WO2024034607A1

WO2024034607A1 - Coated metal sheet

Info

Publication number: WO2024034607A1
Application number: PCT/JP2023/028922
Authority: WO
Inventors: 史生柴尾
Original assignee: 日本製鉄株式会社
Priority date: 2022-08-08
Filing date: 2023-08-08
Publication date: 2024-02-15

Abstract

[Problem] To provide a coated metal sheet which can be produced in a simpler manner, can further improve an anti-viral function, and has durability. [Solution] The present invention relates to a coated metal sheet having a metal sheet and a coating layer located on at least one surface of the metal sheet, in which the metal sheet has a zinc-containing metal layer containing at least zinc on at least one surface thereof, and also has, as the coating layer, a first coating layer located on the outermost surface of the coated metal sheet and containing at least a compound having a photocatalytic activity, the average thickness of the first coating layer is 0.05 to 5.00 μm, the total thickness from the surface of the zinc-containing metal layer to the outermost surface of the first coating layer is 15.00 μm or less, and the concentration of zinc ions eluted into a virus-containing solution is 0.60 to 5.00% by mass when the anti-virus test prescribed in JIS R1756:2020 is performed for 4 hours.

Description

painted metal plate

The present invention relates to a painted metal plate.

Due to the effects of the novel coronavirus (COVID-19) that has been occurring for several years, there is a growing need for various products to have antiviral properties, and we are applying drugs that have antiviral effects to the surfaces of various products. The business is thriving. Application of drugs with antiviral effects can be applied to existing buildings. However, applying drugs with antiviral effects has the problem of high labor costs and high running costs, as the drugs are not durable enough and require periodic application. be.

On the other hand, as in Patent Document 1 below, for example, a technique for imparting an antiviral function to steel materials in advance is known. This technique is based on coated steel and sequentially forms a protective layer and a photocatalyst layer on the coated steel.

Japanese Patent Application Publication No. 2009-131960

However, as a result of studies by the present inventors, it has been found that there is room for further improvement in terms of improving the antiviral function in the technology using a photocatalyst as disclosed in Patent Document 1 mentioned above.

Based on this knowledge, an object of the present invention is to provide a coated metal plate that can be manufactured more easily, can further improve the antiviral function, and has durability. .

In order to solve the above problems, the inventors of the present invention made extensive studies and found that a metal plate having a zinc-containing metal layer further formed with a photocatalyst layer was subjected to an antiviral test specified in JIS R1756:2020. It has been experimentally found that the more easily a metal plate dissolves zinc into a virus-containing solution, the better its antiviral properties will be. Based on this knowledge, the present inventors conducted further studies and found that it is possible to further improve the antiviral function of a painted metal plate by creating conditions in which zinc is easily eluted. It was completed.
The gist of the present invention, which was completed based on this knowledge, is as follows.

(1) A painted metal plate comprising a metal plate and a film layer located on at least one surface of the metal plate, wherein the metal plate has a zinc-containing metal containing at least zinc on at least one surface. The metal plate has a layer, and the film layer includes a first film layer located on the outermost surface of the coated metal plate and containing at least a compound having photocatalytic activity, and the average of the first film layer is The thickness is 0.05 to 5.00 μm, and the total thickness from the surface of the zinc-containing metal layer to the outermost surface of the first coating layer is 15.0 μm or less, as specified in JIS R1756:2020. A coated metal plate having a zinc ion concentration of 0.60 to 5.00% by mass eluted into a virus-containing liquid when an antivirus test is conducted for 4 hours.
(2) The thickness of the first coating layer is 0.05 to 0.95 μm, and the total thickness from the surface of the zinc-containing metal layer to the outermost surface of the first coating layer is less than 1.0 μmm. , the painted metal plate according to (1).
(3) The coated metal plate according to (1) or (2), wherein the total content of elements with a nobler potential than zinc in the coating layer is 0 to 20.0% by mass.
(4) The coated metal plate according to (1), wherein the first film layer further contains at least one element selected from the group consisting of Zn, Cu, Fe, Ni, and Ag.
(5) The first coating layer further contains at least one of Si or Zr, and the total content of the elements is 5 to 50% by mass in terms of silica for Si and zirconia for Zr. The painted metal plate according to (1).
(6) A painted metal plate comprising a metal plate and a film layer located on at least one surface of the metal plate, the film layer being located on the outermost surface of the painted metal plate and having photocatalytic activity. and a first film layer containing a zinc element of 0.2 to 20.0% by mass in terms of metallic Zn, and the average thickness of the first film layer is 0.05 to 5% by mass. .00 μm, and the total thickness from the surface of the metal plate to the outermost surface of the first film layer was 60.0 μm or less, and when an antiviral test specified in JIS R1756:2020 was conducted for 4 hours. , a coated metal plate in which the concentration of zinc ions eluted into the virus-containing liquid is 0.60 to 5.00% by mass.
(7) The coated metal plate according to (6), wherein the total content of elements with a nobler potential than zinc in the coating layer is 0 to 20.0% by mass.
(8) The coated metal plate according to (6) or (7), wherein the first film layer further contains at least one element selected from the group consisting of Cu, Fe, Ni, and Ag.
(9) The first coating layer further contains at least one of Si or Zr, and the total content of the elements is 5 to 50% by mass in terms of silica for Si and zirconia for Zr. The painted metal plate according to (6).
(10) The film layer further includes a second film layer located below the first film layer and made of an inorganic component, and the second film layer contains Si or The coated metal plate according to (1) or (6), which contains at least one element of Zr, and wherein the second coating layer has an average thickness of 0.05 to 5.00 μm.
(11) The coated metal plate according to (10), wherein the second film layer further contains at least one of P or V as the inorganic component.
(12) The coated metal plate according to (10), wherein the second coating layer further contains at least one element selected from the group consisting of Zn, Cu, Fe, Ni, and Ag.
(13) The film layer further includes a third film layer located below the second film layer and containing a resin component, and the third film layer has an average thickness of 0.50 to 14 The coated metal plate according to (10), which has a diameter of .00 μm.
(14) The painted metal plate according to (13), wherein the third film layer further contains a colorant.
(15) The coated metal plate according to (1) or (6), wherein the compound having photocatalytic activity is anatase titanium oxide.
(16) The coated metal plate according to (15), wherein the compound having photocatalytic activity is a metal-supported titanium oxide in which at least one of Cu and Fe is supported on titanium oxide.
(17) The painted metal plate according to (1), wherein the metal plate is a zinc-based plated steel plate having a zinc-based plating layer as the zinc-containing metal layer.
(18) The coated metal sheet according to (17), wherein the zinc-based plating layer is a plating layer containing 30% by mass or more of Zn in terms of metallic Zn.
(19) The zinc-based plating layer is any one of a zinc plating layer, a zinc-aluminum alloy plating layer, a zinc-aluminum-magnesium alloy plating layer, a zinc-nickel alloy plating layer, or a zinc-iron alloy plating layer. , the painted metal plate according to (17).
(20) The coated metal plate according to (1) or (6), wherein a hairline along the rolling direction of the metal plate is present on the surface of the metal plate.
(21) The coated metal plate according to (1), wherein a spangle pattern is present on the surface of the zinc-containing metal layer.

As explained above, according to the present invention, it is possible to provide a coated metal plate that is more easily manufactured, has durability, and has improved antiviral function.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing an example of the structure of a coated metal plate according to a first embodiment of the present invention. FIG. 3 is an explanatory diagram schematically showing another example of the structure of the coated metal plate according to the first embodiment of the present invention. FIG. 3 is an explanatory diagram schematically showing another example of the structure of the coated metal plate according to the first embodiment of the present invention. FIG. 3 is an explanatory diagram schematically showing another example of the structure of the coated metal plate according to the first embodiment of the present invention. FIG. 3 is an explanatory diagram schematically showing another example of the structure of the coated metal plate according to the first embodiment of the present invention. FIG. 2 is an explanatory diagram schematically showing an example of the structure of a painted metal plate according to a second embodiment of the present invention. FIG. 7 is an explanatory diagram schematically showing another example of the structure of the coated metal plate according to the second embodiment of the present invention. FIG. 7 is an explanatory diagram schematically showing another example of the structure of the coated metal plate according to the second embodiment of the present invention. FIG. 7 is an explanatory diagram schematically showing another example of the structure of the coated metal plate according to the second embodiment of the present invention. FIG. 7 is an explanatory diagram schematically showing another example of the structure of the coated metal plate according to the second embodiment of the present invention.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that, in this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals and redundant explanation will be omitted.

<<First embodiment>>
Below, first, the painted metal plate according to the first embodiment of the present invention will be described in detail.
A first embodiment of the present invention is a painted metal plate having a metal plate and a film layer located on at least one surface of the metal plate, wherein the metal plate contains at least zinc on at least one surface. The present invention relates to a metal plate having a zinc-containing metal layer.

(About painted metal plates)
<Structure of painted metal plate>
Below, first, the structure of the coated metal plate according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is an explanatory diagram schematically showing an example of the structure of a painted metal plate according to the present embodiment.

As schematically shown in FIG. 1, a coated metal plate 1 according to a first embodiment of the present invention has a coating layer on at least one surface of the metal plate, and has a coating layer on at least one surface of the metal plate 10, and a coating layer on at least one surface of the metal plate. It has at least a photocatalyst layer 20 as an example of a first film layer.

[About the metal plate 10]
In the painted metal plate 1 according to the present embodiment, the metal plate 10 includes a base metal 11 as a base material of the metal plate 10 and a zinc-containing metal layer 13 that is a metal layer containing at least zinc. There is.

Here, various metal plates can be used as the base metal 11. Examples of such metal plates include various steel plates, aluminum plates, stainless steel plates, etc., and may be selected depending on the strength, characteristics, etc. required of the base metal 11.

Further, the zinc-containing metal layer 13 is a metal layer provided on the surface of the base metal 11, and contains at least zinc. The presence of such a zinc-containing metal layer 13 on the surface of the base metal 11 prevents the virus from entering the virus-containing liquid in the antiviral test specified in JIS R1756:2020, which the inventors discovered. leaching of zinc begins to occur. As a result, the antiviral function of the coated metal plate 1 can be further improved over a longer period of time using a simpler method.

More specifically, the zinc-containing metal layer 13 preferably contains zinc in an amount of 30% by mass or more in terms of metal Zn. Further, the zinc-containing metal layer 13 may contain impurities. By setting the zinc content in the zinc-containing metal layer 13 to 30% by mass or more, the amount of zinc eluted into the virus-containing liquid as described above can be further increased while ensuring the corrosion resistance of the base metal 11. becomes possible. This makes it possible to further improve the antiviral function of the coated metal plate 1. The zinc content in the zinc-containing metal layer 13 is more preferably 40% by mass or more, and even more preferably 70% by mass or more. Note that the higher the zinc content in the zinc-containing metal layer 13, the better, and the zinc content in the zinc-containing metal layer 13 may be 100% by mass.

