Decorative film

Abstract

Provided is a decorative film which can be used for interior and exterior applications, such as for vehicles or buildings, and which can highly conceal underlying surfaces even when the decorative film has a color of high chromaticity. The decorative film according to one embodiment includes, in order, a transparent film layer, a first acrylic pressure-sensitive adhesive layer containing a colorant, and a second acrylic pressure-sensitive adhesive layer containing a white colorant.

Description

Technical Field

[0001] The present disclosure relates to a decorative film. Background Art

[0002] Colored decorative films have been widely used for internal and external applications, such as for vehicles (including cars, trains and ships) and for buildings. Colored decorative films are used, for example, in the production of vehicles or the construction of buildings, or the repair of vehicles and buildings. Colored decorative films preferably effectively conceal, for example, the color or pattern of the adherend (bottom layer) surface.

[0003] Patent document 1 (JP 2008-308646 A) describes "a colored tacky acrylic adhesive comprising a carboxyl group-containing (meth) acrylic polymer, a pigment or a dye, and an amino group-containing (meth) acrylic polymer free of an aromatic vinyl monomer", and "a marking film having a base film layer and an adhesive layer formed of the colored tacky acrylic adhesive".

[0004] Patent document 2 (JP 2003-138235 A) describes "an adhesive composition having concealing properties, the adhesive composition comprising: (a) 100 parts by weight of a resin component contained in a copolymer having a (meth) alkyl acrylate monomer as a main component, the (meth) acrylate alkyl ester monomer having an alkyl group containing 1 to 12 carbons, (b) 0.1 to 5 parts by weight of surface-treated aluminum particles having an average particle size of 5 μm to 50 μm and an aspect ratio of 50 to 200, and (c) 5 to 60 parts by weight of titanium oxide"; and "an adhesive sheet obtained by coating the adhesive composition having concealing properties on a substrate sheet and drying it".

[0005] Patent document 3 (JP 2003-183602 A) describes "a decorative adhesive sheet characterized by comprising an adhesive containing: 3 parts by weight to 50 parts by weight of a white pigment relative to 100 parts by weight of a base polymer of the adhesive, and 0.3% by weight to 2% by weight of an aluminum metal sheet relative to the amount of the added white pigment, the adhesive being laminated on one surface of a colored film having a total light transmittance of 3% to 80%." Summary of the invention

[0006] Technical issues

[0007] The color of the underlying surface to which the colored decorative film is applied is various colors, and the color of the decorative film is also various colors. For example, when the color of the decorative film is yellow, magenta, or beige with high chroma, the underlying surface may not be sufficiently concealed by the decorative film. In particular, when the brightness of the underlying surface is low, or when the underlying surface has various hues, brightness, or chroma, or a combination of at least two of these, the lack of concealment of the decorative film may be significantly visually recognized.

[0008] The present disclosure provides a decorative film that can be used for interior and exterior applications, such as for vehicles or buildings, and that can highly conceal an underlying surface even when the decorative film has a high chroma color.

[0009] Solution to the problem

[0010] The inventors of the present invention have found that a decorative film having both high chroma and hiding power can be provided by making the pressure-sensitive adhesive layer of the decorative film have a layered structure including two layers, a first acrylic pressure-sensitive adhesive layer containing a colorant and a second acrylic pressure-sensitive adhesive layer containing a white colorant.

[0011] According to one embodiment, a decorative film is provided, which includes a transparent film layer, a first acrylic pressure-sensitive adhesive layer containing a colorant, and a second acrylic pressure-sensitive adhesive layer containing a white colorant in this order. In a partial laminate that is a component of the decorative film and includes the transparent film layer and the first acrylic pressure-sensitive adhesive layer but does not include the second acrylic pressure-sensitive adhesive layer, when a color difference ΔE is measured from one side of the transparent film layer when the background color is white and black, * When the color difference ΔE between a part of the white background color and a part of the black background color is * is 13 or more, and in the decorative film, when the color difference ΔE is measured from one side of the transparent film layer in the case where the background color is white and black * When the color difference ΔE between a part of the white background color and a part of the black background color is * is 11 or less.

[0012] Advantageous Effects of the Invention

[0013] According to the present disclosure, it is possible to provide a decorative film that can be used for interior and exterior applications, such as for vehicles or buildings, and that can highly conceal an underlying surface even when the decorative film has a color with high chroma.

[0014] It should be noted that the above description is not to be construed as a disclosure of all embodiments of the present invention and advantages associated with the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic cross-sectional view of a decorative film according to an embodiment. DETAILED DESCRIPTION

[0016] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings for the purpose of explaining representative embodiments of the present invention, but the present invention is not limited to these embodiments.

[0017] In the present disclosure, the term "(meth)acrylic" refers to acrylic or methacrylic, and the term "(meth)acrylate" refers to acrylate or methacrylate.

[0018] In the present disclosure, the term "film" encompasses articles referred to as "sheets."

[0019] In the present disclosure, "pressure-sensitive adhesive (adhesion)" refers to a material or composition that adheres to various surfaces in a short time by applying a small pressure within a use temperature range (such as 0°C to 50°C) and does not exhibit a phase change (from liquid to solid). In the present disclosure, "adhesive (adhesion)" can be used interchangeably with "pressure-sensitive adhesive (adhesion)".

[0020] In the present disclosure, “disposed on” refers not only to the case of being directly disposed on but also to the case of being indirectly disposed on, that is, disposed on via another material or layer.

[0021] In this disclosure, "titanium oxide" may be used interchangeably with "titanium dioxide (TiO2)".

[0022] The decorative film of one embodiment includes a transparent film layer, a first acrylic pressure-sensitive adhesive layer containing a colorant, and a second acrylic pressure-sensitive adhesive layer containing a white colorant in this order. In a partial laminate as a component of the decorative film and including the transparent film layer and the first acrylic pressure-sensitive adhesive layer but not including the second acrylic pressure-sensitive adhesive layer, when the color difference ΔE is measured from one side of the transparent film layer in the case where the background color is white and black * When the color difference ΔE between a part of the white background color and a part of the black background color is * In the decorative film, when the color difference ΔE is measured from one side of the transparent film layer when the background color is white and black, * When the color difference ΔE between a part of the white background color and a part of the black background color is * is 11 or less.

[0023] In one embodiment, the decorative film includes a transparent film layer, a first acrylic pressure-sensitive adhesive layer containing a colorant, and a second acrylic pressure-sensitive adhesive layer containing a white colorant in sequence. "Including a transparent film layer, a first acrylic pressure-sensitive adhesive layer containing a colorant, and a second acrylic pressure-sensitive adhesive layer containing a white colorant" means that the decorative film does not include any layer other than the transparent film layer, the first acrylic pressure-sensitive adhesive layer, the second acrylic pressure-sensitive adhesive layer, and the liner removed when used. The decorative film of this embodiment has a simple layer structure, and therefore can more advantageously adapt to the regulations on flame retardancy in each country.

[0024] Figure 1 A schematic cross-sectional view of a decorative film according to an embodiment is shown. The decorative film 10 includes a transparent film layer 12, a first acrylic pressure-sensitive adhesive layer 14, and a second acrylic pressure-sensitive adhesive layer 16 in this order. Figure 1 The decorative film 10 further includes a liner 18 as an optional component. The liner 18 is removed before the decorative film 10 is adhered to an adherend.

[0025] As the transparent film layer, various resin films can be used without particular limitation. Examples of resin films include acrylic resin films, polyvinylidene fluoride (PVdF) films, polyurethane films, polyester films (such as polyethylene terephthalate (PET) films and polyvinyl chloride (PVC) films). The transparent film layer preferably has flexibility. The transparent film layer can be a single layer, or can be a laminate of two or more layers comprising different materials.

[0026] The transparent film layer may contain additives such as a UV absorber, a light stabilizer, an antioxidant, a heat stabilizer, and a filler as optional components.

[0027] The thickness of the transparent film layer may be any thickness, and for example, the thickness may be about 10 μm or more, about 12 μm or more, or about 15 μm or more, and about 200 μm or less, about 150 μm or less, or about 100 μm or less. From the perspective of elongation and non-flammability of the decorative film, the thickness of the transparent film layer is preferably about 80 μm or less, and more preferably about 50 μm or less.

[0028] The transparent film layer is preferably colorless and transparent, or preferably has a degree of transparency that allows visual identification of the presence of the color of the first acrylic pressure-sensitive adhesive layer through the transparent film layer. In one embodiment, the total light transmittance of the transparent film layer in the wavelength range of 380nm to 780nm is about 80% or more, about 85% or more, or about 90% or more, and 100% or less. The total light transmittance in the present disclosure is measured according to JIS A5759:2008. In the decorative film, the transparent film layer with the above-mentioned total light transmittance can promote visual identification of the original hue, brightness and chromaticity of the combination of the first acrylic pressure-sensitive adhesive layer and the second acrylic pressure-sensitive adhesive layer, without substantially changing. Therefore, when forming the first acrylic pressure-sensitive adhesive layer and the second acrylic pressure-sensitive adhesive layer, the workload caused by color matching can be reduced.

