JP2019111750A - Coated metal plate and exterior building material using the same - Google Patents

Abstract

To provide a coated metal plate which not only has high scratch resistance and abrasion resistance during construction and after construction but also prevents occurrence of scratches and coated film powder also during transportation.SOLUTION: A coated metal plate includes a metal plate and a top coated film arranged on the metal plate. The top coated film contains a resin and a particulate impact cushioning material, and the impact cushioning material is composed of a material having a durometer hardness of 70 or more or Vickers hardness of 30 or less, is not broken even at a compressive strength of 4,900 mN, and has an average particle size equal to or larger than an average thickness of the top coated film.SELECTED DRAWING: None

Description

  The present invention relates to a coated metal plate and an exterior building material using the same.

  The coated metal sheet is excellent in versatility, designability, durability and the like, and thus is suitable for various uses, and is often used, for example, for exterior building materials. In the coated metal plate used for such an exterior construction material, it is necessary to suppress the damage | wound of a coating film and the abrasion of a coating film which generate | occur | produce at the time of construction and use after construction. If the coating film is damaged or worn, rust may occur from the portion. Therefore, it has been studied to improve surface hardness by adding hard particles in the coating film, and to improve surface slippage by including a lubricant such as wax.

  For example, Patent Document 1 proposes that a coating composed mainly of a polyester resin includes an aggregate composed of an organic resin, an aggregate composed of an inorganic material, and a lubricant composed of polytetrafluoroethylene. .

JP-A-8-183928

  When various aggregates are contained in a coating film like the said patent document 1, a coating film will become hard and it will become difficult to produce a damage | wound in a coating film at the time of construction, or after construction. However, when the coating film contains hard particles having a large particle size, even if the lubricant is contained, the top coat film is easily damaged during transport of the coated metal sheet. Specifically, when transporting a plurality of coated metal plates, top coats of the coated metal plates may be arranged and loaded so as to face each other. When vibration was transmitted from the vehicle or the like in such a state, hard particles of one top coat film were likely to scrape the other top coat film, and it was easy to cause a scratch on the top coat film. In addition, when a load is applied to the surface of the topcoat film during transportation of the coated metal sheet, the hard particles may be broken or dropped off to generate coating powder. And, such coating powder works like an abrasive between facing top coats. Accordingly, there is also a problem that the surface of the top coat film is further damaged. That is, in the case of the coated metal sheet containing the conventional very hard particle | grains, although the damage resistance at the time of construction or after construction can be improved, it was difficult to improve the damage resistance at the time of transport.

  The present invention has been made in view of such a point, and is not only high in scratch resistance and wear resistance at the time of construction and after construction, but also is a coated metal sheet in which scratches and coating powder are less likely to occur during transportation. The purpose is to provide

The first of the present invention is the following coated metal plate.
[1] A coated metal plate having a metal plate and a top coat film disposed on the metal plate, wherein the top coat film includes a resin and a particulate shock absorbing material, and the shock buffer The coated metal sheet is made of a material having a Type D durometer hardness of 70 or more or a Vickers hardness of 30 or less, not broken even at a compressive strength of 4900 mN, and having an average particle diameter of at least the average thickness of the topcoat film. .

[2] The coated metal plate according to [1], wherein the resin is a polyester resin.
[3] The coated metal sheet according to [1] or [2], wherein the average particle diameter of the shock absorbing material is 1 to 4 times the average thickness of the topcoat film.
[4] The coated metal sheet according to any one of [1] to [3], which further has a primer coating film between the metal plate and the top coat film.
[5] The coated metal sheet according to any one of [1] to [4], which is a coated metal sheet for exterior.

A second aspect of the present invention is the following exterior building material.
[6] An exterior building material, which is made of the coated metal plate according to any one of the above [1] to [5].

  According to the present invention, not only scratch resistance and wear resistance at the time of construction and after construction are high, but also a coated metal plate which hardly generates scratches and coating powder even during transportation thereof, and an exterior building material using the same Can be provided.

It is a figure which shows the test method of evaluation 2 of damage resistance in an Example.

(About painted metal plate)
The coated metal sheet according to the present invention has a metal sheet and a top coat film disposed on the metal sheet. The coated metal sheet may contain a configuration other than the metal sheet and the top coat, and for example, an undercoat may be disposed between the metal sheet and the top coat if necessary. Good. The coated metal sheet of the present invention is suitably used, for example, for exterior building materials and the like, but is not limited thereto.