Examples of such a zinc-containing metal layer 13 include a zinc vapor-deposited layer in which metallic zinc or the like is vapor-deposited, and a zinc-based plating layer that is a plating layer containing zinc. Here, from the viewpoint that it is easy to manufacture a zinc-based plating layer at an excellent manufacturing cost by using various existing zinc-based plating layer manufacturing lines, etc., zinc-based plating is used as the zinc-containing metal layer 13. Preferably, a layer is provided.

A preferred zinc-based plating layer as the zinc-containing metal layer 13 is a zinc-based plating layer containing 30% by mass or more of zinc in terms of metal Zn. Moreover, such a zinc-based plating layer may contain impurities. By setting the zinc content in the zinc-based plating layer to 30% by mass or more, it is possible to further increase the amount of zinc eluted into the virus-containing liquid as described above while ensuring the corrosion resistance of the base metal 11. This makes it possible to further improve the antiviral function of the coated metal plate 1. The zinc content in the zinc-based plating layer is more preferably 40% by mass or more, and even more preferably 70% by mass or more. Note that the zinc content in the zinc-based plating layer may be 100% by mass.

As such a zinc-based plating layer, various types of plating can be used, such as a zinc plating layer, a zinc-aluminum alloy plating layer, a zinc-aluminum-magnesium alloy plating layer, a zinc-nickel alloy plating layer, a zinc-iron alloy plating layer, etc. layers can be mentioned. Further, from the viewpoint of further increasing the amount of zinc eluted, it is more preferable to provide a zinc-nickel alloy plating layer or a zinc-iron alloy plating layer as the zinc-based plating layer.

In particular, the element Fe is an element that promotes the elution of zinc from the viewpoint of ionization tendency, and the coexistence of metal Fe and zinc is advantageous in terms of potential from the viewpoint of zinc elution, so it is preferable.

The amount of adhesion of the zinc-containing metal layer 13 as described above is preferably 8 g/m ² or more, more preferably 17 g/m ² or more in terms of metal Zn per one side of the base metal 11. preferable. By setting the adhesion amount to 8 g/m ² or more, more preferably 17 g/m ^{2 or} more, it becomes possible to elute a sufficient amount of zinc while ensuring the corrosion resistance of the base metal 11. On the other hand, the adhesion amount of the zinc-containing metal layer 13 as described above is preferably 250 g/m ² or less, more preferably 170 g/m ² or less, in terms of metal Zn per one side of the base metal 11. preferable. By setting the adhesion amount to 250 g/m ² or less, more preferably 170 g/m ² or less, a sufficient amount of zinc can be eluted while ensuring the corrosion resistance of the base metal 11.

Based on the above, it is more convenient to use various zinc-based plated steel sheets having various zinc-based plating layers as described above as the metal plate 10 having the zinc-containing metal layer 13.

Here, the thickness of the metal plate 10 as described above is not particularly limited, and depends on the mechanical strength (for example, tensile strength, etc.), workability, etc. required for the coated metal plate 1 according to the present embodiment. It may be set as appropriate depending on the situation.

Furthermore, various patterns such as a hairline pattern or a spangle pattern along the rolling direction of the base metal 11 may be present on the surface of the zinc-containing metal layer 13. By providing such a pattern, it becomes possible to further improve the design of the painted metal plate 1.

Moreover, since the hairline pattern in particular is a pattern realized by forming fine irregularities on the surface of the zinc-containing metal layer 13, the surface area of the zinc-containing metal layer 13 is increased. As a result, it becomes possible to further increase the amount of zinc eluted from the zinc-containing metal layer 13, which is more preferable not only from the viewpoint of design but also from the viewpoint of antiviral properties.

Although FIG. 1 shows a form in which the zinc-containing metal layer 13 is formed on one surface of the base metal 11, the zinc-containing metal layer 13 may be formed on both surfaces of the base metal 11. may have been done.

[About the photocatalyst layer 20]
In the coated metal plate 1 according to the present embodiment, the photocatalyst layer 20 as an example of the first film layer is formed on the outermost surface of the film layer on at least one surface of the metal plate 10, as schematically shown in FIG. It is a layer located in the photocatalyst and contains at least a compound having photocatalytic activity (hereinafter sometimes abbreviated as "photocatalytic compound"). Since the photocatalytic layer 20 contains a compound having photocatalytic activity, the compound having photocatalytic activity causes a photocatalytic reaction by light (particularly light in the ultraviolet to visible light band) incident on the photocatalytic layer 20. As a result, the photocatalytic layer 20 according to the present embodiment exhibits various photocatalytic effects including antiviral effects and sterilizing effects. Thereby, the coated metal plate 1 according to the present embodiment can realize various properties including an antiviral effect and a sterilizing effect.

Compounds with such photocatalytic activity include those that react with light in the ultraviolet band (more specifically, when excited by light in the ultraviolet band) to exhibit photocatalytic activity, and compounds that exhibit photocatalytic activity mainly in the visible range. There exists a compound that reacts with light in the optical band (more specifically, is excited by light in the visible light band) and exhibits photocatalytic activity.

Examples of compounds that exhibit photocatalytic activity by reacting with light in the ultraviolet light range include titanium oxide (more specifically, anatase titanium oxide), zinc oxide, cerium oxide, tin oxide, bismuth oxide, zirconium oxide, and Tungsten, chromium oxide, molybdenum oxide, iron oxide, nickel oxide, ruthenium oxide, cobalt oxide, copper oxide, manganese oxide, germanium oxide, lead oxide, cadmium oxide, vanadium oxide, niobium oxide, tantalum oxide, rhodium oxide, rhenium oxide, etc. metal oxides, metal sulfides such as cadmium sulfide and zinc sulfide, and titanium compounds such as strontium titanate and barium titanate. Among them, anatase-type titanium oxide, zinc oxide, tin oxide, zirconium oxide, tungsten oxide, iron oxide, niobium oxide, strontium titanate, etc. are particularly effective as compounds that react with light in the ultraviolet light band to exhibit photocatalytic activity. Anatase titanium oxide is preferably used, and anatase titanium oxide is more preferably used.

In addition, as a compound that reacts with light in the visible light band to exhibit photocatalytic activity, for example, metal-supported titanium oxide, in which at least one of Cu or Fe is supported on titanium oxide (more specifically is anatase-type titanium oxide), anatase-type titanium oxide in which Cr, V, Mn, Ni, and Pt are supported on anatase-type titanium oxide, and anatase-type titanium oxide in which anatase-type titanium oxide is doped with anions such as nitrogen and sulfur. type titanium oxide, a solid solution of AgNbO ₃ and SrTiO ₃ , and the like. Among these, anatase-type titanium oxide in which at least one of Cu and Fe is supported on anatase-type titanium oxide is more preferably used.

In particular, anatase-type titanium oxide on which Cu is supported is particularly preferably used because the attached Cu exhibits the effect of promoting the elution of zinc from the zinc-containing metal layer 13 as described above.

Among such photocatalytic compounds, the average particle size (primary particle size) of anatase-type titanium oxide (including those in a metal-supported state) is preferably 5 nm or more. When the average particle size (primary particle size) of the anatase-type titanium oxide is 5 nm or more, it becomes possible to disperse the anatase-type titanium oxide more uniformly in the photocatalyst layer 20. The average particle size (primary particle size) of the anatase titanium oxide is more preferably 20 nm or more. Further, the average particle size (primary particle size) of anatase-type titanium oxide (including those in a metal-supported state) is preferably 200 nm or less. Since the average particle size (primary particle size) of the anatase-type titanium oxide is 200 nm or less, the anatase-type titanium oxide is more uniformly distributed in the photocatalyst layer 20 while suppressing excessive aggregation of the anatase-type titanium oxide in the photocatalyst layer 20. It becomes possible to disperse the The average particle size (primary particle size) of the anatase titanium oxide is more preferably 100 nm or less.

Here, the average particle size of the above-mentioned anatase-type titanium oxide can be measured, for example, by a dynamic light scattering method using a laser beam. Such a method can easily obtain highly accurate measurement values. However, if the particles of anatase-type titanium oxide are aggregated to some extent, the size of the aggregates (agglomerated particle diameter) may be measured, so it is also possible to directly measure the size of the aggregates using a transmission electron microscope (TEM). It is preferable to check the primary particle size. If the presence of aggregated particles is confirmed as a result of TEM observation, it is preferable to change the dispersion conditions and perform the measurement again using a dynamic light scattering method. Furthermore, if it is difficult to completely disperse the particles to the level of primary particles, the size of the primary particles observed and measured by TEM can be used as the primary particle diameter. In this case, the inventor's experience has shown that by measuring approximately 100 or more arbitrarily selected particles, a value representative of all the particles can be obtained.

Furthermore, when measuring the average particle size of the anatase-type titanium oxide contained in the photocatalyst layer 20 on the coated metal plate 1 on which the photocatalyst layer 20 has already been formed, the following may be performed. That is, a cross section of the photocatalyst layer 20 cut along the thickness direction can be observed or analyzed using a transmission electron microscope (TEM). By using TEM, the primary particle diameter of the photocatalytic compound can be measured. Furthermore, by performing EDS analysis in conjunction with TEM, elements contained in the photocatalytic compound can be measured. Furthermore, the crystal structure of a photocatalytic compound (for example, in the case of titanium oxide, whether it is anatase type or rutile type) can be determined by electron diffraction. In the experience of the present inventor, it has been found that by measuring approximately 100 or more arbitrarily selected particles, a value representative of all particles can be obtained.

Here, the concentration of anatase-type titanium oxide (including metal-supported titanium oxide) in the photocatalyst layer 20 is preferably 50% by mass or more in terms of titania. When the concentration of anatase titanium oxide in the photocatalyst layer 20 is 50% by mass or more, it is possible to reliably exhibit various photocatalytic effects including antiviral effects. The concentration of anatase titanium oxide in the photocatalyst layer 20 is more preferably 60% by mass or more in terms of titania. Further, the concentration of anatase-type titanium oxide (including metal-supported titanium oxide) in the photocatalyst layer 20 is preferably 95% by mass or less in terms of titania. By setting the concentration of anatase titanium oxide in the photocatalytic layer 20 to 95% by mass or less, it is possible to suppress an increase in manufacturing costs and to exhibit various photocatalytic effects including antiviral effects. The concentration of anatase titanium oxide in the photocatalyst layer 20 is more preferably 80% by mass or less in terms of titania.

Similarly to the above, photocatalytic compounds other than anatase titanium oxide preferably have an average particle size of 5 to 200 nm, and the concentration thereof is preferably 50 to 95% by mass.

Note that photocatalytic compounds, such as the anatase-type titanium oxide mentioned above, include not only particles, but also sol-like substances that cannot be called particles, substances produced by heating metal complexes, etc. can also be used as necessary.

