Method for manufacturing exterior decorative panels, transfer sheet, and exterior decorative panel

Abstract

To provide a method for manufacturing an external decorative plate which has a weather-resistant layer having good weather resistance and good adhesion to a design layer, and can manufacture an external decorative plate excellent in incombustibility.SOLUTION: A method for manufacturing an external decorative plate includes: a preparation step of preparing a transfer sheet 10 having a release film 1, a first weather-resistant layer 2, a second weather-resistant layer 3 and a design layer 4 in this order in a thickness direction; and an adhesion step of arranging a resin layer 30 between the surface on the design layer 4 side of the transfer sheet 10, and a calcium silicate plate 20, and bringing the transfer sheet 10, the resin layer 30 and the calcium silicate plate 20 into contact with each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to a method for manufacturing exterior decorative panels, a transfer sheet, and exterior decorative panels. [Background technology]

[0002] Transfer sheets that impart design features to components are known. A transfer sheet, for example, comprises a release film (release fill) and a transfer layer that includes at least a design layer. For example, Patent Document 1 discloses a design transfer sheet that includes a release layer and a design transfer layer that is peelably attached to the release layer.

[0003] On the other hand, calcium silicate board is known as a typical non-combustible building material. For example, Patent Document 2 discloses a fiber-reinforced calcium silicate board that has calcium silicate as its main component, contains reinforcing fibers, and contains fumed silica. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2016-120643 [Patent Document 2] Japanese Patent Publication No. 2011-213510 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Calcium silicate boards are highly non-combustible and also highly water-resistant, making them useful as exterior components (outdoor components) such as eaves and exterior walls. On the other hand, the inventors of this application have conducted extensive research on exterior components (exterior decorative panels) made by providing a decorative layer to calcium silicate boards, with the aim of expanding the applications of calcium silicate boards.

[0006] Specifically, the design layer of exterior decorative panels requires higher weather resistance than the design layer of interior components (components for indoor use). Therefore, the inventors of this application considered manufacturing exterior decorative panels by laminating a decorative sheet having a base sheet, a design layer, and a weather-resistant layer onto a calcium silicate board. In the case of decorative sheets, the base sheet, design layer, and weather-resistant layer are usually formed in this order, so it is relatively easy to manufacture a weather-resistant layer that has high weather resistance and high adhesion to the design layer. On the other hand, in the case of decorative sheets, the organic mass due to the resin contained in the base sheet is relatively large.

[0007] From the standpoint of non-combustibility of exterior decorative panels, it is preferable that the amount of organic mass contained in the exterior decorative panel is small. Therefore, the inventors of this application considered providing a design layer and a weather-resistant layer to a calcium silicate board by a transfer method. Specifically, they considered manufacturing an exterior decorative panel using a transfer sheet having a release film, a weather-resistant layer, and a design layer. When a transfer sheet is used, there is no need to use a base sheet in the decorative sheet, so an exterior decorative panel with a small amount of organic mass can be obtained. On the other hand, if high weather resistance is given to the weather-resistant layer in the transfer sheet, the adhesion between the weather-resistant layer and the design layer tends to decrease, and if the adhesion between the weather-resistant layer and the design layer in the transfer sheet is increased, the weather resistance of the weather-resistant layer tends to decrease.

[0008] This disclosure has been made in view of the above circumstances, and its main purpose is to provide a method for manufacturing exterior decorative panels that can produce exterior decorative panels having good weather resistance, a weather-resistant layer that has good adhesion to the design layer, and furthermore, excellent non-combustibility. [Means for solving the problem]

[0009] In the present disclosure, there is provided a method for manufacturing an exterior decorative board having a calcium silicate board, the method including a preparation step of preparing a transfer sheet having a release film, a first weather-resistant layer, a second weather-resistant layer, and a design layer in this order in the thickness direction, and an adhesion step of disposing a resin layer between the surface of the transfer sheet on the design layer side and the calcium silicate board and bringing the transfer sheet, the resin layer, and the calcium silicate board into close contact with each other.

[0010] In the present disclosure, there is provided a transfer sheet for manufacturing an exterior decorative board having a calcium silicate board, the transfer sheet having a release film, a first weather-resistant layer, a second weather-resistant layer, and a design layer in this order in the thickness direction.

[0011] In the present disclosure, there is provided an exterior decorative board having a calcium silicate board, the exterior decorative board having a first weather-resistant layer, a second weather-resistant layer, a design layer, a resin layer, and the calcium silicate board in this order in the thickness direction.

Advantages of the Invention

[0012] In the present disclosure, there is an effect that an exterior decorative board having good weather resistance, a weather-resistant layer having good adhesion to the design layer, and excellent non-combustibility can be obtained.

Brief Description of the Drawings

[0013] [Figure 1] It is a schematic cross-sectional view illustrating a method for manufacturing an exterior decorative board in the present disclosure.

Embodiments for Carrying Out the Invention

[0014] The embodiments will be described below with reference to the drawings and other figures. However, this disclosure can be implemented in many different ways and should not be limited to the embodiments described below. In addition, the drawings may schematically represent the width, thickness, and shape of each part compared to the actual form in order to make the explanation clearer, but this is merely an example and should not be interpreted as limiting.

[0015] In this specification, when describing a manner in which one member is placed on another member, the term "above" or "below" includes, unless otherwise specified, both cases: when the other member is placed directly above or directly below the member so as to be in contact with it, and when the other member is placed above or below the member via yet another member. Similarly, in this specification, when describing a manner in which one member is placed on the surface of a member, the term "on the surface" includes, unless otherwise specified, both cases: when the other member is placed directly above or directly below the member so as to be in contact with it, and when the other member is placed above or below the member via yet another member.

[0016] The manufacturing method of the exterior decorative panel, the transfer sheet, and the exterior decorative panel as described herein will be explained in detail below.

[0017] A. Manufacturing method of exterior decorative panels Figure 1 is a schematic cross-sectional view illustrating the manufacturing method of the exterior decorative panel in this disclosure. First, as shown in Figure 1(a), a transfer sheet 10 is prepared. The transfer sheet 10 consists of a release film 1, a first weather-resistant layer 2, a second weather-resistant layer 3, and a design layer 4, with the thickness direction D TIn this order, the components are present. Next, as shown in Figure 1(b), the resin layer 30 is placed between the design layer 4 side of the transfer sheet 10 and the calcium silicate board 20, and the transfer sheet 10, resin layer 30 and calcium silicate board 20 are brought into close contact. The "design layer 4 side of the transfer sheet 10" refers to the side of the transfer sheet 10 that is located on the design layer 4 side when the release film 1 is used as a reference. Next, as shown in Figure 1(c), the release film 1 is peeled off the transfer sheet 10. This separates the first weather-resistant layer 2, the second weather-resistant layer 3, the design layer 4, the resin layer 30 and the calcium silicate board 20 in the thickness direction D T In this way, an exterior decorative panel 100 having the layers in this order is obtained. In the transfer sheet 10, the layer that is transferred to the calcium silicate board 20 side is called the transfer layer. In Figure 1, the transfer layer corresponds to the first weather-resistant layer 2, the second weather-resistant layer 3, and the design layer 4.

