JP5759292B2 - Manufacturing method of painted metal plate - Google Patents

Description

  The present invention relates to a method for producing a coated metal plate having a Hammerton pattern top coat.

  As a pattern finish coating, a hammerton pattern coating has been known for a long time, in which irregularities are formed continuously by hitting a metal plate with a hammer. Conventionally, the hammerton pattern has been used only in small quantities for small articles.

  In recent years, the application of a hammerton pattern has been examined for use in home appliances, furniture, building materials, etc. for the purpose of improving the quality of products. For this reason, a pre-coated metal plate having a hammerton pattern is required. As a method for continuously and inexpensively producing a hammerton pattern pre-coated metal plate, a method using a roll coat type continuous coating line is known (see, for example, Patent Documents 1 and 2).

  Patent Documents 1 and 2 disclose a method for producing a hammerton pattern precoated metal plate using a roll coater. In this method, first, an undercoat paint is applied to a metal plate with a first roll coater, and the undercoat paint is dried in a first oven. Next, an intermediate coating containing inorganic pigment powder is applied onto the undercoat coating film with a second roll coater, and immediately after that, an overcoating coating containing a spreading agent is applied with a spray device. As a result, a hammerton pattern appears. Thereafter, the intermediate coating material and the top coating material are dried in the second oven. A hammerton pattern pre-coated metal plate can be manufactured by the above process.

  In addition to the above method, there is also known a method in which silicone oil is applied by a spray device immediately after an intermediate coating containing inorganic pigment powder is applied on an undercoat coating. In any method, a hammerton pattern is developed by generating repelling on the coating film by the action of a paint or silicone oil containing a spreading agent.

Japanese Patent Laid-Open No. 11-612 JP-A-8-216331

  However, the method of manufacturing a coated metal plate having a hammerton pattern as described above has a problem that the intermediate coating and the top coating or silicone oil must be applied separately, and the manufacturing process is complicated. . Further, in addition to the roll coater and the oven, a spray device is further required, and there is a problem that the device becomes large.

  This invention is made | formed in view of this point, and it aims at providing the manufacturing method of a coating metal plate which can manufacture a hammered pattern coating metal plate by a simple process.

  The present inventor has found that a hammerton pattern can be developed by only applying a top coating containing an organic resin, a color pigment, a metallic pigment, a silicone compound and a solvent, and further studies are made to complete the present invention. It was.

That is, this invention relates to the manufacturing method of the following coated metal plates.
[1] A step of preparing a metal plate having an undercoat film formed on the surface; a step of applying an overcoat paint containing an organic resin, a color pigment, a metallic pigment, a silicone compound and a solvent on the undercoat film; A step of allowing the metal plate coated with the top coating to stand to form an irregular pattern and then drying the coated top coating, and the silicone compound comprises dimethylpolysiloxane, methylhydropoly A method for producing a coated metal plate, which is a siloxane, silicone oil, silicone varnish, organochlorosilane, or silanol-reactive silicone monomer.
[2] The method for producing a coated metal plate according to [1], wherein in the step of applying the top coating, the top coating is applied so that the film thickness thereof is non-uniform.
[3] The method for producing a coated metal plate according to [2], wherein in the step of applying the top coating, roping is generated when the top coating is applied by a roll coater.
[4] The top coat is applied by a natural roll coat type roll coater, and the difference between the peripheral speed of the applicator roll of the roll coater and the peripheral speed of the backup roll is 15 m / min or less. Method of manufacturing painted metal plates.

  According to the present invention, a painted metal plate having a hammerton pattern can be manufactured by a simple process. The method for producing a coated metal plate of the present invention is useful as a method for producing an exterior material used for an outer wall of a building, for example.

