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    • 专利摘要:
    methods for producing steel sheet and black coated molded article. the present invention relates to a method for producing a black coated steel blade (here also called “black-plated”) capable of being darkened in a short period of time, and showing an excellent ability to maintain a black appearance after processing. as an original blade, the blade used is a zn-coated steel blade that contains melted al and mg and has a zn coating layer containing melted al and mg, containing al in an amount of 0.1-22.0% by weight, inclusive, and containing mg in an amount of 0.1-1.5% by weight, inclusive. the coating layer is darkened by placing the molten coated steel sheet in contact with the water vapor in a tightly sealed container. when such action is performed, the oxygen concentration within the tightly sealed container is 13% or less.
    公开号:BR112014026502B1
    申请号:R112014026502-0
    申请日:2013-04-23
    公开日:2021-04-13
    发明作者:Tadashi Nakano；Masaya Yamamoto；Hirofumi Taketsu
    申请人:Nisshin Steel Co., Ltd；
    IPC主号:
    专利说明:

    Technical field
    [0001] The present invention relates to a method for producing a black-plated steel sheet and to a method for producing a molded article of the black-plated steel sheet. Background Technique
    [0002] In a field such as roofing materials and external materials of a building, household appliances, and automobiles, the need for steel sheets having a black appearance is increasing from a design point of view, etc. The surface of a steel sheet can be darkened by applying a black coating material to the surface of the steel sheet to form a black coating film. In the field described above, however, coated steel sheets such as Zn coating by hot dip, Zn coating by Al, and Zn coating by Al and Mg by hot dip are used in many cases from the point of view of corrosion resistance. The coated steel blade has a shiny metallic surface with a silvery gray color. Consequently, in order to obtain a black design-quality appearance by applying a black coating material, a black coating film needs to hide the color of the coated steel sheet, resulting in high coating costs. In addition, the thick coating film eliminates welding resistance such as spot welding, which is another disadvantage.
    [0003] As a method to hide the metallic luster with the silvery gray color of a coated steel sheet without the formation of a black coating film, a method has been proposed to darken a coating layer itself (for example, refer to to PTL-1). PTL-1 describes a method for forming a thin black layer on the surface of the coating layer by blowing water vapor at high temperature on a Zn-coated steel sheet containing Al by hot dipping for 24 hours or more. List of citations Patent Literature
    [0004] PTL-1 - Japanese Patent Application Open to Public Inspection No. SHO 64-56881 Summary of the invention Technical problem
    [0005] A problem with the method of producing a black-plated steel sheet described in PTL-1 is that when the coating layer is darkened throughout its thickness, the coating layer is weakened to decrease adhesion, and therefore a thick black layer cannot be formed. Therefore, in the black-plated steel sheet produced by the production method described in PLT-1, when the surface of the coating layer is scratched by processing, etc., a white-prorated color that is the color of the coating layer is exposed , which deteriorates the appearance of the surface, and therefore the black-plated steel blade cannot withstand intense processing. In addition, another problem in the production method of a black-plated steel blade described at PTL-1 is that the browning treatment requires a long time.
    [0006] An objective of the present invention is to provide a method for producing a black-plated steel blade capable of being darkened in a short time and which has an excellent ability to maintain a black appearance after processing. In addition, another objective of the present invention is to provide a method for producing a shaped product of the black-plated steel blade. Solution to the problem
    [0007] The present inventors have discovered that the problems can be solved by using, as the original blade, a steel blade including a hot-dip coated Zn layer containing Al and Mg that includes 0.1% by weight or more and 22.0% by weight or less of Al and 0.1% by weight and less than 1.5% by weight of Mg and by contacting the steel foil coated with water vapor in a closed container, and have done other studies to complete the present invention.
    [0008] That is, the first embodiment of the present invention relates to the method to be followed to produce a black-plated steel blade. [1] A method for producing a black-plated steel sheet including: providing a hot dip Zn coated steel sheet containing Al and Mg including a hot dip Zn coated layer containing Al and Mg which includes 0, 1% by weight or more and 22.0% by weight or less of Al and 0.1% by weight or more and less than 1.5% by weight of Mg; and contact the Zn-coated steel sheet by hot dipping containing Al and Mg with water vapor in a closed container, in which the oxygen concentration in the closed container is 13% or less. [2] The method for producing a black-plated steel sheet according to item [1], also including forming an inorganic coating film on a surface of the Zn-coated steel sheet by hot dip containing Al and Mg. [3] The method for producing a black-plated steel sheet as per item [2], where the inorganic coating film includes one or more compounds selected from the group consisting of a valve metal oxide, a valve metal oxoate , a valve metal hydroxide, a valve metal phosphate, and a valve metal fluoride. [4] The method for producing a black-plated steel blade according to item [3], where the valve metal is one or more metals selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, W, Si, and Al. [5] The method for producing a black sheet as per item [1], also including forming an organic resin coating film on a surface of the Zn-coated steel sheet by hot dip containing Al and Mg. [6] The method for producing a black-plated steel sheet according to item [5], where an organic resin coating film comprised is a urethane-based resin obtained by the reaction of polyols including an ether-based polyol and an ester-based polyol with polyisocyanate, the proportion of the ether-based polyol in the polyols being 5 to 30% by weight. [7] The method for producing a black-plated steel sheet according to item [6], in which the organic resin coating film also includes a polyvalent phenol. [8] The method for producing a black-plated steel sheet according to any of the items [5] to [7], in which the organic resin coating film includes a lubricant. [9] The method for producing a black-plated steel sheet according to any of the items [5] to [8], in which the organic resin coating film includes one or more compounds selected from the group consisting of an oxide of valve metal, a valve metal oxoate, a valve metal hydroxide, a valve metal phosphate, and a valve metal fluoride. [10] The method for producing a black-plated steel blade according to item [9], in which the valve metal is one or more metals selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, W , Si and Al. [11] The method for producing a black-plated steel sheet according to any of the items [5] to [10], in which the organic resin coating film is a laminated layer or a layer of coating. [12] The method for producing a black-plated steel sheet according to any of the items [5] to [11], in which the organic resin coating film is a clear coating film.
    [0009] In addition, the second embodiment of the present invention relates to the method to be followed for producing a molded article of a black-plated steel blade. [13] A method for producing a molded article of a black-plated steel sheet, including providing a hot dip Zn coated steel sheet containing Al and Mg including a hot dip Zn coated layer containing Al and Mg which includes 0.1 mass% or more and 22.0 mass% or less of Al and 0.1 mass% or more and less than 1.5 mass% of Mg; contact the steel sheet coated with Zn by hot immersion containing Al and Mg with water vapor in a closed container; and conform to before or after contacting the Zn-coated steel sheet by hot immersion containing Al and Mg with water vapor, in which the oxygen concentration in the closed container is 13% or less. Advantageous effects of the invention
    [00010] According to the present invention, a black-plated steel blade having an excellent black appearance in design property, the black-plated steel blade having an excellent ability to maintain the black appearance after processing and a molded article it can be produced in a short time. The black-plated steel sheet produced by the present invention is excellent in design, retention of black appearance, ability to form by pressing, and corrosion resistance, being applicable as coated steel sheet for, for example, roofing materials and external materials building, household appliances and automobiles. Brief description of the drawings
    [00011] Figure 1A is an image of a scanning electron microscope illustrating the cross section of a coating layer of a Zn-coated steel sheet by hot dip containing Al and Mg before treatment with water vapor, and Figure 1B is an image of a scanning electron microscope illustrating the cross section of a coating layer of a steel sheet coated with hot dip Zn containing Al and Mg after treatment with water vapor; and
    [00012] figure 2 is a schematic diagram illustrating a laminated state of coated steel sheets and spacers in Experimental Example 3. Description of modalities
    [00013] Method for producing black-plated steel blade
    [00014] The method of producing a black-plated steel sheet of the present invention includes: 1) a first step of providing a hot dip Zn coated steel sheet containing Al and Mg; and 2) a second step of contacting the Zn-coated steel sheet by hot immersion containing Al and Mg with water vapor in a closed container. The method may also include: 3) a third step of forming an inorganic coating film on the surface of the Zn-coated steel sheet by hot dip containing Al and Mg, before or after the second step with an optional step. [First step]
    [00015] A hot-dip Zn-coated steel sheet containing Al and Mg in which the hot-dip Zn layer containing Al and Mg (hereinafter also referred to as "coating layer") is formed on a surface of a steel blade of base material in the first stage. (Base material steel blade)
    [00016] The type of steel blade of base material is not particularly limited. As a base material steel blade, for example, a steel blade including low carbon steel, medium carbon steel, alloy steel, etc. can be used. In the event that a favorable pressing forming capacity is required, a steel sheet for deep drawing including low carbon steel with Ti added low carbon steel with added Nb, or similar is preferable as steel sheet of base material. In addition, a high-strength steel blade to which P, Si, Mn or similar is added can be used. (Zn-coated hot-dip layer containing Al and Mg)
    [00017] As an original sheet to be used in the production process of the present invention, a hot-dip Zn coated steel sheet containing Al and Mg including a hot-dip Zn coated layer containing Al and Mg is used. includes 0.1% by weight or more and 22.0% by weight of Al or less and 0.1% or more and less than 1.5% and mass of Mg. Al and Mg are elements that improve the corrosion resistance of a steel sheet coated with Zn and are essential elements to conduct the darkening in the present invention as will be described later. In the event that the Al content or the Mg content is less than the lower limit value, sufficient corrosion resistance is not achieved. On the other hand, in the case where the content of Al or Mg is less than the limit value, a beautiful sheet of plated steel cannot be obtained due to the excessive generation of oxides (slag) on a plating bath surface during production of the plated steel blade.
