JP5555179B2 - Surface treatment agent for galvanized steel sheet, surface treatment method for galvanized steel sheet, and galvanized steel sheet - Google Patents

Description

  The present invention relates to a surface treatment agent for galvanized steel sheet, a surface treatment method using the surface treatment agent for galvanized steel sheet, and a surface-treated galvanized steel sheet.

  Currently, steel plates are often galvanized from the viewpoint of ensuring corrosion resistance. In addition, alloyed galvanized steel sheets with various metals added are also used to further improve corrosion resistance and paint.

  In particular, places that are affected by acid rain and smoke, such as industrial areas, and places that are affected by sea salt flying particles, such as coastal areas, are extremely harsh environments in which corrosion of steel sheets is likely to proceed. There is a demand for a zinc-based plated steel sheet that is superior in corrosion resistance and can be used in such an environment. In response to such requests, the corrosion resistance of galvanized steel sheets has been further improved, such as hot-dip Zn-5% Al alloy-plated steel sheets, hot-dip zinc-Al-Mg alloy-plated steel sheets, hot-dip zinc-55% Al alloy-plated steel sheets. Proposed.

  However, these various zinc-based plated steel sheets may have insufficient corrosion resistance (white rust resistance) and may have insufficient adhesion to paints when used as a coated steel sheet. As a countermeasure, a treatment containing hexavalent chromium called a temporary rust-proof chromate treatment has been performed on the surface of the galvanized steel sheet. And in the production line (CGL: Continuous Galvanizing Line) of the hot dip galvanized steel plate using this temporary rust-proof chromate treatment, the chromate treatment liquid mainly composed of chromic acid (hexavalent chromium) is sprayed or showered on the steel plate. A method of adjusting the coating amount with a roll or an air squeeze, and further drying with an oven or the like (referred to as spray ringer or shower ringer).

  In the case of chromate treatment, the surface treatment film is a thin film, but has excellent corrosion resistance. However, these films have a problem of containing a large amount of harmful hexavalent chromium. In particular, with the recent increase in awareness of environmental issues, the chromate treatment is being abolished. That is, it is desired to switch to a chromium-free surface treatment method that uses not only harmful hexavalent chromium but also trivalent chromium.

Under such circumstances, many improvement studies have been conducted on surface treatment methods that do not use hexavalent chromium. For example, Patent Document 1 discloses zinc-based coated steel obtained by applying and drying a composition containing an aqueous resin, water, and sulfide ions. Patent Document 2 discloses a galvanized steel sheet coated with a water-dispersed metal surface treatment composition containing a compound having a specific bond, silica, and a resin emulsion. Patent Document 3 discloses a metal surface treatment material in which a film is formed using an aqueous treatment agent containing a specific aqueous dispersion resin, silica particles, and an organic inhibitor. Furthermore, Patent Document 4 discloses a surface-treated metal plate obtained by treating a metal material with a surface treatment composition containing a nonionic aqueous resin dispersion, hydrolyzable titanium, an organic phosphate compound, and a vanadium compound. Yes. Patent Document 5 discloses a water-dispersed rust preventive coating composition containing an ionomer resin and a water-soluble zirconium and / or water-soluble titanium compound that reacts with a carboxyl group. Further, in Patent Document 6, a surface-treated metal obtained by treating a metal material with a metal surface treatment composition containing hydrolyzable titanium, an organic phosphoric acid compound, a nonionic aqueous resin dispersion, a vanadium compound, and a zirconium compound. A plate is disclosed.
In these patent documents 1-6, the method of directly coat | covering the zinc-type plating layer surface with the organic membrane | film | coat (resin membrane | film | coat) which does not contain chromium is proposed.

On the other hand, Patent Document 7 discloses a metal plate having a film containing titanium and / or zircon, a phosphate compound, and a guanidine compound. Patent Document 8 discloses a galvanized steel sheet surface-treated with a treatment agent containing a water-soluble phosphate compound, a chelating agent, and a corrosion inhibitor. Patent Document 9 discloses a surface-treated metal material having a film formed by a metal surface treatment agent containing a vanadium compound and a metal compound such as zirconium. Furthermore, Patent Document 10 proposes a steel sheet having a coating composed of tetravalent vanadium, Si, and a phosphate compound.
In these Patent Documents 7 to 10, a metal material is coated with a chromium-free film mainly composed of an inorganic component. In these techniques, it has been reported that the corrosion resistance is further improved by using a water-based resin in combination.

  However, in the above-described conventional techniques of Patent Documents 1 to 10, particularly in the method of coating with an organic film, it cannot be said that the adhesion of the organic film to the zinc-based plating layer is sufficient, and when employed as a coating ground treatment, There was a problem that the organic film easily peeled off at the interface with the plating layer.

Furthermore, it is also necessary to ensure weldability in the galvanized steel sheet. Further, from the viewpoint of applying the zinc-based plated steel sheet to home appliances and the like, it is necessary to exhibit grounding properties. That is, the galvanized steel sheet is required to have not only corrosion resistance but also grounding and heat resistance.
However, the conventional zinc-based plated steel sheet on which a resin film is formed often requires a resin film amount of 1 g / m ² or more in order to obtain corrosion resistance. For this reason, if the amount of the coating is increased in order to obtain corrosion resistance, there is a problem that the grounding property cannot be obtained. Furthermore, in the case of a resin film, since it decomposes | disassembles in a high temperature environment, any heat resistance was inadequate.

From such a background, instead of an organic component, a steel plate coated with a chromium-free coating mainly composed of an inorganic component has been proposed. For example, Patent Document 11 discloses a steel sheet having a film obtained using a composition containing phosphoric acid, titanium composed of four or more fluorine atoms, zirconium, a silane coupling agent, and the like. Patent Document 12 discloses a steel sheet having a film obtained by using a silane coupling agent having an amino group, a silane coupling agent having a glycidyl group, a treatment agent containing titanium hydrofluoric acid, and the like. Furthermore, Patent Document 13 proposes a steel sheet having a coating made of a silica sol binder, phosphate ions, fluoride ions, and the like.
However, although the steel plates described in Patent Documents 11 to 13 have good corrosion resistance and heat resistance, they have a problem in grounding properties and adhesion because they form a film having many acid components.

  Also, in the case of hot dip galvanizing with a beautiful surface, these technologies form a film with many inorganic components, and the film appears finely cracked and the appearance of the film appears whitish (whitening), or a rainbow interference color appears. There was a problem. In particular, when this whitening occurs, it is mistaken for white rust generated on the surface of the galvanized surface, and there is a problem that the commercial value is lowered.

  In addition, when storing galvanized steel sheets, water droplets often formed on the steel sheet surface due to condensation. When the water droplets are dried, there is a problem that the water droplet traces remain and the commercial value of the steel sheet is lowered. In the prior art, no method for solving these problems has been proposed.

Furthermore, as described above, the temporary rust-proof chromate treatment is carried out by spraying the chromate treatment solution onto the galvanized steel sheet by spraying or showering, adjusting the coating amount with a roll or air squeeze, and drying in an oven. It is common. This surface treatment method is very simple and has high productivity.
However, in the conventional techniques that do not use chromium that have been proposed so far, the treatment agent that has been used may be aqueous, and the active ingredient concentration (or dry solid content) of the composition may be 20 to 30 at most. % By mass. That is, in order to obtain a coating amount of 1 g / m ² (about 1 μm) by applying and drying this, 4 to 5 g / m ² is necessary as the coating amount of the treatment liquid, and in order to control this, a roll There is a tendency to be limited to a coating method (particularly, a method called reverse coating, which is a method of applying a liquid by rotating a roll in the direction opposite to the sheet passing direction). Therefore, the conventional manufacturing equipment cannot be used, and a new capital investment is required for the galvanizing production line (CGL, EGL). Furthermore, in the case of reverse coating, the roll at the edge of the steel plate is particularly shaved during coating, and a through-plate (muscle) scratch according to the plate width is generated on the roll. Since these scratches affect the appearance of the coating, a new problem arises in that it is unavoidable to produce products in the order of wide plate to narrow product, and the productivity in continuous production is sacrificed.