1A and 1B are photographs showing an example of a painted metal plate having a hammerton pattern top coat. 2A to 2D are schematic views for explaining the mechanism of the hammerton pattern. It is a schematic diagram which shows the structure of a roll coater. 4A to 4K are photographs showing the time course of hammerton pattern development in a plated steel sheet coated with a top coating under the conditions of Example 1. FIG. 5A to 5K are photographs showing the time course of the hammerton pattern in the plated steel sheet coated with the top coat under the conditions of Example 2. FIG. 6A to 6K are photographs showing the time course of hammerton pattern development in a plated steel sheet coated with a top coat under the conditions of Example 3. FIG.

  The present invention is a method for producing a coated metal plate having a Hammerton pattern top coat film, which includes 1) a metal plate preparation step for preparing the metal plate, 2) a top coat coating step for applying the top coating, and 3 And a drying step of drying the top coat. Here, the “hammerton pattern” refers to an irregular concavo-convex pattern (an irregular pattern) formed by repelling a paint by a silicone compound when a paint containing a silicone compound is applied to a metal plate.

  FIG. 1 is a photograph showing an example of a painted metal plate having a Hammerton pattern top coat. FIG. 1A is a planar image, and FIG. 1B is an enlarged perspective image. As shown in FIG. 1B, a convex portion (ridge line portion) and a concave portion are formed in the top coat film. Usually, the convex part (ridge line part) has the color tone of the color pigment, and the concave part has the color tone of the metallic pigment.

  Hereinafter, each process of the manufacturing method of the coating metal plate of this invention is demonstrated.

1) Metal plate preparation process In a metal plate preparation process, the metal plate used as a coating original plate is prepared. It is preferable that the metal plate used as the coating original plate has an undercoat coating film formed from the viewpoint of corrosion resistance and the like. For example, an undercoat paint can be formed on the surface of a metal plate by applying an undercoat paint to the surface of a metal plate (coating substrate) and then drying it. Moreover, you may prepare the metal plate in which the undercoat coating film was formed previously.

[Metal plate]
The kind of metal plate used as a coating original plate is not specifically limited. Examples of the metal plate to be the coating original plate include cold rolled steel plate, galvanized steel plate, Zn-Al alloy plated steel plate, Zn-Al-Mg alloy plated steel plate, aluminum plated steel plate, stainless steel plate, aluminum plate, aluminum alloy plate, copper plate Etc. are included. From the viewpoint of corrosion resistance, it is preferable to use various plated steel plates or stainless steel plates as the coating original plate.

[Chemical conversion treatment]
From the viewpoint of improving corrosion resistance and coating film adhesion, the metal plate may have a chemical conversion treatment film formed on the surface thereof.

The type of chemical conversion treatment is not particularly limited. Examples of the chemical conversion treatment include chromate treatment, chromium-free treatment, phosphate treatment and the like. The adhesion amount of the chemical conversion treatment film formed by chemical conversion treatment is not particularly limited as long as it is within a range effective for improving corrosion resistance and coating film adhesion. For example, in the case of a chromate film, the adhesion amount may be adjusted so that the total Cr conversion adhesion amount is 5 to 100 mg / m ² . Further, in the case of a chromium-free coating, the Ti-Mo composite coating has a range of 10 to 500 mg / m ² , and the fluoroacid-based coating has a fluorine equivalent or total metal element equivalent deposit of 3 to 100 mg / m ^2. The adhesion amount may be adjusted. Moreover, what is necessary is just to adjust the adhesion amount so that it may become 5-500 mg / m < ² > in the case of a phosphate membrane | film | coat.

  The chemical conversion film can be formed by a known method. For example, the chemical conversion solution may be applied to the surface of the metal plate by a method such as a roll coating method, a spin coating method, or a spray method, and dried without being washed with water. The drying temperature and drying time are not particularly limited as long as moisture can be evaporated. From the viewpoint of productivity, the drying temperature is preferably in the range of 60 to 150 ° C. as the ultimate plate temperature, and the drying time is preferably in the range of 2 to 10 seconds.

[Undercoat]
As described above, it is preferable that the metal plate serving as the coating original plate has an undercoat coating film formed from the viewpoint of corrosion resistance. The undercoat coating film improves the corrosion resistance and the coating film adhesion. For example, the undercoat coating film is formed by applying an undercoat paint to the surface of a metal plate (original coating plate) and drying it.