    [00018] It sometimes happens that the hot-dip coated Zn layer containing Al and Mg having the composition described above contains a single phase of Al as a metal structure depending on the composition of the coating. For example, the single phase of Al is a primary Al ". Al is an element that forms an amphoteric oxide and has a greater reactivity with H2O when compared to Zn and Mg. Thus the metallic Al immediately becomes an oxide or an oxide hydrated by the following reaction when the metallic Al is connected with water vapor at high temperature In this specification, an oxide and a hydrated oxide are collectively referred to as an oxide. , since Zn, which is poor in reactivity, reacts mainly with H2O, the oxidation reaction requires a lot of time, on the other hand, in the black-plated steel blade of the present invention, since Al, which is rich in reactivity, reacts with H2O as will be described later, the time required for the oxidation reaction is short.
    [00019] The hot-dip coated Zn layer containing Al and Mg having the composition described above includes at least one or more between primary m ", a primary Zn crystal, a primary Zn2Mg crystal, a binary Zn eutectic structure / Al, a binary eutectic structure Al / Zn2Mg, a binary eutectic structure Zn / Zn2Mg, and a ternary eutectic structure Al / Zn / Zn2Mg. For example, in the hot-dip Zn layer containing Al and Mg shown in Figure 1A , the ternary eutectic structure (represented in the figure as "Al / Zn / Zn2Mg") and the single phase of Al (represented in the figure as "! Al phase of the primary crystal") are mixed.
    [00020] As illustrated in figure 1A, the respective phases (Al phase, Zn phase, and Zn2Mg phase) that form the ternary eutectic structure Al / Zn / Zn2Mg are each of an irregular size and shape, and are complicated with each other . The Zn phase (the region showing a light gray color in the ternary eutectic structure in figure 1A) in the ternary eutectic structure Al / Zn / Z2Mg is a solid solution of Zn containing a small amount of Al, and in some cases also containing a small amount of Mg. The Zn2Mg phase in the ternary eutectic structure (the region showing a dark gray color in the ternary eutectic structure in figure 1A and the region distributed in a lamellar form between the Zn phases) is an intermetallic compound phase that is present close to the point where the Zn accounts for about 84% by mass in a Zn-Mg binary equilibrium diagram.
    [00021] In addition, phase Al and phase Al of the primary crystal in the ternary eutectic structure are derived from phase Al "(solid solution of Al that contains Zn and includes a small amount of Mg) at a high temperature in the ternary equilibrium diagram Al-Zn-Mg. The Al "phase at a high temperature generally appears as a thin Al phase and a thin Zn phase separately at normal temperature. The Alpha phase and the thin Zn phase in the ternary eutectic structure are dispersed in the Zn2Mg phase. (Production of Zn-coated steel sheet by hot dip containing Al and Mg)
    [00022] The hot-dip Zn-coated steel sheet containing Al and Mg can be produced, for example, by preparing a hot-dip coating bath including 0.1% by weight or more and 22.0% by weight or less of Al, 0.1% by weight and less than 1.5% by weight of Mg, and the balance being Zn, dipping the steel sheet of base material in the hot dip coating bath, and then pulling up the steel sheet of base material to apply a hot dip coating to the surface of the steel sheet of base material.
    [00023] In addition, Si that can suppress the growth of an Al-Fe alloy layer at the interface of the base material steel blade and the coating layer can be added to the coating bath in a range of 0.005% by mass to 2.0% by mass to improve the adhesion of the steel sheet of base material with the coating layer. In this case, it sometimes happens that an Mg2Si phase is observed as a metallic structure in the coating layer. When the Si concentration exceeds 2.0% by mass, there is a risk that a Si-based oxide that inhibits darkening will be generated on the surface of the coating layer.
    [00024] In addition, Ti, B, and a Ti-B alloy, a compound containing Ti, or a compound containing B can be added to the coating bath to suppress the generation and growth of a Zn11Mg2 phase which gives an adverse influence appearance and corrosion resistance. It is preferable to adjust the amount of these compounds added to be within a range of 0.001% by mass to 0.1% by mass for Uncle, and within a range of 0.0005% by mass to 0.045% by mass for o B. When Ti or B is added in an excessive amount, there is a risk that a precipitate will grow in the coating layer. In addition, the addition of Ti, B, Ti-B alloy, of the compound containing Ti, or of the compound containing B has little influence on browning by treatment with water vapor.
    [00025] In addition, in the present specification, the value of the content of each component in the coating layer is a value obtained by dividing the mass of each metal component contained in the coating layer by the mass of all metals contained in the coating layer and expressed as a percentage. That is, the mass of oxygen and the mass of water contained in the hydrated oxides or oxides are not included as a component in the coating layer. Thus, in the case where the elution of a metallic component does not occur during the treatment with water vapor, the value of the content of each component in the coating layer before and after the treatment with water vapor does not change.
    [00026] The thickness of the coating layer is not particularly limited, however it is preferable that the thickness of the coating layer is within a range of 3 to 100 μm. In the case where the thickness of the coating layer is less than 3 μm, a scratch that may reach the steel sheet of base material during handling is likely to occur, and therefore there is a risk that the corrosion resistance and the ability to maintain a black appearance are diminished. On the other hand, when the thickness of the coating layer exceeds 100 μm, there is a risk that the coating layer and the steel sheet of base material are separated into a processed part because the ductility of the coating layer is different from the ductility of the steel sheet of base material when the coating layer and steel sheet of base material are subjected to compression. [Second stage]
    [00027] The coated steel sheet prepared in the first stage is contacted with water vapor in a closed container to darken the coating layer in the second stage. In the present specification, contacting the steel sheet coated with hot dip Zn containing Al and Mg with water vapor in a closed container is referred to as "water vapor treatment". By treatment with water vapor it is possible to reduce the lightness of the surface (L * value) of the coating layer to 60 or less (preferably 40 or less, more preferably 35 or less). The lightness of the surface (L * value) of the coating layer is measured by a spectral reflection measurement method according to JIS K 5600 using a color difference spectroscopic meter.
    [00028] When the coated steel sheet is contacted with water vapor in the second stage, a black oxide is generated in the coating layer. Here, "in the coating layer" includes both the surface of the coating layer and the interior of the coating layer. The mechanism by which black oxide is generated is not particularly limited, however it is deduced as follows.