[0029] The surface of the transparent film layer may be subjected to surface treatment such as corona treatment or plasma treatment, and a primer layer may be formed on the surface of the transparent film layer. The adhesion between the transparent film layer and the first acrylic pressure-sensitive adhesive layer may be further enhanced by surface treatment or a primer layer.

[0030] The surface of the transparent film layer (the surface on the side opposite to the first acrylic pressure-sensitive adhesive layer) may be embossed-finished, or may be provided with a surface protective layer such as a hard coating layer.

[0031] The first acrylic pressure-sensitive adhesive layer comprises colorant, and mainly contributes to the tone, brightness and chroma of the decorative film.The first acrylic pressure-sensitive adhesive layer can be formed by using adhesive polymer and the first colored adhesive composition containing colorant usually.Adhesive polymer can be (methyl) acrylic polymer.The first acrylic pressure-sensitive adhesive layer can be cross-linked with crosslinking agent (such as bisamide crosslinking agent, aziridine crosslinking agent, carbodiimide crosslinking agent, epoxy crosslinking agent or isocyanate crosslinking agent).

[0032] Examples of colorants include pigments and dyes. The pigment or dye may be used alone, or two or more thereof may be used in combination. The form of the pigment and dye is not particularly limited, and may be subjected to dispersion treatment.

[0033] Examples of the pigment include inorganic pigments such as titanium oxide, zinc carbonate, zinc oxide, zinc sulfide, talc, kaolin, calcium carbonate, carbon black, chrome yellow, yellow iron oxide, red iron oxide, red iron oxide, barium sulfate, aluminum oxide, zirconium oxide, iron oxide-based pigments, iron hydroxide-based pigments, chromium oxide-based pigments, spinel-type calcined pigments, chromic acid-based pigments, chrome vermilion-based pigments, iron blue-based pigments, aluminum powder-based pigments, bronze powder-based pigments, and calcium phosphate; and organic pigments such as phthalocyanine-based pigments. The present invention relates to pigments based on phthalocyanine (such as phthalocyanine blue and phthalocyanine green), azo-based pigments, condensed azo-based pigments, azo lake-based pigments, anthraquinone-based pigments, indigo-based pigments, thioindigo-based pigments, isoindolinone-based pigments, azomethine-based pigments, nigrosine-based pigments, triphenylmethane-based pigments, perinone-based pigments, perylene-based pigments, quinophthalone-based pigments, dioxazine-based pigments, and quinacridone-based pigments (such as quinacridone red).

[0034] Examples of dyes include azo-based dyes, anthraquinone-based dyes, quinophthalone-based dyes, styryl-based dyes, diphenylmethane-based dyes, triphenylmethane-based dyes, oxazine-based dyes, triazine-based dyes, xanthane-based dyes, azomethine-based dyes, acridine-based dyes, and dioxazine-based dyes.

[0035] The content of the colorant may vary based on the desired hue, brightness, and chroma of the decorative film, and may be, for example, about 0.1% by mass or more, about 0.5% by mass or more, or about 1% by mass or more, and about 50% by mass or less, about 45% by mass or less, or about 40% by mass or less based on the mass of the first acrylic pressure-sensitive adhesive layer.

[0036] In one embodiment, the glass transition temperature (Tg) of the adhesive polymer of the first acrylic pressure-sensitive adhesive layer is about -40°C or lower. As described above, the first acrylic pressure-sensitive adhesive layer is a layer having the function of adjusting the color tone, brightness and chromaticity of the decorative film. By setting the glass transition temperature of the adhesive polymer to about -40°C or lower, the first acrylic pressure-sensitive adhesive layer can more appropriately adhere to the transparent film layer and the second acrylic pressure-sensitive adhesive layer. Therefore, the first acrylic pressure-sensitive adhesive layer of this embodiment can also be used as a bonding layer that firmly bonds the transparent film layer and the second acrylic pressure-sensitive adhesive layer, and further enhances the integration of the decorative film.

[0037] In the case where the binder polymer is a (meth)acrylic polymer, the calculated glass transition temperature can be determined according to the following Fox formula (Fox, TG, Bull. Am. Phys. Soc., 1 (1956), p. 123), assuming that each of the polymers is copolymerized with n monomers.

[0038] [Mathematics.1]

[0039]

[0040] In this formula, Tg i represents the glass transition temperature (°C) of the homopolymer of component i, X i represents the mass fraction of the monomer of component i added during polymerization, and i is a natural number from 1 to n, and

[0041] [Mathematics.2]

[0042]

[0043] In one embodiment, the first acrylic pressure-sensitive adhesive layer contains a carboxyl group-containing (meth) acrylic polymer and an amino group-containing (meth) acrylic polymer. The carboxyl group-containing (meth) acrylic polymer and the amino group-containing (meth) acrylic polymer have the ability to stably disperse a large amount of colorants in the first acrylic pressure-sensitive adhesive layer. Therefore, even when the first acrylic pressure-sensitive adhesive layer is made relatively thin, various tones, brightness and chroma can be given to the first acrylic pressure-sensitive adhesive layer. From the perspective of the non-flammability of the decorative film, the ability to thin the first acrylic pressure-sensitive adhesive layer is favorable. In addition, the carboxyl group-containing (meth) acrylic polymer and the amino group-containing (meth) acrylic polymer interact with each other, and the reduction of the cohesive force of the first acrylic pressure-sensitive adhesive layer caused by the dispersion of the colorant can be suppressed, and adhesion can be maintained. Therefore, the lamination of the first acrylic pressure-sensitive adhesive layer and the second acrylic pressure-sensitive adhesive layer can be further promoted, which will be described below as the production method of the decorative film. The carboxyl group-containing (meth)acrylic polymer and / or the amino group-containing (meth)acrylic polymer may be crosslinked with the above-mentioned crosslinking agent.

[0044] The (meth) acrylic polymer containing a carboxyl group can be obtained by copolymerizing a polymerizable composition comprising a (meth) acrylic monomer and a carboxyl group-containing monomer and a monomer having another monoethylenically unsaturated group as required. In the present disclosure, the (meth) acrylic monomer, the carboxyl group-containing monomer, the amino group-containing monomer and the monomer having another monoethylenically unsaturated group are collectively referred to as polymerizable components. The (meth) acrylic monomer, the carboxyl group-containing monomer and the monomer having another monoethylenically unsaturated group can be used alone or in combination of two or more.

[0045] (Meth) acrylic monomers generally include alkyl (meth) acrylates. The number of carbon atoms of the alkyl group of the alkyl (meth) acrylate may be 1 to 12. Examples of alkyl (meth) acrylates include linear or branched alkyl (meth) acrylates, such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-methylbutyl (meth) acrylate, isopentyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, and n-dodecyl (meth) acrylate; and alicyclic (meth) acrylates, such as cyclohexyl (meth) acrylate, 4-tert-butylcyclohexyl (meth) acrylate, and isobornyl (meth) acrylate. The alkyl (meth)acrylate preferably includes methyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl acrylate, or a combination of these.

[0046] The alkyl (meth)acrylate constitutes the main component of the (meth)acrylic polymer containing a carboxyl group. In one embodiment, the (meth)acrylic polymer containing a carboxyl group is obtained by copolymerizing a polymerizable composition containing the alkyl (meth)acrylate in an amount of about 50% by mass or more, about 70% by mass or more, or about 80% by mass or more, and about 99.5% by mass or less, about 99% by mass or less, or about 98% by mass or less relative to the mass of the polymerizable component, and includes structural units derived from the alkyl (meth)acrylate in the above mass ratios.

[0047] The (meth)acrylic monomer may include aromatic (meth)acrylates such as phenyl (meth)acrylate and p-tolyl (meth)acrylate; phenoxyalkyl (meth)acrylates such as phenoxyethyl (meth)acrylate; alkoxyalkyl (meth)acrylates such as methoxypropyl (meth)acrylate and 2-methoxybutyl (meth)acrylate; or cyclic ether-containing (meth)acrylates such as glycidyl (meth)acrylate or tetrahydrofurfuryl (meth)acrylate.

[0048] Examples of carboxyl group-containing monomers include (meth) acrylic acid, (meth) acrylic acid phthalic acid monohydroxyethyl ester, (meth) acrylic acid β-carboxyethyl ester, 2-(meth) acryloyloxyethyl succinic acid, 2-(meth) acryloyloxyethyl hexahydrophthalic acid, crotonic acid, itaconic acid, fumaric acid, citraconic acid and maleic acid. As the carboxyl group-containing monomer, (meth) acrylic acid is preferred. In the present disclosure, substances corresponding to (meth) acrylic monomers and carboxyl group-containing monomers (such as (meth) acrylic acid) are regarded as carboxyl group-containing monomers.