[0018] According to this disclosure, by providing a first weather-resistant layer and a second weather-resistant layer as the weather-resistant layer in the transfer sheet, a weather-resistant layer having good weather resistance and good adhesion to the design layer can be obtained. Specifically, the first weather-resistant layer contributes to improving weather resistance. In contrast, the second weather-resistant layer contributes to improving weather resistance as well as improving adhesion to the design layer. By providing such a first weather-resistant layer and a second weather-resistant layer, a weather-resistant layer having good weather resistance and good adhesion to the design layer can be obtained.

[0019] Furthermore, according to this disclosure, because a transfer sheet is used, an exterior decorative panel with less organic mass can be obtained compared to the case where a decorative sheet including a base sheet is used. In other words, an exterior decorative panel with excellent non-combustibility can be obtained. The above term "non-combustibility" refers to the property of being difficult to burn, and is a concept that includes so-called flame retardancy.

[0020] Furthermore, exterior decorative panels having calcium silicate boards have the following two unique challenges. The first challenge is that, although calcium silicate boards are relatively inexpensive, they have a high surface roughness. When a design layer is transferred to a calcium silicate board with a high surface roughness, the surface roughness affects the design layer, and the design quality of the design layer tends to decrease. In response to this, in this disclosure, a resin layer is placed between the transfer sheet and the calcium silicate board. By placing a resin layer, the decrease in the design quality of the design layer caused by the surface roughness of the calcium silicate board can be suppressed.

[0021] A second challenge is that, due to the high heat retention properties of calcium silicate boards, delamination is likely to occur between the layers constituting the transfer layer due to the influence of heat. In particular, delamination is likely to occur between the weather-resistant layer and the design layer. In response to this, as described above, in this disclosure, a first weather-resistant layer and a second weather-resistant layer are provided as the weather-resistant layer in the transfer sheet, and furthermore, since the second weather-resistant layer has high adhesion to the design layer, delamination between the second weather-resistant layer and the design layer can be suppressed.

[0022] Thus, in this disclosure, by using a predetermined transfer sheet and a resin layer, the specific problems that arise in exterior decorative panels having calcium silicate boards can be effectively solved.

[0023] 1. Preparation process The preparation step in this disclosure is the step of preparing a transfer sheet having a release film, a first weather-resistant layer, a second weather-resistant layer, and a design layer in this order in the thickness direction. As described above, a transfer sheet usually has a release film and a transfer layer. The transfer layer in this disclosure has at least a first weather-resistant layer, a second weather-resistant layer, and a design layer in that order from the release film side.

[0024] From the viewpoint of non-flammability, it is preferable that the organic mass of the transfer layer be low. For example, the organic mass of the transfer layer should be 30 g / m². 2 The following is true: 25g / m 2 It may also be less than 20g / m 2The following may also apply. The organic mass is measured, for example, by an exothermic test based on ISO 5660-1.

[0025] The thickness of the transfer layer is, for example, 10 μm or more, may be 12 μm or more, or 14 μm or more. If the transfer layer is too thin, sufficient weather resistance may not be obtained. On the other hand, the thickness of the transfer layer is, for example, 50 μm or less, may be 40 μm or less, or 30 μm or less. If the transfer layer is too thick, the non-combustibility of the exterior decorative panel may decrease. Similarly, the total thickness of the first weather-resistant layer, the second weather-resistant layer, and the design layer is, for example, 10 μm or more, may be 12 μm or more, or 14 μm or more. If the above total is too small, sufficient weather resistance may not be obtained. On the other hand, the above total is, for example, 40 μm or less, or 30 μm or less. If the above total is too large, the non-combustibility of the exterior decorative panel may decrease.

[0026] (1) 1st weather resistant layer The transfer sheet in this disclosure has a first weather-resistant layer. The first weather-resistant layer contributes to improved weather resistance. Furthermore, the first weather-resistant layer also contributes to improving the surface properties of the exterior decorative panel (e.g., scratch resistance and stain resistance). However, if the hardness of the first weather-resistant layer is increased to improve the surface properties of the exterior decorative panel, the adhesion between the first weather-resistant layer and the design layer tends to decrease. The first weather-resistant layer and the release film may be arranged in direct contact or arranged via other layers.

[0027] The first weather-resistant layer preferably contains a cured product of a curable resin composition as a resin component. The proportion of the cured product of the curable resin composition is, for example, 70% by mass or more, may be 90% by mass or more, may be 95% by mass or more, or may be 100% by mass, relative to the total resin components constituting the first weather-resistant layer.

[0028] Examples of cured products of curable resin compositions include cured products of ionizing radiation-curable resin compositions. Examples of ionizing radiation-curable resin compositions include electron beam-curable resin compositions and ultraviolet-curable resin compositions. Among these, electron beam-curable resin compositions are preferred because they do not require polymerization initiators, have less odor, and are less prone to discoloration.

[0029] An ionizing radiation-curable resin composition is a composition containing a compound having an ionizing radiation-curable functional group (hereinafter also referred to as "ionizing radiation-curable compound"). An ionizing radiation-curable functional group is a group that crosslinks and hardens upon irradiation with ionizing radiation, and examples include functional groups having an ethylenically double bond, such as a (meth)acryloyl group, a vinyl group, or an allyl group. In this disclosure, a (meth)acryloyl group means an acryloyl group or a metacloyl group. In this disclosure, a (meth)acrylate means an acrylate or a methacrylate.

[0030] Ionizing radiation refers to electromagnetic waves or charged particle beams that possess energy quanta capable of polymerizing or bridging molecules. Examples of ionizing radiation include electron beams (EB) and ultraviolet (UV). Other examples of ionizing radiation include electromagnetic waves such as X-rays and gamma rays, and charged particle beams such as alpha rays and ion beams.

[0031] The ionizing radiation-curable compound preferably contains one or more selected from, for example, urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, polycarbonate (meth)acrylate, and acrylic (meth)acrylate. In particular, the ionizing radiation-curable compound preferably contains at least urethane (meth)acrylate. The urethane (meth)acrylate is preferably caprolactone-based urethane acrylate because it easily improves the weather resistance and scratch resistance of the first weather-resistant layer.

