Laminate with excellent chemical resistance and transfer film for its production

Abstract

A laminate with improved chemical resistance and a transfer film for producing the laminate are provided, suppressing the formation of film burrs. The transfer film 11 comprises a separating layer 2, a protective layer 3, an intermediate layer 4, a metal base layer 5, a metal thin-film layer 6, and an adhesive layer 7 formed successively on a substrate 1. The transfer film is characterized in that the thickness fulfilling the following conditions a), b), and c) is equal to the thickness of a functional layer 10, which includes the protective layer 3, the intermediate layer 4, the metal base layer 5, the metal thin-film layer 6, etc.comprising, 3 µm or more and 8 µm or less: a) comprising at least one polyol compound and one polyisocyanate compound; b) the hydroxyl number of the polyol compound is 20 mgKOH / g or more and 60 mgKOH / g or less; and c) the ratio of the total number of isocyanate groups in the polyisocyanate compound to the total number of hydroxyl groups in the polyol compound ([NCO] / [OH] ratio) is 0.5 or more and 3.0 or less.

Description

Laminate with excellent chemical resistance and transfer film for producing same

[0001] The present invention relates to a laminate having excellent chemical resistance and a transfer film from which the same can be obtained.

[0002] A commonly used method has been to use a transfer film having a release layer, a functional layer (protective layer, colored layer, printed layer, hard coat layer, anti-reflection layer, metal thin film layer, etc.) and an adhesive layer formed in this order on a plastic film, and then transfer the functional layer and adhesive layer (hereinafter, these layers are collectively referred to as transfer layer) formed on the release layer of the transfer film onto the surface of a transfer target, thereby forming a transfer layer on the surface of the transfer target, thereby obtaining a laminate imparted with various functions such as design properties such as metallic luster and patterns, hard coat properties and anti-reflection properties.The laminates are used as various products such as home appliances, automobile parts, miscellaneous goods, paper containers, labels, etc.

[0003] When a laminate is used for the interior or exterior of an automobile, chemical resistance is generally required, for example, performance such that no defects occur in the appearance even when a chemical resistance test is conducted in which a test agent such as a sunscreen cosmetic or gasoline is applied to the surface of the laminate and the laminate is left to stand for 10 minutes at a high temperature of 80° C. Furthermore, each automobile manufacturer sets its own standards for chemical resistance, and it is more desirable to have excellent chemical resistance that can meet all of these standards.

[0004] Patent Document 1 discloses a transfer sheet (transfer film) with reduced foil burrs (a phenomenon in which all or part of the transfer layer of the transferred portion near the transfer portion peels off from the base sheet while remaining connected to the transfer layer), which is configured such that a release layer, a protective layer, a design layer (decorative layer), and an adhesive layer are formed in this order on a base sheet (plastic film), and the protective layer is made of a polyol compound and an isocyanurate-modified isocyanate compound. This transfer sheet is intended to reduce the occurrence of foil burrs.

[0005] Japanese Patent Application Laid-Open No. 2003-154794

[0006] When a laminate is obtained using the transfer film described in Patent Document 1, the protective layer is composed of a conventional polyol compound and an isocyanurate-modified isocyanate compound, which is a conventional compound, resulting in less foil burrs during transfer processing and allowing the laminate to be obtained relatively inexpensively. However, the laminate obtained using the transfer film described in Patent Document 1 does not have a strong protective layer because it is composed of a conventional polyol compound and an isocyanurate-modified isocyanate compound. Although certain surface properties such as scratch resistance can be obtained, when the laminate is subjected to a chemical resistance test, the test agent penetrates through the surface of the transfer layer, causing blisters and cracks in the entire transfer layer and the substrate, resulting in a poor appearance. This problem is particularly pronounced when sunscreen cosmetics or gasoline are used as the test agent. Based on the above, an objective of the present invention is to provide a laminate that solves all of the above problems and a transfer film suitable for producing the laminate.

[0007] As a result of extensive research, the inventors have found that providing a functional layer made of a thermosetting resin with a specific composition on the release layer (on the transfer layer side) of a transfer film improves chemical resistance and suppresses the occurrence of foil burrs, and have thus completed the present invention. That is, the transfer film and laminate of the present invention, which solve the above-mentioned problems, have the following configurations.