  As described above, no surface-treated steel sheet that replaces the chromate film has been obtained by any of the above methods, and various characteristics such as film corrosion resistance, appearance, grounding, condensation resistance, and paintability (coating adhesion) There is a strong demand for the development of a surface treatment agent that satisfies the above requirements and can be applied to conventional treatment facilities.

JP-A-8-67834 JP-A-9-221595 Japanese Patent Laid-Open No. 2002-241956 JP 2004-238638 A JP-A-2005-15514 JP 2006-009121 A JP 2004-2950 A JP 2002-155375 A JP 2002-30460 A JP 2005-48199 A JP 2006-213958 A JP 2007-51365 A JP 2007-177314 A

  Therefore, the present invention is excellent in various properties such as corrosion resistance and corrosion resistance after alkaline degreasing, and in particular, the formed film has a good balance of corrosion resistance, appearance, and grounding properties, as well as condensation resistance and paintability (coating properties). An object of the present invention is to provide a surface treatment agent for galvanized steel sheet, which can provide a surface-treated galvanized steel sheet exhibiting excellent properties in a well-balanced (film adhesion). Furthermore, it aims at providing the surface treatment galvanized steel plate which can be manufactured also with the processing method (shower ringer, spray ringer) conventionally used in the manufacturing apparatus of a galvanized steel plate.

  As a result of intensive studies to solve these problems, the present inventors have used a compound having a predetermined functional group containing a silicon atom and a treating agent containing ammonium zirconium carbonate, organic phosphonic acid, and the like. The present inventors have found that the above problems can be solved and have solved the present invention.

（２） 前記炭酸ジルコニウムアンモニウム（Ａ）中のＺｒをＺｒＯ_２に換算したときの質量と、前記化合物（Ｂ）中のＳｉをＳｉＯ_２に換算したときの質量との質量比（Ａ／Ｂ）が０．０１〜６．０であり、
前記有機ホスホン酸（Ｃ）の質量と、前記化合物（Ｂ）中のＳｉをＳｉＯ_２に換算したときの質量との質量比（Ｃ／Ｂ）が０．０１〜５．０であり、
前記金属化合物（Ｄ）中の金属元素の質量と、前記化合物（Ｂ）中のＳｉをＳｉＯ_２に換算したときの質量との質量比（Ｄ／Ｂ）が０．０１〜４．０である、（１）に記載の亜鉛めっき鋼板用表面処理剤。
（３） 化合物（Ｂ）が、反応性官能基（ｂ１）を有するシランカップリング剤と、前記反応性官能基（ｂ１）と反応可能な官能基（ｂ２）を有する化合物とを反応させて得られる化合物であり、前記反応性官能基（ｂ１）および前記官能基（ｂ２）のいずれか一方が、アミノ基またはエポキシ基である、（１）または（２）に記載の亜鉛めっき鋼板用表面処理剤。
（４） さらに、Ｂ、Ｎｂ、Ｓｉ、Ｔａ、Ｔｉ、Ｖ、Ｗ、およびＺｒからなる群から選ばれる少なくとも１種の金属元素を含む金属アルコキシド（Ｅ）を有する、（１）〜（３）のいずれかに記載の亜鉛めっき鋼板用表面処理剤。
（５） 前記化合物（Ｂ）中のＳｉをＳｉＯ_２に換算したときの質量と、前記金属アルコキシド（Ｅ）中に含まれる金属元素の質量との質量比（Ｅ／Ｂ）が０．０１〜２．０である、（４）に記載の亜鉛めっき鋼板用表面処理剤。
（６） さらに、水溶性高分子および水系エマルション樹脂からなる群から選ばれる少なくとも１種の化合物（Ｆ）を含有する、（１）〜（５）のいずれかに記載の亜鉛めっき鋼板用表面処理剤。
（７） 前記化合物（Ｂ）中のＳｉをＳｉＯ_２に換算したときの質量と、前記化合物（Ｆ）の質量との質量比（Ｆ／Ｂ）が０．０１〜３０である、（６）に記載の亜鉛めっき鋼板用表面処理剤。
（８） （１）〜（７）のいずれかに記載の亜鉛めっき鋼板用表面処理剤を亜鉛めっき鋼板表面上に塗布し、加熱乾燥し、皮膜量が２５〜１０００ｍｇ/ｍ^２の皮膜を前記亜鉛めっき鋼板表面上に形成する、亜鉛めっき鋼板の表面処理方法。
（９） （８）に記載の亜鉛めっき鋼板の表面処理方法により得られる、皮膜を有する亜鉛めっき鋼板。That is, the present invention provides the following (1) to (9).
(1) ammonium zirconium carbonate (A),
In one molecule, represented by —SiR ¹ R ² R ³ (wherein R ¹ , R ² and R ³ each independently represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group or a hydroxyl group). A compound (B) having two or more functional groups (a) and a molecular weight (average molecular weight / functional group number) per functional group (a) in the range of 100 to 5,000,
An organic phosphonic acid (C) represented by the general formula (1);
A metal compound containing at least one metal element selected from the group consisting of Zr, Ti, Co, Fe, V, Ce, Mo, Mn, Mg, Al, Ni, Ca, W, Nb, Cr, and Zn ( D) and
A surface treatment agent for galvanized steel sheet, comprising water and having a pH of 6 to 11.

(2) Mass ratio (A / B) of the mass when Zr in the zirconium ammonium carbonate (A) is converted to ZrO ₂ and the mass when Si in the compound (B) is converted to SiO ₂ Is 0.01 to 6.0,
The mass ratio (C / B) between the mass of the organic phosphonic acid (C) and the mass when Si in the compound (B) is converted to SiO ₂ is 0.01 to 5.0,
The mass ratio (D / B) between the mass of the metal element in the metal compound (D) and the mass when Si in the compound (B) is converted to SiO ₂ is 0.01 to 4.0. The surface treating agent for galvanized steel sheets according to (1).
(3) The compound (B) is obtained by reacting a silane coupling agent having a reactive functional group (b1) with a compound having a functional group (b2) capable of reacting with the reactive functional group (b1). The surface treatment for a galvanized steel sheet according to (1) or (2), wherein any one of the reactive functional group (b1) and the functional group (b2) is an amino group or an epoxy group Agent.
(4) Furthermore, it has a metal alkoxide (E) containing at least one metal element selected from the group consisting of B, Nb, Si, Ta, Ti, V, W, and Zr, (1) to (3) The surface treating agent for galvanized steel sheets according to any one of the above.
(5) the mass when the Si in the compound (B) in terms of SiO _2, the mass ratio of the mass of the metal element contained in the metal alkoxide (E) (E / B) is 0.01 The surface treating agent for galvanized steel sheet according to (4), which is 2.0.
(6) The surface treatment for a galvanized steel sheet according to any one of (1) to (5), further comprising at least one compound (F) selected from the group consisting of a water-soluble polymer and an aqueous emulsion resin. Agent.
(7) The mass ratio (F / B) of the mass when the Si in the compound (B) is converted to SiO ₂ and the mass of the compound (F) is 0.01 to 30, (6) The surface treating agent for galvanized steel sheets described in 1.
(8) The surface treatment agent for galvanized steel sheet according to any one of (1) to (7) is applied on the surface of the galvanized steel sheet, dried by heating, and the film having a film amount of 25 to 1000 mg / m ² is applied. A surface treatment method for a galvanized steel sheet, which is formed on the surface of a galvanized steel sheet.
(9) A galvanized steel sheet having a film obtained by the surface treatment method for a galvanized steel sheet according to (8).

  According to the present invention, it is excellent in various properties such as corrosion resistance and corrosion resistance after alkaline degreasing, and in particular, the formed film has a good balance of corrosion resistance, appearance, and grounding properties, as well as condensation resistance and paintability (coating properties). A surface treatment agent for a galvanized steel sheet that can provide a surface-treated galvanized steel sheet that exhibits excellent properties in a well-balanced manner (film adhesion) can also be provided. Furthermore, it is possible to provide a surface-treated galvanized steel sheet that can be manufactured by a conventionally used processing method (shower ringer, spray ringer) in a galvanized steel sheet manufacturing facility.

