JP2008094013A - Coated metallic plate with excellent designability and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coated metallic plate with successful workability, pattern reproducibility, adhesion and designability, and a manufacturing method of the coated metallic plate. <P>SOLUTION: This coated metallic plate with excellent designability has a top coating film 6 which continuously covers the entirety or part of an undercoat treated layer 2, formed on at least one surface of a metallic plate 1 to which an undercoat treatment 2 is applied. In addition, the plate has a top coating film 6 which is of an uneven shape and can develop a pattern appearance with a projecting part and a recessed part. Further, an undercoat film may be formed between the undercoat treated layer 2 and the top coating film 6. Alternatively, the undercoat film of an uneven shape may be used in lieu of the top coating film 6. Thus the coated metallic plate can be manufactured by forming the top coating film 6 or the undercoat film, both having an uneven shape by a roll coating method using a smooth surfaced applicator roll and a metallic pickup roll with a gravure cell engraved on the surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a coated metal plate excellent in design and suitable for use in home appliances, indoor and outdoor building materials, and a method for producing the same.

  In a product using a metal plate, the outer plate touched by human eyes is mostly used with some coating applied for the purpose of improving the corrosion resistance and the design.

  Conventionally, such painting has been performed by an after-coating method in which painting is performed after completion of product assembly, but recently, the use of pre-painted metal sheets (pre-coated metal sheets) has been increasing.

  The percentage of use of coated metal plates is increasing: (1) can help customers skip processes, (2) can avoid complicated tasks such as degreasing and painting, (3) in urban areas In the case of home appliance factories that are located, it is difficult to renew the paint factory, (4) special functions can be added, and (5) design characteristics can be added.

  Among these reasons, a pattern-coated metal plate has been demanded particularly focusing on the design properties of the painted metal plate.

  The conventional technology for pattern-painted metal plates is a modification of metallic paint metal plate and metallic paint layer metal plate that express pattern by changing the reflection direction of light by adding scaly pigment to the coating film. Metallic coated metal plates having a hammer tone pattern (uneven pattern as if struck with a hammer) are known.

  Since the metallic coated metal plate contains scaly pigments such as aluminum flakes in the coating film, the reflection of light greatly changes depending on the orientation direction and the visual recognition direction of the scaly pigments, and a pattern appears. However, there is a problem that the roll eyes are very conspicuous due to the rib-like uneven pattern formed parallel to the coating direction. For this reason, it is made to suppress conspicuous roll eyes by using 3 roll coating or curtain roll coating.

  In addition, proposals have been made to suppress the noticeability of roll eyes without using 3-roll coating or curtain roll coating. For example, Patent Document 1 discloses a metallic material in which a scale-like substrate is coated with a metal such as an Fe-based alloy or an Ni-based alloy together with organic beads to develop a metallic view with no directivity. It is described that a painted metal plate can be obtained.

  On the other hand, there has been proposed a metallic-coated metal plate in which directivity is lost and cosmetics are imparted by combining spray coating with metallic coating. For example, in Patent Document 2, the top coat film is composed of a top coat base paint and a top clear paint, and the top coat base paint contains organic resin fine particles and a color pigment, and the top coat clear paint contains glitter powder. In addition, it is described that the top-coat clear paint is wet-on-wet before the base-coat colored base paint is dried. Further, in Patent Document 3, the top coat film is composed of a top coat base paint and a top clear paint, and the top coat base paint contains organic resin fine particles and a color pigment, and the top coat clear paint contains glitter powder. It is described that the shrink coating material contained is used, and the top clear coating material is wet-on-wet coated before the top coating colored base coating material is dried.

  Next, it has been proposed to produce a metallic coated metal plate having a hammer tone pattern (irregular pattern as if struck with a hammer) by spraying a solvent onto the wet metallic paint. For example, in Patent Document 4, an undercoat paint is applied to the surface of a metal plate, dried, and then an overcoat paint containing aluminum powder, pearl mica powder or stainless steel powder is applied onto the undercoat paint, and this overcoat paint is applied. Describes a method of obtaining a metallic coated metal plate having a hammer tone pattern by spraying a solvent on the top coating material while it is in an undried state, followed by drying and baking.

  In addition, there exists a pattern printing metal plate as something similar to a pattern coating metal plate. In this method, an ink containing a high concentration of pigment is applied to the entire surface of a metal plate, and then an undercoat coating film is dried, and then transferred and printed on the coating film to develop a pattern.

JP 2000-107680 A JP-A-11-19581 Japanese Patent Laid-Open No. 11-19582 JP-A-2005-324122

  In order to prevent the metallic paint metal plate from being conspicuous, three-roll coating or curtain roll coating can be used. However, if three-roll coating is to be performed, it is necessary to newly provide equipment for that purpose. In addition, there is a problem that the cleaning work becomes complicated. In addition, if the curtain flow coating is to be applied, it is not only necessary to newly install equipment for that purpose, but also the paint that can form a stable curtain is limited and the coating is also limited. is there.

  Instead of applying 3-roll coating or curtain flow coating, spray coating is applied on the wet metallic paint as described above to obtain a metallic coated steel sheet having no directivity or a hammer-tone pattern. It has been proposed. However, in order to perform spray coating or spray a solvent, it is necessary to newly install a spray coating facility for that purpose, and since the coating efficiency of the paint is considerably lower than that of a roll coater, the loss of paint and solvent is reduced. large. In addition, there is a problem that the pattern obtained by spray painting has poor reproducibility.