[0008] [Item 1] A transfer film having at least a functional layer and an adhesive layer formed in this order on a plastic film, wherein at least the thickness of the functional layer is 3 μm or more and 8 μm or less, satisfying the following conditions a, b, and c: a) the functional layer is composed of at least a polyol compound and a polyisocyanate compound; b) the polyol compound has a hydroxyl value of 20 mg KOH / g or more and 60 mg KOH / g or less; and c) the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) is 0.5 or more and 3.0 or less. [Item 2] The transfer film according to Item 1, wherein the functional layer is composed of at least a protective layer and an intermediate layer. [Item 3] The transfer film according to Item 1, wherein the functional layer is composed of at least a protective layer, an intermediate layer, and a decorative layer. [Item 4] The transfer film according to Item 3, wherein the decorative layer comprises at least one layer selected from the group consisting of a metal base layer, a metal thin film layer, a colored layer, and a printed layer. [Item 5] The transfer film according to Item 4, wherein the decorative layer comprises a metal base layer and a metal thin film layer. [Item 6] A laminate obtained by transferring the transfer film according to Items 1 to 5 onto a substrate. [Item 7] A laminate having at least an adhesive layer and a functional layer formed in that order on a substrate, wherein at least the thickness of the functional layer that satisfies the following conditions a, b, and c is 3 μm or more and 8 μm or less. a) At least a polyol compound and a polyisocyanate compound are included; b) The polyol compound has a hydroxyl value of 20 mgKOH / g or more and 60 mgKOH / g or less; and c) The ratio of the total number of isocyanate groups included in the polyisocyanate compound to the total number of hydroxyl groups included in the polyol compound ([NCO] / [OH] ratio) is 0.5 or more and 3.0 or less. [Item 8] The laminate according to Item 7, wherein the functional layer comprises at least a protective layer and an intermediate layer. [Item 9] The laminate according to Item 7, wherein the functional layer comprises at least a protective layer, an intermediate layer, and a decorative layer. [Item 10] The laminate according to Item 9, wherein the decorative layer comprises at least one layer selected from a metal base layer, a metal thin film layer, a colored layer, and a printed layer. [Item 11] The laminate according to Item 10, wherein the decorative layer comprises a metal base layer and a metal thin film layer.

[0009] The laminate of the present invention is characterized in that the thickness of the functional layer satisfies the following conditions a, b, and c, and is 3 μm or more and 8 μm or less: a) comprises at least a polyol compound and a polyisocyanate compound; b) the hydroxyl value of the polyol compound is 20 mg KOH / g or more and 60 mg KOH / g or less; and c) the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) is 0.5 or more and 3.0 or less.

[0010] By using the functional layer with the above composition, a transfer layer that is resistant to penetration by various components used in chemical resistance tests can be obtained. As a result, the laminate of the present invention is less susceptible to deterioration in appearance due to damage such as blistering or cracking occurring in the entire transfer layer and the substrate after chemical resistance tests.

[0011] Because the transfer film of the present invention has a functional layer having the above-mentioned composition, the laminate of the present invention obtained using the transfer film of the present invention is less likely to suffer from deterioration in appearance due to damage such as swelling or significant cracking after a chemical resistance test. Furthermore, the functional layer of the present invention easily breaks at the boundary between the transfer portion and the transferred portion, and foil burrs are less likely to occur during transfer processing. Therefore, the transfer film of the present invention is the optimal transfer film for producing the laminate of the present invention.

[0012] Figure 1 is a schematic diagram of the cross-sectional structure of one embodiment of the transfer film of the present invention, in which a release layer, a protective layer, an intermediate layer, a metal underlayer, a metal thin film layer, and an adhesive layer are formed in this order on a plastic film. Figure 2 is a schematic diagram of the cross-sectional structure of one embodiment of the laminate of the present invention, in which an adhesive layer, a metal thin film layer, a metal underlayer, an intermediate layer, and a protective layer are formed in this order on a substrate. Figure 3 is a schematic diagram of the cross-sectional structure of one embodiment of the transfer film of the present invention, in which a release layer, a protective layer, an intermediate layer, and an adhesive layer are formed in this order on a plastic film. Figure 4 is a schematic diagram of the cross-sectional structure of one embodiment of the laminate of the present invention, in which an adhesive layer, an intermediate layer, and a protective layer are formed in this order on a substrate.

[0013] The transfer film of the present invention will be described below.

[0014] (Plastic Film) The plastic film used in the transfer film of the present invention can be any plastic film generally used in transfer films, and various conventionally known plastic films such as polyethylene terephthalate film, polycarbonate film, polyethylene film, polypropylene film, polyamide film, etc. can be used.

[0015] The plastic film may be unstretched, uniaxially stretched, or biaxially stretched, and may contain various additives such as antistatic agents, colorants, heat stabilizers, etc. The type of plastic film may be appropriately selected depending on the desired use and purpose.

[0016] Furthermore, in order to make the transfer film of the present invention more decorative, the surface of the plastic film (the side on which the release layer is formed) may be subjected to an uneven finish such as hairline finishing, matte finishing, embossing, etc.

[0017] The thickness of the plastic film used in the transfer film of the present invention is not particularly limited, but is preferably 12 to 250 μm. A plastic film thinner than 12 μm is not preferred because it may be prone to curling and creases when forming a release layer or the like on the plastic film or when handling the transfer film of the present invention, making it difficult to handle. A plastic film thicker than 250 μm is not preferred because it becomes too stiff and may be difficult to handle when using the transfer film of the present invention for transfer processing, such as being difficult to place on the surface of the substrate to be transferred.

[0018] (Release Layer) The transfer film of the present invention may have a release layer formed thereon. As long as the protective layer described below has sufficient releasability, the release layer need not be formed. The release layer is a layer formed on a plastic film for the purpose of facilitating peeling of the transfer layer from the release layer of the transfer film of the present invention when performing transfer processing using the transfer film of the present invention. Furthermore, the release layer is not transferred or formed on the surface of the transfer target during transfer processing, but is removed from the transfer target together with the plastic film.

