Method for color matching using powder coating

Abstract

To provide a method for color matching using a powder coating that enables a uniformly color-matched state to be obtained.SOLUTION: A method for color matching using a powder coating, the method comprising: a mixing step of dry-blending two or more types of powder coatings having different color tones; a heating step of heating a mixed powder coating composed of the dry-blended powder coatings at a heating temperature lower than a lower-limit temperature of a baking temperature of the powder coating to cause powder particles of the mixed powder coating to be semi-fused to each other; and a pulverizing step of pulverizing a semi-molten coating, in which the powder particles of the mixed powder coating have been semi-fused to each other by the heating, into pulverized powder, and pulverizing the pulverized powder until all of the pulverized powder passes through a metal mesh sieve having a nominal aperture of 150 μm (classification step), to obtain a color-matched powder coating.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technical field of the present specification relates to a color matching method using powder paint. [Background technology]

[0002] Powder paint is a solvent-free, powder-like paint. Because it contains no volatile solvents, it helps prevent air and water pollution and has minimal impact on the environment and human health. Powder paints are commercially available in several base colors pre-tinted by paint manufacturers and shipped to users, such as painting contractors, for painting. The applied powder paint fuses with each other during the baking and drying process after painting, forming a coating that adheres to the substrate. When powder paints with different tones are mixed together to create a color other than the base color, the powder paint particles fuse with each other during the baking and drying process, without intermixing. As a result, the resulting coating has a mottled appearance due to the particles of different tones. Therefore, if a user desires a powder paint in a color other than the base color, the user specifies the color to the paint manufacturer, who then blends the color based on the specified color and produces a powder paint in the specified color. For this reason, it was not possible to quickly respond to specified colors.

[0003] Color matching methods using user-prepared colored powder paints have also been proposed, and Patent Document 1 describes a color matching method using powder paints in which powder paints of different color tones are mixed, pulverized, and granulated with a binder. Patent Documents 2 and 3 each describe a color matching method using powder paints in which powder paints of different color tones are mixed, heated to 10 to 80°C, and then granulated with a granulating agent such as a binder. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-188586 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-281978 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-16432 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional color matching methods using powder coatings have the risk of insufficient mixing of powder coating particles with different color tones, resulting in a mottled coating film due to the particles of different colors. Furthermore, there is also the issue that the addition of granulating agents such as binders can reduce the performance of the coating film.

[0006] The technology of the present specification has been made in consideration of the above points, and aims to provide a color matching method using a powder paint that can achieve a uniform color match. [Means for solving the problem]

[0007] The color matching method using a powder coating material according to an embodiment of the present specification includes a mixing step of dry-blending two or more types of powder coating materials having different color tones; a heating step of heating a mixed powder coating material comprising the dry-blended powder coating materials at a heating temperature lower than the lower limit of the baking temperature of the powder coating material to semi-fuse the powders of the mixed powder coating material to each other; a crushing step of crushing the heated powder mixture into a crushed powder, and crushing the crushed powder until all of the crushed powder passes through a metal mesh sieve with a nominal mesh size of 150 μm to obtain a toned powder coating; The present invention is characterized by having the following.

[0008] According to the color-matching method using the powder paint of the embodiment, the color-matched powder paint made of pulverized powder that passes through a metal mesh sieve with a nominal mesh size of 150 μm can be uniformly color-matched.

[0009] In the above-mentioned method for toning using a powder paint, the heating temperature may be 80° C. or higher.

[0010] This allows the color-matched powder paint to be uniformly toned.

[0011] Furthermore, in the above-mentioned color matching method using powder paint, the powder paint may be a thermosetting powder paint, and the heating temperature may be 10 degrees lower than the lower limit of the baking temperature of the thermosetting powder paint.

[0012] This allows the toned powder paint to be one in which the hardening of the thermosetting powder paint is suppressed and the hardening action in the baking and drying process after application of the toned powder paint is not inhibited.

[0013] In the above-mentioned method for matching colors using a powder paint, the matching powder paint may contain no components other than the powder paint.

