Decorative film and method for producing the same, ink-receiving film, and decorative film kit

Abstract

To provide a decorative film in which the adhesive force of a pressure-sensitive adhesive layer does not decrease even when high-density printing is performed, and a method for producing the same.SOLUTION: A decorative film according to an embodiment includes a transparent surface layer including polycarbonate-based polyurethane, a transparent ink-receiving layer including polyether-based polyurethane, a printed layer disposed on the transparent ink-receiving layer, and a pressure-sensitive adhesive layer in this order.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a decorative film, a method for manufacturing the same, an ink-receiving film, and a decorative film kit.

Background Art

[0002] A decorative film with imparted decorativeness is known by inkjet printing on a film having an ink-receiving layer. Inkjet printing is known as one of the on-demand technologies capable of supplying products according to customer demands in a short delivery period.

[0003] Patent Document 1 (Japanese Patent No. 6598343) describes "a graphic sheet including a partial printing layer, comprising a transparent resin surface layer, the partial printing layer on the back side of the transparent resin surface layer, an ink underlayer, and an adhesive layer in this order, wherein the transparent resin surface layer is a polycarbonate-based urethane resin, and the ink underlayer is an alkyd melamine-based resin, characterized by a graphic sheet".

[0004] Patent Document 2 (Japanese Unexamined Patent Application Publication No. 2014-46671) describes "a printing structure comprising a laminate in which an adhesive layer, a printing layer, and a base film are laminated in this order, wherein the printing layer is printed using a solvent-based ink, the base film is made of a vinyl chloride resin composition containing a vinyl chloride-based resin having an average degree of polymerization of 600 to 1300 and a plasticizer, and the content of the plasticizer is 15 to 40 parts by weight with respect to 100 parts by weight of the vinyl chloride-based resin, the adhesive layer is made of an adhesive composition containing an acrylic adhesive having a weight average molecular weight of 600,000 to 1,000,000, the laminate has a thickness of 65 to 160 μm, and the total calorific value of the heat generation test by a cone calorimeter tester with a 12.5 mm thick gypsum board as a base material is 8 MJ / mm 2 characterized by the following printing structure".

[0005] Patent document 3 (Japanese Patent Publication No. 9-509373) describes a "graphic image overlay composite including a premask layer and a protective layer."

[0006] Patent Document 4 (Japanese Unexamined Patent Publication No. 2009-282471) describes a graphics structure comprising, in this order, a receptor layer, a printed layer created by printing on the receptor layer, and an acrylic white adhesive layer consisting of an acrylic white adhesive, wherein the acrylic white adhesive comprises a carboxyl group-containing (meth)acrylic polymer, 8 to 150 parts by mass of a white pigment per 100 parts by mass of the carboxyl group-containing (meth)acrylic polymer, and an amino group-containing (meth)acrylic polymer that does not contain an aromatic vinyl monomer. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 6598343 specification [Patent Document 2] Japanese Patent Publication No. 2014-46671 [Patent Document 3] Special Publication No. 9-509373 [Patent Document 4] Japanese Patent Publication No. 2009-282471 [Overview of the project] [Problems that the invention aims to solve]

[0008] When manufacturing decorative films using inkjet printing, high-density printing exceeding 200% ink density may be required to achieve opacity or color uniformity. However, if such high-density printing is performed on the ink-receiving layer of a decorative film, the solvent or low-molecular-weight components in the ink may penetrate into the ink-receiving layer and even reach adjacent layers, such as the pressure-sensitive adhesive layer, potentially impairing the function of the adjacent layer, for example, reducing the adhesive strength of the pressure-sensitive adhesive layer.

[0009] This disclosure provides a decorative film and a method for manufacturing the same, in which the adhesive strength of the pressure-sensitive adhesive layer does not decrease even when high-density printing is performed. [Means for solving the problem]

[0010] The inventors have found that by performing high-density printing on the ink-receiving layer of an ink-receiving film having a specific layer structure to form a printed layer, and then laminating a pressure-sensitive adhesive layer on top of the printed layer, the problem of reduced adhesive strength of the pressure-sensitive adhesive layer due to solvents and low-molecular-weight components in the ink can be improved.

[0011] According to one embodiment of the present disclosure, a decorative film is provided comprising, in this order, a transparent surface layer containing a polycarbonate-based polyurethane, a transparent ink-receiving layer containing a polyether-based polyurethane, a printing layer disposed on the transparent ink-receiving layer, and a pressure-sensitive adhesive layer.

[0012] According to another embodiment of the present disclosure, an ink receiving film is provided comprising, in this order, a support film, a transparent surface layer containing a polycarbonate-based polyurethane, and a transparent ink receiving layer containing a polyether-based polyurethane.

[0013] Another embodiment of the present disclosure provides a method for manufacturing a decorative film, comprising: preparing an ink receiving film comprising, in this order, a support film, a transparent surface layer comprising a polycarbonate polyurethane, and a transparent ink receiving layer comprising a polyether polyurethane; preparing a pressure-sensitive adhesive film comprising a pressure-sensitive adhesive layer and a release liner; printing ink onto the transparent ink receiving layer to form a printed layer; laminating the ink receiving film and the pressure-sensitive adhesive film so that the printed layer and the pressure-sensitive adhesive layer are in contact; and removing the support film to form a decorative film.

[0014] According to another embodiment of the present disclosure, there is provided a decorative film kit comprising an ink-receiving film including a support film, a transparent surface layer containing a polycarbonate-based polyurethane, and a transparent ink-receiving layer containing a polyether-based polyurethane, in this order, a pressure-sensitive adhesive film including a pressure-sensitive adhesive layer and a release liner.

Advantages of the Invention

[0015] According to the present disclosure, it is possible to provide a decorative film in which the adhesive strength of the pressure-sensitive adhesive layer does not decrease even when high-concentration printing is performed. The method for manufacturing a decorative film, the ink-receiving film, and the decorative film kit of the present disclosure can be suitably used for the on-demand production of decorative films, including using inkjet printing.

[0016] The above description should not be regarded as disclosing all embodiments of the present invention and all advantages related to the present invention.

Brief Description of the Drawings

[0017] [Figure 1] It is a schematic cross-sectional view of a decorative film according to an embodiment. [Figure 2] It is a schematic cross-sectional view of a decorative film according to another embodiment. [Figure 3] It is an explanatory view of a method for manufacturing a decorative film according to an embodiment.

Modes for Carrying Out the Invention

[0018] Hereinafter, for the purpose of exemplifying typical embodiments of the present invention, a more detailed description will be given with reference to the drawings as necessary, but the present invention is not limited to these embodiments.

[0019] In the present disclosure, the term "film" includes articles called "sheets".

[0020] In the present disclosure, "(meth)acryl" means acrylic or methacrylic, and "(meth)acrylate" means acrylate or methacrylate.

[0021] In the present disclosure, "pressure-sensitive adhesion" means the property of a material or composition that exhibits permanent adhesiveness within the operating temperature range, for example, in the range of 0°C or higher and 50°C or lower, that is, adheres to various surfaces with a short-term light pressure and does not exhibit a phase change (from liquid to solid).

[0022] In the present disclosure, "transparent" means that the average transmittance in the visible light region (wavelength 400 nm to 700 nm) measured in accordance with JIS K 7375:2008 is about 80% or more, desirably about 85% or more, or about 90% or more. There is no particular limitation on the upper limit value of the average transmittance, but for example, it can be less than about 100%, about 99% or less, or about 98% or less.