  Next, the pattern-printed metal plate formed by transferring ink containing a high concentration of pigment forms a pattern by the transferred ink being scattered in a convex shape on the coating film. Unlike those obtained by spray coating, is excellent in reproducibility. However, since the coating film cannot be concealed, the color tone of the pattern printing metal plate must be based on the color tone of the coating film, and the design of the pattern printing metal plate is greatly influenced by the color tone of the coating film. become. In addition, since the transferred ink is scattered in a convex shape on the dried coating film to form a pattern, the adhesion with the coating film is poor, and the ink may be peeled off and the pattern portion may be lost. .

  This invention is made | formed in view of such a problem, and it aims at providing the coating metal plate excellent in the designability, and its manufacturing method.

  As a result of various studies on the appearance of a pattern on a coated metal plate, the present inventor has obtained the following findings (a) to (j).

  (a) A metallic coated metal plate in which a scaly pigment is contained in a coating film can exhibit a metallic appearance having no directivity by using three-roll coating or curtain flow coating. Alternatively, after applying the metallic paint, before the metallic paint is dried, a metallic appearance having no directivity can be developed by spraying the upper surface of the metallic paint or spraying a solvent. However, both require new equipment, and there are many difficulties in workability and pattern reproducibility.

  (b) On the other hand, the pattern printed metal plate is excellent in reproducibility unlike the pattern obtained by spray painting because the pattern is formed by transfer, and can be transferred by a roll. The property is also good. However, an ink containing a high concentration of pigment has a drawback of poor adhesion to a coating film.

  This will be described with reference to the schematic diagram of the pattern-printed metal plate in FIG. This pattern-printed metal plate is printed so that a coating film 3 is formed on one surface of a metal plate 1 as a base material via a base treatment layer 2 and an ink layer 4 forms a pattern on the coating film 3. Is done. Since printing is transferred onto the coating film 3 after drying, the transferred ink layer 4 always has a convex shape, and since the compatibility with the coating film 3 is small, when intense processing is applied, There is a possibility that the ink layer 4 forming the pattern is peeled off and dropped.

  (c) In order to solve this, instead of transferring a pattern made of ink containing a high concentration of pigment, a pattern made of an organic resin paint compatible with the coating film may be transferred. The convex pattern made of an organic resin paint can remarkably improve the adhesion to the ground treatment layer or the coating film than the convex pattern made of ink containing a high concentration of pigment.

  That is, after forming a pattern on a roll using an organic resin paint, if this pattern is transferred to a metal plate that has been ground-treated, or a metal plate that has been coated on the ground-treated layer, the pattern-coated metal plate Will be formed. In order to transfer the pattern onto the metal plate using an organic resin paint, a gravure roll in which a gravure cell made of a concave pattern is engraved on the surface of a roll having a smooth surface is used as an applicator roll. If the organic resin paint in this recessed part is transcribe | transferred to a metal plate after making a paint adhere, the convex part pattern which consists of an organic resin paint will be formed on the said metal plate. In order to attach the organic resin paint only to the concave portion of the roll, the organic resin paint is once attached to the entire surface of the roll, and then attached to the smooth surface of the roll by a blade or the like before the roll surface contacts the metal plate. What is necessary is just to scrape off the organic resin paint.

  This will be described with reference to the schematic diagram of FIG. In this pattern printing metal plate, a coating film 3 is formed on one surface of a metal plate 1 as a base material via a base treatment layer 2, and an island-like pattern coating film 5 is transferred onto the coating film 3. . Here, since the island-like pattern coating film 5 made of an organic resin coating compatible with the coating film 3 can be transferred before the coating film 3 is dried, the coating film 3 and the island formed on one side are transferred. The adhesiveness with the pattern coating 5 is excellent.

  (d) However, the pattern-coated metal plate obtained by this method is scattered in a convex manner on the metal plate coated with the transferred organic resin paint on the base treatment layer or on the base treatment layer. Therefore, since the convex pattern is not changed, it is not possible to hide the base treatment layer or the coating film. Although the hue of the convex pattern part can be changed by adding various pigments, the color tone of the pattern-coated metal plate must be based on the hue of the ground treatment layer or coating film. The degree of freedom of the color tone of the painted metal plate is limited.

  (e) In order to conceal the ground treatment layer or coating film, the transferred organic resin paint is not scattered to form a convex pattern, but the ground treatment layer or coating film is made of the transferred organic resin paint. It is desirable to form a top coating film that continuously covers the entire surface or a part of the coating film, and that the top coating film has a concavo-convex shape and that the pattern appearance is expressed by the convex part or concave part of the top coating film. . Since the coated metal plate provided with the top coat film having such a concavo-convex shape can continuously cover and conceal the entire surface or a part of the base treatment layer or the undercoat film, It does not depend on the hue. Therefore, the degree of freedom of the hue of the pattern-coated metal plate is large. Rather than forming a convex pattern by interspersing an organic resin paint, the pattern appearance is expressed by the uneven shape of the top coat film in which the organic resin paint is continuously connected. Since the entire surface or part of the layer or the undercoat coating film is continuously covered, the adhesion between the organic resin coating film expressing the pattern and the base treatment layer or the undercoat coating film is further increased.

  This will be described with reference to the schematic diagram of the pattern-printed metal plate in FIG. As will be described later, this pattern-printed metal plate is an example of a pattern-coated metal plate according to the present invention, and a top coat film 6 having a concavo-convex shape is formed on a metal plate 1 serving as a substrate via a base treatment layer 2. Is transcribed. Here, since the top coating film 6 has an island-like pattern (convex portion) and the top coating film 6 expresses a pattern appearance, the coating with the top coating film 6 having such an uneven shape is applied. Since the metal plate can continuously cover and conceal the entire surface or a part of the base treatment layer 2, the metal plate does not depend on the hue of the base treatment layer 2.

