JP2010111904A - Surface-treated galvanized steel sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a galvanized steel sheet in which corrosion resistance and fingerprint resistance in a thin film are consistent, and further, which has electroconductivity and adhesion which have not been obtained by the conventional multilayer treatment. <P>SOLUTION: The surface-treated galvanized steel sheet 10 is obtained by providing the surface of a galvanized steel sheet 12 with: a surface treatment layer 14 in which the total amount 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 a silicon-containing layer 16 formed by applying a water base metal surface treatment agent comprising an organic silicone compound (Y) to the surface of the surface treatment layer in this order. <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. The present invention relates to a galvanized steel sheet that not only has both corrosion resistance and fingerprint resistance, but also has conductivity and adhesion that cannot be obtained by conventional surface treatment.

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 relating to 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.

  As a technique mainly using a silane coupling agent, Patent Document 17 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. It is disclosed that a crosslinker crosslinks an organofunctional silane to obtain a dense siloxane film.

  Patent Document 18 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 18 are remarkably lacking in performance such as conductivity and fingerprint resistance of the obtained film, and for improving the quality of products (corrosion resistance, paint adhesion). There are problems such as difficulty in handling all of them. 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 19 discloses that an aqueous dispersion resin is 5 to 30% by mass in solid 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 20 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 obtained by using this treating agent and excellent in corrosion resistance, fingerprint resistance, blackening resistance and paint adhesion is disclosed.

  However, since these techniques disclosed in Patent Documents 19 and 20 exhibit corrosion resistance and fingerprint resistance by coating the surface of a metal material with an organic resin, there is a problem that the performance such as conductivity and spot weldability is inferior. 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 21, 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 described above, no surface-treated steel sheet that replaces the chromate film has been obtained by any of the methods, and comprehensively satisfies various characteristics such as corrosion resistance, paint adhesion, conductivity, and fingerprint resistance, and a short treatment. There is a strong demand for the development of surface-treated galvanized steel sheets that can be manufactured in time.

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 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 achieves both corrosion resistance and fingerprint resistance, but also has conductivity and adhesion that could not be obtained by conventional surface treatment. An object of the present invention is to provide a zinc-based plated steel sheet having excellent performance balance of various properties.

  As a result of intensive studies to solve these problems, the inventors have made a zinc-based plating having a surface treatment layer formed by depositing a predetermined amount of a specific metal element by autodeposition and / or electrolytic deposition. An aqueous metal surface treatment agent containing an organosilicon compound having a specific structure and molecular weight is applied to a steel sheet to form a silicon-containing layer, and the metal element and the organosilicon compound in the surface treatment layer satisfy a specific mass ratio. Thus, the inventors have found that the above problems can be solved, and have completed the present invention.

（一般式（Ｉ）中、Ｘは、エポキシ基、アミノ基、メルカプト基、ビニル基、およびイソシアネート基からなる群から選択されるいずれかの官能基を表す。Ｌは、２価の連結基、または単なる結合手を表す。Ｙは、それぞれ独立に、アルキル基、アルコキシ基、ハロゲン基、水素原子、または水酸基を表す。）
（５） 前記水系金属表面処理剤が、２価以上の金属イオンを含有する金属化合物（Ｃ）、および／または、フッ化水素酸、有機酸およびりん酸からなる群から選択される少なくとも１種の酸（Ｄ）を含有する、（１）〜（４）のいずれかに記載の表面処理亜鉛系めっき鋼板。
（６） 前記金属化合物（Ｃ）に含有される金属イオンが、Ｔｉ、Ｚｒ、Ｈｆ、Ｖ、Ｍｇ、Ｍｎ、Ｚｎ、Ｗ、Ｍｏ、Ａｌ、Ｎｉ、Ｃｏ、ＣｅおよびＣａイオンからなる群から選択される少なくとも１種である、（５）に記載の表面処理亜鉛系めっき鋼板。
（７） Ｚｒ、ＴｉおよびＨｆからなる群から選ばれる少なくとも１つの金属元素（Ｘ）を含む化合物（ｄ）を含有する処理液を用いて、自己析出および／または電解析出により、亜鉛系めっき鋼板の表面上に表面処理層を形成する表面処理層形成工程と、
前記表面処理層形成工程後、有機ケイ素化合物（Ｙ）を含有する水系金属表面処理剤を前記表面処理層上に塗布して、ケイ素含有層を形成するケイ素含有層形成工程と、を備える表面処理亜鉛系めっき鋼板の製造方法であって、
前記有機ケイ素化合物（Ｙ）が、１分子内に、式−ＳｉＲ_１Ｒ_２Ｒ_３（式中、Ｒ_１、Ｒ_２およびＲ_３は、それぞれ独立して、アルキル基、アルコキシ基または水酸基を表し、Ｒ_１、Ｒ_２およびＲ_３のうち少なくとも１つはアルコキシ基を表す。）で表される官能基（ａ）を２個以上と、水酸基（官能基（ａ）に含まれ得るものとは別個のもの）、アミノ基、カルボキシル基、りん酸基、ホスホン酸基、スルホン基、ポリオキシエチレン鎖およびアミド基からなる群から選ばれる少なくとも１種の親水性官能基（ｂ）とを含有し、前記官能基（ｂ）１個当たりの分子量が１００〜１００００である化合物である、表面処理亜鉛系めっき鋼板の製造方法。 That is, the present invention provides the following (1) to (7).
(1) On the galvanized steel sheet, 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-precipitation And / or a surface treatment layer formed by electrolytic deposition and a silicon-containing layer formed by applying an aqueous metal surface treatment agent containing an organosilicon compound (Y) on the surface treatment layer in this order. A surface-treated galvanized steel sheet comprising:
In one molecule, the organosilicon compound (Y) has the formula —SiR ₁ R ₂ R ₃ (wherein R ₁ , R ₂ and R ₃ each independently represents an alkyl group, an alkoxy group or a hydroxyl group). , R ₁ , R ₂ and R ₃ represent at least one functional group (a) represented by two or more functional groups (a) and a hydroxyl group (which can be contained in the functional group (a)) And at least one hydrophilic functional group (b) selected from the group consisting of amino groups, carboxyl groups, phosphoric acid groups, phosphonic acid groups, sulfone groups, polyoxyethylene chains and amide groups. , A compound having a molecular weight of 100 to 10,000 per functional group (b),
The mass ratio [Y / X] of the total amount of element adhesion of the metal element (X) of the surface treatment layer and the amount of Si adhesion derived from the organosilicon compound (Y) of the silicon-containing layer is 0.1 to A surface-treated galvanized steel sheet, characterized by being 100.0.
(2) The organosilicon compound (Y) is represented by at least one reactive functional group and a formula —SiR ₁ R ₂ R ₃ (wherein R ₁ , R ₂ and R ₃ are as defined above). Reacting at least one organosilane compound (A) having a functional group (a) with at least one compound (B) having a functional group capable of reacting with the reactive functional group, The surface-treated zinc-based plated steel sheet according to (1), which is a compound obtained.
(3) The reactive functional group of the organosilane compound (A) and the functional group of the compound (B) are each independently a hydroxyl group (separate from those that can be included in the functional group (a)) ), Glycidyl group, primary amino group, secondary amino group, mercapto group, isocyanate group, carboxyl group, methylol group, active methylene group, imide group, amide group, carbonyl group and vinyl group. The surface-treated zinc-based plated steel sheet according to (2), which is one type.
(4) The surface-treated galvanized steel sheet according to (2) or (3), wherein the organosilane compound (A) is a compound represented by the general formula (I).

