Thermosetting resin sheet, vehicle and vehicle parts and method for manufacturing vehicle and vehicle parts

Abstract

To provide a thermosetting resin sheet capable of suppressing the decrease in usable time and suppressing surface roughness, a vehicle and vehicle parts coated with the thermosetting resin sheet and a method for manufacturing a vehicle and vehicle parts.SOLUTION: There is provided a thermosetting resin sheet comprising a resin layer composed of a thermosetting resin composition and a transfer layer, wherein the thermosetting resin composition comprises a solvent and the outgassing amount derived from a solvent is 5 ppm or more and 5000 ppm or less, as measured by gas chromatography-mass spectrometry (GC-MS) in the resin layer of the thermosetting resin sheet. There are provided a vehicle and vehicle parts coated with the thermosetting resin sheet. There is provided a method for manufacturing a vehicle and vehicle parts which comprises a step of coating with the thermosetting resin sheet.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a thermosetting resin sheet, a vehicle and vehicle parts coated with the thermosetting resin sheet, and a method for manufacturing a vehicle and vehicle parts.

Background Art

[0002] For furniture, steel plates, vehicle bodies, etc., painting and decoration are performed from the viewpoints of design and durability. It is known that decoration is performed using a film such as a decorative film. As such a decorative film, for example, a thermosetting coating sheet mainly composed of an acrylic resin having a plurality of functional groups, a monomer having a plurality of functional groups as a crosslinking agent that reacts with an isocyanate group, and a blocked isocyanate is known as a conventional technique (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The thermosetting coating sheet described in Patent Document 1 is a one-component curable thermosetting resin sheet. By heating the thermosetting coating sheet, the blocking agent of the blocked isocyanate dissociates, and the thermosetting coating sheet cures. Therefore, since the one-component curable thermosetting resin sheet does not cure without heating, the pot life of the thermosetting resin sheet can be extended. In addition to the one-component curable thermosetting resin sheet, there is a two-component curable thermosetting resin sheet for the thermosetting resin sheet. The two-component curable thermosetting resin sheet cures, for example, by the reaction of a polyol and an active isocyanate. For this reason, at the stage of producing the thermosetting resin sheet, the curing of the thermosetting resin sheet starts, so the pot life of the two-component curable thermosetting resin sheet becomes short. For this reason, in the two-component curable thermosetting resin sheet, it is desired to extend the pot life. Further, it is desirable that the surface of the thermosetting resin sheet is not rough and is smooth.

[0005] Therefore, an object of the present invention is to provide a thermosetting resin sheet capable of suppressing a decrease in pot life and suppressing surface roughness, a vehicle and vehicle parts painted using the thermosetting resin sheet, and a method for manufacturing a vehicle and vehicle parts.

Means for Solving the Problems

[0006] As a result of intensive studies, the present inventors have found that by setting the amount of outgas derived from the solvent remaining in the resin layer of the thermosetting resin sheet within a predetermined range, it is possible to suppress a decrease in pot life and suppress surface roughness, and have completed the present invention. That is, the present invention provides the following [1] to

[13] . [1] A thermosetting resin sheet comprising a resin layer made of a thermosetting resin composition and a transfer layer, The thermosetting resin composition contains a solvent, A thermosetting resin sheet in which the amount of outgas derived from the solvent measured by gas chromatography-mass spectrometry (GC-MS method) of the resin layer of the thermosetting resin sheet is 5 ppm or more and 5000 ppm or less. The thermosetting resin sheet according to [1] above, wherein the outgassing amount derived from the solvent measured by the GC-MS method of the resin layer of the thermosetting resin sheet is 5 ppm or more and 500 ppm or less. [3] The thermosetting resin sheet according to [1] or [2] above, which is dried under drying conditions of a drying temperature of 60°C and a drying time of 5 minutes or more and 10 minutes or less. [4] The thermosetting resin sheet according to any one of [1] to [3] above, wherein the thermosetting resin composition contains isocyanate. [5] The thermosetting resin composition contains a polyol resin, The thermosetting resin sheet according to [4] above, wherein the content of the isocyanate is 30 parts by weight or more and 90 parts by weight or less with respect to 100 parts by weight of the polyol resin. [6] The thermosetting resin sheet according to any one of [1] to [5] above, wherein the thermosetting resin composition contains a polyol resin having a weight average molecular weight of 50,000 or more and 1,000,000 or less. [7] The thermosetting resin sheet according to [6] above, wherein the polyol resin is (meth)acrylic polyol. [8] The thermosetting resin sheet according to [6] or [7] above, wherein the polyol resin contains a polyol resin having a hydroxyl value of 100 mgKOH / g or less. [9] The thermosetting resin composition further contains a colorant, The thermosetting resin sheet according to any one of [1] to [8] above, wherein the resin layer is a colored resin layer.

[10] A vehicle painted using the thermosetting resin sheet according to any one of [1] to [9] above.

[11] A vehicle part painted using the thermosetting resin sheet according to any one of [1] to [9] above.

[12] A method for manufacturing a vehicle, including a step of painting using the thermosetting resin sheet according to any one of [1] to [9] above.

[13] A method for manufacturing a vehicle part, including a step of painting using the thermosetting resin sheet according to any one of [1] to [9] above. [Effect of the Invention]

[0007] According to the present invention, it is possible to provide a thermosetting resin sheet that can suppress a decrease in pot life and suppress surface roughness, a vehicle and vehicle parts coated with the thermosetting resin sheet, and a method for manufacturing the vehicle and vehicle parts.

Mode for Carrying Out the Invention

[0008] [Thermosetting Resin Sheet] The thermosetting resin sheet of the present invention includes a resin layer made of a thermosetting resin composition and a transfer layer. The thermosetting resin composition contains a solvent. And, the outgas amount derived from the solvent measured by gas chromatography-mass spectrometry (GC-MS method) of the resin layer of the thermosetting resin sheet of the present invention is 5 ppm or more and 5000 ppm or less. Thereby, a decrease in the pot life of the thermosetting resin sheet can be suppressed, and surface roughness of the thermosetting resin sheet can be suppressed.

