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

Abstract

To provide a thermosetting resin sheet including a resin layer excellent in both hardness and adhesion.SOLUTION: A thermosetting resin sheet has a resin layer that is composed of a thermosetting resin composition with a ratio (A1-H) of a component having low molecular mobility of 72% or less, and a ratio (A1-B) of a component having low molecular mobility of 70% or more.SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] Furniture, steel plates, vehicle bodies, etc. are painted or decorated from the viewpoints of design and durability. It is known that decoration is performed using a film such as a decorative film. Generally, decorative films have a multilayer structure including a resin layer for decoration (paint layer) and a resin layer other than the paint layer such as a transparent resin layer for imparting gloss to the surface of the paint layer. For example, Patent Document 1 discloses a thermosetting coating sheet in which a colored layer is laminated on a transparent resin layer, the transparent resin layer being composed of a reactive acrylic resin having a weight average molecular weight of 10,000 to 1,000,000 and being solid at normal temperature, and a blocked isocyanate, and the colored resin layer being composed of a colored thermosetting resin composition. Further, in the examples of Patent Document 1, it is disclosed that 60 parts of an acrylic polyol having a low molecular weight component is mixed with 100 parts of a thermoplastic acrylic resin.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional decorative film, when a resin for high hardness is used, the wettability of the resin decreases, and the adhesiveness required for the coating film quality cannot be satisfied. On the other hand, when a low molecular weight resin with high fluidity and good adhesiveness is used, the minimum hardness required for the coating film quality cannot be obtained. Thus, conventionally, there has been a problem that it is difficult to achieve both the hardness and adhesiveness of the paint layer.

[0005] Therefore, an object of the present invention is to provide a thermosetting resin sheet including a resin layer having both good hardness and adhesiveness.

Means for Solving the Problems

[0006] As a result of intensive studies, the present inventors focused on the following two points, and by using a resin layer made of a thermosetting resin composition in which the ratio of components with low molecular mobility is below a certain level near 100°C immediately before the start of curing and the ratio of components with low molecular mobility before curing is above a certain level, it was found that the above problems can be solved. First, since the amount of components with low molecular mobility near 100°C immediately before the start of curing is less than a certain amount, the contact area of the resin layer with the adherend becomes sufficiently large, and the adhesiveness between the cured resin layer and the adherend is manifested. Second, since the amount of components with low molecular mobility before curing is more than a certain amount, the minimum hardness in the coating film can be satisfied by the bulk hardness. The present invention provides the following [1] to

[10] .

[0007] [1] A thermosetting resin sheet including a resin layer made of a thermosetting resin composition in which the ratio (A1-H) of components with low molecular mobility defined below is 72% or less and the ratio (A1-B) of components with low molecular mobility defined below is 70% or more. A1-H: After heating the resin layer at 100°C for 3 minutes, using a pulsed NMR apparatus, measuring the resin layer under a temperature control of 100°C by the CPMG method, and fitting the spin-spin relaxation curve of the hydrogen nuclei obtained by the measurement using a two-component decay function (1) represented by the following formula (1), the value of A1. A1-B: The resin layer is measured by the Solid echo method at a temperature of 25°C using a pulsed NMR apparatus, and the 1 value of A1 when the spin-spin relaxation curve of the hydrogen nuclei of H obtained by the measurement is fitted using a two-component decay function (2) represented by the following formula (2). A1*Exp(-t / t1)+A2*Exp(-t / t2), t1 < t2, A1 + A2 = 100 ····(1) A1*Exp(-0.5(t / t1) 2 )+A2*Exp(-t / t2), t1 < t2, A1 + A2 = 100 ····(2) [2] The thermosetting resin sheet according to [1], wherein the A1-H is 10% or more and the A1-B is 98% or less. [3] The thermosetting resin sheet according to [1] or [2], wherein the thermosetting resin composition contains a (meth)acrylic resin and a blocked isocyanate. [4] The thermosetting resin sheet according to any one of [1] to [3], wherein the resin layer includes a clear layer and a colored layer. [5] The thermosetting resin sheet according to [4], wherein the gel fraction of the clear layer is 75% or less. [6] The thermosetting resin sheet according to any one of [1] to [5], further comprising a release film and a transfer layer. [7] A vehicle painted with the thermosetting resin sheet according to any one of [1] to [6]. [8] A vehicle part painted with the thermosetting resin sheet according to any one of [1] to [6]. [9] A method for manufacturing a vehicle, including a step of painting using the thermosetting resin sheet according to any one of [1] to [6].

[10] A method for manufacturing a vehicle part, including a step of painting using the thermosetting resin sheet according to any one of [1] to [6].

Advantages of the Invention

[0008] According to the present invention, it is possible to provide a thermosetting resin sheet having a resin layer with both good hardness and adhesiveness.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0010] [Thermosetting Resin Sheet] (Resin Layer) The thermosetting resin sheet of the present invention comprises a resin layer made of a thermosetting resin composition, in which the ratio (A1-H) of the components with low molecular mobility defined below is 72% or less, and the ratio (A1-B) of the components with low molecular mobility defined below is 70% or more. A1-H is the value of A1 obtained by the following procedure. After heating the resin layer at 100°C for 3 minutes, using a pulsed NMR apparatus, the resin layer is measured by the CPMG method under a temperature control of 100°C. The spin-spin relaxation curve of the hydrogen nuclei obtained by this measurement is fitted using a two-component decay function (1) represented by the following formula (1). A1*Exp(-t / t1)+A2*Exp(-t / t2), t1<t2, A1+A2=100 ····(1) The value of A1 finally obtained by this fitting is defined as A1-H.

[0011] Here, the CPMG method is a type of a series of irradiation pulse operations (pulse sequence) performed within NMR to observe the spin-spin relaxation curve. It is a pulse sequence obtained by Meiboom and Gill's improvement to the CP method established by Carr and Purcell. The CP method is a pulse sequence in which a certain delay time and a 180° pulse follow a 90° pulse, and is expressed as 90x(-2τ - 180x)n. This method has the merit that the relaxation curve can be measured in a single measurement by detecting the magnetization at each n. However, in the CP method, the analysis becomes complicated because the sign of the magnetization intensity is inverted depending on whether n is even or odd, and the flip angle error of consecutive 180° pulses is integrated only by the value of n, which may cause a large error in the long-time region of the relaxation curve. This is a demerit. What Meiboom and Gill improved regarding these demerits in the CP method is the pulse sequence of the CPMG method. In the CPMG method, it is expressed as 90x(-2τ - 180 +x -2τ - 180 -x ) n and a device is made such that the phase of the 90° pulse is shifted by 90° with respect to the 180° pulse so that the echo signal always recombines on the x-axis. As a result, the sign inversion of the magnetization is eliminated, and the error occurring in the 180° pulse is canceled. In the CPMG method, since the 180° pulse is repeatedly irradiated, it is said that the position change due to the diffusion of the molecule and the magnetic field inhomogeneity can be reduced to some extent. On the other hand, since there is a delay time between pulses, it is said that it is not suitable for observing the short-time relaxation component in which relaxation is completed within this time. Therefore, the CPMG method is exclusively used for observing components with a long spin-spin relaxation time, that is, components with high motility.