  Here, the kind in particular of the metal plate contained in a paint metal plate is not restrict | limited, According to the use, it can select suitably from a well-known metal plate. Examples of the metal 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 (austenite, martensite, ferrite, ferrite, Included are martensitic two-phase systems), aluminum plates, aluminum alloy plates, copper plates and the like. When the coated metal sheet is used for the exterior building material, the metal sheet is preferably a plated steel sheet from the viewpoint of corrosion resistance, lightness, etc., and a 55% hot-dip Al-Zn alloy plated steel sheet, a Zn-Al-Mg alloy plated steel sheet, Or it is more preferable that it is an aluminum plating steel plate.

  The metal plate may have a chemical conversion coating on its surface. When the chemical conversion treatment film is formed on the surface of the metal plate, the adhesion between the top coat film (or undercoat film) and the metal plate is enhanced, and the corrosion resistance of the metal plate is further enhanced. The type of chemical conversion treatment is not particularly limited, and examples thereof include chromate treatment, chromium free treatment, phosphate treatment and the like. From the viewpoint of reducing the environmental load, chromium-free chemical conversion treatment is preferable. Examples of chromium-free chemical conversion coatings include Ti-Mo composite coatings, fluoroacid coatings, resin coatings, resins and silane coupling agent coatings, silica coatings, silica and silane coupling agent coatings, zirconium coatings Films, zirconium and silane coupling agent-based films, etc. are included.

The preferable adhesion amount of a chemical conversion treatment film is suitably selected according to the kind of chemical conversion treatment film. For example, in the case of a chromate film, the total Cr equivalent adhesion amount is preferably 5 to 100 mg / m ² . On the other hand, the adhesion amount of the Ti-Mo composite film formed by the chromium-free chemical conversion treatment is preferably 10 to 500 mg / m ² in terms of total Ti and Mo, and the adhesion amount of the fluoro acid film is fluorine It is preferable that it is 3-100 mg / m < ² > in conversion or total metal element conversion.

The adhesion amount of the resin-based film is preferably ¹ to 500 mg / m ² in terms of resin, and the adhesion amount of the resin and the silane coupling agent film is 0.1 to 50 mg / m ² in terms of Si. Is preferred. Furthermore, the adhesion amount of the silica-based film is preferably 0.1 to 200 mg / m ² in terms of Si, and the adhesion amount of the silica and the silane coupling agent film is 0.1 to 200 mg / m in terms of Si. It is preferable that it is ² . Furthermore, the adhesion amount of the zirconium-based film is preferably 0.1 to 100 mg / m ² in terms of Zr, and the adhesion amount of the zirconium and silane coupling agent film is 0.1 to 100 mg / m in terms of Zr. It is preferable that it is ² . Furthermore, it is preferable that the adhesion amount of the phosphate film formed by phosphate process is 0.1-5 g / m < ² > in conversion of phosphorus element.

  The chemical conversion film is formed by applying a chemical conversion solution for forming the film on the surface of the metal plate by a known method such as roll coating, spin coating or spraying, and washing the metal plate after application. It is possible to form by drying without. The drying temperature and the drying time of the metal plate can be, for example, 60 to 150 ° C. at the ultimate temperature of the metal plate from the viewpoint of productivity, and the drying time can be 2 to 10 seconds.

  On the other hand, the top coat film contained in the coated metal plate may contain a resin (binder) and a particulate shock absorbing material, but other components may be contained as required.

  Here, the shock absorbing material contained in the top coat film is made of a material having a Type D durometer hardness of 70 or more or a Vickers hardness of 30 or less, is in the form of particles, and does not break even at a compressive strength of 4900 mN, and its average The particle diameter is equal to or greater than the thickness of the top coat film. For shock absorbers, Vickers hardness is measured when Vickers hardness can be measured, and it is difficult to measure Vickers hardness (when the material is highly elastic, such as recovery from scratches or no damage) Measure the durometer hardness. That is, that the durometer hardness is 70 or more means that a relatively high impact shock absorber has a certain hardness or more. On the other hand, having a Vickers hardness of 30 or less means that a relatively low impact cushioning material has a certain degree of softness or more. Therefore, the shock absorbing material satisfying the durometer hardness or the Vickers hardness has an appropriate hardness.

