JP2010111898A - Chemical conversion-treated metal sheet and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal sheet with a chemical conversion-treated surface which is producible in a short time, and is also excellent in the performance balance of various properties such as adhesion and corrosion resistance in a recycle corrosion resistance test which have not been obtained in the conventional inorganic independent film, and heat resistance or the like which has not been obtained by the conventional resin based multilayer treatment as well as corrosion resistance in a thin film. <P>SOLUTION: The metal sheet with the chemical conversion-treated surface is obtained by providing the surface of a metal sheet with: a surface treatment layer in which the total in element deposition per unit area of at least one metallic element (X) selected from the group consisting of Zr, Ti and Hf is 2 to 50 mg/m<SP>2</SP>, and formed by self-precipitation and/or electrolytic precipitation; and an inorganic film layer formed by applying an inorganic surface treatment agent comprising at least one kind of compound comprising at least one element (Y) selected from the group consisting of Zr, Ti and Si on the surface treatment layer in this order, and the total in element deposition per unit area of the element(s) Y in the inorganic film layer is 5 to 1,000 mg/m<SP>2</SP>. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a surface-treated steel sheet used for molded products such as automobile bodies, automobile parts, building materials, home appliance parts, cast products, sheet coils, etc., and has a performance balance that has not been obtained so far. Not only the corrosion resistance of thin films, but also the adhesion and heat resistance in cyclic corrosion tests that were not possible with conventional inorganic coatings, and post-processing appearance retention and heat resistance that were not possible with conventional resin-based multilayer processing It is related with the metal plate which comprises.

Almost all metallic materials as well as galvanized steel sheets, when left in the atmospheric environment, corrode SO ₂ , NO ₂ , flying sea salt particles, etc. in the presence of moisture physically adsorbed from the atmosphere. Corrosion occurs on the surface due to the action of the accelerated adhesion substance. In order to prevent this corrosion, as a conventional corrosion prevention method for metallic materials such as galvanized steel sheets, the chromate film is deposited or treated by bringing the surface of the metallic material into contact with a treatment liquid containing chromium such as chromate chromate. There is a method in which a liquid is applied on a metal material and then dried to form a chromate film on the surface of the metal material.

Typical examples of depositing a chromate film by bringing the surface of a metal material into contact with a treatment liquid include chromic acid chromate conversion treatment and phosphoric acid chromate chemical conversion treatment. The former chromate chromate conversion treatment was put into practical use around 1950 and is still widely used for galvanized steel sheets. The treatment liquid used for the chromate chromate conversion treatment contains chromic acid (CrO ₃ ) and hydrofluoric acid (HF) as main components, and further contains an accelerator, and contains a precipitate containing hexavalent chromium. A film can be formed.

Moreover, the latter phosphoric acid chromate chemical conversion treatment is based on the method described in Patent Document 1 proposed in 1945, and this chemical conversion treatment solution contains chromic acid (CrO ₃ ), phosphoric acid (H ₃ PO ₄ ), and The deposited film formed containing hydrofluoric acid (HF) contains hydrated chromium phosphate (CrPO ₄ .4H ₂ O) as a main component.

  As described above, in many cases, these chromate type surface treatment liquids contain harmful hexavalent chromium. Not only hexavalent chromium, which is problematic from the environmental and safety aspects, but also the surface of the era in which the use of even trivalent chromium is regulated, and the surface using a treatment liquid containing hexavalent chromium as described above It is desired to switch from a treatment method to a non-chromate type surface treatment method containing no chromium.

  Non-chromate type surface treatment methods include a precipitation type and a coating type, and the precipitation type has already been proven as a surface treatment method for aluminum-containing metal materials. The reason why the non-chromate type treatment liquid has been applied to aluminum-containing metal materials from a relatively early stage is that this metal material has been widely used as a material in contact with food such as aluminum cans.

  As a typical non-chromate type chemical conversion surface treatment solution for an aluminum-containing metal material, there is a treatment solution described in Patent Document 2. This treatment liquid is an acidic aqueous surface treatment liquid containing zirconium or titanium, or a mixture thereof, phosphate and fluoride, and having a pH of about 1.0 to 4.0. When treatment is performed using this chemical conversion treatment solution, a deposited film mainly containing a phosphorus compound of zirconium or titanium is formed on the surface of the aluminum-containing metal material.

  Compared to such a chemical precipitation type surface treatment liquid for aluminum-containing metal materials, there is almost no existing technology for a non-chromate type chemical precipitation type surface treatment liquid for galvanized steel sheets. In addition, in the sheet coil manufacturers of galvanized steel sheets, the coating type surface treatment is now becoming the mainstream rather than the precipitation type surface treatment. However, depending on the sheet coil manufacturer's line, the introduction of coating-type surface treatment may not be possible due to equipment costs and locational reasons, and the existing chromate treatment is replaced with a non-chromate treatment by the precipitation-type equipment. The desire to want is strong.

  As a non-chromate type treatment liquid, for example, Patent Document 3 discloses an aqueous composition for coating an alloy of aluminum, iron, or magnesium, and includes titanium, zirconium, magnesium, and calcium, and dissolved fluorine. An aqueous composition is described that includes ions and has a pH of 2.0 to 5.0 and forms a film with little or no etching. However, it is not described that this aqueous composition is applied to a zinc-based plated steel sheet.

  Patent Documents 4 to 13 contain metals such as zirconium, titanium, and hafnium, fluorine, accelerators, etc., and by adjusting the concentration and molar ratio, do not contain chromium, exhibit high corrosion resistance, and Further, a technique relating to a chemical conversion treatment agent, a chemical conversion treatment method and a chemical conversion treatment material excellent in stability is disclosed. However, in these treatments, it takes a long time to deposit the film, and it cannot be applied to a sheet coil or the like.

  Patent Documents 14 and 15 are chemical conversion treatment agents composed of at least one selected from the group consisting of zirconium, titanium, and hafnium, fluorine, and a water-soluble resin, and have a low environmental load, and iron. In addition, a chemical conversion treatment agent capable of performing a good chemical conversion treatment on all metals such as zinc and aluminum, and a technique relating to a surface-treated metal obtained by using the chemical conversion treatment agent are disclosed. However, even in this technique, the processing time cannot be shortened and cannot be applied to a sheet coil.

  Patent Document 16 discloses a chemical conversion-treated metal plate that includes at least one compound containing at least one element selected from the group consisting of Zr, Ti, Hf, and Si, and is subjected to self-deposition or electrolytic deposition. A technique relating to a chemical conversion treatment metal plate having a treatment layer on the surface of the metal plate is disclosed. This technique can be applied to a sheet coil in that it has corrosion resistance in a short time, and has extremely high industrial value. However, regarding the performance of the chemical conversion film, further improvement in the corrosion resistance of the processed part was necessary.

  On the other hand, with regard to coating type coating agents, chromic acid, dichromic acid or their salts are applied to the surface of the metal material as a technology that provides excellent adhesion to the surface of the metal material and imparts corrosion resistance and fingerprint resistance to the surface of the metal material. There are known methods such as a coating chromate treatment with a treatment solution containing as a main component, a phosphate treatment method, a silane coupling agent treatment method, an organic resin film treatment method, etc. It is used for practical use.

  Patent Document 17 contains at least one vanadium compound and a metal compound containing at least one metal selected from the group consisting of zirconium, titanium, molybdenum, tungsten, manganese, and cerium, and has high corrosion resistance and alkali resistance. A film agent capable of forming an excellent film is disclosed.

  On the other hand, as a technique mainly using a silane coupling agent, Patent Document 18 discloses a method for treating a metal plate with an aqueous solution containing a low concentration of an organofunctional silane and a crosslinking agent in order to obtain a temporary anticorrosive effect. Has been. It is disclosed that a crosslinker crosslinks an organofunctional silane to obtain a dense siloxane film.

  Patent Document 19 discloses that a surface treatment agent containing a compound having two or more alkoxysilanes and a compound selected from an organic acid, phosphoric acid and a complex fluoride is used for corrosion resistance and coating on the surface of a metal. A method of forming a film excellent in adhesion is disclosed.

  However, these techniques described in Patent Documents 17 to 19 are remarkably lacking in performance such as conductivity and fingerprint resistance of the obtained film, and improved product quality (corrosion resistance, paint adhesion, cycle corrosion resistance). ) Is difficult to deal with. In addition, even if it is possible to form a film with excellent corrosion resistance and paint adhesion, it is possible to leave a problem in the environment and safety due to the solvent system, and to supply it stably in the water system. It has problems such as difficulty, and still has a big problem regarding practical use.