[0012] A1 - B is the value of A1 obtained by the following procedure. Using a pulsed NMR apparatus, measure the resin layer under temperature control at 25°C by the Solid echo method. The 1 spin-spin relaxation curve of the hydrogen nuclei of H obtained in this measurement is fitted using a two-component decay function represented by the following formula (2). A1*Exp(-0.5(t / t1) 2 ) + A2*Exp(-t / t2), t1 < t2, A1 + A2 = 100 ····(2) Let the value of A1 finally obtained by this fitting be A1 - B. Here, A1 is the ratio of the component with low molecular mobility, A2 is the ratio of the component with high molecular mobility, t1 is the relaxation time of the component with low molecular mobility, and t2 is the relaxation time of the component with high molecular mobility. t is time.

[0013] The Solid echo method is a type of pulse sequence for observing the spin - spin relaxation curve, similar to the CPMG method. The pulse configuration of the Solid echo method is represented by 90° x -τ - 90° y In pulsed NMR, a dead time is set so that the detector does not operate to protect the detector immediately after pulse irradiation. Since spin - spin relaxation also occurs during the dead time, components with extremely short relaxation times relax completely during the dead time and cannot be detected. The Solid echo method is a technique to solve this problem. By applying two 90° pulses in this method, it is possible to seemingly eliminate the dead time and observe very fast relaxation. On the other hand, in the Solid echo method, the influence of magnetic field inhomogeneity is large. In the case of components with high mobility, it is known that it is difficult to accurately calculate the spin - spin relaxation time due to molecular diffusion during spin - spin relaxation. Therefore, the Solid echo method is exclusively used for observing components with short spin - spin relaxation times, that is, components with low mobility.

[0014] When A1-H exceeds 72%, at the temperature just before the start of curing of the thermosetting resin composition, the components with low molecular mobility increase, the contact area between the resin layer and the adherend becomes small, and there is a risk that the adhesiveness of the resin layer becomes insufficient. Further, when the resin layer has a multilayer structure including, for example, a colored layer and a clear layer, the colored layer is adhered to the adherend. At this time, not only the adhesiveness between the colored layer and the adherend but also the adhesiveness between the colored layer and the clear layer may become insufficient. On the other hand, when A1-B is less than 70%, there is a risk that the hardness required for the resin layer to exhibit the performance of, for example, a coating layer becomes insufficient before the curing of the thermosetting resin composition. From the above viewpoints, A1-H is preferably 69.5% or less, more preferably 69% or less. Also, A1-B is preferably 73% or more, more preferably 75% or more.

[0015] Further, in the thermosetting resin sheet of the present invention, A1-H is preferably 10% or more, more preferably 30% or more, and even more preferably 50% or more. Also, A1-B is preferably 98% or less, more preferably 95% or less, and even more preferably 90% or less. When A1-H is equal to or greater than the above lower limit value, the adhesiveness of the resin layer does not become too high, and stickiness during coating with the thermosetting resin sheet is suppressed, etc., and the handleability can be made excellent. Also, when A1-B is equal to or less than the above upper limit value, the hardness of the resin layer does not become too high, and coating with the thermosetting resin sheet can be easily performed, etc., and the handleability can be made excellent.

[0016] Note that A1-H and A1-B can be adjusted to a desired range by the components contained in the thermosetting resin composition. Specifically, A1-H and A1-B can be adjusted to a desired range by adjusting the mixing ratio of the thermosetting resin and the curing agent, or by changing at least one of the types of the thermosetting resin and the curing agent. Also, for example, A1-H and A1-B can be adjusted depending on the molecular weight of the thermosetting resin. Further, the above adjustment may be made by using a plasticized resin. In that case, for example, the adjustment may be made by adjusting the blending amount of the plasticized resin or appropriately changing the type of the plasticized resin.

[0017] As a detailed measurement procedure for A1-H, for example, when the resin layer has a two-layer structure including a colored layer and a clear layer, it may be performed according to the following procedure. First, prepare two release films. After applying a thermosetting resin composition for a colored layer on the surface of one of the release films (hereinafter also referred to as "release film 1") with an applicator, perform a drying process to complete solvent drying and form a colored layer on release film 1. Then, heat the colored layer at 100 °C for 3 minutes. Next, apply a thermosetting resin composition for a clear layer on the surface of the other release film (hereinafter also referred to as "release film 2") with an applicator, perform a drying process to complete solvent drying, and form a clear layer on release film 2. Then, heat the clear layer at 100 °C for 3 minutes. Furthermore, laminate the colored layer on release film 1 and the clear layer on release film 2 at 25 °C to obtain a laminate in which the release film 1, the colored layer, the clear layer, and the release film 2 are laminated in this order. Remove the two release films from the laminate to obtain a measurement sample. Note that the above drying process may dry the solvent under the same drying conditions as those for obtaining the thermosetting resin sheet, and may be performed in the same manner when pre-drying and main drying are performed. Also, the thickness of each layer may be the same as the thickness of each layer in the thermosetting resin sheet.

[0018] The sample obtained by the above procedure is rolled into a cylindrical shape and introduced into a glass sample tube with a diameter of 10 mm so that the height becomes 15 mm. The sample is placed in a pulsed NMR apparatus and adjusted to 100°C. The measurement is carried out at 100°C by the CPMG method defined under predetermined conditions, and the obtained 1 spin-spin relaxation curve of 1H is fitted using the attenuation function of the above formula (1).

[0019] In the above, an example of a two-layer structure of a resin layer including a clear layer and a colored layer has been described. However, when the resin layer has a structure other than the clear layer and the colored layer, a measurement sample may be obtained and the measurement may be performed in the same manner. Furthermore, when the resin layer has a multilayer structure of three or more layers, measurement samples may be obtained by laminating three or more preheated layers in the same manner. On the other hand, when the resin layer has a single-layer structure, it is advisable to measure 1H in the single-layer resin layer laminated on the release film in the same procedure as above.

[0020] The method for preparing the above measurement sample specifically shows a method when a measurement sample is prepared from a thermosetting resin composition. However, it is not necessary to prepare a measurement sample from a thermosetting resin composition, and a measurement sample may be prepared from a thermosetting resin sheet that has already been manufactured. For example, in the case of a thermosetting resin sheet in which a resin layer is laminated on a release film constituting a transfer layer or the like, the thermosetting resin sheet composed of the release film and the resin layer laminated on the release film is heated at 100°C for 3 minutes, and then the release film is peeled off, and the one composed of the resin layer alone may be used as the measurement sample.

