Coated metal plate

Abstract

To provide a coated metal plate that has a metallic appearance and high weather resistance.SOLUTION: A coated metal plate 1 includes a metal plate 2 and a coating film 3 covering the metal plate 2. The coating film 3 includes a shrink pattern layer 33 made from a shrink paint. The shrink paint comprises a resin component and a pigment component. The resin component comprises a hydroxyl-containing polyester resin, an amino resin, an acid catalyst, and an amine compound. The pigment component comprises a luminous pigment containing mica. A ratio of the mica to a solid content of the shrink paint is 1 mass% or more and 30 mass% or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to painted metal sheets, and more particularly to painted metal sheets having a shrink pattern layer. [Background technology]

[0002] Patent Document 1 describes a coated steel sheet having a chromium-free chemical conversion coating on both sides of a base steel sheet that has been pickled with an aqueous nitric acid solution, an undercoat coating containing a coloring pigment on the chemical conversion coating on one side of the steel sheet, and a topcoat coating that is an organic resin coating containing a luster agent on the undercoat coating, with the total thickness of the undercoat coating and topcoat coating being 10 μm or less. Flake-like Al is described as the luster agent. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-52363 A Summary of the Invention [Problem to be solved by the invention]

[0004] In particular, when used as a building material, the coating film of the coated metal sheet is required to have high weather resistance so as to be resistant to discoloration, scratches, deterioration, etc. over a long period of time.

[0005] However, the aluminum flakes (scale-like Al) disclosed in Patent Document 1 for imparting a metallic appearance to a coated metal sheet are likely to cause deterioration in the weather resistance of the coating film, such as corrosion and discoloration, when the coating film is exposed outdoors for a long period of time. In addition, when imparting a metallic appearance using aluminum flakes, etc., the use of color pigments with concealing properties is restricted, so the light transmittance of the coating film increases, and therefore the coating film is more likely to deteriorate due to light. This reduces the weather resistance of the coating film.

[0006] An object of the present disclosure is to provide a coated metal sheet that has a metallic appearance and high weather resistance. [Means for solving the problem]

[0007] A coated metal sheet according to one embodiment of the present disclosure includes a metal sheet and a coating film covering the metal sheet. The coating film includes a shrink pattern layer made of shrink paint. The shrink paint contains a resin component and a pigment component. The resin component includes a hydroxyl group-containing polyester resin, an amino resin, an acid catalyst, and an amine compound. The pigment component includes a glittering pigment including mica. The ratio of the mica to the solid content of the shrink paint is 1% by mass or more and 30% by mass or less. Effect of the Invention

[0008] According to one embodiment of the present disclosure, a painted metal sheet can have a metallic appearance and high weather resistance. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a coated metal sheet according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The embodiments will be described with reference to FIG. 1. The following embodiments are merely a part of various embodiments of the present disclosure. In addition, the following embodiments can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. All figures referred to below are schematic diagrams, and the dimensional ratios of the components in the figures do not necessarily reflect the actual dimensional ratios. The mechanism of the operation of the embodiments may be described below, but the mechanism is speculated, and the contents of the present disclosure are not bound by the description of the mechanism.

[0011] The coated metal sheet 1 of the embodiment has a metal sheet 2 and a coating film 3 covering the metal sheet 2. The coating film 3 includes a shrink pattern layer 33 made of shrink paint. The shrink paint contains a resin component and a pigment component. The resin component contains a hydroxyl group-containing polyester resin, an amino resin, an acid catalyst, and an amine compound. The pigment component contains a glittering pigment containing mica. The ratio of the mica to the solid content of the shrink paint is 1% by mass or more and 30% by mass or less.

[0012] In the embodiment, the painted metal sheet 1 is given a shrink pattern by the shrink pattern layer 33 and a metallic appearance by the luster pigment, thereby improving the design of the painted metal sheet 1. In addition, the luster pigment contains mica, which is not easily discolored even when exposed to light, so discoloration of the paint coating 3 when exposed to light is suppressed. In addition, the strength of the paint coating 3 is increased by the mica, and mica is not easily discolored by sliding, so the scratch resistance of the paint coating 3 is improved. Furthermore, the shrink pattern and light scattering by the mica suppress light transmission through the paint coating 3, thereby suppressing deterioration of the paint coating 3 due to light, and for example, peeling of the shrink pattern layer 33 due to deterioration of the undercoat layer 32 described later can be suppressed.

[0013] As described above, in this embodiment, the design, weather resistance, and scratch resistance of the coated metal sheet 1 can be improved by a single layer, the shrink pattern layer 33. Therefore, the coated metal sheet 1 has a metallic appearance and high weather resistance and scratch resistance. Note that, in the embodiment, weather resistance refers to the resistance of the coating film 3 to discoloration when irradiated with light such as ultraviolet light, and the resistance of the coating film 3 to peeling due to deterioration. Scratch resistance refers to the resistance of the coating film 3 to damage when an object with high hardness comes into contact with or slides against the coating film 3.

[0014] The coated metal sheet 1 will be described in more detail below.

[0015] The coated metal sheet 1 comprises a metal sheet 2 and a coating film 3, as shown in FIG.

[0016] The metal plate 2 is a plate-like member containing metal as a main component and defines the outer shape of the painted metal plate 1 excluding the shrink pattern formed by the shrink pattern layer 33. The metal plate 2 has a thickness and has a first surface 2A and a second surface 2B. The first surface 2A is located on the opposite side to the second surface 2B in the thickness direction of the metal plate 2.

[0017] The coating film 3 includes a pretreatment layer 31, an undercoat layer 32, and a shrink pattern layer 33. The pretreatment layer 31, the undercoat layer 32, and the shrink pattern layer 33 are laminated in this order on the first surface 2A of the metal plate 2.

[0018] The metal sheet 2 is, for example, an aluminum sheet or a steel sheet 21. The metal sheet 2 may have a plating layer 22. Preferably, the metal sheet 2 is a plated steel sheet 21 including a steel sheet 21 and a plating layer 22 that covers the steel sheet 21. The plated steel sheet 21 has the plating layer 22. The plating layer 22 contains, for example, aluminum and zinc.

[0019] The plating layer 22 may contain, as a constituent element other than aluminum and zinc, for example, magnesium, silicon, strontium, iron, chromium, alkaline earth elements, scandium, yttrium, lanthanoid elements, titanium, boron, etc. Examples of alkaline earth elements include beryllium, calcium, barium, and radium. Examples of lanthanoid elements that can be used include lanthanum, cerium, praseodymium, neodymium, promethium, samarium, and europium.