  On the other hand, as a technique using an organic resin film, Patent Document 20 discloses that an aqueous dispersion resin is 5 to 30% by mass in solid content concentration, 0.1 to 20% by mass of silica particles, and 0.01 to 20% of an organic titanate compound. An aqueous coating material for steel material characterized by containing 20% by mass is disclosed. This coating is a one-component water-based coating suitable for coating steel such as zinc-based coated steel or uncoated steel. The resulting steel is corrosion-resistant, solvent-resistant, alkali-resistant, and paint adhesion. Excellent in adhesion, film adhesion and bath stability.

  Patent Document 21 discloses a specific resin compound, a cationic urethane resin having at least one cationic functional group selected from primary to tertiary amino groups and quaternary ammonium bases, and specific reactivity. Disclosed is a surface treatment agent containing at least one silane coupling agent having a functional group and a specific acid compound, and the content of the cationic urethane resin and the silane coupling agent is within a predetermined range. ing. Furthermore, a non-chromium surface-treated steel sheet excellent in corrosion resistance, blackening resistance and paint adhesion obtained by using this treatment agent and a method for producing the same are disclosed.

  However, since these techniques disclosed in Patent Documents 20 and 21 exhibit corrosion resistance and fingerprint resistance by coating the surface of a metal material with an organic resin, the problems of poor performance such as conductivity and spot weldability. There is. In addition, since the main component is an organic polymer, thermal decomposition at high temperatures, coloring, increase in viscosity, etc. occur, so that it cannot be used for heat resistant applications.

  Further, in Patent Documents 9, 14, and 22, a base film is deposited by a surface treatment agent containing a specific metal element, and a water-soluble polymer or a water-dispersible polymer or resin is contacted as an upper layer to form a film. Techniques for forming the are disclosed. However, these techniques take a long time to deposit the film, and are not applicable to sheet coils. In addition, no performance improvement is observed due to the polymer film formed as the upper layer.

  As mentioned above, no surface-treated plate that replaces the chromate film has been obtained by any of the above methods, and comprehensively satisfies various characteristics such as corrosion resistance, paint adhesion, heat resistance, cycle corrosion resistance, and short processing time. There is a strong demand for the development of metal plates that can be manufactured in Japan.

US Pat. No. 2,438,877 JP 52-131937 A Japanese National Patent Publication No. 9-503823 JP 2004-043913 A Japanese Patent Application Laid-Open No. 2004-218070 JP 2004-218072 A JP 2004-218073 A JP 2004-218074 A JP 2005008982 A JP 2006-124751 A JP 2006-161115 A JP 2007-262577 A JP 2007-314888 A JP 2004-218075 A JP 2004-292874 A International Publication No. 2007/61011 Pamphlet JP 2002-30460 A US Pat. No. 5,292,549 JP 2001-49453 A JP 2003-155451 A JP 2003-105562 A JP 2005-264230 A

  The present invention solves the above-mentioned problems of the prior art, can be manufactured in a short time, and not only corrosion resistance, but also adhesion and cycle resistance in a cyclic corrosion test, which could not be obtained with a conventional inorganic single coating, It aims at providing the chemical conversion surface metal plate excellent in the performance balance of various characteristics, such as heat resistance, which was not obtained by the resin-based multi-layer treatment.

  As a result of intensive studies to solve these problems, the present inventors have obtained a surface treatment layer formed by depositing a predetermined amount of a specific metal element by autodeposition and / or electrolytic deposition. It is found that the above problems can be solved by applying an inorganic surface treatment agent containing an inorganic compound having a specific metal element to a plate to form an inorganic film layer satisfying a specific film amount. The invention has been solved.

That is, the present invention provides the following (1) to (7).
(1) The total amount of element adhesion per unit area of at least one metal element (X) selected from the group consisting of Zr, Ti and Hf on the metal plate is ² to 50 mg / m ² , Alternatively, a surface treatment layer formed by electrolytic deposition and an inorganic surface treatment agent comprising at least one compound containing at least one element (Y) selected from the group consisting of Zr, Ti and Si, the surface treatment A chemical conversion surface metal plate provided with an inorganic coating layer formed by coating on the layer in this order,
The chemical conversion surface metal plate whose element adhesion total amount per unit area of the element (Y) in the said inorganic membrane | film | coat layer is 5-1000 mg / m < ² >.
(2) The chemical conversion treatment metal plate according to (1), wherein the metal plate is a zinc-based plated steel plate.
(3) The inorganic coating layer is formed by applying an inorganic surface treatment agent containing at least one Zr-containing compound on the surface treatment layer, and is mainly composed of a zirconium element and an oxygen element. The chemical conversion treatment metal plate as described in (1) or (2) which is a film layer.
(4) The inorganic surface treatment agent further contains a compound (A) containing at least one metal element selected from the group consisting of V, Mo, Ce, W and Mn. 3) The chemical conversion treatment metal plate in any one of.
(5) Total amount of element adhesion (C _Y ) per unit area of the element (Y) in the inorganic coating layer, and per unit area of the metal element contained in the compound (A) in the inorganic coating layer The chemical conversion treatment metal plate according to (4), wherein the mass ratio (C _A / C _Y ) to the total amount of element adhesion (C _A ) is 0.05 to 1.00.
(6) The inorganic surface treatment agent further includes at least one functional group selected from the group consisting of a hydroxyl group, a carbonyl group, a carboxyl group, a primary to tertiary amino group, an amide group, a phosphoric acid group, and a phosphonic acid group. The chemical conversion treatment metal plate in any one of (1)-(5) containing the organic compound (B) which has group.
(7) The surface of the metal plate by auto-deposition and / or electrolytic deposition using a treatment liquid containing a compound (d) containing at least one metal element (X) selected from the group consisting of Zr, Ti and Hf A surface treatment layer forming step of forming a surface treatment layer thereon;
After the surface treatment layer forming step, an inorganic surface treatment agent containing at least one compound containing at least one element (Y) selected from the group consisting of Zr, Ti and Si is applied onto the surface treatment layer. An inorganic coating layer forming step for forming an inorganic coating layer.
(8) The manufacturing method of the chemical conversion treatment metal plate as described in (7) whose said metal plate is a zinc system plating steel plate.

  The present invention can be manufactured in a short time and is not only corrosion resistant, but also cannot be obtained by conventional resin-based multi-layer treatments, such as adhesion and cycle corrosion resistance that could not be obtained by a conventional inorganic single film. Provided is a chemical conversion surface metal plate excellent in performance balance of various properties such as heat resistance.

  Below, the chemical conversion treatment metal plate which concerns on this invention, and its manufacturing method are described. First, a chemical conversion treatment metal plate is demonstrated in detail based on suitable embodiment shown on drawing.

<Chemical conversion metal plate>
FIG. 1 is a schematic cross-sectional view of one embodiment of a chemical conversion treatment metal plate of the present invention.
The chemical conversion treatment metal plate 10 shown in the figure has a laminated structure in which a metal plate 12, a surface treatment layer 14, and an inorganic coating layer 16 are laminated in this order.
The surface treatment layer 14 has an element deposition total amount of ² to 50 mg / m ² per unit area of at least one metal element (X) selected from the group consisting of Zr, Ti and Hf, It is a layer formed by analysis.
The inorganic coating layer 16 is formed by applying an inorganic surface treatment agent containing at least one compound containing at least one element (Y) selected from the group consisting of Zr, Ti and Si on the surface treatment layer. The total amount of element adhesion per unit area of the element (Y) in the inorganic coating layer is 5 to 1000 mg / m ² .
In FIG. 1, the layer thicknesses of the metal plate 12, the surface treatment layer 14, and the inorganic coating layer 16 are not limited depending on the figure. In FIG. 1, the surface treatment layer 14 and the inorganic coating layer 16 are laminated only on one surface of the metal plate 12. However, as shown in FIG. 2, the surface treatment layer 14 is formed on both surfaces of the metal plate 12. And may have an inorganic coating layer 16.
First, the metal plate 12 and each layer which comprise the chemical conversion treatment metal plate 10 are demonstrated.

