Thermosetting resin sheet and method for manufacturing the same, vehicle and vehicle component, and method for manufacturing vehicle and vehicle component

Abstract

To provide a thermosetting resin sheet having high surface hardness, and having high adhesive force to a coating plate and a method for manufacturing the same, a vehicle and a vehicle component coated using the thermosetting resin sheet, and a method for manufacturing a vehicle and a vehicle component.SOLUTION: A thermosetting resin sheet 1B has at least a top coat layer 10 composed of a first thermosetting resin composition, and a resin layer 20 composed of a second thermosetting resin composition, wherein the first thermosetting resin composition contains a first polyol resin and a first isocyanate curing agent, the second thermosetting resin composition contains a second polyol resin and a second isocyanate curing agent, and a hydroxyl value (OHv1) of the first polyol resin and a hydroxyl value (OHv2) of the second polyol resin satisfy a relation of OHv1≥OHv2. A method for manufacturing a resin sheet includes the steps of: applying a coating of a first coating material onto a transfer layer 40 and manufacturing a first laminate; and applying a coating of a second coating material onto a base material 50 and manufacturing a second laminate.SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] The exterior of vehicles and the like is painted with paint. Generally, painting is performed by spray-applying a paint for a colored resin layer, then applying a paint for a topcoat layer in multiple coats, and heating and drying. The topcoat layer requires a certain degree of hardness to protect the vehicle from external factors, and it is known to increase the hydroxyl value to raise this hardness (see, for example, Patent Document 1).

[0003] Further, as a decorative sheet that can be attached to the surfaces of furniture, steel plates, etc., a thermosetting coating sheet mainly composed of an acrylic resin having a plurality of functional groups, a monomer or oligomer having a plurality of functional groups, and a blocked isocyanate is known as the prior art (see, for example, Patent Document 2). Patent Document 2 describes that a colorant such as a pigment or a dye may be contained in this thermosetting coating sheet.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the case of conventional spray painting, after applying the paint for the colored resin layer, the paint for the top coat layer is immediately overlaid. Therefore, if the hydroxyl value of the paint for the top coat layer is increased to enhance the strength of the top coat layer, the paint for the top coat layer may be compatible with the colored resin layer, and a good two-layer structure composed of the colored resin layer and the top coat layer may not be obtained. On the other hand, if the hydroxyl value of the paint for the colored resin layer is increased to prevent compatibility with the top coat layer, the adhesion to the substrate deteriorates. Also, in the conventional thermosetting coating sheet, when there is no top coat layer and an attempt is made to increase the surface hardness, the adhesion to the substrate becomes insufficient, and when an attempt is made to increase the adhesion to the substrate, the surface hardness may become insufficient.

[0006] Therefore, an object of the present invention is to provide a thermosetting resin sheet having a high surface hardness and a high adhesive force to an adherend such as a coated plate, a method for producing the same, a vehicle and vehicle parts coated with the thermosetting resin sheet, and a method for producing the vehicle and vehicle parts.

Means for Solving the Problems

[0007] As a result of intensive studies, the present inventor has found that the above problems can be solved by the hydroxyl value of the polyol resin used in the top coat layer and the hydroxyl value of the polyol resin used in the resin layer having a predetermined relationship, and has completed the present invention. The gist of the present invention is as follows. [1] A thermosetting resin sheet having at least a top coat layer made of a first thermosetting resin composition and a resin layer made of a second thermosetting resin composition, The first thermosetting resin composition contains a first polyol resin and a first curing agent, The second thermosetting resin composition contains a second polyol resin and a second curing agent, A thermosetting resin sheet in which the hydroxyl value (OHv1) of the first polyol resin and the hydroxyl value (OHv2) of the second polyol resin satisfy the relationship of the following formula (1). OHv1≧OHv2 (1) [2] The thermosetting resin sheet according to [1] above, wherein the hydroxyl value (OHv1) of the first polyol resin is 50 mgKOH / g or more and 250 mgKOH / g or less. [3] The thermosetting resin sheet according to [1] or [2] above, wherein the hydroxyl value (OHv2) of the second polyol resin is 20 mgKOH / g or more and 150 mgKOH / g or less. [4] The thermosetting resin sheet according to any one of [1] to [3] above, wherein the logarithm of the dynamic loss tangent (log(tan δ)) of the thermosetting resin sheet at 25 °C measured by viscoelasticity measurement using a dynamic viscoelasticity measuring device (DMA) is 1 or less. [5] The thermosetting resin sheet according to [4] above, wherein the second thermosetting resin composition further contains a colorant. [6] The thermosetting resin sheet according to any one of [1] to [5] above, wherein the weight average molecular weights of the first polyol resin and the second polyol resin are each 50,000 or more and 1,000,000 or less. [7] The thermosetting resin sheet according to any one of [1] to [6] above, wherein both the first polyol resin and the second polyol resin contain a (meth)acrylic resin having a plurality of hydroxyl groups. [8] The thermosetting resin sheet according to any one of [1] to [7] above, wherein the reaction start temperatures of both the first curing agent and the second curing agent are 180 °C or lower. [9] A step of applying and drying a first paint containing a first thermosetting resin composition containing a first polyol resin and a first curing agent to a transfer layer to form a transfer layer and a top coat layer provided on the transfer layer and made of the first thermosetting resin composition to produce a first laminate, A step of applying and drying a second paint containing a second thermosetting resin composition containing a second polyol resin and a second curing agent to a substrate to form a substrate and a resin layer provided on the substrate and made of the second thermosetting resin composition to produce a second laminate, and A step of bonding the first laminate and the second laminate so that the top coat layer and the resin layer face each other. A method for manufacturing a thermosetting resin sheet, wherein the hydroxyl value (OHv1) of the first polyol resin and the hydroxyl value (OHv2) of the second polyol resin satisfy the relationship of the following formula (1). OHv1≧OHv2 (1)

[10] A vehicle painted using the thermosetting resin sheet according to any one of [1] to [8] above.