[0023] In the present disclosure, "translucent" means that the average transmittance in the visible light region (wavelength 400 nm to 700 nm) measured in accordance with JIS K 7375:2008 is about 40% or more and less than about 80%, desirably about 75% or less.

[0024] In the present disclosure, "opaque" means that the material or composition is neither transparent nor translucent.

[0025] In the present disclosure, "non-PVC-based" means that the decorative film does not substantially contain polyvinyl chloride, for example, a polyvinyl chloride film or a polyvinyl chloride layer. In one embodiment, the polyvinyl chloride content of the decorative film is about 1% by mass or less, about 0.5% by mass or less, or about 0.1% by mass or less. <000011​​​​​​Figure 1 shows a schematic cross-sectional view of a decorative film according to one embodiment. The decorative film 10 includes a transparent surface layer 11, a transparent ink-receiving layer 12, a printing layer 14, and a pressure-sensitive adhesive layer 16 in that order. The decorative film 10 may further include a release liner 18 as an optional element.

[0028] The decorative film may further include a transparent pressure-sensitive adhesive layer between the transparent surface layer and the transparent ink-receiving layer. The transparent pressure-sensitive adhesive layer interposed between the transparent surface layer and the transparent ink-receiving layer can enhance the embossability of the decorative film. The decorative film of this embodiment can be suitably used, for example, as a graphic film for license plates.

[0029] Figure 2 shows a schematic cross-sectional view of a decorative film of another embodiment. The decorative film 10 includes a transparent surface layer 11, a transparent ink-receiving layer 12, a printing layer 14, and a pressure-sensitive adhesive layer 16 in that order, and further includes a transparent pressure-sensitive adhesive layer 13 between the transparent surface layer 11 and the transparent ink-receiving layer 12.

[0030] The transparent surface layer, transparent ink receiving layer, printing layer, pressure-sensitive adhesive layer, liner, transparent pressure-sensitive adhesive layer, and other elements constituting the decorative film will be described below in relation to the manufacturing method of the decorative film.

[0031] In one embodiment, the decorative film is manufactured by preparing an ink-receiving film comprising, in this order, a support film, a transparent surface layer containing polycarbonate polyurethane, and a transparent ink-receiving layer containing polyether polyurethane; preparing a pressure-sensitive adhesive film comprising a pressure-sensitive adhesive layer and a release liner; printing ink onto the transparent ink-receiving layer to form a printed layer; laminating the ink-receiving film and the pressure-sensitive adhesive film so that the printed layer and the pressure-sensitive adhesive layer are in contact; and removing the support film to form the decorative film.

[0032] The manufacturing method for decorative films will be explained below with reference to Figure 3.

[0033] The ink-receiving film includes a support film, a transparent surface layer, and a transparent ink-receiving layer in that order. Figure 3(a) shows an ink-receiving film 20 which includes a support film 22, a transparent surface layer 11, and a transparent ink-receiving layer 12 in that order from top to bottom.

[0034] The support film can improve the handling of the ink-receiving film and decorative film, and can also protect the transparent surface layer during the manufacturing, storage, transportation, or use of the decorative film. The support film is removed before the decorative film is used.

[0035] As the support film, for example, a resin film containing polyester such as polyethylene terephthalate, polyolefin such as polyethylene or polypropylene, acrylic polymer, urethane polymer, or fluoropolymer can be used.

[0036] The thickness of the support film can be appropriately selected according to the manufacturing conditions and usage of the decorative film. For example, the thickness of the support film can be approximately 5 μm or more, or approximately 10 μm or more, approximately 500 μm or less, or approximately 300 μm or less.

[0037] The support film may be transparent, translucent, or opaque. When an ink-receiving film with a transparent support film is used, ultraviolet light can be irradiated from the support film side through the transparent surface layer and the transparent ink-receiving layer, thereby curing the UV-curable ink printed on the transparent ink-receiving layer.

[0038] The surface (back) of the support film opposite the transparent surface layer may be treated with a surface treatment such as an anti-blocking treatment. An ink-receiving film or decorative film having a support film treated with an anti-blocking treatment can be stored in stacks as sheets or wound into a roll.

[0039] The transparent surface layer contains polycarbonate polyurethane. Because polycarbonate polyurethane is relatively hard and rigid, it can suppress damage to the surface of the decorative film and impart strength and chemical resistance to the decorative film. Furthermore, since polycarbonate polyurethane has excellent weather resistance and water resistance, the decorative film can withstand use on the exterior walls of buildings, the exteriors of vehicles, kitchens, washrooms, bathrooms, etc.

[0040] Polycarbonate-based polyurethanes have structural units derived from polycarbonate polyols and structural units derived from polyisocyanates. Polycarbonate-based polyurethanes can be obtained by reacting polycarbonate polyols and polyisocyanates in known ways.

[0041] Polycarbonate polyols are compounds having multiple carbonate groups (-OC(=O)-O-) and multiple hydroxyl groups in their main chain, and can be obtained by reacting a polyol with a carbonate compound using known methods.

[0042] Examples of polyols include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, and neopentyl glycol; aliphatic triols such as glycerin; and alicyclic diols such as 1,4-cyclohexanedimethanol. Polyols can be used alone or in combination of two or more types.

[0043] Examples of carbonate compounds include dimethyl carbonate, ethylene carbonate, and diphenyl carbonate.

[0044] In one embodiment, the polycarbonate polyol is a polycarbonate diol having hydroxyl groups at both ends of the carbonate main chain.

[0045] Examples of polyisocyanates include aliphatic diisocyanates such as hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate; alicyclic diisocyanates such as 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, trans and / or cis-1,4-cyclohexane diisocyanate, norbornene diisocyanate, and hydrogenated diphenylmethane diisocyanate; aromatic diisocyanates such as diphenylmethane diisocyanate and toluene diisocyanate; and their burettes, isocyanurates, and adducts. Polyisocyanates can be used alone or in combination of two or more. Polyisocyanates may also be blocked isocyanates blocked by a blocking agent.

[0046] From the viewpoint of weather resistance of the decorative film, the polyisocyanate is preferably a non-yellowing aliphatic diisocyanate or alicyclic diisocyanate, and more preferably an alicyclic diisocyanate capable of forming a highly durable transparent surface layer.

[0047] Polycarbonate-based polyurethane may further contain structural units derived from polyols other than polycarbonate polyols. The content of structural units derived from other polyols can be about 30% by mass or less, about 20% by mass or less, or about 10% by mass or less of the polycarbonate-based polyurethane. In one embodiment, the polycarbonate-based polyurethane does not contain structural units derived from other polyols.

[0048] Other polyols include, for example, low molecular weight polyols with 2 to 20 carbon atoms such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and glycerin; hydroxyl-free (meth)acrylates such as methyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and ethylene glycol (meth)acrylic acid diester, and 2-hydroxyethyl (meth)acrylate. Examples of polyols include (meth)acrylic polyols, which are copolymers with hydroxyl-containing (meth)acrylates such as ethylene glycol methacrylic acid monoester; polyester polyols such as polycaprolactone diol and polycaprolactone triol; and polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, their propylene oxide adducts, glycerin propylene oxide adducts, sorbitol, sucrose and other sugars propylene oxide adducts, and ethylenediamine and other compounds containing active hydrogen. Other polyols can be used alone or in combination of two or more.