Below, the surface treatment agent for galvanized steel sheets which concerns on this invention, the surface treatment method using the treatment agent, and also the galvanized steel sheet which has a film | membrane obtained by the surface treatment method are demonstrated.
First, the surface treating agent for galvanized steel sheet will be described.

<Surface treatment agent for galvanized steel sheet>
The surface treating agent for galvanized steel sheet according to the present invention is composed of ammonium zirconium carbonate (A) and -SiR ¹ R ² R ³ in one molecule (wherein R ¹ , R ² and R ³ are each independently , Which represents 2 or more functional groups (a) represented by 1 to 4 carbon atoms, an alkoxy group, or a hydroxyl group), and the molecular weight per functional group (a) (average molecular weight / number of functional groups). ) In the range of 100 to 5000, the organic phosphonic acid (C) represented by the general formula (1), Zr, Ti, Co, Fe, V, Ce, Mo, Mn, Mg, Al A treatment agent comprising a metal compound (D) containing at least one metal element selected from the group consisting of Ni, Ca, W, Nb, Cr, and Zn, and water, and having a pH of 6 to 11. is there.
Below, each component contained in the surface treating agent for galvanized steel sheets is demonstrated.

<Ammonium zirconium carbonate (A)>
The surface treating agent for galvanized steel sheet according to the present invention contains ammonium zirconium carbonate (A). Zirconium ammonium carbonate mainly imparts effects such as corrosion resistance of the film obtained, corrosion resistance after alkali degreasing, heat resistance, weldability, continuous workability, and condensation resistance to the film.
More specifically, carbonic acid and ammonium in ammonium zirconium carbonate are volatilized by drying, and the remaining zirconium is polymerized to form a hardly soluble film.
The content of ammonium zirconium carbonate in the surface treatment agent for galvanized steel sheet is not particularly limited, but from the viewpoint of better corrosion resistance, corrosion resistance after alkali degreasing, and dew condensation resistance, the total solid content in the treatment agent The content is preferably 0.1 to 70% by mass, and more preferably 1 to 50% by mass. The total solid content means a solid component constituting a film described later, and does not include a solvent.

<Compound (B)>
In the surface treatment agent for galvanized steel sheet of the present invention, -SiR ¹ R ² R ³ (wherein R ¹ , R ² and R ³ are each independently alkyl having 1 to 4 carbon atoms) in one molecule. 2 or more, and the molecular weight (average molecular weight / number of functional groups) per functional group (a) is in the range of 100 to 5,000. Certain compounds (B) are included.
Compound (B) undergoes a crosslinking reaction with the zirconium zirconium carbonate described above to form a film having a three-dimensional crosslinked structure, so that the resulting film has corrosion resistance, corrosion resistance after alkali degreasing, heat resistance, weldability, It is estimated that continuous processability and condensation resistance have improved. Moreover, since the functional group (a) of the compound (B) has good adhesion to the base material to be described later, it is presumed that the appearance of the resulting film and the paintability (coating adhesion) are improved. . Furthermore, since the molecular weight (average molecular weight / number of functional groups) per functional group (a) is in the range of 100 to 5000, it is presumed that the grounding property and fingerprint resistance of the film have been improved.
Thus, various performance improves by using together a compound (B) and the above-mentioned ammonium zirconium carbonate. In particular, it is possible to produce a film exhibiting excellent corrosion resistance and grounding properties that cannot be obtained by using each single substance.

Compound (B) contains —SiR ¹ R ² R ³ (wherein R ¹ , R ² and R ³ are each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group, or a hydroxyl group) It has two or more functional groups (a) represented by: Especially, 2-8 pieces are more preferable. In addition, when only one functional group (a) is contained in one molecule, adhesion to the surface of the galvanized steel sheet is lowered, which is not preferable.
R ¹ , R ² and R ³ each independently represent an alkyl group having 1 to 4 carbon atoms, an alkoxy group or a hydroxyl group. Of these, an alkoxy group and a hydroxyl group are preferable.
As a C1-C4 alkyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group etc. are mentioned, for example, Preferably they are a methyl group and an ethyl group.
As an alkoxy group, a C1-C3 alkoxy group is mentioned preferably, for example.

The compound (B) preferably has a molecular weight (average molecular weight / functional group number) per functional group (a) in the range of 100 to 5000, more preferably in the range of 120 to 4000, and particularly preferably 150. It is in the range of ~ 3000. When the molecular weight per functional group (a) is less than 100, the synthesis of the compound is difficult, and the corrosion resistance and adhesion of the resulting film are inferior. On the other hand, when it exceeds 5000, since the adhesiveness with respect to the galvanized steel plate surface which is the characteristics of a functional group (a) falls, it is unpreferable.
In addition, as a measuring method of the said molecular weight, it can measure using gel permeation chromatography (GPC) and NMR.
The skeleton of the compound (B) is not particularly limited, but preferably has a bond such as an ester bond, an ether bond, an acid amide bond, an amide bond, a urethane bond, a urea bond, or a vinyl bond.

The method for producing the compound (B) is not particularly limited. For example, (1) a method of reacting a compound having two or more active hydrogen-containing functional groups with chlorosilane, and (2) a silane coupling agent having a vinyl group (3) 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 And (4) a method of modifying the hydrophilic group in the polyfunctional silane coupling agent.
Of these, (2) or (3) is preferable, and (3) is most preferable. Each manufacturing method will be described below.

One preferred embodiment of the compound (B) is a compound (reaction product) obtained by reaction (polymerization) of a silane coupling agent having a vinyl group and a copolymerizable vinyl compound. This method corresponds to the manufacturing method (2) above.
The silane coupling agent having a vinyl group is not particularly limited as long as it has a vinyl group, and examples thereof include γ-methacryloxypropyltriethoxysilane, vinyltrichlorosilane, and vinyltrimethoxycinlane.
In addition, the copolymerizable vinyl compound is not particularly limited, and examples thereof include acrylic acid, butyl acrylate, methyl acrylate, and 2-hydroxyethyl methacrylate.

The reaction form using the above-mentioned compound is not particularly limited, and examples thereof include anionic polymerization, cationic polymerization, and radical polymerization. Of these, radical polymerization is preferred. In addition, according to the reaction form selected, you may use a well-known polymerization initiator etc. suitably.
In the reaction, a solvent may be appropriately used, and examples thereof include methanol, ethanol, propanol, isopropyl alcohol, acetone, methyl ethyl ketone, diacetyl alcohol, and water.

As another preferred embodiment of the compound (B), a compound having a silane coupling agent having a reactive functional group (b1) and a functional group (b2) capable of reacting with the reactive functional group (b1) And a compound (reaction product) obtained by the reaction.
The reactive functional group (b1) is not particularly limited as long as it is a group that reacts with other functional groups to form a bond. For example, an epoxy group, an amino group, a mercapto group, an acryloxy group, a ureido group, an isocyanic group. A functional group selected from the group consisting of a nate group and a vinyl group is preferred. Of these, an epoxy group and an amino group are preferable.

  One preferred embodiment of the silane coupling agent having a reactive functional group (b1) is a compound represented by the general formula (2).

  In general formula (2), X represents any functional group selected from the group consisting of an epoxy group, an amino group, a mercapto group, an acryloxy group, a ureido group, an isocyanate group, and a vinyl group. L represents a divalent linking group or a simple bond. Y represents a C1-C4 alkyl group, an alkoxy group, or a hydroxyl group each independently.

  In general formula (2), X represents any functional group selected from the group consisting of an epoxy group, an amino group, a mercapto group, an acryloxy group, a ureido group, an isocyanate group, and a vinyl group. Of these, an epoxy group and an amino group are preferable.

In general formula (2), 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 (2) is directly connected to Si (silicon atom).