  As described above, when the topcoat film contains hard particles having a large particle diameter, the hardness of the coating film is increased, and the scratch resistance at the time of application and after application is enhanced. However, when the topcoat films are arranged to face each other (for example, during transportation), the opposing topcoat films tend to be damaged. On the other hand, when the particles contained in the topcoat film become excessively soft, the hardness of the topcoat film decreases, and when in contact with a hard object, the topcoat film is easily damaged. In addition, if the particles are excessively soft, for example, when an object comes in contact with the top coat, the particles are deformed and the contact area of the particles is increased. As a result, their lubricity deteriorates and the top coat tends to wear.

  On the other hand, the shock absorber used in the present invention has an appropriate hardness as described above. Therefore, even if the top coats are arranged to be opposed to each other, it is difficult for the opposed top coats to be scratched by appropriate deformation of the shock absorbing material. On the other hand, the shock absorbing material has an appropriate hardness (hard to a certain extent). Therefore, the hardness of the topcoat film can be sufficiently increased, and even if a hard object comes into contact with the topcoat film, it is hard to be damaged. Furthermore, since the shock absorber does not deform excessively, it is possible to keep a small contact area with an object in contact with the top coat. Therefore, the abrasion resistance of the top coat is also improved.

  Here, the above-mentioned "type D durometer hardness" is measured according to JIS K6253-3: 2012 (how to determine the hardness of vulcanized rubber and thermoplastic rubber type D (corresponding to ISO 7619-1: 2010)) Value. More specifically, after a sample made of impact shock absorbing material or the same material is formed into a bulk, it is measured by a rubber / plastic hardness tester (for example, an IRHD hardness tester manufactured by TEFLOCK, GS-680sel, etc.) Value. The durometer hardness of the material constituting the shock absorbing material is more preferably 70 to 100, and still more preferably 75 to 100.

  On the other hand, Vickers hardness is a value measured according to JIS Z 2244: 2009 (Vickers hardness test-test method (corresponding to ISO 6507-4: 2005)). Also in this method, after a sample made of impact shock absorbing material or the same material as that of the shock absorbing material is formed into a bulk shape, a Vickers hardness tester (for example, Micro Vickers hardness tester manufactured by Mitutoyo, HM-200 system C, etc.) is used. It is a value measured at a test force of 98 mN. The Vickers hardness of the material constituting the shock absorbing material is more preferably 25 or less, and still more preferably 20 or less.

  Further, the shock absorbing material (particles) used in the present invention does not break even at a compressive strength of 4900 mN. In the present specification, "does not break even at a compressive strength of 4900 mN" means that the shock absorber is elastically deformed even at a compressive strength of 4900 mN. Whether or not the impact shock absorber is broken at a compressive strength of 4900 mN, for example, using a micro compression tester (MCT-W) manufactured by Shimadzu Corporation, the impact shock absorber is an upper addition consisting of a flat indenter of diamond 50 μm in diameter. It can be judged from the shape of the shock absorbing material after being sandwiched between the pressure indenter and the lower pressure plate made of alloy tool steel SKS, given a load speed of 4.9 mN / sec, and compressed to 4900 mN.

  Even with the above-mentioned appropriate hardness, it is difficult to keep the contact area between the top coat film and the object in contact with the top coat film small with an impact shock absorber which breaks when a load is applied. The lubricity of the surface can not be maintained. Furthermore, when the coating film pieces of irregular shape generated by breakage act like an abrasive, the top coat film is easily scratched. On the other hand, if it is the shock absorbing material which can endure compressive strength 4900 mN, scratch resistance and abrasion resistance can be made good at the time of transportation of a painting metal plate, construction time, and after construction.

  The average particle diameter of the shock absorbing material may be larger than the average thickness of the top coat described later, but is preferably 1 to 4 times the average thickness, and more preferably 1 to 2 times. If the average particle size of the impact shock absorber is larger than the average thickness of the topcoat film, as described above, the contact area between the topcoat film and the object in contact with the topcoat film can be reduced. The abrasion resistance of the film is improved. Here, the average particle size of the shock absorbing material can be an average value of the particle sizes of ten or more shock absorbing materials when observing the cross section of the top coat film. In addition, it is preferable that it is 10 micrometers-50 micrometers, and, as for the average particle diameter of a shock absorbing material, it is more preferable that it is 15-30 micrometers. On the other hand, the average thickness of the topcoat film can be an average value of the thickness of ten or more points in the region not including the shock absorbing material when the cross section of the topcoat film is observed.