[0049] In one embodiment, the carboxyl group-containing (meth) acrylic polymer is obtained by copolymerizing a polymerizable composition containing a carboxyl group-containing monomer in an amount of about 0.5 mass % or more, about 1 mass % or more, or about 2 mass % or more, and about 15 mass % or less, about 10 mass % or less, or about 8 mass % or less, relative to the mass of the polymerizable component, and includes structural units derived from the carboxyl group-containing monomer in the above mass ratios.

[0050] Examples of (meth)acrylic monomers or monomers having another monoethylenically unsaturated group include amide group-containing monomers such as (meth)acrylamide, N-vinyl pyrrolidone, and N-vinyl caprolactam; hydroxyl group-containing monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; unsaturated nitriles such as (meth)acrylonitrile; aromatic vinyl monomers such as styrene, α-methylstyrene, and vinyltoluene; and vinyl esters such as vinyl acetate.

[0051] The copolymerization of the (meth) acrylic polymer containing a carboxyl group can be performed by free radical polymerization. As free radical polymerization, known polymerization methods such as solution polymerization, suspension polymerization, emulsion polymerization and bulk polymerization can be used. It is advantageous to use a solution polymerization that can easily synthesize a polymer with a high molecular weight. As a polymerization initiator, for example, an organic peroxide such as benzoyl peroxide, lauroyl peroxide or bis(4-tert-butylcyclohexyl) peroxydicarbonate can be used; or an azo polymerization initiator such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), dimethyl-2,2-azobis(2-methylpropionate), 4,4'-azobis(4-cyanovaleric acid), dimethyl 2,2'-azobis(2-methylpropionate) or azobis(2,4-dimethylvaleronitrile) (AVN) can be used. The polymerization initiator is usually used in an amount of about 0.01 parts by mass or more, or about 0.05 parts by mass or more, and about 5 parts by mass or less, or about 3 parts by mass or less, relative to 100 parts by mass of the polymerizable component.

[0052] The amino group-containing (meth) acrylic polymer increases the cohesive force of the first acrylic pressure-sensitive adhesive layer by interacting with the carboxyl group-containing (meth) acrylic polymer, and can improve the adhesion of the first acrylic pressure-sensitive adhesive layer. The increase in cohesive force also contributes to the improvement of the adhesion between the first acrylic pressure-sensitive adhesive layer and the second acrylic pressure-sensitive adhesive layer.

[0053] The amino group-containing (meth) acrylic polymer can be obtained by copolymerizing a polymerizable composition comprising a (meth) acrylic monomer and an amino group-containing monomer and, as required, a monomer having another monoethylenically unsaturated group. The (meth) acrylic monomer, the amino group-containing monomer, and the monomer having another monoethylenically unsaturated group may be used alone or in combination of two or more.

[0054] As the (meth)acrylic monomer and the monomer having another monoethylenically unsaturated group, the same ones as those described with respect to the carboxyl group-containing (meth)acrylic polymer can be used.

[0055] The alkyl (meth)acrylate constitutes the main component of the (meth)acrylic polymer containing an amino group. In one embodiment, the (meth)acrylic polymer containing an amino group is obtained by copolymerizing a polymerizable composition containing the alkyl (meth)acrylate in an amount of about 50% by mass or more, about 70% by mass or more, or about 80% by mass or more, and about 99.5% by mass or less, about 99% by mass or less, or about 98% by mass or less relative to the mass of the polymerizable component, and includes structural units derived from the alkyl (meth)acrylate in the above mass ratios.

[0056] Examples of amino group-containing monomers include aminoalkyl (meth)acrylates, such as aminoethyl (meth)acrylate; monoalkylaminoalkyl (meth)acrylates, such as butylaminoethyl (meth)acrylate; dialkylaminoalkyl (meth)acrylates, such as N,N-dimethylaminoethyl acrylate (DMAEA) and N,N-dimethylaminoethyl methacrylate (DMAEMA); dialkylaminoalkyl (meth)acrylamides, such as N,N-dimethylaminopropyl acrylamide (DMAPAA) and N,N-dimethylaminopropyl methacrylamide; and dialkylaminoalkyl vinyl ethers, such as N,N-dimethylaminoethyl vinyl ether and N,N-diethylaminoethyl vinyl ether. As the amino group-containing monomer, preferred is dialkylaminoalkyl (meth)acrylate, such as N,N-dimethylaminoethyl acrylate (DMAEA) or N,N-dimethylaminoethyl methacrylate (DMAEMA). In the present disclosure, a substance corresponding to a (meth)acrylic monomer and an amino group-containing monomer, such as aminoethyl (meth)acrylate, is regarded as an amino group-containing monomer.

[0057] In one embodiment, the amino group-containing (meth)acrylic polymer is obtained by copolymerizing a polymerizable composition containing an amino group-containing monomer in an amount of about 0.5 mass % or more, about 1 mass % or more, or about 2 mass % or more, and about 20 mass % or less, about 15 mass % or less, or about 10 mass % or less, relative to the mass of the polymerizable component, and includes structural units derived from the amino group-containing monomer in the above mass ratios.

[0058] The amino group-containing (meth) acrylic polymer is preferably an amino group-containing (meth) acrylic polymer not containing a monomer unit derived from an aromatic vinyl monomer (hereinafter also referred to as "amino group-containing non-aromatic (meth) acrylic polymer" in the present disclosure). The amino group-containing non-aromatic (meth) acrylic polymer has excellent miscibility with the carboxyl group-containing (meth) acrylic polymer, and thus can make the interaction with the carboxyl group-containing (meth) acrylic polymer more effective.

[0059] The non-aromatic (meth) acrylic polymer containing an amino group does not contain a structural unit derived from an aromatic vinyl monomer. Examples of aromatic vinyl monomers include (meth) acrylamides of styrene, α-methylstyrene, vinyl toluene, vinyl naphthalene, vinyl anthracene, vinyl anthraquinone, aromatic amines, and (meth) acrylic esters of aromatic compounds containing hydroxyl groups. Examples of aromatic amines include aniline, benzylamine, naphthylamine, aminoanthracene, aminoanthraquinone, and derivatives thereof. Examples of aromatic compounds containing hydroxyl groups include compounds containing hydroxyl groups corresponding to the aromatic amines described above.

[0060] The copolymerization of the (meth) acrylic polymer containing an amino group can be carried out by free radical polymerization in the same manner as the copolymerization of the (meth) acrylic polymer containing a carboxyl group. The polymerization method, polymerization initiator and the amount thereof used are the same as those described for the copolymerization of the (meth) acrylic polymer containing a carboxyl group.

[0061] In the first acrylic pressure-sensitive adhesive layer, at least one of a carboxyl group-containing (meth) acrylic polymer or an amino group-containing (meth) acrylic polymer is used as an acrylic adhesive polymer. The acrylic adhesive polymer imparts pressure-sensitive adhesiveness to the first acrylic pressure-sensitive adhesive layer at an operating temperature (e.g., 5° C. to 35° C.).

[0062] The glass transition temperature (Tg) of the acrylic adhesive polymer may be from about -70°C to about -40°C. In one embodiment, the glass transition temperature of the acrylic adhesive polymer is about -65°C or higher or about -60°C or higher, and about -45°C or lower or about -50°C or lower. By setting the glass transition temperature of the acrylic adhesive polymer to about -70°C or higher, the first acrylic pressure-sensitive adhesive layer can be given an adhesive strength to the second acrylic pressure-sensitive adhesive layer. By setting the glass transition temperature of the acrylic adhesive polymer to about -40°C or lower, the first acrylic pressure-sensitive adhesive layer can be more appropriately adhered to the transparent film layer and the second acrylic pressure-sensitive adhesive layer. Therefore, the first acrylic pressure-sensitive adhesive layer can also be used as a bonding layer that firmly bonds the transparent film layer and the second acrylic pressure-sensitive adhesive layer, and further enhances the integration of the decorative film. The glass transition temperature (Tg) of the acrylic adhesive polymer can be determined as the calculated glass transition temperature by using the above-mentioned Fox formula.

[0063] In one embodiment, the weight average molecular weight (Mw) of the acrylic adhesive polymer is about 150,000 or more, about 200,000 or more, or about 250,000 or more, and about 2,000,000 or less, about 1,500,000 or less, or about 1,000,000 or less. In the present disclosure, "weight average molecular weight" is the molecular weight according to polystyrene standards by gel permeation chromatography (GPC).