<Metal plate>
The metal plate 12 applicable in this invention is for laminating | stacking and supporting each layer of the surface treatment layer 14 and the inorganic membrane | film | coat layer 16 which are mentioned later.
Although it does not specifically limit as a metal material which comprises the metal plate 12, For example, iron, an iron base alloy, aluminum, an aluminum base alloy, copper, a copper base alloy etc. are mentioned, For example, the plating metal plated on arbitrary metal plates A board can also be used. Especially, in this invention, a zinc-plated steel plate can be used suitably. Zinc-coated steel sheets include galvanized steel sheets, zinc-nickel plated steel sheets, zinc-iron plated steel sheets, zinc-chromium plated steel sheets, zinc-aluminum plated steel sheets, zinc-titanium plated steel sheets, zinc-magnesium plated steel sheets, zinc-manganese. Examples thereof include zinc-based plated steel sheets such as plated steel sheets, zinc-aluminum-magnesium plated steel sheets, and zinc-aluminum-magnesium-silicon plated steel sheets.
Furthermore, cobalt, molybdenum, tungsten, nickel, titanium, chromium, aluminum, manganese, iron, magnesium, lead, bismuth, antimony, tin, copper, cadmium, arsenic as a small amount of different metal elements or impurities in these plating layers In which inorganic substances such as silica, alumina, and titania are dispersed. Furthermore, the present invention can also be applied to multilayer plating in combination with the above plating and other types of plating, such as iron plating, iron-phosphorus plating, nickel plating, cobalt plating, and the like.
The plating method is not particularly limited, and any known method such as electroplating, hot dipping, vapor deposition, dispersion plating, and vacuum plating may be used.
Further, the size and thickness of the metal plate 12 are not particularly limited.

<Surface treatment layer>
The surface treatment layer 14 in the chemical conversion treatment metal plate 10 of the present invention is laminated on the metal plate 12 described above, and mainly imparts corrosion resistance. Further, once formed, the surface treatment layer 14 is not attacked by acid or alkali, follows the bending process, and imparts excellent coverage.
The surface treatment layer 14 has an element deposition total amount of ² to 50 mg / m ² per unit area of at least one metal element (X) selected from the group consisting of Zr, Ti and Hf, It is a layer formed by analysis.

The total amount of element adhesion of at least one metal element (X) selected from the group consisting of Zr, Ti and Hf in the surface treatment layer 14 is ² to 50 mg / m ² and 5 to 30 mg / m ² . It is preferably 7 to 25 mg / m ² . If the total adhesion amount of the metal element (X) is less than 2 mg / m ^2, it is not preferable because corrosion resistance is not expressed, and if it exceeds 50 mg / m ² , it is not preferable because adhesion to a metal plate or the like cannot be obtained.
In addition, the adhesion amount of metal element (X) can be measured with a fluorescent X-ray analyzer (XRF).

The main constituent elements of the surface treatment layer 14 are mainly oxides, fluorides and / or hydroxides of at least one metal element (X) selected from the group consisting of Zr, Ti and Hf. In addition, additives (for example, oxides and / or hydroxides of V, Mn, W and Mo, and metal elements such as Ni, Co, and Cu) may be contained. Among them, it is preferable that at least one metal element (X) selected from the group consisting of Zr, Ti, and Hf and a fluorine element are the main constituent elements in that the obtained layer has fewer defects.
The surface treatment layer 14 is a layer formed by self-deposition and / or electrolytic deposition, and the manufacturing method thereof will be described later.

<Inorganic coating layer>
The inorganic coating layer 16 in the chemical conversion treatment metal plate 10 of the present invention is laminated on the surface treatment layer 14 described above, and mainly provides physical and temporal blocking ability of corrosion factors.
The inorganic coating layer 16 includes at least one compound containing at least one element (Y) selected from the group consisting of Zr (zirconium element), Ti (titanium element), and Si (silicon element). Is applied to the surface treatment layer, and the total amount of element adhesion per unit area of the element (Y) in the inorganic coating layer is 5 to 1000 mg / m ² .
Among the elements (Y), Zr and Si are preferable, and Zr is more preferable in that various properties of the obtained chemical conversion metal plate are more excellent.

The total amount of element adhesion per unit area of at least one element (Y) selected from the group consisting of Zr, Ti and Si in the inorganic coating layer 16 is 5 to 1000 mg / m ² and 10 to 750 mg / m ^{2. 2} is preferable, and 20 to 500 mg / m ² is more preferable. When the total amount of the element (Y) is less than 5 mg / m ² , the effect of improving the corrosion resistance by the inorganic coating layer is not exhibited, which is not preferable. Moreover, it is not preferable that the total adhesion amount of the element (Y) exceeds 1000 mg / m ^{2 because} cohesive failure is likely to occur in the inorganic coating layer and good adhesion cannot be obtained.
The amount of the element (Y) attached can be measured with an X-ray fluorescence analyzer (XRF).

  The main constituent elements of the inorganic coating layer 16 are mainly oxides, hydroxides and / or carbonates of at least one element (Y) selected from the group consisting of Zr, Ti and Si. The additives described below may be contained. Especially, it is preferable that at least 1 element (Y) chosen from the group which consists of Zr, Ti, and Si and an oxygen element are made into a main structural element at the point which the various performance of the chemical conversion treatment metal plate obtained is more excellent.

  In addition, it is preferable that the inorganic coating layer 16 does not substantially contain fluorine element from the viewpoint that the performance balance is more excellent. Here, “substantially not contained” means that the content of the fluorine element in the inorganic coating layer 16 is 0.5 mass% or less, more preferably 0.05 mass% or less. . Most preferably, it is 0 mass%.

The inorganic coating layer 16 is a metal element (V, Mo, Ce, W, Mn) derived from the compound (A) containing at least one metal element selected from the group consisting of V, Mo, Ce, W and Mn, which will be described later. ) May be contained.
Especially, the mass ratio (C _A ) of the total amount of element adhesion (C _Y ) per unit area of the element ( _Y ) and the total amount of element deposition (C _A ) per unit area of the metal element derived from the compound (A) ( C _A / C _Y ) is preferably 0.05 to 1.00, more preferably 0.05 to 0.8, and even more preferably 0.05 to 0.7. When the mass ratio is within the above range, the barrier property is more excellent, and further excellent corrosion resistance is exhibited by the inhibitor effect derived from the compound (A). As the compound (A), those containing V are more preferable.

<Other additives>
The film (surface treatment layer 14 and inorganic film layer 16) of the chemical conversion treatment metal plate 10 of the present invention may contain an additive as long as the effects of the invention are not impaired.
For example, a surfactant called a wettability improver for forming a uniform film on the surface to be coated, a thickener, a conductivity improver, a color pigment for improving design properties, and a film forming property A film-forming aid or the like can be contained. Moreover, organic lubricants, such as polyethylene wax and paraffin wax, solid lubricants, such as graphite, mica, and molybdenum disulfide, etc. can be mix | blended as a lubricity imparting agent.

Moreover, in the film | membrane (surface treatment layer 14, inorganic coating layer 16) of the chemical conversion treatment metal plate 10 of this invention, in order to further improve corrosion resistance, C = O group, C = C group in one molecule called an organic inhibitor, Selected from the group consisting of at least one unsaturated group selected from the group consisting of C≡C group, C═N group, C≡N group and N═N group, NN group, or a functional group having S element. A compound having at least one functional group can be blended.
The compounds having these functional groups are not particularly limited, but aldehydes such as formaldehyde and acetaldehyde, C═O group-containing compounds such as ketones such as acetone and methyl ethyl ketone, benzene and its derivatives, naphthalene and its derivatives, acrylic C = C group-containing compounds such as acid and methacrylic acid and derivatives thereof, alkyl carboxylic acid esters and alkyl aldehydes, C≡C group-containing compounds such as acetylene alcohol and acetylene derivatives, azines, triazines, osazone dyes, triphenylmethane dyes, C═N group-containing compounds such as kunidine, pyrimidine, pyrazole, imidazole, pyridinium and quinolinium compounds, C≡N-containing compounds such as ethylene cyanohydrin, hydrazine compounds and their derivatives, etc. N-N group-containing compounds, N = N group-containing compounds such as azo dyes, sulphonic acid, sulphonate, Surufoamido, S element-containing compounds such as thiourea and cyclic thiourea, and the like.

<Method for producing chemical conversion coating>
Although the manufacturing method of the chemical conversion treatment film of this invention is not specifically limited, The manufacturing method mainly provided with the following processes is preferable.
(1) The surface of a metal plate by self-deposition and / or electrolytic deposition using a treatment liquid containing a compound (d) containing at least one metal element (X) selected from the group consisting of Zr, Ti and Hf Surface treatment layer forming step for forming a surface treatment layer thereon (2) After the surface treatment layer formation step, at least one compound containing at least one element (Y) selected from the group consisting of Zr, Ti and Si is included. Inorganic coating layer forming step of forming an inorganic coating layer by applying an inorganic surface treatment agent on the surface treatment layer. Each step will be described in detail below together with the materials used.

