Transfer film and molded body using said transfer film, and ultraviolet curable resin composition used therefor

Abstract

The present invention provides: a transfer film that does not require post-processing (top coating with a hard coating material, and ultraviolet irradiation) after the transfer process; a molded body which uses the transfer film; and an ultraviolet curable resin composition.　A transfer film according to the present invention is used for in-mold molding, and is characterized in that: the transfer film has a layer configuration in which at least a mold release layer, a hard coating layer, a primer layer, and an adhesive layer are sequentially formed in the stated order on a base material; the hard coating layer has a layer thickness of 3 μm or more; and the hard coating layer is obtained by completely curing an ultraviolet curable resin composition which contains at least a photopolymerization initiator and a urethane (meth)acrylate oligomer that has a weight average molecular weight (Mw) of 1,000 or more and a functionality of 3 or less.

Description

Transfer film, molded body using said transfer film, and ultraviolet-curable resin composition used therefor

[0001] The present invention relates to a transfer film that does not require post-processing such as topcoating of a hard coat paint or UV irradiation after transfer processing, a molded article using the transfer film, and an UV-curable resin composition used therein.

[0002] Conventionally, a widely used method involves using 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 substrate, and transferring the functional layer and adhesive layer (hereinafter these layers are collectively referred to as the transfer layer) formed on the release layer of the transfer film onto the surface of a resin molded article from above the release layer of the transfer film, thereby forming a transfer layer on the surface of the resin molded article and obtaining a molded article imparted with various surface properties such as metallic luster, design (e.g., pattern), hard coat properties, abrasion resistance, weather resistance, etc. The molded article is then used in various products such as home appliances, automobile parts, miscellaneous goods, paper containers, and labels.

[0003] For example, in order to obtain a molded article having surface properties such as hard coating properties, abrasion resistance, and weather resistance, a conventional transfer film having a hard coating layer formed by completely curing an ultraviolet-curable resin composition can be used to obtain a molded article having surface properties.

[0004] For example, as a conventional transfer film, Patent Document 1 below discloses a curable resin composition (ultraviolet-curable resin composition) that can give a cured product having excellent abrasion resistance, weather resistance, and chemical resistance, and a transfer film and a laminate (molded product) obtained using the same.

[0005] Conventional transfer films, such as the transfer film described in Patent Document 1, can be used without any practical problems when transferred to a resin molded product with a flat surface or minimal surface irregularities (when the elongation of the transfer film is less than 5%). However, when using the transfer film to transfer to a resin molded product with significant surface irregularities to obtain a molded product with a three-dimensional appearance (when the elongation of the transfer film is 5% or more but less than 30%), the transfer film used is required to have high elongation. If the transfer film does not have sufficient elongation, cracks may occur in the hard coat layer depending on the transfer processing conditions. Furthermore, cracks in the hard coat layer not only cause appearance defects, but also cause surface performance defects such as reduced hard coat properties, abrasion resistance, and weather resistance. Therefore, when using conventional transfer films, it has not been possible to reliably obtain a molded product without cracks in the hard coat layer, resulting in appearance defects and reduced surface performance defects. Furthermore, when transferring onto a resin molded product with particularly large surface irregularities (when the elongation of the transfer film is 30% or more), cracks always occur in the hard coat layer regardless of the transfer processing conditions, and therefore conventional transfer films having a hard coat layer formed by completely curing an ultraviolet-curable resin composition could not be used in practice.

[0006] To solve the above problems, a transfer film without a hard coat layer is first used to impart design, and then a decorative layer such as a colored layer, a printed layer, or a metal thin film layer is transferred onto the surface of a resin molded product. Then, in order to obtain the desired surface performance, a hard coat paint is further applied over the transfer film. However, in addition to the necessity of the above-mentioned overcoating process, there is a demand for a transfer film that does not require such overcoating process, from the viewpoint of reducing emissions of VOCs (volatile organic compounds).

[0007] Furthermore, instead of performing topcoating of the hard coat paint after transfer processing, when using a transfer film on which a hard coat layer using an ultraviolet curable resin composition is formed, in order to prevent cracks from occurring in the hard coat layer during transfer processing, a method may be adopted in which the ultraviolet curable resin composition used for the hard coat layer is not completely cured during the production of the transfer film, and ultraviolet irradiation processing is further performed after the transfer processing to completely cure the ultraviolet curable resin composition. However, even in this case, there is a problem in that the transfer film cannot be stably produced because it is necessary to further perform ultraviolet irradiation processing after the transfer processing and it is necessary to control the amount of ultraviolet irradiation during the production of the transfer film.

[0008] For these reasons, there has been a demand for a transfer film used to obtain a molded body that does not require post-processing (topcoating of hard coat paint, UV irradiation) after transfer processing, does not cause cracks in the hard coat layer, and does not cause defects in appearance or deterioration of surface performance.

[0009] JP 2012-011677 A

[0010] The present invention aims to solve all of the above problems and to provide a transfer film that does not require post-processing (topcoating of hard coat paint, UV irradiation) after transfer processing, that is reliably free from cracks in the hard coat layer, and that is free from defects in appearance and defects that reduce surface performance, as well as a molded product obtained using the same, and an UV-curable resin composition that constitutes the hard coat layer formed on the molded product.

[0011] As a result of extensive research, the present inventors discovered that by using a transfer film having a hard coat layer formed by fully curing a UV-curable resin composition having specific characteristics, post-processing (topcoating of hard coat paint, UV irradiation) after transfer processing is not required, and no cracks are generated in the hard coat layer, resulting in a molded product that is free from defects in appearance or degradation of surface performance, and thus completed the present invention. Specifically, by using the transfer film of the present invention, even when transferring to a resin molded product with large surface irregularities, post-processing (topcoating of hard coat paint, UV irradiation) after transfer processing is not required, and no cracks are generated in the hard coat layer, resulting in a molded product of the present invention that is free from defects in appearance or degradation of surface performance. Furthermore, even when transferring to a resin molded product with particularly large surface irregularities, by adjusting the transfer processing conditions, post-processing (topcoating of hard coat paint, UV irradiation) after transfer processing is not required, and no cracks are generated in the hard coat layer, resulting in a molded product of the present invention that is free from defects in appearance or degradation of surface performance.

[0012] The transfer film of the present invention is a transfer film having at least a release layer, a hard coat layer, a primer layer, and an adhesive layer formed in this order on a substrate, characterized in that the hard coat layer has a thickness of 3 μm or more, and the hard coat layer is a layer formed by completely curing an ultraviolet-curable resin composition containing at least a urethane (meth)acrylate oligomer having a weight-average molecular weight (Mw) of 1,000 or more and having no more than three functionalities, and a photopolymerization initiator.

[0013] The present invention is also characterized in that, in the transfer film having the above-mentioned characteristics, at least one layer selected from the group consisting of a colored layer, a printed layer, a metal base layer, and a metal thin film layer is formed between the primer layer and the adhesive layer.

[0014] Furthermore, the present invention is characterized in that in the transfer film having the above characteristics, the interlayer peel strength between the release layer and the hard coat layer is 0.001 N / mm or more and 0.008 N / mm or less.

[0015] The molded article of the present invention is a molded article in which an adhesive layer, a primer layer, and a hard coat layer are formed in this order on a resin molded article, and is characterized in that the hard coat layer has a thickness of 3 μm or more, and is a layer in which an ultraviolet-curable resin composition containing at least a urethane (meth)acrylate oligomer having a weight-average molecular weight (Mw) of 1,000 or more and a functionality of 3 or less, and a photopolymerization initiator is completely cured.

[0016] Furthermore, the present invention is characterized in that in the molded body having the above characteristics, at least one layer selected from the group consisting of a colored layer, a printed layer, a metal base layer, and a metal thin film layer is formed between the primer layer and the adhesive layer.

[0017] Furthermore, the ultraviolet-curable resin composition of the present invention is an ultraviolet-curable resin composition having the above-mentioned characteristics for forming a hard coat layer formed on a transfer film or a molded product, and is characterized in that the ultraviolet-curable resin composition contains at least a urethane (meth)acrylate oligomer having a weight-average molecular weight (Mw) of 1,000 or more and having no more than three functionalities, and a photopolymerization initiator.