[0032] In addition, the radiation-curable compound may contain a caprolactone-based urethane acrylate and a urethane (meth)acrylate that is not caprolactone-modified. In this case, the content of the caprolactone-based urethane acrylate contained in the first weather-resistant layer is denoted as M CLUA and the content of the urethane (meth)acrylate that is not caprolactone-modified is denoted as M UA . M UA and M CLUA The mass ratio of M CLUA to the sum of M CLUA / (M UA +M CLUA )) is, for example, 40% by mass or more and 90% by mass or less, and may be 45% by mass or more and 80% by mass or less, or may be 50% by mass or more and 70% by mass or less.

[0033] The caprolactone-based urethane acrylate can usually be obtained by reacting a caprolactone-based polyol, an organic isocyanate, and a hydroxy (meth)acrylate. Examples of the synthesis method include a method in which a polycaprolactone-based polyol and an organic polyisocyanate are reacted to produce a polyurethane prepolymer containing -NCO groups (isocyanate groups) at both ends, and then reacted with a hydroxy (meth)acrylate.

[0034] As the caprolactone-based polyol, commercially available polyols can be used, preferably those having two hydroxyl groups and a number-average molecular weight of preferably 500 to 3000, more preferably 750 to 2000. In addition, polyols other than caprolactone-based polyols, such as ethylene glycol, diethylene glycol, 1,4-butanediol, and 1,6-hexanediol, can be used in any proportion by mixing one or more types. As the organic polyisocyanate, diisocyanates having two isocyanate groups are preferred, and from the viewpoint of suppressing yellowing, isophorone diisocyanate, hexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, trimethylhexamethylene diisocyanate, etc. are preferred. As the hydroxy(meth)acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, caprolactone-modified 2-hydroxyethyl acrylate, etc. are preferred.

[0035] When an ionizing radiation-curable resin composition contains a caprolactone-based polyol, the caprolactone-based urethane acrylate is preferably a caprolactone diol-based urethane acrylate. A caprolactone diol-based urethane acrylate refers to a urethane acrylate among caprolactone-based urethane acrylates in which the terminal end is diethylene glycol. By using a caprolactone diol-based urethane acrylate, cracking and whitening of the first weather-resistant layer can be suppressed.

[0036] The number-average molecular weight of the ionizing radiation-curable compound is, for example, between 1,000 and 10,000, and may also be between 2,000 and 10,000. The number-average molecular weight is measured by GPC analysis and is the average molecular weight converted to standard polystyrene.

[0037] For example, if the ionizing radiation-curable compound is an ultraviolet-curable compound, it is preferable that the ionizing radiation-curable compound contains at least one of a photopolymerization initiator and a photopolymerization accelerator. Examples of photopolymerization initiators include acetophenone, benzophenone, α-hydroxyalkylphenone, Michler ketone, benzoin, benzyldimethyl ketal, benzoyl benzoate, α-acyloxime ester, acylphosphine oxide, and thioxanthones. Examples of photopolymerization accelerators include isoamyl p-dimethylaminobenzoate and ethyl p-dimethylaminobenzoate.

[0038] The first weather-resistant layer contains a weather-resistant agent. Examples of weather-resistant agents include ultraviolet absorbers and light stabilizers. Preferably, the first weather-resistant layer contains at least one of an ultraviolet absorber and a light stabilizer. The first weather-resistant layer may contain one or more ultraviolet absorbers. Similarly, the first weather-resistant layer may contain one or more light stabilizers.

[0039] Examples of UV absorbers included in the first weather-resistant layer include organic UV absorbers such as triazine-based UV absorbers, benzotriazole-based UV absorbers, benzophenone-based UV absorbers, oxybenzophenone-based UV absorbers, salicylic acid ester-based UV absorbers, and cyano(meth)acrylate-based UV absorbers, as well as inorganic UV absorbers such as titanium dioxide, cerium oxide, and zinc oxide. Among these, triazine-based UV absorbers are more preferred. As mentioned above, calcium silicate boards have the unique problem of high heat retention, but triazine-based UV absorbers have high heat resistance, which can suppress the occurrence of bleed-out.

[0040] Examples of triazine-based UV absorbers include hydroxyphenyltriazine-based UV absorbers. Examples of hydroxyphenyltriazine-based UV absorbers include 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3,5-triazine. Examples include azine, 2-[4-[(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5[2-(2-ethylhexanoyloxy)ethoxy]phenol.

[0041] The amount of ultraviolet absorber contained in the first weather-resistant layer is, for example, 0.5 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the ionizing radiation-curable compound, and may be 0.8 parts by mass or more and 8 parts by mass or 1 part by mass or more and 5 parts by mass. If the amount of ultraviolet absorber is too high, bleed-out of the ultraviolet absorber may occur, and if the amount of ultraviolet absorber is too low, sufficient ultraviolet absorption performance may not be obtained.

[0042] Examples of light stabilizers included in the first weather-resistant layer include hindered amine-based light stabilizers. Examples of hindered amine-based light stabilizers include 1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, methyl(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, and 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)amino]-6-(2-hydroxyethylamine)-1,3,5-triazine).

[0043] The amount of light stabilizer contained in the first weather-resistant layer is, for example, 1 to 10 parts by mass per 100 parts by mass of the ionizing radiation-curable compound, and may be 1.5 to 8 parts by mass, or 2 to 5 parts by mass. If the amount of light stabilizer is too high, bleed-out of the light stabilizer may occur, and if the amount of light stabilizer is too low, sufficient photostability may not be obtained.

[0044] The first weather-resistant layer may contain additives such as silicone compounds, polymerization inhibitors, crosslinking agents, antistatic agents, adhesion improvers, antioxidants, leveling agents, thixotropic agents, coupling agents, plasticizers, antifouling agents, defoaming agents, and fillers. The thickness of the first weather-resistant layer is, for example, 2 μm to 20 μm, may be 3 μm to 15 μm, or 4 μm to 10 μm. If the first weather-resistant layer is too thin, sufficient weather resistance may not be obtained, and if the first weather-resistant layer is too thick, the non-combustibility of the exterior decorative panel may decrease.

[0045] (2)Second weather-resistant layer The transfer sheet in this disclosure has a second weather-resistant layer. The second weather-resistant layer contributes to improved weather resistance while also contributing to improved adhesion with the design layer. The second weather-resistant layer and the first weather-resistant layer may be arranged in direct contact or with other layers in between.

[0046] The second weather-resistant layer contains a resin. Examples of the resin include (meth)acrylic resins, urethane resins, butyral resins, polyolefins, chlorinated polyolefins, vinyl chloride-vinyl acetate copolymers, and polyesters. Among these, urethane resins are preferred. The second weather-resistant layer preferably contains a cured product of the above resin.

[0047] The second weather-resistant layer preferably contains a cured product of a curable resin composition (particularly a cured product of a thermosetting resin composition). The thermosetting resin composition is a composition containing at least a thermosetting resin, and is a resin composition that hardens upon heating. Examples of thermosetting resins include (meth)acrylic resins, urethane resins, urethane acrylic resins, phenolic resins, urea melamine resins, epoxy resins, unsaturated polyester resins, and silicone resins. The thermosetting resin composition may also be obtained by adding a curing agent such as an isocyanate curing agent or an epoxy curing agent to these resins.