The photocatalyst layer 20 further contains at least one element of Si or Zr, and the total concentration of these elements is 5% by mass or more in terms of silica for Si and zirconia for Zr. It is preferable. In other words, the photocatalytic layer 20 is an inorganic film having a skeleton of an inorganic component having a three-dimensional network structure containing at least one element of Si or Zr, and possibly impurities. Alternatively, the total concentration of at least one element of Zr is preferably 5% by mass or more in terms of silica for Si and zirconia for Zr. By containing at least one element of Si or Zr at the above concentration, it is possible to realize a photocatalyst layer 20 with even better corrosion resistance. The total content of at least one element of Si or Zr is more preferably 10% by mass or more. Here, the inorganic component means a component that does not contain an organic resin.

The photocatalytic layer 20 further contains at least one element of Si or Zr, and the total concentration of these elements is 50% by mass or less in terms of silica for Si and zirconia for Zr. It is preferable. By containing at least one element of Si or Zr at the above concentration, it is possible to realize a photocatalyst layer 20 with even better corrosion resistance. The total content of at least one element of Si or Zr is more preferably 40% by mass or less. Here, the Si or Zr contained preferably has excellent light transmittance, and is preferably an inorganic component that is less susceptible to decomposition by photocatalysts. Examples of such inorganic components containing Si and Zr include silica and zirconia.

In addition to the photocatalytic compound and at least one element of Si or Zr, the photocatalytic layer 20 further contains at least one element selected from the group consisting of Zn, Cu, Fe, Ni, and Ag. It is preferable to contain. Here, the elements Cu, Fe, Ni, and Ag are elements that promote the elution of zinc from the zinc-containing metal layer 13 as described above, so that the photocatalyst layer 20 further contains these elements, thereby making it more effective. This is preferable because a large amount of zinc is eluted from the zinc-containing metal layer 13. Furthermore, the elements Cu, Zn, and Ag are particularly preferable because they are also elements that exhibit antibacterial effects. Moreover, it is more preferable that the photocatalyst layer 20 further contains the element Zn, since it is possible to further increase the amount of zinc eluted from the coated metal plate 1.

The total content of at least one element selected from the group consisting of Zn, Cu, Fe, Ni, and Ag in the photocatalyst layer 20 is preferably 0.2% by mass or more in terms of metal elements. When the total content of the metal elements is 0.2% by mass or more, the above effects can be expressed in a more preferable state. The total content of the metal elements is more preferably 0.6% by mass or more, and still more preferably 1.0% by mass or more. On the other hand, the total content of at least one element selected from the group consisting of Zn, Cu, Fe, Ni, and Ag in the photocatalyst layer 20 is preferably 5.0% by mass or less in terms of metal elements. . By setting the total content of the above-mentioned metal elements to 5.0% by mass or less, it is possible to maintain the content of the photocatalytic compound while producing the above-mentioned effects without saturating them. . The total content of the metal elements is more preferably 3.5% by mass or less, still more preferably 2.5% by mass or less.

Note that the photocatalyst layer 20 containing the above photocatalytic compound may contain an antibacterial agent and an adsorbent such as activated carbon or zeolite, as necessary, within a range that does not impair the effects of the present invention.

The average thickness d ₁ of the photocatalyst layer 20 (in the case of the layer structure shown in FIG. 1 , the total thickness d from the surface of the metal plate 10 to the outermost surface of the photocatalyst layer 20 (which can also be considered as the outermost surface of the film layer) _T ) is 0.05 μm or more. If the average thickness _d1 of the photocatalytic layer 20 is less than 0.05 μm, it will be difficult to uniformly form the photocatalytic layer 20 as described above, and the obtained photocatalytic effect will be uneven, so it is preferable. do not have. By setting the average thickness _d1 to 0.05 μm or more, the elution route for zinc from the zinc-containing metal layer 13 is ensured, and the zinc is sufficiently eluted, and the desired photocatalytic effect is uniformly distributed over the entire photocatalytic layer 20. It becomes possible to express it.

On the other hand, the average thickness d ₁ of the photocatalyst layer 20 (in the case of the layer configuration shown in FIG. 1, this is also the total thickness d _T from the surface of the metal plate 10 to the outermost surface of the photocatalyst layer 20) is 5.00 μm or less It is. If the average thickness d ₁ of the photocatalyst layer 20 exceeds 5.00 μm, the resulting photocatalytic effect will be saturated while the manufacturing cost will increase, which is not preferable. Furthermore, it becomes difficult to ensure a sufficient amount of zinc eluted from the zinc-containing metal layer 13, which is also unfavorable from this point of view. Furthermore, since the photocatalyst layer is an inorganic film, processability is reduced. By setting the average thickness d ₁ to 5.00 μm or less, it is possible to suppress deterioration in ease of manufacturing and deterioration in workability, and to secure a route for elution of zinc from the zinc-containing metal layer 13 to sufficiently elute zinc. Furthermore, it becomes possible to uniformly exhibit the desired photocatalytic effect over the entire photocatalytic layer 20.

Normally, light that passes through the photocatalyst layer 20 without hitting the photocatalyst compound is generated with a certain probability. Conventionally, such light that does not interact with the photocatalytic compound ends up being light that cannot produce a photocatalytic effect. In this embodiment, by reflecting such light on the surface of the metal plate 10, it is possible to increase the probability that the light incident on the photocatalyst layer 20 will collide with the photocatalyst compound. Thereby, in this embodiment, the photocatalytic effect can be further improved. In the case of the _layer structure shown in FIG. (In other words, the reflected light reflected at the interface between the metal plate 10 and the photocatalyst layer 20) can be used for the photocatalytic reaction by the photocatalytic compound, so the photocatalytic effect can be further improved.

The average thickness _d1 of the photocatalyst layer 20 is preferably 0.10 μm or more, more preferably 0.15 μm or more. Further, the average thickness _d1 of the photocatalyst layer 20 is preferably 2.00 μm or less, more preferably 1.00 μm or less, still more preferably less than 1.0 μm, even more preferably 0.80 μm or less. , 0.60 μm or less, or 0.50 μm or less.

Although FIG. 1 shows a configuration in which the photocatalyst layer 20 is formed on one surface of the metal plate 10, the photocatalyst layer 20 may be formed on both surfaces of the metal plate 10.

<Concentration of zinc ions eluted into virus-containing liquid in antiviral test>
The structure of the painted metal plate 1 as described above has a zinc ion concentration of 0.60 to 5.5% when an antiviral test specified in JIS R1756:2020 is conducted for 4 hours. This is one of the conditions for the content to be within the range of 0.00% by mass.

The reason why the above structure is one of the conditions is that in the coated metal plate 1 according to the present embodiment, the zinc-containing metal layer 13 is provided in an appropriate state, and the photocatalyst layer 20 is further removed from the surface of the metal plate 10. This is because since the total thickness _dT to the outermost surface is within a specific range, an appropriate amount of zinc can be eluted from the zinc-containing metal layer 13. In this way, in the coated metal plate 1 according to the present embodiment, the zinc-containing metal layer 13, which is originally provided to ensure the corrosion resistance of the metal plate 10, improves the antiviral properties of the coated metal plate 1. It also works for this purpose.

Note that the amount of zinc eluted from the zinc-containing metal layer 13 can be controlled to a desired state by adjusting the amount of attachment of the zinc-containing metal layer 13 and the total thickness _dT . Furthermore, the amount of zinc leached from the zinc-containing metal layer 13 can also be controlled by further controlling the density of the film layer existing on the path from the zinc-containing metal layer 13 to the outermost surface of the photocatalyst layer 20. It is possible.

Here, when the zinc ion concentration in the virus-containing liquid is less than 0.60% by mass, it means that the amount of zinc eluted from the zinc-containing metal layer 13 is insufficient, and the coated metal plate 1 shows Antiviral function cannot be further improved. The zinc ion concentration in the virus-containing liquid is preferably 0.90% by mass or more, more preferably 1.20% by mass or more.

On the other hand, when the zinc ion concentration in the virus-containing liquid is more than 5.00% by mass, the amount of zinc eluted from the zinc-containing metal layer 13 becomes too large, making it impossible to ensure the corrosion resistance of the metal plate 10. The zinc ion concentration in the virus-containing liquid is preferably 4.50% by mass or less, more preferably 3.50% by mass or less.

In addition, in the coated metal plate 1 according to the present embodiment, the total content of elements having a nobler potential than zinc (more specifically, ions) present in the coating layer is 20.0 in terms of metal elements. It is preferably less than % by mass. Here, examples of elements having a nobler potential than zinc include Cu, Ag, and the like. By setting the total content of elements with a nobler potential than zinc in the film layer to 20.0% by mass or less, the zinc ion concentration in the virus-containing liquid as described above is 5.00% by mass or less. This makes it possible to further achieve both excellent antiviral properties and excellent corrosion resistance. The total content of elements with a nobler potential than zinc in the coating layer is more preferably 15.0% by mass or less, still more preferably 11.0% by mass or less, and even more preferably 7.5% by mass. % by mass or less. Note that the lower limit of the total content of elements having a nobler potential than zinc in the coating layer is not particularly specified, and may be 0% by mass.

Here, the above antiviral test is conducted for 4 hours in accordance with the method specified in JIS R1756:2020. Further, the concentration of zinc ions eluted into the virus-containing liquid may be measured by inductively coupled plasma (ICP) emission spectrometry.

<Modification example-1>
The coated metal plate 1 according to the present embodiment, which has the layer structure shown in FIG. 1, has an additional film layer that functions as a chemical conversion film layer between the metal plate 10 and the photocatalyst layer 20. It's okay. By providing a chemical conversion coating layer between the metal plate 10 and the photocatalyst layer 20, it becomes possible to further improve the adhesion between the metal plate 10 and the photocatalyst layer 20. Furthermore, it is also possible to further improve the corrosion resistance and the like of the painted metal plate 1 according to this embodiment.

Hereinafter, the further film layer that functions as the chemical conversion film layer will be described in detail with reference to FIGS. 2A and 2B. FIGS. 2A and 2B are explanatory diagrams schematically showing other examples of the structure of the coated metal plate according to the present embodiment.

2A and 2B are schematic diagrams schematically showing the layer structure of the coated metal plate 1 in the case of providing an inorganic film layer 30 functioning as a chemical conversion film layer as an example of the second film layer. . In such a case, the painted metal plate 1 according to the present embodiment has an inorganic film layer 30 as an example of a second film layer between the metal plate 10 and the photocatalyst layer 20 as described above.

Photocatalytic compounds, typified by anatase-type titanium oxide, have extremely excellent oxidizing properties, so when a film layer is provided below the layer where the photocatalytic compound is present, protection is required to protect the film layer. Often forms layers. However, as explained below, by forming the chemical conversion coating layer from an inorganic component, it becomes possible to arrange the chemical conversion coating layer without providing a protective layer. Here, the inorganic component means a component that does not contain an organic resin.