[0018] By using the transfer film of the present invention, which has a hard coat layer formed on a release layer by fully curing a UV-curable resin composition having the above-mentioned specific characteristics, even when transferred to a resin molded product with a large surface unevenness, post-processing (topcoating of hard coat paint, UV irradiation) after transfer processing is not required, and cracks do not occur in the hard coat layer, resulting in a molded product of the present invention that is free from defects in appearance or degradation of surface performance. Furthermore, because the molded product of the present invention has the above-mentioned specific characteristics, not only does it have strong adhesion between the resin molded product and the transfer layer, but it also has strong adhesion between each layer of the transfer layer, including the hard coat layer, resulting in excellent hard coat properties and abrasion resistance. Furthermore, even when the transfer film of the present invention is used to transfer to a resin molded product with particularly large surface unevenness, by adjusting the transfer processing conditions, it is possible to obtain a molded product of the present invention that does not require post-processing (topcoating of hard coat paint, UV irradiation) after transfer processing and that does not cause cracks in the hard coat layer. Furthermore, the UV-curable resin composition of the present invention is optimal for forming a hard coat layer made of a UV-curable resin composition having the specific characteristics formed on the transfer film or molded product of the present invention.

[0019] 1 is a diagram showing an example of the layer structure of a transfer film according to one embodiment of the present invention, in which a release layer 2, a hard coat layer 3, a primer layer 4, and an adhesive layer 5 are sequentially formed on a substrate 1.

[0034] FIG. 1 is a diagram showing an example of the layer structure of a transfer film of the present invention, which has a layer structure in which, in addition to the layers shown in FIG. 1, a colored layer 6, a metal underlayer 7, and a metal thin film layer 8 are added between the primer layer 4 and the adhesive layer 5.

[0035] FIG. 1 is a diagram showing an example of the layer structure of a molded body of the present invention obtained using the transfer film of FIG. 1, in which an adhesive layer 5, a primer layer 4, and a hard coat layer 3 are formed in this order by transfer on the surface of a resin molded product 9.

[0036] FIG. 2 is a diagram showing an example of the layer structure of a molded body of the present invention obtained using the transfer film of FIG. 2, in which an adhesive layer 5, a metal thin film layer 8, a metal underlayer 7, a colored layer 6, a primer layer 4, and a hard coat layer 3 are formed in this order by transfer on the surface of a resin molded product 9.

[0020] The transfer film of the present invention that can solve the above-mentioned problems includes the following configurations, but may have configurations other than those below. A) Substrate 1 / release layer 2 / hard coat layer 3 / primer layer 4 / adhesive layer 5 B) Substrate 1 / release layer 2 / hard coat layer 3 / primer layer 4 / colored layer 6 / adhesive layer 5 C) Substrate 1 / release layer 2 / hard coat layer 3 / primer layer 4 / printed layer / adhesive layer 5 D) Substrate 1 / release layer 2 / hard coat layer 3 / primer layer 4 / colored layer 6 / metallic base layer 7 / metallic thin film layer 8 / adhesive layer 5 E) Substrate 1 / release layer 2 / hard coat layer 3 / primer layer 4 / printed layer / metallic base layer 7 / metallic thin film layer 8 / adhesive layer 5 F) Substrate 1 / release layer 2 / hard coat layer 3 / primer layer 4 / printed layer / colored layer 6 / metallic base layer 7 / metallic thin film layer 8 / adhesive layer 5 G) Substrate 1 / release layer 2 / hard coat layer 3 / primer layer 4 / anchor layer / colored layer 6 / metallic base layer 7 / metallic thin film layer 8 / vapor-deposited protective layer / adhesive layer 5 H) Substrate 1 / Release layer 2 / Hard coat layer 3 / Primer layer 4 / Interference prevention layer / Metal underlayer 7 / Metal thin film layer 8 / Vapor-deposited protective layer / Adhesive layer 5 Each layer constituting the transfer film of the present invention will be explained below.

[0021] (Substrate 1) The substrate 1 used in the transfer film of the present invention can be any material that can form a release layer or the like that constitutes the transfer film of the present invention when performing transfer processing using the transfer film of the present invention, and paper, plastic film, etc. can be selected as appropriate. However, it is preferable to use a plastic film because it is less likely to curl and less likely to cause creases during processing such as forming a release layer or the like on the substrate 1.

[0022] (Plastic Film) The plastic film used for the substrate 1 can be any plastic film generally used for transfer films, and various conventionally known plastic films such as polyethylene terephthalate film, polycarbonate film, polyethylene film, polypropylene film, and polyamide film can be used.

[0023] 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.

[0024] Furthermore, in order to make the transfer film of the present invention more decorative, the surface of the substrate 1 (the surface on which the release layer is formed) may be subjected to various processes such as hairline processing, matte processing, embossing, etc.

[0025] The thickness of the substrate 1 used in the transfer film of the present invention is not particularly limited, but is preferably 12 μm or more and 250 μm or less. Furthermore, when transferring to a resin molded product with particularly large surface irregularities, it is particularly preferable to set the thickness of the substrate 1 to 25 μm or more and 50 μm or less. A substrate 1 thickness of less than 12 μm is undesirable because it may be prone to curling when forming a release layer or the like on the substrate 1 or during the production of the transfer film of the present invention, as well as to the risk of creases occurring. A substrate 1 thickness of more than 250 μm is undesirable because it becomes too stiff, which may make it difficult to closely contact the surface of the mold used to produce the resin molded product when performing transfer processing using the transfer film of the present invention, or may make it difficult to follow the surface irregularities of a resin molded product with particularly large surface irregularities.

[0026] (Release layer 2) The release layer 2 in the present invention is a layer formed on the substrate 1 for the purpose of facilitating peeling of the transfer layer from the release layer 2 of the transfer film of the present invention when performing transfer processing using the transfer film of the present invention. Furthermore, the release layer 2 is not transferred or formed on the surface of the resin molded product during transfer processing, but is removed from the resin molded product together with the substrate 1.

[0027] The release layer 2 is a layer made of resin. The resin used for the release layer 2 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. One or a mixture of two or more of these resins may be used, and the resin may be appropriately selected depending on the purpose. Furthermore, by adjusting the interlayer peel strength between the release layer 2 and the hard coat layer 3, the occurrence of foil burrs (a phenomenon in which all or part of the transfer layer in the non-transferred portion near the transfer layer in the transfer portion peels off from the release layer while remaining connected to the transfer portion during transfer processing) can be suppressed. In particular, the hard coat layer 3 described below is a layer obtained by fully curing an ultraviolet-curable resin composition and is also extensible, and therefore is more susceptible to foil burrs and foil scattering (a phenomenon in which part of the transfer layer peels off and falls off from the release layer during the production of the transfer film) than a transfer film formed with a hard coat layer obtained by fully curing a conventional ultraviolet-curable resin composition. Therefore, in order to prevent foil burrs and foil scattering, it is necessary to increase the interlayer peel strength between the release layer 2 and the hard coat layer 3, but if it is made too strong, foil chipping (a phenomenon in which part or all of the transfer layer in the transfer portion does not peel off from the release layer during transfer processing and part or all of the transfer layer is chipped) is more likely to occur. For this reason, in order to suppress the occurrence of foil scattering, foil burrs, and foil chipping, it is preferable to adjust the interlayer peel strength between the release layer 2 and the hard coat layer 3 of the transfer film of the present invention to a range of 0.001 N / mm or more and 0.008 N / mm or less, and in order to further suppress the occurrence of foil scattering, foil burrs, and foil chipping, it is more preferable to adjust it to a range of 0.001 N / mm or more and 0.005 N / mm or less. Furthermore, the method for adjusting the interlayer peel strength can be selected from conventionally known methods as needed.

[0028] The thickness of the release layer 2 may be appropriately selected within a range that can achieve the above-mentioned purpose, and is preferably in the range of 0.5 μm to 5 μm. The method for forming the release layer 2 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.

