Transfer foil

Abstract

The present invention provides a transfer foil that can suppress blocking, does not restrict the surface shape of the transfer layer, and can be manufactured using the same manufacturing process and equipment as conventional methods. [Solution] A base layer comprising a base film and a release layer, It comprises a hard coat layer and an adhesive layer, and a transfer layer laminated on the substrate layer, A transfer foil in which the release layer, the hard coat layer, and the adhesive layer are laminated in this order on one surface of the base film, A transfer foil in which the air leakage index between the outer transfer foil and the inner transfer foil that are in contact with each other when rolled up is 50 or less.

Description

Technical Field

[0001] The present invention relates to a transfer foil for transferring a transfer layer onto an object. Background Art

[0002] A transfer foil is obtained by laminating a transfer layer on a base material, and protects and decorates the surface of a transfer-receiving object, which is the target object, by transferring the transfer layer onto the surface of the transfer-receiving object via an adhesive layer. After being produced and before being used in a transfer step, this transfer foil is often transported and stored in a rolled state. In the rolled state, the transfer foil is stacked in multiple layers, so that the adhesive layer of the inner-wound transfer foil and the base material of the outer-wound transfer foil come into contact with each other. When stored for a long period of time with the adhesive layer and the base material kept in contact in this manner, the adhesive layer may unintentionally adhere to the base material, and when the transfer foil is unwound from the roll for use, a phenomenon called blocking may occur, in which part of the adhesive layer and decorative layer adhere to the base material.

[0003] As methods for suppressing blocking as much as possible, various measures have been devised, such as including particles in the adhesive layer (Patent Document 1), and further forming a release layer on the surface of the base material opposite to the side where the decorative layer and the adhesive layer are formed (the surface on which blocking occurs) (Patent Document 2). Prior Art Literature Patent Literature

[0004] Patent Document 1 Japanese Unexamined Patent Publication No. 2007-015205 Patent Document 2 Japanese Unexamined Patent Publication No. 2002-036793 Summary of the Invention Problems to be Solved by the Invention

[0005] However, our investigations have revealed that when a transfer foil is used in which the adhesive layer contains large particles with a particle size of 2 μm or more, as in Patent Document 1, when the transfer layer is transferred to the target object, the particles contained in the adhesive layer cause irregularities to form on the surface of the transfer layer. Therefore, it is unsuitable when a smooth surface is desired after transfer.

[0006] Furthermore, if a release layer is added to the surface where blocking of the substrate occurs, as in Patent Document 2, there is a problem that the manufacturing process of the transfer foil will be increased.

[0007] The present invention has been made in view of the above problems, and one of its objectives is to provide a transfer foil that can suppress blocking, does not restrict the surface shape, can be manufactured using the same manufacturing process and equipment as conventional methods, and furthermore, allows for smooth winding or unwinding when rolled (i.e., has good transportability). [Means for solving the problem]

[0008] In other words, the transfer foil according to the present invention is as follows. [1] A base layer comprising a base film and a release layer, It comprises a hard coat layer and an adhesive layer, and a transfer layer laminated on the substrate layer, A transfer foil in which the release layer, the hard coat layer, and the adhesive layer are laminated in this order on one surface of the base film, A transfer foil in which the air leakage index between the outer transfer foil and the inner transfer foil that are in contact with each other when rolled up is 50 or less. [2] The transfer foil according to [1], wherein the transfer layer comprises the hard coat layer, the decorative layer, and the adhesive layer in this order. [3] The transfer foil according to [1] or [2], wherein the base film forms one of the outer surfaces in the thickness direction of the transfer layer, and the arithmetic mean height (Sa) of the base film on the outer surface is 1 nm or more. [4] The transfer foil according to any one of [1] to [3], wherein the thickness of the base film is 1 μm or more and 100 μm or less. [5] The transfer foil according to any one of [1] to [4], wherein the stretching ratio of the hard coat layer is 120% or more. [6] The transfer foil according to any one of [1] to [5], wherein the stretching ratio of the release layer is 120% or more. [7] The transfer foil according to any one of [1] to [6], wherein the release layer comprises an acrylic melamine resin. [8] The transfer foil according to any one of [1] to [7], wherein the thickness of the release layer is 0.01 μm or more and 10 μm or less. [9] The transfer foil according to any one of the items [1] to [8], wherein the hard coat layer contains an ionizing radiation-curable resin.

[10] The transfer foil according to any one of [1] to [9], wherein the hard coat layer contains 50% by mass or more of a (meth)acrylate compound.

[11] The transfer foil according to any one of [1] to

[10] , wherein the hard coat layer is thermosetting.

[12] The transfer foil according to any one of [1] to

[11] , wherein the hard coat layer contains an acrylic copolymer having hydroxyl groups and an isocyanate curing agent.

[13] The transfer foil according to any one of [1] to

[12] , wherein the hard coat layer further contains an ultraviolet absorber.

[14] The transfer foil according to

[13] , wherein the ultraviolet absorber is a triazine-based ultraviolet absorber.

[15] The transfer foil according to any one of [1] to

[14] , wherein the thickness of the hard coat layer is 0.5 μm or more and 50 μm or less.

[16] The transfer foil according to any one of [1] to

[15] , wherein the light reflectance at 340 nm on the surface of the hard coat layer is 30% or less.

[17] The transfer foil according to any one of [1] to

[16] , wherein the light reflectance at 380 nm on the surface of the hard coat layer is 10% or more.

[18] The transfer foil according to [2], wherein the decorative layer is a thin metal film layer.

[19] The transfer foil according to

[18] , wherein the metal thin film layer comprises either indium or tin.

[20] The transfer foil according to

[18] or

[19] , wherein the thickness of the metal thin film layer is 0.0001 μm or more and 0.1 μm or less.

[21] The transfer foil according to [2], wherein the decorative layer is a colored layer.

[22] The transfer foil according to

[21] , wherein the thickness of the colored layer is 0.1 μm or more and 20 μm or less.

[23] The transfer foil according to any one of [1] to

[22] , wherein the adhesive layer comprises a polyester resin or a modified polyolefin.

[24] The transfer foil according to any one of [1] to

[23] , wherein the thickness of the adhesive layer is 0.1 μm or more and 20 μm or less.

[25] The transfer foil according to any one of [1] to

[24] , further comprising a top coat layer between the hard coat layer and the adhesive layer.

[26] The transfer foil according to

[25] , wherein the thickness of the top coat layer is 0.01 μm or more and 10 μm or less.

[27] A transfer foil according to any one of items [1] to

[26] , having a film width of 50 mm or more and a winding length of 50 m or more.

[28] The transfer foil described in

[27] , which is wound on a core with a diameter of 1 inch or more. A transfer foil as described in any one of items

[29] [1] to

[28] , which is wound on a core, and is used as an automotive transfer foil in the manufacture of automobile parts.

[30] A base layer comprising a base film and a release layer, It comprises a hard coat layer and an adhesive layer, and a transfer layer laminated on the substrate layer, A transfer foil in which the release layer, the hard coat layer, and the adhesive layer are laminated in this order on one surface of the base film, Using a transfer foil in which the air leakage index between the outer transfer foil and the inner transfer foil that are in contact with each other when rolled up is 50 or less, A transfer method comprising heating at a temperature of 100°C to 250°C using a hot stamping method, peeling off the substrate layer, and adhering the transfer layer to the object to be transferred.

[31] The transfer method according to

[30] , wherein the transfer layer comprises the hard coat layer, a decorative layer, and the adhesive layer in this order.

[32] The transfer method according to

[30] or

[31] , wherein the transfer-receiving body is made of one or more resins selected from the group consisting of polycarbonate resin, ABS resin, ASA resin and polypropylene resin.

[33] The transfer method according to any one of

[30] to

[32] , wherein a surface of the transfer-receiving body has a curved shape or an uneven shape.

[34] The transfer method according to any one of

[30] to

[33] , wherein the transfer-receiving body is an automotive component. Effects of the Invention

[0009] According to the transfer foil configured as described above, by setting the air leakage index between the base material and the adhesive layer in the rolled state within the aforementioned range, blocking of the transfer foil can be sufficiently suppressed without incorporating particles having a large particle diameter into the adhesive layer or providing an additional release layer as in conventional cases. Furthermore, with the transfer foil having the aforementioned configuration, it is only necessary to set the air leakage index between the base material and the adhesive layer in the rolled state within the aforementioned range. Therefore, the present invention can be applied not only to transfer foils that form a smooth surface, but also can be produced without requiring special production equipment or additional production steps. Brief Description of the Drawings

[0010] [Figure 1] A schematic diagram showing a cross-section of a transfer foil according to an embodiment of the present invention. [Figure 2] A schematic diagram showing a cross-section of a transfer foil according to an embodiment of the present invention during transfer. [Figure 3] A schematic diagram showing a cross-section of a transfer foil according to an embodiment of the present invention after transfer. [Figure 4] A schematic diagram showing a cross-section of a transfer foil according to another embodiment of the present invention. [Figure 5] A schematic diagram showing a cross-section of a transfer foil according to another embodiment of the present invention. [Figure 6] A schematic diagram showing a cross-section of a transfer foil according to another embodiment of the present invention. [Modes for carrying out the invention]

[0011] One embodiment of the present invention will be described below with reference to the drawings. In this specification, when "X~Y" (where X and Y are any numbers) is used, unless otherwise specified, it means "greater than or equal to X and less than or equal to Y," and also includes the meaning of "preferably greater than X" or "preferably less than Y." Similarly, when "greater than or equal to X" (where X is any number) or "less than or equal to Y" (where Y is any number) is used, it also includes the intention that "preferably greater than X" or "preferably less than Y." Furthermore, the terms "film" and "sheet" used in the following explanation are not clearly distinguished; the term "film" may include "sheet," and vice versa. In this specification, when the expression "(meth)acrylic" is used, "(meth)acrylic" means either or both "acrylic" and "methacrylic". Similarly, "(meth)acrylic acid" means either or both "acrylic acid" and "methacrylic acid", "(meth)acrylate" means either or both "acrylate" and "methacrylate", and "(meth)acryloyl" means either or both "acryloyl" and "methacryloyl". The same applies to other terms. In this specification, when the expression "mass %" is used, unless otherwise specified, it means "the content ratio of the components constituting each layer."

[0012] <Transfer foil> The transfer foil 100 according to this embodiment comprises, for example, a base layer 1 and a transfer layer 2 laminated on the base layer 1, as shown in Figure 1, and modifies the surface of the object to be transferred S by transferring the transfer layer 2 from the base layer 1 onto the object to be transferred S, as shown in Figures 2 and 3. The base layer 1 comprises, for example, a base film 11 that supports the transfer layer 2 and a release layer 12 for peeling the transfer layer 2 from the base film 11. The transfer layer 2 comprises, for example, a hard coat layer 21, a decorative layer 22, and an adhesive layer 23. As shown in Figures 1 and 2, the base material layer 1 and the transfer layer 2 are laminated on one surface of the base material film 11 in the order of the release layer 12, hard coat layer 21, decorative layer 22, and adhesive layer 23. The direction in which these layers are laminated, that is, the thickness direction of each layer, will be referred to as the lamination direction below. The following provides a detailed explanation of each layer.