[0048] The cured product of the thermosetting resin composition is preferably a cured product of a thermosetting resin composition containing a (meth)acrylic resin, a urethane resin, or a urethane-acrylic resin, and more preferably a cured product of a thermosetting resin composition containing a urethane-acrylic resin. Furthermore, the thermosetting resin composition preferably contains an isocyanate-based curing agent or an epoxy-based curing agent to make the structure of the cured product more rigid, and more preferably contains an isocyanate-based curing agent.

[0049] Furthermore, if the second weather-resistant layer contains a urethane acrylic resin, the urethane acrylic resin is preferably a urethane acrylic copolymer, and more preferably a polycarbonate-based urethane acrylic copolymer. The polycarbonate-based urethane acrylic copolymer is a resin obtained by radical polymerization of an acrylic monomer to a polycarbonate-based polyurethane polymer obtained by reacting a polycarbonate diol with a (di)isocyanate.

[0050] Examples of (di)isocyanates include aromatic isocyanates such as 4,4'-diphenylmethane diisocyanate, 2,4-tole diisocyanate, 1,5-naphthalene diisocyanate, n-isocyanate phenylsulfonyl isocyanate, o-isocyanate phenylsulfonyl isocyanate, and p-isocyanate phenylsulfonyl isocyanate; aliphatic isocyanates such as 1,6-hexamethylene diisocyanate; and alicyclic isocyanates such as isophorone diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate.

[0051] Examples of acrylic monomers include alkyl esters of (meth)acrylate such as (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, and isobutyl (meth)acrylate.

[0052] In a polycarbonate-based urethane-acrylic copolymer, the mass ratio of the urethane component to the total of the acrylic and urethane components ([urethane component] / ([acrylic component]+[urethane component]) is, for example, 75% by mass or more and 95% by mass or less, and may be 80% by mass or more and 90% by mass or less. By setting the above mass ratio to 75% by mass or more, the proportion of the polycarbonate structure in the polycarbonate-based urethane-acrylic copolymer can be increased, making the structure of the polycarbonate-based urethane-acrylic copolymer more rigid. Therefore, deformation due to temperature changes can be reduced. Furthermore, by setting the above mass ratio to 95% by mass or less, it becomes easier to ensure the flexibility of the second weather-resistant layer and the adhesion with the design layer is improved.

[0053] The second weather-resistant layer contains a weathering agent. Examples of weathering agents include ultraviolet absorbers and light stabilizers. Preferably, the second weather-resistant layer contains at least one of an ultraviolet absorber and a light stabilizer. The preferred types and forms of the weathering agents are the same as those described in "(1) First Weather-Resistant Layer" above, so they are omitted here. In particular, it is preferable that the second weather-resistant layer contains a triazine-based ultraviolet absorber. It is also preferable that the second weather-resistant layer contains a hindered amine-based light stabilizer.

[0054] The amount of ultraviolet absorber contained in the second weather-resistant layer is, for example, 0.1 parts by mass or more and 50 parts by mass or less per 100 parts by mass of resin component, and may be 3 parts by mass or more and 40 parts by mass or 10 parts by mass or more and 35 parts by mass. Furthermore, the amount of ultraviolet absorber contained in the second weather-resistant layer (per 100 parts by mass of resin component) may be greater than the amount of ultraviolet absorber contained in the first weather-resistant layer (per 100 parts by mass of resin component).

[0055] The amount of light stabilizer contained in the second weather-resistant layer is, for example, 0.1 parts by mass or more and 15 parts by mass or less per 100 parts by mass of resin component, and may be 1 part by mass or more and 15 parts by mass or less, or 3 parts by mass or more and 10 parts by mass or less. Furthermore, the amount of light stabilizer contained in the second weather-resistant layer (amount per 100 parts by mass of resin component) may be greater than the amount of light stabilizer contained in the first weather-resistant layer (amount per 100 parts by mass of resin component).

[0056] The second weather-resistant layer may contain additives such as silicone compounds, polymerization inhibitors, crosslinking agents, antistatic agents, adhesion enhancers, antioxidants, leveling agents, thixotropic agents, coupling agents, plasticizers, antifouling agents, defoaming agents, and fillers. The thickness of the second weather-resistant layer may be, for example, 2 μm to 10 μm, 3 μm to 8 μm, or 3 μm to 5 μm. If the second weather-resistant layer is too thin, adhesion to the decorative layer may be insufficient, and if the second weather-resistant layer is too thick, the non-combustibility of the exterior decorative panel may decrease.

[0057] (3) Design layer The transfer sheet in this disclosure has a design layer on the side of the second weather-resistant layer opposite to the first weather-resistant layer. The design layer improves the aesthetic appearance of the exterior decorative panel. The design layer and the second weather-resistant layer may be arranged in direct contact or may be arranged via other layers.

[0058] Design layers include, for example, solid color layers (layers with solid ink coverage) and pattern layers (layers with printed ink). Patterns (designs) in the pattern layer include, for example, wood grain patterns, stone patterns, sand patterns, tile patterns, brick patterns, fabric patterns, leather patterns, geometric figures, letters, symbols, abstract patterns, and floral patterns.

[0059] The design layer typically contains a coloring agent and a binder resin. Examples of coloring agents include inorganic pigments such as carbon black (ink), iron black, titanium white, antimony white, lead yellow, titanium yellow, reddish-brown, cadmium red, ultramarine, and cobalt blue; organic pigments (including dyes) such as quinacridone red, isoindolinone yellow, nickel azo complex, phthalocyanine blue, and azomethine azoblack; metallic pigments such as aluminum and brass; and pearl pigments such as titanium dioxide-coated mica and basic lead carbonate.

[0060] Examples of binder resins include urethane resins, acrylic polyol resins, (meth)acrylic resins, ester resins, amide resins, butyral resins, styrene resins, urethane-acrylic copolymers, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-acrylic copolymers, chlorinated propylene resins, nitrocellulose resins, and cellulose acetate resins.

[0061] The design layer may contain additives such as ultraviolet absorbers, light stabilizers, curing agents, plasticizers, and catalysts, as needed. The thickness of the design layer may be, for example, 0.5 μm or more and 20 μm or less, 1 μm or more and 10 μm or less, or 2 μm or more and 5 μm or less.

[0062] (4) Release film The transfer sheet in this disclosure has a release film (first release film) on the side of the first weather-resistant layer opposite to the second weather-resistant layer. The release film and the first weather-resistant layer may be arranged in direct contact or with other layers in between.