[0049] The transparent surface layer can be formed by applying a reactive polyurethane composition containing polycarbonate polyol and polyisocyanate, and optionally other polyols, or a polyurethane resin composition containing polycarbonate-based polyurethane and an organic solvent or water, onto a support film using, for example, a knife coat, bar coat, blade coat, doctor coat, roll coat, cast coat, etc., and heating or drying as necessary. In the reactive polyurethane composition, the polycarbonate polyol, polyisocyanate, and any other polyol react during heating or drying to generate polycarbonate-based polyurethane in situ.

[0050] In a reactive polyurethane composition or a polycarbonate-based polyurethane contained in a polyurethane resin composition, the equivalent ratio of polyisocyanate to the total of polycarbonate polyols and other polyols can be approximately 0.7 equivalents or more, approximately 0.9 equivalents or more, approximately 2 equivalents or less, or approximately 1.2 equivalents or less for every 1 equivalent of the total of polycarbonate polyols and other polyols.

[0051] The reactive polyurethane composition may contain a catalyst. Examples of catalysts commonly used in polyurethane resin formation include di-n-butyltin dilaurate, zinc naphthenate, zinc octonate, and triethylenediamine. The amount of catalyst used is generally about 0.005 parts by mass or more, or about 0.01 parts by mass or more, about 0.5 parts by mass or less, or about 0.2 parts by mass or less, per 100 parts by mass of the reactive polyurethane composition.

[0052] Reactive polyurethane compositions and polyurethane resin compositions may contain organic solvents, for example, to improve workability and coating properties. Examples of organic solvents include ketones such as methyl ethyl ketone, methyl isobutyl ketone, and acetylacetone; aromatic hydrocarbons such as toluene and xylene; alcohols such as ethanol and isopropyl alcohol; esters such as ethyl acetate and butyl acetate; and ethers such as tetrahydrofuran, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and dipropylene glycol monomethyl ether acetate. The amount of organic solvent used is generally about 1 part by mass or more, or about 5 parts by mass or more, about 90 parts by mass or less, or about 80 parts by mass or less, per 100 parts by mass of the composition.

[0053] The polyurethane resin composition may be an aqueous polyurethane resin composition containing water as a solvent. The aqueous polycarbonate polyurethane contained in the aqueous polyurethane resin composition may contain chain extenders such as diamine compounds as structural units, and may have anionic groups such as carboxyl groups and sulfonic acid groups.

[0054] The polycarbonate polyurethane is preferably a water-based polycarbonate polyurethane. By using a water-based polycarbonate polyurethane, the amount of organic solvent used in the manufacture of decorative films can be reduced. Because water-based polycarbonate polyurethane has relatively low affinity for organic solvents or low-molecular-weight organic compounds, the chemical resistance of the transparent surface layer can be further improved.

[0055] In one embodiment, the polycarbonate-based polyurethane has an alicyclic structure. An example of a polycarbonate-based polyurethane having an alicyclic structure is a linear polyurethane resin obtained by reacting a polyurethane prepolymer, which is obtained by reacting a polyurethane prepolymer obtained by reacting a polycarbonate diol having an alicyclic structure with an aliphatic diol containing a carboxyl group and a polyisocyanate component containing 4,4'-dicyclohexylmethane diisocyanate, with a diamine chain extender, and then crosslinking the resulting linear polyurethane resin with a crosslinking agent.

[0056] Examples of polycarbonate diols having an alicyclic structure include polycarbonate diols synthesized from 1,4-cyclohexanedimethanol and 1,6-hexanediol.

[0057] Examples of aliphatic diols containing a carboxyl group include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, and 3,3-dimethylolpropionic acid.

[0058] The amount of 4,4'-dicyclohexylmethane diisocyanate contained in the polyisocyanate component is not particularly limited, but for example, it can be about 30% by mass or more, or about 50% by mass or more, of the polyisocyanate component.

[0059] Polyurethane prepolymers can be obtained by reacting a polycarbonate diol having an alicyclic structure, an aliphatic diol containing a carboxyl group, and a polyisocyanate component containing 4,4'-dicyclohexylmethane diisocyanate by known methods.

[0060] Linear polyurethane resins can be obtained by reacting a polyurethane prepolymer with a diamine chain extender. Examples of diamine chain extenders include diamine compounds such as ethylenediamine, propylenediamine, and putrescine.

[0061] As the crosslinking agent, known crosslinking agents that react with carboxyl groups contained in linear polyurethane resins can be used, such as polycarbodiimide compounds, aziridine compounds, and oxazoline compounds.

[0062] The weight-average molecular weight of polycarbonate polyurethanes is generally about 30,000 or more, about 50,000 or more, or about 80,000 or more, about 300,000 or less, about 200,000 or less, or about 150,000 or less. In this disclosure, the weight-average molecular weight of polyurethane is the molecular weight calculated using gel permeation chromatography (GPC) with tetrahydrofuran (THF) or N-methylpyrrolidone (NMP) as the solvent, and using standard polystyrene (when the solvent is THF) or standard polymethyl methacrylate (when the solvent is NMP).

[0063] In one embodiment, the transparent surface layer contains approximately 50% by mass or more, approximately 60% by mass or more, or approximately 70% by mass, 100% by mass or less, approximately 95% by mass or less, or approximately 90% by mass or less of polycarbonate-based polyurethane. Preferably, the resin component of the transparent surface layer is made of polycarbonate-based polyurethane.

[0064] The transparent surface layer may also contain additives such as UV absorbers, light stabilizers, heat stabilizers, dispersants, plasticizers, flow enhancers, and leveling agents as other optional components.

[0065] The thickness of the transparent surface layer is not particularly limited, but for example, it can be approximately 5 μm or more, approximately 10 μm or more, or approximately 25 μm or more, approximately 500 μm or less, approximately 200 μm or less, or approximately 100 μm or less. By making the thickness of the transparent surface layer approximately 5 μm or more, weather resistance and chemical resistance can be imparted to the decorative film. By making the thickness of the transparent surface layer approximately 500 μm or less, shape conformability can be imparted to the decorative film.

[0066] In one embodiment, the wetting tension of the transparent surface layer, when evaluated using a wetting tension reagent in accordance with JIS K 6768:1999, is approximately 30 mN / m or more, or approximately 35 mN / m or more, approximately 50 mN / m or less, or approximately 48 mN / m or less.

[0067] The transparent ink-receiving layer contains polyether-based polyurethane. The polyether-based polyurethane can impart ink-receiving ability to the transparent ink-receiving layer.

[0068] Polyether polyurethanes have structural units derived from polyalkylene glycol and structural units derived from polyisocyanate. Polyether polyurethanes can be obtained by reacting polyalkylene glycol and polyisocyanate in a known manner.

[0069] Examples of polyalkylene glycols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and polyhexamethylene glycol.

[0070] As the polyisocyanate, the polycarbonate-based polyurethane contained in the transparent surface layer described herein can be used. From the viewpoint of weather resistance of the decorative film, the polyisocyanate is preferably a non-yellowing aliphatic diisocyanate or an alicyclic diisocyanate, and more preferably an aliphatic diisocyanate capable of forming a transparent ink-receiving layer with excellent ink-receiving properties.

[0071] The polyether-based polyurethane may further contain structural units derived from polyols other than polyalkylene glycol. The content of structural units derived from other polyols can be about 30% by mass or less, about 20% by mass or less, or about 10% by mass or less of the polyether-based polyurethane. In one embodiment, the polyether-based polyurethane does not contain structural units derived from other polyols.