  The amount of the shock absorbing material contained in the top coat film is preferably 0.01 to 15% by volume, and more preferably 0.6 to 10% by volume. When the amount of the shock absorbing material is 0.6% by volume or more, the scratch resistance and the abrasion resistance of the top coat film are likely to be enhanced. On the other hand, when the amount of the shock absorbing material is 10% by volume or less, the amount of the resin (binder) relatively becomes relatively high, and the adhesion between the top coat film and the metal plate becomes high.

  Further, the shape of each shock absorbing material is not particularly limited, but it is difficult to damage an object (for example, other top coating film etc.) in contact with the top coating film, and the viewpoint that the contact area with these can be kept small. Therefore, it is preferable that it is spherical.

  The material which comprises an impact shock absorbing material will not be restrict | limited especially if it is a material which satisfy | fills the above-mentioned durometer hardness or Vickers hardness, and can form the particle | grains which do not break even by 4900 mN of compressive strength. Examples include acrylonitrile-butadiene rubber (NBR), ethylene-propylene-diene rubber (EPDM), styrene-butadiene rubber (SBR), chloroprene rubber (CR), epichlorohydrin rubber (ECO), hydrogenated acrylonitrile-butadiene rubber (HNBR), various rubbers such as fluoro rubber; or resins such as acrylic resin and urethane resin; and the like. Among these, chloroprene rubber (CR) and hydrogenated acrylonitrile-butadiene rubber (HNBR) are particularly preferable.

  On the other hand, the resin (binder) contained in the top coat film is not particularly limited as long as it does not impair the purpose and effects of the present invention, and it is a resin which is hard to be damaged by the above-mentioned impact shock absorbers, Is preferred. Examples of the resin include polyester, epoxy resin, urethane resin and the like. Among these, polyester is preferable from the viewpoint that the hardness of the top coat film can be increased, and further, the weather resistance is good.

  The amount of the resin contained in the topcoat film is preferably 60 to 95% by volume, and more preferably 70 to 90% by volume. When the amount of the resin is 70% by volume or more, adhesion between the top coat and the metal plate (or undercoat coat) tends to be good. In addition, when the amount of the resin is 90% by volume or less, the amount of the shock absorbing material becomes relatively sufficient, and the scratch resistance and the abrasion resistance become high.

  The top coat film may further contain a coloring agent and the like as long as the effects and purposes of the present invention are not impaired. Examples of colorants include inorganic pigments such as titanium oxide, calcium carbonate, carbon black, iron black, iron yellow, titanium yellow, red iron oxide, bitumen, cobalt blue, cerulian blue, ultramarine blue, cobalt green, molybdenum red, etc .; CoAl, Composite calcined pigment containing metal component such as CoCrAl, CoCrZnMgAl, CoNiZnTi, CoCrZnTi, NiSbTi, CrSbTi, FeCrZnNi, MnSbTi, FeCr, FeCrNi, FeNi, FeCrNiMn, CoCr, Mn, Co, SnZnTi etc; Al, resin coated Al, Ni Metallic pigments such as: quinacridone red, resole red B, brilliant toscarette G, pigmented scarlet 3B, brilliant carmine 6B, lake red C, lake red , Permanent Red 4R, Bordeaux 10 B, Fast Yellow G, Fast Yellow 10 G, Para Red, Watching Red, Benzidine Yellow, Benzidine Orange, Bon Maroon L, Bon Maroon M, Brilliant Fast Scarlet, Vermillion Red, Phthalocyanine Blue, Phthalocyanine Green, Fast And organic pigments such as sky blue and aniline black. It is preferable that the said coloring agent is small enough with respect to the thickness of top coat film, for example, it is preferable that an average particle diameter is 0.01-1.5 micrometers. Moreover, it is preferable that content of the coloring agent in top coat film is 2-20 volume%.

  The top coat film may further contain a lubricant from the viewpoint of preventing galling that occurs during processing of a coated metal sheet. Examples of the lubricant include organic waxes such as fluorine wax, polyethylene wax, styrene wax and polypropylene wax; and inorganic lubricants such as molybdenum disulfide and talc. The content of the lubricant in the topcoat film can be, for example, 0 to 10% by volume.

  Further, from the viewpoint of improving the weather resistance, etc., the top coat may further contain 10 vol% or less of an ultraviolet absorber (UVA), a light stabilizer (HALS), and the like. Furthermore, from the viewpoint of preventing rain streaks, etc., the top coat may contain a hydrophilizing agent, and for example, 30% by volume or less of a partially hydrolyzed condensate of tetraalkoxysilane, etc. It is also good.