  This will be described with reference to the schematic diagram of the pattern-printed metal plate in FIG. As will be described later, this pattern-printed metal plate is another example of the pattern-coated metal plate according to the present invention, and an undercoat film 7 is provided between the base treatment layer 2 and the topcoat film 6 having an uneven shape. It is a pattern-coated metal plate when provided. It can be seen that the same effect can be obtained even in this case.

  (f) The above is a description of a coated metal plate provided with a top coat film having a concavo-convex shape and having a pattern appearance expressed by a convex portion or a concave portion of the top coat film, but the concavo-convex shape is formed in the top coat film. Instead of forming an uneven shape on the undercoat film, forming an overcoat film with a certain thickness on it, and expressing the pattern appearance on the topcoat film by the protrusions or recesses formed on the undercoat film Also good. That is, it is a coated metal plate provided with an upper coating film of a certain thickness covering the whole surface or a part of the undercoating film on at least one surface of the metal plate having the undercoating film through the base treatment layer, It may have a concavo-convex shape and continuously cover the entire surface or part of the base treatment layer or the undercoat coating film, and the top coating film may have a pattern appearance by the convex portions or concave portions of the undercoat coating film.

  This will be described with reference to the schematic diagram of the pattern-printed metal plate in FIG. As will be described later, this pattern-printed metal plate is another example of the pattern-coated metal plate according to the present invention, and an undercoating having a concavo-convex shape is provided on a metal plate 1 serving as a base material via a base treatment layer 2. The film 8 is transferred, and an overcoat film 9 having a constant film thickness is applied thereon. The uneven shape formed in the undercoat coating film is reflected in the topcoat coating film 9 so that the topcoat film 9 can have a pattern appearance. In this case, the undercoat film 8 having a concavo-convex shape continuously covers the whole surface or a part of the base treatment layer 2, and the top coat film 9 further covers the whole or a part of the undercoat film 8 having a concavo-convex shape. Since it can be continuously covered and concealed, it is not affected by the hue of the base treatment layer 2 or the undercoat film 8 having an uneven shape.

  (g) Instead of forming a convex pattern by interspersing the transferred organic resin paint, it is possible to continuously cover the entire surface or part of the undercoat or undercoat with the transferred organic resin paint. In order to form a top coat film having a concavo-convex shape, roll coating may be performed using an applicator roll having a smooth surface and a metal pickup roll having a gravure cell partially engraved on the surface. . That is, a metal gravure roll engraved with a gravure cell having a concave pattern on the surface of a smooth roll is used as a pickup roll, and the organic resin paint adhering to both the concave part and the roll smooth surface of the pickup roll is scraped with a blade or the like. What is necessary is just to transcribe | transfer to an applicator roll, and to transcribe | transfer the organic resin coating material on an applicator roll further to a metal plate, without taking.

  (h) First, roll coating will be described. In roll coating, a paint strip is applied to a steel strip wound around a backup roll using a pickup roll and an applicator roll. When the pickup roll rotates while contacting the paint in the paint pan, the paint is lifted to the pickup roll, and the thickness of the paint is adjusted by the gap between the pickup roll and the applicator roll, and the paint is applied to the applicator roll. Is transcribed. The paint whose thickness is adjusted is unwound from the coil, transferred to a steel strip that is wound around a backup roll so as to be in contact with the applicator roll, and is coated. The steel strip is then heated by suitable means, the coating is baked, and after cooling, it is wound on a coil.

  FIG. 6 shows a schematic diagram of roll coating of the two-roll / reverse method. In the two-roll / reverse method, the rotation direction of the applicator roll 21 is opposite to the conveying direction of the steel strip 20 to be coated. There is also a natural rotation method in which the rotation direction of the applicator roll 21 is the same as the conveying direction of the steel strip 20 to be coated. However, the reverse rotation method can be used for thicker coating, and coating is not generated. Since the finish is improved, the reverse rotation method is more often used in the manufacture of coated steel sheets. In the two-roll type roll coating using the pick-up roll 22 and the applicator roll 21, the coating thickness is controlled by the gap between these two rolls, so that the organic resin paint 25 smoothly fills this gap. The pick-up roll 22 is normally rotated naturally with respect to the applicator roll 21 so that it can pass through.

  (i) When performing such 2-roll / reverse roll coating, an applicator roll having a smooth surface and a metal pickup roll having a gravure cell partially engraved on the surface may be used.

  FIG. 7 is an example of a coating apparatus for producing a pattern-coated metal plate according to the present invention, as will be described later. A state in which a gravure cell pattern is transferred to an applicator roll 21 using a pick-up roll 22 having a gravure cell engraved on the surface, and further transferred to a steel strip 20 wound around a backup roll 23 is shown.

  That is, an organic resin paint 25 is picked up using a metal gravure roll engraved with a gravure cell (not shown) having a concave pattern on the surface of a smooth roll as the pickup roll 21, and the concave portion of the pickup roll 21 and the roll smoothness are picked up. The organic resin paint adhering to both surfaces may be transferred to the applicator roll 21 without scraping with a blade or the like, and then the organic resin paint adhering to the applicator roll 21 may be further transferred to a metal plate.