Such an inorganic film layer 30 is formed by a chemical conversion treatment after impurities such as oil and surface oxides adhering to the surface of the metal plate 10 are removed by a known degreasing process and cleaning process. This inorganic film layer 30 is preferably made of an inorganic component such as a silane compound or a zirconia compound containing at least one element of Si or Zr. Further, the inorganic film layer 30 may further contain an inorganic component containing at least one element of P or V.

Since the inorganic film layer 30 contains an inorganic component having the above-mentioned elements, it improves the film formability after application of the chemical conversion treatment solution and the barrier property (denseness) of the film against corrosion factors such as moisture and corrosive ions. ), it improves the adhesion of the film to the metal plate surface, contributing to raising the corrosion resistance of the film.

Here, as the inorganic component containing Si, for example, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-(2- Examples include aminoethyl)aminopropyltriethoxysilane and the like. Examples of the inorganic component containing Zr include zirconium carbonate, ammonium zirconium carbonate, potassium zirconium carbonate, sodium zirconium carbonate, and ammonium zirconium carbonate.

Examples of inorganic components containing P include phosphoric acids and their salts such as phosphoric acid, orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, and tetraphosphoric acid, ammonium dihydrogen phosphate, etc. be able to. Examples of inorganic components containing V include ammonium metavanadate (V), potassium metavanadate (V), sodium metavanadate (V), vanadyl sulfate (IV), and the like.

In the inorganic film layer 30 according to the present embodiment, the various inorganic components described above can be used alone or in combination. Further, the contents of the various inorganic components as described above may be adjusted as appropriate.

The average thickness _d2 of the inorganic film layer 30 is preferably 0.05 μm or more, more preferably 0.10 μm or more. This makes it possible to uniformly form the inorganic film layer 30 on the surface of the metal plate 10 and to stably exhibit various effects of providing the chemical conversion film layer as described above. Further, the average thickness _d2 of the inorganic film layer 30 is preferably 5.00 μm or less, more preferably 1.00 μm or less, even more preferably less than 1.00 μm, and 0.80 μm or less. , 0.60 μm or less, or even more preferably 0.50 μm or less. This makes it possible to uniformly form the inorganic film layer 30 on the surface of the metal plate 10 and to stably exhibit various effects of providing the chemical conversion film layer as described above.

Further, it is preferable that the inorganic film layer 30 according to the present embodiment further contains at least one element selected from the group consisting of Zn, Cu, Fe, Ni, and Ag, similarly to the photocatalyst layer 20. .

The total content of at least one element selected from the group consisting of Zn, Cu, Fe, Ni, and Ag in the inorganic film layer 30 is preferably 0.2% by mass or more in terms of metal elements. . When the total content of the metal elements is 0.2% by mass or more, the above effects can be expressed in a more preferable state. The total content of the metal elements is more preferably 0.6% by mass or more, and still more preferably 1.0% by mass or more. On the other hand, the total content of at least one element selected from the group consisting of Zn, Cu, Fe, Ni, and Ag in the inorganic film layer 30 is 10.0% by mass or less in terms of metal elements. is preferred. By setting the total content of the above-mentioned metal elements to 10.0% by mass or less, it is possible to maintain the content of the photocatalytic compound while producing the above-mentioned effects without saturating them. . The total content of the metal elements is more preferably 7.5% by mass or less, still more preferably 5.0% by mass or less.

Moreover, the painted metal plate 1 according to the present embodiment further includes various known layers between the photocatalyst layer 20 and the inorganic film layer 30, as schematically shown in FIG. 2B. It's okay.

Here, even in the cases shown in FIGS. 2A and 2B, the total thickness d _T (=d ₁ +d ₂ +α) from the surface of the metal plate 10 to the outermost surface of the photocatalyst layer 20 is 15.00 μm or less. do. This suppresses a decrease in manufacturing simplicity and processability, secures an elution route for zinc from the zinc-containing metal layer 13, allows sufficient zinc to be eluted, and further improves the desired photocatalytic effect. It becomes possible to achieve uniform expression over the entire layer 20. The total thickness d _T (=d ₁ + d ₂ + α) from the surface of the metal plate 10 to the outermost surface of the photocatalyst layer 20 is preferably 10.00 μm or less, more preferably 7.00 μm or less, and even more preferably , 1.00 μm or less, less than 1.00 μm, 0.90 μm or less, 0.80 μm or less, or 0.70 μm or less.

<Modification example-2>
In addition to the inorganic film layer 30 located between the metal plate 10 and the photocatalyst layer 20, the painted metal plate 1 according to the present embodiment has a third film layer further below the inorganic film layer 30 as an example of a third film layer. It may have a resin film layer 40 of.
Below, the resin film layer 40 will be explained in detail with reference to FIGS. 3A and 3B. 3A and 3B are explanatory diagrams schematically showing other examples of the structure of the coated metal plate according to the present embodiment.

FIGS. 3A and 3B are schematic diagrams schematically showing the layer structure of the coated metal plate 1 in the case where a resin film layer 40 as an example of the third film layer is provided. In such a case, the painted metal plate 1 according to the present embodiment has a resin film layer 40 as an example of a third film layer below the inorganic film layer 30 as described above.

The resin film layer 40 is formed by a chemical conversion treatment after impurities such as oil and surface oxides adhering to the surface of the metal plate 10 are removed by a known degreasing process and cleaning process.

The resin film layer 40 according to the present embodiment contains, for example, a resin, and further contains a silane coupling agent, a zirconium compound, silica, phosphoric acid and its salt, a fluoride, a vanadium compound, and tannin or tannic acid. It may contain one or more selected from the group consisting of: Containing these substances further improves film formability after application of a chemical conversion treatment solution, barrier properties (denseness) of the film against corrosion factors such as moisture and corrosive ions, and adhesion of the film to the surface of the metal plate. etc., contributing to raising the level of corrosion resistance of the film.

In particular, when the resin film layer 40 contains one or more of a silane coupling agent or a zirconium compound, a crosslinked structure is formed within the resin film layer 40 and the bond with the metal plate surface is also strengthened. , it becomes possible to further improve the adhesion and barrier properties of the film.

Furthermore, when the resin film layer 40 contains one or more of silica, phosphoric acid and its salts, fluoride, or a vanadium compound, it functions as an inhibitor and forms a precipitated film or a passive film on the metal plate surface. By doing so, it becomes possible to further improve corrosion resistance.

Hereinafter, details of each component that may be included in the resin film layer 40 as described above will be explained while giving examples.

[resin]
As the resin, for example, known organic resins such as polyester resin, polyurethane resin, epoxy resin, phenol resin, acrylic resin, polyolefin resin, etc. can be used. In order to further improve the adhesion with the metal plate, it is preferable to use at least one resin having a forced moiety or polar functional group in its molecular chain (polyester resin, urethane resin, epoxy resin, acrylic resin, etc.). . The resins may be used alone or in combination of two or more.

The content of the resin in the resin film layer 40 is preferably 0% by mass or more, and more preferably 1% by mass or more, based on the solid content of the film, for example. Thereby, corrosion resistance can be improved. Further, the resin content in the resin film layer 40 is preferably 85% by mass or less, more preferably 60% by mass or less, and 40% by mass or less, based on the solid content of the film, for example. is even more preferable. By setting the resin content to 85% by mass or less, the corrosion resistance of the film can be improved while ensuring the performance required for the film other than corrosion resistance.

[Silane coupling agent]
Examples of the silane coupling agent include γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, and γ-(2-aminoethyl)aminopropyltriethoxysilane. , γ-(2-aminoethyl)aminopropylmethyldiethoxysilane, γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ- Methacryloxypropyltriethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(N-vinylbenzylaminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltriethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropylmethyldiethoxy Silane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane , γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldiethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, vinyltriacetoxysilane, γ-Chloropropyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropylmethyldiethoxysilane, hexamethyldisilazane, γ-anilinopropyltrimethoxysilane, γ-aniline Linopropylmethyldimethoxysilane, γ-anilinopropyltriethoxysilane, γ-anilinopropylmethyldiethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, octadecyldimethyl [3 -(trimethoxysilyl)propyl]ammonium chloride, octadecyldimethyl[3-(methyldimethoxysilyl)propyl]ammonium chloride, octadecyldimethyl[3-(triethoxysilyl)propyl]ammonium chloride, octadecyldimethyl[3-(methyldiethoxy) silyl)propyl] ammonium chloride, γ-chloropropylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, and the like. The amount of the silane coupling agent added in the chemical conversion treatment agent for forming the resin film layer 40 can be, for example, 2 to 80 g/L. By adding the silane coupling agent in an amount of 2 g/L or more, it is possible to improve the adhesion to the metal plate surface and improve the processing adhesion of the coating film. Furthermore, by controlling the amount of the silane coupling agent added to 80 g/L or less, it is possible to maintain the cohesive force of the coating and improve the processing adhesion of the coating. The silane coupling agents as exemplified above may be used alone or in combination of two or more.

[Zirconium compound]
Examples of the zirconium compound include zirconium normal propylate, zirconium normal butyrate, zirconium tetraacetylacetonate, zirconium monoacetylacetonate, zirconium bisacetylacetonate, zirconium monoethylacetoacetate, zirconium acetylacetonate bisethylacetoacetate, Examples include zirconium acetate, zirconium monostearate, zirconium carbonate, ammonium zirconium carbonate, potassium zirconium carbonate, and sodium zirconium carbonate. The amount of the zirconium compound added in the chemical conversion treatment agent for forming the resin film layer 40 can be, for example, 2 to 80 g/L. By adding the zirconium compound in an amount of 2 g/L or more, it is possible to improve the adhesion to the metal plate surface and improve the processing adhesion of the coating film. Furthermore, by controlling the amount of the zirconium compound to be 80 g/L or less, it is possible to maintain the cohesive force of the coating and improve the processing adhesion of the coating. Such zirconium compounds may be used alone or in combination of two or more.

[silica]
Examples of commercially available silica include "Snowtex N", "Snowtex C", "Snowtex UP", and "Snowtex PS" manufactured by Nissan Chemical Co., Ltd., and "Adelite AT-20Q" manufactured by ADEKA Co., Ltd. or powdered silica such as Aerosil #300 manufactured by Nippon Aerosil Co., Ltd. can be used. Silica can be selected as appropriate depending on the required performance of the coated metal plate. The amount of silica added in the chemical conversion treatment agent for forming the resin film layer 40 is preferably 1 to 40 g/L. By adding silica in an amount of 1 g/L or more, it is possible to improve the processing adhesion of the coating film. Further, by controlling the amount of silica added to 40 g/L or less, it is possible to achieve both effects of processing adhesion and corrosion resistance while suppressing an increase in cost.

[Phosphoric acid and its salts]
Examples of phosphoric acid and its salts include phosphoric acids and their salts such as orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, and tetraphosphoric acid; ammonium salts such as triammonium phosphate and diammonium hydrogen phosphate; Phosphonic acids such as aminotri(methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra(methylenephosphonic acid), diethylenetriaminepenta(methylenephosphonic acid) and their salts, organic phosphoric acids such as phytic acid and salts thereof. Note that examples of salts of phosphoric acid other than ammonium salts include metal salts with Na, Mg, Al, K, Ca, Mn, Ni, Zn, Fe, and the like. Phosphoric acid and its salts may be used alone or in combination of two or more.