[0029] (Hard Coat Layer 3) The hard coat layer 3 in the present invention is a layer formed by completely curing the ultraviolet-curable resin composition of the present invention, which contains at least a urethane (meth)acrylate oligomer having a weight-average molecular weight (Mw) of 1,000 or more and a functionality of 3 or less, and a photopolymerization initiator.

[0030] Therefore, the ultraviolet-curable resin composition of the present invention used in the hard coat layer 3 of the present invention will be described below. In this specification, "(meth)acrylate" refers to acrylate and / or methacrylate, "(meth)acryloyl group" refers to acryloyl group and / or methacryloyl group, and "(meth)acryloyloxy group" refers to acryloyloxy group and / or methacryloyloxy group. "Solid content" refers to the ultraviolet-curable resin composition excluding volatile components such as solvents, and indicates the components that constitute the hard coat layer when completely cured.

[0031] (UV-Curable Resin Composition) The UV-curable resin composition of the present invention is a layer composed of a cured product obtained by crosslinking and curing a resin composition containing a UV-curable acrylate and / or methacrylate (hereinafter referred to as (meth)acrylate). Such a (meth)acrylate contains a urethane (meth)acrylate oligomer (a1) having a weight-average molecular weight (Mw) of 1,000 or more and a functionality of 3 or less. Component (a1) is a compound having a urethane bond (—NHCOO—) and three or less (meth)acryloyl groups as functional groups in the molecule. This compound is, for example, a urethane reaction product of a polyisocyanate, a hydroxyl group-containing (meth)acrylate, and an optional polyol. In this reaction, an isocyanate group-containing urethane prepolymer may be synthesized from the polyisocyanate and the polyol, and then the hydroxyl group-containing (meth)acrylate may be added thereto. Also, instead of or together with the polyisocyanate, an isocyanate group-containing (meth)acrylate, such as 2-(meth)acryloyloxyethyl isocyanate, may be used. Furthermore, optionally, other copolymerizable (meth)acrylates, such as alkyl (meth)acrylates, such as methyl (meth)acrylate, may be used. Examples of polyisocyanates include aliphatic or alicyclic polyisocyanates, and specific examples include aliphatic diisocyanates such as hexamethylene diisocyanate and pentamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate, norbornane diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, 1,3-bis(isocyanatomethyl)-cyclohexane and dicyclohexylmethane-4,4'-diisocyanate; biuret, isocyanurate or allophanate forms of these compounds; and compounds in which a portion of the isocyanate groups of these compounds have been modified with alcohols such as trimethylolpropane, tricyclodecane dimethanol, 1,4-cyclohexane dimethanol, amides such as δ-lactams, imides such as phthalimide, carbodiimides, epoxides, etc.Examples of hydroxy group-containing (meth)acrylates include hydroxyalkyl group-containing monofunctional (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 1,4-cyclohexanedimethanol mono(meth)acrylate; hydroxy group-containing polyfunctional (meth)acrylates such as glycerin di(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate; and alkylene oxide- or caprolactone-modified versions of these. Examples of polyols include aliphatic or alicyclic polyols such as 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, glycerin, and hydrogenated bisphenol A.

[0032] The weight-average molecular weight of component (a1) measured by GPC is preferably 1,000 or more, more preferably 1,200 to 20,000, even more preferably 1,500 to 15,000, even more preferably 1,700 to 10,000, and particularly preferably 1,700 to 4,500. If the weight-average molecular weight of component (a1) is within the above-mentioned range, the hard coat layer 3 can easily be provided with the desired elongation, hard coat properties, and abrasion resistance. Specifically, if the weight-average molecular weight of component (a1) exceeds the above-mentioned range, the hard coat properties and abrasion resistance of the hard coat layer 3 may be reduced, which is undesirable. If it is below the above-mentioned range, the elongation of the hard coat layer 3 may be reduced, which is undesirable. The measurement conditions for the GPC method are described below. Apparatus: HLC-8120GPC manufactured by Tosoh Corporation Column: Super H2000+H4000 manufactured by Tosoh Corporation (inner diameter 6 mm, length 15 cm) Developing solvent: tetrahydrofuran (THF) Column thermostat temperature: 40°C Flow rate: 0.5 ml / min Reference: monodisperse polystyrene Detector: refractive index detector

[0033] The number of functional groups of the (meth)acryloyl group in component (a1) is 3 or less. If the number of functional groups exceeds 3, the hard coat properties of the resulting hard coat layer 3 are improved, but the desired elongation may not be obtained, which is not preferred. Also, if the number of functional groups in component (a1) is less than 2, the desired hard coat properties of the resulting hard coat layer 3 may not be obtained, which is not preferred. To ensure that the hard coat layer 3 has both the desired hard coat properties and elongation, it is preferable that component (a1) be trifunctional.

[0034] The content of component (a1) is preferably 50% by weight or more and 95% by weight or less, more preferably 55% by weight or more and 90% by weight or less, and even more preferably 57% by weight or more and 85% by weight or less, based on the solid content of the ultraviolet-curable resin composition. When the content of component (a1) is within the above range, the hard coat layer 3 can easily have the desired elongation, hard coat properties, and abrasion resistance.

[0035] The UV-curable (meth)acrylate contained in the UV-curable resin composition may contain a polyfunctional (meth)acrylate monomer (a2) other than the component (a1). The polyfunctional (meth)acrylate monomer refers to a compound having two or more (meth)acryloyl groups as functional groups in the molecule. Examples of such component (a2) include bifunctional (meth)acrylate monomers and trifunctional or higher polyfunctional (meth)acrylate monomers.

[0036] Examples of bifunctional (meth)acrylate monomers include alkylene glycol di(meth)acrylates such as ethylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, and neopentyl glycol di(meth)acrylate; diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, and the like. Polyoxyalkylene glycol di(meth)acrylates such as aluminum di(meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polytetramethylene glycol di(meth)acrylate; di(meth)acrylates of halogen-substituted alkylene glycols such as tetrafluoroethylene glycol di(meth)acrylate; trimethylolpropane di(meth)acrylate, ditrimethylolpropane di(meth)acrylate di(meth)acrylates of aliphatic polyols such as cyclopentadiene, pentaerythritol di(meth)acrylate; di(meth)acrylates of hydrogenated dicyclopentadiene or tricyclodecane dialkanol such as hydrogenated dicyclopentadienyl di(meth)acrylate and tricyclodecane dimethanol di(meth)acrylate; di(meth)acrylates of dioxane glycol or dioxane dialkanol such as 1,3-dioxane-2,5-diyl di(meth)acrylate [also known as dioxane glycol di(meth)acrylate]; bisphenol A Di(meth)acrylates of alkylene oxide adducts of bisphenol A or bisphenol F, such as ethylene oxide adduct diacrylates and bisphenol F ethylene oxide adduct diacrylates; epoxy di(meth)acrylates of bisphenol A or bisphenol F, such as acrylic acid adduct of bisphenol A diglycidyl ether and acrylic acid adduct of bisphenol F diglycidyl ether; silicone di(meth)acrylates; di(meth)acrylates of hydroxypivalic acid neopentyl glycol ester;Examples include 2,2-bis[4-(meth)acryloyloxyethoxyethoxyphenyl]propane, 2,2-bis[4-(meth)acryloyloxyethoxyethoxycyclohexyl]propane, 2-(2-hydroxy-1,1-dimethylethyl)-5-ethyl-5-hydroxymethyl-1,3-dioxane]di(meth)acrylate, tris(hydroxyethyl)isocyanurate di(meth)acrylate, etc. These may be used alone or in combination of two or more. Examples of the trifunctional or higher polyfunctional (meth)acrylate monomer include poly(meth)acrylates of trivalent or higher aliphatic polyols such as glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. These may be used alone or in combination of two or more. Among the above polyfunctional (meth)acrylate monomers, it is preferable to use pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc.;

[0037] The content of component (a2) is preferably 35 wt% or less, more preferably 25 wt% or less, and even more preferably 20 wt% or less, based on the solid content of the ultraviolet-curable resin composition. Furthermore, the ultraviolet-curable resin composition does not necessarily contain component (a2). By adding component (a2), the hard coat properties of the hard coat layer can be easily adjusted. If the content is within the above range, the desired hard coat properties can be easily obtained without significantly impairing the elongation of the hard coat layer 3.

