Method for transferring a curable resin layer, vehicle parts, and vehicle

Abstract

The present invention provides a simple method for transferring a curable resin layer that eliminates the need for a trimming process, as well as vehicle parts and vehicles having a coating formed by this transfer method. [Solution] A method for transferring a curable resin layer 21 made of a curable resin composition to a transfer area 11 of an adherend 10, comprising: a first step of attaching a laminated sheet 20, in which a transfer layer 22 and a curable resin layer are laminated, to an adherend by vacuum forming or vacuum pressure forming, such that the curable resin layer is in contact with the adherend and the laminated sheet extends beyond the transfer area of ​​the adherend 10; a second step of curing the surface of the curable resin layer that is in contact with the adherend and the surface of the curable resin layer that is in contact with the transfer layer; and a third step of holding the portion of the laminated sheet that extends beyond the transfer area, peeling the transfer layer from the curable resin layer that has been adhered to the adherend, and removing the extended portion of the curable resin layer together with the transfer layer.

Description

Technical Field

[0001] The present invention relates to a transfer method for a curable resin layer, as well as a vehicle component and a vehicle coated by the transfer method for the curable resin layer.

Background Art

[0002] For molded articles obtained from various materials such as plastics and metals, surface decoration is generally performed for the purpose of imparting design properties to the surface or protecting the surface. As one of such decoration methods, a film decoration method using a laminated film is known. This is a method in which a layer for decorating a molded article is prepared as a film, and the film is adhered onto the molded article to perform decoration.

[0003] As for such a decoration method, there is known a method in which a base film is provided on the design layer in advance so that the design layer is not damaged by scratches or the like during molding, and the base film is peeled off after molding. The laminated film used in the decoration method is referred to as a transfer type and has been studied. As a method for attaching a laminated film to a three-dimensional shaped object, there are vacuum forming and vacuum pressure forming (for example, see Patent Document 1). In these attaching methods, after the laminated film is attached to the molded article, excess film at the end needs to be trimmed using a laser or the like.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, this trimming process presents many challenges, including the difficulty in setting trimming conditions that allow for clean cutting of the laminated film without damaging the molded product, the difficulty in reproducibly fixing the molded product in the same location, and the time-consuming process of needing to trim the laminated film on the back of the molded product. For these reasons, there is a need for a laminated film application method that eliminates the need for a trimming process.

[0006] Therefore, the present invention aims to provide a method for transferring a curable resin layer that does not require a trimming process and can be transferred in a simple manner, as well as vehicle parts and vehicles having a coating formed by this curable resin layer transfer method. [Means for solving the problem]

[0007] As a result of diligent research, the inventors of the present invention have found that the above problems can be solved by attaching a laminated sheet, in which a transfer layer and a curable resin layer are laminated, to a substrate by vacuum forming or vacuum pressure forming, curing the curable resin layer, and then peeling the laminated sheet from the substrate, thereby completing the present invention. In other words, the present invention is summarized in the following [1] to [9]. [1] A method for transferring a curable resin layer made of a curable resin composition to a transfer region of an adherend, A first step involves attaching a laminated sheet, in which a transfer layer and the curable resin layer are laminated, to a substrate by vacuum forming or vacuum pressure forming, such that the curable resin layer is in contact with the substrate and the laminated sheet extends beyond the transfer area of ​​the substrate. A second step of curing the surface of the curable resin layer that is in contact with the adherend and the surface of the curable resin layer that is in contact with the transfer layer, A method for transferring a curable resin layer to an adherend, comprising: a third step of holding the portion of the laminated sheet that protrudes from the transfer area, peeling the transfer layer from the curable resin layer that has adhered to the adherend, and removing the protruding portion of the curable resin layer together with the transfer layer. [2] A method for transferring the curable resin layer described in [1] above to an adherend, wherein the curable resin layer is made of a thermosetting resin composition. [3] A method for transferring a curable resin layer to an adherend according to [1] or [2] above, further comprising a fourth step of further curing the curable resin layer after the third step. [4] A method for transferring a curable resin layer to an adherend according to any one of [1] to [3] above, wherein the total thickness of the curable resin layer is 10 to 200 μm. [5] A method for transferring a curable resin layer to an adherend according to any one of the above [1] to [4], wherein the thickness of the transfer layer is 30 to 200 μm. [6] The curable resin layer is made of a thermosetting resin composition, The second step is a method for transferring a curable resin layer to an adherend according to any one of [1] to [5] above, wherein the laminated sheet is heated using a heater in a vacuum pressure forming machine to cure the surface of the curable resin layer that contacts the adherend and the surface of the curable resin layer that contacts the transfer layer. [7] The third step is a method for transferring a curable resin layer to an adherend according to any one of [1] to [6] above, wherein the third step is performed by holding the portion of the laminated sheet that extends beyond the transfer area and separating the adherend from the laminated sheet. [8] A vehicle part having a coating formed by the method of transferring a curable resin layer to an adherend as described in any one of [1] to [7] above. [9] A vehicle having a paint coating formed by the transfer method of a curable resin layer to an adherend described in any one of [1] to [7] above. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a method for transferring a curable resin layer that does not require a trimming process and can be transferred in a simple manner, as well as vehicle parts and vehicles having a coating formed by the curable resin layer transfer method. [Brief explanation of the drawing]

[0009] [Figure 1]Figure 1 is a diagram for explaining the first step of the transfer method according to one embodiment of the present invention. [Figure 2] Figure 2 is a diagram for explaining the first step of the transfer method according to one embodiment of the present invention. [Figure 3] Figure 3 is a diagram for explaining the second step of the transfer method according to one embodiment of the present invention. [Figure 4] Figure 4 is a diagram for explaining the third step of the transfer method according to one embodiment of the present invention. [Figure 5] Figure 5 is a schematic view of a laminate obtained by the transfer method according to one embodiment of the present invention. [Figure 6] Figure 6 is a diagram for explaining the fourth step of the transfer method according to one embodiment of the present invention. [Modes for Carrying Out the Invention]

[0010] [Method for Transferring Curable Resin Layer to Adherend] Hereinafter, a method for transferring a curable resin layer to an adherend according to one embodiment of the present invention will be described. The method for transferring a curable resin layer to an adherend according to one embodiment of the present invention (hereinafter sometimes simply referred to as the transfer method) is a method of transferring a curable resin layer made of a curable resin composition to a transfer region of the adherend. The transfer method according to one embodiment of the present invention includes the following first step, second step, and third step.