[0072] Other polyols include, for example, low molecular weight polyols with 2 to 20 carbon atoms such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and glycerin; hydroxyl-free (meth)acrylates such as methyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and ethylene glycol (meth)acrylic acid diester, and 2-hydroxyethyl (meth) Examples include (meth)acrylic polyols, which are copolymers of acrylates and hydroxyl-containing (meth)acrylates such as ethylene glycol methacrylic acid monoester; polyester polyols such as polycaprolactone diol and polycaprolactone triol; propylene oxide adducts of polyalkylene glycols such as polypropylene glycol and polytetramethylene glycol, propylene oxide adducts of glycerin, propylene oxide adducts of sugars such as sorbitol and sucrose, and propylene oxide adducts of compounds having active hydrogen such as ethylenediamine. Other polyols can be used alone or in combination of two or more.

[0073] The transparent ink-receiving layer can be manufactured by a method similar to that described for the transparent surface layer. Specifically, the transparent ink-receiving layer can be formed by applying a reactive polyurethane composition containing polyalkylene glycol and polyisocyanate, and optionally other polyols, or a polyurethane resin composition containing polyether-based polyurethane and an organic solvent or water, onto the transparent surface layer using, for example, a knife coat, bar coat, blade coat, doctor coat, roll coat, cast coat, etc., and heating or drying as necessary.

[0074] In a reactive polyurethane composition or an ether-based polyurethane contained in a polyurethane resin composition, the equivalent ratio of polyisocyanate to the total of polyalkylene glycol and other polyols can be approximately 0.7 equivalents or more, approximately 0.9 equivalents or more, approximately 2 equivalents or less, or approximately 1.2 equivalents or less of polyisocyanate per 1 equivalent of the total of polyalkylene glycol and other polyols.

[0075] As the catalyst for the reactive polyurethane composition, and as the organic solvent for the reactive polyurethane composition and the polyurethane resin composition, those described for the transparent surface layer can be used.

[0076] The polyurethane resin composition may be an aqueous polyurethane resin composition containing water as a solvent. The aqueous polyether polyurethane contained in the aqueous polyurethane resin composition may contain chain extenders such as diamine compounds as structural units, and may have anionic groups such as carboxyl groups and sulfonic acid groups.

[0077] The polyether-based polyurethane is preferably a water-based polyether-based polyurethane. By using a water-based polyether-based polyurethane, the amount of organic solvent used in the manufacture of decorative films can be reduced. The affinity of the transparent ink-receiving layer containing the water-based polyether-based polyurethane to solvent-based inks is relatively low. Therefore, in printing using solvent-based inks, the absorption of the solvent from the ink into the transparent ink-receiving layer is moderately suppressed, and the pigment of the ink remains relatively abundantly on the surface of the transparent ink-receiving layer. As a result, dot gain can be increased.

[0078] Polyether-based polyurethanes may be crosslinked with a crosslinking agent. Known crosslinking agents that react with carboxyl groups, etc., can be used, and examples include polycarbodiimide compounds, aziridine compounds, and oxazoline compounds.

[0079] The weight-average molecular weight of polyether-based polyurethanes is generally about 30,000 or more, about 50,000 or more, or about 80,000 or more, about 300,000 or less, about 200,000 or less, or about 150,000 or less.

[0080] In one embodiment, the transparent ink receiving layer contains approximately 50% by mass or more, approximately 60% by mass or more, or approximately 70% by mass, 100% by mass or less, approximately 95% by mass or less, or approximately 90% by mass or less of polyether polyurethane.

[0081] The transparent ink-receiving layer may further contain other resins such as polyester polyurethane or polyacrylate. Polyester polyurethane and polyacrylate can impart blocking resistance to the transparent ink-receiving layer. Therefore, the ink-receiving film can be stacked or wound into a roll shape while the transparent ink-receiving layer of the ink-receiving film remains exposed.

[0082] In one embodiment, the transparent ink receiving layer does not contain polycarbonate-based polyurethane.

[0083] The transparent ink receiving layer may also contain additives such as UV absorbers, light stabilizers, heat stabilizers, dispersants, plasticizers, flow enhancers, and leveling agents as other optional components.

[0084] The thickness of the transparent ink-receiving layer is not particularly limited, but can be appropriately determined according to the printing method and ink used. For example, the thickness of the transparent ink-receiving layer can be about 1 μm or more, or about 5 μm or more, about 100 μm or less, or about 50 μm or less.

[0085] The total thickness of the transparent surface layer and the transparent ink-receiving layer can be approximately 10 μm or more, or approximately 20 μm or more and approximately 80 μm or less, or approximately 60 μm or less. By setting the total thickness of the transparent surface layer and the transparent ink-receiving layer within the above range, the non-flammability or flame retardancy of the substrate to which the decorative film is applied can be avoided, and the environmental burden from disposal after use can also be reduced.

[0086] In one embodiment, the wetting tension of the transparent ink-receiving layer, when evaluated using a wetting tension reagent in accordance with JIS K 6768:1999, is approximately 45 mN / m or more, or approximately 50 mN / m or more, approximately 73 mN / m or less, or approximately 65 mN / m or less.

[0087] The transparent ink receiving layer may have a primer layer to improve printability, and may also undergo surface treatments such as plasma treatment, corona treatment, flame treatment, electron beam irradiation treatment, surface roughening, and ozone treatment.

[0088] The ink-receiving film may further include a transparent pressure-sensitive adhesive layer between the transparent surface layer and the transparent ink-receiving layer. The transparent pressure-sensitive adhesive layer can improve the embossing suitability of the decorative film.

[0089] A transparent pressure-sensitive adhesive layer can be formed on a transparent surface layer using commonly used acrylic, polyolefin, polyurethane, polyester, or rubber-based pressure-sensitive adhesives. Subsequently, a transparent ink-receiving layer can be formed directly on the transparent pressure-sensitive adhesive layer or formed separately on a liner and then transferred and laminated onto the transparent pressure-sensitive adhesive layer.

[0090] The thickness of the transparent pressure-sensitive adhesive layer can be approximately 10 μm or more, or approximately 20 μm or more, approximately 50 μm or less, or approximately 40 μm or less.

[0091] The pressure-sensitive adhesive film includes a pressure-sensitive adhesive layer and a release liner. Figure 3(a) shows a pressure-sensitive adhesive film 30 including a pressure-sensitive adhesive layer 16 and a release liner 18.

[0092] The pressure-sensitive adhesive layer can be formed on the release liner using commonly used acrylic, polyolefin, polyurethane, polyester, or rubber-based pressure-sensitive adhesives. The pressure-sensitive adhesive contained in the pressure-sensitive adhesive layer may be crosslinked with a crosslinking agent.

[0093] The pressure-sensitive adhesive layer is preferably an acrylic pressure-sensitive adhesive layer containing an acrylic pressure-sensitive adhesive. The acrylic pressure-sensitive adhesive layer has excellent durability, weather resistance, and adhesive strength. The acrylic pressure-sensitive adhesive may be crosslinked with a crosslinking agent such as a bisamide crosslinking agent, an aziridine crosslinking agent, a carbodiimide crosslinking agent, an epoxy crosslinking agent, or an isocyanate crosslinking agent.