    [00029] An oxide of Al which is an easily oxidizable element is present on the surface of the coating layer. When water vapor treatment is started, an oxidation layer on the surface reacts with H2O to be changed into a hydrated oxide on first bond, and H2O having passed through the oxide layer reacts with a metal in the coating layer. At that time, the Zn that is present in the largest amount in the coating layer is oxidized to become oxide or a hydrated oxide. In the present specification, an oxide and a hydrated oxide are selectively referred to as an oxide. The oxidation of Zn progresses towards the depth of the thick layer as time passes. In this state, when the Al that has a high reactivity with oxygen is present close to the Zn oxide, since the oxygen potential is decreased by the water vapor atmosphere, the Al that has a high reactivity removes the oxide from Zn of oxygen to become an Al oxide. Therefore, Zn oxide is considered to be changed into an oxygen-deficient type oxide (eg, ZnO (1-x) and so on) with non-stoichiometric composition. In addition, since the oxygen potential is low, it is considered that a part of the Al oxide also becomes an oxygen-deficient type oxide. When oxygen-deficient Zn oxide is generated as described here, the light is blocked at the level of the defect, and thus the oxide appears black.
    [00030] In the production method of PTL-1, only the surface of the coating layer is darkened due to the generation of ZnO1-x needle crystal. On the other hand, in the production method of the present invention, a layer of black oxide on the surface of the coating layer, and the black oxide is dispersed within the coating layer, taking into account the reaction mechanism mentioned above. Thus, in the black-plated steel sheet produced by the production method of the present invention, even when a scratch occurs in the coating layer by processing, the black appearance is maintained. The darkened oxides inside the coating layer can be confirmed by microscopic observation of the cross section of a coating layer, or by amalgamating Zn, Al and Mg metals in a coating layer with saturated HgCl2 solution for removal and collection of oxides only. In addition, the black oxide dispersed in the coating layer can be darkened inside or just on its surface.
    [00031] When oxygen is present in the atmosphere when conducting the water vapor treatment in the second stage, the darkening cannot be conducted sufficiently. This is believed to be because when water vapor treatment is conducted in the atmosphere where a large amount of oxygen is contained, the formation of basic aluminum zinc carbonate showing a gray color in the surface layer takes precedence over the formation of oxygen-deficient Zn oxide showing a black color. In the second stage, therefore, it is necessary to reduce the concentration of oxygen in the atmosphere (partial pressure of oxygen) for treatment with water vapor. Specifically, it is preferable that the oxygen concentration during treatment with water vapor is 13% or less. The method for reducing the concentration of oxygen in the atmosphere is not particularly limited. For example, the water vapor concentration (relative humidity) can be increased, the air in the container can be replaced with inert gas, or the air in the container can be removed by a vacuum pump or the like. In either case, it is necessary that the water vapor treatment be carried out in a closed container. (Treatment temperature)
    [00032] It is preferable that the temperature for the treatment with water vapor is within a range of 50 ° C or more and 350 ° C or less. When the temperature for water vapor treatment is less than 50 ° C, the browning rate is slow and productivity is decreased. In addition, when water is heated to 100 ° C or more in the closed vessel, the pressure in the vessel becomes a pressure of 1 atmosphere or greater and the oxygen concentration in the atmosphere can easily be reduced, and therefore is more preferable than the temperature for treatment with water vapor is 100 ° C or more. On the other hand, when the temperature for the treatment with water vapor exceeds 350 ° C, the control of the browning rate becomes difficult due to an extremely high browning rate. In addition, when the temperature for water vapor treatment exceeds 350 ° C, not only large treatment equipment is required, but also the total treatment time including the treatment time required to increase and reduce the temperature it becomes long, which is not practical. Thus, it is particularly preferable from the point of view of removing oxygen from the atmosphere and controlling the browning rate that the temperature for water vapor treatment is within a range of 100 ° C or more and 200 ° C or less.
    [00033] In the case where it is desired that the temperature for the treatment with water vapor be reduced to less than 100 ° C, an inert gas can be placed in the container to suppress the oxygen mixture by adjusting the pressure in the container to atmospheric pressure or higher. The type of inert gas is not particularly limited, as long as the inert gas has no relation to the browning reaction. Examples of inert gas include Ar, N2, He, Ne, Kr and Xe. Among these inert gases, Ar, N2, and He, which are available at low cost, are preferable. In addition, water vapor treatment can be conducted after the air is removed from the container by a vacuum pump or similar. (Relative humidity)
    [00034] It is preferable that the relative humidity of the water vapor during treatment with water vapor is within a range of 30% or more and 100% or less, more preferably within a range of 30% or more and less than 100%. In the case where the relative humidity of the water vapor is less than 30%, the browning rate is slow and the productivity is decreased. In addition, in the event that the relative humidity of the water vapor is 100%, there is a risk that a poor appearance is possible due to the adhesion of dew condensation water to the surface of the coated steel blade.
    [00035] The treatment time for the water vapor treatment can be adjusted accordingly depending on the conditions of the water vapor treatment (temperature, relative humidity, pressure, etc.), the amount of Al and Mg in the water layer. coating, the required lightness etc. (Preheating)
    [00036] Furthermore, when the coated steel sheet is heated before conducting the water vapor treatment to form Zn11Mg2 from Zn2Mg in the coating layer, it is possible to shorten the time of the water vapor treatment to obtain the black appearance of the coating layer. It is preferable that the heating temperature of the coated steel sheet at this time is in the range of 150 to 350 ° C. In the case where the heating temperature is less than 150 ° C, the treatment time until the Zn11Mg2 is formed from the Zn2Mg by preheating becomes long, and therefore the merit of shortening the time for the treatment with water vapor it is not obtained. On the other hand, although a heating temperature higher than 350 ° C allows the change from Zn2Mg to Zn11Mg2 in a short time, the progress of the reaction can form a coating layer having less resistance to corrosion due to the separation of each of the phases with the progress of the change of state of the coated layer, so that the preheating cannot be easily controlled. The preheat treatment time can be adjusted accordingly depending on the treatment temperature, the amount of Al and Mg in the coating layer, etc. Generally, heating at 250 ° C for about 2 hours may be sufficient. Preheating is considered to be effective when the Mg content in the coating layer is 0.3% by weight or more, taking into account that the Zn2Mg phase generally appears when the Mg content in the coating layer is 0.3% in mass. mass or more.
    [00037] Water vapor treatment can be conducted for any steel sheet wound in the form of a coil, for a planar coated steel sheet before forming, and for a steel sheet after conducting the forming, welding, or similar. [Optional step]
    [00038] An inorganic coating film or an organic resin coating film is formed on the surface of the Zn-coated steel sheet by hot dipping containing Al and Mg in an optional step that is optionally conducted before or after the second step. The inorganic coating film and the organic resin coating film improves the corrosion resistance and exfoliation resistance (retention of black appearance) of a black-plated steel blade. [Inorganic coating film]
    [00039] The inorganic coating film preferably includes one or more compounds (hereinafter referred to as valve metal translation compound) selected from the group consisting of a valve metal oxide, a valve metal oxoate, a valve metal hydroxide, a valve metal phosphate, and a valve metal fluoride. The inclusion of a valve metal compound reduces the environmental load and imparts an excellent barrier function. The valve metal means a metal whose oxide has high resistance to insulation. Examples of the valve metal include one or more metals selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, W, Si and Al. A known compound can be used as a valve metal compound.
    [00040] The inclusion of a soluble fluoride from a valve metal in an inorganic coating film can transmit a self-repair function. The valve metal fluoride dissolved in the humidity in the atmosphere forms oxides or hydroxides having poor solubility, precipitating again in the exposed steel sheet from defective regions in a coating film in order to hide the defect regions. For inclusion of soluble valve metal fluoride in an inorganic coating film, a soluble valve metal fluoride can be added to the inorganic coating material or a soluble fluoride such as (NH4) F can be added in addition to a valve metal compound. .