(In General Formula (I), X represents any functional group selected from the group consisting of an epoxy group, an amino group, a mercapto group, a vinyl group, and an isocyanate group. L represents a divalent linking group, Or represents a simple bond, each Y independently represents an alkyl group, an alkoxy group, a halogen group, a hydrogen atom, or a hydroxyl group.)
(5) The aqueous metal surface treatment agent is at least one selected from the group consisting of a metal compound (C) containing a divalent or higher-valent metal ion and / or hydrofluoric acid, an organic acid and phosphoric acid. The surface-treated zinc-based plated steel sheet according to any one of (1) to (4), which contains the acid (D).
(6) The metal ion contained in the metal compound (C) is selected from the group consisting of Ti, Zr, Hf, V, Mg, Mn, Zn, W, Mo, Al, Ni, Co, Ce and Ca ions. The surface-treated zinc-based plated steel sheet according to (5), which is at least one kind.
(7) Zinc-based plating by autodeposition 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 on the surface of the steel sheet;
After the surface treatment layer formation step, a silicon-containing layer formation step of forming a silicon-containing layer by applying an aqueous metal surface treatment agent containing an organosilicon compound (Y) onto the surface treatment layer A method for producing a galvanized steel sheet,
In one molecule, the organosilicon compound (Y) has the formula —SiR ₁ R ₂ R ₃ (wherein R ₁ , R ₂ and R ₃ each independently represents an alkyl group, an alkoxy group or a hydroxyl group). , R ₁ , R ₂ and R ₃ represent at least one functional group (a) represented by two or more functional groups (a) and a hydroxyl group (which can be contained in the functional group (a)) And at least one hydrophilic functional group (b) selected from the group consisting of amino groups, carboxyl groups, phosphoric acid groups, phosphonic acid groups, sulfone groups, polyoxyethylene chains and amide groups. The manufacturing method of the surface treatment zinc-plated steel plate which is a compound whose molecular weight per said functional group (b) is 100-10000.

  The present invention can be manufactured in a short period of time, and not only achieves both corrosion resistance and fingerprint resistance, but also has a performance balance of various properties having conductivity and adhesion that could not be obtained by conventional surface treatment. A galvanized steel sheet excellent in quality is provided.

  The surface-treated zinc-based plated steel sheet according to the present invention and a method for producing the same are described below. First, the surface-treated zinc-based plated steel sheet will be described in detail based on a preferred embodiment shown in the drawings.

<Surface-treated galvanized steel sheet>
FIG. 1 is a schematic cross-sectional view of one embodiment of a surface-treated zinc-based plated steel sheet according to the present invention.
A surface-treated galvanized steel sheet 10 shown in the figure has a laminated structure in which a galvanized steel sheet 12, a surface-treated layer 14, and a silicon-containing 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 silicon-containing layer 16 is a layer formed by applying an aqueous metal surface treatment agent containing an organosilicon compound (Y) on the surface treatment layer.
In FIG. 1, the layer thicknesses of the zinc-based plated steel sheet 12, the surface treatment layer 14, and the silicon-containing layer 16 are not limited depending on the figure. Further, in FIG. 1, the surface treatment layer 14 and the silicon-containing layer 16 are laminated only on one surface of the zinc-based plated steel sheet 12, but as shown in FIG. The surface treatment layer 14 and the silicon-containing layer 16 may be included.
First, the zinc-based plated steel sheet 12 and each layer constituting the surface-treated zinc-based plated steel sheet 10 will be described.