[11] A vehicle part painted using the thermosetting resin sheet according to any one of [1] to [8] 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 [8] 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 [8] above. [Advantages of the Invention]

[0008] According to the present invention, it is possible to provide a thermosetting resin sheet having high surface hardness and high adhesion to an adherend such as a coated plate, and a method for manufacturing the same, a vehicle and a vehicle part painted using the thermosetting resin sheet, and a method for manufacturing the vehicle and the vehicle part. [Brief Description of the Drawings]

[0009]

Figure 1

Figure 2

Figure 3

[0010] [Thermosetting Resin Sheet] The thermosetting resin sheet of the present invention has at least a top coat layer made of a first thermosetting resin composition and a resin layer made of a second thermosetting resin composition. The first thermosetting resin composition contains a first polyol resin and a first curing agent, and the second thermosetting resin composition contains a second polyol resin and a second curing agent. Here, the first polyol resin and the second polyol resin respectively refer to the polyol resin contained in the first thermosetting resin composition and the polyol resin contained in the second thermosetting resin composition. Therefore, when the first thermosetting resin composition contains a plurality of types of polyol resins, the plurality of types of polyol resins are combined as the first polyol resin, and when the second thermosetting resin composition contains a plurality of types of polyol resins, the plurality of types of polyol resins are combined as the second polyol resin. Further, the thermosetting resin sheet of the present invention may consist only of the top coat layer and the resin layer, or may have other layers in addition to the top coat layer and the resin layer. Furthermore, the hydroxyl value (OHv1) of the first polyol resin and the hydroxyl value (OHv2) of the second polyol resin satisfy the relationship of the following formula (1). OHv1≧OHv2 (1)

[0011] (Thermosetting resin composition) The first thermosetting resin composition contains a first thermosetting resin, and the second thermosetting resin composition contains a second thermosetting resin. The thermosetting resin contained in the first thermosetting resin composition may be the same as or different from the thermosetting resin contained in the second thermosetting resin composition. The first thermosetting resin and the second thermosetting resin preferably have functional groups, and the functional groups are preferably functional groups that react with the reactive groups (isocyanate groups) contained in the curing agent. Examples of the types of functional groups include hydroxyl groups, carboxyl groups, amino groups, etc., and among these, hydroxyl groups are preferred. The thermosetting resin may have only one type of functional group or two or more types of functional groups. Also, two or more functional groups are preferably contained in one molecule. The first and second thermosetting resins may each have two or more hydroxyl groups to become the first and second polyol resins described later.

[0012] Examples of the first thermosetting resin and the second thermosetting resin include (meth)acrylic resins, polycarbonate resins, polyester resins, epoxy resins, and the like. These thermosetting resins can be used alone or in combination of two or more. Among these, (meth)acrylic resins are preferred.

[0013] The content of the first thermosetting resin in the first thermosetting resin composition and the content of the second thermosetting resin in the second thermosetting resin composition are each preferably 20% by mass or more and 80% by mass or less, more preferably 30% by mass or more and 70% by mass or less, and still more preferably 35% by mass or more and 60% by mass or less. Note that the content of the first thermosetting resin in the first thermosetting resin composition may be the same as or different from the content of the second thermosetting resin in the second thermosetting resin composition. Note that although the thermosetting resin composition may be diluted with volatile components such as a solvent as described later, in this specification, the content (% by mass) of each component in the thermosetting resin composition means a value based on the solid content excluding the volatile components.

[0014] <Polyol resin> The first thermosetting resin composition contains a first polyol resin, and the second thermosetting resin composition contains a second polyol resin. That is, the first thermosetting resin contains the first polyol resin, and the second thermosetting resin contains the second polyol resin. Note that the first polyol resin and the second polyol resin may be the same or different.

[0015] Examples of the first polyol resin and the second polyol resin include (meth)acrylic polyol resins, polycarbonate polyol resins, polyester polyol resins, epoxy resin-modified polyol resins, and the like. Among these, (meth)acrylic polyol resins are preferred.

[0016] The hydroxyl value (OHv1) of the first polyol resin and the hydroxyl value (OHv2) of the second polyol resin satisfy the relationship of the following formula (1). If the hydroxyl value (OHv1) of the first polyol resin and the hydroxyl value (OHv2) of the second polyol resin do not satisfy the relationship of the following formula (1), there is a risk that the hardness of the surface of the thermosetting resin sheet will decrease or the adhesive strength of the thermosetting resin sheet to the coated plate will decrease. When the first thermosetting resin composition and the second thermosetting resin composition contain a plurality of types of polyol resins, the hydroxyl value (OHv1) of the first polyol resin and the hydroxyl value (OHv2) of the second polyol resin are the weighted average values of the hydroxyl values of the polyol resins contained in the respective thermosetting resin compositions. For example, when two types of polyol resins, polyol resin (d1) and polyol resin (d2), are used as the polyol resin, if the hydroxyl value of polyol resin (d1) is X1, the blending ratio is m1, the hydroxyl value of polyol resin (d2) is X2, and the blending ratio is m2, the weighted average value of the hydroxyl value is represented by the following formula. The blending ratio is based on mass. Weighted average value of hydroxyl value (mgKOH / g) = X1 × (m1 / (m1 + m2)) + X2 × (m2 / (m1 + m2)) Also, the hydroxyl value can be measured in accordance with JIS K 1557-1:2007. OHv1 ≥ OHv2 (1) Furthermore, when the first thermosetting resin composition and the second thermosetting resin composition contain a plasticizer, the hydroxyl value (OHv1) of the first polyol resin and the hydroxyl value (OHv2) of the second polyol resin are the weighted average values of the hydroxyl value of the polyol resin contained in each thermosetting resin composition and the hydroxyl value of the plasticizer contained in each thermosetting resin composition.

[0017] From the above viewpoints, the hydroxyl value (OHv1) of the first polyol resin is preferably higher than the hydroxyl value (OHv2) of the second polyol resin. Also, the value obtained by subtracting the hydroxyl value (OHv2) of the second polyol resin from the hydroxyl value (OHv1) of the first polyol resin is preferably 200 mgKOH / g or less, more preferably 150 mgKOH / g or less, and even more preferably 120 mgKOH / g or less. Further, the value obtained by subtracting the hydroxyl value (OHv2) of the second polyol resin from the hydroxyl value (OHv1) of the first polyol resin is preferably 20 mgKOH / g or more, more preferably 50 mgKOH / g or more, and even more preferably 60 mgKOH / g or more. By setting the value obtained by subtracting the hydroxyl value (OHv2) of the second polyol resin from the hydroxyl value (OHv1) of the first polyol resin within the above range, it is possible to increase the surface hardness of the thermosetting resin sheet and the adhesive force to the adherend, while making it difficult for delamination to occur between the resin layers.