  The kind of organic resin used as the base of the paint is not particularly limited as long as it is an organic resin that can be applied to the paint for the precoated steel sheet. Examples of organic resins that can be used include polyester resins, melamine resins, and epoxy resins. These organic resins may be used alone or in combination of two or more. The kind of the solvent for the paint is not particularly limited as long as it is a solvent that can dissolve the organic resin as a base.

  The undercoat paint preferably contains a rust preventive pigment from the viewpoint of improving the corrosion resistance of the coated metal plate. Examples of rust preventive pigments include zinc phosphate, zinc phosphite, magnesium magnesium phosphate, magnesium phosphate, magnesium phosphite, silica, calcium ion exchanged silica, zirconium phosphate, aluminum trihydrogen phosphate, zinc oxide , Zinc phosphomolybdate, barium metaborate, strontium chromate, barium chromate, zinc chromate.

  The undercoat paint preferably contains a color pigment from the viewpoint of improving the base concealing property of the undercoat coating film. The kind of coloring pigment is not particularly limited, and can be appropriately selected from known pigments. Examples of coloring pigments include inorganic pigments such as titanium oxide, carbon black, iron black, titanium yellow, bengara, bitumen, cobalt blue, cerulean blue, ultramarine blue, cobalt green, molybdenum red, resol red B, brilliant scarlet G, Pigment Scarlet 3B, Brilliant Carmine 6B, Lake Red C, Lake Red D, Permanent Red 4R, Bordeaux 10B, Fast Yellow G, Fast Yellow 10G, Para Red, Watching Red, Benzidine Yellow, Benzidine Orange, Bon Maroon L, Bon Maroon M, Organic pigments such as brilliant fast scarlet, vermilion red, phthalocyanine blow, phthalocyanine green, fast sky blue, aniline black and the like are included.

  The thickness of the undercoat coating film is not particularly limited, but is preferably in the range of 0.5 to 30 μm. If the film thickness is less than 0.5 μm, the corrosion resistance and coating film adhesion may not be sufficiently improved. On the other hand, when the film thickness is more than 30 μm, the surface of the coating film becomes a cocoon skin shape and the appearance is deteriorated, and a crack is easily generated when baking. In addition, when the undercoat coating film is a colored coating film, a film thickness of 3 μm or more is preferable in order to conceal the color of the coating original plate.

  The method for applying the undercoat paint is not particularly limited, and may be appropriately selected from methods used for producing precoated steel sheets. Examples of the coating method include a roll coating method, a curtain coating method, a spray coating method, and a die coating method. The baking conditions may be, for example, baking at an ultimate plate temperature of 150 to 300 ° C. for 15 to 100 seconds.

2) Topcoat paint application process In the topcoat paint application process, a topcoat paint is applied on the undercoat film to develop a Hammerton pattern. Specifically, after a top coat is applied to the surface of the metal plate on which the undercoat coating film has been formed, it is left for a predetermined time to develop a hammerton pattern.

[Top coat]
One feature of the production method of the present invention is that the hammerton pattern is developed only by applying the top coating material once. In order to realize this, in the manufacturing method of the present invention, a top coating material further containing a silicone compound is used in addition to the organic resin, the solvent, the color pigment and the metallic pigment.

  The kind of organic resin used as the base of the paint is not particularly limited as long as it is a resin that can be applied to the paint for the precoated steel sheet. Examples of resins that can be used include polyester resins, polymer polyester resins, polyurethane resins, and acrylic resins. These resins may be used alone or in combination of two or more. The type of solvent (solvent) for the coating is not particularly limited as long as it is a solvent that can dissolve the base resin.

  The colored pigment imparts a color tone to the convex portion (ridge line portion) of the hammerton pattern, thereby making the hammerton pattern clearer (see FIG. 1B). The type of the color pigment is not particularly limited and can be appropriately selected from known pigments. Examples of the color pigment include inorganic pigments and organic pigments contained in the above-described undercoat paint.