[0013] [Base film] As mentioned above, the base film 11 is for supporting the transfer layer 2. As the transfer foil 100 according to this embodiment can also be used in a thermal transfer method, as will be described later, it is preferable that the base film 11 has heat resistance so that it does not melt even when heat used in a thermal transfer method (for example, heat of 100°C to 250°C) is applied for several seconds to several tens of seconds. Furthermore, it goes without saying that the transfer foil 100 according to this embodiment is applicable when transferring the transfer layer 2 onto a flat surface, but for example, if the surface shape of the object to be transferred S is three-dimensional with a curved or uneven shape, it is preferable that the transfer foil 100 can be deformed to conform to the surface shape of the object to be transferred S.

[0014] A resin film is an example of the base film 11. Examples of resin films include those formed by creating a film of polymers such as polyethylene, polypropylene, cycloolefin polymer (COP), polyester, polystyrene, acrylic resin, polycarbonate, polyurethane, triacetylcellulose (TAC), polyvinyl chloride, polyethersulfone, polyamide, polyimide, and polyamideimide. If film formation is possible, these materials may also be mixtures (polymer blends) or composites of constituent units (polymers).

[0015] Among the resin films exemplified above, polyester film is particularly preferred due to its excellent physical properties such as heat resistance, flatness, optical properties, and strength. The polyester film may be a single-layer or multi-layer structure, and may be a multi-layer structure of four or more layers, in addition to two or three layers, as long as it does not exceed the essence of the present invention; it is not particularly limited. Polyesters used in polyester films can be obtained by polycondensation of a dicarboxylic acid and a diol, and among these, those obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol are preferred. Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid. Examples of aliphatic glycols include ethylene glycol, diethylene glycol, trimethylene glycol, tetramethylene glycol, and neopentyl glycol. The aliphatic glycol may also be an alicyclic glycol such as 1,4-cyclohexanedimethanol.

[0016] Examples of typical polyesters include polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN), and polybutylene terephthalate. Such polyesters may be homopolymers that are not copolymerized. Alternatively, they may be copolymerized polyesters in which 30 mol% or less of the dicarboxylic acid component is a dicarboxylic acid component other than the main component, and / or 30 mol% or less of the diol component is a diol component other than the main component. For example, polyethylene terephthalate may be a copolymerized polyester in which, of 100 mol% of dicarboxylic acid units, approximately 30 mol% or less are dicarboxylic acid units other than terephthalic acid, and of 100 mol% of diol units, approximately 30 mol% or less are diol units other than ethylene glycol. Furthermore, the polyester may be a mixture of homopolymer and copolymer polyester.

[0017] The thickness of the base film 11 is not particularly limited, but for example, as described above, if the surface shape of the object to be transferred S is three-dimensional with a curved or uneven shape, it is preferable to set the thickness to a range of 1 μm to 100 μm, more preferably 5 μm to 50 μm, and even more preferably 10 μm to 25 μm, so that the transfer foil 100 can be deformed along the surface shape of the object to be transferred S.

[0018] The surface shape of the base film 11 in the lamination direction may be smooth or it may have irregularities. When the goal is to achieve a smooth surface shape after transfer (i.e., to make the shape of the outer surface 21a after transfer, which is the outer surface of the hard coat layer 21 after peeling off the base layer 1 as shown in Figures 2 and 3), it is preferable that the arithmetic mean height (Sa) of the surface of the base film 11 in the lamination direction be 1 nm or more and 50 nm or less, more preferably 2 nm or more and 30 nm or less, and even more preferably 5 nm or more and 15 nm or less. When the goal is to have an uneven surface shape after transfer (i.e., to have an uneven shape on the outer surface 21a after transfer), it is preferable to set the arithmetic mean height (Sa) of the base film 11 to 50 nm or more, more preferably to 100 nm or more, and even more preferably to 200 nm or more. The base film 11 may have the aforementioned arithmetic mean height (Sa) on both sides in the lamination direction, or it may have the aforementioned arithmetic mean height (Sa) on only one side in the lamination direction and the other side be smooth. In this embodiment, as shown in Figure 1, the base film 11 forms one of the outer surfaces of the transfer foil 100 before transfer in the lamination direction (also referred to as the pre-transfer base material side outer surface 11a). For example, when using a base film 11 with only one side having the aforementioned arithmetic mean height (Sa), it is preferable to arrange the base film so that the side having the aforementioned arithmetic mean height (Sa) forms the pre-transfer base material side outer surface 11a.

[0019] [Release layer] The release layer is a layer provided to smoothly peel the transfer layer from the substrate. The functions required of a release layer include surface properties for uniform formation of the transfer layer, durability to reduce damage from solvents and heat during transfer layer formation, appropriate adhesion so that it does not peel off during processing but peels off during transfer, and shape conformability (high-temperature stretchability) for application to transfer to three-dimensional shapes. The composition of the release layer is not particularly limited, and a wide range of conventional release layers used in transfer foils can be used. Preferably, the release layer has heat resistance that prevents it from fusing due to the high heat during transfer, similar to the substrate, and also allows for smooth peeling of the transfer layer so that no burrs are generated on the outer edge of the transfer layer during transfer.

[0020] There are no particular restrictions on the release agent used to form the release layer, and conventionally known release agents can be used. Examples include long-chain alkyl group-containing compounds, fluorine compounds, silicone compounds, melamine resin (a thermosetting resin obtained by polycondensation of a condensate of melamine and an aldehyde by heating), wax, and the like. Among these, long-chain alkyl group-containing compounds and silicone compounds are preferred because they have low contamination in terms of the transfer of the release agent to the surface of the hard coat layer after transfer, and have excellent water repellency. In particular, long-chain alkyl group-containing compounds are preferred because they have good release properties from the adhesive layer. These release agents may be used individually or in combination of multiple types.

[0021] {long-chain alkyl group-containing compounds} Long-chain alkyl group-containing compounds are compounds having a linear or branched alkyl group with typically 6 or more carbon atoms, preferably 8 or more, and more preferably 12 or more. The upper limit of the carbon number is not particularly limited, but for example, it is 30. Examples of alkyl groups include hexyl, octyl, decyl, lauryl, octadecyl, and behenyl groups. Examples of compounds containing alkyl groups include various long-chain alkyl group-containing polymer compounds, long-chain alkyl group-containing amine compounds, long-chain alkyl group-containing ether compounds, and long-chain alkyl group-containing quaternary ammonium salts. Considering heat resistance and stain resistance, long-chain alkyl group-containing polymer compounds (also referred to as "long-chain alkyl pendant polymers") are preferred. Furthermore, from the viewpoint of effectively obtaining mold release properties, polymer compounds having long-chain alkyl groups in their side chains are even more preferred.

[0022] Polymeric compounds having long-chain alkyl groups as side chains can be obtained by reacting a polymer having a reactive group with a compound having an alkyl group that can react with the reactive group. Examples of the reactive group include hydroxyl groups, amino groups, carboxyl groups, and acid anhydrides. Examples of compounds having these reactive groups include polyvinyl alcohol, polyethyleneimine, polyethyleneamine, reactive group-containing polyester resin, and reactive group-containing poly(meth)acrylic resin. Among these, polyvinyl alcohol is preferred considering its release properties and ease of handling.

[0023] Compounds having alkyl groups that can react with the above-mentioned reactive groups include, for example, long-chain alkyl group-containing isocyanates such as hexyl isocyanate, octyl isocyanate, decyl isocyanate, lauryl isocyanate, octadecyl isocyanate, and behenyl isocyanate; long-chain alkyl group-containing chlorides such as hexyl chloride, octyl chloride, decyl chloride, lauryl chloride, octadecyl chloride, and behenyl chloride; long-chain alkyl group-containing amines; and long-chain alkyl group-containing alcohols. Among these, long-chain alkyl group-containing isocyanates are preferred, and octadecyl isocyanate is particularly preferred, considering release properties and ease of handling.

[0024] The polymer compound having a long-chain alkyl group as a side chain may be a polymer of long-chain alkyl (meth)acrylate or an acrylic release agent having a long-chain alkyl group, such as a copolymer of long-chain alkyl (meth)acrylate and other vinyl group-containing monomers. Examples of long-chain alkyl (meth)acrylates include hexyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, octadecyl (meth)acrylate, and behenyl (meth)acrylate.

[0025] Acrylic mold release agents containing long-chain alkyl groups allow for adjustment of release strength and wettability by appropriately adjusting the type and amount of monomer, and are relatively suitable for the above-mentioned applications. However, when using acrylic mold release agents containing long-chain alkyl groups to achieve a moderate release strength, the number of carbon atoms in the alkyl group must be relatively large, and the crystallinity of the alkyl group may reduce the curability of the mold release agent. Therefore, when forming a release layer using acrylic mold release agents containing long-chain alkyl groups, it is preferable to use various crosslinking agents in combination to strengthen the release layer and stabilize properties such as water repellency.

[0026] (Crosslinking agent) When forming a release layer, conventionally known materials can be used as crosslinking agents in combination with acrylic release agents having long-chain alkyl groups. Examples include melamine compounds, epoxy compounds, oxazoline compounds, isocyanate compounds, carbodiimide compounds, silane coupling compounds, hydrazide compounds, and aziridine compounds. Among these, melamine compounds, epoxy compounds, isocyanate compounds, oxazoline compounds, carbodiimide compounds, and silane coupling compounds are preferred. Furthermore, from the viewpoint of maintaining appropriate water repellency and strengthening the release layer, melamine compounds, oxazoline compounds, and isocyanate compounds are preferred, with melamine compounds being particularly preferred. These crosslinking agents can be used individually or in combination of two or more.

[0027] (Melamine compound) Melamine compounds are compounds that have a melamine skeleton in their composition. For example, alkylolated melamine derivatives, compounds partially or completely etherified by reacting alkylolated melamine derivatives with alcohol, and mixtures thereof can be used. Suitable alcohols for etherification include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, and isobutanol. The melamine compound may be a monomer, a polymer of two or more, or a mixture thereof. Considering the reactivity with various compounds, it is preferable that the melamine compound contains a hydroxyl group. Furthermore, melamine can be used in which urea or other substances are co-condensed with a portion of the melamine, and catalysts can also be used to increase the reactivity of the melamine compound.

[0028] (Oxazoline compounds) Oxazoline compounds are compounds having an oxazoline group in their molecule, and polymers containing an oxazoline group are particularly preferred. These can be obtained by polymerization of an addition-polymerizable oxazoline group-containing monomer alone or with other monomers. Examples of addition-polymerizable oxazoline group-containing monomers include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline. One of these can be used alone, or two or more can be used in combination. Among these, 2-isopropenyl-2-oxazoline is preferred because it is readily available industrially.