[0018] The hydroxyl value (OHv1) of the first polyol resin is preferably 50 mgKOH / g or more and 250 mgKOH / g or less. When the hydroxyl value (OHv1) of the first polyol resin is 50 mgKOH / g or more, the surface hardness of the top coat layer can be further increased, and as a result, the surface hardness of the thermosetting resin sheet can be further increased. Also, when the hydroxyl value (OHv1) of the first polyol resin is 250 mgKOH / g or less, peeling of the first resin layer from other resin layers such as the resin layer can be suppressed. From such viewpoints, the hydroxyl value (OHv1) of the first polyol resin is more preferably 80 mgKOH / g or more and 225 mgKOH / g or less, and even more preferably 110 mgKOH / g or more and 200 mgKOH / g or less.

[0019] The hydroxyl value (OHv2) of the second polyol resin is preferably 20 mgKOH / g or more and 150 mgKOH / g or less. When the hydroxyl value (OHv1) of the second polyol resin is 20 mgKOH / g or more, the strength of the resin layer can be increased. Further, when the hydroxyl value (OHv2) of the second polyol resin is 150 mgKOH / g or less, the adhesion of the resin layer to an adherend such as a coated plate can be further increased, and as a result, the adhesion of the thermosetting resin sheet to an adherend such as a coated plate can be further increased. From such a viewpoint, the hydroxyl value (OHv2) of the second polyol resin is more preferably 30 mgKOH / g or more and 135 mgKOH / g or less, and still more preferably 40 mgKOH / g or more and 120 mgKOH / g or less.

[0020] The weight average molecular weight of the first polyol resin and the second polyol resin is each preferably 50,000 or more and 1,000,000 or less. When the weight average molecular weight of the first polyol resin and the second polyol resin is 100,000 or more and 1,000,000 or less, it becomes easy to make the coating properties, curability, tackiness, stretchability, etc. of the top coat layer and the resin layer well-balanced. From such a viewpoint, the weight average molecular weight of the first polyol resin and the second 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 the present specification, the weight average molecular weight is measured by gel permeation chromatography (GPC) and is determined as a standard polystyrene conversion value. Also, the weight average molecular weight of the first polyol resin and the second polyol resin may be the same or different.

[0021] Both the first polyol resin and the second polyol resin preferably contain a (meth)acrylic resin having a plurality of hydroxyl groups. That is, the first polyol resin and the second polyol resin are preferably (meth)acrylic polyol resins. In each of the first polyol resin and the second polyol resin, the number of hydroxyl groups is not particularly limited as long as it is 2 or more. (Meth)acrylic resins may have functional groups other than hydroxyl groups. Examples of functional groups other than hydroxyl groups include amino groups, carboxyl groups, and the like.

[0022] (Meth)acrylic resins ((meth)acrylic polyol resins) are preferably acrylic polymers obtained by polymerizing a monomer mixture containing a (meth)acrylate monomer 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 hydroxyl group-containing monomer. Note that (meth)acrylic means methacrylic or acrylic, and the same applies to other similar terms.

[0023] Examples of the above (meth)acrylate monomers include (meth)acrylate monomers having no functional groups, 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.

[0024] The above hydroxyl group-containing monomers are not particularly limited, and examples include (meth)acrylate monomers having a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate.

[0025] In addition, the monomer mixture may include monomers containing functional groups other than hydroxyl groups, such as the above-mentioned (meth)acrylate monomers such as styrene derivative monomers and monomers containing hydroxyl groups. By using monomers containing functional groups other than hydroxyl groups, such as amino groups and carboxyl groups, in addition to the 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.

[0026] 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.

[0027] Within the range that does not inhibit the effects of the present invention, the first thermosetting resin may include a thermosetting resin other than the first polyol resin, and the second thermosetting resin may include a thermosetting resin other than the second polyol resin. Examples of the thermosetting resin other than the first polyol resin and the thermosetting resin other than the second polyol resin include (meth)acrylic resins other than polyol resins, polycarbonate resins other than polyol resins, polyester resins other than polyol resins, epoxy resins other than polyol resins, and the like. These thermosetting resins can be used alone or in combination of two or more.

[0028] <Hardener> The first thermosetting resin composition contains a first curing agent, and the second thermosetting resin composition contains a second curing agent.

[0029] The first curing agent and the second curing agent are each preferably a blocked isocyanate curing agent. A blocked isocyanate curing agent is a compound in which isocyanate groups are blocked by a protecting group. When exposed to high temperatures, the protecting group (blocking moiety) undergoes thermal dissociation and detaches, and a curing reaction occurs between the generated isocyanate groups and the functional groups (typically, the hydroxyl groups of a polyol resin) in the above-described curable resin. The 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 compound having two or more isocyanate groups in one molecule is not particularly limited, and examples thereof include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, or modified products thereof. Examples of the blocking agent include pyrazole, phenols, oximes, lactams, malonic esters, and the like. Note that the above-described blocked isocyanate curing agent may be used alone or in combination of two or more. Also, the first blocked isocyanate curing agent and the second blocked isocyanate curing agent may be the same or different.

[0030] When the first curing agent and the second curing agent are blocked isocyanate curing agents, the reaction start temperatures of the first curing agent and the second curing agent are both preferably 180°C or lower. The reaction start temperature is the temperature at which the blocked isocyanate curing agent dissociates to generate isocyanate groups (thermal dissociation temperature). When the reaction start temperatures of the first curing agent and the second curing agent are both 180°C or lower, it is preferable because the thermosetting resin sheet can be cured at a relatively low temperature. From the viewpoint of curing the thermosetting resin sheet at a low temperature, the reaction start temperatures of the first curing agent and the second curing agent are both more preferably 160°C or lower, and even more preferably 140°C or lower. Also, from the viewpoint of the storage stability of the thermosetting resin sheet, the reaction start temperatures of the first curing agent and the second curing agent are both preferably 40°C or higher, and more preferably 60°C or higher. The reaction start temperature can be measured, for example, by mixing a resin having high reactivity with isocyanate in an equivalent amount to the blocked isocyanate, such as a polyol resin, stirring for 6 hours at a predetermined temperature, and then evaluating the gel fraction.

[0031] When the first curing agent and the second curing agent are blocked isocyanate curing agents, the content of the first curing agent in the first thermosetting resin composition and the content of the second curing agent in the second thermosetting resin composition are preferably adjusted so that the number of functional groups in the thermosetting 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 curing agent.

[0032] When the first curing agent and the second curing agent are blocked isocyanate curing agents, the content of the first curing agent in the first thermosetting resin composition and the content of the second curing agent in the second thermosetting resin composition are 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. However, each is preferably 20% by mass or more and 80% by mass or less, more preferably 30% by mass or more and 70% by mass or less, and still more preferably 40% by mass or more and 60% by mass or less. The content of the first curing agent in the first thermosetting resin composition may be the same as or different from the content of the second curing agent in the second thermosetting resin composition.