    [00041] The inorganic coating film may also include a melt of a poorly soluble metal phosphate or a complex phosphate. The soluble phosphate eluted from the inorganic coating film for regions with defects in a coating film reacts with the metal of a coated steel sheet to form an insoluble phosphate, complementing the valve metal's self-repair function transmitted by the soluble fluoride. The poorly soluble phosphate is dispersed in the inorganic coating film in order to improve the strength of the coating film. Examples of the metal contained in the soluble metal phosphate or the complex phosphate include an alkali metal, an alkaline earth metal and Mn. Examples of poorly soluble metal phosphate or complex phosphate include Al, Ti, Zr, Hf and Zn.
    [00042] The inorganic coating film can be formed by a known method. For example, an inorganic coating material including a valve metal or similar compound can be applied to the surface of the Zn-coated steel sheet by hot dipping containing Al and Mg before or after contact with water vapor, and then dried without washing with water. Examples of the coating method include a cylinder coating method, a rotary coating method, and a spray coating method. In the event that the valve metal compound is added to the inorganic coating material, an organic acid having a chelate function can be added to the inorganic coating material so that the valve metal compound can be stably present in the inorganic coating material . Examples of organic acid include tannic acid, tartaric acid, citric acid, oxalic acid, malonic acid, lactic acid, and acetic acid. (Organic resin coating film)
    [00043] The organic resin to form the organic resin coating can be a urethane-based resin, an epoxy-based resin, an olefin-based resin, a styrene-based resin, a polyester-based resin, an acrylic-based resin, a fluorine-based resin, a combination of these resins, or a copolymer or a modified product of these resins. The use of these organic resins having flexibility prevents the occurrence of fractures during the production of the black- plated, improving corrosion resistance. In addition, the valve metal compounds included in the organic resin film can be dispersed in the organic resin film (organic resin matrix), as described below.
    [00044] Preferably the organic resin coating film includes a lubricant. The inclusion of a lubricant reduces the friction between a mold and the surface of a coated steel blade during processing such as pressing so that the exfoliation of the coated steel blade can be suppressed (improved resistance to exfoliation). The type of lubricant is not specifically limited and can be selected from known lubricants. Examples of lubricant include an organic wax such as a fluorine-based wax, a polyethylene-based wax, and a styrene-based wax, and an inorganic lubricant such as molybdenum disulfide and talc.
    [00045] Similar to the inorganic coating film, the organic coating film preferably includes the valve metal compound described above. The inclusion of a valve metal compound reduces the environmental load and transmits excellent barrier function.
    [00046] Similar to an inorganic coating film, organic coating film can also include a metallic phosphate or complex soluble or poorly soluble phosphate. The soluble phosphate eluted from the organic coating film to defective regions in a coating film reacts with the metal of the coated steel sheet to form an insoluble phosphate, complementing the valve metal's self-repair function transmitted by the soluble fluoride. The poorly soluble phosphate is dispersed in the organic coating film in order to improve the resistance of the coating film.
    [00047] The organic resin coating film including a valve metal compound and a phosphate generally allows the formation of an interface reaction layer between the coated steel sheet and the organic resin coating film. The interface reaction layer is a dense layer formed of zinc fluoride, zinc phosphate, and a valve metal fluoride or a phosphate which are the reaction products of a fluoride or phosphate contained in the organic coating material with the metals contained in the coated steel blade or a valve metal. The interface reaction layer has an excellent ability to block the environment, preventing corrosive components in the atmosphere from reaching the coated steel sheet. Meanwhile, the organic resin coating film includes valve metal oxide, valve metal hydroxide, valve metal fluoride and phosphate particles, which are dispersed in an organic resin matrix. Since the oxide particles from the valve metal, etc., are dispersed three-dimensionally in an organic resin matrix, corrosive components such as moisture passing through the organic resin matrix can be captured. As a result, the organic resin coating film substantially reduces the corrosive components that reach the interface reaction layer. Due to the organic resin coating film and the interface reaction layer, an excellent anti-corrosion effect can be achieved.
    [00048] The organic resin coating film can be, for example, a urethane-based resin coating film that contains urethane-based resin having excellent flexibility. The urethane-based resin to form the urethane-based coating resin film can be obtained by reacting polyol with polyisocyanate. In the case of reacting with water vapor for browning after the formation of the urethane-based resin coating film, the polyol for use preferably includes a combination of an ether-based polyol (polyol having an ether bond), and a ester-based polyol (polyol having an ester bond) at a predetermined ratio.
    [00049] A urethane-based resin coating film formed only of ester-based polyol as a polyol allows ester bonds in the urethane-based resin to be hydrolyzed by water vapor, so that corrosion resistance cannot be sufficiently improved. On the other hand, a urethane-based resin coating film formed only of ether-based polyol as a polyol has insufficient adherence to the coated steel sheet, so that the corrosion resistance cannot be improved sufficiently. In contrast, the present inventors have found that the use of the combination of an ether-based polyol and an ester-based polyol at a predetermined ratio remarkably improves the corrosion resistance of a coated steel blade, making effective use of the advantages both of the polyol, based on ether and of the polyol based on ester, and complementing the disadvantages of each one. The effect of the urethane-based resin coating film to improve corrosion resistance can therefore be maintained even when treated with water vapor to transmit the black color after the formation of the urethane-based resin coating film . A black coated steel blade that is black in color and has excellent corrosion resistance can thus be produced.
    [00050] The type of ether-based polyol is not specifically limited, and can be selected appropriately from those known. Examples of an ether-based polyol include polyethylene glycol, polypropylene glycol, and a straight chain polyalkylene polyol such as ethylene oxide or propylene oxide added to glycerin.
    [00051] The type of ester-based polyol is also not specifically limited, and can be appropriately selected from the known ones. The ester-based polyol for use can be, for example, a linear polyester having a hydroxyl group in a molecular chain that is obtained by reacting dibasic acid with low molecular weight polyol. Examples of dibasic acid include adipic acid, azelaic acid, dodecanedioic acid, dimer acid, isophthalic acid, hexahydro phthalic anhydride, terephthalic acid, dimethyl terephthalate, itaconic acid, fumaric acid, malic anhydride, and esters of each of the acids.
    [00052] The ratio of the ester-based polyol to the polyol formed from a combination of an ester-based polyol and an ester-based polyol is preferably in the range of 5 to 30% by weight. A proportion of the ether-based polyol of less than 5% by weight results in an excessively increased proportion of the ester-based polyol, so that the urethane-based resin coating film is easily hydrolyzed. Consequently, corrosion resistance may not be sufficiently improved. On the other hand, the proportion of the ether-based polyol of more than 30% by weight results in an excessively increased proportion of the ether-based polyol, so that adherence to a coated steel sheet is reduced. Consequently, corrosion resistance may not be sufficiently improved.
    [00053] The type of polyisocyanate is not specifically limited, and can be selected appropriately from those known. The polyisocyanate for use can be, for example, a compound polyisocyanate having an aromatic ring. Examples of the compound polyisocyanates having an aromatic ring include hexamethylene, o-, m- or p-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate, 2,4- or 2-diisocyanate, 6 tolylene diisocyanate having a hydrogenated aromatic ring, diphenylmethane-4,4'-diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, ®, ®'-diisocyanate-1, 4-dimethylbenzene, and ®, ®'-diisocyanate-1,3-dimethylbenzene. These can be used alone or can be used in combination of two or more.
    [00054] Preferably also includes a polyvalent phenol. A urethane-based resin coating film including a polyvalent phenol allows the formation of a polyvalent phenol layer concentrated at the interface between the coated steel sheet and the polyvalent phenol in order to make the adhesion between them strong. Consequently, the mixture of polyvalent phenol in the urethane-based resin coating film also improves the corrosion resistance of the urethane-based resin coating film.