[0020] The plating layer 22 is, for example, a hot-dip plating layer 22.

[0021] An alloy layer may be interposed between the plating layer 22 and the steel sheet 21. The alloy layer is a layer formed by alloying a hot-dip plating bath with a surface layer portion of the steel sheet 21 during the process of producing the plating layer 22 by hot-dip plating treatment.

[0022] The proportion of aluminum in the plating layer 22 is, for example, 1% by mass or more and 75% by mass or less. The proportion of aluminum is preferably 1% by mass or more and 10% by mass or less. It is also preferable that the proportion of aluminum is 25% by mass or more and 75% by mass or less. In this case, it is more preferable that the proportion of aluminum is 45% by mass or more, and even more preferable that the proportion of aluminum is 50% by mass or more. It is also preferable that the proportion of aluminum is 65% by mass or less, and even more preferable that the proportion of aluminum is 60% by mass or less.

[0023] The proportion of magnesium in the plating layer 22 is, for example, 0.5% by mass or more and 10% by mass or less. In this case, magnesium can improve the corrosion resistance of the plating layer 22. It is more preferable that the proportion of magnesium is 1% by mass or more. It is also more preferable that the proportion of magnesium is 5% by mass or less, and further more preferable that the proportion of magnesium is 3% by mass or less.

[0024] The plating layer 22 may further contain components other than zinc, aluminum, and magnesium.

[0025] The plating layer 22 may contain, for example, silicon. When the plating layer 22 contains silicon, the amount of silicon relative to the amount of aluminum contained in the plating layer 22 is preferably 0.5 mass% or more and 10 mass% or less, and more preferably 1.0 mass% or more and 5.0 mass% or less.

[0026] The plating layer 22 may further contain at least one selected from the group consisting of chromium, strontium, iron, alkaline earth elements, scandium, yttrium, lanthanoid elements, titanium, and boron. Examples of alkaline earth elements include beryllium, calcium, barium, and radium. Examples of lanthanoid elements include lanthanum, cerium, praseodymium, neodymium, promethium, samarium, and europium.

[0027] Of course, the plating layer 22 may contain elements other than those mentioned above that are inevitably mixed in.

[0028] The total proportion of zinc, aluminum, and magnesium in the plating layer 22 is preferably 95 mass % or more. When the plating layer 22 contains silicon, the total proportion of zinc, aluminum, silicon, and magnesium in the plating layer 22 is preferably 95 mass % or more.

[0029] The composition of the plating layer 22 is not limited to the above.

[0030] The pretreatment layer 31 is a coating formed on the surface of the metal sheet 2 by chemical conversion treatment before the undercoat layer 32 is formed.

[0031] When forming the pretreatment layer 31, a chemical conversion treatment agent is used. Examples of the chemical conversion treatment agent include chromium-containing treatment agents such as chromate treatment agents and trivalent chromium treatment agents; phosphoric acid-based treatment agents such as zinc phosphate treatment agents and iron phosphate treatment agents; oxide treatment agents containing metal oxides such as cobalt, nickel, tungsten, and zirconium alone or in combination; treatment agents containing an inhibitor component that prevents corrosion; treatment agents in which a binder component (organic, inorganic, organic-inorganic composite, etc.) and an inhibitor component are combined; treatment agents in which an inhibitor component and a metal oxide are combined; and treatment agents in which a binder component and a sol such as silica, titania, and zirconia are combined. In addition, the chemical conversion treatment agent may not contain a chromium compound. Not containing a chromium compound means that a chromium compound is not intentionally contained, and a chromium compound may be contained as an unavoidable impurity.

[0032] The undercoat layer 32 is a cured product of a coating film made of an undercoat paint. By providing the coated metal sheet 1 with the undercoat layer 32, the undercoat layer 32 can strongly adhere to the shrink pattern layer 33, making it difficult for the shrink pattern layer 33 to fall off over time.

[0033] The undercoat paint contains a resin component, an anti-rust pigment, and a solvent. The undercoat paint is preferably a paint that hardens when heated (a baked cross-linking type paint) rather than a thermoplastic resin paint such as polyvinyl chloride.

[0034] Examples of the resin component include epoxy resin paint, urea resin paint, polyester resin paint containing a crosslinking agent, polyvinyl chloride resin, and aqueous polymer. The resin component preferably contains at least one resin selected from the group consisting of a urea resin consisting of a reaction product of polyamine and polyisocyanate, a polyester resin crosslinked with a melamine resin, a polyester resin crosslinked with an isocyanate resin, a polyester resin crosslinked with a melamine resin and an isocyanate resin, an epoxy resin, and an aqueous polymer, which will be described later.

[0035] The urea resin paint preferably contains a blocked isocyanate and a polyamine. The urea resin paint makes it easy to thicken the undercoat layer 32, and this paint can form a thick undercoat layer 32 without generating bubbles (air bubbles). When the urea resin paint contains a blocked isocyanate, the urea resin paint can be made into a one-component paint.

[0036] When urea resin-based paint is heated, the blocking agent dissociates from the blocked isocyanate, regenerating the isocyanate group (-NCO). This isocyanate group reacts with the amino group (-NH2) in the polyamine to form a urea bond (-NHCONH-), which then polymerizes.

[0037] A blocked isocyanate is a compound obtained by reacting the isocyanate group of a polyisocyanate with a blocking agent to block the isocyanate group.

[0038] Polyisocyanate is a compound containing a plurality of isocyanates in one molecule. Examples of such polyisocyanates include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, naphthalene diisocyanate, and tolidine diisocyanate. Among them, it is preferable that the polyisocyanate contains tolylene diisocyanate. In this case, the performance of the urea resin-based paint can be improved and the cost of the urea resin-based paint can be reduced. The polyisocyanate is not a monomer, but may be a derivative such as a prepolymer, an adduct (an adduct of trimethylolpropane, etc.), an isocyanurate, or a biuret. Two or more kinds of polyisocyanates or their derivatives may be used in combination.

[0039] The blocking agent for polyisocyanate preferably contains a compound having a dissociation temperature (dissociation temperature) of 150° C. or higher at which it dissociates from the blocked isocyanate. In particular, the blocking agent preferably contains ε-caprolactam having a dissociation temperature of 170° C. The upper limit of the dissociation temperature is not particularly limited, but may be, for example, 200° C. or lower, specifically, 180° C. or lower. When the dissociation temperature is 200° C. or lower, the energy required for forming the undercoat layer 32 (for example, baking temperature and baking time) can be reduced. Examples of blocking agents having a dissociation temperature lower than 150° C. include cresol having a dissociation temperature of 120° C. and methyl ethyl ketone oxime having a dissociation temperature of 140° C.