[0019] The release layer is a layer made of a resin. The resin used for the release layer is not particularly limited as long as it can achieve the above-mentioned purpose, and conventionally known resins such as polyethylene resins, polypropylene resins, polystyrene resins, vinyl chloride resins, polyester resins, acrylic resins, urethane resins, melamine resins, and epoxy resins can be used. Any one of these resins or a mixture of two or more of them may be used, and the resin may be appropriately selected depending on the purpose.

[0020] The thickness of the release layer may be appropriately selected within a range that can achieve the above-mentioned purpose, and is preferably in the range of 0.5 to 5 μm. The method for forming the release layer may be a conventionally known coating method such as gravure coating, reverse coating, die coating, reverse gravure coating, or bar coating, and may be appropriately selected depending on the purpose.

[0021] (Functional Layer) The functional layer of the present invention is formed to have a layer thickness of 3 μm or more and 8 μm or less, satisfying the following conditions: a) consisting of at least a polyol compound and a polyisocyanate compound; b) the hydroxyl value of the polyol compound is 20 mg KOH / g or more and 60 mg KOH / g or less; and c) the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) is 0.5 or more and 3.0 or less.

[0022] The polyol compound is not particularly limited, and for example, acrylic polyol, polyester polyol, polyether polyol, hydroxyl group-containing fluorine-based resin, etc. can be used alone or in any combination of two or more. In particular, from the viewpoint of imparting weather resistance in addition to chemical resistance, it is most desirable to use an acrylic polyol compound.

[0023] The isocyanate compound is not particularly limited, and examples thereof include aromatic diisocyanate compounds such as tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and xylylene diisocyanate (XDI), aliphatic diisocyanate compounds such as hexamethylene diisocyanate (HDI), and alicyclic diisocyanate compounds such as isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), and hydrogenated xylylene diisocyanate (hydrogenated XDI), which can be used alone or in any combination of two or more. In the following description, resins that satisfy the above conditions are referred to as resins that are characteristic of the present invention.

[0024] The functional layer may also include a layer that does not satisfy the above conditions, and the material for that layer may be a conventionally known resin such as a polyethylene resin, a polypropylene resin, a polystyrene resin, a vinyl chloride resin, a polyester resin, an acrylic resin, a urethane resin, a melamine resin, or an epoxy resin, or may be one or a mixture of two or more of these resins, and may be appropriately selected depending on the purpose of forming the layer. Furthermore, a curing agent such as an isocyanate compound may also be included.

[0025] The hydroxyl value of the polyol compound in the resin characteristic of the present invention is preferably 20 mgKOH / g or more and 60 mgKOH / g or less. If it is less than 20 mgKOH / g, sufficient crosslinking density cannot be obtained, resulting in poor chemical resistance. If it is greater than 60 mgKOH / g, burrs are likely to occur. Furthermore, the ratio of the total number of isocyanate groups contained in the polyisocyanate to the total number of hydroxyl groups contained in the polyol ([NCO] / [OH] ratio) is preferably 0.5 or more and 3.0 or less. If it is less than 0.5, sufficient crosslinking density cannot be obtained, resulting in poor chemical resistance. Even if it is greater than 3.0, chemical resistance may be poor. Furthermore, the total thickness of the functional layer made of the resin characteristic of the present invention is preferably 3 μm or more and 8 μm or less. If it is thinner than 3 μm, the test agent will easily penetrate during chemical resistance testing, resulting in a deterioration in appearance. If it is thicker than 8 μm, burrs are likely to occur during transfer processing.

[0026] Examples of the functional layer configuration of the present invention include the following combinations: (release layer) / protective layer / intermediate layer / (adhesive layer), (release layer) / protective layer / colored layer / (adhesive layer), (release layer) / protective layer / intermediate layer / colored layer / (adhesive layer), (release layer) / protective layer / intermediate layer / metal base layer / metal thin film layer / (adhesive layer), (release layer) / protective layer / intermediate layer / colored layer / metal base layer / metal thin film layer / (adhesive layer). In the above examples, the layers in parentheses indicate the layers located above and below the illustrated functional layer in the thickness direction. Of course, other combinations of layers can also be used depending on the desired purpose. Any combination of these layers may be made of a resin that is a characteristic of the present invention. For example, the protective layer and intermediate layer may be made of a resin that is a characteristic of the present invention, and the other layers may be made of a resin that is not a characteristic of the present invention, or the colored layer and metal base layer may be made of a specific resin that is a characteristic of the present invention, and the other layers may be made of a resin that is not a characteristic of the present invention. Any combination of resin layers, which is a feature of the present invention, can provide chemical resistance as long as the total thickness of the resin layers is 3 μm or more.

[0027] (Protective Layer) The protective layer of the present invention is formed on the plastic film or release layer on the transfer layer side for the purpose of stabilizing the releasability of the transfer film of the present invention. During transfer, the protective layer is peeled off at the interface between the plastic film or release layer and the protective layer. As a result, the protective layer is transferred and formed on the surface of the transfer target, protecting the transfer layer of the resulting laminate.