  (j) Although the top coat film is formed by the organic resin paint to be transferred, in order to express the pattern appearance by the convex part or the concave part of the top coat film, as the organic resin paint for forming the top coat film, Any one of (i) a paint containing scaly pigments, (ii) a low gloss paint, and (iii) a shrink paint may be used.

  (i) Since the gloss of the top coat film made of paint containing scaly pigments changes depending on the orientation of the scaly pigments in the paint film, it may become blackish or whitish depending on the viewing angle . When a top coat film having a concavo-convex shape in which organic resin paints are continuously connected is formed using a paint containing a flaky pigment, the orientation angle of the scaly pigment is obtained between the flat portion and the inclined portion of the concavo-convex shape. Therefore, the convex outline appears as a pattern. Also, instead of forming a concavo-convex shape on the topcoat film, a concavo-convex shape is formed on the undercoat film, a topcoat film of a certain thickness is formed thereon, and a convex or concave portion formed on the undercoat film The pattern appearance may be expressed in the top coat film. Since the uneven shape of the undercoat film is also reflected in the topcoat film, the convex outline of the topcoat film appears as a pattern in the same manner. In addition, as a scaly pigment, aluminum flakes, mica, etc. can be used.

  (ii) The low gloss paint is a fine silica particle or resin bead paint, and the surface of the top coat film is made to protrude upward from the surface of the top coat film of the silica particles or resin beads. A fine convex part is given to the film, and the gloss of the coating film can be lowered. As 60 degree gloss, it is generally 30 or less in the broad sense and 10 or less in the narrow sense. The gloss of such a low gloss paint changes due to the fine irregularities of the silica particles and resin beads on the surface of the top coat film. That is, if the silica particles or resin beads on the surface of the top coat film are large, the gloss becomes low, and if the degree of protrusion is small or does not protrude at all, the gloss becomes high. Therefore, when a top coat film having a concavo-convex shape is formed using a low gloss paint, the convex portions are likely to be high gloss and the concave portions are likely to be low gloss. Therefore, when an uneven top coat film is formed using a low-gloss paint, a pattern-coated metal plate consisting of high-gloss convex portions and low-gloss concave portions can be obtained. Also, instead of forming a concavo-convex shape on the topcoat film, a concavo-convex shape is formed on the undercoat film, a topcoat film of a certain thickness is formed thereon, and a convex or concave portion formed on the undercoat film The pattern appearance may be expressed in the top coat film. Since the uneven shape of the undercoat is also reflected in the topcoat, covering the uneven undercoat with a low-gloss topcoat is similar to a pattern consisting of high-gloss convex portions and low-gloss concave portions. A painted metal plate is obtained. In the case of a coating film made of a dark paint, the high gloss portion looks blackish and the low gloss portion looks whitish.

  (iii) A shrinkage paint is a paint that can form small wrinkles (fine irregular surfaces) on the surface of the paint film by utilizing the difference in curing speed between the paint film surface and the inside of the paint film. The gloss decreases. This gloss reduction method is also affected by the thickness of the coating film. That is, when a top coat film having a concavo-convex shape is formed using a shrink paint, the convex portion tends to form wrinkles and tends to be low gloss, and the concave portion is difficult to form wrinkles and tends to become high gloss. Therefore, when a top coat film having a concavo-convex shape is formed using a shrink paint, a pattern-coated metal plate composed of a low-gloss convex portion and a high-gloss concave portion is obtained. Also, instead of forming a concavo-convex shape on the topcoat film, a concavo-convex shape is formed on the undercoat film, a topcoat film of a certain thickness is formed thereon, and a convex or concave portion formed on the undercoat film The pattern appearance may be expressed in the top coat film. Since the uneven shape of the undercoat film is also reflected in the topcoat film, when the uneven undercoat film is covered with a topcoat paint made of shrinkage paint, it consists of low glossy convex parts and high glossy concave parts. A patterned metal sheet is obtained.

  The present invention has been completed based on the above findings (a) to (j), the gist of which is the coated metal plate shown in the following (1) to (9) and the following (10) and (10) This is a method for producing a coated metal sheet shown in 11).

  (1) A coated metal plate provided with a top coating film that continuously covers the entire surface or a part of the ground treatment layer on at least one surface of the metal plate subjected to the ground treatment, and the top coating film has an uneven shape. A coated metal plate excellent in design, characterized in that a pattern appearance is expressed by convex portions or concave portions of the top coat film.

  (2) A coated metal plate comprising a top coat film that continuously covers the entire surface or a part of the undercoat film on at least one side of the metal plate having the undercoat film through the base treatment layer, wherein the top coat film is A coated metal plate excellent in design, which has a concavo-convex shape and expresses a pattern appearance by convex portions or concave portions of a top coat film.

  (3) The coated metal plate having excellent design properties according to the above (1) or (2), wherein the top coat film contains a scaly pigment.

  (4) The coated metal plate having excellent design properties according to the above (1) or (2), wherein the top coat film comprises a low gloss paint.

  (5) The coated metal plate having excellent design properties according to the above (1) or (2), wherein the top coat film is made of a shrink paint.

  (6) A coated metal plate provided with a top coat film covering the whole or part of the undercoat film on at least one side of the metal plate having the undercoat film through the base treatment layer, wherein the undercoat film has an uneven shape. It has a design that is characterized in that the entire surface or part of the undercoat layer or undercoat film is continuously covered, and the pattern appearance is expressed in the topcoat film by the protrusions or recesses of the undercoat film. Excellent painted metal plate.