[0094] In one embodiment, the pressure-sensitive adhesive layer contains a white coloring agent. By making the pressure-sensitive adhesive layer white, the underlying color to which the decorative film is applied can be concealed. Examples of white coloring agents include white pigments such as titanium dioxide, zinc carbonate, zinc oxide, and zinc sulfide.

[0095] The acrylic pressure-sensitive adhesive layer may contain a carboxyl group-containing (meth)acrylic polymer, an amino group-containing (meth)acrylic polymer, and a white colorant such as titanium dioxide. The carboxyl group-containing (meth)acrylic polymer and the amino group-containing (meth)acrylic polymer can stably disperse a larger amount of white colorant in the pressure-sensitive adhesive layer, thereby increasing the opacity of the pressure-sensitive adhesive layer, and at the same time suppressing the decrease in cohesive force of the pressure-sensitive adhesive layer caused by the dispersion of the white colorant, thereby maintaining its adhesiveness. Because the adhesiveness is maintained in this way, when laminating the ink-receiving film and the pressure-sensitive adhesive film, the printed layer and the pressure-sensitive adhesive layer can be bonded more firmly. 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.

[0096] The thickness of the pressure-sensitive adhesive layer can be approximately 10 μm or more, approximately 20 μm or more, or approximately 30 μm or more, approximately 200 μm or less, approximately 120 μm or less, or approximately 80 μm or less.

[0097] Examples of release liners include paper having a surface that has been treated with a silicone release agent or the like; films containing plastic materials such as polyethylene, polypropylene, polyester, and cellulose acetate; and laminated paper coated with such plastic materials.

[0098] The thickness of the release liner can be approximately 5 μm or more, approximately 15 μm or more, or approximately 25 μm or more, approximately 300 μm or less, approximately 200 μm or less, or approximately 150 μm or less.

[0099] The printed layer is formed by printing ink onto the transparent ink-receiving layer of the ink-receiving film. By printing the ink onto the transparent ink-receiving layer, the printed layer is formed separately from the pressure-sensitive adhesive layer. This prevents a decrease in the adhesive strength of the pressure-sensitive adhesive layer due to solvents and low-molecular-weight components contained in the ink. Although solvents and low-molecular-weight components contained in the ink may penetrate the transparent ink-receiving layer and come into contact with or permeate the transparent surface layer, as mentioned above, the transparent surface layer has high chemical resistance, so its surface quality and strength can be maintained within a practical range.

[0100] Figure 3(b) shows the printed layer 14 formed on the ink receiving layer 12 of the ink receiving film 20.

[0101] Printing methods include, for example, gravure direct printing, gravure offset printing, inkjet printing, laser printing, and screen printing.

[0102] Since it is suitable for on-demand manufacturing, the ink layer is preferably an inkjet printed layer formed by inkjet printing. The inkjet printing may be high-density printing, such as ink density of 200% or more.

[0103] Examples of inks include solvent-based inks, solvent-free inks, water-based inks, and UV-curable inks. In one embodiment, the ink is a solvent-based ink with excellent printability. In another embodiment, the ink is a UV-curable ink. UV-curable inks have properties suitable for inkjet printing and can reduce the thermal effects on the ink-receiving film.

[0104] The thickness of the printed layer is not particularly limited, but for example, it can be approximately 1 μm or more, or approximately 2 μm or more, approximately 20 μm or less, or approximately 10 μm or less.

[0105] The ink-receiving film and the pressure-sensitive adhesive film are laminated so that the printed layer and the pressure-sensitive adhesive layer are in contact. Lamination can be performed by heating and / or pressurizing as needed.

[0106] Figure 3(c) shows a state in which the ink receiving film and the pressure-sensitive adhesive film are laminated so that the printed layer 14 and the pressure-sensitive adhesive layer 16 are in contact.

[0107] A decorative film is formed by removing the support film from the laminate obtained by the above lamination process. The support film may cover the transparent surface layer of the decorative film until immediately before use.

[0108] Figure 3(d) shows the decorative film with the support film 22 removed.

[0109] The thickness of the decorative film can be approximately 10 μm or more, or approximately 20 μm or more and approximately 1 mm or less, or approximately 500 μm or less. The thickness of the decorative film does not include the thickness of the support film or the release liner.

[0110] In one embodiment, the decorative film consists of a transparent surface layer, a transparent ink-receiving layer, a printing layer, and a pressure-sensitive adhesive layer, and has a thickness of approximately 50 μm or more and approximately 150 μm or less. Thin decorative films with such a simple laminated structure have low combustion heat and use less organic material. Therefore, the non-flammability or flame retardancy of the substrate to which the decorative film is applied is not impaired, and the environmental burden from disposal after use can also be reduced.

[0111] In one embodiment, the decorative film is a non-PVC decorative film.

[0112] The decorative film may be transparent, semi-transparent, or opaque. Transparent or semi-transparent decorative films can be used for internally illuminated signs.

[0113] In one embodiment, the 2% tensile strength of the decorative film is approximately 4 N / 25 mm or more, approximately 5 N / 25 mm or more, or approximately 6 N / 25 mm or more, approximately 40 N / 25 mm or less, approximately 30 N / 25 mm or less, or approximately 20 N / 25 mm or less. The 2% tensile strength of the decorative film is determined by the method described in the example.

[0114] In one embodiment, the yield strength of the decorative film is approximately 6 N / 25 mm or more, approximately 9 N / 25 mm or more, or approximately 12 N / 25 mm or more, approximately 90 N / 25 mm or less, approximately 60 N / 25 mm or less, or approximately 30 N / 25 mm or less. The yield strength of the decorative film is determined by the method described in the example.

[0115] In one embodiment, the elongation of the decorative film is approximately 30% or more, approximately 40% or more, or approximately 50% or more, approximately 500% or less, approximately 400% or less, or approximately 300% or less. The elongation of the decorative film is determined by the method described in the examples.

[0116] In one embodiment, the adhesive strength of the decorative film is approximately 4N / 25mm or more, approximately 6N / 25mm or more, or approximately 8N / 25mm or more, approximately 50N / 25mm or less, approximately 40N / 25mm or less, or approximately 30N / 25mm or less when peeled at 180 degrees at a temperature of 20°C and a peeling speed of 300mm / min. The adhesive strength of the decorative film is determined by the method described in the examples.

[0117] The decorative film disclosed herein exhibits excellent low-temperature impact resistance because its transparent surface layer and transparent ink-receiving layer are based on polyurethane. A decorative film of one embodiment can pass the Gardner impact resistance test at a temperature of -20°C. This embodiment of the decorative film is suitably used as a graphic film for license plates.

[0118] The decorative film disclosed herein can be used for vehicles and their parts used indoors and outdoors, buildings (interior and exterior walls, columns, etc.), traffic signs, packaging materials, signs, internally illuminated signs, etc.

[0119] In one embodiment, the above-mentioned ink-receiving film and pressure-sensitive adhesive film are provided in the form of a decorative film kit. The user can use the decorative film kit to form a printed layer by on-demand printing and manufacture a decorative film on the spot. [Examples]

[0120] The following examples illustrate specific embodiments of the present disclosure, but the present invention is not limited thereto. All parts and percentages are by mass unless otherwise specified. Numerical values ​​include errors inherent to the measurement principle and measuring device. Numerical values ​​are shown with significant figures after normal rounding.

[0121] Table 1 shows the raw materials and reagents used in the production of the decorative film.