Note that the content of phosphoric acid and its salts is preferably 0% by mass or more, more preferably 1% by mass or more, based on the solid content of the film. Further, the content of phosphoric acid and its salt is preferably 20% by mass or less, more preferably 10% by mass or less, based on the solid content of the film. When the content of phosphoric acid and its salts is 20% by mass or less, it is possible to prevent the film from becoming brittle, and it is possible to prevent a decrease in processing adhesion of the film when forming the coated metal plate. .

[Fluoride]
Examples of the fluoride include zircon ammonium fluoride, ammonium silicofluoride, titanium ammonium fluoride, sodium fluoride, potassium fluoride, calcium fluoride, lithium fluoride, titanium hydrofluoride, zircon hydrofluoride, and the like. . Such fluorides may be used alone or in combination of two or more.

Note that the content of fluoride is preferably 0% by mass or more, more preferably 1% by mass or more, based on the solid content of the film. Further, the content of fluoride is preferably 20% by mass or less, more preferably 10% by mass or less, based on the solid content of the film. When the fluoride content is 20% by mass or less, it is possible to prevent the coating from becoming brittle, and it is possible to prevent a decrease in processing adhesion of the coating when forming a coated metal plate.

[Vanadium compound]
Examples of vanadium compounds include vanadium compounds obtained by reducing pentavalent vanadium compounds such as vanadium pentoxide, metavanadate, ammonium metavanadate, sodium metavanadate, and vanadium oxytrichloride to divalent to tetravalent vanadium compounds with a reducing agent, and vanadium trioxide. , vanadium dioxide, vanadium oxysulfate, vanadium oxyoxalate, vanadium oxyacetylacetonate, vanadium acetylacetonate, vanadium trichloride, phosphovanadomolybdic acid, vanadium sulfate, vanadium dichloride, vanadium oxide, etc. with an oxidation number of 4 to 2. Examples include vanadium compounds. Such vanadium compounds may be used alone or in combination of two or more.

Note that the content of the vanadium compound is preferably 0% by mass or more, and more preferably 1% by mass or more, based on the solid content of the film. Further, the content of the vanadium compound is preferably 20% by mass or less, more preferably 10% by mass or less, based on the solid content of the film. When the content of the vanadium compound is 20% by mass or less, it is possible to prevent the film from becoming brittle, and it is possible to prevent a decrease in processing adhesion of the film when forming a coated metal plate.

[Tannin or tannic acid]
As the tannin or tannic acid, either a hydrolyzable tannin or a condensed tannin can be used. Examples of tannins and tannic acids include hameta tannin, pentad tannin, gallic tannin, myrobalan tannin, zibijibi tannin, algarobilla tannin, valonia tannin, catechin, and the like. The amount of tannin or tannic acid added in the chemical conversion treatment agent for forming the resin film layer 40 can be 2 to 80 g/L. By adding tannin or tannic acid in an amount of 2 g/L or more, it is possible to improve the adhesion to the metal plate surface and improve the processing adhesion of the coating film. Further, by controlling the amount of tannin or tannic acid added to 80 g/L or less, the cohesive force of the coating can be maintained and the processing adhesion of the coating can be improved.

Furthermore, the resin film layer 40 may further contain a colorant in addition to the above components. Thereby, it becomes possible to make the appearance of the painted metal plate 1 according to this embodiment a desired color tone, and it becomes possible to further improve the design of the painted metal plate 1.

Here, the type and content of the colorant contained in the resin film layer 40 are not particularly defined and may be adjusted as appropriate.

Additionally, acid, alkali, etc. may be added to the chemical conversion treatment agent for forming the resin film layer 40 for pH adjustment within a range that does not impair performance.

The average thickness _d3 of the resin film layer 40 is preferably 0.20 μm or more, more preferably 0.50 μm or more, and even more preferably 2.50 μm or more. Thereby, while forming the resin film layer 40 uniformly on the surface of the metal plate 10, it becomes possible to stably exhibit various effects caused by providing the film layer as described above. Further, the average thickness _d3 of the resin film layer 40 is preferably 60.00 μm or less, more preferably 30.00 μm or less, 15.00 μm or less, 1.00 μm or less, less than 1.00 μm, or , more preferably 0.80 μm or less. Thereby, while forming the resin film layer 40 uniformly on the surface of the metal plate 10, it becomes possible to stably exhibit various effects caused by providing the film layer as described above.

Moreover, the painted metal plate 1 according to the present embodiment further includes various known layers between the inorganic film layer 30 and the resin film layer 40, as schematically shown in FIG. 3B. You can leave it there.

Here, also in the cases shown in FIGS. 3A and 3B, the total thickness d _T (=d ₁ + d ₃ + d ₄ +α) from the surface of the metal plate 10 to the outermost surface of the photocatalyst layer 20 is 60.00 μm. The following shall apply. This suppresses a decrease in manufacturing simplicity and processability, secures an elution route for zinc from the zinc-containing metal layer 13, allows sufficient zinc to be eluted, and further improves the desired photocatalytic effect. It becomes possible to achieve uniform expression over the entire layer 20. The total thickness d _T (=d ₁ + d ₃ + d ₄ + α) from the surface of the metal plate 10 to the outermost surface of the photocatalyst layer 20 is preferably 15.00 μm or less, more preferably 10.00 μm or less, and It is preferably 7.00 μm or less, and even more preferably 1.00 μm or less, less than 1.00 μm, 0.90 μm or less, 0.80 μm or less, or 0.70 μm or less.

Here, in each of the modified examples as explained above, when the antiviral test specified in JIS R1756:2020 is conducted on the coated metal plate 1 for 4 hours, the concentration of zinc ions eluted into the virus-containing liquid is within the range of 0.60 to 5.00% by mass.

Note that although FIGS. 2A to 3B illustrate the case where each layer is provided on one side of the metal plate 10, each layer may be provided on both sides of the metal plate 10. In this case, the total thickness d _T from the surface of the metal plate 10 to the surface of the photocatalyst layer 20 is set to be 60.00 μm or less on each surface of the coated metal plate 1 .

The painted metal plate according to the first embodiment of the present invention has been described in detail above with reference to FIGS. 1 to 3B.

<How to measure the average thickness of each layer>
Here, the average thickness of each layer including the photocatalyst layer can be measured by observing the layer of interest from a cross-sectional direction using a microscope. As a method for preparing a sample to be observed from the cross-sectional direction, known methods such as embedding in resin and polishing the observation surface, FIB processing, microtome method, etc. can be used. Furthermore, as the type of microscope, known devices such as SEM and TEM can be used.

(About the manufacturing method of painted metal plates)
In the painted metal plate according to the present embodiment as described above, the surface of the metal plate 10 serving as the base material is subjected to various pretreatments such as cleaning as necessary, and then the photocatalyst layer 20 is formed. A photocatalytic treatment agent for forming the inorganic coating layer 30, an organic chemical conversion treatment agent for forming the resin coating layer 40, etc. are used in a desired layer configuration. It can be manufactured by coating, drying, and baking.

Here, the various paints can be applied by generally known coating methods, such as roll coating, curtain flow coating, air spray, airless spray, dipping, bar coating, and brush coating. Particularly preferred is roll coating, which allows stable coating with a thin film, which is a feature of this product.

Furthermore, the conditions for drying and baking are not particularly limited, and may be set as appropriate depending on the paint used.

<<Second embodiment>>
Next, a painted metal plate according to a second embodiment of the present invention will be described in detail.
A second embodiment of the present invention provides a coated metal plate having a metal plate and a coating layer located on at least one surface of the metal plate. The present invention relates to an embodiment having a first coating layer containing an active compound and 0.2 to 20.0% by mass of zinc element in terms of metallic Zn.

(About painted metal plates)
<Structure of painted metal plate>
Below, first, the structure of the painted metal plate according to the second embodiment of the present invention will be described with reference to FIG. 4. FIG. 4 is an explanatory diagram schematically showing an example of the structure of the painted metal plate according to the present embodiment.

As schematically shown in FIG. 4, the coated metal plate 3 according to the second embodiment of the present invention has a film layer on at least one surface of the metal plate, and the coated metal plate 3 has a film layer on at least one surface of the metal plate. It has at least a photocatalyst layer 25 as an example of a first film layer.

[About the metal plate 10]
In the painted metal plate 3 according to the present embodiment, the metal plate 10 is constructed using various base metals 11 as the base material of the metal plate 10. Here, various metal plates can be used as the base metal 11. Examples of such metal plates include various steel plates, aluminum plates, stainless steel plates, etc., and may be selected depending on the strength, characteristics, etc. required of the base metal 11.

Furthermore, in the painted metal plate 3 according to the present embodiment, various plating layers may be provided on the surface of the base metal 11 that constitutes the metal plate 10. Here, a plating layer not containing zinc may be provided as the various plating layers.

Here, the thickness of the metal plate 10 as described above is not particularly limited, and depends on the mechanical strength (for example, tensile strength, etc.), workability, etc. required of the coated metal plate 3 according to the present embodiment. It may be set as appropriate depending on the situation.

Furthermore, various patterns such as a hairline pattern or a spangle pattern along the rolling direction of the base metal 11 may be present on the surface of the metal plate 10. By providing such a pattern, it becomes possible to further improve the design of the painted metal plate 3.

[About the photocatalyst layer 25]
In the painted metal plate 3 according to the present embodiment, the photocatalyst layer 25 as an example of the first film layer is formed on the outermost surface of the film layer on at least one surface of the metal plate 10, as schematically shown in FIG. This is the layer located in The photocatalytic layer 25 is a layer containing at least a compound having photocatalytic activity (hereinafter sometimes abbreviated as "photocatalytic compound") and element Zn.

Since the photocatalytic layer 25 according to the present embodiment contains a compound having photocatalytic activity, the compound having photocatalytic activity can undergo a photocatalytic reaction by light (particularly light in the ultraviolet to visible light range) that is incident on the photocatalytic layer 25. cause As a result, the photocatalytic layer 25 according to this embodiment exhibits various photocatalytic effects including antiviral effects and sterilizing effects. Thereby, the coated metal plate 3 according to the present embodiment can realize various properties including an antiviral effect and a sterilizing effect.

Furthermore, since the photocatalyst layer 25 according to the present embodiment contains the element Zn, the element Zn contained in the photocatalyst layer 25 is different from the Zn contained in the zinc-containing metal layer 13 as described in the first embodiment. serves a similar function. As a result, zinc elutes into the virus-containing solution in the antiviral test specified in JIS R1756:2020, which was discovered by the present inventors. As a result, the coated metal plate 3 according to the present embodiment can achieve the same effect as the coated metal plate 1 according to the first embodiment described above, and the antivirus function of the coated metal plate 3 can be achieved more easily. This method makes it possible to improve performance over a longer period of time.