  (7) The coated metal sheet having excellent design properties according to (6) above, wherein the top coat film contains a scaly pigment.

  (8) The coated metal plate having excellent design properties as described in (6) above, wherein the top coat film comprises a low gloss paint.

  (9) The coated metal sheet having excellent design properties as described in (6) above, wherein the top coat film is made of a shrink paint.

  (10) A method for producing a coated metal plate having excellent design properties according to any one of (1) to (5) above, wherein an applicator roll having a smooth surface and a gravure cell are partially engraved on the surface A method for producing a coated metal sheet excellent in design, characterized in that a top coat film having an uneven shape is formed by roll coating using a metal pickup roll.

  (11) A method for producing a coated metal plate having excellent design properties according to any one of the above (6) to (9), wherein an applicator roll having a smooth surface and a gravure cell are partially engraved on the surface A method for producing a coated metal sheet excellent in design, characterized in that an undercoating film having irregularities is formed by roll coating using a metal pickup roll.

  According to the present invention, it is possible to provide a pattern-coated metal plate having good workability, pattern reproducibility and adhesion, and having excellent design properties, and a method for producing the same.

  Below, the coated metal plate excellent in the designability of this invention and its manufacturing method are demonstrated.

(1) Metal plate that is the base material of the painted metal plate:
The metal plate that is the base material of the painted metal plate is not particularly limited, and examples thereof include a cold-rolled steel plate, a stainless steel plate, and an aluminum plate.

  In the case of a coated metal plate used for indoor and outdoor building materials and for home appliances, a zinc-based or aluminum-based plated steel plate is preferable in terms of corrosion resistance and economy.

  The plated metal plate may be plated by any method such as hot dipping, electroplating, vapor phase plating, etc., and zinc, tin, aluminum, etc. and alloys thereof are used as the plating metal species. Specifically, a hot-dip galvanized metal plate, a hot-dip Zn—Al alloy-plated metal plate containing 5% Al, a hot-dip aluminum-plated metal plate, a hot-dip Al—Zn alloy-plated metal plate containing 55% Al, and the like can be mentioned. .

(2) About ground treatment:
In order to improve the adhesion between the base metal plate and the coating film, the metal plate serving as the base material of the coated metal plate forms a base treatment layer by applying a base treatment to the surface of the metal plate.

The ground treatment is performed by chemical conversion treatment such as zinc phosphate treatment and chromate treatment. As the chromate treatment, electrolytic or reactive chromate treatment can also be applied, but coating chromate treatment is preferable from the viewpoint of workability. The chromate adhesion amount in terms of metallic chromium is preferably in the range of ^{20 to} 80 mg / m ² . If the amount of chromate attached is too small, sufficient adhesion of the coating film cannot be obtained, and if it is excessive, workability will be reduced. One example of a commercially available coating-type chromate treatment solution suitable for use in the present invention is “NRC 300” manufactured by Nippon Paint Co., Ltd. The coating type chromate treatment liquid may be applied by a roll coater or the like according to a conventional method, heated to 50 to 100 ° C. with hot air and dried to carry out the ground treatment.

If it is not desired to perform chromate treatment using hexavalent chromium due to environmental problems, a chromium-free ground treatment containing silica, resin, zirconium or titanium can also be performed. One example suitable for use in the present invention is “Surfcoat EC2000” manufactured by Nippon Paint Co., Ltd., which is a silica-based surface treatment solution.
(3) About the undercoat film:
After applying the base treatment to the surface of the metal plate, a top coat film may be directly formed. However, depending on the application, particularly when corrosion resistance is required, one layer or two or more layers are formed under the top coat film. It is preferable to form an undercoat film.

  For example, epoxy-based, polyester-based, and urethane-based resins can be used as the paint for the undercoat coated on the metal plate serving as the base of the coated metal plate. A resin capable of forming a coating film having excellent adhesion to the metal plate and good workability is preferable. The solvent of the paint used may be either an aqueous or organic solvent, or may be a powder paint that does not use a solvent.

  Various types of epoxy paints are commercially available, and these may be used as appropriate. For example, an epoxy paint containing melamine, amine, or isocyanate as a crosslinking agent may be used. As the epoxy resin type, a bisphenol type epoxy resin is preferable.

  As an example of a polyester-type coating material, what mix | blended melamine and isocyanate as a crosslinking agent with the thermoplastic polyester resin is mentioned. As the polyester, a so-called high molecular weight polyester resin having a molecular weight of about 5,000 to 20,000 is preferable from the viewpoint of processability. As the crosslinking agent, melamine modified with ethyl alcohol or butyl alcohol can be used, and in some cases, paratoluenesulfonic acid, dodecylbenzenesulfonic acid, or the like can be appropriately used as a catalyst.

  Examples of urethane-based paints include those in which a polyester polyol is subjected to a crosslinking reaction with a yellowing polyisocyanate or a non-yellowing polyisocyanate. As examples of the crosslinking agent, isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HMDI) and the like can be used. In this case also, a catalyst such as dibutyltin dilaurate (DBTDL) may be used as appropriate.

  The paint for the undercoat film may contain two or more kinds of resin. The undercoating film may be a single layer, but may be two or more layers depending on the application. The undercoat coating film may contain additives such as rust preventive pigments. Examples of the rust preventive pigment include chromium-based rust preventive pigments such as strontium chromate and zinc chromate, and phosphate-based rust preventive pigments.

  The film thickness and shape of the undercoat film vary depending on the shape of the topcoat film formed on the undercoat film.