<Zinc-based plated steel sheet>
The galvanized steel sheet 12 used for the surface-treated galvanized steel sheet of the present invention is for laminating and supporting each of the surface treatment layer 14 and the silicon-containing layer 16 described later.
Although it does not specifically limit as a kind of galvanized steel plate 12, For example, a galvanized steel plate, a zinc-nickel plating steel plate, a zinc-iron plating steel plate, a zinc-chromium plating steel plate, a zinc-aluminum plating steel plate, a zinc-titanium plating steel plate Zinc-magnesium-plated steel sheets, zinc-manganese-plated steel sheets, zinc-aluminum-magnesium-plated steel sheets, zinc-plated steel sheets such as zinc-aluminum-magnesium-silicon-plated steel sheets, and the like.
In addition, as a small amount of different metal elements or impurities in these plating layers, cobalt, molybdenum, tungsten, nickel, titanium, chromium, aluminum, manganese, iron, magnesium, lead, bismuth, antimony, tin, copper, cadmium, arsenic, etc. In which inorganic substances such as silica, alumina, titania and the like are dispersed. In addition, among the above-described plating, a multi-layer plated steel sheet in which two or more layers of the same type or different types are plated can also be used.
The plating method is not particularly limited, and examples thereof include a known electrogalvanizing method and hot dip galvanizing method.
Further, the size and thickness of the galvanized steel sheet 12 are not particularly limited.

<Surface treatment layer>
The surface treatment layer 14 in the surface-treated galvanized steel sheet 10 of the present invention is laminated on the galvanized steel sheet 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.
More specifically, the surface treatment layer 14 has a 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. A deposited and / or electrolytically deposited layer.

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 in the surface treatment layer 14 is ² to 50 mg / m ² , and 5 to 30 mg / m ^2. m ² is preferable, and 7 to 25 mg / m ² is more preferable. If the total adhesion amount of the metal element (X) is less than 2 mg / m ² , corrosion resistance is not exhibited, which is not preferable. Moreover, when the total adhesion amount exceeds 50 mg / m ² , it is not preferable because adhesion to a steel 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 component of the surface treatment layer 14 is mainly an oxide, fluoride, and / or hydroxide of at least one metal element (X) selected from the group consisting of Zr, Ti, and Hf. And additives (for example, oxides and / or hydroxides of V, Mn, W, or 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.

<Silicon-containing layer>
The silicon-containing layer 16 in the surface-treated zinc-based plated steel sheet 10 of the present invention is laminated on the surface-treated layer 14 described above, and mainly imparts fingerprint resistance and barrier properties.
The silicon-containing layer 16 is a layer formed by applying an aqueous metal surface treatment agent containing an organosilicon compound (Y) described later on the surface treatment layer, and is mainly composed of an organosilicon compound (Y). .

In the silicon-containing layer 14, the element adhesion amount per unit area of Si (silicon atom) derived from the organosilicon compound (Y) (hereinafter also simply referred to as Si adhesion amount) is the same as the metal element (X) described later. Although it will not restrict | limit if mass relation is satisfied, 10-200 mg / m < ² > is preferable and 30-150 mg / m < ² > is more preferable. If it is in the said range, various characteristics, such as corrosion resistance, electroconductivity, and adhesiveness, will improve more.
In addition, Si adhesion amount can be measured with a fluorescent X-ray analyzer (XRF).

  In the surface-treated zinc-based plated steel sheet 10 of the present invention, the total amount of element adhesion (hereinafter also referred to as X) of at least one metal element (X) selected from the group consisting of Zr, Ti and Hf in the surface treatment layer 14. ) And the Si adhesion amount (hereinafter also referred to as Y) derived from the organosilicon compound (Y) in the silicon-containing layer 16 is 0.1 to 100.0, and 1 It is preferable that it is -30, and it is more preferable that it is 2-15. If the above mass ratio [Y / X] range is not satisfied, a good balance between the corrosion resistance and adhesion of the surface-treated galvanized steel sheet to be obtained is not preferable. More specifically, when the mass ratio [Y / X] is large, particularly when Y is large, waste such as debris is easily generated during processing, and when X is small, fingerprint resistance is deteriorated. When the mass ratio [Y / X] is small, particularly when Y is small, the corrosion resistance deteriorates, and when X is large, the adhesion deteriorates and the corrosion resistance also deteriorates.

  In the coating of the surface-treated zinc-based plated steel sheet 10 of the present invention (surface-treated layer 14 and silicon-containing layer 16), a surfactant called a wettability improver for forming a uniform coating on the coated surface, Further, a thickener, a conductivity improver, a color pigment for improving the design property, a film forming aid for improving the film forming property, and 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.

In addition, the coating (surface treatment layer 14 and silicon-containing layer 16) of the surface-treated zinc-based plated steel sheet 10 of the present invention has a C = O group, C = C in one molecule called an organic inhibitor for further improvement of corrosion resistance. A group consisting of at least one unsaturated group selected from the group consisting of a group, a C≡C group, a C═N group, a C≡N group and an N═N group, an N—N group and a functional group having an S element A compound having at least one selected 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 surface-treated galvanized steel sheet>
Although the manufacturing method of the surface treatment zinc-plated steel plate of this invention is not specifically limited, The manufacturing method mainly provided with the following processes is preferable.
(1) 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, self-precipitation and / or on the surface of the galvanized steel sheet Alternatively, after the surface treatment layer forming step (2) surface treatment layer formation step for forming the surface treatment layer by electrolytic deposition, an aqueous metal surface treatment agent containing an organosilicon compound (Y) is applied on the surface treatment layer. The silicon-containing layer forming step for forming the silicon-containing layer Each step and other optional steps will be described in detail below together with the materials used.