[0040] To obtain the blocked isocyanate, the polyisocyanate and the blocking agent can be reacted by any method. For example, the blocked isocyanate can be obtained by reacting the polyisocyanate in a solvent with a stoichiometric amount or a slightly excess amount of the blocking agent under heating.

[0041] The number average molecular weight of the blocked isocyanate is preferably within a range of 1000 to 4000. In this embodiment, an appropriate blocked isocyanate can be selected and used from commercially available products.

[0042] Polyamines are compounds containing multiple amino groups in one molecule. Examples of such polyamines include aliphatic (including alicyclic) polyamines and aromatic polyamines. Among them, polyamines preferably contain alicyclic polyamines. Examples of alicyclic polyamines include 1-cyclohexylamino-3-aminopropane, diaminocyclohexanes, bis(4-aminocyclohexyl)methane, bis(4-aminocyclohexyl)sulfone, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and isophoronediamine. Among them, alicyclic polyamines preferably contain 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane. Polyamines can contain one or more compounds selected from the group described above.

[0043] In the urea resin-based paint, the ratio of the blocked isocyanate to the polyamine is preferably such that the molar ratio of isocyanate group / amino group is within the range of 0.6 to 2.0, more preferably 0.8 to 1.2.

[0044] The polyester resin-based paint may contain at least one polyester resin selected from the group consisting of polyester resins crosslinked with melamine resins, polyester resins crosslinked with isocyanate resins, and polyester resins crosslinked with melamine resins and isocyanate resins. The melamine resin is a crosslinking agent made of a resin containing a residue derived from a melamine compound. Examples of the melamine compound include methylated melamine and butylated melamine. The isocyanate resin is a crosslinking agent made of a compound having an isocyanate group and a resin containing a residue derived from the compound.

[0045] In this embodiment, any epoxy resin paint suitable for the coated metal sheet 1 can be used as the epoxy resin paint.

[0046] Examples of the aqueous polymer include acrylic resin, urethane resin, and polyester resin. The aqueous polymer can be used as an aqueous polymer coating material. An example of an aqueous polymer coating material containing an acrylic resin is Arumatex, manufactured by Mitsui Chemicals, Inc. An example of an aqueous polymer coating material containing a urethane resin is Superflex, manufactured by Daiichi Kogyo Seiyaku Co., Ltd. An example of an aqueous polymer coating material containing a polyester resin is Hardlen, manufactured by Toyobo Co., Ltd.

[0047] When the undercoat paint contains a paint other than a urea resin-based paint as a resin component, the thickness of the coating film that can be formed in one coat without causing popping is about 20 μm, and the coating film tends to be thinner than in the case of a urea resin-based paint. In this case, in this embodiment, the undercoat paint can be applied two or more times as necessary to adjust the thickness of the undercoat layer 32.

[0048] As described above, the undercoat paint contains an anti-rust pigment. The anti-rust pigment is a component that imparts color to the undercoat layer 32 and makes it difficult for rust to form on the metal plate 2. The anti-rust pigment contains, for example, a chromate-based anti-rust pigment or a chromate-free anti-rust pigment.

[0049] The chromate-based rust-preventive pigment contains a chromate compound, such as strontium chromate, zinc chromate, calcium chromate, potassium chromate, and barium chromate.

[0050] Chromate-free rust-preventive pigments are rust-preventive pigments that do not contain chromate compounds. Examples of chromate-free rust-preventive pigments include phosphate-based rust-preventive pigments that contain phosphates such as zinc phosphate, iron phosphate, aluminum phosphate, and magnesium phosphate; molybdic acid-based rust-preventive pigments that contain molybdates such as calcium molybdate, aluminum molybdate, and barium molybdate; and water-dispersible silica and fine silica such as fumed silica. In this specification, "not containing chromate compounds" means that chromate compounds are not intentionally contained, and chromate compounds may be contained as inevitable impurities.

[0051] As described above, the undercoat paint contains a solvent, such as water, hydrocarbon solvents such as toluene and xylene, ester solvents such as ethyl acetate and butyl acetate, ethyl solvents such as cellosolves, and ketone solvents such as methyl isobutyl ketone, methyl ethyl ketone, isophorone, and cyclohexanone.

[0052] The undercoat paint may further contain any additive. Examples of the additive include pigments other than the anti-rust pigment, antifoaming agents, pigment dispersants, sagging prevention agents, leveling agents, silane coupling agents, and catalysts for the reaction between polyisocyanate and polyamide (e.g., organotin compounds). Examples of the pigments other than the anti-rust pigment include silica, alumina, talc, calcium carbonate, and titania.

[0053] When applying the undercoat paint, a suitable application method such as roll coating, curtain flow coating, spray coating, etc. can be used. Among them, it is preferable to adopt roll coating as the application method.

[0054] The thickness of the undercoat paint is preferably 3 μm or more and 10 μm or less. When the thickness of the undercoat paint is 3 μm or more, the undercoat layer 32 can improve the rust prevention of the coated metal sheet 1. When the amount of the undercoat paint applied is 7 μm or less, the energy (e.g., baking temperature and baking time) required for forming the undercoat layer 32 can be reduced.

[0055] As described above, the coated metal sheet 1 includes the shrink pattern layer 33. The shrink pattern layer 33 is a layer that imparts a shrink pattern to the coated metal sheet 1, and is a cured product of a coating film made from a shrink paint. The shrink pattern is formed when the coating film shrinks on the metal sheet 2 and along the first surface 2A as it hardens.

[0056] The shrink pattern layer 33 has a concave-convex structure made up of shrink patterns on its surface. This concave-convex structure has protruding portions and recessed portions.

[0057] The convex portion is a portion of the shrink pattern layer 33 that is convex toward the opposite side to the metal plate 2 in the direction in which the shrink pattern layer 33 and the metal plate 2 are aligned. The convex portion is formed by fine cracks that occur when the coating film made of shrink paint shrinks and hardens. When the shrink paint is dried and baked in a hot air oven, the amino compound on the surface layer first evaporates, activating the acid catalyst, which promotes the reaction between the hydroxyl group-containing polyester resin and the amino resin to form a coating film. At that time, the coating film shrinks in volume and forms fine cracks, and the coating film is formed while the bulk of the paint is constantly supplied to the cracked areas, forming convex portions and concave portions in other areas.