  That is, when the topcoat film is a coating film having a concavo-convex shape, a coating film with a constant film thickness is used, whereas when the topcoat film is a coating film with a constant film thickness, As the film, a coating film having an uneven shape is used.

  When a top coat film having a concavo-convex shape is provided, the pattern appearance is expressed by the convex part or the concave part formed in the top coat film. In this case, the undercoat coating film is a coating film having a constant film thickness, and is preferably a coating film thickness of about 1 to 30 μm as a dry film thickness. Adhesiveness and corrosion resistance are good when the coating thickness is 1 μm or more. However, when the coating thickness exceeds 30 μm, the corrosion resistance is saturated, but not only the cost increases, but also the workability decreases. In addition, depending on the type of resin, “waxing” occurs.

  On the other hand, when the top coat film is a coating film having a constant film thickness, the coating film having a concavo-convex shape is used as the undercoat film. Reflected in the surface shape, the pattern appearance is expressed by the convex portions or concave portions formed on the surface of the top coat film. In this case, the thickness of the undercoating film having an uneven shape is preferably about 10 to 30 μm in dry film thickness at the convex part, and 1 to 15 μm in dry film thickness at the concave part. It is preferable to set the degree. The thickness of the coating film may be determined as appropriate, but the coating thickness is preferably 5 μm or more at the uneven portion. If the coating film thickness is thick, the adhesion and corrosion resistance are good, but if it is too thick, the corrosion resistance is saturated, but not only the cost increases, but also the workability decreases. In addition, depending on the type of resin, “waxing” occurs.

  An undercoating paint having a certain film thickness is applied onto a metal plate subjected to a base treatment using an appropriate coating apparatus such as a roll coater. The coating may be performed not only by coating but also by electrostatic coating or electrodeposition coating using a spray coater.

  The undercoat paint having an uneven shape is applied onto a metal plate subjected to a ground treatment using an applicator roll having a smooth surface and a metal pickup roll having a gravure cell engraved on the surface.

  The viscosity of the paint is adjusted to 30 to 150 seconds with Ford Cup # 4, and after painting, it is heated and baked. The baking can be performed by baking for about 20 to 60 seconds so that the maximum temperature of the metal plate is about 150 to 230 ° C., and a conventional hot air blowing type oven or a heating method such as induction heating or infrared heating can be used. Available.

  The undercoat coating film may be baked at the same time as the coating of the topcoat film or before the coating of the topcoat film is applied.

(4) About top coat film:
The top coat film is formed directly or via an undercoat film on a metal plate subjected to a base treatment.

  The film thickness and shape of the topcoat film vary depending on the presence or absence of the undercoat film and the shape of the undercoat film.

  That is, when the top coat film is formed directly on the base treatment layer and when the top coat film is formed through a certain thickness of the undercoat film, the top coat film is a film having an uneven shape. On the other hand, when a coating film having a concavo-convex shape is used as the undercoat coating film, a coating film having a certain thickness is used as the top coating film.

  When a top coat film having a concavo-convex shape is provided, the pattern appearance is expressed by the convex part or the concave part formed in the top coat film. In this case, the thickness of the top coat film having a concavo-convex shape is preferably about 15 to 40 μm in dry film thickness at the convex part, and 10 to 30 μm in dry film thickness at the concave part. It is preferable to set the degree. The thickness of the coating film may be determined as appropriate, but the coating thickness is preferably 5 μm or more at the uneven portion. If the coating film thickness is thick, the adhesion and corrosion resistance are good, but if it is too thick, the corrosion resistance is saturated, but not only the cost increases, but also the workability decreases. In addition, depending on the type of resin, “waxing” occurs. If the coating film thickness is too thin, the concealability is poor and coloring may be insufficient. In addition, ultraviolet rays are likely to be transmitted through the undercoat layer, and the weather resistance may be poor. In addition, when the difference in the coating film thickness between the convex part and the concave part is too small, it is difficult to exhibit the design properties.

  On the other hand, when the top coat film is a coating film having a constant film thickness, the coating film having a concavo-convex shape is used as the undercoat film. Reflected in the surface shape, the pattern appearance is expressed by the convex portions or concave portions formed on the surface of the top coat film. In this case, the top coat film preferably has a dry film thickness of about 10 to 40 μm. The thickness of the coating film may be determined as appropriate, but the coating thickness is preferably 5 μm or more at the uneven portion. If the coating film thickness is thick, the adhesion and corrosion resistance are good, but if it is too thick, the corrosion resistance is saturated, but not only the cost increases, but also the workability decreases. In addition, depending on the type of resin, “waxing” occurs. If the coating film thickness is too thin, the concealability is poor and coloring may be insufficient. In addition, ultraviolet rays are likely to be transmitted through the undercoat layer, and the weather resistance may be poor. In addition, when the difference in the coating film thickness between the convex part and the concave part is too small, it is difficult to exhibit the design properties.

  The coating film of the top coat film having a concavo-convex shape was obtained by applying a ground treatment to a metal plate, or an applicator roll having a smooth surface and a gravure cell engraved on the surface directly or through an undercoat film of a certain thickness. It is painted using a metal pickup roll.

  The paint of the top coat film having a certain film thickness is applied on the metal plate subjected to the base treatment, on the base coat film having an uneven shape using an appropriate coating device such as a roll coater. . The coating may be performed not only by coating but also by electrostatic coating or electrodeposition coating using a spray coater.

  In the case where the top coat is applied through the undercoat paint film, the top coat paint is preferably applied after the undercoat paint is dried and cured.