[0064] The mass ratio of the (meth)acrylic polymer containing a carboxyl group to the (meth)acrylic polymer containing an amino group is 100: about 0.1 to 50, 100: about 1 to 40 or 100: about 2 to 30 (when the (meth)acrylic polymer containing a carboxyl group is used as the acrylic adhesive polymer), or about 0.1 to 50:100, about 1 to 40:100 or about 2 to 30:100 (when the (meth)acrylic polymer containing an amino group is used as the acrylic adhesive polymer).

[0065] In one embodiment, another (meth) acrylic polymer different from the (meth) acrylic polymer used as the acrylic adhesive polymer can be used as an acrylic polymer additive. That is, in the case where a (meth) acrylic polymer containing a carboxyl group is used as the acrylic adhesive polymer, a (meth) acrylic polymer containing an amino group can be used as an acrylic polymer additive, and in the case where a (meth) acrylic polymer containing an amino group is used as the acrylic adhesive polymer, a (meth) acrylic polymer containing a carboxyl group can be used as an acrylic polymer additive. By interacting with the acid (carboxyl group)-base (amino group) of the acrylic adhesive polymer, the acrylic polymer additive can suppress the reduction of cohesive force caused by the depolymerization of the acrylic adhesive polymer caused by exposure to sunlight, etc., and the adhesive strength of the first acrylic pressure-sensitive adhesive layer can be maintained at a desired level.

[0066] In one embodiment, the (meth)acrylic polymer containing a carboxyl group is an acrylic adhesive polymer, and the (meth)acrylic polymer containing an amino group is an acrylic polymer additive.

[0067] The glass transition temperature (Tg) of the acrylic polymer additive may be from about 20°C to about 120°C. In one embodiment, the glass transition temperature of the acrylic polymer additive is about 30°C or higher or about 45°C or higher, and about 100°C or lower or about 80°C or lower. By setting the glass transition temperature of the acrylic polymer additive to about 20°C or higher, the reduction in cohesive force caused by the depolymerization of the acrylic adhesive polymer due to exposure to sunlight, etc. can be suppressed, and the adhesive strength of the first acrylic pressure-sensitive adhesive layer can be maintained at a desired level. By setting the glass transition temperature of the acrylic polymer additive to about 120°C or lower, adhesion within a normal temperature range can be ensured. The glass transition temperature of the acrylic polymer additive can be determined by using a Fox formula similar to that of the acrylic adhesive polymer.

[0068] In one embodiment, the acrylic polymer additive has a weight average molecular weight (Mw) of about 1,000 or greater, about 5,000 or greater, or about 10,000 or greater, and about 200,000 or less, about 100,000 or less, or about 80,000 or less.

[0069] At least one of the (meth) acrylic polymer containing carboxyl groups and the (meth) acrylic polymer containing amino groups can be used as a dispersant for the colorant. In this embodiment, a premix (also referred to as a grinding base) can be prepared by mixing the colorant with the (meth) acrylic polymer used as a dispersant, and the resulting premix can be mixed with other components of the first colored adhesive composition for forming the first acrylic pressure-sensitive adhesive layer. Therefore, a large amount of colorant can be stably dispersed in the first acrylic pressure-sensitive adhesive layer. A premix is ​​prepared for each colorant in a plurality of colorants, and these premixes are appropriately mixed, thereby color matching can also be promoted.

[0070] The carboxyl group-containing (meth) acrylic polymer or amino group-containing (meth) acrylic polymer used as a dispersant may be the same as or different from the substance used as an acrylic adhesive polymer or an acrylic polymer additive. In the latter case, the first acrylic pressure-sensitive adhesive layer contains two or more carboxyl group-containing (meth) acrylic polymers or amino group-containing (meth) acrylic polymers, that is, a carboxyl group-containing (meth) acrylic polymer or amino group-containing (meth) acrylic polymer used as a dispersant, and a carboxyl group-containing (meth) acrylic polymer or amino group-containing (meth) acrylic polymer used as an acrylic adhesive polymer or an acrylic polymer additive.

[0071] The weight average molecular weight (Mw) of the carboxyl group-containing (meth)acrylic polymer or the amino group-containing (meth)acrylic polymer used as the dispersant may generally be about 1,000 or more or about 10,000 or more, and about 1,500,000 or less or about 800,000 or less.

[0072] The first acrylic pressure-sensitive adhesive layer can be formed on a transparent film layer or a liner by using a first colored adhesive composition containing a carboxyl group-containing (meth)acrylic polymer, an amino group-containing (meth)acrylic polymer and a colorant, and, if necessary, a crosslinking agent, a solvent and / or other additives.

[0073] Before preparing the first colored adhesive composition, a premix can be prepared by mixing a colorant, a (meth) acrylic polymer containing a carboxyl group as a dispersant or a (meth) acrylic polymer containing an amino group. Mixing can be performed by using, for example, a paint stirrer, a sand mill, a ball mill, a vertical mill or a three-roll mill. When mixing, a water-based solvent or an organic solvent can be added as required. The gained premix is ​​mixed with the additional components of the first colored adhesive composition, and the first colored adhesive composition can be prepared. When using a variety of colorants, a premix can be prepared for each colorant, and these premixes are suitably mixed to match color, and then the premix mixture can be mixed with another component of the first colored adhesive composition.

[0074] The mass ratio of the total amount of the colorant to the amount of the dispersant may be about 1 to 100: about 5 to 1000, about 1 to 100: about 10 to 700, or about 1 to 100: about 10 to 500. The entire amount of the dispersant may be used during the preparation of the premix, or a portion of the dispersant may be used during the preparation of the premix, and the remaining dispersant may be used during the preparation of the first colored adhesive composition.

[0075] The crosslinking agent is not particularly limited as long as the crosslinking agent can form crosslinks between polymer chains of the carboxyl group-containing (meth) acrylic polymer or the amino group-containing (meth) acrylic polymer. For example, as the crosslinking agent of the carboxyl group-containing (meth) acrylic polymer, an epoxy crosslinking agent, a bisamide crosslinking agent, an aziridine crosslinking agent, a carbodiimide crosslinking agent or an isocyanate crosslinking agent can be used.

[0076] Examples of epoxy crosslinking agents include N,N,N',N'-tetraglycidyl-1,3-phenylenedi(methylamine) (trade name: TETRAD-X (Mitsubishi Gas Chemical Company Inc., Chiyoda-ku, Tokyo, Japan), E-AX and E-5XM (all from Soken Chemical & Engineering Co., Ltd., Toshima-ku, Tokyo, Japan); and N,N'-(cyclohexane-1,3-diylbismethylene)bis(diglycidylamine) (trade name: TETRAD-C (Mitsubishi Gas Chemical Company Inc., Chiyoda-ku, Tokyo, Japan) and E-5C (Soken Chemical & Engineering Co., Ltd., Toshima-ku, Tokyo, Japan)).

[0077] Examples of the bisamide crosslinking agent include 1,1′-isophthalyl-bis(2-propyleneimide), 1,4-bis(vinyliminocarbonylamino)benzene, 4,4′-bis(vinyliminocarbonylamino)diphenylmethane, and 1,8-bis(vinyliminocarbonylamino)octane.

[0078] Examples of aziridine crosslinking agents include 2,2-bis(hydroxymethyl)butanol-tris[3-(1-aziridinyl)propionate (trade name: CHEMITITE (trade name) PZ-33 (Nippon Shokubai Co., Ltd. Osaka-shi, Osaka, Japan)) and crosslinker CX-100 (DSM Coating Resins BV Zwolle, Netherlands).

[0079] Examples of carbodiimide crosslinkers include Carbodilite V-03, V-05, and V-07 (all from Nisshinbo Chemical Inc. Chuo-ku, Tokyo, Japan).

[0080] Examples of isocyanate crosslinking agents include Coronate L and Coronate HK (both available from Tosoh Corporation Minato-ku, Tokyo, Japan).

[0081] The crosslinking agent may be used in an amount of about 0.01 parts by mass or more, about 0.02 parts by mass or more, or about 0.05 parts by mass or more, and about 0.5 parts by mass or less, about 0.4 parts by mass or less, or about 0.3 parts by mass or less, based on 100 parts by mass of the carboxyl group-containing (meth)acrylic polymer or the amino group-containing (meth)acrylic polymer used as the acrylic binder polymer.

[0082] Examples of the solvent include methanol, ethanol, hexane, heptane, toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, and mixed solvents thereof.

[0083] Examples of other additives include UV absorbers, antioxidants, heat stabilizers, fillers, and tackifiers.

[0084] The thickness of the first acrylic pressure-sensitive adhesive layer may vary based on the desired hue, lightness, and chromaticity of the decorative film, and may be, for example, about 5 μm or more, about 10 μm or more, or about 15 μm or more, and about 100 μm or less, about 80 μm or less, or about 50 μm or less. From the perspective of the non-flammability of the decorative film, the thickness of the first acrylic pressure-sensitive adhesive layer is preferably about 80 μm or less, and more preferably about 50 μm or less.