[0014] This allows the coating film formed from the toned powder coating material to exhibit the coating film performance of the powder coating material. [Effects of the Invention]

[0015] According to the color matching method using the powder paint of the embodiment, it is possible to achieve a uniform color match. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a flow chart showing a color-matching process of a color-matching method using a powder paint according to an embodiment. [Figure 2] FIG. 1 is a diagram showing an example of an appropriate baking range of a powder paint. [Figure 3] 1A is a general photograph of a test specimen (150×70 mm) in the heating step at 70° C. in Example 1, and FIG. 1B is an enlarged photograph of the same. [Figure 4] 1A is a general photograph of the test specimen in the heating step at 80° C. in Example 1, and FIG. 1B is an enlarged photograph of the same. [Figure 5] 1A is a general photograph of the test specimen in the heating step at 90° C. in Example 1, and FIG. 1B is an enlarged photograph of the same. [Figure 6] 1A is a general photograph of the test specimen in the heating step at 170° C. in Example 1, and FIG. 1B is an enlarged photograph of the same. [Figure 7] 1A is a general photograph of the test specimen in the heating step at 70° C. in Example 2, and FIG. 1B is an enlarged photograph of the same. [Figure 8] 1A is a general photograph of the test specimen in the heating step at 80° C. in Example 2, and FIG. 1B is an enlarged photograph of the same. [Figure 9] 1A is a general photograph of the test specimen in the heating step at 90° C. in Example 2, and FIG. 1B is an enlarged photograph of the same. [Figure 10] 1A is a general photograph of the test specimen in the heating step at 240° C. in Example 2, and FIG. 1B is an enlarged photograph of the same. [Figure 11] 1A is a general photograph of the test specimen in the heating step at 70° C. in Example 3, and FIG. 1B is an enlarged photograph of the same. [Figure 12] 1A is a general photograph of the test specimen in the heating step at 80° C. in Example 3, and FIG. 1B is an enlarged photograph of the same. [Figure 13] 1A is a general photograph of the test specimen in the heating step at 90° C. in Example 3, and FIG. 1B is an enlarged photograph of the same. [Figure 14] 1A is a general photograph of the test specimen in the heating step at 160° C. in Example 3, and FIG. 1B is an enlarged photograph of the same. [Figure 15] 1A is a general photograph of the test specimen in the heating step at 70° C. in Example 4, and FIG. 1B is an enlarged photograph of the same. [Figure 16] 1A is a general photograph of the test specimen in the heating step at 120° C. in Example 4, and FIG. 1B is an enlarged photograph of the same. [Figure 17] 1A is a general photograph of the test specimen in the heating step at 70° C. in Example 5, and FIG. 1B is an enlarged photograph of the same. [Figure 18] 1A is a general photograph of the test specimen in the heating step at 130° C. in Example 5, and FIG. 1B is an enlarged photograph of the same. DETAILED DESCRIPTION OF THE INVENTION

[0017] The following describes a color matching method using powder paint according to an embodiment. In the color matching method using powder paint according to the embodiment, a user mixes two or more types of powder paint with different color tones to match a specified color.

[0018] The powder paint used in the color matching method of the embodiment is a powder paint that does not contain solvents except for unavoidable components. Because it does not contain solvents such as volatile organic solvents, it helps prevent air pollution and water contamination and has extremely little impact on the environment and human body, making it a type of paint that has attracted attention. Powder paint is applied to the substrate using electrostatic coating or dip coating in the painting process, and in the baking and drying process, the substrate is heated to the baking temperature of the powder coating, causing the powder paint particles to fuse and adhere to the substrate, forming a coating film. Powder paints are classified into thermosetting powder paints and thermoplastic powder paints, based on the difference in the coating film formation process.

[0019] Thermosetting powder paints contain a resin binder, a curing agent, and optionally additives such as coloring pigments. When heated in the baking and drying process, the curing action of the curing agent progresses, hardening the resin binder and forming a coating film.

[0020] The thermosetting powder paint may be a fluororesin-based powder paint, a polyester-based powder paint, an epoxy polyester-based powder paint, an epoxy-based powder paint, etc., depending on the composition of the resin binder. In another embodiment, a fluororesin-based powder paint or a polyester-based powder paint, which has excellent versatility, may be used.

[0021] As the curing agent for the thermosetting powder coating, hexamethylene diisocyanate, blocked isocyanate, TGIC (triglycidyl isocyanurate), Primid (Primid XL552 (β-hydroxyalkylamide)), ethyl methyl ketone peroxide, organic peroxide, aliphatic polyamine, polyamidoamine, etc. can be appropriately selected and used.