    [00055] The type of polyvalent phenol is not specifically limited and can be appropriately selected from those known. Examples of polyvalent phenol include tannic acid, gallic acid, hydroquinone, catechol and floroglucinol. The amount of polyvalent phenol mixed in the urethane-based resin coating film is preferably in the range of 0.2 to 30% by weight. A mixed amount of polyvalent phenol of less than 0.2% by mass has insufficient effect of the polyvalent phenol. On the other hand, with a mixed polyvalent amount of more than 30% by mass, the stability of the coating material can be reduced.
    [00056] The organic resin coating film can be a coating layer or a laminate layer. The organic resin coating film is preferably a clear coating film to take advantage of the dark appearance of the black-plated steel blade.
    [00057] The organic coating film can be formed by a known method. For example, in the case of an organic resin coating film formed from a coating layer, an organic coating material containing an organic resin and a valve metal, etc. can be applied to the surface of a steel sheet coated with Zn by hot immersion containing Al and Mg before or after contact with water vapor, and then dried without washing with water. Examples of the application method include a cylinder coating method, a rotary coating method, and a spray coating method. In the case of adding a valve metal compound to an organic coating material, an organic acid having a chelate function can be added to the organic coating material so that the valve metal compound can exist stably in the organic coating material. In the case of application of an organic coating material containing an organic resin, a valve metal compound, a fluoride, and a phosphate on the surface of a coated steel sheet, a coating film (interface reaction layer) consisting of a product of the reaction of negative inorganic ions such as fluoride ions and phosphoric ions with metals contained in the coated steel sheet or a valve metal is preferably and densely formed on the surface of the coated steel sheet, on which a resin coating film is formed organic material including dispersed particles of valve metal oxides, valve metal hydroxides, valve metal fluorides, and phosphates. In contrast, in the case of an organic resin coating film formed from a laminated layer, an organic resin film containing a valve metal or the like can be laminated to the surface of a coated steel sheet.
    [00058] According to the procedures described above, a coating layer can be darkened to produce an excellent black-plated steel blade in retaining the black appearance and forming capability by pressing.
    [00059] The production method of the present invention uses water vapor for darkening so that a sheet of black-plated steel is produced without placing a charge on the environment.
    [00060] In addition, in the black-plated steel sheet obtained by the production method of the present invention, the black oxide that transmits a black color tone is present not only on the surface of the coating layer but also within the coating layer. Thus, the black-plated steel sheet obtained by the production method of the present invention can maintain the black appearance even when the surface of the coating layer is scratched, and has an excellent ability to maintain the black appearance.
    [00061] In addition, in the black-plated steel blade obtained by the production method of the present invention, the black oxide that transmits a black color tone is dispersed in the coating layer without forming a single film. Thus, the sheet of black-plated steel obtained by the production method of the present invention has excellent capacity for forming by pressing without reducing the adhesion of the coating layer. As is obvious, the black-plated steel sheet obtained by the production method of the present invention has an excellent corrosion resistance similar to the corrosion resistance of a standard hot-dip Zn coated steel sheet containing Al and Mg.
    [00062] In addition, the black-plated steel sheet obtained by the production method of the present invention does not have a coating film, and therefore spot welding can also be conducted in the same way as on a Zn coated steel sheet. by usual hot dipping.
    [00063] Method for producing a black-plated steel sheet molded article The method for producing a black-plated steel sheet article of the present invention includes 1) providing a Zn-coated steel sheet by hot dip containing Al and Mg, 2) contacting the hot-dip Zn-coated steel sheet containing Al and Mg with water vapor in a closed container, and 3) forming the hot-dip Zn-coated steel sheet containing Al and Mg before or after 2). [First stage and second stage]
    [00064] The first and second steps above are the same as the first and second steps of the method described above to produce a black-plated steel blade. [Third step]
    [00065] The steel sheet coated with hot dip Zn containing Al and Mg is formed in the third stage which is conducted before or after the second stage. Specifically, in the case where the third stage is conducted after the second stage, the black-plated steel blade that contacted the water vapor is shaped to obtain a molded article of the black-plated steel blade. On the other hand, in the case where the third stage is conducted before the second stage, the coated steel sheet is formed before being contacted with the water vapor. In this case, the molded article of the coated steel sheet is darkened by the contact of the molded article of the steel sheet coated with water vapor in the second stage conducted after forming.
    [00066] The method for forming the hot-dip Zn-coated steel sheet containing Al and Mg is not particularly limited, and can be appropriately selected from known methods such as pressing, punching and stamping methods.
    [00067] The molded article of the black-plated steel blade which has an excellent ability to maintain a black appearance and an excellent capacity for forming by pressing can be produced by the above procedures.
    [00068] In the production method of the present invention, browning is conducted using water vapor, and therefore the molded article of the black-plated steel blade can be produced without applying a load to the environment.
    [00069] In addition, in the molded article of the black-plated steel blade obtained by the production method of the present invention, the black oxide that transmits a black color tone is present not only on the surface of the coating layer but also within the layer of coating. Thus, the molded article of the black-plated steel blade obtained by the production method of the present invention can maintain the black appearance even when the surface of the coating layer is scratched, and has an excellent ability to maintain the black appearance.
    [00070] Furthermore, the molded article of the black-plated steel sheet obtained by the production method of the present invention does not have a coating film, and therefore spot welding can also be conducted in the same manner as in a usual molded article. of the steel sheet coated with Zn by hot immersion containing Al and Zn. EXAMPLES
    [00071] The following examples also illustrate the present invention, but the scope of the present invention is not limited to the examples. [Experimental example 1]
    [00072] A hot-dip Zn-coated steel sheet containing Al and Mg having a coating layer with a thickness of 3 to 100 μm was prepared from a SPCC substrate with a blade thickness of 1.2 mm . The composition of the coating bath (concentration of Zn, Al, Mg, Si, Ti, and B) was changed to prepare 29 types of coated steel sheets, each of which had a coating layer with a different composition. The composition of the coating bath and the thickness of the coating layer for each of the 29 types of prepared coated steel sheets are shown in Table 1. The composition of the coating bath and the composition of the coating layer are the same. [Table 1]


    [00073] Figure 1A is an electron microscope photograph illustrating the cross section of a coated steel sheet No. 2. In figure 1A. "A" denotes the part corresponding to the Zn phase, "B" denotes the part corresponding to the Zn / Al phase, and "C" denotes the part corresponding to the Al / Zn / Zn2Mg phase.
    [00074] Each prepared coated steel layer was placed in a high-temperature, high-pressure hot moisture treatment equipment (Hisaka Works, Ltd.) to contact the coating layer with water vapor under the conditions shown in the Tables 2 and 3. In the treatment of high temperature and high pressure hot humidity, the conditions for contacting the hot-dip zinc-coated steel sheet containing Al and Mg with water vapor were controlled and measured as follows. Regarding the temperature, a thermocouple with a protection tube was inserted next to the steel sheet coated with Zn by hot immersion containing Al and Mg placed in the high temperature and high pressure hot moisture treatment equipment, and the value indicated by the thermocouple was measured by a wet bulb thermometer. In relation to the absolute pressure, a small pressure calibrator of the current signal conversion system was attached to the top section of the high temperature and high pressure hot moisture treatment equipment, and the value indicated by the present calibrator was recorded. An auxiliary tank that communicates with the high temperature and high pressure hot moisture treatment equipment through a valve and a tube was installed for the purpose of measuring the oxygen concentration. The auxiliary tank includes a heating mechanism and a cooling mechanism as the high temperature and high pressure hot moisture treatment equipment (main body) also includes. The valve was opened and the atmosphere of the main body was fractionated to the auxiliary tank through the communication tube while the temperature of the auxiliary tank was maintained to be the same as that of the main body. Subsequently, the valve was closed, only the auxiliary tank was cooled to normal temperature to condense the water vapor, so the amount of water condensed from the steam was measured, and the residual gas was analyzed to determine the oxygen concentration in the auxiliary tank. . The oxygen concentration determined quantitatively was converted to the oxygen concentration in the main body by determining the water vapor concentration in the main body from the measured amount of water.