[0009] (Outgas Amount) The outgas amount derived from the solvent measured by gas chromatography-mass spectrometry (GC-MS method) of the resin layer of the thermosetting resin sheet of the present invention is 5 ppm or more and 5000 ppm or less. When the outgas amount is less than 5 ppm, the pot life of the thermosetting resin sheet may decrease. When the outgas amount is greater than 5000 ppm, the surface of the thermosetting resin sheet may become rough. From such a viewpoint, the outgas amount is preferably 5 ppm or more and 500 ppm or less, and more preferably 5 ppm or more and 13 ppm or less. The outgas amount derived from the solvent of the resin layer of the thermosetting resin sheet can be measured by the method described in the examples below. Also, the outgas amount derived from the solvent of the resin layer of the thermosetting resin sheet can be adjusted according to the drying conditions when manufacturing the thermosetting resin sheet.

[0010] In addition, regarding the amount of outgas derived from the solvent in the resin layer of the thermosetting resin sheet, it is advisable to identify the peak of the solvent used and calculate the amount of outgas derived from the solvent from the peak area of that peak. Also, when the solvent used is unknown, it is advisable to identify the peak of the solvent by a known method and calculate the amount of outgas derived from the solvent in the resin layer from the peak area. For the identification of the peak of the solvent, for example, referring to the NIST library (The 2014 version of the NIST / EPA / NIH Mass Spectral Library (NIST 14)) by the GCMS analysis software Escrime of JEOL Ltd., it is advisable to estimate the structure with a high matching rate from the mass spectrum of each peak. Also, the amount of outgas in the resin layer of the thermosetting resin sheet is preferably measured in the state of the resin layer after peeling the transfer layer from the thermosetting resin sheet. It may also be measured in a state where the transfer layer is laminated on one surface of the resin layer. Further, for example, when another layer such as a protective layer is laminated on the other surface of the resin layer, it is advisable to peel off the other layer such as the protective layer and measure in a state where the other surface of the resin layer is exposed.

[0011] (Resin layer) The resin layer in the thermosetting resin sheet of the present invention is composed of a thermosetting resin composition. The thermosetting resin composition contains a solvent. Further, the thermosetting resin composition preferably contains a polyol resin. Also, the thermosetting resin composition preferably contains an isocyanate.

[0012] <Polyol resin> Examples of the polyol resin include (meth)acrylic polyol resin, polycarbonate polyol resin, polyester polyol resin, epoxy resin-modified polyol resin, etc. Among them, (meth)acrylic polyol resin is preferable.

[0013] In the polyol resin, the number of hydroxyl groups is not particularly limited as long as it is 2 or more. Also, the polyol resin may have a functional group other than the hydroxyl group. Examples of the functional group other than the hydroxyl group include an amino group, a carboxyl group, etc.

[0014] The polyol resin preferably contains a (meth)acrylic resin having a plurality of functional groups, particularly a plurality of hydroxyl groups. (The (meth)acrylic resin may have functional groups other than hydroxyl groups. Examples of the functional groups other than hydroxyl groups include an amino group, a carboxyl group, and the like.)

[0015] (The (meth)acrylic resin is preferably an acrylic polymer obtained by polymerizing a monomer mixture containing a (meth)acrylate monomer having no functional group and a functional group-containing monomer having a hydroxyl group. Such an alkyl polymer can contain a hydroxyl group in the acrylic polymer by means of the functional group-containing monomer having a hydroxyl group. Note that (meth)acrylic means methacrylic or acrylic, and the same applies to other similar terms.)

[0016] Examples of the (meth)acrylate monomer include (meth)acrylate monomers having no functional group, such as alkyl (meth)acrylates having 1 to 18 carbon atoms in the alkyl group, 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.

[0017] The functional group-containing monomer having a hydroxyl group is not particularly limited, and examples thereof include (meth)acrylate monomers having a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate.

[0018] In addition, the monomer mixture may contain monomers having functional groups other than hydroxyl groups, such as the above-mentioned (meth)acrylate monomers such as styrene derivative monomers and monomers other than hydroxyl group-containing monomers. By using monomers having functional groups other than hydroxyl groups, such as amino groups and carboxyl groups, in addition to hydroxyl group-containing monomers, 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 thereof include (meth)acrylate monomers having an amino group, such as 2-aminoethyl (meth)acrylate. The carboxyl group-containing monomer is not particularly limited, and examples thereof include (meth)acrylic acid. The styrene derivative monomer is not particularly limited, and examples thereof include styrene, α-methylstyrene, α-ethylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-ethoxystyrene, p-chlorostyrene, m-chlorostyrene, o-chlorostyrene and the like.

[0019] In addition, as the (meth)acrylic resin, a copolymer obtained by block or graft polymerization of the above-mentioned acrylic polymer and another monomer or polymer may be used. In this case, examples of the other monomer or polymer include acrylic-based, styrene-based, maleic acid-based, imide-based, silicone-based, fluorine-based monomers, or polymers of these monomers.

[0020] The thermosetting resin composition preferably contains a polyol resin having a weight average molecular weight of 50,000 or more and 1,000,000 or less (hereinafter also referred to as a high molecular weight polyol resin). By including a high molecular weight polyol resin in the thermosetting resin composition, it becomes easier to balance and improve the coatability, curability, tackiness, stretchability, etc. of the resin layer. From such a viewpoint, the weight average molecular weight of the high molecular weight polyol resin is more preferably 60,000 or more and 800,000 or less, still more preferably 70,000 or more and 600,000 or less, and even more preferably 80,000 or more and 600,000 or less. In this specification, the weight average molecular weight is measured by gel permeation chromatography (GPC) and is determined as a standard polystyrene conversion value.