[0063] The release film is preferably a resin film. Examples of resins included in the resin film include ester resins, olefin resins, styrene resins, vinyl resins, (meth)acrylic resins, amide resins, imide resins, and carbonate resins.

[0064] The release film preferably contains an ester resin or an olefin resin. Examples of ester resins include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and polyethylene terephthalate-isophthalate copolymer. Among these, PET or PBT are preferred, and PET is more preferred, from the viewpoint of being less susceptible to thermal shrinkage during the manufacture of the transfer sheet and shrinkage due to irradiation with ionizing radiation.

[0065] Examples of olefin resins include polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, and ethylene-propylene-butene copolymer. Among these, polypropylene is preferred from the viewpoint of being less susceptible to thermal shrinkage during the manufacture of the transfer sheet and shrinkage due to irradiation with ionizing radiation.

[0066] The release film may be a stretched film or an unstretched film. The stretching ratio in the mechanical direction (MD) of the stretched film is, for example, 5 times or more and 30 times or less. The stretching ratio in the width direction (TD) of the stretched film is, for example, 5 times or more and 30 times or less. The thickness of the release film is, for example, 10 μm or more and 200 μm or less, may be 15 μm or more and 150 μm or less, or 20 μm or more and 100 μm or less.

[0067] (5) Transfer sheet The transfer sheet in this disclosure comprises a release film, a first weather-resistant layer, a second weather-resistant layer, and a design layer, in this order in the thickness direction. Preferably, the nanoindation hardness of the first weather-resistant layer is greater than that of the second weather-resistant layer. The nanoindation hardness is calculated by the method described in Japanese Patent No. 6954505.

[0068] In the transfer layer, it is preferable that two adjacent layers have similar thermal properties. As mentioned above, calcium silicate boards have high heat retention, and due to the influence of this heat, delamination is likely to occur between the layers constituting the transfer layer. By making the thermal properties similar, the occurrence of delamination can be suppressed.

[0069] Here, A1 is the absolute value of the difference between the linear expansion coefficient of the first weather-resistant layer and the linear expansion coefficient of the second weather-resistant layer in the temperature range of 40°C to 50°C. On the other hand, B1 is the absolute value of the difference between the linear expansion coefficient of the first weather-resistant layer and the linear expansion coefficient of the second weather-resistant layer in the temperature range of 70°C to 80°C. It is preferable that the difference between B1 and A1 is small, for example, 5 × 10⁻⁶. -4 (1 / ℃) or less, 3 × 10 -4 It may be less than (1 / ℃), and 1 × 10 -4 It may be below (1 / ℃).

[0070] The coefficient of linear expansion is measured in accordance with JIS K 7179:1991. Specifically, a single layer film (20 μm thick) of the layer to be evaluated is prepared. Next, the single layer film is cut to prepare a measurement sample measuring 10 mm in length, 5 mm in width, and 20 μm in thickness. The prepared sample is set in a thermomechanical analyzer (TMA-60, manufactured by Shimadzu Corporation), and the coefficient of linear expansion is measured under the following conditions. <Measurement conditions> • Atmosphere gas: Nitrogen • Load: 2g / 5mm • Measurement mode: Tensile and temperature programs Step 1: Heat the temperature at a rate of 10°C / min to 30°C, then maintain the temperature at 30°C for 10 minutes. Step 2: Heat the temperature at a rate of 5°C / min to 100°C, then hold at 100°C for 1 minute. Step 3: Cool to 0°C at -30°C / min.

[0071] Furthermore, A2 is defined as the absolute value of the difference between the linear expansion coefficient of the second weather-resistant layer and the linear expansion coefficient of the design layer in the temperature range of 40°C to 50°C. On the other hand, B2 is defined as the absolute value of the difference between the linear expansion coefficient of the second weather-resistant layer and the linear expansion coefficient of the design layer in the temperature range of 70°C to 80°C. It is preferable that the difference between B2 and A2 be small, for example, 5 × 10⁻⁶. -4 (1 / ℃) or less, 3 × 10 -4 It may be less than (1 / ℃), and 1 × 10 -4 It may be below (1 / ℃).

[0072] The transfer sheet in this disclosure may or may not have an adhesive layer on the side of the design layer opposite to the second weather-resistant layer. The adhesive layer contains a resin. Examples of the resin include ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), ethylene-methacrylic acid copolymer (EMAA), (meth)acrylic resin, styrene resin, ester resin, urethane resin, chlorinated polyolefin, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, alkyd resin, petroleum resin, ketone resin, epoxy resin, melamine resin, fluororesin, silicone resin, and rubber resin. The thickness of the adhesive layer is, for example, 0.1 μm or more and 10 μm or less.

[0073] The transfer sheet in this disclosure may have a second release film on the side of the design layer opposite to the second weather-resistant layer. For example, when the transfer sheet is manufactured by winding it into a roll, the occurrence of blocking can be suppressed. The second release film is usually peeled off from the transfer sheet before the adhesion process described later. Details of the second release film are the same as those described for the first release film above, so they are omitted here.

[0074] (6) Method for forming a transfer sheet The transfer sheet in this disclosure is not particularly limited, but examples include a method in which a first weather-resistant layer is formed on the surface of a release film, a second weather-resistant layer is formed on the surface of the first weather-resistant layer opposite to the release film, and a design layer is formed on the surface of the second weather-resistant layer opposite to the first weather-resistant layer.

[0075] One method for forming the first weather-resistant layer is to coat the surface of a release film with a composition for forming the first weather-resistant layer and then cure it. Examples of coating methods for the above composition include gravure printing, bar coating, roll coating, reverse roll coating, and comma coating. Examples of curing methods include irradiation with ionizing radiation such as electron beams and ultraviolet rays.

[0076] As a method for forming the second weather-resistant layer, for example, a composition for forming the second weather-resistant layer is applied to the side of the first weather-resistant layer opposite to the release film, and cured as necessary. As a method for applying the above composition, for example, gravure printing, bar coating, roll coating, reverse roll coating, and comma coating are used. As a curing method, for example, heat is used. Furthermore, as a method for forming the design layer, for example, an ink containing a colorant, a binder resin, and a solvent is applied to the side of the second weather-resistant layer opposite to the first weather-resistant layer.

[0077] 2. Adhesion process The adhesion step in this disclosure is a step of placing a resin layer between the surface of the transfer sheet on the design layer side and the calcium silicate board, thereby bringing the transfer sheet and the calcium silicate board into close contact.

[0078] (1) Calcium silicate board The calcium silicate board in this disclosure is a member containing calcium silicate as its main component. The calcium silicate board may further contain reinforcing fibers such as pulp fibers. The shape of the calcium silicate board is not particularly limited, but for example, it is plate-shaped. The calcium silicate board may be a plate with a flat surface or a plate with a curved surface.