[0021] As a detailed measurement procedure for 1H-13C, for example, the following procedure may be adopted. A measurement sample is obtained by the same method as when obtaining a measurement sample for 1H-13C, except that the resin layer is not heated at 100°C for 3 minutes. The sample is rolled into a cylindrical shape and introduced into a glass sample tube with a diameter of 10 mm so that the height becomes 15 mm. The sample is placed in a pulsed NMR apparatus and adjusted to 25°C. The measurement is carried out at 25°C by the Solid echo method defined under predetermined conditions, and the obtained1 The spin-spin relaxation curve of H is fitted using the attenuation function of the above formula (2).

[0022] As described above, the resin layer provided in the thermosetting resin sheet of the present invention is composed of a thermosetting resin composition. The thermosetting resin composition preferably contains a (meth)acrylic resin and a blocked isocyanate. When the thermosetting resin composition contains these two components, the (meth)acrylic resin may be contained as a thermosetting resin and the blocked isocyanate may be contained as a curing agent, respectively. By the thermosetting resin composition containing these components, A1-H and A1-B can be adjusted to a desired range, and it becomes easier to obtain a resin layer excellent in hardness and adhesiveness.

[0023] <(meth)acrylic resin> Examples of the (meth)acrylic resin used in the thermosetting resin composition include (meth)acrylic resins having a plurality of functional groups. Specific examples of the functional group include a hydroxyl group, a carboxyl group, and an amino group, and among these, a hydroxyl group is preferable. The (meth)acrylic resin may have only one type of functional group or two or more types of functional groups. Therefore, the (meth)acrylic resin preferably contains a (meth)acrylic polyol having a plurality of hydroxyl groups, and more preferably contains an acrylic polyol.

[0024] The (meth)acrylic resin is preferably an acrylic polymer obtained by polymerizing a monomer mixture containing a (meth)acrylate monomer and a functional group-containing monomer having the above functional groups such as a hydroxyl group, an amino group, and a carboxyl group. The monomer mixture may also contain components other than the (meth)acrylate monomer and the functional group-containing monomer such as a styrene derivative monomer. Note that (meth)acrylic means methacrylic or acrylic, and the same applies to other similar terms.

[0025] Examples of the (meth)acrylic acid ester monomer include (meth)acrylic acid ester monomers having no functional groups described above, such as alkyl (meth)acrylates with an alkyl group having about 1 to 18 carbon atoms, benzyl (meth)acrylate, (meth)acrylates having an aromatic ring such as phenoxydiethylene glycol (meth)acrylate, and 2-ethoxyethyl (meth)acrylate. Examples of the functional group-containing monomer include (meth)acrylic acid ester monomers having a hydroxyl group such as 2-hydroxyethyl (meth)acrylate, (meth)acrylic acid ester monomers having an amino group such as 2-aminoethyl (meth)acrylate, and monomers having a carboxyl group such as (meth)acrylic acid. As the (meth)acrylic resin, a copolymer obtained by block or graft polymerization of the above-described acrylic polymer and another monomer or polymer may be used.

[0026] The content of the (meth)acrylic resin in the thermosetting resin composition is not particularly limited, but based on the total amount of the thermosetting resin composition, it is preferably 20% by mass or more and 70% by mass or less, more preferably 25% by mass or more and 65% by mass or less, and even more preferably 30% by mass or more and 60% by mass or less. By setting the content of the (meth)acrylic resin within the above range, it is easy to improve the coatability, curability, etc. of the resin layer. 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.

[0027] The thermosetting resin composition preferably contains, as the above (meth)acrylic resin, a (meth)acrylic resin having a weight average molecular weight (Mw) of 50,000 or more and 1,000,000 or less, being solid, and having a plurality of functional groups (hereinafter also referred to as a high molecular weight (meth)acrylic resin). By including a (meth)acrylic resin having a weight average molecular weight of not less than the above lower limit value, A1-B becomes high, and it becomes easy to improve the hardness of the resin layer. Further, by including a (meth)acrylic resin having a weight average molecular weight of not more than the above upper limit value, A1-H becomes low, and it becomes easy to improve the adhesiveness of the resin layer. The above weight average molecular weight is preferably 100,000 or more and 500,000 or less, more preferably 120,000 or more and 400,000 or less. In the present specification, the weight average molecular weight (Mw) is measured by gel permeation chromatography (GPC) and is determined as a standard polystyrene conversion value. Further, being solid means being solid at normal temperature (23°C) and normal pressure (1 atm).

[0028] The above high molecular weight (meth)acrylic resin is preferably a (meth)acrylic polyol having a plurality of hydroxyl groups. As described above, the (meth)acrylic polyol can be obtained, for example, by polymerizing a monomer mixture containing a (meth)acrylate monomer and a hydroxyl group-containing monomer. In the thermosetting resin composition, the (meth)acrylic resin may be used alone or in combination of two or more.

[0029] <Plasticized resin> The thermosetting resin composition may contain, as the thermosetting resin, in addition to the above high molecular weight (meth)acrylic resin, a resin having a weight average molecular weight of less than 50,000 (hereinafter also referred to as a plasticized resin). By containing, in addition to the high molecular weight (meth)acrylic resin, a plasticized resin having a low weight average molecular weight, the thermosetting resin composition can easily balance and improve coatability, curability, tackiness, stretchability, etc. Further, the wettability with respect to the adherend can be improved, and the adhesive strength with respect to the adherend can be increased.

[0030] As the plasticizable resin, those which are compatible with a high molecular weight (meth)acrylic resin and have a thermosetting functional group are preferred. Examples of the resin used for the plasticizable resin include (meth)acrylic resins, polycarbonate resins, polyester resins, and epoxy resins, and among them, (meth)acrylic resins or polycarbonate resins are preferred. Examples of the (meth)acrylic resin used as the plasticizable resin include (meth)acrylic polymers having functional groups such as hydroxyl groups, amino groups, and carboxyl groups. Among these, (meth)acrylic polymers having hydroxyl groups are preferred. Also, poly(meth)acrylate having a carboxyl group is also preferred. Further, as the polycarbonate resin used as the plasticizable resin, polycarbonate polyol is preferred. The weight average molecular weight of the plasticizable resin is preferably 400 or more and 30,000 or less, more preferably 450 or more and 20,000 or less, and still more preferably 450 or more and 5000 or less. Also, the plasticizable resin is desirably liquid at normal temperature and normal pressure. As the plasticizable resin, at least one of a (meth)acrylic polymer having a hydroxyl group or polycarbonate polyol is preferred.