<Pretreatment process>
If necessary, the surface of the zinc-based plated steel sheet to be used may be cleaned before the surface treatment layer forming step described later. This washing removes oil and dirt adhering to the surface of the galvanized steel sheet. 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.
Moreover, you may perform surface adjustment by an acid, an alkali, etc. before and / or after washing | cleaning the surface of a zinc-plated steel plate. By performing such treatment, the adhesion between the surface treatment layer formed on the surface of the zinc-based plated steel sheet and the zinc-based plated steel sheet is improved. Furthermore, the formation (precipitation) efficiency per time of the surface treatment layer is improved.
In addition, after washing | cleaning and / or adjusting the surface of the zinc-plated steel plate mentioned above, it is preferable to wash with water so that a cleaning agent etc. may not remain on the surface of a zinc-plated steel 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, This is a step of forming a surface treatment layer by self-deposition and / or electrolytic deposition. 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 galvanized steel sheet only by bringing a predetermined treatment liquid into contact with the galvanized steel sheet 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 zinc-based plated steel sheet 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 an optimal amount as appropriate depending on the type of zinc-based plated steel sheet used, etc. Is selected.
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 method for contacting the treatment liquid and the zinc-based plated steel sheet 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 galvanized steel sheet 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.

  In addition, the contact time between the treatment liquid and the zinc-based plated steel sheet means, for example, the time during which the zinc-based plated steel sheet is immersed in the treatment liquid in the case of an immersion method. Moreover, in the case of the spray method, it means the time during which the treatment liquid is sprayed on the surface of the galvanized steel sheet.

  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 zinc-based plated steel sheet by bringing it into contact with a zinc-based plated steel sheet using a predetermined treatment liquid as a 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 zinc-based plated steel sheet 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 or 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 total amount of the metal element (X) in the surface treatment layer formed by this electrolysis treatment In order for the 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 zinc-based plated steel sheet having the surface treatment layer may be performed.
Although the method of washing with water is not particularly limited, it can be performed by, for example, 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 zinc-plated steel plate is immersed in the washing water, for example, when it is a case of an 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 galvanized steel sheet.

  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.

<Silicon-containing layer formation process>
The silicon-containing layer forming step of the present invention is a step of forming a silicon-containing layer by applying an aqueous metal surface treating agent containing an organosilicon compound (Y) on the surface-treated layer after the surface-treated layer forming step. is there.
Note that the organic silicon compound (Y) is, in one molecule, wherein -SiR ₁ R ₂ R _{3 (wherein,} R 1, _{R 2} and _{R 3} are each independently an alkyl group, an alkoxy group or a hydroxyl group And at least one of R ₁ , R ₂ and R ₃ represents an alkoxy group) and two or more functional groups (a) and a hydroxyl group (which can be included in the functional group (a)) And at least one hydrophilic functional group (b) selected from the group consisting of amino group, carboxyl group, phosphoric acid group, phosphonic acid group, sulfone group, polyoxyethylene chain and amide group And a compound having a molecular weight of 100 to 10,000 per functional group (b).
First, the organosilicon compound (Y) will be described.

<Organic silicon compound (Y)>
The organosilicon compound (Y) has two or more functional groups (a) represented by the formula —SiR ₁ R ₂ R ₃ in one molecule.
In the formula, R ₁ , R ₂ and R ₃ each independently represents an alkyl group, an alkoxy group or a hydroxyl group, and at least one of R ₁ , R ₂ and R ₃ represents an alkoxy group. Of these, an alkoxy group is preferable.
Although carbon number of an alkyl group and an alkoxy group is not specifically limited, C1-C6 is preferable, C1-C4 is more preferable, and C1-C2 is especially preferable.

The organosilicon compound (Y) has a hydroxyl group (separate from that which can be contained in the functional group (a)), amino group, carboxyl group, phosphoric acid group, phosphonic acid group, sulfone group, poly It has at least one hydrophilic functional group (b) selected from the group consisting of an oxyethylene chain and an amide group.
As the hydrophilic functional group (b), an amino group is preferable.

Regarding the relationship between the molecular weight of the hydrophilic functional group (b) and the organosilicon compound (Y), the molecular weight per hydrophilic functional group (b) is from 100 to 10,000, and preferably from 200 to 5,000. In the organosilicon compound (Y), when the molecular weight per hydrophilic functional group (b) is less than 100, the water resistance of the formed film is remarkably lowered. Moreover, when the molecular weight per hydrophilic functional group (b) is larger than 10,000, it is difficult to stably dissolve or disperse the organosilicon compound (Y).
In addition, as a measuring method of the said molecular weight, it can measure using GPC.

  The method for producing the organosilicon compound (Y) of the present invention is not particularly limited. For example, (1) a method of reacting two or more compounds having an active hydrogen-containing functional group with chlorosilane, (2) a vinyl group And (3) a silane coupling agent having a specific reactive functional group and at least one functional group capable of reacting with the reactive functional group. (4) a method of reacting a silane coupling agent having a specific reactive functional group with a compound having a functional group capable of reacting with the reactive functional group, 5) A method of modifying a hydrophilic group in the polyfunctional silane coupling agent is exemplified.

As one of the preferable embodiments of the organosilicon compound (Y) of the present invention, at least one reactive functional group and a formula -SiR ₁ R ₂ R ₃ (wherein R ₁ , R ₂ and R ₃ are At least one organosilane compound (A) having a functional group (a) represented by the same definition), and at least one compound (B) having a functional group capable of reacting with a reactive functional group, And the resulting compound (reaction product).
In addition, the organic silane compound (A) and the compound (B) may each be used alone or in combination.

The organosilane compound (A) has at least one reactive functional group. It reacts with the compound (B) described later via this reactive functional group. The organosilane compound (A) may have two or more reactive functional groups.
The reactive functional group is not particularly limited as long as it is a group that reacts with other functional groups to form a bond. For example, a hydroxyl group, glycidyl group, primary amino group, secondary amino group, mercapto group, isocyanato group And a functional group selected from the group consisting of a carboxyl group, a methylol group, an active methylene group, an imide group, an amide group, a carbonyl group and a vinyl group. Of these, a glycidyl group, a primary amino group, a methylol group, and the like are preferable.