  In general formula (2), Y represents a C1-C4 alkyl group, an alkoxy group, or a hydroxyl group each independently. Especially, a C1-C3 alkoxy group and a hydroxyl group are preferable.

  Examples of the silane coupling agent having a reactive functional group (b1) include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2- (3,4-epoxycyclohexyl) ethyl. Epoxy silanes such as trimethoxysilane, aminosilanes such as N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N- (aminoethyl) 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane; Mercaptosilanes such as 3-mercaptopropyltrimethoxysilane, isocyanate silanes such as 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, vinyltriethoxysilane, p-styryltrimethoxy Vinyl group-containing silane, such as orchids and the like.

  The functional group (b2) in the compound having the functional group (b2) is not particularly limited as long as it can react with the reactive functional group (b1). An epoxy group, an amino group, a mercapto group, an acryloxy group, Examples thereof include a ureido group, an isocyanate group, and a vinyl group, and an epoxy group or an amino group is preferable. Of these, a functional group different from the reactive functional group (b1) is preferably exemplified.

Examples of the compound having the functional group (b2) include the silane coupling agents exemplified as the silane coupling agent having the reactive functional group (b1), amine compounds such as ethylenediamine and aminopropanethiol, and trimethylolpropane poly. Examples thereof include ether compounds such as glycidyl ether and pentaerythritol polyglycidyl ether.
Especially, the silane coupling agent illustrated with the silane coupling agent which has a reactive functional group (b1) is preferable. That is, the compound (B) is a reaction product of a silane coupling agent having a reactive functional group (b1) and a silane coupling agent having a functional group (b2) capable of reacting with the functional group (b1). preferable.

The reaction ratio of the silane coupling agent having the reactive functional group (b1) and the compound having the functional group (b2) is not particularly limited, but the silane coupling agent: compound (molar ratio) = 9: 1 to 1 : 9 is preferable, and 7: 3 to 3: 7 is more preferable.
As the reaction conditions, 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.

  The content of the compound (B) in the surface treatment agent for galvanized steel sheet is not particularly limited, but in the treatment agent from the viewpoint that the corrosion resistance, fingerprint resistance, appearance, grounding property and paintability of the resulting film are more excellent. The total solid content is preferably 0.1 to 70% by mass, and more preferably 1 to 50% by mass.

<Organic phosphonic acid (C)>
The surface treatment agent for galvanized steel sheet of the present invention contains an organic phosphonic acid represented by the general formula (1). Since these compounds react with the galvanized steel sheet to form a hardly soluble salt, it is presumed that the corrosion resistance and paintability (coating film adhesion) of the film were improved. In addition, the organic phosphonic acid is necessary for stably dissolving the metal compound (D) described later in the aqueous treatment liquid, and contributes to the improvement of the storage stability of the surface treating agent for galvanized steel sheet.

  The content of the organic phosphonic acid (C) in the surface treatment agent for galvanized steel sheet is not particularly limited, but from the viewpoint that the corrosion resistance of the resulting film, the corrosion resistance after alkaline degreasing, the grounding property, and the condensation resistance are more excellent 0.05-50 mass% is preferable with respect to the total solid in a processing agent, and 0.1-30 mass% is more preferable.

<Metal compound (D)>
The surface treatment agent for galvanized steel sheet of the present invention is selected from the group consisting of Zr, Ti, Co, Fe, V, Ce, Mo, Mn, Mg, Al, Ni, Ca, W, Nb, Cr, and Zn. And a metal compound (D) containing at least one metal element. The metal compound (D) forms a hardly soluble salt with the above-described organic phosphonic acid (C). Therefore, it is estimated that the organic phosphonic acid (C) is fixed in the film, and the condensation resistance and paintability (coating film adhesion) of the film are improved.

Metal compound as (D), for example, nitrate containing said metal, sulfate, acetate, phosphate, ammonium salts, fluorides, and the like.
More specifically, examples of the metal compound containing Zr include zirconium nitrate, zirconium oxynitrate, zirconyl acetate, zircon ammonium fluoride, zirconyl sulfate, zircon hydrofluoric acid, and zirconia sol. Moreover, the zirconic acid and its salt which are produced by ion-exchange and alkali neutralizing the aqueous solution of a water-soluble zirconium salt are also mentioned.

  Examples of the metal compound containing Ti include titanyl sulfate, titanyl nitrate, titanium nitrate, titanyl chloride, titanium chloride, titania sol, titanium oxide, ammonium titanium fluoride, potassium oxalate titanate, titanium lactate, titanium acetylacetonate, and diisopropyl titanium. Examples thereof include bisacetylacetone. Further, metatitanic acid obtained by hydrolyzing an aqueous solution of titanyl sulfate, orthotitanic acid obtained by alkali neutralization, and salts thereof are also included.

  Examples of the metal compound containing Co include cobalt sulfate, cobalt nitrate, cobalt carbonate, cobalt phosphate, cobalt chloride, cobalt oxide, and cobalt hydroxide.

  Examples of the metal compound containing Fe include iron sulfate, iron nitrate, iron chloride, iron phosphate, iron oxide, iron hydroxide, and iron powder.

  Examples of the metal compound containing V include vanadium pentoxide, ammonium metavanadate, sodium metavanadate, vanadium oxytrichloride, vanadium trioxide, vanadium dioxide, vanadium oxysulfate, vanadium oxyacetylacetonate, vanadium acetylacetonate, 3 Examples thereof include vanadium chloride, phosphovanadomolybthenic acid, and vanadium sulfate.

  Examples of the metal compound containing Ce include cerium nitrate, cerium acetate, cerium chloride, and cerium sol.

  Examples of the metal compound containing Mo include ammonium molybdate, sodium molybdate, potassium molybdate, ammonium molybdate, and natriun molybdate.

  Examples of metal compounds containing Mn include potassium permanganate, ammonium permanganate, sodium permanganate, permanganate, manganese sulfate, manganese nitrate, manganese oxide, manganese carbonate, manganese chloride, manganese phosphate, and the like. Is mentioned.

  Examples of the metal compound containing Mg include magnesium sulfate, magnesium nitrate, magnesium carbonate, magnesium phosphate, magnesium chloride, magnesium oxide, and magnesium hydroxide.

  Examples of the metal compound containing Al include aluminum oxide, aluminum hydroxide, aluminum sulfate, aluminum nitrate, aluminum phosphate, and aluminum chloride.

  Examples of the metal compound containing Ni include nickel oxide, nickel hydroxide, nickel sulfate, nickel nitrate, nickel phosphate, and nickel chloride.

  Examples of the metal compound containing Ca include calcium oxide, calcium hydroxide, calcium sulfate, calcium nitrate, calcium phosphate, and calcium chloride.

  Examples of the metal compound containing W include ammonium metatungstate, sodium metatungstate, potassium metatungstate, paratungstic acid, ammonium paratungstate, and sodium paratungstate.

  Examples of the metal compound containing Nb include niobium oxalate, niobium oxide, and niobium sol.

  Examples of the metal compound containing Cr include trivalent chromium, such as chromium sulfate, chromium nitrate, chromium chloride, chromium hydroxide, chromium oxide, and chromium phosphate.

Examples of the metal compound containing Zn include zinc oxide, zinc hydroxide, zinc sulfate, zinc nitrate, zinc chloride, zinc phosphate, and acetyl zinc. In addition, since zinc is an amphoteric metal, alkali side And sodium zincate and potassium zincate produced in
Of these, metal compounds containing V, Mg, Al, or Zn, and salts thereof are more preferable in that the effect of improving corrosion resistance is high.

  The content of the metal compound (D) in the surface treatment agent for galvanized steel sheet is not particularly limited, but the corrosion resistance of the resulting film, corrosion resistance after alkali degreasing, weldability, continuous workability, appearance, and condensation resistance are more. From the viewpoint of being excellent, 0.01 to 40% by mass is preferable and 0.1 to 30% by mass is more preferable with respect to the total solid content in the treatment agent.