[0038] The photopolymerization initiator (component (b)) for crosslinking and curing the (meth)acrylate is not particularly limited, and any conventionally known photopolymerization initiator for ultraviolet curing can be used, such as an acylphosphine oxide photopolymerization initiator, an alkylphenone photopolymerization initiator, a benzoyl formate polymerization initiator, a thioxanthone polymerization initiator, an oxime ester polymerization initiator, a benzophenone polymerization initiator, etc. Examples of the acylphosphine oxide photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide. Examples of alkylphenone photopolymerization initiators include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethyl-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 1-[4-(2-hydroxyethoxyl)-phenyl]-2-hydroxy-methylpropanone, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone, and 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone. Examples of benzoyl formate photopolymerization initiators include methyl benzoyl formate. Examples of thioxanthone-based photopolymerization initiators include isopropylthioxanthone. Examples of oxime ester-based photopolymerization initiators include 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime). Examples of benzophenone-based photopolymerization initiators include benzophenone, 4-chlorobenzophenone, and 4,4'-diaminobenzophenone.

[0039] The content of this photopolymerization initiator is preferably 0.1 wt % or more and 15.0 wt % or less, more preferably 0.5 wt % or more and 10.0 wt % or less, and even more preferably 1.0 wt % or more and 7.0 wt % or less, based on the solid content of the ultraviolet-curable resin composition. If the content of the photopolymerization initiator is within the above numerical range, the hard coat layer 3 can easily be provided with the desired hard coat properties and abrasion resistance.

[0040] The ultraviolet-curable resin composition may further contain an ultraviolet-absorbing compound to impart weather resistance. The ultraviolet-absorbing compound is not particularly limited, and conventionally known ultraviolet absorbers can be used. Examples of ultraviolet absorbers include benzotriazole-based ultraviolet absorbers, hydroxyphenyltriazine-based ultraviolet absorbers, and benzophenone-based ultraviolet absorbers. These ultraviolet absorbers may be used alone or in combination of two or more. Furthermore, a compound having a functional group polymerizable with the (meth)acryloyl group contained in component (a1) or component (a2) and a ultraviolet-absorbing skeleton may also be used. Examples of functional groups polymerizable with the (meth)acryloyl group contained in component (a1) or component (a2) include a (meth)acryloyl group, a (meth)acryloyloxy group, a vinyl group, and an allyl group. Examples of ultraviolet-absorbing skeletons include a benzotriazole skeleton, a benzophenone skeleton, an oxybenzophenone skeleton, a triazine skeleton, a phenyl salicylate skeleton, and a cyano(meth)acrylate skeleton. Such compounds may be oligomers or polymers. These compounds may be used alone or in combination of two or more. It is more preferable to use a compound having a functional group copolymerizable with component (a1) or component (a2) and an ultraviolet absorbing skeleton, because the ultraviolet absorbing compound is fixed in the hard coat layer, thereby suppressing bleeding out.

[0041] When an ultraviolet absorber is used as the ultraviolet absorbing compound, the content thereof is preferably 0.1 to 10% by weight, more preferably 0.5 to 7% by weight, based on the solid content of the ultraviolet curable resin composition.

[0042] Furthermore, when a compound having a functional group copolymerizable with component (a1) or component (a2) and having an ultraviolet absorbing skeleton is used as the ultraviolet absorbing compound, the upper limit of its content is preferably 40% by weight or less, more preferably 35% by weight or less, based on the solid content of the ultraviolet curable resin composition, and the lower limit of its content is preferably 10% by weight or more, more preferably 15% by weight or more, based on the ultraviolet curable resin composition. If the content of the ultraviolet absorbing compound is within the above numerical range, it is possible to obtain a cured coating film with good weather resistance without inhibiting the curability of the ultraviolet curable resin composition.

[0043] (Other Components) The ultraviolet-curable resin composition may contain components other than the above components, as long as the purpose of the present invention is not impaired. Examples of other components that can be used as needed include antistatic agents, polymerization inhibitors, matting agents, antifoaming agents, dispersants, anti-settling agents, leveling agents, water and oil repellents, heat stabilizers, light stabilizers, adhesion improvers, photosensitizers, antibacterial agents, antifungal agents, antiviral agents, silane coupling agents, anti-scratch agents, and thermoplastic components. The ultraviolet-curable resin composition of the present invention can be obtained by mixing and stirring the above components using a conventionally known device such as a mixer, disperser, or stirrer. Examples of such devices include a mixing / dispersion mill, a homodisper, a mortar mixer, a roll, a paint shaker, and a homogenizer.

[0044] The ultraviolet-curable resin composition can be diluted with a solvent as needed, for example, to adjust the viscosity to a level suitable for application. The solvent is not particularly limited as long as it dissolves the resin component in the ultraviolet-curable resin composition. Specific examples include aromatic hydrocarbons (e.g., toluene, xylene, and ethylbenzene), esters or ether esters (e.g., ethyl acetate, butyl acetate, and methoxybutyl acetate), ethers (e.g., diethyl ether, tetrahydrofuran, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and diethylene glycol monoethyl ether), ketones (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, di-n-butyl ketone, and cyclohexanone), alcohols (e.g., methanol, ethanol, n- or i-propanol, n-, i-, sec-, or t-butanol, 2-ethylhexyl alcohol, and benzyl alcohol), amides (e.g., dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc.), and sulfoxides (e.g., dimethyl sulfoxide). These solvents may be used alone or in combination of two or more.

[0045] As described above, the hard coat layer 3 in the present invention is a layer formed by fully curing the ultraviolet-curable resin composition of the present invention, which contains at least a urethane (meth)acrylate oligomer (a1) having a weight-average molecular weight (Mw) of 1,000 or more and a functional group of 3 or less, and a photopolymerization initiator (b). The lower limit of the thickness of the hard coat layer 3 in the present invention may be selected appropriately within a range that satisfies the above-mentioned characteristics, as long as it is 3 μm or more. If the thickness of the hard coat layer is less than 3 μm, the molded product may not exhibit the desired surface performance, such as hard coat properties, abrasion resistance, and weather resistance. The upper limit of the thickness of the hard coat layer may be selected appropriately, but from the viewpoint of suppressing the occurrence of foil burrs and foil scattering, it is preferably 15 μm or less, and more preferably 10 μm or less. The hard coat layer 3 can be formed by any conventional coating method, such as gravure coating, reverse coating, die coating, reverse gravure coating, or bar coating, and may be selected appropriately depending on the purpose. The curing method can be ultraviolet irradiation.

[0046] The hard coat layer 3 formed from the ultraviolet-curable resin composition of the present invention has extensibility even when the ultraviolet-curable resin composition is completely cured during the production stage of the transfer film, and even when transferred to a resin molded product with a large surface unevenness, the hard coat layer does not crack and has hard coat properties.

[0047] Furthermore, the ultraviolet-curable resin composition of the present invention has at least all of the properties of elongation, hard coating properties, abrasion resistance, and weather resistance. Therefore, the hard coating layer obtained by completely curing the ultraviolet-curable resin composition of the present invention, and the transfer film of the present invention having the hard coating layer formed thereon, also naturally have at least all of the properties of elongation, hard coating properties, abrasion resistance, and weather resistance.

[0048] In this specification, the ultraviolet-curable resin composition of the present invention and the hard coat layer obtained by completely curing the ultraviolet-curable resin composition have elongation, hard coat properties, abrasion resistance, and weather resistance, meaning that they each satisfy the following characteristics.