Organic silane compound (A), _(wherein, R 1, _{R 2} and _{R 3} are the same meaning as defined above) wherein -SiR ₁ R ₂ R ₃ having the functional group (a) represented by. This functional group (a) is synonymous with the functional group (a) of the organosilicon compound (Y) described above. The organosilane compound (A) may have two or more functional groups (a).

  The molecular weight of the organosilane compound (A) is not particularly limited, but is preferably 150 to 500, more preferably 200 to 400, from the viewpoint of ease of handling.

  One preferred embodiment of the organosilane compound (A) is a compound represented by the general formula (I).

  In general formula (I), X represents any functional group selected from the group consisting of an epoxy group, an amino group, a mercapto group, a vinyl group, and an isocyanate group. L represents a divalent linking group or a simple bond. Y each independently represents an alkyl group, an alkoxy group, a halogen group, a hydrogen atom, or a hydroxyl group.

  In general formula (I), X represents any functional group selected from the group consisting of an epoxy group, an amino group, a mercapto group, a vinyl group, and an isocyanate group. Of these, an epoxy group and an amino group are preferable.

In general formula (I), L represents a divalent linking group or a simple bond.
Examples of the linking group represented by L include an alkylene group (preferably having 1 to 20 carbon atoms), —O—, —S—, an arylene group, —CO—, —NH—, —SO ₂ —, —COO. -, -CONH-, or a combination thereof. Of these, an alkylene group is preferable. In the case of a simple bond, it means that X in the general formula (I) is directly connected to Si (silicon atom).

  In general formula (I), Y represents an alkyl group, an alkoxy group, a halogen group, a hydrogen atom, or a hydroxyl group each independently. Of these, an alkoxy group and a hydroxyl group are preferable. In addition, it is preferable that at least one of Y represents an alkoxy group.

  Specific examples of the organic silane compound (A) include, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like. Epoxysilanes, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N- (aminoethyl) 3-aminopropyltrimethoxysilane, and aminosilanes such as 3-aminopropyltriethoxysilane, 3-mercaptopropyl Mercaptosilane such as trimethoxysilane, isocyanate silane such as 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, vinyl triethoxysilane, vinyl such as p-styryltrimethoxysilane Etc. containing silane.

The structure of the compound (B) is not particularly limited as long as it has a group capable of reacting with the reactive functional group of the organosilane compound (A). Moreover, the compound (B) may have a functional group (a) represented by the formula —SiR ₁ R ₂ R ₃ . Further, the compound (B) may be a compound represented by the above-mentioned organosilane compound (A). That is, the organosilicon compound (Y) may be obtained by reaction between the organosilane compounds (A).
The reactive functional group is not particularly limited, and examples thereof include a hydroxyl group, a glycidyl group, a primary amino group, a secondary amino group, a mercapto group, an isocyanato group, a carboxyl group, a methylol group, an active methylene group, and an imide group. A functional group selected from the group consisting of amide group, carbonyl group and vinyl group is preferred.
The molecular weight of the compound (B) is not particularly limited, but is preferably 100 to 3000 from the viewpoint of ease of handling.

  Specific examples of the compound (B) include epoxies such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. Aminosilanes such as silane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N- (aminoethyl) 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxy Mercaptosilane such as silane, isocyanate group such as 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, vinyl group-containing sila such as vinyltriethoxysilane, p-styryltrimethoxysilane , Epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, isocyanate compounds such as tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, methylol such as melamine, dimethylol propionic acid, etc. Compounds, active methylene-containing compounds such as acetoacetoxy acrylate, imide compounds such as N′N isopropylcarbodiimide, amine compounds such as isophorone diamine, piperazine, diphenylmethane diamine, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl Ether, hydrogenated bisphenol A diglycidyl ether Polyoxyethylene adducts of epoxy compounds, hydroxylamines such as ethanolamine and propanolamine, polyhydric alcohols such as glycol, amine thiols such as 2-aminoethanethiol and 2-aminopropanethiol, tartaric acid, L-ascorbic acid, etc. Hydroxycarboxylic acids, aminosulfonic acids such as 2-amino-1-naphthalenesulfonic acid, hydroxyphosphonic acids such as α-glycerophosphonic acid, amino acids such as diaminoalkylsulfonic acid, glycine, alanine, and glutamic acid.

The reaction ratio between the organosilane compound (A) and the compound (B) is not particularly limited, but is preferably 10: 1 to 1:10 in terms of the organosilane compound (A): the compound (B) (molar ratio). 1-1: 5 is more preferable.
As the reaction conditions between these organosilane compounds (A) and compounds (B), optimum conditions are appropriately selected depending on the compounds used. Moreover, you may use a solvent (for example, alcohol etc.) etc. in the case of reaction.

  As a suitable combination of the organic silane compound (A) and the compound (B), when both are compounds represented by the general formula (1), 3-aminopropyltrimethoxysilane and γ-glycidoxypropyltrimethoxy A combination of silanes can be mentioned.

  The content of the organosilicon compound (Y) in the aqueous metal surface treatment agent is not particularly limited, but is preferably 2 to 20% by mass and 5 to 15% by mass with respect to the total amount of the treatment agent from the viewpoint of ease of handling. Is more preferable.

  As a solvent used for the aqueous metal surface treatment agent, water is used as a main component. Note that the treatment agent may contain an organic solvent (for example, alcohol).

  The pH of the aqueous metal surface treatment agent is not particularly limited, but is preferably acidic, specifically 2.5 to 6 is preferable, and 3.5 to 5 is more preferable. If it is in the said range, stability of a water-system metal surface treating agent will improve more.