<Water>
The surface treatment agent for galvanized steel sheet of the present invention contains water as a solvent.
Although content of the water in the surface treating agent for galvanized steel sheets is not specifically limited, 30-99 mass% is preferable with respect to the processing agent whole quantity from a viewpoint that the handling of a treating agent is easier, 40- 95 mass% is more preferable.

<PH>
6-11 are preferable and, as for pH of the surface treating agent for galvanized steel sheets of this invention, 7-10 are more preferable. When the pH is less than 6, ammonium zirconium carbonate cannot be stably dissolved, and the stability of the surface treatment agent for galvanized steel sheet becomes poor. When the pH exceeds 11, the odor of ammonia becomes extremely inferior in workability, and the obtained film performance is also inferior.
Ammonia, carbonic acid, acetic acid, nitric acid and the like are preferably used for pH adjustment. Moreover, by adjusting to pH 6-11, the excessive etching of the galvanized steel plate by a processing agent was suppressed, and it is estimated that the grounding property of the surface treatment galvanized steel plate improved.

When Zr (Zr mass) in the above-described zirconium ammonium carbonate (A) in the treatment agent is converted to ZrO ₂ and Si (Si mass) in the compound (B) is converted to SiO ₂ The mass ratio (A / B) to the mass is preferably 0.01 to 6.0, and more preferably 0.1 to 4.0. If it is less than 0.01, the amount of easily dissolved components increases, and the corrosion resistance and dew condensation resistance of the film after alkaline degreasing may decrease. On the other hand, if it exceeds 6.0, the film becomes hard and paintability (paint adhesion) may be lowered.

The mass ratio (C / B) between the mass of the organic phosphonic acid (C) described above in the treating agent and the mass when Si in the compound (B) is converted to SiO ₂ is 0.01 to 5. It is preferably 0, more preferably 0.05 to 4.0, and still more preferably 0.05 to 3.0. If it is less than 0.01, the corrosion resistance of the film may be inferior, and if it exceeds 5.0, the corrosion resistance and dew condensation resistance of the film after alkaline degreasing may be inferior.

The mass ratio (D / B) between the mass of the metal element in the metal compound (D) and the mass when Si in the compound (B) is converted to SiO ₂ in the treatment agent is 0.01 to It is preferable that it is 4.0, More preferably, it is 0.05-3.0. If it is less than 0.01, the effect of improving the corrosion resistance of the film may not be obtained. If it exceeds 4.0, the amount of dissolved components increases, and the corrosion resistance of the film may be reduced.

In addition to the above-mentioned compounds, the surface treating agent for galvanized steel sheet of the present invention contains at least one compound (F) selected from the group consisting of the following metal alkoxides (E), water-soluble polymers and aqueous emulsion resins. You may do it.
Below, each component is demonstrated.

<Metal alkoxide (E)>
The surface treating agent for galvanized steel sheet of the present invention may contain a metal alkoxide (E). More specifically, it may contain a metal alkoxide (E) containing at least one metal element selected from the group consisting of B, Nb, Si, Ta, Ti, V, W, and Zr.
By containing the metal alkoxide (E), the surface treating agent for galvanized steel sheet according to the present invention can provide a film that is more excellent in corrosion resistance (particularly the processed portion). It is presumed that the metal alkoxide (E) promotes the crosslinking reaction of the compound (B) described above and enables formation of a film having a denser network structure. The reason is not clear, but Si and Ti are preferably selected from the viewpoint of improving the corrosion resistance.

The metal alkoxide (E) is not particularly limited as long as it has an alkoxy group directly bonded to a metal, and conventionally known ones can be appropriately selected and used. The metal alkoxide may be a hydroxyl group in which an alkoxy group directly bonded to a metal is hydrolyzed.
Among these, preferably, the general formula Me (OR) n (wherein R independently represents an alkyl group or a hydrogen atom, and at least one represents an alkyl group. N represents a valence of the metal) Me represents the above metal).
The alkyl group represented by R is preferably an alkyl group having 1 to 4 carbon atoms.

  Examples of the metal alkoxide (E) include titanium tetraisopropoxide, titanium tetraethoxide, titanium butoxide dimer, titanium tetra-2-ethylhexoside, vanadium oxytriethoxide, vanadium triisopropoxide, zirconium ethoxide, zirconium tetra. Ethoxide, zirconium tetrapropoxide, niobium tetramethoxysilane, tetramethoxysilane, tetraethoxysilane, tetranormal propoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methyltriethoxysilane, Cyclohexylmethyldimethoxysilane, n-hexyltrimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, E sulfonyl trimethoxysilane, phenyl triethoxysilane, decyl trimethoxysilane, octadecyl trimethoxysilane, octadecyl triethoxysilane, and isobutyl trimethoxy silane.

As a preferred embodiment of the metal alkoxide (E), an alkoxysilane containing Si element (silicon element) is preferable from the viewpoint that the corrosion resistance of the resulting film and the corrosion resistance after alkaline degreasing are more preferable. ) ₄ (R represents an alkyl group) is preferred.

  The content of the metal alkoxide (E) in the surface treatment agent for galvanized steel sheet is not particularly limited, but is 0.01% with respect to the total solid content in the treatment agent from the viewpoint of better corrosion resistance of the resulting film. -50 mass% is preferable and 0.1-30 mass% is more preferable.

The mass ratio (E / B) between the mass of the metal element contained in the metal alkoxide (E) and the mass when Si in the compound (B) is converted to SiO ₂ in the treatment agent is 0. It is preferable that it is 01-2.0, More preferably, it is 0.5-1.5. If it is less than 0.01, the effect of improving the corrosion resistance of the film may not be obtained, and if it exceeds 2.0, the amount of dissolved components in the film increases, and the corrosion resistance may decrease.

<Water-soluble polymer and / or water-based emulsion resin>
The surface treating agent for galvanized steel sheet of the present invention may contain at least one compound (F) selected from the group consisting of a water-soluble polymer and an aqueous emulsion resin. By adding these components, the fingerprint resistance, corrosion resistance, and lubricity of the coating are improved.
The water-soluble polymer and / or water-based emulsion resin is not particularly limited, and examples thereof include water-soluble polymers such as polyacrylic acid, polymethacrylic acid, polyacrylamide, and polyvinyl alcohol, acrylic resin in a form dispersed in water, and urethane. Examples thereof include resins, epoxy resins, polyester resins, polyamide resins, polyolefin resins, ethylene-acrylic resins, polybutyral resins, polyacetal resins, and fluororesins.

  The total content of the compound (F) in the surface treatment agent for galvanized steel sheet is not particularly limited, but from the viewpoint of better corrosion resistance, fingerprint resistance, condensation resistance, and paintability of the resulting film, 0.1-90 mass% is preferable with respect to the total solid, and 1-70 mass% is more preferable.

The mass ratio (F / B) between the mass of the compound (F) in the treating agent and the mass when Si in the compound (B) is converted to SiO ₂ is 0.01 to 30. Preferably, it is 0.1-20. If it is less than 0.01, the fingerprint resistance and lubricity of the film may not be improved, and if it exceeds 30, the corrosion resistance and heat resistance in the film may decrease.

<Fluorine compound>
The surface treating agent for galvanized steel sheet of the present invention may contain a fluorine compound as necessary. In particular, in hot-dip galvanized steel sheets with a thick surface oxide film, adding a fluorine compound to increase the etching property of the treatment agent increases the reaction layer (non-conductive layer) with the surface of the material. Expected to improve corrosion resistance. However, when a fluorine compound is added to the treating agent, the etching property is increased, and therefore the grounding property may be lowered due to dissolution other than the surface oxide film. In addition, the amount of Zn and Fe mixed in the aqueous treatment liquid may increase, and the stability of the surface treatment agent for galvanized steel sheets may decrease. Further, measures against fluorine are required in disposal of the liquid. Therefore, it is preferable to set the range in consideration of these.
Although content of the fluorine compound in the surface treating agent for galvanized steel sheets of the present invention is not particularly limited, it is preferable to set 50 g as an upper limit in 1 kg of the treating agent.
Examples of the fluorine compound include ammonium fluoride, ammonium silicofluoride, ammonium titanium fluoride, and zircon ammonium fluoride.