    [00075] Figure 1B is a photograph of an electron microscope illustrating the cross section of the coating layer of the coated steel sheet of Example 4 after treatment with water vapor. In figure 1B, "A" denotes the part corresponding to the Zn phase, "B" denotes the part corresponding to the Zn / Al phase, and "C" denotes the part corresponding to the Al / Zn / Zn2Mg phase. When figure 1A and figure 1B are compared, it is understood that changes occur mainly in the Zn / Al phase and in the Al / Zn / Zn2Mg phase.
    [00076] The lightness (L * value) of the coating layer surface was measured for each of the coated steel sheets after treatment with water vapor (Examples 1 to 40 and Comparative Examples 1 to 11) by spectral reflection with a spectroscopic color difference meter (TC-1800, produced by Tokyo Denshoku Co., Ltd.), according to JIS K 5600. The measurement conditions are shown below: Optical conditions: d / 8 ° method (system double ray optical) Visual field: two degrees Measurement method: reflectometry Standard light: C Color system: CIELAB Measurement wavelength: 380 to 780 nm Measurement wavelength range: 5 nm Spectroscope: diffraction grid 1,200 / mm Lighting: halogen lamp (voltage: 12 V, power: 50W, nominal life: 2,000 hours) Measurement area: diameter = 7.25 mm
    [00077] Detection element: photomultiplier (R928 produced by Hamamatsu Photonics K. K.) Reflection: 0 to 150% Measurement temperature: 23 ° C Standard blade: white
    [00078] For each of the coated steel sheets after treatment with water vapor (Examples 1 to 40 and Comparative Examples 1 to 11), having an L * value of 35 or less was rated as "A" over 35 and 40 or less as "B", more than 40 and 60 or less as "C", and more than 60 as "D".
    [00079] Corrosion resistance was assessed for each of the coated steel sheets after treatment with water vapor (Examples 1 to 40 and Comparative Examples 1 to 11). After sealing the extreme faces of a sample piece (150 mm long and 70 mm wide) cut from each of the coated steel sheets, the sample piece was subjected to repeated cycles including a salt water spraying step, a drying step, and a wetting step in one cycle (8 hours). The assessment was made based on the number of cycles when the proportion of area with red rust reached 5%. In the salt water spraying step, 5% aqueous NaCl solution at 35 ° C was sprayed on the sample piece for 2 hours. In the drying step, the sample piece was left for 4 hours in an environment at an atmospheric temperature of 60 ° C and a relative humidity of 30%. In the humidification stage, the sample piece was left for 2 hours in an environment at an atmospheric temperature of 50 ° C and a relative humidity of 95%. The sample piece that requires more than 70 cycles for the proportion of red rust area to reach 5% was rated as "A", 30 cycles or more and 70 or less as "B", and less than 30 cycles as "D" ".
    [00080] The lightness and the results of the corrosion resistance test for the surface of the coating layer of each of the coated steel sheets after treatment with water vapor are shown in Tables 2 and 3. [Table 2]

    [Table 3]


    [00081] As shown in Tables 2 and 3, in the coated steel sheets of Comparative Examples 1 and 2, the Al content in the coating layer was outside the appropriate range, and therefore the corrosion resistance was decreased. In the coated steel sheets of Comparative Examples 5 and 6, the Mg content in the coating layer was outside the appropriate range, and therefore the corrosion resistance was decreased. In addition, in the coated steel sheets of Comparative Examples 3, 4, 7 and 8, the amount of an oxide (sludge) generated on the surface of the coating bath becomes large and the sludge adhered to the surface of the coating bath in the production of coated steel blade, and therefore a beautiful coating was not obtained. In the coated steel sheets of Comparative Examples 9 to 11, the oxygen concentration during the treatment with water vapor was high, and therefore the browning was not able to be conducted sufficiently. In contrast, the coated steel sheets of Examples 1 to 40 were sufficiently darkened and the corrosion resistance of the coating layers was favorable.
    [00082] In addition, the adhesion of the coating layer was also evaluated for each coated steel sheet after treatment with water vapor. The adhesion assessment was conducted by cutting a test piece from each coated steel sheet after treatment with water vapor, bending the test piece to 180 ° (8 t), and conducting a test of peeling with cellophane tape for the folded portion. On any of the coated steel sheets of Examples 1 to 40, the ratio of the peeled area was 10% or less, and it was confirmed that a favorable processing adhesion was maintained even after steam treatment.
    [00083] It is understood from the results above that the method for producing a black-plated steel blade of the present invention can produce a black-plated steel blade that has an excellent ability to maintain the black appearance and an excellent forming ability by pressing. [Experimental example 2]
    [00084] Each of the coated steel sheets from nos. 1 to 3 in table 1 was placed in an incubator (PV (H) -331; ESPEC CORP.) And was preheated in the atmosphere under the conditions shown in Table 4. Next the preheated coated steel blade was placed on the high temperature and high pressure hot moisture treatment equipment to contact the coating layer with water vapor under the conditions shown in Table 4.
    [00085] The lightness of the surface (L * value) of the coating layer for each coated steel sheet after treatment with water vapor (Examples 41 to 51) was measured using the color difference spectroscopic meter. The lightness to the surface of the coating layer of each of the coated steel sheets after treatment with water vapor is shown in Table 4. [Table 4]

    [00086] As shown in Table 4, in the coated steel sheets of examples 43 to 47, 49 and 51 for which preheating was performed before treatment with water vapor, the lightness was reduced even by treatment in a short time compared to the lightness of the coated steel sheets for which the preheating was not conducted.
    [00087] It is understood from the results above that the time required for steam treatment can be shortened by the preheating condition before steam treatment. [Experimental example 3]
    [00088] From each of the steel sheets coated in numbers 1, 2 and 4 in Table 1, 7 specimens (500 mm x 500 mm) were cut. In addition, from non-woven polypropylene fabric having a thickness of about 0.7 mm, 9 planar spacers (450 mm x 450 mm) were cut. As illustrated in figure 2, a laminated body was formed including 21 specimens (coated steel sheets) and 9 spacers (non-woven fabric). Looking at the coated steel blade # 1, there are 3 parts where the coated steel sheets are contacted directly with each other, and there are 3 parts where the spacer is kept between the coated steel sheets. Also in each of the coated steel sheets in 2 and 4, there are 3 parts in which the coated steel sheets are contacted directly with each other and there are 3 parts in which the spacer is kept between the coated steel sheets.
    [00089] The laminated body was placed on the high temperature, high speed, hot moisture treatment equipment, and the water vapor treatment was conducted under the conditions shown in Table 5. [Table 5]

    [00090] Darkening uniformity and corrosion resistance were evaluated for each specimen after treatment with water vapor. First, the laminated body was disassembled and, for each steel blade, the specimens (3 pieces on the bottom side in figure 2) subjected to water vapor treatment in a state in which the spacer was not kept between the sheets coated steel and the specimens (3 pieces on the upper side in figure 2) subjected to water vapor treatment in a state in which the spacer was kept between the coated steel sheets were removed.
    [00091] The lightness (L * value) in the peripheral parts (4 arbitrary parts located 20 mm inward from the edge of the specimen) and the central parts (4 arbitrary parts located close to the center per specimen) were measured using a spectroscopic color difference meter for each of the 3 specimens, the water vapor treatment conditions for each were the same. The average value of 3 pieces was calculated for each of the peripheral parts and the central parts. And the difference ΔL *, from the average of the L * values in the central parts was used as an index of evaluation of the uniformity of browning. Each specimen was rated "A" in the case where the value was 5 or less, "B" in the case where the ΔL * value was greater than 5 and 10 or less, "C" in the case where the value ΔL * was greater than 10 and 15 or less, and "D" in the case where the ΔL * value was greater than 15.
    [00092] In addition, a 70 mm x 150 mm specimen was cut from the central part of each specimen, and the corrosion resistance was assessed in the same procedure as in Experimental Example 1.