[0058] The recesses are adjacent to the protrusions on the surface of the shrink pattern layer 33 and are lower than the protrusions.

[0059] The shrink pattern layer 33 has a thickness. The thickness direction of the shrink pattern layer 33 is parallel to the direction in which the shrink pattern layer 33 and the metal plate 2 are arranged. The thickness of the shrink pattern layer 33 is preferably 15 μm or more and 30 μm or less. When the thickness of the shrink pattern layer 33 is 15 μm or more, the shrink pattern and color tone are likely to be stable. When the thickness of the shrink pattern layer 33 is 30 μm or less, the energy (e.g., baking temperature and baking time) required to form the 30 μm shrink pattern layer 33 can be reduced. In this case, the shrink pattern layer 33 tends to improve the weather resistance and chemical resistance of the coated metal plate 1. The thickness of the shrink pattern layer 33 is represented, for example, by the distance between a straight line passing through the center of a curve along the uneven structure of the shrink pattern layer 33 and a straight line along the bottom surface of the shrink pattern layer 33 in a cross section of the coated metal plate 1 along the direction in which the shrink pattern layer 33 and the metal plate 2 are arranged.

[0060] The shrink pattern layer 33 forms a concave-convex structure, and a measurement value (ten-point average roughness Rzjis) using a two-dimensional roughness meter is usually used as a physical property value representing the structure. This ten-point average roughness Rzjis is 12 μm or more and 70 μm or less. When the ten-point average roughness Rzjis is within this range, the shrink pattern layer 33 can easily obtain a low gloss surface and color depth, and the shrink pattern layer 33 can enhance the design of the coated metal sheet 1. Moreover, since the first surface 2A of the metal sheet 2 is covered with the shrink pattern layer 33, which has excellent weather resistance, a coated metal sheet 1 having excellent design and good weather resistance can be obtained. The ten-point average roughness Rzjis is more preferably 12 μm or more and 26 μm or less.

[0061] Examples of surface roughness that indicate the ten-point average roughness Rzjis include two-dimensional surface roughness and three-dimensional surface roughness.

[0062] The ten-point average roughness Rzjis can be measured by a two-dimensional roughness meter in accordance with JIS B 0601:2001 or JIS B 0651:2001. In the cross section of the coated metal sheet 1 along the direction in which the shrink pattern layer 33 and the metal sheet 2 are arranged, a curve along the uneven structure of the shrink pattern layer 33 is measured by a two-dimensional roughness meter in accordance with the JIS standard.

[0063] In addition, since an amine compound described below volatilizes when the shrink paint hardens, the shrink pattern layer 33 may not contain this amine compound. In this specification, "the shrink pattern layer 33 does not contain an amine compound" includes not only an embodiment in which the content of the amine compound in the shrink pattern layer 33 is 0 mass %, but also an embodiment in which the shrink pattern layer 33 contains a small amount of the amine compound.

[0064] The shrink paint has a property of shrinking along the surface to which the shrink paint is applied when cured. The shrink paint contains a resin component and a pigment component. The shrink paint may contain a solvent as needed. The shrink paint may contain additives other than the above as needed.

[0065] The resin component is a component that constitutes the main part of the shrink pattern layer 33. The resin component contains a hydroxyl group-containing polyester resin, an amino resin, an amine compound, and an acid catalyst. The shrink paint is preferably a paint that hardens under heat (baking hardening paint).

[0066] The hydroxyl-containing polyester resin is a resin containing a hydroxyl group as a functional group that reacts with the amino resin when the shrink coating is cured. Specifically, the hydroxyl group of the hydroxyl-containing polyester resin reacts with the methoxy group of the amino resin, which will be described later. Examples of such hydroxyl-containing polyester resins include oil-modified polyester resins, oil-free polyester resins, and silicone-modified polyester resins. The hydroxyl-containing polyester resin can contain at least one resin selected from the above group.

[0067] An example of the oil-modified polyester resin is "Beckolite M-6601-60-S" manufactured by DIC Corporation.

[0068] Examples of oil-free polyester resins include "Beckolite-M6602-60-S" and "Beckolite 46-118" manufactured by DIC Corporation, and "Alumatex P-646" manufactured by Mitsui Chemicals, Inc.

[0069] The hydroxyl-containing polyester resin may be an unmodified resin other than the above-mentioned resins. Such a hydroxyl-containing polyester resin may be a resin that is blended in a normal paint, as long as it can react with the amino resin when the shrink paint is cured.

[0070] The amount of the hydroxyl-containing polyester resin is preferably 30% by mass or more and 70% by mass or less based on the solid content of the shrink coating material.

[0071] The amino resin is a resin that reacts with the hydroxyl-containing polyester resin when the shrink paint hardens, and contains a methoxy group. As described above, this methoxy group reacts with the hydroxyl group of the hydroxyl-containing polyester resin. By reacting with the hydroxyl-containing polyester resin, the amino resin plays a role of forming a crosslinked structure and of imparting a shrink pattern to the shrink pattern layer 33. Specifically, such an amino resin is a hexakisalkoxymethylated melamine resin. The hexakisalkoxymethylated melamine resin is a resin in which six methylol groups in a methylated melamine resin are alkoxylated. Moreover, the methylated melamine resin is a resin having six methylol groups in which formaldehyde is added to three amino groups of a melamine ring.

[0072] Examples of hexakisalkoxymethylated melamine resins include "Cymel 300", "Cymel 303", and "Cymel 1130-266J" manufactured by Nippon Cytec Industries, "Nicalac MW-30" and "Nicalac MX-40" manufactured by Sanwa Chemical Co., Ltd., and "Sumimal M-100C" and "Sumimal M-40S" manufactured by Sumitomo Chemical Co., Ltd.

[0073] Moreover, examples of resins similar to methylated melamine resin include butylated melamine resins, which react slowly with hydroxyl-containing polyester resins and are less likely to give the coated metal sheet 1 a shrink pattern.

[0074] The proportion of the amino resin is preferably 5% by mass or more and 20% by mass or less based on the solid content of the shrink paint, which can further improve the weather resistance and scratch resistance of the shrink pattern layer 33.