<Antifoaming agent>
The surface treating agent for galvanized steel sheet of the present invention may contain an antifoaming agent (G) as necessary. The surface treatment agent for galvanized steel sheet containing this antifoaming agent is sprayed on the galvanized steel sheet by spraying or showering, and after adjusting the coating amount with a roll or air squeeze, it is dried at 50 to 250 ° C. as the maximum plate temperature. It is preferable to form a film on the surface of the zinc-based plated steel sheet.
Although it does not specifically limit as an antifoamer, The thing which stably emulsified mineral oil, the fatty acid, silicone, etc., and the thing of a water-soluble activator type can be used. Both may be used in combination. The content of the antifoaming agent in the surface treatment agent for galvanized steel sheet of the present invention is appropriately selected depending on the type used, but is 0.1 to 3.0 g per kg of the treatment liquid. Is preferred. If the content of the antifoaming agent is too small, the defoaming property cannot be obtained, and if it is too much, the coating property is inferior.

<Lubricant>
The surface treatment agent for galvanized steel sheet of the present invention may contain an additive (lubricant) for improving lubricity, if necessary. The lubricant is effective in improving the lubricity of the surface treatment film to prevent scratches and reducing damage to the galvanized steel sheet during processing.
Examples of the lubricant include solid lubricants such as polyethylene wax, oxidized polyethylene wax, oxidized polypropylene wax, carnauba wax, paraffin wax, montan wax, and Teflon (registered trademark). Among these solid lubricants, 1 Species or two or more may be used.
The content of the lubricant in the surface treatment agent for galvanized steel sheet of the present invention is not particularly limited, but is preferably up to 50 g per kg of the treatment liquid. If it exceeds this, not only can it not be stably added, but the original purpose may be impaired.

  The surface treating agent for galvanized steel sheet of the present invention may contain a solvent (for example, alcohol) other than the above water as necessary.

  The preparation method of the surface treating agent for galvanized steel sheet of the present invention is not particularly limited. For example, by thoroughly mixing ammonium zirconium carbonate (A), compound (B), organic phosphonic acid (C), metal compound (D), other additives, and water using a stirrer such as a mixing mixer. Can be manufactured.

<Surface treatment method>
The surface treatment method using the surface treatment agent for galvanized steel sheet of the present invention is not particularly limited, but the above-described surface treatment agent for galvanized steel sheet is applied on the surface of the galvanized steel sheet and dried, and the coating amount is 25 to 25. A surface treatment method for forming a 1000 mg / m ² film on the surface of the galvanized steel sheet is preferred.
The surface treatment method will be described below.

Prior to application, the galvanized steel sheet may be pretreated for the purpose of removing oil and dirt on the surface of the galvanized steel sheet, if necessary. Galvanized steel sheets are often coated with rust-preventing oil for the purpose of rust prevention. Moreover, even when not coated with rust preventive oil, there are oil and dirt adhered during the work. By performing the pretreatment, the surface of the galvanized steel sheet is cleaned and the surface of the galvanized steel sheet is easily wetted by the surface treatment agent for galvanized steel sheet of the present invention. In the case where there is no oil or dirt and the surface of the material is uniformly wetted with the surface treating agent for galvanized steel sheet of the present invention, the pretreatment process is not particularly necessary.
The pretreatment method is not particularly limited, and examples thereof include hot water washing, solvent washing, and alkaline degreasing washing.

  The galvanized steel sheet used is a hot dip galvanized steel sheet (GI), an alloyed hot dip galvanized steel sheet (GA) obtained by alloying the same, a hot dip zinc Zn-5% Al alloy plated steel sheet (GF), or hot dip zinc. Examples include -55% aluminum alloy plated steel sheet (GL), electrogalvanized steel sheet (EG), and electrozinc-Ni alloy plated steel sheet (Zn-Ni). Moreover, it is applicable also to the iron plate which has not plated.

The method of applying the treatment agent of the present invention to the galvanized steel sheet is not particularly limited as long as the treatment agent can be uniformly applied to the surface of the galvanized steel sheet, and examples thereof include a roll coating method, a dipping method, and a spray coating method.
Further, the treatment (application) temperature and the treatment (application) time are not particularly limited, but in general, the treatment (application) temperature is preferably 10 to 40 ° C., and the treatment (application) time is 0.1 to 10 seconds. Preferably there is.

As heating temperature at the time of drying the coating film formed on the galvanized steel plate surface, 50-250 degreeC is preferable and 60-180 degreeC is more preferable. The heating and drying method is not particularly limited, and the treatment agent may be dried by heating with hot air, an induction heater, infrared rays, near infrared rays, or the like.
The heating time is appropriately selected according to the type of compound in the surface treatment agent for galvanized steel sheet used. Especially, from points, such as productivity, 0.1-60 seconds are preferable and 1-30 seconds are more preferable.

The amount of film formed on the galvanized steel sheet surface is preferably 25 to 1000 mg / m ^2, more preferably ^{50~800mg / m 2, 100~600mg / m} 2 is particularly preferred. If it is less than 25 mg / m ² , the surface treatment agent for galvanized steel sheet cannot be uniformly applied to the surface of the steel sheet, and various target properties such as workability, corrosion resistance, and paintability cannot be exhibited in a well-balanced manner. When it exceeds 1000 mg / m ² , the appearance is lowered and the paintability is inferior. In addition, the grounding property and the weldability deteriorate. Furthermore, in the press working, the amount of peeling of the film increases, which not only hinders press molding, but also increases the manufacturing cost.
In addition, said film | membrane amount means the film | membrane amount on the single side | surface of a steel plate.

  On the film formed by the above surface treatment method, an organic polymer film is formed so that the film thickness after drying becomes 0.1 to 3.0 μm, and further higher corrosion resistance, fingerprint resistance, and lubricity. Can be granted. As such an organic polymer film, a known resin emulsion such as acrylic, urethane, epoxy, and the like, to which silica, a rust preventive agent, a lubricant, an ultraviolet absorber, a pigment and the like are added can be used.

  By performing the surface treatment using the surface treating agent for galvanized steel sheet of the present invention, the surface of the galvanized steel sheet has corrosion resistance, heat resistance, weldability, continuous workability, grounding property, fingerprint resistance, It is possible to form a surface-treated film that has excellent corrosion resistance and appearance of the formed film, and can exhibit excellent properties in a well-balanced manner in condensation resistance and paintability (coating film adhesion).

The coating amount in the spray or shower ringer method is usually about 1 to 3 g / m ² . Further, from the viewpoint of operability (coating uniformly), a treatment liquid in which the solid content concentration of the surface treatment agent is adjusted to 10 to 20% by mass is often used. The surface treatment agent can be adjusted to a solid content concentration of 10 to 20% by mass, and when applied by these methods, a film of 100 to 600 mg / m ² can be obtained, and drying also volatilizes water. Is enough. That is, since the desired performance can be obtained with this small amount of film, the surface-treated galvanized steel sheet of the present invention can be produced by these methods. This makes it possible to manufacture a desired steel sheet without requiring new production equipment and without reducing the productivity of actual production lines (CGL, EGL).

As described above, according to the present invention, it has corrosion resistance, heat resistance, weldability, continuous workability, grounding properties, and fingerprint resistance, and in particular, the formed film has good corrosion resistance and appearance, and is resistant to condensation. A surface-treated zinc-based plated steel sheet that can exhibit excellent properties in a well-balanced formability and paintability (coating film adhesion) can be realized.
Such a steel plate is effective as a material used in various fields such as architecture, electricity, and automobiles. Furthermore, in the galvanizing production line (CGL), since it can be produced with the same processing equipment as the conventional temporary antirust chromate treatment, the actual productivity is high and more effective.