[0079] The surface of a calcium silicate board typically has a high surface roughness. Here, the maximum height of the resin layer side of the calcium silicate board is defined as Rz [μm]. The maximum height Rz is calculated as the sum of the highest point (maximum peak height: Rp) and the deepest point (maximum valley depth: Rv) in the roughness curve measured by a roughness meter. The Rz of the resin layer side of the calcium silicate board is, for example, 50 μm or more, may be 60 μm or more, or may be 70 μm or more. The Rz of the resin layer side of the calcium silicate board is, for example, 100 μm or less.

[0080] Furthermore, the arithmetic mean roughness of the resin-layered side of the calcium silicate board is defined as Ra [μm]. The arithmetic mean roughness Ra is calculated as the average value of the surface irregularities in the roughness curve measured with a roughness meter. The Ra of the resin-layered side of the calcium silicate board is, for example, 50 μm or more, may be 60 μm or more, or 70 μm or more. The Ra of the resin-layered side of the calcium silicate board is, for example, 100 μm or less.

[0081] (2) Resin layer The resin layer in this disclosure is disposed between the design layer side of the transfer sheet and the calcium silicate board. The resin contained in the resin layer preferably has heat-sealing properties. Examples of the resin include (meth)acrylic resins such as polymethyl methacrylate, urethane resins, vinyl chloride resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-acrylic copolymers, ester resins, amide resins, cyanoacrylate resins, and epoxy resins.

[0082] Here, the thickness of the resin layer is T R Let the thickness be [μm].R This is defined as the average thickness of the resin layer. Resin layer thickness T R It is preferable that the height Rz is greater than the maximum height Rz in the calcium silicate board described above. This is because it can suppress the deterioration of the design quality of the design layer caused by the surface roughness of the calcium silicate board. R The difference between and Rz is, for example, 1 μm or more, may be 3 μm or more, or 5 μm or more. On the other hand, T R The difference between the Rz and other parameters is, for example, 10 μm or less. If the above difference is large, the fire resistance of the exterior decorative panel may decrease.

[0083] Also, the thickness T of the resin layer R It is preferable that the surface roughness Ra of the calcium silicate board described above is greater than that of the calcium silicate board. This is because it can suppress the deterioration of the design quality of the design layer caused by the surface roughness of the calcium silicate board. R The difference between and Ra is, for example, 1 μm or more, may be 3 μm or more, or may be 5 μm or more. On the other hand, T R The difference in Ra is, for example, 10 μm or less. If the above difference is large, the non-combustibility of the exterior decorative panel may decrease.

[0084] Thickness T of the resin layer R This also depends on the surface roughness of the calcium silicate board, but for example, it may be 30 μm or more and 110 μm or less, 50 μm or more and 100 μm or less, or 70 μm or more and 90 μm or less.

[0085] The organic mass of the resin layer is, for example, 120 g / m². 2 The following is true: 110g / m² 2 It may also be less than 100g / m 2 The following is also acceptable. If the organic mass of the resin layer is high, the non-combustibility of the exterior decorative panel may decrease. On the other hand, the organic mass of the resin layer may be, for example, 30 g / m². 2 That concludes the explanation. If the organic mass of the resin layer is low, it may not be possible to adequately suppress the deterioration of the design quality of the design layer caused by the surface roughness of the calcium silicate board.

[0086] (3) Method of adhesion In the adhesion process, a resin layer is placed between the design layer side of the transfer sheet and the calcium silicate board, thereby adhering the transfer sheet, resin layer, and calcium silicate board to each other. The resin layer may be pre-integrated with the transfer sheet or pre-integrated with the calcium silicate board.

[0087] One method for bonding the transfer sheet, resin layer, and calcium silicate board is lamination. In lamination, for example, the laminate of the transfer sheet, resin layer, and calcium silicate board is heated and pressurized from the transfer sheet side. One method for heating and pressurizing is to use a roll transfer device. The roll temperature of the roll transfer device is, for example, 200°C or less, and may be 180°C or less. If the roll temperature is too high, the transfer sheet may soften more than necessary. On the other hand, the roll temperature of the roll transfer device is, for example, 100°C or higher, and may be 110°C or higher, and may be 120°C or higher. Furthermore, the method for manufacturing exterior decorative panels in this disclosure may include a peeling step after the bonding step in which a release film is peeled off from the first weather-resistant layer.

[0088] 3. Exterior decorative panels The exterior decorative panel in this disclosure has a first weather-resistant layer, a second weather-resistant layer, a design layer, a resin layer, and a calcium silicate board in this order in the thickness direction. The exterior decorative panel may be an exterior decorative panel with a release film having a release film on the side of the first weather-resistant layer opposite to the second weather-resistant layer, or it may be an exterior decorative panel without a release film.

[0089] The organic mass of the exterior decorative panel (excluding the organic mass of the release film) is, for example, 140 g / m². 2 The following is true: 130g / m 2 It may also be less than 120g / m². 2 The following is also acceptable. If the organic mass of the exterior decorative panel is high, the non-combustibility of the exterior decorative panel may decrease. On the other hand, the organic mass of the exterior decorative panel is, for example, 60 g / m². 2 That's all.

[0090] The exterior decorative panels in this disclosure preferably qualify as flame-retardant materials under the Building Standards Act in a heat generation test based on ISO 5660-1, more preferably as semi-noncombustible materials, and even more preferably as noncombustible materials. Specifically, the amount of heat generated during heating is measured using a cone calorimeter, and the heating time that satisfies all of the following conditions (i) to (iii) is measured. If this heating time is 5 minutes or more, it qualifies as a flame-retardant material; if it is 10 minutes or more, it qualifies as a semi-noncombustible material; and if it is 20 minutes or more, it qualifies as a noncombustible material. (i) Total heat output is 8 MJ / m³ 2 The following is (ii) The maximum heating rate exceeds 200 kW / m² for more than 10 seconds continuously. 2 Do not exceed (iii) No cracks or holes that penetrate to the back surface and are harmful to fire safety.

[0091] The exterior decorative panels described in this disclosure are typically used outdoors. Examples of applications for exterior decorative panels include building materials and insulation materials. Specific examples of building materials include exterior components such as eaves, exterior walls, and roofs of buildings such as houses, factories, shops, and hospitals. Specific examples of insulation materials include exterior components used to insulate piping or equipment in factories.

[0092] B. Transfer sheet The transfer sheet in this disclosure is a transfer sheet for manufacturing an exterior decorative panel having a calcium silicate board, and comprises a release film, a first weather-resistant layer, a second weather-resistant layer, and a design layer in this order in the thickness direction.

[0093] According to this disclosure, the transfer sheet has a first weather-resistant layer and a second weather-resistant layer, thus providing good weather resistance and good adhesion to the design layer. Furthermore, by using this transfer sheet, an exterior decorative panel with excellent non-combustibility can be obtained. The transfer sheet in this disclosure is the same as the one described in "A. Method for Manufacturing Exterior Decorative Panels" above, so a description is omitted here.