[0029] (Isocyanate compounds) Isocyanate compounds are compounds that have an isocyanate derivative structure, such as isocyanates or blocked isocyanates. Examples of isocyanates include aromatic isocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylenediphenyl diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate; aliphatic isocyanates having an aromatic ring such as α,α,α',α'-tetramethylxylylene diisocyanate; aliphatic isocyanates such as methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, and hexamethylene diisocyanate; and alicyclic isocyanates such as cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylenebis(4-cyclohexyl isocyanate), and isopropylidene dicyclohexyl diisocyanate. Furthermore, polymers and derivatives of these isocyanates, such as biuretized, isocyanurateized, uretdioneized, and carbodiimide-modified compounds, can also be mentioned. These may be used individually or in combination of multiple types. Among the above isocyanates, aliphatic isocyanates or alicyclic isocyanates are more preferred than aromatic isocyanates in order to avoid yellowing due to ultraviolet light. When used in the form of blocked isocyanates, suitable blocking agents include active methylene compounds, mercaptan compounds, lactam compounds, amine compounds, acid amide compounds, and oxime compounds. These may be used individually or in combination of two or more. It is preferable that the isocyanate compound is blocked by an active methylene compound. Isocyanate compounds may be used alone, or as mixtures or binders with various polymers. To improve the dispersibility and crosslinking properties of isocyanate compounds, it is preferable to use mixtures or binders with polyester resins or urethane resins.

[0030] (Epoxy compound) Epoxy compounds are compounds that have an epoxy group in their molecule. Examples include condensates of epichlorohydrin with hydroxyl or amino groups of ethylene glycol, polyethylene glycol, glycerin, polyglycerin, bisphenol A, etc., and include polyepoxy compounds, diepoxy compounds, monoepoxy compounds, glycidylamine compounds, etc. Among these, polyether-based epoxy compounds are preferred from the standpoint of having good various properties. Furthermore, in terms of the amount of epoxy groups, polyfunctional polyepoxy compounds with three or more functions are preferred over those with only two functions.

[0031] (Carbodiimide compounds) Carbodiimide compounds are compounds that have one or more carbodiimide or carbodiimide derivative structures in their molecule. For better release layer strength and other reasons, polycarbodiimide compounds having two or more carbodiimide structures in their molecule are more preferable. Carbodiimide compounds can be synthesized using conventionally known techniques, and are generally synthesized by condensation reactions of diisocyanate compounds. The diisocyanate compound is not particularly limited, and both aromatic and aliphatic diisocyanates can be used. Specifically, examples include tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexanediyl diisocyanate, and dicyclohexylmethane diisocyanate. Furthermore, to the extent that the effects of the present invention are not impaired, surfactants or hydrophilic monomers such as polyalkylene oxides, quaternary ammonium salts of dialkylamino alcohols, and hydroxyalkyl sulfonates may be added to improve the water solubility and water dispersibility of the polycarbodiimide compounds.

[0032] (Silane coupling compounds) Silane coupling compounds are organosilicon compounds that have an organic functional group and a hydrolysis group such as an alkoxy group in a single molecule. Examples include epoxy group-containing compounds, vinyl group-containing compounds, styryl group-containing compounds, (meth)acrylic group-containing compounds, amino group-containing compounds, isocyanurate group-containing compounds, and mercapto group-containing compounds. Among the above compounds, epoxy group-containing silane coupling compounds, double bond-containing silane coupling compounds such as vinyl groups and (meth)acrylic groups, and amino group-containing silane coupling compounds are more preferred from the viewpoint of the strength of the release layer.

[0033] Furthermore, since these crosslinking agents are used in the drying and film-forming processes to react and improve the performance of the release layer, it can be inferred that unreacted crosslinking agents, reacted compounds, or mixtures thereof are present in the formed release layer.

[0034] {silicone compounds} Silicone compounds that can be used as mold release agents are compounds that have a silicone structure within their molecule. Examples include alkyl silicones such as dimethyl silicone and diethyl silicone, phenyl silicones having phenyl groups, and methylphenyl silicone. Silicone compounds having various functional groups in their silicone structure can also be used. Examples include silicone compounds having polyether groups, hydroxyl groups, amino groups, epoxy groups, carboxylic acid groups, halogen groups such as fluorine, perfluoroalkyl groups, hydrocarbon groups such as various alkyl groups and various aromatic groups in their silicone structure. Silicones having vinyl groups and hydrogen silicones in which hydrogen atoms are directly bonded to silicon atoms are also common, and it is possible to use addition-curing type silicones (hereinafter also called cured silicones) by using both in combination.

[0035] While there are no restrictions on the type of curable silicone resin used in this invention, from the viewpoint of excellent release properties such as easy peelability, the use of a curable silicone resin containing an alkenyl group is preferred in this invention. Examples of curable silicone resins containing an alkenyl group include diorganopolysiloxanes.

[0036] The release layer 12 is preferably a layer obtained by curing a silicone resin composition containing the above-mentioned curable silicone resin and a curing agent for curing the curable silicone resin. Examples of curing agents include polyorganosiloxanes containing SiH groups. Polyorganosiloxanes containing SiH groups can react with curable silicone resins containing alkenyl groups to form a stronger silicone release layer. As the SiH group-containing polyorganosiloxane, an organohydrogenpolysiloxane having at least two, preferably three or more, hydrogen atoms bonded to silicon atoms in one molecule can be used, and can be linear, branched, or cyclic. The release layer formed by the curable silicone resin preferably further contains a platinum-based catalyst that promotes addition reactions.

[0037] Among the release agents described above, the combination of long-chain alkyl (meth)acrylate and melamine compound (also called "acrylic melamine resin") is preferred because it allows for easy adjustment of the release properties, heat resistance, and high-temperature stretchability of the release layer 12. By increasing the long-chain alkyl (meth)acrylate component, release properties and high-temperature stretchability can be improved, and by increasing the melamine compound, heat resistance can be improved.

[0038] (Various polymers) The release layer may contain various polymers such as polyester resin, acrylic resin, urethane resin, and vinyl resin in addition to the aforementioned release agent, in order to improve the appearance and transparency of the coating, and to control water repellency and slipperiness. Among the various polymers, polyester resin, acrylic resin, urethane resin, and vinyl resin are preferred from the viewpoint of being easy to control water repellency, and it is more preferable to contain one or more of polyester resin and acrylic resin.

[0039] The thickness of the release layer is not particularly limited, but is preferably 0.01 μm or more and 10 μm or less, more preferably 0.1 μm or more and 5 μm or less, and even more preferably 0.5 μm or more and 1 μm or less. If you want to make the outer surface 21a smoother after transfer, it is preferable to increase the thickness of the release layer.

[0040] [Hard coat layer] The hard coat layer 21 is a layer that functions as a protective layer for the transferred object and the decorative layer after transfer. The functions required of the hard coat layer 21 include hardness and scratch resistance to protect the transfer target and decorative layer from scratches, chemical resistance to protect from chemicals, weather resistance to protect from light and temperature / humidity, appropriate adhesion so that it does not peel off during processing but peels off during transfer, shape conformability (high temperature stretchability) for application to transfer to three-dimensional shapes, transparency to improve the visibility of the transfer target and decorative layer, and a smooth or uneven surface shape depending on the application. The resin composition for forming the hard coat layer 21 is not particularly limited and can be appropriately selected depending on the application. For example, thermoplastic resins, curing resins such as thermosetting resins and ionizing radiation curing resins, or curing resins that combine thermosetting and ionizing radiation curing can be used. The content of the aforementioned thermoplastic resin and / or cured resin in the hard coat layer 21 is not particularly limited, but is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.

[0041] {thermoplastic resin} Examples of thermoplastic resins include polyester resin, acrylic resin, urethane resin, vinyl resin, polystyrene resin, and polycarbonate resin. Among these, acrylic resin, which has excellent hardness and transparency, is preferred.

[0042] {Ionizing radiation curable resin} As ionizing radiation-curable resins, resins that harden with electron beams or light are used, and a wide range of conventionally used resins can be applied, such as (meth)acrylate, polyester (meth)acrylate, urethane (meth)acrylate, epoxy (meth)acrylate, polyether (meth)acrylate, polyol (meth)acrylate, melamine (meth)acrylate, triazine-based acrylate, and mixtures of unsaturated ethylene monomers and unsaturated ethylene oligomers as appropriate.

[0043] Specific examples of (meth)acrylates include trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, tris-2-hydroxyethyl isocyanurate tri(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ditrimethylolpropane penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and ditrimethylolpropane hexa(meth)acrylate, which contain three ethylenically unsaturated groups. Examples include polyfunctional (meth)acrylates containing three or more functions; modified polyfunctional (meth)acrylate compounds in which some of these (meth)acrylates are replaced with alkyl groups or ε-caprolactone; polyfunctional (meth)acrylates having nitrogen atom-containing heterocyclic structures such as polyfunctional (meth)acrylates having an isocyanurate structure; polyfunctional (meth)acrylates having a highly branched resinous structure such as polyfunctional (meth)acrylates having a dendrimer structure or polyfunctional (meth)acrylates having a hyperbranched structure; urethane (meth)acrylates obtained by adding hydroxyl group-containing (meth)acrylates such as pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, or dipentaerythritol penta(meth)acrylate to polyisocyanates such as diisocyanates and triisocyanates, or trimers (isocyanurates) thereof. Furthermore, the (meth)acrylate having a hydroxyl group is preferably polyfunctional, having two or more ethylenically unsaturated groups. It is also preferable that the (meth)acrylate includes urethane (meth)acrylate.

[0044] Specifically, as (meth)acrylates, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate are preferred in terms of compatibility with (meth)acrylic polymers, and pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and dipentaerythritol penta( Preferred are meth)acrylate, urethane(meth)acrylate which is a reaction product of pentaerythritol tri(meth)acrylate and hexamethylene diisocyanate, urethane(meth)acrylate which is a reaction product of pentaerythritol tri(meth)acrylate and isophorone diisocyanate, urethane(meth)acrylate which is a reaction product of dipentaerythritol penta(meth)acrylate and hexamethylene diisocyanate, and urethane(meth)acrylate which is a reaction product of dipentaerythritol penta(meth)acrylate and isophorone diisocyanate. These may be used individually or in combination of two or more.

[0045] Among the above, polyfunctional (meth)acrylates with three to six functionalities, or urethane (meth)acrylates obtained by adding polyfunctional (meth)acrylates having hydroxyl groups (for example, three to five functionalities) to polyisocyanates are more preferred, and it is also more preferable to use the above-mentioned polyfunctional (meth)acrylates and urethane (meth)acrylates in combination. The mass-average molecular weight of the (meth)acrylate is, for example, 250 or more and 100,000 or less, more preferably 1,000 or more and 70,000 or less, even more preferably 5,000 or more and 50,000 or less, and even more preferably 10,000 or more and 30,000 or less. The (meth)acrylate content is 100% by mass of the entire hard coat layer 21. In this case, it is preferably 50% by mass or more, more preferably 60% by mass or more, and more preferably 70% by mass or more.