[0021] The thermosetting resin composition preferably contains a polyol resin having a hydroxyl value of 100 mgKOH / g or less. By including a polyol resin having a hydroxyl value of 100 mgKOH / g or less in the thermosetting resin composition, a further decrease in the pot life of the thermosetting resin sheet can be suppressed. Also, the adhesive strength of the resin layer can be further increased. From such a viewpoint, the hydroxyl value of the polyol resin having a hydroxyl value of 100 mgKOH / g or less is more preferably 90 mgKOH / g or less, and still more preferably 80 mgKOH / g or less.

[0022] The hydroxyl value of the polyol resin having a hydroxyl value of 100 mgKOH / g or less is not particularly limited, but is preferably 10 mgKOH / g or more. When the hydroxyl value of the polyol resin is 10 mgKOH / g or more, the hardness of the resin layer can be increased. From such a viewpoint, the hydroxyl value of the polyol resin is more preferably 20 mgKOH / g or more, and still more preferably 30 mgKOH / g or more. In addition, the polyol resin having a hydroxyl value of 100 mgKOH / g or less is preferably the above-mentioned high molecular weight polyol resin. Further, when the high molecular weight polyol resin in the thermosetting resin composition contains a plurality of types of polyol resins, a polyol resin having a hydroxyl value of 100 mgKOH / g or less and a polyol resin having a hydroxyl value greater than 100 mgKOH / g may be used in combination, but it is preferable that the hydroxyl value of each polyol resin is 100 mgKOH / g or less.

[0023] In addition to the high molecular weight polyol resin, the thermosetting resin composition may contain a plasticizing resin having a weight average molecular weight of less than 50,000. The plasticizing resin is preferably a liquid at normal temperature and normal pressure. By containing a plasticizing resin having a low weight average molecular weight, the thermosetting resin composition can easily make the coating property, curability, tackiness, stretchability, etc. of the thermosetting resin sheet well-balanced. Further, the wettability to the object to be coated can be improved, and the adhesive strength of the thermosetting resin sheet to the object to be coated can be increased. As the plasticizing resin, a polyol resin having a weight average molecular weight of less than 50,000 is preferable. The weight average molecular weight of the above polyol resin used as the plasticizing resin is preferably 200 or more and 8000 or less, more preferably 300 or more and 6000 or less, and still more preferably 400 or more and 4000 or less.

[0024] As the polyol resin used as the plasticizing resin, (meth)acrylic polyol and polycarbonate polyol are preferable, and polycarbonate polyol is more preferable.

[0025] The glass transition temperature of the polyol resin used as the plasticizing resin is preferably 10°C or less, more preferably -80°C or more and 0°C or less.

[0026] The hydroxyl value of the polyol resin used as the plasticizable resin is preferably 20 mgKOH / g or more and 350 mgKOH / g or less, more preferably 40 mgKOH / g or more and 300 mgKOH / g, and still more preferably 60 mgKOH / g or more and 250 mgKOH / g. When the plasticizable resin in the thermosetting resin composition contains a plurality of polyol resins, the hydroxyl value of each polyol resin is preferably within the above range.

[0027] When the thermosetting resin composition in the resin layer contains a polyol resin used as the plasticizable resin, the content of the polyol resin used as the plasticizable resin in the polyol resin contained in the thermosetting resin composition is preferably 5% by weight or more and 60% by weight or less, more preferably 10% by weight or more and 50% by weight or less, and still more preferably 15% by weight or more and 45% by weight or less. Also, in this case, the content of the polyol resin having a weight average molecular weight of 50,000 or more and 1,000,000 or less in the polyol resin contained in the thermosetting resin composition is preferably 40% by weight or more and 95% by weight or less, more preferably 50% by weight or more and 90% by weight or less, and still more preferably 55% by weight or more and 85% by weight or less.

[0028] The content of the polyol resin in the thermosetting resin composition is preferably 20% by weight or more and 80% by weight or less, more preferably 30% by weight or more and 75% by weight or less, and still more preferably 35% by weight or more and 70% by weight or less. The thermosetting resin composition for forming the resin layer may be diluted with volatile components such as a solvent as described later. In this specification, the content (weight%) of each component in the resin layer or the thermosetting resin composition means a value based on the solid content excluding the volatile components. Also, the content in the thermosetting resin composition here means the content of each component in the entire resin layer. For example, when the resin layer is multilayered, it means the content of each component of the thermosetting resin composition in the entire resin layer constituted by the entire multilayer. The same applies to the following regulations.

[0029] Within the range that does not inhibit the effects of the present invention, the thermosetting resin composition may contain a thermosetting resin other than the polyol resin. Examples of the thermosetting resin other than the polyol resin include (meth)acrylic resins other than the polyol resin, polycarbonate resins other than the polyol resin, polyester resins other than the polyol resin, epoxy resins other than the polyol resin, and the like. These thermosetting resins can be used alone or in combination of two or more. The thermosetting resin other than the polyol resin may be a plasticized resin having a weight average molecular weight of less than 50,000 as described above, or a resin having a weight average molecular weight of 50,000 or more.

[0030] <Isocyanate> The thermosetting resin composition preferably contains isocyanate. The isocyanate is an active isocyanate and is not particularly limited as long as it can cure the above polyol resin. The isocyanate may be a polyisocyanate or a polyisocyanate prepolymer which is a multimer of the polyisocyanate, but a polyisocyanate prepolymer is preferred. As the polyisocyanate, a diisocyanate is preferred. Examples of the polyisocyanate prepolymer include adducts of diisocyanates, biurets of diisocyanates, isocyanurates of diisocyanates, and the like. Examples of the diisocyanate include 4,4'-diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), m-xylene diisocyanate (XDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), bis(isocyanatomethyl)cyclohexane (H6XDI), and the like. Among these, the isocyanurate of HDI is preferred.

[0031] The content of isocyanate in the thermosetting resin composition is preferably adjusted so that the number of functional groups in the polyol resin is 0.4 or more and 1.8 or less, more preferably 0.6 or more and 1.5 or less, relative to the number of isocyanate groups in the isocyanate.