<Pretreatment process>
The surface of the metal plate to be used may be cleaned before the surface treatment layer forming step described later, if necessary. This cleaning removes oil and dirt adhering to the surface of the metal plate. The cleaning method is not particularly limited, and a known method can be applied. For example, a method of washing with a degreasing agent or an acidic degreasing agent, hot water washing or solvent washing may be mentioned.
Further, before and / or after cleaning the surface of the metal plate, the surface may be adjusted with acid, alkali or the like. By performing such a treatment, the adhesion between the surface treatment layer formed on the surface of the metal plate and the metal plate is improved. Furthermore, the formation (precipitation) efficiency per time of the surface treatment layer is improved.
In addition, after performing the cleaning and / or surface adjustment of the surface of the metal plate described above, it is preferable to further wash with water so that a cleaning agent or the like does not remain on the surface of the metal plate.

<Surface treatment layer forming step>
The surface treatment layer forming step of the present invention uses a treatment liquid containing a compound (d) containing at least one metal element (X) selected from the group consisting of Zr, Ti, and Hf, and performs autodeposition and / or electroanalysis. In this step, a surface treatment layer is formed on the surface of the metal plate. By this step, the surface treatment layer 14 containing the predetermined amount of the metal element (X) is formed.
In the surface treatment layer forming step, the surface treatment layer containing the metal element (X) is formed by the autodeposition reaction (embodiment 1) and / or the electrolytic deposition reaction (embodiment 2).
Below, each reaction aspect is demonstrated.

<Self-precipitation>
In the self-deposition reaction, a surface treatment layer is formed on the metal plate only by bringing a predetermined treatment solution into contact with the metal plate without requiring any external treatment such as electrolytic treatment.
The treatment liquid used includes at least one compound (d) containing at least one metal element (X) selected from the group consisting of Zr, Ti and Hf, hydrofluoric acid, nitric acid, sulfuric acid, and these It is preferable to contain at least one acid component (e) selected from the group consisting of salts. The compound (d) containing the metal element (X) acts as a main component of the surface treatment layer. In addition, the acid component (e) exhibits effects such as dissolving the compound (d) containing the metal element (X), etching the surface of the metal material, and serving as a starting point for the self-deposition reaction.
Among these, a treatment liquid containing at least one metal element (X) and fluorine element selected from the group consisting of at least one kind of Zr, Ti, and Hf is preferable.

The compound (d) containing at least one metal element (X) selected from the group consisting of Zr, Ti and Hf is not particularly limited as long as it contains Zr, Ti or Hf. Oxide, hydroxide , A complex compound, an inorganic acid, or a salt of an organic acid. Among these, at least one selected from the group consisting of organic complex compounds, fluoride complexes, sulfates and nitrates is preferable. These anionic components of acids and salts thereof are preferable because they can be easily removed in the washing step after the chemical conversion treatment, and even if they remain slightly, they do not adversely affect the corrosion resistance.
Examples of the compound (d) include zirconyl nitrate, zirconyl acetate, zirconyl sulfate, ammonium zirconium carbonate, zircon hydrofluoric acid, titanyl sulfate, a reaction product of lactic acid and titanium alkoxide, titanium laurate, titanium hydrofluoric acid, hafnium lactate. Hafnium nitrate, hafnium fluoride, hafnium hydrofluoric acid, and the like. Among them, zircon hydrofluoric acid, titanium hydrofluoric acid, hafnium hydrofluoric acid, and the like are preferable.

  The content of the compound (d) containing the metal element (X) in the treatment liquid is appropriately selected depending on the type of metal plate used. Especially, it is preferable that the total content (concentration) of Zr, Ti, and Hf element in the compound (d) in the treatment liquid is 0.01 to 10 g / L, and 0.05 to 5 g / L. More preferably, it is more preferably 0.1-1 g / L. When it is 0.01 g / L or more, the formation rate of the surface treatment layer becomes faster, which is preferable for industrial use. Moreover, it is preferable that it is 10 g / L or less since the dissolution stability of the compound (d) can be more easily maintained in the treatment liquid.

Examples of hydrofluoric acid, nitric acid, sulfuric acid, and salts thereof in the treatment liquid include hydrofluoric acid (HF), zircon hydrofluoric acid (H ₂ ZrF ₆ ), and titanium hydrofluoric acid (H ₂ TiF ₆ ). or hafnium hydrofluoric acid (H 2 _{HfF 6)} acid by a fluoride complex such as news nitric acid, such as sulfuric acid or a salt thereof.

The content of at least one acid component (e) selected from the group consisting of hydrofluoric acid, nitric acid, sulfuric acid and salts thereof in the treatment liquid is appropriately selected depending on the type of metal plate used. The
Especially, it is preferable that it is 0.005-20 g / L, and, as for content (concentration) of the acid component (e) in a process liquid, it is more preferable that it is 0.02-10 g / L. When it is 0.005 g / L or more, sufficient etching ability for the surface of the metal plate can be expected. When it is 20 g / L or less, the etching ability becomes appropriate, and a uniform surface treatment layer can be deposited.

  Although it does not specifically limit as a solvent used for a process liquid, From a viewpoint of environmental protection, water is preferable. In addition, the processing liquid may contain an organic solvent (for example, alcohol, glycol, glycerin, acetone).

  The pH of the treatment liquid is not particularly limited, but acidic conditions are preferable. Specifically, the pH is preferably 2.0 to 6.0, and more preferably 2.5 to 4.5. If it is in the said range, the precipitation property of metal element (X) will improve more.

The treatment liquid used for self-deposition (Aspect 1) further includes a compound (f) containing at least one element selected from the group consisting of Fe, Mn, Ni, Co, Ag, Mg, Al, Zn, Cu, and Ce. ) Is preferably contained. Compound (f) promotes the autodeposition reaction. Compound (f) may be an oxide, hydroxide, complex compound, inorganic acid, or salt of an organic acid. Among these, at least one selected from the group consisting of organic complex compounds, fluoride complexes, sulfates and nitrates is preferable.
Examples of the compound (f) include permanganic acid, potassium permanganate, sodium permanganate, manganese nitrate, manganese sulfate, manganese fluoride, manganese carbonate, manganese acetate, magnesium nitrate, magnesium oxide, magnesium hydroxide, sulfuric acid. Magnesium, magnesium acetate, aluminum nitrate, aluminum oxide, aluminum hydroxide, aluminum sulfate, aluminum acetate, cerium (III) acetate, cerium (IV) acetate, cerium (III) nitrate, cerium (IV) nitrate, nickel chloride, nickel sulfate , Nickel nitrate, nickel fluoride, nickel oxide, nickel hydroxide, cobalt chloride, cobalt sulfate, cobalt nitrate, cobalt fluoride, cobalt oxide, cobalt hydroxide, silver chloride, silver sulfate, silver nitrate, silver fluoride, silver oxide, Silver hydroxide, zinc chloride, sulfuric acid Examples include zinc, zinc nitrate, zinc fluoride, zinc oxide, and zinc hydroxide.

Furthermore, the conditions of the treatment liquid for self-deposition (Aspect 1) include a free fluorine ion concentration of 1 to 30 mg / L in the treatment liquid, and Fe, Mn, Ni, Co, Ag, Mg, The ratio (F / D) of the total mass concentration F of the elements Al, Zn, Cu and Ce to the total mass concentration D of the metal elements (X) of Zr, Ti and Hf in the compound (d) is 1 to 200. And it is preferable that pH of a process liquid is 2.0 or more, and also satisfy | fills the following formula | equation (1).
Formula (1) pH ≦ −0.02 × (F / D) +6
When the treatment liquid satisfies all of these conditions, a film having excellent performance can be formed in an extremely short time.

Here, the free fluorine ion concentration can be adjusted to 1 to 30 mg / L by adjusting the addition amount of the element in the compound (f) (that is, the total mass concentration F).
Further, the pH of the treatment liquid for self-deposition (Aspect 1) can be adjusted by the content of the acid component (e) and the addition of an alkaline substance. The alkaline substance is not limited as long as it can adjust the pH without greatly degrading the performance of the treatment liquid. Preferred examples of such an alkaline substance include ammonia, sodium carbonate, organic amines (diethanolamine, triethylamine, etc.) and inorganic hydroxides (sodium hydroxide, potassium hydroxide, etc.).

<Self-deposition: treatment conditions>
The contact method between the treatment liquid and the metal plate in the self-deposition reaction is not particularly limited, and a known method such as a spray coating method, a roll coating method, or a dipping method can be used. Of these, the spray coating method is preferable.
As the contact conditions (contact time, treatment liquid temperature, etc.), optimum conditions are appropriately selected depending on the type of treatment liquid used. Especially, it is preferable that it is 0.5 to 20 seconds, and it is more preferable that it is 1 to 10 seconds. If the contact time is too short, the surface of the treatment liquid and the metal plate may not sufficiently react, and a surface treatment layer with excellent corrosion resistance may not be obtained. Moreover, when this contact time is too long, the performance improvement of the surface treatment layer obtained is not seen, and it is not preferable also from the point of the operation efficiency in a line.