The photocatalytic compound contained in the photocatalytic layer 25 according to the present embodiment is the same as the photocatalytic compound contained in the photocatalytic layer 20 according to the first embodiment, and the photocatalytic compound according to the first embodiment It has the same effect as the photocatalytic compound contained in the layer 20. Therefore, detailed description of the photocatalytic compound will be omitted below.

In the photocatalyst layer 25 according to the present embodiment, the content of the element Zn contained in the photocatalyst layer 25 is 0.2% by mass or more in terms of metal Zn. When the Zn content is less than 0.2% by mass, the amount of zinc eluted from the photocatalyst layer 25 is too small, and as a result, the antibacterial effect as described above cannot be expressed. When the Zn content is 0.2% by mass or more, it becomes possible to exhibit the antibacterial effect as described above. The content of the element Zn is more preferably 0.6% by mass or more, still more preferably 1.0% by mass or more.

On the other hand, the Zn content in the photocatalyst layer 25 is 20.0% by mass or less in terms of metal Zn. When the content of Zn is more than 20.0% by mass, the amount of zinc eluted from the photocatalytic layer 25 becomes too large, the density of the photocatalytic layer 25 decreases, and corrosion factors easily enter from the outside. As a result, the corrosion resistance of the painted metal plate 3 deteriorates. By setting the total content of the element Zn to 20.0% by mass or less, it is possible to ensure the content of the photocatalytic compound and to express the above-mentioned effects without saturating the effects. It is also possible to ensure the corrosion resistance of the painted metal plate 3. The total content of the element Zn is preferably 18.0% by mass or less, more preferably 16.0% by mass or less, still more preferably 5.0% by mass or less, and even more preferably 3% by mass or less. .5% by mass or less, or 2.5% by mass or less.

The photocatalytic layer 25 further contains at least one element of Si or Zr, and the total concentration of these elements is 5% by mass or more in terms of silica for Si and zirconia for Zr. It is preferable. In other words, the photocatalytic layer 25 is an inorganic film having a skeleton of an inorganic component having a three-dimensional network structure containing at least one element of Si or Zr, and possibly impurities. Alternatively, the total concentration of at least one element of Zr is preferably 5% by mass or more in terms of silica for Si and zirconia for Zr. By containing at least one element of Si or Zr at the above concentration, it becomes possible to realize the photocatalyst layer 25 with even better corrosion resistance. The total content of at least one element of Si or Zr is more preferably 10% by mass or more. Here, the inorganic component means a component that does not contain an organic resin.

The photocatalytic layer 25 further contains at least one element of Si or Zr, and the total concentration of these elements is 50% by mass or less in terms of silica for Si and zirconia for Zr. It is preferable. By containing at least one element of Si or Zr at the above concentration, it becomes possible to realize the photocatalyst layer 25 with even better corrosion resistance. The total content of at least one element of Si or Zr is more preferably 40% by mass or less. Here, the Si or Zr contained preferably has excellent light transmittance, and is preferably an inorganic component that is less susceptible to decomposition by photocatalysts. Examples of such inorganic components containing Si and Zr include silica and zirconia.

Further, the photocatalytic layer 25 further contains at least one element selected from the group consisting of Cu, Fe, Ni, and Ag, in addition to the photocatalytic compound and at least one element of Si or Zr. It is preferable to do so. Here, the elements Cu, Fe, Ni, and Ag are elements that promote the elution of zinc from the photocatalyst layer 25, so when the photocatalyst layer 25 further contains these elements, more zinc is absorbed into the photocatalyst layer. This is preferable because it elutes from No. 25. Further, the elements Cu and Ag are particularly preferable because they are also elements that exhibit antibacterial effects.

The total content of at least one element selected from the group consisting of Cu, Fe, Ni, and Ag in the photocatalyst layer 25 is preferably 0.2% by mass or more in terms of metal elements. When the total content of the metal elements is 0.2% by mass or more, the above effects can be expressed in a more preferable state. The total content of the metal elements is more preferably 0.6% by mass or more, and still more preferably 1.0% by mass or more. On the other hand, the total content of at least one element selected from the group consisting of Cu, Fe, Ni, and Ag in the photocatalyst layer 25 is preferably 5.0% by mass or less in terms of metal elements. By setting the total content of the above-mentioned metal elements to 5.0% by mass or less, it is possible to maintain the content of the photocatalytic compound while producing the above-mentioned effects without saturating them. . The total content of the metal elements is more preferably 3.5% by mass or less, still more preferably 2.5% by mass or less.

Note that the photocatalyst layer 25 containing the photocatalytic compound described above may contain an antibacterial agent and an adsorbent such as activated carbon or zeolite, as necessary, within a range that does not impair the effects of the present invention.

The average thickness _d1 ' of the photocatalyst layer 25 (in the case of the layer structure shown in FIG. 4, the total thickness from the surface of the metal plate 10 to the outermost surface of the photocatalyst layer 25 (which can also be considered as the outermost surface of the film layer) d _T ) is 0.05 μm or more. If the average thickness d ₁ ' of the photocatalytic layer 25 is less than 0.05 μm, it will be difficult to uniformly form the photocatalytic layer 25 as described above, and the obtained photocatalytic effect will be uneven. Undesirable. By setting the average thickness d _{1 ′} to 0.05 μm or more, the elution route for zinc from the photocatalyst layer 25 is secured and zinc is sufficiently eluted, and the desired photocatalytic effect is uniformly distributed over the entire photocatalyst layer 25. It becomes possible to express it.

On the other hand, the average thickness _d1 ' of the photocatalyst layer 25 (in the case of the layer structure shown in FIG. 4, it is also the total thickness _dT from the surface of the metal plate 10 to the outermost surface of the photocatalyst layer 25) is 5.00 μm. It is as follows. If the average thickness d ₁ ' of the photocatalyst layer 25 exceeds 5.00 μm, the resulting photocatalytic effect will be saturated while the manufacturing cost will increase, which is not preferable. Furthermore, it becomes difficult to ensure a sufficient amount of zinc eluted from the photocatalyst layer 25, which is also unfavorable from this point of view. Furthermore, since the photocatalyst layer is an inorganic film, processability is reduced. By setting the average thickness d _{1 ′} to 5.00 μm or less, a decrease in ease of manufacture and a decrease in workability is suppressed, and a route for zinc elution from the photocatalyst layer 25 is secured to ensure sufficient zinc elution. Furthermore, it becomes possible to uniformly exhibit the desired photocatalytic effect over the entire photocatalytic layer 25.

Normally, light that passes through the photocatalyst layer 25 without hitting the photocatalyst compound is generated with a certain probability. Conventionally, such light that does not interact with the photocatalytic compound ends up being light that cannot produce a photocatalytic effect. In this embodiment, by reflecting such light on the surface of the metal plate 10, it is possible to increase the probability that the light incident on the photocatalyst layer 25 will collide with the photocatalyst compound. Thereby, in this embodiment, the photocatalytic effect can be further improved. In the case of the layer structure shown in FIG. 4, the total thickness _dT from the surface of the metal plate 10 to the outermost surface of the photocatalyst layer 25 is naturally less than 5.00 μm, and as a result, the incident light is transmitted to the surface of the metal plate 10. (In other words, the reflected light at the interface between the metal plate 10 and the photocatalyst layer 25) can be used for the photocatalytic reaction by the photocatalytic compound, thereby further improving the photocatalytic effect while suppressing costs. be able to.

The average thickness d ₁ ' of the photocatalyst layer 25 is preferably 0.10 μm or more, more preferably 0.15 μm or more. Further, the average thickness d ₁ ' of the photocatalyst layer 20 is preferably 2.00 μm or less, more preferably 1.00 μm or less, still more preferably less than 1.00 μm, and even more preferably 0.80 μm. Below, it is 0.60 μm or less, or 0.50 μm or less.

Note that although FIG. 4 shows a configuration in which the photocatalyst layer 25 is formed on one surface of the metal plate 10, the photocatalyst layer 25 may be formed on both surfaces of the metal plate 10.

<Concentration of zinc ions eluted into virus-containing liquid in antiviral test>
The structure of the painted metal plate 3 as described above has a zinc ion concentration of 0.60 to 5.0% when an antiviral test specified in JIS R1756:2020 is conducted for 4 hours. This is one of the conditions for the content to be within the range of 0.00% by mass.

The reason why the above structure is one of the conditions is that in the coated metal plate 3 according to this embodiment, the photocatalyst layer 25 is provided in an appropriate state, and furthermore, the outermost surface of the photocatalyst layer 25 from the surface of the metal plate 10 is Since the total thickness d _T and the Zn content in the photocatalyst layer 25 are each within specific ranges, an appropriate amount of zinc can be eluted from the photocatalyst layer 25 .

Note that the amount of zinc eluted from the photocatalyst layer 25 can be controlled to a desired state by adjusting the Zn content in the photocatalyst layer 25 and the total thickness _dT .

Here, when the zinc ion concentration in the virus-containing liquid is less than 0.60% by mass, it means that the amount of zinc eluted from the photocatalyst layer 25 is insufficient, and the anti-virus exhibited by the coated metal plate 3 Functionality cannot be further improved. The zinc ion concentration in the virus-containing liquid is preferably 0.90% by mass or more, more preferably 1.20% by mass or more.

On the other hand, when the zinc ion concentration in the virus-containing liquid is more than 5.00% by mass, the amount of zinc eluted from the photocatalyst layer 25 becomes too large, making it impossible to ensure the corrosion resistance of the metal plate 10. The zinc ion concentration in the virus-containing liquid is preferably 4.50% by mass or less, more preferably 3.50% by mass or less.

In addition, in the coated metal plate 3 according to the present embodiment, the total content of elements (more specifically, ions) having a nobler potential than zinc that is present in the coating layer is 20.0 in terms of metal elements. It is preferably less than % by mass. Here, examples of elements having a nobler potential than zinc include Cu, Ag, and the like. By setting the total content of elements with a nobler potential than zinc in the film layer to 20.0% by mass or less, the zinc ion concentration in the virus-containing liquid as described above is 5.00% by mass or less. This makes it possible to further achieve both excellent antiviral properties and excellent corrosion resistance. The total content of elements with a nobler potential than zinc in the coating layer is more preferably 15.0% by mass or less, still more preferably 11.0% by mass or less, and even more preferably 7.5% by mass. mass% or less. Note that the lower limit of the total content of elements having a nobler potential than zinc in the coating layer is not particularly specified, and may be 0% by mass.

<Modification example-3>
The coated metal plate 3 according to this embodiment, which has the layer structure shown in FIG. 4, has an additional film layer that functions as a chemical conversion film layer between the metal plate 10 and the photocatalyst layer 25. It's okay. By providing a chemical conversion coating layer between the metal plate 10 and the photocatalyst layer 25, it is possible to further improve the adhesion between the metal plate 10 and the photocatalyst layer 25. Furthermore, it is also possible to further improve the corrosion resistance and the like of the painted metal plate 3 according to this embodiment.