[0032] The content of isocyanate in the thermosetting resin composition is preferably 30 parts by weight or more and 90 parts by weight or less with respect to 100 parts by weight of the polyol resin. When the content of isocyanate is 30 parts by weight or more with respect to 100 parts by weight of the polyol resin, the thermosetting resin composition can be cured more sufficiently. When the content of isocyanate is 90 parts by weight or less with respect to 100 parts by weight of the polyol resin, the outgas amount of the resin layer of the thermosetting resin sheet can be further reduced. From such a viewpoint, the content of isocyanate is more preferably 33 parts by weight or more and 88 parts by weight or less, and still more preferably 36 parts by weight or more and 86 parts by weight or less, with respect to 100 parts by weight of the polyol resin.

[0033] <Solvent> The solvent contained in the thermosetting resin composition is preferably a solvent that does not contain active hydrogen that reacts with NCO. Examples of solvents that do not contain active hydrogen that reacts with NCO include esters, ketones, aliphatic hydrocarbons, and aromatic hydrocarbons. Examples of esters include methyl acetate, ethyl acetate, butyl acetate, and amyl acetate. Examples of ketones include acetone, methyl ethyl ketone, cyclohexanone, and methyl cyclohexanone. Examples of aliphatic hydrocarbons include hexane, heptane, and octane. Examples of aromatic hydrocarbons include benzene, toluene, and xylene. These solvents can be used alone or in combination of two or more. Among these, ethyl acetate and MEK are preferred. The content of the solvent in the thermosetting resin composition is not particularly limited as long as the outgas amount derived from the solvent measured by gas chromatography-mass spectrometry (GC-MS method) of the resin layer of the thermosetting resin sheet is within the above range. Further, the solvent may be a solvent contained in the raw materials of the thermosetting resin composition, a solvent added to reduce the viscosity of the thermosetting resin composition, or a solvent added to dilute or dissolve each component. Further, it may be a solvent separately added to adjust the amount of the solvent.

[0034] In addition to the curable resin and the curing agent, the thermosetting resin composition may appropriately contain components according to the performance required for the coating formed from the thermosetting resin sheet. For example, when the coating formed from the thermosetting resin sheet is a colored coating, colorants such as pigments, dyes, and brighteners may be contained in the thermosetting resin composition. Further, when the coating formed from the thermosetting resin sheet is a heat-insulating coating, a heat-insulating material may be contained in the thermosetting resin composition. The thermosetting resin composition may also contain components other than those described above. For example, it may contain additives other than those described above. Examples of the additives include crosslinking agents, dispersants, inorganic fillers other than pigments and brighteners, anti-aging agents, antioxidants, and rust preventives. Furthermore, the resin layer may be composed of a clear layer described later. Among these, the thermosetting resin composition preferably contains at least a colorant. Thereby, the resin layer becomes a colored resin layer.

[0035] Examples of the pigments used as colorants include metal oxide pigments such as titanium oxide 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, benzimidazolone pigments, vat pigments, isoindoline pigments, isoindolinone pigments, metal chelate azo pigments, phthalocyanine pigments, indanthrone pigments, dioxane pigments, and indigo pigments, but are not limited thereto. As the dye, known dyes can be used, and examples include azo dyes, anthraquinone dyes, indigoid dyes, and stilbene dyes. The brightener is a compound that can impart brightness to the resin layer and can impart the property of showing gloss when observed from multiple directions. The brightener is not particularly limited, and examples include compounds provided with a titanium oxide layer on the surface of natural mica, synthetic mica, alumina flakes, glass flakes, and the like. The thermosetting resin composition preferably contains at least one of a pigment or a brightening material as a colorant, more preferably contains a pigment, and also preferably contains both a pigment and a brightening material. The content of the colorant in the thermosetting resin composition is not particularly limited, but is, for example, about 0.05 to 20% by weight, preferably 0.1 to 15% by weight, and more preferably 0.3 to 10% by weight. In addition to the above-mentioned additives such as colorants and heat shielding materials, the thermosetting resin composition may appropriately contain additives such as inorganic fillers, curing catalysts, curing accelerators, surface modifiers, defoaming agents, crosslinking agents, dispersants, anti-aging agents, and antioxidants.

[0036] The resin layer may be composed of a single layer or may have a multilayer structure of two or more layers, but a multilayer structure is preferred. By having a multilayer structure, various functions can be imparted to the coating formed from the resin layer. When the resin layer has a multilayer structure, it is only necessary for the entire resin layer to satisfy the above requirements, and it is not necessary for a part of the layer constituting the resin layer to satisfy the above requirements.

[0037] When the resin layer is a single layer, the resin layer is preferably composed of a thermosetting resin composition containing a polyol resin, an isocyanate, and a solvent. The thermosetting resin composition may also contain a colorant and other additives in addition to these.

[0038] When the resin layer has a multilayer structure, each layer is preferably composed of a thermosetting resin composition containing a polyol resin, an isocyanate, and a solvent. Each layer may also contain a colorant as described above to form a colored resin layer, may contain a heat shielding material to form a heat shielding layer, or may be a clear layer without substantially containing a colorant.

[0039] In the case of a multilayer structure, the resin layer preferably has at least a colored resin layer and a clear layer. When having a colored resin layer and a clear layer, the clear layer and the colored resin layer may be arranged in this order from the transfer layer side. With such a layer configuration, when the thermosetting resin sheet is attached to the object to be coated, the colored resin layer and the clear layer will be arranged in this order from the object to be coated side. By having a colored resin layer, the resin layer can color the object to be coated with the coating formed by the resin layer. Further, by providing a clear layer in addition to the colored resin layer, the colored resin layer can be protected or gloss can be imparted to the colored resin layer. The colored resin layer preferably contains a pigment as a colorant. Therefore, it is particularly preferable that the resin layer includes a clear layer and a pigment layer.