[0031] The content of the plasticizable resin in the thermosetting resin composition is, for example, 0 or more and 0.95 or less, preferably 0.01 or more and 0.9 or less, and more preferably 0.03 or more and 0.7 or less in terms of mass ratio with respect to the content of the high molecular weight (meth)acrylic resin. By setting the content of the plasticizable resin to be equal to or higher than the above lower limit value, A1-H can be adjusted to be a certain value or less, and it becomes easier to improve the adhesiveness of the resin layer. Also, by setting the content of the plasticizable resin to be equal to or lower than the above upper limit value, A1-B can be adjusted to be a certain value or more, and it becomes easier to improve the hardness of the resin layer.

[0032] <Block isocyanate> A blocked isocyanate is a compound in which isocyanate groups are blocked by a protecting group. When exposed to high temperatures, the protecting group (blocking agent) undergoes thermal dissociation and detaches, and a curing reaction occurs between the generated isocyanate groups and the functional groups (typically, the hydroxyl groups of polyols) in the above-described thermosetting resin. The blocked isocyanate can be obtained, for example, by reacting a blocking agent with an isocyanate compound having two or more isocyanate groups in one molecule.

[0033] 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. Among these, at least one selected from hexamethylene diisocyanate and isophorone diisocyanate is preferable. Among them, from the viewpoint of easily improving the adhesiveness of the resin layer, it is more preferable to contain hexamethylene diisocyanate. Examples of the blocking agent include pyrazoles, phenols, oximes, lactams, active methylenes, and the like. The content of the blocked isocyanate in the thermosetting resin composition is preferably adjusted so that the number of functional groups in the thermosetting resin (number of functional groups / number of isocyanate groups) is 0.4 or more and 1.8 or less, more preferably 0.6 or more and 1.5 or less, with respect to the number of isocyanate groups in the blocked isocyanate. By setting the number of functional groups / number of isocyanate groups to the above lower limit value or more, A1-H becomes low and it becomes easy to improve the adhesiveness of the resin layer. Further, by setting the number of functional groups / number of isocyanate groups to the above upper limit value or less, A1-B becomes high and it becomes easy to improve the hardness of the resin layer.

[0034] Note that the thermosetting resin contained in the thermosetting resin composition of the present invention is not limited to the above-described (meth)acrylic resin and plasticized resin, and may contain a polycarbonate resin, a polyester resin, an epoxy resin, or the like. Further, the curing agent contained in the composition is not limited to blocked isocyanate, and may contain a melamine-based compound or the like.

[0035] A melamine-based compound is a compound having a melamine skeleton in the compound, and a compound that causes a dehydration condensation reaction may be used. For example, alkylolated melamine derivatives such as monomethylol melamine and hexamethylol melamine obtained by reacting melamine and formaldehyde under an alkali, compounds partially etherified by reacting an alkylolated melamine derivative with alcohol, and mixtures thereof can be mentioned. The melamine-based compound may be either a monomer or a multimer of dimer or higher, or a mixture thereof may be used.

[0036] <Other Components> In addition to the thermosetting resin and the curing agent, the thermosetting resin composition may appropriately contain components according to the performance required for the coating formed from the resin layer. For example, when the coating formed by the resin layer is a colored coating, a resin layer containing a colorant such as a pigment, a dye, and a brightening material may be used as the colored layer. Further, when the coating formed by the resin layer is a heat-insulating coating, a heat-insulating material may be contained in the thermosetting resin composition, and the resin layer may be used as the heat-insulating layer. Further, the resin layer may contain components other than the above, for example, additives other than the above. Examples of the additives include a crosslinking agent, a dispersant, an inorganic filler other than a pigment and a brightening material, an anti-aging agent, an antioxidant, and a rust preventive agent. Furthermore, the resin layer may be composed of a clear layer described later. Among these, it is preferable that the thermosetting resin composition contains at least a colorant.

[0037] Examples of 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 brightening agent 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 brightening agent is not particularly limited, and examples include compounds having a titanium oxide layer provided on the surface of natural mica, synthetic mica, alumina flakes, glass flakes, etc. The resin layer more preferably contains at least one of a pigment or a brightening agent as a colorant, and even more preferably contains a pigment. It is also preferable that the resin layer contains both a pigment and a brightening agent. The content of the colorant in the thermosetting resin composition is not particularly limited, but is, for example, about 0.1 to 25% by mass, preferably 0.3 to 20% by mass, and more preferably 0.5 to 12% by mass. In addition to the above-mentioned additives such as colorants and heat insulation materials, the thermosetting resin composition may appropriately contain additives such as inorganic fillers, catalysts such as urethanization catalysts, curing accelerators, surface modifiers, defoaming agents, crosslinking agents, dispersants, anti-aging agents, antioxidants, and ultraviolet absorbers.

[0038] 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 preferable. By having a multilayer structure, various functions can be imparted to, for example, the coating formed from the resin layer. In the case of a multilayer structure, each layer of the resin layer is preferably composed of the above-described thermosetting resin composition. Further, each layer may contain a colorant as described above to form a colored 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 layer and a clear layer. When the resin layer has a colored layer and a clear layer and a transfer layer described later is provided, the clear layer and the colored layer are preferably arranged in this order from the transfer layer side. With such a layer configuration, when the thermosetting resin sheet is attached to the adherend, the colored layer and the clear layer are arranged in this order from the adherend side. By having a colored layer, the resin layer can color the adherend, for example, by coating formed by the resin layer. Further, by providing a clear layer in addition to the colored layer, the colored layer can be protected or gloss can be imparted to the colored layer. The colored layer preferably contains a pigment as a colorant. Therefore, it is particularly preferable that the resin layer includes a clear layer and a colored layer.

[0040] Both the colored layer and the clear layer are preferably composed of the above-described thermosetting resin composition. The thermosetting resin composition for the colored layer may contain a colorant as described above. Further, when, for example, a (meth)acrylic resin is used as the thermosetting resin in the thermosetting resin composition for the colored layer, it may contain at least a high molecular weight (meth)acrylic resin, but it is preferable to contain both a high molecular weight (meth)acrylic resin and a plasticized resin. On the other hand, the clear layer is a transparent layer and may have transparency such that the color of the colored 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 impaired. Further, when, for example, a (meth)acrylic resin is used as the thermosetting resin in the thermosetting resin composition for the clear layer, it may contain at least a high molecular weight (meth)acrylic resin, but in that case, it may or may not contain a plasticized resin.

[0041] Of course, when the resin layer has a multilayer structure, it is not limited to a two-layer structure of a clear layer and a colored layer, and it can have various laminated structures. It is also possible to provide two or more colored layers and one or more clear layers to form a structure of three or more layers, or it may be composed of two colored layers with the clear layer omitted. Further, two or more clear layers may be provided. Also, a heat insulating layer or the like may be provided between the clear layer and the colored layer to form a structure of three or more layers.