[0122] [Table 1]

[0123] <Example 1> A transparent ink-receiving layer composition was prepared by mixing polyurethane 1 (PU1) and polyurethane 2 (PU2) using a mixer (TK Auto Homo Mixer, Primix Co., Ltd., Awaji City, Hyogo Prefecture, Japan). The mass ratio of PU1 to PU2 was 100:10 based on solid content. The solid content of the transparent ink-receiving layer composition was approximately 30% by mass.

[0124] Using a knife coater, polyurethane 3 (PU3) was applied onto a 50 μm thick polyester film (support film), and dried at 95°C for 5 minutes to form a transparent surface layer with a thickness of 18 μm. Using a knife coater, a transparent ink-receiving layer composition was applied onto the transparent surface layer, and dried at 95°C for 5 minutes to form a transparent ink-receiving layer with a thickness of 20 μm. In this way, an ink-receiving film was prepared in which the support film, transparent surface layer, and transparent ink-receiving layer were laminated in this order.

[0125] A premix was prepared containing white pigment 1 (WP1, Ti-Pure® R960, The Chemours Company (Wilmington, Delaware, USA)), dispersant 1 (D1), and methyl ethyl ketone (MEK). The mass ratio of WP1 to D1 was 5:1 based on solids content. The solids content of the premix was approximately 66% by mass.

[0126] A premix was mixed with adhesive polymer 1 (ADH1). The mass ratio of ADH1, white pigment 1, and D1 was 100:50:10 based on solid content. Crosslinking agent 1 (CL1) was mixed into the resulting mixture to prepare white pressure-sensitive adhesive 1 (WA1). The mass ratio of ADH1 to CL1 was 100:0.2 based on solid content. The solid content of WA1 was approximately 35% by mass.

[0127] Using a knife coater, WA1 was applied onto a silicone-coated polyethylene laminate paper liner and dried at 95°C for 5 minutes to form a 65 μm thick white pressure-sensitive adhesive layer. In this way, a pressure-sensitive adhesive film including the white pressure-sensitive adhesive layer and a release liner was prepared.

[0128] A printed layer was formed on the transparent ink-receiving layer of an ink-receiving film by inkjet printing using a JV5 printer and ES3 ink (Mimaki Engineering Co., Ltd., Tomi City, Nagano Prefecture, Japan). The ink densities were C66, M67, and Y67. A white pressure-sensitive adhesive layer was laminated on top of the printed layer, and the support film was removed to produce the decorative film of Example 1.

[0129] <Example 2> The decorative film for Example 2 was fabricated using the same procedure as in Example 1, except that PU3 was replaced with polyurethane 4 (PU4), and the thickness of the transparent surface layer was changed to 30 μm and the thickness of the transparent ink-receiving layer to 20 μm.

[0130] <Example 3> White pressure-sensitive adhesive 3 (WA3) was prepared using the same procedure as in Example 1, except that ADH1 was replaced with adhesive polymer 3 (ADH3) and CL1 was replaced with crosslinking agent 2 (CL2). The mass ratio of ADH3, WP1, and D1 was 100:40:8 based on solid content. The mass ratio of ADH3 to CL2 was 100:0.05 based on solid content. The solid content of WA3 was approximately 38% by mass.

[0131] Using a knife coater, WA3 was applied onto a silicone-coated polyethylene laminate paper liner and dried at 95°C for 5 minutes to form a 40 μm thick white pressure-sensitive adhesive layer. In this way, a pressure-sensitive adhesive film including the white pressure-sensitive adhesive layer and a release liner was prepared. The decorative film of Example 3 was prepared using the same procedure as in Example 1, except that this pressure-sensitive adhesive film was used.

[0132] <Example 4> The decorative film for Example 4 was prepared using the same procedure as in Example 2, except that the pressure-sensitive adhesive film used in Example 3 was used.

[0133] <Example 5> The decorative film of Example 5 was prepared using the transparent surface layer and transparent ink-receiving layer as shown in Table 2.

[0134] <Example 6> White pressure-sensitive adhesive 2 (WA2) was prepared using the same procedure as in Example 1, except that ADH1 was replaced with adhesive polymer 2 (ADH2) and CL1 was replaced with CL2. The mass ratio of ADH2, WP1, and D1 was 100:50:10 based on solid content. The mass ratio of ADH2 to CL2 was 100:0.23 based on solid content. The solid content of WA2 was approximately 58% by mass.

[0135] Using a knife coater, WA2 was applied onto a silicone-coated polyethylene laminate paper liner and dried at 95°C for 5 minutes to form a 30 μm thick white pressure-sensitive adhesive layer. In this way, a pressure-sensitive adhesive film including the white pressure-sensitive adhesive layer and a release liner was prepared. The decorative film of Example 6 was prepared using the same procedure as in Example 2, except that this pressure-sensitive adhesive film was used.

[0136] <Examples 7-9> Decorative films for Examples 7 to 9 were prepared using the transparent surface layer and transparent ink-receiving layer as shown in Table 2.

[0137] <Example 10> A transparent ink-receiving layer composition was prepared by mixing the transparent ink-receiving layer composition of Example 1 with crosslinking agent 3 (CL3). Based on a total of 100 parts by mass of PU1 and PU2, the CL3 content was 3 parts by mass. Using this transparent ink-receiving layer composition, the decorative film of Example 10 was prepared using the same procedure as in Example 1, except that the thickness of the transparent ink-receiving layer was changed to 9 μm.

[0138] <Examples 11-13> Decorative films for Examples 11 to 13 were prepared using the transparent surface layer and transparent ink-receiving layer as shown in Table 2.

[0139] <Example 14> The decorative film of Example 14 was prepared using the transparent surface layer and transparent ink-receiving layer as shown in Table 2.

[0140] <Reference example 1~Reference example 13> The laminated films of Reference Examples 1 to 13 were prepared using the same procedure as in Examples 1 to 13, except that a printed layer was not included. Reference Examples 1 to 13 have the same layer configuration as Examples 1 to 13, except that they do not have a printed layer, and were prepared to investigate the effect of the presence or absence of a printed layer on the properties of the decorative film, such as 2% tensile strength and yield strength.

[0141] <Reference example 14> Using a knife coater, PU3 was applied onto a 50 μm thick polyester film (support film), and dried at 95°C for 5 minutes to form an 18 μm thick transparent surface layer. The support film was peeled off to prepare the film of Reference Example 14.

[0142] <Reference example 15> A 50 μm thick polyester film (support film) was coated with polyurethane 4 (PU4) using a knife coater, and dried at 95°C for 5 minutes to form a 30 μm thick transparent surface layer. The support film was peeled off to prepare the film of Reference Example 15.

[0143] <Reference example 16> Using a knife coater, the transparent ink-receiving layer composition of Example 1 was applied onto the film of Reference Example 15 and dried at 95°C for 5 minutes to form a transparent ink-receiving layer with a thickness of 10 μm. The support film was peeled off to prepare the laminated film of Reference Example 16.

[0144] <Comparative Example 1> Using a knife coater, the transparent ink-receiving layer composition of Example 1 (a mixture of PU1 and PU2) was applied onto a 50 μm thick polyester film (support film) and dried at 95°C for 5 minutes to form a transparent surface layer with a thickness of 18 μm. Using a knife coater, PU3 was applied onto the transparent surface layer and dried at 95°C for 5 minutes to form a transparent ink-receiving layer with a thickness of 20 μm. In this way, an ink-receiving film was prepared in which the support film / transparent surface layer / transparent ink-receiving layer was laminated in this order. A decorative film for Comparative Example 1 was prepared using the same procedure as in Example 1, except that this ink-receiving film was used.