[0040] Both the colored resin layer and the clear layer are preferably made of a thermosetting resin composition containing a polyol resin, an isocyanate, and a solvent. The thermosetting resin composition for the colored resin layer may contain a colorant as described above. The thermosetting resin composition for the colored resin layer may be adjusted so that the content of the colorant in the entire resin layer is within the above range. Further, the thermosetting resin composition for the colored resin layer preferably contains a polyol resin having a weight average molecular weight of 50,000 or more and 1,000,000 or less, and preferably contains a plasticizing resin in addition to the polyol resin. As the plasticizing resin, a polyol resin having a weight average molecular weight of less than 50,000 as described above is preferable.

[0041] On the other hand, the clear layer is a transparent layer and may have transparency such that the color of the colored resin layer can be visually recognized from the outside through the clear layer. For example, the transmittance of light with a wavelength of 450 nm is preferably 80% or more. The clear layer is preferably a coating film that does not contain a colorant, but may contain a small amount of a colorant as long as its function is not inhibited. The thermosetting resin composition for the clear layer preferably contains a polyol resin having a weight average molecular weight of 50,000 or more and 1,000,000 or less as described above, but may or may not contain a plasticizing resin in addition to the polyol resin.

[0042] Of course, when the resin layer has a multilayer structure, it is not limited to the two-layer structure of the clear layer and the colored resin layer, and it can have various laminated structures. It is also possible to provide two or more colored resin layers and one or more clear layers to form a structure of three or more layers, or it may be composed of two colored resin layers with the clear layer omitted. Also, two or more clear layers may be provided. Further, a heat insulating layer or the like may be provided between the clear layer and the colored resin layer to form a structure of three or more layers. In the case of a multilayer structure, the content of each component in the thermosetting resin composition for each layer may be appropriately adjusted so that the content of each component in the entire resin layer is within the above range.

[0043] The thickness of the resin layer is not particularly limited, but for example, it is 20 μm or more and 200 μm or less, preferably 30 μm or more and 100 μm or less. Also, when a colored resin layer and a clear layer are provided in the resin layer, the thickness of the colored resin layer is not particularly limited, but for example, it is 10 μm or more and 100 μm or less, preferably 15 μm or more and 50 μm or less. Also, the thickness of the clear layer is not particularly limited, but for example, it is 10 μm or more and 100 μm or less, preferably 15 μm or more and 50 μm or less.

[0044] (Transfer layer) The transfer layer protects the resin layer from damage and adhesion of foreign substances, and also serves as a support when attaching the resin layer to the object to be coated. The transfer layer is preferably capable of being formed by vacuum forming and preferably capable of being processed by cutting.

[0045] The transfer layer is preferably formed from a resin film. Examples of the resin used for the resin film include polyolefin resins such as polyethylene resin and polypropylene resin, and polyimide resin. Among these, from the viewpoints of production cost and handleability, it is more preferable to contain polypropylene resin or polyethylene resin, and from the viewpoint of heat resistance, it is more preferable to contain polypropylene resin or polyimide resin.

[0046] As the polypropylene resin, homopolypropylene may be used, or a copolymer of propylene such as random polypropylene and a small amount (for example, 10% by weight or less) of other α-olefins may also be used. Examples of other α-olefins include linear α-olefins having 1 to 12 carbon atoms such as ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-nonene, and 1-decene. As the polyethylene resin, low-density polyethylene (LDPE, density: less than 0.930 g / cm 3 ), medium-density polyethylene (MDPE, density: 0.930 g / cm 3 or more and less than 0.942 g / cm 3 ), high-density polyethylene (HDPE, density: 0.942 g / cm 3 or more), linear low-density polyethylene (LLDPE), etc. may be mentioned.

[0047] The resin film constituting the transfer layer may be a single-layer film composed of a single layer, or may be a multilayer film of two or more layers. Further, in the resin film constituting the transfer layer, the resin contained in the resin film may be used alone or two or more kinds may be used in combination. When two or more kinds of resins are used in combination, different kinds of resins may be used for each layer to form a multilayer film. Further, a single-layer film may be formed by mixing two or more kinds of resins, or one or two or more layers in the multilayer film may be formed.

[0048] The transfer layer may be a release agent such as a silicone-based release agent or a fluorine-based release agent, and at least one surface thereof may be release-treated. When the transfer layer is release-treated, the release-treated surface preferably constitutes the surface on the resin layer side. The transfer layer is easily peeled from the resin layer by being release-treated. However, the transfer layer does not necessarily need to be release-treated as long as it can be peeled from the resin layer.

[0049] The thickness of the transfer layer is not particularly limited, but for example, it is 10 μm or more and 1000 μm or less, preferably 30 μm or more and 700 μm or less, more preferably 50 μm or more and 500 μm or less. When the thickness of the transfer layer is equal to or less than the above upper limit value, the air permeability value is likely to be below a certain level, and it becomes easier to vent the gas generated from the resin layer. Also, when the thickness of the transfer layer is equal to or more than the above lower limit value, a certain strength can be imparted to the transfer layer.

[0050] (Protective layer) The thermosetting resin sheet may be provided with a protective layer. The protective layer is a member that protects the resin layer from being damaged and from adhering foreign substances. The protective layer is preferably formed from a resin film. Examples of the resin used for the resin film for the protective layer include thermoplastic resins. Also, it is preferable to use a resin whose elongation at break can be adjusted within the above-mentioned desired range. The protective layer is preferably capable of being formed by vacuum forming and is preferably capable of being processed by cutting. Specific examples of the resin used for the resin film include polyolefin resins, polyester resins such as polybutylene terephthalate and polyethylene terephthalate, polyamide resins, polycarbonate resins, acrylic resins, fluororesins, soft vinyl chloride resins, polymethylpentene resins, tetrafluoroethylene resins, etc. When using a polyolefin resin, the same one as the above transfer layer can be used. Among the above, polyester resins are preferred.