[0042] When the resin layer has a multilayer structure including a colored layer and a clear layer, the gel fraction of the clear layer is preferably 75% or less, more preferably 72% or less, and even more preferably 70% or less. By the gel fraction of the clear layer being below the above upper limit value, it becomes easier to adjust the hardness of the clear layer to an appropriate range. Also, the lower limit of the gel fraction of the clear layer is not particularly limited and may be 0% or more.

[0043] When the resin layer has a multilayer structure, the content of the (meth)acrylic resin in the thermosetting resin composition constituting the colored layer is not particularly limited, but based on the total amount of the thermosetting resin composition, it is preferably 20% by mass or more and 60% by mass or less, more preferably 25% by mass or more and 55% by mass or less, and even more preferably 30% by mass or more and 50% by mass or less. By setting the content of the (meth)acrylic resin within the above range, it becomes easier to improve the hardness, adhesiveness, etc. of the colored layer.

[0044] When the resin layer has a multilayer structure, the content of the (meth)acrylic resin in the thermosetting resin composition constituting the clear layer is not particularly limited, but based on the total amount of the thermosetting resin composition, it is preferably 25% by mass or more and 70% by mass or less, more preferably 30% by mass or more and 65% by mass or less, and even more preferably 40% by mass or more and 60% by mass or less. By setting the content of the (meth)acrylic resin within the above range, it becomes easier to improve the hardness, adhesiveness, etc. of the clear layer.

[0045] When the resin layer has a multilayer structure, the content of the plasticized resin in the thermosetting resin composition constituting the colored layer is, based on the content of the high molecular weight (meth)acrylic resin, in terms of mass ratio, for example, 0.2 or more and 0.95 or less, preferably 0.3 or more and 0.92 or less, more preferably 0.4 or more and 0.9 or less. By setting the content of the plasticized resin to be not less than the above lower limit value, the adhesiveness of the colored layer is improved, and in particular, the adhesiveness to the adherend is likely to be improved. Also, by setting the content of the plasticized resin to be not more than the above upper limit value, it becomes easier to improve the hardness of the colored layer.

[0046] When the resin layer has a multilayer structure, the content of the plasticized resin in the thermosetting resin composition constituting the clear layer is, based on the content of the high molecular weight (meth)acrylic resin, in terms of mass ratio, for example, 0 or more and 0.35 or less, preferably 0.01 or more and 0.32 or less, more preferably 0 or more and 0.3 or less. By setting the content of the plasticized resin to be not less than the above lower limit value, the adhesiveness of the clear layer is improved, and in particular, the adhesiveness to the colored layer is likely to be improved. Also, by setting the content of the plasticized resin to be not more than the above upper limit value, it becomes easier to improve the hardness of the clear layer.

[0047] When the resin layer has a multilayer structure, the content of the colorant in the thermosetting resin composition constituting the colored layer is not particularly limited, but for example, it is about 1 to 25% by mass, preferably 3 to 20% by mass, more preferably 5 to 12% by mass.

[0048] When the resin layer has a multilayer structure, the content of the colorant in the thermosetting resin composition constituting the clear layer is not particularly limited, but for example, it is about 0 to 0.01% by mass, preferably 0 to 0.005% by mass, more preferably 0 to 0.002% by mass.

[0049] 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. When a coloring layer and a clear layer are provided in the resin layer, the thickness of the coloring layer is not particularly limited, but is, for example, 10 μm or more and 100 μm or less, preferably 15 μm or more and 50 μm or less. Further, the thickness of the clear layer is not particularly limited, but is, for example, 10 μm or more and 100 μm or less, preferably 15 μm or more and 50 μm or less.

[0050] (Transfer layer) The thermosetting resin sheet of the present invention only needs to include at least a resin layer. For example, as shown in FIG. 1, it includes a resin layer 11 and a transfer layer 12, and the resin layer 11 may be formed on one surface of the transfer layer 12. The transfer layer is a member that protects the resin layer from damage and foreign matter adhesion and also serves as a support when the resin layer is attached to an adherend. The transfer layer is preferably formed from a resin film. As the resin used for the resin film, for example, a thermoplastic resin may be used. Specific examples of the resin used for the resin film include cyclic polyolefin resins, polyolefin resins, polyester resins such as polybutylene terephthalate (PBT) and polyethylene terephthalate (PET), polyamide resins, polycarbonate resins, acrylic resins, fluorine resins, vinyl chloride resins (PVC) such as soft vinyl chloride resin, polymethylpentene resins, tetrafluoroethylene resins, acrylonitrile-butadiene-styrene copolymer (ABS) resins, and the like. The cyclic polyolefin resin is a polymer containing a structural unit derived from a cyclic olefin. The polyolefin resin is a polyolefin resin other than the cyclic polyolefin resin, and specific examples include polypropylene resin (PP), polyethylene resin (PE), and the like. Examples of the polyethylene resin include low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene (LLDPE). These resins can be used alone or in combination of two or more. Among these resins, cyclic olefin resins, PET, PBT, PVC, ABS, PE, and PP are preferred from the viewpoints of vacuum formability and transferability.

[0051] 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. However, the transfer layer does not necessarily have to be release-treated as long as it can be peeled off from the resin layer. 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 20 μm or more and 600 μm or less, more preferably 30 μm or more and 400 μm or less.

[0052] (Release film) Further, the thermosetting resin sheet 10 may have a layer other than the transfer layer 12. For example, as shown in FIG. 2, the thermosetting resin sheet 10 may include a release film 13, and the release film 13 may be attached to the surface of the resin layer 11. When the transfer layer 12 is provided, the release film 13 is preferably provided on the surface of the resin layer 11 opposite to the side where the transfer layer 12 is provided. The release film 13 is not particularly limited as long as a known release film is used, and it may be made of a resin film, or at least one surface thereof may be release-treated with a release agent such as a silicone-based release agent, a non-silicone-based (organic release agents), or a fluorine-based release agent on the surface of the resin film. When the release film 13 is release-treated, the release-treated surface is preferably disposed at a position in contact with the resin layer 11. The release film 13 is preferably peeled off from the resin layer 11 and removed from the thermosetting resin sheet 10 before attaching the thermosetting resin sheet 10 to the object to be coated. Further, although not shown, the thermosetting resin sheet 10 may include a support layer instead of the release film, and the support layer may be attached to the surface of the resin layer 11. The support layer is preferably formed of resin, rubber, or the like. Further, similar to the release film, the surface of the support layer in contact with the resin layer 11 may be release-treated. The support layer is preferably provided on the surface of the resin layer 11 opposite to the side where the transfer layer 12 is provided.