<Other additives>
The aqueous metal surface treatment agent preferably further contains a metal compound (C) containing a divalent or higher valent metal ion. By containing the metal compound (C), the corrosion resistance of the metal material treated with the aqueous metal surface treatment agent is improved.
The divalent or higher valent metal ion contained in the metal compound (C) is at least one selected from Ti, Zr, Hf, V, Mg, Mn, Zn, W, Mo, Al, Ni, Co and Ca ions. Preferably there is.
Examples of the metal compound (C) containing a divalent or higher metal ion include the above metals and inorganic acids such as fluoro acid, phosphoric acid, nitric acid and sulfuric acid, formic acid, acetic acid, butyric acid, oxalic acid, succinic acid, lactic acid, Salts with organic acids such as L-ascorbic acid, tartaric acid, citric acid, DL-malic acid, malonic acid, maleic acid, phthalic acid, or alkoxides, alkylacetonates, alkanediolates, lactates, aminates of the above metals Or complex salts, such as a stearate, etc. are mentioned. For example, the V ion (vanadium ion) -containing compound is not particularly limited, but vanadium pentoxide V ₂ O ₅ , metavanadate HVO ₃ , ammonium metavanadate, sodium metavanadate, vanadium oxytrichloride VOCl ₃ , three Vanadium oxide V ₂ O ₃ , vanadium dioxide VO ₂ , vanadium oxysulfate VOSO ₄ , vanadium oxyacetylacetonate VO (OC (═CH ₂ ) CH ₂ COCH ₃ )) ₂ , vanadium acetylacetonate V (OC (═CH ₂ ) CH ₂ COCH ₃ )) ₃ , vanadium trichloride VCl ₃ , phosphovanadomolybdic acid and the like. When a pentavalent vanadium compound is used, it is at least one 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. What reduced to bivalent-tetravalent with the organic compound which has a functional group can also be used.
These metal compounds (C) may be used alone or in combination of two or more.
The content of the metal compound (C) in the aqueous metal surface treatment agent is not particularly limited, but is 0.5 to 20% by mass with respect to the total solid content in the treatment agent from the viewpoint of the formation rate of the silicon-containing layer. Preferably, 1-10 mass% is more preferable. In addition, solid content refers to the component which comprises the silicon containing layer except a solvent (for example, water) in a processing agent.

The aqueous metal surface treatment agent preferably further contains at least one acid (D) selected from the group consisting of hydrofluoric acid, organic acid and phosphoric acid. Corrosion resistance improves by containing an acid (D).
In addition to the etching effect, hydrofluoric acid exhibits a chelating action and improves the corrosion resistance of the surface-treated zinc-based plated steel sheet. Since organic acids are acids with relatively low acidity among acids, they do not etch the metal surface strongly, but they remove the non-uniform and extremely thin oxide film on the surface. Improve the corrosion resistance. Phosphoric acid forms a phosphate-based chemical conversion film on the metal surface, but it improves the corrosion resistance of the surface-treated galvanized steel sheet.
The content of the acid (D) in the aqueous metal surface treatment agent is not particularly limited, but is 0.5 to 20% by mass with respect to the total solid content in the treatment agent from the point of formation rate of the silicon-containing layer. Preferably, 1-10 mass% is more preferable. In addition, solid content refers to the component which comprises the silicon containing layer except a solvent (for example, water) in a processing agent.

<Processing conditions>
The silicon-containing layer is formed by applying an aqueous metal surface treatment agent containing an organosilicon compound (Y) on the surface treatment layer after the surface treatment layer forming step described above, and drying it 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 aqueous metal surface treatment agent is not particularly limited, and optimum conditions are appropriately selected depending on the components contained in the treatment agent.

<Application>
The surface-treated zinc-based plated steel sheet of the present invention has a structure in which a surface-treated layer and a silicon-containing layer are laminated on a zinc-based plated steel sheet as described above. The surface-treated zinc-based plated steel sheet having such a configuration exhibits excellent corrosion resistance, fingerprint resistance, conductivity, and coating film adhesion. A galvanized steel sheet having such various characteristics in a well-balanced manner has not been provided conventionally, and the surface-treated galvanized steel sheet of the present invention can be applied to various applications. 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 surface treatment zinc-plated steel 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 surface-treated zinc-based plated steel sheet of the present invention has excellent corrosion resistance, fingerprint resistance, electrical conductivity, and coating film adhesion, which cannot be obtained by conventional surface treatment methods. The reason is presumed as follows. The surface treatment layer of the surface-treated zinc-based plated steel sheet of the present invention mainly imparts corrosion resistance. This surface treatment layer is not attacked by acids and alkalis and follows the bending process and shows excellent coating properties. However, it is a very thin film, so it has a physical and temporal blocking ability against corrosion factors, so-called barrier properties. May not be enough. When the surface treatment layer is formed thick in order to provide barrier properties, not only the surface of the surface treatment layer becomes a sparse film, but also peeling and the like are likely to occur due to cohesive failure in the layer, etc. And conductivity deteriorate. Therefore, by laminating the above-described silicon-containing layer on the surface treatment layer, it is possible to impart barrier properties while preventing the above-described adverse effects.