[0094] C. Exterior decorative panels The exterior decorative panel in this disclosure is an exterior decorative panel having a calcium silicate board, and having a first weather-resistant layer, a second weather-resistant layer, a design layer, a resin layer, and a calcium silicate board in this order in the thickness direction.

[0095] According to this disclosure, the exterior decorative panel has a first weather-resistant layer and a second weather-resistant layer, and therefore has a weather-resistant layer that has good weather resistance and good adhesion to the design layer. The exterior decorative panel in this disclosure is the same as described in "A. Method for Manufacturing Exterior Decorative Panels" above, so the description is omitted here.

[0096] This disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of this disclosure and achieves similar effects is included within the technical scope of this disclosure. [Examples]

[0097] [Example 1] (Preparation of transfer sheet) A 25 μm thick PET release film was prepared as the release film. The following resin composition for forming the first weather-resistant layer was applied to the surface of the PET release film, with a coating amount of 6.5 g / m² after drying. 2 The material was coated in this manner and dried at 70°C for 1 minute. Subsequently, it was irradiated with an electron beam (pressure voltage: 175 keV, 5 Mrad (50 kGy)) to form a first weather-resistant layer with a thickness of 5 μm. <Resin composition for forming the first weather-resistant layer> • Urethane acrylate: 100 parts by mass (Bifunctional caprolactone-modified urethane acrylate / Polyfunctional urethane acrylate = 50 / 50 (mass ratio)) • Triazine-based UV absorber: 4 parts by mass (3 parts by mass of "Tinuvin 479" (BASF), 1 part by mass of "Tinuvin 400" (BASF)) • Light stabilizer: 3 parts by mass (Product name: LS-3410, manufactured by Nippon Emulsifier Co., Ltd.) • Nanosilica: 2 parts by mass Non-reactive silicone: 0.3 parts by mass • Solvent: appropriate amount (Methyl ethyl ketone)

[0098] Next, the following resin composition for forming the second weather-resistant layer is applied to the surface of the obtained first weather-resistant layer, with a coating amount of 5.2 g / m² after drying. 2 The surface was coated in this manner and dried at 70°C for 1 minute to form a second weather-resistant layer with a thickness of 4 μm. <Resin composition for forming the second weather-resistant layer> • Polycarbonate-based urethane-acrylic copolymer: 100 parts by mass (Urethane component / Acrylic component = 90 / 10 (by mass)) • Triazine-based UV absorber: 35 parts by mass (18 parts by mass of "Tinuvin 479" (manufactured by BASF), 17 parts by mass of "Tinuvin 400" (manufactured by BASF)) • Light stabilizer: 3.5 parts by mass ("Tinuvin 123" (made by BASF)) • Silica: 5 parts by mass • Hexamethylene diisocyanate-based curing agent: 6 parts by mass • Solvent: appropriate amount (Methyl ethyl ketone)

[0099] Next, using a gravure printing press, an ink containing a vinyl chloride-vinyl acetate-acrylic copolymer (manufactured by Showa Ink) was applied to the surface of the obtained second weather-resistant layer, with a coating weight of 3.9 g / m² after drying. 2 The material was coated and dried to form a 3 μm thick design layer. This resulted in a transfer sheet having a release film, a first weather-resistant layer, a second weather-resistant layer, and a design layer in that order in the thickness direction.

[0100] (Fabrication of exterior decorative panels) An ink containing a vinyl chloride-vinyl acetate-acrylic copolymer (manufactured by Showa Ink Co., Ltd.) was applied to a calcium silicate board with a maximum height Rz of 70 μm, and dried to form a resin layer (thickness 70 μm). Next, the obtained resin layer and the design layer of the transfer sheet were placed opposite each other, and using a laminator (RT-300 manufactured by Navitas Machinery Co., Ltd.), heating and pressurizing were applied from the transfer sheet side under conditions of a laminating roll temperature of 160°C and a conveying speed of 2 m / min to adhere the transfer sheet, resin layer, and calcium silicate board to each other. After that, the release film was peeled off to obtain an exterior decorative panel. The thickness, mass, and organic mass of each layer in the obtained exterior decorative panel are shown in Table 1.

[0101] [Table 1]

[0102] [Comparative Example 1] Except for not forming a second weather-resistant layer and changing the thickness of the first weather-resistant layer to 9 μm, an exterior decorative panel was obtained in the same manner as in Example 1.

[0103] [evaluation] The exterior decorative panels prepared in Example 1 and Comparative Example 1 were subjected to an accelerated weathering test using a metal halide lamp (MWOM) for 300 hours. This test involved irradiating the panels with ultraviolet light for 20 hours under the irradiation conditions described below, followed by condensation for 4 hours under the condensation conditions described below, with this cycle being repeated for each cycle. <Conditions for accelerated weathering test> (Test equipment) Manufactured by Dipla Wintes, product name "Dipla Metal Weather" (Irradiation conditions) Illuminance: 65mW / cm 2 Black panel temperature: 63°C, chamber humidity: 50%RH, time: 20 hours (Condensation conditions) Illuminance: 0mW / cm 2 , Humidity inside the tank: 98%RH, Time: 4 hours

[0104] Adhesive tape ("Sellotape®", manufactured by Nichiban Co., Ltd.) was applied to the exterior decorative panel after the accelerated weathering test, extending approximately 5 cm beyond the edge, covering an area of ​​2.5 cm x 2.5 cm. Then, the excess portion of the applied adhesive tape was pinched and peeled off at a 45° angle to the surface of the exterior decorative panel. As a result, in Example 1, no delamination occurred in the second weather-resistant layer and the design layer, but in Comparative Example 1, delamination occurred in the second weather-resistant layer and the design layer. Thus, it was confirmed that the exterior decorative panel in Example 1 had good adhesion between the second weather-resistant layer and the design layer. [Explanation of Symbols]

[0105] 1… Release film 2 … 1st weather resistant layer 3…Second weather-resistant layer 4. Design layer 10… Transfer sheet 20... Calcium silicate board 30… Resin layer 100 ... Exterior decorative panels

Claims

1. A method for manufacturing exterior decorative panels having calcium silicate boards, A preparation step of preparing a transfer sheet having a release film, a first weather-resistant layer, a second weather-resistant layer, and a design layer in this order in the thickness direction, A bonding step is to place a resin layer between the surface of the transfer sheet facing the design layer and the calcium silicate board, thereby bringing the transfer sheet, the resin layer, and the calcium silicate board into close contact. It has, The first weather-resistant layer includes a cured product of an ionizing radiation-curable resin composition, The second weather-resistant layer includes a cured product of a thermosetting resin composition, The first weather-resistant layer contains at least one of an ultraviolet absorber and a light stabilizer, The second weather-resistant layer contains at least one of an ultraviolet absorber and a light stabilizer, A method for manufacturing an exterior decorative panel, wherein the sum of the thicknesses of the first weather-resistant layer, the second weather-resistant layer, and the design layer is 12 μm or more and 50 μm or less.