[0011] (First step) In the first step, a laminated sheet having a transfer layer and a curable resin layer laminated thereon is attached to the adherend by a vacuum forming method or a vacuum pressure forming method such that the curable resin layer is in contact with the adherend, and the laminated sheet protrudes from the transfer region of the adherend.

[0012] <Laminated sheet> The laminated sheet is a laminate in which a transfer layer and a curable resin layer are laminated.

[0013] (Curable resin layer) The curable resin layer is composed of a curable resin composition. The curable resin composition is not particularly limited as long as it is a curable resin composition. The curable resin composition may be, for example, a thermosetting resin composition curable by heat, or a moisture-curable resin composition curable by moisture. Among these, the thermosetting resin composition is preferred from the viewpoints of easy control of the cured state and the ability to cure in a short time in a molding machine. At the time of attaching an adherend to be described later, the curable resin layer is preferably uncured, but may be cured. However, even when the curable resin layer is cured, it is not completely cured and retains curability.

[0014] The thermosetting resin composition preferably contains a curable resin having a functional group that can react with the resin itself or a curing agent under heat to cure. Examples of the curable resin used in the thermosetting resin composition include (meth)acrylic resins, polycarbonate resins, polyester resins, and epoxy resins. Among these, (meth)acrylic resins are preferred from the viewpoint of the foil cutting property of the curable resin layer. If the foil cutting property of the curable resin layer is poor, after the laminated sheet is attached to an adherend, when the laminated sheet is peeled off from the adherend, the curable resin layer may be transferred to a region outside the transfer region of the adherend, or the curable resin layer that should be transferred to the transfer region of the adherend may remain on the peeled laminated sheet.

[0015] The thermosetting resin composition preferably contains a curing agent for curing the aforementioned curable resin, and from the viewpoint of achieving appropriate curing by heating and improving the foil cutting property of the curable resin layer, it is preferable to contain a blocked isocyanate curing agent as the curing agent. The blocked isocyanate curing agent is a compound having an isocyanate group, and details thereof will be described later. By containing the blocked isocyanate curing agent, the thermosetting resin composition can be easily cured by heat.

[0016] Furthermore, the thermosetting resin composition may contain a functional group that is reactive to the isocyanate group contained in the curing agent, such as a blocked isocyanate curing agent. Specifically, examples include hydroxyl groups, amino groups, and carboxyl groups, with hydroxyl groups being preferred among these. The functional group that is reactive to the isocyanate group is contained in the curable resin. The curable resin preferably has multiple functional groups in one molecule, and more preferably has multiple hydroxyl groups.

[0017] The (meth)acrylic resin used as a curable resin is preferably an acrylic polymer obtained by polymerizing a monomer mixture containing a (meth)acrylic acid ester monomer and a monomer containing a hydroxyl group-containing functional group. In such an acrylic polymer, hydroxyl groups can be incorporated into the acrylic polymer by the hydroxyl group-containing monomer. (Meth)acrylic means methacrylic or acrylic, and the same applies to other similar terms.

[0018] Examples of the above-mentioned (meth)acrylic acid ester monomers include (meth)acrylic acid ester monomers that do not have functional groups, such as alkyl (meth)acrylates with an alkyl group having 1 to 18 carbon atoms, such as methyl (meth)acrylate and ethyl (meth)acrylate; (meth)acrylates having an aromatic ring, such as benzyl (meth)acrylate and phenoxydiethylene glycol (meth)acrylate; and 2-ethoxyethyl (meth)acrylate.

[0019] The above-mentioned hydroxyl group-containing monomers are not particularly limited, and include (meth)acrylic acid ester monomers having hydroxyl groups, such as 2-hydroxyethyl (meth)acrylate.

[0020] Furthermore, the monomer mixture may also contain monomers other than the above-mentioned (meth)acrylic acid ester monomers and hydroxyl group-containing monomers, such as monomers containing functional groups other than hydroxyl groups and styrene derivative monomers. By using monomers containing functional groups other than hydroxyl groups, such as amino groups and carboxyl groups, in addition to hydroxyl groups, functional groups other than hydroxyl groups can be introduced into the (meth)acrylic resin. The amino group-containing monomer is not particularly limited, and examples include (meth)acrylic acid ester monomers having amino groups, such as 2-aminoethyl (meth)acrylate. The carboxyl group-containing monomer is not particularly limited, and examples include (meth)acrylic acid. The styrene derivative monomer is not particularly limited and includes, for example, styrene, α-methylstyrene, α-ethylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-ethoxystyrene, p-chlorostyrene, m-chlorostyrene, o-chlorostyrene, and the like.

[0021] Furthermore, as the (meth)acrylic resin, a copolymer obtained by block or graft polymerization of the above-mentioned acrylic polymer with another monomer or polymer may be used. In this case, examples of other monomers or polymers include acrylic, styrene, maleic acid, imide, silicone, and fluorine monomers, or polymers of these monomers.

[0022] The content of the curable resin in the thermosetting resin composition is preferably 30% by mass or more and 90% by mass or less, more preferably 40% by mass or more and 85% by mass or less, and even more preferably 50% by mass or more and 80% by mass or less. Although thermosetting resin compositions may be diluted with volatile components such as solvents as described later, in this specification, the content (mass%) of each component in the thermosetting resin composition refers to the value based on solid content excluding volatile components.