[0033] <Plasticizer> The first thermosetting resin composition and the second thermosetting resin composition may contain a plasticizer. In particular, it is preferable that the second thermosetting resin layer contains a plasticizer. The plasticizer is preferably a (meth)acrylic polymer. Examples of the (meth)acrylic polymer used as the plasticizer include a non-functional group type (meth)acrylic polymer, a (meth)acrylic polymer having a hydroxyl group, a (meth)acrylic polymer having a carboxyl group, a (meth)acrylic polymer having an epoxy group, and a (meth)acrylic polymer having an alkoxysilyl group. These (meth)acrylic polymers can be used alone or in combination of two or more. Among these (meth)acrylic polymers, a (meth)acrylic polymer having a hydroxyl group is preferable.

[0034] The weight average molecular weight of the (meth)acrylic polymer used as the plasticizer is preferably 300 or more and 8000 or less, more preferably 500 or more and 6000 or less, and still more preferably 1000 or more and 4000 or less.

[0035] The glass transition temperature of the (meth)acrylic polymer used as the plasticizer is preferably 10°C or lower, more preferably -80°C or higher and 0°C or lower. The glass transition temperature of the (meth)acrylic polymer refers to that measured in accordance with JIS K 7121.

[0036] The hydroxyl value of the (meth)acrylic polymer used as a plasticizer is preferably 20 mgKOH / g or more and 250 mgKOH / g or less, more preferably 50 mgKOH / g or more and 200 mgKOH / g, and still more preferably 80 mgKOH / g or more and 150 mgKOH / g.

[0037] When the first thermosetting resin composition and the second thermosetting resin composition contain a plasticizer, the content of the plasticizer in the thermosetting resin composition is preferably 1 part by mass or more and 40 parts by mass or less, more preferably 5 parts by mass or more and 30 parts by mass or less, and still more preferably 7 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass in total of the contents of the polyol resin, the curing agent, and the plasticizer.

[0038] The plasticizer in the first thermosetting resin composition may be the same as or different from the plasticizer in the second thermosetting resin composition. Also, the content of the plasticizer in the first thermosetting resin composition may be the same as or different from the content of the plasticizer in the second thermosetting resin composition.

[0039] As described above, when the first thermosetting resin composition and the second thermosetting resin composition contain a plasticizer, the hydroxyl value (OHv1) of the first polyol resin and the hydroxyl value (OHv2) of the second polyol resin are weighted average values of the hydroxyl value of the polyol resin contained in each thermosetting resin composition and the hydroxyl value of the plasticizer contained in each thermosetting resin composition.

[0040] <Colorant> The second thermosetting resin composition may contain a colorant. By containing the colorant, the resin layer can be colored, and the resin layer becomes a colored resin layer. Thereby, the design property of the thermosetting resin sheet can be enhanced. Examples of the colorant include pigments, dyes, brightening agents, etc. Examples of the pigment 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, 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, indigo pigments, and other organic pigments. Examples of the dye include azo dyes, anthraquinone dyes, indigoid dyes, stilbene dyes, etc. Examples of the brightening agent include compounds provided with a titanium oxide layer on the surface of natural mica, synthetic mica, alumina flakes, glass flakes, etc. These colorants can be used alone or in combination of two or more.

[0041] The content of the active ingredient of the colorant in the second thermosetting resin composition, that is, the content of the colorant excluding the binder resin, dispersant, and additive, varies depending on the color of the colorant. For example, the content of the white colorant required to impart hiding properties to the second thermosetting resin composition is much larger than the content of the black colorant. For example, when the colorant is a black colorant such as carbon black, the content of the colorant is, for example, 0.5 parts by mass or more, preferably 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 25 parts by mass or less, more preferably 20 parts by mass or less, and still more preferably 12 parts by mass or less with respect to 100 parts by mass of the total content of the second thermosetting resin and the second curing agent.

[0042] <Other components> The first thermosetting resin composition and the second thermosetting resin composition may each contain components other than those described above. For example, they may contain additives other than those described above. Examples of the additives include surface modifiers, defoamers, urethanization catalysts, crosslinking agents, dispersants, inorganic fillers other than pigments and brightening agents, anti-aging agents, antioxidants, rust preventives, and the like.

[0043] In addition to the first polyol resin and the first curing agent, the first thermosetting resin composition may contain a colorant, but it may not contain a colorant or, if it does, the amount should not inhibit transparency. The topcoat layer is preferably a so-called clear layer. The clear layer is a transparent layer, and transparency means that the transmittance of light with a wavelength of 450 nm is 80% or more. On the other hand, the second thermosetting resin composition preferably contains a colorant. In this case, the resin layer becomes a colored resin layer and is preferably an opaque layer. By making the resin layer a colored resin layer and the topcoat layer a clear layer, the coloring by the resin layer can be sufficiently visually recognized from the outside, enhancing the design property.

[0044] Also, the topcoat layer is preferably the outermost layer when the thermosetting resin sheet is laminated on the adherend. On the other hand, the resin layer is preferably the layer that contacts the adherend when the thermosetting resin sheet is laminated on the adherend.

[0045] <Thickness> The thickness of the topcoat 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 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.

[0046] (Logarithm of the dynamic loss tangent (log(tan δ)) of the thermosetting resin sheet) The logarithm of the dynamic loss tangent (log(tan δ)) at 25°C of the thermosetting resin sheet of the present invention measured by viscoelasticity measurement using a dynamic viscoelasticity measuring device (DMA) is 1 or less. If the log(tan δ) of the thermosetting resin sheet at 25°C is greater than 1, the hardness of the thermosetting resin sheet after heating and curing may be low. From such a viewpoint, the log(tan δ) at 25°C of the thermosetting resin sheet of the present invention measured by viscoelasticity measurement using DMA is preferably 0.5 or less, more preferably 0.2 or less, still more preferably 0.15 or less, and even more preferably 0.13 or less. The log(tan δ) at 25°C of the thermosetting resin sheet measured by viscoelasticity measurement using DMA can be measured by the method described in the examples below. The log(tan δ) at 25°C of the thermosetting resin sheet measured by viscoelasticity measurement using DMA can be adjusted by the hydroxyl value of the first polyol resin and the hydroxyl value of the second polyol resin, the weight average molecular weight of the first polyol resin and the weight average molecular weight of the second polyol resin, etc. Incidentally, the greater the hydroxyl value of the first polyol resin, the hydroxyl value of the second polyol resin, the weight average molecular weight of the first polyol resin, and the weight average molecular weight of the second polyol resin, the smaller the value of the above log(tan δ) of the thermosetting resin sheet.