    [00093] The lightness of the coating layer surface and the result of the corrosion resistance test for each specimen after treatment with water vapor are shown in Table 6. [Table 6]

    [00094] As shown in Table 6, in the specimens (Examples 53, 55, 57, 59, 61, 63, 65, 67 and 69) each subjected to treatment with water vapor in a state in which the spacer it was not maintained between the coated steel sheets, the darkening in the peripheral parts was sufficient, however the darkening in the central parts was insufficient. The reason is that the specimens are contacted without a gap and a sufficient amount of water vapor has not been able to reach the central parts. On the other hand, in the specimens (Examples 52, 54, 56, 58, 60, 62, 64, 66, and 68) each subjected to treatment with water vapor in a state in which the spacer was kept between the coated steel sheets, not only the peripheral parts but also the central parts were sufficiently darkened, and the uniformity of the darkening was also favorable. In these specimens, no traces of the spacer were left.
    [00095] It is understood from the results above that the black-plated steel sheet which has an excellent appearance and excellent corrosion resistance can be produced by maintaining the spacer between the coated steel sheets in the event that the steam treatment water is conducted simultaneously to a plurality of coated steel sheets. [Experimental example 4]
    [00096] Each inorganic chemical treatment liquid shown in Table 7 was applied to the coated steel sheet No. 2 in Table 1, and the coated steel sheet was placed in an electric oven without washing with water, and then heated and dried in a condition where the temperature of the blade end point was to be 120 ° C to form an inorganic coating film on the surface of the coated steel blade. [Table 7]

    [00097] The coated steel sheet on which the inorganic coating film was formed was placed on the high temperature and high pressure hot moisture treatment equipment to contact the coating layer with water vapor under the conditions shown in the Table 8.
    [00098] The lightness of the surface (L * value) of the coating layer for each coated steel sheet (Examples 70 to 85) after treatment with water vapor was measured using the color difference spectroscopic meter. In addition, the corrosion resistance test for each coated steel sheet (Examples 70 to 85) after treatment with water vapor was also conducted. The corrosion resistance test was conducted by spraying an aqueous solution of NaCl having a temperature of 35 ° C in the specimen for 12 hours according to JISS Z 2371. The case in which the area ratio of the generation of rust white after spraying was 0% was rated as "A", the case of more than 0% and 5% or less was rated as "B", the case of more than 5% and 10% or less was rated as "C" ", and the case of more than 10% was rated" D ".
    [00099] The lightness of the coating layer surface and the result of the corrosion resistance test for each coated steel sheet after treatment as water vapor are shown in Table 8. [Table 8]

    [000100] As shown in Table 8, the coated steel sheets of Examples 70 to 84 on which the inorganic coating film was formed had more excellent corrosion resistance compared to the coated steel sheet of Example 85 on which the film inorganic coating has not been formed.
    [000101] It is understood from the above results that the corrosion resistance of a black-plated steel blade can be improved by the formation of an inorganic coating film. [Experimental example 5]
    [000102] The coated steel blade No. 2 in Table 1 was placed in the high temperature and high pressure hot moisture treatment equipment, and the coating layer was contacted with water vapor under the conditions shown in Table 9 to obtain a black-plated steel blade. [Table 9]

    [000103] Each organic chemical treatment liquid shown in Table 10 was applied to the obtained black-plated steel blade, and the black-plated steel blade was placed in an electric oven without washing with water, and then heated and dried in a condition where the temperature of the blade end point should be 160 ° C to form an organic resin coating film on the surface of the coated steel blade. [Table 10]

    [000104] Lubricant: polyethylene-based wax (average particle diameter: 1.0 μ)
    [000105] The corrosion resistance test and the exfoliation resistance test were conducted for each coated steel sheet (Examples 86 to 101) on which the organic resin coating film was formed. The corrosion resistance test was conducted by spraying an aqueous solution of NaCl having a temperature of 35 ° C the specimen for 12 hours according to JIS Z2371. In the exfoliation resistance test, a 30 mm x 250 mm specimen was subjected to a granule design test (granule height: 4 mm, applied pressure: 3.0 kN), and the sliding surface was observed visually after the test. The specimen with a proportion of scratched area on the sliding surface of 0% (without scratches) was rated as "A", more than 0% and less than 5% as "B", 5% or more and less than 10 % as "C", and 10% or more as "D".
    [000106] The results of the corrosion resistance test and the exfoliation resistance test for each coated steel blade are shown in Table 11. [Table 11]


    [000107] As shown in Table 11, the coated steel sheets of Examples 86 to 100 in which the organic resin coating film was formed had a more excellent corrosion resistance compared to the coated steel sheet of Example 101 on which the organic resin coating film has not been formed.
    [000108] It is understood from the above results that the corrosion resistance and exfoliation resistance of a black-plated steel blade can be improved by the formation of an organic resin coating film. [Experimental example 6]
    [000109] The coated steel sheet No. 2 in Table 1 was coated with an organic chemical treatment liquid shown in Table 12, and placed in an electric oven without washing with water in order to be heated and dried under conditions for temperature the blade reaches 160 ° C. Consequently, an organic resin coating film (urethane-based resin coating film) was formed on the surface of the coated steel sheet. The ether-based polyol for use was polypropylene glycol. The ester-based polyol for use was adipic acid. The polyisocyanate for use was hydrogenated tolylenedioisocyanate. [Table 12]

    [000110] The coated steel sheet having the organic resin coating film was placed on a high temperature and high pressure hot moisture treatment equipment, and the coating layer was contacted with water vapor under the conditions shown in Table 13.
    [000111] The lightness of the surface (L * value) of the coating layer for each coated steel sheet (Examples 102 to 126) after treatment with water vapor was measured using the color difference spectroscopic meter. In addition, the corrosion resistance test was also conducted for each coated steel sheet (Examples 102 to 126) after treatment with water vapor.
    [000112] The lightness of the surface of the coating layer and the result of the corrosion resistance test for each coated steel sheet after treatment with water vapor are shown in Table 13. [Table 13]

    [000113] In the present Experimental Example, the organic resin coating film was formed on the Zn-coated steel sheet by hot dipping containing Al and Mg, and subsequently the coated steel sheet on which the organic resin coating film was formed was contacted with water vapor to darken. In that case, it sometimes occurs that the corrosion resistance cannot be improved sufficiently even when the organic resin coating film is formed (see Examples 118 to 126). In contrast, the corrosion resistance of the black-plated steel blade of Examples 102 to 117 in which the resin coating film of a urethane resin obtained by combining an ether-based polyol and an ester-based polyol in one predetermined ratio was formed has been improved sufficiently.
    [000114] This application claims the benefit of Japanese Patent Application No. 2012-100440, registered on April 25, 2012 and Japanese Patent Application No. 2013-062220, registered on March 25, 2013, the descriptions of which include specifications and drawings are hereby incorporated in their entirety by reference. Industrial Applicability
    [000115] The black-plated steel blade of the present invention has excellent design properties, the ability to maintain a black appearance, the ability to form by pressing, and to resist corrosion, and therefore is useful as a coated steel blade to be used for example, a roofing material or a building exterior material, a power tool, an automobile, etc.
    权利要求:
    Claims (11)
    [0001]
    1. Method for producing a black coated steel blade, characterized by the fact that it comprises: reducing the oxygen concentration in a closed container to 13% or less, replacing the air in the closed container with an inert gas or removing the air in the container closed; provide a steel sheet coated with Zn containing Al and Mg by hot dipping comprising a layer coated with Zn containing Al and Mg by hot dipping comprising 0.1% by weight or more and 22.0% by weight or less than Al is 0.1% by weight or more and less than 1.5% by weight of Mg; and place the steel sheet coated with Zn containing Al and Mg by hot immersion in contact with water vapor in the closed container.
    [0002]
    Method for producing a black coated steel sheet according to claim 1, characterized in that it additionally comprises forming an inorganic coating film on the surface of the steel sheet coated with Zn containing Al and Mg by hot dipping.