[0028] The protective layer can be made of the resin described above for the functional layer. Furthermore, the protective layer may contain one or more additives, such as antistatic agents, ultraviolet absorbers, heat stabilizers, and curing agents, as needed. The amounts of the additives added can be appropriately selected depending on the purpose. When using the resin characteristic of the present invention as a protective layer, it is desirable to provide the release layer described above from the standpoint of releasability. If no release layer is provided or if the release layer alone does not provide stable releasability, the resin characteristic of the present invention may not be usable from the standpoint of releasability. In such cases, a resin with good releasability other than the resin characteristic of the present invention can be used. Resins with good releasability may have poor chemical resistance. In such cases, by making the thickness of the protective layer 1 μm or less and using the resin characteristic of the present invention in the intermediate layer, etc., as described below, deterioration of the appearance can be suppressed to a level that does not interfere with practical use.

[0029] The thickness of the protective layer may be appropriately selected within a range that allows the above-mentioned purpose to be achieved, and is preferably in the range of 0.5 to 5 μm. The protective layer may be formed by a conventionally known coating method such as gravure coating, reverse coating, die coating, reverse gravure coating, or bar coating, and may be appropriately selected depending on the purpose.

[0030] (Intermediate Layer) The intermediate layer of the transfer film of the present invention is a layer formed on the protective layer for the purpose of complementing the chemical resistance of the functional layers other than the intermediate layer. That is, if the functional layers other than the intermediate layer are made of the resin characteristic of the present invention and have chemical resistance, there is no need to form an intermediate layer. Furthermore, if the thickness of the layer made of the resin characteristic of the present invention in the functional layers other than the intermediate layer is insufficient, chemical resistance can be obtained by providing an intermediate layer made of the resin characteristic of the present invention. If the protective layer, metal base layer, colored layer, or printed layer described above or below cannot use the resin characteristic of the present invention in light of their purpose, it is preferable to form an intermediate layer in order to make the layer made of the resin characteristic of the present invention 3 μm or more thick.

[0031] The intermediate layer can be made of the resin characteristic of the present invention described above for the functional layer. Furthermore, the intermediate layer may contain one or more additives, such as an antistatic agent, an ultraviolet absorber, a heat stabilizer, or a curing agent, if necessary. The amounts of the additives added may be appropriately selected depending on the purpose.

[0032] The thickness of the intermediate layer may be appropriately selected within a range that allows the above-mentioned object to be achieved, and is preferably in the range of 0.5 to 5 μm. The method for forming the intermediate layer may be a conventionally known coating method such as gravure coating, reverse coating, die coating, reverse gravure coating, or bar coating, and may be appropriately selected depending on the object.

[0033] (Decorative Layer) The transfer film of the present invention may be formed with a colored layer using a colorant, a printed layer, or a metal thin film layer for the purpose of imparting a design to the transfer target.

[0034] (Colored Layer and Printed Layer) The colored layer is a layer formed by adding a pigment or dye to a resin and covering the entire surface or a desired portion of the transfer film of the present invention. The printed layer is a layer in which a colored portion is formed in a desired pattern. The resins described above for the functional layer can be used for the colored layer and the printed layer. The resin characteristic of the present invention may also be used for the colored layer and the printed layer. Furthermore, if the resin characteristic of the present invention cannot be used for the colored layer and the printed layer, it is preferable to provide an intermediate layer made of the resin characteristic of the present invention. Furthermore, if necessary, one or more types of additives such as antistatic agents, ultraviolet absorbers, heat stabilizers, and curing agents may be added, and the amounts of the various additives added may be selected appropriately depending on the purpose.

[0035] The thickness of the colored layer and the printed layer may be any thickness that can achieve the desired colored layer and printed layer effects, and is preferably in the range of 0.5 to 5 μm, and may be appropriately selected depending on the purpose of forming the colored layer and the printed layer. Furthermore, the colored layer and the printed layer may be formed using a conventionally known coating method such as gravure coating, reverse coating, die coating, reverse gravure coating, bar coating, screen printing, or offset printing, and may be appropriately selected depending on the purpose.

[0036] (Metallic Underlayer) The metallic underlayer is a layer formed for the purpose of adhering the metallic thin film layer described below to the protective layer, intermediate layer, colored layer or printed layer when forming the metallic thin film layer on the transfer film of the present invention.

[0037] The resin described above for the functional layer can be used for the metal underlayer. Furthermore, when a resin having the characteristics of the present invention is used for the metal underlayer, it is more preferable to use a resin in which the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) is 1.0 or more, since this strengthens adhesion to the metal thin film layer. Furthermore, when the resin having the characteristics of the present invention cannot be used for the metal underlayer, it is preferable to provide an intermediate layer made of the resin having the characteristics of the present invention. If necessary, one or more additives such as an antistatic agent, an ultraviolet absorber, a heat stabilizer, and a curing agent may be added, and the amount of each additive added may be appropriately selected depending on the purpose.