[0046] (Photoinitiator) To improve curability, if the ionizing radiation-curable resin is a photocurable resin, it is preferable to include a photoinitiator. The photoinitiator is a photopolymerization initiator, and known ones can be used. Examples of photopolymerization initiators include photoradical generators and photoacid generators. Some photoradical generators react to ultraviolet light or visible light, but those that react to ultraviolet light, which is less likely to interfere with the design of the decorative layer, are preferred. Furthermore, if the hard coat layer 21 contains an ultraviolet absorber as described later, it is preferable to use a photoradical generator that reacts at a wavelength that does not correspond to the absorption wavelength of the ultraviolet absorber.

[0047] {Thermosetting resin} Examples of thermosetting resins include unsaturated polyester resins, melamine resins, epoxy resins, and urethane resins. Among these, urethane resin is preferred, and acrylic urethane resin containing an acrylic copolymer having hydroxyl groups and an isocyanate-based curing agent (crosslinking agent) is more preferred.

[0048] (Acrylic copolymer containing hydroxyl groups) Acrylic copolymers containing hydroxyl groups that constitute thermosetting resins are obtained by copolymerizing monomers containing hydroxyl groups with other monomers that do not contain hydroxyl groups. In other words, acrylic copolymers are copolymers consisting of units derived from monomers containing hydroxyl groups and units derived from other monomers. Examples of monomers having a hydroxyl group include hydroxyalkyl (meth)acrylates and compounds obtained by adding ε-caprolactone to the hydroxyalkyl (meth)acrylate, with hydroxyalkyl (meth)acrylates being preferred.

[0049] Specific examples of hydroxyalkyl (meth)acrylates include hydroxyalkyl (meth)acrylates with 1 to 4 carbon atoms in the alkyl group, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Specific examples of compounds obtained by adding ε-caprolactone to hydroxyalkyl (meth)acrylate include ε-caprolactone adducts of hydroxyalkyl (meth)acrylates having 1 to 4 carbon atoms, such as 1 molar ε-caprolactone adduct of 2-hydroxyethyl (meth)acrylate, 2 molar ε-caprolactone adduct of 2-hydroxyethyl (meth)acrylate, 3 molar ε-caprolactone adduct of 2-hydroxyethyl (meth)acrylate, 1,1-dihydroxymethyl (meth)acrylate, 1,2-dihydroxyethyl (meth)acrylate, 2,2-dihydroxyethyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, and monomers obtained by reacting a (meth)acryloyl monomer having an epoxy group in one molecule with a compound having one functional group that can react with the epoxy group and a hydroxyl group in one molecule, or with water, and opening the epoxy group. However, the present invention is not limited to these examples. These hydroxyl group-containing monomers may be used individually or in combination.

[0050] Other acrylic monomers that do not have hydroxyl groups include various monomers such as alkyl (meth)acrylates, monomers having alicyclic hydrocarbon groups, monomers having epoxy groups, and monomers having ether groups.

[0051] Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isoamyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, tert-butylhexyl (meth)acrylate, and other alkyl (meth)acrylates, as well as 2-acetoacetoxyethyl (meth)acrylate and phenoxyethyl (meth)acrylate.

[0052] Examples of monomers having an alicyclic hydrocarbon group include cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, cyclododecyl (meth)acrylate, bornyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentanyl (meth)acrylate.

[0053] Examples of monomers having an epoxy group include glycidyl (meth)acrylate, α-methylglycidyl acrylate, α-methylglycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, and 3,4-epoxycyclohexylmethyl methacrylate.

[0054] Examples of monomers having an ether group include diethylene glycol monomethyl ether methacrylate.

[0055] The acrylic copolymer having a hydroxyl group is preferably obtained by polymerizing a methacrylate monomer from among the various monomers mentioned above.

[0056] Methods for polymerizing the aforementioned monomers to produce acrylic copolymers include, for example, solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization, but the present invention is not limited to such polymerization methods. Among these polymerization methods, solution polymerization is preferred because the resulting reaction mixture can be used as is.

[0057] Acrylic copolymers may have an acid value. Having an acid value promotes the reaction between the hydroxyl group and the isocyanate, thus enabling the production of a highly durable cured film. One method for imparting an acid value to an acrylic copolymer is by copolymerizing an acid-value monomer with another monomer. Examples of acid-value monomers include (meth)acrylic acid, maleic anhydride, 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl phthalic acid, and 2-(meth)acryloyloxyethyl acid phosphate, among which (meth)acrylic acid is preferred.

[0058] The mass-average molecular weight (Mw) of the acrylic copolymer is 10,000 to 1,000,000, preferably between 20,000 and 800,000. Generally, hard acrylic copolymers are brittle, and acrylic copolymers with good extensibility tend to have low strength. By setting the mass-average molecular weight to 10,000 or more, it is possible to achieve both moldability and surface hardness. By setting the mass-average molecular weight to 1,000,000 or less, the formation of gels can be prevented, and a hard coat layer 21 with good surface smoothness can be obtained.

[0059] The polydispersity (Mw / Mn) of acrylic copolymers is preferably 1 to 10. When comparing polymers with similar mass-average molecular weights, polymers with low polydispersity contain relatively fewer low-molecular-weight components, while polymers with high polydispersity contain relatively more low-molecular-weight components. Polymers may also contain molecules that do not directly participate in the curing reaction. Among the molecules that do not directly participate in the curing reaction, low-molecular-weight components act as plasticizers, and therefore the properties of the cured film change significantly depending on the polydispersity. In other words, a polydispersity of 1 or higher moderately reduces the crosslinking density of the cured coating film, improving its moldability. On the other hand, a polydispersity of 10 or lower moderately suppresses the plasticity of the cured coating film, maintaining its abrasion resistance. A polydispersity of 2 to 9 is more preferable, and even more preferable is 3 to 8. The content of acrylic copolymer in 100% by mass of acrylic urethane resin is preferably 50% by mass or more, more preferably 60% by mass or more, and more preferably 70% by mass or more.

[0060] (Crosslinking agent) For example, the materials described above in the section on release agents can be used as crosslinking agents. Among these, isocyanate compounds are preferred, and those having an isocyanurate structure are more preferred. Polyisocyanate isocyanurates are particularly preferred, and HDI trimers ([[(hexahydro-2,4,6-trioxo-1,3,5-triazine)-1,3,5-triyl]tris(hexamethylene)trisisocyanate) can be given as an example. The content of the crosslinking agent in the hard coat layer 21 is not particularly limited, but is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less.

[0061] (Additives) To further improve the resistance of the hard coat layer 21 to ultraviolet irradiation, the hard coat layer 21 may further contain ultraviolet absorbers and light stabilizers in addition to the components described above.

[0062] (UV absorber) Examples of UV absorbers include benzophenone-based, benzotriazole-based, triazine-based, and salicylate-based types. Among these, triazine-based types are preferred.

[0063] Examples of benzophenone-based UV absorbers include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2-hydroxy-4-n-octadecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, 2-hydroxy-5-chlorobenzophenone, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, and 2,2',4,4'-tetrahydroxybenzophenone.

[0064] Benzotriazole-based UV absorbers can be any UV absorber having a benzotriazole skeleton. Specifically, examples include hydroxyphenyl-substituted benzotriazole compounds such as 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-t-butylphenyl)benzotriazole, 2-(2-hydroxy-3,5-dimethylphenyl)benzotriazole, 2-(2-methyl-4-hydroxyphenyl)benzotriazole, 2-(2-hydroxy-3-methyl-5-t-butylphenyl)benzotriazole, 2-(2-hydroxy-3,5-di-t-amylphenyl)benzotriazole, and 2-(2-hydroxy-3,5-di-t-butylphenyl)benzotriazole.

[0065] Triazine-based UV absorbers can be any UV absorber having a triazine skeleton. Specifically, examples include hydroxyphenyltriazine compounds such as hydroxyphenyltriazine, 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl]-5-(octyloxy)phenol, and 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-(hexyloxy)phenol, as well as trisbiphenyltriazine.

[0066] Examples of salicylate ester-based UV absorbers include phenyl salicylate and p-octylphenyl salicylate. These UV absorbers may be used individually or in combination of two or more types.

[0067] Among these, triazine-based UV absorbers are preferred, and trisbiphenyltriazine is preferred, considering weather resistance and bleed-out during long-term use.

[0068] The amount of ultraviolet absorber in the hard coat layer 21 is not particularly limited as long as it can maintain its function as a hard coat layer 21, but for example, it is contained in the range of 0.1 to 10% by mass, preferably 0.5 to 8% by mass, and more preferably 1 to 5% by mass.

[0069] (Light stabilizer) A wide range of commercially available light stabilizers can be used, with hindered amines (HALS) being particularly preferred. Examples of hindered amines include those having a 2,2,6,6-tetramethylpiperidine structure, such as bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate. The amount of light stabilizer in the hard coat layer 21 is not particularly limited as long as it can maintain its function as a hard coat layer 21, but for example, it is contained in the range of 0.1 to 10% by mass, preferably 0.5 to 8% by mass, and more preferably 1 to 5% by mass.

[0070] The thickness of the hard coat layer 21 is not particularly limited, but is preferably 0.5 μm or more and 50 μm or less, more preferably 1 μm or more and 30 μm or less, and even more preferably 3 μm or more and 10 μm or less.

[0071] [Decorative layer] Although the decorative layer is not an essential component, in this embodiment, a decorative layer 22 is provided to decorate the surface of the transfer target S. The decorative layer 22 may be formed by selecting a material according to the desired decoration and using a forming method appropriate to the selected material. For example, the decorative layer may be a colored layer, a thin metal film layer, or the like.

[0072] (colored layer) If the decorative layer 22 is a colored layer, the material used for the colored layer may be appropriately selected from known inks. For example, it may be an ink prepared by adding a coloring agent such as a dye or pigment, an extender, to a vehicle, and then optionally adding a plasticizer, stabilizer, wax, grease, drying agent, hardening agent, thickener, dispersant, filler, etc., and then thoroughly diluting and stirring it with a solvent, diluent, etc., or it may be an ink containing a metallic pigment.

[0073] (metal thin film layer) If the decorative layer 22 is a thin metal layer, the material used for the thin metal layer may be appropriately selected from materials that have a glossy finish. For example, metals such as aluminum, tin, chromium, nickel, gold, platinum, silver, copper, indium, titanium, and zinc, as well as their oxides and alloys or compounds thereof, may be used as the thin metal layer for the metallic gloss layer or metallic-looking printed layer. Among these, tin and indium are preferred because they can give the transfer layer light transmittance and electromagnetic wave transmittance.

[0074] The decorative layer 22 may be a single layer or a multilayer structure. If the decorative layer is a multilayer structure, each layer forming the decorative layer may be of the same type or of different types.