[0075] The acid catalyst is a component that catalyzes the reaction between the hydroxyl-containing polyester resin and the amino resin when the shrink paint hardens. Specifically, the acid catalyst includes a sulfonic acid compound. Therefore, the sulfonic acid compound exists in the shrink paint as a neutralized product with the amine compound, so that unused shrink paint can be easily stored. The sulfonic acid compound is a compound containing a sulfonic acid group. Examples of the sulfonic acid compound include paratoluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalene disulfonic acid, methanesulfonic acid, and dinonylnaphthalenesulfonic acid. The sulfonic acid can contain at least one component selected from the above group. In addition to the above components, the acid catalyst can contain any compound that catalyzes the reaction between the hydroxyl-containing polyester resin and the amino resin.

[0076] The amount of the acid catalyst is not particularly limited as long as it catalyzes the reaction between the hydroxyl-containing polyester resin and the amino resin when the shrink coating is cured and is less than that of the amine compound. The amount of the acid catalyst is, for example, 0.1% by mass or more and 5% by mass or less based on the solid content of the shrink coating.

[0077] The amine compound is a compound that suppresses the catalytic action of the acid catalyst in the uncured shrink paint. Therefore, the amine compound functions as a blocking agent against the acid catalyst in the shrink paint. The shrink paint may contain more amine compounds than the acid catalyst. In this case, in the shrink paint, a part of the amine compound forms a neutralized product with the acid catalyst, and the remaining part of the amine compound remains unreacted. In addition, when preparing the shrink paint, an excess amount of the amine compound is added to the acid catalyst, and the amine compound and the acid catalyst are mixed until there is no unreacted acid catalyst to prepare a neutralized product, and the mixture of the neutralized product and the amine compound may be mixed with a hydroxyl group-containing polyester resin or the like. In this way, the shrink paint contains an amine compound, and the amine compound causes the acid catalyst to exist as a neutralized product, making it easier to store unused shrink paint.

[0078] When the amine compound is in a liquid state at room temperature, the amine compound that has not reacted with the acid catalyst is present in the shrink paint as a solvent.

[0079] Furthermore, when the shrink coating hardens, the neutralized product dissociates into the acid catalyst and the amine compound, and the amine compound volatilizes.

[0080] The boiling point of the amine compound is preferably from 50° C. to 300° C., and more preferably from 80° C. to 150° C. When the boiling point of the amine compound is in this range, the amine compound can be appropriately volatilized when the shrink paint hardens, and the shrink pattern can be easily and stably formed.

[0081] The amine compound preferably includes at least one compound selected from the group consisting of secondary amine compounds and tertiary amine compounds.

[0082] Examples of the secondary amine compound include diethylamine, morpholine, piperidine, diisopropylamine, and di(n-propyl)amine.

[0083] Examples of tertiary amine compounds include triethylamine, tributylamine, triallylamine, N-methyldiallylamine, N-methylmorpholine, N,N,N',N'-tetramethyl-1,2-diaminoethane, N-methylpiperidine, pyridine, and 4-ethylpyridine.

[0084] The amine compound is not limited to the specific compounds listed above.

[0085] The amount of the amine compound is not particularly limited as long as it suppresses the catalytic action of the acid catalyst when the shrink paint is uncured and is greater than the acid catalyst. The ratio of the amine compound is, for example, 0.1% by mass or more and 5% by mass or less based on the solid content of the shrink paint. If the ratio of the amine compound is 5% by mass or less, the weather resistance and scratch resistance of the shrink pattern layer 33 can be further improved. In addition, the molar ratio of the amine compound to the acid catalyst is 1.0 or more and 3.0 or less.

[0086] The pigment component is a particulate component dispersed in the shrink pattern layer 33. The pigment component contains a glittering pigment. The pigment component may further contain at least one selected from the group consisting of a coloring pigment, an extender pigment, an anti-rust pigment, and an aggregate.

[0087] The luster pigment contains mica. Mica is a scaly powder and can exhibit good light reflectivity, so it can impart a metallic appearance to the shrink pattern layer 33. In addition, mica is less likely to discolor due to die sliding, as occurs with aluminum flakes, and is also less likely to discolor over time due to corrosion when exposed to light. Therefore, mica is less likely to cause discoloration of the shrink pattern layer 33. In addition, mica is effective in terms of scratch resistance, so it can also ensure the function of the aggregate.

[0088] The mica may be untreated or may be surface-treated, such as with a titanium oxide coating.

[0089] The average particle size of the mica is preferably 10 μm or more and 30 μm or less. Note that this average particle size indicates the 50% value (D50, median diameter) of the cumulative particle size distribution measured by a laser diffraction measuring device.

[0090] The ratio of mica to the solid content of the shrink paint is 1% by mass or more and 30% by mass or less. When this ratio is 5% by mass or more, a particularly good metallic appearance can be imparted to the shrink pattern layer 33. Furthermore, mica can increase the scratch resistance of the shrink pattern layer 33. This ratio is more preferably 7% by mass or more, and even more preferably 10% by mass or more. Furthermore, when this ratio is 30% by mass or less, there is an advantage that good processability can be imparted to the shrink pattern layer 33. This ratio is more preferably 25% by mass or less, and even more preferably 20% by mass or less.

[0091] The luster pigment may contain only mica, but may also contain materials other than mica. Materials other than mica are preferably used to the extent that weather resistance is not excessively impaired. The luster pigment may contain, for example, aluminum flakes as materials other than mica. The aluminum flakes can increase the brightness of the shrink pattern layer 33. When the luster pigment contains aluminum flakes, the ratio of the aluminum flakes to the solid content of the shrink paint is preferably 0.1% by mass or more and 5% by mass or less.

[0092] The ratio of mica to the bright pigment is preferably 70% by mass or more. In this case, deterioration of weather resistance caused by materials other than mica can be suppressed. The ratio of mica is more preferably 80% by mass or more, and even more preferably 95% by mass or more.

[0093] The color pigment is a pigment that exhibits hiding power in the shrink pattern layer 33. The color pigment contains at least one selected from the group consisting of inorganic pigments such as titanium dioxide, carbon black, iron oxide, and yellow lead, and organic pigments such as cyanine green and cyanine blue. When the pigment component contains a color pigment, the ratio of the color pigment to the solid content of the shrink paint is, for example, 0.5% by mass or more and 25% by mass or less.

[0094] The extender pigment is a pigment, excluding aggregate, that does not exhibit hiding power in the shrink pattern layer 33. The extender pigment contains at least one selected from the group consisting of barium sulfate, calcium carbonate, talc, etc. When the pigment component contains an extender pigment, the ratio of the extender pigment to the solid content of the shrink paint is, for example, 0.01% by mass or more and 1% by mass or less.