2. A method for manufacturing an exterior decorative panel according to claim 1, further comprising a peeling step of peeling the release film from the transfer sheet after the adhesion step.

3. The organic mass of the exterior decorative panel (excluding the organic mass of the release film) is 140 g / m². ２ The method for manufacturing an exterior decorative panel according to claim 1 or claim 2, as follows:

4. A method for manufacturing an exterior decorative panel according to any one of claims 1 to 3, wherein the first weather-resistant layer contains a triazine-based ultraviolet absorber.

5. A method for manufacturing an exterior decorative panel according to any one of claims 1 to 4, wherein the second weather-resistant layer contains a triazine-based ultraviolet absorber.

6. The method for manufacturing an exterior decorative panel according to any one of claims 1 to 5, wherein the ionizing radiation-curable resin composition is an electron beam-curable resin composition.

7. A method for manufacturing an exterior decorative panel according to any one of claims 1 to 6, wherein the thickness of the resin layer is greater than the maximum height Rz of the surface of the calcium silicate board on the resin layer side.

8. The method for manufacturing an exterior decorative panel according to claim 7, wherein the maximum height Rz of the resin layer side surface of the calcium silicate board is 70 μm or more.

9. A method for manufacturing an exterior decorative panel according to any one of claims 1 to 8, wherein the thickness of the resin layer is greater than the arithmetic mean roughness Ra of the surface of the calcium silicate board on the resin layer side.

10. The method for manufacturing an exterior decorative panel according to claim 9, wherein the arithmetic mean roughness Ra of the resin layer side surface of the calcium silicate board is 70 μm or more.

11. A is the absolute value of the difference between the linear expansion coefficient of the first weather-resistant layer and the linear expansion coefficient of the second weather-resistant layer in the temperature range of 40°C to 50°C. １ The absolute value of the difference between the linear expansion coefficient of the first weather-resistant layer and the linear expansion coefficient of the second weather-resistant layer in the temperature range of 70°C to 80°C is B. １ In that case, B １ -A １ However, 5 x 10 －４ A method for manufacturing an exterior decorative panel according to any one of claims 1 to 10, wherein the temperature is (1 / °C) or less.

12. Let the absolute value of the difference between the linear expansion coefficient of the second weather-resistant layer and the linear expansion coefficient of the design layer in the temperature range of 40°C or higher and 50°C or lower be A ２ and let the absolute value of the difference between the linear expansion coefficient of the second weather-resistant layer and the linear expansion coefficient of the design layer in the temperature range of 70°C or higher and 80°C or lower be B ２ When this is the case, B ２ −A ２ is 5 × 10 －４ (1 / °C) or less. The method for manufacturing an exterior decorative panel according to any one of claims 1 to 11

13. A transfer sheet for manufacturing exterior decorative panels having calcium silicate boards, The release film, first weather-resistant layer, second weather-resistant layer, and design layer are arranged in this order in the thickness direction. The first weather-resistant layer includes a cured product of an ionizing radiation-curable resin composition, The second weather-resistant layer includes a cured product of a thermosetting resin composition, The first weather-resistant layer contains at least one of an ultraviolet absorber and a light stabilizer, The second weather-resistant layer contains at least one of an ultraviolet absorber and a light stabilizer, A transfer sheet in which the sum of the thicknesses of the first weather-resistant layer, the second weather-resistant layer, and the design layer is 12 μm or more and 50 μm or less.

14. The transfer sheet according to claim 13, wherein the ionizing radiation-curable resin composition is an electron beam-curable resin composition.

15. Exterior decorative panel having calcium silicate board, The first weather-resistant layer, the second weather-resistant layer, the design layer, the resin layer, and the calcium silicate board are arranged in this order in the thickness direction. The first weather-resistant layer includes a cured product of an ionizing radiation-curable resin composition, The second weather-resistant layer includes a cured product of a thermosetting resin composition, The first weather-resistant layer contains at least one of an ultraviolet absorber and a light stabilizer, The second weather-resistant layer contains at least one of an ultraviolet absorber and a light stabilizer, An exterior decorative panel in which the sum of the thicknesses of the first weather-resistant layer, the second weather-resistant layer, and the design layer is 12 μm or more and 50 μm or less.

16. The organic mass of the exterior decorative panel is 140 g / m². ２ The exterior decorative panel according to claim 15, which is as follows:

17. The exterior decorative panel according to claim 15 or claim 16, wherein the first weather-resistant layer contains a triazine-based ultraviolet absorber.

18. The exterior decorative panel according to any one of claims 15 to 17, wherein the second weather-resistant layer contains a triazine-based ultraviolet absorber.

19. The exterior decorative panel according to any one of claims 15 to 18, wherein the ionizing radiation-curable resin composition is an electron beam-curable resin composition.

20. The exterior decorative panel according to any one of claims 15 to 19, wherein the thickness of the resin layer is greater than the maximum height Rz of the surface of the calcium silicate board on the resin layer side.

21. The exterior decorative panel according to claim 20, wherein the maximum height Rz of the resin layer side surface of the calcium silicate board is 70 μm or more.

22. The exterior decorative panel according to any one of claims 15 to 21, wherein the thickness of the resin layer is greater than the arithmetic mean roughness Ra of the surface of the calcium silicate board on the resin layer side.

23. The exterior decorative panel according to claim 22, wherein the arithmetic mean roughness Ra of the resin layer side surface of the calcium silicate board is 70 μm or more.

24. A is the absolute value of the difference between the linear expansion coefficient of the first weather-resistant layer and the linear expansion coefficient of the second weather-resistant layer in the temperature range of 40°C to 50°C. １ The absolute value of the difference between the linear expansion coefficient of the first weather-resistant layer and the linear expansion coefficient of the second weather-resistant layer in the temperature range of 70°C to 80°C is B. １ In that case, B １ -A １ However, 5 x 10 －４ An exterior decorative panel according to any one of claims 15 to 23, wherein the temperature is (1 / °C) or less.

25. A is the absolute value of the difference between the linear expansion coefficient of the second weather-resistant layer and the linear expansion coefficient of the design layer in the temperature range of 40°C to 50°C. ２ The absolute value of the difference between the linear expansion coefficient of the second weather-resistant layer and the linear expansion coefficient of the design layer in the temperature range of 70°C to 80°C is B. ２ In that case, B ２ -A ２ However, 5 x 10 －４ An exterior decorative panel according to any one of claims 15 to 24, wherein the temperature is (1 / °C) or less.

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