JP2007244992A - Metallic tone coated metallic sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metallic tone coated metallic sheet having high light resistance and chemical resistance and excellent durability. <P>SOLUTION: A metallic tone coating film containing stainless powder and at least one of an ultraviolet absorbent and a light stabilizer is applied on a metallic sheet. Metallic luster is given to the coating film with the stainless powder to exhibit high designing property, has high weather resistance and chemical resistance and is capable of suppressing discoloration or occurrence of blister on the coating film even when exposed to outdoors for a long period of time to exhibit excellent durability. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a metallic paint metal plate having a coating film to which a bright pigment is added.

  Conventionally, a coated metal plate obtained by pre-coating a metal plate such as a stainless steel plate or a plated steel plate has been widely used in the field of building materials and the like, and aluminum flakes are dispersed as such a coated metal plate. Some of them have a metallic metallic coating with glitter (see Patent Document 1).

  Such a metallic-tone coated metal plate has a high design property in which a metallic luster is imparted to the coating film, and has a high heat shielding property because of high solar heat reflectivity.

  However, even for aluminum, which is generally said to have high stability, when a coating film containing this aluminum flake is exposed outdoors for a long period of time, the aluminum flake in the coating will change color, causing discoloration of the coating film. In addition, blistering may occur in the coating film when it is attacked by acid or alkali. For this reason, when using metallic-coated metal sheets as exterior building materials, etc., the appearance deteriorates over time, and it is necessary to refurbish, such as repainting or replacing metallic-coated metal sheets. Due to recent demands for resource saving, it has been demanded to improve the durability of metallic-coated metal sheets and increase the time required for refurbishment.

Therefore, a metallic paint plate using stainless steel flakes instead of aluminum flakes as a luster pigment is also conceivable. In this case, the weather resistance and chemical resistance can be improved as compared with the case of using aluminum flakes. It has been demanded to improve the durability.
JP 2001-29883 A, paragraph 0043

  The present invention has been made in view of the above points, and an object of the present invention is to provide a metallic paint metal plate having high light resistance and chemical resistance and excellent durability.

  The metallic coating metal plate according to the present invention is characterized in that a metallic coating film containing stainless steel powder and at least one of an ultraviolet absorber and a light stabilizer is formed on the metallic plate.

  The stainless steel powder is preferably scaly.

  Moreover, it is preferable that the said metallic tone coating film is a coating film of the polyester resin-type coating material or fluororesin-type coating material which contains stainless steel powder and contains at least one among an ultraviolet absorber and a light stabilizer.

  According to the present invention, it is possible to impart a metallic luster to the coating film with stainless steel powder to reveal a high designability, and it has high weather resistance and chemical resistance. It is possible to suppress the occurrence of discoloration and blistering and to exhibit excellent durability.

  Moreover, when a scaly thing is used as a stainless steel powder, the metallic luster which was further excellent in metallic-tone coating film can be provided, and the design property can be improved further.

  Furthermore, when the metallic coating film is formed of a polyester resin-based paint or a fluororesin-based paint film, good workability and excellent durability can be imparted as a pre-coated metal plate.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The metal plate used in the present invention is not particularly limited, and examples thereof include an aluminum plated steel plate, a galvanized steel plate, an aluminum-galvanized steel plate, a stainless steel plate, and a mild steel plate. Moreover, as such a metal plate, a long thing can be used.

  A chemical conversion treatment layer can be formed on the metal plate prior to the formation of the coating film. Examples of the chemical conversion treatment layer include a chromate (chromate) treatment layer, a phosphate treatment layer, and a composite oxide film formation.

  In the formation of the chromate (chromate) treatment layer, the surface of the metal plate can be treated with an aqueous solution containing hexavalent chromium and an inorganic acid such as sulfuric acid. A layer made of a hydrated oxide containing chromium is formed. Moreover, a phosphate process layer is a layer which consists of a tertiary phosphate formed by processing the metal plate surface using the aqueous solution containing a primary phosphate and phosphoric acid. Examples of the type of phosphate include zinc phosphate, manganese phosphate, and iron phosphate. In addition, the thickness of the chemical conversion treatment layer is generally in the range of 1 to 2 μm in the case of the phosphate treatment layer.