  It does not specifically limit as an organic resin coating material which forms a top coat film. The paint of the top coat film can be appropriately selected according to the part of the product for which the coated metal plate is used, but it has excellent adhesion with the base treatment layer or the undercoat film. preferable.

  As the resin type used for the top coat, a fluorine-based resin can be used in addition to the resin type described above for the undercoat. When weather resistance and workability are required, polyester-based, urethane-based and fluorine-based resins are preferable. Specific embodiments of the epoxy-type, polyester-type and urethane-type resin types are the same as those described in the above (3) Undercoat film.

  Examples of the fluororesin paint include a mixture of an acrylic resin and PVdF (polyvinylidene fluoride). A mass ratio of 50:50 to 10:90 is preferred. The fluorine-based resin paint is particularly suitable for applications requiring weather resistance.

  The solvent of the paint used may be either an aqueous or organic solvent, or may be a powder paint that does not use a solvent.

  The paint for the top coat film may contain two or more kinds of resin. The top coat film may be a single layer, but may be two or more layers depending on the application. The top coat film may contain a color pigment as required.

  In a normal coated metal plate, it is sufficient to form only one layer of the top coat film, but it is also possible to make the top coat film into two or more layers depending on the purpose.

  The coating of the top coat can be baked in the same manner as described for the undercoat. The viscosity of the paint is adjusted to 30 to 150 seconds with Ford Cup # 4, and after painting, it is heated and baked. The top coating film can be baked by baking for about 40 to 80 seconds so that the maximum temperature reached by the metal plate is 180 to 250 ° C.

  In addition, it is necessary to perform baking of the top coat film before applying the paint of the top coat film.

(5) Other:
In addition, although the coating film according to this invention may be formed only in the single side | surface used as the outer plate | plate of a raw material, you may form in both surfaces of a raw material if desired. In the case of forming only on one side, the unpainted surface may be bare, or may be subjected only to a ground treatment, or may be coated differently from the present invention. When forming on both surfaces, the structure of the pattern coating film may be the same on both surfaces, or may be different.

A molten 55% Al—Zn alloy-plated metal plate (metal plate thickness: 0.35 mm) having a plating composition of Al: 55 mass%, Zn: 44 mass% and Si: 1 mass% is used as a base material. As a treatment, a coating type chromate treatment liquid (manufactured by Nippon Paint Co., Ltd. [NRC 300]) was applied with a bar coater so that the amount of chromium deposited was 30 mg / m ^2, and the maximum temperature reached 100 ° C. 5 The chromate treatment was applied by heating for 2 seconds and drying.

  Separately, prepare an epoxy paint (epoxy primer “NEP48” manufactured by Nippon Fine Coatings Co., Ltd.) as a paint to be used for the undercoat, and add thinner to make the paint viscosity 40 seconds in Ford Cup # 4. It was adjusted.

  In addition, a polyester resin-based metallic paint (“Metallic Paint SE506” manufactured by Nippon Fine Coatings Co., Ltd.) is prepared as a paint to be used for the top coating film, and the paint viscosity is 40 seconds in Ford Cup # 4. It was adjusted.

  Using the above-described chromate-treated Al—Zn alloy-plated metal plate (300 mm × 2000 mm), roll coating of the undercoat and topcoat was performed using a roll coater tester of a two-roll / reverse method.

  The roll coater testing machine used had a pick-up roll made of metal roll and an applicator roll lined with urethane rubber, and was placed on the lower side of the applicator roll, with a backup roll lined with urethane rubber, painted metal plate The substrate can be conveyed at a constant speed in the horizontal direction.

  The rotation direction of each roll is the same as that shown in FIG. 7, and the paint lifted by the pickup roll is transferred to the applicator roll by natural rotation and then transferred to the substrate by reverse rotation. .

  For the undercoating, a gravure roll engraved with an oval pattern was used as a pickup roll, and a dot pattern having a diameter of 5 mm was formed on a test coater (width 300 mm × length 1000 mm). The peripheral speeds of the pickup roll, applicator roll, and backup roll were 30 m / min, 96 m / min, and 80 m / min, respectively. The undercoating film after the undercoating was dried by baking for about 60 seconds so that the maximum reached temperature of the metal plate was 200 ° C. As a result, an undercoat coating film having a concavo-convex shape in which the central portion of the dot was recessed was formed. The thickness of the coating film was 15 μm at the convex part and 5 μm at the concave part.

  Next, after applying a metallic paint using a flat pickup roll on the undercoat film having the uneven shape, baking is performed for about 60 seconds so that the maximum temperature of the metal plate is 230 ° C. The top coat film was formed. Here, top coating films having three kinds of constant film thicknesses were obtained by changing various coating conditions. The film thickness of the top coating film was three types of 10 μm, 16 μm, and 23 μm at the time of drying.

  Each coated metal plate reflects the uneven shape of the undercoat film, and the pattern appearance is expressed on the surface of the topcoat film. It was emphasized and excellent in design. Moreover, the coating metal plate of any film thickness had good concealment properties, and no occurrence of cracks was observed.

In the same manner as in Example 1, a molten 55% Al—Zn alloy plated metal plate (metal plate thickness: 0.35 mm) having a plating composition of Al: 55 mass%, Zn: 44 mass%, and Si: 1 mass% is used as a raw material. As a base treatment on one side of this material, a coating type chromate treatment liquid (NRC 300 [NRC 300] manufactured by Nippon Paint Co., Ltd.) was applied with a bar coater so that the amount of chromium deposited was 30 mg / m ^2, and the maximum temperature reached The chromate treatment was carried out by heating for 5 seconds so as to be 100 ° C. and drying.