[0023] Within the limits that do not impede the effects of the present invention, when a thermosetting resin composition uses (meth)acrylic resin as the curable resin, it may also contain curable resins other than (meth)acrylic resin. Examples of curable resins other than (meth)acrylic resin include polycarbonate resin, polyester resin, epoxy resin, etc. These curable resins can be used individually or in combination of two or more.

[0024] The curable resin preferably contains a curable resin with a weight-average molecular weight of 50,000 to 1,000,000 (hereinafter also referred to as "high molecular weight curable resin"). When the curable resin contains a high molecular weight curable resin with a weight-average molecular weight of 50,000 to 1,000,000, it becomes easier to achieve a good balance of properties such as coating properties, curability, tackiness, and extensibility of the curable resin layer, and it becomes easier to transfer it to adherends with complex shapes. In addition, the resin sheet having the curable resin layer can be properly maintained in a sheet shape. From this viewpoint, the weight-average molecular weight of the high molecular weight curable resin is more preferably 60,000 to 800,000, even more preferably 70,000 to 600,000, and even more preferably 80,000 to 600,000. In this specification, the weight-average molecular weight is measured by gel permeation chromatography (GPC) and is determined as a standard polystyrene equivalent value.

[0025] When the high molecular weight curable resin is a (meth)acrylic resin, the weight-average molecular weight of the (meth)acrylic resin constituting the high molecular weight curable resin is preferably 50,000 to 1,000,000. When the curable resin layer contains a (meth)acrylic resin with a weight-average molecular weight of 50,000 to 1,000,000, it becomes easier to achieve a good balance of properties such as coating properties, curability, tackiness, and extensibility of the curable resin layer. Furthermore, the resin sheet having the curable resin layer can be properly maintained in a sheet shape. From this viewpoint, the weight-average molecular weight of the (meth)acrylic resin constituting the high molecular weight curable resin is more preferably 60,000 to 800,000, even more preferably 70,000 to 600,000, and even more preferably 80,000 to 600,000.

[0026] High molecular weight curable resins may have one functional group, but it is preferable that they have two or more; therefore, (meth)acrylic resins having multiple functional groups are preferred. Furthermore, high molecular weight curable resins may have one hydroxyl group, but it is preferable that they have two or more. Therefore, (meth)acrylic polyol resins are preferred as high molecular weight curable resins.

[0027] The hydroxyl value of the high molecular weight curable resin is preferably 10 mg KOH / g or more and 300 mg KOH / g or less. If the hydroxyl value of the high molecular weight curable resin is 10 mg KOH / g or more, the hardness of the cured product of the curable resin layer can be further increased. If the hydroxyl value of the curable resin is 300 mg KOH / g or less, the adhesive strength of the curable resin layer can be increased. From this viewpoint, the hydroxyl value of the high molecular weight curable resin is more preferably 30 mg KOH / g or more and 250 mg KOH / g or less, and even more preferably 60 mg KOH / g or more and 220 mg KOH / g or less. In the case where the thermosetting resin composition contains multiple types of high molecular weight curable resins, the hydroxyl value of the high molecular weight curable resin is the weighted average value of the hydroxyl values ​​of the high molecular weight curable resins contained in the thermosetting resin composition. For example, when using two types of high molecular weight curable resins, high molecular weight curable resin (d1) and high molecular weight curable resin (d2), if the hydroxyl value of high molecular weight curable resin (d1) is X1 and the mixing ratio is m1, and the hydroxyl value of high molecular weight curable resin (d2) is X2 and the mixing ratio is m2, then the weighted average value of the hydroxyl values ​​is expressed by the following formula. Note that the mixing ratio is on a mass basis. The same applies to the hydroxyl values ​​of plasticizer resins, which will be discussed later. Weighted average value of hydroxyl value (mgKOH / g) = X1 × (m1 / (m1+m2)) + X2 × (m2 / (m1+m2)) Furthermore, the hydroxyl value can be measured in accordance with JIS K 1557-1:2007.

[0028] The content of high molecular weight curable resin in the thermosetting resin composition is preferably 30% by mass or more and 80% by mass or less, more preferably 35% by mass or more and 75% by mass or less, and even more preferably 40% by mass or more and 70% by mass or less.

[0029] When the thermosetting resin composition contains a (meth)acrylic resin, the content of the (meth)acrylic resin in the thermosetting resin composition that has the weight-average molecular weight of the high molecular weight curable resin and has multiple functional groups is preferably 60 to 100% by mass, more preferably 70 to 100% by mass, and even more preferably 75 to 100% by mass.

[0030] The thermosetting resin composition preferably contains a plasticizer resin in addition to the high molecular weight curable resin described above. The plasticizer resin preferably has a weight-average molecular weight of less than 50,000. Furthermore, it is desirable that the plasticizer resin is liquid at room temperature and atmospheric pressure. The plasticizer resin is preferably a (meth)acrylic resin or a polycarbonate resin, but more preferably a (meth)acrylic polymer.

[0031] Examples of (meth)acrylic resins used as plasticizing resins include non-functional group type (meth)acrylic resins, (meth)acrylic resins having hydroxyl groups, (meth)acrylic resins having carboxyl groups, (meth)acrylic resins having epoxy groups, and (meth)acrylic resins having alkoxysilyl groups. It is preferable that the plasticizing resin has the above-mentioned functional groups to constitute a curable resin.

[0032] Furthermore, among the (meth)acrylic resins used as plasticizing resins, (meth)acrylic resins having hydroxyl groups are preferred, and (meth)acrylic polyols are more preferred among them. In addition, among polycarbonate resins, polycarbonate polyols are more preferred.