[0075] When the decorative layer 22 is a colored layer, its thickness is preferably 0.1 μm or more and 20 μm or less, more preferably 1 μm or more and 15 μm or less, and even more preferably 3 μm or more and 10 μm or less. When the decorative layer 22 is a thin metal layer, its thickness is preferably 0.0001 μm or more and 0.1 μm or less, more preferably 0.001 μm or more and 0.05 μm or less, and even more preferably 0.005 μm or more and 0.03 μm or less. When the transfer foil 100 according to this embodiment is used, for example, for decorating parts of automobiles or electrical equipment, it is preferable that the decorative layer 22 is made of a material that has radio wave transparency.

[0076] [Adhesive layer] The adhesive layer 23 is a layer used to adhere the transfer layer 2 to the transfer target S. The resin used to form the adhesive layer 23 can be a wide range of resins that have been used in conventional transfer foils 100. For example, one or more resins selected from the group consisting of modified polyolefin resins, polyester resins, polyamide resins, vinyl resins, (meth)acrylic resins such as acrylic and methacrylic resins, acrylic ester resins, maleic acid resins, butyral resins, phenolic resins, melamine resins, cellulose resins, polyurethane resins, polyvinyl ether resins, silicone resins, and copolymers of chlorinated vinyl acetate can be used. Furthermore, the resin used in the adhesive layer can be used in combination with crosslinking agents such as melamine-based and isocyanate-based materials.

[0077] As for the resin that forms the adhesive layer 23, among those mentioned above, it is preferable that it does not discriminate against the material of the transfer object S, and has sufficient adhesion even to resins that are difficult to bond. In particular, when the transfer foil 100 according to this embodiment is used for decorating automobile exterior parts, etc., it is preferable that it has sufficient adhesion to the transfer target S, even if the transfer target S, such as automobile parts, is made of one or more difficult-to-bond resins such as polycarbonate (PC), acrylonitrile butadiene styrene (ABS), polypropylene (PP), and acrylonitrile styrene acrylate (ASA). Furthermore, it is preferable that it does not react with adjacent layers, such as the decorative layer 22.

[0078] When the decorative layer 22 is a thin metal film layer, it is preferable that the adhesive layer 23 is made of a material that does not release corrosive substances when heated. Among the resins mentioned above, polyester resins and modified polyolefin resins are particularly preferred to satisfy these properties.

[0079] The thickness of the adhesive layer 23 is not particularly limited, but is preferably 0.1 μm or more and 20 μm or less, more preferably 0.5 μm or more and 10 μm or less, and even more preferably 1 μm or more and 5 μm or less.

[0080] <Performance and effects of transfer foil> The transfer foil 100 according to this embodiment, as described above, can achieve the following performance and effects. [Transportability] The transfer foil 100 according to this embodiment is often manufactured as a long film-like transfer foil 100 for ease of manufacture, transported and stored in a roll, and unwound from the roll when in use. For example, in the case of transfer foil 100 used for applications such as decorating the surface of a mass-produced transfer target S on a factory production line, it may be manufactured as a transfer foil 100 with a film width of 1000 mm or more and a roll length of 2000 m or more. Such long transfer foil 100 is wound onto a large roll with a core of about 6 inches or 3 inches in diameter during manufacturing, but afterwards it may be wound onto a smaller core, for example, with a diameter of 1 inch, with a film width of 50 mm or more and a roll length of 50 m or more, for transport and storage. In this rolled state, the transfer foil 100 wound on the inside and the transfer foil 100 wound on the outside are stacked on top of each other in multiple layers. In this state, the base film 11 and adhesive layer 23 of adjacent transfer foils 100, one located on the inside of the roll and the other on the outside of the roll, come into contact with each other. This can cause the adhesive layer 23 to unintentionally adhere to the base film 11, and when the transfer foil 100 is unwound from the roll for use, a phenomenon called blocking may occur where the adhesive layer 23 and the decorative layer 22 partially adhere to the base film 11. For the winding or unwinding of the material in roll form to be smooth (i.e., good transportability), it is important to satisfy the blocking evaluation and sliding angle evaluation described later. To achieve this, the air leakage index must be 50 or less, preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less. The air leakage index must take into account a combination of factors, including the surface roughness of the base layer 1 and the adhesive layer 23, and the material of the adhesive layer. Here, surface roughness can be expressed as the arithmetic mean height (Sa). The arithmetic mean height (Sa) is a parameter that extends Ra (the arithmetic mean height of a line) to a surface, and represents the average of the absolute differences in height of each point relative to the average plane of the surface.

[0081] [Transferability] For the transfer layer 2 to be transferred to the transfer target S, the peeling force between the release layer 12 and the hard coat layer 21, and the adhesive force between the adhesive layer 23 and the transfer target S are important. If the balance between the peeling force and adhesive force is appropriate, only the necessary parts will be transferred according to the unevenness of the transfer target S and the shape of the plate material (good foil tearing). If the peeling force is too low, foil tearing will be poor, and if the peeling force is too high, the transfer layer 2 will not be able to be peeled off from the base layer 1. Also, if the adhesive force is too low, the transfer layer 2 will easily peel off from the transfer target S, resulting in insufficient adhesion. For transferability, it is important to adjust the tape peeling force of the release layer 12, and in particular, to adjust the high-temperature tape peeling force or residual adhesion rate so that it can withstand the high temperatures during heat transfer. Also, since the overall strength of the transfer layer 2 affects foil tearing, it is important to moderately reduce the strength by lowering the thickness or by including particles with a small particle size that do not affect air or the surface shape of the transfer layer after transfer.

[0082] [Shape following ability] To obtain parts with a three-dimensional surface shape, methods such as transferring a transfer layer 2 to a flat transfer target S (referred to as "planar transfer") and then three-dimensionally molding the transfer target S and the transfer layer 2 are used, or transferring a transfer layer 2 while following the surface shape of a transfer target S that already has a three-dimensional surface shape (referred to as "three-dimensional transfer"). When performing three-dimensional molding after planar transfer, it is preferable that the stretch ratio at 120°C (high-temperature stretchability) of each layer forming the transfer layer 2 be 120% or more (i.e., 1.2 or more if the original dimension is 1), more preferably 150% or more, even more preferably 200% or more, and particularly preferably 300% or more. When performing three-dimensional transfer, it is preferable that the stretch ratio at 120°C (high-temperature stretchability) of each layer forming the transfer foil 100 be 120% or more, more preferably 150% or more, and particularly preferably 300% or more. To obtain such properties, for example, one can select a resin used for the release layer and hard coat layer that has little or no crosslinking properties, or select a resin that is flexible. However, generally, a release layer made of such a resin has difficulty satisfying heat-resistant tape release properties, and generally, a hard coat layer made of such a resin has difficulty satisfying heat resistance and solvent resistance properties, so it is important to have appropriate crosslinking properties and flexibility. This shape conformability can be easily evaluated using the moldability evaluation device "MaykuFormbox". By selecting the shape of the three-dimensional form, different stretch ratios can be evaluated, preferably 120% or more, more preferably 150% or more, more preferably 200% or more, and especially preferably 300% or more, where no cracks occur when molding or three-dimensional transfer is performed after planar transfer. By satisfying the above range, it is possible to provide moldability that can accommodate complex three-dimensional shapes, such as those used for automotive interiors.

[0083] [Durability] After transferring the transfer layer 2 to the transfer target S, various durability properties such as scratch resistance, heat resistance, chemical resistance, and weather resistance are required depending on the usage environment. For example, if the object to be transferred S is a vehicle part or something that is used exposed outdoors, the transfer layer 2 transferred to the surface of the object to be transferred S must have weather resistance and heat resistance to withstand wind, rain, ultraviolet rays, and temperature changes outdoors for many years. If it is a part of furniture or home appliances used indoors, it must have scratch resistance and chemical resistance to withstand daily cleaning. These characteristics are largely due to the properties of the hard coat layer 21 that forms the outer surface of the transfer layer 2 after transfer (post-transfer outer surface 21a). Therefore, it is preferable to use a hard coat layer 21 with a composition that has high weather resistance and heat resistance. Here, in order to achieve high weather resistance, it is preferable that the light transmittance at a wavelength of 340 nm in the hard coat layer 21 be 10% or less, more preferably 5% or less, and more preferably 3% or less, in order to prevent exposure to ultraviolet rays. On the other hand, if the light transmittance of visible light is too low, it will appear yellow and affect the aesthetic appearance, so it is preferable that the light transmittance at a wavelength of 380 nm be 30% or more, more preferably 40% or more, and more preferably 50% or more. Furthermore, although the actual product after transfer to the transfer target S is affected by the brightness (reflectance) of the decorative layer, it is preferable that the light reflectance at a wavelength of 340 nm be 30% or less, more preferably 20% or less, and more preferably 10% or less. It is preferable that the light reflectance at a wavelength of 380 nm be 10% or more, more preferably 30% or more, and more preferably 50% or more. To obtain such properties, for example, an ultraviolet absorber can be included in the hard coat layer, or the thickness of the hard coat layer can be set to 2 μm or more.

[0084] <Manufacturing method> The transfer foil 100 according to this embodiment can be manufactured, for example, by laminating a release layer 12, a hard coat layer 21, a decorative layer 22, and an adhesive layer 23 in that order on the surface of the base film 11.

[0085] The release layer 12, the hard coat layer 21, and the adhesive layer 23 can be formed by preparing a coating solution in which the resin composition forming each of these layers is suspended or dissolved in a suitable solvent, and then applying and drying this coating solution. The methods for applying each of the aforementioned coating liquids are not particularly limited, but examples include brush application, spray coating, dip coating, spin coating, curtain coating, and coating methods using microgravure coaters, direct gravure coaters, die coaters, etc.

[0086] As mentioned above, there are various types of decorative layers 22, so they can be formed in the following ways depending on the type of decorative layer 22. For example, if the decorative layer 22 is a colored layer, the decorative layer 22 can be formed using a known printing method as appropriate, depending on the physical properties of the ink selected for the material used for the decorative layer 22. Specifically, for example, gravure printing, offset printing, intaglio printing, screen printing, flexographic printing, electrostatic printing, inkjet printing, etc., may be used as the printing method. When the decorative layer 22 is a thin metal film layer, the method for forming the decorative layer 22 may be appropriately selected from known thin film formation methods depending on the properties of the material having metallic luster selected according to the material used for the decorative layer 22. As the aforementioned method for forming the thin metal film layer, for example, vacuum deposition, sputtering, ion plating, plating, etc. may be used.

[0087] <Transfer method> As described above, the transfer foil 100 according to this embodiment modifies the surface of the object to be transferred S by transferring the transfer layer 2 from the base layer 1 to the object to be transferred S. The method of transferring the transfer layer 2 to the surface of the object to be transferred S is not particularly limited, but for example, a heat transfer method can be used in which the transfer foil 100 is pressed against the surface of the object to be transferred S using a hot stamping device equipped with a heated plate member.