  Hereinafter, the effects of the present invention will be specifically described by way of examples. However, the following examples are not intended to limit the present invention, and it is included in the technical scope of the present invention to change the design according to changes in conditions. It is what

(1) Test material (material)
The following commercially available materials were used as test materials.
(I) Electrogalvanized steel sheet (EG): thickness 0.8 mm, basis weight = 20/20 (g / m ² )
(Ii) Hot-dip galvanized steel sheet (GI): thickness 0.8 mm, basis weight = 60/60 (g / m ² )
(Iii) Alloyed hot-dip galvanized steel sheet (GA): thickness 0.8 mm, basis weight = 40/40 (g / m ² )
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 .

(2) Pretreatment (cleaning)
As a method for preparing the test plate, first, the surface of the above-mentioned test material was treated with Palclean N364S manufactured by Nihon Parkerizing to remove oil and dirt on the surface. Next, after rinsing with tap water and confirming that the surface of the galvanized steel sheet was 100% wet with water, pure water was further poured, and water removed from the oven in a 100 ° C. atmosphere was used as a test plate.

(3) Preparation of treatment agent for galvanized steel sheet Each component was mixed in water at the blending amounts shown in Table 1 (Examples 1 to 49 and Comparative Examples 50 to 65) to obtain a treatment liquid.
In addition, the compounding quantity of component (A)-(F) in Table 1 represents the quantity (g) mix | blended in 1 kg of surface treatment liquid for galvanized steel sheets. Moreover, components other than component (A)-(F) contained in each processing agent are mainly water.
The amount of the ingredients in Table 1 (A) represents the mass (g) when the Zr in zirconium ammonium carbonate (A) and (Zr mass) was converted into ZrO _2. The compounding quantity of the component (B) in Table 1 represents mass (g) when Si (Si mass) in the compound (B) is converted to SiO ₂ . The amount of component (D) in Table 1 represents the mass (g) of the metal element in the metal compound (D). The compounding quantity of the metal alkoxide (E) in Table 1 represents the mass (g) of the metal element contained in the metal alkoxide (E).
The mass ratio A / B in Table 1, and the mass when converted mass when converted to Zr in zirconium ammonium carbonate (A) to ZrO _2, the Si in the compound (B) to SiO ₂ Represents the mass ratio. The mass ratio C / B represents a mass ratio between the mass of the organic phosphonic acid (C) and the mass when Si in the compound (B) is converted to SiO ₂ . The mass ratio D / B represents a mass ratio between the mass of the metal element in the metal compound (D) and the mass when Si in the compound (B) is converted to SiO ₂ . The mass ratio E / B represents a mass ratio between the mass of the metal element contained in the metal alkoxide (E) and the mass when Si in the compound (B) is converted to SiO ₂ . The mass ratio F / B represents a mass ratio between the mass of the compound (F) and the mass when Si in the compound (B) is converted to SiO ₂ .

  The compounds used in Table 1 will be described below.

<Ammonium zirconium carbonate (A)>
A1: Ammonium zirconium carbonate

<Compound (B)>
B1: 1 mol of hexamethylenediamine and 2 mol of γ-glycidoxypropyltrimethoxysilane were reacted in ethanol to obtain a product. Then, deionized water was added and diluted to a solid content concentration of 5% by mass.
The number of functional groups (a) in one molecule of the obtained product was 2, and the molecular weight per one functional group (a) (average molecular weight / functional group number) was about 294.

B2: 1 mol of # 828 type bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin) and 2 mol of γ-aminopropyltriethoxysilane were reacted in N-methyl-2-pyrrolidone to obtain a product. . Then, deionized water was added and diluted to a solid content concentration of 5% by mass.
In addition, the number of functional groups (a) in one molecule of the obtained product was two, and the molecular weight (average molecular weight / functional group number) per functional group (a) was about 411.

B3: A product was obtained by emulsion polymerization of 1 mol of acrylic acid, 5 mol of butyl acrylate, 5 mol of methyl methacrylate and 3 mol of γ-methacryloxypropyltriethoxysilane in deionized water. Then, deionized water was added and diluted to a solid content concentration of 5% by mass.
In addition, the number of functional groups (a) in one molecule of the obtained product was 3, and the molecular weight (average molecular weight / functional group number) per functional group (a) was about 694.

B4: 1 mol of aminopropyltriethoxysilane and 2 mol of γ-glycidoxypropyltrimethoxysilane were reacted in ethanol to obtain a product. Then, deionized water was added and diluted with deionized water to a solid content concentration of 5% by mass.
The number of functional groups (a) in one molecule of the obtained product was 2, and the molecular weight per one functional group (a) (average molecular weight / number of functional groups) was about 894.

B5: Aqueous urethane resin having a tertiary and quaternary amino group (registered trademark: Adekabon titer HUX-760, manufactured by Asahi Denka Kogyo Co., Ltd.) 200 mass with respect to 100 mass parts of bis (trimethoxysilylpropyl) amine The resulting mixture was further diluted with deionized water to a solid content concentration of 5% by mass.
The number of functional groups (a) in one molecule of the obtained compound is 2, the molecular weight per functional group (a) (average molecular weight / number of functional groups) is about 171 and bis (trimethoxysilylpropyl). ) The solid content weight ratio (A) / (B) of the amine (A) and the urethane resin (B) was 1/2.

B6: emulsion polymerization of 50 moles of acrylic acid, 100 moles of butyl acrylate, 100 moles of methyl methacrylate, 100 moles of 2-hydroxyethyl methacrylate, and 1 mole of γ-methacryloxypropyltriethoxysilane in deionized water. Obtained. Then, deionized water was added and diluted to a solid content concentration of 5% by mass.
In addition, the number of functional groups (a) in one molecule of the obtained product is one, the molecular weight per functional group (a) is about 40,000, and the range of the functional group equivalent of the component (B) component It was outside.

B7: Diluted with deionized water to a concentration of 5% by mass with respect to γ-mercaptopropyltrimethoxysilane.
The number of functional groups (a) in one molecule of the compound was 1, which was outside the scope of the present invention.

<Organic phosphonic acid (C)>
C1: 1-hydroxyethylidene-1, 1-diphosphonic acid

<Metal compound (D)>
D1: ammonium metavanadate D2: magnesium nitrate D3: aluminum nitrate D4: zinc oxide

<Metal alkoxide (E)>
E1: Titanium isopropoxide E2: Tetraethoxysilane

<Compound (F)>
F1: Acrylic resin (Showa Polymer Co., Ltd., Polyzol AM-2386)

(4) Treatment method The above-mentioned surface treatment agent for galvanized steel sheet is coated on each test plate by the bar coat coating method or the spray & ringer coating method, and then placed in an oven without being washed with water. The film was dried at the drying temperature shown in the table to form a film having the film amount shown in Table 2. The coating amount refers to the coating amount per one side of the steel plate.
The drying temperature was adjusted by the atmospheric temperature in the oven and the time in the oven. The drying temperature indicates the temperature reached on the test plate surface. Specific methods of bar coating and spray & ringer painting are as follows.

Bar coat coating: The treatment agent was dropped onto the test plate and painted with a # 3-5 bar coater. It adjusted so that it might become a predetermined | prescribed film quantity with the count of the bar coater used and the density | concentration of a process liquid.
Spray & Ringer coating: The treatment agent was poured on the surface of the test plate to wet the entire surface, and then the excess liquid was cut off with a roll composed of two flat rubber rolls to adjust the coating amount. It adjusted so that it might become the predetermined | prescribed film quantity with the amount of draining with a roll, and the density | concentration of a process liquid.