[0049] (Extensibility) A hard coat layer obtained by completely curing a 3 μm-thick ultraviolet-curable resin composition is formed on a 188 μm-thick polyethylene terephthalate film, and the film is punched out using a No. 1 dumbbell punch for tensile testing as specified in JIS K 6251 to prepare a test sample. The test sample is subjected to a tensile test using a universal testing machine, and the elongation at which the hard coat layer does not crack or fall off from the polyethylene terephthalate film is 30% or more. In this specification, the elongation refers to the ratio of the elongated length to the initial length of the coating film. For example, if a coating film is stretched from 100 mm to 130 mm, the elongation is 30 mm, so the elongation is 30%. (Hard Coating Properties) A ​​hard coat layer obtained by completely curing a 3 μm thick ultraviolet-curable resin composition is formed on a 100 μm thick polyethylene terephthalate film, and the surface hardness measured using the film in accordance with JIS K 5600-5-4 (Mechanical Properties of Coating Films - Scratch Hardness (Pencil Method)) is F or more. (Abrasion Resistance) A hard coat layer obtained by completely curing a 3 μm thick ultraviolet-curable resin composition is formed on a 1 mm thick ABS plate, and the film is used to test for abrasion resistance using a Taber abrasion tester specified in JIS K 7204 with an abrasion wheel "CS10" and a load of 4.9 N, and the number of abrasions until the exposed ABS plate is abraded is 1,000 or more times. (Weather resistance) A hard coat layer obtained by completely curing a 3 μm-thick ultraviolet-curable resin composition was formed on a 100 μm-thick polyethylene terephthalate film, and the film was irradiated with a cumulative dose of 500 MJ / m using a xenon arc lamp specified in JIS K 5600-7-8. ２ The difference ΔEab in color difference measured in accordance with JIS Z 8722 before and after irradiation is 3 or less.

[0050] The molded article of the present invention obtained using the transfer film of the present invention, which has a hard coat layer formed by completely curing the UV-curable resin composition of the present invention, naturally has hard coat properties, abrasion resistance, and weather resistance. Furthermore, no post-processing (topcoating of hard coat paint, UV irradiation) is required after the transfer process, and no cracks occur in the hard coat layer, resulting in no defects in appearance.

[0051] (Primer Layer 4) In the present invention, the primer layer 4 is a layer formed to ensure adhesion between the hard coat layer 3 and each layer formed thereon. The resin used to form the primer layer 4 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. One or more of these resins may be used alone or in combination, and the resin may be selected appropriately depending on the purpose. Furthermore, the primer layer 4 may contain one or more additives, such as antistatic agents, ultraviolet absorbers, heat stabilizers, and curing agents, as needed. The amounts of the various additives added may be selected appropriately depending on the purpose.

[0052] In the present invention, the thickness of the primer layer 4 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 μm to 5 μm. The method for forming the primer layer 4 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.

[0053] (Adhesive Layer 5) The adhesive layer 5 formed in 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 resins, or two or more of these may be copolymer resins, and the adhesive layer may be appropriately selected depending on the resin molded product to be used as the transfer target. Furthermore, using a resin that is compatible with the resin of the resin molded product is preferable because it also has good compatibility with the resin molded product.

[0054] The thickness of the adhesive layer 5 may be appropriately selected within a range that allows the above-mentioned purpose to be achieved, and is preferably in the range of 0.1 μm 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.

[0055] The transfer film of the present invention may have a layer structure formed of one or more of a colored layer 6, a metal base layer 7, and a metal thin film layer 8 made of a metal or metal compound, which are formed for the purpose of imparting design to a resin molded product, as shown in Figure 2, and a printed layer may be provided between the primer layer 4 and the colored layer 6 or the metal base layer 7.

[0056] (Colored Layer 6, Printed Layer) The colored layer 6 is a layer formed on the entire surface or a desired portion of the transfer film of the present invention by adding a pigment or dye to a resin. The printed layer is a layer formed on the transfer film of the present invention by adding a pigment or dye to a resin to form a desired pattern. The resin used for the colored layer 6 and the printed layer is not particularly limited as long as it can achieve the above-mentioned purpose. Conventional 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. One or more of these resins may be used, or a mixture of two or more of these resins may be used. The colored layer 6 and the printed layer may also contain one or more additives, such as antistatic agents, UV absorbers, heat stabilizers, and curing agents, as needed. The amounts of the various additives added may be selected appropriately depending on the purpose.

[0057] The thickness of the colored layer 6 and the printed layer may be any thickness that can achieve the desired effect of the colored layer 6 and the printed layer, and is preferably in the range of 0.1 μm to 5 μm, respectively, and may be appropriately selected depending on the purpose of forming the colored layer 6 and the printed layer. Furthermore, the colored layer 6 and the printed layer may be formed using any conventionally known coating method such as gravure coating, reverse coating, die coating, reverse gravure coating, bar coating, screen printing, offset printing, etc., and may be appropriately selected depending on the purpose.

[0058] (Metallic base layer 7) The metallic base layer 7 in the present invention is a layer formed for the purpose of improving adhesion between the metallic thin film layer 8 described later and the primer layer 4, colored layer 6, printed layer, anti-interference layer and anchor layer described later, etc. when forming the metallic thin film layer 8 described later on the transfer film of the present invention.

[0059] The resin used for the metal underlayer 7 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, and any one of these or a mixture of two or more of these resins may be used, and the resin may be selected appropriately depending on the purpose. Furthermore, the metal underlayer 7 may contain one or more additives such as an antistatic agent, an ultraviolet absorber, a heat stabilizer, and a curing agent, as necessary, and the amount of each additive added may be selected appropriately depending on the purpose.

[0060] The thickness of the metal underlayer 7 may be appropriately selected within a range that allows the above-mentioned purpose to be achieved, and is preferably in the range of 0.1 μm to 2 μm. The method for forming the metal underlayer 7 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.

[0061] (Metal thin film layer 8) The metal thin film layer 8 in the present invention is a layer formed mainly for the purpose of imparting metallic luster to the resin molded product, and is a layer that is transferred and formed on the surface of the resin molded product together with the adhesive layer when transfer processing is performed. Furthermore, by using a metal compound described below in the metal thin film layer, properties such as barrier properties and electrical conductivity may be imparted in addition to or instead of the metallic luster.

[0062] The metal used for the metal thin film layer 8 may be any of various conventionally known metals such as aluminum, chromium, tin, gold, silver, copper, zinc, silicon, nickel, indium, lead, zinc, bismuth, titanium, iron, cobalt, and germanium, or alloys thereof, 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 8 may be a single layer or a multi-layer structure of two or more layers. When the metal thin film layer 8 is a multi-layer structure of two or more layers, the metals used in each layer may be different or the same. Furthermore, it is preferable to use a discontinuous metal thin film layer having a so-called sea-island structure for the metal thin film layer 8, as this reduces cracking of the metal thin film layer 8 due to elongation during mold transfer and the resulting loss of design.

[0063] The discontinuous metal thin film layer having a sea-island structure is generally a metal thin film layer having a metallic luster, in which the island size is in the range of 1 nm to 2000 nm and the island spacing is in the range of 2 nm to 500 nm. In particular, the use of indium or tin as the metal makes it possible to easily obtain the discontinuous metal thin film layer having a sea-island structure, which is more preferable.

[0064] The thickness of the metal thin film layer 8 is preferably in the range of 10 nm to 200 nm. A thickness thinner than 10 nm is undesirable because it may not be possible to impart the desired metallic luster, etc. to the transfer film of the present invention. A thickness thicker than 200 nm is undesirable because the heat generated when forming the metal thin film layer or during transfer processing may cause the plastic film to deform or deteriorate, the metal thin film layer may not have a sea-island structure, or cracks may occur in the metal thin film layer during transfer processing, making it impossible to impart the desired metallic luster, etc. to the transfer film of the present invention. In the present invention, a vapor-deposited protective layer for protecting the metal thin film layer 8 may be formed on the metal thin film layer 8, and the material, formation method, thickness, etc. of the protective layer may be conventionally known depending on the purpose.

[0065] The metal thin film layer 8 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.

[0066] When imparting design to the transfer film of the present invention by forming the colored layer 6, printed layer, metal base layer 7, metal thin film layer 8, etc., the types of the colored layer 6, printed layer, metal base layer 7, and metal thin film layer 8 and the order in which they are formed may be selected appropriately depending on the purpose. The colored layer 6, printed layer, metal base layer 7, metal thin film layer 8, and adhesive layer 5 may be formed over the entire surface of the primer layer 4 or may be formed partially, and the positions at which they are formed may be selected appropriately depending on the purpose.