  Here, in the case of the spray coating method, there is a tendency that the formation efficiency (precipitation efficiency) of the surface treatment layer is increased by performing intermittent spraying twice or more at intervals of 0.2 to 5 seconds. In this case, when the treatment liquid foams and causes a problem, it is preferable to add an antifoaming agent to the treatment liquid. The type of the antifoaming agent is not particularly limited, and a known one can be used as long as it does not impair the later paint adhesion.

  Note that the contact time between the treatment liquid and the metal plate means, for example, the time during which the metal plate is immersed in the treatment liquid in the case of an immersion method. In the case of the spray method, it means the time during which the treatment liquid is sprayed on the surface of the metal plate.

  Although the temperature of a process liquid is not specifically limited, 5-60 degreeC is preferable and 15-40 degreeC is more preferable. If it is in the said range, energy efficiency will increase, maintaining a suitable reaction rate, and a cost demerit will not arise easily.

<Electrolytic deposition>
In the electrolytic deposition reaction, a surface treatment layer is formed on the surface of the metal plate by bringing a predetermined treatment solution into contact with the metal plate using the cathode and energizing the anode.
The treatment liquid used in the electrolytic deposition includes at least one compound (d) containing at least one metal element (X) selected from the group consisting of Zr, Ti and Hf, hydrofluoric acid, nitric acid, It is preferable to contain at least one acid component (g) selected from the group consisting of sulfuric acid, phosphoric acid and salts thereof. The compound (d) acts as a supply source of the main component of the surface treatment layer. The acid component (g) exhibits effects such as dissolving the compound (d) and increasing the conductivity of the treatment liquid.
Among these, a treatment liquid containing at least one metal element (X) and fluorine element selected from the group consisting of at least one kind of Zr, Ti, and Hf is preferable.

The compound (d) used in the electrolytic deposition is synonymous with the compound used in the above-described autodeposition treatment solution.
As the content (concentration) of the compound (d) containing the metal element (X) in the treatment liquid, an optimal amount is appropriately selected depending on the type of the metal plate used. A preferable content is the same as the content of the metal element (X) in the treatment liquid used in the above-described self-precipitation.

Examples of the acid component (g) include the exemplified components listed in the above acid component (e) and phosphoric acid. These may use only 1 type and may use 2 or more types together.
The total content (concentration) of the acid component (g) in the treatment liquid is preferably 5 to 30 g / L, and more preferably 10 to 25 g / L. When it is 5 g / L or more, sufficient etching ability for the surface of the metal plate can be expected. When it is 30 g / L or less, the etching ability becomes appropriate, and a uniform surface treatment layer can be deposited.

  Although it does not specifically limit as a solvent used for a process liquid, From a viewpoint of environmental protection, water is preferable. In addition, the processing liquid may contain an organic solvent (for example, alcohol, glycol, glycerin, acetone).

  The pH of the treatment liquid is not particularly limited, but acidic conditions are preferable. Specifically, the pH is preferably 2.0 to 6.0, and more preferably 2.5 to 4.5. If it is in the said range, the precipitation property of metal element (X) will improve more.

  The treatment liquid used in the electrolytic deposition preferably has a free fluorine ion concentration of 1 to 30 mg / L in the treatment liquid and a pH of the treatment liquid of 2.0 or more.

  Although the temperature of the process liquid in electrolytic deposition is not specifically limited, 5-60 degreeC is preferable and 15-40 are more preferable. If it is in the said range, energy efficiency will increase, maintaining a suitable reaction rate, and a cost demerit will not arise easily.

<Electrolytic deposition: treatment conditions>
The method for electrolytic deposition is not particularly limited, and a known electrolytic method can be applied.
Under the electrolysis conditions, stainless steel or a Pb-based alloy is used as the counter electrode (anode), the temperature is normal temperature to 40 ° C., and the current density is 0.5 to 30 A / dm ² (more preferably 1 to 10 A / dm ² ). It is preferable.
The electrolysis time is set according to the required amount of the metal element (X) contained in the target compound (d). The electrolysis time of the metal element (X) in the surface treatment layer 14 formed by this electrolysis treatment is set. In order for the total adhesion amount to be ² to 50 mg / m ² , for example, it is preferable to perform the treatment at a current density of 3 A / dm ² for about 0.5 to 3 seconds.

  Only one of the autodeposition reaction and the electrolytic deposition reaction described above may be performed, or may be performed alternately. Moreover, you may implement several times.

<Washing process>
After the surface treatment layer forming step, if necessary, a step (washing step) of washing and drying the metal plate having the surface treatment layer may be performed.
Although the method of washing with water is not particularly limited, it can be performed, for example, by a known dipping method or spray method. The washing temperature (the temperature of the washing water) is not particularly limited and may be a commonly applied temperature, but is preferably 5 to 60 ° C, and more preferably 15 to 40 ° C. At such a temperature, the cleaning efficiency is further increased.
As washing water used for washing, drain water, industrial water, city water, or deionized water can be preferably used.
Also, the washing time is not particularly limited. For example, in the case of the dipping method or the spray method, it is preferably 0.1 to 10 seconds, and more preferably 1 to 5 seconds. If the washing time is too short, the excess treatment liquid component remaining on the surface of the surface treatment layer is not sufficiently removed, and a surface treatment layer having excellent corrosion resistance may not be obtained. Further, even if the washing time is too long, the performance of the obtained surface treatment layer is not improved, and it is not preferable from the viewpoint of operation efficiency in the line.

  In addition, this washing | cleaning time means the time when the metal plate is immersed in washing water, for example, when it is a case of the immersion method. Moreover, in the case of the spray method, it means the time during which flush water is sprayed on the surface of the metal plate.

  After such washing with water, the surface is preferably dried. When only the adhered water is removed, physical removal such as air drying or air blowing may be performed. Heat-drying treatment is effective for bringing the formed surface treatment layer into close contact with the surface of the metal plate and making it chemically stable. In this case, the heating condition is preferably heat drying so that the maximum temperature (PMT) of the surface of the metal plate on which the surface treatment layer is formed is 30 to 250 ° C, more preferably 40 to 150 ° C. preferable.

<Inorganic coating layer forming process>
The inorganic coating layer forming step of the present invention contains at least one element (Y) selected from the group consisting of Zr (zirconium element), Ti (titanium element) and Si (silicon element) after the surface treatment layer forming step. In this step, an inorganic surface treatment agent containing at least one compound is applied onto the surface treatment layer to form an inorganic coating layer.
In addition, as a structural component of an inorganic type surface treating agent, it is preferable that it contains at least one element of Zr, Ti, and Si, and does not contain a fluorine element substantially.

  The compound containing the element (Y) is not particularly limited as long as it contains at least one metal element of Zr, Ti, and Si. For example, oxides, hydroxides, complex compounds, inorganic acids, or salts of organic acids containing these metal elements. Especially, the compound containing Zr and Si is preferable at the point which the various characteristics of the chemical conversion treatment metal plate obtained are more excellent, and the compound containing Zr is more preferable.

Preferred examples of the compound containing Zr include zirconium oxide, zirconyl nitrate, zirconyl acetate, zirconyl sulfate, zirconyl ammonium carbonate, and zirconium acetate.
Preferred examples of the compound containing Ti include titanium oxide, titanyl sulfate, titanium lactate, diisopropoxytitanium bisacetylacetone, and a reaction product of lactic acid and titanium alkoxide.
Examples of the compound containing Si include silica such as colloidal silica and vapor phase silica, alkoxysilane such as tetramethoxysilane, tetraethoxysilane, monomethyltrimethoxysilane, and dimethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3 -Glycidoxypropylmethyldimethoxysilane, and epoxysilanes such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (amino Ethyl) -3-aminopropyltrimethoxysilane, and aminosilanes such as 3-aminopropyltriethoxysilane, mercaptosilanes such as 3-mercaptopropyltrimethoxysilane, and 3-isocyanatopropyltrimethoxy. Silane, isocyanate silane such as 3-isocyanate propyl triethoxysilane, vinyltriethoxysilane, vinyl group-containing silane such as p- styryl trimethoxysilane preferred.

  Although content in particular of the compound containing the said element (Y) in an inorganic type surface treating agent is not restrict | limited, 2-20 mass% is preferable with respect to the processing agent whole quantity from the point of the ease of handling, 15 mass% is more preferable.