[0047] (Layer structure of the thermosetting resin sheet) As shown in FIG. 1, the thermosetting resin sheet 1 may be composed only of the top coat layer 10 and the resin layer 20. In addition, another resin layer may be provided between the top coat layer and the resin layer. For example, as shown in FIG. 2, the thermosetting resin sheet 1A may include a top coat layer 10, a resin layer 20, and another resin layer (second resin layer 30) provided between the top coat layer 10 and the resin layer 20. When another resin layer is provided, the same material as that of the top coat layer and the resin layer is preferably used for the other resin layer. The other resin layer preferably contains, for example, a polyol resin and a curing agent. In such a manner, even if another resin layer is provided between the top coat layer and the resin layer, the peel strength between each resin layer can be increased, and interfacial peeling between the resin layers can be prevented. When another resin layer is provided between the top coat layer and the resin layer and the other resin layer contains a polyol resin, the hydroxyl value (OHv3) of the polyol resin is preferably a value equal to or less than the hydroxyl value (OHv1) of the first polyol resin, and more preferably a value equal to or greater than the hydroxyl value (OHv2) of the second polyol resin. Further, when the hydroxyl value (OHv3) of the polyol resin in the other resin layer is greater than the hydroxyl value (OHv2) of the second polyol resin, it is preferably a value closer to the hydroxyl value (OHv2) of the second polyol resin than the hydroxyl value (OHv1) of the first polyol resin. Thereby, the hardness of the surface of the thermosetting resin sheet can be increased, the adhesive force to an adherend such as a coated plate can be increased, and peeling between the top coat layer or the resin layer and the other resin layer can be suppressed. The other resin layer may contain a colorant in addition to the polyol resin and the curing agent. The designability of the thermosetting resin sheet can be further improved by combining a resin layer containing a colorant and another resin layer containing a colorant. The other resin layer may be two or more layers.

[0048] (Transfer layer) The thermosetting resin sheet of the present invention may further have a transfer layer provided on the side opposite to the resin layer side of the top coat layer. For example, as shown in FIG. 3, the thermosetting resin sheet 1B may further have a transfer layer 40 provided on the side opposite to the resin layer side of the top coat layer 10. The transfer layer used for the thermosetting resin sheet is a member that protects the top coat layer from scratches and foreign matter adhesion. Also, as will be described later, it is a member that serves as a support when attaching the top coat layer and the resin layer to the adherend, and typically serves as a support when transferring the top coat layer and the resin layer of the thermosetting resin sheet to the adherend. The transfer layer is preferably formed from a resin film. Examples of the resin used for the resin film include thermoplastic resins. Specific examples of the resin used for the resin film include cyclic polyolefin resins, polyolefin resins, polyester resins such as polybutylene terephthalate and polyethylene terephthalate, polyamide resins, polycarbonate resins, acrylic resins, fluorine resins, soft vinyl chloride resins, polymethylpentene resins, tetrafluoroethylene resins, and the like. Among these, cyclic polyolefin resins or polyolefin resins are preferred.

[0049] The cyclic polyolefin resin is a polymer containing a structural unit derived from a cyclic olefin. Examples of the cyclic olefin include tetracyclododecene, norbornene, cyclic conjugated dienes, and the like. The cyclic polyolefin resin may be a polymer of a cyclic olefin, a copolymer of a cyclic olefin and an α-olefin, or a hydrogenated product thereof. Examples of the above α-olefin include chain α-olefins having 1 or more and about 12 or less carbon atoms such as ethylene, propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, etc., and among these, ethylene is preferred.

[0050] The polyolefin resin is a polyolefin resin other than the cyclic polyolefin resin, and specific examples include polypropylene resin, polyethylene resin, and the like. Among these, polyethylene resin is preferred. 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 mass 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.

[0051] The resin film may be a single-layer film composed of one layer, or a multilayer film of two or more layers. Further, in the resin film constituting the release layer, the resin contained in the resin film may be used alone or in combination of two or more. When two or more resins are used in combination, different types of resins may be used for each layer to form a multilayer film. Also, a single-layer film may be formed from a mixture of two or more resins, or one or more layers in a multilayer film may be formed. In the multilayer film, examples include a multilayer film in which a layer composed of a cyclic polyolefin resin or a polyolefin resin and a layer composed of a polyester resin are laminated, for example, a multilayer film in which a polyester resin layer, a polyolefin resin layer, and a polyester resin layer are laminated in this order.

[0052] Each layer in the transfer layer may contain additives in addition to the resin. As the additives, known additives blended in the resin film may be used. Specific additives include a nucleating agent, a fluorescent brightening agent, an antioxidant, a stabilizer, an ultraviolet absorber, a surfactant, a lubricant, a filler, a crosslinking agent, a crosslinking accelerator, an antistatic agent, a flame retardant, a dispersant, a pigment, a dye, a processing aid, and the like.

[0053] The resin film may be a stretched resin film or an unstretched resin film that has not been stretched, but it is preferably an unstretched resin film. Therefore, as the resin film, an unstretched cyclic polyolefin resin film and an unstretched polyolefin resin film are preferable. By using an unstretched resin film, it becomes easier to adjust the elongation at break as described above to a desired range, and it becomes easier to prevent breakage, wrinkles, etc. from occurring during vacuum forming. Further, the unstretched resin film may be a multilayer film. For example, in addition to the polyolefin resin layer as described above, it may be a multilayer film having a polyester resin layer.

[0054] 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 topcoat layer side. By release-treating the transfer layer, the peelability from the topcoat layer can be easily improved. However, as long as the transfer layer can be peeled from the topcoat layer, it does not necessarily need to be release-treated. 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 600 μm or less, more preferably 50 μm or more and 400 μm or less.

[0055] (Substrate) The thermosetting resin sheet of the present invention may further have a base material provided on the side opposite to the top coat layer side of the resin layer. For example, as shown in FIG. 3, the thermosetting resin sheet 1B may further have a base material 50 provided on the side opposite to the top coat layer side of the resin layer 20. The base material used for the thermosetting resin sheet is a member that protects the resin layer from being damaged and from adhering foreign substances. The base material is preferably formed from a resin film. Examples of the resin used for the resin film include thermoplastic resins. Specific examples of the thermoplastic resin used for the base material are the same as the resins that can be used for the release layer, but among them, polyester resins are preferable.