[0022] Thermoplastic powder paints contain a resin binder and, if necessary, additives such as color pigments, and are heated in a baking and drying process to melt the resin binder, which is then cooled to solidify and form a coating film.Vinyl chloride-based thermoplastic powder paints, polyethylene-based thermoplastic powder paints, nylon-based thermoplastic powder paints, etc. can be used as thermoplastic powder paints, depending on the resin composition.

[0023] Color pigments are additives that impart color to coating films formed from powder coatings by being added to the powder coating. Depending on the color, color pigments include, for example, white; titanium oxide, zinc white, black; carbon black, red; red iron oxide, quinacridone, blue; cobalt blue, phthalocyanine blue, yellow; nickel titanium yellow, monoazo yellow, etc.; and to obtain brilliance, mica powder, pearl powder, aluminum powder, etc. can be used. The color pigment is added to the powder coating in the form of a finely dispersed powder.

[0024] Powder coatings may contain other additives such as ultraviolet absorbers (UVA), light stabilizers (HALS), antibacterial agents, rust inhibitors, curing catalysts, fillers, and flow adjusters, as needed.

[0025] These powder coatings (thermosetting powder coatings, thermoplastic powder coatings) can be commercially available powder coatings colored by paint manufacturers. Examples of commercially available powder coatings that can be used include the V-PET series, Powderflon series (manufactured by Dai Nippon Paint Co., Ltd.), Konalon series (manufactured by Chugoku Paint Co., Ltd.), Toa Powder series (manufactured by Tohpe Corporation), Nissin Powder series (manufactured by Kubo Takashi Paint Co., Ltd.), Neoflon series (manufactured by Daikin Industries, Ltd.), Konal series (manufactured by Sanno Co., Ltd. and Masty Co., Ltd.), and RAL series (manufactured by Tiger Drylac Japan Co., Ltd.).

[0026] Each of these commercially available powder coatings has its own appropriate baking range, as shown in Figure 2, where the temperature on the vertical axis indicates the lower and upper limit baking temperatures. The lower and upper limit baking temperatures can generally be in the baking temperature range of 150°C (lower limit temperature) to 220°C (upper limit temperature), and in another embodiment, the baking temperature can be in the range of 180 to 210°C.

[0027] Next, a color matching method using a powder paint will be described. Figure 1 shows a flow diagram illustrating the color matching steps of the color matching method using a powder paint. The color matching method using a powder paint of this embodiment includes a mixing step of dry-blending two or more types of powder paints with different color tones, a heating step of heating a mixed powder paint made of the dry-blended powder paints at a heating temperature below the lower limit of the baking temperature of the powder paint to semi-fuse the powder of the mixed powder paint to each other, and a crushing step of crushing the heated semi-fused paint in which the powder of the mixed powder paint is semi-fused to each other to form crushed powder, and crushing the crushed powder until all of the crushed powder passes through a metal mesh sieve with a nominal mesh size of 150 μm (classification step) to form a color-matched powder paint.

[0028] The mixing process involves filling a container with two or more different basic color powder paints with a mixing ratio determined according to the desired specified color tone, and then dry-mixing the mixture so that the powder paint particles are mixed evenly. Dry-mixing is carried out using a mixer such as a tumbler mixer, mortar mixer, or dissolver mixer. In the mixing process, two or more types of powder paint are dry-blended uniformly to form a mixed powder paint.

[0029] The heating step is a step of heating the mixed powder coating material made of the powder coating materials dry-blended in the mixing step to semi-fuse the powders of the mixed powder coating material together. Semi-fusing refers to a state in which only the surfaces of the individual powders of the mixed powder coating material are fused together, rather than a state in which the powders of the mixed powder coating material are fused together as if they were a uniform composite. Heating is performed using a hot air circulating oven or a far-infrared heater oven. In another embodiment, a hot air circulating oven can be used, which allows for easy temperature control.

[0030] The heating temperature during the heating process can be set to 80°C or higher but below the minimum baking temperature of the powder coating. This is because the surfaces of the powders in the mixed powder coating, which is a dry blend of two or more different colors, are moderately fused to each other to form a semi-fused state, and the toned powder coating formed by pulverizing the semi-fused coating formed from the mixed powder coating can be uniformly toned. If the heating temperature during the heating process is lower than 80°C, the semi-fused state will not be reached, the powder coating particles will not be mixed sufficiently, and the resulting coating film may have a mottled appearance due to particles of different colors. On the other hand, if the heating temperature is higher than the minimum baking temperature of the powder coating, the binder resin of the powder coating may be cut, resulting in poor coating properties. Furthermore, in thermosetting powder coatings, heat curing may proceed, which may prevent the toned powder coating from progressing when it is applied and baked. In another embodiment, the heating temperature of the heating step can be 90°C or higher and not higher than a temperature that is 10 degrees lower than the lowest bakeable temperature of the powder paint, and in yet another embodiment, it can be 100°C or higher and not higher than a temperature that is 20 degrees lower than the lowest bakeable temperature of the powder paint.