[0067] In addition to the layers mentioned above, the transfer film of the present invention may further include an anti-interference layer formed on the primer layer 4 to prevent the appearance of interference patterns in the hard coat layer, and an anchor layer to improve adhesion between the layers. The materials, formation methods, thicknesses, formation positions, etc. used for the anti-interference layer, anchor layer, etc. may be conventionally known depending on the purpose.

[0068] The molded body of the present invention is a resin molded product on which the above-mentioned layers are sequentially formed. The molded body of the present invention can be easily obtained by transferring the transfer layer formed on the transfer film of the present invention onto the resin molded product. The following are examples of the configurations of molded bodies of the present invention obtained using the transfer films A) to H) of the present invention exemplified above. The molded body of the present invention using the transfer film A) of the present invention corresponds to a), and the transfer films B) to H) of the present invention correspond to the molded products b) to h), respectively. The molded body of the present invention may have a configuration other than that exemplified below. a) Hard coat layer 3 / primer layer 4 / adhesive layer 5 / resin molded product 9 b) Hard coat layer 3 / primer layer 4 / colored layer 6 / adhesive layer 5 / resin molded product 9 c) Hard coat layer 3 / primer layer 4 / printed layer / adhesive layer 5 / resin molded product 9 d) Hard coat layer 3 / primer layer 4 / colored layer 6 / metal base layer 7 / metal thin film layer 8 / adhesive layer 5 / resin molded product 9 e) Hard coat layer 3 / primer layer 4 / printed layer / metal base layer 7 / metal thin film layer 8 / adhesive layer 5 / resin molded product 9 f) Hard coat layer 3 / primer layer 4 / printed layer / colored layer 6 / metal base layer 7 / metal thin film layer 8 / adhesive layer 5 / resin molded product 9 g) Hard coat layer 3 / primer layer 4 / anchor layer / colored layer 6 / metal base layer 7 / metal thin film layer 8 / vapor-deposited protective layer / adhesive layer 5 / resin molded product 9 h) Hard coat layer 3 / primer layer 4 / interference prevention layer / metal underlayer 7 / metal thin film layer 8 / vapor deposition protective layer / adhesive layer 5 / resin molded product 9

[0069] When the transfer film of the present invention is used to obtain the molded body of the present invention, a thermal transfer method can be used in which the adhesive layer of the transfer film is brought into close contact with the surface of the resin molded article and a transfer machine such as a roll transfer machine or an up-down transfer machine. However, the simultaneous molding and transfer method (in-mold molding method) described below, in which molding and transfer (decoration) to the surface of the molded article are performed simultaneously, is more suitable because it allows the molded body to be obtained at the same time as molding.

[0070] [Simultaneous molding transfer method (in-mold molding method)] In the simultaneous molding transfer method (in-mold molding method), first, an in-mold molding mold having a cavity of the desired shape and a transfer film are prepared, and the transfer film is placed inside the mold with the adhesive layer facing the resin molded product. Then, suction is applied, the mold is closed, and the transfer film is sandwiched inside the injection molding mold. After that, a thermoplastic resin is injected into the mold, and the transfer layer of the transfer film is transferred to the surface of the resin molded product by heat and pressure. After cooling, the molded product is removed from the mold, thereby obtaining a molded product with a transfer layer formed on the surface of the resin molded product.

[0071] Furthermore, since the molded body of the present invention has a hard coat layer formed thereon that has the above-mentioned weather resistance characteristics, the molded body can be used in applications where weather resistance is required, such as automobile exterior applications, but it can also naturally be used in applications where weather resistance is not required.

[0072] (Resin Molded Product 9) The resin constituting the resin molded product 9 may be a conventionally known resin, 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, depending on the desired purpose. The resin may also be a mixed resin of one or more of these resins, or a copolymer resin of two or more of these resins. These resins may be transparent or colored.

[0073] 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.

[0074] [Preparation of UV-Curable Resin Composition] [Example 1] 100 parts by weight of a urethane acrylate oligomer (EBECRYL 8701 manufactured by Daicel Allnex Corporation, 100% solids) having a weight average molecular weight of 2,000 and three functional groups as component (a1), 5 parts by weight of an alkylphenone-based polymerization initiator (Omnirad 184 manufactured by IGM Resin Systems, 100% solids) as photopolymerization initiator (b), and 100 parts by weight of Compound A (55% solids, containing butyl acetate) having an acryloyl reactive group as a UV-absorbing component and a benzotriazole skeleton as a UV-absorbing skeleton were mixed to prepare a UV-curable resin composition of Example 1. The content of each component relative to the solids content in this composition was 62.5 wt% for component (a1), 3.1 wt% for component (b), and 34.4 wt% for the UV-absorbing component.

[0075] [Example 2] 10 parts by weight of pentaerythritol tri / tetraacrylate (PETIA manufactured by Daicel Allnex Corporation, solids content 100%) as component (a2) was further added to the ultraviolet-curable resin composition of Example 1 to prepare an ultraviolet-curable resin composition of Example 2. The content of each component relative to the solids content in this composition was 58.8 wt% for component (a1), 5.9 wt% for component (a2), 2.9 wt% for component (b), and 32.4 wt% for the ultraviolet-absorbing component.

[0076] [Example 3] 20 parts by weight of pentaerythritol tri / tetraacrylate (PETIA manufactured by Daicel Allnex Corporation, solids content 100%) as component (a2) was further added to the ultraviolet-curable resin composition of Example 1 to prepare an ultraviolet-curable resin composition of Example 3. The content of each component relative to the solids content in this composition was 55.5 wt% for component (a1), 11.1 wt% for component (a2), 2.8 wt% for component (b), and 30.6 wt% for the ultraviolet-absorbing component.

[0077] Example 4 An ultraviolet-curable resin composition of the present invention for Example 4 was prepared in the same manner as in Example 1, except that a urethane acrylate resin having a weight average molecular weight of 5,000 and two functional groups (EBECRYL 230 manufactured by Daicel-Allnex Corporation, solids content 100%) was used instead of component (a1) used in Example 1, and 10 weight percent of pentaerythritol tri / tetraacrylate (PETIA manufactured by Daicel-Allnex Corporation, solids content 100%) was further added as component (a2). The content of each component relative to the solid content in this composition was 58.8 wt% for component (a1), 5.9 wt% for component (a2), 2.9 wt% for component (b), and 32.4 wt% for the ultraviolet-absorbing component.

[0078] Example 5 An ultraviolet-curable resin composition of the present invention in Example 5 was prepared in the same manner as in Example 1, except that 2 parts by weight of a hydroxyphenyltriazine ultraviolet absorber (Tinuvin 400 manufactured by BASF Japan, 85% solids, containing 1-methoxy-2-hydroxypropane) was added instead of the ultraviolet-absorbing component used in the ultraviolet-curable resin composition of the present invention in Example 1, and 20 parts by weight of pentaerythritol tri / tetraacrylate (PETIA manufactured by Daicel Allnex Corporation, 100% solids) was further added as component (a2). The content of each component relative to the solid content in this composition was 78.9 wt% for component (a1), 15.8 wt% for component (a2), 4.0 wt% for component (b), and 1.3 wt% for the ultraviolet absorber.

[0079] Comparative Example 1 An ultraviolet-curable resin composition of Comparative Example 1 was prepared by adding and mixing 20 parts by weight of pentaerythritol tri / tetraacrylate (PETIA manufactured by Daicel-Allnex Corporation, solids content 100%) as component (a2) to 100 parts by weight of a urethane acrylate oligomer having a weight-average molecular weight of 1,200 and 10 functional groups (KRM8452 manufactured by Daicel-Allnex Corporation, solids content 100%), 5 parts by weight of an alkylphenone-based polymerization initiator (Omnirad 184 manufactured by IGM ResinS, solids content 100%) as photopolymerization initiator (b), and 0.5 parts by weight of a hydroxyphenyltriazine-based ultraviolet absorber (Tinuvin 400 manufactured by BASF Japan, solids content 85%, containing 1-methoxy-2-hydroxypropane) as an ultraviolet-absorbing component. The content of each component relative to the solid content in this composition was 79.7% by weight for oligomer, 15.9% by weight for component (a2), 4.0% by weight for component (b), and 0.4% by weight for ultraviolet absorber.