[0085] The second acrylic pressure-sensitive adhesive layer contains a white colorant and mainly contributes to the concealment and adhesiveness of the decorative film. The decorative film can be given both high chromaticity and high concealment by making the pressure-sensitive adhesive layer of the decorative film have a layered structure including two layers, namely, a first acrylic pressure-sensitive adhesive layer containing a colorant and a second acrylic pressure-sensitive adhesive layer containing a white colorant.

[0086] The second acrylic pressure-sensitive adhesive layer can be formed by generally using an adhesive polymer and a second colored adhesive composition containing a white colorant. The adhesive polymer can be a (meth) acrylic polymer described for the first acrylic pressure-sensitive adhesive. The second acrylic pressure-sensitive adhesive layer can be cross-linked by the cross-linking agent described for the first acrylic pressure-sensitive adhesive layer.

[0087] The example of white colorant includes white pigment, such as titanium oxide, zinc carbonate, zinc oxide, calcium carbonate and zinc sulfate. White colorant can be used as one type or as a combination of two or more types. The form of white colorant is not particularly limited, and white colorant can be dispersed.

[0088] The white pigment is preferably titanium oxide. Titanium oxide acts as a flame retardant and can also improve the flame retardancy of the decorative film.

[0089] The average particle size of titanium oxide may be about 0.1 μm or more or about 0.15 μm or more, and about 5 μm or less or about 3 μm or less. The average particle size in the present disclosure is not the value of aggregated particles (secondary particles), but the value of primary particles. The average particle size of titanium oxide is the volume cumulative particle size D that can be determined by laser diffraction / scattering particle size distribution measurement. 50 .

[0090] The content of the white colorant may vary based on the concealment and adhesion required for the decorative film, and may be, for example, about 5% by mass or more, about 10% by mass or more, or about 15% by mass or more, and about 50% by mass or less, about 45% by mass or less, or about 40% by mass or less, based on the mass of the second acrylic pressure-sensitive adhesive layer. The second acrylic pressure-sensitive adhesive layer contains about 5% by mass to about 50% by mass of titanium oxide, and this may partially or completely conceal the surface of the adherend (bottom layer) to which the decorative film is applied.

[0091] In addition to the white colorant, the second acrylic pressure-sensitive adhesive layer may further include a second colorant. Examples of the second colorant include pigments and dyes. The pigment or dye may be used alone, or two or more of them may be used in combination. The form of the pigment and dye is not particularly limited, and may be subjected to a dispersion treatment.

[0092] Examples of the pigment and dye include, among the pigments and dyes described for the first acrylic pressure-sensitive adhesive layer, inorganic pigments and organic pigments other than white pigments, and dyes.

[0093] When the second colorant is used, the second colorant is preferably a colorant exhibiting colorlessness, ie, a black colorant. By using a black colorant as the second colorant, the brightness and chromaticity of the decorative film can be adjusted without changing the color tone of the first acrylic pressure-sensitive adhesive layer.

[0094] When a second colorant is used, the content of the second colorant may be about 0.1% by mass or more, about 0.5% by mass or more, or about 1% by mass or more, and about 45% by mass or less, about 40% by mass or less, or about 35% by mass or less, based on the mass of the second acrylic pressure-sensitive adhesive layer.

[0095] When a second colorant is used, the total content of the white colorant and the second colorant may be about 5% by mass or more, about 10% by mass or more, or about 15% by mass or more, and about 50% by mass or less, about 45% by mass or less, or about 40% by mass or less, based on the mass of the second acrylic pressure-sensitive adhesive layer.

[0096] In one embodiment, the glass transition temperature (Tg) of the adhesive polymer of the second acrylic pressure-sensitive adhesive layer is about -40°C or less. By setting the glass transition temperature of the adhesive polymer to about -40°C or less, initial adhesiveness (tackiness) can be effectively imparted to the second acrylic pressure-sensitive adhesive layer.

[0097] In one embodiment, the second acrylic pressure-sensitive adhesive layer contains carboxyl-containing (meth) acrylic polymer and amino-containing (meth) acrylic polymer. Carboxyl-containing (meth) acrylic polymer and amino-containing (meth) acrylic polymer have the ability to stably disperse a large amount of white coloring agents in the second acrylic pressure-sensitive adhesive layer. Therefore, even when the second acrylic pressure-sensitive adhesive layer is relatively thin, the second acrylic pressure-sensitive adhesive layer can be given high concealment. From the perspective of the non-flammability of the decorative film, the ability to thin the second acrylic pressure-sensitive adhesive layer is favorable. In addition, carboxyl-containing (meth) acrylic polymer and amino-containing (meth) acrylic polymer interact with each other, and the reduction of the cohesive force of the second acrylic pressure-sensitive adhesive layer caused by the dispersion of the white coloring agent can be suppressed, and adhesion can be maintained. Carboxyl-containing (meth) acrylic polymer and / or amino-containing (meth) acrylic polymer can be cross-linked with the above-mentioned cross-linking agent.

[0098] Representative and preferred compositions and preparation methods of the carboxyl group-containing (meth)acrylic polymer and the amino group-containing (meth)acrylic polymer are as described for the first acrylic pressure-sensitive adhesive layer.

[0099] In the second acrylic pressure-sensitive adhesive layer, at least one of a carboxyl group-containing (meth) acrylic polymer or an amino group-containing (meth) acrylic polymer is used as an acrylic adhesive polymer. The acrylic adhesive polymer imparts pressure-sensitive adhesiveness to the second acrylic pressure-sensitive adhesive layer at an operating temperature (e.g., 5° C. to 35° C.).

[0100] The glass transition temperature (Tg) of the acrylic adhesive polymer may be from about -70°C to about -40°C. In one embodiment, the glass transition temperature of the acrylic adhesive polymer is about -65°C or higher or about -60°C or higher, and about -45°C or lower or about -50°C or lower. By setting the glass transition temperature of the acrylic adhesive polymer to about -70°C or higher, the second acrylic pressure-sensitive adhesive layer can be given adhesive strength and holding strength. By setting the glass transition temperature of the acrylic adhesive polymer to about -40°C or lower, the second acrylic pressure-sensitive adhesive layer can be effectively given initial adhesion (tack). The glass transition temperature (Tg) of the acrylic adhesive polymer can be determined as the calculated glass transition temperature by using the above-mentioned Fox formula.

[0101] Representative and preferred embodiments of the weight average molecular weight (Mw) of the acrylic adhesive polymer, the mass ratio of the carboxyl group-containing (meth) acrylic polymer to the amino group-containing (meth) acrylic polymer, the acrylic polymer additive, the glass transition temperature (Tg) and the weight average molecular weight (Mw) thereof are the same as those described for the first acrylic pressure-sensitive adhesive layer.

[0102] At least one of a carboxyl group-containing (meth) acrylic polymer or an amino group-containing (meth) acrylic polymer can be used as a dispersant for the white colorant and the optional second colorant. Representative and preferred dispersants and premixes in this embodiment are the same as those described for the first acrylic pressure-sensitive adhesive layer.

[0103] The second acrylic pressure-sensitive adhesive layer may be formed on the first acrylic pressure-sensitive adhesive layer or liner by using a second colored adhesive composition containing a carboxyl group-containing (meth)acrylic polymer, an amino group-containing (meth)acrylic polymer, and a white colorant, and, as needed, a second colorant, a crosslinking agent, a solvent, and / or other additives.

[0104] Before preparing the second colored adhesive composition, a white colorant and an optional second colorant and a carboxyl group-containing (meth) acrylic polymer or an amino group-containing (meth) acrylic polymer used as a dispersant may be mixed to prepare a premix. The preparation of the premix and the second colored adhesive composition may be performed by a procedure similar to that described for the first acrylic pressure-sensitive adhesive layer, except that "white colorant and optional second colorant" are used instead of "colorant".

[0105] Representative and preferred crosslinking agents, solvents, and other additives are the same as those described for the first acrylic pressure-sensitive adhesive layer.

[0106] The thickness of the second acrylic pressure-sensitive adhesive layer may vary based on the concealment and adhesion required for the decorative film, and may be, for example, about 5 μm or more, about 10 μm or more, or about 15 μm or more, and about 100 μm or less, about 80 μm or less, or about 50 μm or less. From the perspective of the non-flammability of the decorative film, the thickness of the second acrylic pressure-sensitive adhesive layer is preferably about 80 μm or less, and more preferably about 50 μm or less.