[0053] [Manufacturing method of thermosetting resin sheet] The manufacturing method of the thermosetting resin sheet of the present invention is not particularly limited. For example, it is preferable to prepare a coating liquid obtained by diluting a thermosetting resin composition with a solvent, apply it onto a transfer layer composed of a resin film or the like, and then dry it. The coating liquid is not particularly limited, but for example, it may be obtained by mixing each component constituting a thermosetting resin composition including a thermosetting resin, a curing agent, a pigment, and additives other than these in a solvent.

[0054] Examples of the above solvent include ethyl acetate, butyl acetate, toluene, etc. From the viewpoints of ease of obtaining a desired thermosetting resin sheet and workability, ethyl acetate is preferable. The amount of the solvent used is not particularly limited, but for example, it is 50 parts by mass or more and 1000 parts by mass or less, preferably about 100 parts by mass or more and 500 parts by mass or less, based on 100 parts by mass of a thermosetting resin such as a (meth)acrylic resin.

[0055] The method of applying the coating liquid onto the transfer layer is not particularly limited, and it is preferable to apply it onto the transfer layer using a known coating device. Also, the drying performed after applying the first coating liquid onto the release film may be carried out in one step, or may be carried out in two steps including a pre-drying step and a main drying step described later, but it is preferable to carry out it in one step. When drying the thermosetting resin composition in one step, the drying temperature is preferably 50°C or higher and 80°C or lower, more preferably 55°C or higher and 75°C or lower. Also, when drying the thermosetting resin composition in one step, the drying time is preferably 1 minute or more and 45 minutes or less, more preferably 2 minutes or more and 30 minutes or less.

[0056] In the pre-drying step, the drying temperature is preferably 50°C or higher and 70°C or lower, more preferably 55°C or higher and 65°C or lower. The drying time in the pre-drying step is preferably 1 minute or more and 30 minutes or less, more preferably 2 minutes or more and 20 minutes or less.

[0057] In this drying process, the drying temperature is preferably 50°C or higher and 100°C or lower, more preferably 60°C or higher and 90°C or lower. When the drying temperature is at or above these lower limits, the solvent is more likely to be appropriately removed from the coating liquid, preventing the generation of bubbles due to the vaporization of the solvent or the like when curing the resin layer. Also, by setting it below the above upper limit, it is possible to prevent the thermosetting resin composition from curing more than necessary during drying. In this drying process, the drying time is preferably 1 minute or longer and 30 minutes or shorter, more preferably 2 minutes or longer and 20 minutes or shorter. By setting the drying time at or above these lower limits, the solvent is more likely to be appropriately removed from the coating liquid, preventing the generation of bubbles due to the vaporization of the solvent when curing the resin layer or the like. Also, by setting it below the above upper limit, it is possible to prevent the thermosetting resin composition from curing more than necessary during drying.

[0058] Also, the thermosetting resin sheet after drying may be initially cured as necessary. Initial curing means curing the thermosetting resin composition constituting the resin layer to a semi-cured state. Initial curing may be performed by heating or by irradiation with active energy rays. When performing it by heating, it is advisable to perform it under conditions such as a heating temperature of 135°C or higher and 150°C or lower and a heating time of 5 minutes or longer and 10 minutes or shorter.

[0059] Also, 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 layer, laminate the colored layer formed on the release film and the clear layer formed on the transfer layer, and on the transfer layer, obtain a thermosetting resin sheet composed of a laminate in which the clear layer, the colored layer, and the release film are laminated in this order.

[0060] (Method of using the thermosetting resin sheet) The thermosetting resin sheet of the present invention is preferably used for forming a coating with various articles (coated objects) as adherends. Specifically, after attaching the thermosetting resin sheet to various coated objects, the resin layer may be cured, and the cured resin layer may be used as the coating. Note that the transfer layer may be peeled off from the resin layer attached to the coated object and removed from the coated object.

[0061] The coated object to be coated with the thermosetting resin sheet is not particularly limited, but includes vehicle parts such as electric appliances, interior materials for vehicles, and exterior materials for vehicles. More specifically, interior materials for vehicles such as automotive interior materials and interior materials for transportation equipment other than automobiles, exterior materials for vehicles such as automotive exterior materials and exterior materials for transportation equipment other than automobiles, sundries, heavy machinery, ship exteriors, aircraft exteriors, exterior walls or roofing materials for houses and buildings, bridges, steel frames, plants, wind power generation blades, etc. Among these, vehicle parts are preferred, and exterior materials for vehicles such as automotive exterior materials are more preferred. Examples of exterior materials for vehicles include hoods, roofs, door panels, bumpers, fuel filler panels, trunk lids, rear gates, etc. 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 may be attached to the exterior material before being attached to the vehicle body. Also, the material of the coated object 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. Metal materials such as steel materials are difficult to apply a coating simultaneously with the molding of the coated object by insert molding, and it is difficult to apply a coating with a resin sheet. However, by using the thermosetting resin sheet of the present invention, it is possible to easily apply a coating to such materials.

[0062] The method of attaching the thermosetting resin sheet to the object to be coated is not particularly limited, and it may be performed by hand attachment using a squeegee or the like, or it may be performed using a laminating device. Further, it may be performed by press molding, insert injection, vacuum molding, etc. Among these, the method of attaching by vacuum molding is preferable. When attaching by vacuum molding, the thermosetting resin sheet may be heated to, for example, 90°C or higher and 130°C or lower, preferably 100°C or higher and 125°C or lower, and then vacuum molding may be performed.

[0063] The thermosetting resin sheet may be preformed into a shape corresponding to the shape of the object to be coated by vacuum molding, press molding, pressure air molding, etc., and then attached to the object to be coated. When performing preforming, the thermosetting resin sheet is preferably preformed in a state where the support layer is bonded to the resin layer. Preforming is performed by shaping the thermosetting resin sheet into a certain shape using a jig. By preforming the thermosetting resin sheet in a state where it has a support layer, it is possible to prevent the resin layer from sticking to the jig. Among the above, preforming is preferably performed by vacuum molding. Further, the preformed thermosetting resin sheet may be attached to the object to be coated after the support layer is removed. At this time, the thermosetting resin sheet may be attached by hand, or may be attached to the object to be coated using a laminating device, or may be attached by other methods.

[0064] The thermosetting resin sheet attached to the object to be coated as described above may have the resin layer cured. Curing of the resin layer may be performed by heating. The heating temperature when curing by heating is not particularly limited as long as the resin layer can be cured. For example, it is 70°C or higher and 170°C or lower, preferably 75°C or higher and 160°C or lower. The heating time is, for example, 10 minutes or longer and 90 minutes or shorter, preferably 15 minutes or longer and 60 minutes or shorter.

[0065] The present invention also provides a method for manufacturing a vehicle and a method for manufacturing vehicle parts. The method for manufacturing a vehicle or vehicle parts according to the present invention includes a step of coating using the thermosetting resin sheet of the present invention. In the coating step, the vehicle or vehicle parts may be coated by the method described in the above usage method.