[0033] The weight-average molecular weight of the plasticizing resin is preferably 300 to 8000, more preferably 500 to 6000, and even more preferably 1000 to 4000.

[0034] The glass transition temperature of the (meth)acrylic polymer used as a plasticizing resin is preferably 10°C or lower, and more preferably -80°C or higher and 0°C or lower.

[0035] The hydroxyl value of the (meth)acrylic polymer used as a plasticizing resin is preferably 20 mg KOH / g or more and 250 mg KOH / g or less, more preferably 50 mg KOH / g or more and 200 mg KOH / g or less, and even more preferably 80 mg KOH / g or more and 150 mg KOH / g or less.

[0036] When the thermosetting resin composition contains a plasticizer resin, the content of the plasticizer resin in the thermosetting resin composition is preferably 1.0% by mass or more and 40% by mass or less, more preferably 1.5% by mass or more and 30% by mass or less, and even more preferably 1.8% by mass or more and 20% by mass or less.

[0037] Blocked isocyanate curing agents are compounds in which isocyanate groups are blocked by protecting groups. When exposed to high temperatures, the protecting groups (blocking portions) thermally dissociate and detach, and a curing reaction occurs between the resulting isocyanate groups and the functional groups (typically hydroxyl groups) in the curable resin described above. A blocked isocyanate curing agent can be obtained, for example, by reacting a blocking agent with an isocyanate compound having two or more isocyanate groups in one molecule. The isocyanate compounds having two or more isocyanate groups in a single molecule are not particularly limited, but examples include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, or modified versions thereof. Examples of blocking agents include pyrazoles, phenols, oximes, lactams, and malonic acid esters. Each type of blocked isocyanate curing agent may be used individually or in combination of two or more types.

[0038] The thermal dissociation temperature of the blocked isocyanate curing agent is preferably 180°C or lower. The thermal dissociation temperature is the temperature at which the blocked isocyanate curing agent dissociates and generates isocyanate groups. A thermal dissociation temperature of 180°C or lower is preferable because it allows the resin sheet to be cured at a relatively low temperature. From the viewpoint of curing the resin layer at a low temperature, the thermal dissociation temperature of the blocked isocyanate curing agent is more preferably 160°C or lower, and even more preferably 140°C or lower. Furthermore, from the viewpoint of storage stability of the resin sheet, the thermal dissociation temperature of the blocked isocyanate curing agent is preferably 40°C or higher, and more preferably 60°C or higher. The thermal dissociation temperature can be measured, for example, by mixing an equivalent amount of isocyanate-reactive resin, such as a curable resin, with a block isocyanate curing agent, stirring at a predetermined temperature for 6 hours, and then evaluating the gel fraction.

[0039] The content of the blocked isocyanate curing agent in the thermosetting resin composition is preferably adjusted so that the number of functional groups in the thermosetting resin is 0.4 to 1.8, more preferably 0.6 to 1.5, relative to the number of isocyanate groups in the blocked isocyanate curing agent.

[0040] The content of the blocked isocyanate curing agent in the thermosetting resin composition is not particularly limited as long as the ratio of the number of functional groups to the number of isocyanate groups is adjusted to be within the above range, but is preferably 5% by mass or more and 60% by mass or less, more preferably 10% by mass or more and 50% by mass or less, and even more preferably 15% by mass or more and 40% by mass or less.

[0041] In addition to the thermosetting resin and curing agent, the thermosetting resin composition may contain components appropriate to the performance required for the coating formed from the curable resin layer. For example, if the coating formed from the curable resin layer is to be a colored coating, a coloring agent may be included in the thermosetting resin composition. In this case, the curable resin layer becomes a colored layer. Furthermore, if the coating formed from the curable resin layer is to be a heat-shielding coating, a heat-shielding material may be included in the thermosetting resin composition.

[0042] Furthermore, the thermosetting resin composition may contain components other than those mentioned above, for example, other additives. Examples of additives include surface modifiers, defoamers, crosslinking agents, dispersants, inorganic fillers other than pigments and brighteners, anti-aging agents, antioxidants, and rust inhibitors.

[0043] Furthermore, the curable resin layer may consist of a clear layer, as described later. Among these, the thermosetting resin composition preferably contains at least a coloring agent.

[0044] Examples of colorants include pigments, dyes, and luminescent materials. Examples of pigments include metal oxide pigments such as titanium dioxide and iron oxide, inorganic pigments such as carbon black, clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, talc, silica, and alumina white, and organic pigments such as azo pigments, quinacridone pigments, diketopyrrolopyrrole pigments, perylene pigments, perinone pigments, benzimidazolon pigments, vat pigments, isoindoline pigments, isoindolinone pigments, metal chelate azo pigments, phthalocyanine pigments, indanthrone pigments, dioxane pigments, and indigo pigments. Examples of dyes include azo dyes, anthraquinone dyes, indigoid dyes, and stilbene dyes. Examples of luminescent materials include compounds in which a titanium dioxide layer is provided on the surface of natural mica, synthetic mica, alumina flakes, glass flakes, etc. These colorants can be used individually or in combination of two or more.

[0045] The active ingredient content of the colorant in the thermosetting resin composition, i.e., the colorant content excluding the binder resin, dispersant, and additives, is, for example, about 0.1 to 25% by mass, preferably 0.3 to 20% by mass, and more preferably 0.5 to 12% by mass.

[0046] The curable resin layer may consist of a single layer or have a multilayer structure of two or more layers, but a multilayer structure is preferred. A multilayer structure allows for the imparting of various functions to the coating formed from the curable resin layer, for example. In the case of a multilayer structure of the curable resin layer, each layer may consist of the thermosetting resin composition described above. Furthermore, each layer may contain a coloring agent as described above to form a colored layer, or it may contain a heat-shielding material to form a heat-shielding layer, or it may be a clear layer without substantially containing a coloring agent.