  Here, the average thickness specified by the above-mentioned method of top coat film can be usually about 13-20 micrometers. When the average thickness of the top coat film is too thick, the productivity of the coated metal sheet is likely to be reduced, the cost may be increased, and the like. On the other hand, if the thickness is too thin, it is difficult to obtain desired design and durability. For example, when the coated metal sheet is applied to the exterior building material, the thickness of the top coat film is more preferably 14 μm or more, further preferably 15 μm or more from the viewpoint of durability and the like. On the other hand, the thickness of the top coat film is more preferably 19 μm or less, and still more preferably 18 μm or less.

  In addition, the thickness of top coat film is not limited to the said range, For example, according to the color of top coat film, it can set suitably. For example, when the lightness of the top coat film is high, the thickness is preferably large. On the other hand, when the lightness of the top coat film is low, it is possible to make it thin. For example, when the L value of the top coat film is 80 or less, the thickness can be 15 μm or less. On the other hand, when L value of top coat film is over 80, it is preferable that the thickness is over 15 micrometers.

  Also, the thickness of the topcoat film can be set from the difference in lightness between the desired topcoat film color and the color of the surface of the steel plate before topcoat film formation (for example, undercoat film described later). . Although it can not generally be said, for example, if the absolute value ΔL of the difference between the L value of the desired topcoat film and the L value of the color of the surface of the steel plate before the coating film formation is 10 or less, the thickness of the topcoat film Can be 13 μm or less. On the other hand, if ΔL is 20 or less, the thickness can be set to 15 μm or less, and if ΔL is 50 or less, the thickness can be set to 17 μm or less. In addition, L value of the surface of a top coat film or a steel plate can be calculated and calculated | required by a hunter color difference type | formula from the measurement result by a commercially available spectral colorimeter (for example, "CM3700d" by Konica Minolta Optics, Inc.).

  The above-mentioned top coat film can be prepared, for example, by applying a paint for top coat film on the surface of a metal plate or the surface of the below-mentioned undercoat coat, drying (if necessary, curing) . The paint for the top coat film can be prepared by dissolving or dispersing the above-mentioned shock absorbing material, resin (or precursor thereof), aggregate or the like in a solvent.

  Examples of the solvent include hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; ethers such as cellosolve; and ketones such as methyl isobutyl ketone, methyl ethyl ketone, isophorone and cyclohexanone and the like.

  In addition, the coating material may contain a curing agent for curing the resin, a curing accelerator, and the like. The curing agent is not particularly limited as long as it can crosslink polyester or acrylic resin, and can be appropriately selected according to the type of resin and the like. Examples of such curing agents include melamine compounds and isocyanate compounds. These may be used in combination. Examples of the melamine compound include melamine compounds of imino group type, methylolimino group type, methylol group type or complete alkyl group type. The isocyanate compound may be any of aromatic, aliphatic and alicyclic, and examples thereof include m-xylene diisocyanate, hexamethylene diisocyanate, naphthalene diisocyanate, isophorone diisocyanate and block compounds thereof. The amounts of the curing agent and the curing accelerator contained in the paint are appropriately selected according to the type of resin and the like.

  There is no particular limitation on the method of applying the paint for the top coat on the metal plate and the undercoat coat, and for example, known methods such as roll coating, curtain flow coating, spray coating and dip coating may be used. be able to. Moreover, a top-coat coating film is formed by heating the metal plate by which the said coating material was apply | coated so that the attainment temperature may become 200-250 degreeC after application | coating of a coating material.

  In the coated metal plate, an undercoating film or the like may be formed between the metal plate and the top coat film. The undercoat film contains, for example, a resin (binder) and various pigments (anticorrosion pigment, color pigment, metallic pigment, extender pigment, etc.).

  Examples of the resin (binder) contained in the primer coating include epoxy resin, polyester, epoxy-modified polyester resin, acrylic resin and phenoxy resin.

  On the other hand, non-chromium rust preventive pigments such as modified silica, vanadate, magnesium hydrogen phosphate, magnesium phosphate, zinc phosphate, and aluminum polyphosphate are examples of rust preventive pigments contained in the undercoat film. included. Further, examples of the coloring pigment include titanium oxide, carbon black, chromium oxide, iron oxide, bengal, titanium yellow, cobalt blue, cobalt green, aniline black and phthalocyanine blue. Examples of the metallic pigment include aluminum flakes (non-leafing type), bronze flakes, copper flakes, stainless steel flakes, nickel flakes and the like. Examples of the above-mentioned extender pigment include barium sulfate, titanium oxide, silica, calcium carbonate and the like.