  As a solvent used for the inorganic surface treatment agent, water is used as a main component. In addition, the processing agent may contain an organic solvent (for example, alcohol, glycol, glycerin).

  The pH of the inorganic surface treatment agent is not particularly limited, but is preferably alkaline, specifically 7 to 12, and more preferably 8 to 11. If it is in the said range, stability of an inorganic type surface treating agent will improve more.

<Other additives>
The inorganic surface treatment agent preferably further contains a compound (A) containing at least one metal element selected from the group consisting of V, Mo, Ce, W and Mn. These components are effective in raising the corrosion resistance by the inorganic coating layer.

  Although the thing containing V as a compound (A) is not specifically limited, For example, the oxidation number of vanadium is a pentavalent, tetravalent, trivalent, or bivalent vanadium compound. More specifically, vanadium pentoxide, metavanadate, ammonium metavanadate, sodium metavanadate, vanadium oxide trivalent vanadium compounds such as vanadium trioxide, vanadium trioxide, vanadium dioxide, vanadium oxysulfate, vanadium oxyacetylacetate And vanadium acetylacetonate, vanadium trichloride, phosphovanadomolybdic acid, vanadium sulfate, vanadium dichloride, vanadium oxide and the like.

  Further, as the compound (A) containing V, the ratio of the pentavalent oxide vanadium ion to the total vanadium (V5 + / V) (where V5 + and V are the mass of the pentavalent oxide vanadium, and The total vanadium mass) is preferably from 0 to 0.6, more preferably from 0 to 0.4, even more preferably from 0 to 0.2, and from 0 to 0.1. Most preferred. When the ratio exceeds 0.6, the stability of the vanadium compound in the treatment agent is generally deteriorated, and the corrosion resistance and alkali resistance of the formed film are lowered. The vanadium compound (A) of the present invention most preferably contains a vanadium compound having an oxidation number of 4 or less (usually 2 to 4).

  Although it does not specifically limit as a compound (A) containing Mo, Molybdic acid, ammonium molybdate, sodium molybdate, a molybdophosphoric acid compound (For example, ammonium molybdate, sodium molybdophosphate) etc. are mentioned.

The compound (A) containing Ce is not particularly limited, and examples thereof include cerium acetate [Ce (CH ₃ CO ₂ ) ₃ ], cerium nitrate, and cerium chloride.

  Although it does not specifically limit as a compound (A) containing Mn, Permanganic acid, potassium permanganate, sodium permanganate, manganese dihydrogen phosphate, manganese nitrate, manganese sulfate, manganese fluoride, manganese carbonate, acetic acid Manganese etc. are mentioned.

  Although content in particular of a compound (A) in an inorganic type surface treating agent is not restrict | limited, From the point which the corrosion resistance of the chemical conversion treatment metal plate obtained improves more, it is 0.5 with respect to the solid content whole quantity in a processing agent. -20 mass% is preferable, and 1-10 mass% is more preferable. In addition, solid content refers to the component which comprises the inorganic membrane | film | coat layer except a solvent (for example, water) in a processing agent.

Further, the inorganic surface treatment agent is an organic compound having at least one functional group selected from the group consisting of a hydroxyl group, a carbonyl group, a carboxyl group, a primary to tertiary amino group, an amide group, a phosphoric acid group, and a phosphonic acid group. It is preferable to contain (B). These components are effective in raising the corrosion resistance by the inorganic coating layer.
The organic compound (B) is not particularly limited, but alcohols such as methanol, ethanol, isopropanol, ethylene glycol, formaldehyde, acetaldehyde, furfural, acetylacetone, ethyl acetoacetate, dipivaloylmethane, 3-methylpentanedione, etc. Carbonyl compounds, organic acids such as formic acid, acetic acid, propionic acid, tartaric acid, ascorbic acid, gluconic acid, citric acid and malic acid, amine compounds such as triethylamine, triethanolamine, ethylenediamine, pyridine, imidazole, pyrrole, morpholine and piperazine Acid amide compounds such as formamide, acetamide, propionamide, N-methylpropionamide, amino acids such as glycine, alanine, proline, glutamic acid, aminotri (meth Phosphonic acid), 1-hydroxyethylidene-1,1'-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), organic phosphoric acid such as phytic acid, monosaccharides such as glucose, mannose and galactose, oligosaccharides such as maltose and sucrose Synthesis of natural polysaccharides such as saccharides, starch, cellulose, aromatic compounds such as tannic acid, humic acid, lignin sulfonic acid, polyphenol, polyvinyl alcohol, polyethylene glycol, polyacrylic acid, polyacrylamide, polyethyleneimine, water-soluble nylon, etc. Examples thereof include polymers. Among these organic compounds, an organic compound containing two or more of at least one selected from the above functional groups in a molecule is preferable, and further, the above functional groups include a hydroxyl group, a carbonyl group, a carboxyl group, a phosphate group, and a phosphone. An organic compound containing at least two selected from acid groups in one molecule is more preferable.

  Although content in particular of the organic compound (B) in an inorganic type surface treating agent is not restrict | limited, From the point which the corrosion resistance of the chemical conversion treatment metal plate obtained improves more, it is 0. 5-20 mass% is preferable and 1-10 mass% is more preferable. In addition, solid content refers to the component which comprises the inorganic membrane | film | coat layer except a solvent (for example, water) in a processing agent.

<Processing conditions>
The inorganic coating layer is a surface treatment layer containing an inorganic surface treatment agent containing at least one compound containing at least one element (Y) selected from the group consisting of Zr, Ti and Si after the surface treatment layer forming step described above. It is formed by coating on top and drying as necessary.
The application method is not particularly limited, and examples thereof include a spin coating method, a roll coating method, a dipping method, and a spray coating method.
After forming the coating film, the coating film may be washed with water as necessary.
In order to form an industrially practical film, it is preferable to heat-dry the coated film after coating. In this case, the drying temperature is preferably 30 to 300 ° C., more preferably 40 to 250 ° C., and particularly preferably 60 to 200 ° C. as the ultimate plate temperature. The drying time is not particularly limited as long as the ultimate plate temperature satisfies the above conditions.

  The use temperature of the inorganic surface treatment agent is not particularly limited, and optimum conditions are appropriately selected depending on the components contained in the treatment agent.

<Application>
The chemical conversion treatment metal plate of this invention is equipped with the structure where the surface treatment layer and the inorganic membrane | film | coat layer were laminated | stacked on the metal plate as mentioned above. The chemical conversion treatment metal plate having such a configuration exhibits excellent corrosion resistance, coating film adhesion, cycle corrosion resistance, and heat resistance. A metal plate having such various characteristics in a well-balanced manner has not been provided conventionally, and the chemical conversion-treated metal plate of the present invention can be applied to various uses. For example, household appliances, building materials, automobile steel plates, and the like can be given.

Moreover, it can be used also as a coating board by apply | coating a primer to the chemical conversion treatment metal plate of this invention, drying, and then apply | coating and drying a topcoat paint. The primer contains a resin and may contain a color pigment, a rust preventive pigment, or the like as necessary.
The resin may be in any form such as aqueous, solvent-based, and powder-based.
As the coloring pigment, known coloring pigments such as inorganic pigments such as titanium oxide and carbon black, and organic pigments such as azo pigments can be used.
Antirust pigments include chromate rust preventive pigments such as strontium chromate and zinc chromate, phosphate rust preventive pigments such as zinc phosphate, molybdate rust preventive pigments such as calcium molybdate, and fine particles such as water-dispersible silica. Silica and the like can also be used.
However, it is desirable not to use chromate-based anticorrosive pigments because they are environmentally toxic.
Moreover, you may mix | blend additives, such as a defoamer, a dispersion adjuvant, or a diluent for reducing a coating-material viscosity suitably.
Moreover, it does not specifically limit as a topcoat paint here, A well-known topcoat for coating can be used. For example, it contains a resin, and may further contain a color pigment, a rust preventive pigment, or the like as necessary. As the resin, the color pigment, the rust preventive pigment, and the additive, those similar to those used in the primer can be used.