[0095] The aggregate is an optically transparent particle, and contains, for example, at least one selected from the group consisting of glass particles, glass fibers, silica, and resin particles.

[0096] In the embodiment, the pigment component preferably does not contain aggregate. When the pigment component contains aggregate, the ratio of aggregate to the pigment component is preferably 1 mass % or less. Aggregate may promote deterioration of the coating film 3 due to light by increasing the light transmittance of the shrink pattern layer 33, but if the pigment component does not contain aggregate or the ratio of aggregate to the pigment component is 1 mass % or less, deterioration of the shrink pattern layer 33 due to light can be suppressed. Furthermore, aggregate is generally used to improve the scratch resistance of the coating, but in the present embodiment, even if the shrink pattern layer 33 does not contain aggregate or the content ratio of aggregate is low, the scratch resistance of the shrink pattern layer 33 can be improved by mica.

[0097] The ratio of mica to the pigment component is preferably 15% by mass or more and 90% by mass or less. When the ratio of mica to the pigment component is 15% by mass or more, it is possible to suppress deterioration of scratch resistance, weather resistance, metallic feel, etc. of the shrunken pattern layer 33 caused by materials other than mica in the pigment component. When the ratio of mica to the pigment component is 90% by mass or less, it is possible to ensure hiding power in the shrunken pattern layer 33 by other coloring pigments. The ratio of mica to the pigment component is more preferably 30% by mass or more, and even more preferably 70% by mass or more.

[0098] The shrink paint may further contain a wax component. In this case, the wax component may increase the scratch resistance of the shrink pattern layer 33. Examples of the wax component include natural wax components and synthetic wax components.

[0099] The natural wax component is a component obtained by extracting from a natural component and producing the extract as necessary. Examples of the natural wax component include carnauba, Japan wax, beeswax, lanolin, paraffin, yellow petrolatum, white petrolatum, and microcrystalline.

[0100] Synthetic wax components are components artificially produced by chemical reactions, and examples of synthetic wax components include polyethylene, polypropylene, polytetrafluoroethylene, and ethylene bis(stearic acid amide).

[0101] The wax component may contain at least one component selected from the group consisting of the above materials. Among them, the wax component preferably contains polytetrafluoroethylene.

[0102] The shrink paint may further contain optional additives, such as pigment dispersants, leveling agents, anti-settling agents, and defoamers.

[0103] When applying the shrink coating material, a suitable application method such as roll coating, curtain flow coating, spray coating, etc. can be used. Among them, it is preferable to use roll coating as the application method.

[0104] When the coating film of the shrink paint is baked under heat to harden it, the baking temperature of this coating film may be 200° C. or more and 250° C. or less, and the baking time may be 20 seconds or more and 2 minutes or less.

[0105] The ultraviolet transmittance of the shrink pattern layer 33 is preferably less than 0.5%. In this case, ultraviolet rays are blocked from reaching the undercoat 32, and deterioration of the undercoat 32 is suppressed, so that peeling of the shrink pattern layer 33 can be suppressed for a long period of time. A method for measuring the ultraviolet transmittance of the shrink pattern layer 33 will be described in the description of the examples given later.

[0106] In this embodiment, the coated metal sheet 1 includes a protective layer 4 that covers the second surface 2B of the metal sheet 2. In this case, the second surface 2B of the metal sheet 2 is less likely to be exposed to rain, wind, chemicals, etc. Therefore, the coated metal sheet 1 can have excellent weather resistance and chemical resistance.

[0107] In the present embodiment, the protective layer 4 is not particularly limited, but may include a pretreatment layer 41, an undercoat layer 42, and a topcoat layer 43. The pretreatment layer 41, the undercoat layer 42, and the topcoat layer 43 are laminated in this order on the second surface 2B of the metal plate 2.

[0108] The pretreatment layer 41 in the protective layer 4 may have a structure similar to that of the pretreatment layer 31 in the coating 3 described above.

[0109] The undercoat layer 42 in the protective layer 4 may have a configuration similar to that of the undercoat layer 42 in the coating film 3 described above.

[0110] The topcoat layer 43 is made of an appropriate paint composition (hereinafter referred to as topcoat paint). The topcoat paint contains a resin component and, if necessary, one or more components selected from the group consisting of a pigment component, a wax component, a solvent, and an additive.

[0111] The resin component in the topcoat paint contains at least one resin selected from the group consisting of polyester resin, epoxy resin, acrylic resin, fluororesin, silicone resin, amino resin, urethane resin, and vinyl chloride resin.

[0112] When the topcoat paint contains a pigment, the pigment may contain aggregate 5. That is, the topcoat layer 43 may contain aggregate 5. The aggregate 5 contains at least one type selected from the group consisting of, for example, glass fiber, glass particles, silica, and resin particles. The resin particles contain at least one type selected from the group consisting of, for example, urea resin particles, acrylic resin beads, and the like.

[0113] The proportion of the aggregate is, for example, 1 mass % or less relative to the solid content of the topcoat paint.

[0114] When the topcoat paint contains a wax component, the wax component may contain 0.5 to 3 mass % of a solid lubricant with a thickness 1.1 to 1.9 times that of the topcoat layer 43, based on the solid content of the paint composition. In this case, a highly lubricating topcoat layer 43 can be formed without reducing gloss and pressure mark resistance. Therefore, the coated metal sheet 1 has high processability and excellent mold galling resistance in press processing. Examples of the solid lubricant include synthetic solid lubricants such as polyethylene solid lubricants and polypropylene solid lubricants, and fluorine-based lubricants such as polytetrafluoroethylene and polyvinyl fluoride. Any of synthetic solid lubricants, fluorine-based solid lubricants, and mixtures thereof may be used, and the type is not limited.

[0115] As the method for applying the topcoat paint, known methods such as roll coating, curtain coating, spraying, immersion, electrolytic treatment, and air knife methods can be adopted. After the coating composition is applied, the paint is dried at room temperature, or dried or baked using a heating device such as a hot air oven, an electric oven, or an induction heating oven, as necessary, to form the topcoat layer 43. When an energy ray curable topcoat paint is used, the topcoat paint after application may be cured by irradiating the applied topcoat paint with energy rays such as infrared rays, ultraviolet rays, and electron beams to form the topcoat layer 43. The temperature and drying time for drying the topcoat paint are appropriately determined depending on the type of topcoat paint used, the desired productivity, and the like. The topcoat layer 43 becomes a continuous or discontinuous film.