[0056] The resin film may be a single-layer film consisting of a single layer, or may be a multilayer film of two or more layers. Also, in the resin film constituting the release 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. Also, a single-layer film may be formed from a mixture of two or more kinds of resins, or one or two or more layers in a multilayer film may be formed. Each layer of the base material may contain additives in addition to the resin. Specific examples of the additives are as described for the transfer layer.

[0057] The resin film in the base material may be a stretched resin film or an unstretched resin film that has not been stretched, but an unstretched resin film is preferable. Therefore, as the resin film, an unstretched polyester resin film is preferable. By using an unstretched resin film, it becomes easy to adjust the elongation at break as described above to a desired range, and it is possible to prevent breakage, wrinkles, etc. from occurring during vacuum forming.

[0058] The base material may be a release agent such as a silicone-based release agent or a fluorine-based release agent, with at least one surface being release-treated. When the base material is release-treated, the release-treated surface preferably constitutes the surface on the resin layer side. The base material is easily made to have good releasability from the resin layer by being release-treated. However, the base material does not necessarily need to be release-treated as long as it can be peeled off from the resin layer. The thickness of the base material 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. In addition, when layers other than the top coat layer, the resin layer, or the resin layer disposed between these, such as the above-described transfer layer and base material, are provided, the viscoelasticity measurement is performed after removing the transfer layer and the base material.

[0059] [Method for manufacturing a thermosetting resin sheet] The method for manufacturing the thermosetting resin sheet of the present invention includes the following steps A, B, and C. And the hydroxyl value (OHv1) of the first polyol resin and the hydroxyl value (OHv2) of the second polyol resin satisfy the relationship of the following formula (1). OHv1≧OHv2 (1) (1) Step A In step A, a first coating material containing a first thermosetting resin composition containing a first polyol resin and a first curing agent is applied to the transfer layer and dried to produce a first laminate including the transfer layer and a top coat layer provided on the transfer layer and made of the first thermosetting resin composition. Since the first thermosetting resin composition, the transfer layer, and the top coat layer have been described in the item of the above-mentioned "thermosetting resin sheet", the description of the first thermosetting resin composition, the transfer layer, and the top coat layer is omitted.

[0060] The first coating material may be composed of the first thermosetting resin composition, but from the viewpoint of improving workability such as coatability, it is preferable that the first thermosetting resin composition is diluted with a solvent. Examples of the solvent include ethyl acetate, butyl acetate, toluene, and the like.

[0061] Also, the drying performed after applying the first paint to the transfer layer is preferably drying that includes at least the main drying process described later, and more preferably drying that performs the pre-drying process and the main drying process described later in this order.

[0062] The drying temperature in the pre-drying process is preferably 50°C or higher and 70°C or lower, and more preferably 55°C or higher and 65°C or lower. The drying time in the pre-drying process is preferably 1 minute or more and 30 minutes or less, and more preferably 2 minutes or more and 15 minutes or less. The drying temperature in the main drying process is preferably 85°C or higher and 130°C or lower, and more preferably 90°C or higher and 120°C or lower. When the drying temperature is at or above these lower limit values, the solvent is more easily removed appropriately, preventing the solvent from vaporizing and generating bubbles when curing the resin layer. Also, by setting it below the upper limit value, it is possible to prevent the thermosetting resin composition from curing more than necessary during drying. The drying time in the main drying process is preferably 1 minute or more and 30 minutes or less, and more preferably 2 minutes or more and 15 minutes or less. By setting the drying time at or above the lower limit value, the solvent is more easily removed appropriately, preventing the solvent from vaporizing and generating bubbles when curing the resin layer. Also, by setting it below the upper limit value, it is possible to prevent the thermosetting resin composition from curing more than necessary during drying.

[0063] Also, initial curing may be performed on the dried resin layer as needed. Initial curing means curing the thermosetting resin composition constituting the resin layer to a semi-cured state. Initial curing can be performed by heating, and it is preferably performed under conditions such as a heating temperature of 90°C or higher and 150°C or lower and a heating time of 2 minutes or more and 5 minutes or less.

[0064] (2) Process B In Process B, a second coating material containing a second thermosetting resin composition containing a second polyol resin and a second curing agent is applied to a base material and dried to produce a second laminate provided on the base material and having a resin layer made of the second thermosetting resin composition. Since the second thermosetting resin composition, the base material, and the resin layer are described in the above item of "thermosetting resin sheet", the description of the second thermosetting resin composition, the base material, and the resin layer is omitted.

[0065] The second coating material may be composed of the second thermosetting resin composition, but from the viewpoint of improving workability such as coatability, it is preferable that the second thermosetting resin composition is diluted with a solvent. Examples of the solvent include ethyl acetate, butyl acetate, toluene, and the like.

[0066] Also, the drying performed after applying the second coating material to the transfer layer is preferably drying including at least the main drying process described later, similar to the drying performed after applying the first coating material to the transfer layer, and more preferably drying that performs the pre-drying process and the main drying process described later in this order. Since the pre-drying process and the main drying process are described in the item of "Process A", the description of the pre-drying process and the main drying process is omitted.

[0067] (3) Process C In Process C, the first laminate and the second laminate are bonded together so that the top coat layer and the resin layer face each other. As a result, a thermosetting resin sheet having a laminated structure of transfer layer / top coat layer / resin layer / base material can be manufactured. In this way, by manufacturing a thermosetting sheet by bonding the first laminate and the second laminate, it is possible to prevent the top coat layer and the resin layer from being compatible with each other, and a high-quality two-layer structure composed of the top coat layer and the resin layer can be obtained. Further, by peeling the transfer layer and the base material from this thermosetting resin sheet, a thermosetting resin sheet composed of the top coat layer and the resin layer can be manufactured.

[0068] Also, as described above, when another resin layer is further provided between the top coat layer and the resin layer, first, another resin layer is formed on a separately provided release film or the like to produce a third laminate. Then, the third laminate is bonded to the first laminate to form another resin layer on the top coat layer of the first laminate, or the third laminate is bonded to the second laminate to form another resin layer on the resin layer of the second laminate. Thereafter, by bonding the first laminate and the second laminate as in the above-described step C, a thermosetting resin sheet including the top coat layer, the resin layer, and another resin layer provided between the top coat layer and the resin layer can be manufactured. At that time, the release film is preferably peeled off after or before laminating another resin layer on the second resin layer or the first resin layer. As the release film, a release polyethylene terephthalate film (release PET film) or the like may be used.

[0069] In addition, the thermosetting resin sheet of the present invention can be manufactured by a method other than the manufacturing method of the thermosetting resin sheet of the present invention described above.