  Moreover, an undercoat coating film can also be formed on a metal plate as needed. In the case of forming an undercoat film, the paint (undercoat paint) is, for example, a thermosetting resin varnish such as an epoxy resin varnish or an epoxy urethane resin varnish, an extender pigment such as titanium oxide, fine powder clay, or calcium carbonate, An epoxy resin paint in which a rust pigment or the like is dispersed can be used. As the rust preventive pigment, for example, those mainly composed of chromate salts such as strontium chromate, calcium chromate, barium chromate, potassium chromate and the like can be used. It is preferable to make it contain in 15-60 weight% with respect to a component.

  In the undercoating, an undercoating material having the above composition is applied to one surface of the metal plate, and in some cases, the undercoating material is applied to the other surface of the metal plate. Further, a back coating material having a composition different from that of the base coating material may be applied to the other surface of the metal plate. Application of the undercoating material or the back coating material can be performed by an appropriate application device composed of dipping, spraying, brushing, roll coater, air knife, electrostatic coating or the like.

  After the primer coating is applied, the metal plate can be baked and cured by continuously passing the metal plate through a heating furnace or the like to form the primer coating film.

  The thickness of the undercoat coating film is not particularly limited and is appropriately set, but is preferably in the range of 3 to 25 μm.

  Next, a coating film (metallic coating film) containing stainless steel powder is formed on the surface of the metal plate. As a paint for forming a metallic paint film (metallic paint), a polyester resin paint or a fluororesin paint is preferably used, but an acrylic resin, a vinyl chloride resin, a urethane resin, an epoxy resin. An appropriate coating material such as a modified epoxy resin system, a silicone resin system, or an alkyd resin system may be used.

  In this metallic paint, stainless steel powder is blended as an essential component as described above, thereby giving a metallic luster to the metallic paint metal sheet and exhibiting an excellent design, as well as high heat shielding properties. . As the stainless steel powder in the metallic tone coating film, it is particularly preferable to use scaly stainless powder (stainless flakes). In this case, particularly excellent metallic luster is imparted to the metallic tone coating film.

  The average particle size of such stainless steel powder is preferably in the range of 5 to 150 μm. Within this range, it is possible to ensure excellent durability of the coated metal plate, and if it is not less than this range, it will be difficult to impart sufficient durability. There is sex.

  The content of the stainless steel powder is not particularly limited, but is preferably in the range of 5 to 20% by weight with respect to the total amount of the resin component in the metallic paint. Within this range, it is possible to ensure excellent durability of the coated metal plate, and if it is not less than this range, it will be difficult to impart sufficient durability. There is sex.

  The metallic paint contains at least one of an ultraviolet absorber (UVA) and a light stabilizer (HALS).

  As the ultraviolet absorber, a benzotriazole ultraviolet absorber as shown in the following formula (1), a hydroxyphenyl triazine ultraviolet absorber as shown in the following formulas (2) to (7), etc. can be used. May be used alone or in combination of two or more. Examples of such UV absorbers include product numbers “TINIVIN 384-2”, “TINIVIN 400”, “TINIVIN 411L”, “TINIVIN 900”, “TINIVIN 928” and the like provided by Ciba Specialty Chemicals Co., Ltd. Can be used.

  Further, as the light stabilizer (HALS), high molecular weight type hindered amine light stabilizers as shown in the following formulas (8) and (9), and hindered amine light stabilizers as shown in the following formulas (10) to (13). These can be used alone or in combination of two or more. Examples of such light stabilizers include product numbers “TINUVIN 111 FDL”, “TINUVIN 123”, “TINUVIN 144”, and “TINUVIN 292” provided by Ciba Specialty Chemicals.