[0047] The colored layer and the clear layer may both be made of the thermosetting resin composition described above, and the thermosetting resin composition for the colored layer may contain the coloring agent as described above. Furthermore, the thermosetting resin composition for the colored layer may contain at least a high molecular weight curable resin, but it is preferable to contain both a high molecular weight curable resin and a plasticizer resin. The content of the plasticizer resin in the thermosetting resin composition constituting the colored layer is, for example, 0.1 to 0.9 by mass ratio with respect to the content of the high molecular weight curable resin, preferably 0.15 to 0.8, and more preferably 0.2 to 0.6. By setting the content of the plasticizer resin above the lower limit, the adhesion of the colored layer is improved, and in particular, the adhesion to the adherend is easily improved. Furthermore, by setting the content of the plasticizer resin below the upper limit, the hardness of the cured product of the colored layer is easily improved.

[0048] On the other hand, the clear layer is a transparent layer, and it is sufficient that it has enough transparency to allow the color of the colored layer to be visible from the outside through the clear layer. For example, it is desirable that the transmittance of light with a wavelength of 450 nm be 80% or more. The clear layer does not contain a coloring agent, but it may contain a small amount of a coloring agent as long as it does not impair its function. The thermosetting resin composition for the clear layer contains a high molecular weight curable resin, but it may or may not contain a plasticizer resin. The content of the plasticizer resin in the thermosetting resin composition constituting the clear layer is, for example, 0 to 0.5, preferably 0 to 0.3, and more preferably 0 to 0.15, in mass ratio with respect to the content of the high molecular weight curable resin. By setting the content of the plasticizer resin above the lower limit, the adhesion of the clear layer is improved, and in particular, the adhesion to the colored layer is easily improved. Also, by setting the content of the plasticizer resin below the upper limit, the hardness of the cured clear layer is easily improved.

[0049] The total thickness of the curable resin layer is not particularly limited, but is preferably 10 μm to 200 μm, more preferably 20 μm to 150 μm, and even more preferably 30 μm to 100 μm. The total thickness of the curable resin layer is the thickness of the curable resin layer if it is a single-layer structure, and the sum of the thicknesses of the layers constituting the curable resin layer if it is a multilayer structure. Furthermore, when a colored layer and a clear layer are provided in the curable resin layer, the thickness of the clear layer is not particularly limited, but is preferably 5 μm to 100 μm, more preferably 10 μm to 75 μm, and even more preferably 15 μm to 50 μm. Similarly, the thickness of the colored layer is not particularly limited, but is preferably 5 μm to 100 μm, more preferably 10 μm to 75 μm, and even more preferably 15 μm to 50 μm.

[0050] (Transfer layer) The transfer layer is a component that protects the curable resin layer from scratches and the adhesion of foreign matter, and also serves as a support when the curable resin layer is attached to the substrate. The transfer layer is preferably formed from a resin film. The resin used in the resin film is preferably a thermoplastic resin, but other resins may also be used. Specifically, examples of resins used in the resin film include polyolefin resins such as cyclic polyolefin resins, ethylene vinyl acetate copolymer resins, polyethylene resins, and polypropylene resins; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyamide resins; acrylonitrile butadiene styrene resins; polycarbonate resins; acrylic resins; fluororesins; vinyl chloride resins; polymethylpentene resins; and tetrafluoroethylene resins. Among these resins, polyolefin resins such as polyethylene resins, polypropylene resins, and ethylene vinyl acetate copolymer resins, and polyethylene terephthalate are preferred, with polyolefin resins being more preferred.

[0051] The resin film constituting the transfer layer may be a single-layer film consisting of one layer, or a multilayer film consisting of two or more layers. Furthermore, in the resin film constituting the transfer layer, the resin contained in the resin film may be used alone, or two or more types may be used in combination. When two or more types of resin are used in combination, different types of resin may be used in each layer to form a multilayer film. Alternatively, a single-layer film may be formed by mixing two or more types of resin, or one or more layers in a multilayer film may be formed by mixing them. For example, the multilayer film may be a multilayer film of polyolefin resin-based films such as polyethylene resin layer / EVA layer / polyethylene resin layer. Furthermore, the resin film used in the transfer layer may be a stretched resin film or an unstretched resin film.

[0052] The transfer layer may be a release film in which at least one surface has been treated with a release agent such as a silicone-based release agent, a long-chain alkyl-based release agent, or a fluorine-based release agent to create a release layer. The release layer is preferably provided on at least the surface that contacts the surface layer. Therefore, the transfer layer is preferably one of a silicone-based release film, a long-chain alkyl-based release film, or a fluorine-based release film that has been treated with a silicone-based release agent.

[0053] The thickness of the transfer layer is not particularly limited, but is, for example, 10 μm or more and 1000 μm or less, preferably 30 μm or more and 200 μm or less, more preferably 40 μm or more and 180 μm or less, and even more preferably 50 μm or more and 150 μm or less.

[0054] (Method of manufacturing laminated sheets) The method for manufacturing the laminated sheet is not particularly limited, but it can be manufactured by known methods. For example, a curable resin composition can be prepared, the prepared curable resin composition can be applied to a transfer layer, and the curable resin layer can be formed by drying as needed. The details and content of each component in the curable resin composition are as described above.

[0055] <Attaching laminated sheets to the substrate> The process of attaching the laminated sheet to the substrate can be carried out using either vacuum forming or vacuum pressure forming, with vacuum pressure forming (TOM forming) being more preferable. TOM stands for "Three-dimensional Overlay Method," and applying the TOM forming method allows for the attachment of laminated sheets to substrates with complex shapes. The first step will be explained below using TOM forming as an example.