[0031] The pulverization process is a process in which the fused powder coating is pulverized into pulverized powder. Pulverization can be performed using an automatic mortar, ball mill, powder coating pulverizer, or the like. In this process, pulverization is performed until all of the pulverized powder passes through a metal mesh sieve with a nominal mesh size of 150 μm (Test Sieve Part 1: Metal Mesh Sieves (JIS Z 8801-1:2019)). In other words, a metal mesh sieve with a nominal mesh size of 150 μm is used (classification process), and the pulverized powder that does not pass through the sieve is pulverized again, and pulverization is performed until all of the pulverized powder passes through. If pulverized powder does not pass through the 150 μm metal mesh sieve, the surface of the resulting coating film may become uneven and not be smooth. In another embodiment, pulverization can be performed until all of the pulverized powder passes through a metal mesh sieve with a nominal mesh size of 75 μm. This allows for the formation of a smoother coating film.

[0032] The toned powder paint toned by the toning method using the powder paint of the embodiment is applied to the object to be coated by electrostatic coating, dip coating, etc. in the coating process, and in the baking and drying process, the object to be coated is heated together with the toned object to the baking temperature of the powder coating, causing the particles of the powder paint to fuse and adhere to the object to form a coating film.

[0033] Tone-matching powder paints are made by dry-blending two or more types of powder paints with different color tones in a mixing process, and then by heating the surfaces of the dry-blended powder paint powders to a moderate degree to form a semi-fusible paint, which is then pulverized to reduce the particle size of the powder paints with different color tones.The tone-matching powder paint is applied to the object to be coated, and then heated to the baking temperature in the baking and drying process, whereby the two or more types of powder paints with different color tones, whose particle sizes have been reduced, are fused together again, resulting in a uniform color tone and a uniformly matched color. [Example]

[0034] Figure 1 shows a flow diagram illustrating the color-matching steps of a color-matching method using powder paint. In the examples, color-matched powder paints were prepared by changing the conditions of the heating step in the color-matching step. Each prepared color-matched powder paint was applied to a bonded steel plate and baked to form a coating film, and the color tone of the coating film was evaluated. The conditions for each step of the color-matching step, the conditions for painting and baking, and the method for evaluating the color tone are described below.

[0035] ·Mixing process In the mixing process, black and white powder paints with the same resin composition were mixed in a 1:1 mass ratio and stirred for 5 minutes in a dissolver mixer to produce a mixed powder paint. Note that the toned powder paint formed from the powder paint does not contain any components other than the powder paint.

[0036] ·Heating process In the heating step, the mixed powder coating material was heated in a hot air circulation oven under the heating conditions described in each example to obtain a semi-fusible coating material.

[0037] Crushing process In the pulverization step, the semi-fusible coating material was pulverized in a ball mill for 30 minutes to obtain a pulverized powder.

[0038] ·Classification process In the classification process, the crushed powder was passed through a metal mesh sieve with a nominal mesh size of 75 μm, and the crushed powder that did not pass through the sieve was crushed again in the crushing process until all the crushed powder had passed through the sieve, and the crushed powder that passed through the sieve was used as the toned powder paint.

[0039] ·Painting ·Baking drying Object to be painted: Bonded steel plate (150 x 70 mm) Coating: Electrostatic coating (120g / m 2 ) Baking and drying: Hot air circulation oven (190°C, 20 minutes) Painting and baking drying were carried out under the above conditions.

[0040] Color evaluation The color tone was evaluated by electrostatically coating each of the toned powder coating materials of the examples on a bonded steel plate, baking and drying the plate to form a coating film, and evaluating the color tone of the test specimen. The test specimen was then visually inspected from a distance of 10 cm, with no visible black and white particle spots, as indicated by a circle; the test specimen was visually inspected from a distance of 10 cm, but no visible black and white particle spots, as indicated by a triangle; and the test specimen was visually inspected from a distance of 1 m, with no visible black and white particle spots, as indicated by an x.