[0116] The coated metal sheet 1 of the embodiment can be suitably used, in particular, as a building material for exterior use, although the uses of the coated metal sheet 1 are not limited to the above.

[0117] (Modification) In the embodiment, the surface of the shrink pattern layer 33 is exposed, that is, the shrink pattern layer 33 is the outermost layer of the paint coating 3. In the embodiment, the design, weather resistance, and scratch resistance of the painted metal sheet 1 can be improved by a single layer, the shrink pattern layer 33, so that the painted metal sheet 1 can have high weather resistance and high scratch resistance even without providing a layer for improving weather resistance or scratch resistance on the shrink pattern layer 33. However, one or more clear layers may be formed on the shrink pattern layer 33, that is, the paint coating 3 may have one or more clear layers overlapping the shrink pattern layer 33. In this case, the clear layer covers the shrink pattern layer 33, so that the weather resistance and chemical resistance of the painted metal sheet 1 can be further improved. The clear layer can be formed by applying any clear paint to the surface of the shrink pattern layer 33.

[0118] In the embodiment, the painted metal plate 1 includes the pretreatment layer 31, but may not include the pretreatment layer 31. In this case, the undercoat layer 32 is formed on the surface of the metal plate 2. EXAMPLES

[0119] The present disclosure will now be described in detail with reference to examples.

[0120] 1. Paint Preparation A paint was obtained by mixing the components shown in Tables 1 and 2 below. When preparing the paint, a sulfonic acid compound was added to the amine compound in the container, and the contents of the container were then mixed until the sulfonic acid compound was completely neutralized by the amine compound. Details of the components shown in Tables 1 and 2 below are as follows. - Mica: Iriodin 103 manufactured by Merck Performance Materials LLC (average particle size (median diameter D50) 21 μm, silvery white, titanium oxide-coated natural mica). - Aluminum paste: Asahi Kasei Metals Corporation CR300 (average particle size (median diameter D50) 20 μm). - Color pigment #1: 10C909Z (complex oxide black pigment) made by Shepherd Color Japan Inc. - Color pigment #2: TAROXLL-XLO (yellow iron oxide pigment) manufactured by Titan Kogyo Co., Ltd. - Hydroxyl-containing polyester resin: Beckolite 46-118 manufactured by DIC Corporation (non-volatile content 60%, hydroxyl value 115, number average molecular weight 2500). - Amino resin: Cymel 303 (100% non-volatile content, hexakisalkoxymethylated melamine resin) manufactured by Japan Cytec Industries. - Amine compounds: triethylamine. - Sulfonic acid compounds: paratoluenesulfonic acid. - Aggregate #1: MBX-20 (acrylic resin beads, average particle size 20 μm) manufactured by Sekisui Chemical Co., Ltd. - Aggregate #2: Surface strand REV-1 manufactured by Owens Coating Japan Co., Ltd. (glass fiber, diameter 13 μm, average fiber length 35 μm). - Wax ingredient: KTL-8N (polytetrafluoroethylene) made by Kitamura Co., Ltd.

[0121] 2. Manufacturing of painted metal sheets A coated metal sheet was prepared using the paint in the following procedure. Details of the chemical conversion coating agent and undercoat paint are as follows. - Chemical conversion treatment agent: chromate pretreatment material (Nihon Parkerizing Co., Ltd. ZM1300), - Primer: Polyester / melamine resin paint (AkzoNobel Coatings FX39 Primer).

[0122] The metal plate was a 55% Al-Zn-Mg hot-dip galvanized steel plate called "SGL (registered trademark)" (manufactured by Nippon Steel & Sumitomo Metal Corporation, plate thickness: 0.8 mm, double-sided coating weight: 150 g / m 2 ) (hereinafter sometimes referred to as SGL) was prepared.

[0123] A chemical conversion treatment agent was applied to the surface of this metal sheet by roll coating to perform chemical conversion treatment, thereby forming a pretreatment layer.

[0124] Next, a primer paint was applied to the surface of the pretreatment layer by roll coating so that the thickness of the primer layer was 3 to 10 μm on one side of the metal plate. Then, the steel plate coated with the primer paint was heated at a baking temperature of 200 to 220° C. for 30 to 50 seconds to bake the coating film of the primer paint and form the primer layer. After the formation of the primer layer, a coating film was formed by applying the paint by roll coating so that the thickness of the shrink pattern layer was 15 to 30 μm. Then, the steel plate on which this coating film was formed was heated at a baking temperature of 220 to 240° C. for 30 to 50 seconds to produce the shrink pattern layer. In this way, a painted metal plate was obtained.

[0125] 3.Evaluation Test The coated metal sheets were evaluated as follows, and the evaluation results are shown in Tables 1 and 2 below.

[0126] (1) Paint film cracks The surface of the painted metal plate was visually inspected, and if popping was found, which is a bubble-like defect caused by volatile components in the paint film not being completely removed during the paint baking and hardening process, it was rated as "present", and if no popping was found, it was rated as "absent".

[0127] (2) Shrinkage pattern The surface of the coated metal plate was visually inspected, and the case where a shrinkage pattern was observed was rated as "present", and the case where no shrinkage pattern was observed was rated as "absent".

[0128] (3) Surface roughness A roughness curve obtained from the surface of the coated metal plate was created by the stylus method. Then, using this roughness curve, the ten-point average roughness Rzjis, which indicates the surface roughness of the coated metal plate, was measured in accordance with JIS B 0601:2001. To measure the surface roughness of the coated metal plate, a two-dimensional roughness meter (SURFCOM 1500SD-JDE12 (model number) manufactured by Tokyo Seimitsu Co., Ltd.) was used, and the measurement length was set to 8.0 mm and the cutoff value was set to 0.8 mm.

[0129] (4) Glossiness The glossiness Gs obtained from the surface of the coated metal plate was measured using a glossmeter (VG-7000 manufactured by Nippon Denshoku Industries Co., Ltd.). At this time, the incident angle θ of light with respect to the normal line of the coated metal plate surface was set to 60°, and the percentage of the light flux φos incident on the surface of the coated metal plate and the light flux φ specularly reflected from the surface of the coated metal plate was calculated using the following formula (1). This percentage was taken as the glossiness Gs. Note that before measuring the glossiness Gs, the measurement value of the glossmeter was zero-point corrected using a resin standard plate. Glossiness Gs(θ)(%)=φs / φos×100 (1) For reference, according to the JIS standard (JIS Z 8741), for a glass plate with a refractive index of 1.567, when the incident angle θ is 60° and the specular reflectance of the glass plate surface is 10%, the glossiness Gs(60°) is 100%, and when the incident angle θ is 20° and the specular reflectance of the glass plate surface is 5%, the glossiness (20°) is 100%.