[0056] As shown in Figure 1, the TOM molding machine 100 includes a table 110, a heater 120, and a clamp 130. The table 110 is movable in the vertical direction, and the workpiece 10 placed on the table 110 pushes up the laminated sheet 20, causing the laminated sheet 20 to adhere closely to the surface of the workpiece 10 and be bonded to it. The plate of the table 110 is provided with numerous through holes (not shown). The presence of through holes in the plate of the table 110 allows for vacuum suction of the space 100b, which in turn allows the air present between the laminated sheet 20 and the workpiece 10 to be sucked out through the through holes, resulting in the laminated sheet 20 adhering closely to the workpiece 10 and being bonded to it. In addition, the surface of the plate of the table 110 is treated to prevent the laminated sheet 20 from sticking. The heater 120 emits infrared rays to heat the laminated sheet 20, which in turn cures the curable resin layer 21 of the laminated sheet 20. The clamp 130 grips the laminated sheet 20 to prevent it from falling off when it is attached to the adherend 10.

[0057] In the first step, the workpiece 10 is first placed on the table 110. The laminated sheet 20 is then placed in the TOM molding machine 100 and secured with clamps 130. At this time, the laminated sheet 20 is positioned so that the side of the laminated sheet 20 with the curable resin layer faces the workpiece 10. The inside of the TOM molding machine 100 is divided into an upper space 100a and a lower space 100b by the laminated sheet 20. The TOM molding machine 100 can vacuum-suction the inside of the upper space 100a and the inside of the lower space 100b, release them to the atmosphere, or pressurize them with compressed air, respectively.

[0058] Subsequently, the interior of the upper space 100a and the lower space 100b of the TOM molding machine 100 are vacuum-suctioned. Next, as shown in Figure 2, with the interior of the upper space 100a and the lower space 100b of the TOM molding machine 100 vacuum-suctioned, the table 110 is immediately moved upward, and the laminated sheet 20 is pushed up by the workpiece 10 placed on the table 110.

[0059] As shown in Figure 3, with the lower space 100b of the TOM molding machine 100 under vacuum, the upper space 100a of the TOM molding machine 100 is opened to the atmosphere and returned to atmospheric pressure. As a result, the laminated sheet 20 adheres closely to the surface of the adherend 10 with the curable resin layer 21 in contact with the adherend 10, and the laminated sheet 20 extends beyond the transfer area 11 (see Figure 1) of the adherend 10. Next, with the lower space 100b of the TOM molding machine 100 under vacuum, the upper space 100a of the TOM molding machine 100 is pressurized with compressed air. As a result, the laminated sheet 20 can conform even more to the three-dimensional shape of the surface of the adherend 10, and the adhesion force of the laminated sheet 20 to the adherend 10 is further increased. As a result, the laminated sheet 20 adheres to the adherend 10 such that the curable resin layer 21 is in contact with the adherend 10, and the laminated sheet 20 extends beyond the transfer area 11 (see Figure 1) of the adherend 10.

[0060] (Second step) In the second step, the surface of the curable resin layer that contacts the adherend and the surface of the curable resin layer that contacts the transfer layer are cured. For example, as shown in Figure 3, the laminated sheet 20 is heated using a heater 120, thereby curing the surface of the curable resin layer 21 that contacts the adherend 10 and the surface of the curable resin layer 21 that contacts the transfer layer 22. As a result, the adhesive strength of the curable resin layer 21 to the adherend 10 is increased, while the adhesive strength of the curable resin layer 21 to the transfer layer 22 is weakened. In addition, this makes the curable resin layer 21 less stretchable and improves the foil tearability of the curable resin layer 21.

[0061] In the second step, the curable resin layer may be fully cured or partially cured. If the curable resin layer is partially cured, it is preferable to perform the fourth step, which will be described later. Here, partial curing means that the curable resin composition has not been completely cured, and that further curing will proceed by heating or other means.

[0062] From the above viewpoint, the heating temperature of the laminated sheet 20 is preferably 60°C to 200°C, more preferably 80°C to 180°C, and even more preferably 100°C to 160°C, when the curable resin is (meth)acrylic resin. Also from the above viewpoint, the heating time of the laminated sheet 20 is preferably 1 minute to 1 hour, more preferably 3 minutes to 45 minutes, and even more preferably 5 minutes to 30 minutes, when the curable resin is (meth)acrylic resin. The heating temperature can be measured by measuring the surface temperature of the laminated sheet 20 using a radiation thermometer.

[0063] (Third step) In the third step, the portion of the laminated sheet that protrudes from the transfer area is held, and the transfer layer is peeled away from the curable resin layer that adhered to the adherend, removing the curable resin layer of the protruding portion together with the transfer layer. For example, as shown in Figure 4, the table 110 is lowered while the portion 23 of the laminated sheet 20 that protrudes from the transfer area is held by the clamp 130. At this time, the curable resin layer 21 in the transfer area 11 (see Figure 1) of the adherend 10 remains on the surface of the adherend 10 because it is adhered to the adherend 10. On the other hand, as described above, the surface of the table 110 is treated to prevent the laminated sheet 20 from sticking, so the curable resin layer 21 of the laminated sheet 20 in the area that was in close contact with the table 110, that is, the portion 23 of the laminated sheet 20 that protruded from the transfer area 11 (see Figure 1) of the adherend 10, does not stick to the table 110. Therefore, the portion of the curable resin layer 21 that extends beyond the transfer area 11 (see Figure 1) remains on the peeled laminated sheet 20. Consequently, the curable resin layer 21 is cut (so-called foil breakage), the transfer layer 22 is peeled off from the curable resin layer 21 adhered to the substrate 10, and the extended portion of the curable resin layer 21 23 is also removed along with the transfer layer 22. This eliminates the need for trimming, which involves cutting off the unnecessary portion of the curable resin layer attached to the substrate 10.