[0070] [Usage method of thermosetting resin sheet] The thermosetting resin sheet of the present invention is a sheet for forming a decorative body such as painting on various articles (adherends), and is used by being attached to the adherend. Specifically, after peeling off the base material, the thermosetting resin sheet may be bonded to the adherend via the resin layer, and the thermosetting resin sheet bonded to the adherend may be heated. The method of peeling off the base material is not particularly limited, and it may be peeled off by a peeling device or manually. The bonding of the thermosetting resin sheet to the adherend is not particularly limited, and it may be performed by manual pasting using a squeegee or the like, or by using a laminating device. Further, when the thermosetting resin sheet is heated, the top coat layer and the resin layer are cured, and a decorative body is formed by the cured top coat layer and resin layer.

[0071] Further, the transfer layer is removed by being peeled off after the substrate is peeled off. Typically, after the transfer layer is peeled off, the thermosetting resin sheet may be heated as described above to cure the top coat layer and the resin layer. Also, the transfer layer is preferably peeled off from the top coat layer after the thermosetting resin sheet is adhered to the adherend through the resin layer. Thereby, the transfer layer serves as a support for supporting the top coat layer and the resin layer when the thermosetting resin sheet is adhered to the adherend. The method of peeling off the transfer layer is not particularly limited and may be peeled off by a peeling device or manually. Furthermore, the peeling of the transfer layer may be performed at room temperature or a temperature in the vicinity thereof (about 15 to 35 °C), or may be performed after cooling the top coat layer.

[0072] The thermosetting resin sheet of the present invention may be preformed into a shape corresponding to the shape of the adherend by vacuum molding, press molding, pressure-air molding, etc., and then adhered to the adherend. When performing preforming, in the thermosetting resin sheet, it may be performed before peeling the substrate from the resin layer, or may be performed after peeling the substrate from the resin layer. By performing preforming, even if the adherend has a complicated shape, the thermosetting resin sheet can be easily adhered to and bonded to the adherend. Among the above, preforming is preferably performed by vacuum molding. Preforming may be performed by pressing the thermosetting resin sheet against a jig or a mold by vacuum molding, and shaping the thermosetting resin sheet into a shape corresponding to the surface shape of the adherend while stretching it by the jig or the mold. Here, the vacuum molding is preferably TOM molding. TOM is "Three dimension Overlay Method", and when TOM molding is applied, it is possible to shape into a complicated shape.

[0073] The adherend to which the thermosetting resin sheet of the present invention is attached is not particularly limited. For example, it includes vehicles such as electric appliances, automobiles, and transportation equipment, vehicle parts of vehicles such as automobiles and transportation equipment, miscellaneous goods, heavy machinery, ship exteriors, aircraft, etc., exterior walls or roof materials of houses and buildings, bridges, steel structures, plants, wind power generation blades, etc. Vehicle parts include, for example, vehicle interior materials and vehicle exterior materials. Among these, vehicles and vehicle parts are preferred, vehicle parts are more preferred, and vehicle exterior materials are even more preferred. Examples of vehicle exterior materials include hoods, roofs, door panels, bumpers, fuel filler panels, trunk lids, rear gates, etc. When the thermosetting resin sheet of the present invention is attached to a vehicle exterior material, it may be attached to the exterior material attached to the vehicle body or to the exterior material before being attached to the vehicle body. Also, the material of the adherend is not particularly limited and may be any of resin materials, inorganic materials such as ceramics, and metal materials such as steel materials. Among these, metal materials such as steel materials are preferred. It is difficult to perform painting simultaneously with the molding of the adherend by insert molding for metal materials such as steel materials, and it is difficult to paint with a resin sheet. However, by using the thermosetting resin sheet of the present invention, it is possible to easily paint even such materials.

[0074] [Vehicle, Vehicle Parts, Vehicle Manufacturing Method, Vehicle Part Manufacturing Method] The vehicle and vehicle parts of the present invention are painted using the thermosetting resin sheet of the present invention. Therefore, the vehicle manufacturing method and vehicle part manufacturing method 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 method for forming the above-mentioned painting.

Examples

[0075] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited by these examples.

[0076] The measurement method and evaluation method in this example are as follows. (Film hardness after baking) For the thermosetting resin sheets obtained in each example and comparative example, after peeling off the base material, they were bonded to a steel plate through the resin layer, and then the transfer layer was peeled off. The resin layer (top coat layer and resin layer) bonded to the steel plate was cured by heating at 140 °C for 30 minutes. The pencil hardness of the surface of the obtained cured product was measured in accordance with JIS K 5600-5-4 and evaluated according to the following evaluation criteria. <Evaluation criteria> ◎: No scratches occurred at a pencil hardness of HB. ○: Scratches occurred at a pencil hardness of HB, but no scratches occurred at a pencil hardness of B. ×: Scratches occurred at a pencil hardness of B.

[0077] (Adhesion to coated plate) For the thermosetting resin sheets obtained in each example and comparative example, after peeling off the base material, they were bonded to a steel plate through the resin layer, and then the transfer layer was peeled off. The resin layer (top coat layer and resin layer) bonded to the steel plate was cured by heating at 140 °C for 30 minutes. A cross-cut test was carried out on the obtained cured product in accordance with JIS K 5600-5-6 and evaluated according to the following evaluation criteria. <Evaluation criteria> ◎: The classification of the test result is 0 or 1 ○: The classification of the test result is 2 ×: The classification of the test result is 3 or more

[0078] (Dynamic loss tangent (tan δ)) The dynamic loss tangent (tan δ) at 25 °C was measured by viscoelasticity measurement using a dynamic viscoelasticity measuring device ("DVA-200" manufactured by IT Measurement & Control Co., Ltd.). The measurement was carried out in shear mode under the conditions of a frequency of 10 Hz and a strain of 0.02%.