[0130] (5) Ultraviolet transmittance A shrink pattern layer was formed on a Teflon (registered trademark) plate using the same method and conditions as in the production of a painted metal plate, so that the shrink pattern layer had a thickness of 14 μm.

[0131] The shrink pattern layer formed on the Teflon plate was peeled off, and the ultraviolet transmittance of the shrink pattern layer was measured. At this time, the spectral transmittance of ultraviolet light with a wavelength of 310 to 330 nm was measured using a spectrophotometer (Shimadzu Corporation UV3600) in accordance with JIS L1925.

[0132] As a result, a UV transmittance of less than 0.2% was rated as good, a UV transmittance of 0.2% or more but less than 0.5% was rated as passable, and a UV transmittance of 0.5% or more was rated as poor.

[0133] (6) Weather resistance (color difference) The coated metal sheets were subjected to a sunshine carbon arc lamp dew cycle accelerated weathering test in accordance with JIS Z 9107 6.2.23.

[0134] The surface color of the coated metal sheet before and after the 600-hour test was measured using a spectrophotometer SE-2000 manufactured by Nippon Denshoku Industries Co., Ltd. under the measurement light source C condition and observation conditions of a 2° field of view relative to the measurement light source, and the color difference ΔE between the surface color before and after the test was calculated. ΔE is calculated using the Hunter color difference formula.

[0135] (7) Weather resistance (gloss retention) The coated metal sheets were subjected to a sunshine carbon arc lamp dew cycle accelerated weathering test in accordance with JIS Z 9107 6.2.23.

[0136] After the 600-hour test, the gloss of the coated metal sheet was measured by the method shown in "(3) Gloss" above.

[0137] The percentage of the gloss after the test to the gloss before the test was calculated as the gloss retention.

[0138] (8) Scratch resistance Using an Erichsen testing machine, a painted metal plate with its surface extruded 5 mm was attached to an arm weighing 200 g, and the arm's own weight was applied to bring it into contact with the surface of the shrink-pattern layer of the same painted metal plate. In this state, the arm was moved back and forth using a Gakushin abrasion tester, causing the surfaces of the shrink-pattern layers to slide against each other. After the arm was moved back and forth 50 times, the surface of the shrink-pattern layer on the testing machine side was visually observed, and the case where discoloration or damage to the shrink-pattern layer was observed was rated as "poor", and the case where no discoloration or damage was observed was rated as "good".

[0139] [Table 1]

[0140] [Table 2]

[0141] (Aspect) The coated metal sheet (1) according to the first embodiment has a metal sheet (2) and a coating film (3) covering the metal sheet (2). The coating film (3) includes a shrink pattern layer (33) made of shrink paint. The shrink paint contains a resin component and a pigment component. The resin component contains a hydroxyl group-containing polyester resin, an amino resin, an acid catalyst, and an amine compound. The pigment component contains a glittering pigment containing mica. The ratio of mica to the solid content of the shrink paint is 1% by mass or more and 30% by mass or less.

[0142] According to this embodiment, the coated metal sheet (1) has a metallic appearance and can have high weather resistance.

[0143] In the second embodiment, the ratio of mica to the pigment component in the first embodiment is 15% by mass or more and 90% by mass or less.

[0144] In a third embodiment, the pigment component in the first or second embodiment further contains a color pigment.

[0145] In a fourth aspect, in any one of the first to third aspects, the pigment component does not contain aggregate, or the pigment component contains aggregate and the ratio of the aggregate to the pigment component is 1 mass% or less.

[0146] In a fifth aspect, in any one of the first to fourth aspects, the amine compound contains at least one selected from the group consisting of secondary amine compounds and tertiary amine compounds.

[0147] In a sixth aspect, in any one of the first to fifth aspects, the acid catalyst contains a sulfonic acid compound.

[0148] In a seventh aspect, in any one of the first to sixth aspects, the ratio of the amino resin to the solid content of the shrink paint is 5 mass% or more and 20 mass% or less, and the ratio of the amine compound to the solid content of the shrink paint is 0.1 mass% or more and 5 mass% or less.

[0149] In an eighth embodiment, the shrink paint according to any one of the first to seventh embodiments further contains a wax component.

[0150] In a ninth aspect, in any one of the first to eighth aspects, the ten-point average roughness Rzjis of the shrink pattern layer (33) is 12 μm or more and 70 μm or less.

[0151] In a tenth aspect, in any one of the first to ninth aspects, the metal plate (2) is a plated steel plate (21). [Explanation of symbols]

[0152] 1. Painted metal plate 2 metal plate 3 Paint coating 33 Shrinkage pattern layer

Claims

1. A metal plate and a coating film covering the metal plate, The paint coating includes a shrink pattern layer made from shrink paint; The shrink paint contains a resin component and a pigment component, The resin component contains a hydroxyl group-containing polyester resin, an amino resin, an acid catalyst, and an amine compound, The pigment component contains a glittering pigment containing mica, The ratio of the mica to the solid content of the shrink paint is 1% by mass or more and 30% by mass or less. Painted metal plate.

2. The ratio of the mica to the pigment component is 15% by mass or more and 90% by mass or less. The coated metal sheet according to claim 1.

3. The pigment component further contains a color pigment. The coated metal sheet according to claim 1.

4. the pigment component does not contain aggregate, or The pigment component contains an aggregate, and the ratio of the aggregate to the pigment component is 1 mass% or less. The coated metal sheet according to claim 1.

5. The amine compound contains at least one selected from the group consisting of a secondary amine compound and a tertiary amine compound. The coated metal sheet according to claim 1.

6. The acid catalyst contains a sulfonic acid compound. The coated metal sheet according to claim 1.

7. The ratio of the amino resin to the solid content of the shrink paint is 5% by mass or more and 20% by mass or less, The ratio of the amine compound to the solid content of the shrink paint is 0.1% by mass or more and 5% by mass or less. The coated metal sheet according to claim 1.

8. The shrink paint further contains a wax component. The coated metal sheet according to claim 1.

9. The ten-point average roughness Rzjis of the shrink pattern layer is 12 μm or more and 70 μm or less. The coated metal sheet according to claim 1.

10. The metal sheet is a plated steel sheet. The coated metal sheet according to claim 1.

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