Examples

[0066] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited by these examples.

[0067] The measurement methods and evaluation methods for various physical properties in the present invention are as follows.

[0068] [A1-H] Regarding the colored layer and the clear layer obtained in each example and comparative example, with each layer formed on a release film, they were each heated under the conditions of 100°C for 3 minutes. After the above heating, the colored layer on release film 1 and the clear layer on release film 2 were bonded together and laminated at room temperature to obtain a laminate laminated in the order of release film 1, colored layer, clear layer, and release film 2. Two release films were removed from the laminate to obtain a measurement sample.

[0069] The sample obtained by the above procedure was rolled into a cylinder and filled to a height of 15 mm in a glass sample tube (manufactured by Bruker Japan, 10 mm in diameter and 180 mm in length, with a flat bottom) with a diameter of 10 mm. The sample tube was inserted into a pulsed NMR apparatus (Bruker Japan's "minispec mq20") whose temperature was controlled at 100 °C. In order to make the temperature of the sample uniform, the measurement was carried out after providing a temperature adjustment time of at least 20 minutes from the insertion. The spin-spin relaxation curve of the hydrogen nuclei of the sample was measured using the Carr-Purcell-Meiboom-Gill (CPMG) method. At that time, the interval (2τ) of the 180° pulse was 0.21 ms, and the number of repetitions of the 180° pulse was 1000 times. The average value of the relaxation intensity of the latter 10% of the observation time of the obtained spin-spin relaxation curve was regarded as the baseline, and baseline correction was carried out by subtracting it from the relaxation curve. Also, the relaxation curve was normalized by multiplying it by a constant so that the initial value of the relaxation curve after baseline correction became 100. The normalized relaxation curve was fitted by the method of least squares with respect to the error using the following attenuation function. A1*Exp(-t / t1)+A2*Exp(-t / t2), t1<t2, A1+A2=100 Here, A1 is the ratio of the component with low molecular mobility, A2 is the ratio of the component with high molecular mobility, t1 is the spin-spin relaxation time of the component with low molecular mobility, and t2 is the spin-spin relaxation time of the component with high molecular mobility. t is the observation time of the relaxation curve.

[0070] [A1-B] Measurement samples were obtained in the same manner as when obtaining the measurement samples for A1-H, except that the colored layers and clear layers obtained in each example and comparative example were not heated under the conditions of 100°C for 3 minutes. The samples were rolled into a cylindrical shape and filled to a height of 15 mm in a glass sample tube (manufactured by Bruker Japan, 10 mm in diameter and 180 mm in length, with a flat bottom) with a diameter of 10 mm. The sample tube was inserted into a pulse NMR apparatus (Bruker Japan's "minispec mq20") adjusted to 25°C. The spin-spin relaxation curve of hydrogen nuclei was measured using the Solid echo method. The 90° pulse interval at that time was 640 ns, and the number of observation points was 93,670 points. The average value of the relaxation intensity in the latter half of 10% of the observation time of the obtained relaxation curve was regarded as the baseline, and baseline correction was performed by subtracting it from the relaxation curve. Further, the relaxation curve was normalized by multiplying it by a constant so that the initial value of the relaxation curve after baseline correction became 100. Fitting was performed by the method of least squares with the following attenuation function. A1*Exp(-0.5(t / t1) 2 )+A2*Exp(-t / t2), t1 < t2, A1 + A2 = 100 A1, A2, t, t1, and t2 are as described above.

[0071] [Gel fraction] The clear layers obtained in each example and comparative example were collected and weighed for the weight W0 (with 0.15 g as a reference amount), and about 300 mL of acetone was added and sealed in a vial. This sample was shaken with a shaker (130 rpm or more) for 16 hours or more. On the other hand, a wire mesh (100 mesh) was prepared, heated at 105°C for 30 minutes or more, and then the weight W1 of the wire mesh was measured. Then, after filtering the above-mentioned shaken sample with the same wire mesh, the sample was heated at 105°C for 30 minutes or more in a state of being placed on the wire mesh, and again, the total weight W2 of the sample and the wire mesh was measured. From the results obtained in the above steps, the gel fraction of the clear layer was calculated using the following formula (A). (W2 - W1) / W0 × 100...(A) [Hardness] The thermosetting resin sheets obtained in each of the examples and comparative examples were transferred to "SPCC-SD 0.8*300*300 φ5-2 cationic electrodeposition (gray) + urethane coating (white) + urethane clear" (manufactured by Standard Test Piece Co., Ltd.) (hereinafter also referred to as "adhered board"). The transfer was carried out as follows. The release film 1 was peeled off, and the thermosetting resin sheet was attached to the adhered board so that the colored layer was in contact with the adhered board. Then, the release film 2 was peeled off to form a laminate composed of a colored layer and a clear layer on the adhered board. Further, as a baking process (curing process), the laminate was heated at 140 °C for 30 minutes. Regarding the laminate transferred by the above procedure, the pencil hardness was measured in accordance with JIS K 5600 5-4, and the hardness of the laminate was evaluated according to the following evaluation criteria. 〇: The pencil hardness of the laminate was HB or higher. ×: The pencil hardness of the laminate was B or lower.

[0072] [Adhesion] In the same procedure as in the hardness evaluation, a laminate formed on the adhered board and composed of a colored layer and a clear layer was obtained, and the laminate was used as a sample. For the sample, the adhesion was evaluated by an adhesion evaluation based on the cross-cut method in accordance with JIS K 5600 5-6. The evaluation criteria for adhesion are as follows. 〇: The test result by the above cross-cut method was classified as 1 or higher. ×: The test result by the above cross-cut method was classified as 2 or lower.

[0073] The components used in the examples and comparative examples are as follows.

[0074] <(Meth)acrylic resin> Acrylic polyol resin (1): Weight average molecular weight 250,000, hydroxyl value 170 mgKOH / g, solid content concentration (NV) = 28.9 mass% (solvent: ethyl acetate) Acrylic polyol resin (2): Weight average molecular weight 290,000, 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 150 mg KOH / g, solid content concentration (NV) = 32.4 mass% (solvent: ethyl acetate) Acrylic polyol resin (4): weight-average molecular weight 50,000, hydroxyl value 80 mg KOH / g, solid content concentration (NV) = 50.5 mass% (solvent: ethyl acetate) Acrylic polyol resin (5): weight-average molecular weight 50,000, hydroxyl value 140 mg KOH / g, solid content concentration (NV) = 45.9 mass% (solvent: ethyl acetate)

[0075] <Plasticized resin> Acrylic polymer having a hydroxyl group ("ARUFON UH-2041" manufactured by Toagosei Co., Ltd.): weight-average molecular weight 2,500, solid content concentration (NV) = 100 mass% Polycarbonate diol ("PH-50" manufactured by UBE Industries, Ltd.): weight-average molecular weight 500, solid content concentration (NV) = 100 mass%

[0076] <Block isocyanate curing agent> Hexamethylene diisocyanate-based block isocyanate (HDI-based nurate), blocking agent type: 3,5-dimethylpyrazole (DMP), solid content concentration (NV) = 68%, solvent contains ethyl acetate. Isophorone diisocyanate-based block isocyanate (IPDI-based nurate), blocking agent type: 3,5-dimethylpyrazole (DMP), solid content concentration (NV) = 65%, solvent contains ethyl acetate.