  The blending amount of the color pigment is preferably in the range of 0.1 to 50 parts by mass, particularly preferably in the range of 0.5 to 30 parts by mass with respect to 100 parts by mass of the organic resin. When the blending amount of the color pigment is less than 0.1 parts by mass, the tone of the hammerton pattern cannot be sufficiently imparted, and the hammerton pattern may become unclear. On the other hand, when the blending amount of the color pigment is more than 50 parts by mass, the cohesive force of the top coat film is lowered and the processability may be lowered.

  The metallic pigment imparts a color tone to the recesses of the hammerton pattern to make the hammerton pattern clearer (see FIG. 1B). The type of metallic pigment is not particularly limited as long as a clear hammerton pattern can be obtained. Although the mechanism of the hammerton pattern will be described later, it is preferable to use a metallic pigment having a large specific gravity with respect to the solvent in order to obtain a clear hammerton pattern. Examples of such metallic pigments include aluminum flakes (non-leafing type), bronze flakes, copper flakes, stainless steel flakes, nickel flakes.

  The compounding amount of the metallic pigment is preferably in the range of 0.5 to 20 parts by mass with respect to 100 parts by mass of the organic resin. When the compounding amount of the metallic pigment is less than 0.5 parts by mass, the color tone cannot be sufficiently imparted to the concave portion of the hammerton pattern, and the boundary between the convex portion (ridge line portion) and the concave portion in the hammerton pattern is unclear. There is a risk. On the other hand, when the compounding amount of the metallic pigment is more than 20 parts by mass, the width of the convex portion (ridge line portion) of the hammerton pattern becomes thin, and the hammerton pattern may become unclear.

  The silicone compound forms a recess in the top coat film to develop a hammerton pattern. The type of the silicone compound is not particularly limited as long as it can form a recess in the top coat film by repelling the base organic resin and solvent. As the silicone compound to be blended in the top coat film, those having a number average molecular weight in the range of 50,000 to 500,000 are preferably used. Examples of such silicone compounds include silicone water repellents such as dimethylpolysiloxane, methylhydropolysiloxane, silicone oil, silicone varnish, organochlorosilane, silanol reactive silicone monomer. The silicone varnish can be added to the top coating as a solution obtained by dissolving the silicone varnish in a solvent or as an oil-in-water emulsion of the silicone varnish.

  The compounding amount of the silicone compound is preferably in the range of 0.05 to 0.4 parts by mass with respect to 100 parts by mass of the resin. When the compounding amount of the silicone compound is less than 0.05 parts by mass, the repelling action cannot be sufficiently obtained, and the hammerton pattern may be sparse. On the other hand, when the compounding amount of the silicone compound is more than 0.4 parts by mass, a large number of repelling parts due to the silicone compound are generated, and there is a possibility that a Hammerton pattern with a small concave part diameter is formed.

[Method of applying top coat]
The method for applying the top coat is not particularly limited, and may be appropriately selected from methods used for producing precoated steel sheets. Examples of such coating methods include roll coating, bar coating, flow coating, curtain flow, spraying, and the like. After applying the top coat, it is allowed to stand for a predetermined time (for example, 10 to 20 seconds), so that a clear hammerton pattern appears.

  As a result of detailed observation of the state of the coating film after applying the top coating, the present inventor has elucidated the mechanism of the hammerton pattern. Then, with reference to FIG. 2, the hammering pattern expression mechanism discovered by the present inventor will be described.

  When the top coat 130 is applied on the undercoat 120 formed on the surface of the metal plate 110, the silicone compound 132 (repellent component) contained in the top coat 130 repels the surrounding top coat 130 to form a small repellent area. (See FIG. 2A). Each small repelling area grows into a large repelling area (see FIG. 2B). Next, the repelling areas are gathered to form a larger repelling area (see FIG. 2C). Thereby, the convex part 140 and the recessed part 150 are formed in the coating film of the top coat 130.