[0107] Decorative film can be prepared according to the first method including the following process, for example. The first colored adhesive composition is applied on the liner and dried to form the first acrylic pressure-sensitive adhesive layer by using a knife coater or a bar coater. In order to make the reaction of the cross-linking agent as an optional component proceed, the first acrylic pressure-sensitive adhesive layer can be heated by hot air or an oven during drying. On the first acrylic pressure-sensitive adhesive layer obtained, a transparent film layer is stacked by a method such as dry lamination, thereby preparing a decorative film precursor. The second colored adhesive composition is applied on the liner and dried to form the second acrylic pressure-sensitive adhesive layer by using a knife coater or a bar coater. In order to make the reaction of the cross-linking agent as an optional component proceed, the second acrylic pressure-sensitive adhesive layer can be heated by hot air or an oven during drying. Remove the liner from the decorative film precursor, and stack the first acrylic pressure-sensitive adhesive layer and the second acrylic pressure-sensitive adhesive layer in a way that they contact by a method such as dry lamination, thereby preparing a decorative film. The first acrylic pressure-sensitive adhesive layer and the second acrylic pressure-sensitive adhesive layer both have pressure-sensitive adhesive properties, thereby preparing a decorative film by the above-mentioned procedure. In this embodiment, since the liner included in the decorative film precursor can be used as a support for the transparent film layer, even when the transparent film layer is thin, it can be handled.

[0108] The decorative film can also be prepared by a second method including the following process. The first colored adhesive composition is directly applied to the transparent film layer using a knife coater or a bar coater, and optionally a first acrylic pressure-sensitive adhesive layer is formed by heat drying. The second colored adhesive composition is applied to the liner using a knife coater or a bar coater, and optionally a second acrylic pressure-sensitive adhesive layer is formed by heat drying. The first acrylic pressure-sensitive adhesive layer and the second acrylic pressure-sensitive adhesive layer are stacked in a manner that they are in contact by a method such as dry lamination, thereby preparing the decorative film.

[0109] The decorative film can also be prepared by a third method including the following process. A first colored adhesive composition is directly applied to a transparent film layer using a knife coater or a bar coater, and optionally a first acrylic pressure-sensitive adhesive layer is formed by heating and drying. A second colored adhesive composition is directly applied to the first acrylic pressure-sensitive adhesive layer using a knife coater or a bar coater, and optionally a second acrylic pressure-sensitive adhesive layer is formed by heating and drying. A liner is laminated on the second acrylic pressure-sensitive adhesive layer as needed to form a decorative film.

[0110] The decorative film can also be prepared by a fourth method including the following process. The second acrylic pressure-sensitive adhesive layer is formed by applying the second colored adhesive composition on the liner using a knife coater or a bar coater and optionally by heating and drying. The first acrylic pressure-sensitive adhesive layer is formed by directly applying the first colored adhesive composition on the second acrylic pressure-sensitive adhesive layer using a knife coater or a bar coater and optionally by heating and drying. On the first acrylic pressure-sensitive adhesive layer, a transparent film layer is laminated by a method such as dry lamination to form a decorative film.

[0111] The decorative film may include a liner on the surface of the second acrylic pressure-sensitive adhesive layer. Examples of the liner as an optional component include plastic materials such as polyethylene, polypropylene, polyester and cellulose acetate, paper and laminated paper of plastic materials. These liners may have a surface treated with a release liner with silicone or the like. The thickness of the liner may generally be about 10 μm or more or about 25 μm or more, and about 500 μm or less or about 200 μm or less.

[0112] The adhesive surface of the second acrylic pressure-sensitive adhesive layer can be flat or can have depression and projection.The adhesive surface with groove and projection comprises the adhesive surface of the second acrylic pressure-sensitive adhesive layer (forming therein the projection of the solid component of the solid component of the second colored adhesive composition or reaction product and around the groove of this projection), and when adhesive surface is attached to adherend, between adherend surface and adhesive surface, form communication channel, this communication channel is limited by groove and is communicated with the external space.The example of the method for forming this adhesive surface with groove and projection will be described below.

[0113] Preparation has the liner of stripping surface, and this stripping surface comprises predetermined groove and convex structure.The second colored adhesive composition is applied to the stripping surface of liner, and heats as required, thereby forms the second acrylic pressure-sensitive adhesive layer.Therefore, the groove of liner and projection (negative structure) are transferred to the surface of the second acrylic pressure-sensitive adhesive layer, and this surface contacts (adhesive surface as the decorative film) with liner, thereby forms the adhesive surface with the groove that comprises predetermined structure (positive structure) and projection at adhesive surface place.As mentioned above, the groove of adhesive surface and projection are designed to comprise groove in advance, and this groove allows to form communication passage when projection is attached to adherend.The second acrylic pressure-sensitive adhesive layer that forms on liner can be used for above-mentioned first method, second method and the 4th method.

[0114] For the groove of the second acrylic pressure-sensitive adhesive layer, the groove with consistent shape can be arranged at the adhesive surface to form a regular patterned groove according to a regular pattern, or the groove with an undetermined shape can be arranged to form an irregular patterned groove. In the case where a plurality of grooves are formed to be arranged substantially parallel to each other, the interval of the groove is preferably about 10 μm or larger or about 100 μm or larger, and about 2000 μm or smaller or about 1000 μm or smaller. The depth of the groove (the distance from the bottom of the adhesive surface to the groove measured toward the direction of the transparent film layer) is generally about 10 μm or larger and about 100 μm or smaller. The shape of the groove is not particularly limited either, as long as the effect of the present invention is not compromised. For example, at the cross section of the groove perpendicular to the direction of the adhesive surface, the shape of the groove can be roughly rectangular (including trapezoidal), roughly semicircular or roughly semi-elliptical.

[0115] In a partial laminate as a component of a decorative film and including a transparent film layer and a first acrylic pressure-sensitive adhesive layer but not including a second acrylic pressure-sensitive adhesive layer, when the color difference ΔE is measured from one side of the transparent film layer in the case where the background color is white and black * When the color difference ΔE between a part of the white background color and a part of the black background color is * About 13 or more. Color difference ΔE * It may be about 15 or more, or about 20 or more. The partial laminate of the present disclosure is defined as a laminate including all layers constituting the decorative film, such as a primer layer and a surface protective layer optionally disposed on the transparent film layer in addition to the transparent film layer and the first acrylic pressure-sensitive adhesive layer, but excluding the second acrylic pressure-sensitive adhesive layer and the liner. The partial laminate of the present disclosure may be obtained by removing the second acrylic pressure-sensitive adhesive layer from the decorative film. Color difference ΔE * About 13 or more means that the first acrylic pressure-sensitive adhesive layer is a layer that mainly contributes to the hue, brightness, and chroma of the decorative film and hardly contributes to the concealing property of the decorative film. * It was measured by using a spectrophotometer according to the procedure described in the section "3. Hiding ability" of the Examples.

[0116] In decorative films, when the color difference ΔE is measured from one side of the transparent film layer with the background colors of white and black * When the color difference ΔE between a part of the white background color and a part of the black background color is * is about 11 or less. * In the case of the decorative film, the liner is not included. Color difference ΔE * It is preferably about 8 or less, and more preferably about 6 or less. Considering the color difference ΔE of a part of the laminate *The color difference ΔE is about 13 or more * About 11 or less means that the second acrylic pressure-sensitive adhesive layer is a layer that mainly contributes to the concealment of the decorative film. * It was measured by using a spectrophotometer according to the procedure described in the section "3. Hiding ability" of the Examples.

[0117] In one embodiment, when the decorative film is attached to an aluminum plate and the chromaticity C is measured from one side of the transparent film layer, * When the chromaticity C * About 40 or more. Chroma C * It may be about 50 or more, about 65 or more, or about 80 or more. Chroma C * About 40 or more means that the visually recognized color of the decorative film has high chroma. Chroma C * According to "4. Chroma C * The procedure described in the " section was determined by using a spectrophotometer.

[0118] The decorative film may have various thicknesses; however, from the perspective of flame retardancy, the thickness of the decorative film is preferably about 240 μm or less. A decorative film having a thickness of about 240 μm or less may impart the desired flame retardancy to the decorative film. In the present disclosure, the thickness of the decorative film does not include the thickness of the liner. The thickness of the decorative film may be about 200 μm or less or about 100 μm or less. The thickness of the decorative film may be about 30 μm or more, about 40 μm or more, or about 50 μm or more.

[0119] The decorative film has a heat release rate of 8 MJ / m 20 minutes after the start of heating as measured according to the ISO 5660-1 cone calorimeter test. 2 In one embodiment, the total heat release is about 7 MJ / m 2 or less or about 6MJ / m 2 or less. will have 8MJ / m 2 Decorative films with a total heat release of 0.1% or less are evaluated as non-flammable.