    [0003]
    Method for producing a black coated steel sheet according to claim 2, characterized in that the inorganic coating film comprises one or more compounds selected from the group consisting of an oxide, a hydroxide, a phosphate, and a fluoride , of one or more atoms, the atoms being selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, W, Si and Al, and (NH4) VO3, (NH4) 2ZrO (CO3) 2, Zr ( SO4) 2, Al (NO3) 3-9H2O, and ZrO (NO3) 2-2H2O.
    [0004]
    Method for producing a black coated steel sheet according to claim 1, characterized in that it additionally comprises the formation of an organic resin coating film on a surface of the steel sheet coated with Zn containing Al and Mg by immersion the hot.
    [0005]
    5. Method for producing a black coated steel sheet according to claim 4, characterized by the fact that: an organic resin composed of an organic resin coating film is a urethane-based resin obtained by the reaction of polyols consisting of an ether-based polyol and an ester-based polyol with polyisocyanate, the proportion of the ether-based polyol in the polyols being 5 to 30% by weight.
    [0006]
    Method for producing a black coated steel sheet according to claim 5, characterized in that the organic resin coating film additionally comprises a polyvalent phenol.
    [0007]
    Method for producing a black coated steel sheet according to claim 4, characterized in that the organic resin coating film comprises a lubricant.
    [0008]
    Method for producing a black coated steel sheet according to any one of claims 4 to 7, characterized in that the organic resin coating film comprises one or more compounds selected from the group consisting of an oxide, a hydroxide, a phosphate, and a fluoride, one or more atoms, the atoms being selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, W, Si and Al, and (NH4) VO3, (NH4) 2ZrO (CO3 ) 2, Zr (SO4) 2, Al (NO3) 3-9H2O, and ZrO (NO3) 2-2H2O.
    [0009]
    Method for producing a black coated steel sheet according to claim 4, characterized in that the organic resin coating film is a laminated layer or a coating layer.
    [0010]
    10. Method for producing a black coated steel sheet according to claim 4, characterized in that the organic resin coating film is a clear coating film.
    [0011]
    Method for producing a black coated steel sheet according to any one of claims 1 to 10, characterized in that it additionally comprises: forming the steel sheet coated with Zn containing Al and Mg by hot immersion before or after place the steel sheet coated with Zn containing Al and Mg by hot immersion in contact with water vapor.
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    同族专利:
    公开号 | 公开日
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    PH12014502367B1|2015-01-12|
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    WO2013161269A1|2013-10-31|
    MX2014012958A|2015-05-08|
    CA2871293A1|2013-10-31|
    KR20150002668A|2015-01-07|
    US9598759B2|2017-03-21|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    JPS6456881A|1987-08-28|1989-03-03|Nippon Steel Corp|Black molten zinc-aluminum alloy plated steel sheet and its production|
    DE69230523T2|1991-07-11|2000-06-29|Nippon Kokan Kk|STEEL SHEET COATED WITH ORGANIC COMPOSITE FILM WITH EXCELLENT GLOSS AND RUST RESISTANCE AND THE PRODUCTION THEREOF|
    DE69224742T2|1991-12-12|1998-08-06|Nippon Kokan Kk|GALVANIZED STEEL PLATE WITH HIGH PRESSURE FORMABILITY AND HIGH CORROSION RESISTANCE|
    JP3179446B2|1998-07-02|2001-06-25|新日本製鐵株式会社|Coated steel sheet and coated steel sheet excellent in corrosion resistance and method for producing the same|
    US6465114B1|1999-05-24|2002-10-15|Nippon Steel Corporation|-Zn coated steel material, ZN coated steel sheet and painted steel sheet excellent in corrosion resistance, and method of producing the same|
    WO2001031079A1|1999-10-25|2001-05-03|Nippon Steel Corporation|Metal plated steel wire having excellent resistance to corrosion and workability and method for production thereof|
    JP2005008953A|2003-06-19|2005-01-13|Nisshin Steel Co Ltd|Metal sheet for mechanical caulking-jointing and method of mechanical caulking-jointing|
    DE10330656A1|2003-07-08|2005-01-27|Sms Demag Ag|Device for the hot dip coating of a metal strand|
    DE102006039307B3|2006-08-22|2008-02-21|Thyssenkrupp Steel Ag|Process for coating a 6-30 wt.% Mn-containing hot or cold rolled steel strip with a metallic protective layer|
    EP2119804A1|2008-05-14|2009-11-18|ArcelorMittal France|Method of manufacturing a covered metal strip with improved appearance|
    JP5168332B2|2010-09-24|2013-03-21|Ｊｆｅスチール株式会社|Surface treatment liquid for galvanized steel sheet, galvanized steel sheet and method for producing the same|JP6121227B2|2012-04-25|2017-04-26|日新製鋼株式会社|Method for producing black-plated steel sheet|
    EP3075879B1|2013-11-29|2018-04-18|Nisshin Steel Co., Ltd.|Method for treating surface of zinc-aluminum-magnesium alloy-plated steel sheet|
    JP2016141870A|2015-02-04|2016-08-08|日新製鋼株式会社|Black plated steel sheet excellent in slipperiness|
    DE102016102504A1|2016-02-08|2017-08-10|Salzgitter Flachstahl Gmbh|Aluminum-based coating for steel sheets or steel strips and method of making same|
    JP2017145441A|2016-02-16|2017-08-24|日新製鋼株式会社|Black surface coated high strength steel sheet and manufacturing method therefor|
    JP6072952B1|2016-03-01|2017-02-01|日新製鋼株式会社|Method for producing black-plated steel sheet, apparatus for producing black-plated steel sheet, and system for producing black-plated steel sheet|
    JP6087461B1|2016-04-26|2017-03-01|日本ペイント・インダストリアルコ−ティングス株式会社|Surface treated steel|
    CA3031255A1|2016-07-20|2018-01-25|Tata Steel Ijmuiden B.V.|Method for providing a zn-al-mg coating, and such coating|
    CN106282904A|2016-08-26|2017-01-04|安徽皖南电机股份有限公司|The oxidation technology of motor stamping|
    KR20180071108A|2016-12-19|2018-06-27|주식회사 포스코|Black metal steel sheet and method for manufacturing the same|
    JP6676555B2|2017-01-18|2020-04-08|日鉄日新製鋼株式会社|Method and apparatus for producing black plated steel sheet|
    JP6583317B2|2017-03-14|2019-10-02|Ｊｆｅスチール株式会社|Film-coated molten Zn-Al-Mg-based plated steel sheet and method for producing the same|
    JP6886936B2|2017-03-31|2021-06-16|日本製鉄株式会社|Manufacturing method and manufacturing equipment for steam-treated products|
    JP6232157B1|2017-03-31|2017-11-15|日新製鋼株式会社|Quality evaluation method for steam-treated products|
    CN108690944B|2018-06-12|2021-01-08|武汉钢铁有限公司|Method for producing hot-dip coated steel sheet having excellent blackening resistance and corrosion resistance|
    KR102300792B1|2019-09-25|2021-09-09|주식회사 포스코|Black color plated sheet and manufacturing method thereof|
    JPWO2021176768A1|2020-03-03|2021-09-10|
    法律状态:
    2018-03-06| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2019-09-17| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2020-09-29| B06A| Notification to applicant to reply to the report for non-patentability or inadequacy of the application [chapter 6.1 patent gazette]|
    2021-03-02| B09A| Decision: intention to grant|
    2021-04-13| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 23/04/2013, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    JP2012100440|2012-04-25|
    JP2012-100440|2012-04-25|
    JP2013-062220|2013-03-25|
    JP2013062220A|JP5341270B1|2012-04-25|2013-03-25|Method for producing black-plated steel sheet and method for producing molded body of black-plated steel sheet|
    PCT/JP2013/002718|WO2013161269A1|2012-04-25|2013-04-23|Method for producing black-plated steel sheet, and method for producing molded article of black-plated steel sheet|
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