[0077] <Catalyst> "XK-639" manufactured by Kusumoto Chemicals, urethanization catalyst "D0303" manufactured by Tokyo Chemical Industry Co., Ltd., dibutyltin dilaurate "Neo-Stan U-200" manufactured by Nitto Kasei Co., Ltd., urethanization catalyst

[0078] <Pigment> "NSP-UP 841B" manufactured by Nihon Hiromitsu Binks Co., Ltd., effective pigment concentration = 9 mass%, solid content concentration (NV) = 24 mass% <Brightening agent> Material coated with a metal oxide containing at least one layer of titanium dioxide on alumina flakes, "Xiramic T60-10 WNT Crystal Silver" manufactured by Merck

[0079] <Surface conditioner> "BYK-378" manufactured by BYK, silicone-based <Antioxidant> "ADEKA STAB AO-50" manufactured by ADEKA, phenolic <UV absorber> "Tinuvin 405" manufactured by BASF Japan Ltd., triazine-based "Tinuvin 123" manufactured by BASF Japan Ltd., hindered amine-based <Other additives> "JP-508" manufactured by Johoku Chemical Co., Ltd., 2-ethylhexyl acid phosphate

[0080] The above components and ethyl acetate as a solvent were added in the formulations shown in Tables 1 to 5 to prepare thermosetting resin compositions A to L, N, P, R to T such that the solid content concentrations of the respective compositions were as shown in Tables 1 to 5. Thermosetting resin composition M was prepared by adding ethyl acetate in an amount of 11.2 parts by mass with respect to 100 parts by mass of the solid content of the total amount of the thermosetting resin composition in addition to the formulation shown in Tables 1 to 5. Thermosetting resin composition O was prepared by adding ethyl acetate in an amount of 8.3 parts by mass with respect to 100 parts by mass of the solid content of the total amount of the thermosetting resin composition in addition to the formulation shown in Tables 1 to 5. Thermosetting resin composition Q was prepared by adding ethyl acetate in an amount of 11.0 parts by mass with respect to 100 parts by mass of the solid content of the total amount of the thermosetting resin composition in addition to the formulation shown in Tables 1 to 5.

[0081]

Table 1

[0082]

Table 2

[0083]

Table 3

[0084]

Table 4

[0085]

Table 5

[0086] [Example 1] Two release films (Release Film 1 and 2) were prepared, and the thermosetting resin composition A for the colored layer was applied onto the surface of Release Film 1 using an applicator. Then, the drying process was carried out under the conditions of a drying temperature of 60°C and a drying time of 3 minutes to form a colored layer with a thickness of 30 μm on Release Film 1. Next, the thermosetting resin composition B for the clear layer was applied onto the surface of Release Film 2 using an applicator. Then, the drying process was carried out under the conditions of a drying temperature of 60°C and a drying time of 3 minutes to form a clear layer with a thickness of 30 μm on Release Film 2. The colored layer on Release Film 1 and the clear layer on Release Film 2 were laminated together and laminated at room temperature to obtain a thermosetting resin sheet laminated in the order of Release Film 1, colored layer, clear layer, and Release Film 2.

[0087] [Examples 2 to 10, Comparative Examples 1 to 3] The procedure was the same as in Example 1, except that the types of the thermosetting resin compositions were changed as shown in Tables 6 and 7.

[0088]

Table 6

[0089]

Table 7

[0090] As is clear from the above examples, the thermosetting resin sheet that satisfies the requirements of the present invention has a resin layer with both good hardness and adhesiveness. On the other hand, for the thermosetting resin sheets produced in Comparative Examples 1 and 3, since A1-H of the thermosetting resin composition constituting the resin layer exceeded 72%, the adhesiveness of the resin layer was insufficient. Also, for the thermosetting resin sheet produced in Comparative Example 2, since A1-B of the thermosetting resin composition constituting the resin layer was less than 70%, the hardness of the resin layer was insufficient.

Explanation of Signs

[0091] 10 Thermosetting resin sheet 11 Resin layer 12 Transfer layer 13 Release film

Claims

1. A thermosetting resin sheet comprising a resin layer made of a thermosetting resin composition, wherein the proportion (A1-H) of components with low molecular mobility defined below is 72% or less, and the proportion (A1-B) of components with low molecular mobility defined below is 70% or more. A1-H: After heating the resin layer at 100°C for 3 minutes, using a pulsed NMR apparatus, measuring the resin layer under a temperature control of 100°C by the CPMG method, and fitting the spin-spin relaxation curve of hydrogen nuclei obtained by this measurement using a two-component decay function (1) represented by the following formula (1), it is the value of A1. A1 - B: The resin layer was measured by the Solid echo method at a temperature of 25°C using a pulsed NMR apparatus, and the １ value of A1 when the spin - spin relaxation curve of the hydrogen nuclei of H was fitted using a two - component decay function (2) represented by the following formula (2). A1*Exp(−t / t1) + A2*Exp(−t / t2), t1 < t2, A1 + A2 = 100... (1) A1 * Exp(-0.5(t / t1)) ２ ) + A2 * Exp(-t / t2), t1 < t2, A1 + A2 = 100...(2)

2. The thermosetting resin sheet according to Claim 1, wherein the A1-H is 10% or more and the A1-B is 98% or less.

3. The thermosetting resin sheet according to Claim 1 or 2, wherein the thermosetting resin composition contains a (meth)acrylic resin and a blocked isocyanate.

4. The thermosetting resin sheet according to Claim 1 or 2, wherein the resin layer includes a clear layer and a colored layer.

5. The thermosetting resin sheet according to Claim 4, wherein the gel fraction of the clear layer is 75% or less.

6. The thermosetting resin sheet according to Claim 1 or 2, further comprising a release film and a transfer layer.

7. A vehicle painted with the thermosetting resin sheet according to Claim 1 or 2.

8. A vehicle part painted with the thermosetting resin sheet according to Claim 1 or 2.

9. A method for manufacturing a vehicle, including a step of painting using the thermosetting resin sheet according to Claim 1 or 2.

10. A method for manufacturing a vehicle part, including a step of painting using the thermosetting resin sheet according to Claim 1 or 2.

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