Hereinafter, the further film layer that functions as the chemical conversion film layer will be described in detail with reference to FIGS. 5A and 5B. FIGS. 5A and 5B are explanatory diagrams schematically showing other examples of the structure of the coated metal plate according to the present embodiment.

5A and 5B are schematic diagrams schematically showing the layer structure of the coated metal plate 3 when an inorganic film layer 30 functioning as a chemical conversion film layer is provided as an example of the second film layer. . In such a case, the painted metal plate 3 according to this embodiment has an inorganic film layer 30 as an example of a second film layer between the metal plate 10 and the photocatalyst layer 25 as described above.

Moreover, the painted metal plate 3 according to this embodiment further includes various known layers between the photocatalyst layer 25 and the inorganic film layer 30, as schematically shown in FIG. 5B. It's okay.

Here, the inorganic film layer 30 of the painted metal plate 3 according to the present embodiment has the same configuration as the inorganic film layer 30 of the painted metal plate 1 according to the first embodiment of the present invention, Further, since similar effects are achieved, detailed explanation will be omitted below.

Furthermore, even in the cases shown in FIGS. 5A and 5B, the total thickness d _T (=d ₁ '+d ₂ +α) from the surface of the metal plate 10 to the outermost surface of the photocatalyst layer 25 is 60.00 μm or less. do. This suppresses deterioration in manufacturing simplicity and processability, secures an elution route for zinc from the photocatalytic layer 25, sufficiently elutes zinc, and further provides the desired photocatalytic effect on the photocatalytic layer 25. can be expressed uniformly throughout the entire area. The total thickness d _T (=d ₁ '+d ₂ +α) from the surface of the metal plate 10 to the outermost surface of the photocatalyst layer 25 is preferably 15.00 μm or less, more preferably 10.00 μm or less, and even more preferably is 7.00 μm or less, and even more preferably 1.00 μm or less, less than 1.00 μm, 0.90 μm or less, 0.80 μm or less, or 0.70 μm or less.

<Modification example-4>
In addition to the inorganic film layer 30 located between the metal plate 10 and the photocatalyst layer 25, the painted metal plate 3 according to the present embodiment has a third film layer further below the inorganic film layer 30 as an example of a third film layer. It may have a resin film layer 40 of.
Below, the resin film layer 40 will be explained in detail with reference to FIGS. 6A and 6B. 6A and 6B are explanatory diagrams schematically showing other examples of the structure of the coated metal plate according to the present embodiment.

FIGS. 6A and 6B are schematic diagrams schematically showing the layer structure of the coated metal plate 3 when a resin film layer 40 as an example of the third film layer is provided. In such a case, the painted metal plate 3 according to the present embodiment has a resin film layer 40 as an example of a third film layer below the inorganic film layer 30 as described above.

Moreover, the painted metal plate 3 according to the present embodiment further includes various known layers between the inorganic film layer 30 and the resin film layer 40, as schematically shown in FIG. 6B. You can leave it there.

Here, the resin film layer 40 that the painted metal plate 3 according to the present embodiment has has the same configuration as the resin film layer 40 that the painted metal plate 1 according to the first embodiment of the present invention has, and Since similar effects are achieved, detailed explanation will be omitted below.

The average thickness _d3 of the resin film layer 40 is preferably 0.20 μm or more, more preferably 0.50 μm or more, and even more preferably 2.50 μm or more. Thereby, while forming the resin film layer 40 uniformly on the surface of the metal plate 10, it becomes possible to stably exhibit various effects caused by providing the film layer as described above. Further, the average thickness _d3 of the resin film layer 40 is preferably 60.00 μm or less, more preferably 30.00 μm or less, even more preferably 12.00 μm or less, 1.00 μm or less, It is even more preferable that it is less than 1.00 μm or 0.90 μm or less. Thereby, while forming the resin film layer 40 uniformly on the surface of the metal plate 10, it becomes possible to stably exhibit various effects caused by providing the film layer as described above.

Here, also in the case shown in FIGS. 6A and 6B, the total thickness d _T (=d ₁ '+d ₃ +d ₄ +α) from the surface of the metal plate 10 to the outermost surface of the photocatalyst layer 25 is 60. 00 μm or less. This suppresses deterioration in manufacturing simplicity and processability, secures an elution route for zinc from the photocatalytic layer 25, sufficiently elutes zinc, and further provides the desired photocatalytic effect on the photocatalytic layer 25. can be expressed uniformly throughout the entire area. The total thickness d _T (=d ₁ '+d ₃ +d ₄ +α) from the surface of the metal plate 10 to the outermost surface of the photocatalyst layer 25 is preferably 15.00 μm or less, more preferably 10.00 μm or less, More preferably, it is 7.00 μm or less, and still more preferably 1.00 μm or less, less than 1.00 μm, 0.90 μm or less, 0.80 μm or less, or 0.60 μm or less.

Here, in each of the modified examples as explained above, when the antiviral test specified in JIS R1756:2020 is conducted on the painted metal plate 3 for 4 hours, the concentration of zinc ions eluted into the virus-containing liquid is within the range of 0.60 to 5.00% by mass.

Note that although FIGS. 5A to 6B illustrate the case where each layer is provided on one side of the metal plate 10, each layer may be provided on both sides of the metal plate 10. In this case, the total thickness d _T from the surface of the metal plate 10 to the surface of the photocatalyst layer 25 is set to be 60.00 μm or less on each surface of the coated metal plate 3 .

The painted metal plate according to the second embodiment of the present invention has been described in detail above with reference to FIGS. 4 to 6B.

(About the manufacturing method of painted metal plates)
In the painted metal plate according to the present embodiment as described above, the surface of the metal plate 10 serving as the base material is subjected to various pretreatments such as cleaning as necessary, and then the photocatalyst layer 25 is formed. A photocatalytic treatment agent for forming the inorganic coating layer 30, an organic chemical conversion treatment agent for forming the resin coating layer 40, etc. are used in a desired layer configuration. It can be manufactured by coating, drying, and baking.

Hereinafter, the coated metal plate according to the present invention will be specifically explained while showing Examples and Comparative Examples. In addition, the Example shown below is only an example of the painted metal plate based on this invention, and the painted metal plate based on this invention is not limited to the following example.

Nine types of metal plates shown in Table 1 below were prepared as metal plates to serve as base materials for coated metal plates. In Table 1, the six types of metal plates represented as SD, ZL, GI, GL, AL, and GA are various plated steel plates using steel plates as a base material. The thickness of each metal plate, and the plating composition and coating weight/standard of each plated steel plate are as shown in Table 1 below. In addition, a zinc-containing film layer using zinc was separately formed on the stainless steel plate by vapor deposition at a coating weight of 20 g/m ² to obtain Stainless Steel-2.

Seven types of compounds shown in Table 2 below were prepared as compounds having photocatalytic activity (photocatalytic compounds). All photocatalyst compounds used were commercially available ones. The supported metal and average particle size are also listed in Table 2.

<Organic chemical conversion treatment agent>
The raw materials of the water-based paint (chemical conversion treatment agent) for forming the organic chemical conversion treatment film used to form the resin film layer and the concentrations in the dried film are shown in Table 3 below. The amount of each component added was adjusted so that the concentration of each component would be a predetermined concentration in the dry film. Ion-exchanged water was added to adjust the solid content concentration of the treatment agent to 20% by mass. Each treatment agent was applied to give the dry film thickness shown in Tables 4-1, 4-2, and 6 below. Thereafter, the metal plate was dried in an induction heating furnace to reach a temperature of 150° C., and then water-cooled by spraying.

<Photocatalyst treatment agent, inorganic chemical conversion treatment agent>
The photocatalyst treatment agent used and the method for producing the inorganic chemical conversion treatment agent will be explained.
The inorganic chemical conversion treatment agent for forming the inorganic film layer was adjusted to have a solid content concentration of 8% by mass in consideration of storage stability. Concentrations were adjusted by diluting with n-butanol. Further, in some examples, ammonium dihydrogen phosphate was contained as a P source and sodium metavanadate was contained as a V source in the following inorganic chemical conversion treatment agent. The photocatalyst treatment agent was prepared by adding a predetermined amount of the compound shown in Table 2 to the following inorganic chemical conversion treatment agent. The solid content concentration of the photocatalytic compound is as shown in Table 4-1, Table 4-2, and Table 6 below.

(1) Inorganic chemical conversion treatment agent (Si-based): tetraethoxysilane (22.5 parts by mass), methacryloxypropyltrimethoxysilane (2.8 parts by mass), n-butanol (26 parts by mass), were mixed and stirred at 60°C for 2 hours. While stirring this mixture, a mixed solution of 26% by mass hydrochloric acid (3 parts by mass) and n-butanol (26 parts by mass) was added dropwise at a rate of 1 drop/second. Thereafter, the mixture was kept at 60° C. for 2 hours while stirring to obtain a processing agent. A series of operations were performed in a nitrogen atmosphere.

(2) Inorganic conversion treatment agent (Zr type): zirconium n-butoxide (34.5 parts by mass), n-butanol (11.6 parts by mass), 1,5-diaminopentane (0.5 parts by mass) ) and yttrium nitrate (2.8 parts by mass) were mixed and stirred for 1 hour. Then, glacial acetic acid (4.8 parts by mass) was added and stirred for 40 hours. Thereafter, concentrated nitric acid (0.6 parts by mass) was added dropwise at a rate of 1 drop/second, and the mixture was stirred for 2 hours to obtain a processing agent. A series of operations were performed in a nitrogen atmosphere.

In some cases, for the above-mentioned photocatalytic treatment agent and inorganic chemical conversion treatment agent, ultrafine particle zinc oxide (trade name: FZO) manufactured by Ishihara Sangyo Co., Ltd. is used as a Zn source, and as a Cu source. is nanoparticle cuprous oxide (product name: FRC-N10) manufactured by Furukawa Chemicals Co., Ltd., Fe source is Fe ₂ O ₃ nanopowder (product name: 544884) manufactured by Sigma-Aldrich Co., Ltd., and Ni source is Iwatani Co., Ltd. A 50 nm nickel nanopowder manufactured by Sangyo Co., Ltd. was used as an Ag source, and Ag nanopowder (trade name: 576832) manufactured by Sigma-Aldrich Co., Ltd. was included.

Using the metal plates and photocatalytic compounds shown above, coat two coated metal plates for each level by roll coating with the configurations shown in Tables 4-1, 4-2, and Table 6 below. Manufactured one by one. Note that each layer was formed on one side of the metal plate. In addition, some of the painted metal plates were subjected to a design process to form a hairline pattern on the surface of the metal plate. In addition, for some painted metal plates, spangles can be produced by adjusting the solidification rate of hot-dip galvanizing using a hot-dip galvanizing bath containing 0.1% by mass of Sb and 0.2% by mass of Al. A plated steel plate with a pattern formed thereon was used as the base material.