[0145] <Comparative Example 2> An ink-receiving film was prepared by laminating a 30 μm thick acrylic film (transparent surface layer and transparent ink-receiving layer) with a 50 μm thick polyester film (support film). A decorative film for Comparative Example 2 was prepared using the same procedure as in Example 1, except for the use of this ink-receiving film.

[0146] <Comparative Example 3> Using a knife coater, the transparent ink-receiving layer composition of Example 1 (a mixture of PU1 and PU2) was applied onto a 50 μm thick polyester film (support film), and dried at 95°C for 5 minutes to form a 30 μm thick transparent surface layer (which also serves as a transparent ink-receiving layer). In this way, an ink-receiving film including a support film and a transparent surface layer (which also serves as a transparent ink-receiving layer) was prepared. The decorative film of Comparative Example 3 was prepared using the same procedure as in Example 1, except that this ink-receiving film was used.

[0147] <2% tensile strength> Test specimens were prepared by cutting the film to a width of 25 mm and a length of 150 mm. The tensile strength at 2% elongation at 20°C was measured using a tensile testing machine (Tensilon universal tester, model number: RTC-1210A, A&D Company, Limited (Toshima-ku, Tokyo, Japan)) under the conditions of 20°C, a gripping distance of 100 mm, and a tensile speed of 300 mm / min.

[0148] <Yield strength> Test specimens were prepared by cutting the film to a width of 25 mm and a length of 150 mm. The tensile strength at the yield point at 20°C was measured using a tensile testing machine (Tensilon universal tester, model number: RTC-1210A, A&D Company, Limited (Toshima-ku, Tokyo, Japan)) under the conditions of 20°C, a gripping distance of 100 mm, and a tensile speed of 300 mm / min.

[0149] <stretch> Test specimens were prepared by cutting the film to a width of 25 mm and a length of 150 mm. The elongation at 20°C was measured using a tensile testing machine (Tensilon universal tester, model number: RTC-1210A, A&D Company, Limited (Toshima-ku, Tokyo, Japan)) under the conditions of 20°C, a gripping distance of 100 mm, and a tensile speed of 300 mm / min. Elongation is defined by the following formula. Elongation (%) = (Length of test specimen after test - Length of test specimen before test) / Length of test specimen before test

[0150] <Adhesive force 1> Test specimens were prepared by cutting the film to a width of 25 mm and a length of 150 mm. The test specimens were attached to a melamine-coated panel (Paltec Co., Ltd., Hiratsuka City, Kanagawa Prefecture, Japan) using a roller at 23°C. The attachment method conformed to JIS Z 0237:2009. The test specimens were left at 20°C for 48 hours. The adhesive strength was measured using a tensile testing machine (Tensilon universal testing machine, model number: RTC-1210A, A&D Company, Limited, Toshima Ward, Tokyo, Japan) at 20°C and a peeling speed of 300 mm / min when peeled 180 degrees.

[0151] <Weather resistance 1> A test specimen was prepared by cutting the film into 65 mm squares. The test specimen was attached to a 1 mm thick aluminum panel at room temperature using a squeegee. The test specimen was exposed to xenon light for 500 hours using a xenon weathering test apparatus, Ci5000 Weather-Ometer (Toyo Seiki Seisakusho Co., Ltd., Kita-ku, Tokyo, Japan). The test conditions conformed to JIS K 5600-7-7:2008. A specimen was evaluated as A if no discoloration was observed. A specimen was evaluated as B if discoloration was observed. A specimen was evaluated as C if it peeled off from the aluminum panel.

[0152] <Weather resistance 2> A test specimen was prepared by cutting the film into 65 mm squares. The test specimen was attached to a 1 mm thick aluminum panel at room temperature using a squeegee. The test specimen was exposed to xenon light for 2500 hours using a xenon weathering test apparatus, Ci5000 Weather-Ometer (Toyo Seiki Seisakusho Co., Ltd., Kita-ku, Tokyo, Japan). The test conditions conformed to JIS K 5600-7-7:2008. A specimen was evaluated as A if no discoloration was observed. A specimen was evaluated as B if discoloration was observed. A specimen was evaluated as C if it peeled off from the aluminum panel.

[0153] <Inkjet printability> Inkjet printing was performed on the transparent ink-receiving layer of the film using a JV5 printer and ES3 ink (Mimaki Engineering Co., Ltd., Tomi City, Nagano Prefecture, Japan). The ink densities were C66, M67, and Y67. Prints with high ink density and a uniform, even print surface were evaluated as A. Prints with low ink density and an uneven print surface were evaluated as B. Prints with A were judged to be acceptable.

[0154] <Solvent resistance> Isopropanol (IPA) was dropped onto the transparent surface layer of the film, and the appearance of the film after drying was observed. Films with no visible traces of IPA were rated A. Films with no visible traces of IPA but no visible traces of IPA were rated B. Films with visible dissolution were rated C. Films rated A and B were deemed acceptable.

[0155] <Wetting Tension Test> The wettability of the film surface was evaluated using a wettability test reagent in accordance with JIS K 6768:1999. The maximum value of the reagent number that resulted in good wettability was recorded. The wettability of the film formed using the transparent ink-receiving layer composition of Example 1 (a mixture of PU1 and PU2) was 54 mN / m or higher, the wettability of the film formed using PU3 was 42 mN / m, and the wettability of the film formed using PU4 was 45 mN / m.

[0156] Table 2 shows the details and evaluation results of Examples 1-14, Reference Examples 1-16, and Comparative Examples 1-3.

[0157] [Table 2-1]

[0158] [Table 2-2]

[0159] <Example 15> A transparent ink-receiving layer composition was prepared by mixing polyurethane 1 (PU1) and polyurethane 5 (PU5) using a mixer (TK Auto Homo Mixer, Primix Co., Ltd., Awaji City, Hyogo Prefecture, Japan). The mass ratio of PU1 to PU5 was 100:10 based on solid content. The solid content of the transparent ink-receiving layer composition was approximately 30% by mass.

[0160] Using a knife coater, polyurethane 3 (PU3) was applied onto a 50 μm thick polyester film (support film), and dried at 95°C for 5 minutes to form a transparent surface layer with a thickness of 18 μm.

[0161] A transparent ink-receiving layer composition was applied to a 50 μm thick polyester film using a knife coater, and dried at 95°C for 5 minutes to form a 20 μm thick transparent ink-receiving layer.

[0162] A transparent pressure-sensitive adhesive was prepared by mixing adhesive polymer 4 (ADH4) and crosslinking agent 1 (CL1). The mass ratio of ADH4 to CL1 was 100:0.2 based on solid content.

[0163] A transparent pressure-sensitive adhesive was applied to a silicone-coated polyethylene laminate paper liner using a knife coater and dried at 95°C for 5 minutes to form a transparent pressure-sensitive adhesive layer with a thickness of 10 μm.

[0164] A transparent pressure-sensitive adhesive layer was laminated on top of a transparent ink-receiving layer. The polyester film on top of the transparent ink-receiving layer was removed. The silicone-coated polyethylene laminate paper liner on top of the transparent pressure-sensitive adhesive layer was removed. A transparent surface layer was laminated on top of the exposed transparent pressure-sensitive adhesive layer. In this way, an ink-receiving film was fabricated in which the support film / transparent surface layer / transparent pressure-sensitive adhesive layer / transparent ink-receiving layer were laminated in this order.