[0051] The resin film forming the protective layer may be a single-layer film composed of a single layer, or may be a multilayer film of two or more layers. Also, in the resin film constituting the protective layer, the resin contained in the resin film may be used alone or two or more kinds may be used in combination. The resin film used for the protective layer may be a stretched resin film or an unstretched resin film that has not been stretched, but an unstretched resin film is preferred. The protective layer may be a release agent such as a silicone-based release agent or a fluorine-based release agent, and at least one surface thereof may be release-treated. When the protective layer is release-treated, the release-treated surface preferably constitutes the surface on the resin layer side. By subjecting the protective layer to release treatment, the peelability from the resin layer can be easily improved. However, as long as the protective layer can be peeled from the resin layer, it does not necessarily have to be release-treated. The thickness of the protective layer is not particularly limited, but for example, it is 10 μm or more and 1000 μm or less, preferably 30 μm or more and 700 μm or less, more preferably 50 μm or more and 500 μm or less.

[0052] (Method for manufacturing a thermosetting resin sheet) The method for manufacturing the thermosetting resin sheet is not particularly limited, but it can be manufactured by a known method. For example, a thermosetting resin composition is prepared, and the prepared thermosetting resin composition is applied onto the transfer layer and dried as necessary to form a resin layer. When the thermosetting resin sheet is provided with a protective layer, the thermosetting resin composition may be applied onto the protective layer and dried as necessary to form a resin layer, and then a transfer layer may be further laminated onto the resin layer formed on the obtained protective layer to obtain a thermosetting resin sheet. When applying the thermosetting resin composition onto the transfer layer or the protective layer, the thermosetting resin composition may be appropriately diluted with a solvent or the like. Examples of the solvent include ethyl acetate, butyl acetate, toluene, and the like. When the resin layer is multilayered, it may be formed by sequentially forming and laminating each layer. For example, when having a clear layer and a colored resin layer, the clear layer and the colored resin layer may be laminated in this order onto the transfer layer. When the thermosetting resin sheet is provided with a protective layer, a thermosetting resin sheet may be obtained by laminating the colored resin layer formed on the protective layer and the clear layer formed on the transfer layer.

[0053] It is preferable to dry the produced thermosetting resin sheet. This makes it easier to adjust the solvent content in the thermosetting resin composition so that the outgassing amount derived from the solvent in the resin layer is within the above-mentioned range. The drying temperature is preferably 40°C or higher and 90°C or lower, more preferably 50°C or higher and 80°C or lower, and even more preferably 60°C. Also, the drying time is preferably 1 minute or longer and 30 minutes or shorter, more preferably 3 minutes or longer and 15 minutes or shorter, and even more preferably 5 minutes or longer and 10 minutes or shorter.

[0054] (Frozen storage) The thermosetting resin sheet of the present invention can be stored without reducing the pot life by storing it frozen. The temperature when storing the thermosetting resin sheet frozen is not particularly limited as long as it can suppress the activity of the isocyanate, but is preferably -10°C or lower, more preferably -15°C or lower, and even more preferably -20°C or lower. The thermosetting resin sheet of the present invention is preferably frozen after production and transported in the frozen state. Then, at the site, it is preferable to thaw the frozen thermosetting resin sheet and attach the thawed thermosetting resin sheet to the object to be coated. Note that the pot life of the thermosetting resin sheet in this case is the time during which the thermosetting resin sheet is usable after thawing.

[0055] [Coating method] Hereinafter, a coating method for coating an object to be coated using the thermosetting resin sheet of the present invention is provided. The coating method according to one embodiment of the present invention includes the following first and second steps. First step: A step of attaching the thermosetting resin sheet to the object to be coated Second step: A step of curing the thermosetting resin sheet

[0056] (First step) The first step is a step of attaching a thermosetting resin sheet to an object to be coated. The object to be coated to which the thermosetting resin sheet is attached is not particularly limited, and examples include vehicles such as electrical appliances, automobiles, and transportation equipment other than automobiles, vehicle parts of vehicles such as automobiles and transportation equipment other than automobiles, miscellaneous goods, heavy machinery, ships, exterior materials of aircraft, etc., exterior walls or roof materials of houses, buildings, etc., bridges, steel structures, plants, wind power generation blades, and the like. Vehicle parts include, for example, interior materials for vehicles and exterior materials for vehicles. Among these, vehicles and vehicle parts are preferred, vehicle parts are more preferred, and exterior materials for vehicles are even more preferred. Examples of exterior materials for vehicles include hoods, roofs, door panels, bumpers, fuel filler panels, trunk lids, rear gates, and the like. When the thermosetting resin sheet is attached to an exterior material for a vehicle, it may be attached to the exterior material attached to the vehicle body, or it may be attached to the exterior material before being attached to the vehicle body. Also, the material of the object to be coated is not particularly limited, and it may be any of resin materials, inorganic materials such as ceramics, and metal materials such as steel materials, but among these, metal materials such as steel materials are preferred.

[0057] The thermosetting resin sheet used in the first step is a sheet for forming a coating on an object to be coated. The thermosetting resin sheet includes a resin layer and a transfer layer formed on one surface of the resin layer. The resin layer is made of a thermosetting resin composition and can be cured by heating. The resin layer constitutes a part of the coating formed on the object to be coated.

[0058] Before the thermosetting resin sheet is attached to the object to be coated, a protective layer may be laminated on the other surface of the resin layer. When the protective layer is laminated, the transfer-type thermosetting resin may be peeled off the protective layer from the resin layer before being attached to the object to be coated to expose the resin layer and then attached to the object to be coated. The method of peeling off the protective layer is not particularly limited and may be peeled off by a peeling device or manually. Of course, in the thermosetting resin sheet, the protective layer may be omitted.

[0059] In this project, it is advisable to attach a thermosetting resin sheet with the resin layer exposed to the object to be coated by bringing the resin layer into contact therewith. At this time, the attachment of the thermosetting resin sheet to the object to be coated is not particularly limited, and it may be performed by manual attachment using a squeegee or the like, or it may be performed using a laminating device. Since the resin layer is composed of a thermosetting resin composition and is uncured at the time of attachment, it is easy to ensure a certain degree of flexibility. Therefore, the resin layer can adhere properly to the object to be coated and can be temporarily fixed to the object 20 to be coated with an appropriate adhesive strength.