The average film thickness of each layer in the above-mentioned painted metal plate was measured by embedding the obtained painted metal plate in resin, polishing the cross section, and observing the observed surface using a microscope.

In addition, after carrying out an antiviral test specified in JIS R1756:2020 for 4 hours on one of the obtained coated metal plates, the concentration of zinc ions eluted into the virus-containing liquid was determined according to the method explained earlier. was measured.

A test piece was prepared using the other side of the obtained coated metal plate, and evaluated from the viewpoints of antiviral properties, processing adhesion, and corrosion resistance. The detailed evaluation method is as follows.

<Antiviral properties>
The antiviral properties were verified by measuring the viral infectivity through the following antiviral test in accordance with the antiviral standards stipulated by the Photocatalyst Industry Association. More specifically, a test piece (dimensions: 50 x 50 mm ² ) prepared from each painted metal plate was placed in a petri dish with the evaluation side facing up, and a virus suspension containing bacteriophage Qβ was dropped onto the evaluation surface. . Thereafter, a film was placed over the test piece to bring the virus suspension into close contact with the entire evaluation surface, and then a petri dish lid was placed on the test piece. The petri dish was left standing for 4 hours in a room at 25° C. with an illuminance of 500 lux, simulating the room of a general office. Thereafter, the virus on the film surface and the surface of the evaluation surface was washed, and the virus infectivity titer (unit: PFU, PFU: Plaque Forming Units) in the obtained washing solution was measured by the plaque measurement method, and inductively coupled plasma (ICP) ) The concentration of eluted zinc ions in the cleaning solution was measured using an emission spectrometer (7700X manufactured by Agilent).

Separately from the painted metal plate, anti-virus tests were also conducted on each metal plate without a photocatalyst layer, and the virus infection value of the painted metal plate was compared with that of the metal plate without a photocatalyst layer. The extent to which the infectious titer decreased was evaluated as an activity value. If the virus has decreased by 10 ² or more (in other words, if the activity value is 1 x 10 ² or more), the use of the certification seal stipulated by the Photocatalyst Industry Association is permitted, so the obtained activity Those with a value of 1×10 ² or more were judged to have passed. Note that in Tables 5-1, 5-2, and 7 below, the obtained activity values are expressed in logarithms.

<Processing adhesion>
The test piece was subjected to 0T bending (180° bending), and the coating on the outside of the bent portion was peeled off with adhesive tape (Cello Tape (registered trademark) manufactured by Nichiban, tape width 15 mm), and the state of coating adhesion to the tape side was observed. . Processing adhesion was evaluated using the following evaluation criteria. In this adhesion test, the passing level was 3 or higher. Specifically, a score of 4 or higher was determined to be excellent in adhesion, and a score of 3 or higher was determined to be acceptable (passing level).

(Evaluation criteria)
5: No film adhering to the tape side 4: There are several film peeling points on the tape side, and the peeling length on the steel plate side is less than 5% of the total length of the processed part on one side of the test piece 3: There are several peeling points on the tape side The peeling length on the steel plate side is 5% or more and less than 10% of the total length of the processed part on one side of the test piece when there is film peeling at a point. 2: There is film peeling on the tape side and the peeling length on the steel plate side is 10% or more and less than 20% of the total length of the processed area on one side of the test piece 1: There is film peeling on the tape side, and the peeling length on the steel plate side is 20% or more of the total length of the processed area on one side of the test piece.

<Corrosion resistance of flat plate part>
The end face of the test piece was sealed with tape, and a salt spray test (SST) in accordance with JIS Z 2371:2015 was conducted for 72 hours. After the test, the rust occurrence on the flat plate portion was observed, and the corrosion resistance was evaluated using the following evaluation criteria. The passing level was 3 or higher.

(Evaluation criteria)
5: White rust occurrence area is less than 1% of the total area of one side of the test piece 4: White rust occurrence area is 1% or more and less than 5% of the total area of one side of the test piece 3: White rust occurrence area is 5% or more and less than 10% of the total area of one side of the test piece. 2: The area where white rust occurs is 10% or more and less than 30% of the total area of one side of the test piece. 1: The area where white rust occurs is less than 10% of the total area of one side of the test piece. 30% or more of the total area of one side of the piece

<Corrosion resistance of processed parts>
For each test piece, a test material was obtained by processing (7 mm extrusion) according to the Erichsen test (JIS Z2247:2006). The test material was subjected to a salt spray test (SST) in accordance with JIS Z 2371 for 72 hours with the end face sealed with tape. The state of rust occurrence in the processed parts was observed after the test, and the corrosion resistance was evaluated using the following evaluation criteria. The passing level was 3 or above.

(Evaluation criteria)
5: White rust occurrence area is less than 5% of the total area of the processed part of the test piece 4: White rust occurrence area is 5% or more and less than 10% of the total area of the processed part of the test piece 3: White rust The area where white rust occurs is 10% or more and less than 30% of the total area of the processed part of the test piece 2: The area where white rust occurs is 30% or more and less than 50% of the total area of the processed part of the test piece 1: White rust The generated area is 50% or more of the total area of the processed part of the test piece.

The obtained results are summarized in Table 5-1, Table 5-2, and Table 7 below.
As is clear from Table 5-1, Table 5-2, and Table 7 below, the coated metal sheets corresponding to the examples of the present invention exhibit excellent antiviral properties, processing adhesion, and corrosion resistance, while The coated metal plate corresponding to the comparative example of the invention failed in the evaluation results of antiviral properties or processing adhesion.

Although preferred embodiments of the present invention have been described above in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person with ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea stated in the claims. It is understood that these also naturally fall within the technical scope of the present invention.

The embodiments disclosed herein are illustrative in all respects and are not restrictive. The above-described embodiments may be omitted, replaced, or modified in various forms without departing from the scope of the appended claims and the configurations and gist of the present invention as described below. For example, the constituent features of the above embodiments can be combined arbitrarily within a range that does not impair the effects. Further, from the arbitrary combination, the functions and effects of the respective constituent elements related to the combination can be obtained as a matter of course, and other functions and other effects that are obvious to a person skilled in the art from the description of this specification can be obtained. .

Furthermore, the effects described in this specification are merely explanatory or illustrative, and are not limiting. In other words, the technology according to the present invention can produce other effects that are obvious to those skilled in the art from the description of this specification, in addition to or in place of the above effects.

1, 3 Painted metal plate 10 Metal plate 11 Base metal 13 Zinc-containing

metal layer

20, 25 Photocatalyst layer (first film layer)
30 Inorganic film layer (second film layer)
40 Resin film layer (third film layer)

Claims

A painted metal plate comprising a metal plate and a coating layer located on at least one surface of the metal plate,
The metal plate is a metal plate having a zinc-containing metal layer containing at least zinc on at least one surface,
The coating layer includes a first coating layer located on the outermost surface of the coated metal plate and containing at least a compound having photocatalytic activity;
The average thickness of the first film layer is 0.05 to 5.00 μm,
The total thickness from the surface of the zinc-containing metal layer to the outermost surface of the first coating layer is 15.00 μm or less,
A coated metal plate having a concentration of zinc ions eluted into a virus-containing liquid of 0.60 to 5.00% by mass when an antiviral test specified in JIS R1756:2020 is conducted for 4 hours.
The thickness of the first film layer is 0.05 to 0.95 μm,
The coated metal plate according to claim 1, wherein the total thickness from the surface of the zinc-containing metal layer to the outermost surface of the first coating layer is less than 1.0 μmm.
The coated metal sheet according to claim 1 or 2, wherein the total content of elements with a nobler potential than zinc in the coating layer is 0 to 20.0% by mass.
The coated metal plate according to claim 1, wherein the first film layer further contains at least one element selected from the group consisting of Zn, Cu, Fe, Ni, and Ag.
The first film layer further contains at least one of Si or Zr,
The coated metal plate according to claim 1, wherein the total content of the elements is 5 to 50% by mass in terms of silica for Si and zirconia for Zr.
A painted metal plate comprising a metal plate and a coating layer located on at least one surface of the metal plate,
The coating layer includes a first coating layer located on the outermost surface of the coated metal plate and containing a compound having photocatalytic activity and 0.2 to 20.0% by mass of zinc element in terms of metal Zn. and
The average thickness of the first film layer is 0.05 to 5.00 μm,
The total thickness from the surface of the metal plate to the outermost surface of the first coating layer is 60.0 μm or less,
A coated metal plate having a concentration of zinc ions eluted into a virus-containing liquid of 0.60 to 5.00% by mass when an antiviral test specified in JIS R1756:2020 is conducted for 4 hours.
The coated metal sheet according to claim 6, wherein the total content of elements with a nobler potential than zinc in the coating layer is 0 to 20.0% by mass.
The coated metal plate according to claim 6 or 7, wherein the first film layer further contains at least one element selected from the group consisting of Cu, Fe, Ni, and Ag.
The first film layer further contains at least one of Si or Zr,
The coated metal plate according to claim 6, wherein the total content of the elements is 5 to 50% by mass in terms of silica for Si and zirconia for Zr.
The film layer further includes a second film layer located below the first film layer and made of an inorganic component,
The second film layer contains at least one of Si or Zr as the inorganic component,
The coated metal plate according to claim 1 or 6, wherein the second coating layer has an average thickness of 0.05 to 5.00 μm.
The coated metal plate according to claim 10, wherein the second coating layer further contains at least one of P or V as the inorganic component.
The coated metal plate according to claim 10, wherein the second coating layer further contains at least one element selected from the group consisting of Zn, Cu, Fe, Ni, and Ag.
The film layer further includes a third film layer located below the second film layer and containing a resin component,
The coated metal plate according to claim 10, wherein the third coating layer has an average thickness of 0.50 to 14.00 μm.
The painted metal plate according to claim 13, wherein the third film layer further contains a colorant.
The coated metal plate according to claim 1 or 6, wherein the compound having photocatalytic activity is anatase titanium oxide.
The coated metal plate according to claim 15, wherein the compound having photocatalytic activity is a metal-supported titanium oxide in which at least one of Cu and Fe is supported on titanium oxide.
The painted metal sheet according to claim 1, wherein the metal sheet is a zinc-based plated steel sheet having a zinc-based plating layer as the zinc-containing metal layer.
The coated metal plate according to claim 17, wherein the zinc-based plating layer is a plating layer containing 30% by mass or more of Zn in terms of metallic Zn.
The zinc-based plating layer is any one of a zinc plating layer, a zinc-aluminum alloy plating layer, a zinc-aluminum-magnesium alloy plating layer, a zinc-nickel alloy plating layer, or a zinc-iron alloy plating layer. 17. The painted metal plate according to 17.
The coated metal plate according to claim 1 or 6, wherein a hairline along the rolling direction of the metal plate exists on the surface of the metal plate.
The painted metal plate according to claim 1, wherein a spangle pattern is present on the surface of the zinc-containing metal layer.