[0041] Example 1 Konar PU (blocked isocyanate-curing polyester powder coating manufactured by Sanno Co., Ltd. and Masty Co., Ltd. Minimum baking conditions: 170°C for 30 minutes) Heating process conditions and color evaluation Heating process: 70℃, 5 minutes Color rating: × Heating process: 80℃, 5 minutes Color rating: △ Heating process: 90℃ for 5 minutes Color evaluation: Good Heating process: 100℃ for 5 minutes Color evaluation: Good Heating process: 120℃ for 5 minutes Color rating: Good Heating process: 150℃ for 5 minutes Color evaluation: Good Heating process: 160℃ for 5 minutes Color rating: Good Heating process: 170℃ for 5 minutes Color rating: Good In Example 1, a blocked isocyanate-curing polyester powder coating was used for color matching. When the heating temperature was 70°C, the color tone was evaluated as × (visually observed from a distance of 1 m from the test specimen, with black and white particles forming mottle). This is presumed to be because the dry-blended mixed powder coating powder had not reached a semi-fused state. When the heating temperature was 80°C, the color tone was evaluated as △ (visually observed from a distance of 10 cm from the test specimen, with black and white particles forming mottle, but not from a distance of 1 m). This is presumed to be because the dry-blended mixed powder coating powder was not sufficiently semi-fused. When the heating temperature was between 90°C and the lower baking temperature (170°C), the color tone was evaluated as ○ (visually observed from a distance of 10 cm from the test specimen, with black and white particles forming mottle). However, when the heating temperature was 170°C, irregularities were observed on the surface of the coating film after baking and drying. It is assumed that excessive heating caused the binder resin in the powder coating to break. Photographs of the test specimens are shown in Figure 3 (70°C), Figure 4 (80°C), Figure 5 (90°C), and Figure 6 (170°C). The scale bar in the enlarged photographs (Figure (B)) is 1000 μm. Example 2 Konaron P7100 (TGIC curing polyester powder coating manufactured by Chugoku Paint Co., Ltd., minimum baking conditions: 160°C, 20 minutes) Heating process conditions and color evaluation Heating process: 70℃, 5 minutes Color rating: × Heating process: 80℃, 5 minutes Color rating: △ Heating process: 90℃ for 5 minutes Color evaluation: Good Heating process: 100℃ for 5 minutes Color evaluation: Good Heating process: 120℃ for 5 minutes Color rating: Good Heating process: 150℃ for 5 minutes Color evaluation: Good Heating process: 160℃ for 5 minutes Color rating: Good Heating process: 170℃ for 5 minutes Color rating: Good Heating process: 220℃ for 5 minutes Color rating: Good Heating process: 230℃ for 5 minutes Color evaluation: Good Heating process: 240℃ for 5 minutes Color rating: Good In Example 2, a TGIC-cured polyester powder coating was used for color matching. When the heating temperature was 70°C, the color tone was evaluated as "poor." It is presumed that the dry-blended powder mixture did not reach a semi-fused state. When the heating temperature was 80°C, the color tone was evaluated as "fair." It is presumed that the dry-blended powder mixture was not semi-fused enough. When the heating temperature was between 90°C and 240°C, 80°C higher than the lower baking temperature (160°C), the color tone was evaluated as "good." However, when the heating temperature was 220°C or higher, unevenness was observed on the surface of the coating film after baking and drying. It is presumed that excessive heating caused the binder resin of the powder coating to break. Photographs of the test specimens are shown in Figure 7 (70°C), Figure 8 (80°C), Figure 9 (90°C), and Figure 10 (170°C).

[0042] Example 3 RAL (Tiger Drylac Japan Co., Ltd. Primid-curing polyester powder paint, minimum baking conditions: 170°C, 20 minutes) Heating process conditions and color evaluation Heating process: 70℃, 5 minutes Color rating: × Heating process: 80℃, 5 minutes Color rating: △ Heating process: 90℃ for 5 minutes Color evaluation: Good Heating process: 100℃ for 5 minutes Color evaluation: Good Heating process: 120℃ for 5 minutes Color rating: Good Heating process: 150℃ for 5 minutes Color evaluation: Good Heating process: 160℃ for 5 minutes Color rating: Good In Example 3, a Primid-curing polyester powder paint was used for color matching. When the heating temperature was 70°C, the color tone was evaluated as "poor." It is presumed that the dry-blended mixed powder paint powder had not reached a semi-fused state. When the heating temperature was 80°C, the color tone was evaluated as "fair." It is presumed that the dry-blended mixed powder paint powder was not sufficiently semi-fused. When the heating temperature was between 90°C and 160°C, which is 10 degrees lower than the lower baking temperature (170°C), the color tone was evaluated as "good." Photographs of the test specimens are shown in Figure 11 (70°C), Figure 12 (80°C), Figure 13 (90°C), and Figure 14 (160°C), respectively.