[0079] The components of the transfer layer film, base material film, and resin layer used in the examples and comparative examples are as follows. <Transfer layer film> Unstretched cyclic polyolefin film (Toray's "Decofit Q17CK", thickness 100 μm), tensile elongation at break at 100 °C (MD = 1850%, TD = 1850%)

[0080] <Film for base material layer> Unstretched polyethylene terephthalate film (A-PET) ((A-PET manufactured by Nakamoto Pax Co., Ltd., thickness 200 μm), tensile elongation at break at 100 °C (MD = 1200%, TD = 980%))

[0081] <Polyol resin> Acrylic polyol resin (1): Weight average molecular weight 240,000, hydroxyl value 40 mgKOH / g, solid content concentration (NV) = 30 mass% (solvent: ethyl acetate) Acrylic polyol resin (2): Weight average molecular weight 250,000, hydroxyl value 80 mgKOH / g, solid content concentration (NV) = 30 mass% (solvent: ethyl acetate) Acrylic polyol resin (3): Weight average molecular weight 250,000, hydroxyl value 110 mgKOH / g, solid content concentration (NV) = 30 mass% (solvent: ethyl acetate) Acrylic polyol resin (4): Weight average molecular weight 320,000, hydroxyl value 170 mgKOH / g, solid content concentration (NV) = 30 mass% (solvent: ethyl acetate) Acrylic polyol resin (5): Weight average molecular weight 250,000, hydroxyl value 200 mgKOH / g, solid content concentration (NV) = 30 mass% (solvent: ethyl acetate)

[0082] <Plasticizer> (Meth)acrylic polymer having a hydroxyl group, weight average molecular weight 2500, "ARUFON UH-2041" manufactured by Toagosei Co., Ltd.), hydroxyl value 120 mgKOH / mg, solid content concentration (NV) = 100 mass%, glass transition temperature -50 °C

[0083] <Curing agent> Hexamethylene diisocyanate-based blocked isocyanate (HDI-based), blocking agent type: 3,5-dimethylpyrazole (DMP), solid content concentration (NV) = 70%, solvent is ethyl acetate, reaction start temperature = 120 °C

[0084] <Pigment (Colorant)> "NSP-UP 841B" manufactured by Nichibiki Co., Ltd., effective pigment concentration = 9% by mass, solid content concentration (NV) = 24% by mass

[0085] [Preparation of Thermosetting Resin Compositions A to L] Each component was added in the formulation as shown in Table 1, and ethyl acetate was added as a solvent to prepare paints of thermosetting resin compositions A to L so that the solid content concentration was 30% by mass.

[0086] [Example 1] After applying thermosetting resin composition A onto the surface of the film for the transfer layer using an applicator, a pre-drying process was carried out under the conditions of a drying temperature of 60°C and a drying time of 30 minutes, and then a main drying process was carried out under the conditions of a drying temperature of 90°C and a drying time of 5 minutes to form a top coat layer with a thickness of 30 μm on the transfer layer. Next, after applying thermosetting resin composition G onto the surface of the film for the substrate using an applicator, a pre-drying process was carried out under the conditions of a drying temperature of 60°C and a drying time of 30 minutes, and then a main drying process was carried out under the conditions of a drying temperature of 90°C and a drying time of 5 minutes to form a resin layer with a thickness of 30 μm on the substrate. The top coat layer on the transfer layer and the resin layer on the substrate were laminated together and laminated at 25°C to obtain a laminate in which the transfer layer, top coat layer, resin layer, and substrate were laminated in this order. Using the obtained laminate, the above evaluation was carried out. The evaluation results are shown in Table 2.

[0087] [Examples 2 to 7, Comparative Examples 1 to 3] The procedure was the same as in Example 1 except that the composition of the thermosetting resin composition was changed as shown in Table 1. The evaluation results are shown in Table 2.

[0088]

Table 1

[0089]

Table 2

[0090] By comparing Examples 1 to 7 and Comparative Examples 1 to 3, it was found that by making the value of the hydroxyl value of the polyol resin in the top coat layer be a value equal to or higher than the value of the hydroxyl value of the polyol resin in the resin layer, a thermosetting resin sheet having high surface hardness and high adhesiveness to the coated plate can be obtained.

Explanation of Reference Signs

[0091] 1, 1A, 1B Thermosetting Resin Sheet 10 Top Coat Layer 20 Resin Layer 30 Second Resin Layer 40 Transfer Layer 50 Substrate

Claims

1. A thermosetting resin sheet having at least a top coat layer made of a first thermosetting resin composition and a resin layer made of a second thermosetting resin composition, wherein the first thermosetting resin composition contains a first polyol resin and a first curing agent, the second thermosetting resin composition contains a second polyol resin and a second curing agent, and a hydroxyl value (OHv1) of the first polyol resin and a hydroxyl value (OHv2) of the second polyol resin satisfy the relationship of the following formula (1). OHv1 ≧ OHv2 (1)

2. The thermosetting resin sheet according to claim 1, wherein the hydroxyl value (OHv1) of the first polyol resin is 50 mgKOH / g or more and 250 mgKOH / g or less.

3. The thermosetting resin sheet according to claim 1, wherein the hydroxyl value (OHv2) of the second polyol resin is 20 mgKOH / g or more and 150 mgKOH / g or less.

4. The thermosetting resin sheet according to claim 1, wherein a logarithm (log(tan δ)) of a dynamic loss tangent at 25° C. of the thermosetting resin sheet measured by viscoelasticity measurement using a dynamic viscoelasticity measuring device (DMA) is 1 or less.

5. The thermosetting resin sheet according to claim 4, wherein the second thermosetting resin composition further contains a colorant.

6. The thermosetting resin sheet according to claim 1, wherein a weight average molecular weight of the first polyol resin and the second polyol resin is 50,000 or more and 1,000,000 or less, respectively.

7. The thermosetting resin sheet according to claim 1, wherein both the first polyol resin and the second polyol resin contain a (meth)acrylic resin having a plurality of hydroxyl groups.

8. The thermosetting resin sheet according to claim 1, wherein a reaction start temperature of the first curing agent and the second curing agent is both 180° C. or less.

9. A step of applying and drying a first paint containing a first thermosetting resin composition containing a first polyol resin and a first curing agent to a transfer layer to produce a first laminate including the transfer layer and a top coat layer provided on the transfer layer and made of the first thermosetting resin composition, A step of applying a second coating containing a second thermosetting resin composition containing a second polyol resin and a second curing agent to a substrate and drying it to produce a second laminate including the substrate and a resin layer provided on the substrate and made of the second thermosetting resin composition, and a step of bonding the first laminate and the second laminate so that the top coat layer and the resin layer face each other, A method for producing a thermosetting resin sheet, wherein the hydroxyl value (OHv1) of the first polyol resin and the hydroxyl value (OHv2) of the second polyol resin satisfy the relationship of the following formula (1). OHv1 ≧ OHv2 (1)

10. A vehicle painted using the thermosetting resin sheet according to any one of Claims 1 to 8.

11. A vehicle part painted using the thermosetting resin sheet according to any one of Claims 1 to 8.

12. A method for manufacturing a vehicle, including a step of painting using the thermosetting resin sheet according to any one of Claims 1 to 8.

13. A method for manufacturing a vehicle part, including a step of painting using the thermosetting resin sheet according to any one of Claims 1 to 8.

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