[0038] The thickness of the metal underlayer may be appropriately selected within a range that allows the above-mentioned purpose to be achieved, and is preferably in the range of 0.5 to 2 μm. The method for forming the metal underlayer may be a conventionally known coating method such as gravure coating, reverse coating, die coating, reverse gravure coating, or bar coating, and may be appropriately selected depending on the purpose.

[0039] (Metal thin film layer) The metal thin film layer is a layer formed mainly for the purpose of imparting metallic luster to a transfer target, and is a layer that is transferred and formed on the surface of a transfer target together with an adhesive layer when a transfer process is performed. Furthermore, by using a metal compound described later in the metal thin film layer, properties such as barrier properties and electrical conductivity may be imparted in addition to or instead of metallic luster.

[0040] The metal used in the metal thin film layer may be any of various conventionally known metals such as aluminum, chromium, tin, gold, silver, copper, zinc, silicon, nickel, and indium, or metal compounds such as oxides, sulfides, and nitrides of the above conventionally known metals, and may be appropriately selected depending on the desired purpose. The metal thin film layer may be a single layer or a multi-layer structure of two or more layers, and when the metal thin film layer is a multi-layer structure of two or more layers, the metals used in each layer may be different or the same.

[0041] The thickness of the metal thin film layer is preferably in the range of 10 to 200 nm. If it is thinner than 10 nm, it may not be possible to impart the desired metallic luster to the transfer film of the present invention, which is undesirable, while if it is thicker than 200 nm, it may not be possible to impart the desired metallic luster to the transfer film of the present invention, which is undesirable, because the plastic film may be deformed or deteriorated by the heat during the formation of the metal thin film layer or the heat during the transfer processing.

[0042] The metal thin film layer can be formed by a conventional method for forming a metal thin film layer, such as vacuum deposition, sputtering, or chemical vapor deposition (CVD), and may be appropriately selected depending on the purpose.

[0043] When forming a decorative layer on the transfer film of the present invention, the types of the metal thin film layer, colored layer, printed layer, and metal base layer to be formed and the order in which they are formed may be appropriately selected depending on the purpose. Furthermore, the metal thin film layer, colored layer, printed layer, metal base layer, and adhesive layer described below may be formed entirely or partially on the protective layer, and the positions at which they are formed may be appropriately selected depending on the purpose.

[0044] (Adhesive Layer) The adhesive layer formed on the transfer film of the present invention is not particularly limited as long as it is a thermoplastic resin generally used in transfer films, and conventionally known resins such as acrylic resins, polyethylene resins, polypropylene resins, polystyrene resins, vinyl chloride resins, polyester resins, urethane resins, and vinyl acetate resins can be used. One or more of these may be mixed, or two or more of these may be copolymerized, and the adhesive layer may be appropriately selected depending on the material to be transferred. Furthermore, using a resin that is compatible with the resin used in the material to be transferred also ensures good compatibility with the material to be transferred, which is preferable.

[0045] The thickness of the adhesive layer may be appropriately selected within a range that allows the above-mentioned purpose to be achieved, and is preferably in the range of 0.5 to 10 μm. The adhesive layer may be formed by a conventionally known coating method such as gravure coating, reverse coating, die coating, reverse gravure coating, or bar coating, and may be appropriately selected depending on the purpose.

[0046] The laminate of the present invention can be obtained by sequentially forming the above-mentioned layers on a substrate, which is a transfer target. The optimal method for obtaining the laminate of the present invention is to form each layer on a substrate using the transfer film of the present invention.

[0047] (Substrate) Depending on the desired purpose, the substrate may be a conventionally known material such as an acrylic resin, a polyethylene resin, a polypropylene resin, a polystyrene resin, a vinyl chloride resin, a polyester resin, a urethane resin, a vinyl acetate resin, an ABS resin, or a polycarbonate resin, or may be one of these, a mixed resin of two or more of these, or a copolymer resin of two or more of these. Furthermore, these substrates may be transparent or colored.

[0048] The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0049] Examples 1-11 and Comparative Examples 1-8 Preparation of Transfer Films The following steps 1-4 were carried out in order to obtain transfer films in which a release layer, a protective layer, an intermediate layer, and an adhesive layer were sequentially formed on a polyethylene terephthalate film. (Step 1) A thermosetting acrylic melamine resin was coated on a 25 μm-thick polyethylene terephthalate film using a bar coating method to form a 0.5 μm-thick release layer. (Step 2) A thermoplastic acrylic resin was coated on the release layer using a bar coating method to form a 1 μm-thick protective layer. (Step 3) An acrylic polyol resin and an HDI-based polyisocyanate compound were mixed and coated on the protective layer using a bar coating method to form an intermediate layer. The hydroxyl value of the acrylic polyol, the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio), and the thickness of the intermediate layer were as shown in Table 1. (Step 4) A copolymer resin of an acrylic resin and a vinyl acetate resin was coated on the intermediate layer by a bar coating method to form an adhesive layer with a thickness of 2 μm. [Preparation of Laminate] The transfer film obtained by carrying out the above steps was placed on an ABS substrate with the adhesive layer facing the substrate side, and pressure and heat were applied from the plastic film side using a roll transfer machine. Transfer processing was carried out at a transfer temperature of 200° C. and a transfer speed of 50 mm / sec, and then the plastic film including the release layer was quickly peeled off to obtain a laminate.