  The amount of pigment contained in the undercoating film is appropriately selected according to the type of pigment and the like, and for example, the amount of rust preventive pigment can be 10 to 70% by volume.

  The undercoating film can be prepared, for example, by applying a coating material for the undercoating film to the surface of a metal plate and drying it (if necessary, curing it). The paint for the undercoat film can be prepared by dissolving or dispersing the above-mentioned resin (or its precursor), a pigment and the like in a solvent. The paint may contain a crosslinking agent. The solvent and the crosslinking agent contained in the paint for undercoat coating can be the same as those contained in the paint for top coat.

  Moreover, the coating method can also be made to be the same as the coating method of the coating material for top coat films, and it is preferable to apply | coat so that it may become dry thickness of 1-10 micrometers (preferably 3-7 micrometers). Moreover, an undercoat film is formed by heating a metal plate so that the reach | attainment temperature of a metal plate may be 180-240 degreeC after application | coating of a coating material.

(effect)
As described above, the coated metal sheet of the present invention is made of a material having a predetermined durometer hardness or a predetermined Vickers hardness, is in the form of particles, does not break even at a compressive strength of 4900 mN, It has a top coat including an impact shock absorber having a large average particle size. According to the coated metal sheet, even if the top coats are arranged to face each other during transportation, the hardness of the shock absorbing material is in an appropriate range, so that the top coats facing each other are damaged. There are few etc. On the other hand, since the hardness of the topcoat film is sufficiently high, the topcoat film is not easily damaged even when in contact with a hard object. Furthermore, according to the top coat, the contact area with the object in contact with the top coat can be kept small. Therefore, it is difficult to wear over a long period of time, and a good surface condition can be maintained. Furthermore, since the shock absorbing material contained in the top coat does not break even at a compressive strength of 4900 mN, even if the coated metal plates are stacked, it is difficult to generate a coating powder derived from the shock absorbing material. Therefore, the top coat film is not damaged by the coating powder, and the appearance of the coated metal sheet is hardly impaired.

(Use of painted metal plate)
The above-mentioned coated metal sheet is suitable for exteriors from the viewpoint of very good scratch resistance and wear resistance. "Exterior" means a portion exposed to the outside air, such as a roof, a wall, a character, a signboard, and an outdoor installation device, which is used for exposure to sunlight or its reflected light. Examples of the exterior coated metal sheet include exterior building materials and the like.

  When applying the said coated metal plate to exterior construction materials, bending process, drawing process, overhang process, embossing, roll molding etc. are performed as needed. In addition, the exterior construction material may further include configurations other than the above-described coated metal plate. In addition to the above-mentioned coated metal plate, the exterior building materials include, for example, a member for fixing the exterior building materials to the building, a member for connecting the exterior building materials, a mark indicating the direction when the exterior building materials are attached, and heat insulation. A foam sheet, a foam layer, or the like for improvement may be included.

  Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited by these examples.

[Production of painted original plate 1]
The hot-dip 55% Al-Zn alloy plated steel sheet with an adhesion amount of 150 g / m ^{2 on} both sides was subjected to alkaline degreasing. Then, the following chromate free processing liquid (liquid temperature: 20 degreeC) was apply | coated to the surface of the plating layer of the said plated steel plate as a pre-coating process. Thereafter, the plated steel sheet was dried at 100 ° C. without washing with water, to obtain a chromate-free conversion-treated steel sheet with a deposition amount of 10 mg / m ^{2 in} terms of Ti.
(Chromate-free processing solution)
Hexafluorotitanic acid: 55 g / L
Hexafluorozirconate: 10 g / L
Aminomethyl substituted polyvinyl phenol: 72 g / L
Water: the rest

  The following undercoat resin 1 based on epoxy resin was applied to the surface of the chromate-free conversion-treated steel sheet, and the above-mentioned conversion-treated steel sheet was heated so that the ultimate temperature of the plated steel sheet would be 200 ° C. Thereby, the coating original plate 1 which has the undercoat 5 whose dry thickness is 5 micrometers was obtained.