[0080] [Comparative Example 2] An ultraviolet-curable resin composition of Comparative Example 2 was prepared in the same manner as in Comparative Example 1, except that 100 parts by weight of compound A (solid content 55%, containing butyl acetate) having an acryloyl group as the reactive group and a benzotriazole skeleton as the ultraviolet-absorbing skeleton was added as the ultraviolet-absorbing component instead of the ultraviolet-absorbing component used in the ultraviolet-curable resin composition of Comparative Example 1. The contents of each component relative to the solid content in this composition were 55.5% by weight for oligomer, 11.1% by weight for component (a2), 2.8% by weight for component (b), and 30.6% by weight for the ultraviolet-absorbing component.

[0081] The ultraviolet-curable resin compositions of Examples 1 to 5 of the present invention and the ultraviolet-curable resin compositions of Comparative Examples 1 and 2 were used as ultraviolet-curable resin paints prepared by adding methyl ethyl ketone as a dilution solvent to adjust the solid content to 50%, and the properties of the ultraviolet-curable resin compositions were evaluated and measured by the following methods.

[0082] [Elongation] A 188 μm thick polyethylene terephthalate film was coated with an ultraviolet-curable resin coating by the reverse coating method, and then completely cured by irradiating with ultraviolet light to form a 3 μm thick hard coat layer. The film was punched out using a dumbbell No. 1 for tensile testing in accordance with JIS K 6251, and two test samples were prepared. Then, the test samples were punched out using the dumbbell No. 1. The test samples were stretched using a universal testing machine to an elongation of 30%, and the occurrence of cracks in the hard coat layer or the occurrence of peeling off of the hard coat layer from the polyethylene terephthalate film was confirmed and evaluated. The evaluation results are shown in Table 1.

[0083] [Hard Coating Properties] A 100 μm thick polyethylene terephthalate film was coated with an ultraviolet-curable resin coating by the reverse coating method, and then completely cured by irradiating with ultraviolet light to form a 3 μm thick hard coat layer to prepare a test sample. The surface hardness of the test sample was then measured in accordance with JIS K 5600-5-4 (mechanical properties of coating film - scratch hardness (pencil method)). The measurement results are shown in Table 1.

[0084] A hard coat layer was formed on an ABS plate with a thickness of 1 mm by completely curing a 3 μm-thick ultraviolet-curable resin composition, and the abrasion resistance of the film was tested using a Taber abrasion tester specified in JIS K 7204 with an abrasion wheel "CS10" and a load of 4.9 N to measure the number of abrasion cycles until the ABS plate was exposed. The measurement results are shown in Table 1.

[0085] [Weather resistance] A test sample was prepared by coating a 100 μm thick polyethylene terephthalate film with an ultraviolet-curable resin coating by a reverse coating method, irradiating it with ultraviolet light to completely cure it, and forming a 3 μm thick hard coat layer. The test sample was then irradiated with a xenon arc lamp specified in JIS K 5600-7-8 at an accumulated irradiation dose of 500 MJ / m ２ The difference in color difference (ΔEab) was measured before and after the irradiation in accordance with JIS Z 8722. The measurement results are shown in Table 1.

[0086]

[0087] As shown in Table 1, all of the ultraviolet-curable resin compositions of the present invention used in Examples 1 to 5 did not cause cracks or peeling of the hard coat layer even when the test samples were stretched, and the surface hardness was F or more. In the abrasion resistance test, the number of abrasion cycles until the ABS plate was exposed was 1,000 or more, and the cumulative irradiation dose was 500 MJ / m. ２ The difference in color difference (ΔEab) before and after irradiation was 3 or less. Therefore, the ultraviolet-curable resin compositions of the present invention used in Examples 1 to 5 satisfied all of the above-mentioned characteristics of elongation, hard coat properties, abrasion resistance, and weather resistance, and were optimal as ultraviolet-curable resin compositions to be used in the hard coat layer of the transfer film of the present invention and the molded article of the present invention. In contrast, the ultraviolet-curable resin compositions used in Comparative Examples 1 and 2 all had a surface hardness of 2H, and in the abrasion resistance test, the number of abrasion cycles until the ABS plate was exposed was 1,500 or more, satisfying the above-mentioned characteristics of hard coat properties and abrasion resistance. However, when the test samples were stretched, cracks or peeling of the hard coat layer were observed in all cases, and the elongation characteristic was not satisfied. Furthermore, when the cumulative irradiation dose was 500 MJ / m ２ The difference in color difference (ΔEab) before and after irradiation was 8.0 for Comparative Example 1 and 2.5 for Comparative Example 2, and Comparative Example 1 did not satisfy the above-mentioned characteristic of weather resistance. From this, it was found that the ultraviolet-curable resin compositions used in Comparative Examples 1 and 2 did not satisfy all of the above-mentioned characteristics of elongation, hard coat properties, abrasion resistance, and weather resistance, and therefore were not suitable as ultraviolet-curable resin compositions to be used in the transfer film of the present invention and the hard coat layer of the molded product of the present invention.

[0088] [Preparation of Transfer Film] [Example 6] The transfer film of Example 6 was prepared by carrying out the following steps 1 to 7. (Step 1) A 38 μm thick polyethylene terephthalate film (Lumirror S105 manufactured by Toray Industries, Inc.) was coated by gravure coating with a mixed coating of two thermosetting resins (TM-REX JF-1 manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd. and TM-REX HF-1 manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) mixed at a weight ratio of JF-1:HF-1 = 50:50 to form a 1 μm thick release layer. (Step 2) A UV-curable resin coating prepared by adding methyl ethyl ketone as a dilution solvent to the UV-curable resin composition of the present invention of Example 1 to adjust the solids content to 50% was coated by reverse coating on the release layer, and the coating was completely cured by irradiating with UV light to form a 5 μm thick hard coat layer. (Step 3) A mixed paint containing 100 parts by weight of an acrylic polyol resin (TM-VMAC manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) and 6 parts by weight of an HDI polyisocyanate curing agent was coated onto the hard coat layer by microgravure coating to form a 1 μm thick primer layer. (Step 4) A mixed paint containing 100 parts by weight of a mixed resin of a urethane resin, a vinyl chloride resin, and a vinyl acetate resin copolymer resin, and 5 parts by weight of an HDI polyisocyanate curing agent with a black colorant added, was coated onto the primer layer by gravure coating to form a 1 μm thick colored layer. (Step 5) A mixed paint containing 100 parts by weight of a urethane resin (Olestar Q164 manufactured by Mitsui Chemicals, Inc.) and 10.8 parts by weight of an HDI polyisocyanate curing agent was coated onto the colored layer by gravure coating to form a 1 μm thick metal undercoat layer. (Step 6) Indium was formed on the metal underlayer by vacuum deposition to form a 50 nm thick discontinuous indium thin film layer (metal thin film layer) with a sea-island structure. (Step 7) A mixed resin of an acrylic resin and a copolymer resin of a vinyl chloride resin and a vinyl acetate resin was coated on the vapor-deposited protective layer by gravure coating to form an adhesive layer with a thickness of 1.5 μm.

[0089] [Examples 7 to 10] Transfer films of the present invention of Examples 7 to 10 were produced in the same manner as in Example 6, except that the ultraviolet-curable resin composition of Example 1 used in (Step 2) of Example 6 was replaced with the ultraviolet-curable resin composition of the present invention of Examples 2 to 5, respectively.

[0090] Example 11 A transfer film of the present invention of Example 11 was produced in the same manner as in Example 6, except that in (Step 1) of Example 6, two types of thermosetting resins (TM-REX JF-1 manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd. and TM-REX HF-1 manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) mixed with an acrylic resin and a melamine resin were used, and a mixed coating material was used in which the weight ratio of JF-1:HF-1 was 70:30.

[0091] [Example 12] A transfer film of Example 12 of the present invention was produced in the same manner as in Example 6, except that in (Step 1) of Example 6, two types of thermosetting resins (TM-REX JF-1 manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd. and TM-REX HF-1 manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) mixed with an acrylic resin and a melamine resin were used, and a mixed coating material was used in which the weight ratio of JF-1:HF-1 was 30:70.