[0120] In one embodiment, the decorative film is substantially free of flame retardants. Note that "substantially free" means that the content of the flame retardant is less than about 1 mass %, less than about 0.5 mass %, or less than about 0.2 mass % relative to the mass of the decorative film. Examples of flame retardants include organic flame retardants such as bromine-based flame retardants, phosphorus-based flame retardants, and chlorine-based flame retardants; and inorganic flame retardants such as antimony compounds, metal hydroxides, nitrogen compounds, and boron compounds. In the present disclosure, pigments that can be used as flame retardants (such as titanium oxide) are not included in the content of the flame retardant.

[0121] The decorative films of the present disclosure may be suitable for interior and exterior applications, such as for vehicles (including cars, trains and ships) and for buildings; and for exterior applications, such as for the exterior walls of storage tanks and transformer facilities. In one embodiment, the decorative film is used in vehicles.

[0122] Example

[0123] In the following examples, specific embodiments of the present disclosure will be illustrated, but the present invention is not limited to these embodiments. Unless otherwise specified, all "parts" and "percents" are by mass.

[0124] The raw materials used to prepare the decorative films are shown in Table 1.

[0125] Table 1

[0126]

[0127]

[0128]

[0129] 1) MMA: methyl methacrylate, BMA: n-butyl methacrylate, DMAEMA: 2-(dimethylamino)ethyl methacrylate, BA: n-butyl acrylate, 2EHA: 2-ethylhexyl acrylate, Vac: vinyl acetate, AA: acrylic acid, ACM: acrylamide, AN: acrylonitrile, EtOAc: ethyl acetate

[0130] The compositions of Millbase 1 to Millbase 3 (premixes) used to prepare decorative films are shown in Table 2.

[0131] Table 2

[0132]

[0133] 1) MEK: methyl ethyl ketone, MIBK: methyl isobutyl ketone

[0134] The compositions of the colored adhesive compositions CA1 to CA13 used to prepare the decorative films are shown in Table 3. The colored adhesive compositions CA1 to CA13 were prepared by mixing the mill bases 1 to 6 and the materials.

[0135] Table 3 (values ​​are dry mass %)

[0136]

[0137] Example 1

[0138] The colored adhesive composition CA1 was applied to the liner 1 (L1) by using a knife coater and dried at 95°C for 5 minutes. After drying, a first acrylic pressure-sensitive adhesive layer having a thickness of 30 μm was obtained. The first acrylic pressure-sensitive adhesive layer was adhered to the film 1 (FL1), thereby obtaining a decorative film precursor. The colored adhesive composition CA2 was then applied to L1 by using a knife coater and dried at 95°C for 5 minutes. After drying, a second acrylic pressure-sensitive adhesive layer having a thickness of 30 μm was obtained. L1 of the decorative film precursor was peeled off, and the second acrylic pressure-sensitive adhesive layer was laminated on the first acrylic pressure-sensitive adhesive layer, thereby obtaining the decorative film of Example 1.

[0139] Example 2

[0140] The colored adhesive composition CA3 was applied to L1 by using a knife coater and dried at 95°C for 5 minutes. After drying, a first acrylic pressure-sensitive adhesive layer having a thickness of 22 μm was obtained. The first acrylic pressure-sensitive adhesive layer was adhered to film 2 (FL2) to obtain a decorative film precursor. The colored adhesive composition CA4 was then applied to L1 by using a knife coater and dried at 95°C for 5 minutes. After drying, a second acrylic pressure-sensitive adhesive layer having a thickness of 40 μm was obtained. L1 of the decorative film precursor was peeled off, and the second acrylic pressure-sensitive adhesive layer was stacked on the first acrylic pressure-sensitive adhesive layer to obtain the decorative film of Example 2.

[0141] Example 3

[0142] The decorative film of Example 3 was obtained by the same procedure as in Example 2, except that the colored adhesive composition was changed from CA4 to CA5, and the thickness of the second acrylic pressure-sensitive adhesive layer was changed to 23 μm.

[0143] Example 4

[0144] A decorative film of Example 4 was obtained by the same procedure as in Example 3, except that the thickness of the second acrylic pressure-sensitive adhesive layer was changed to 15 μm.

[0145] Example 5

[0146] A decorative film of Example 5 was obtained by the same procedure as in Example 3, except that the thickness of the second acrylic pressure-sensitive adhesive layer was changed to 34 μm.

[0147] Example 6

[0148] The colored adhesive composition CA6 was applied to L1 by using a knife coater and dried at 95°C for 5 minutes. After drying, a first acrylic pressure-sensitive adhesive layer having a thickness of 20 μm was obtained. The first acrylic pressure-sensitive adhesive layer was adhered to FL2 to obtain a decorative film precursor. The colored adhesive composition CA7 was then applied to liner 2 (L2) by using a knife coater and dried at 95°C for 5 minutes. After drying, a second acrylic pressure-sensitive adhesive layer having a thickness of 34 μm was obtained. L1 of the decorative film precursor was peeled off, and the second acrylic pressure-sensitive adhesive layer was laminated on the first acrylic pressure-sensitive adhesive layer to obtain the decorative film of Example 6.

[0149] Example 7

[0150] The decorative film of Example 7 was obtained by the same procedure as Example 6, except that the colored adhesive composition was changed from CA7 to CA8 containing a different crosslinking agent content, and the thickness of the second acrylic pressure-sensitive adhesive layer was changed to 33 μm.

[0151] Example 8

[0152] The colored adhesive composition CA6 was applied to L1 by using a knife coater and dried at 95°C for 5 minutes. After drying, a first acrylic pressure-sensitive adhesive layer having a thickness of 20 μm was obtained. The first acrylic pressure-sensitive adhesive layer was adhered to FL2, thereby obtaining a decorative film precursor. The colored adhesive composition CA9 was then applied to L1 by using a knife coater and dried at 95°C for 5 minutes. After drying, a second acrylic pressure-sensitive adhesive layer having a thickness of 30 μm was obtained. L1 of the decorative film precursor was peeled off, and the second acrylic pressure-sensitive adhesive layer was laminated on the first acrylic pressure-sensitive adhesive layer, thereby obtaining the decorative film of Example 8.

[0153] Example 9

[0154] A decorative film of Example 9 was obtained by the same procedure as in Example 8, except that the thickness of the first acrylic pressure-sensitive adhesive layer was changed to 40 μm.

[0155] Example 10

[0156] Colored adhesive composition CA6 was applied to film 3 (FL3) by using a knife coater and dried at 95°C for 5 minutes. After drying, a first acrylic pressure-sensitive adhesive layer having a thickness of 21 μm was obtained. Colored adhesive composition CA8 was then applied to the first acrylic pressure-sensitive adhesive layer by using a knife coater and dried at 95°C for 5 minutes. After drying, a second acrylic pressure-sensitive adhesive layer having a thickness of 36 μm was obtained. L1 was laminated on the second acrylic adhesive layer, and the support film of FL3 (attached to FL3 when obtained) was removed to obtain the decorative film of Example 10.

[0157] Embodiment 11

[0158] The decorative film of Example 11 was obtained by the same procedure as Example 10, except that FL3 was changed to Film 4 (FL4), the thickness of the first acrylic pressure-sensitive adhesive layer was changed to 16 μm, and the thickness of the second acrylic pressure-sensitive adhesive layer was changed to 38 μm.

[0159] Example 12

[0160] The colored adhesive composition CA9 was applied to L1 by using a knife coater and dried at 95°C for 5 minutes. After drying, a second acrylic pressure-sensitive adhesive layer having a thickness of 29 μm was obtained. The colored adhesive composition CA6 was then applied to the second acrylic pressure-sensitive adhesive layer by using a knife coater and dried at 95°C for 5 minutes. After drying, a first acrylic pressure-sensitive adhesive layer having a thickness of 20 μm was obtained. FL2 was laminated on the first acrylic pressure-sensitive adhesive layer to obtain the decorative film of Example 12.

[0161] Example 13

[0162] The decorative film of Example 13 was obtained by the same procedure as Example 12, except that the transparent film layer was changed from FL2 to FL5.

[0163] Example 14 to Example 21

[0164] Decorative films of Examples 14 to 21 were each obtained by the same procedure as in Example 8, except that the first acrylic pressure-sensitive adhesive layer was changed as described in Table 4.

[0165] Comparative Example 1

[0166] A decorative film of Comparative Example 1 was obtained by the same procedure as in Example 1, except that the second acrylic pressure-sensitive adhesive layer was not used.

[0167] Comparative Example 2

[0168] A decorative film of Comparative Example 2 was obtained by the same procedure as in Example 2, except that the second acrylic pressure-sensitive adhesive layer was not used.

[0169] Comparative Example 3

[0170] A decorative film of Comparative Example 3 was obtained by the same procedure as in Example 5, except that the first acrylic pressure-sensitive adhesive layer was not used.

[0171] Comparative Examples 4 to 11

[0172] Decorative films of Comparative Examples 4 to 11 were respectively obtained by the same procedures as Examples 14 to 21, except that the second acrylic pressure-sensitive adhesive layer was not used.