  In addition, as in the case of Example 1, an epoxy paint (epoxy primer “NEP48” manufactured by Nippon Fine Coatings Co., Ltd.) was prepared as the paint used for the undercoat film, and the paint viscosity was changed to Ford Cup # 4. Adjusted to 40 seconds.

  However, polyester resin matte black paint (“matte black paint MZ911” manufactured by Kansai Paint Co., Ltd.) is used as the paint for the top coat so that the viscosity of the paint is 80 seconds with Ford Cup # 4. Adjusted and used.

  Using the above-described chromate-treated Al—Zn alloy-plated metal plate (300 mm × 2000 mm), roll coating of the undercoat and topcoat was performed using a roll coater tester of a two-roll / reverse method. The roll coater testing machine used and the rotation direction of each roll are the same as in Example 1.

  The undercoat film is coated with an epoxy paint undercoat using a flat pick-up roll so that the dry film thickness is 5 μm, and then the maximum temperature of the metal plate is about 200 ° C. It was formed by baking for 60 seconds.

  Next, in the same manner as in Example 1, a gravure roll engraved with a rectangular pattern was used as a pickup roll, and a square pattern with a side of 50 mm was formed with a test coater (width 300 mm × length 1000 mm). The peripheral speeds of the pickup roll, applicator roll, and backup roll were 30 m / min, 96 m / min, and 80 m / min, respectively. The top coating film after top coating was dried by baking for about 60 seconds so that the maximum temperature reached by the metal plate was 230 ° C. As a result, a top coat film having a concavo-convex shape in which the center part of the dots protruded was formed. The thickness of the top coat film was 20 to 25 μm at the convex portion and 10 to 15 μm at the concave portion.

  This coated metal plate had a pattern appearance on the surface of the top coat film due to the uneven shape of the top coat film, had a dot pattern with different gloss), and was excellent in design. The convex portion had a high gloss and a glossiness of 10 to 12, and the concave portion had a low gloss and a glossiness of 5 to 8. In addition, this coated metal plate had good concealability and no occurrence of cracks.

  In addition, the measurement of glossiness cut out the recessed part and the convex part, respectively, and measured it with the glossiness meter.

  According to the present invention, it is possible to provide a coated metal plate having good workability, pattern reproducibility and adhesion, and excellent in design, and a method for producing the same.

It is an example of a pattern printing metal plate. It is an example of a pattern coating metal plate. It is an example of the pattern coating metal plate which concerns on this invention. It is another example of the pattern coating metal plate which concerns on this invention. It is another example of the pattern coating metal plate which concerns on this invention. A schematic diagram of two-roll / reverse roll coating is shown. It is an example of the coating apparatus for manufacturing the pattern coating metal plate which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal plate 2 Ground treatment layer 3 Coating film 4 Ink layer 5 Pattern coating film 6 Top coat film which has uneven shape 7 Undercoat film 8 Undercoat film which has uneven shape 9 Top coat film 20 Steel strip 21 Applicator roll 22 Pickup Roll 23 Backup roll 25 Organic resin paint

Claims (11)

  It is a coated metal plate provided with a top coat film that continuously covers the entire surface or a part of the base treatment layer on at least one side of the metal plate subjected to the base treatment, and the top coat film has an uneven shape, A coated metal plate excellent in design, characterized in that a pattern appearance is expressed by convex portions or concave portions of a top coat film.   A coated metal plate having a top coat film that continuously covers the entire surface or a part of the undercoat film on at least one side of the metal plate having the undercoat film through the base treatment layer, wherein the top coat film has an uneven shape. A coated metal sheet having excellent design characteristics, characterized by having a pattern appearance expressed by convex portions or concave portions of the top coat film.   The coated metal plate excellent in design properties according to claim 1 or 2, wherein the top coat film contains a scaly pigment.   The coated metal sheet having excellent design properties according to claim 1 or 2, wherein the top coat film is made of a low gloss paint.   The coated metal sheet having excellent design properties according to claim 1 or 2, wherein the top coat film is made of a shrink paint.   A coated metal plate comprising a top coat film covering the entire surface or a part of the undercoat film on at least one side of the metal plate having the undercoat film through the base treatment layer, the undercoat film has an uneven shape, and Coating with excellent design, characterized by continuously covering the entire surface or part of the undercoat layer or the undercoat film, and expressing the pattern appearance on the topcoat film by the convexity or recesses of the undercoat film Metal plate.   The coated metal sheet having excellent design properties according to claim 6, wherein the top coat film contains a scaly pigment.   The coated metal plate having excellent design properties according to claim 6, wherein the top coat film is made of a low gloss paint.   The coated metal plate excellent in design properties according to claim 6, wherein the top coat film is made of a shrink paint.   A method for producing a coated metal plate having excellent design properties according to any one of claims 1 to 5, wherein the applicator roll has a smooth surface and a metal pickup in which a gravure cell is partially engraved. The manufacturing method of the coating metal plate excellent in the designability characterized by forming the top coat film which has uneven | corrugated shape by roll coating using a roll.   A method for producing a coated metal plate having excellent design properties according to any one of claims 6 to 9, wherein the applicator roll has a smooth surface, and the metal pickup has a gravure cell partially engraved on the surface. The manufacturing method of the coating metal plate excellent in the designability characterized by forming the base coat film which has uneven | corrugated shape by roll coating using a roll.

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