[0088] Alternatively, the heat transfer may be performed using a roller-type transfer device in which the plate member is roll-shaped. An example of a roll-shaped plate member is a roll-shaped device in which the aforementioned heating plate is rotatably supported, and a plate foil is attached to its surface. When using such a roll-shaped plate member, the transfer layer 2 of the transfer foil 100 is transferred to the surface of the object to be transferred S by pressing the transfer foil 100 against the surface of the object to be transferred S using the heated roll-shaped plate member and rotating the plate member.

[0089] The material of the transfer target S is appropriately selected depending on the application, but examples include polycarbonate (PC), acrylonitrile butadiene styrene (ABS), polypropylene (PP), and acrylonitrile styrene acrylate (ASA).

[0090] The plate component can be modified as appropriate depending on the purpose and application; for example, it may consist of a heating plate and a plate foil attached to the heating plate. The plate foil forming the surface of the plate component that contacts the transfer foil can be made of a wide range of materials, such as rubber made of resin or metal.

[0091] The surface of the foil plate that comes into direct contact with the transfer foil 100 may have irregularities formed on it that correspond to the pattern to be transferred to the transfer body S by the transfer layer 2. If irregularities are formed on the surface of the foil plate, these irregularities may be formed by etching, engraving, or a combination of these processes.

[0092] The temperature of the printing plate is not particularly limited, but as an example, the temperature of the surface of the printing plate that is in contact with the transfer foil 100 (engraving temperature) can be 100°C to 250°C. By using a printing plate at such a temperature, when the printing plate is pressed against the transfer foil 100, the adhesive layer 23 of the transfer foil 100 is more easily melted, and the transfer layer 2 of the transfer foil 100 is more easily transferred to the surface of the object to be transferred S.

[0093] The pressure (pressing load) applied when pressing the plate material against the transfer foil 100 is not particularly limited, but as an example, the pressure applied during pressing can be 3 MPa to 10 MPa.

[0094] The time for which the transfer foil 100 is pressed against the surface of the object to be transferred S by the plate member is not particularly limited, but may be, for example, 0.1 seconds to 10 seconds.

[0095] When using roll-shaped printing plate components, the roll movement speed can also be changed as appropriate, for example, from 10 mm / second to 100 mm / second.

[0096] As described above, after pressing the plate member, a peeling step is performed to separate the base material layer 1 from the transfer layer 2. This peeling step may be performed, for example, when the plate member that was pressed against the transfer foil 100 is lifted up. In this peeling step, the base material layer 1 and the transfer layer 2 are separated between the release layer 12 of the base material layer 1 and the hard coat layer 21 of the transfer layer 2, as shown in Figure 2. As a result, the hard coat layer 21 forms the outermost surface (outer surface after transfer 21a), and the transfer of the transfer layer 2 to the surface of the object to be transferred S is completed.

[0097] <Application> The transfer foil 100 according to the present invention can be used for a variety of applications. The transfer foil 100 according to the present invention can also be made to exhibit high transfer performance by following a three-dimensional shape, so it can be used, for example, in applications where the surface of the transfer target S is three-dimensional, and of course it can also be used for applications where decorations, etc., are transferred to a flat transfer target S. Furthermore, since the transfer foil 100 according to the present invention can also exhibit high weather resistance, the transfer target S can be the interior of buildings and vehicles, furniture and home appliances used indoors, and also the exterior of buildings and vehicles used outdoors.

[0098] <Other Embodiments> However, the present invention is not limited to the embodiments described above. For example, as shown in Figure 4, the transfer layer 2 may comprise a hard coat layer 21 and an adhesive layer 23, but may not include a decorative layer.

[0099] The transfer layer 2 may also include other layers as appropriate, depending on the intended use and purpose, in addition to the layers mentioned above. For example, when a thin metal film is used as the decorative layer 22, a top coat layer 24 may be provided to encapsulate the thin metal film and protect it from chemical reactions such as oxidation, as shown in Figure 5. Alternatively, an anchor coat layer 25 may be provided to enhance the adhesion between the decorative layer and the hard coat layer, as shown in Figure 6.

[0100] Examples of resins used in the topcoat layer or anchor coat layer include unsaturated polyester resins, melamine resins, epoxy resins, urethane resins, and acrylic resins. They can also be used in combination with crosslinking agents such as melamine-based and isocyanate-based agents.

[0101] The thickness of the top coat layer 24 or anchor coat layer 25 is not particularly limited, but is preferably 0.01 μm or more and 10 μm or less, more preferably 0.1 μm or more and 5 μm or less, and even more preferably 0.5 μm or more and 1 μm or less.

[0102] In addition to the spirit of the present invention, inorganic particles or organic particles may be added to each of the aforementioned layers as other components for the purpose of improving foil tearing or weather resistance. Examples of inorganic particles include silica particles with a particle diameter of less than 2 μm, nanosilica particles, titanium oxide particles, and alumina particles with a particle diameter of less than 0.5 μm. Examples of organic particles include cross-linked acrylic particles, cross-linked polycarbonate particles, and cross-linked polystyrene particles with a particle diameter of less than 2 μm. The particle size of these inorganic or organic particles is not particularly limited, as long as it is small enough not to affect the surface shape of the transfer layer after transfer. Specifically, "small enough not to affect the surface shape of the transfer layer after transfer" means that when the aforementioned particles are added to an adhesive layer that does not form the outer surface of the transfer layer after transfer, the average particle size is 2 times or less the thickness of the adhesive layer, and when the aforementioned particles are added to a hard coat layer that forms the outer surface of the transfer layer after transfer, the average particle size is 5 times or less the thickness of the hard coat layer. Furthermore, various modifications and combinations of embodiments are permitted, as long as they do not contradict the spirit of the present invention. [Examples]

[0103] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0104] In this embodiment, the evaluation method described below was used. [Air Leakage Index] Ten pieces of transfer foil (sample) were prepared, each cut to a size of 70 mm square with a 5 mm diameter hole punched in the center. These were then laminated so that the base film 11 and the adhesive layer 23 faced each other and the outer surface 11a of the base material before transfer and the surface 23a of the adhesive layer were in contact. The air leakage index between the outer surface 11a of the base material before transfer and the surface 23a of the adhesive layer was measured. The air leakage index was measured using a Digibec smoothness tester (DB-2, manufactured by Toyo Seiki Co., Ltd.) under conditions of 23°C and 50% RH humidity. The pressurizing device pressure was set to 100 kPa, and a small 38 ml vacuum container was used. The time it took for 1 ml of air to flow, i.e., the time (in seconds) for the pressure inside the container to change from 50.7 kPa to 48.0 kPa, was measured. The resulting number of seconds was divided by 1000 to determine the air leakage index. If no pressure change was observed after one day of testing, measurement was deemed impossible.

[0105] [Arithmetic mean height (Sa)] Using the VertScan® R550GML non-contact surface and layer cross-sectional shape measurement system manufactured by Ryoka Systems Co., Ltd., a 640 μm × 480 μm area was measured using a SONY HR-50 1 / 3' CCD camera, 20x objective lens, 1X Body lens barrel, No Relay zoom lens, 530 white wavelength filter, and Wave measurement mode. The arithmetic mean height (Sa) was calculated using the output corrected by a fourth-order polynomial. Ten measurements were taken, and the average value was taken as the arithmetic mean height (Sa) of the film surface.

[0106] [blocking] Three 50mm square pieces of transfer foil (sample) were prepared. The base film 11 and adhesive layer 23 were stacked facing each other, with the outer surface 11a of the base material before transfer and the surface 23a of the adhesive layer in contact. A load of 50kgf was applied using a torque wrench, and the samples were left standing at a predetermined temperature for 17 hours. Afterwards, the removed samples were loosened by hand, and the blocking was evaluated according to the following criteria. ○: No blocking or slight snagging △: It makes a sound when peeled off, but leaves no residue. ×: Peels off but leaves a mark, or does not peel off.

[0107] [Slip angle] A transfer foil (sample) was cut to a size of 100 mm square and attached to a glass plate with the base film facing the outermost surface to serve as the base. After cutting the transfer foil (sample) to a size of 30 mm x 80 mm, it was attached to a 30 mm square, 50 g weight with the adhesive layer facing the outermost surface to serve as the sample. After placing the sample on the base so that the entire surface of the adhesive layer was in contact with it, one side of the base was gradually lifted by hand. When the sample began to slide, the hand was stopped, and the angle indicated by the base was measured using a protractor to determine the sliding angle, which was then evaluated according to the following criteria. If the sample fell without sliding, measurement was deemed impossible. ○: 0~25° △: 25~50° ×: 50° or more, or measurement impossible.

[0108] [High temperature stretchability] A sample of PET film with a 25 μm thickness, on which a release layer or hard coat layer was formed, was cut to a size of 10 mm x 150 mm, marked with a scale at 10 mm intervals, and left to stand for 1 minute on a hot plate set to 120°C. After that, both ends of the sample were supported with pliers and the film was gradually stretched by pulling. The surface of the release layer or hard coat layer was observed visually and with an optical microscope, and the distance between the gauge marks when cracks appeared was measured with calipers to determine the stretching ratio. <Stretch ratio = Dimensions after stretching / Dimensions before stretching × 100 (%)>

[0109] [Transferability to flat surfaces] A resin plate with a rectangular prism shape measuring 2 mm thick x 150 mm square, and recesses measuring 0.2 mm deep x 10 mm wide x 150 mm long formed on its surface at 30 mm intervals, was used as the transfer target. A transfer foil (sample) cut to a 150 mm square size was placed on top, and the transfer layer was transferred by heating it at a speed of 30 mm / second using a roll transfer type hot stamping machine (RT-150D manufactured by Navitas Co., Ltd.) set to a predetermined roll temperature. The obtained samples were evaluated as follows. <Foil Cutting> I checked the appearance after the transfer. 5: No transfer layer remains in the recessed areas. 3: Some of the transfer layer remains in the recessed areas. 1: The transfer layer remains on the entire surface. <Close-up> A 1mm x 25 grid was cross-cut onto the flat area where the transfer layer had been applied. Acrylic adhesive tape (Nichiban Co., Ltd.'s "Cellotape No. 405") was then applied and vigorously peeled off by hand, and the remaining grid lines were examined. 5:20~25 squares 3:10~20 squares 1:0~10 squares

[0110] [Moldability after flat transfer] A 0.5mm thick x 300mm square ABS resin sheet was used as the transfer substrate. A 150mm square transfer foil (sample) was placed in the center of the sheet, and the transfer layer was transferred using a roll transfer type hot stamping machine (RT-150D, manufactured by Navitas Co., Ltd.) at a roll temperature of 180°C and a speed of 30mm / second to obtain the sample. Next, using the moldability evaluation device "MaykuFormbox," we observed whether or not cracks occurred when the sample was heat-pressed for 1 minute on a plaster mold with a square base of 60 mm and a height of 30 mm, using the temperature dial at setting 6. 5: No cracks occur. 3: Some cracks may occur. 1: Cracks appear all over.