[0060] The thermosetting resin sheet may be preformed by vacuum forming, press forming, pressure air forming, etc., and may be shaped into a shape corresponding to the shape of the object to be coated, and the shaped thermosetting resin sheet may be attached to the object to be coated. The preforming may be performed before peeling the protective layer from the resin layer when the thermosetting resin sheet is provided with a protective layer, or may be performed after peeling the protective layer from the resin layer. By performing the preforming, even if the object to be coated has a complex shape, the thermosetting resin sheet can be easily adhered and attached to the object to be coated. Among the above, the preforming is preferably performed by vacuum forming. The preforming may be performed by pressing the coating sheet against a jig or a mold by vacuum forming, and shaping the thermosetting resin sheet into a shape corresponding to the surface shape of the object to be coated while stretching it with the jig or the mold. Here, the vacuum forming is preferably TOM forming. TOM stands for "Three dimension Overlay Method", and when TOM forming is applied, it is possible to shape into a complex shape.

[0061] (Second step) The second step is a step performed after the first step, and cures the resin layer of the thermosetting resin sheet. In this step, it is advisable to cure the resin layer sufficiently until it can be used as a coating.

[0062] In the second step, the thermosetting resin sheet may be heated using a heating device such as an oven or an infrared heater while being attached to the object to be painted. The heating temperature is preferably 50°C or higher and 100°C or lower, more preferably 60°C or higher and 90°C or lower. The heating time is, for example, 30 minutes or longer and 300 minutes or shorter, preferably 60 minutes or longer and 180 minutes or shorter.

[0063] In the painting method of the present invention, it is further preferable to include a step of peeling the transfer layer from the resin layer. The peeling of the transfer layer may be performed by a peeling device or manually. The peeling of the transfer layer may be performed before the above-described second step, after the second step, or during the second step, but it is preferably performed before the second step.

[0064] [Vehicle, vehicle parts, method for manufacturing a vehicle, method for manufacturing vehicle parts] The vehicle and vehicle parts of the present invention are painted using the thermosetting resin sheet of the present invention. Therefore, the method for manufacturing a vehicle and the method for manufacturing vehicle parts of the present invention include a step of painting using the thermosetting resin sheet of the present invention. The painting step may be performed by the method described in the above painting method.

Examples

[0065] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0066] <Outgassing amount> The amount of outgas derived from the solvent in the resin layer was measured as follows: A thermosetting resin sheet composed of a transfer layer and a resin layer was cut into pieces of 5 mm × 5 mm. The transfer layer was peeled off from the cut thermosetting resin sheet to prepare a measurement sample composed of the resin layer. The amount of outgas of the measurement sample was measured using thermal desorption GC-MS (thermal desorption device: manufactured by PerkinElmer, trade name "TurboMatrix 350", GC-MS device: manufactured by JEOL Ltd., trade name "JMS 1500GC"). Then, from the measurement results, the peak of the solvent was identified, and the amount of outgas derived from the solvent in the resin layer was calculated from the peak area of the peak. In this example, since ethyl acetate and MEK were used as the solvents, the peaks of ethyl acetate and MEK were identified, and the amount of outgas derived from the solvent in the resin layer was calculated from the peak areas of the peaks. The detailed measurement conditions are as follows. (Measurement conditions) Device: Outgas analysis Device: TurboMatrix 350 (manufactured by PerkinElmer) Heating: The above peak top temperature (T1), 30 min (20 mL / min) Secondary desorption: 350 °C Split: Inlet 25 mL / min, outlet 25 mL / min, injection volume 2.5% GC / MS device: Agilent7890B&JMS-Q1500GC Column: EQUITY-1 (non-polar) 0.32 mm × 60 m × 0.25 μm Column temperature: 40 °C (4 min) → 10 °C / min → 300 °C (10 min) He flow rate: 1.5 mL / min (split ratio 1:30) MS temperature: Ion source; 230 °C, Interface; 250 °C MS measurement range: 29 - 600 Ionization method: EI method Measurement mode: Scan Ionization voltage: 70 eV

[0067] (Adhesion) Using a construction liquid (manufactured by Lintec Corporation, product name "Real Paerfect"), a 5 cm × 5 cm thermosetting resin sheet was pasted onto a glass plate with water. After peeling off the transfer layer, it was baked at 60 °C for 120 minutes to produce a cured resin sheet. A cross-cut test conforming to JIS K 5600-5-6 was carried out on the obtained cured resin sheet and evaluated according to the following evaluation criteria. <Evaluation Criteria> ○: The classification of the test result is 0 to 2 ×: The classification of the test result is 3 or more

[0068] (Pot life) The produced thermosetting resin sheet was left in an environment at a temperature of 25 °C for the pot life shown in Table 1 and Table 2. Then, using a construction liquid (manufactured by Lintec Corporation, product name "Real Paerfect"), a 5 cm × 5 cm thermosetting resin sheet was pasted onto a glass plate with water. After peeling off the transfer layer, it was baked at 60 °C for 120 minutes to produce a cured resin sheet. A cross-cut test conforming to JIS K 5600-5-6 was carried out on the obtained cured resin sheet and evaluated according to the following evaluation criteria. And the longest pot life with the following evaluation being "○" was taken as the pot life of the thermosetting resin sheet. <Evaluation Criteria> ○: The classification of the test result is 0 to 2 ×: The classification of the test result is 3 or more

[0069] (Appearance) Using a construction liquid (manufactured by Lintec Corporation, product name "Real Paerfect"), a 5 cm × 5 cm thermosetting resin sheet was pasted onto a glass plate with water. After peeling off the transfer layer, it was baked at 60 °C for 120 minutes to produce a cured resin sheet. The produced cured resin sheet was visually observed and evaluated according to the following evaluation criteria. <Evaluation Criteria> ○: The surface of the cured resin sheet was smooth. △: The surface of the cured resin sheet was smooth, but a wrinkle was observed. ×: The surface of the cured resin sheet was rough and at a level that was a problem in practical use.