[0050] Example 12 Preparation of Transfer Film The following steps 1 to 6 were performed in order to obtain a transfer film in which a release layer, a protective layer, an intermediate layer, a metal underlayer, a metal thin film layer, and an adhesive layer were sequentially formed on a polyethylene terephthalate film. (Step 1) A thermosetting acrylic melamine resin was coated on a 25 μm-thick polyethylene terephthalate film using a bar coating method to form a 0.5 μm-thick release layer. (Step 2) A thermoplastic acrylic resin was coated on the release layer using a bar coating method to form a 1 μm-thick protective layer. (Step 3) An acrylic polyol resin with a hydroxyl value of 24 mg KOH / g and an HDI-based polyisocyanate compound were mixed so that the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) was 0.8, and the mixture was coated on the protective layer using a bar coating method to form a 2 μm-thick intermediate layer. (Step 4) An acrylic polyol resin with a hydroxyl value of 24 mg KOH / g and an HDI-based polyisocyanate compound were mixed on the intermediate layer so that the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) was 2.0, and the mixture was bar-coated to form a 1 μm-thick metal underlayer. (Step 5) Chromium was formed on the metal underlayer by vacuum deposition to form a 50 nm-thick chromium thin film layer. (Step 6) A copolymer resin of an acrylic resin and a vinyl acetate resin was bar-coated on the chromium thin film layer to form a 2 μm-thick adhesive layer. [Laminate Preparation] A laminate was prepared in the same manner as in Example 1 using the transfer film obtained after the above steps.

[0051] Example 13 Preparation of Transfer Film The following steps 1 to 4 were performed in order to obtain a transfer film in which a release layer, a protective layer, an intermediate layer, and an adhesive layer were sequentially formed on a polyethylene terephthalate film. (Step 1) A thermosetting acrylic melamine resin was coated on a 25 μm-thick polyethylene terephthalate film using a bar coating method to form a 0.5 μm-thick release layer. (Step 2) A thermoplastic acrylic resin was coated on the release layer using a bar coating method to form a 1 μm-thick protective layer. (Step 3) An acrylic polyol resin with a hydroxyl value of 24 mg KOH / g and an HDI-based polyisocyanate compound were mixed so that the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) was 0.8, and the mixture was coated on the protective layer using a bar coating method to form a 3 μm-thick intermediate layer. (Step 4) A copolymer resin of an acrylic resin and a vinyl acetate resin was coated on the intermediate layer by a bar coating method to form an adhesive layer having a thickness of 2 μm. [Preparation of Laminate] A laminate was prepared in the same manner as in Example 1 using the transfer film obtained by the above steps.

[0052] [Example 14] [Preparation of Transfer Film] The following steps 1 to 4 were carried out in order to obtain a transfer film in which a release layer, a protective layer, a colored layer, and an adhesive layer were sequentially formed on a polyethylene terephthalate film. (Step 1) A thermosetting acrylic melamine resin was coated on a 25 μm thick polyethylene terephthalate film by the bar coating method to form a 0.5 μm thick release layer. (Step 2) A thermoplastic acrylic resin was coated on the release layer by the bar coating method to form a 1 μm thick protective layer. (Step 3) An acrylic polyol resin with a hydroxyl value of 24 mg KOH / g and an HDI-based polyisocyanate compound were mixed on the protective layer so that the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) was 0.8, and a black pigment was added at a weight ratio of 10% to the resin. This mixture was then coated by bar coating to form a 3 μm-thick colored layer. (Step 4) A copolymer resin of an acrylic resin and a vinyl acetate resin was coated on the colored layer by bar coating to form a 2 μm-thick adhesive layer. [Preparation of Laminate] A laminate was prepared in the same manner as in Example 1 using the transfer film obtained after the above steps.

[0053] Example 15 Preparation of Transfer Film The following steps 1 to 5 were performed in order to obtain a transfer film in which a release layer, a protective layer, a metal underlayer, a metal thin film layer, and an adhesive layer were sequentially formed on a polyethylene terephthalate film. (Step 1) A thermosetting acrylic melamine resin was coated on a 25 μm-thick polyethylene terephthalate film using a bar coating method to form a 0.5 μm-thick release layer. (Step 2) A thermoplastic acrylic resin was coated on the release layer using a bar coating method to form a 1 μm-thick protective layer. (Step 3) An acrylic polyol resin with a hydroxyl value of 24 mg KOH / g and an HDI-based polyisocyanate compound were mixed so that the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) was 2.0, and the mixture was coated on the protective layer using a bar coating method to form a 3 μm-thick metal underlayer. (Step 4) Chromium was formed on the metal underlayer by vacuum deposition to form a 50 nm thick chromium thin film layer. (Step 5) A copolymer resin of acrylic resin and vinyl acetate resin was coated on the chromium thin film layer by bar coating to form a 2 μm thick adhesive layer. [Preparation of Laminate] A laminate was obtained in the same manner as in Example 1 using the transfer film obtained by performing the above steps.