  The metallic paint may contain only one of these ultraviolet absorbers and light stabilizers, but it is more preferred to contain both of them. At this time, the contents of the UV absorber and the light stabilizer are appropriately adjusted. However, if these contents are excessive, the metallic paint film may be yellowed, and the metallic paint is stored. Sometimes, in a low temperature environment, the ultraviolet absorber or the light stabilizer is likely to crystallize and aggregate, and it may be difficult to regenerate it. Therefore, when only the ultraviolet absorber is contained in the metallic paint, the content is preferably in the range of 1 to 3% by weight with respect to the total amount of the resin component in the metallic paint, and only the light stabilizer is included. When it contains, it is preferable to make the content into the range of 1-3 weight% with respect to the resin component whole quantity. When the ultraviolet absorber and the light stabilizer are used in combination, the content of the ultraviolet absorber is in the range of 0.5 to 3% by weight relative to the total amount of the resin component, and the content of the light stabilizer is the total amount of the resin component. On the other hand, it is preferable that the range is 0.5 to 3% by weight, and the total amount of both is preferably 1 to 5% by weight with respect to the total amount of the resin components.

  In addition, an appropriate colorant may be contained in this metallic paint. Specific examples of the colorant include titanium oxide, carbon black, iron oxide yellow, iron oxide red (Bengara), aluminum flakes, mica flakes, colored glass flakes, and organic blue (phthalocyanine blue) as pigments. Examples of the dye include “AIZEN SPILON dye series” manufactured by Hodogaya Chemical Co., Ltd. The blending ratio of such a colorant in the metallic paint is preferably 20% by weight or less based on the total amount of resin components in the metallic paint.

  The metallic paint film can be formed by coating and forming the above metallic paint in an appropriate manner. For example, apply metallic paint by roll coating, spray coating, curtain flow coating, bar coater coating, roller curtain coating, dip coating, etc., and under appropriate conditions depending on the properties of the metallic paint as necessary. It can be cured by heating to form a metallic coating film. Alternatively, the metallic paint film may be formed by a film laminating method using a film in which a metallic paint is previously formed.

  Moreover, you may provide further weather resistance to a metallic tone coating metal plate by forming a clear coating film as needed in the outer side of a metallic tone coating film. As the clear paint for forming the clear coating film, appropriate ones such as a thermosetting transparent paint such as polyester and a thermoplastic transparent paint such as fluorine can be used. The clear coating can be applied by an appropriate coating apparatus including dipping, spraying, brushing, roll coater, air knife, electrostatic coating and the like. And after application | coating of a clear coating material, a metal plate can be baked and hardened by passing a metal plate continuously at a heating furnace etc., and a clear coating film can be formed.

  Although the thickness of a clear coating film is adjusted suitably, it is preferable to make it become the range of 2-25 micrometers.

  In the metallic coating metal plate configured as described above, the stainless steel powder contained as a glitter pigment in the metallic coating film is less likely to be discolored when irradiated with sunlight. Since at least one of the ultraviolet absorber and the light stabilizer is contained in the film, the occurrence of discoloration due to the irradiation of the stainless powder with sunlight is further suppressed. Moreover, when this metallic-tone coating film contains colorants, such as pigments and dyes other than stainless steel powder, the discoloration of the colorant when the coating film is irradiated with sunlight is also suppressed. Thereby, when using a metallic paint metal plate for an exterior material, it can suppress remarkably that yellowing and discoloration generate | occur | produce in a coating film even if it exposes outdoors for a long period of time.

  Moreover, this metallic-tone coating film has high chemical resistance, and when it is attacked by acid or alkali, the generation of blisters is suppressed.

  For this reason, the metallic coating metal plate as described above has high durability, and even if it is exposed to the outdoors for a long period of time, it can be used suitably as an exterior building material because it suppresses discoloration and blistering of the coating film. It can be done.

(Examples 1-12, Comparative Examples 1-4)
Galvalume steel plate (registered trademark, JIS-SGLCC, thickness 0.35 mm) manufactured by Nippon Steel & Steel Co., Ltd. was used as the metal plate, and this surface was coated with a coating type chromate solution (Nippon Parkerizing Co., Ltd., product number ZM-1300AN). Chemical conversion treatment was performed.