  At this time, the repelling force of the silicone compound 132 present in the recess 150 is so strong as to repel the top coat 130 containing the metallic pigment 134, but there is no force to push up the metallic pigment 134 having a specific gravity larger than that of the solvent to the vicinity of the top of the protrusion 140. . As a result, a metallic pigment low concentration portion 142 in which the metallic pigment 134 hardly exists is formed near the apex of the convex portion 140. In the low-concentration portion 142 of the metallic pigment, the metallic pigment 134 is hardly present, but the colored pigment is present. Therefore, the color tone near the apex (ridge line portion) of the convex portion 140 is the color tone (for example, black) of the color pigment. On the other hand, a region (such as the concave portion 150) other than the vicinity of the apex (ridge line portion) of the convex portion 140 has a color tone (for example, silver white) of the metallic pigment 134. Due to the difference in color tone between the ridge line portion and the other areas, a hammerton pattern is formed on the surface of the metal plate 110 as if it was hit with a hammer.

  Thereafter, the hammerton pattern is fixed by volatilization of the solvent contained in the top coat 130 (see FIG. 2D).

  Considering the mechanism of the hammerton pattern revealed by the present inventor, it can be seen that the height of the metallic pigment low concentration portion 142 in the convex portion 140 can be increased by increasing the thickness of the coating film of the top coat 130. As a result, it is expected that the difference in color tone between the ridge line portion and the other area becomes clearer and a clear hammerton pattern is formed. However, if the coating film of the top coat 130 is thickened, it becomes difficult for the silicone compound 132 to form a repelling region, and the recess 150 may not be formed.

  In order to achieve both the clarification of the ridge line part and the formation of the concave part, it is preferable to apply the top coat so as to have a non-uniform film thickness. By applying a top coating with a non-uniform film thickness and forming some irregularities from the beginning, the repelling effect of the silicone compound is sufficiently exhibited in the concave portions (see FIG. 2A), and the metallic pigment is formed in the convex portions. It is possible to increase the height of the portion that does not contain (metallic pigment low concentration portion). The average thickness of the coating film immediately after the top coating is applied is preferably about 5 to 30 μm.

  The method for applying the top coat with a non-uniform film thickness is not particularly limited. For example, a top coat can be applied with a non-uniform film thickness by using a bar coater. Moreover, you may generate | occur | produce roping when apply | coating topcoat using a roll coater as follows.

[Roll coat method]
FIG. 3 is a schematic diagram of the roll coater 200. As shown in FIG. 3, the roll coater 200 is of a so-called natural coat type, and includes a storage trough 210 that stores the top coating 130, a pickup roll 220 that scrapes the top coating 130 from the storage tank 210, and a pickup roll 220. An applicator roll 230 that transfers and coats the top coat 130 onto the metal plate 110, a backup roll 240 that sandwiches the metal plate 110 and contacts the applicator roll 230, and conveys the metal plate 110 downstream in the metal plate feed direction; ,have.

  A part of the lower side of the pickup roll 220 is immersed in the top coat 130 of the storage tank 210, and the top coat 130 is scraped up by rotating. In addition, the thing of this embodiment is what is rotating clockwise in the side view. The applicator roll 230 rotates in the reverse direction of the pickup roll 220 and transfers the transferred top coat 130 to the metal plate 110. The backup roll 240 rotates in the reverse direction of the applicator roll 230 and conveys the metal plate 110 downstream in the feed direction. That is, while the metal plate 110 is conveyed toward the rotation direction of the applicator roll 230, the top coat 130 is applied to the surface (more precisely, on the undercoat film 120) (natural coating).

  Here, the peripheral speed of the pickup roll 220 is in the range of 4 to 20 m / min, the peripheral speed of the applicator roll 230 is in the range of 15 to 65 m / min, and the peripheral speed of the backup roll 240 is 23. It is preferable to be within a range of ˜80 m / min. In this case, it is preferable that the difference (absolute value) between the peripheral speed of the applicator roll 230 and the peripheral speed of the backup roll 240 is controlled within 15 m / min. Either the peripheral speed of the applicator roll 230 or the peripheral speed of the backup roll 240 may be faster. By adjusting in this way, the top coat 130 can be applied to the surface of the metal plate 110 on which the undercoat coating film 120 is formed in a state where roping is generated.