As a feature of the silicon-containing layer, first, when a part of the silicon compound (Y) is concentrated by drying or the like, the silicon compound (Y) reacts with each other to form a continuous film, and organic silicon A significant barrier effect is exhibited when the —OR group formed by hydrolysis of a part of the compound (Y) forms a Si—OM bond (M: metal element on the surface of the object to be coated) with the metal surface. It is estimated that the corrosion resistance is improved. In addition, since a dense film can be formed, the film can be thinned and the conductivity is improved. Further, with respect to the structure, since the arrangement of the silicon-organic chain is regular and the organic chain is relatively short, the silicon-containing part and the organic part are regularly and densely arranged in a very small area in the film. That is, the inorganic substance and the organic substance are arranged. Therefore, it is presumed that it becomes possible to form a new film having both the conductivity that the inorganic film normally has and the fingerprint resistance that the organic film normally has.
In addition, as a result of the study by the inventors, in the surface-treated zinc-based plated steel sheet having a single-layer structure of the surface treatment layer containing the silicon compound (Y) of the present invention, in particular, fingerprint resistance and corrosion resistance deteriorate, The performance balance as described above could not be obtained. That is, by using a laminated structure as in the present invention, a surface-treated galvanized steel sheet excellent in performance balance of various properties can be obtained for the first time.

  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) Method for cleaning zinc-based plated steel sheet The surface (both sides) of the above test material is treated with sodium hydroxide-based degreasing agent Fine Cleaner L4460 (registered trademark: manufactured by Nihon Parkerizing Co., Ltd.) and adhered to the surface. Removed garbage 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 use as 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 processed under the treatment liquid (solvent: water) and treatment liquid conditions shown in Table 4 to obtain a test plate having the surface treatment layer shown in Table 5. It was. The processing solution was used at a temperature of 50 to 60 ° C. The test plate was used as a cathode and the thin plate 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 R4) 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 R4: Treatment liquid obtained by adding 5 g / L of S1 (described later) to the above-mentioned P1 treatment liquid Note that the reactive chromate treatment (R2) is a zinc chromate treatment. Using 3367 (registered trademark: manufactured by Nippon Parkerizing Co., Ltd.), the amount of Cr deposited was 15 mg / m ² in accordance with the instruction manual.
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 silicon-containing layer A water-based metal surface treatment agent represented by the following (S1) to (S3) on the test plate prepared in the above (3-1) to (3-3), or ( The treating agent for comparative example represented by S4) was applied with a bar coater to form a silicon-containing layer on the surface treatment layer.
The silicon-containing layer was baked so that the ultimate plate temperature was 150 ° C. after application.
(S1):
3-glycidoxypropyltrimethoxysilane (2 mol) and 3-aminopropyltriethoxysilane (1 mol) are reacted in ethanol (100 mL) to synthesize an organosilicon compound (Y), and then mixed with pure water. The solid content was adjusted to 10% by mass. The product organosilicon compound (Y) has an amino group and a hydroxyl group, the number of functional groups (a) contained is 3, and the molecular weight per functional group (b) was 700. .
(S2):
Phosphoric acid was added to the aqueous metal surface treatment agent (S1) so as to be 5% by mass with respect to the solid content.
(S3):
To the aqueous metal surface treatment agent (S1), phosphoric acid and ammonium metavanadate were added so as to be 5% by mass and 2% by mass, respectively, based on the solid content.
(S4):
Colloidal silica (Snowtex N Nissan Chemical Co., Ltd.) was added to urethane resin (HYDRAN HW-340, manufactured by DIC Corporation) so as to be 15% by mass with respect to the solid content. Pure water was added to the treatment agent 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 silicon-containing layer formed using the treatment agent represented by (S1) to (S4) is as follows. In combination as shown in Table 6, a surface-treated galvanized steel sheet including a surface-treated layer and a silicon-containing layer was produced.
The total adhesion amount per unit area of the metal element (X) in the surface treatment layer and the Si adhesion amount per unit area in the silicon-containing layer were measured by fluorescent X-rays, and the mass ratio [Y / X ] Was requested.

(5) Evaluation method (5-1) Environmental impact property About each surface treatment zinc-plated steel plate obtained by said method, based on the following judgment criteria, environmental impact property was evaluated from the component contained in a steel plate. . 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 surface treatment zinc-plated steel 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) Corrosion resistance of flat surface after degreasing Fine cleaner L4460 (standard building bath: A agent 20 g / L, B agent 12 g / L, temperature 60 ° C., 2 minutes, for each surface-treated galvanized steel sheet obtained Degreasing was performed by washing with water after immersion), 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 (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 Each surface-treated zinc-based plated steel sheet was subjected to 7 mm extrusion using an Erichsen tester, and a salt spray test specified in JIS-Z2371 was performed for 120 hours. Next, the white rust generation area ratio was visually measured and evaluated. 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) Fingerprint resistance On each surface-treated zinc-plated steel sheet obtained, petrolatum was applied, and the color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., color meter ZE2000) increased or decreased the L value before and after petrolatum application. (ΔL) was measured. The evaluation criteria are as follows.
<Evaluation criteria>
◎ = △ L is less than 1.0 ○ = △ L is 1.0 or more and less than 2.0 △ = △ L is 2.0 or more and less than 3.0 × = △ L is 3.0 or more

(5-6) Conductivity For each of the obtained surface-treated zinc-based plated steel sheets, the interlayer resistance was measured using an interlayer resistance measuring machine (manufactured by TOEI KOGYO, LRT-1A). The evaluation criteria are as follows.
<Evaluation criteria>
◎ = Interlayer resistance is less than 1.0Ω ○ = Interlayer resistance is 1.0Ω or more and less than 2.0Ω △ = Interlayer resistance is 2.0Ω or more and less than 3.0Ω × = Interlayer resistance is less than 3.0Ω

(5-7) Adhesiveness Using a paint (Amirac # 1000 (white paint) manufactured by Kansai Paint Co., Ltd.), each surface-treated galvanized steel sheet 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, after each coating, 1 mm square, 100 grids were cut with an NT cutter, and 5 mm was extruded with an Erichsen testing machine, and then the extruding convex part was peeled with an adhesive tape. And evaluated by the number of peeled coating films. 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

  Table 7 shows the results of the above evaluations (5-1) to (5-7) for the surface-treated galvanized steel sheets obtained in Examples 1 to 24 and Comparative Examples 1 to 8.