  Next, the undercoat paint shown in Table 1 was applied and baked and cured by heating at a final reached plate temperature of 200 ° C. for 30 seconds to form an undercoat paint film having the thickness shown in Table 1.

  Next, a metallic paint having the composition shown in Table 1 below is applied to the surface of the undercoat coating film, and it is baked and cured by heating at a final reached plate temperature of 230 ° C. for 30 seconds to form a metallic paint having a film thickness of 15 μm. A film was formed to obtain a metallic paint metal plate.

  Here, the product name “NSC667 Primer” manufactured by Nippon Fine Coatings Co., Ltd. or the product number “FX31P” manufactured by BASF Coatings Japan Co., Ltd. was used as the primer coating.

  Further, as the base paint of the metallic paint, the product number “HD0030” manufactured by BASF Coatings Japan Co., Ltd. was used as the polyester paint, and the product number “8800” manufactured by BASF Coatings Japan Co., Ltd. was used as the fluorine-based paint.

  In addition, stainless steel flakes “RFA2000 (average particle size 50 μm)” and “RFA4000 (average particle size 100 μm)” manufactured by Toyo Aluminum Co., Ltd. were used as the scaly stainless powder.

  Moreover, “TINUVIN400” manufactured by Ciba Specialty Chemical Co., Ltd. is used as an ultraviolet absorber (UVA), and “TINUVIN144” manufactured by Ciba Specialty Chemical Co., Ltd. is used as a light stabilizer (HALS). After dissolving in xylol, it was blended.

  In addition, as a colorant, “FASTOGEN Blue GFA” manufactured by Dainippon Ink & Chemicals, Inc. is used as a blue colorant, and “FASTOGEN Super Red 400RG” manufactured by Dainippon Ink & Chemicals, Inc. is used as a red colorant. The hue of the coating film appearing with the agent is shown in Table 1 below. “(Silver)” indicates that the color of the metal powder appears without containing a colorant.

(Weather resistance test)
The surface of the metallic coating film of the metallic coating metal plate obtained in each example and comparative example was irradiated with light from a carbon arc with a sunshine weatherometer (manufactured by Suga Test Instruments Co., Ltd.) at a black panel temperature of 63 ° C. The surface color difference of the metallic tone coating film was measured with a color difference photometer.

(Acid resistance test)
The metallic coated metal plate obtained in each Example and Comparative Example was immersed in an acidic solution of 5% HCl aqueous solution for 24 hours, and the color difference of the surface after immersion was measured with a color difference photometer.

(Alkali resistance test)
The metallic coated metal plate obtained in each Example and Comparative Example was immersed in 5% NaOH aqueous solution that is an alkaline solution for 24 hours, and the color difference of the surface after immersion was measured with a color difference photometer.

  The above results are also shown in Table 1.

  As is apparent from the results, in each Example, a coated metal plate having excellent weather resistance, acid resistance, and alkali resistance and overall performance superior to those of each Comparative Example was obtained.

  Moreover, in Example 1, compared with the comparative example 1 which has the same composition except not containing a ultraviolet absorber and a light stabilizer, especially a weather resistance improves and also compared with the comparative example 2 which used aluminum powder as metal powder. As a result, the weather resistance, acid resistance, and alkali resistance were all improved.

  Moreover, in Example 5, compared with the comparative example 3 which has the same composition except not containing a ultraviolet absorber and a light stabilizer, especially a weather resistance improved and compared with the comparative example 4 which used aluminum powder as metal powder. As a result, the weather resistance, acid resistance, and alkali resistance were all improved.

Claims (3)

  A metallic-coated metal sheet comprising a metallic-coated film containing stainless steel powder and at least one of an ultraviolet absorber and a light stabilizer.   2. The metallic paint metal plate according to claim 1, wherein the stainless steel powder has a scale shape.   The metallic paint film is a polyester resin paint or a fluororesin paint film containing stainless steel powder and containing at least one of an ultraviolet absorber and a light stabilizer. Metallic-tone painted metal sheet according to 2.