[0064] By the method for transferring a curable resin layer to an adherend according to one embodiment of the present invention, a laminate 1 comprising an adherend 10 and a curable resin layer 21 attached to the surface of the adherend 10, as shown in Figure 5, can be manufactured without trimming the curable resin layer 21.

[0065] (Fourth step) The method for transferring a curable resin layer to an adherend according to one embodiment of the present invention may further include a fourth step of further curing the curable resin layer after the third step. For example, as shown in Figure 5, the curable resin layer 21 adhering to the surface of the adherend 10 may be heated using a heater 120 to further cure the curable resin layer 21 adhering to the surface of the adherend 10. This can further increase the adhesive strength of the curable resin layer 21 to the adherend 10 and further increase the hardness of the cured product of the curable resin layer 21.

[0066] From the above viewpoint, the heating temperature of the laminated sheet 20 is preferably 60°C to 200°C, more preferably 80°C to 180°C, and even more preferably 100°C to 160°C, when the curable resin is (meth)acrylic resin. Also from the above viewpoint, the heating time of the laminated sheet 20 is preferably 1 minute to 1 hour, more preferably 5 minutes to 45 minutes, and even more preferably 10 minutes to 30 minutes, when the curable resin is (meth)acrylic resin. The heating temperature can be measured by measuring the surface temperature of the curable resin layer 21 using a radiation thermometer.

[0067] The method for transferring a curable resin layer to an adherend according to one embodiment of the present invention, as described above, is merely one example of the method for transferring a curable resin layer to an adherend according to the present invention. Therefore, the method for transferring a curable resin layer to an adherend according to one embodiment of the present invention does not limit the method for transferring a curable resin layer to an adherend according to the present invention. For example, in the second and fourth steps, if the curable resin composition is a moisture-curable resin composition, the curable resin layer may be cured by leaving it in the atmosphere or a humid environment instead of the heat curing described above. Also, although the method described above involves performing the second and subsequent steps inside the molding machine, the laminate with the laminated sheet attached to the adherend may be removed from the molding machine before performing the second step.

[0068] The method for transferring a curable resin layer to an adherend according to the present invention can be used to transfer a curable resin layer to various adherends and form a coating. The adherends to which the curable resin layer is transferred are not particularly limited, but examples include vehicle parts such as interior materials for automobiles and interior materials for transportation equipment other than automobiles, exterior materials for automobiles and exterior materials for transportation equipment other than automobiles, exterior materials for electrical appliances, general merchandise, heavy machinery, ships, aircraft, exterior walls or roofing materials for houses and buildings, bridges, steel frames, plants, wind turbine blades, and the like. Among these, it is preferable that the material be used on vehicles or vehicle parts, and in particular, it is preferable that the adherend be a vehicle exterior material, such as an automotive exterior material or an exterior material for transportation equipment other than automobiles. The vehicle exterior material is preferably the exterior of the vehicle body, but it may also be a hood, roof, door panel, bumper, fuel filler panel, trunk lid, rear gate, etc. When the curable resin layer is attached to a vehicle exterior material, it may be attached to the exterior material attached to the vehicle body, or it may be attached to the exterior material before it is attached to the vehicle body. Furthermore, the material of the adherend is not particularly limited, but may be any of resin materials, inorganic materials such as ceramics, or metallic materials such as steel, although metallic materials such as steel are preferred among these. Furthermore, a base layer or the like may be appropriately formed on the surface of the adherend to which the curable resin layer is transferred.

[0069] [Vehicles, vehicle parts] The vehicle and vehicle parts of the present invention have a coating formed by the transfer method of the curable resin layer of the present invention onto an adherend. Therefore, the method for manufacturing a vehicle and a vehicle part of the present invention includes a step of transferring the curable resin layer onto an adherend (vehicle or vehicle part) by the transfer method described above. [Examples]

[0070] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by these examples.

[0071] The components of the transfer layer film, protective film, and resin layer used in the examples and comparative examples are as follows. <Transfer layer film and protective film> Convenience Store PE: Unstretched polyethylene / EVA multilayer film (Okamoto Co., Ltd.'s "Convenience Store PE", 200 μm thickness)

[0072] <Polyol resin> Acrylic polyol resin (1): Weight-average molecular weight 250,000, hydroxyl value 80 mg KOH / g, solids content concentration (NV) = 23.3% by mass (solvent: ethyl acetate) Acrylic polyol resin (2): Weight-average molecular weight 250,000, hydroxyl value 170 mg KOH / g, solids content concentration (NV) = 29.6% by mass (solvent: ethyl acetate)

[0073] <Plasticized resin> Polycarbonate diol: Hydroxyl value 204-244 mgKOH / g, weight-average molecular weight 500, "PH-50", manufactured by UBE Corporation.

[0074] <Blocked Isocyanates> Mitsui Chemicals, Inc.'s "Takenate B-882N" is a hexamethylene diisocyanate-based blocked isocyanate curing agent (HDI type), with 3,5-dimethylpyrazole (DMP) as the blocking agent, a solids content concentration (NV) of 70%, and petroleum naphtha as the solvent. Its thermal dissociation temperature is 120°C.

[0075] <Urethane catalyst> "XK-639", manufactured by Kusumoto Kasei Co., Ltd., solid content concentration (NV) = 100% by mass

[0076] <Pigments (colorants)> Nichihiro Bix Co., Ltd. "NSP-UP 841B", effective pigment concentration = 24.0% by mass, solids content (NV) = 24.0% by mass, solvent is MEK

[0077] <Glossy finish (coloring agent)> "Xirallic T60-10 WNT Crystal Silver" manufactured by Merck, solid content concentration (NV) = 100% by mass

[0078] [Preparation of thermosetting resin compositions A and B] As shown in Table 1, each component was added, and ethyl acetate was added as a solvent to prepare paints of thermosetting resin compositions A and B with a solid content concentration of 30% by mass.