[0111] [3D transferability] A 0.5mm thick x 300mm square ABS resin sheet was used as the transfer target. Using the moldability evaluation device "MaykuFormbox," the sample was heat-pressed onto a 60mm square base x 30mm high square pyramidal plaster mold at temperature setting 6 for 1 minute. After temporarily adhering the transfer foil (sample), cut to a 300mm square size, to the moldable ABS resin sheet, the sample was heat-pressed onto the "MaykuFormbox" at temperature setting 3 for 1 minute to achieve temporary adhesion. Then, using an automatic iron (Toshiba "TA-404A"), each side of the material was pressed for 2 seconds at high temperature, and the presence or absence of cracks during three-dimensional transfer was observed. 5: No cracks occur. 3: Some cracks may occur. 1: Cracks appear all over.

[0112] [Water droplet contact angle] A sample of PET film with a release layer formed to a predetermined thickness was cut into 50mm squares, placed in a water droplet contact angle meter (DMe-211, manufactured by Kyowa Interface Science Co., Ltd.), and 1 μL of pure water was dropped onto the surface of the release layer. The angle after 1 second was defined as the water droplet contact angle.

[0113] [Tape removal] A sample was prepared by forming a release layer of a predetermined thickness on a PET film. Acrylic adhesive tape (Nitto Denko Corporation's "31B") was applied to the surface of the release layer, cut to a size of 50 mm x 300 mm, and then left to stand at 23°C and 50% RH for 20 hours. After that, the 180° peel force was measured using a tensile testing machine (Shimadzu Corporation's "EZ-SX") under conditions of a tensile speed of 300 mm / min.

[0114] [Heat-resistant tape release] A sample was prepared by forming a release layer of a predetermined thickness on a PET film. Acrylic adhesive tape (Nitto Denko Corporation's "31B") was applied to the surface of the release layer, cut to a size of 50 mm x 300 mm, and then treated at 100°C for 1 hour. After that, the 180° peel force was measured using a tensile testing machine (Shimadzu Corporation's "EZ graph") under conditions of a tensile speed of 300 mm / min.

[0115] [Residual adhesion rate] Acrylic adhesive tape ("31B" manufactured by Nitto Denko Corporation) was applied to the surface of the release layer of a PET film sample with a predetermined thickness, cut to a size of 50 mm x 300 mm, and then treated at 100°C for 1 hour. After cooling at room temperature for 1 hour, the 31B tape was peeled off, reattached to the PET film, and left to stand for another 1 hour. The 180° peel force measured using a tensile testing machine ("EZ graph" manufactured by Shimadzu Corporation) under conditions of a tensile speed of 300 mm / min was divided by the 180° peel force measured after the 31B tape had been attached to the PET film and left to stand for 1 hour to obtain the residual adhesion rate.

[0116] [Scratch resistance] As the transfer target, a 0.5mm thick x 150mm square ABS resin sheet was used as the transfer target, and a transfer foil (sample) cut to a 150mm square size was placed in the center. Using a roll transfer type hot stamping machine (RT-150D, manufactured by Navitas Co., Ltd.), the transfer layer was transferred by heating at a roll temperature of 180°C and a speed of 30mm / second to obtain the sample. Next, using a JSPS-type friction tester (RT-300, manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.), a cotton cloth (Kanakin No. 3) was fixed to the friction element, and the hard-coated surface was subjected to 100 back-and-forth passes at 200gf. The appearance was then visually inspected and evaluated according to the following criteria. 5: No visible damage 4: 1 to 5 scars are visible. 3: 5 to 30 scars are visible. 2: 30 to 100 scars are visible. 1: The entire surface appears white or the paint film disappears.

[0117] [Heat resistance] As the transfer substrate, a 0.5mm thick x 150mm square ABS resin sheet was used, with a transfer foil (sample) cut to a 150mm square size placed in the center. Using a roll transfer type hot stamping machine (Navitas Co., Ltd. "RT-150D"), the transfer layer was transferred by heating at a roll temperature of 180°C and a speed of 30mm / second to obtain the sample. Next, using a pencil scratch hardness tester (Yasuda Seiki Seisakusho Co., Ltd. "553-M"), a steel needle with a tip diameter of 0.7mm was fixed, and the hard coat surface was scratched once with 200gf in an 80°C atmosphere. The appearance after the scratch was visually inspected and evaluated according to the following criteria. 5: No visible damage 4: A faint scratch is visible. 3: The wound is clearly visible. 2: A severe wound is visible. 1: The coating disappears.

[0118] [Solvent resistance] A 0.5mm thick x 150mm square ABS resin sheet was used as the transfer substrate. A transfer foil (sample) cut to a 150mm square size was placed in the center of the sheet, and the transfer layer was transferred using a roll transfer type hot stamping machine (Navitas Co., Ltd. "RT-150D") by heating at a roll temperature of 180°C and a speed of 30mm / second to obtain the sample. Next, a gauze moistened with solvent was placed on the hard coat surface, and after being left to stand for a predetermined time with a PET film covering it to prevent solvent evaporation, it was wiped off, and then left to stand at 50°C for 1 hour before the obtained sample was evaluated. <Standing time> Gasoline: 1 minute Ethanol: 48 hours 10% hydrochloric acid aqueous solution: 48 hours 10% sodium hydroxide aqueous solution: 48 hours Neutrogena: 48 hours <Exterior> 5: No discoloration or cracks. 3: Discoloration and cracks are present. 1: The transfer layer has disappeared. <Close-up> A 1mm x 25 grid was cross-cut onto a flat surface, acrylic adhesive tape (Nichiban Co., Ltd.'s "Cellotape No. 405") was applied, and after forcefully peeling it off by hand, the remaining grid lines were examined. 5:20~25 squares 3:10~20 squares 1:0~10 squares

[0119] [Weather resistance] A 0.5mm thick x 150mm square ABS resin sheet was used as the transfer substrate. A transfer foil (sample) cut to a 150mm square size was placed in the center of the sheet, and the transfer layer was transferred using a roll transfer type hot stamping machine (Navitas Co., Ltd. "RT-150D") by heating at a roll temperature of 180°C and a speed of 30mm / second. Next, a weather resistance tester (Q-Lab Inc. "QUV") was used to measure the luminescence energy intensity of 3.0mW / cm². 2 The sample was subjected to UV irradiation at 60°C for 4 hours, followed by condensation (wetness) at 50°C for 4 hours, and this process was repeated until the specified time was reached. <Exterior> 5: No discoloration or cracks. 3: Discoloration and cracks are present. 1: The transfer layer has disappeared. <Close-up> A 1mm x 25 grid was cross-cut onto the flat area where the transfer layer had been applied. Acrylic adhesive tape (Nichiban Co., Ltd.'s "Cellotape No. 405") was then applied and vigorously peeled off by hand, and the remaining grid lines were examined. 5:20~25 squares 3:10~20 squares 1:0~10 squares

[0120] [Accelerated weather resistance] A 150mm square transfer foil (sample) was placed in the center of a 0.5mm thick x 150mm square black ABS resin sheet (manufactured by Okamoto Co., Ltd.). Using a roll transfer hot stamping machine ("RT-150D" manufactured by Navitas Co., Ltd.), the transfer layer was transferred by heating at a roll temperature of 180°C and a speed of 30mm / second to create the sample. The reference color was measured using a colorimeter ("CM-7600A" manufactured by Konica Minolta, Inc.). Subsequently, a metal weather resistance tester ("KW-R5TP" manufactured by Daipla Wintes Co., Ltd.) was used to measure the luminescence energy intensity of 90mW / cm². 2 The samples were then treated at 50°C and 50% RH for a specified period of time. <ΔE> The ΔE value was calculated by comparing the color to a reference color using a colorimeter (Konica Minolta, Inc. "CM-7600A"). <Exterior> 5: No discoloration or cracks. 4: There are light, spotted discolorations. 3: There are dark, spotted discolorations. 2: Discoloration is present throughout. 1: There is a crack.

[0121] [Spectral transmittance] A sample consisting of a 25 μm thick PET film with a hard coat layer was cut into 50 mm squares, and measurements were taken at 1 nm intervals from 300 to 800 nm using a UV-Vis-Near-Infrared spectrophotometer (JASCO Corporation "V770").

[0122] [Spectral reflectance] A 0.5 mm thick x 150 mm square ABS resin sheet was used as the transfer substrate. A 150 mm square transfer foil (sample) was placed in the center of the sheet and heated using a roll transfer type hot stamping machine (Navitas Co., Ltd. "RT-150D") at a roll temperature of 180°C and a speed of 30 mm / second to transfer the transfer layer and create the sample. The sample was then cut into 50 mm squares and measured at 1 nm intervals from 300 to 800 nm using a UV-Vis-Near-Infrared spectrophotometer (JASCO Corporation "V770"). The obtained values ​​were averaged within a predetermined wavelength range of ±5 nm.

[0123] In this embodiment, the following materials were used. [Base film] • Base material 1: PET film, manufactured by Mitsubishi Chemical Corporation, Diafoil E130 • Substrate 2: PET film, manufactured by Toray Industries, Inc., S105 • Base material 3: PET film, manufactured by Mitsubishi Chemical Corporation, Diafoil G521

[0124] [Release layer] • Release agent 1: As an acrylic melamine resin, a paint was used in which 10 parts by mass of "EX115D Medium" manufactured by Dainichi Seika Kogyo Co., Ltd. was mixed with 10 parts by mass of "PTC No. 7 hardener". After coating with a bar coater, it was dried at 180°C for 3 minutes. • Release agent 2: As an acrylic melamine resin, a paint was used in which 100 parts by mass of "FS9309N" manufactured by Nippon Chemical Paint Co., Ltd. was mixed with 8 parts by mass of "FS9309L" and 4 parts by mass of "FS hardener". After coating with a bar coater, it was dried at 180°C for 3 minutes. • Release agent 3: As a long-chain alkyl pendant polymer, "P-Royl 1050" manufactured by Lion Specialty Chemicals Co., Ltd. was applied using a bar coater and then dried at 160°C for 3 minutes. • Release 4: PET film with silicone release layer, manufactured by Mitsubishi Chemical Corporation, Diafoil MRV

[0125] [Hard coat layer] Hard coat 1: As the acrylic resin, a paint made by diluting "Dianaal BR80" manufactured by Mitsubishi Chemical Corporation with MEK was used, applied with a bar coater, and then dried at 80°C for 1 minute. • Hard coat 2: As the light-curing resin, "Diolet P5820TAH-1" manufactured by Daido Chemical Industries, Ltd. was used. After coating with a bar coater, it was dried at 80°C for 1 minute, and then treated with a high-pressure mercury lamp at an integrated light intensity of 200 mJ / cm². 2 Ultraviolet light was irradiated in such a manner. • Hard coat 3: As the light-curing resin, Sunopco Co., Ltd.'s "SHC-019L" was used. After coating with a bar coater, it was dried at 80°C for 1 minute, and then exposed to a high-pressure mercury lamp with an integrated light intensity of 200 mJ / cm². 2 Ultraviolet light was irradiated in such a manner. Hard Coat 4: A thermosetting resin containing hydroxyl groups, with a number average molecular weight of 8500 and a weight average molecular weight of 23000, was mixed with 100 parts by mass of HDI isocyanurate as a crosslinking agent. The mixture was dried at 120°C for 3 minutes, and then heat-treated at 50°C for 3 days to form a hard coat layer. Hard coat 5: A hard coat layer was formed in the same manner as hard coat 4, except that 1 part by mass of trisbiphenyltriazine was added as an ultraviolet absorber and 1 part by mass of hindered amine was added as a light stabilizer to 100 parts by mass of thermosetting resin.