3) Drying process In the drying process, the solvent of the top coat is volatilized to fix the hammerton pattern. For example, a metal plate with a hammerton pattern may be heated in an oven. The heating temperature is preferably in the range of 150 to 300 ° C. as the ultimate plate temperature, and the heating time is preferably in the range of 20 to 130 seconds.

  As described above, according to the method for producing a coated metal plate of the present invention, a hammerton pattern can be easily formed by only applying the top coat paint once.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail with reference to an Example, this invention is not limited by these Examples.

1. Preparation of coated metal plate After degreasing the surface of 55% Al-Zn alloy-plated steel sheet (painted original sheet), a commercially available coating-type chromate treatment solution (Surfcoat 300NS; Nippon Paint Co., Ltd.) has a total Cr conversion deposit of 40 mg / was coated by a roll coater so that the m ^2. The steel plate coated with the chromate treatment liquid was heated at a final plate temperature of 120 ° C. for 10 seconds to form a chemical conversion treatment film.

  Next, a polyester resin-based undercoating material (base resin: Byron 63CS (Toyobo Co., Ltd.), curing agent: Cymel 303 (Mitsui Cytec Co., Ltd.)) is applied to the surface of the coated raw plate subjected to chemical conversion treatment, and the ultimate plate temperature 200 Baking was performed at 0 ° C. to form an undercoat film having a dry film thickness of 5 μm.

  Next, a top coat was applied to the surface of the undercoat coating film with a natural coat type roll coater and left for 20 seconds to develop a hammerton pattern. The top coating material is a polyester resin based top coating material (base resin: Byron 63CS (Toyobo Co., Ltd.), curing agent: Cymel 303 (Mitsui Cytec Co., Ltd.)), and carbon black (MA100; Mitsui Chemicals, Inc.) as a color pigment, Aluminum flakes (Alpaste; Toyo Aluminum Co., Ltd.) as a metallic pigment and dimethylpolysiloxane (KP310; Shin-Etsu Chemical Co., Ltd.) as a silicone compound were prepared. The compounding quantity of carbon black was 5 mass parts with respect to 100 mass parts of polyester resins. The compounding quantity of aluminum flakes was 10 parts by mass with respect to 100 parts by mass of the polyester resin. The blending amount of dimethylpolysiloxane was 0.2 parts by mass with respect to 100 parts by mass of the polyester resin. After the hammerton pattern was developed, it was baked at an ultimate plate temperature of 200 ° C. to form a top coat film of the hammerton pattern.

Table 1 shows the setting conditions of the roll coater in each example.

2. Hammerton pattern development process The hammerton pattern development process was observed for the plated steel sheets coated with the top coat under the conditions of Examples 1 to 3.

  FIG. 4 is a photograph showing a process of developing a hammerton pattern in a plated steel sheet coated with a top coat under the conditions of Example 1. FIG. 4A is a photograph immediately after applying the top coat. 4B is 1 second after application, FIG. 4C is 3 seconds after application, FIG. 4D is 5 seconds after application, FIG. 4E is 8 seconds after application, FIG. 4F is 10 seconds after application, and FIG. 4G is after application. After 13 seconds, FIG. 4H is 15 seconds after coating, FIG. 4I is 18 seconds after coating, and FIG. 4J is 20 seconds after coating. FIG. 4K is a photograph after baking.

  FIG. 5 is a photograph showing a process of developing a hammerton pattern in a plated steel sheet coated with a top coat under the conditions of Example 2. FIG. 5A is a photograph immediately after applying the top coat. 5B is 1 second after application, FIG. 5C is 3 seconds after application, FIG. 5D is 5 seconds after application, FIG. 5E is 8 seconds after application, FIG. 5F is 10 seconds after application, and FIG. 5G is after application. After 13 seconds, FIG. 5H is a photograph after 15 seconds after coating, FIG. 5I is a photograph after 18 seconds after coating, and FIG. 5J is a photograph after 20 seconds after coating. FIG. 5K is a photograph after baking.