[0079] [Table 1] *Table 1 shows the amount of each component in thermosetting resin compositions A and B based on solid content, with the total solid content of the acrylic polyol resin, plasticizer resin, and blocked isocyanate being set to 100 parts by mass. *The amount of active ingredients in the pigment is the value in Table 1 multiplied by 9 / 24.

[0080] <Example 1> [Fabrication of Laminated Sheet 1] After coating the surface of the transfer layer film with thermosetting resin composition B using an applicator, a pre-drying process was carried out at a drying temperature of 60°C for 30 minutes, followed by a main drying process at a drying temperature of 90°C for 30 minutes to form a curable resin layer with a thickness of 60 μm on the transfer layer, thereby producing laminated sheet 1.

[0081] [Transfer of laminated sheet 1 to the substrate] Using a TOM molding machine (manufactured by Fuse Vacuum Co., Ltd., product name "NGF-T-203"), the laminated sheet 1 was heated at a heating temperature of 73°C for 30 minutes, and then the laminated sheet 1 was bonded to the adherend (a cylindrical body made of polycarbonate (PC) with a diameter of 80 mm and a height of 13 mm). The laminated sheet 1, while bonded to the adherend, was cured by heating it at 120°C for 5 minutes in the TOM molding machine. Subsequently, using the clamp of the TOM molding machine, the transfer layer was peeled off from the curable resin layer bonded to the adherend, and the unnecessary portion of the curable resin layer along with the transfer layer was also removed to obtain an adherend with a laminated cured curable resin layer. Therefore, in Example 1, trimming work to cut off the unnecessary portion of the curable resin layer bonded to the adherend was not necessary.

[0082] <Example 2> [Preparation of Laminated Sheet 2] After coating the surface of the transfer layer film with a thermosetting resin composition A using an applicator, a pre-drying process was carried out at a drying temperature of 60°C for 30 minutes, followed by a main drying process at a drying temperature of 90°C for 30 minutes to form a 30 μm thick clear layer on the transfer layer. Next, thermosetting resin composition B was applied to the surface of the protective film using an applicator. A pre-drying process was then carried out at a drying temperature of 60°C for 30 minutes, followed by a main drying process at a drying temperature of 90°C for 30 minutes to form a colored layer with a thickness of 30 μm on the protective film. A laminate was obtained by bonding a clear layer on a transfer layer and a colored layer on a protective film, and laminating them at 25°C, in the order of transfer layer, clear layer, colored layer, and protective film. The protective film was peeled off from the laminate, and a laminated sheet 2 was prepared by laminating the transfer layer and a curable resin layer consisting of the clear layer and the colored layer.

[0083] [Transfer of laminated sheet 2 to the substrate] Using a TOM molding machine (manufactured by Fuse Vacuum Co., Ltd., product name "NGF-T-203"), the laminated sheet 2 was heated at a heating temperature of 73°C for 30 minutes, and then the laminated sheet 2 was bonded to the adherend (a cylindrical body made of polycarbonate (PC) with a diameter of 80 mm and a height of 13 mm). The laminated sheet 2, while bonded to the adherend, was cured by heating it at 120°C for 5 minutes in the TOM molding machine. Subsequently, using the clamp of the TOM molding machine, the transfer layer was peeled off from the curable resin layer bonded to the adherend, and the unnecessary portion of the curable resin layer along with the transfer layer was also removed to obtain an adherend with a laminated cured curable resin layer. Therefore, in Example 2 as well, the trimming work of cutting off the unnecessary portion of the curable resin layer bonded to the adherend was not necessary. [Explanation of Symbols]

[0084] 1. Laminate 10 Adherent 11 Transcription region 20 Laminated Sheets 21 Curable resin layer 22 Transfer layer 100 TOM forming machine 100a Upper space 100b lower space 110 Tables 120 Heater 130 Clamp

Claims

1. A method for transferring a curable resin layer, comprising a curable resin composition, to a transfer region of the adherend, A first step involves attaching a laminated sheet, in which a transfer layer and the curable resin layer are laminated, to a substrate by vacuum forming or vacuum pressure forming, such that the curable resin layer is in contact with the substrate and the laminated sheet extends beyond the transfer area of ​​the substrate. A second step of curing the surface of the curable resin layer that is in contact with the adherend and the surface of the curable resin layer that is in contact with the transfer layer, A method for transferring a curable resin layer to an adherend, comprising: a third step of holding the portion of the laminated sheet that protrudes from the transfer area, peeling the transfer layer from the curable resin layer that has adhered to the adherend, and removing the protruding portion of the curable resin layer together with the transfer layer.

2. The method for transferring a curable resin layer to an adherend according to claim 1, wherein the curable resin layer comprises a thermosetting resin composition.

3. A method for transferring a curable resin layer to an adherend according to claim 1, further comprising a fourth step of further curing the curable resin layer after the third step.

4. The method for transferring a curable resin layer to an adherend according to claim 1, wherein the total thickness of the curable resin layer is 10 to 200 μm.

5. The method for transferring a curable resin layer to an adherend according to claim 1, wherein the thickness of the transfer layer is 30 to 200 μm.

6. The curable resin layer consists of a thermosetting resin composition. The method for transferring a curable resin layer to an adherend according to claim 1, wherein the second step involves heating the laminated sheet using a heater in a vacuum pressure forming machine to cure the surface of the curable resin layer that contacts the adherend and the surface of the curable resin layer that contacts the transfer layer.

7. The third step is performed by holding the portion of the laminated sheet that protrudes from the transfer area and separating the adherend from the laminated sheet, as described in claim 1, for transferring a curable resin layer to an adherend.

8. A vehicle part having a coating formed by the method of transferring a curable resin layer to an adherend as described in claim 1.

9. A vehicle having a coating formed by the method of transferring a curable resin layer to an adherend as described in claim 1.

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