, and then dried for 2 minutes at 60° C. in a hot air circulating oven, thereby obtaining a laminate comprising a PVC film or an acrylic film and a black layer having a thickness of 2 μm, 6 μm, or 10 μm formed on the film.

[0142] An acrylic film was placed on the black layer of a laminate comprising a PVC film and a black layer, and the resulting laminate was sandwiched between two polyethylene terephthalate (PET) films (Cosmoshine (registered trademark) A4100, Toyobo Co., Ltd.). The PET film was placed so that the non-adhesive side of the PET film was in contact with the laminate. In this state, the laminate was subjected to a thermal lamination treatment at 180°C, after which the two PET films were removed, and a release PET film with a 50 μm-thick adhesive layer was laminated to the PVC film at room temperature to obtain a decorative sheet. In Table 1, this decorative sheet is referred to as decorative sheet (1).

[0143] Similarly, a PVC film was placed on the black layer of a laminate comprising an acrylic film and a black layer, and the resulting laminate was sandwiched between two of the above-mentioned PET films. The PET film was placed so that its non-adhesive side was in contact with the laminate. In this state, the laminate was subjected to a thermal lamination treatment at 180°C, after which the two PET films were removed, and a release PET film with a 50 μm-thick adhesive layer was laminated to the PVC film at room temperature to obtain a decorative sheet. In Table 1, this decorative sheet is referred to as decorative sheet (2).

[0144] [Stretching process] The resulting decorative sheet was cut to a width of 15 mm after peeling off the release PET film, and then the cut decorative sheet was stretched under the following conditions using a material testing machine "Instron 5565" (Instron Japan). Chuck distance: 50mm Pulling speed: 50mm / min ·Temperature: Room temperature (25℃) Stretching rate: 40% or 100%

[0145] [Appearance and color evaluation] The cut decorative sheet and the decorative sheet stretched to the above stretch ratio were attached to a 1.5 mm thick black ABS plate (HA-ABS, Showa Denko Materials Co., Ltd.) so that the adhesive layer was in contact with the black ABS plate. The acrylic film surface of the decorative sheet was measured using a spectrophotometer (CM-700d, Konica Minolta Inc.) using the SCE L * , a * and b * was measured.

[0146] [Table 1]

[0147] ΔL at 40% elongation * The decorative sheet having a ΔL of 1.5 or less maintained a good black color even after stretching. * The decorative sheet with a ΔL of more than 1.5 showed a decrease in blackness due to stretching. * The decorative sheets having a ΔE of 1.5 or less and a ΔE of 1.5 or less at a stretching ratio of 40% maintained particularly good black color even after stretching.

[0148] ΔL at 100% elongation * The decorative sheet having a ΔL of 3.5 or less maintained a good black color even after stretching. * The decorative sheet with a ΔL of more than 3.5 showed a decrease in blackness due to stretching. * The decorative sheets having a ΔE of 3.5 or less and a ΔE of 3.5 or less at a stretch ratio of 100% maintained a particularly good black color even after stretching.

[0149] Figure 4 shows images of the cross sections of decorative sheets (1) and (2) after stretching at room temperature and a stretch ratio of 40% observed with a laser microscope (KEYENCE VK-X150). The cross-sectional direction was the same as the stretching direction, and the observation magnification was 50x. Figure 4(a) is the above-mentioned image of the cross section of decorative sheet (1)-3, which has a black layer with a thickness of 10 μm. In this example, no large voids were observed in the black layer. Figure 4(b) is the above-mentioned image of the cross section of decorative sheet (2)-3, which has a black layer with a thickness of 10 μm. In this example, large voids were observed in the black layer.

[0150] In the decorative sheet (2), the surface of the acrylic film coated with the resin composition for the black layer was embrittled by the solvent, and voids were generated on the coated surface of the acrylic film during the stretching process, which presumably caused voids to be generated in the black layer as well. The presence of voids presumably made incident light more likely to be scattered, reducing the blackness of the decorative sheet (2). [Explanation of symbols]

[0151] 1. Decorative sheet 10...Resin base material layer 12...Colored layer 14...Transparent resin layer 16...adhesive layer 18···Cover film 20...Adherent (molded object) 100 Decorative molding products

Claims

【Request Item 1】 A decorative sheet having a resin substrate layer, a colored layer, and a transparent resin layer in this order in the thickness direction, * a * b * In the color system, the decorative sheet was subjected to a tensile test (room temperature, elongation rate 40%) and then measured from the transparent resin layer side using the SCE method. * and L measured by the SCE method from the transparent resin layer side before subjecting the decorative sheet to the tensile test. * The absolute value of the difference between the values ​​is 1.5 or less.

Images