[0054] Example 16 Preparation of Transfer Film The following steps 1 to 6 were performed in order to obtain a transfer film in which a release layer, a protective layer, a colored layer, a metal underlayer, a metal thin film layer, and an adhesive layer were sequentially formed on a polyethylene terephthalate film. (Step 1) A thermosetting acrylic melamine resin was coated on a 25 μm-thick polyethylene terephthalate film using a bar coating method to form a 0.5 μm-thick release layer. (Step 2) An acrylic polyol resin with a hydroxyl value of 24 mg KOH / g and an HDI-based polyisocyanate compound were mixed so that the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) was 0.8, and the mixture was coated on the release layer using a bar coating method to form a 1 μm-thick protective layer. (Step 3) On the protective layer, an acrylic polyol resin having a hydroxyl value of 24 mg KOH / g and an HDI-based polyisocyanate compound were mixed so that the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) was 0.8, and a black pigment was added at a weight ratio of 10% to the resin, and this was coated by a bar coating method to form a 1 μm thick colored layer. (Step 4) On the colored layer, an acrylic polyol resin having a hydroxyl value of 24 mg KOH / g and an HDI-based polyisocyanate compound were mixed so that the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) was 2.0, and this was coated by a bar coating method to form a 1 μm thick metal underlayer. (Step 5) Chromium was formed on the metal underlayer by vacuum deposition to form a 50 nm thick chromium thin film layer. (Step 6) A copolymer resin of acrylic resin and vinyl acetate resin was coated on the chromium thin film layer by bar coating to form a 2 μm thick adhesive layer. [Preparation of Laminate] A laminate was obtained in the same manner as in Example 1 using the transfer film obtained by performing the above steps.

[0055] Comparative Example 7 Preparation of Transfer Film The following steps 1 to 5 were carried out in order to obtain a transfer film in which a release layer, a protective layer, a metal underlayer, a metal thin film layer, and an adhesive layer were sequentially formed on a polyethylene terephthalate film. (Step 1) A thermosetting acrylic melamine resin was coated on a 25 μm-thick polyethylene terephthalate film by bar coating to form a 0.5 μm-thick release layer. (Step 2) An acrylic polyol resin with a hydroxyl value of 24 mg KOH / g and an HDI-based polyisocyanate compound were mixed so that the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) was 0.8, and the mixture was coated on the release layer by bar coating to form a 1 μm-thick protective layer. (Step 3) An acrylic polyol resin with a hydroxyl value of 24 mg KOH / g and an HDI-based polyisocyanate compound were mixed on the protective layer so that the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) was 2.0, and the mixture was bar-coated to form a 1 μm-thick metal underlayer. (Step 4) Chromium was formed on the metal underlayer by vacuum deposition to form a 50 nm-thick chromium thin film layer. (Step 5) A copolymer resin of an acrylic resin and a vinyl acetate resin was bar-coated on the metal thin film layer to form a 2 μm-thick adhesive layer. [Preparation of Laminate] A laminate was prepared in the same manner as in Example 1 using the transfer film obtained after the above steps.

[0056] Examples 17 to 20 Preparation of Transfer Film and Laminate Laminates were obtained in the same manner as in Example 1, except that the polyol compounds and polyisocyanate compounds in step 3 of Example 1 were combined as shown in Table 3.

[0057] Examples 21-29 and Comparative Examples 8-14 Preparation of Transfer Films Transfer films were prepared by combining and laminating the functional layers (protective layer, intermediate layer, colored layer, metal base layer, and metal thin film layer) of the present invention as shown in Table 3. The lamination order was plastic film / release layer / protective layer / intermediate layer / colored layer / metal base layer / metal thin film layer / adhesive layer. That is, the layers constituting the functional layers of the present invention shown in Table 4 were formed in order from left to right in the table. Transfer films were prepared by forming each layer in the same manner as in Examples 1-16. The hydroxyl value of the acrylic polyol, the ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio), and the thickness of each layer were as shown in Table 3. However, layers with a thickness of 0 μm were not formed. The protective layers of Examples 21-25, Comparative Examples 8-12, and Comparative Example 14 were made of the same thermoplastic acrylic resin as in Step 2 (protective layer) of Example 1. In Comparative Example 9, a thermoplastic acrylic resin was used as the intermediate layer, and a 1 μm thick intermediate layer was formed by bar coating. Furthermore, a 6 μm thick colored layer was formed by bar coating using a thermoplastic acrylic resin to which a black pigment was added at a weight ratio of 10% to the resin. In the table, Al, Cr, and In represent aluminum, chromium, and indium, respectively. Each metal thin film layer was formed to a thickness of 50 nm by vacuum deposition. [Laminate Preparation] Using the transfer film obtained as described above, a laminate was prepared in the same manner as in Example 1.