[0092] Example 13 A transfer film of the present invention of Example 13 was produced in the same manner as in Example 6, except that in (Step 2) of Example 6, the thickness of the hard coat layer was set to 3 μm.

[0093] Example 14 A transfer film of the present invention of Example 14 was produced in the same manner as in Example 6, except that in (Step 2) of Example 6, the thickness of the hard coat layer was set to 10 μm.

[0094] [Example 15] A transfer film of Example 15 was produced in the same manner as in Example 6, except that in (Step 1) of Example 6, only a thermosetting resin (TM-REX JF-1 manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) mixed with an acrylic resin and a melamine resin was used.

[0095] [Example 16] A transfer film of Example 16 was produced in the same manner as in Example 6, except that in (Step 1) of Example 6, only a thermosetting resin (TM-REX HF-1 manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) mixed with an acrylic resin and a melamine resin was used.

[0096] Example 17 A transfer film of Example 17 was produced in the same manner as in Example 6, except that in (Step 2) of Example 6, the thickness of the hard coat layer was set to 15 μm.

[0097] [Comparative Examples 3 and 4] Transfer films of Comparative Examples 3 and 4 were produced in the same manner as in Example 6, except that the ultraviolet-curable resin composition of Example 1 used in (Step 2) of Example 6 was replaced with the ultraviolet-curable resin compositions of Comparative Examples 1 and 2, respectively.

[0098] Comparative Example 5 A transfer film of Comparative Example 5 was produced in the same manner as in Example 6, except that in (Step 2) of Example 6, the thickness of the hard coat layer was set to 2 μm.

[0099] [Preparation of Molded Articles] The transfer films of Examples 6 to 17 and Comparative Examples 3 to 5 obtained above were placed inside an in-mold mold having convex portions with elongation percentages of 20%, 30%, and 40% so that the adhesive layer of the transfer film faced the resin molded article. A mixed resin of polycarbonate resin and ABS resin was injected from the adhesive layer side using an injection molding machine to obtain molded articles. The mold temperature was 260°C, and the resin extrusion temperature was 70°C.

[0100] The properties of each molded article obtained using the transfer films of Examples 6 to 17 of the present invention and the transfer films of Comparative Examples 3 to 5 were evaluated according to the following criteria. [Moldability and Appearance Test] The 20% convex areas, 30% convex areas, and 40% convex areas of the molded article were visually and under a microscope to check for the presence or absence of cracks in the transfer layer. The evaluation results are shown in Table 2. ⊚: No cracks in the transfer layer at all. ◯: Slight cracks in the transfer layer (no problem in practical use). ×: Cracks in the transfer layer occurred over the entire convex area (unusable in practical use).

[0101] [Abrasion Resistance Test] The abrasion resistance of the hard coat layer surface (flat areas, not convex areas) of the molded article was tested using a Taber abrasion tester specified in JIS K 7204 with an abrasion wheel "CS10" and a load of 4.9 N. The evaluation results are shown in Table 2. ⊚: No exposed resin molded product even after 1500 abrasions. ◯: No exposed resin molded product after 1000 abrasions (no practical use problems). ×: Exposed resin molded product after less than 1000 abrasions (unusable for practical use).

[0102] [Weather resistance test] The molded body was subjected to a cumulative irradiation dose of 500 MJ / m using a xenon arc lamp specified in JIS K 5600-7-8. ２ The difference in color difference (ΔEab) measured in accordance with JIS Z 8722 was measured before and after irradiation. Measurements were taken on flat areas of each molded body, not convex areas. The measurement results are shown in Table 2. ⊚: The color difference after the accelerated weather resistance test of the molded body is ΔEab 2.5 or less. ◯: The color difference after the accelerated weather resistance test of the molded body is ΔEab more than 2.5 and 3.0 or less (no problem in practical use). ×: The color difference after the accelerated weather resistance test of the molded body is ΔEab more than 3.0 (unusable in practical use).

[0103] The properties of the transfer films of Examples 6 to 17 of the present invention and the transfer films of Comparative Examples 3 to 5 were measured and evaluated by the following methods.

[0104] [Interlayer Peel Strength] The transfer films of Examples 6 to 17 of the present invention and the transfer films of Comparative Examples 3 to 5 were cut to a width of 18 mm, and the interlayer peel strength between the release layer and the hard coat layer was measured at a peel rate of 1000 mm / min (180° peel). The measured interlayer peel strength was converted to N / mm. The measurement results are shown in Table 3.

[0105] [Evaluation of Peelability] Visually check for the presence or absence of foil chipping in the transfer layer and the presence or absence of foil burrs on the outer edge of the molded body. The evaluation results are shown in Table 3. ⊚: No foil chipping in the transfer layer and no foil burrs on the molded body. ◯: Either slight foil chipping of less than 1 mm has occurred in the transfer layer or slight foil burrs of less than 1 mm have occurred on the molded body (this does not interfere with practical use). ×: Either foil chipping of 1 mm or more has occurred in the transfer layer or foil burrs of 1 mm or more have occurred on the molded body.

[0106]

[0107] As shown in Table 2, the molded articles obtained using the transfer films of Examples 6 to 17 of the present invention were rated as either ◎ or ○ in the moldability / appearance test, abrasion resistance test, and weather resistance test, and all were suitable for practical use. In contrast, the molded articles obtained using the transfer films of Comparative Examples 3 to 5 were rated × in any of the moldability / appearance test, abrasion resistance test, and weather resistance test, and were therefore deemed unusable for practical use.

[0108]

[0109] As shown in Table 3, the transfer films of Examples 6 to 14 of the present invention all had an interlayer peel strength between the release layer and the hard coat, etc. of 0.001 N / mm or more and 0.005 N / mm or less, and the peelability evaluation was rated as ⊚ or ◯. In contrast, the transfer films of Examples 15 and 16 had an interlayer peel strength between the release layer and the hard coat, etc. of 0.0005 N / mm and 0.010 N / mm, respectively, and as shown in Table 2, they were rated ⊚ in all of the moldability / appearance test, abrasion resistance test, and weather resistance test, and were practically satisfactory. However, during the production of the transfer films of Examples 15 and 17, some foil scattering occurred, and in the case of the transfer film of Example 16, some foil chipping occurred.

[0110] REFERENCE SIGNS LIST 1 substrate 2 release layer 3 hard coat layer 4 primer layer 5 adhesive layer 6 colored layer 7 metal underlayer 8 metal thin film layer 9 resin molded product

Claims

1. A transfer film having at least a release layer, a hard coat layer, a primer layer, and an adhesive layer formed in that order on a substrate, wherein the hard coat layer has a thickness of 3 μm or more, and the hard coat layer is a layer of a completely cured ultraviolet-curable resin composition containing at least a urethane (meth)acrylate oligomer having a weight-average molecular weight (Mw) of 1,000 or more and a functionality of 3 or less, and a photopolymerization initiator.

2. The transfer film according to claim 1, characterized in that at least one of a colored layer, a printed layer, a metal base layer, and a metal thin film layer is formed between the primer layer and the adhesive layer.

3. The transfer film according to claim 1 or 2, characterized in that the interlayer peel strength between the release layer and the hard coat layer is 0.001 N / mm or more and 0.008 N / mm or less.

4. A molded product in which an adhesive layer, a primer layer, and a hard coat layer are formed in that order on a resin molded product, the hard coat layer having a thickness of 3 μm or more, and the hard coat layer being a layer of a completely cured ultraviolet-curable resin composition containing at least a urethane (meth)acrylate oligomer having a weight-average molecular weight (Mw) of 1,000 or more and a functionality of 3 or less, and a photopolymerization initiator.

5. The molded article according to claim 4, characterized in that at least one of a colored layer, a printed layer, a metal undercoat layer, and a metal thin film layer is formed between the primer layer and the adhesive layer.

6. An ultraviolet-curable resin composition for forming a hard coat layer formed on the transfer film according to claim 1 or 2, or on the molded article according to claim 4 or 5, characterized in that the ultraviolet-curable resin composition contains at least a urethane (meth)acrylate oligomer having a weight-average molecular weight (Mw) of 1,000 or more and a functionality of 3 or less, and a photopolymerization initiator.