  6 is a photograph showing a process of developing a hammerton pattern in a plated steel sheet coated with a top coat under the conditions of Example 3. FIG. FIG. 6A is a photograph immediately after applying the top coat. 6B is 1 second after application, FIG. 6C is 3 seconds after application, FIG. 6D is 5 seconds after application, FIG. 6E is 8 seconds after application, FIG. 6F is 10 seconds after application, and FIG. 6G is after application. After 13 seconds, FIG. 6H is a photograph after 15 seconds after coating, FIG. 6I is a photograph after 18 seconds after coating, and FIG. 6J is a photograph after 20 seconds after coating. FIG. 6K is a photograph after baking.

  4 to 6, it can be seen that the Hammerton pattern can be developed only by applying the top coating containing an organic resin, a color pigment, a metallic pigment, a silicone compound and a solvent only once. It can also be seen that the hammerton pattern can be expressed more vividly in a shorter time by generating roping with a roll coater and applying the top coat with a non-uniform film thickness.

  3. Hammerton pattern evaluation

  About the coating plating steel plate of said Examples 1-3, the sharpness of a Hammerton pattern and the recessed part diameter were evaluated.

  The sharpness of the Hammerton pattern was evaluated by measuring the 60-degree specular reflectance according to JIS Z8741. In the evaluation of sharpness, “60” when the 60-degree specular reflectance is 30% or more and less than 40%, “○” when 40% or more and less than 50%, and 50% or more or less than 30%. The case was set as “x”.

For the Hammerton pattern concave diameter, an average value of the diameters (longest diameter) of all the concaves within a range of 1 cm ² selected at random was calculated. The diameter (longest diameter) of each recess was measured using a caliper. The hammerton pattern is evaluated as “◎” when the recess diameter is 1.5 mm or more and less than 3.0 mm, and when the recess diameter is 1.0 mm or more and less than 1.5 mm, or 3.0 mm or more and less than 4.0 mm, “ The case of “O” is 4.0 mm or more or less than 1.0 mm is “X”.

Table 2 shows the evaluation results of the hammerton pattern of each coated plated steel sheet.

  As shown in Table 2, even when any of Examples 1 to 3 was used, the 60-degree specular reflectance and the recess diameter of the Hammerton pattern were good.

  From the above results, it can be seen that the method for producing a painted metal plate of the present invention can easily produce a painted metal plate having a clear hammerton pattern.

  The method for producing a coated metal plate according to the present invention is useful as a method for producing a pre-coated metal plate used for, for example, home appliances, furniture, and building materials because a painted metal plate having a clear hammerton pattern can be easily produced. .

DESCRIPTION OF SYMBOLS 110 Metal plate 120 Undercoat film 130 Topcoat paint 132 Silicone compound 134 Metallic pigment 140 Convex part 142 Metallic pigment low concentration part 150 Concave part 200 Roll coater 210 Reservoir 220 Pickup roll 230 Applicator roll 240 Backup roll

Claims (1)

Preparing a metal plate having an undercoat film formed on the surface;
On the undercoat coating film, a step of applying an overcoat paint containing an organic resin, a color pigment, a metallic pigment, a silicone compound and a solvent;
And leaving the metal plate coated with the top coating to form an irregular pattern, and then drying the coated top coating.
In the step of applying the top coating material, the difference between the peripheral speed of the applicator roll and the peripheral speed of the backup roll in the roll coater of the natural roll coating method is set to 15 m / min or less, and roping is generated when the top coating material is applied. And apply the top coating so that the film thickness is non-uniform,
The silicone compound is dimethylpolysiloxane, methylhydropolysiloxane, silicone oil, silicone varnish, organochlorosilane or silanol reactive silicone monomer,
Manufacturing method of painted metal sheet.