From Table 7, the surface-treated zinc-based plated steel sheet of the present invention having a laminated structure of a surface-treated layer and a silicon-containing layer is good in all the items of environmental impact, corrosion resistance, fingerprint resistance, conductivity, and adhesion. The evaluation result was shown.
In the comparative example, the chromate treatment of Comparative Example 6 showed the same characteristics as the surface-treated galvanized steel sheet of the present invention, but was inferior in environmental impact in that it contained chromium. Moreover, it turned out that the surface-treated zinc-based plated steel sheet of the present invention has a very good performance balance even when compared with Comparative Examples 2 to 4 using a resin-based film instead of the silicon-containing layer. . Further, as in Comparative Example 1 and Comparative Example 5, sufficient performance could not be obtained with only the surface treatment layer or the silicon-containing layer single layer.
Moreover, in the comparative example 8 which made the single layer structure by mixing the processing liquid which forms a surface treatment layer, and the processing liquid which forms a silicon containing layer, it was inferior to corrosion resistance and fingerprint resistance.

1 is a schematic cross-sectional view of one embodiment of a surface-treated zinc-based plated steel sheet according to the present invention. 1 is a schematic cross-sectional view of one embodiment of a surface-treated zinc-based plated steel sheet according to the present invention.

Explanation of symbols

10, 20 Surface-treated galvanized steel sheet 12 Zinc-based galvanized steel sheet 14 Surface-treated layer 16 Silicon-containing layer

Claims (7)

On the galvanized steel sheet, 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 A surface treatment comprising a surface treatment layer formed by electrolytic deposition and a silicon-containing layer formed by applying an aqueous metal surface treatment agent containing an organosilicon compound (Y) on the surface treatment layer in this order. A galvanized steel sheet,
In one molecule, the organosilicon compound (Y) has the formula —SiR ₁ R ₂ R ₃ (wherein R ₁ , R ₂ and R ₃ each independently represents an alkyl group, an alkoxy group or a hydroxyl group). , R ₁ , R ₂ and R ₃ represent at least one functional group (a) represented by two or more functional groups (a) and a hydroxyl group (which can be contained in the functional group (a)) And at least one hydrophilic functional group (b) selected from the group consisting of amino groups, carboxyl groups, phosphoric acid groups, phosphonic acid groups, sulfone groups, polyoxyethylene chains and amide groups. , A compound having a molecular weight of 100 to 10,000 per functional group (b),
The mass ratio [Y / X] of the total amount of element adhesion of the metal element (X) of the surface treatment layer and the amount of Si adhesion derived from the organosilicon compound (Y) of the silicon-containing layer is 0.1 to A surface-treated galvanized steel sheet, characterized by being 100.0. The organosilicon compound (Y) is a functional group represented by at least one reactive functional group and a formula —SiR ₁ R ₂ R ₃ (wherein R ₁ , R ₂ and R ₃ are as defined above). Compound obtained by reacting at least one organic silane compound (A) having a group (a) with at least one compound (B) having a functional group capable of reacting with the reactive functional group The surface-treated zinc-based plated steel sheet according to claim 1, wherein   The reactive functional group of the organosilane compound (A) and the functional group of the compound (B) are each independently a hydroxyl group (separate from those that can be contained in the functional group (a)), glycidyl At least one selected from the group consisting of a group, a primary amino group, a secondary amino group, a mercapto group, an isocyanate group, a carboxyl group, a methylol group, an active methylene group, an imide group, an amide group, a carbonyl group and a vinyl group The surface-treated zinc-based plated steel sheet according to claim 2. The surface-treated galvanized steel sheet according to claim 2 or 3, wherein the organosilane compound (A) is a compound represented by the general formula (I).

(In General Formula (I), X represents any functional group selected from the group consisting of an epoxy group, an amino group, a mercapto group, a vinyl group, and an isocyanate group. L represents a divalent linking group, Or represents a simple bond, each Y independently represents an alkyl group, an alkoxy group, a halogen group, a hydrogen atom, or a hydroxyl group.)   The aqueous metal surface treatment agent is a metal compound (C) containing a divalent or higher valent metal ion and / or at least one acid selected from the group consisting of hydrofluoric acid, organic acid and phosphoric acid ( The surface-treated galvanized steel sheet according to any one of claims 1 to 4, comprising D).   The metal ion contained in the metal compound (C) is at least selected from the group consisting of Ti, Zr, Hf, V, Mg, Mn, Zn, W, Mo, Al, Ni, Co, Ce and Ca ions. The surface-treated zinc-based plated steel sheet according to claim 5, which is one type. Surface of galvanized steel sheet by auto-deposition and / or electrolytic deposition using treatment liquid containing 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 formation step, a silicon-containing layer formation step of forming a silicon-containing layer by applying an aqueous metal surface treatment agent containing an organosilicon compound (Y) onto the surface treatment layer A method for producing a galvanized steel sheet,
In one molecule, the organosilicon compound (Y) has the formula —SiR ₁ R ₂ R ₃ (wherein R ₁ , R ₂ and R ₃ each independently represents an alkyl group, an alkoxy group or a hydroxyl group). , R ₁ , R ₂ and R ₃ represent at least one functional group (a) represented by two or more functional groups (a) and a hydroxyl group (which can be contained in the functional group (a)) And at least one hydrophilic functional group (b) selected from the group consisting of amino groups, carboxyl groups, phosphoric acid groups, phosphonic acid groups, sulfone groups, polyoxyethylene chains and amide groups. The manufacturing method of the surface treatment zinc-plated steel plate which is a compound whose molecular weight per said functional group (b) is 100-10000.

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