[0165] A premix containing white pigment 1 (WP1), dispersant 1 (D1), and methyl ethyl ketone (MEK) was prepared. The mass ratio of WP1 to D1 was 5:1 based on solid content. The solid content of the premix was approximately 66% by mass.

[0166] A premix was mixed with adhesive polymer 1 (ADH1). The mass ratio of ADH1, white pigment 1, and D1 was 100:50:10 based on solid content. Crosslinking agent 4 (CL4) was mixed into the resulting mixture to prepare white pressure-sensitive adhesive 4 (WA4). The mass ratio of ADH1 to CL4 was 100:0.2 based on solid content. The solid content of WA4 was approximately 55% by mass.

[0167] Using a knife coater, WA4 was applied onto a silicone-coated polyethylene laminate paper liner and dried at 95°C for 5 minutes to form a 65 μm thick white pressure-sensitive adhesive layer. In this way, a pressure-sensitive adhesive film including the white pressure-sensitive adhesive layer and a release liner was prepared.

[0168] A 6 μm thick printed layer was formed on the transparent ink-receiving layer of an ink-receiving film by inkjet printing using a JV5 printer and ES3 ink (Mimaki Engineering Co., Ltd., Tomi City, Nagano Prefecture, Japan). The ink densities were C66, M67, and Y67. A white pressure-sensitive adhesive layer was laminated on top of the printed layer, and the support film was removed to produce the decorative film of Example 15.

[0169] <Reference example 17> The laminated film of Reference Example 17 was prepared using the same procedure as in Example 15, except that a printed layer was not included. Reference Example 17 has the same layer structure as Example 15 except that a printed layer is not included, and was prepared for the purpose of investigating the effect of the presence or absence of a printed layer on the properties of the decorative film, such as 5% tensile strength and embossability.

[0170] <5% tensile strength> Test specimens were prepared by cutting the film to a width of 25 mm and a length of 150 mm. The tensile strength at 5% elongation at 20°C was measured using a tensile testing machine (Tensilon universal tester, model number: RTC-1210A, A&D Company, Limited (Toshima-ku, Tokyo, Japan)) under the conditions of 20°C, a gripping distance of 100 mm, and a tensile speed of 300 mm / min.

[0171] <Embossing suitability> Test specimens were prepared by attaching a film to a 1 mm thick aluminum plate at room temperature. An embossing machine (Amada Corporation, Isehara City, Kanagawa Prefecture, Japan) was used to emboss the test specimens with patterns of kanji characters and numbers. The embossing pressure was approximately 15 MPa. The embossing depth was approximately 1.25 mm. The test specimens were cut and their cross-sections were observed under an optical microscope. Specimens without film lifting were evaluated as good, while those with film lifting were evaluated as poor.

[0172] <Impact Resistance> Impact resistance was evaluated in accordance with JIS K 5600-5-3:1999 (ASTM D 2794). Specifically, using the IM-201 DuPont® impact tester (Tester Industries Co., Ltd., Iruma City, Saitama Prefecture, Japan), the impact pin was dropped onto the film surface under the following conditions: weight of 500gf, height of 500mm, impact pin tip diameter of 6.3mm, and temperature of -20℃. After the test, the appearance of the film was visually inspected, and those in which no cracks were observed were evaluated as good, while those in which cracks were observed were evaluated as poor.

[0173] <Adhesive force 2> Test specimens were prepared by cutting the film to a width of 25 mm and a length of 150 mm. The test specimens were attached to an A5052P aluminum panel (Paltec Co., Ltd., Hiratsuka City, Kanagawa Prefecture, Japan) using a roller at 23°C. The attachment method conformed to JIS Z 0237:2009. The test specimens were left at 20°C for 48 hours. The adhesive strength was measured using a tensile testing machine (Tensilon universal testing machine, model number: RTC-1210A, A&D Company, Limited, Toshima Ward, Tokyo, Japan) at 20°C and a peeling speed of 300 mm / min when peeled 180 degrees.

[0174] Table 3 shows the details and evaluation results of Example 15 and Reference Example 17.

[0175] [Table 3]

[0176] It will be apparent to those skilled in the art that the above embodiments and examples can be modified in various ways without departing from the basic principles of the present invention. Furthermore, it will be apparent to those skilled in the art that various improvements and modifications of the present invention can be implemented without departing from the spirit and scope of the invention. [Explanation of symbols]

[0177] 10 Decorative film 11 Transparent surface layer 12 Transparent ink receiving layer 13 Transparent pressure-sensitive adhesive layer 14 Printing layer 16 Pressure-sensitive adhesive layer 18. Release Liner 20 Ink-receiving film 22 Support film 30 Pressure-sensitive adhesive film

Claims

1. A decorative film comprising, in this order, a transparent surface layer containing a polycarbonate-based polyurethane, a transparent ink-receiving layer containing a polyether-based polyurethane, a printing layer disposed on the transparent ink-receiving layer, and a pressure-sensitive adhesive layer.

2. 2. The decorative film according to claim 1, wherein the polyether-based polyurethane of the transparent ink-receiving layer is a water-based polyether-based polyurethane.

3. 3. The decorative film according to claim 1, wherein the polycarbonate-based polyurethane of the transparent surface layer has an alicyclic structure.

4. The decorative film according to any one of claims 1 to 3, wherein the printed layer is an inkjet printed layer.

5. The decorative film according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive layer comprises a white colorant.

6. The decorative film according to any one of claims 1 to 5, wherein the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer.

7. The decorative film according to any one of claims 1 to 6, further comprising a transparent pressure-sensitive adhesive layer between said transparent surface layer and said transparent ink-receiving layer.

8. An ink-receiving film comprising, in order, a support film, a transparent surface layer comprising a polycarbonate-based polyurethane, and a transparent ink-receiving layer comprising a polyether-based polyurethane.

9. The ink-receiving film of claim 8 , wherein the polyether-based polyurethane of the clear ink-receiving layer is a water-based polyether-based polyurethane.

10. 10. The ink-receptive film according to claim 8 or 9, wherein the polycarbonate-based polyurethane of the transparent surface layer has an alicyclic structure.

11. providing an ink-receiving film comprising, in order, a support film, a transparent surface layer comprising a polycarbonate-based polyurethane, and a transparent ink-receiving layer comprising a polyether-based polyurethane; Providing a pressure-sensitive adhesive film including a pressure-sensitive adhesive layer and a release liner; printing an ink on the transparent ink receiving layer to form a printing layer; laminating the ink receptive film and the pressure-sensitive adhesive film such that the printing layer and the pressure-sensitive adhesive layer are in contact; and removing the support film to form a decorative film; A method for producing a decorative film comprising the steps of:

12. The method of claim 11 , wherein the polyether-based polyurethane of the clear ink-receiving layer is a water-based polyether-based polyurethane.

13. The method of claim 12 wherein the ink is a solvent-based ink.

14. The method according to any one of claims 11 to 13, wherein the polycarbonate-based polyurethane of the transparent surface layer has an alicyclic structure.

15. an ink-receiving film comprising, in this order, a support film, a transparent surface layer comprising a polycarbonate-based polyurethane, and a transparent ink-receiving layer comprising a polyether-based polyurethane; A pressure-sensitive adhesive film including a pressure-sensitive adhesive layer and a release liner; A decorative film kit consisting of:

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