(Composition of undercoat paint 1 (ratio to solid content))
Phosphate mixture: 5% by volume
Barium sulfate: 5% by volume
Silica: 1% by volume
Clear paint (NSC Fine Coatings Co., Ltd. "NSC 680"): Residue The above-mentioned phosphate mixture is a mixture of magnesium hydrogen phosphate, magnesium phosphate, zinc phosphate, and aluminum tripolyphosphate.

[Production of painted original plate 2]
A coated base plate 2 having an undercoat film 2 having a dry thickness of 5 μm was obtained in the same manner as the coated base plate 1 except that the undercoat coating 2 was used instead of the undercoat coating 1.

(Composition of undercoat 2 (ratio to solid content))
Calcium vanadate: 15% by volume
Barium sulfate: 5% by volume
Silica: 1% by volume
Clear paint (NSC Fine Coatings Co., Ltd. "NSC 680"): Remainder

[Production of painted original plate 3]
A 55% Al-Zn alloy plated steel sheet with an adhesion amount of 150 g / m ^{2 on} both sides is alkali degreased, and a chromate treatment liquid (liquid temperature: 20 ° C., Nippon Paint Co., Ltd.) as a pretreatment for coating on the surface of the plated layer of the plated steel sheet. A “Surfcoat NRC300NS” (“Surfcoat” is a registered trademark of the company) was applied. Thereafter, the plated steel sheet was dried at 100 ° C. without washing with water, to obtain a chromate-treated steel sheet with a deposition amount of 20 mg / m ^{2 in} terms of chromium.

  The following undercoat coating 3 of epoxy resin type was applied on the surface of the above-mentioned chromate-treated steel plate, and the above-mentioned chemical conversion-treated steel plate was heated so that the ultimate temperature of the above-mentioned plated steel plate became 200 ° C. Thereby, the coating original plate 3 which has the undercoat 3 whose dry thickness is 5 micrometers was obtained.

(Composition of undercoat 3 (ratio to solid content))
Strontium chromate: 15% by volume
Barium sulfate: 5% by volume
Silica: 1% by volume
Clear paint (NSC Fine Coatings Co., Ltd. "NSC 680"): Remainder

[Preparation of top coat paint]
As shown in Table 1, the top coat which contains 95 mass parts of base components 1-3 of the following composition, and 5 mass parts of shock absorbing materials was prepared. The rubber shock absorbing material was prepared by crushing and classifying various rubbers.

(Composition of base component 1 (ratio to solid content))
Carbon black: 7% by volume
Gloss adjusting agent (Tosoh Silica Corporation "Nip Gel AZ-400" average particle diameter 3.3 μm): 5% by volume
Clear paint ("CA clear paint" manufactured by Japan Fine Coatings Co., Ltd.): Remainder

(Composition of base component 2 (ratio to solid content))
Carbon black: 7% by volume
Gloss adjusting agent (Tosoh Silica Corporation "Nip Gel AZ-400" average particle diameter 3.3 μm): 5% by volume
Clear paint ("QK clear paint" manufactured by Japan Fine Coatings Co., Ltd.): Remainder

(Composition of base component 3 (ratio to solid content))
Carbon black: 7% by volume
Gloss adjusting agent (Tosoh Silica Corporation "Nip Gel AZ-400" average particle diameter 3.3 μm): 5% by volume
Clear paint ("NSC 3300 clear paint" manufactured by Japan Fine Coatings, Inc.): Remainder

[Preparation of Painted Metal Plates 1 to 23]
The top-coat paint of the composition shown in Table 1 was apply | coated to the undercoat coating film surface of the coating original plate shown in Table 1. And it heated so that the reach | attainment temperature of a coating original plate might be 220 degreeC, and dry thickness prepared the top coat film of 15 micrometers. In addition, dry thickness of top coat film was made into the average thickness of 10 points | pieces of the area | region which does not contain an impact shock absorbing material in the cross section of top coat film.

[Evaluation]
With regard to the shock absorbing material contained in the top coat, the average particle diameter, durometer hardness, Vickers hardness, and destructive property at a compressive strength of 4900 mN were confirmed by the following method. Moreover, damage resistance and abrasion resistance were confirmed about the obtained coated metal plates 1-23. The results are shown in Table 1.

(1) Average particle diameter A sample was prepared by adding 0.01 to 0.1 g of each impact buffer to 5 to 10 mL of an organic solvent (MEK, ethyl alcohol, etc.) not affecting the measurement. The said sample was measured by Shimadzu Corporation make "a laser diffraction type particle diameter measuring apparatus (SALD-7100)."