[0173] The decorative films were evaluated for the following items.

[0174] 1. Adhesion

[0175] The test piece was prepared by cutting the decorative film into a width of 25 mm and a length of 150 mm. The test piece was adhered to a melamine-coated plate (Paltek Corporation, Hiratsuka-shi, Kanagawa, Japan) at 20°C. The adhesion method was according to JIS Z 0237:2009 8.2.3. The test piece was kept at 20°C for 48 hours. A tensile tester (Tensilon (registered trademark) universal testing machine, model: RTC-1210A, A&D Company, Limited, Toshima-ku, Tokyo, Japan) was used to measure the adhesion strength (N / 25mm) when 180 degrees of peeling was performed at a peeling rate of 300 mm / min at a temperature of 20°C.

[0176] 2. Heat shrinkage

[0177] The test piece was prepared by cutting the decorative film into a width of 50 mm and a length of 100 mm. The test piece was adhered to an aluminum plate A5052P (Partek Co., Ltd., Hiratsuka City, Kanagawa Prefecture, Japan) by a roller in an environment of 23°C and placed in an environment of 23°C for 24 hours. On the test piece, a cross shape was cut with a utility knife. The test piece was then heated at 65°C for 48 hours. After heat aging, the shrinkage (mm) of the film was measured by a microscope, and the maximum value was recorded.

[0178] 3. Concealment

[0179] The test piece was prepared by cutting the decorative film into a square with a side length of 50 mm. The test piece was adhered to the hiding ability chart (inspection item, hiding ability chart, SEIEIDO Printing Co., Ltd., Yonezawa-shi, Yamagata, Japan). For the white area and the black area, the L of the test piece was measured by using a spectrophotometer (CM-3700d, Konica Minolta Japan, Inc., Minato-ku, Tokyo, Japan) * 、a * and b * Take the measured value of the white area as L1 * 、a1 * 、b1 * , and take the measured value of the black area as L2 * 、a2 * 、b2 * , the color difference ΔE of the concealment capability index is calculated by the following formula * :

[0180] ΔE * =[(L2 * -L1 * ) 2 +(a2 * -a1 * ) 2 +(b2 * -b1 * ) 2 ] 1 / 2 .

[0181] Color difference ΔE * The case with less than 6 is evaluated as "A", and the color difference ΔE * The case where the color difference ΔE is 6 or more and less than 12 is evaluated as "B", and the color difference ΔE * The case of 12 or more was evaluated as "C". "A" was evaluated as having excellent concealment, and "B" was evaluated as having good concealment.

[0182] 4. Chroma C *

[0183] The test pieces prepared for the hiding ability test were adhered to an aluminum plate (Partek Co., Ltd., Hiratsuka-shi, Kanagawa, Japan), and the L * 、a * and b * Value. Chroma C* Determined by calculation based on the following formula:

[0184] C * =[(a * ) 2 +(b * ) 2 ] 1 / 2 .

[0185] 5. Non-flammability test

[0186] The decorative film was adhered to a galvanized steel plate (thickness: 0.27 mm). The test was conducted according to ISO 5660-1 cone calorimeter heat release test. As a parameter, a cone calorimeter (available from Toyo Seiki Seisaku-sho, Ltd.) was used to measure the heat release rate (kW / m 2 ) and total heat release (MJ / m 2 ). The total heat release in 20 minutes after the start of heating is 8MJ / m 2 or less and shows a heat release rate exceeding 200kW / m 2 When the total time is 10 seconds or less, the decorative film is determined to be qualified, otherwise the decorative film is determined to be unqualified.

[0187] The compositions and evaluation results of the decorative films of Examples 1 to 21 and Comparative Examples 1 to 11 are shown in Tables 4 and 5.

[0188] Table 4

[0189]

[0190] Table 5

[0191]

[0192] Without departing from the basic principles of the present invention, various modifications of the above embodiments and embodiments will be apparent to those skilled in the art. It will also be apparent to those skilled in the art that various improvements and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Some embodiments of the present disclosure are described below.

[0193] First aspect

[0194] A decorative film, the decorative film sequentially comprising: a transparent film layer, a first acrylic pressure-sensitive adhesive layer containing a colorant, and a second acrylic pressure-sensitive adhesive layer containing a white colorant,

[0195] Wherein, in a partial laminate as a component of the decorative film and including the transparent film layer and the first acrylic pressure-sensitive adhesive layer but not including the second acrylic pressure-sensitive adhesive layer, when the color difference ΔE is measured from one side of the transparent film layer when the background color is white and black * When the color difference ΔE between a portion of the white background color and a portion of the black background color is * is 13 or greater, and

[0196] In the decorative film, when the color difference ΔE is measured from the one side of the transparent film layer when the background colors are white and black, * When the color difference ΔE between a portion of the white background color and a portion of the black background color is * is 11 or less.

[0197] Second aspect

[0198] The decorative film according to the first aspect, wherein when the decorative film is attached to the aluminum plate, C is measured from the one side of the transparent film layer. * When the chromaticity C * 40 or more.

[0199] The third aspect

[0200] The decorative film according to the first or second aspect, wherein the adhesive polymer of the first acrylic pressure-sensitive adhesive layer has a glass transition temperature of -40°C or lower.

[0201] The fourth aspect

[0202] The decorative film according to any one of the first to third aspects, wherein the first acrylic pressure-sensitive adhesive layer contains a carboxyl group-containing (meth)acrylic polymer and an amino group-containing (meth)acrylic polymer.

[0203] Fifth Aspect

[0204] The decorative film according to any one of the first to fourth aspects, wherein the glass transition temperature of the adhesive polymer of the second acrylic pressure-sensitive adhesive layer is -40°C or lower.

[0205] The sixth aspect

[0206] The decorative film according to any one of the first to fifth aspects, wherein the second acrylic pressure-sensitive adhesive layer contains a carboxyl group-containing (meth)acrylic polymer and an amino group-containing (meth)acrylic polymer.

[0207] Seventh Aspect

[0208] The decorative film according to any one of the first to sixth aspects, wherein a thickness of the decorative film is 240 μm or less.

[0209] Eighth Aspect

[0210] The decorative film according to any one of the first to seventh aspects, wherein the total heat release 20 minutes after the start of heating measured according to ISO 5660-1 heat release rate (cone calorimeter method) is 8 MJ / m 2 or less.

[0211] Ninth Aspect

[0212] The decorative film according to any one of the first to eighth aspects, wherein the decorative film is substantially free of flame retardants.

[0213] Reference numerals list

[0214] 10Decorative film

[0215] 12 transparent film layer

[0216] 14 first acrylic pressure-sensitive adhesive layer

[0217] 16 Second acrylic pressure-sensitive adhesive layer

[0218] 18 pads

Claims

1. A decorative film, comprising: a transparent film layer, a first acrylic pressure-sensitive adhesive layer containing a colorant, and a second acrylic pressure-sensitive adhesive layer containing a white colorant, Wherein, in a partial laminate as a component of the decorative film and including the transparent film layer and the first acrylic pressure-sensitive adhesive layer but not including the second acrylic pressure-sensitive adhesive layer, when the color difference ΔE is measured from one side of the transparent film layer when the background color is white and black * When the color difference ΔE between a portion of the white background color and a portion of the black background color is * is 13 or greater, and In the decorative film, when the color difference ΔE is measured from the one side of the transparent film layer when the background colors are white and black, * When the color difference ΔE between a portion of the white background color and a portion of the black background color is * is 11 or less.

2. The decorative film according to claim 1, wherein the chromaticity C is measured from the one side of the transparent film layer when the decorative film is attached to an aluminum plate. * When the chromaticity C * 40 or more. 3 . The decorative film according to claim 1 , wherein the adhesive polymer of the first acrylic pressure-sensitive adhesive layer has a glass transition temperature of −40° C. or less. 4 . The decorative film according to claim 1 , wherein the first acrylic pressure-sensitive adhesive layer contains a carboxyl group-containing (meth)acrylic polymer and an amino group-containing (meth)acrylic polymer. 5 . The decorative film according to claim 1 , wherein the adhesive polymer of the second acrylic pressure-sensitive adhesive layer has a glass transition temperature of −40° C. or less. 6 . The decorative film according to claim 1 , wherein the second acrylic pressure-sensitive adhesive layer contains a carboxyl group-containing (meth)acrylic polymer and an amino group-containing (meth)acrylic polymer. 7 . The decorative film according to claim 1 , wherein a thickness of the decorative film is 240 μm or less.

8. The decorative film according to claim 1 or 2, wherein the total heat release 20 minutes after the start of heating measured according to ISO 5660-1 heat release rate (cone calorimeter method) is 8 MJ / m 2 or less.

9. The decorative film according to claim 1 or 2, wherein the decorative film is substantially free of flame retardants.

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