The chemical conversion treatment metal plate of the present invention has a performance balance that the surface treatment layer has not been obtained so far, and not only the corrosion resistance of the thin film, but also the adhesion and cycle corrosion test that could not be obtained with the conventional inorganic single film. Corrosion resistance, and heat resistance not obtained by conventional resin-based multilayer processing. The reason is presumed as follows, but the present invention is not limited to such presumption.
In the present invention, a surface treatment layer containing Zr, Ti or the like is formed on a metal plate by autodeposition and / or electrolytic treatment. Corrosion resistance is considered to be manifested mainly by the surface treatment layer densely covering the surface of the metal plate material. This surface-treated layer is not attacked by acids and alkalis, and follows the bending process and has excellent coating properties. However, it is a very thin film, so it is capable of physically and temporally blocking corrosion factors, so-called barrier properties. Is not enough. If the surface treatment layer is made thick in order to impart barrier properties, not only a surface treatment layer with a sparse surface is formed but also peeling due to cohesive failure in the surface treatment layer is likely to occur. By subjecting the surface treatment layer having such properties to a multilayer treatment that forms an inorganic coating layer as an upper layer, barrier properties can be imparted to the surface treatment layer.

Since the inorganic coating layer is formed of a water-based coating-type treatment agent, some moisture is retained in the coating during film formation. Therefore, since hydrogen bonds remain in the inorganic coating layer, the coating is slightly more flexible than the chemical conversion coating having strong covalent bonding.
On the other hand, the interlayer adhesion between the surface treatment layer and the inorganic coating layer becomes very strong as compared with the case where the resin layer is used. The reason is that the metal element constituting the inorganic coating layer is the same Zr and Ti as the metal element constituting the surface treatment layer described above, or Si having a chemical property very similar to Zr. This is presumably because the physical properties of the layer and the inorganic coating layer are similar. Furthermore, since both the surface treatment layer and the inorganic coating layer are mainly polymerized films such as oxo bonds or all bonds of Zr and Ti, hydrogen bonding and sharing between the surface treatment layer and the inorganic coating layer are possible. This is presumably because bonds are easily formed.
By using the inorganic surface treating agent having such characteristics, it is presumed that the chemical conversion-treated metal plate of the present invention has a performance balance that cannot be obtained by the conventional resin-based surface-treated metal plate.
In particular, when the present inventors examined the cycle corrosion resistance, it was found that a single layer structure of a surface treatment layer or an inorganic coating layer does not provide sufficient performance. That is, it can be said that the effect is exhibited for the first time by taking a laminated structure of the surface treatment layer and the inorganic coating layer described in the present invention.

  EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples of the present invention, but the present invention is not limited thereto. The adjustment of the test plate, examples and comparative examples will be described below.

(1) Test material Commercially available materials shown in Table 1 below were used.

In Table 1 above, the basis weight indicates the basis weight on the main surface of each steel plate. For example, in the case of an electrogalvanized steel sheet, it is 20/20 (g / m ² ), which means that each surface of the steel sheet has a plating of 20 g / m ² .
In Table 1, “Aspect 1” refers to a steel plate used for forming a surface treatment by self-deposition, and “Aspect 2” refers to a steel plate used for forming a surface treatment by electrolytic deposition. Sure.

(2) Metal plate cleaning method The surface (both sides) of the above test material is treated with sodium hydroxide degreasing agent Fine Cleaner L4460 (registered trademark: manufactured by Nihon Parkerizing Co., Ltd.) and adhered to the surface. Removed dust and oil. The treatment conditions were spray treatment for 30 seconds under the conditions of standard concentration and temperature of 40 ° C. described in the instruction manual. After the treatment, the test material was washed with pure water for 30 seconds and dried to obtain a test plate.

(3-1) Formation of surface treatment layer (Aspect 1: Autodeposition)
The test plate (surface 1) shown in Table 1 subjected to degreasing treatment was treated with the treatment liquid (solvent: water) and treatment liquid conditions shown in Table 2 below, and the test plate having the surface treatment layer shown in Table 3 Got. The use temperature of the treatment liquid was 50 to 60 ° C. and contacted with the test plate by spray treatment. The treatment time was 2 seconds to 10 seconds, and treatment was performed until the metal element (X) adhesion amount shown in Table 3 below was obtained.
From the ESCA measurement, it was found that the surface treatment layer was mainly composed of metal element (X) (zirconium element, titanium element or hafnium element) and fluorine element.
The concentration (D) in Table 2 represents the mass concentration of the metal element (X), and the concentration (F) represents the mass concentration of each metal used.

The pH in Table 2 was adjusted to a predetermined pH with ammonia. The free fluorine concentration was measured with a fluorine ion meter.
Further, in Table 2, “Expression (1)” represents the above-described Expression (1): pH ≦ −0.02 × (F / D) +6, and the pH of each treatment solution is related to Expression (1). When satisfied, it is assumed that “success / failure: ○”.

  In Table 3, the adhesion amount of the metal element (X) was measured with fluorescent X-rays.

(3-2) Formation of surface treatment layer (Aspect 2: Electrodeposition)
The test plate (embodiment 1) shown in Table 1 subjected to degreasing treatment was treated under the treatment liquid (solvent: water) and treatment liquid conditions shown in Table 4 to obtain a test plate having a surface treatment layer. The processing solution was used at a temperature of 50 to 60 ° C. The test plate was used as a cathode, and a thin plate made of SUS304 was used as an anode, and at the same time, a predetermined amount of current was applied to the test plate. The treatment time was between 2 seconds and 10 seconds until the metal element (X) adhesion amount shown in Table 5 was obtained.
From the ESCA measurement, it was confirmed that the surface treatment layers in Q1 to Q9 and Q11 were mainly composed of a metal element (X) (zirconium element, titanium element, or hafnium element) and a fluorine element. In addition, it was confirmed that the surface treatment layer in Q10 is mainly composed of a zirconium element and an oxygen element. In addition, the concentration (D) in Table 4 represents the mass concentration of the metal element (X).

  In Table 5, the adhesion amount of the metal element (X) was measured with fluorescent X-rays.

(3-3) Formation of surface treatment layer (comparative example)
The following comparative examples (R1 to R3) were processed. In addition, as a test board, the electrogalvanized steel plate (EG) was used.
R1: No surface treatment layer R2: Reactive chromate treatment R3: Zinc phosphate treatment Note that the reactive chromate treatment (R2) uses Zinchrome 3367 (registered trademark: manufactured by Nihon Parkerizing Co., Ltd.) and is in accordance with the instruction manual. It processed so that it might become 15 mg / m < ² > by Cr adhesion amount.
In addition, zinc phosphate treatment (R3) uses Palbond 3305 (registered trademark: manufactured by Nihon Parkerizing Co., Ltd.), and the coating amount by the chromic acid peeling method is 1.0 g / m ² according to the instruction manual. Processed.

(4) Formation of inorganic coating layer On the test plate prepared in the above (3-1) to (3-3), an inorganic surface treatment agent represented by the following (S1) to (S5), or ( The treating agent for comparative example represented by S6) was applied with a bar coater to form an inorganic coating layer on the surface treatment layer.
The inorganic coating layer was baked so that the ultimate plate temperature was 150 ° C. after application.
Further, from the ESCA measurement, the inorganic coating layer obtained using the inorganic surface treatment agent represented by (S1) to (S5) is mainly composed of element (Y) (zirconium element or silicon element) and oxygen element. Confirmed to be composed.
(S1):
The treatment agent was adjusted by diluting ammonium zirconium carbonate with pure water so that the solid content was 10% by mass. The pH of the treatment agent was adjusted to 9.5.
(S2):
To the inorganic surface treatment agent (S1), ammonium metavanadate was added so as to be 3% by mass with respect to the solid content. In addition, (C _A / C _Y ) in the inorganic coating layer after the treatment was 0.09. The pH of the treatment agent was adjusted to 9.5.
(S3):
To the inorganic surface treatment agent (S1), ammonium metavanadate and 1-hydroxyethylidene-1,1′-diphosphonic acid were added so as to be 3% by mass and 2% by mass, respectively, based on the solid content. In addition, (C _A / C _Y ) in the inorganic coating layer after the treatment was 0.09. The pH of the treatment agent was adjusted to 9.5.
(S4):
A treatment agent was prepared by diluting colloidal silica (Snowtex UP, manufactured by Nissan Chemical Co., Ltd.) with pure water so that the solid content was 10% by mass. The pH of the treatment agent was adjusted to 9.5.
(S5):
3-glycidoxypropyltrimethoxysilane (2 mol) and 3-aminopropyltriethoxysilane (1 mol) are reacted in ethanol (100 mL), and then mixed with pure water, so that the solid content becomes 10% by mass. It adjusted so that it might become. The pH of the treatment agent was adjusted to 4.5.
(S6):
Pure water was added to urethane resin (HYDRAN HW-340 manufactured by DIC Corporation) to adjust the total solid content to 20% by mass.