(2) Type D Durometer Hardness Type D durometer hardness was measured for each sample having the same composition as each shock absorbing material. Type D durometer hardness was measured according to JIS K6253: 2012 (How to Determine Vulcanized Rubber and Thermoplastic Rubber Hardness D Type). As an apparatus, an IRHD hardness tester made by Teflock Co., Ltd., GS-680sel was used.

(3) Vickers Hardness The Vickers hardness of each of the samples having the same composition as each shock absorbing material was measured. Vickers hardness was measured according to JIS Z2244: 2009 (Vickers hardness test-test method). The apparatus used was a Mitutoyo Micro Vickers Hardness Tester, HM-200 System C. Also, the test force was 98 mN.

(4) Destructive property at a compressive strength of 4900 mN Using a micro compression tester (MCT-W) manufactured by Shimadzu Corporation, the shock absorber is an upper pressure indenter consisting of a flat indenter of diamond diameter 50 μm and alloy tool steel SKS It was held between lower pressure plates made of aluminum and subjected to a load speed of 4.9 mN / sec and compressed to a maximum of 4900 mN. And what was not destroyed by compression was evaluated as "(circle)" and what was destroyed was evaluated as "x".

(5) Evaluation of scratch resistance 1
The top coat of the coated metal plate was subjected to a Clemens-type scratch test by applying a load of 400 g using a 125 μmφ diamond needle, and was evaluated based on the following criteria.
(Evaluation criteria)
○: no flaw reaching the substrate (metal plate) is observed ×: a flaw reaching the substrate (metal plate)

(6) Evaluation of scratch resistance 2
The test method of evaluation 2 of damage resistance is shown in FIG. Two identical coated metal plates (1 and 2) were prepared, and one of the coated metal plates 1 was placed with the top coat 1a on top. Next, the other coated metal plate 2 was bent with the top coat 2a on the outside. At this time, R of the bent portion was 5 mm. Then, the upper coated film 2a of the other coated metal plate 2 was pressed against the upper coated film 1a of one coated metal plate 1 with a load of 20 kg, and was reciprocated 50 times in the direction of the white arrow in FIG. And after 50 reciprocations, what did not have exposure of a undercoat coating film was evaluated as "(circle)", and what the undercoat coating film exposed was evaluated as "x". The coated metal sheet from which the undercoat film was not exposed is excellent in scratch resistance when the top coat film is made to face.

  As shown in Table 1 above, the average particle size is made of a material having a durometer hardness of 70 or more, or a Vickers hardness of 30 or less, and does not break even at a compressive strength of 4900 mN, and has an average particle size of at least the thickness of the topcoat film No. 1 including an impact shock absorber having 1 to 9 and No. The coated metal sheets of 15 to 23 were excellent in both scratch resistance and abrasion resistance.

  On the other hand, when the shock absorbing material is too hard (when the Vickers hardness is more than 30), when the top coats are disposed facing each other, they scratch each other, and the scratch resistance 2 is evaluated. It fell (No. 12-14). On the other hand, when the shock absorbing material was too soft (when the durometer hardness was less than 70), the strength of the top coat film did not sufficiently increase, and the evaluation of scratch resistance 1 was reduced (No. 10 and 11) )

  The coated metal sheet according to the present invention not only has high scratch resistance and wear resistance at the time of construction and after construction, but also scars and coating powder are less likely to occur during transportation. Therefore, it is suitable for exterior building materials and the like.

1, 2 Painted metal sheet 1a, 2a top coat

Claims (6)

It is a coated metal plate which has a metal plate and the top coat film arrange | positioned on the said metal plate, Comprising:
The top coat includes a resin and a particulate shock absorber.
The shock absorbing material is made of a material having a Type D durometer hardness of 70 or more or a Vickers hardness of 30 or less, and does not break even at a compressive strength of 4900 mN, and has an average particle diameter of at least the average thickness of the topcoat film.
Painted metal plate. The resin is a polyester resin,
The coated metal plate according to claim 1. The average particle diameter of the shock absorbing material is 1 to 4 times the average thickness of the topcoat film,
The coated metal plate according to claim 1 or 2. A primer coat is further provided between the metal plate and the top coat,
The coated metal plate as described in any one of Claims 1-3. Exterior coated metal plate,
The coated metal plate as described in any one of Claims 1-4.   The exterior construction material comprised with the coated metal plate as described in any one of Claims 1-5.

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