[0058] [Evaluation of Each Transfer Film and Laminate] The transfer films obtained in Examples 1 to 29 and Comparative Examples 1 to 14 and the laminates obtained using them were evaluated for chemical resistance and burr formation as described below. The results are shown in Tables 1 to 3. [Chemical Resistance Test (Sunscreen Cosmetic)] 0.15 g of a commercially available sunscreen cosmetic was uniformly applied to a 50 mm x 50 mm area on the surface (protective layer surface) of the laminate obtained above. This was left in a thermostatic chamber at 55°C for 24 hours. The laminate was removed, and the sunscreen cosmetic was washed off with a cleaning solution. The condition of the area where the sunscreen cosmetic was applied (test surface) was visually observed and evaluated according to the following criteria. A commercially available sunscreen cosmetic with SPF 50 was used. ⊚: No change in appearance such as blistering, cracking, or discoloration. ◯: Slight change in appearance such as blistering, cracking, or discoloration, but no problem in practical use. △: Changes in appearance such as swelling, cracking, discoloration, etc. ×: Significant changes in appearance such as swelling, cracking, discoloration, etc.

[0059] Chemical resistance tests (gasoline) were conducted under the following three conditions. Regular automotive gasoline as specified in JIS-K-2202 was used for all tests. (1) 0.1 ml of gasoline was dropped onto the surface (protective layer side) of the laminate at 25°C, and after 5 minutes had passed since evaporation, the appearance of the area where the gasoline was dropped (test surface) was evaluated. (2) After the test in (1), the laminate was further placed in a thermostatic chamber at 80°C, and after 10 minutes, the appearance of the area where the gasoline was dropped (test surface) was evaluated. (3) The test surface was immersed at 25°C and evaluated for 30 minutes. ◎: No change in appearance such as blistering, cracking, or discoloration was observed in any of the tests in (1) to (3). ○: Slight change in appearance such as blistering, cracking, or discoloration was observed in any of the tests in (1) to (3), but this did not interfere with practical use. △: In any of the tests (1) to (3), there is a change in appearance such as swelling, cracking, discoloration, etc. ×: In any of the tests (1) to (3), there is a significant change in appearance such as swelling, cracking, discoloration, etc.

[0060] [Evaluation of foil burrs] When a laminate was produced using the transfer film, it was evaluated whether foil burrs were generated. ⊚: No foil burrs were generated. ◯: A slight amount of foil burrs were generated, but this did not cause any problems in practical use. ×: Foil burrs were generated.

[0061]

[0062]

[0063]

[0064]

[0065] As described above, the transfer film of the present invention can provide a laminate with little generation of foil burrs and good chemical resistance.

[0066] REFERENCE SIGNS LIST 1 plastic film 2 release layer 3 protective layer 4 intermediate layer 5 metal underlayer 6 metal thin film layer 7 adhesive layer 8 substrate 10 transfer layer 11 transfer film 12 laminate

Claims

1. A transfer film in which at least a functional layer and an adhesive layer are formed in that order on a plastic film, characterized in that at least the thickness of the functional layer that satisfies the following conditions a, b, and c is 3 μm or more and 8 μm or less. a) Consists of at least a polyol compound and a polyisocyanate compound; b) The hydroxyl value of the polyol compound is 20 mgKOH / g or more and 60 mgKOH / g or less; and c) The ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) is 0.5 or more and 3.0 or less.

2. The transfer film according to claim 1, wherein the functional layer comprises at least a protective layer and an intermediate layer.

3. The transfer film according to claim 1, wherein the functional layer comprises at least a protective layer, an intermediate layer, and a decorative layer.

4. The transfer film according to claim 3, wherein the decorative layer comprises at least one layer selected from the group consisting of a metal underlayer, a metal thin film layer, a colored layer, and a printed layer.

5. The transfer film according to claim 4, wherein the decorative layer comprises a metal underlayer and a metal thin film layer.

6. A laminate obtained by transferring the transfer film according to any one of claims 1 to 5 onto a substrate.

7. A laminate in which at least an adhesive layer and a functional layer are formed in this order on a substrate, characterized in that at least the thickness of the functional layer that satisfies the following conditions a, b, and c is 3 μm or more and 8 μm or less. a) Consists of at least a polyol compound and a polyisocyanate compound; b) The hydroxyl value of the polyol compound is 20 mgKOH / g or more and 60 mgKOH / g or less; and c) The ratio of the total number of isocyanate groups contained in the polyisocyanate compound to the total number of hydroxyl groups contained in the polyol compound ([NCO] / [OH] ratio) is 0.5 or more and 3.0 or less.

8. The laminate according to claim 7, wherein the functional layer comprises at least a protective layer and an intermediate layer.

9. The laminate according to claim 7, wherein the functional layer comprises at least a protective layer, an intermediate layer, and a decorative layer.

10. The laminate according to claim 9, wherein the decorative layer comprises at least one layer selected from the group consisting of a metal base layer, a metal thin film layer, a colored layer, and a printed layer.

11. The laminate according to claim 10, wherein the decorative layer comprises a metal base layer and a metal thin film layer.

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