[0043] Example 4 Konar FH (fluororesin hybrid powder coating manufactured by Sanno Co., Ltd. and Masty Co., Ltd. Minimum baking conditions: 180°C for 20 minutes) Heating process conditions and color evaluation Heating process: 70℃, 5 minutes Color rating: × Heating process: 80℃, 5 minutes Color rating: △ Heating process: 90℃ for 5 minutes Color evaluation: Good Heating process: 100℃ for 5 minutes Color evaluation: Good Heating process: 120℃ for 5 minutes Color rating: Good Heating process: 150℃ for 5 minutes Color evaluation: Good Heating process: 160℃ for 5 minutes Color rating: Good In Example 4, a fluorine hybrid resin powder paint was toned. When the heating temperature in the heating process was 70°C, the color tone was evaluated as x. It is presumed that the powder of the dry-blended mixed powder paint had not reached a semi-fused state. When the heating temperature in the heating process was 80°C, the color tone was evaluated as fair. It is presumed that the powder of the dry-blended mixed powder paint was not in a semi-fused state. When the heating temperature in the heating process was between 90°C and 160°C, which is 20 degrees lower than the lower baking temperature (180°C), the color tone was evaluated as ○. Photographs of the test specimens are shown in Figure 15 (70°C) and Figure 16 (120°C), respectively.

[0044] Example 5 Nissin Powder EP752 (Kubo Paint Co., Ltd. epoxy polyester resin powder coating; minimum baking conditions: 170°C for 20 minutes) Heating process conditions and color evaluation Heating process: 70℃, 5 minutes Color rating: × Heating process: 80℃, 5 minutes Color rating: × Heating process: 90℃ for 5 minutes Color evaluation: Good Heating process: 100℃ for 5 minutes Color evaluation: Good Heating process: 110℃ for 5 minutes Color rating: Good Heating process: 120℃ for 5 minutes Color rating: Good Heating process: 130℃ for 5 minutes Color evaluation: Good Heating process: 140℃ for 5 minutes Color rating: Good Heating process: 150℃ for 5 minutes Color evaluation: Good In Example 5, an epoxy polyester resin powder coating was used for color matching. When the heating process temperatures were 70°C and 80°C, the color tone was evaluated as "poor." This is presumably because the dry-blended powder of the mixed powder coating did not reach a semi-fused state. When the heating process temperature was between 90°C and 150°C, which is 20°C lower than the lower baking temperature limit (170°C), the color tone was evaluated as "good." However, a decrease in gloss was confirmed at heating temperatures of 140°C and 150°C. Photographs of the test specimens are shown in Figure 17 (70°C) and Figure 18 (130°C), respectively.

Claims

1. a mixing step of dry-blending two or more types of powder coatings having different color tones; a heating step of heating a mixed powder coating material comprising the dry-blended powder coating materials at a heating temperature lower than the lower limit of the baking temperature of the powder coating material to semi-fuse the powders of the mixed powder coating material to each other; a crushing step of crushing the heated powder of the mixed powder coating material so that the powders of the mixed powder coating material are semi-fused to each other into crushed powder, and crushing the crushed powder until all of the crushed powder passes through a metal mesh sieve with a nominal mesh size of 150 μm to obtain a toned powder coating material; A color matching method using a powder paint, comprising:

2. 2. The method for toning a powder paint according to claim 1, wherein the heating temperature is 80° C. or higher.

3. 3. The color matching method using powder paint according to claim 2, wherein the powder paint is a thermosetting powder paint, and the heating temperature is not more than a temperature 10 degrees lower than the lower limit of the baking temperature of the thermosetting powder paint.

4. 4. The method for matching powder paint according to claim 1, wherein the matching powder paint does not contain any component other than the powder paint.

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