[0126] [Decorative layer] • Decoration 1: As a coloring resin, a paint was used, which was formulated with 100 parts by mass of "ELAC144 Red" manufactured by Toyo Color Co., Ltd. and 8 parts of "Z202S hardener". After coating with a bar coater, it was dried at 80°C for 3 minutes. • Decoration 2: Aluminum was formed as a thin metal film by vacuum deposition. • Decoration 3: Indium was formed as a thin metallic film by vacuum deposition.

[0127] [Adhesive layer] • Adhesion 1: A coating was used in which 100 parts by mass of "Nichigo Polyester TP-235" manufactured by Mitsubishi Chemical Corporation was used as the polyester resin, and 0.2 parts by mass of "Coronate HX" manufactured by Tosoh Corporation was used as the crosslinking agent. After coating with a bar coater, it was dried at 120°C for 3 minutes. • Bonding 2: As the modified polyolefin resin, "Unistol H-100" manufactured by Mitsui Chemicals, Inc. was used and dried at 80°C for 3 minutes. • Bonding 3: As the urethane resin, "OW-5007-1" manufactured by Nippon Chemical Paint Co., Ltd. was used and dried at 100°C for 3 minutes.

[0128] [others] • Topcoat 1: A paint was used, which was formulated with 100 parts by mass of Toyobo Co., Ltd.'s "Byron 200" as the polyester resin and 6 parts by mass of Mitsui Chemicals, Inc.'s "Takenate D215" as the isocyanate curing agent. The paint was applied with a bar coater and then dried at 150°C for 1 minute.

[0129] First, test specimens with the compositions shown in Table 1 were prepared, and the following evaluations were performed on them. These test specimens consisted of a base film with a release layer, a hard coat layer, and an adhesive layer laminated in that order on one side. In each evaluation in Table 1, the presence or absence of a decorative layer did not affect the results.

[0130] [Table 1]

[0131] The results in Table 1 indicate that for test specimens with an air leakage index of 50 or less, sufficiently good results were achieved in both blocking suppression and sliding angle, resulting in a transfer foil with sufficiently high transportability. Furthermore, Table 1 shows that the air leakage index varies not only depending on the arithmetic mean height (Sa) of the base film and adhesive layer, but also on the material of the adhesive layer, etc.

[0132] Next, test specimens as shown in Table 2 were prepared, and the following evaluations were performed on them.

[0133] [Table 2]

[0134] The results in Table 2 confirm that various types of resins can be used as release layers. It was found that adjusting the tape release appropriately allows for both foil tearing and adhesion, which is desirable. Furthermore, it was found that using acrylic melamine resin with high heat-resistant tape release and residual adhesion is desirable because it can withstand transfer at high temperatures. Moreover, by selecting the resin for the adhesive layer, good adhesion can be obtained even with ASA resin and PP resin, which are difficult to adhere to, which is particularly desirable.

[0135] Furthermore, test specimens as shown in Table 3 were prepared, and the following evaluations were performed on them.

[0136] [Table 3]

[0137] The results in Table 3 show that using a resin that is easily stretchable at high temperatures for the hard coat layer results in excellent moldability after planar transfer. Furthermore, it was found that using a resin that is easily stretchable at high temperatures not only for the hard coat layer but also for the release layer results in very high transferability when the three-dimensional molded object is the transfer target. Regarding this three-dimensional moldability, it is preferable that the high-temperature stretchability of both the release layer and the hard coat layer be 120% or more, and it is particularly preferable that the high-temperature stretchability of the hard coat layer be 150% or more. As a resin for the hard coat layer that is easily stretchable at high temperatures, it was found that it is preferable to use a resin composition containing an acrylic copolymer having hydroxyl groups and an isocyanate-based curing agent. In addition, all test specimens achieved a sufficiently practical range of scratch resistance. In particular, scratch resistance could be further improved by using a photocurable resin or a thermosetting resin as the hard coat layer.

[0138] Furthermore, test specimens as shown in Table 4 were prepared, and the following evaluations were performed on them.

[0139] [Table 4]

[0140] The results in Table 4 show that by using a photocurable resin or thermosetting resin as the hard coat layer, solvent resistance at a level necessary for practical application was achieved. Furthermore, it is preferable to include a top coat layer combining polyester resin and a crosslinking agent, as this improves heat resistance.

[0141] Next, test specimens as shown in Table 5 were prepared, and the following evaluations were performed on them.

[0142] [Table 5]

[0143] The results in Table 5 show that weather resistance was improved when the hard coat layer contained a UV absorber and the reflectivity of the hard coat layer surface was appropriately adjusted, compared to when the hard coat layer did not contain a UV absorber. Therefore, it is preferable for the hard coat layer to contain a UV absorber in order to further improve weather resistance.

[0144] Furthermore, test specimens as shown in Table 6 were prepared, and the following evaluations were performed on them.

[0145] [Table 6]

[0146] The results in Table 6 show that, compared to experimental example 20 where no transfer was performed, the accelerated weathering resistance was significantly improved in experimental examples 21-24, in which the transfer foil according to the present invention was used. Furthermore, by evaluating the spectral transmittance while varying the thickness of the hard coat layer, it was confirmed that the desired spectral transmittance could be achieved and the surface of the object to be transferred could be sufficiently protected by adjusting the thickness of the hard coat layer. Therefore, it was confirmed that even when a hard coat layer is provided without a separate decorative layer, the necessary optical properties can be achieved by adjusting the thickness of the hard coat layer, and the surface of the object to be transferred can be sufficiently protected. [Explanation of symbols]

[0147] 100...transfer foil 1...Base material layer 11 ··Base film 12 ·Release layer 2 ···Transfer layer 21 ··Hard coat layer 22 ·· Decorative layer 23 ·Adhesive layer 24 ··Top coat layer 25 ··Anchor coat layer

Claims

1. A base layer comprising a base film and a release layer, It comprises a hard coat layer and an adhesive layer, and a transfer layer laminated on the substrate layer, A transfer foil in which the release layer, the hard coat layer, and the adhesive layer are laminated in this order on one surface of the base film, A transfer foil in which the air leakage index between an outer transfer foil and an inner transfer foil that are in contact with each other when rolled up is 50 or less.

2. The transfer foil according to claim 1, wherein the transfer layer comprises the hard coat layer, the decorative layer, and the adhesive layer in this order.

3. The transfer foil according to claim 1, wherein the base film forms one of the outer surfaces in the thickness direction of the transfer layer, and the arithmetic mean height (Sa) of the base film on the outer surface is 1 nm or more.

4. The transfer foil according to claim 1, wherein the thickness of the base film is 1 μm or more and 100 μm or less.

5. The transfer foil according to claim 1, wherein the stretching ratio of the hard coat layer is 120% or more.

6. The transfer foil according to claim 1, wherein the stretching ratio of the release layer is 120% or more.

7. The transfer foil according to claim 1, wherein the release layer contains acrylic melamine resin.

8. The transfer foil according to claim 1, wherein the thickness of the release layer is 0.01 μm or more and 10 μm or less.

9. The transfer foil according to claim 1, wherein the hard coat layer contains an ionizing radiation-curable resin.

10. The transfer foil according to claim 1, wherein the hard coat layer contains 50% by mass or more of a (meth)acrylate compound.

11. The transfer foil according to claim 1, wherein the hard coat layer is thermosetting.

12. The transfer foil according to claim 1, wherein the hard coat layer comprises an acrylic copolymer having hydroxyl groups and an isocyanate-based curing agent.

13. The transfer foil according to claim 1, wherein the hard coat layer further contains an ultraviolet absorber.

14. The transfer foil according to claim 13, wherein the ultraviolet absorber is triazine-based.

15. The transfer foil according to claim 1, wherein the thickness of the hard coat layer is 0.5 μm or more and 50 μm or less.

16. The transfer foil according to claim 1, wherein the light reflectance at 340 nm on the surface of the hard coat layer is 30% or less.

17. The transfer foil according to claim 1, wherein the light reflectance at 380 nm on the surface of the hard coat layer is 10% or more.

18. The transfer foil according to claim 2, wherein the decorative layer is a thin metal film layer.

19. The transfer foil according to claim 18, wherein the metal thin film layer comprises either indium or tin.

20. The transfer foil according to claim 19, wherein the thickness of the metal thin film layer is 0.0001 μm or more and 0.1 μm or less.

21. The transfer foil according to claim 2, wherein the decorative layer is a colored layer.

22. The transfer foil according to claim 21, wherein the thickness of the colored layer is 0.1 μm or more and 20 μm or less.

23. The transfer foil according to claim 1, wherein the adhesive layer comprises a polyester resin or a modified polyolefin.

24. The transfer foil according to claim 1, wherein the thickness of the adhesive layer is 0.1 μm or more and 20 μm or less.

25. The transfer foil according to claim 1, further comprising a top coat layer between the hard coat layer and the adhesive layer.

26. The transfer foil according to claim 25, wherein the thickness of the top coat layer is 0.01 μm or more and 10 μm or less.

27. The transfer foil according to claim 1, wherein the film width is 50 mm or more and the winding length is 50 m or more.

28. The transfer foil according to claim 27, which is wound on a core with a diameter of 1 inch or more.

29. A transfer foil according to any one of claims 1 to 28, which is wound on a core and is used in the manufacture of automobile parts.

30. A base layer comprising a base film and a release layer, It comprises a hard coat layer and an adhesive layer, and a transfer layer laminated on the substrate layer, A transfer foil in which the release layer, the hard coat layer, and the adhesive layer are laminated in this order on one surface of the base film, Using a transfer foil in which the air leakage index between the outer transfer foil and the inner transfer foil that are in contact with each other when rolled up, A transfer method comprising heating at a temperature of 100°C to 250°C by hot stamping, peeling off the substrate layer, and adhering the transfer layer to the object to be transferred.

31. The transfer method according to claim 30, wherein the transfer layer comprises the hard coat layer, the decorative layer, and the adhesive layer in this order.

32. The transfer method according to claim 30, wherein the object to be transferred is made of one or more resins selected from the group consisting of polycarbonate resin, ABS resin, ASA resin, and polypropylene resin.

33. The transfer method according to claim 30, wherein the surface of the object to be transferred has a curved or uneven shape.

34. The transfer method according to claim 30, wherein the object to be transferred is an automobile part.

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