(5) Evaluation test method (5-1) Corrosion resistance (and corrosion resistance after alkaline degreasing)
The obtained surface-treated zinc-based plated steel sheet was cut into a size of 70 × 150 mm, and a test piece with the back side and end sealed with cellophane tape was subjected to a salt spray test specified in JIS Z2371, and white rust was 5% ( Area ratio) Time until occurrence was evaluated.
In addition, an alkaline degreasing agent (Nippon Parkerizing Co., Ltd., Pulclean N364S) 20 g / L, 60 ° C., sprayed for 2 minutes, and then washed with water, and was similarly evaluated. did. The evaluation criteria at this time are shown below.
A: 120 hours or more until 5% of white rust occurs: 48 hours or more, less than 120 hours until 5% of white rust occurs: 24 hours or more, less than 48 hours until 5% of white rust occurs: 24 Less than time On the other hand, the evaluation criteria regarding GA are shown below.
◎: 48% or more until white rust 5% occurrence ○: 24 hours or more until white rust occurrence 5%, less than 48 hours Δ: 12% or more until white rust occurrence 5%, less than 24 hours ×: 12% until white rust occurrence 5% Less than an hour

(5-2) Appearance The surface appearance of the obtained surface-treated galvanized steel sheet was evaluated. The evaluation criteria at this time are shown below.
◎: Whitening, no interference color ○: Ultra thin whitening, interference color △: Whitening, interference color ×: Remarkably whitening, interference color

(5-3) Condensation resistance The obtained surface-treated zinc-based plated steel sheet was left in a freezer at -5 ° C for 1 hour, and then left in a high-temperature and humidity chamber (50 ° C, humidity 95%) for 2 hours. It was confirmed that water droplets (condensation) were generated on the surface of the surface-treated zinc-based plated steel sheet when the surface-treated zinc-based plated steel sheet was placed in the high temperature and humidity layer (if it could not be confirmed, it was placed in the freezer again for 1 hour) . It was taken out from the high temperature and humidity chamber, and it was confirmed that the surface of the surface-treated galvanized steel sheet was dry (when it was not dry, it was left as it was and left until the surface was dry).
The water-drop (condensation) trace on the surface-treated galvanized steel sheet surface was visually evaluated. The evaluation criteria at this time are shown below.
◎: Drop marks are not visible ○: Drop marks are very slight Δ: Visible ×: Remarkably visible

(5-4) Paintability After applying a melamine paint [“Amirac # 1000” manufactured by Kansai Paint Co., Ltd.] to the surface-treated zinc-based plated steel sheet, the coating thickness after baking at 160 ° C. is 20 μm. did. After coating, the film was immersed in boiling water for 1 hour, and then 100 squares of 1 mm square grids were put into the coating film, extruded 5 mm with an Erichsen extruder, and then the tape was peeled off to evaluate the residual rate of mass. The evaluation criteria at this time are shown below.
A: Remaining rate 91-100%
○: Remaining rate 71-90%
Δ: Remaining rate 51-70%
X: Residual rate 0 to 50%

(5-5) Earth property The interlayer resistance of the obtained surface-treated galvanized steel sheet was measured with an interlayer resistance measuring machine. Evaluation was made according to the following criteria.
◎: Less than 1Ω ○: 1Ω or more, less than 2Ω Δ: 2Ω or more, less than 3Ω ×: 3Ω or more

(5-6) Blackening resistance The test target surfaces of the obtained surface-treated zinc-based plated steel sheets were put together, wrapped on one side with vinyl-coated kraft paper, and placed in a constant temperature and humidity chamber with 50 ° C. and 98% humidity. . At this time, a 1 kg weight was placed on the packed specimen for fixing and adhesion of the surface-treated galvanized steel sheet. This state was maintained for 10 days, taken out, and the appearance of the surface-treated galvanized steel sheet was visually evaluated according to the following criteria.
◎: No change in appearance ○: Slight discoloration is observed △: Light black discoloration or local black discoloration is observed as a whole ×: Black discoloration is clearly observed

Evaluation of said (5-1)-(5-6) regarding the surface treatment galvanized steel sheet obtained using the surface treating agent for galvanized steel sheets of Examples 1-49 and Comparative Examples 50-65 Table 3 shows the results of the above.
From a practical viewpoint, it is necessary that there is no “x” in the evaluation items.
In Comparative Example 64, the treatment liquid was unstable and a film could not be formed, and various measurements could not be performed.

As shown in Table 3, the surface-treated galvanized steel sheet treated with a treating agent using various components specified in the present invention at a predetermined ratio has good corrosion resistance and corrosion resistance after alkali degreasing, and appearance, It was found that excellent characteristics were exhibited in a well-balanced manner in terms of dew condensation, paintability (coating adhesion), and grounding properties. It was also found that an excellent surface-treated galvanized steel sheet can be produced by the spray and ringer method.
In particular, it was found that the treatment agent containing a predetermined amount of the components (A) to (F) exhibits excellent performance in all the above items. Moreover, as can be seen from the comparison between Example 3 and Example 31, Component B obtained by reacting silane coupling agents among components (B) exhibits better performance. Moreover, it was found from the comparison between Example 37 and Example 49 that when the alkoxysilane was used as the metal alkoxide, the obtained film properties (corrosion resistance) were more excellent.

  In the comparative example, a surface-treated galvanized steel sheet that comprehensively satisfies various characteristics could not be obtained. For example, in Comparative Examples 50 to 56 in which Component B was not included, the corrosion resistance and the grounding property were inferior. Similarly, Comparative Example 59 containing no component A was also inferior in corrosion resistance and grounding property. On the other hand, it was found that in the present invention including components A to D and using both component A and component B, a film excellent in corrosion resistance and grounding properties can be obtained.

Claims (9)

Ammonium zirconium carbonate (A);
In one molecule, -SiR ¹ R ² R ³ (wherein R ¹ , R ² and R ³ each independently represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group, or a hydroxyl group) A compound (B) having two or more functional groups (a) and a molecular weight (average molecular weight / number of functional groups) per functional group (a) in the range of 100 to 5,000,
An organic phosphonic acid (C) represented by the general formula (1);
A metal compound containing at least one metal element selected from the group consisting of Zr, Ti, Co, Fe, V, Ce, Mo, Mn, Mg, Al, Ni, Ca, W, Nb, Cr, and Zn ( D) and
A surface treatment agent for galvanized steel sheet, comprising water and having a pH of 6 to 11.

The mass ratio (A / B) of the mass when Zr in the zirconium ammonium carbonate (A) is converted to ZrO ₂ and the mass when Si in the compound (B) is converted to SiO ₂ is 0. 01-6.0,
The mass ratio (C / B) between the mass of the organic phosphonic acid (C) and the mass when Si in the compound (B) is converted to SiO ₂ is 0.01 to 5.0,
The mass ratio (D / B) between the mass of the metal element in the metal compound (D) and the mass when Si in the compound (B) is converted to SiO ₂ is 0.01 to 4.0. The surface treating agent for galvanized steel sheets according to claim 1.   Compound obtained by reacting the compound (B) with a silane coupling agent having a reactive functional group (b1) and a compound having a functional group (b2) capable of reacting with the reactive functional group (b1) The surface treatment agent for galvanized steel sheet according to claim 1 or 2, wherein either one of the reactive functional group (b1) and the functional group (b2) is an amino group or an epoxy group.   Furthermore, it has a metal alkoxide (E) containing the at least 1 sort (s) of metal element chosen from the group which consists of B, Nb, Si, Ta, Ti, V, W, and Zr. Surface treatment agent for galvanized steel sheets. The mass ratio (E / B) of the mass when Si in the compound (B) is converted to SiO ₂ and the mass of the metal element contained in the metal alkoxide (E) is 0.01 to 2.0. The surface treating agent for galvanized steel sheets according to claim 4, wherein   Furthermore, the surface treating agent for galvanized steel sheets in any one of Claims 1-5 containing the at least 1 sort (s) of compound (F) chosen from the group which consists of water-soluble polymer and water-system emulsion resin. And the mass when converted to Si in the compound (B) to SiO _2, a mass ratio (F / B) is 0.01 to 30 and the mass of said compound (F), according to claim 6 Surface treatment agent for galvanized steel sheet. The surface treatment agent for galvanized steel sheet according to any one of claims 1 to 7 is applied on the surface of the galvanized steel sheet, dried by heating, and a film having a film amount of 25 to 1000 mg / m ² is formed on the surface of the galvanized steel sheet. A surface treatment method for a galvanized steel sheet.   A galvanized steel sheet having a coating obtained by the surface treatment method for a galvanized steel sheet according to claim 8.