[0070] The components of the film for the transfer layer and the resin layer used in the examples and comparative examples are as follows. <Film for Transfer Layer> Convenience PE: Unstretched polyethylene / EVA multilayer film ("Convenience PE" manufactured by Okamoto & Co., Ltd., thickness 200 μm)

[0071] <Polyol Resin> Acrylic polyol resin (1): Weight average molecular weight 250,000, hydroxyl value 80 mgKOH / g, glass transition temperature 40 °C, solid content concentration (NV) = 29.6 wt% (solvent: ethyl acetate) Acrylic polyol resin (2): Weight average molecular weight 250,000, hydroxyl value 110 mgKOH / g, glass transition temperature -50 °C, solid content concentration (NV) = 40 wt% (solvent: ethyl acetate) Polycarbonate diol: Weight average molecular weight 500, hydroxyl value 224 mgKOH / g, solid content concentration (NV) = 100 wt%, manufactured by UBE Industries, Ltd., "PH-50"

[0072] <Isocyanate> Isocyanate (1): Hexamethylene diisocyanate-based (HDI-based) isocyanurate, manufactured by Mitsui Chemicals, Inc., "D-160N", effective NCO content 12.6 wt%, solid content concentration (NV) = 75 wt% (solvent: ethyl acetate) Isocyanate (2): Hexamethylene diisocyanate-based (HDI-based) isocyanurate, manufactured by Mitsui Chemicals, Inc., "D-127N", effective NCO content 13.6 wt%, solid content concentration (NV) = 75 wt% (solvent: ethyl acetate)

[0073] <Pigment (Colorant)> Pigment (1): "NSP-RF 655C BLUE" manufactured by Nichihon Binks Co., Ltd., effective pigment concentration = 25 wt%, solid content concentration (NV) = 25 wt%, solvent is MEK Pigment (2): "NSP-RF 001A WHITE" manufactured by Nichihon Binks Co., Ltd., effective pigment concentration = 70 wt%, solid content concentration (NV) = 70 wt%, solvent is MEK

[0074] [Example 1] Based on solids content, 60 parts by weight of acrylic polyol (1), 40 parts by weight of polycarbonate diol, 61.4 parts by weight of isocyanate (1), 0.81 part by weight of pigment (1) and 11.3 parts by weight of pigment (2) were added, and ethyl acetate was added as a solvent to prepare a diluted solution of the thermosetting resin composition so that the solids concentration became 40% by weight. On the surface of the film for the transfer layer, the thermosetting resin composition was coated with an applicator, and then the drying process was carried out under the conditions of a drying temperature of 60 °C and a drying time of 10 minutes to form a thermosetting resin sheet of Example 1 with a thickness of 20 μm on the transfer layer. The evaluation results of the obtained thermosetting resin sheet are shown in Table 1.

[0075] [Examples 2 to 9 and Comparative Examples 1 to 2] It was the same as in Example 1 except that the thermosetting resin composition and the drying time were changed as shown in Tables 1 and 2.

[0076]

Table 1

[0077]

Table 2

[0078] For the thermosetting resin sheets of Examples 1 to 9, since the amount of outgas derived from the solvent in the resin layer was 5 ppm or more, the pot life of the thermosetting resin sheet could be extended. Further, for the thermosetting resin sheets of Examples 1 to 9, since the amount of outgas derived from the solvent in the resin layer was 5000 ppm or less, the appearance was also good. Since the amount of outgas derived from the solvent in the resin layer of the thermosetting resin sheet of Comparative Example 1 was 5 ppm or more, the pot life of the thermosetting resin sheet could be extended. However, since the amount of outgas derived from the solvent in the resin layer of the thermosetting resin sheet of Comparative Example 1 was greater than 5000 ppm, the appearance was poor. Since the amount of outgas derived from the solvent in the resin layer of the thermosetting resin sheet of Comparative Example 2 was less than 5 ppm, the pot life of the thermosetting resin sheet of Comparative Example 2 was short.

Claims

1. A thermosetting resin sheet comprising a resin layer made of a thermosetting resin composition and a transfer layer, wherein the thermosetting resin composition contains a solvent, and the outgassing amount derived from the solvent measured by gas chromatography-mass spectrometry (GC-MS method) of the resin layer of the thermosetting resin sheet is 5 ppm or more and 5000 ppm or less.

2. The thermosetting resin sheet according to claim 1, wherein the outgassing amount derived from the solvent measured by GC-MS method of the resin layer of the thermosetting resin sheet is 5 ppm or more and 500 ppm or less.

3. The thermosetting resin sheet according to claim 1 or 2, which is dried under drying conditions of a drying temperature of 60 ° C and a drying time of 5 minutes or more and 10 minutes or less.

4. The thermosetting resin sheet according to claim 1 or 2, wherein the thermosetting resin composition contains isocyanate.

5. The thermosetting resin composition contains a polyol resin, and the content of the isocyanate is 30 parts by weight or more and 90 parts by weight or less with respect to 100 parts by weight of the polyol resin.

6. The thermosetting resin sheet according to claim 1 or 2, wherein the thermosetting resin composition contains a polyol resin having a weight average molecular weight of 50,000 or more and 1,000,000 or less.

7. The thermosetting resin sheet according to claim 6, wherein the polyol resin is (meth)acrylic polyol.

8. The thermosetting resin sheet according to claim 6, wherein the polyol resin contains a polyol resin having a hydroxyl value of 100 mgKOH / g or less.

9. The thermosetting resin composition further contains a colorant, and the resin layer is a colored resin layer.

10. A vehicle painted using the thermosetting resin sheet according to claim 1 or 2.

11. A vehicle part painted using the thermosetting resin sheet according to claim 1 or 2.

12. A method for manufacturing a vehicle, comprising a step of painting using the thermosetting resin sheet according to claim 1 or 2.

13. A method for manufacturing a vehicle part, comprising a step of painting using the thermosetting resin sheet according to claim 1 or 2.

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