Production of the surface treatment layer described in the above (3-1) to (3-3) and the inorganic coating layer using the treatment agent represented by (S1) to (S6) is shown in Table 6 below. As shown, a chemical conversion-treated metal plate having a surface treatment layer and an inorganic coating layer was produced.
In addition, the adhesion amount of the metal element (X) in the surface treatment layer and the Zr adhesion amount or the Si adhesion amount per unit area of the element (Y) in the inorganic coating layer were measured by fluorescent X-rays.

(5) Evaluation method (5-1) Environmental impact property About each chemical conversion treatment metal plate obtained by said method, the environmental impact property was evaluated from the component contained in a metal plate based on the following judgment criteria. The evaluation criteria are as follows.
<Evaluation criteria>
○: not containing chromium ×: containing chromium

(5-2) Plane part corrosion resistance The salt spray test prescribed | regulated to JIS-Z2371 was implemented with respect to each obtained chemical conversion treatment metal plate for 240 hours. Next, the white rust generation area ratio was visually measured and evaluated. Here, the white rust generation area ratio is a percentage of the area of the white rust generation site to the area of the observation site (7 cm × 15 cm). The evaluation criteria are as follows.
<Evaluation criteria>
◎: White rust generation area ratio less than 5% ○: White rust generation area ratio of 5% or more and less than 10% △: White rust generation area ratio of 10% or more and less than 50% ×: White rust generation area ratio of 50% or more

(5-3) Plane portion corrosion resistance after degreasing For each of the obtained chemical conversion treated metal plates, fine cleaner L4460 (standard building bath: A agent 20 g / l, B agent 12 g / L, temperature 60 ° C., after immersion for 2 minutes The water was degreased and the salt spray test specified in JIS-Z2371 was performed for 120 hours. Next, the white rust generation area ratio was visually measured and evaluated. Here, the white rust generation area ratio is a percentage of the area of the white rust generation site to the area of the observation site (7 cm × 15 cm). The evaluation criteria are as follows.
<Evaluation criteria>
◎: White rust generation area ratio less than 5% ○: White rust generation area ratio of 5% or more and less than 10% △: White rust generation area ratio of 10% or more and less than 50% ×: White rust generation area ratio of 50% or more

(5-4) Processed part corrosion resistance The obtained chemical conversion metal plates were subjected to 7 mm extrusion using an Erichsen tester, and a salt spray test defined in JIS-Z2371 was performed for 120 hours. Next, the white rust generation area ratio was visually measured and evaluated. Here, the white rust generation area ratio is a percentage of the area of the white rust generation site to the area of the observation site. The evaluation criteria are as follows.
<Evaluation criteria>
◎: White rust generation area ratio less than 5% ○: White rust generation area ratio of 5% or more and less than 10% △: White rust generation area ratio of 10% or more and less than 50% ×: White rust generation area ratio of 50% or more

(5-5) Adhesiveness Using a paint (Amirac # 1000 (white paint) manufactured by Kansai Paint Co., Ltd.), the obtained chemical conversion treatment metal plate was subjected to a coating treatment. The coating was performed by bar coating. After coating, baking was performed at 140 ° C. for 20 minutes, and a film having a thickness of 25 μm was formed after drying.
Next, 100 mm grids of 1 mm square are cut into each post-painted metal plate with an NT cutter, and this is extruded 5 mm with an Erichsen tester, and then a peel test is performed on the extruded convex portion with an adhesive tape. Evaluation was based on the number of coating films peeled. The evaluation criteria are as follows.
<Evaluation criteria>
◎: No peeling ○: Number of peeled 1 or more, less than 10 △: Number of peeled 11 or more, less than 50 ×: Number of peeled 51 or more

(5-6) Cycle Corrosion Resistance Test 100 cycles of the cycle corrosion resistance test defined in JASO-M602 were performed on each of the obtained chemical conversion treated metal plates. Next, the white rust generation area ratio was visually measured and evaluated. Here, the white rust generation area ratio is a percentage of the area of the white rust generation site to the area of the observation site (7 cm × 15 cm). The evaluation criteria are as follows.
<Evaluation criteria>
◎: White rust generation area rate less than 10% ○: White rust generation area rate of 10% or more, less than 20% △: White rust generation area rate of 20% or more, less than 50% ×: White rust generation area rate of 50% or more

(5-7) Heat resistance Each obtained chemical conversion treatment metal plate was subjected to a heat treatment in an oven at 250 ° C for 2 hours, and the appearance was evaluated. Specifically, it evaluated from the color difference ((DELTA) E) using the color difference meter (The Nippon Denshoku Industries Co., Ltd. make, color meter ZE2000). The evaluation criteria are as follows.
<Evaluation criteria>
◎: ΔE is less than 1.5 ○: ΔE is 1.5 or more and less than 3.0 Δ: ΔE is 3.0 or more and less than 5.0 ×: ΔE is 5.0 or more

  Table 7 shows the results of the evaluation of the above (5-1) to (5-7) for the chemical conversion treatment metal plates obtained in Examples 1 to 26 and Comparative Examples 1 to 7.

From Table 7, the chemical conversion treatment metal plate of the present invention having a laminated structure of a surface treatment layer and an inorganic coating layer has a good evaluation in all items of environmental impact, corrosion resistance, adhesion, cycle corrosion resistance test, and heat resistance. Results are shown.
In the comparative example, the chromate treatment of Comparative Example 6 showed the same characteristics as the chemical conversion treated metal plate of the present invention, but was inferior in environmental load in that it contained chromium. Moreover, it turned out that the chemical conversion treatment metal plate of this invention has a very favorable performance balance also compared with the comparative examples 2-4 which use a resin-type membrane | film | coat instead of an inorganic membrane | film | coat layer.
In Comparative Example 1 having a single surface treatment layer and Comparative Example 5 having a single inorganic coating layer, good cycle corrosion resistance was not obtained.

It is typical sectional drawing of one Embodiment of the chemical conversion treatment metal plate which concerns on this invention. It is typical sectional drawing of one Embodiment of the chemical conversion treatment metal plate which concerns on this invention.

Explanation of symbols

10, 20 Chemical conversion treatment metal plate 12 Metal plate 14 Surface treatment layer 16 Inorganic coating layer

Claims (8)

On the metal plate, the total amount of element adhesion per unit area of at least one metal element (X) selected from the group consisting of Zr, Ti and Hf is ² to 50 mg / m ² , and self-deposition and / or electroanalysis An inorganic surface treatment agent comprising at least one compound containing at least one element (Y) selected from the group consisting of Zr, Ti and Si, and a surface treatment layer formed by the above treatment on the surface treatment layer; A chemical conversion surface metal plate provided with an inorganic coating layer formed by coating in this order,
The chemical conversion surface metal plate whose element adhesion total amount per unit area of the element (Y) in the said inorganic membrane | film | coat layer is 5-1000 mg / m < ² >.   The chemical conversion treatment metal plate according to claim 1, wherein the metal plate is a zinc-based plated steel plate.   The inorganic coating layer is an inorganic coating layer formed by applying an inorganic surface treatment agent containing at least one compound containing Zr on the surface treatment layer, the main component being a zirconium element and an oxygen element. The chemical conversion treatment metal plate according to claim 1 or 2.   The inorganic surface treatment agent further contains a compound (A) containing at least one metal element selected from the group consisting of V, Mo, Ce, W and Mn. The chemical conversion treatment metal plate of description. Total amount of element adhesion (C _Y ) per unit area of the element (Y) in the inorganic coating layer, and total element deposition per unit area of the metal element contained in the compound (A) in the inorganic coating layer the amount _{(C a)} and the mass ratio of the _(C a / C _Y) is 0.05 to 1.00, chemical conversion treated metal sheet as claimed in claim 4.   The inorganic surface treatment agent further has at least one functional group selected from the group consisting of a hydroxyl group, a carbonyl group, a carboxyl group, a primary to tertiary amino group, an amide group, a phosphoric acid group, and a phosphonic acid group. The chemical conversion treatment metal plate in any one of Claims 1-5 containing an organic compound (B). Using the treatment liquid containing the compound (d) containing at least one metal element (X) selected from the group consisting of Zr, Ti and Hf, it is formed on the surface of the metal plate by autodeposition and / or electrolytic deposition. A surface treatment layer forming step of forming a surface treatment layer;
After the surface treatment layer forming step, an inorganic surface treatment agent containing at least one compound containing at least one element (Y) selected from the group consisting of Zr, Ti and Si is applied onto the surface treatment layer. An inorganic coating layer forming step for forming an inorganic coating layer.   The manufacturing method of the chemical conversion treatment metal plate of Claim 7 whose said metal plate is a zinc-plated steel plate.

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